[PATCH v2 06/18] drm: Add drm_format_plane_width() and drm_format_plane_height()

[Daniel Vetter]

On Wed, Jan 20, 2016 at 09:05:27PM +0200, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Add a few helpers to get the dimensions of the chroma plane(s).
> 
> v2: Add kernel-doc (Daniel)
> 
> Cc: dri-devel at lists.freedesktop.org
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>  include/drm/drm_crtc.h | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index c65a212db77e..91195c403422 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -2482,6 +2482,36 @@ extern int drm_format_num_planes(uint32_t format);
>  extern int drm_format_plane_cpp(uint32_t format, int plane);
>  extern int drm_format_horz_chroma_subsampling(uint32_t format);
>  extern int drm_format_vert_chroma_subsampling(uint32_t format);
> +/**
> + * drm_format_plane_width - width of the plane given the first plane
> + * @width: width of the first plane
> + * @format: pixel format
> + * @plane: plane index
> + *

kerneldoc style is

+ * Returns:
+ * blabla

> + * Returns the width of @plane, given that the width of the first plane
> + * is @width.
> + */
> +static inline int drm_format_plane_width(int width, uint32_t format, int plane)
> +{

For consistency with other helpers I think we should put an

	if (plane >= drm_format_num_planes(format))
		return 0;

here. Also I think static inline is overkill for these, and grouping them
together with the others in drm_crtc.c will make it easier to extract them
into a new file (since drm_crtc.c is kinda sprawling a bit).

With those nitpicks applied: Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> +	if (plane == 0)
> +		return width;
> +	return width / drm_format_horz_chroma_subsampling(format);
> +}
> +/**
> + * drm_format_plane_height - height of the plane given the first plane
> + * @height: height of the first plane
> + * @format: pixel format
> + * @plane: plane index
> + *
> + * Returns the height of @plane, given that the height of the first plane
> + * is @height.
> + */
> +static inline int drm_format_plane_height(int height, uint32_t format, int plane)
> +{
> +	if (plane == 0)
> +		return height;
> +	return height / drm_format_vert_chroma_subsampling(format);
> +}
>  extern const char *drm_get_format_name(uint32_t format);
>  extern struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
>  							      unsigned int supported_rotations);
> -- 
> 2.4.10
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch