video: add fb_edid_add_monspecs for parsing extended edid information

Modern monitors/tvs have more extended EDID information blocks which can
contain extra detailed modes.  This adds a fb_edid_add_monspecs function
which drivers can use to parse those additions blocks.

Signed-off-by: Erik Gilling <konkers@android.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index 563a98b88e9b..a0b5a93b72d2 100644
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c
@@ -973,6 +973,63 @@ void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
         DPRINTK("========================================\n");
 }
 
+void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
+{
+        unsigned char *block;
+        struct fb_videomode *mode, *m;
+        int num = 0, i, first = 1;
+
+        if (edid == NULL)
+                return;
+
+        if (!edid_checksum(edid))
+                return;
+
+        if (edid[0] != 0x2)
+                return;
+
+        mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
+        if (mode == NULL)
+                return;
+
+        block = edid + edid[0x2];
+
+        DPRINTK("  Extended Detailed Timings\n");
+
+        for (i = 0; i < (128 - edid[0x2]) / DETAILED_TIMING_DESCRIPTION_SIZE;
+             i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
+                if (!(block[0] == 0x00 && block[1] == 0x00)) {
+                        get_detailed_timing(block, &mode[num]);
+                        if (first) {
+                                mode[num].flag |= FB_MODE_IS_FIRST;
+                                first = 0;
+                        }
+                        num++;
+                }
+        }
+
+        /* Yikes, EDID data is totally useless */
+        if (!num) {
+                kfree(mode);
+                return;
+        }
+
+        m = kzalloc((specs->modedb_len + num) *
+                       sizeof(struct fb_videomode), GFP_KERNEL);
+
+        if (!m) {
+                kfree(mode);
+                return;
+        }
+
+        memmove(m, specs->modedb, specs->modedb_len * sizeof(struct fb_videomode));
+        memmove(m + specs->modedb_len, mode, num * sizeof(struct fb_videomode));
+        kfree(mode);
+        kfree(specs->modedb);
+        specs->modedb = m;
+        specs->modedb_len = specs->modedb_len + num;
+}
+
 /*
  * VESA Generalized Timing Formula (GTF)
  */