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[PATCH 5/5] drm/bridge: simple-bridge: Add next panel support

Liu Ying posted 5 patches 11 months, 1 week ago
[PATCH 5/5] drm/bridge: simple-bridge: Add next panel support
Posted by Liu Ying 11 months, 1 week ago 
The next bridge connected to a simple bridge could be a panel, e.g.,
a DPI panel connected to a DPI color encoder. Add the next panel support,
instead of supporting non-panel next bridge only.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
 drivers/gpu/drm/bridge/Kconfig         |  1 +
 drivers/gpu/drm/bridge/simple-bridge.c | 32 ++++++++++++++++----------
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index d20f1646dac2..92187dbdd32b 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -310,6 +310,7 @@ config DRM_SIMPLE_BRIDGE
 	tristate "Simple DRM bridge support"
 	depends on OF
 	select DRM_KMS_HELPER
+	select DRM_PANEL_BRIDGE
 	help
 	  Support for non-programmable DRM bridges, such as ADI ADV7123, TI
 	  THS8134 and THS8135 or passive resistor ladder DACs.
diff --git a/drivers/gpu/drm/bridge/simple-bridge.c b/drivers/gpu/drm/bridge/simple-bridge.c
index c0445bd20e07..4c585e5583ca 100644
--- a/drivers/gpu/drm/bridge/simple-bridge.c
+++ b/drivers/gpu/drm/bridge/simple-bridge.c
@@ -19,6 +19,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_of.h>
+#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 
@@ -35,6 +36,7 @@ struct simple_bridge {
 	const struct simple_bridge_info *info;
 
 	struct drm_bridge	*next_bridge;
+	struct drm_panel	*next_panel;
 	struct regulator	*vdd;
 	struct gpio_desc	*enable;
 
@@ -114,6 +116,10 @@ static int simple_bridge_attach(struct drm_bridge *bridge,
 	struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
 	int ret;
 
+	if (sbridge->next_panel)
+		return drm_bridge_attach(bridge->encoder, sbridge->next_bridge,
+					 bridge, flags);
+
 	ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,
 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 	if (ret < 0)
@@ -247,7 +253,6 @@ static int simple_bridge_get_dpi_color_coding(struct simple_bridge *sbridge,
 static int simple_bridge_probe(struct platform_device *pdev)
 {
 	struct simple_bridge *sbridge;
-	struct device_node *remote;
 	int ret;
 
 	sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);
@@ -257,17 +262,20 @@ static int simple_bridge_probe(struct platform_device *pdev)
 	sbridge->info = of_device_get_match_data(&pdev->dev);
 
 	/* Get the next bridge in the pipeline. */
-	remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
-	if (!remote)
-		return -EINVAL;
-
-	sbridge->next_bridge = of_drm_find_bridge(remote);
-	of_node_put(remote);
-
-	if (!sbridge->next_bridge) {
-		dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
-		return -EPROBE_DEFER;
-	}
+	ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, 1, -1,
+					  &sbridge->next_panel,
+					  &sbridge->next_bridge);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "Next panel or bridge not found\n");
+
+	if (sbridge->next_panel)
+		sbridge->next_bridge = devm_drm_panel_bridge_add(&pdev->dev,
+								 sbridge->next_panel);
+
+	if (IS_ERR(sbridge->next_bridge))
+		return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->next_bridge),
+				     "Next bridge not found\n");
 
 	/* Get the regulator and GPIO resources. */
 	sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
-- 
2.34.1
Re: [PATCH 5/5] drm/bridge: simple-bridge: Add next panel support
Posted by Maxime Ripard 11 months, 1 week ago 
On Tue, Mar 04, 2025 at 06:15:30PM +0800, Liu Ying wrote:
> The next bridge connected to a simple bridge could be a panel, e.g.,
> a DPI panel connected to a DPI color encoder. Add the next panel support,
> instead of supporting non-panel next bridge only.
> 
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
>  drivers/gpu/drm/bridge/Kconfig         |  1 +
>  drivers/gpu/drm/bridge/simple-bridge.c | 32 ++++++++++++++++----------
>  2 files changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index d20f1646dac2..92187dbdd32b 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -310,6 +310,7 @@ config DRM_SIMPLE_BRIDGE
>  	tristate "Simple DRM bridge support"
>  	depends on OF
>  	select DRM_KMS_HELPER
> +	select DRM_PANEL_BRIDGE
>  	help
>  	  Support for non-programmable DRM bridges, such as ADI ADV7123, TI
>  	  THS8134 and THS8135 or passive resistor ladder DACs.
> diff --git a/drivers/gpu/drm/bridge/simple-bridge.c b/drivers/gpu/drm/bridge/simple-bridge.c
> index c0445bd20e07..4c585e5583ca 100644
> --- a/drivers/gpu/drm/bridge/simple-bridge.c
> +++ b/drivers/gpu/drm/bridge/simple-bridge.c
> @@ -19,6 +19,7 @@
>  #include <drm/drm_crtc.h>
>  #include <drm/drm_edid.h>
>  #include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
>  #include <drm/drm_print.h>
>  #include <drm/drm_probe_helper.h>
>  
> @@ -35,6 +36,7 @@ struct simple_bridge {
>  	const struct simple_bridge_info *info;
>  
>  	struct drm_bridge	*next_bridge;
> +	struct drm_panel	*next_panel;
>  	struct regulator	*vdd;
>  	struct gpio_desc	*enable;
>  
> @@ -114,6 +116,10 @@ static int simple_bridge_attach(struct drm_bridge *bridge,
>  	struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
>  	int ret;
>  
> +	if (sbridge->next_panel)
> +		return drm_bridge_attach(bridge->encoder, sbridge->next_bridge,
> +					 bridge, flags);
> +
>  	ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,
>  				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>  	if (ret < 0)
> @@ -247,7 +253,6 @@ static int simple_bridge_get_dpi_color_coding(struct simple_bridge *sbridge,
>  static int simple_bridge_probe(struct platform_device *pdev)
>  {
>  	struct simple_bridge *sbridge;
> -	struct device_node *remote;
>  	int ret;
>  
>  	sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);
> @@ -257,17 +262,20 @@ static int simple_bridge_probe(struct platform_device *pdev)
>  	sbridge->info = of_device_get_match_data(&pdev->dev);
>  
>  	/* Get the next bridge in the pipeline. */
> -	remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
> -	if (!remote)
> -		return -EINVAL;
> -
> -	sbridge->next_bridge = of_drm_find_bridge(remote);
> -	of_node_put(remote);
> -
> -	if (!sbridge->next_bridge) {
> -		dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
> -		return -EPROBE_DEFER;
> -	}
> +	ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, 1, -1,
> +					  &sbridge->next_panel,
> +					  &sbridge->next_bridge);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret,
> +				     "Next panel or bridge not found\n");
> +
> +	if (sbridge->next_panel)
> +		sbridge->next_bridge = devm_drm_panel_bridge_add(&pdev->dev,
> +								 sbridge->next_panel);
> +
> +	if (IS_ERR(sbridge->next_bridge))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->next_bridge),
> +				     "Next bridge not found\n");

This makes sense in general, but I think a better approach would be to
use devm/drmm_of_get_bridge here.

