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path: root/drivers/gpu/drm/display/drm_dp_helper.c
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Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_helper.c')
-rw-r--r--drivers/gpu/drm/display/drm_dp_helper.c139
1 files changed, 99 insertions, 40 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index f2a6559a2710..1ecc3df7e316 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -24,6 +24,7 @@
#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>
@@ -692,6 +693,34 @@ void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered)
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
@@ -712,20 +741,8 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
{
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;
}
@@ -3940,23 +3957,31 @@ 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 };
/* 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;
+ } 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, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, sizeof(buf));
+ ret = drm_dp_dpcd_write_data(aux, offset, buf, sizeof(buf));
if (ret < 0) {
drm_err(aux->drm_dev,
"%s: Failed to write aux backlight level: %d\n",
@@ -4019,7 +4044,7 @@ 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;
@@ -4029,6 +4054,9 @@ 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_write_byte(aux, DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count);
if (ret < 0)
@@ -4192,7 +4220,7 @@ 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_read_byte(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg);
@@ -4209,17 +4237,37 @@ 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_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->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];
+ }
}
/*
@@ -4234,10 +4282,12 @@ 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.
@@ -4249,8 +4299,9 @@ 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;
@@ -4260,18 +4311,26 @@ 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)
@@ -4350,7 +4409,7 @@ 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;
@@ -4374,8 +4433,8 @@ 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,
- &current_level, &current_mode);
+ ret = drm_edp_backlight_init(aux, &bl->info, 0, 0, edp_dpcd,
+ &current_level, &current_mode, false);
if (ret < 0)
return ret;
generated by cgit (git 2.34.1) at 2025-07-31 12:03:27 +0000