drm/edid: add function to help find SADs

Add a function to find the start of the SADs in the ELD.  This
complements the helper to retrieve the SAD count.

[airlied: this fixes a build problem with the alsa eld helper
which required this].

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Russell King 2015-03-28 18:13:52 +00:00 committed by Dave Airlie
parent 82bd279d0b
commit 1c73d3b10e

View File

@ -347,6 +347,25 @@ static inline int drm_eld_mnl(const uint8_t *eld)
return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
}
/**
* drm_eld_sad - Get ELD SAD structures.
* @eld: pointer to an eld memory structure with sad_count set
*/
static inline const uint8_t *drm_eld_sad(const uint8_t *eld)
{
unsigned int ver, mnl;
ver = (eld[DRM_ELD_VER] & DRM_ELD_VER_MASK) >> DRM_ELD_VER_SHIFT;
if (ver != 2 && ver != 31)
return NULL;
mnl = drm_eld_mnl(eld);
if (mnl > 16)
return NULL;
return eld + DRM_ELD_CEA_SAD(mnl, 0);
}
/**
* drm_eld_sad_count - Get ELD SAD count.
* @eld: pointer to an eld memory structure with sad_count set