drm: add bit depth parsing

EDID 1.4 digital monitors report the bit depth supported in the input
field.  Add support for parsing this out and storing the info in the
display_info structure for use by drivers.

[airlied: tweaked to fix inter-patch dependency]
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 52 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index adc9358c9bec..fe0d3dcd4d31 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1413,6 +1413,57 @@ end:
 EXPORT_SYMBOL(drm_detect_monitor_audio);
 
 /**
+ * drm_add_display_info - pull display info out if present
+ * @edid: EDID data
+ * @info: display info (attached to connector)
+ *
+ * Grab any available display info and stuff it into the drm_display_info
+ * structure that's part of the connector.  Useful for tracking bpp and
+ * color spaces.
+ */
+static void drm_add_display_info(struct edid *edid,
+                                 struct drm_display_info *info)
+{
+        info->width_mm = edid->width_cm * 10;
+        info->height_mm = edid->height_cm * 10;
+
+        /* driver figures it out in this case */
+        info->bpc = 0;
+
+        /* Only defined for 1.4 with digital displays */
+        if (edid->revision < 4)
+                return;
+
+        if (!(edid->input & DRM_EDID_INPUT_DIGITAL))
+                return;
+
+        switch (edid->input & DRM_EDID_DIGITAL_DEPTH_MASK) {
+        case DRM_EDID_DIGITAL_DEPTH_6:
+                info->bpc = 6;
+                break;
+        case DRM_EDID_DIGITAL_DEPTH_8:
+                info->bpc = 8;
+                break;
+        case DRM_EDID_DIGITAL_DEPTH_10:
+                info->bpc = 10;
+                break;
+        case DRM_EDID_DIGITAL_DEPTH_12:
+                info->bpc = 12;
+                break;
+        case DRM_EDID_DIGITAL_DEPTH_14:
+                info->bpc = 14;
+                break;
+        case DRM_EDID_DIGITAL_DEPTH_16:
+                info->bpc = 16;
+                break;
+        case DRM_EDID_DIGITAL_DEPTH_UNDEF:
+        default:
+                info->bpc = 0;
+                break;
+        }
+}
+
+/**
  * drm_add_edid_modes - add modes from EDID data, if available
  * @connector: connector we're probing
  * @edid: edid data
@@ -1460,8 +1511,7 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
         if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
                 edid_fixup_preferred(connector, quirks);
 
-        connector->display_info.width_mm = edid->width_cm * 10;
-        connector->display_info.height_mm = edid->height_cm * 10;
+        drm_add_display_info(edid, &connector->display_info);
 
         return num_modes;
 }