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>

drivers/gpu/drm/drm_edid.c

@@ -1412,6 +1412,57 @@ bool drm_detect_monitor_audio(struct edid *edid)
 }
 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
@@ -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;
 }

include/drm/drm_crtc.h

@@ -198,6 +198,7 @@ struct drm_display_info {
 	unsigned int min_vfreq, max_vfreq;
 	unsigned int min_hfreq, max_hfreq;
 	unsigned int pixel_clock;
+	unsigned int bpc;
 
 	enum subpixel_order subpixel_order;
 

include/drm/drm_edid.h

@@ -155,7 +155,22 @@ struct detailed_timing {
 #define DRM_EDID_INPUT_SEPARATE_SYNCS  (1 << 3)
 #define DRM_EDID_INPUT_BLANK_TO_BLACK  (1 << 4)
 #define DRM_EDID_INPUT_VIDEO_LEVEL     (3 << 5)
-#define DRM_EDID_INPUT_DIGITAL         (1 << 7) /* bits below must be zero if set */
+#define DRM_EDID_INPUT_DIGITAL         (1 << 7)
+#define DRM_EDID_DIGITAL_DEPTH_MASK    (7 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_UNDEF   (0 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_6       (1 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_8       (2 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_10      (3 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_12      (4 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_14      (5 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_16      (6 << 4)
+#define DRM_EDID_DIGITAL_DEPTH_RSVD    (7 << 4)
+#define DRM_EDID_DIGITAL_TYPE_UNDEF    (0)
+#define DRM_EDID_DIGITAL_TYPE_DVI      (1)
+#define DRM_EDID_DIGITAL_TYPE_HDMI_A   (2)
+#define DRM_EDID_DIGITAL_TYPE_HDMI_B   (3)
+#define DRM_EDID_DIGITAL_TYPE_MDDI     (4)
+#define DRM_EDID_DIGITAL_TYPE_DP       (5)
 
 #define DRM_EDID_FEATURE_DEFAULT_GTF      (1 << 0)
 #define DRM_EDID_FEATURE_PREFERRED_TIMING (1 << 1)