[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.c b/drivers/media/usb/gspca/sn9c2028.c
index e59576c..c75b738 100644 (file)
--- a/drivers/media/usb/gspca/sn9c2028.c
+++ b/drivers/media/usb/gspca/sn9c2028.c
@@ -33,6 +33,16 @@ struct sd {
        struct gspca_dev gspca_dev;  /* !! must be the first item */
        u8 sof_read;
        u16 model;
+
+#define MIN_AVG_LUM 8500
+#define MAX_AVG_LUM 10000
+       int avg_lum;
+       u8 avg_lum_l;
+
+       struct { /* autogain and gain control cluster */
+               struct v4l2_ctrl *autogain;
+               struct v4l2_ctrl *gain;
+       };
 };
 
 struct init_command {
@@ -251,6 +261,78 @@ static int run_start_commands(struct gspca_dev *gspca_dev,
        return 0;
 }
 
+static void set_gain(struct gspca_dev *gspca_dev, s32 g)
+{
+       struct sd *sd = (struct sd *) gspca_dev;
+
+       struct init_command genius_vcam_live_gain_cmds[] = {
+               {{0x1d, 0x25, 0x10 /* This byte is gain */,
+                 0x20, 0xab, 0x00}, 0},
+       };
+       if (!gspca_dev->streaming)
+               return;
+
+       switch (sd->model) {
+       case 0x7003:
+               genius_vcam_live_gain_cmds[0].instruction[2] = g;
+               run_start_commands(gspca_dev, genius_vcam_live_gain_cmds,
+                                  ARRAY_SIZE(genius_vcam_live_gain_cmds));
+               break;
+       default:
+               break;
+       }
+}
+
+static int sd_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+       struct gspca_dev *gspca_dev =
+               container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
+       struct sd *sd = (struct sd *)gspca_dev;
+
+       gspca_dev->usb_err = 0;
+
+       if (!gspca_dev->streaming)
+               return 0;
+
+       switch (ctrl->id) {
+       /* standalone gain control */
+       case V4L2_CID_GAIN:
+               set_gain(gspca_dev, ctrl->val);
+               break;
+       /* autogain */
+       case V4L2_CID_AUTOGAIN:
+               set_gain(gspca_dev, sd->gain->val);
+               break;
+       }
+       return gspca_dev->usb_err;
+}
+
+static const struct v4l2_ctrl_ops sd_ctrl_ops = {
+       .s_ctrl = sd_s_ctrl,
+};
+
+
+static int sd_init_controls(struct gspca_dev *gspca_dev)
+{
+       struct v4l2_ctrl_handler *hdl = &gspca_dev->ctrl_handler;
+       struct sd *sd = (struct sd *)gspca_dev;
+
+       gspca_dev->vdev.ctrl_handler = hdl;
+       v4l2_ctrl_handler_init(hdl, 2);
+
+       switch (sd->model) {
+       case 0x7003:
+               sd->gain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
+                       V4L2_CID_GAIN, 0, 20, 1, 0);
+               sd->autogain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
+                       V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
+               break;
+       default:
+               break;
+       }
+
+       return 0;
+}
 static int start_spy_cam(struct gspca_dev *gspca_dev)
 {
        struct init_command spy_start_commands[] = {
@@ -640,6 +722,9 @@ static int start_genius_videocam_live(struct gspca_dev *gspca_dev)
        if (r < 0)
                return r;
 
+       if (sd->gain)
+               set_gain(gspca_dev, v4l2_ctrl_g_ctrl(sd->gain));
+
        return r;
 }
 
@@ -756,6 +841,8 @@ static int sd_start(struct gspca_dev *gspca_dev)
                return -ENXIO;
        }
 
+       sd->avg_lum = -1;
+
        return err_code;
 }
 
@@ -775,6 +862,39 @@ static void sd_stopN(struct gspca_dev *gspca_dev)
                PERR("Camera Stop command failed");
 }
 
+static void do_autogain(struct gspca_dev *gspca_dev, int avg_lum)
+{
+       struct sd *sd = (struct sd *) gspca_dev;
+       s32 cur_gain = v4l2_ctrl_g_ctrl(sd->gain);
+
+       if (avg_lum == -1)
+               return;
+
+       if (avg_lum < MIN_AVG_LUM) {
+               if (cur_gain == sd->gain->maximum)
+                       return;
+               cur_gain++;
+               v4l2_ctrl_s_ctrl(sd->gain, cur_gain);
+       }
+       if (avg_lum > MAX_AVG_LUM) {
+               if (cur_gain == sd->gain->minimum)
+                       return;
+               cur_gain--;
+               v4l2_ctrl_s_ctrl(sd->gain, cur_gain);
+       }
+
+}
+
+static void sd_dqcallback(struct gspca_dev *gspca_dev)
+{
+       struct sd *sd = (struct sd *) gspca_dev;
+
+       if (sd->autogain == NULL || !v4l2_ctrl_g_ctrl(sd->autogain))
+               return;
+
+       do_autogain(gspca_dev, sd->avg_lum);
+}
+
 /* Include sn9c2028 sof detection functions */
 #include "sn9c2028.h"
 
@@ -809,8 +929,10 @@ static const struct sd_desc sd_desc = {
        .name = MODULE_NAME,
        .config = sd_config,
        .init = sd_init,
+       .init_controls = sd_init_controls,
        .start = sd_start,
        .stopN = sd_stopN,
+       .dq_callback = sd_dqcallback,
        .pkt_scan = sd_pkt_scan,
 };
 

diff --git a/drivers/media/usb/gspca/sn9c2028.h b/drivers/media/usb/gspca/sn9c2028.h
index 8fd1d3e..f85bc10 100644 (file)
--- 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 @@ static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev,
 
        /* 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."