[PATCH v2 04/10] drm: Add Gamma correction structure

[Jindal, Sonika]

On 6/4/2015 7:12 PM, Kausal Malladi wrote:
> From: Kausal Malladi <Kausal.Malladi at intel.com>
>
> This patch adds a new structure in DRM layer for Gamma color correction.
> This structure will be used by all user space agents to configure
> appropriate Gamma precision and Gamma level.
>
> struct drm_intel_gamma {
>         __u32 gamma_level;
> 	(The gamma_level variable indicates if the Gamma correction is to be
Do you have any macro defines for these levels? Maybe an enum will be 
better?
> 	applied on Pipe/plane)
>         __u32 gamma_precision;
> 	(The Gamma precision indicates the Gamma mode to be applied)
>
> 	Supported precisions are -
> 	#define I915_GAMMA_PRECISION_UNKNOWN	0
> 	#define I915_GAMMA_PRECISION_CURRENT	0xFFFFFFFF
> 	#define I915_GAMMA_PRECISION_LEGACY	(1 << 0)
> 	#define I915_GAMMA_PRECISION_10BIT	(1 << 1)
> 	#define I915_GAMMA_PRECISION_12BIT	(1 << 2)
> 	#define I915_GAMMA_PRECISION_14BIT	(1 << 3)
> 	#define I915_GAMMA_PRECISION_16BIT	(1 << 4)
>
> 	__u32 num_samples;
> 	(The num_samples indicates the number of Gamma correction
> 	coefficients)
> 	__u32 reserved;
You need this reserved?
> 	__u16 values[0];
> 	(An array of size 0, to accommodate the "num_samples" number of
> 	R16G16B16 pixels, dynamically)
> };
>
> v2: Addressing Daniel Stone's comment, added a variable sized array to
> carry Gamma correction values as blob property.
>
> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> Signed-off-by: Kausal Malladi <Kausal.Malladi at intel.com>
> ---
>   include/drm/drm_crtc.h |  3 +++
>   include/uapi/drm/drm.h | 10 ++++++++++
>   2 files changed, 13 insertions(+)
>
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 2a75d7d..bc44f27 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -483,6 +483,9 @@ struct drm_crtc {
>   	 * acquire context.
>   	 */
>   	struct drm_modeset_acquire_ctx *acquire_ctx;
> +
Just trying to understand, why do we need to store the blob id separately?
> +	/* Color Management Blob IDs */
> +	u32 gamma_blob_id;
>   };
>
>   /**
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 3801584..fc2661c 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -829,6 +829,16 @@ struct drm_event_vblank {
>   	__u32 reserved;
>   };
>
> +/* Color Management structure for Gamma */
> +struct drm_gamma {
> +	__u32 flags;
> +	__u32 gamma_level;
> +	__u32 gamma_precision;
> +	__u32 num_samples;
> +	__u32 reserved;
> +	__u16 values[0];
> +};
> +
>   /* typedef area */
>   #ifndef __KERNEL__
>   typedef struct drm_clip_rect drm_clip_rect_t;
>