Subject: Re: [PATCH] drm/stm: ltdc: add pinctrl for DPI encoder mode

From: Philippe CORNU <[email-masked]>
Date: Mon, 2 Sep 2019 08:47:06 +0000

Hi Yannick,

On 8/2/19 4:47 PM, Yannick Fertré wrote:
> The implementation of functions encoder_enable and encoder_disable
> make possible to control the pinctrl according to the encoder type.
> The pinctrl must be activated only if the encoder type is DPI.
> This helps to move the DPI-related pinctrl configuration from
> all the panel or bridge to the LTDC dt node.
> 
> Signed-off-by: Yannick Fertré <[email-masked]>
> ---
>   drivers/gpu/drm/stm/ltdc.c | 35 +++++++++++++++++++++++++++++++++++
>   1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index 3ab4fbf..1c4fde0 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -15,6 +15,7 @@
>   #include <linux/module.h>
>   #include <linux/of_address.h>
>   #include <linux/of_graph.h>
> +#include <linux/pinctrl/consumer.h>
>   #include <linux/platform_device.h>
>   #include <linux/pm_runtime.h>
>   #include <linux/reset.h>
> @@ -1040,6 +1041,36 @@ static const struct drm_encoder_funcs ltdc_encoder_funcs = {
>   	.destroy = drm_encoder_cleanup,
>   };
>   
> +static void ltdc_encoder_disable(struct drm_encoder *encoder)
> +{
> +	struct drm_device *ddev = encoder->dev;
> +
> +	DRM_DEBUG_DRIVER("\n");
> +
> +	/* Set to sleep state the pinctrl whatever type of encoder */
> +	pinctrl_pm_select_sleep_state(ddev->dev);
> +}
> +
> +static void ltdc_encoder_enable(struct drm_encoder *encoder)
> +{
> +	struct drm_device *ddev = encoder->dev;
> +
> +	DRM_DEBUG_DRIVER("\n");
> +
> +	/*
> +	 * Set to default state the pinctrl only with DPI type.
> +	 * Others types like DSI, don't need pinctrl due to
> +	 * internal bridge (the signals do not come out of the chipset).
> +	 */
> +	if (encoder->encoder_type == DRM_MODE_ENCODER_DPI)
> +		pinctrl_pm_select_default_state(ddev->dev);
> +}
> +
> +static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = {
> +	.disable = ltdc_encoder_disable,
> +	.enable = ltdc_encoder_enable,
> +};
> +
>   static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
>   {
>   	struct drm_encoder *encoder;
> @@ -1055,6 +1086,8 @@ static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
>   	drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
>   			 DRM_MODE_ENCODER_DPI, NULL);
>   
> +	drm_encoder_helper_add(encoder, &ltdc_encoder_helper_funcs);
> +
>   	ret = drm_bridge_attach(encoder, bridge, NULL);
>   	if (ret) {
>   		drm_encoder_cleanup(encoder);
> @@ -1280,6 +1313,8 @@ int ltdc_load(struct drm_device *ddev)
>   
>   	clk_disable_unprepare(ldev->pixel_clk);
>   
> +	pinctrl_pm_select_sleep_state(ddev->dev);
> +

Reviewed-by: Philippe Cornu <[email-masked]>

Thanks
Philippe :)

>   	pm_runtime_enable(ddev->dev);
>   
>   	return 0;
> 
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