This series adds the support for the eDP panel that needs the backlight
controlling over the DP AUX channel using DPCD registers of the panel
as per the VESA's standard.
This series also adds support for the Samsung eDP AMOLED panel that
needs DP AUX to control the backlight, and introduces new delays in the
@panel_desc.delay to support this panel.
This patch series depends on the following two series:
- Doug's series [1], exposed the DP AUX channel to the panel-simple.
- Lyude's series [2], introduced new drm helper functions for DPCD
backlight.
This series is the logical successor to the series [3].
Changes in v1:
- Created dpcd backlight helper with very basic functionality, added
backlight registration in the ti-sn65dsi86 bridge driver.
Changes in v2:
- Created a new DisplayPort aux backlight driver and moved the code from
drm_dp_aux_backlight.c (v1) to the new driver.
Changes in v3:
- Fixed module compilation (kernel test bot).
Changes in v4:
- Added basic DPCD backlight support in panel-simple.
- Added support for a new Samsung panel ATNA33XC20 that needs DPCD
backlight controlling and has a requirement of delays between enable
GPIO and regulator.
Changes in v5:
Addressed review suggestions from Douglas:
- Created a new API drm_panel_dp_aux_backlight() in drm_panel.c
- Moved DP AUX backlight functions from panel-simple.c to drm_panel.c
- panel-simple probe() calls drm_panel_dp_aux_backlight() to create
backlight when the backlight phandle is not specified in panel DT
and DP AUX channel is present.
- Added check for drm_edp_backlight_supported() before registering.
- Removed the @uses_dpcd_backlight flag from panel_desc as this
should be auto-detected.
- Updated comments/descriptions.
Changes in v6:
- Rebased
- Updated wanrning messages, fixed word wrapping in comments.
- Fixed ordering of memory allocation
[1] https://lore.kernel.org/dri-devel/[email protected]/
[2] https://lore.kernel.org/dri-devel/[email protected]/
[3] https://lore.kernel.org/dri-devel/[email protected]/
Rajeev Nandan (5):
drm/panel: add basic DP AUX backlight support
drm/panel-simple: Support DP AUX backlight
drm/panel-simple: Support for delays between GPIO & regulator
dt-bindings: display: simple: Add Samsung ATNA33XC20
drm/panel-simple: Add Samsung ATNA33XC20
.../bindings/display/panel/panel-simple.yaml | 2 +
drivers/gpu/drm/drm_panel.c | 108 +++++++++++++++++++++
drivers/gpu/drm/panel/panel-simple.c | 67 +++++++++++++
include/drm/drm_panel.h | 15 ++-
4 files changed, 188 insertions(+), 4 deletions(-)
--
2.7.4
Add Samsung 13.3" FHD eDP AMOLED panel.
Signed-off-by: Rajeev Nandan <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Acked-by: Rob Herring <[email protected]>
---
(no changes since v4)
Changes in v4:
- New
Documentation/devicetree/bindings/display/panel/panel-simple.yaml | 2 ++
1 file changed, 2 insertions(+)
diff --git a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
index 4a0a5e1..f5acfd6 100644
--- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
+++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
@@ -242,6 +242,8 @@ properties:
- rocktech,rk101ii01d-ct
# Rocktech Display Ltd. RK070ER9427 800(RGB)x480 TFT LCD panel
- rocktech,rk070er9427
+ # Samsung 13.3" FHD (1920x1080 pixels) eDP AMOLED panel
+ - samsung,atna33xc20
# Samsung 12.2" (2560x1600 pixels) TFT LCD panel
- samsung,lsn122dl01-c01
# Samsung Electronics 10.1" WSVGA TFT LCD panel
--
2.7.4
Some panels datasheets may specify a delay between the enable GPIO and
the regulator. Support this in panel-simple.
