[PATCH v10 13/15] drm/gma500: add connector luminance support
From: Mario Limonciello (AMD)
Date: Mon Nov 02 2026 - 15:12:22 EST
From: Mario Limonciello <mario.limonciello@xxxxxxx>
Expose GMA500 panel brightness through the connector LUMINANCE property
when DRM_LUMINANCE is enabled. Route updates through the existing platform
backlight operations and preserve legacy registration otherwise.
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
drivers/gpu/drm/gma500/Kconfig | 2 +-
drivers/gpu/drm/gma500/backlight.c | 45 +++++++++++++++++++++------------
drivers/gpu/drm/gma500/cdv_intel_lvds.c | 2 ++
drivers/gpu/drm/gma500/psb_drv.c | 2 +-
drivers/gpu/drm/gma500/psb_drv.h | 4 ++-
drivers/gpu/drm/gma500/psb_intel_lvds.c | 3 ++-
6 files changed, 38 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/gma500/Kconfig b/drivers/gpu/drm/gma500/Kconfig
index dc4c566388192..08871a8f6fa22 100644
--- a/drivers/gpu/drm/gma500/Kconfig
+++ b/drivers/gpu/drm/gma500/Kconfig
@@ -9,7 +9,7 @@ config DRM_GMA500
select I2C_ALGOBIT
# GMA500 depends on ACPI_VIDEO when ACPI is enabled, just like i915
select ACPI_VIDEO if ACPI
- select BACKLIGHT_CLASS_DEVICE if ACPI
+ select BACKLIGHT_CLASS_DEVICE if ACPI && !DRM_LUMINANCE
select INPUT if ACPI
select ACPI_WMI if ACPI
help
diff --git a/drivers/gpu/drm/gma500/backlight.c b/drivers/gpu/drm/gma500/backlight.c
index c8f1716a12d52..4bb39fba04539 100644
--- a/drivers/gpu/drm/gma500/backlight.c
+++ b/drivers/gpu/drm/gma500/backlight.c
@@ -8,7 +8,6 @@
*/
#include <linux/backlight.h>
-
#include <acpi/video.h>
#include <drm/drm_print.h>
@@ -73,10 +72,9 @@ static const struct backlight_ops gma_backlight_ops __maybe_unused = {
.update_status = gma_backlight_update_status,
};
-int gma_backlight_init(struct drm_device *dev)
+int gma_backlight_init(struct drm_device *dev, struct drm_connector *connector)
{
struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
- struct backlight_properties props __maybe_unused = {};
int ret;
dev_priv->backlight_enabled = true;
@@ -92,28 +90,43 @@ int gma_backlight_init(struct drm_device *dev)
return 0;
}
-#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
- props.brightness = dev_priv->backlight_level;
- props.max_brightness = PSB_MAX_BRIGHTNESS;
- props.type = BACKLIGHT_RAW;
+ if (IS_ENABLED(CONFIG_DRM_LUMINANCE))
+ return drm_connector_attach_luminance_property(connector, 0,
+ PSB_MAX_BRIGHTNESS,
+ dev_priv->backlight_level);
+
+ {
+ struct backlight_properties props = {};
- dev_priv->backlight_device =
- backlight_device_register(dev_priv->ops->backlight_name,
- dev->dev, dev,
- &gma_backlight_ops, &props);
- if (IS_ERR(dev_priv->backlight_device))
- return PTR_ERR(dev_priv->backlight_device);
-#endif
+ props.brightness = dev_priv->backlight_level;
+ props.max_brightness = PSB_MAX_BRIGHTNESS;
+ props.type = BACKLIGHT_RAW;
+
+ dev_priv->backlight_device =
+ backlight_device_register(dev_priv->ops->backlight_name,
+ dev->dev, dev,
+ &gma_backlight_ops, &props);
+ if (IS_ERR(dev_priv->backlight_device))
+ return PTR_ERR(dev_priv->backlight_device);
+ }
return 0;
}
