[media] gspca: sn9c2028: Add gain and autogain controls Genius Videocam Live v2
Autogain algorithm is very simple, if average luminance is low - increase gain,
if it's high - decrease gain. Gain granularity is low enough for this algo to
stabilize quickly.
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/usb/gspca/sn9c2028.h b/drivers/media/usb/gspca/sn9c2028.h
index 8fd1d3e..f85bc10 100644
--- a/drivers/media/usb/gspca/sn9c2028.h
+++ b/drivers/media/usb/gspca/sn9c2028.h
@@ -21,8 +21,15 @@
*
*/
-static const unsigned char sn9c2028_sof_marker[5] =
- { 0xff, 0xff, 0x00, 0xc4, 0xc4 };
+static const unsigned char sn9c2028_sof_marker[] = {
+ 0xff, 0xff, 0x00, 0xc4, 0xc4, 0x96,
+ 0x00,
+ 0x00, /* seq */
+ 0x00,
+ 0x00,
+ 0x00, /* avg luminance lower 8 bit */
+ 0x00, /* avg luminance higher 8 bit */
+};
static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev,
unsigned char *m, int len)
@@ -32,8 +39,13 @@
/* Search for the SOF marker (fixed part) in the header */
for (i = 0; i < len; i++) {
- if (m[i] == sn9c2028_sof_marker[sd->sof_read]) {
+ if ((m[i] == sn9c2028_sof_marker[sd->sof_read]) ||
+ (sd->sof_read > 5)) {
sd->sof_read++;
+ if (sd->sof_read == 11)
+ sd->avg_lum_l = m[i];
+ if (sd->sof_read == 12)
+ sd->avg_lum = (m[i] << 8) + sd->avg_lum_l;
if (sd->sof_read == sizeof(sn9c2028_sof_marker)) {
PDEBUG(D_FRAM,
"SOF found, bytes to analyze: %u."