Signed-off-by: Rajeev Nandan <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
---
Changes in v4:
- New
Changes in v5:
- Update description (Douglas)
- Warn if "power_to_enable" or "disable_to_power_off" is non-zero and panel->enable_gpio
is NULL (Douglas)
Changes in v6:
- Update warning message to make it more meaningful. (Douglas)
drivers/gpu/drm/panel/panel-simple.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 26555ec..86e5a45 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -133,6 +133,22 @@ struct panel_desc {
unsigned int prepare_to_enable;
/**
+ * @delay.power_to_enable: Time for the power to enable the display on.
+ *
+ * The time (in milliseconds) to wait after powering up the display
+ * before asserting its enable pin.
+ */
+ unsigned int power_to_enable;
+
+ /**
+ * @delay.disable_to_power_off: Time for the disable to power the display off.
+ *
+ * The time (in milliseconds) to wait before powering off the display
+ * after deasserting its enable pin.
+ */
+ unsigned int disable_to_power_off;
+
+ /**
* @delay.enable: Time for the panel to display a valid frame.
*
* The time (in milliseconds) that it takes for the panel to
@@ -347,6 +363,10 @@ static int panel_simple_suspend(struct device *dev)
struct panel_simple *p = dev_get_drvdata(dev);
gpiod_set_value_cansleep(p->enable_gpio, 0);
+
+ if (p->desc->delay.disable_to_power_off)
+ msleep(p->desc->delay.disable_to_power_off);
+
regulator_disable(p->supply);
p->unprepared_time = ktime_get();
@@ -407,6 +427,9 @@ static int panel_simple_prepare_once(struct panel_simple *p)
return err;
}
+ if (p->desc->delay.power_to_enable)
+ msleep(p->desc->delay.power_to_enable);
+
gpiod_set_value_cansleep(p->enable_gpio, 1);
delay = p->desc->delay.prepare;
@@ -782,6 +805,11 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc,
break;
}
+ if (!panel->enable_gpio && desc->delay.disable_to_power_off)
+ dev_warn(dev, "Need a delay after disabling panel GPIO, but a GPIO wasn't provided\n");
+ if (!panel->enable_gpio && desc->delay.power_to_enable)
+ dev_warn(dev, "Need a delay before enabling panel GPIO, but a GPIO wasn't provided\n");
+
dev_set_drvdata(dev, panel);
/*
--
2.7.4
Some panels support backlight control over DP AUX channel using
VESA's standard backlight control interface.
Using new DRM eDP backlight helpers, add support to create and
register a backlight for those panels in drm_panel to simplify
the panel drivers.
The panel driver with access to "struct drm_dp_aux" can create and
register a backlight device using following code snippet in its
probe() function:
err = drm_panel_dp_aux_backlight(panel, aux);
if (err)
return err;
Then drm_panel will handle backlight_(enable|disable) calls
similar to the case when drm_panel_of_backlight() is used.
Currently, we are not supporting one feature where the source
device can combine the backlight brightness levels set through
DP AUX and the BL_PWM_DIM eDP connector pin. Since it's not
required for the basic backlight controls, it can be added later.
Signed-off-by: Rajeev Nandan <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
---
Changes in v5:
- New
Changes in v6:
- Fixed ordering of memory allocation (Douglas)
- Updated word wrapping in a comment (Douglas)
drivers/gpu/drm/drm_panel.c | 108 ++++++++++++++++++++++++++++++++++++++++++++
include/drm/drm_panel.h | 15 ++++--
2 files changed, 119 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index f634371..9e65342 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -26,12 +26,20 @@
#include <linux/module.h>
#include <drm/drm_crtc.h>
+#include <drm/drm_dp_helper.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
static DEFINE_MUTEX(panel_lock);
static LIST_HEAD(panel_list);
+struct dp_aux_backlight {
+ struct backlight_device *base;
+ struct drm_dp_aux *aux;
+ struct drm_edp_backlight_info info;
+ bool enabled;
+};
+
/**
* DOC: drm panel
*
@@ -342,6 +350,106 @@ int drm_panel_of_backlight(struct drm_panel *panel)
return 0;
}
EXPORT_SYMBOL(drm_panel_of_backlight);
+
+static int dp_aux_backlight_update_status(struct backlight_device *bd)
+{
+ struct dp_aux_backlight *bl = bl_get_data(bd);
+ u16 brightness = backlight_get_brightness(bd);
+ int ret = 0;
+
+ if (brightness > 0) {
+ if (!bl->enabled) {
+ drm_edp_backlight_enable(bl->aux, &bl->info, brightness);
+ bl->enabled = true;
+ return 0;
+ }
+ ret = drm_edp_backlight_set_level(bl->aux, &bl->info, brightness);
+ } else {
+ if (bl->enabled) {
+ drm_edp_backlight_disable(bl->aux, &bl->info);
+ bl->enabled = false;
+ }
+ }
+
+ return ret;
+}
+
+static const struct backlight_ops dp_aux_bl_ops = {
+ .update_status = dp_aux_backlight_update_status,
+};
+
+/**
+ * drm_panel_dp_aux_backlight - create and use DP AUX backlight
+ * @panel: DRM panel
+ * @aux: The DP AUX channel to use
+ *
+ * Use this function to create and handle backlight if your panel
+ * supports backlight control over DP AUX channel using DPCD
+ * registers as per VESA's standard backlight control interface.
+ *
+ * When the panel is enabled backlight will be enabled after a
+ * successful call to &drm_panel_funcs.enable()
+ *
+ * When the panel is disabled backlight will be disabled before the
+ * call to &drm_panel_funcs.disable().
+ *
+ * A typical implementation for a panel driver supporting backlight
+ * control over DP AUX will call this function at probe time.
+ * Backlight will then be handled transparently without requiring
+ * any intervention from the driver.
+ *
+ * drm_panel_dp_aux_backlight() must be called after the call to drm_panel_init().
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+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;
+ u8 current_mode;
+ u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
+ int ret;
+
+ if (!panel || !panel->dev || !aux)
+ return -EINVAL;
+
+ ret = drm_dp_dpcd_read(aux, DP_EDP_DPCD_REV, edp_dpcd,
+ EDP_DISPLAY_CTL_CAP_SIZE);
+ if (ret < 0)
+ return ret;
+
+ if (!drm_edp_backlight_supported(edp_dpcd)) {
+ DRM_DEV_INFO(panel->dev, "DP AUX backlight is not supported\n");
+ return 0;
+ }
+
+ bl = devm_kzalloc(panel->dev, sizeof(*bl), GFP_KERNEL);
+ if (!bl)
+ return -ENOMEM;
+
+ bl->aux = aux;
+
+ ret = drm_edp_backlight_init(aux, &bl->info, 0, edp_dpcd,
+ ¤t_level, ¤t_mode);
+ if (ret < 0)
+ return ret;
+
+ props.type = BACKLIGHT_RAW;
+ props.brightness = current_level;
+ props.max_brightness = bl->info.max;
+
+ bl->base = devm_backlight_device_register(panel->dev, "dp_aux_backlight",
+ panel->dev, bl,
+ &dp_aux_bl_ops, &props);
+ if (IS_ERR(bl->base))
+ return PTR_ERR(bl->base);
+
+ panel->backlight = bl->base;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_panel_dp_aux_backlight);
#endif
MODULE_AUTHOR("Thierry Reding <[email protected]>");
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index 33605c3..3ebfaa6 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -32,6 +32,7 @@ struct backlight_device;
struct device_node;
struct drm_connector;
struct drm_device;
+struct drm_dp_aux;
struct drm_panel;
struct display_timing;
@@ -64,8 +65,8 @@ enum drm_panel_orientation;
* the panel. This is the job of the .unprepare() function.
*
* Backlight can be handled automatically if configured using
- * drm_panel_of_backlight(). Then the driver does not need to implement the
- * functionality to enable/disable backlight.
+ * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver
+ * does not need to implement the functionality to enable/disable backlight.
*/
struct drm_panel_funcs {
/**
@@ -144,8 +145,8 @@ struct drm_panel {
* Backlight device, used to turn on backlight after the call
* to enable(), and to turn off backlight before the call to
* disable().
- * backlight is set by drm_panel_of_backlight() and drivers
- * shall not assign it.
+ * backlight is set by drm_panel_of_backlight() or
+ * drm_panel_dp_aux_backlight() and drivers shall not assign it.
*/
struct backlight_device *backlight;
@@ -208,11 +209,17 @@ static inline int of_drm_get_panel_orientation(const struct device_node *np,
#if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
(IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
int drm_panel_of_backlight(struct drm_panel *panel);
+int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
#else
static inline int drm_panel_of_backlight(struct drm_panel *panel)
{
return 0;
}
+static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
+ struct drm_dp_aux *aux)
+{
+ return 0;
+}
#endif
#endif
--
2.7.4
Add Samsung 13.3" FHD eDP AMOLED panel.
Signed-off-by: Rajeev Nandan <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
---
(no changes since v5)
Changes in v4:
- New
Changes in v5:
- Remove "uses_dpcd_backlight" property, not required now. (Douglas)
drivers/gpu/drm/panel/panel-simple.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 86e5a45..23242fc 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -3562,6 +3562,36 @@ static const struct panel_desc rocktech_rk101ii01d_ct = {
.connector_type = DRM_MODE_CONNECTOR_LVDS,
};
+static const struct drm_display_mode samsung_atna33xc20_mode = {
+ .clock = 138770,
+ .hdisplay = 1920,
+ .hsync_start = 1920 + 48,
+ .hsync_end = 1920 + 48 + 32,
+ .htotal = 1920 + 48 + 32 + 80,
+ .vdisplay = 1080,
+ .vsync_start = 1080 + 8,
+ .vsync_end = 1080 + 8 + 8,
+ .vtotal = 1080 + 8 + 8 + 16,
+ .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NVSYNC,
+};
+
+static const struct panel_desc samsung_atna33xc20 = {
+ .modes = &samsung_atna33xc20_mode,
+ .num_modes = 1,
+ .bpc = 10,
+ .size = {
+ .width = 294,
+ .height = 165,
+ },
+ .delay = {
+ .disable_to_power_off = 150,
+ .power_to_enable = 150,
+ .hpd_absent_delay = 200,
+ .unprepare = 500,
+ },
+ .connector_type = DRM_MODE_CONNECTOR_eDP,
+};
+
static const struct drm_display_mode samsung_lsn122dl01_c01_mode = {
.clock = 271560,
.hdisplay = 2560,
@@ -4563,6 +4593,9 @@ static const struct of_device_id platform_of_match[] = {
.compatible = "rocktech,rk101ii01d-ct",
.data = &rocktech_rk101ii01d_ct,
}, {
+ .compatible = "samsung,atna33xc20",
+ .data = &samsung_atna33xc20,
+ }, {
.compatible = "samsung,lsn122dl01-c01",
.data = &samsung_lsn122dl01_c01,
}, {
--
2.7.4
If there is no backlight specified in the device tree and the panel
has access to the DP AUX channel then create a DP AUX backlight if
supported by the panel.
Signed-off-by: Rajeev Nandan <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
---
(no changes since v5)
This patch depends on the previous patch (2/5) of this series.
Changes in v4:
- New
Changes in v5:
- Address review comments and move backlight functions to drm_panel.c (Douglas)
- Create and register DP AUX backlight if there is no backlight specified in the
device tree and panel has the DP AUX channel. (Douglas)
- The new drm_panel_dp_aux_backlight() will do the drm_edp_backlight_supported() check.
drivers/gpu/drm/panel/panel-simple.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index df6fbd1..26555ec 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -800,6 +800,12 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc,
if (err)
goto disable_pm_runtime;
+ if (!panel->base.backlight && panel->aux) {
+ err = drm_panel_dp_aux_backlight(&panel->base, panel->aux);
+ if (err)
+ goto disable_pm_runtime;
+ }
+
drm_panel_add(&panel->base);
return 0;
--
2.7.4
Hi,
On Sat, Jun 12, 2021 at 5:09 AM Rajeev Nandan <[email protected]> wrote:
>
> +static const struct panel_desc samsung_atna33xc20 = {
> + .modes = &samsung_atna33xc20_mode,
> + .num_modes = 1,
> + .bpc = 10,
> + .size = {
> + .width = 294,
> + .height = 165,
> + },
> + .delay = {
> + .disable_to_power_off = 150,
> + .power_to_enable = 150,
As per <https://crrev.com/c/2966167> it's apparently been discovered
that these should be:
.disable_to_power_off = 200,
.power_to_enable = 400,
Reviewed-by: Lyude Paul <[email protected]>
On Sat, 2021-06-12 at 17:37 +0530, Rajeev Nandan wrote:
> Some panels support backlight control over DP AUX channel using
> VESA's standard backlight control interface.
> Using new DRM eDP backlight helpers, add support to create and
> register a backlight for those panels in drm_panel to simplify
> the panel drivers.
>
> The panel driver with access to "struct drm_dp_aux" can create and
> register a backlight device using following code snippet in its
> probe() function:
>
> err = drm_panel_dp_aux_backlight(panel, aux);
> if (err)
> return err;
>
> Then drm_panel will handle backlight_(enable|disable) calls
> similar to the case when drm_panel_of_backlight() is used.
>
> Currently, we are not supporting one feature where the source
> device can combine the backlight brightness levels set through
> DP AUX and the BL_PWM_DIM eDP connector pin. Since it's not
> required for the basic backlight controls, it can be added later.
>
> Signed-off-by: Rajeev Nandan <[email protected]>
> Reviewed-by: Douglas Anderson <[email protected]>
> ---
>
> Changes in v5:
> - New
>
> Changes in v6:
> - Fixed ordering of memory allocation (Douglas)
> - Updated word wrapping in a comment (Douglas)
>
> drivers/gpu/drm/drm_panel.c | 108
> ++++++++++++++++++++++++++++++++++++++++++++
> include/drm/drm_panel.h | 15 ++++--
> 2 files changed, 119 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
> index f634371..9e65342 100644
> --- a/drivers/gpu/drm/drm_panel.c
> +++ b/drivers/gpu/drm/drm_panel.c
> @@ -26,12 +26,20 @@
> #include <linux/module.h>
>
> #include <drm/drm_crtc.h>
> +#include <drm/drm_dp_helper.h>
> #include <drm/drm_panel.h>
> #include <drm/drm_print.h>
>
> static DEFINE_MUTEX(panel_lock);
> static LIST_HEAD(panel_list);
>
> +struct dp_aux_backlight {
> + struct backlight_device *base;
> + struct drm_dp_aux *aux;
> + struct drm_edp_backlight_info info;
> + bool enabled;
> +};
> +
> /**
> * DOC: drm panel
> *
> @@ -342,6 +350,106 @@ int drm_panel_of_backlight(struct drm_panel *panel)
> return 0;
> }
> EXPORT_SYMBOL(drm_panel_of_backlight);
> +
> +static int dp_aux_backlight_update_status(struct backlight_device *bd)
> +{
> + struct dp_aux_backlight *bl = bl_get_data(bd);
> + u16 brightness = backlight_get_brightness(bd);
> + int ret = 0;
> +
> + if (brightness > 0) {
> + if (!bl->enabled) {
> + drm_edp_backlight_enable(bl->aux, &bl->info,
> brightness);
> + bl->enabled = true;
> + return 0;
> + }
> + ret = drm_edp_backlight_set_level(bl->aux, &bl->info,
> brightness);
> + } else {
> + if (bl->enabled) {
> + drm_edp_backlight_disable(bl->aux, &bl->info);
> + bl->enabled = false;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static const struct backlight_ops dp_aux_bl_ops = {
> + .update_status = dp_aux_backlight_update_status,
> +};
> +
> +/**
> + * drm_panel_dp_aux_backlight - create and use DP AUX backlight
> + * @panel: DRM panel
> + * @aux: The DP AUX channel to use
> + *
> + * Use this function to create and handle backlight if your panel
> + * supports backlight control over DP AUX channel using DPCD
> + * registers as per VESA's standard backlight control interface.