+void gma_connector_set_luminance(const struct drm_connector_state *conn_state)
+{
+ gma_backlight_set(conn_state->connector->dev, conn_state->luminance);
+}
+
+void gma_connector_disable_luminance(const struct drm_connector_state *conn_state)
+{
+ gma_backlight_disable(conn_state->connector->dev);
+}
+
void gma_backlight_exit(struct drm_device *dev)
{
-#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
if (dev_priv->backlight_device)
backlight_device_unregister(dev_priv->backlight_device);
-#endif
}
diff --git a/drivers/gpu/drm/gma500/cdv_intel_lvds.c b/drivers/gpu/drm/gma500/cdv_intel_lvds.c
index 336ab411d6995..cef97f1532358 100644
--- a/drivers/gpu/drm/gma500/cdv_intel_lvds.c
+++ b/drivers/gpu/drm/gma500/cdv_intel_lvds.c
@@ -412,6 +412,8 @@ static const struct drm_connector_helper_funcs
.get_modes = cdv_intel_lvds_get_modes,
.mode_valid = cdv_intel_lvds_mode_valid,
.best_encoder = gma_best_encoder,
+ .set_luminance = gma_connector_set_luminance,
+ .disable_luminance = gma_connector_disable_luminance,
};
static const struct drm_connector_funcs cdv_intel_lvds_connector_funcs = {
diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index d17cb5b4a4bf2..5de7af651ac39 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -396,7 +396,7 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags)
if (gma_encoder->type == INTEL_OUTPUT_LVDS ||
gma_encoder->type == INTEL_OUTPUT_MIPI) {
- ret = gma_backlight_init(dev);
+ ret = gma_backlight_init(dev, connector);
if (ret == 0)
acpi_video_register_backlight();
break;
diff --git a/drivers/gpu/drm/gma500/psb_drv.h b/drivers/gpu/drm/gma500/psb_drv.h
index db197b865b90a..4fc22c66e6c8f 100644
--- a/drivers/gpu/drm/gma500/psb_drv.h
+++ b/drivers/gpu/drm/gma500/psb_drv.h
@@ -604,11 +604,13 @@ int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
#endif
/* backlight.c */
-int gma_backlight_init(struct drm_device *dev);
+int gma_backlight_init(struct drm_device *dev, struct drm_connector *connector);
void gma_backlight_exit(struct drm_device *dev);
void gma_backlight_disable(struct drm_device *dev);
void gma_backlight_enable(struct drm_device *dev);
void gma_backlight_set(struct drm_device *dev, int v);
+void gma_connector_set_luminance(const struct drm_connector_state *conn_state);
+void gma_connector_disable_luminance(const struct drm_connector_state *conn_state);
/* oaktrail_crtc.c */
extern const struct drm_crtc_helper_funcs oaktrail_helper_funcs;
diff --git a/drivers/gpu/drm/gma500/psb_intel_lvds.c b/drivers/gpu/drm/gma500/psb_intel_lvds.c
index cd882786d9461..fa0bc8492ff7f 100644
--- a/drivers/gpu/drm/gma500/psb_intel_lvds.c
+++ b/drivers/gpu/drm/gma500/psb_intel_lvds.c
@@ -610,6 +610,8 @@ const struct drm_connector_helper_funcs
.get_modes = psb_intel_lvds_get_modes,
.mode_valid = psb_intel_lvds_mode_valid,
.best_encoder = gma_best_encoder,
+ .set_luminance = gma_connector_set_luminance,
+ .disable_luminance = gma_connector_disable_luminance,
};
const struct drm_connector_funcs psb_intel_lvds_connector_funcs = {
@@ -808,4 +810,3 @@ void psb_intel_lvds_init(struct drm_device *dev,
err_free_encoder:
kfree(gma_encoder);
}
-
--
2.53.0