diff options
Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/display/drm_dp_helper.c | 1507 |
1 files changed, 1227 insertions, 280 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index 16565a0a5da6..f9fdf19de74a 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -22,19 +22,23 @@ #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 <linux/dynamic_debug.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> @@ -120,6 +124,14 @@ bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], } 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) { @@ -325,7 +337,7 @@ static int __read_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SI if (offset < DP_RECEIVER_CAP_SIZE) { rd_interval = dpcd[offset]; } else { - if (drm_dp_dpcd_readb(aux, offset, &rd_interval) != 1) { + 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 */ @@ -356,7 +368,7 @@ int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux) int unit; u8 val; - if (drm_dp_dpcd_readb(aux, DP_128B132B_TRAINING_AUX_RD_INTERVAL, &val) != 1) { + 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 */ @@ -457,6 +469,64 @@ void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux, } 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) { @@ -533,6 +603,15 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, 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 @@ -600,6 +679,57 @@ int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset) 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 @@ -612,26 +742,16 @@ EXPORT_SYMBOL(drm_dp_dpcd_probe); * 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; - /* - * 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. - */ - if (!aux->is_remote) { - ret = drm_dp_dpcd_probe(aux, DP_DPCD_REV); + if (dpcd_access_needs_probe(aux)) { + ret = drm_dp_dpcd_probe(aux, DP_TRAINING_PATTERN_SET); if (ret < 0) return ret; } @@ -660,6 +780,8 @@ EXPORT_SYMBOL(drm_dp_dpcd_read); * 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) @@ -682,14 +804,13 @@ EXPORT_SYMBOL(drm_dp_dpcd_write); * @aux: DisplayPort AUX channel * @status: buffer to store the link status in (must be at least 6 bytes) * - * Returns the number of bytes transferred on success or a negative error - * code on failure. + * 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(aux, DP_LANE0_1_STATUS, 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); @@ -712,30 +833,20 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, { int ret; - if (dp_phy == DP_PHY_DPRX) { - ret = drm_dp_dpcd_read(aux, - DP_LANE0_1_STATUS, - link_status, - DP_LINK_STATUS_SIZE); - - if (ret < 0) - return ret; - - WARN_ON(ret != DP_LINK_STATUS_SIZE); + if (dp_phy == DP_PHY_DPRX) + return drm_dp_dpcd_read_data(aux, + DP_LANE0_1_STATUS, + link_status, + DP_LINK_STATUS_SIZE); - return 0; - } - - ret = drm_dp_dpcd_read(aux, - DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy), - link_status, - DP_LINK_STATUS_SIZE - 1); + 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; - WARN_ON(ret != DP_LINK_STATUS_SIZE - 1); - /* 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], @@ -746,8 +857,202 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status); -static bool is_edid_digital_input_dp(const struct edid *edid) +/** + * 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; @@ -779,13 +1084,13 @@ 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 - * @edid: EDID + * @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 edid *edid) + const struct drm_edid *drm_edid) { if (dpcd[DP_DPCD_REV] < 0x11) { switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { @@ -798,7 +1103,7 @@ bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { case DP_DS_PORT_TYPE_DP_DUALMODE: - if (is_edid_digital_input_dp(edid)) + if (is_edid_digital_input_dp(drm_edid)) return false; fallthrough; case DP_DS_PORT_TYPE_DVI: @@ -823,15 +1128,15 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, { u8 link_edid_read = 0, auto_test_req = 0, test_resp = 0; - if (drm_dp_dpcd_read(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, - &auto_test_req, 1) < 1) { + 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(aux, DP_TEST_REQUEST, &link_edid_read, 1) < 1) { + 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; @@ -844,23 +1149,23 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, return false; } - if (drm_dp_dpcd_write(aux, DP_DEVICE_SERVICE_IRQ_VECTOR, - &auto_test_req, 1) < 1) { + 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(aux, DP_TEST_EDID_CHECKSUM, - &real_edid_checksum, 1) < 1) { + 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(aux, DP_TEST_RESPONSE, &test_resp, 1) < 1) { + 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; @@ -897,12 +1202,10 @@ static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) return 0; - ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext, - sizeof(dpcd_ext)); + ret = drm_dp_dpcd_read_data(aux, DP_DP13_DPCD_REV, &dpcd_ext, + sizeof(dpcd_ext)); if (ret < 0) return ret; - if (ret != sizeof(dpcd_ext)) - return -EIO; if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { drm_dbg_kms(aux->drm_dev, @@ -939,10 +1242,10 @@ int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, { int ret; - ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); + ret = drm_dp_dpcd_read_data(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); if (ret < 0) return ret; - if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0) + if (dpcd[DP_DPCD_REV] == 0) return -EIO; ret = drm_dp_read_extended_dpcd_caps(aux, dpcd); @@ -992,11 +1295,9 @@ int drm_dp_read_downstream_info(struct drm_dp_aux *aux, if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) len *= 4; - ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); + ret = drm_dp_dpcd_read_data(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); if (ret < 0) return ret; - if (ret != len) - return -EIO; drm_dbg_kms(aux->drm_dev, "%s: DPCD DFP: %*ph\n", aux->name, len, downstream_ports); @@ -1036,14 +1337,14 @@ 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 - * @edid: EDID + * @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 edid *edid) + const struct drm_edid *drm_edid) { if (!drm_dp_is_branch(dpcd)) return 0; @@ -1059,7 +1360,7 @@ int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { case DP_DS_PORT_TYPE_DP_DUALMODE: - if (is_edid_digital_input_dp(edid)) + if (is_edid_digital_input_dp(drm_edid)) return 0; /* * It's left up to the driver to check the @@ -1101,14 +1402,14 @@ 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 - * @edid: EDID + * @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 edid *edid) + const struct drm_edid *drm_edid) { if (!drm_dp_is_branch(dpcd)) return 0; @@ -1124,7 +1425,7 @@ int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { case DP_DS_PORT_TYPE_DP_DUALMODE: - if (is_edid_digital_input_dp(edid)) + if (is_edid_digital_input_dp(drm_edid)) return 0; fallthrough; case DP_DS_PORT_TYPE_DVI: @@ -1145,13 +1446,13 @@ EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock); * bits per component * @dpcd: DisplayPort configuration data * @port_cap: downstream facing port capabilities - * @edid: EDID + * @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 edid *edid) + const struct drm_edid *drm_edid) { if (!drm_dp_is_branch(dpcd)) return 0; @@ -1169,7 +1470,7 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], case DP_DS_PORT_TYPE_DP: return 0; case DP_DS_PORT_TYPE_DP_DUALMODE: - if (is_edid_digital_input_dp(edid)) + if (is_edid_digital_input_dp(drm_edid)) return 0; fallthrough; case DP_DS_PORT_TYPE_HDMI: @@ -1353,7 +1654,7 @@ EXPORT_SYMBOL(drm_dp_downstream_mode); */ int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]) { - return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6); + return drm_dp_dpcd_read_data(aux, DP_BRANCH_ID, id, 6); } EXPORT_SYMBOL(drm_dp_downstream_id); @@ -1362,14 +1663,14 @@ EXPORT_SYMBOL(drm_dp_downstream_id); * @m: pointer for debugfs file * @dpcd: DisplayPort configuration data * @port_cap: port capabilities - * @edid: EDID + * @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 edid *edid, + const struct drm_edid *drm_edid, struct drm_dp_aux *aux) { bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & @@ -1418,13 +1719,13 @@ void drm_dp_downstream_debug(struct seq_file *m, drm_dp_downstream_id(aux, id); seq_printf(m, "\t\tID: %s\n", id); - len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1); - if (len > 0) + 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(aux, DP_BRANCH_SW_REV, rev, 2); - if (len > 0) + 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) { @@ -1432,15 +1733,15 @@ void drm_dp_downstream_debug(struct seq_file *m, if (clk > 0) seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); - clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, edid); + 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, edid); + 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, edid); + bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, drm_edid); if (bpc > 0) seq_printf(m, "\t\tMax bpc: %d\n", bpc); @@ -1562,11 +1863,9 @@ int drm_dp_read_sink_count(struct drm_dp_aux *aux) u8 count; int ret; - ret = drm_dp_dpcd_readb(aux, DP_SINK_COUNT, &count); + ret = drm_dp_dpcd_read_byte(aux, DP_SINK_COUNT, &count); if (ret < 0) return ret; - if (ret != 1) - return -EIO; return DP_GET_SINK_COUNT(count); } @@ -1855,20 +2154,26 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, 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; - 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); + + 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 @@ -1887,6 +2192,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, 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); /* @@ -1904,15 +2211,17 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, } if (err >= 0) err = num; - /* 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); + 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; } @@ -1952,13 +2261,13 @@ static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc) u8 buf, count; int ret; - ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); + 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_readb(aux, DP_TEST_SINK_MISC, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK_MISC, &buf); if (ret < 0) return ret; @@ -1972,11 +2281,7 @@ static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc) * At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes * per component (RGB or CrYCb). */ - ret = drm_dp_dpcd_read(aux, DP_TEST_CRC_R_CR, crc, 6); - if (ret < 0) - return ret; - - return 0; + 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) @@ -2075,7 +2380,7 @@ EXPORT_SYMBOL(drm_dp_aux_init); * 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_DP_AUX_CHARDEV is enabled. + * %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 @@ -2099,11 +2404,10 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) if (!aux->ddc.algo) drm_dp_aux_init(aux); - aux->ddc.class = I2C_CLASS_DDC; aux->ddc.owner = THIS_MODULE; aux->ddc.dev.parent = aux->dev; - strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(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); @@ -2176,11 +2480,11 @@ int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc) u8 buf; int ret; - ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); if (ret < 0) return ret; - ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START); + ret = drm_dp_dpcd_write_byte(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START); if (ret < 0) return ret; @@ -2203,11 +2507,11 @@ int drm_dp_stop_crc(struct drm_dp_aux *aux) u8 buf; int ret; - ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_TEST_SINK, &buf); if (ret < 0) return ret; - ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START); + ret = drm_dp_dpcd_write_byte(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START); if (ret < 0) return ret; @@ -2242,8 +2546,16 @@ static const struct dpcd_quirk dpcd_quirk_list[] = { { 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 @@ -2286,6 +2598,27 @@ drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) #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 @@ -2302,28 +2635,76 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, { struct drm_dp_dpcd_ident *ident = &desc->ident; unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI; - int ret, dev_id_len; + int ret; - ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident)); + ret = drm_dp_read_ident(aux, offset, ident); if (ret < 0) return ret; desc->quirks = drm_dp_get_quirks(ident, is_branch); - dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id)); - - drm_dbg_kms(aux->drm_dev, - "%s: DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n", - aux->name, is_branch ? "branch" : "sink", - (int)sizeof(ident->oui), ident->oui, dev_id_len, - ident->device_id, ident->hw_rev >> 4, ident->hw_rev & 0xf, - ident->sw_major_rev, ident->sw_minor_rev, desc->quirks); + 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 @@ -2449,17 +2830,173 @@ int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_S 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; - if (color_depth & DP_DSC_8_BPC) - dsc_bpc[num_bpc++] = 8; + + /* 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) @@ -2474,13 +3011,11 @@ static int drm_dp_read_lttpr_regs(struct drm_dp_aux *aux, int ret; for (offset = 0; offset < buf_size; offset += block_size) { - ret = drm_dp_dpcd_read(aux, - address + offset, - &buf[offset], block_size); + ret = drm_dp_dpcd_read_data(aux, + address + offset, + &buf[offset], block_size); if (ret < 0) return ret; - - WARN_ON(ret != block_size); } return 0; @@ -2576,6 +3111,67 @@ int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) 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 * @@ -2634,12 +3230,12 @@ int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, int err; u8 rate, lanes; - err = drm_dp_dpcd_readb(aux, DP_TEST_LINK_RATE, &rate); + 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_readb(aux, DP_TEST_LANE_COUNT, &lanes); + 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; @@ -2647,22 +3243,22 @@ int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, if (lanes & DP_ENHANCED_FRAME_CAP) data->enhanced_frame_cap = true; - err = drm_dp_dpcd_readb(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern); + 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(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0, - &data->custom80, sizeof(data->custom80)); + 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(aux, DP_TEST_HBR2_SCRAMBLER_RESET, - &data->hbr2_reset, - sizeof(data->hbr2_reset)); + err = drm_dp_dpcd_read_data(aux, DP_TEST_HBR2_SCRAMBLER_RESET, + &data->hbr2_reset, + sizeof(data->hbr2_reset)); if (err < 0) return err; } @@ -2689,15 +3285,15 @@ int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux, if (dp_rev < 0x12) { test_pattern = (test_pattern << 2) & DP_LINK_QUAL_PATTERN_11_MASK; - err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET, - test_pattern); + 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_writeb(aux, - DP_LINK_QUAL_LANE0_SET + i, - test_pattern); + err = drm_dp_dpcd_write_byte(aux, + DP_LINK_QUAL_LANE0_SET + i, + test_pattern); if (err < 0) return err; } @@ -2862,25 +3458,156 @@ static const char *dp_content_type_get_name(enum dp_content_type content_type) } } -void drm_dp_vsc_sdp_log(const char *level, struct device *dev, - const struct drm_dp_vsc_sdp *vsc) +void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc) { -#define DP_SDP_LOG(fmt, ...) dev_printk(level, dev, fmt, ##__VA_ARGS__) - DP_SDP_LOG("DP SDP: %s, revision %u, length %u\n", "VSC", + drm_printf(p, "DP SDP: VSC, revision %u, length %u\n", vsc->revision, vsc->length); - DP_SDP_LOG(" pixelformat: %s\n", + drm_printf(p, " pixelformat: %s\n", dp_pixelformat_get_name(vsc->pixelformat)); - DP_SDP_LOG(" colorimetry: %s\n", + drm_printf(p, " colorimetry: %s\n", dp_colorimetry_get_name(vsc->pixelformat, vsc->colorimetry)); - DP_SDP_LOG(" bpc: %u\n", vsc->bpc); - DP_SDP_LOG(" dynamic range: %s\n", + drm_printf(p, " bpc: %u\n", vsc->bpc); + drm_printf(p, " dynamic range: %s\n", dp_dynamic_range_get_name(vsc->dynamic_range)); - DP_SDP_LOG(" content type: %s\n", + drm_printf(p, " content type: %s\n", dp_content_type_get_name(vsc->content_type)); -#undef DP_SDP_LOG } 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 @@ -2929,16 +3656,13 @@ EXPORT_SYMBOL(drm_dp_get_pcon_max_frl_bw); */ int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd) { - int ret; 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; - ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); - - return ret; + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); } EXPORT_SYMBOL(drm_dp_pcon_frl_prepare); @@ -2953,7 +3677,7 @@ bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux) int ret; u8 buf; - ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); if (ret < 0) return false; @@ -2982,7 +3706,7 @@ int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps, int ret; u8 buf; - ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); if (ret < 0) return ret; @@ -3017,11 +3741,7 @@ int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps, return -EINVAL; } - ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); - if (ret < 0) - return ret; - - return 0; + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); } EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1); @@ -3047,7 +3767,7 @@ int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask, else buf &= ~DP_PCON_FRL_LINK_TRAIN_EXTENDED; - ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf); + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf); if (ret < 0) return ret; @@ -3063,13 +3783,7 @@ EXPORT_SYMBOL(drm_dp_pcon_frl_configure_2); */ int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux) { - int ret; - - ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, 0x0); - if (ret < 0) - return ret; - - return 0; + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, 0x0); } EXPORT_SYMBOL(drm_dp_pcon_reset_frl_config); @@ -3084,7 +3798,7 @@ int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux) int ret; u8 buf = 0; - ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf); + 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)) { @@ -3093,11 +3807,7 @@ int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux) return -EINVAL; } buf |= DP_PCON_ENABLE_HDMI_LINK; - ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); - if (ret < 0) - return ret; - - return 0; + return drm_dp_dpcd_write_byte(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf); } EXPORT_SYMBOL(drm_dp_pcon_frl_enable); @@ -3112,7 +3822,7 @@ bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux) u8 buf; int ret; - ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf); if (ret < 0) return false; @@ -3137,7 +3847,7 @@ int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask) int mode; int ret; - ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_POST_FRL_STATUS, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_PCON_HDMI_POST_FRL_STATUS, &buf); if (ret < 0) return ret; @@ -3166,7 +3876,7 @@ void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux, struct drm_hdmi_info *hdmi = &connector->display_info.hdmi; for (i = 0; i < hdmi->max_lanes; i++) { - if (drm_dp_dpcd_readb(aux, DP_PCON_HDMI_ERROR_STATUS_LN0 + i, &buf) < 0) + 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; @@ -3301,7 +4011,7 @@ int drm_dp_pcon_configure_dsc_enc(struct drm_dp_aux *aux, u8 pps_buf_config) u8 buf; int ret; - ret = drm_dp_dpcd_readb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); if (ret < 0) return ret; @@ -3312,11 +4022,7 @@ int drm_dp_pcon_configure_dsc_enc(struct drm_dp_aux *aux, u8 pps_buf_config) buf |= pps_buf_config << 2; } - ret = drm_dp_dpcd_writeb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); - if (ret < 0) - return ret; - - return 0; + return drm_dp_dpcd_write_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); } /** @@ -3328,13 +4034,7 @@ int drm_dp_pcon_configure_dsc_enc(struct drm_dp_aux *aux, u8 pps_buf_config) */ int drm_dp_pcon_pps_default(struct drm_dp_aux *aux) { - int ret; - - ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_DISABLED); - if (ret < 0) - return ret; - - return 0; + return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_DISABLED); } EXPORT_SYMBOL(drm_dp_pcon_pps_default); @@ -3350,15 +4050,11 @@ int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]) { int ret; - ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVERRIDE_BASE, &pps_buf, 128); - if (ret < 0) - return ret; - - ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); + ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVERRIDE_BASE, &pps_buf, 128); if (ret < 0) return ret; - return 0; + return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); } EXPORT_SYMBOL(drm_dp_pcon_pps_override_buf); @@ -3375,21 +4071,17 @@ int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]) { int ret; - ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_HEIGHT, &pps_param[0], 2); + 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(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_WIDTH, &pps_param[2], 2); + 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(aux, DP_PCON_HDMI_PPS_OVRD_BPP, &pps_param[4], 2); + ret = drm_dp_dpcd_write_data(aux, DP_PCON_HDMI_PPS_OVRD_BPP, &pps_param[4], 2); if (ret < 0) return ret; - ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); - if (ret < 0) - return ret; - - return 0; + return drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER); } EXPORT_SYMBOL(drm_dp_pcon_pps_override_param); @@ -3405,7 +4097,7 @@ int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc) int ret; u8 buf; - ret = drm_dp_dpcd_readb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); + ret = drm_dp_dpcd_read_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); if (ret < 0) return ret; @@ -3414,11 +4106,7 @@ int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc) else buf &= ~DP_CONVERSION_RGB_YCBCR_MASK; - ret = drm_dp_dpcd_writeb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); - if (ret < 0) - return ret; - - return 0; + return drm_dp_dpcd_write_byte(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); } EXPORT_SYMBOL(drm_dp_pcon_convert_rgb_to_ycbcr); @@ -3434,28 +4122,38 @@ EXPORT_SYMBOL(drm_dp_pcon_convert_rgb_to_ycbcr); * 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, - u16 level) + u32 level) { int ret; - u8 buf[2] = { 0 }; + 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) + if (!(bl->aux_set || bl->luminance_set)) return 0; - if (bl->lsb_reg_used) { + 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(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, sizeof(buf)); - if (ret != sizeof(buf)) { + 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 < 0 ? ret : -EIO; + return ret; } return 0; @@ -3473,22 +4171,22 @@ drm_edp_backlight_set_enable(struct drm_dp_aux *aux, const struct drm_edp_backli if (!bl->aux_enable) return 0; - ret = drm_dp_dpcd_readb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &buf); - if (ret != 1) { + 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 < 0 ? ret : -EIO; + return ret; } if (enable) buf |= DP_EDP_BACKLIGHT_ENABLE; else buf &= ~DP_EDP_BACKLIGHT_ENABLE; - ret = drm_dp_dpcd_writeb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, buf); - if (ret != 1) { + 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 < 0 ? ret : -EIO; + return ret; } return 0; @@ -3513,7 +4211,7 @@ drm_edp_backlight_set_enable(struct drm_dp_aux *aux, const struct drm_edp_backli * 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 u16 level) + const u32 level) { int ret; u8 dpcd_buf; @@ -3523,16 +4221,20 @@ int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backli 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_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count); - if (ret != 1) + 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_writeb(aux, DP_EDP_BACKLIGHT_FREQ_SET, bl->pwm_freq_pre_divider); - if (ret != 1) + 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); @@ -3540,8 +4242,8 @@ int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backli dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; } - ret = drm_dp_dpcd_writeb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf); - if (ret != 1) { + 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; @@ -3591,22 +4293,61 @@ drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_inf { int fxp, fxp_min, fxp_max, fxp_actual, f = 1; int ret; - u8 pn, pn_min, pn_max; + u8 pn, pn_min, pn_max, bit_count; if (!bl->aux_set) return 0; - ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT, &pn); - if (ret != 1) { + 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; } - pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK; + 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 (!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. @@ -3630,21 +4371,6 @@ drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_inf * - FxP is within 25% of desired value. * Note: 25% is arbitrary value and may need some tweak. */ - ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min); - if (ret != 1) { - drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap min: %d\n", - aux->name, ret); - return 0; - } - ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max); - if (ret != 1) { - drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap max: %d\n", - aux->name, ret); - return 0; - } - pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; - pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; - /* Ensure frequency is within 25% of desired value */ fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); @@ -3662,12 +4388,17 @@ drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_inf break; } - ret = drm_dp_dpcd_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, pn); - if (ret != 1) { +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; @@ -3685,11 +4416,11 @@ drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_i u8 *current_mode) { int ret; - u8 buf[2]; + u8 buf[3]; u8 mode_reg; - ret = drm_dp_dpcd_readb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg); - if (ret != 1) { + 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; @@ -3702,17 +4433,37 @@ drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_i if (*current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { int size = 1 + bl->lsb_reg_used; - ret = drm_dp_dpcd_read(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, size); - if (ret != size) { - drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight level: %d\n", - aux->name, ret); - return ret < 0 ? ret : -EIO; - } + 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; + } - if (bl->lsb_reg_used) - return (buf[0] << 8) | buf[1]; - else - return buf[0]; + /* + * 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]; + } } /* @@ -3727,10 +4478,12 @@ drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_i * 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. @@ -3742,8 +4495,9 @@ drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_i */ 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], - u16 *current_level, u8 *current_mode) + u32 *current_level, u8 *current_mode, bool need_luminance) { int ret; @@ -3753,18 +4507,26 @@ drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl 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)) { + 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 supports neither AUX or PWM brightness control? Aborting\n", + "%s: Panel does not support AUX, PWM or luminance-based brightness control. Aborting\n", aux->name); return -EINVAL; } - ret = drm_edp_backlight_probe_max(aux, bl, driver_pwm_freq_hz, edp_dpcd); - if (ret < 0) - return ret; + 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) @@ -3843,7 +4605,7 @@ 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 }; - u16 current_level; + u32 current_level; u8 current_mode; u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]; int ret; @@ -3851,8 +4613,8 @@ int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux) if (!panel || !panel->dev || !aux) return -EINVAL; - ret = drm_dp_dpcd_read(aux, DP_EDP_DPCD_REV, edp_dpcd, - EDP_DISPLAY_CTL_CAP_SIZE); + ret = drm_dp_dpcd_read_data(aux, DP_EDP_DPCD_REV, edp_dpcd, + EDP_DISPLAY_CTL_CAP_SIZE); if (ret < 0) return ret; @@ -3867,8 +4629,8 @@ int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux) bl->aux = aux; - ret = drm_edp_backlight_init(aux, &bl->info, 0, edp_dpcd, - ¤t_level, ¤t_mode); + ret = drm_edp_backlight_init(aux, &bl->info, 0, 0, edp_dpcd, + ¤t_level, ¤t_mode, false); if (ret < 0) return ret; @@ -3891,3 +4653,188 @@ int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux) 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); |