> + *
> + * When the panel is enabled backlight will be enabled after a
> + * successful call to &drm_panel_funcs.enable()
> + *
> + * When the panel is disabled backlight will be disabled before the
> + * call to &drm_panel_funcs.disable().
> + *
> + * A typical implementation for a panel driver supporting backlight
> + * control over DP AUX will call this function at probe time.
> + * Backlight will then be handled transparently without requiring
> + * any intervention from the driver.
> + *
> + * drm_panel_dp_aux_backlight() must be called after the call to
> drm_panel_init().
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +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;
> + u8 current_mode;
> + u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
> + int ret;
> +
> + if (!panel || !panel->dev || !aux)
> + return -EINVAL;
> +
> + ret = drm_dp_dpcd_read(aux, DP_EDP_DPCD_REV, edp_dpcd,
> + EDP_DISPLAY_CTL_CAP_SIZE);
> + if (ret < 0)
> + return ret;
> +
> + if (!drm_edp_backlight_supported(edp_dpcd)) {
> + DRM_DEV_INFO(panel->dev, "DP AUX backlight is not
> supported\n");
> + return 0;
> + }
> +
> + bl = devm_kzalloc(panel->dev, sizeof(*bl), GFP_KERNEL);
> + if (!bl)
> + return -ENOMEM;
> +
> + bl->aux = aux;
> +
> + ret = drm_edp_backlight_init(aux, &bl->info, 0, edp_dpcd,
> + ¤t_level, ¤t_mode);
> + if (ret < 0)
> + return ret;
> +
> + props.type = BACKLIGHT_RAW;
> + props.brightness = current_level;
> + props.max_brightness = bl->info.max;
> +
> + bl->base = devm_backlight_device_register(panel->dev,
> "dp_aux_backlight",
> + panel->dev, bl,
> + &dp_aux_bl_ops, &props);
> + if (IS_ERR(bl->base))
> + return PTR_ERR(bl->base);
> +
> + panel->backlight = bl->base;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_panel_dp_aux_backlight);
> #endif
>
> MODULE_AUTHOR("Thierry Reding <[email protected]>");
> diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
> index 33605c3..3ebfaa6 100644
> --- a/include/drm/drm_panel.h
> +++ b/include/drm/drm_panel.h
> @@ -32,6 +32,7 @@ struct backlight_device;
> struct device_node;
> struct drm_connector;
> struct drm_device;
> +struct drm_dp_aux;
> struct drm_panel;
> struct display_timing;
>
> @@ -64,8 +65,8 @@ enum drm_panel_orientation;
> * the panel. This is the job of the .unprepare() function.
> *
> * Backlight can be handled automatically if configured using
> - * drm_panel_of_backlight(). Then the driver does not need to implement the
> - * functionality to enable/disable backlight.
> + * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the
> driver
> + * does not need to implement the functionality to enable/disable
> backlight.
> */
> struct drm_panel_funcs {
> /**
> @@ -144,8 +145,8 @@ struct drm_panel {
> * Backlight device, used to turn on backlight after the call
> * to enable(), and to turn off backlight before the call to
> * disable().
> - * backlight is set by drm_panel_of_backlight() and drivers
> - * shall not assign it.
> + * backlight is set by drm_panel_of_backlight() or
> + * drm_panel_dp_aux_backlight() and drivers shall not assign it.
> */
> struct backlight_device *backlight;
>
> @@ -208,11 +209,17 @@ static inline int of_drm_get_panel_orientation(const
> struct device_node *np,
> #if IS_ENABLED(CONFIG_DRM_PANEL) &&
> (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
> (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
> int drm_panel_of_backlight(struct drm_panel *panel);
> +int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux
> *aux);
> #else
> static inline int drm_panel_of_backlight(struct drm_panel *panel)
> {
> return 0;
> }
> +static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
> + struct drm_dp_aux *aux)
> +{
> + return 0;
> +}
> #endif
>
> #endif
--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat