diff options
Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/display/drm_dp_helper.c | 4840 |
1 files changed, 4840 insertions, 0 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c new file mode 100644 index 000000000000..f9fdf19de74a --- /dev/null +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -0,0 +1,4840 @@ +/* + * Copyright © 2009 Keith Packard + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting documentation, and + * that the name of the copyright holders not be used in advertising or + * publicity pertaining to distribution of the software without specific, + * written prior permission. The copyright holders make no representations + * about the suitability of this software for any purpose. It is provided "as + * is" without express or implied warranty. + * + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE + * OF THIS SOFTWARE. + */ + +#include <linux/backlight.h> +#include <linux/delay.h> +#include <linux/dynamic_debug.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/minmax.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/seq_file.h> +#include <linux/string_helpers.h> + +#include <drm/display/drm_dp_helper.h> +#include <drm/display/drm_dp_mst_helper.h> +#include <drm/drm_edid.h> +#include <drm/drm_fixed.h> +#include <drm/drm_print.h> +#include <drm/drm_vblank.h> +#include <drm/drm_panel.h> + +#include "drm_dp_helper_internal.h" + +DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0, + "DRM_UT_CORE", + "DRM_UT_DRIVER", + "DRM_UT_KMS", + "DRM_UT_PRIME", + "DRM_UT_ATOMIC", + "DRM_UT_VBL", + "DRM_UT_STATE", + "DRM_UT_LEASE", + "DRM_UT_DP", + "DRM_UT_DRMRES"); + +struct dp_aux_backlight { + struct backlight_device *base; + struct drm_dp_aux *aux; + struct drm_edp_backlight_info info; + bool enabled; +}; + +/** + * DOC: dp helpers + * + * These functions contain some common logic and helpers at various abstraction + * levels to deal with Display Port sink devices and related things like DP aux + * channel transfers, EDID reading over DP aux channels, decoding certain DPCD + * blocks, ... + */ + +/* Helpers for DP link training */ +static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r) +{ + return link_status[r - DP_LANE0_1_STATUS]; +} + +static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_LANE0_1_STATUS + (lane >> 1); + int s = (lane & 1) * 4; + u8 l = dp_link_status(link_status, i); + + return (l >> s) & 0xf; +} + +bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + u8 lane_align; + u8 lane_status; + int lane; + + lane_align = dp_link_status(link_status, + DP_LANE_ALIGN_STATUS_UPDATED); + if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0) + return false; + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_channel_eq_ok); + +bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + int lane; + u8 lane_status; + + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_LANE_CR_DONE) == 0) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_clock_recovery_ok); + +bool drm_dp_post_lt_adj_req_in_progress(const u8 link_status[DP_LINK_STATUS_SIZE]) +{ + u8 lane_align = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); + + return lane_align & DP_POST_LT_ADJ_REQ_IN_PROGRESS; +} +EXPORT_SYMBOL(drm_dp_post_lt_adj_req_in_progress); + +u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT : + DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT; +} +EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage); + +u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT : + DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT; +} +EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); + +/* DP 2.0 128b/132b */ +u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_TX_FFE_PRESET_LANE1_SHIFT : + DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return (l >> s) & 0xf; +} +EXPORT_SYMBOL(drm_dp_get_adjust_tx_ffe_preset); + +/* DP 2.0 errata for 128b/132b */ +bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + u8 lane_align, lane_status; + int lane; + + lane_align = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); + if (!(lane_align & DP_INTERLANE_ALIGN_DONE)) + return false; + + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if (!(lane_status & DP_LANE_CHANNEL_EQ_DONE)) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_128b132b_lane_channel_eq_done); + +/* DP 2.0 errata for 128b/132b */ +bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + u8 lane_status; + int lane; + + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if (!(lane_status & DP_LANE_SYMBOL_LOCKED)) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_128b132b_lane_symbol_locked); + +/* DP 2.0 errata for 128b/132b */ +bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]) +{ + u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); + + return status & DP_128B132B_DPRX_EQ_INTERLANE_ALIGN_DONE; +} +EXPORT_SYMBOL(drm_dp_128b132b_eq_interlane_align_done); + +/* DP 2.0 errata for 128b/132b */ +bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]) +{ + u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); + + return status & DP_128B132B_DPRX_CDS_INTERLANE_ALIGN_DONE; +} +EXPORT_SYMBOL(drm_dp_128b132b_cds_interlane_align_done); + +/* DP 2.0 errata for 128b/132b */ +bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]) +{ + u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED); + + return status & DP_128B132B_LT_FAILED; +} +EXPORT_SYMBOL(drm_dp_128b132b_link_training_failed); + +static int __8b10b_clock_recovery_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) +{ + if (rd_interval > 4) + drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n", + aux->name, rd_interval); + + if (rd_interval == 0) + return 100; + + return rd_interval * 4 * USEC_PER_MSEC; +} + +static int __8b10b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) +{ + if (rd_interval > 4) + drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n", + aux->name, rd_interval); + + if (rd_interval == 0) + return 400; + + return rd_interval * 4 * USEC_PER_MSEC; +} + +static int __128b132b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval) +{ + switch (rd_interval) { + default: + drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x\n", + aux->name, rd_interval); + fallthrough; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_400_US: + return 400; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_4_MS: + return 4000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_8_MS: + return 8000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_12_MS: + return 12000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_16_MS: + return 16000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_32_MS: + return 32000; + case DP_128B132B_TRAINING_AUX_RD_INTERVAL_64_MS: + return 64000; + } +} + +/* + * The link training delays are different for: + * + * - Clock recovery vs. channel equalization + * - DPRX vs. LTTPR + * - 128b/132b vs. 8b/10b + * - DPCD rev 1.3 vs. later + * + * Get the correct delay in us, reading DPCD if necessary. + */ +static int __read_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr, bool cr) +{ + int (*parse)(const struct drm_dp_aux *aux, u8 rd_interval); + unsigned int offset; + u8 rd_interval, mask; + + if (dp_phy == DP_PHY_DPRX) { + if (uhbr) { + if (cr) + return 100; + + offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL; + mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; + parse = __128b132b_channel_eq_delay_us; + } else { + if (cr && dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) + return 100; + + offset = DP_TRAINING_AUX_RD_INTERVAL; + mask = DP_TRAINING_AUX_RD_MASK; + if (cr) + parse = __8b10b_clock_recovery_delay_us; + else + parse = __8b10b_channel_eq_delay_us; + } + } else { + if (uhbr) { + offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); + mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; + parse = __128b132b_channel_eq_delay_us; + } else { + if (cr) + return 100; + + offset = DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy); + mask = DP_TRAINING_AUX_RD_MASK; + parse = __8b10b_channel_eq_delay_us; + } + } + + if (offset < DP_RECEIVER_CAP_SIZE) { + rd_interval = dpcd[offset]; + } else { + if (drm_dp_dpcd_read_byte(aux, offset, &rd_interval) < 0) { + drm_dbg_kms(aux->drm_dev, "%s: failed rd interval read\n", + aux->name); + /* arbitrary default delay */ + return 400; + } + } + + return parse(aux, rd_interval & mask); +} + +int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr) +{ + return __read_delay(aux, dpcd, dp_phy, uhbr, true); +} +EXPORT_SYMBOL(drm_dp_read_clock_recovery_delay); + +int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, bool uhbr) +{ + return __read_delay(aux, dpcd, dp_phy, uhbr, false); +} +EXPORT_SYMBOL(drm_dp_read_channel_eq_delay); + +/* Per DP 2.0 Errata */ +int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux) +{ + int unit; + u8 val; + + if (drm_dp_dpcd_read_byte(aux, DP_128B132B_TRAINING_AUX_RD_INTERVAL, &val) < 0) { + drm_err(aux->drm_dev, "%s: failed rd interval read\n", + aux->name); + /* default to max */ + val = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; + } + + unit = (val & DP_128B132B_TRAINING_AUX_RD_INTERVAL_1MS_UNIT) ? 1 : 2; + val &= DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK; + + return (val + 1) * unit * 1000; +} +EXPORT_SYMBOL(drm_dp_128b132b_read_aux_rd_interval); + +void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_TRAINING_AUX_RD_MASK; + int delay_us; + + if (dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) + delay_us = 100; + else + delay_us = __8b10b_clock_recovery_delay_us(aux, rd_interval); + + usleep_range(delay_us, delay_us * 2); +} +EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); + +static void __drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux, + u8 rd_interval) +{ + int delay_us = __8b10b_channel_eq_delay_us(aux, rd_interval); + + usleep_range(delay_us, delay_us * 2); +} + +void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + __drm_dp_link_train_channel_eq_delay(aux, + dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_TRAINING_AUX_RD_MASK); +} +EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); + +/** + * drm_dp_phy_name() - Get the name of the given DP PHY + * @dp_phy: The DP PHY identifier + * + * Given the @dp_phy, get a user friendly name of the DP PHY, either "DPRX" or + * "LTTPR <N>", or "<INVALID DP PHY>" on errors. The returned string is always + * non-NULL and valid. + * + * Returns: Name of the DP PHY. + */ +const char *drm_dp_phy_name(enum drm_dp_phy dp_phy) +{ + static const char * const phy_names[] = { + [DP_PHY_DPRX] = "DPRX", + [DP_PHY_LTTPR1] = "LTTPR 1", + [DP_PHY_LTTPR2] = "LTTPR 2", + [DP_PHY_LTTPR3] = "LTTPR 3", + [DP_PHY_LTTPR4] = "LTTPR 4", + [DP_PHY_LTTPR5] = "LTTPR 5", + [DP_PHY_LTTPR6] = "LTTPR 6", + [DP_PHY_LTTPR7] = "LTTPR 7", + [DP_PHY_LTTPR8] = "LTTPR 8", + }; + + if (dp_phy < 0 || dp_phy >= ARRAY_SIZE(phy_names) || + WARN_ON(!phy_names[dp_phy])) + return "<INVALID DP PHY>"; + + return phy_names[dp_phy]; +} +EXPORT_SYMBOL(drm_dp_phy_name); + +void drm_dp_lttpr_link_train_clock_recovery_delay(void) +{ + usleep_range(100, 200); +} +EXPORT_SYMBOL(drm_dp_lttpr_link_train_clock_recovery_delay); + +static u8 dp_lttpr_phy_cap(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE], int r) +{ + return phy_cap[r - DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1]; +} + +void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux, + const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE]) +{ + u8 interval = dp_lttpr_phy_cap(phy_cap, + DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) & + DP_TRAINING_AUX_RD_MASK; + + __drm_dp_link_train_channel_eq_delay(aux, interval); +} +EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay); + +/** + * drm_dp_lttpr_wake_timeout_setup() - Grant extended time for sink to wake up + * @aux: The DP AUX channel to use + * @transparent_mode: This is true if lttpr is in transparent mode + * + * This function checks if the sink needs any extended wake time, if it does + * it grants this request. Post this setup the source device can keep trying + * the Aux transaction till the granted wake timeout. + * If this function is not called all Aux transactions are expected to take + * a default of 1ms before they throw an error. + */ +void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode) +{ + u8 val = 1; + int ret; + + if (transparent_mode) { + static const u8 timeout_mapping[] = { + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_1_MS] = 1, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_20_MS] = 20, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_40_MS] = 40, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_60_MS] = 60, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_80_MS] = 80, + [DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_100_MS] = 100, + }; + + ret = drm_dp_dpcd_readb(aux, DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_REQUEST, &val); + if (ret != 1) { + drm_dbg_kms(aux->drm_dev, + "Failed to read Extended sleep wake timeout request\n"); + return; + } + + val = (val < sizeof(timeout_mapping) && timeout_mapping[val]) ? + timeout_mapping[val] : 1; + + if (val > 1) + drm_dp_dpcd_writeb(aux, + DP_EXTENDED_DPRX_SLEEP_WAKE_TIMEOUT_GRANT, + DP_DPRX_SLEEP_WAKE_TIMEOUT_PERIOD_GRANTED); + } else { + ret = drm_dp_dpcd_readb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, &val); + if (ret != 1) { + drm_dbg_kms(aux->drm_dev, + "Failed to read Extended sleep wake timeout request\n"); + return; + } + + val = (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) ? + (val & DP_EXTENDED_WAKE_TIMEOUT_REQUEST_MASK) * 10 : 1; + + if (val > 1) + drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT, + DP_EXTENDED_WAKE_TIMEOUT_GRANT); + } +} +EXPORT_SYMBOL(drm_dp_lttpr_wake_timeout_setup); + +u8 drm_dp_link_rate_to_bw_code(int link_rate) +{ + switch (link_rate) { + case 1000000: + return DP_LINK_BW_10; + case 1350000: + return DP_LINK_BW_13_5; + case 2000000: + return DP_LINK_BW_20; + default: + /* Spec says link_bw = link_rate / 0.27Gbps */ + return link_rate / 27000; + } +} +EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code); + +int drm_dp_bw_code_to_link_rate(u8 link_bw) +{ + switch (link_bw) { + case DP_LINK_BW_10: + return 1000000; + case DP_LINK_BW_13_5: + return 1350000; + case DP_LINK_BW_20: + return 2000000; + default: + /* Spec says link_rate = link_bw * 0.27Gbps */ + return link_bw * 27000; + } +} +EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate); + +#define AUX_RETRY_INTERVAL 500 /* us */ + +static inline void +drm_dp_dump_access(const struct drm_dp_aux *aux, + u8 request, uint offset, void *buffer, int ret) +{ + const char *arrow = request == DP_AUX_NATIVE_READ ? "->" : "<-"; + + if (ret > 0) + drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d) %*ph\n", + aux->name, offset, arrow, ret, min(ret, 20), buffer); + else + drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d)\n", + aux->name, offset, arrow, ret); +} + +/** + * DOC: dp helpers + * + * The DisplayPort AUX channel is an abstraction to allow generic, driver- + * independent access to AUX functionality. Drivers can take advantage of + * this by filling in the fields of the drm_dp_aux structure. + * + * Transactions are described using a hardware-independent drm_dp_aux_msg + * structure, which is passed into a driver's .transfer() implementation. + * Both native and I2C-over-AUX transactions are supported. + */ + +static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, + unsigned int offset, void *buffer, size_t size) +{ + struct drm_dp_aux_msg msg; + unsigned int retry, native_reply; + int err = 0, ret = 0; + + memset(&msg, 0, sizeof(msg)); + msg.address = offset; + msg.request = request; + msg.buffer = buffer; + msg.size = size; + + mutex_lock(&aux->hw_mutex); + + /* + * If the device attached to the aux bus is powered down then there's + * no reason to attempt a transfer. Error out immediately. + */ + if (aux->powered_down) { + ret = -EBUSY; + goto unlock; + } + + /* + * The specification doesn't give any recommendation on how often to + * retry native transactions. We used to retry 7 times like for + * aux i2c transactions but real world devices this wasn't + * sufficient, bump to 32 which makes Dell 4k monitors happier. + */ + for (retry = 0; retry < 32; retry++) { + if (ret != 0 && ret != -ETIMEDOUT) { + usleep_range(AUX_RETRY_INTERVAL, + AUX_RETRY_INTERVAL + 100); + } + + ret = aux->transfer(aux, &msg); + if (ret >= 0) { + native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK; + if (native_reply == DP_AUX_NATIVE_REPLY_ACK) { + if (ret == size) + goto unlock; + + ret = -EPROTO; + } else + ret = -EIO; + } + + /* + * We want the error we return to be the error we received on + * the first transaction, since we may get a different error the + * next time we retry + */ + if (!err) + err = ret; + } + + drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up. First error: %d\n", + aux->name, err); + ret = err; + +unlock: + mutex_unlock(&aux->hw_mutex); + return ret; +} + +/** + * drm_dp_dpcd_probe() - probe a given DPCD address with a 1-byte read access + * @aux: DisplayPort AUX channel (SST) + * @offset: address of the register to probe + * + * Probe the provided DPCD address by reading 1 byte from it. The function can + * be used to trigger some side-effect the read access has, like waking up the + * sink, without the need for the read-out value. + * + * Returns 0 if the read access suceeded, or a negative error code on failure. + */ +int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset) +{ + u8 buffer; + int ret; + + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, 1); + WARN_ON(ret == 0); + + drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, ret); + + return ret < 0 ? ret : 0; +} +EXPORT_SYMBOL(drm_dp_dpcd_probe); + +/** + * drm_dp_dpcd_set_powered() - Set whether the DP device is powered + * @aux: DisplayPort AUX channel; for convenience it's OK to pass NULL here + * and the function will be a no-op. + * @powered: true if powered; false if not + * + * If the endpoint device on the DP AUX bus is known to be powered down + * then this function can be called to make future transfers fail immediately + * instead of needing to time out. + * + * If this function is never called then a device defaults to being powered. + */ +void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered) +{ + if (!aux) + return; + + mutex_lock(&aux->hw_mutex); + aux->powered_down = !powered; + mutex_unlock(&aux->hw_mutex); +} +EXPORT_SYMBOL(drm_dp_dpcd_set_powered); + +/** + * drm_dp_dpcd_set_probe() - Set whether a probing before DPCD access is done + * @aux: DisplayPort AUX channel + * @enable: Enable the probing if required + */ +void drm_dp_dpcd_set_probe(struct drm_dp_aux *aux, bool enable) +{ + WRITE_ONCE(aux->dpcd_probe_disabled, !enable); +} +EXPORT_SYMBOL(drm_dp_dpcd_set_probe); + +static bool dpcd_access_needs_probe(struct drm_dp_aux *aux) +{ + /* + * HP ZR24w corrupts the first DPCD access after entering power save + * mode. Eg. on a read, the entire buffer will be filled with the same + * byte. Do a throw away read to avoid corrupting anything we care + * about. Afterwards things will work correctly until the monitor + * gets woken up and subsequently re-enters power save mode. + * + * The user pressing any button on the monitor is enough to wake it + * up, so there is no particularly good place to do the workaround. + * We just have to do it before any DPCD access and hope that the + * monitor doesn't power down exactly after the throw away read. + */ + return !aux->is_remote && !READ_ONCE(aux->dpcd_probe_disabled); +} + +/** + * drm_dp_dpcd_read() - read a series of bytes from the DPCD + * @aux: DisplayPort AUX channel (SST or MST) + * @offset: address of the (first) register to read + * @buffer: buffer to store the register values + * @size: number of bytes in @buffer + * + * Returns the number of bytes transferred on success, or a negative error + * code on failure. -EIO is returned if the request was NAKed by the sink or + * if the retry count was exceeded. If not all bytes were transferred, this + * function returns -EPROTO. Errors from the underlying AUX channel transfer + * function, with the exception of -EBUSY (which causes the transaction to + * be retried), are propagated to the caller. + * + * In most of the cases you want to use drm_dp_dpcd_read_data() instead. + */ +ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, + void *buffer, size_t size) +{ + int ret; + + if (dpcd_access_needs_probe(aux)) { + ret = drm_dp_dpcd_probe(aux, DP_TRAINING_PATTERN_SET); + if (ret < 0) + return ret; + } + + if (aux->is_remote) + ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size); + else + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, + buffer, size); + + drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret); + return ret; +} +EXPORT_SYMBOL(drm_dp_dpcd_read); + +/** + * drm_dp_dpcd_write() - write a series of bytes to the DPCD + * @aux: DisplayPort AUX channel (SST or MST) + * @offset: address of the (first) register to write + * @buffer: buffer containing the values to write + * @size: number of bytes in @buffer + * + * Returns the number of bytes transferred on success, or a negative error + * code on failure. -EIO is returned if the request was NAKed by the sink or + * if the retry count was exceeded. If not all bytes were transferred, this + * function returns -EPROTO. Errors from the underlying AUX channel transfer + * function, with the exception of -EBUSY (which causes the transaction to + * be retried), are propagated to the caller. + * + * In most of the cases you want to use drm_dp_dpcd_write_data() instead. + */ +ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, + void *buffer, size_t size) +{ + int ret; + + if (aux->is_remote) + ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size); + else + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, + buffer, size); + + drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret); + return ret; +} +EXPORT_SYMBOL(drm_dp_dpcd_write); + +/** + * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) + * @aux: DisplayPort AUX channel + * @status: buffer to store the link status in (must be at least 6 bytes) + * + * Returns a negative error code on failure or 0 on success. + */ +int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, + u8 status[DP_LINK_STATUS_SIZE]) +{ + return drm_dp_dpcd_read_data(aux, DP_LANE0_1_STATUS, status, + DP_LINK_STATUS_SIZE); +} +EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); + +/** + * drm_dp_dpcd_read_phy_link_status - get the link status information for a DP PHY + * @aux: DisplayPort AUX channel + * @dp_phy: the DP PHY to get the link status for + * @link_status: buffer to return the status in + * + * Fetch the AUX DPCD registers for the DPRX or an LTTPR PHY link status. The + * layout of the returned @link_status matches the DPCD register layout of the + * DPRX PHY link status. + * + * Returns 0 if the information was read successfully or a negative error code + * on failure. + */ +int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, + enum drm_dp_phy dp_phy, + u8 link_status[DP_LINK_STATUS_SIZE]) +{ + int ret; + + if (dp_phy == DP_PHY_DPRX) + return drm_dp_dpcd_read_data(aux, + DP_LANE0_1_STATUS, + link_status, + DP_LINK_STATUS_SIZE); + + ret = drm_dp_dpcd_read_data(aux, + DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy), + link_status, + DP_LINK_STATUS_SIZE - 1); + + if (ret < 0) + return ret; + + /* Convert the LTTPR to the sink PHY link status layout */ + memmove(&link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS + 1], + &link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS], + DP_LINK_STATUS_SIZE - (DP_SINK_STATUS - DP_LANE0_1_STATUS) - 1); + link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS] = 0; + + return 0; +} +EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status); + +/** + * drm_dp_link_power_up() - power up a DisplayPort link + * @aux: DisplayPort AUX channel + * @revision: DPCD revision supported on the link + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_power_up(struct drm_dp_aux *aux, unsigned char revision) +{ + u8 value; + int err; + + /* DP_SET_POWER register is only available on DPCD v1.1 and later */ + if (revision < DP_DPCD_REV_11) + return 0; + + err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); + if (err < 0) + return err; + + value &= ~DP_SET_POWER_MASK; + value |= DP_SET_POWER_D0; + + err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); + if (err < 0) + return err; + + /* + * According to the DP 1.1 specification, a "Sink Device must exit the + * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink + * Control Field" (register 0x600). + */ + usleep_range(1000, 2000); + + return 0; +} +EXPORT_SYMBOL(drm_dp_link_power_up); + +/** + * drm_dp_link_power_down() - power down a DisplayPort link + * @aux: DisplayPort AUX channel + * @revision: DPCD revision supported on the link + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_power_down(struct drm_dp_aux *aux, unsigned char revision) +{ + u8 value; + int err; + + /* DP_SET_POWER register is only available on DPCD v1.1 and later */ + if (revision < DP_DPCD_REV_11) + return 0; + + err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); + if (err < 0) + return err; + + value &= ~DP_SET_POWER_MASK; + value |= DP_SET_POWER_D3; + + err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); + if (err < 0) + return err; + + return 0; +} +EXPORT_SYMBOL(drm_dp_link_power_down); + +static int read_payload_update_status(struct drm_dp_aux *aux) +{ + int ret; + u8 status; + + ret = drm_dp_dpcd_read_byte(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); + if (ret < 0) + return ret; + + return status; +} + +/** + * drm_dp_dpcd_write_payload() - Write Virtual Channel information to payload table + * @aux: DisplayPort AUX channel + * @vcpid: Virtual Channel Payload ID + * @start_time_slot: Starting time slot + * @time_slot_count: Time slot count + * + * Write the Virtual Channel payload allocation table, checking the payload + * update status and retrying as necessary. + * + * Returns: + * 0 on success, negative error otherwise + */ +int drm_dp_dpcd_write_payload(struct drm_dp_aux *aux, + int vcpid, u8 start_time_slot, u8 time_slot_count) +{ + u8 payload_alloc[3], status; + int ret; + int retries = 0; + + drm_dp_dpcd_write_byte(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, + DP_PAYLOAD_TABLE_UPDATED); + + payload_alloc[0] = vcpid; + payload_alloc[1] = start_time_slot; + payload_alloc[2] = time_slot_count; + + ret = drm_dp_dpcd_write_data(aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "failed to write payload allocation %d\n", ret); + goto fail; + } + +retry: + ret = drm_dp_dpcd_read_byte(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "failed to read payload table status %d\n", ret); + goto fail; + } + + if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { + retries++; + if (retries < 20) { + usleep_range(10000, 20000); + goto retry; + } + drm_dbg_kms(aux->drm_dev, "status not set after read payload table status %d\n", + status); + ret = -EINVAL; + goto fail; + } + ret = 0; +fail: + return ret; +} +EXPORT_SYMBOL(drm_dp_dpcd_write_payload); + +/** + * drm_dp_dpcd_clear_payload() - Clear the entire VC Payload ID table + * @aux: DisplayPort AUX channel + * + * Clear the entire VC Payload ID table. + * + * Returns: 0 on success, negative error code on errors. + */ +int drm_dp_dpcd_clear_payload(struct drm_dp_aux *aux) +{ + return drm_dp_dpcd_write_payload(aux, 0, 0, 0x3f); +} +EXPORT_SYMBOL(drm_dp_dpcd_clear_payload); + +/** + * drm_dp_dpcd_poll_act_handled() - Poll for ACT handled status + * @aux: DisplayPort AUX channel + * @timeout_ms: Timeout in ms + * + * Try waiting for the sink to finish updating its payload table by polling for + * the ACT handled bit of DP_PAYLOAD_TABLE_UPDATE_STATUS for up to @timeout_ms + * milliseconds, defaulting to 3000 ms if 0. + * + * Returns: + * 0 if the ACT was handled in time, negative error code on failure. + */ +int drm_dp_dpcd_poll_act_handled(struct drm_dp_aux *aux, int timeout_ms) +{ + int ret, status; + + /* default to 3 seconds, this is arbitrary */ + timeout_ms = timeout_ms ?: 3000; + + ret = readx_poll_timeout(read_payload_update_status, aux, status, + status & DP_PAYLOAD_ACT_HANDLED || status < 0, + 200, timeout_ms * USEC_PER_MSEC); + if (ret < 0 && status >= 0) { + drm_err(aux->drm_dev, "Failed to get ACT after %d ms, last status: %02x\n", + timeout_ms, status); + return -EINVAL; + } else if (status < 0) { + /* + * Failure here isn't unexpected - the hub may have + * just been unplugged + */ + drm_dbg_kms(aux->drm_dev, "Failed to read payload table status: %d\n", status); + return status; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dpcd_poll_act_handled); + +static bool is_edid_digital_input_dp(const struct drm_edid *drm_edid) +{ + /* FIXME: get rid of drm_edid_raw() */ + const struct edid *edid = drm_edid_raw(drm_edid); + + return edid && edid->revision >= 4 && + edid->input & DRM_EDID_INPUT_DIGITAL && + (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP; +} + +/** + * drm_dp_downstream_is_type() - is the downstream facing port of certain type? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @type: port type to be checked. Can be: + * %DP_DS_PORT_TYPE_DP, %DP_DS_PORT_TYPE_VGA, %DP_DS_PORT_TYPE_DVI, + * %DP_DS_PORT_TYPE_HDMI, %DP_DS_PORT_TYPE_NON_EDID, + * %DP_DS_PORT_TYPE_DP_DUALMODE or %DP_DS_PORT_TYPE_WIRELESS. + * + * Caveat: Only works with DPCD 1.1+ port caps. + * + * Returns: whether the downstream facing port matches the type. + */ +bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], u8 type) +{ + return drm_dp_is_branch(dpcd) && + dpcd[DP_DPCD_REV] >= 0x11 && + (port_cap[0] & DP_DS_PORT_TYPE_MASK) == type; +} +EXPORT_SYMBOL(drm_dp_downstream_is_type); + +/** + * drm_dp_downstream_is_tmds() - is the downstream facing port TMDS? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @drm_edid: EDID + * + * Returns: whether the downstream facing port is TMDS (HDMI/DVI). + */ +bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct drm_edid *drm_edid) +{ + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return true; + default: + return false; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(drm_edid)) + return false; + fallthrough; + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + return true; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_is_tmds); + +/** + * drm_dp_send_real_edid_checksum() - send back real edid checksum value + * @aux: DisplayPort AUX channel + * @real_edid_checksum: real edid checksum for the last block + * + * Returns: + * True on success + */ +bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, + u8 real_edid_checksum) +{ + u8 link_edid_read = 0, auto_test_req = 0, test_resp = 0; + + if (drm_dp_dpcd_read_byte(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, + &auto_test_req) < 0) { + drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n", + aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); + return false; + } + auto_test_req &= DP_AUTOMATED_TEST_REQUEST; + + if (drm_dp_dpcd_read_byte(aux, DP_TEST_REQUEST, &link_edid_read) < 0) { + drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n", + aux->name, DP_TEST_REQUEST); + return false; + } + link_edid_read &= DP_TEST_LINK_EDID_READ; + + if (!auto_test_req || !link_edid_read) { + drm_dbg_kms(aux->drm_dev, "%s: Source DUT does not support TEST_EDID_READ\n", + aux->name); + return false; + } + + if (drm_dp_dpcd_write_byte(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, + auto_test_req) < 0) { + drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", + aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR); + return false; + } + + /* send back checksum for the last edid extension block data */ + if (drm_dp_dpcd_write_byte(aux, DP_TEST_EDID_CHECKSUM, + real_edid_checksum) < 0) { + drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", + aux->name, DP_TEST_EDID_CHECKSUM); + return false; + } + + test_resp |= DP_TEST_EDID_CHECKSUM_WRITE; + if (drm_dp_dpcd_write_byte(aux, DP_TEST_RESPONSE, test_resp) < 0) { + drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n", + aux->name, DP_TEST_RESPONSE); + return false; + } + + return true; +} +EXPORT_SYMBOL(drm_dp_send_real_edid_checksum); + +static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK; + + if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4) + port_count = 4; + + return port_count; +} + +static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; + int ret; + + /* + * Prior to DP1.3 the bit represented by + * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. + * If it is set DP_DPCD_REV at 0000h could be at a value less than + * the true capability of the panel. The only way to check is to + * then compare 0000h and 2200h. + */ + if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) + return 0; + + ret = drm_dp_dpcd_read_data(aux, DP_DP13_DPCD_REV, &dpcd_ext, + sizeof(dpcd_ext)); + if (ret < 0) + return ret; + + if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { + drm_dbg_kms(aux->drm_dev, + "%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n", + aux->name, dpcd[DP_DPCD_REV], dpcd_ext[DP_DPCD_REV]); + return 0; + } + + if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext))) + return 