drm/edid: Add detailed block walk for CEA extensions

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 3d6abde..30b286b 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -684,6 +684,33 @@ EXPORT_SYMBOL(drm_mode_find_dmt);
 
 typedef void detailed_cb(struct detailed_timing *timing, void *closure);
 
+static void
+cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
+{
+       int i, n = 0;
+       u8 rev = ext[0x01], d = ext[0x02];
+       u8 *det_base = ext + d;
+
+       switch (rev) {
+       case 0:
+               /* can't happen */
+               return;
+       case 1:
+               /* have to infer how many blocks we have, check pixel clock */
+               for (i = 0; i < 6; i++)
+                       if (det_base[18*i] || det_base[18*i+1])
+                               n++;
+               break;
+       default:
+               /* explicit count */
+               n = min(ext[0x03] & 0x0f, 6);
+               break;
+       }
+
+       for (i = 0; i < n; i++)
+               cb((struct detailed_timing *)(det_base + 18 * i), closure);
+}
+
 static void
 drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
 {
@@ -696,7 +723,16 @@ drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
        for (i = 0; i < EDID_DETAILED_TIMINGS; i++)
                cb(&(edid->detailed_timings[i]), closure);
 
-       /* XXX extension block walk */
+       for (i = 1; i <= raw_edid[0x7e]; i++) {
+               u8 *ext = raw_edid + (i * EDID_LENGTH);
+               switch (*ext) {
+               case CEA_EXT:
+                       cea_for_each_detailed_block(ext, cb, closure);
+                       break;
+               default:
+                       break;
+               }
+       }
 }
 
 static void

diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 39e2cc5..5881fad 100644 (file)
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -28,6 +28,12 @@
 #define EDID_LENGTH 128
 #define DDC_ADDR 0x50
 
+#define CEA_EXT            0x02
+#define VTB_EXT            0x10
+#define DI_EXT     0x40
+#define LS_EXT     0x50
+#define MI_EXT     0x60
+
 struct est_timings {
        u8 t1;
        u8 t2;