[PATCH 1/3] gspca_zc3xx: Implement proper autogain and exposure control for OV7648

From: Ondrej Zary
Date: Thu May 24 2018 - 10:17:20 EST


The ZS0211 internal autogain causes pumping and flickering with OV7648
sensor on 0ac8:307b webcam.
Implement OV7648 autogain and exposure control and use that instead.

Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
---
drivers/media/usb/gspca/zc3xx.c | 42 +++++++++++++++++++++++++++++++++--------
1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/drivers/media/usb/gspca/zc3xx.c b/drivers/media/usb/gspca/zc3xx.c
index 25b4dbe8e049..992918b3ad0c 100644
--- a/drivers/media/usb/gspca/zc3xx.c
+++ b/drivers/media/usb/gspca/zc3xx.c
@@ -5778,16 +5778,34 @@ static void setcontrast(struct gspca_dev *gspca_dev,

static s32 getexposure(struct gspca_dev *gspca_dev)
{
- return (i2c_read(gspca_dev, 0x25) << 9)
- | (i2c_read(gspca_dev, 0x26) << 1)
- | (i2c_read(gspca_dev, 0x27) >> 7);
+ struct sd *sd = (struct sd *) gspca_dev;
+
+ switch (sd->sensor) {
+ case SENSOR_HV7131R:
+ return (i2c_read(gspca_dev, 0x25) << 9)
+ | (i2c_read(gspca_dev, 0x26) << 1)
+ | (i2c_read(gspca_dev, 0x27) >> 7);
+ case SENSOR_OV7620:
+ return i2c_read(gspca_dev, 0x10);
+ default:
+ return -1;
+ }
}

static void setexposure(struct gspca_dev *gspca_dev, s32 val)
{
- i2c_write(gspca_dev, 0x25, val >> 9, 0x00);
- i2c_write(gspca_dev, 0x26, val >> 1, 0x00);
- i2c_write(gspca_dev, 0x27, val << 7, 0x00);
+ struct sd *sd = (struct sd *) gspca_dev;
+
+ switch (sd->sensor) {
+ case SENSOR_HV7131R:
+ i2c_write(gspca_dev, 0x25, val >> 9, 0x00);
+ i2c_write(gspca_dev, 0x26, val >> 1, 0x00);
+ i2c_write(gspca_dev, 0x27, val << 7, 0x00);
+ break;
+ case SENSOR_OV7620:
+ i2c_write(gspca_dev, 0x10, val, 0x00);
+ break;
+ }
}

static void setquality(struct gspca_dev *gspca_dev)
@@ -5918,7 +5936,12 @@ static void setlightfreq(struct gspca_dev *gspca_dev, s32 val)

static void setautogain(struct gspca_dev *gspca_dev, s32 val)
{
- reg_w(gspca_dev, val ? 0x42 : 0x02, 0x0180);
+ struct sd *sd = (struct sd *) gspca_dev;
+
+ if (sd->sensor == SENSOR_OV7620)
+ i2c_write(gspca_dev, 0x13, val ? 0xa3 : 0x80, 0x00);
+ else
+ reg_w(gspca_dev, val ? 0x42 : 0x02, 0x0180);
}

/*
@@ -6439,6 +6462,9 @@ static int sd_init_controls(struct gspca_dev *gspca_dev)
if (sd->sensor == SENSOR_HV7131R)
sd->exposure = v4l2_ctrl_new_std(hdl, &zcxx_ctrl_ops,
V4L2_CID_EXPOSURE, 0x30d, 0x493e, 1, 0x927);
+ else if (sd->sensor == SENSOR_OV7620)
+ sd->exposure = v4l2_ctrl_new_std(hdl, &zcxx_ctrl_ops,
+ V4L2_CID_EXPOSURE, 0, 255, 1, 0x41);
sd->autogain = v4l2_ctrl_new_std(hdl, &zcxx_ctrl_ops,
V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
if (sd->sensor != SENSOR_OV7630C)
@@ -6458,7 +6484,7 @@ static int sd_init_controls(struct gspca_dev *gspca_dev)
return hdl->error;
}
v4l2_ctrl_cluster(3, &sd->gamma);
- if (sd->sensor == SENSOR_HV7131R)
+ if (sd->sensor == SENSOR_HV7131R || sd->sensor == SENSOR_OV7620)
v4l2_ctrl_auto_cluster(2, &sd->autogain, 0, true);
return 0;
}
--
Ondrej Zary