Re: [PATCH v4 3/4] drm: sun4i: dsi: Convert to bridge driver

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jagan,

Thank you for the patch.

On Mon, Mar 22, 2021 at 07:31:51PM +0530, Jagan Teki wrote:
> DRM bridge drivers have build-in handling of treating all display
> pipeline components as bridges.
> 
> So, convert the existing to a drm bridge driver with a built-in
> encoder support for compatibility with existing component drivers.

It would be best if possible to move this patch before 2/4, to first
convert to the bridge model, and then build on top of it.

> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
> Changes for v4:
> - none
> Changes for v3:
> - new patch
> 
>  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 75 ++++++++++++++++----------
>  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |  6 +++
>  2 files changed, 54 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> index 39321299dc27..6f3c5330a468 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> @@ -714,10 +714,10 @@ static int sun6i_dsi_start(struct sun6i_dsi *dsi,
>  	return 0;
>  }
>  
> -static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
> +static void sun6i_dsi_bridge_enable(struct drm_bridge *bridge)
>  {
> -	struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
> -	struct sun6i_dsi *dsi = encoder_to_sun6i_dsi(encoder);
> +	struct drm_display_mode *mode = &bridge->encoder->crtc->state->adjusted_mode;
> +	struct sun6i_dsi *dsi = bridge_to_sun6i_dsi(bridge);
>  	struct mipi_dsi_device *device = dsi->device;
>  	union phy_configure_opts opts = { };
>  	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
> @@ -801,9 +801,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
>  	sun6i_dsi_start(dsi, DSI_START_HSD);
>  }
>  
> -static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder)
> +static void sun6i_dsi_bridge_disable(struct drm_bridge *bridge)
>  {
> -	struct sun6i_dsi *dsi = encoder_to_sun6i_dsi(encoder);
> +	struct sun6i_dsi *dsi = bridge_to_sun6i_dsi(bridge);
>  
>  	DRM_DEBUG_DRIVER("Disabling DSI output\n");
>  
> @@ -852,9 +852,40 @@ static const struct drm_connector_funcs sun6i_dsi_connector_funcs = {
>  	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
>  };
>  
> -static const struct drm_encoder_helper_funcs sun6i_dsi_enc_helper_funcs = {
> -	.disable	= sun6i_dsi_encoder_disable,
> -	.enable		= sun6i_dsi_encoder_enable,
> +static int sun6i_dsi_bridge_attach(struct drm_bridge *bridge,
> +				   enum drm_bridge_attach_flags flags)
> +{
> +	struct sun6i_dsi *dsi = bridge_to_sun6i_dsi(bridge);
> +	int ret;
> +
> +	if (dsi->panel_bridge)
> +		return drm_bridge_attach(bridge->encoder, dsi->panel_bridge, NULL, 0);
> +
> +	if (dsi->panel) {
> +		drm_connector_helper_add(&dsi->connector,
> +					 &sun6i_dsi_connector_helper_funcs);
> +		ret = drm_connector_init(bridge->dev, &dsi->connector,
> +					 &sun6i_dsi_connector_funcs,
> +					 DRM_MODE_CONNECTOR_DSI);
> +		if (ret) {
> +			dev_err(dsi->dev, "Couldn't initialise the DSI connector\n");
> +			goto err_cleanup_connector;
> +		}
> +
> +		drm_connector_attach_encoder(&dsi->connector, &dsi->encoder);
> +	}
> +
> +	return 0;
> +
> +err_cleanup_connector:
> +	drm_encoder_cleanup(&dsi->encoder);
> +	return ret;
> +}
> +
> +static const struct drm_bridge_funcs sun6i_dsi_bridge_funcs = {
> +	.enable		= sun6i_dsi_bridge_enable,
> +	.disable	= sun6i_dsi_bridge_disable,
> +	.attach		= sun6i_dsi_bridge_attach,
>  };
>  
>  static u32 sun6i_dsi_dcs_build_pkt_hdr(struct sun6i_dsi *dsi,
> @@ -1063,8 +1094,6 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
>  	struct sun6i_dsi *dsi = dev_get_drvdata(dev);
>  	int ret;
>  
> -	drm_encoder_helper_add(&dsi->encoder,
> -			       &sun6i_dsi_enc_helper_funcs);
>  	ret = drm_simple_encoder_init(drm, &dsi->encoder,
>  				      DRM_MODE_ENCODER_DSI);
>  	if (ret) {
> @@ -1073,27 +1102,12 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
>  	}
>  	dsi->encoder.possible_crtcs = BIT(0);
>  
> -	drm_connector_helper_add(&dsi->connector,
> -				 &sun6i_dsi_connector_helper_funcs);
> -	ret = drm_connector_init(drm, &dsi->connector,
> -				 &sun6i_dsi_connector_funcs,
> -				 DRM_MODE_CONNECTOR_DSI);
> +	ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
>  	if (ret) {
> -		dev_err(dsi->dev,
> -			"Couldn't initialise the DSI connector\n");
> +		dev_err(dsi->dev, "Couldn't attach drm bridge\n");
>  		goto err_cleanup_connector;
>  	}
>  
> -	drm_connector_attach_encoder(&dsi->connector, &dsi->encoder);
> -
> -	if (dsi->panel_bridge) {
> -		ret = drm_bridge_attach(&dsi->encoder, dsi->panel_bridge, NULL, 0);
> -		if (ret) {
> -			dev_err(dsi->dev, "Couldn't attach drm bridge\n");
> -			goto err_cleanup_connector;
> -		}
> -	}
> -
>  	return 0;
>  
>  err_cleanup_connector:
> @@ -1199,6 +1213,12 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
>  		goto err_unprotect_clk;
>  	}
>  
> +	dsi->bridge.funcs = &sun6i_dsi_bridge_funcs;
> +	dsi->bridge.of_node = dev->of_node;
> +	dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
> +
> +	drm_bridge_add(&dsi->bridge);
> +
>  	ret = component_add(&pdev->dev, &sun6i_dsi_ops);
>  	if (ret) {
>  		dev_err(dev, "Couldn't register our component\n");
> @@ -1222,6 +1242,7 @@ static int sun6i_dsi_remove(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct sun6i_dsi *dsi = dev_get_drvdata(dev);
>  
> +	drm_bridge_remove(&dsi->bridge);
>  	component_del(&pdev->dev, &sun6i_dsi_ops);
>  	mipi_dsi_host_unregister(&dsi->host);
>  	clk_rate_exclusive_put(dsi->mod_clk);
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> index 370ecb356a63..5e70666089ad 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> @@ -16,6 +16,7 @@
>  #define SUN6I_DSI_TCON_DIV	4
>  
>  struct sun6i_dsi {
> +	struct drm_bridge	bridge;
>  	struct drm_connector	connector;
>  	struct drm_encoder	encoder;

The drm_encoder should be dropped from this driver, the encoder should
be created by the main display driver.

>  	struct mipi_dsi_host	host;
> @@ -38,6 +39,11 @@ static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host)
>  	return container_of(host, struct sun6i_dsi, host);
>  };
>  
> +static inline struct sun6i_dsi *bridge_to_sun6i_dsi(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct sun6i_dsi, bridge);
> +}
> +
>  static inline struct sun6i_dsi *connector_to_sun6i_dsi(struct drm_connector *connector)
>  {
>  	return container_of(connector, struct sun6i_dsi, connector);

-- 
Regards,

Laurent Pinchart