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authorDave Airlie <airlied@redhat.com>2025-07-04 11:54:21 +1000
committerDave Airlie <airlied@redhat.com>2025-07-04 11:54:31 +1000
commit17d081ef84a6f3c2a1867cc753d7c8459a34d829 (patch)
tree7980b7dd7fc4df747edff85802b30c0324e03b84 /drivers/gpu/drm/display
parentMerge tag 'drm-intel-gt-next-2025-07-02' of https://gitlab.freedesktop.org/dr... (diff)
parentdrm/dp: Add documentation for luminance_set (diff)
downloadlinux-17d081ef84a6f3c2a1867cc753d7c8459a34d829.tar.gz
linux-17d081ef84a6f3c2a1867cc753d7c8459a34d829.zip
Merge tag 'drm-misc-next-2025-07-03' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next
drm-misc-next for 6.17: UAPI Changes: Cross-subsystem Changes: Core Changes: - bridge: More reference counting - dp: Implement backlight control helpers - fourcc: Add half-float and 32b float formats, RGB161616, BGR161616 - mipi-dsi: Drop MIPI_DSI_MODE_VSYNC_FLUSH flag - ttm: Improve eviction Driver Changes: - i915: Use backlight control helpers for eDP - tidss: Add AM65x OLDI bridge support - panels: - panel-edp: Add CMN N116BCJ-EAK support - raydium-rm67200: misc cleanups, optional reset - new panel: DJN HX83112B Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maxime Ripard <mripard@redhat.com> Link: https://lore.kernel.org/r/20250703-chirpy-lilac-dalmatian-2c5838@houat
Diffstat (limited to 'drivers/gpu/drm/display')
-rw-r--r--drivers/gpu/drm/display/drm_dp_helper.c92
1 files changed, 67 insertions, 25 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 385a1bfdb272..db7896c7edb8 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -3957,23 +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",
@@ -4036,7 +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;
@@ -4046,6 +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)
@@ -4209,7 +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);
@@ -4226,17 +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];
+ }
}
/*
@@ -4251,10 +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.
@@ -4266,8 +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;
@@ -4277,18 +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)
@@ -4367,7 +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;
@@ -4391,8 +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;