drm: add support for additional stereo 3D modes

Parse the 3D_Structure_ALL and 3D_MASK fields of the HDMI Vendor
Specific Data Block to expose more stereo 3D modes.

v2: Use (1 << 0) for consistency. (Ville Syrjälä)
    Skip adding any modes if 3D_MASK is indicated as being present but
    the length only includes 3D_Structure_ALL. (Ville Syrjälä)
    Check that the value of HDMI_3D_LEN is large enough to include
    3D_Structure_ALL and 3D_MASK, if they are present. (Ville Syrjälä)
v3: Increment offset before the length checks. (Ville Syrjälä)

Signed-off-by: Thomas Wood <thomas.wood@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 94 insertions, 9 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 9e81609b1e29..f1764ec5818b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2652,6 +2652,50 @@ static int add_hdmi_mode(struct drm_connector *connector, u8 vic)
         return 1;
 }
 
+static int add_3d_struct_modes(struct drm_connector *connector, u16 structure,
+                               const u8 *video_db, u8 video_len, u8 video_index)
+{
+        struct drm_device *dev = connector->dev;
+        struct drm_display_mode *newmode;
+        int modes = 0;
+        u8 cea_mode;
+
+        if (video_db == NULL || video_index > video_len)
+                return 0;
+
+        /* CEA modes are numbered 1..127 */
+        cea_mode = (video_db[video_index] & 127) - 1;
+        if (cea_mode >= ARRAY_SIZE(edid_cea_modes))
+                return 0;
+
+        if (structure & (1 << 0)) {
+                newmode = drm_mode_duplicate(dev, &edid_cea_modes[cea_mode]);
+                if (newmode) {
+                        newmode->flags |= DRM_MODE_FLAG_3D_FRAME_PACKING;
+                        drm_mode_probed_add(connector, newmode);
+                        modes++;
+                }
+        }
+        if (structure & (1 << 6)) {
+                newmode = drm_mode_duplicate(dev, &edid_cea_modes[cea_mode]);
+                if (newmode) {
+                        newmode->flags |= DRM_MODE_FLAG_3D_TOP_AND_BOTTOM;
+                        drm_mode_probed_add(connector, newmode);
+                        modes++;
+                }
+        }
+        if (structure & (1 << 8)) {
+                newmode = drm_mode_duplicate(dev, &edid_cea_modes[cea_mode]);
+                if (newmode) {
+                        newmode->flags = DRM_MODE_FLAG_3D_SIDE_BY_SIDE_HALF;
+                        drm_mode_probed_add(connector, newmode);
+                        modes++;
+                }
+        }
+
+        return modes;
+}
+
 /*
  * do_hdmi_vsdb_modes - Parse the HDMI Vendor Specific data block
  * @connector: connector corresponding to the HDMI sink
@@ -2662,10 +2706,13 @@ static int add_hdmi_mode(struct drm_connector *connector, u8 vic)
  * also adds the stereo 3d modes when applicable.
  */
 static int
-do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len)
+do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len,
+                   const u8 *video_db, u8 video_len)
 {
-        int modes = 0, offset = 0, i;
-        u8 vic_len;
+        int modes = 0, offset = 0, i, multi_present = 0;
+        u8 vic_len, hdmi_3d_len = 0;
+        u16 mask;
+        u16 structure_all;
 
         if (len < 8)
                 goto out;
@@ -2689,11 +2736,16 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len)
 
         /* 3D_Present */
         offset++;
-        if (db[8 + offset] & (1 << 7))
+        if (db[8 + offset] & (1 << 7)) {
                 modes += add_hdmi_mandatory_stereo_modes(connector);
 
+                /* 3D_Multi_present */
+                multi_present = (db[8 + offset] & 0x60) >> 5;
+        }
+
         offset++;
         vic_len = db[8 + offset] >> 5;
+        hdmi_3d_len = db[8 + offset] & 0x1f;
 
         for (i = 0; i < vic_len && len >= (9 + offset + i); i++) {
                 u8 vic;
@@ -2701,6 +2753,35 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len)
                 vic = db[9 + offset + i];
                 modes += add_hdmi_mode(connector, vic);
         }
+        offset += 1 + vic_len;
+
+        if (!(multi_present == 1 || multi_present == 2))
+                goto out;
+
+        if ((multi_present == 1 && len < (9 + offset)) ||
+            (multi_present == 2 && len < (11 + offset)))
+                goto out;
+
+        if ((multi_present == 1 && hdmi_3d_len < 2) ||
+            (multi_present == 2 && hdmi_3d_len < 4))
+                goto out;
+
+        /* 3D_Structure_ALL */
+        structure_all = (db[8 + offset] << 8) | db[9 + offset];
+
+        /* check if 3D_MASK is present */
+        if (multi_present == 2)
+                mask = (db[10 + offset] << 8) | db[11 + offset];
+        else
+                mask = 0xffff;
+
+        for (i = 0; i < 16; i++) {
+                if (mask & (1 << i))
+                        modes += add_3d_struct_modes(connector,
+                                                     structure_all,
+                                                     video_db,
+                                                     video_len, i);
+        }
 
 out:
         return modes;
@@ -2759,8 +2840,8 @@ static int
 add_cea_modes(struct drm_connector *connector, struct edid *edid)
 {
         const u8 *cea = drm_find_cea_extension(edid);
-        const u8 *db, *hdmi = NULL;
-        u8 dbl, hdmi_len;
+        const u8 *db, *hdmi = NULL, *video = NULL;
+        u8 dbl, hdmi_len, video_len = 0;
         int modes = 0;
 
         if (cea && cea_revision(cea) >= 3) {
@@ -2773,8 +2854,11 @@ add_cea_modes(struct drm_connector *connector, struct edid *edid)
                         db = &cea[i];
                         dbl = cea_db_payload_len(db);
 
-                        if (cea_db_tag(db) == VIDEO_BLOCK)
-                                modes += do_cea_modes(connector, db + 1, dbl);
+                        if (cea_db_tag(db) == VIDEO_BLOCK) {
+                                video = db + 1;
+                                video_len = dbl;
+                                modes += do_cea_modes(connector, video, dbl);
+                        }
                         else if (cea_db_is_hdmi_vsdb(db)) {
                                 hdmi = db;
                                 hdmi_len = dbl;
@@ -2787,7 +2871,8 @@ add_cea_modes(struct drm_connector *connector, struct edid *edid)
          * be patching their flags when the sink supports stereo 3D.
          */
         if (hdmi)
-                modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len);
+                modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len, video,
+                                            video_len);
 
         return modes;
 }