[PATCH] drm: add bit depth parsing

[PATCH] drm: add bit depth parsing

[Jesse Barnes]

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.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/drm_edid.c |   54 ++++++++++++++++++++++++++++++++++++++++++-
 include/drm/drm_edid.h     |   25 +++++++++++++++++++-
 2 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index adc9358..fb5ebd9 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->bpp = 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->bpp = 6;
+		break;
+	case DRM_EDID_DIGITAL_DEPTH_8:
+		info->bpp = 8;
+		break;
+	case DRM_EDID_DIGITAL_DEPTH_10:
+		info->bpp = 10;
+		break;
+	case DRM_EDID_DIGITAL_DEPTH_12:
+		info->bpp = 12;
+		break;
+	case DRM_EDID_DIGITAL_DEPTH_14:
+		info->bpp = 14;
+		break;
+	case DRM_EDID_DIGITAL_DEPTH_16:
+		info->bpp = 16;
+		break;
+	case DRM_EDID_DIGITAL_DEPTH_UNDEF:
+	default:
+		info->bpp = 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;
 }
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 5881fad..eacb415 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -155,12 +155,35 @@ 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)
 #define DRM_EDID_FEATURE_STANDARD_COLOR   (1 << 2)
+/* If analog */
 #define DRM_EDID_FEATURE_DISPLAY_TYPE     (3 << 3) /* 00=mono, 01=rgb, 10=non-rgb, 11=unknown */
+/* If digital */
+#define DRM_EDID_FEATURE_COLOR_MASK	  (3 << 3)
+#define DRM_EDID_FEATURE_RGB		  (0 << 3)
+#define DRM_EDID_FEATURE_RGB_YCRCB444	  (1 << 3)
+#define DRM_EDID_FEATURE_RGB_YCRCB422	  (2 << 3)
+#define DRM_EDID_FEATURE_RGB_YCRCB	  (3 << 3) /* both 4:4:4 and 4:2:2 */
+
 #define DRM_EDID_FEATURE_PM_ACTIVE_OFF    (1 << 5)
 #define DRM_EDID_FEATURE_PM_SUSPEND       (1 << 6)
 #define DRM_EDID_FEATURE_PM_STANDBY       (1 << 7)
-- 
1.7.4.1

Re: [PATCH] drm: add bit depth parsing

[Adam Jackson]

On 4/15/11 2:22 PM, Jesse Barnes wrote:
> 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.
>
> Signed-off-by: Jesse Barnes<jbarnes@virtuousgeek.org>

Very nice.

Reviewed-by: Adam Jackson <ajax@redhat.com>

- ajax

Re: [PATCH] drm: add bit depth parsing

[Jesse Barnes]

On Fri, 15 Apr 2011 14:29:50 -0400
Adam Jackson <ajax@redhat.com> wrote:

> On 4/15/11 2:22 PM, Jesse Barnes wrote:
> > 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.
> >
> > Signed-off-by: Jesse Barnes<jbarnes@virtuousgeek.org>
> 
> Very nice.
> 
> Reviewed-by: Adam Jackson <ajax@redhat.com>
> 

Sigh as I went to convert my display code to use this instead of
parsing in the driver, I discovered that bpc != bpp.  Will send an
updated patch.

-- 
Jesse Barnes, Intel Open Source Technology Center