[PATCH resend 2/2] drm: Parse color format information in CEA blocks

[Lars-Peter Clausen]

The CEA extension block has a field which describes which YCbCr modes are
supported by the device, use it to fill the drm_display_info color_formats
fields. Also the existence of a CEA extension block is used as indication
that the device supports RGB.

Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/drm_edid.c |   31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 8a4580c..e074910 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1312,6 +1312,8 @@ add_detailed_modes(struct drm_connector *connector, 
struct edid *edid,
 #define VENDOR_BLOCK    0x03
 #define SPEAKER_BLOCK  0x04
 #define EDID_BASIC_AUDIO       (1 << 6)
+#define EDID_CEA_YCRCB444      (1 << 5)
+#define EDID_CEA_YCRCB422      (1 << 4)

 /**
  * Search EDID for CEA extension block.
@@ -1666,13 +1668,29 @@ static void drm_add_display_info(struct edid *edid,
        info->bpc = 0;
        info->color_formats = 0;

-       /* Only defined for 1.4 with digital displays */
-       if (edid->revision < 4)
+       if (edid->revision < 3)
                return;

        if (!(edid->input & DRM_EDID_INPUT_DIGITAL))
                return;

+       /* Get data from CEA blocks if present */
+       edid_ext = drm_find_cea_extension(edid);
+       if (edid_ext) {
+               info->cea_rev = edid_ext[1];
+
+               /* The existence of a CEA block should imply RGB support */
+               info->color_formats = DRM_COLOR_FORMAT_RGB444;
+               if (edid_ext[3] & EDID_CEA_YCRCB444)
+                       info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
+               if (edid_ext[3] & EDID_CEA_YCRCB422)
+                       info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
+       }
+
+       /* Only defined for 1.4 with digital displays */
+       if (edid->revision < 4)
+               return;
+
        switch (edid->input & DRM_EDID_DIGITAL_DEPTH_MASK) {
        case DRM_EDID_DIGITAL_DEPTH_6:
                info->bpc = 6;
@@ -1698,18 +1716,11 @@ static void drm_add_display_info(struct edid *edid,
                break;
        }

-       info->color_formats = DRM_COLOR_FORMAT_RGB444;
+       info->color_formats |= DRM_COLOR_FORMAT_RGB444;
        if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB444)
                info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
        if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB422)
                info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
-
-       /* Get data from CEA blocks if present */
-       edid_ext = drm_find_cea_extension(edid);
-       if (!edid_ext)
-               return;
-
-       info->cea_rev = edid_ext[1];
 }

 /**
-- 
1.7.9.5