msm_fb: HDMI: Support VCDB parsing of EDID data
This change enhances the EDID parser to read the
Video Capability Data Block (VCDB) in order to check
whether a sink supports underscan mode.
Change-Id: Id4e48db4ff7f54fd72d40a413e2f03b692b662c1
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>
diff --git a/drivers/video/msm/external_common.c b/drivers/video/msm/external_common.c
index 90702f3..eec600e 100644
--- a/drivers/video/msm/external_common.c
+++ b/drivers/video/msm/external_common.c
@@ -18,6 +18,9 @@
/* #define DEBUG */
#define DEV_DBG_PREFIX "EXT_COMMON: "
+/* The start of the data block collection within the CEA Extension Version 3 */
+#define DBC_START_OFFSET 4
+
#include "msm_fb.h"
#include "hdmi_msm.h"
#include "external_common.h"
@@ -317,6 +320,18 @@
return ret;
}
+static ssize_t hdmi_common_rda_edid_scan_info(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t ret = snprintf(buf, PAGE_SIZE, "%d, %d, %d\n",
+ external_common_state->pt_scan_info,
+ external_common_state->it_scan_info,
+ external_common_state->ce_scan_info);
+ DEV_DBG("%s: '%s'\n", __func__, buf);
+
+ return ret;
+}
+
static ssize_t hdmi_common_rda_hdcp(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -681,6 +696,8 @@
static DEVICE_ATTR(hpd, S_IRUGO | S_IWUGO, hdmi_common_rda_hpd,
hdmi_common_wta_hpd);
static DEVICE_ATTR(hdcp, S_IRUGO, hdmi_common_rda_hdcp, NULL);
+static DEVICE_ATTR(scan_info, S_IRUGO,
+ hdmi_common_rda_edid_scan_info, NULL);
static DEVICE_ATTR(3d_present, S_IRUGO, hdmi_common_rda_3d_present, NULL);
static DEVICE_ATTR(hdcp_present, S_IRUGO, hdmi_common_rda_hdcp_present, NULL);
#endif
@@ -699,6 +716,7 @@
&dev_attr_edid_modes.attr,
&dev_attr_hdcp.attr,
&dev_attr_hpd.attr,
+ &dev_attr_scan_info.attr,
&dev_attr_3d_present.attr,
&dev_attr_hdcp_present.attr,
#endif
@@ -926,11 +944,12 @@
31500, 60000, 108108, 60000, TRUE},
};
-static const uint8 *hdmi_edid_find_block(const uint8 *in_buf, uint8 type,
- uint8 *len)
+static const uint8 *hdmi_edid_find_block(const uint8 *in_buf,
+ uint32 start_offset, uint8 type, uint8 *len)
{
/* the start of data block collection, start of Video Data Block */
- uint32 offset = 4;
+ uint32 offset = start_offset;
+ uint32 end_dbc_offset = in_buf[2];
*len = 0;
@@ -938,11 +957,11 @@
present.
edid buffer 1, byte 2 being 0 menas no non-DTD/DATA block collection
present and no DTD data present.*/
- if ((in_buf[2] == 0) || (in_buf[2] == 4)) {
+ if ((end_dbc_offset == 0) || (end_dbc_offset == 4)) {
DEV_WARN("EDID: no DTD or non-DTD data present\n");
return NULL;
}
- while (offset < 0x80) {
+ while (offset < end_dbc_offset) {
uint8 block_len = in_buf[offset] & 0x1F;
if ((in_buf[offset] >> 5) == type) {
*len = block_len;
@@ -970,7 +989,8 @@
static uint32 hdmi_edid_extract_ieee_reg_id(const uint8 *in_buf)
{
uint8 len;
- const uint8 *vsd = hdmi_edid_find_block(in_buf, 3, &len);
+ const uint8 *vsd = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 3,
+ &len);
if (vsd == NULL)
return 0;
@@ -983,7 +1003,8 @@
static void hdmi_edid_extract_3d_present(const uint8 *in_buf)
{
uint8 len, offset;
- const uint8 *vsd = hdmi_edid_find_block(in_buf, 3, &len);
+ const uint8 *vsd = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 3,
+ &len);
external_common_state->present_3d = 0;
if (vsd == NULL || len < 9) {
@@ -1003,7 +1024,8 @@
static void hdmi_edid_extract_latency_fields(const uint8 *in_buf)
{
uint8 len;
- const uint8 *vsd = hdmi_edid_find_block(in_buf, 3, &len);
+ const uint8 *vsd = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 3,
+ &len);
if (vsd == NULL || len < 12 || !(vsd[8] & BIT(7))) {
external_common_state->video_latency = (uint16)-1;
@@ -1021,7 +1043,8 @@
static void hdmi_edid_extract_speaker_allocation_data(const uint8 *in_buf)
{
uint8 len;
- const uint8 *sad = hdmi_edid_find_block(in_buf, 4, &len);
+ const uint8 *sad = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 4,
+ &len);
if (sad == NULL)
return;
@@ -1041,7 +1064,8 @@
