This series modifies drm dp edp helpers so that drivers can now use them
to manipulate brightness using luminance value via the
PANEL_TARGET_LUMINANCE_VALUE register. This feature was
introduced frin eDP 1.5.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
Suraj Kandpal (13):
drm/dp: Introduce new member in drm_backlight_info
drm/dp: Add argument in drm_edp_backlight_init
drm/dp: Add argument for luminance range info in
drm_edp_backlight_init
drm/dp: Move from u16 to u32 for max in drm_edp_backlight_info
drm/dp: Change current_level argument type to u32
drm/dp: Modify drm_edp_probe_state
drm/dp: Change argument type for drm_edp_backlight_set_level
drm/dp: Modify drm_edp_backlight_set_level
drm/dp: Change argument type of drm_edp_backlight_enable
drm/dp: Enable backlight control using luminance
drm/i915/backlight: Use drm helper to initialize edp backlight
drm/i915/backlight: Use drm helper to set edp backlight
drm/i915/backlight: Use drm_edp_backlight_enable
drivers/gpu/drm/display/drm_dp_helper.c | 92 +++++++----
.../drm/i915/display/intel_dp_aux_backlight.c | 143 ++++++------------
drivers/gpu/drm/nouveau/dispnv50/disp.c | 2 +-
drivers/gpu/drm/nouveau/nouveau_backlight.c | 9 +-
include/drm/display/drm_dp_helper.h | 10 +-
5 files changed, 128 insertions(+), 128 deletions(-)
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:28 UTC
[PATCH 01/13] drm/dp: Introduce new member in drm_backlight_info
Introduce luminance_set flag which indicates if we can manipulate
backlight using luminance value or not which is only possible
after eDP v1.5.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 8 ++++++--
include/drm/display/drm_dp_helper.h | 1 +
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index 57828f2b7b5a..41de7a92d76d 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4253,11 +4253,15 @@ 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))
+ 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;
}
diff --git a/include/drm/display/drm_dp_helper.h
b/include/drm/display/drm_dp_helper.h
index d9614e2c8939..b8fdc09737fc 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -844,6 +844,7 @@ struct drm_edp_backlight_info {
bool lsb_reg_used : 1;
bool aux_enable : 1;
bool aux_set : 1;
+ bool luminance_set : 1;
};
int
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:28 UTC
[PATCH 02/13] drm/dp: Add argument in drm_edp_backlight_init
Add bool argument in drm_edp_backlight init to provide the drivers
option to choose if they want to use luminance values to
manipulate brightness.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 7 ++++---
drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 2 +-
drivers/gpu/drm/nouveau/nouveau_backlight.c | 2 +-
include/drm/display/drm_dp_helper.h | 2 +-
4 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index 41de7a92d76d..99b27e5e3365 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4231,6 +4231,7 @@ drm_edp_backlight_probe_state(struct drm_dp_aux *aux,
struct drm_edp_backlight_i
* @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.
@@ -4243,7 +4244,7 @@ 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,
u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
- u16 *current_level, u8 *current_mode)
+ u16 *current_level, u8 *current_mode, bool need_luminance)
{
int ret;
@@ -4254,7 +4255,7 @@ drm_edp_backlight_init(struct drm_dp_aux *aux, struct
drm_edp_backlight_info *bl
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))
+ (DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE) && need_luminance)
bl->luminance_set = true;
/* Sanity check caps */
@@ -4372,7 +4373,7 @@ 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);
+ ¤t_level, ¤t_mode, false);
if (ret < 0)
return ret;
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 8173de8aec63..6dab8a0c0d74 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -601,7 +601,7 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
} else {
ret = drm_edp_backlight_init(&intel_dp->aux,
&panel->backlight.edp.vesa.info,
panel->vbt.backlight.pwm_freq_hz, intel_dp->edp_dpcd,
- ¤t_level, ¤t_mode);
+ ¤t_level, ¤t_mode, false);
if (ret < 0)
return ret;
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c
