[PATCH 1/3] drm: add drm_of_encoder_active_endpoint helpers

[Daniel Kurtz]

On Tue, Feb 24, 2015 at 7:02 PM, Philipp Zabel <p.zabel at pengutronix.de> wrote:
>
> This patch adds a helper to parse the encoder endpoint connected to the
> encoder's crtc and two helpers to return its id and port id.
>
> This can be used to determine input mux setting from endpoint or port ids.
>
> Suggested-by: Daniel Kurtz <djkurtz at chromium.org>
> Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>

Reviewed-by: Daniel Kurtz <djkurtz at chromium.org>

> ---
>  drivers/gpu/drm/drm_of.c | 34 ++++++++++++++++++++++++++++++++++
>  include/drm/drm_of.h     | 32 ++++++++++++++++++++++++++++++++
>  2 files changed, 66 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
> index aaa1307..a526301 100644
> --- a/drivers/gpu/drm/drm_of.c
> +++ b/drivers/gpu/drm/drm_of.c
> @@ -61,3 +61,37 @@ uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
>         return possible_crtcs;
>  }
>  EXPORT_SYMBOL(drm_of_find_possible_crtcs);
> +
> +/*
> + * drm_of_encoder_active_endpoint - return the active encoder endpoint
> + * @node: device tree node containing encoder input ports
> + * @encoder: drm_encoder
> + *
> + * Given an encoder device node and a drm_encoder with a connected crtc,
> + * parse the encoder endpoint connecting to the crtc port.
> + */
> +int drm_of_encoder_active_endpoint(struct device_node *node,
> +                                  struct drm_encoder *encoder,
> +                                  struct of_endpoint *endpoint)
> +{
> +       struct device_node *ep;
> +       struct drm_crtc *crtc = encoder->crtc;
> +       struct device_node *port;
> +       int ret;
> +
> +       if (!node || !crtc)
> +               return -EINVAL;
> +
> +       for_each_endpoint_of_node(node, ep) {
> +               port = of_graph_get_remote_port(ep);
> +               of_node_put(port);
> +               if (port == crtc->port) {
> +                       ret = of_graph_parse_endpoint(ep, endpoint);
> +                       of_node_put(ep);
> +                       return ret;
> +               }
> +       }
> +
> +       return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
> diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h
> index 2441f71..8a95126 100644
> --- a/include/drm/drm_of.h
> +++ b/include/drm/drm_of.h
> @@ -1,18 +1,50 @@
>  #ifndef __DRM_OF_H__
>  #define __DRM_OF_H__
>
> +#include <linux/of_graph.h>
> +
>  struct drm_device;
>  struct device_node;
>
>  #ifdef CONFIG_OF
>  extern uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
>                                            struct device_node *port);
> +extern int drm_of_encoder_active_endpoint(struct device_node *node,
> +                                         struct drm_encoder *encoder,
> +                                         struct of_endpoint *endpoint);
>  #else
>  static inline uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
>                                                   struct device_node *port)
>  {
>         return 0;
>  }
> +
> +static inline int drm_of_encoder_active_endpoint(struct device_node *node,
> +                                                struct drm_encoder *encoder,
> +                                                struct of_endpoint *endpoint)
> +{
> +       return -EINVAL;
> +}
>  #endif
>
> +static inline int drm_of_encoder_active_endpoint_id(struct device_node *node,
> +                                                   struct drm_encoder *encoder)
> +{
> +       struct of_endpoint endpoint;
> +       int ret = drm_of_encoder_active_endpoint(node, encoder,
> +                                                &endpoint);
> +
> +       return ret ?: endpoint.id;
> +}
> +
> +static inline int drm_of_encoder_active_port_id(struct device_node *node,
> +                                               struct drm_encoder *encoder)
> +{
> +       struct of_endpoint endpoint;
> +       int ret = drm_of_encoder_active_endpoint(node, encoder,
> +                                                &endpoint);
> +
> +       return ret ?: endpoint.port;
> +}
> +
>  #endif /* __DRM_OF_H__ */
> --
> 2.1.4
>