static void hdmi_edid_extract_audio_data_blocks(const uint8 *in_buf)
{
uint8 len;
- const uint8 *sad = hdmi_edid_find_block(in_buf, 1, &len);
+ const uint8 *sad = hdmi_edid_find_block(in_buf, DBC_START_OFFSET, 1,
+ &len);
uint32 *adb = external_common_state->audio_data_blocks;
if (sad == NULL)
@@ -1060,6 +1084,63 @@
}
}
+static void hdmi_edid_extract_extended_data_blocks(const uint8 *in_buf)
+{
+ uint8 len = 0;
+ uint8 const *prev_etag = in_buf;
+ uint32 start_offset = DBC_START_OFFSET;
+
+ /* A Tage code of 7 identifies extended data blocks */
+ uint8 const *etag = hdmi_edid_find_block(in_buf, start_offset, 7, &len);
+
+ while (etag != NULL) {
+ /* The extended data block should at least be 2 bytes long */
+ if (len < 2) {
+ DEV_DBG("EDID: Found an extended data block of length"
+ "less than 2 bytes. Ignoring ...\n");
+ } else {
+ /*
+ * The second byte of the extended data block has the
+ * extended tag code
+ */
+ switch (etag[1]) {
+ case 0:
+ /* Video Capability Data Block */
+ DEV_DBG("EDID: VCDB=%02X %02X\n", etag[1],
+ etag[2]);
+
+ /*
+ * Check if the sink specifies underscan
+ * support for:
+ * BIT 5: preferred video format
+ * BIT 3: IT video format
+ * BIT 1: CE video format
+ */
+ external_common_state->pt_scan_info = (etag[2] &
+ (BIT(4) | BIT(5))) >> 4;
+ external_common_state->it_scan_info = (etag[2] &
+ (BIT(3) | BIT(2))) >> 2;
+ external_common_state->ce_scan_info = etag[2] &
+ (BIT(1) | BIT(0));
+ DEV_DBG("EDID: Scan Information (pt|it|ce): "
+ "(%d|%d|%d)",
+ external_common_state->pt_scan_info,
+ external_common_state->it_scan_info,
+ external_common_state->ce_scan_info);
+ break;
+ default:
+ DEV_DBG("EDID: Extend Tag Code %d not"
+ "supported\n", etag[1]);
+ break;
+ }
+ }
+
+ /* There could be more that one extended data block */
+ start_offset = etag - prev_etag + len + 1;
+ prev_etag = etag;
+ etag = hdmi_edid_find_block(in_buf, start_offset, 7, &len);
+ }
+}
static void hdmi_edid_detail_desc(const uint8 *data_buf, uint32 *disp_mode)
{
@@ -1204,7 +1285,8 @@
const uint8 *edid_blk0 = &data_buf[0x0];
const uint8 *edid_blk1 = &data_buf[0x80];
const uint8 *svd = num_og_cea_blocks ?
- hdmi_edid_find_block(data_buf+0x80, 2, &len) : NULL;
+ hdmi_edid_find_block(data_buf+0x80, DBC_START_OFFSET,
+ 2, &len) : NULL;
disp_mode_list->num_of_elements = 0;
if (svd != NULL) {
@@ -1216,6 +1298,11 @@
video_format = (*svd & 0x7F) - 1;
add_supported_video_format(disp_mode_list,
video_format);
+ /* Make a note of the preferred video format */
+ if (i == 0) {
+ external_common_state->preferred_video_format =
+ video_format;
+ }
if (video_format == HDMI_VFRMT_640x480p60_4_3)
has480p = TRUE;
}
@@ -1238,6 +1325,11 @@
video_format);
if (video_format == HDMI_VFRMT_640x480p60_4_3)
has480p = TRUE;
+ /* Make a note of the preferred video format */
+ if (i == 0) {
+ external_common_state->preferred_video_format =
+ video_format;
+ }
desc_offset += 0x12;
++i;
}
@@ -1258,6 +1350,11 @@
video_format);
if (video_format == HDMI_VFRMT_640x480p60_4_3)
has480p = TRUE;
+ /* Make a note of the preferred video format */
+ if (i == 0) {
+ external_common_state->preferred_video_format =
+ video_format;
+ }
desc_offset += 0x12;
++i;
}
@@ -1281,6 +1378,11 @@
video_format);
if (video_format == HDMI_VFRMT_640x480p60_4_3)
has480p = TRUE;
+ /* Make a note of the preferred video format */
+ if (i == 0) {
+ external_common_state->preferred_video_format =
+ video_format;
+ }
desc_offset += 0x12;
++i;
}
@@ -1359,6 +1461,7 @@
/* EDID_BLOCK_SIZE[0x80] Each page size in the EDID ROM */
uint8 edid_buf[0x80 * 4];
+ external_common_state->preferred_video_format = 0;
external_common_state->present_3d = 0;
memset(&external_common_state->disp_mode_list, 0,
sizeof(external_common_state->disp_mode_list));
@@ -1410,6 +1513,7 @@
edid_buf+0x80);
hdmi_edid_extract_audio_data_blocks(edid_buf+0x80);
hdmi_edid_extract_3d_present(edid_buf+0x80);
+ hdmi_edid_extract_extended_data_blocks(edid_buf+0x80);
}
break;
case 2: