[PATCH v2 1/2] drm/fsl-dcu: rework codes to support of_graph dt binding for panel

[Stefan Agner]

On 2016-06-28 02:32, Meng Yi wrote:
> This patch rework the output code to add of_graph dt binding support
> for panel device and also keeps the backward compatibility
> 
> Signed-off-by: Meng Yi <meng.yi at nxp.com>
> ---
> Changes in V2:
> -fix some coding style issue
> -add fsl_dev->connector.panel check
> -use fsl_dev->np and drop fsl_dev->dev->of_node
> -return 'ret' when fsl_dcu_attach_panel failed
> ---
>  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c    |  2 +-
>  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h |  3 +-
>  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c    | 79 ++++++++++++++++++++--------
>  3 files changed, 60 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c
> index c564ec6..b48ffa7 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c
> @@ -43,7 +43,7 @@ int fsl_dcu_drm_modeset_init(struct
> fsl_dcu_drm_device *fsl_dev)
>  	if (ret)
>  		goto fail_encoder;
>  
> -	ret = fsl_dcu_drm_connector_create(fsl_dev, &fsl_dev->encoder);
> +	ret = fsl_dcu_create_outputs(fsl_dev);
>  	if (ret)
>  		goto fail_connector;
>  
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h
> index 7093109..5a7b88e 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h
> @@ -25,9 +25,8 @@ to_fsl_dcu_connector(struct drm_connector *con)
>  		     : NULL;
>  }
>  
> -int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
> -				 struct drm_encoder *encoder);
>  int fsl_dcu_drm_encoder_create(struct fsl_dcu_drm_device *fsl_dev,
>  			       struct drm_crtc *crtc);
> +int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev);
>  
>  #endif /* __FSL_DCU_DRM_CONNECTOR_H__ */
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
> index 98c998d..b23cc58 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
> @@ -10,6 +10,7 @@
>   */
>  
>  #include <linux/backlight.h>
> +#include <linux/of_graph.h>
>  
>  #include <drm/drmP.h>
>  #include <drm/drm_atomic_helper.h>
> @@ -141,15 +142,15 @@ static const struct drm_connector_helper_funcs
> connector_helper_funcs = {
>  	.mode_valid = fsl_dcu_drm_connector_mode_valid,
>  };
>  
> -int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
> -				 struct drm_encoder *encoder)
> +static int fsl_dcu_attach_panel(struct fsl_dcu_drm_device *fsl_dev,
> +				struct drm_panel *panel)

Align the second line with the beginning of the arguments of the first
line (using tabs first, and if necessary spaces).

>  {
> +	struct drm_encoder *encoder = &fsl_dev->encoder;
>  	struct drm_connector *connector = &fsl_dev->connector.base;
>  	struct drm_mode_config *mode_config = &fsl_dev->drm->mode_config;
> -	struct device_node *panel_node;
>  	int ret;
>  
> -	fsl_dev->connector.encoder = encoder;
> +	fsl_dev->connector.encoder = &fsl_dev->encoder;

You don't need to change this line since you created a local variable
above.

>  
>  	ret = drm_connector_init(fsl_dev->drm, connector,
>  				 &fsl_dcu_drm_connector_funcs,
> @@ -170,21 +171,7 @@ int fsl_dcu_drm_connector_create(struct
> fsl_dcu_drm_device *fsl_dev,
>  				      mode_config->dpms_property,
>  				      DRM_MODE_DPMS_OFF);
>  
> -	panel_node = of_parse_phandle(fsl_dev->np, "fsl,panel", 0);
> -	if (!panel_node) {
> -		dev_err(fsl_dev->dev, "fsl,panel property not found\n");
> -		ret = -ENODEV;
> -		goto err_sysfs;
> -	}
> -
> -	fsl_dev->connector.panel = of_drm_find_panel(panel_node);
> -	if (!fsl_dev->connector.panel) {
> -		ret = -EPROBE_DEFER;
> -		goto err_panel;
> -	}
> -	of_node_put(panel_node);
> -
> -	ret = drm_panel_attach(fsl_dev->connector.panel, connector);
> +	ret = drm_panel_attach(panel, connector);
>  	if (ret) {
>  		dev_err(fsl_dev->dev, "failed to attach panel\n");
>  		goto err_sysfs;
> @@ -192,11 +179,61 @@ int fsl_dcu_drm_connector_create(struct
> fsl_dcu_drm_device *fsl_dev,
>  
>  	return 0;
>  
> -err_panel:
> -	of_node_put(panel_node);
>  err_sysfs:
>  	drm_connector_unregister(connector);
>  err_cleanup:
>  	drm_connector_cleanup(connector);
>  	return ret;
>  }
> +
> +static int fsl_dcu_attach_endpoint(struct fsl_dcu_drm_device *fsl_dev,
> +				const struct of_endpoint *ep)
> +{
> +	struct device_node *np;
> +	int ret;
> +
> +	np = of_graph_get_remote_port_parent(ep->local_node);
> +
> +	fsl_dev->connector.panel = of_drm_find_panel(np);
> +	if (fsl_dev->connector.panel) {
> +		of_node_put(np);

After using np we need to put np unconditionally since we don't use it
(yet). Moved that line one line up.

> +		ret = fsl_dcu_attach_panel(fsl_dev, fsl_dev->connector.panel);
> +		if (ret)
> +			return ret;

You should return whatever fsl_dcu_attach_panel returns here and...

> +	}
> +
> +	return 0;

... return -ENODEV so that the driver doesn't load when no panel has
been found.

> +}
> +
> +int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev)
> +{
> +	struct of_endpoint ep;
> +	struct device_node *ep_node, *panel_node;
> +	int ret;
> +
> +	/* This is for the backward compatibility */

Remove "the"

> +	panel_node = of_parse_phandle(fsl_dev->np, "fsl,panel", 0);
> +	if (panel_node) {
> +		fsl_dev->connector.panel = of_drm_find_panel(panel_node);
> +		of_node_put(panel_node);
> +		if (!fsl_dev->connector.panel)
> +			return -EPROBE_DEFER;
> +		ret = fsl_dcu_attach_panel(fsl_dev, fsl_dev->connector.panel);
> +		if (ret)
> +			return ret;
> +		return 0;

Same here, just return whatever fsl_dcu_attach_panel returns.

> +	}
> +
> +	ep_node = of_graph_get_next_endpoint(fsl_dev->np, NULL);
> +	if (!ep_node)
> +		return -ENODEV;
> +
> +	ret = of_graph_parse_endpoint(ep_node, &ep);
> +	if (ret) {
> +		of_node_put(ep_node);
> +		return -ENODEV;
> +	}
> +	fsl_dcu_attach_endpoint(fsl_dev, &ep);

Directly return the return value of fsl_dcu_attach_endpoint here.

--
Stefan

> +
> +	return 0;
> +}