Maxime
Re: [PATCH 5/5] drm/bridge: simple-bridge: Add next panel support
Posted by Liu Ying 11 months, 1 week ago 
On 03/04/2025, Maxime Ripard wrote:
> On Tue, Mar 04, 2025 at 06:15:30PM +0800, Liu Ying wrote:
>> The next bridge connected to a simple bridge could be a panel, e.g.,
>> a DPI panel connected to a DPI color encoder. Add the next panel support,
>> instead of supporting non-panel next bridge only.
>>
>> Signed-off-by: Liu Ying <victor.liu@nxp.com>
>> ---
>>  drivers/gpu/drm/bridge/Kconfig         |  1 +
>>  drivers/gpu/drm/bridge/simple-bridge.c | 32 ++++++++++++++++----------
>>  2 files changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>> index d20f1646dac2..92187dbdd32b 100644
>> --- a/drivers/gpu/drm/bridge/Kconfig
>> +++ b/drivers/gpu/drm/bridge/Kconfig
>> @@ -310,6 +310,7 @@ config DRM_SIMPLE_BRIDGE
>>  	tristate "Simple DRM bridge support"
>>  	depends on OF
>>  	select DRM_KMS_HELPER
>> +	select DRM_PANEL_BRIDGE
>>  	help
>>  	  Support for non-programmable DRM bridges, such as ADI ADV7123, TI
>>  	  THS8134 and THS8135 or passive resistor ladder DACs.
>> diff --git a/drivers/gpu/drm/bridge/simple-bridge.c b/drivers/gpu/drm/bridge/simple-bridge.c
>> index c0445bd20e07..4c585e5583ca 100644
>> --- a/drivers/gpu/drm/bridge/simple-bridge.c
>> +++ b/drivers/gpu/drm/bridge/simple-bridge.c
>> @@ -19,6 +19,7 @@
>>  #include <drm/drm_crtc.h>
>>  #include <drm/drm_edid.h>
>>  #include <drm/drm_of.h>
>> +#include <drm/drm_panel.h>
>>  #include <drm/drm_print.h>
>>  #include <drm/drm_probe_helper.h>
>>  
>> @@ -35,6 +36,7 @@ struct simple_bridge {
>>  	const struct simple_bridge_info *info;
>>  
>>  	struct drm_bridge	*next_bridge;
>> +	struct drm_panel	*next_panel;
>>  	struct regulator	*vdd;
>>  	struct gpio_desc	*enable;
>>  
>> @@ -114,6 +116,10 @@ static int simple_bridge_attach(struct drm_bridge *bridge,
>>  	struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
>>  	int ret;
>>  
>> +	if (sbridge->next_panel)
>> +		return drm_bridge_attach(bridge->encoder, sbridge->next_bridge,
>> +					 bridge, flags);
>> +
>>  	ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,
>>  				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>>  	if (ret < 0)
>> @@ -247,7 +253,6 @@ static int simple_bridge_get_dpi_color_coding(struct simple_bridge *sbridge,
>>  static int simple_bridge_probe(struct platform_device *pdev)
>>  {
>>  	struct simple_bridge *sbridge;
>> -	struct device_node *remote;
>>  	int ret;
>>  
>>  	sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);
>> @@ -257,17 +262,20 @@ static int simple_bridge_probe(struct platform_device *pdev)
>>  	sbridge->info = of_device_get_match_data(&pdev->dev);
>>  
>>  	/* Get the next bridge in the pipeline. */
>> -	remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
>> -	if (!remote)
>> -		return -EINVAL;
>> -
>> -	sbridge->next_bridge = of_drm_find_bridge(remote);
>> -	of_node_put(remote);
>> -
>> -	if (!sbridge->next_bridge) {
>> -		dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
>> -		return -EPROBE_DEFER;
>> -	}
>> +	ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, 1, -1,
>> +					  &sbridge->next_panel,
>> +					  &sbridge->next_bridge);
>> +	if (ret)
>> +		return dev_err_probe(&pdev->dev, ret,
>> +				     "Next panel or bridge not found\n");
>> +
>> +	if (sbridge->next_panel)
>> +		sbridge->next_bridge = devm_drm_panel_bridge_add(&pdev->dev,
>> +								 sbridge->next_panel);
>> +
>> +	if (IS_ERR(sbridge->next_bridge))
>> +		return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->next_bridge),
>> +				     "Next bridge not found\n");
> 
> This makes sense in general, but I think a better approach would be to
> use devm/drmm_of_get_bridge here.

I chose to open-code devm_of_get_bridge() because sbridge->next_panel can
be grabbed and used to determine the logics in simple_bridge_attach() and
the flags handled over to drm_bridge_attach().

However, if a separate driver is needed for the DPI color encoder, I won't
touch this driver.

> 
> Maxime

-- 
Regards,
Liu Ying

Patchew 2.1-devel-b67e4c2

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