drm: add drm_edid_to_eld helper extracting SADs from EDID (v2)

Some devices (ATI/AMD cards) don't support passing ELD struct to the
hardware but just require filling specific registers and then the
hardware/firmware does the rest. In such cases we need to read the info
from SAD blocks and put them in the correct registers.

agd5f: note that the returned pointer needs to be kfreed as per
Christian's suggestion.

v2: fix warning

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 5da1b4ae7d84..fc481fc17085 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -244,12 +244,21 @@ struct edid {
 
 #define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8))
 
+/* Short Audio Descriptor */
+struct cea_sad {
+        u8 format;
+        u8 channels; /* max number of channels - 1 */
+        u8 freq;
+        u8 byte2; /* meaning depends on format */
+};
+
 struct drm_encoder;
 struct drm_connector;
 struct drm_display_mode;
 struct hdmi_avi_infoframe;
 
 void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid);
+int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads);
 int drm_av_sync_delay(struct drm_connector *connector,
                       struct drm_display_mode *mode);
 struct drm_connector *drm_select_eld(struct drm_encoder *encoder,