b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index d47442125fa1..b938684a9422 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -262,7 +262,7 @@ nv50_backlight_init(struct nouveau_backlight *bl,
nv_conn->base.name);
ret = drm_edp_backlight_init(&nv_conn->aux, &bl->edp_info, 0,
edp_dpcd,
- ¤t_level, ¤t_mode);
+ ¤t_level, ¤t_mode, false);
if (ret < 0)
return ret;
diff --git a/include/drm/display/drm_dp_helper.h
b/include/drm/display/drm_dp_helper.h
index b8fdc09737fc..ef0786a0af4a 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -850,7 +850,7 @@ struct drm_edp_backlight_info {
int
drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info
*bl,
u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
- u16 *current_level, u8 *current_mode);
+ u16 *current_level, u8 *current_mode, bool need_luminance);
int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
u16 level);
int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:28 UTC
[PATCH 03/13] drm/dp: Add argument for luminance range info in drm_edp_backlight_init
Add new argument to drm_edp_backlight_init which gives the
drm_luminance_range_info struct which will be needed to set the min
and max values for backlight.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 5 ++++-
drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 5 +++--
drivers/gpu/drm/nouveau/nouveau_backlight.c | 5 ++++-
include/drm/display/drm_dp_helper.h | 1 +
4 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index 99b27e5e3365..3b309ac5190b 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4227,6 +4227,8 @@ 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
+ * @lr: The &drm_luminance_range_info struct which is used to get the min
max when using
+ *luminance override
* @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
@@ -4243,6 +4245,7 @@ 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,
+ struct drm_luminance_range_info *lr,
u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
u16 *current_level, u8 *current_mode, bool need_luminance)
{
@@ -4372,7 +4375,7 @@ 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,
+ ret = drm_edp_backlight_init(aux, &bl->info, NULL, 0, edp_dpcd,
¤t_level, ¤t_mode, false);
if (ret < 0)
return ret;
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 6dab8a0c0d74..22af5cf83b1e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -600,8 +600,9 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
connector->base.base.id, connector->base.name);
} else {
ret = drm_edp_backlight_init(&intel_dp->aux,
&panel->backlight.edp.vesa.info,
- panel->vbt.backlight.pwm_freq_hz, intel_dp->edp_dpcd,
- ¤t_level, ¤t_mode, false);
+ luminance_range, panel->vbt.backlight.pwm_freq_hz,
+ intel_dp->edp_dpcd, ¤t_level, ¤t_mode,
+ false);
if (ret < 0)
return ret;
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c
b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index b938684a9422..a3681e101d56 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -234,6 +234,8 @@ nv50_backlight_init(struct nouveau_backlight *bl,
const struct backlight_ops **ops)
{
struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
+ struct drm_luminance_range_info *luminance_range +
&nv_conn->base.display_info.luminance_range;
/*
* Note when this runs the connectors have not been probed yet,
@@ -261,7 +263,8 @@ nv50_backlight_init(struct nouveau_backlight *bl,
NV_DEBUG(drm, "DPCD backlight controls supported on %s\n",
nv_conn->base.name);
- ret = drm_edp_backlight_init(&nv_conn->aux, &bl->edp_info, 0,
edp_dpcd,
+ ret = drm_edp_backlight_init(&nv_conn->aux, &bl->edp_info,
+ luminance_range, 0, edp_dpcd,
¤t_level, ¤t_mode, false);
if (ret < 0)
return ret;
diff --git a/include/drm/display/drm_dp_helper.h
b/include/drm/display/drm_dp_helper.h
index ef0786a0af4a..6f53921f5dce 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -849,6 +849,7 @@ struct drm_edp_backlight_info {
int
drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info
*bl,
+ struct drm_luminance_range_info *lr,
u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
u16 *current_level, u8 *current_mode, bool need_luminance);
int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 04/13] drm/dp: Move from u16 to u32 for max in drm_edp_backlight_info
Use u32 instead of u16 for max variable in drm_edp_backlight_info
since it can now hold max luminance range value which is u32.
We will set this max with max_luminance value when luminance_set is
true.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 10 +++++++---
include/drm/display/drm_dp_helper.h | 2 +-
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index 3b309ac5190b..1322bdfb6c8b 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4270,9 +4270,13 @@ drm_edp_backlight_init(struct drm_dp_aux *aux, struct
drm_edp_backlight_info *bl
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 = lr->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)
diff --git a/include/drm/display/drm_dp_helper.h
b/include/drm/display/drm_dp_helper.h
index 6f53921f5dce..39d644495f3e 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -839,7 +839,7 @@ drm_dp_has_quirk(const struct drm_dp_desc *desc, enum
drm_dp_quirk quirk)
struct drm_edp_backlight_info {
u8 pwmgen_bit_count;
u8 pwm_freq_pre_divider;
- u16 max;
+ u32 max;
bool lsb_reg_used : 1;
bool aux_enable : 1;
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 05/13] drm/dp: Change current_level argument type to u32
Change the current_level argument type to u32 from u16
since it can now carry the value which it gets from
DP_EDP_PANEL_TARGET_LUMINANCE_VALUE.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 4 ++--
drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 2 +-
drivers/gpu/drm/nouveau/nouveau_backlight.c | 2 +-
include/drm/display/drm_dp_helper.h | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index 1322bdfb6c8b..c58973d8c5f0 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4247,7 +4247,7 @@ int
drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info
*bl,
struct drm_luminance_range_info *lr,
u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
- u16 *current_level, u8 *current_mode, bool need_luminance)
+ u32 *current_level, u8 *current_mode, bool need_luminance)
{
int ret;
@@ -4355,7 +4355,7 @@ 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;
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 22af5cf83b1e..72cdb6b499c0 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -581,7 +581,7 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
&connector->base.display_info.luminance_range;
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct intel_panel *panel = &connector->panel;
- u16 current_level;
+ u32 current_level;
u8 current_mode;
int ret;
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c
b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index a3681e101d56..a430ee30060e 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -247,7 +247,7 @@ nv50_backlight_init(struct nouveau_backlight *bl,
if (nv_conn->type == DCB_CONNECTOR_eDP) {
int ret;
- u16 current_level;
+ u32 current_level;
u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
u8 current_mode;
diff --git a/include/drm/display/drm_dp_helper.h
b/include/drm/display/drm_dp_helper.h
index 39d644495f3e..62be80417ded 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -851,7 +851,7 @@ int
drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info
*bl,
struct drm_luminance_range_info *lr,
u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
- u16 *current_level, u8 *current_mode, bool need_luminance);
+ u32 *current_level, u8 *current_mode, bool need_luminance);
int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
u16 level);
int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
--
2.34.1
Modify drm_edp_probe_state to read current level from
DP_EDP_PANEL_TARGET_LUMINANCE_VALUE. We divide it by
1000 since the value in this register is in millinits.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 35 ++++++++++++++++++-------
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index c58973d8c5f0..bb1242a1bf6b 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4185,7 +4185,7 @@ 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);
@@ -4202,17 +4202,32 @@ 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];
+ 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];
+ }
}
/*
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 07/13] drm/dp: Change argument type for drm_edp_backlight_set_level
Use u32 for level variable as one may need to pass value for
DP_EDP_PANEL_TARGET_LUMINANCE_VALUE.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 6 +++---
include/drm/display/drm_dp_helper.h | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index bb1242a1bf6b..895ed4a22fc3 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -3933,7 +3933,7 @@ 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 };
@@ -4047,7 +4047,7 @@ int drm_edp_backlight_enable(struct drm_dp_aux *aux, const
struct drm_edp_backli
return ret < 0 ? ret : -EIO;
}
- ret = drm_edp_backlight_set_level(aux, bl, level);
+ ret = drm_edp_backlight_set_level(aux, bl, (u32)level);
if (ret < 0)
return ret;
ret = drm_edp_backlight_set_enable(aux, bl, true);
@@ -4327,7 +4327,7 @@ static int dp_aux_backlight_update_status(struct
backlight_device *bd)
bl->enabled = true;
return 0;
}
- ret = drm_edp_backlight_set_level(bl->aux, &bl->info, brightness);
+ ret = drm_edp_backlight_set_level(bl->aux, &bl->info,
(u32)brightness);
} else {
if (bl->enabled) {
drm_edp_backlight_disable(bl->aux, &bl->info);
diff --git a/include/drm/display/drm_dp_helper.h
b/include/drm/display/drm_dp_helper.h
index 62be80417ded..6bce0176efd3 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -853,7 +853,7 @@ drm_edp_backlight_init(struct drm_dp_aux *aux, struct
drm_edp_backlight_info *bl
u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
u32 *current_level, u8 *current_mode, bool need_luminance);
int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
- u16 level);
+ u32 level);
int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
u16 level);
int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl);
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 08/13] drm/dp: Modify drm_edp_backlight_set_level
Modify drm_edp_backlight_set_level to be able to set the value
for register in DP_EDP_PANEL_TARGET_LUMINANCE_VALUE. We multiply
the level with 1000 since we get the value in Nits and the
register accepts it in milliNits.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index 895ed4a22fc3..bbe3ff91fedc 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -3936,20 +3936,28 @@ int drm_edp_backlight_set_level(struct drm_dp_aux *aux,
const struct drm_edp_bac
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",
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 09/13] drm/dp: Change argument type of drm_edp_backlight_enable
Change the argument type to u32 for the default level being sent
since it has to now account for luminance value which has to be
set for DP_EDP_PANEL_LUMINANCE_TARGET_VALUE.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 6 +++---
drivers/gpu/drm/nouveau/dispnv50/disp.c | 2 +-
include/drm/display/drm_dp_helper.h | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index bbe3ff91fedc..0a2ec1147006 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4020,7 +4020,7 @@ 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;
@@ -4055,7 +4055,7 @@ int drm_edp_backlight_enable(struct drm_dp_aux *aux, const
struct drm_edp_backli
return ret < 0 ? ret : -EIO;
}
- ret = drm_edp_backlight_set_level(aux, bl, (u32)level);
+ ret = drm_edp_backlight_set_level(aux, bl, level);
if (ret < 0)
return ret;
ret = drm_edp_backlight_set_enable(aux, bl, true);
@@ -4331,7 +4331,7 @@ static int dp_aux_backlight_update_status(struct
backlight_device *bd)
if (!backlight_is_blank(bd)) {
if (!bl->enabled) {
- drm_edp_backlight_enable(bl->aux, &bl->info, brightness);
+ drm_edp_backlight_enable(bl->aux, &bl->info, (u32)brightness);
bl->enabled = true;
return 0;
}
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c
b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 725331638a15..c9b3cac47e17 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1829,7 +1829,7 @@ nv50_sor_atomic_enable(struct drm_encoder *encoder, struct
drm_atomic_state *sta
backlight = nv_connector->backlight;
if (backlight && backlight->uses_dpcd)
drm_edp_backlight_enable(&nv_connector->aux,
&backlight->edp_info,
- (u16)backlight->dev->props.brightness);
+ (u32)backlight->dev->props.brightness);
#endif
break;
diff --git a/include/drm/display/drm_dp_helper.h
b/include/drm/display/drm_dp_helper.h
index 6bce0176efd3..b6c03d3ca6c3 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -855,7 +855,7 @@ drm_edp_backlight_init(struct drm_dp_aux *aux, struct
drm_edp_backlight_info *bl
int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
u32 level);
int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl,
- u16 level);
+ u32 level);
int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct
drm_edp_backlight_info *bl);
#if IS_ENABLED(CONFIG_DRM_KMS_HELPER) &&
(IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 10/13] drm/dp: Enable backlight control using luminance
Add flag to enable brightness control via luminance value
when enabling edp backlight.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index 0a2ec1147006..b204ed48976d 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4030,6 +4030,9 @@ 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)
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 11/13] drm/i915/backlight: Use drm helper to initialize edp backlight
Now that drm_edp_backlight init has been to be able to setup
brightness manipulation via luminance we can just use that.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
.../drm/i915/display/intel_dp_aux_backlight.c | 100 +++++++++---------
1 file changed, 49 insertions(+), 51 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 72cdb6b499c0..509f3992c9c8 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -585,9 +585,36 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
u8 current_mode;
int ret;
- if (panel->backlight.edp.vesa.luminance_control_support) {
+ ret = drm_edp_backlight_init(&intel_dp->aux,
&panel->backlight.edp.vesa.info,
+ luminance_range, panel->vbt.backlight.pwm_freq_hz,
+ intel_dp->edp_dpcd, ¤t_level, ¤t_mode, true);
+ if (ret < 0)
+ return ret;
+
+ drm_dbg_kms(display->drm,
+ "[CONNECTOR:%d:%s] AUX VESA backlight enable is controlled through
%s\n",
+ connector->base.base.id, connector->base.name,
+ dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_enable));
+ drm_dbg_kms(display->drm,
+ "[CONNECTOR:%d:%s] AUX VESA backlight level is controlled through
%s\n",
+ connector->base.base.id, connector->base.name,
+ dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_set));
+
+ if (!panel->backlight.edp.vesa.info.luminance_set ||
+ !panel->backlight.edp.vesa.info.aux_set ||
+ !panel->backlight.edp.vesa.info.aux_enable) {
+ ret = panel->backlight.pwm_funcs->setup(connector, pipe);
+ if (ret < 0) {
+ drm_err(display->drm,
+ "[CONNECTOR:%d:%s] Failed to setup PWM backlight controls for eDP
backlight: %d\n",
+ connector->base.base.id, connector->base.name, ret);
+ return ret;
+ }
+ }
+
+ if (panel->backlight.edp.vesa.info.luminance_set) {
if (luminance_range->max_luminance) {
- panel->backlight.max = luminance_range->max_luminance;
+ panel->backlight.max = panel->backlight.edp.vesa.info.max;
panel->backlight.min = luminance_range->min_luminance;
} else {
panel->backlight.max = 512;
@@ -596,57 +623,28 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
panel->backlight.level = intel_dp_aux_vesa_get_backlight(connector, 0);
panel->backlight.enabled = panel->backlight.level != 0;
drm_dbg_kms(display->drm,
- "[CONNECTOR:%d:%s] AUX VESA Nits backlight level is controlled
through DPCD\n",
- connector->base.base.id, connector->base.name);
- } else {
- ret = drm_edp_backlight_init(&intel_dp->aux,
&panel->backlight.edp.vesa.info,
- luminance_range, panel->vbt.backlight.pwm_freq_hz,
- intel_dp->edp_dpcd, ¤t_level, ¤t_mode,
- false);
- if (ret < 0)
- return ret;
-
- drm_dbg_kms(display->drm,
- "[CONNECTOR:%d:%s] AUX VESA backlight enable is controlled through
%s\n",
- connector->base.base.id, connector->base.name,
- dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_enable));
- drm_dbg_kms(display->drm,
- "[CONNECTOR:%d:%s] AUX VESA backlight level is controlled through
%s\n",
- connector->base.base.id, connector->base.name,
- dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_set));
-
- if (!panel->backlight.edp.vesa.info.aux_set ||
- !panel->backlight.edp.vesa.info.aux_enable) {
- ret = panel->backlight.pwm_funcs->setup(connector, pipe);
- if (ret < 0) {
- drm_err(display->drm,
- "[CONNECTOR:%d:%s] Failed to setup PWM backlight controls for eDP
backlight: %d\n",
- connector->base.base.id, connector->base.name, ret);
- return ret;
- }
+ "[CONNECTOR:%d:%s] AUX VESA Nits backlight level is controlled
through DPCD\n",
+ connector->base.base.id, connector->base.name);
+ } else if (panel->backlight.edp.vesa.info.aux_set) {
+ panel->backlight.max = panel->backlight.edp.vesa.info.max;
+ panel->backlight.min = 0;
+ if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) {
+ panel->backlight.level = current_level;
+ panel->backlight.enabled = panel->backlight.level != 0;
+ } else {
+ panel->backlight.level = panel->backlight.max;
+ panel->backlight.enabled = false;
}
-
- if (panel->backlight.edp.vesa.info.aux_set) {
- panel->backlight.max = panel->backlight.edp.vesa.info.max;
- panel->backlight.min = 0;
- if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) {
- panel->backlight.level = current_level;
- panel->backlight.enabled = panel->backlight.level != 0;
- } else {
- panel->backlight.level = panel->backlight.max;
- panel->backlight.enabled = false;
- }
+ } else {
+ panel->backlight.max = panel->backlight.pwm_level_max;
+ panel->backlight.min = panel->backlight.pwm_level_min;
+ if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_PWM) {
+ panel->backlight.level +
panel->backlight.pwm_funcs->get(connector, pipe);
+ panel->backlight.enabled = panel->backlight.pwm_enabled;
} else {
- panel->backlight.max = panel->backlight.pwm_level_max;
- panel->backlight.min = panel->backlight.pwm_level_min;
- if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_PWM) {
- panel->backlight.level -
panel->backlight.pwm_funcs->get(connector, pipe);
- panel->backlight.enabled = panel->backlight.pwm_enabled;
- } else {
- panel->backlight.level = panel->backlight.max;
- panel->backlight.enabled = false;
- }
+ panel->backlight.level = panel->backlight.max;
+ panel->backlight.enabled = false;
}
}
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 12/13] drm/i915/backlight: Use drm helper to set edp backlight
Now that the drm helper sets the backlight using luminance
too we can use that. Remove the obselete function.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
.../drm/i915/display/intel_dp_aux_backlight.c | 34 ++-----------------
1 file changed, 3 insertions(+), 31 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 509f3992c9c8..0cd9fd72ebbb 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -476,31 +476,6 @@ static u32 intel_dp_aux_vesa_get_backlight(struct
intel_connector *connector, en
return connector->panel.backlight.level;
}
-static int
-intel_dp_aux_vesa_set_luminance(struct intel_connector *connector, u32 level)
-{
- struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
- u8 buf[3];
- int ret;
-
- level = level * 1000;
- level &= 0xffffff;
- buf[0] = (level & 0x0000ff);
- buf[1] = (level & 0x00ff00) >> 8;
- buf[2] = (level & 0xff0000) >> 16;
-
- ret = drm_dp_dpcd_write(&intel_dp->aux,
DP_EDP_PANEL_TARGET_LUMINANCE_VALUE,
- buf, sizeof(buf));
- if (ret != sizeof(buf)) {
- drm_err(intel_dp->aux.drm_dev,
- "%s: Failed to set VESA Aux Luminance: %d\n",
- intel_dp->aux.name, ret);
- return -EINVAL;
- } else {
- return 0;
- }
-}
-
static void
intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state,
u32 level)
{
@@ -508,11 +483,6 @@ intel_dp_aux_vesa_set_backlight(const struct
drm_connector_state *conn_state, u3
struct intel_panel *panel = &connector->panel;
struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
- if (panel->backlight.edp.vesa.luminance_control_support) {
- if (!intel_dp_aux_vesa_set_luminance(connector, level))
- return;
- }
-
if (!panel->backlight.edp.vesa.info.aux_set) {
const u32 pwm_level = intel_backlight_level_to_pwm(connector, level);
@@ -538,7 +508,9 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
if (ret == 1)
return;
- if (!intel_dp_aux_vesa_set_luminance(connector, level))
+ if (!drm_edp_backlight_set_level(&intel_dp->aux,
+ &panel->backlight.edp.vesa.info,
+ level))
return;
}
--
2.34.1
Suraj Kandpal
2025-Apr-11 04:29 UTC
[PATCH 13/13] drm/i915/backlight: Use drm_edp_backlight_enable
Use drm dp helper to enable backlight now that it has been modified
to set PANEL_LUMINANCE_CONTROL_ENABLE bit based on if capability
supports it and the driver wants it. Remove the dead code.
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
.../gpu/drm/i915/display/intel_dp_aux_backlight.c | 14 --------------
1 file changed, 14 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 0cd9fd72ebbb..57782697144e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -499,20 +499,6 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
struct intel_connector *connector =
to_intel_connector(conn_state->connector);
struct intel_panel *panel = &connector->panel;
struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
- int ret;
-
- if (panel->backlight.edp.vesa.luminance_control_support) {
- ret = drm_dp_dpcd_writeb(&intel_dp->aux,
DP_EDP_BACKLIGHT_MODE_SET_REGISTER,
- DP_EDP_PANEL_LUMINANCE_CONTROL_ENABLE);
-
- if (ret == 1)
- return;
-
- if (!drm_edp_backlight_set_level(&intel_dp->aux,
- &panel->backlight.edp.vesa.info,
- level))
- return;
- }
if (!panel->backlight.edp.vesa.info.aux_enable) {
u32 pwm_level;
--
2.34.1