[PATCH 1/3] xfree86: Add a xf86MonitorFindHDMIBlock()
Damien Lespiau
damien.lespiau at intel.com
Wed Aug 21 10:25:47 PDT 2013
The HDMI CEA vendor specific block has some interesting information,
such as the maximum TMDS dot clock.
v2: Don't parse CEA blocks with invalid offsets, remove spurious
brackets (Chris Wilson)
Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>
---
hw/xfree86/ddc/interpret_edid.c | 91 +++++++++++++++++++++++++++++++++++++++++
hw/xfree86/ddc/xf86DDC.h | 2 +
2 files changed, 93 insertions(+)
diff --git a/hw/xfree86/ddc/interpret_edid.c b/hw/xfree86/ddc/interpret_edid.c
index e6b4d5b..eff928e 100644
--- a/hw/xfree86/ddc/interpret_edid.c
+++ b/hw/xfree86/ddc/interpret_edid.c
@@ -332,6 +332,97 @@ xf86ForEachVideoBlock(xf86MonPtr mon, handle_video_fn fn, void *data)
}
}
+static Bool
+cea_db_offsets(Uchar *cea, int *start, int *end)
+{
+ /* Data block offset in CEA extension block */
+ *start = CEA_EXT_MIN_DATA_OFFSET;
+ *end = cea[2];
+ if (*end == 0);
+ *end = CEA_EXT_MAX_DATA_OFFSET;
+ if (*end < CEA_EXT_MIN_DATA_OFFSET || *end > CEA_EXT_MAX_DATA_OFFSET)
+ return FALSE;
+ return TRUE;
+}
+
+static int
+cea_db_len(Uchar *db)
+{
+ return db[0] & 0x1f;
+}
+
+static int
+cea_db_tag(Uchar *db)
+{
+ return db[0] >> 5;
+}
+
+typedef void (*handle_cea_db_fn) (Uchar *, void *);
+
+static void
+cea_for_each_db(xf86MonPtr mon, handle_cea_db_fn fn, void *data)
+{
+ int i;
+
+ if (!mon)
+ return;
+
+ if (!(mon->flags & EDID_COMPLETE_RAWDATA))
+ return;
+
+ if (!mon->no_sections)
+ return;
+
+ if (!mon->rawData)
+ return;
+
+ for (i = 0; i < mon->no_sections; i++) {
+ int start, end, offset;
+ Uchar *ext;
+
+ ext = mon->rawData + EDID1_LEN * (i + 1);
+ if (ext[EXT_TAG] != CEA_EXT)
+ continue;
+
+ if (!cea_db_offsets(ext, &start, &end))
+ continue;
+
+ for (offset = start;
+ offset < end && offset + cea_db_len(&ext[i]) < end;
+ offset += cea_db_len(&ext[offset]) + 1)
+ fn(&ext[offset], data);
+ }
+}
+
+struct find_hdmi_block_data {
+ struct cea_data_block *hdmi;
+};
+
+static void find_hdmi_block(Uchar *db, void *data)
+{
+ struct find_hdmi_block_data *result = data;
+ int oui;
+
+ if (cea_db_tag(db) != CEA_VENDOR_BLK)
+ return;
+
+ if (cea_db_len(db) < 5)
+ return;
+
+ oui = (db[3] << 16) + (db[2] << 8) + db[1];
+ if (oui == IEEE_ID_HDMI)
+ result->hdmi = (struct cea_data_block *)db;
+}
+
+struct cea_data_block *xf86MonitorFindHDMIBlock(xf86MonPtr mon)
+{
+ struct find_hdmi_block_data result = { NULL };
+
+ cea_for_each_db(mon, find_hdmi_block, &result);
+
+ return result.hdmi;
+}
+
xf86MonPtr
xf86InterpretEEDID(int scrnIndex, Uchar * block)
{
diff --git a/hw/xfree86/ddc/xf86DDC.h b/hw/xfree86/ddc/xf86DDC.h
index bdc7648..de8e718 100644
--- a/hw/xfree86/ddc/xf86DDC.h
+++ b/hw/xfree86/ddc/xf86DDC.h
@@ -98,4 +98,6 @@ typedef void (*handle_video_fn) (struct cea_video_block *, void *);
void xf86ForEachVideoBlock(xf86MonPtr, handle_video_fn, void *);
+struct cea_data_block *xf86MonitorFindHDMIBlock(xf86MonPtr mon);
+
#endif
--
1.8.3.1
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