0; + + drm_dbg_kms(aux->drm_dev, "%s: Base DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext)); + + return 0; +} + +/** + * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if + * available + * @aux: DisplayPort AUX channel + * @dpcd: Buffer to store the resulting DPCD in + * + * Attempts to read the base DPCD caps for @aux. Additionally, this function + * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if + * present. + * + * Returns: %0 if the DPCD was read successfully, negative error code + * otherwise. + */ +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + int ret; + + ret = drm_dp_dpcd_read_data(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); + if (ret < 0) + return ret; + if (dpcd[DP_DPCD_REV] == 0) + return -EIO; + + ret = drm_dp_read_extended_dpcd_caps(aux, dpcd); + if (ret < 0) + return ret; + + drm_dbg_kms(aux->drm_dev, "%s: DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + return ret; +} +EXPORT_SYMBOL(drm_dp_read_dpcd_caps); + +/** + * drm_dp_read_downstream_info() - read DPCD downstream port info if available + * @aux: DisplayPort AUX channel + * @dpcd: A cached copy of the port's DPCD + * @downstream_ports: buffer to store the downstream port info in + * + * See also: + * drm_dp_downstream_max_clock() + * drm_dp_downstream_max_bpc() + * + * Returns: 0 if either the downstream port info was read successfully or + * there was no downstream info to read, or a negative error code otherwise. + */ +int drm_dp_read_downstream_info(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]) +{ + int ret; + u8 len; + + memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS); + + /* No downstream info to read */ + if (!drm_dp_is_branch(dpcd) || dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) + return 0; + + /* Some branches advertise having 0 downstream ports, despite also advertising they have a + * downstream port present. The DP spec isn't clear on if this is allowed or not, but since + * some branches do it we need to handle it regardless. + */ + len = drm_dp_downstream_port_count(dpcd); + if (!len) + return 0; + + if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) + len *= 4; + + ret = drm_dp_dpcd_read_data(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); + if (ret < 0) + return ret; + + drm_dbg_kms(aux->drm_dev, "%s: DPCD DFP: %*ph\n", aux->name, len, downstream_ports); + + return 0; +} +EXPORT_SYMBOL(drm_dp_read_downstream_info); + +/** + * drm_dp_downstream_max_dotclock() - extract downstream facing port max dot clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Returns: Downstream facing port max dot clock in kHz on success, + * or 0 if max clock not defined + */ +int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) + return 0; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_VGA: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 0; + return port_cap[1] * 8000; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_dotclock); + +/** + * drm_dp_downstream_max_tmds_clock() - extract downstream facing port max TMDS clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @drm_edid: EDID + * + * Returns: HDMI/DVI downstream facing port max TMDS clock in kHz on success, + * or 0 if max TMDS clock not defined + */ +int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct drm_edid *drm_edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return 165000; + default: + return 0; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(drm_edid)) + return 0; + /* + * It's left up to the driver to check the + * DP dual mode adapter's max TMDS clock. + * + * Unfortunately it looks like branch devices + * may not fordward that the DP dual mode i2c + * access so we just usually get i2c nak :( + */ + fallthrough; + case DP_DS_PORT_TYPE_HDMI: + /* + * We should perhaps assume 165 MHz when detailed cap + * info is not available. But looks like many typical + * branch devices fall into that category and so we'd + * probably end up with users complaining that they can't + * get high resolution modes with their favorite dongle. + * + * So let's limit to 300 MHz instead since DPCD 1.4 + * HDMI 2.0 DFPs are required to have the detailed cap + * info. So it's more likely we're dealing with a HDMI 1.4 + * compatible* device here. + */ + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 300000; + return port_cap[1] * 2500; + case DP_DS_PORT_TYPE_DVI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 165000; + /* FIXME what to do about DVI dual link? */ + return port_cap[1] * 2500; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_tmds_clock); + +/** + * drm_dp_downstream_min_tmds_clock() - extract downstream facing port min TMDS clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @drm_edid: EDID + * + * Returns: HDMI/DVI downstream facing port min TMDS clock in kHz on success, + * or 0 if max TMDS clock not defined + */ +int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct drm_edid *drm_edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return 25000; + default: + return 0; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(drm_edid)) + return 0; + fallthrough; + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + /* + * Unclear whether the protocol converter could + * utilize pixel replication. Assume it won't. + */ + return 25000; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock); + +/** + * drm_dp_downstream_max_bpc() - extract downstream facing port max + * bits per component + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * @drm_edid: EDID + * + * Returns: Max bpc on success or 0 if max bpc not defined + */ +int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct drm_edid *drm_edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_DP: + return 0; + default: + return 8; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return 0; + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(drm_edid)) + return 0; + fallthrough; + case DP_DS_PORT_TYPE_HDMI: + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_VGA: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 8; + + switch (port_cap[2] & DP_DS_MAX_BPC_MASK) { + case DP_DS_8BPC: + return 8; + case DP_DS_10BPC: + return 10; + case DP_DS_12BPC: + return 12; + case DP_DS_16BPC: + return 16; + default: + return 8; + } + break; + default: + return 8; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_bpc); + +/** + * drm_dp_downstream_420_passthrough() - determine downstream facing port + * YCbCr 4:2:0 pass-through capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can pass through YCbCr 4:2:0 + */ +bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return true; + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_420_passthrough); + +/** + * drm_dp_downstream_444_to_420_conversion() - determine downstream facing port + * YCbCr 4:4:4->4:2:0 conversion capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0 + */ +bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion); + +/** + * drm_dp_downstream_rgb_to_ycbcr_conversion() - determine downstream facing port + * RGB->YCbCr conversion capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * @color_spc: Colorspace for which conversion cap is sought + * + * Returns: whether the downstream facing port can convert RGB->YCbCr for a given + * colorspace. + */ +bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + u8 color_spc) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & color_spc; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_rgb_to_ycbcr_conversion); + +/** + * drm_dp_downstream_mode() - return a mode for downstream facing port + * @dev: DRM device + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Provides a suitable mode for downstream facing ports without EDID. + * + * Returns: A new drm_display_mode on success or NULL on failure + */ +struct drm_display_mode * +drm_dp_downstream_mode(struct drm_device *dev, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) + +{ + u8 vic; + + if (!drm_dp_is_branch(dpcd)) + return NULL; + + if (dpcd[DP_DPCD_REV] < 0x11) + return NULL; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_NON_EDID: + switch (port_cap[0] & DP_DS_NON_EDID_MASK) { + case DP_DS_NON_EDID_720x480i_60: + vic = 6; + break; + case DP_DS_NON_EDID_720x480i_50: + vic = 21; + break; + case DP_DS_NON_EDID_1920x1080i_60: + vic = 5; + break; + case DP_DS_NON_EDID_1920x1080i_50: + vic = 20; + break; + case DP_DS_NON_EDID_1280x720_60: + vic = 4; + break; + case DP_DS_NON_EDID_1280x720_50: + vic = 19; + break; + default: + return NULL; + } + return drm_display_mode_from_cea_vic(dev, vic); + default: + return NULL; + } +} +EXPORT_SYMBOL(drm_dp_downstream_mode); + +/** + * drm_dp_downstream_id() - identify branch device + * @aux: DisplayPort AUX channel + * @id: DisplayPort branch device id + * + * Returns branch device id on success or NULL on failure + */ +int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]) +{ + return drm_dp_dpcd_read_data(aux, DP_BRANCH_ID, id, 6); +} +EXPORT_SYMBOL(drm_dp_downstream_id); + +/** + * drm_dp_downstream_debug() - debug DP branch devices + * @m: pointer for debugfs file + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @drm_edid: EDID + * @aux: DisplayPort AUX channel + * + */ +void drm_dp_downstream_debug(struct seq_file *m, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct drm_edid *drm_edid, + struct drm_dp_aux *aux) +{ + bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & + DP_DETAILED_CAP_INFO_AVAILABLE; + int clk; + int bpc; + char id[7]; + int len; + uint8_t rev[2]; + int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; + bool branch_device = drm_dp_is_branch(dpcd); + + seq_printf(m, "\tDP branch device present: %s\n", + str_yes_no(branch_device)); + + if (!branch_device) + return; + + switch (type) { + case DP_DS_PORT_TYPE_DP: + seq_puts(m, "\t\tType: DisplayPort\n"); + break; + case DP_DS_PORT_TYPE_VGA: + seq_puts(m, "\t\tType: VGA\n"); + break; + case DP_DS_PORT_TYPE_DVI: + seq_puts(m, "\t\tType: DVI\n"); + break; + case DP_DS_PORT_TYPE_HDMI: + seq_puts(m, "\t\tType: HDMI\n"); + break; + case DP_DS_PORT_TYPE_NON_EDID: + seq_puts(m, "\t\tType: others without EDID support\n"); + break; + case DP_DS_PORT_TYPE_DP_DUALMODE: + seq_puts(m, "\t\tType: DP++\n"); + break; + case DP_DS_PORT_TYPE_WIRELESS: + seq_puts(m, "\t\tType: Wireless\n"); + break; + default: + seq_puts(m, "\t\tType: N/A\n"); + } + + memset(id, 0, sizeof(id)); + drm_dp_downstream_id(aux, id); + seq_printf(m, "\t\tID: %s\n", id); + + len = drm_dp_dpcd_read_data(aux, DP_BRANCH_HW_REV, &rev[0], 1); + if (!len) + seq_printf(m, "\t\tHW: %d.%d\n", + (rev[0] & 0xf0) >> 4, rev[0] & 0xf); + + len = drm_dp_dpcd_read_data(aux, DP_BRANCH_SW_REV, rev, 2); + if (!len) + seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]); + + if (detailed_cap_info) { + clk = drm_dp_downstream_max_dotclock(dpcd, port_cap); + if (clk > 0) + seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); + + clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, drm_edid); + if (clk > 0) + seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); + + clk = drm_dp_downstream_min_tmds_clock(dpcd, port_cap, drm_edid); + if (clk > 0) + seq_printf(m, "\t\tMin TMDS clock: %d kHz\n", clk); + + bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, drm_edid); + + if (bpc > 0) + seq_printf(m, "\t\tMax bpc: %d\n", bpc); + } +} +EXPORT_SYMBOL(drm_dp_downstream_debug); + +/** + * drm_dp_subconnector_type() - get DP branch device type + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + */ +enum drm_mode_subconnector +drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + int type; + if (!drm_dp_is_branch(dpcd)) + return DRM_MODE_SUBCONNECTOR_Native; + /* DP 1.0 approach */ + if (dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) { + type = dpcd[DP_DOWNSTREAMPORT_PRESENT] & + DP_DWN_STRM_PORT_TYPE_MASK; + + switch (type) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + /* Can be HDMI or DVI-D, DVI-D is a safer option */ + return DRM_MODE_SUBCONNECTOR_DVID; + case DP_DWN_STRM_PORT_TYPE_ANALOG: + /* Can be VGA or DVI-A, VGA is more popular */ + return DRM_MODE_SUBCONNECTOR_VGA; + case DP_DWN_STRM_PORT_TYPE_DP: + return DRM_MODE_SUBCONNECTOR_DisplayPort; + case DP_DWN_STRM_PORT_TYPE_OTHER: + default: + return DRM_MODE_SUBCONNECTOR_Unknown; + } + } + type = port_cap[0] & DP_DS_PORT_TYPE_MASK; + + switch (type) { + case DP_DS_PORT_TYPE_DP: + case DP_DS_PORT_TYPE_DP_DUALMODE: + return DRM_MODE_SUBCONNECTOR_DisplayPort; + case DP_DS_PORT_TYPE_VGA: + return DRM_MODE_SUBCONNECTOR_VGA; + case DP_DS_PORT_TYPE_DVI: + return DRM_MODE_SUBCONNECTOR_DVID; + case DP_DS_PORT_TYPE_HDMI: + return DRM_MODE_SUBCONNECTOR_HDMIA; + case DP_DS_PORT_TYPE_WIRELESS: + return DRM_MODE_SUBCONNECTOR_Wireless; + case DP_DS_PORT_TYPE_NON_EDID: + default: + return DRM_MODE_SUBCONNECTOR_Unknown; + } +} +EXPORT_SYMBOL(drm_dp_subconnector_type); + +/** + * drm_dp_set_subconnector_property - set subconnector for DP connector + * @connector: connector to set property on + * @status: connector status + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Called by a driver on every detect event. + */ +void drm_dp_set_subconnector_property(struct drm_connector *connector, + enum drm_connector_status status, + const u8 *dpcd, + const u8 port_cap[4]) +{ + enum drm_mode_subconnector subconnector = DRM_MODE_SUBCONNECTOR_Unknown; + + if (status == connector_status_connected) + subconnector = drm_dp_subconnector_type(dpcd, port_cap); + drm_object_property_set_value(&connector->base, + connector->dev->mode_config.dp_subconnector_property, + subconnector); +} +EXPORT_SYMBOL(drm_dp_set_subconnector_property); + +/** + * drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink + * count + * @connector: The DRM connector to check + * @dpcd: A cached copy of the connector's DPCD RX capabilities + * @desc: A cached copy of the connector's DP descriptor + * + * See also: drm_dp_read_sink_count() + * + * Returns: %True if the (e)DP connector has a valid sink count that should + * be probed, %false otherwise. + */ +bool drm_dp_read_sink_count_cap(struct drm_connector *connector, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const struct drm_dp_desc *desc) +{ + /* Some eDP panels don't set a valid value for the sink count */ + return connector->connector_type != DRM_MODE_CONNECTOR_eDP && + dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 && + dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT && + !drm_dp_has_quirk(desc, DP_DPCD_QUIRK_NO_SINK_COUNT); +} +EXPORT_SYMBOL(drm_dp_read_sink_count_cap); + +/** + * drm_dp_read_sink_count() - Retrieve the sink count for a given sink + * @aux: The DP AUX channel to use + * + * See also: drm_dp_read_sink_count_cap() + * + * Returns: The current sink count reported by @aux, or a negative error code + * otherwise. + */ +int drm_dp_read_sink_count(struct drm_dp_aux *aux) +{ + u8 count; + int ret; + + ret = drm_dp_dpcd_read_byte(aux, DP_SINK_COUNT, &count); + if (ret < 0) + return ret; + + return DP_GET_SINK_COUNT(count); +} +EXPORT_SYMBOL(drm_dp_read_sink_count); + +/* + * I2C-over-AUX implementation + */ + +static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | + I2C_FUNC_10BIT_ADDR; +} + +static void drm_dp_i2c_msg_write_status_update(struct drm_dp_aux_msg *msg) +{ + /* + * In case of i2c defer or short i2c ack reply to a write, + * we need to switch to WRITE_STATUS_UPDATE to drain the + * rest of the message + */ + if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE) { + msg->request &= DP_AUX_I2C_MOT; + msg->request |= DP_AUX_I2C_WRITE_STATUS_UPDATE; + } +} + +#define AUX_PRECHARGE_LEN 10 /* 10 to 16 */ +#define AUX_SYNC_LEN (16 + 4) /* preamble + AUX_SYNC_END */ +#define AUX_STOP_LEN 4 +#define AUX_CMD_LEN 4 +#define AUX_ADDRESS_LEN 20 +#define AUX_REPLY_PAD_LEN 4 +#define AUX_LENGTH_LEN 8 + +/* + * Calculate the duration of the AUX request/reply in usec. Gives the + * "best" case estimate, ie. successful while as short as possible. + */ +static int drm_dp_aux_req_duration(const struct drm_dp_aux_msg *msg) +{ + int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + + AUX_CMD_LEN + AUX_ADDRESS_LEN + AUX_LENGTH_LEN; + + if ((msg->request & DP_AUX_I2C_READ) == 0) + len += msg->size * 8; + + return len; +} + +static int drm_dp_aux_reply_duration(const struct drm_dp_aux_msg *msg) +{ + int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN + + AUX_CMD_LEN + AUX_REPLY_PAD_LEN; + + /* + * For read we expect what was asked. For writes there will + * be 0 or 1 data bytes. Assume 0 for the "best" case. + */ + if (msg->request & DP_AUX_I2C_READ) + len += msg->size * 8; + + return len; +} + +#define I2C_START_LEN 1 +#define I2C_STOP_LEN 1 +#define I2C_ADDR_LEN 9 /* ADDRESS + R/W + ACK/NACK */ +#define I2C_DATA_LEN 9 /* DATA + ACK/NACK */ + +/* + * Calculate the length of the i2c transfer in usec, assuming + * the i2c bus speed is as specified. Gives the "worst" + * case estimate, ie. successful while as long as possible. + * Doesn't account the "MOT" bit, and instead assumes each + * message includes a START, ADDRESS and STOP. Neither does it + * account for additional random variables such as clock stretching. + */ +static int drm_dp_i2c_msg_duration(const struct drm_dp_aux_msg *msg, + int i2c_speed_khz) +{ + /* AUX bitrate is 1MHz, i2c bitrate as specified */ + return DIV_ROUND_UP((I2C_START_LEN + I2C_ADDR_LEN + + msg->size * I2C_DATA_LEN + + I2C_STOP_LEN) * 1000, i2c_speed_khz); +} + +/* + * Determine how many retries should be attempted to successfully transfer + * the specified message, based on the estimated durations of the + * i2c and AUX transfers. + */ +static int drm_dp_i2c_retry_count(const struct drm_dp_aux_msg *msg, + int i2c_speed_khz) +{ + int aux_time_us = drm_dp_aux_req_duration(msg) + + drm_dp_aux_reply_duration(msg); + int i2c_time_us = drm_dp_i2c_msg_duration(msg, i2c_speed_khz); + + return DIV_ROUND_UP(i2c_time_us, aux_time_us + AUX_RETRY_INTERVAL); +} + +/* + * FIXME currently assumes 10 kHz as some real world devices seem + * to require it. We should query/set the speed via DPCD if supported. + */ +static int dp_aux_i2c_speed_khz __read_mostly = 10; +module_param_unsafe(dp_aux_i2c_speed_khz, int, 0644); +MODULE_PARM_DESC(dp_aux_i2c_speed_khz, + "Assumed speed of the i2c bus in kHz, (1-400, default 10)"); + +/* + * Transfer a single I2C-over-AUX message and handle various error conditions, + * retrying the transaction as appropriate. It is assumed that the + * &drm_dp_aux.transfer function does not modify anything in the msg other than the + * reply field. + * + * Returns bytes transferred on success, or a negative error code on failure. + */ +static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{ + unsigned int retry, defer_i2c; + int ret; + /* + * DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device + * is required to retry at least seven times upon receiving AUX_DEFER + * before giving up the AUX transaction. + * + * We also try to account for the i2c bus speed. + */ + int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz)); + + for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { + ret = aux->transfer(aux, msg); + if (ret < 0) { + if (ret == -EBUSY) + continue; + + /* + * While timeouts can be errors, they're usually normal + * behavior (for instance, when a driver tries to + * communicate with a non-existent DisplayPort device). + * Avoid spamming the kernel log with timeout errors. + */ + if (ret == -ETIMEDOUT) + drm_dbg_kms_ratelimited(aux->drm_dev, "%s: transaction timed out\n", + aux->name); + else + drm_dbg_kms(aux->drm_dev, "%s: transaction failed: %d\n", + aux->name, ret); + return ret; + } + + + switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) { + case DP_AUX_NATIVE_REPLY_ACK: + /* + * For I2C-over-AUX transactions this isn't enough, we + * need to check for the I2C ACK reply. + */ + break; + + case DP_AUX_NATIVE_REPLY_NACK: + drm_dbg_kms(aux->drm_dev, "%s: native nack (result=%d, size=%zu)\n", + aux->name, ret, msg->size); + return -EREMOTEIO; + + case DP_AUX_NATIVE_REPLY_DEFER: + drm_dbg_kms(aux->drm_dev, "%s: native defer\n", aux->name); + /* + * We could check for I2C bit rate capabilities and if + * available adjust this interval. We could also be + * more careful with DP-to-legacy adapters where a + * long legacy cable may force very low I2C bit rates. + * + * For now just defer for long enough to hopefully be + * safe for all use-cases. + */ + usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); + continue; + + default: + drm_err(aux->drm_dev, "%s: invalid native reply %#04x\n", + aux->name, msg->reply); + return -EREMOTEIO; + } + + switch (msg->reply & DP_AUX_I2C_REPLY_MASK) { + case DP_AUX_I2C_REPLY_ACK: + /* + * Both native ACK and I2C ACK replies received. We + * can assume the transfer was successful. + */ + if (ret != msg->size) + drm_dp_i2c_msg_write_status_update(msg); + return ret; + + case DP_AUX_I2C_REPLY_NACK: + drm_dbg_kms(aux->drm_dev, "%s: I2C nack (result=%d, size=%zu)\n", + aux->name, ret, msg->size); + aux->i2c_nack_count++; + return -EREMOTEIO; + + case DP_AUX_I2C_REPLY_DEFER: + drm_dbg_kms(aux->drm_dev, "%s: I2C defer\n", aux->name); + /* DP Compliance Test 4.2.2.5 Requirement: + * Must have at least 7 retries for I2C defers on the + * transaction to pass this test + */ + aux->i2c_defer_count++; + if (defer_i2c < 7) + defer_i2c++; + usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); + drm_dp_i2c_msg_write_status_update(msg); + + continue; + + default: + drm_err(aux->drm_dev, "%s: invalid I2C reply %#04x\n", + aux->name, msg->reply); + return -EREMOTEIO; + } + } + + drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up\n", aux->name); + return -EREMOTEIO; +} + +static void drm_dp_i2c_msg_set_request(struct drm_dp_aux_msg *msg, + const struct i2c_msg *i2c_msg) +{ + msg->request = (i2c_msg->flags & I2C_M_RD) ? + DP_AUX_I2C_READ : DP_AUX_I2C_WRITE; + if (!(i2c_msg->flags & I2C_M_STOP)) + msg->request |= DP_AUX_I2C_MOT; +} + +/* + * Keep retrying drm_dp_i2c_do_msg until all data has been transferred. + * + * Returns an error code on failure, or a recommended transfer size on success. + */ +static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg) +{ + int err, ret = orig_msg->size; + struct drm_dp_aux_msg msg = *orig_msg; + + while (msg.size > 0) { + err = drm_dp_i2c_do_msg(aux, &msg); + if (err <= 0) + return err == 0 ? -EPROTO : err; + + if (err < msg.size && err < ret) { + drm_dbg_kms(aux->drm_dev, + "%s: Partial I2C reply: requested %zu bytes got %d bytes\n", + aux->name, msg.size, err); + ret = err; + } + + msg.size -= err; + msg.buffer += err; + } + + return ret; +} + +/* + * Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX + * packets to be as large as possible. If not, the I2C transactions never + * succeed. Hence the default is maximum. + */ +static int dp_aux_i2c_transfer_size __read_mostly = DP_AUX_MAX_PAYLOAD_BYTES; +module_param_unsafe(dp_aux_i2c_transfer_size, int, 0644); +MODULE_PARM_DESC(dp_aux_i2c_transfer_size, + "Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)"); + +static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, + int num) +{ + struct drm_dp_aux *aux = adapter->algo_data; + unsigned int i, j; + unsigned transfer_size; + struct drm_dp_aux_msg msg; + int err = 0; + + if (aux->powered_down) + return -EBUSY; + + dp_aux_i2c_transfer_size = clamp(dp_aux_i2c_transfer_size, 1, DP_AUX_MAX_PAYLOAD_BYTES); + + memset(&msg, 0, sizeof(msg)); + + for (i = 0; i < num; i++) { + msg.address = msgs[i].addr; + + if (!aux->no_zero_sized) { + drm_dp_i2c_msg_set_request(&msg, &msgs[i]); + /* Send a bare address packet to start the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.buffer = NULL; + msg.size = 0; + err = drm_dp_i2c_do_msg(aux, &msg); + } + + /* + * Reset msg.request in case in case it got + * changed into a WRITE_STATUS_UPDATE. + */ + drm_dp_i2c_msg_set_request(&msg, &msgs[i]); + + if (err < 0) + break; + /* We want each transaction to be as large as possible, but + * we'll go to smaller sizes if the hardware gives us a + * short reply. + */ + transfer_size = dp_aux_i2c_transfer_size; + for (j = 0; j < msgs[i].len; j += msg.size) { + msg.buffer = msgs[i].buf + j; + msg.size = min(transfer_size, msgs[i].len - j); + + if (j + msg.size == msgs[i].len && aux->no_zero_sized) + msg.request &= ~DP_AUX_I2C_MOT; + err = drm_dp_i2c_drain_msg(aux, &msg); + + /* + * Reset msg.request in case in case it got + * changed into a WRITE_STATUS_UPDATE. + */ + drm_dp_i2c_msg_set_request(&msg, &msgs[i]); + + if (err < 0) + break; + transfer_size = err; + } + if (err < 0) + break; + } + if (err >= 0) + err = num; + + if (!aux->no_zero_sized) { + /* Send a bare address packet to close out the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.request &= ~DP_AUX_I2C_MOT; + msg.buffer = NULL; + msg.size = 0; + (void)drm_dp_i2c_do_msg(aux, &msg); + } + return err; +} + +static const struct i2c_algorithm drm_dp_i2c_algo = { + .functionality = drm_dp_i2c_functionality, + .master_xfer = drm_dp_i2c_xfer, +}; + +static struct drm_dp_aux *i2c_to_aux(struct i2c_adapter *i2c) +{ + return container_of(i2c, struct drm_dp_aux, ddc); +} + +static void lock_bus(struct i2c_adapter *i2c, unsigned int flags) +{ + mutex_lock(&i2c_to_aux(i2c)->hw_mutex); +} + +static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags) +{ + return mutex_trylock(&i2c_to_aux(i2c)->hw_mutex); +} + +static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) +{ + mutex_unlock(&i2c_to_aux(i2c)->hw_mutex); +} + +static const struct i2c_lock_operations drm_dp_i2c_lock_ops = { + .lock_bus = lock_bus, + .trylock_bus = trylock_bus, + .unlock_bus = unlock_bus, +}; + +static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc) +{ + u8 buf, count; + int ret; + + ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); + if (ret < 0) + return ret; + + WARN_ON(!(buf & DP_TEST_SINK_START)); + + ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK_MISC, &buf); + if (ret < 0) + return ret; + + count = buf & DP_TEST_COUNT_MASK; + if (count == aux->crc_count) + return -EAGAIN; /* No CRC yet */ + + aux->crc_count = count; + + /* + * At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes + * per component (RGB or CrYCb). + */ + return drm_dp_dpcd_read_data(aux, DP_TEST_CRC_R_CR, crc, 6); +} + +static void drm_dp_aux_crc_work(struct work_struct *work) +{ + struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux, + crc_work); + struct drm_crtc *crtc; + u8 crc_bytes[6]; + uint32_t crcs[3]; + int ret; + + if (WARN_ON(!aux->crtc)) + return; + + crtc = aux->crtc; + while (crtc->crc.opened) { + drm_crtc_wait_one_vblank(crtc); + if (!crtc->crc.opened) + break; + + ret = drm_dp_aux_get_crc(aux, crc_bytes); + if (ret == -EAGAIN) { + usleep_range(1000, 2000); + ret = drm_dp_aux_get_crc(aux, crc_bytes); + } + + if (ret == -EAGAIN) { + drm_dbg_kms(aux->drm_dev, "%s: Get CRC failed after retrying: %d\n", + aux->name, ret); + continue; + } else if (ret) { + drm_dbg_kms(aux->drm_dev, "%s: Failed to get a CRC: %d\n", aux->name, ret); + continue; + } + + crcs[0] = crc_bytes[0] | crc_bytes[1] << 8; + crcs[1] = crc_bytes[2] | crc_bytes[3] << 8; + crcs[2] = crc_bytes[4] | crc_bytes[5] << 8; + drm_crtc_add_crc_entry(crtc, false, 0, crcs); + } +} + +/** + * drm_dp_remote_aux_init() - minimally initialise a remote aux channel + * @aux: DisplayPort AUX channel + * + * Used for remote aux channel in general. Merely initialize the crc work + * struct. + */ +void drm_dp_remote_aux_init(struct drm_dp_aux *aux) +{ + INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); +} +EXPORT_SYMBOL(drm_dp_remote_aux_init); + +/** + * drm_dp_aux_init() - minimally initialise an aux channel + * @aux: DisplayPort AUX channel + * + * If you need to use the drm_dp_aux's i2c adapter prior to registering it with + * the outside world, call drm_dp_aux_init() first. For drivers which are + * grandparents to their AUX adapters (e.g. the AUX adapter is parented by a + * &drm_connector), you must still call drm_dp_aux_register() once the connector + * has been registered to allow userspace access to the auxiliary DP channel. + * Likewise, for such drivers you should also assign &drm_dp_aux.drm_dev as + * early as possible so that the &drm_device that corresponds to the AUX adapter + * may be mentioned in debugging output from the DRM DP helpers. + * + * For devices which use a separate platform device for their AUX adapters, this + * may be called as early as required by the driver. + * + */ +void drm_dp_aux_init(struct drm_dp_aux *aux) +{ + mutex_init(&aux->hw_mutex); + mutex_init(&aux->cec.lock); + INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); + + aux->ddc.algo = &drm_dp_i2c_algo; + aux->ddc.algo_data = aux; + aux->ddc.retries = 3; + + aux->ddc.lock_ops = &drm_dp_i2c_lock_ops; +} +EXPORT_SYMBOL(drm_dp_aux_init); + +/** + * drm_dp_aux_register() - initialise and register aux channel + * @aux: DisplayPort AUX channel + * + * Automatically calls drm_dp_aux_init() if this hasn't been done yet. This + * should only be called once the parent of @aux, &drm_dp_aux.dev, is + * initialized. For devices which are grandparents of their AUX channels, + * &drm_dp_aux.dev will typically be the &drm_connector &device which + * corresponds to @aux. For these devices, it's advised to call + * drm_dp_aux_register() in &drm_connector_funcs.late_register, and likewise to + * call drm_dp_aux_unregister() in &drm_connector_funcs.early_unregister. + * Functions which don't follow this will likely Oops when + * %CONFIG_DRM_DISPLAY_DP_AUX_CHARDEV is enabled. + * + * For devices where the AUX channel is a device that exists independently of + * the &drm_device that uses it, such as SoCs and bridge devices, it is + * recommended to call drm_dp_aux_register() after a &drm_device has been + * assigned to &drm_dp_aux.drm_dev, and likewise to call + * drm_dp_aux_unregister() once the &drm_device should no longer be associated + * with the AUX channel (e.g. on bridge detach). + * + * Drivers which need to use the aux channel before either of the two points + * mentioned above need to call drm_dp_aux_init() in order to use the AUX + * channel before registration. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_aux_register(struct drm_dp_aux *aux) +{ + int ret; + + WARN_ON_ONCE(!aux->drm_dev); + + if (!aux->ddc.algo) + drm_dp_aux_init(aux); + + aux->ddc.owner = THIS_MODULE; + aux->ddc.dev.parent = aux->dev; + + strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), + sizeof(aux->ddc.name)); + + ret = drm_dp_aux_register_devnode(aux); + if (ret) + return ret; + + ret = i2c_add_adapter(&aux->ddc); + if (ret) { + drm_dp_aux_unregister_devnode(aux); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_aux_register); + +/** + * drm_dp_aux_unregister() - unregister an AUX adapter + * @aux: DisplayPort AUX channel + */ +void drm_dp_aux_unregister(struct drm_dp_aux *aux) +{ + drm_dp_aux_unregister_devnode(aux); + i2c_del_adapter(&aux->ddc); +} +EXPORT_SYMBOL(drm_dp_aux_unregister); + +#define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x) + +/** + * drm_dp_psr_setup_time() - PSR setup in time usec + * @psr_cap: PSR capabilities from DPCD + * + * Returns: + * PSR setup time for the panel in microseconds, negative + * error code on failure. + */ +int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]) +{ + static const u16 psr_setup_time_us[] = { + PSR_SETUP_TIME(330), + PSR_SETUP_TIME(275), + PSR_SETUP_TIME(220), + PSR_SETUP_TIME(165), + PSR_SETUP_TIME(110), + PSR_SETUP_TIME(55), + PSR_SETUP_TIME(0), + }; + int i; + + i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT; + if (i >= ARRAY_SIZE(psr_setup_time_us)) + return -EINVAL; + + return psr_setup_time_us[i]; +} +EXPORT_SYMBOL(drm_dp_psr_setup_time); + +#undef PSR_SETUP_TIME + +/** + * drm_dp_start_crc() - start capture of frame CRCs + * @aux: DisplayPort AUX channel + * @crtc: CRTC displaying the frames whose CRCs are to be captured + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc) +{ + u8 buf; + int ret; + + ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); + if (ret < 0) + return ret; + + ret = drm_dp_dpcd_write_byte(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START); + if (ret < 0) + return ret; + + aux->crc_count = 0; + aux->crtc = crtc; + schedule_work(&aux->crc_work); + + return 0; +} +EXPORT_SYMBOL(drm_dp_start_crc); + +/** + * drm_dp_stop_crc() - stop capture of frame CRCs + * @aux: DisplayPort AUX channel + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_stop_crc(struct drm_dp_aux *aux) +{ + u8 buf; + int ret; + + ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); + if (ret < 0) + return ret; + + ret = drm_dp_dpcd_write_byte(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START); + if (ret < 0) + return ret; + + flush_work(&aux->crc_work); + aux->crtc = NULL; + + return 0; +} +EXPORT_SYMBOL(drm_dp_stop_crc); + +struct dpcd_quirk { + u8 oui[3]; + u8 device_id[6]; + bool is_branch; + u32 quirks; +}; + +#define OUI(first, second, third) { (first), (second), (third) } +#define DEVICE_ID(first, second, third, fourth, fifth, sixth) \ + { (first), (second), (third), (fourth), (fifth), (sixth) } + +#define DEVICE_ID_ANY DEVICE_ID(0, 0, 0, 0, 0, 0) + +static const struct dpcd_quirk dpcd_quirk_list[] = { + /* Analogix 7737 needs reduced M and N at HBR2 link rates */ + { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, + /* LG LP140WF6-SPM1 eDP panel */ + { OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a', 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, + /* Apple panels need some additional handling to support PSR */ + { OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) }, + /* CH7511 seems to leave SINK_COUNT zeroed */ + { OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) }, + /* Synaptics DP1.4 MST hubs can support DSC without virtual DPCD */ + { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) }, + /* Synaptics DP1.4 MST hubs require DSC for some modes on which it applies HBLANK expansion. */ + { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC) }, + /* MediaTek panels (at least in U3224KBA) require DSC for modes with a short HBLANK on UHBR links. */ + { OUI(0x00, 0x0C, 0xE7), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC) }, + /* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */ + { OUI(0x00, 0x10, 0xfa), DEVICE_ID(101, 68, 21, 101, 98, 97), false, BIT(DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS) }, + /* Synaptics Panamera supports only a compressed bpp of 12 above 50% of its max DSC pixel throughput */ + { OUI(0x90, 0xCC, 0x24), DEVICE_ID('S', 'Y', 'N', 'A', 0x53, 0x22), true, BIT(DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT) }, + { OUI(0x90, 0xCC, 0x24), DEVICE_ID('S', 'Y', 'N', 'A', 0x53, 0x31), true, BIT(DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT) }, + { OUI(0x90, 0xCC, 0x24), DEVICE_ID('S', 'Y', 'N', 'A', 0x53, 0x33), true, BIT(DP_DPCD_QUIRK_DSC_THROUGHPUT_BPP_LIMIT) }, +}; + +#undef OUI + +/* + * Get a bit mask of DPCD quirks for the sink/branch device identified by + * ident. The quirk data is shared but it's up to the drivers to act on the + * data. + * + * For now, only the OUI (first three bytes) is used, but this may be extended + * to device identification string and hardware/firmware revisions later. + */ +static u32 +drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) +{ + const struct dpcd_quirk *quirk; + u32 quirks = 0; + int i; + u8 any_device[] = DEVICE_ID_ANY; + + for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) { + quirk = &dpcd_quirk_list[i]; + + if (quirk->is_branch != is_branch) + continue; + + if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0) + continue; + + if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 && + memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0) + continue; + + quirks |= quirk->quirks; + } + + return quirks; +} + +#undef DEVICE_ID_ANY +#undef DEVICE_ID + +static int drm_dp_read_ident(struct drm_dp_aux *aux, unsigned int offset, + struct drm_dp_dpcd_ident *ident) +{ + return drm_dp_dpcd_read_data(aux, offset, ident, sizeof(*ident)); +} + +static void drm_dp_dump_desc(struct drm_dp_aux *aux, + const char *device_name, const struct drm_dp_desc *desc) +{ + const struct drm_dp_dpcd_ident *ident = &desc->ident; + + drm_dbg_kms(aux->drm_dev, + "%s: %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", + aux->name, device_name, + (int)sizeof(ident->oui), ident->oui, + (int)strnlen(ident->device_id, sizeof(ident->device_id)), ident->device_id, + ident->hw_rev >> 4, ident->hw_rev & 0xf, + ident->sw_major_rev, ident->sw_minor_rev, + desc->quirks); +} + +/** + * drm_dp_read_desc - read sink/branch descriptor from DPCD + * @aux: DisplayPort AUX channel + * @desc: Device descriptor to fill from DPCD + * @is_branch: true for branch devices, false for sink devices + * + * Read DPCD 0x400 (sink) or 0x500 (branch) into @desc. Also debug log the + * identification. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, + bool is_branch) +{ + struct drm_dp_dpcd_ident *ident = &desc->ident; + unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI; + int ret; + + ret = drm_dp_read_ident(aux, offset, ident); + if (ret < 0) + return ret; + + desc->quirks = drm_dp_get_quirks(ident, is_branch); + + drm_dp_dump_desc(aux, is_branch ? "DP branch" : "DP sink", desc); + + return 0; +} +EXPORT_SYMBOL(drm_dp_read_desc); + +/** + * drm_dp_dump_lttpr_desc - read and dump the DPCD descriptor for an LTTPR PHY + * @aux: DisplayPort AUX channel + * @dp_phy: LTTPR PHY instance + * + * Read the DPCD LTTPR PHY descriptor for @dp_phy and print a debug message + * with its details to dmesg. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy) +{ + struct drm_dp_desc desc = {}; + int ret; + + if (drm_WARN_ON(aux->drm_dev, dp_phy < DP_PHY_LTTPR1 || dp_phy > DP_MAX_LTTPR_COUNT)) + return -EINVAL; + + ret = drm_dp_read_ident(aux, DP_OUI_PHY_REPEATER(dp_phy), &desc.ident); + if (ret < 0) + return ret; + + drm_dp_dump_desc(aux, drm_dp_phy_name(dp_phy), &desc); + + return 0; +} +EXPORT_SYMBOL(drm_dp_dump_lttpr_desc); + +/** + * drm_dp_dsc_sink_bpp_incr() - Get bits per pixel increment + * @dsc_dpcd: DSC capabilities from DPCD + * + * Returns the bpp precision supported by the DP sink. + */ +u8 drm_dp_dsc_sink_bpp_incr(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) +{ + u8 bpp_increment_dpcd = dsc_dpcd[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT]; + + switch (bpp_increment_dpcd & DP_DSC_BITS_PER_PIXEL_MASK) { + case DP_DSC_BITS_PER_PIXEL_1_16: + return 16; + case DP_DSC_BITS_PER_PIXEL_1_8: + return 8; + case DP_DSC_BITS_PER_PIXEL_1_4: + return 4; + case DP_DSC_BITS_PER_PIXEL_1_2: + return 2; + case DP_DSC_BITS_PER_PIXEL_1_1: + return 1; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_bpp_incr); + +/** + * drm_dp_dsc_sink_max_slice_count() - Get the max slice count + * supported by the DSC sink. + * @dsc_dpcd: DSC capabilities from DPCD + * @is_edp: true if its eDP, false for DP + * + * Read the slice capabilities DPCD register from DSC sink to get + * the maximum slice count supported. This is used to populate + * the DSC parameters in the &struct drm_dsc_config by the driver. + * Driver creates an infoframe using these parameters to populate + * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC + * infoframe using the helper function drm_dsc_pps_infoframe_pack() + * + * Returns: + * Maximum slice count supported by DSC sink or 0 its invalid + */ +u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], + bool is_edp) +{ + u8 slice_cap1 = dsc_dpcd[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT]; + + if (is_edp) { + /* For eDP, register DSC_SLICE_CAPABILITIES_1 gives slice count */ + if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) + return 4; + if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) + return 2; + if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) + return 1; + } else { + /* For DP, use values from DSC_SLICE_CAP_1 and DSC_SLICE_CAP2 */ + u8 slice_cap2 = dsc_dpcd[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT]; + + if (slice_cap2 & DP_DSC_24_PER_DP_DSC_SINK) + return 24; + if (slice_cap2 & DP_DSC_20_PER_DP_DSC_SINK) + return 20; + if (slice_cap2 & DP_DSC_16_PER_DP_DSC_SINK) + return 16; + if (slice_cap1 & DP_DSC_12_PER_DP_DSC_SINK) + return 12; + if (slice_cap1 & DP_DSC_10_PER_DP_DSC_SINK) + return 10; + if (slice_cap1 & DP_DSC_8_PER_DP_DSC_SINK) + return 8; + if (slice_cap1 & DP_DSC_6_PER_DP_DSC_SINK) + return 6; + if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK) + return 4; + if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK) + return 2; + if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK) + return 1; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count); + +/** + * drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits + * @dsc_dpcd: DSC capabilities from DPCD + * + * Read the DSC DPCD register to parse the line buffer depth in bits which is + * number of bits of precision within the decoder line buffer supported by + * the DSC sink. This is used to populate the DSC parameters in the + * &struct drm_dsc_config by the driver. + * Driver creates an infoframe using these parameters to populate + * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC + * infoframe using the helper function drm_dsc_pps_infoframe_pack() + * + * Returns: + * Line buffer depth supported by DSC panel or 0 its invalid + */ +u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) +{ + u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT]; + + switch (line_buf_depth & DP_DSC_LINE_BUF_BIT_DEPTH_MASK) { + case DP_DSC_LINE_BUF_BIT_DEPTH_9: + return 9; + case DP_DSC_LINE_BUF_BIT_DEPTH_10: + return 10; + case DP_DSC_LINE_BUF_BIT_DEPTH_11: + return 11; + case DP_DSC_LINE_BUF_BIT_DEPTH_12: + return 12; + case DP_DSC_LINE_BUF_BIT_DEPTH_13: + return 13; + case DP_DSC_LINE_BUF_BIT_DEPTH_14: + return 14; + case DP_DSC_LINE_BUF_BIT_DEPTH_15: + return 15; + case DP_DSC_LINE_BUF_BIT_DEPTH_16: + return 16; + case DP_DSC_LINE_BUF_BIT_DEPTH_8: + return 8; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth); + +/** + * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per component + * values supported by the DSC sink. + * @dsc_dpcd: DSC capabilities from DPCD + * @dsc_bpc: An array to be filled by this helper with supported + * input bpcs. + * + * Read the DSC DPCD from the sink device to parse the supported bits per + * component values. This is used to populate the DSC parameters + * in the &struct drm_dsc_config by the driver. + * Driver creates an infoframe using these parameters to populate + * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC + * infoframe using the helper function drm_dsc_pps_infoframe_pack() + * + * Returns: + * Number of input BPC values parsed from the DPCD + */ +int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], + u8 dsc_bpc[3]) +{ + int num_bpc = 0; + u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT]; + + if (!drm_dp_sink_supports_dsc(dsc_dpcd)) + return 0; + + if (color_depth & DP_DSC_12_BPC) + dsc_bpc[num_bpc++] = 12; + if (color_depth & DP_DSC_10_BPC) + dsc_bpc[num_bpc++] = 10; + + /* A DP DSC Sink device shall support 8 bpc. */ + dsc_bpc[num_bpc++] = 8; + + return num_bpc; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); + +/* + * See DP Standard v2.1a 2.8.4 Minimum Slices/Display, Table 2-159 and + * Appendix L.1 Derivation of Slice Count Requirements. + */ +static int dsc_sink_min_slice_throughput(int peak_pixel_rate) +{ + if (peak_pixel_rate >= 4800000) + return 600000; + else if (peak_pixel_rate >= 2700000) + return 400000; + else + return 340000; +} + +/** + * drm_dp_dsc_sink_max_slice_throughput() - Get a DSC sink's maximum pixel throughput per slice + * @dsc_dpcd: DSC sink's capabilities from DPCD + * @peak_pixel_rate: Cumulative peak pixel rate in kHz + * @is_rgb_yuv444: The mode is either RGB or YUV444 + * + * Return the DSC sink device's maximum pixel throughput per slice, based on + * the device's @dsc_dpcd capabilities, the @peak_pixel_rate of the transferred + * stream(s) and whether the output format @is_rgb_yuv444 or yuv422/yuv420. + * + * Note that @peak_pixel_rate is the total pixel rate transferred to the same + * DSC/display sink. For instance to calculate a tile's slice count of an MST + * multi-tiled display sink (not considering here the required + * rounding/alignment of slice count):: + * + * @peak_pixel_rate = tile_pixel_rate * tile_count + * total_slice_count = @peak_pixel_rate / drm_dp_dsc_sink_max_slice_throughput(@peak_pixel_rate) + * tile_slice_count = total_slice_count / tile_count + * + * Returns: + * The maximum pixel throughput per slice supported by the DSC sink device + * in kPixels/sec. + */ +int drm_dp_dsc_sink_max_slice_throughput(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], + int peak_pixel_rate, bool is_rgb_yuv444) +{ + int throughput; + int delta = 0; + int base; + + throughput = dsc_dpcd[DP_DSC_PEAK_THROUGHPUT - DP_DSC_SUPPORT]; + + if (is_rgb_yuv444) { + throughput = (throughput & DP_DSC_THROUGHPUT_MODE_0_MASK) >> + DP_DSC_THROUGHPUT_MODE_0_SHIFT; + + delta = ((dsc_dpcd[DP_DSC_RC_BUF_BLK_SIZE - DP_DSC_SUPPORT]) & + DP_DSC_THROUGHPUT_MODE_0_DELTA_MASK) >> + DP_DSC_THROUGHPUT_MODE_0_DELTA_SHIFT; /* in units of 2 MPixels/sec */ + delta *= 2000; + } else { + throughput = (throughput & DP_DSC_THROUGHPUT_MODE_1_MASK) >> + DP_DSC_THROUGHPUT_MODE_1_SHIFT; + } + + switch (throughput) { + case 0: + return dsc_sink_min_slice_throughput(peak_pixel_rate); + case 1: + base = 340000; + break; + case 2 ... 14: + base = 400000 + 50000 * (throughput - 2); + break; + case 15: + base = 170000; + break; + } + + return base + delta; +} +EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_throughput); + +static u8 dsc_branch_dpcd_cap(const u8 dpcd[DP_DSC_BRANCH_CAP_SIZE], int reg) +{ + return dpcd[reg - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0]; +} + +/** + * drm_dp_dsc_branch_max_overall_throughput() - Branch device's max overall DSC pixel throughput + * @dsc_branch_dpcd: DSC branch capabilities from DPCD + * @is_rgb_yuv444: The mode is either RGB or YUV444 + * + * Return the branch device's maximum overall DSC pixel throughput, based on + * the device's DPCD DSC branch capabilities, and whether the output + * format @is_rgb_yuv444 or yuv422/yuv420. + * + * Returns: + * - 0: The maximum overall throughput capability is not indicated by + * the device separately and it must be determined from the per-slice + * max throughput (see @drm_dp_dsc_branch_slice_max_throughput()) + * and the maximum slice count supported by the device. + * - > 0: The maximum overall DSC pixel throughput supported by the branch + * device in kPixels/sec. + */ +int drm_dp_dsc_branch_max_overall_throughput(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE], + bool is_rgb_yuv444) +{ + int throughput; + + if (is_rgb_yuv444) + throughput = dsc_branch_dpcd_cap(dsc_branch_dpcd, + DP_DSC_BRANCH_OVERALL_THROUGHPUT_0); + else + throughput = dsc_branch_dpcd_cap(dsc_branch_dpcd, + DP_DSC_BRANCH_OVERALL_THROUGHPUT_1); + + switch (throughput) { + case 0: + return 0; + case 1: + return 680000; + default: + return 600000 + 50000 * throughput; + } +} +EXPORT_SYMBOL(drm_dp_dsc_branch_max_overall_throughput); + +/** + * drm_dp_dsc_branch_max_line_width() - Branch device's max DSC line width + * @dsc_branch_dpcd: DSC branch capabilities from DPCD + * + * Return the branch device's maximum overall DSC line width, based on + * the device's @dsc_branch_dpcd capabilities. + * + * Returns: + * - 0: The maximum line width is not indicated by the device + * separately and it must be determined from the maximum + * slice count and slice-width supported by the device. + * - %-EINVAL: The device indicates an invalid maximum line width + * (< 5120 pixels). + * - >= 5120: The maximum line width in pixels. + */ +int drm_dp_dsc_branch_max_line_width(const u8 dsc_branch_dpcd[DP_DSC_BRANCH_CAP_SIZE]) +{ + int line_width = dsc_branch_dpcd_cap(dsc_branch_dpcd, DP_DSC_BRANCH_MAX_LINE_WIDTH); + + switch (line_width) { + case 0: + return 0; + case 1 ... 15: + return -EINVAL; + default: + return line_width * 320; + } +} +EXPORT_SYMBOL(drm_dp_dsc_branch_max_line_width); + +static int drm_dp_read_lttpr_regs(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], int address, + u8 *buf, int buf_size) +{ + /* + * At least the DELL P2715Q monitor with a DPCD_REV < 0x14 returns + * corrupted values when reading from the 0xF0000- range with a block + * size bigger than 1. + */ + int block_size = dpcd[DP_DPCD_REV] < 0x14 ? 1 : buf_size; + int offset; + int ret; + + for (offset = 0; offset < buf_size; offset += block_size) { + ret = drm_dp_dpcd_read_data(aux, + address + offset, + &buf[offset], block_size); + if (ret < 0) + return ret; + } + + return 0; +} + +/** + * drm_dp_read_lttpr_common_caps - read the LTTPR common capabilities + * @aux: DisplayPort AUX channel + * @dpcd: DisplayPort configuration data + * @caps: buffer to return the capability info in + * + * Read capabilities common to all LTTPRs. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + return drm_dp_read_lttpr_regs(aux, dpcd, + DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, + caps, DP_LTTPR_COMMON_CAP_SIZE); +} +EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps); + +/** + * drm_dp_read_lttpr_phy_caps - read the capabilities for a given LTTPR PHY + * @aux: DisplayPort AUX channel + * @dpcd: DisplayPort configuration data + * @dp_phy: LTTPR PHY to read the capabilities for + * @caps: buffer to return the capability info in + * + * Read the capabilities for the given LTTPR PHY. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + enum drm_dp_phy dp_phy, + u8 caps[DP_LTTPR_PHY_CAP_SIZE]) +{ + return drm_dp_read_lttpr_regs(aux, dpcd, + DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy), + caps, DP_LTTPR_PHY_CAP_SIZE); +} +EXPORT_SYMBOL(drm_dp_read_lttpr_phy_caps); + +static u8 dp_lttpr_common_cap(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE], int r) +{ + return caps[r - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV]; +} + +/** + * drm_dp_lttpr_count - get the number of detected LTTPRs + * @caps: LTTPR common capabilities + * + * Get the number of detected LTTPRs from the LTTPR common capabilities info. + * + * Returns: + * -ERANGE if more than supported number (8) of LTTPRs are detected + * -EINVAL if the DP_PHY_REPEATER_CNT register contains an invalid value + * otherwise the number of detected LTTPRs + */ +int drm_dp_lttpr_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + u8 count = dp_lttpr_common_cap(caps, DP_PHY_REPEATER_CNT); + + switch (hweight8(count)) { + case 0: + return 0; + case 1: + return 8 - ilog2(count); + case 8: + return -ERANGE; + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(drm_dp_lttpr_count); + +/** + * drm_dp_lttpr_max_link_rate - get the maximum link rate supported by all LTTPRs + * @caps: LTTPR common capabilities + * + * Returns the maximum link rate supported by all detected LTTPRs. + */ +int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + u8 rate = dp_lttpr_common_cap(caps, DP_MAX_LINK_RATE_PHY_REPEATER); + + return drm_dp_bw_code_to_link_rate(rate); +} +EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate); + +/** + * drm_dp_lttpr_set_transparent_mode() - set the LTTPR in transparent mode + * @aux: DisplayPort AUX channel + * @enable: Enable or disable transparent mode + * + * Returns: 0 on success or a negative error code on failure. + */ +int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable) +{ + u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : + DP_PHY_REPEATER_MODE_NON_TRANSPARENT; + int ret = drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE, val); + + if (ret < 0) + return ret; + + return (ret == 1) ? 0 : -EIO; +} +EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_mode); + +/** + * drm_dp_lttpr_init() - init LTTPR transparency mode according to DP standard + * @aux: DisplayPort AUX channel + * @lttpr_count: Number of LTTPRs. Between 0 and 8, according to DP standard. + * Negative error code for any non-valid number. + * See drm_dp_lttpr_count(). + * + * Returns: 0 on success or a negative error code on failure. + */ +int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count) +{ + int ret; + + if (!lttpr_count) + return 0; + + /* + * See DP Standard v2.0 3.6.6.1 about the explicit disabling of + * non-transparent mode and the disable->enable non-transparent mode + * sequence. + */ + ret = drm_dp_lttpr_set_transparent_mode(aux, true); + if (ret) + return ret; + + if (lttpr_count < 0) + return -ENODEV; + + if (drm_dp_lttpr_set_transparent_mode(aux, false)) { + /* + * Roll-back to transparent mode if setting non-transparent + * mode has failed + */ + drm_dp_lttpr_set_transparent_mode(aux, true); + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_lttpr_init); + +/** + * drm_dp_lttpr_max_lane_count - get the maximum lane count supported by all LTTPRs + * @caps: LTTPR common capabilities + * + * Returns the maximum lane count supported by all detected LTTPRs. + */ +int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) +{ + u8 max_lanes = dp_lttpr_common_cap(caps, DP_MAX_LANE_COUNT_PHY_REPEATER); + + return max_lanes & DP_MAX_LANE_COUNT_MASK; +} +EXPORT_SYMBOL(drm_dp_lttpr_max_lane_count); + +/** + * drm_dp_lttpr_voltage_swing_level_3_supported - check for LTTPR vswing3 support + * @caps: LTTPR PHY capabilities + * + * Returns true if the @caps for an LTTPR TX PHY indicate support for + * voltage swing level 3. + */ +bool +drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) +{ + u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); + + return txcap & DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED; +} +EXPORT_SYMBOL(drm_dp_lttpr_voltage_swing_level_3_supported); + +/** + * drm_dp_lttpr_pre_emphasis_level_3_supported - check for LTTPR preemph3 support + * @caps: LTTPR PHY capabilities + * + * Returns true if the @caps for an LTTPR TX PHY indicate support for + * pre-emphasis level 3. + */ +bool +drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]) +{ + u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1); + + return txcap & DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED; +} +EXPORT_SYMBOL(drm_dp_lttpr_pre_emphasis_level_3_supported); + +/** + * drm_dp_get_phy_test_pattern() - get the requested pattern from the sink. + * @aux: DisplayPort AUX channel + * @data: DP phy compliance test parameters. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, + struct drm_dp_phy_test_params *data) +{ + int err; + u8 rate, lanes; + + err = drm_dp_dpcd_read_byte(aux, DP_TEST_LINK_RATE, &rate); + if (err < 0) + return err; + data->link_rate = drm_dp_bw_code_to_link_rate(rate); + + err = drm_dp_dpcd_read_byte(aux, DP_TEST_LANE_COUNT, &lanes); + if (err < 0) + return err; + data->num_lanes = lanes & DP_MAX_LANE_COUNT_MASK; + + if (lanes & DP_ENHANCED_FRAME_CAP) + data->enhanced_frame_cap = true; + + err = drm_dp_dpcd_read_byte(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern); + if (err < 0) + return err; + + switch (data->phy_pattern) { + case DP_PHY_TEST_PATTERN_80BIT_CUSTOM: + err = drm_dp_dpcd_read_data(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0, + &data->custom80, sizeof(data->custom80)); + if (err < 0) + return err; + + break; + case DP_PHY_TEST_PATTERN_CP2520: + err = drm_dp_dpcd_read_data(aux, DP_TEST_HBR2_SCRAMBLER_RESET, + &data->hbr2_reset, + sizeof(data->hbr2_reset)); + if (err < 0) + return err; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_get_phy_test_pattern); + +/** + * drm_dp_set_phy_test_pattern() - set the pattern to the sink. + * @aux: DisplayPort AUX channel + * @data: DP phy compliance test parameters. + * @dp_rev: DP revision to use for compliance testing + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux, + struct drm_dp_phy_test_params *data, u8 dp_rev) +{ + int err, i; + u8 test_pattern; + + test_pattern = data->phy_pattern; + if (dp_rev < 0x12) { + test_pattern = (test_pattern << 2) & + DP_LINK_QUAL_PATTERN_11_MASK; + err = drm_dp_dpcd_write_byte(aux, DP_TRAINING_PATTERN_SET, + test_pattern); + if (err < 0) + return err; + } else { + for (i = 0; i < data->num_lanes; i++) { + err = drm_dp_dpcd_write_byte(aux, + DP_LINK_QUAL_LANE0_SET + i, + test_pattern); + if (err < 0) + return err; + } + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_set_phy_test_pattern); + +static const char *dp_pixelformat_get_name(enum dp_pixelformat pixelformat) +{ + if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) + return "Invalid"; + + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "RGB"; + case DP_PIXELFORMAT_YUV444: + return "YUV444"; + case DP_PIXELFORMAT_YUV422: + return "YUV422"; + case DP_PIXELFORMAT_YUV420: + return "YUV420"; + case DP_PIXELFORMAT_Y_ONLY: + return "Y_ONLY"; + case DP_PIXELFORMAT_RAW: + return "RAW"; + default: + return "Reserved"; + } +} + +static const char *dp_colorimetry_get_name(enum dp_pixelformat pixelformat, + enum dp_colorimetry colorimetry) +{ + if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED) + return "Invalid"; + + switch (colorimetry) { + case DP_COLORIMETRY_DEFAULT: + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "sRGB"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.601"; + case DP_PIXELFORMAT_Y_ONLY: + return "DICOM PS3.14"; + case DP_PIXELFORMAT_RAW: + return "Custom Color Profile"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_RGB_WIDE_FIXED: /* and DP_COLORIMETRY_BT709_YCC */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "Wide Fixed"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.709"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_RGB_WIDE_FLOAT: /* and DP_COLORIMETRY_XVYCC_601 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "Wide Float"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "xvYCC 601"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_OPRGB: /* and DP_COLORIMETRY_XVYCC_709 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "OpRGB"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "xvYCC 709"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_DCI_P3_RGB: /* and DP_COLORIMETRY_SYCC_601 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "DCI-P3"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "sYCC 601"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_RGB_CUSTOM: /* and DP_COLORIMETRY_OPYCC_601 */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "Custom Profile"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "OpYCC 601"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_BT2020_RGB: /* and DP_COLORIMETRY_BT2020_CYCC */ + switch (pixelformat) { + case DP_PIXELFORMAT_RGB: + return "BT.2020 RGB"; + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.2020 CYCC"; + default: + return "Reserved"; + } + case DP_COLORIMETRY_BT2020_YCC: + switch (pixelformat) { + case DP_PIXELFORMAT_YUV444: + case DP_PIXELFORMAT_YUV422: + case DP_PIXELFORMAT_YUV420: + return "BT.2020 YCC"; + default: + return "Reserved"; + } + default: + return "Invalid"; + } +} + +static const char *dp_dynamic_range_get_name(enum dp_dynamic_range dynamic_range) +{ + switch (dynamic_range) { + case DP_DYNAMIC_RANGE_VESA: + return "VESA range"; + case DP_DYNAMIC_RANGE_CTA: + return "CTA range"; + default: + return "Invalid"; + } +} + +static const char *dp_content_type_get_name(enum dp_content_type content_type) +{ + switch (content_type) { + case DP_CONTENT_TYPE_NOT_DEFINED: + return "Not defined"; + case DP_CONTENT_TYPE_GRAPHICS: + return "Graphics"; + case DP_CONTENT_TYPE_PHOTO: + return "Photo"; + case DP_CONTENT_TYPE_VIDEO: + return "Video"; + case DP_CONTENT_TYPE_GAME: + return "Game"; + default: + return "Reserved"; + } +} + +void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc) +{ + drm_printf(p, "DP SDP: VSC, revision %u, length %u\n", + vsc->revision, vsc->length); + drm_printf(p, " pixelformat: %s\n", + dp_pixelformat_get_name(vsc->pixelformat)); + drm_printf(p, " colorimetry: %s\n", + dp_colorimetry_get_name(vsc->pixelformat, vsc->colorimetry)); + drm_printf(p, " bpc: %u\n", vsc->bpc); + drm_printf(p, " dynamic range: %s\n", + dp_dynamic_range_get_name(vsc->dynamic_range)); + drm_printf(p, " content type: %s\n", + dp_content_type_get_name(vsc->content_type)); +} +EXPORT_SYMBOL(drm_dp_vsc_sdp_log); + +void drm_dp_as_sdp_log(struct drm_printer *p, const struct drm_dp_as_sdp *as_sdp) +{ + drm_printf(p, "DP SDP: AS_SDP, revision %u, length %u\n", + as_sdp->revision, as_sdp->length); + drm_printf(p, " vtotal: %d\n", as_sdp->vtotal); + drm_printf(p, " target_rr: %d\n", as_sdp->target_rr); + drm_printf(p, " duration_incr_ms: %d\n", as_sdp->duration_incr_ms); + drm_printf(p, " duration_decr_ms: %d\n", as_sdp->duration_decr_ms); + drm_printf(p, " operation_mode: %d\n", as_sdp->mode); +} +EXPORT_SYMBOL(drm_dp_as_sdp_log); + +/** + * drm_dp_as_sdp_supported() - check if adaptive sync sdp is supported + * @aux: DisplayPort AUX channel + * @dpcd: DisplayPort configuration data + * + * Returns true if adaptive sync sdp is supported, else returns false + */ +bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 rx_feature; + + if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_13) + return false; + + if (drm_dp_dpcd_read_byte(aux, DP_DPRX_FEATURE_ENUMERATION_LIST_CONT_1, + &rx_feature) < 0) { + drm_dbg_dp(aux->drm_dev, + "Failed to read DP_DPRX_FEATURE_ENUMERATION_LIST_CONT_1\n"); + return false; + } + + return (rx_feature & DP_ADAPTIVE_SYNC_SDP_SUPPORTED); +} +EXPORT_SYMBOL(drm_dp_as_sdp_supported); + +/** + * drm_dp_vsc_sdp_supported() - check if vsc sdp is supported + * @aux: DisplayPort AUX channel + * @dpcd: DisplayPort configuration data + * + * Returns true if vsc sdp is supported, else returns false + */ +bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 rx_feature; + + if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_13) + return false; + + if (drm_dp_dpcd_read_byte(aux, DP_DPRX_FEATURE_ENUMERATION_LIST, &rx_feature) < 0) { + drm_dbg_dp(aux->drm_dev, "failed to read DP_DPRX_FEATURE_ENUMERATION_LIST\n"); + return false; + } + + return (rx_feature & DP_VSC_SDP_EXT_FOR_COLORIMETRY_SUPPORTED); +} +EXPORT_SYMBOL(drm_dp_vsc_sdp_supported); + +/** + * drm_dp_vsc_sdp_pack() - pack a given vsc sdp into generic dp_sdp + * @vsc: vsc sdp initialized according to its purpose as defined in + * table 2-118 - table 2-120 in DP 1.4a specification + * @sdp: valid handle to the generic dp_sdp which will be packed + * + * Returns length of sdp on success and error code on failure + */ +ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, + struct dp_sdp *sdp) +{ + size_t length = sizeof(struct dp_sdp); + + memset(sdp, 0, sizeof(struct dp_sdp)); + + /* + * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119 + * VSC SDP Header Bytes + */ + sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */ + sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */ + sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */ + sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */ + + if (vsc->revision == 0x6) { + sdp->db[0] = 1; + sdp->db[3] = 1; + } + + /* + * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry + * Format as per DP 1.4a spec and DP 2.0 respectively. + */ + if (!(vsc->revision == 0x5 || vsc->revision == 0x7)) + goto out; + + /* VSC SDP Payload for DB16 through DB18 */ + /* Pixel Encoding and Colorimetry Formats */ + sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */ + sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */ + + switch (vsc->bpc) { + case 6: + /* 6bpc: 0x0 */ + break; + case 8: + sdp->db[17] = 0x1; /* DB17[3:0] */ + break; + case 10: + sdp->db[17] = 0x2; + break; + case 12: + sdp->db[17] = 0x3; + break; + case 16: + sdp->db[17] = 0x4; + break; + default: + WARN(1, "Missing case %d\n", vsc->bpc); + return -EINVAL; + } + + /* Dynamic Range and Component Bit Depth */ + if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA) + sdp->db[17] |= 0x80; /* DB17[7] */ + + /* Content Type */ + sdp->db[18] = vsc->content_type & 0x7; + +out: + return length; +} +EXPORT_SYMBOL(drm_dp_vsc_sdp_pack); + +/** + * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Returns maximum frl bandwidth supported by PCON in GBPS, + * returns 0 if not supported. + */ +int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + int bw; + u8 buf; + + buf = port_cap[2]; + bw = buf & DP_PCON_MAX_FRL_BW; + + switch (bw) { + case DP_PCON_MAX_9GBPS: + return 9; + case DP_PCON_MAX_18GBPS: + return 18; + case DP_PCON_MAX_24GBPS: + return 24; + case DP_PCON_MAX_32GBPS: + return 32; + case DP_PCON_MAX_40GBPS: + return 40; + case DP_PCON_MAX_48GBPS: + return 48; + case DP_PCON_MAX_0GBPS: + default: + return 0; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_get_pcon_max_frl_bw); + +/** + * drm_dp_pcon_frl_prepare() - Prepare PCON for FRL. + * @aux: DisplayPort AUX channel + * @enable_frl_ready_hpd: Configure DP_PCON_ENABLE_HPD_READY. + * + * Returns 0 if success, else returns negative error code. + */ +int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd) +{ + u8 buf = DP_PCON_ENABLE_SOURCE_CTL_MODE | + DP_PCON_ENABLE_LINK_FRL_MODE; + + if (enable_frl_ready_hpd) + buf |= DP_PCON_ENABLE_HPD_READY; + + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); +} +EXPORT_SYMBOL(drm_dp_pcon_frl_prepare); + +/** + * drm_dp_pcon_is_frl_ready() - Is PCON ready for FRL + * @aux: DisplayPort AUX channel + * + * Returns true if success, else returns false. + */ +bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux) +{ + int ret; + u8 buf; + + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); + if (ret < 0) + return false; + + if (buf & DP_PCON_FRL_READY) + return true; + + return false; +} +EXPORT_SYMBOL(drm_dp_pcon_is_frl_ready); + +/** + * drm_dp_pcon_frl_configure_1() - Set HDMI LINK Configuration-Step1 + * @aux: DisplayPort AUX channel + * @max_frl_gbps: maximum frl bw to be configured between PCON and HDMI sink + * @frl_mode: FRL Training mode, it can be either Concurrent or Sequential. + * In Concurrent Mode, the FRL link bring up can be done along with + * DP Link training. In Sequential mode, the FRL link bring up is done prior to + * the DP Link training. + * + * Returns 0 if success, else returns negative error code. + */ + +int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps, + u8 frl_mode) +{ + int ret; + u8 buf; + + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); + if (ret < 0) + return ret; + + if (frl_mode == DP_PCON_ENABLE_CONCURRENT_LINK) + buf |= DP_PCON_ENABLE_CONCURRENT_LINK; + else + buf &= ~DP_PCON_ENABLE_CONCURRENT_LINK; + + switch (max_frl_gbps) { + case 9: + buf |= DP_PCON_ENABLE_MAX_BW_9GBPS; + break; + case 18: + buf |= DP_PCON_ENABLE_MAX_BW_18GBPS; + break; + case 24: + buf |= DP_PCON_ENABLE_MAX_BW_24GBPS; + break; + case 32: + buf |= DP_PCON_ENABLE_MAX_BW_32GBPS; + break; + case 40: + buf |= DP_PCON_ENABLE_MAX_BW_40GBPS; + break; + case 48: + buf |= DP_PCON_ENABLE_MAX_BW_48GBPS; + break; + case 0: + buf |= DP_PCON_ENABLE_MAX_BW_0GBPS; + break; + default: + return -EINVAL; + } + + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); +} +EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1); + +/** + * drm_dp_pcon_frl_configure_2() - Set HDMI Link configuration Step-2 + * @aux: DisplayPort AUX channel + * @max_frl_mask : Max FRL BW to be tried by the PCON with HDMI Sink + * @frl_type : FRL training type, can be Extended, or Normal. + * In Normal FRL training, the PCON tries each frl bw from the max_frl_mask + * starting from min, and stops when link training is successful. In Extended + * FRL training, all frl bw selected in the mask are trained by the PCON. + * + * Returns 0 if success, else returns negative error code. + */ +int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask, + u8 frl_type) +{ + int ret; + u8 buf = max_frl_mask; + + if (frl_type == DP_PCON_FRL_LINK_TRAIN_EXTENDED) + buf |= DP_PCON_FRL_LINK_TRAIN_EXTENDED; + else + buf &= ~DP_PCON_FRL_LINK_TRAIN_EXTENDED; + + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL(drm_dp_pcon_frl_configure_2); + +/** + * drm_dp_pcon_reset_frl_config() - Re-Set HDMI Link configuration. + * @aux: DisplayPort AUX channel + * + * Returns 0 if success, else returns negative error code. + */ +int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux) +{ + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, 0x0); +} +EXPORT_SYMBOL(drm_dp_pcon_reset_frl_config); + +/** + * drm_dp_pcon_frl_enable() - Enable HDMI link through FRL + * @aux: DisplayPort AUX channel + * + * Returns 0 if success, else returns negative error code. + */ +int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux) +{ + int ret; + u8 buf = 0; + + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); + if (ret < 0) + return ret; + if (!(buf & DP_PCON_ENABLE_SOURCE_CTL_MODE)) { + drm_dbg_kms(aux->drm_dev, "%s: PCON in Autonomous mode, can't enable FRL\n", + aux->name); + return -EINVAL; + } + buf |= DP_PCON_ENABLE_HDMI_LINK; + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); +} +EXPORT_SYMBOL(drm_dp_pcon_frl_enable); + +/** + * drm_dp_pcon_hdmi_link_active() - check if the PCON HDMI LINK status is active. + * @aux: DisplayPort AUX channel + * + * Returns true if link is active else returns false. + */ +bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux) +{ + u8 buf; + int ret; + + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); + if (ret < 0) + return false; + + return buf & DP_PCON_HDMI_TX_LINK_ACTIVE; +} +EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_active); + +/** + * drm_dp_pcon_hdmi_link_mode() - get the PCON HDMI LINK MODE + * @aux: DisplayPort AUX channel + * @frl_trained_mask: pointer to store bitmask of the trained bw configuration. + * Valid only if the MODE returned is FRL. For Normal Link training mode + * only 1 of the bits will be set, but in case of Extended mode, more than + * one bits can be set. + * + * Returns the link mode : TMDS or FRL on success, else returns negative error + * code. + */ +int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask) +{ + u8 buf; + int mode; + int ret; + + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_POST_FRL_STATUS, &buf); + if (ret < 0) + return ret; + + mode = buf & DP_PCON_HDMI_LINK_MODE; + + if (frl_trained_mask && DP_PCON_HDMI_MODE_FRL == mode) + *frl_trained_mask = (buf & DP_PCON_HDMI_FRL_TRAINED_BW) >> 1; + + return mode; +} +EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_mode); + +/** + * drm_dp_pcon_hdmi_frl_link_error_count() - print the error count per lane + * during link failure between PCON and HDMI sink + * @aux: DisplayPort AUX channel + * @connector: DRM connector + * code. + **/ + +void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux, + struct drm_connector *connector) +{ + u8 buf, error_count; + int i, num_error; + struct drm_hdmi_info *hdmi = &connector->display_info.hdmi; + + for (i = 0; i < hdmi->max_lanes; i++) { + if (drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_ERROR_STATUS_LN0 + i, &buf) < 0) + return; + + error_count = buf & DP_PCON_HDMI_ERROR_COUNT_MASK; + switch (error_count) { + case DP_PCON_HDMI_ERROR_COUNT_HUNDRED_PLUS: + num_error = 100; + break; + case DP_PCON_HDMI_ERROR_COUNT_TEN_PLUS: + num_error = 10; + break; + case DP_PCON_HDMI_ERROR_COUNT_THREE_PLUS: + num_error = 3; + break; + default: + num_error = 0; + } + + drm_err(aux->drm_dev, "%s: More than %d errors since the last read for lane %d", + aux->name, num_error, i); + } +} +EXPORT_SYMBOL(drm_dp_pcon_hdmi_frl_link_error_count); + +/* + * drm_dp_pcon_enc_is_dsc_1_2 - Does PCON Encoder supports DSC 1.2 + * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder + * + * Returns true is PCON encoder is DSC 1.2 else returns false. + */ +bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) +{ + u8 buf; + u8 major_v, minor_v; + + buf = pcon_dsc_dpcd[DP_PCON_DSC_VERSION - DP_PCON_DSC_ENCODER]; + major_v = (buf & DP_PCON_DSC_MAJOR_MASK) >> DP_PCON_DSC_MAJOR_SHIFT; + minor_v = (buf & DP_PCON_DSC_MINOR_MASK) >> DP_PCON_DSC_MINOR_SHIFT; + + if (major_v == 1 && minor_v == 2) + return true; + + return false; +} +EXPORT_SYMBOL(drm_dp_pcon_enc_is_dsc_1_2); + +/* + * drm_dp_pcon_dsc_max_slices - Get max slices supported by PCON DSC Encoder + * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder + * + * Returns maximum no. of slices supported by the PCON DSC Encoder. + */ +int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) +{ + u8 slice_cap1, slice_cap2; + + slice_cap1 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_1 - DP_PCON_DSC_ENCODER]; + slice_cap2 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_2 - DP_PCON_DSC_ENCODER]; + + if (slice_cap2 & DP_PCON_DSC_24_PER_DSC_ENC) + return 24; + if (slice_cap2 & DP_PCON_DSC_20_PER_DSC_ENC) + return 20; + if (slice_cap2 & DP_PCON_DSC_16_PER_DSC_ENC) + return 16; + if (slice_cap1 & DP_PCON_DSC_12_PER_DSC_ENC) + return 12; + if (slice_cap1 & DP_PCON_DSC_10_PER_DSC_ENC) + return 10; + if (slice_cap1 & DP_PCON_DSC_8_PER_DSC_ENC) + return 8; + if (slice_cap1 & DP_PCON_DSC_6_PER_DSC_ENC) + return 6; + if (slice_cap1 & DP_PCON_DSC_4_PER_DSC_ENC) + return 4; + if (slice_cap1 & DP_PCON_DSC_2_PER_DSC_ENC) + return 2; + if (slice_cap1 & DP_PCON_DSC_1_PER_DSC_ENC) + return 1; + + return 0; +} +EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slices); + +/* + * drm_dp_pcon_dsc_max_slice_width() - Get max slice width for Pcon DSC encoder + * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder + * + * Returns maximum width of the slices in pixel width i.e. no. of pixels x 320. + */ +int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) +{ + u8 buf; + + buf = pcon_dsc_dpcd[DP_PCON_DSC_MAX_SLICE_WIDTH - DP_PCON_DSC_ENCODER]; + + return buf * DP_DSC_SLICE_WIDTH_MULTIPLIER; +} +EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slice_width); + +/* + * drm_dp_pcon_dsc_bpp_incr() - Get bits per pixel increment for PCON DSC encoder + * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder + * + * Returns the bpp precision supported by the PCON encoder. + */ +int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) +{ + u8 buf; + + buf = pcon_dsc_dpcd[DP_PCON_DSC_BPP_INCR - DP_PCON_DSC_ENCODER]; + + switch (buf & DP_PCON_DSC_BPP_INCR_MASK) { + case DP_PCON_DSC_ONE_16TH_BPP: + return 16; + case DP_PCON_DSC_ONE_8TH_BPP: + return 8; + case DP_PCON_DSC_ONE_4TH_BPP: + return 4; + case DP_PCON_DSC_ONE_HALF_BPP: + return 2; + case DP_PCON_DSC_ONE_BPP: + return 1; + } + + return 0; +} +EXPORT_SYMBOL(drm_dp_pcon_dsc_bpp_incr); + +static +int drm_dp_pcon_configure_dsc_enc(struct drm_dp_aux *aux, u8 pps_buf_config) +{ + u8 buf; + int ret; + + ret = drm_dp_dpcd_read_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); + if (ret < 0) + return ret; + + buf |= DP_PCON_ENABLE_DSC_ENCODER; + + if (pps_buf_config <= DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER) { + buf &= ~DP_PCON_ENCODER_PPS_OVERRIDE_MASK; + buf |= pps_buf_config << 2; + } + + return drm_dp_dpcd_write_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); +} + +/** + * drm_dp_pcon_pps_default() - Let PCON fill the default pps parameters + * for DSC1.2 between PCON & HDMI2.1 sink + * @aux: DisplayPort AUX channel + * + * Returns 0 on success, else returns negative error code. + */ +int drm_dp_pcon_pps_default(struct drm_dp_aux *aux) +{ + return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_DISABLED); +} +EXPORT_SYMBOL(drm_dp_pcon_pps_default); + +/** + * drm_dp_pcon_pps_override_buf() - Configure PPS encoder override buffer for + * HDMI sink + * @aux: DisplayPort AUX channel + * @pps_buf: 128 bytes to be written into PPS buffer for HDMI sink by PCON. + * + * Returns 0 on success, else returns negative error code. + */ +int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]) +{ + int ret; + + ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVERRIDE_BASE, &pps_buf, 128); + if (ret < 0) + return ret; + + return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); +} +EXPORT_SYMBOL(drm_dp_pcon_pps_override_buf); + +/* + * drm_dp_pcon_pps_override_param() - Write PPS parameters to DSC encoder + * override registers + * @aux: DisplayPort AUX channel + * @pps_param: 3 Parameters (2 Bytes each) : Slice Width, Slice Height, + * bits_per_pixel. + * + * Returns 0 on success, else returns negative error code. + */ +int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]) +{ + int ret; + + ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_HEIGHT, &pps_param[0], 2); + if (ret < 0) + return ret; + ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_WIDTH, &pps_param[2], 2); + if (ret < 0) + return ret; + ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVRD_BPP, &pps_param[4], 2); + if (ret < 0) + return ret; + + return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); +} +EXPORT_SYMBOL(drm_dp_pcon_pps_override_param); + +/* + * drm_dp_pcon_convert_rgb_to_ycbcr() - Configure the PCon to convert RGB to Ycbcr + * @aux: displayPort AUX channel + * @color_spc: Color-space/s for which conversion is to be enabled, 0 for disable. + * + * Returns 0 on success, else returns negative error code. + */ +int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc) +{ + int ret; + u8 buf; + + ret = drm_dp_dpcd_read_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); + if (ret < 0) + return ret; + + if (color_spc & DP_CONVERSION_RGB_YCBCR_MASK) + buf |= (color_spc & DP_CONVERSION_RGB_YCBCR_MASK); + else + buf &= ~DP_CONVERSION_RGB_YCBCR_MASK; + + return drm_dp_dpcd_write_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); +} +EXPORT_SYMBOL(drm_dp_pcon_convert_rgb_to_ycbcr); + +/** + * drm_edp_backlight_set_level() - Set the backlight level of an eDP panel via AUX + * @aux: The DP AUX channel to use + * @bl: Backlight capability info from drm_edp_backlight_init() + * @level: The brightness level to set + * + * Sets the brightness level of an eDP panel's backlight. Note that the panel's backlight must + * already have been enabled by the driver by calling drm_edp_backlight_enable(). + * + * Returns: %0 on success, negative error code on failure + */ +int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, + u32 level) +{ + int ret; + unsigned int offset = DP_EDP_BACKLIGHT_BRIGHTNESS_MSB; + u8 buf[3] = { 0 }; + size_t len = 2; + + /* The panel uses the PWM for controlling brightness levels */ + if (!(bl->aux_set || bl->luminance_set)) + return 0; + + if (bl->luminance_set) { + level = level * 1000; + level &= 0xffffff; + buf[0] = (level & 0x0000ff); + buf[1] = (level & 0x00ff00) >> 8; + buf[2] = (level & 0xff0000) >> 16; + offset = DP_EDP_PANEL_TARGET_LUMINANCE_VALUE; + len = 3; + } else if (bl->lsb_reg_used) { + buf[0] = (level & 0xff00) >> 8; + buf[1] = (level & 0x00ff); + } else { + buf[0] = level; + } + + ret = drm_dp_dpcd_write_data(aux, offset, buf, len); + if (ret < 0) { + drm_err(aux->drm_dev, + "%s: Failed to write aux backlight level: %d\n", + aux->name, ret); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(drm_edp_backlight_set_level); + +static int +drm_edp_backlight_set_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, + bool enable) +{ + int ret; + u8 buf; + + /* This panel uses the EDP_BL_PWR GPIO for enablement */ + if (!bl->aux_enable) + return 0; + + ret = drm_dp_dpcd_read_byte(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &buf); + if (ret < 0) { + drm_err(aux->drm_dev, "%s: Failed to read eDP display control register: %d\n", + aux->name, ret); + return ret; + } + if (enable) + buf |= DP_EDP_BACKLIGHT_ENABLE; + else + buf &= ~DP_EDP_BACKLIGHT_ENABLE; + + ret = drm_dp_dpcd_write_byte(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, buf); + if (ret < 0) { + drm_err(aux->drm_dev, "%s: Failed to write eDP display control register: %d\n", + aux->name, ret); + return ret; + } + + return 0; +} + +/** + * drm_edp_backlight_enable() - Enable an eDP panel's backlight using DPCD + * @aux: The DP AUX channel to use + * @bl: Backlight capability info from drm_edp_backlight_init() + * @level: The initial backlight level to set via AUX, if there is one + * + * This function handles enabling DPCD backlight controls on a panel over DPCD, while additionally + * restoring any important backlight state such as the given backlight level, the brightness byte + * count, backlight frequency, etc. + * + * Note that certain panels do not support being enabled or disabled via DPCD, but instead require + * that the driver handle enabling/disabling the panel through implementation-specific means using + * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false, + * this function becomes a no-op, and the driver is expected to handle powering the panel on using + * the EDP_BL_PWR GPIO. + * + * Returns: %0 on success, negative error code on failure. + */ +int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl, + const u32 level) +{ + int ret; + u8 dpcd_buf; + + if (bl->aux_set) + dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; + else + dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_PWM; + + if (bl->luminance_set) + dpcd_buf |= DP_EDP_PANEL_LUMINANCE_CONTROL_ENABLE; + + if (bl->pwmgen_bit_count) { + ret = drm_dp_dpcd_write_byte(aux, DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count); + if (ret < 0) + drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n", + aux->name, ret); + } + + if (bl->pwm_freq_pre_divider) { + ret = drm_dp_dpcd_write_byte(aux, DP_EDP_BACKLIGHT_FREQ_SET, + bl->pwm_freq_pre_divider); + if (ret < 0) + drm_dbg_kms(aux->drm_dev, + "%s: Failed to write aux backlight frequency: %d\n", + aux->name, ret); + else + dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; + } + + ret = drm_dp_dpcd_write_byte(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux backlight mode: %d\n", + aux->name, ret); + return ret < 0 ? ret : -EIO; + } + + ret = drm_edp_backlight_set_level(aux, bl, level); + if (ret < 0) + return ret; + ret = drm_edp_backlight_set_enable(aux, bl, true); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL(drm_edp_backlight_enable); + +/** + * drm_edp_backlight_disable() - Disable an eDP backlight using DPCD, if supported + * @aux: The DP AUX channel to use + * @bl: Backlight capability info from drm_edp_backlight_init() + * + * This function handles disabling DPCD backlight controls on a panel over AUX. + * + * Note that certain panels do not support being enabled or disabled via DPCD, but instead require + * that the driver handle enabling/disabling the panel through implementation-specific means using + * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false, + * this function becomes a no-op, and the driver is expected to handle powering the panel off using + * the EDP_BL_PWR GPIO. + * + * Returns: %0 on success or no-op, negative error code on failure. + */ +int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl) +{ + int ret; + + ret = drm_edp_backlight_set_enable(aux, bl, false); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL(drm_edp_backlight_disable); + +static inline int +drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, + u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]) +{ + int fxp, fxp_min, fxp_max, fxp_actual, f = 1; + int ret; + u8 pn, pn_min, pn_max, bit_count; + + if (!bl->aux_set) + return 0; + + ret = drm_dp_dpcd_read_byte(aux, DP_EDP_PWMGEN_BIT_COUNT, &bit_count); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap: %d\n", + aux->name, ret); + return -ENODEV; + } + + bit_count &= DP_EDP_PWMGEN_BIT_COUNT_MASK; + + ret = drm_dp_dpcd_read_byte(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap min: %d\n", + aux->name, ret); + return -ENODEV; + } + pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; + + ret = drm_dp_dpcd_read_byte(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap max: %d\n", + aux->name, ret); + return -ENODEV; + } + pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; + + if (unlikely(pn_min > pn_max)) { + drm_dbg_kms(aux->drm_dev, "%s: Invalid pwmgen bit count cap min/max returned: %d %d\n", + aux->name, pn_min, pn_max); + return -EINVAL; + } + + /* + * Per VESA eDP Spec v1.4b, section 3.3.10.2: + * If DP_EDP_PWMGEN_BIT_COUNT is less than DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, + * the sink must use the MIN value as the effective PWM bit count. + * Clamp the reported value to the [MIN, MAX] capability range to ensure + * correct brightness scaling on compliant eDP panels. + * Only enable this logic if the [MIN, MAX] range is valid in regard to Spec. + */ + pn = bit_count; + if (bit_count < pn_min) + pn = clamp(bit_count, pn_min, pn_max); + + bl->max = (1 << pn) - 1; + if (!driver_pwm_freq_hz) { + if (pn != bit_count) + goto bit_count_write_back; + + return 0; + } + + /* + * Set PWM Frequency divider to match desired frequency provided by the driver. + * The PWM Frequency is calculated as 27Mhz / (F x P). + * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the + * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) + * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the + * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) + */ + + /* Find desired value of (F x P) + * Note that, if F x P is out of supported range, the maximum value or minimum value will + * applied automatically. So no need to check that. + */ + fxp = DIV_ROUND_CLOSEST(1000 * DP_EDP_BACKLIGHT_FREQ_BASE_KHZ, driver_pwm_freq_hz); + + /* Use highest possible value of Pn for more granularity of brightness adjustment while + * satisfying the conditions below. + * - Pn is in the range of Pn_min and Pn_max + * - F is in the range of 1 and 255 + * - FxP is within 25% of desired value. + * Note: 25% is arbitrary value and may need some tweak. + */ + /* Ensure frequency is within 25% of desired value */ + fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); + fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); + if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) { + drm_dbg_kms(aux->drm_dev, + "%s: Driver defined backlight frequency (%d) out of range\n", + aux->name, driver_pwm_freq_hz); + return 0; + } + + for (pn = pn_max; pn >= pn_min; pn--) { + f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); + fxp_actual = f << pn; + if (fxp_min <= fxp_actual && fxp_actual <= fxp_max) + break; + } + +bit_count_write_back: + ret = drm_dp_dpcd_write_byte(aux, DP_EDP_PWMGEN_BIT_COUNT, pn); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n", + aux->name, ret); + return 0; + } + + if (!driver_pwm_freq_hz) + return 0; + + bl->pwmgen_bit_count = pn; + bl->max = (1 << pn) - 1; + + if (edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) { + bl->pwm_freq_pre_divider = f; + drm_dbg_kms(aux->drm_dev, "%s: Using backlight frequency from driver (%dHz)\n", + aux->name, driver_pwm_freq_hz); + } + + return 0; +} + +static inline int +drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, + u8 *current_mode) +{ + int ret; + u8 buf[3]; + u8 mode_reg; + + ret = drm_dp_dpcd_read_byte(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight mode: %d\n", + aux->name, ret); + return ret < 0 ? ret : -EIO; + } + + *current_mode = (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK); + if (!bl->aux_set) + return 0; + + if (*current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { + int size = 1 + bl->lsb_reg_used; + + if (bl->luminance_set) { + ret = drm_dp_dpcd_read_data(aux, DP_EDP_PANEL_TARGET_LUMINANCE_VALUE, + buf, sizeof(buf)); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, + "%s: Failed to read backlight level: %d\n", + aux->name, ret); + return ret; + } + + /* + * Incase luminance is set we want to send the value back in nits but + * since DP_EDP_PANEL_TARGET_LUMINANCE stores values in millinits we + * need to divide by 1000. + */ + return (buf[0] | buf[1] << 8 | buf[2] << 16) / 1000; + } else { + ret = drm_dp_dpcd_read_data(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, + buf, size); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, + "%s: Failed to read backlight level: %d\n", + aux->name, ret); + return ret; + } + + if (bl->lsb_reg_used) + return (buf[0] << 8) | buf[1]; + else + return buf[0]; + } + } + + /* + * If we're not in DPCD control mode yet, the programmed brightness value is meaningless and + * the driver should assume max brightness + */ + return bl->max; +} + +/** + * drm_edp_backlight_init() - Probe a display panel's TCON using the standard VESA eDP backlight + * interface. + * @aux: The DP aux device to use for probing + * @bl: The &drm_edp_backlight_info struct to fill out with information on the backlight + * @max_luminance: max luminance when need luminance is set as true + * @driver_pwm_freq_hz: Optional PWM frequency from the driver in hz + * @edp_dpcd: A cached copy of the eDP DPCD + * @current_level: Where to store the probed brightness level, if any + * @current_mode: Where to store the currently set backlight control mode + * @need_luminance: Tells us if a we want to manipulate backlight using luminance values + * + * Initializes a &drm_edp_backlight_info struct by probing @aux for it's backlight capabilities, + * along with also probing the current and maximum supported brightness levels. + * + * If @driver_pwm_freq_hz is non-zero, this will be used as the backlight frequency. Otherwise, the + * default frequency from the panel is used. + * + * Returns: %0 on success, negative error code on failure. + */ +int +drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl, + u32 max_luminance, + u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE], + u32 *current_level, u8 *current_mode, bool need_luminance) +{ + int ret; + + if (edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) + bl->aux_enable = true; + if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) + bl->aux_set = true; + if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) + bl->lsb_reg_used = true; + if ((edp_dpcd[0] & DP_EDP_15) && edp_dpcd[3] & + (DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE) && need_luminance) + bl->luminance_set = true; + + /* Sanity check caps */ + if (!bl->aux_set && !(edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP) && + !bl->luminance_set) { + drm_dbg_kms(aux->drm_dev, + "%s: Panel does not support AUX, PWM or luminance-based brightness control. Aborting\n", + aux->name); + return -EINVAL; + } + + if (bl->luminance_set) { + bl->max = max_luminance; + } else { + ret = drm_edp_backlight_probe_max(aux, bl, driver_pwm_freq_hz, edp_dpcd); + if (ret < 0) + return ret; + } + + ret = drm_edp_backlight_probe_state(aux, bl, current_mode); + if (ret < 0) + return ret; + *current_level = ret; + + drm_dbg_kms(aux->drm_dev, + "%s: Found backlight: aux_set=%d aux_enable=%d mode=%d\n", + aux->name, bl->aux_set, bl->aux_enable, *current_mode); + if (bl->aux_set) { + drm_dbg_kms(aux->drm_dev, + "%s: Backlight caps: level=%d/%d pwm_freq_pre_divider=%d lsb_reg_used=%d\n", + aux->name, *current_level, bl->max, bl->pwm_freq_pre_divider, + bl->lsb_reg_used); + } + + return 0; +} +EXPORT_SYMBOL(drm_edp_backlight_init); + +#if IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \ + (IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)) + +static int dp_aux_backlight_update_status(struct backlight_device *bd) +{ + struct dp_aux_backlight *bl = bl_get_data(bd); + u16 brightness = backlight_get_brightness(bd); + int ret = 0; + + if (!backlight_is_blank(bd)) { + if (!bl->enabled) { + drm_edp_backlight_enable(bl->aux, &bl->info, brightness); + bl->enabled = true; + return 0; + } + ret = drm_edp_backlight_set_level(bl->aux, &bl->info, brightness); + } else { + if (bl->enabled) { + drm_edp_backlight_disable(bl->aux, &bl->info); + bl->enabled = false; + } + } + + return ret; +} + +static const struct backlight_ops dp_aux_bl_ops = { + .update_status = dp_aux_backlight_update_status, +}; + +/** + * drm_panel_dp_aux_backlight - create and use DP AUX backlight + * @panel: DRM panel + * @aux: The DP AUX channel to use + * + * Use this function to create and handle backlight if your panel + * supports backlight control over DP AUX channel using DPCD + * registers as per VESA's standard backlight control interface. + * + * When the panel is enabled backlight will be enabled after a + * successful call to &drm_panel_funcs.enable() + * + * When the panel is disabled backlight will be disabled before the + * call to &drm_panel_funcs.disable(). + * + * A typical implementation for a panel driver supporting backlight + * control over DP AUX will call this function at probe time. + * Backlight will then be handled transparently without requiring + * any intervention from the driver. + * + * drm_panel_dp_aux_backlight() must be called after the call to drm_panel_init(). + * + * Return: 0 on success or a negative error code on failure. + */ +int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux) +{ + struct dp_aux_backlight *bl; + struct backlight_properties props = { 0 }; + u32 current_level; + u8 current_mode; + u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]; + int ret; + + if (!panel || !panel->dev || !aux) + return -EINVAL; + + ret = drm_dp_dpcd_read_data(aux, DP_EDP_DPCD_REV, edp_dpcd, + EDP_DISPLAY_CTL_CAP_SIZE); + if (ret < 0) + return ret; + + if (!drm_edp_backlight_supported(edp_dpcd)) { + DRM_DEV_INFO(panel->dev, "DP AUX backlight is not supported\n"); + return 0; + } + + bl = devm_kzalloc(panel->dev, sizeof(*bl), GFP_KERNEL); + if (!bl) + return -ENOMEM; + + bl->aux = aux; + + ret = drm_edp_backlight_init(aux, &bl->info, 0, 0, edp_dpcd, + ¤t_level, ¤t_mode, false); + if (ret < 0) + return ret; + + props.type = BACKLIGHT_RAW; + props.brightness = current_level; + props.max_brightness = bl->info.max; + + bl->base = devm_backlight_device_register(panel->dev, "dp_aux_backlight", + panel->dev, bl, + &dp_aux_bl_ops, &props); + if (IS_ERR(bl->base)) + return PTR_ERR(bl->base); + + backlight_disable(bl->base); + + panel->backlight = bl->base; + + return 0; +} +EXPORT_SYMBOL(drm_panel_dp_aux_backlight); + +#endif + +/* See DP Standard v2.1 2.6.4.4.1.1, 2.8.4.4, 2.8.7 */ +static int drm_dp_link_data_symbol_cycles(int lane_count, int pixels, + int bpp_x16, int symbol_size, + bool is_mst) +{ + int cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size * lane_count); + int align = is_mst ? 4 / lane_count : 1; + + return ALIGN(cycles, align); +} + +/** + * drm_dp_link_symbol_cycles - calculate the link symbol count with/without dsc + * @lane_count: DP link lane count + * @pixels: number of pixels in a scanline + * @dsc_slice_count: number of slices for DSC or '0' for non-DSC + * @bpp_x16: bits per pixel in .4 binary fixed format + * @symbol_size: DP symbol size + * @is_mst: %true for MST and %false for SST + * + * Calculate the link symbol cycles for both DSC (@dsc_slice_count !=0) and + * non-DSC case (@dsc_slice_count == 0) and return the count. + */ +int drm_dp_link_symbol_cycles(int lane_count, int pixels, int dsc_slice_count, + int bpp_x16, int symbol_size, bool is_mst) +{ + int slice_count = dsc_slice_count ? : 1; + int slice_pixels = DIV_ROUND_UP(pixels, slice_count); + int slice_data_cycles = drm_dp_link_data_symbol_cycles(lane_count, + slice_pixels, + bpp_x16, + symbol_size, + is_mst); + int slice_eoc_cycles = 0; + + if (dsc_slice_count) + slice_eoc_cycles = is_mst ? 4 / lane_count : 1; + + return slice_count * (slice_data_cycles + slice_eoc_cycles); +} +EXPORT_SYMBOL(drm_dp_link_symbol_cycles); + +/** + * drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream + * @lane_count: DP link lane count + * @hactive: pixel count of the active period in one scanline of the stream + * @dsc_slice_count: number of slices for DSC or '0' for non-DSC + * @bpp_x16: bits per pixel in .4 binary fixed point + * @flags: DRM_DP_OVERHEAD_x flags + * + * Calculate the BW allocation overhead of a DP link stream, depending + * on the link's + * - @lane_count + * - SST/MST mode (@flags / %DRM_DP_OVERHEAD_MST) + * - symbol size (@flags / %DRM_DP_OVERHEAD_UHBR) + * - FEC mode (@flags / %DRM_DP_OVERHEAD_FEC) + * - SSC/REF_CLK mode (@flags / %DRM_DP_OVERHEAD_SSC_REF_CLK) + * as well as the stream's + * - @hactive timing + * - @bpp_x16 color depth + * - compression mode (@dsc_slice_count != 0) + * Note that this overhead doesn't account for the 8b/10b, 128b/132b + * channel coding efficiency, for that see + * @drm_dp_link_bw_channel_coding_efficiency(). + * + * Returns the overhead as 100% + overhead% in 1ppm units. + */ +int drm_dp_bw_overhead(int lane_count, int hactive, + int dsc_slice_count, + int bpp_x16, unsigned long flags) +{ + int symbol_size = flags & DRM_DP_BW_OVERHEAD_UHBR ? 32 : 8; + bool is_mst = flags & DRM_DP_BW_OVERHEAD_MST; + u32 overhead = 1000000; + int symbol_cycles; + + if (lane_count == 0 || hactive == 0 || bpp_x16 == 0) { + DRM_DEBUG_KMS("Invalid BW overhead params: lane_count %d, hactive %d, bpp_x16 " FXP_Q4_FMT "\n", + lane_count, hactive, + FXP_Q4_ARGS(bpp_x16)); + return 0; + } + + /* + * DP Standard v2.1 2.6.4.1 + * SSC downspread and ref clock variation margin: + * 5300ppm + 300ppm ~ 0.6% + */ + if (flags & DRM_DP_BW_OVERHEAD_SSC_REF_CLK) + overhead += 6000; + + /* + * DP Standard v2.1 2.6.4.1.1, 3.5.1.5.4: + * FEC symbol insertions for 8b/10b channel coding: + * After each 250 data symbols on 2-4 lanes: + * 250 LL + 5 FEC_PARITY_PH + 1 CD_ADJ (256 byte FEC block) + * After each 2 x 250 data symbols on 1 lane: + * 2 * 250 LL + 11 FEC_PARITY_PH + 1 CD_ADJ (512 byte FEC block) + * After 256 (2-4 lanes) or 128 (1 lane) FEC blocks: + * 256 * 256 bytes + 1 FEC_PM + * or + * 128 * 512 bytes + 1 FEC_PM + * (256 * 6 + 1) / (256 * 250) = 2.4015625 % + */ + if (flags & DRM_DP_BW_OVERHEAD_FEC) + overhead += 24016; + + /* + * DP Standard v2.1 2.7.9, 5.9.7 + * The FEC overhead for UHBR is accounted for in its 96.71% channel + * coding efficiency. + */ + WARN_ON((flags & DRM_DP_BW_OVERHEAD_UHBR) && + (flags & DRM_DP_BW_OVERHEAD_FEC)); + + symbol_cycles = drm_dp_link_symbol_cycles(lane_count, hactive, + dsc_slice_count, + bpp_x16, symbol_size, + is_mst); + + return DIV_ROUND_UP_ULL(mul_u32_u32(symbol_cycles * symbol_size * lane_count, + overhead * 16), + hactive * bpp_x16); +} +EXPORT_SYMBOL(drm_dp_bw_overhead); + +/** + * drm_dp_bw_channel_coding_efficiency - Get a DP link's channel coding efficiency + * @is_uhbr: Whether the link has a 128b/132b channel coding + * + * Return the channel coding efficiency of the given DP link type, which is + * either 8b/10b or 128b/132b (aka UHBR). The corresponding overhead includes + * the 8b -> 10b, 128b -> 132b pixel data to link symbol conversion overhead + * and for 128b/132b any link or PHY level control symbol insertion overhead + * (LLCP, FEC, PHY sync, see DP Standard v2.1 3.5.2.18). For 8b/10b the + * corresponding FEC overhead is BW allocation specific, included in the value + * returned by drm_dp_bw_overhead(). + * + * Returns the efficiency in the 100%/coding-overhead% ratio in + * 1ppm units. + */ +int drm_dp_bw_channel_coding_efficiency(bool is_uhbr) +{ + if (is_uhbr) + return 967100; + else + /* + * Note that on 8b/10b MST the efficiency is only + * 78.75% due to the 1 out of 64 MTPH packet overhead, + * not accounted for here. + */ + return 800000; +} +EXPORT_SYMBOL(drm_dp_bw_channel_coding_efficiency); + +/** + * drm_dp_max_dprx_data_rate - Get the max data bandwidth of a DPRX sink + * @max_link_rate: max DPRX link rate in 10kbps units + * @max_lanes: max DPRX lane count + * + * Given a link rate and lanes, get the data bandwidth. + * + * Data bandwidth is the actual payload rate, which depends on the data + * bandwidth efficiency and the link rate. + * + * Note that protocol layers above the DPRX link level considered here can + * further limit the maximum data rate. Such layers are the MST topology (with + * limits on the link between the source and first branch device as well as on + * the whole MST path until the DPRX link) and (Thunderbolt) DP tunnels - + * which in turn can encapsulate an MST link with its own limit - with each + * SST or MST encapsulated tunnel sharing the BW of a tunnel group. + * + * Returns the maximum data rate in kBps units. + */ +int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes) +{ + int ch_coding_efficiency = + drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(max_link_rate)); + + return DIV_ROUND_DOWN_ULL(mul_u32_u32(max_link_rate * 10 * max_lanes, + ch_coding_efficiency), + 1000000 * 8); +} +EXPORT_SYMBOL(drm_dp_max_dprx_data_rate); |