From 81898671247a6cfa6bfd6a32faee18b3999b6610 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Thu, 4 Mar 2010 18:50:34 -0300 Subject: [PATCH] V4L/DVB: ov7670: Wire up V4L2_CID_GAIN and V4L2_CID_AUTOGAIN Allow applications to play with the gain settings. Signed-off-by: Jonathan Corbet Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/ov7670.c | 73 ++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c index 95507770f120..e7555d1f90e6 100644 --- a/drivers/media/video/ov7670.c +++ b/drivers/media/video/ov7670.c @@ -1131,6 +1131,67 @@ static int ov7670_s_vflip(struct v4l2_subdev *sd, int value) return ret; } +/* + * GAIN is split between REG_GAIN and REG_VREF[7:6]. If one believes + * the data sheet, the VREF parts should be the most significant, but + * experience shows otherwise. There seems to be little value in + * messing with the VREF bits, so we leave them alone. + */ +static int ov7670_g_gain(struct v4l2_subdev *sd, __s32 *value) +{ + int ret; + unsigned char gain; + + ret = ov7670_read(sd, REG_GAIN, &gain); + *value = gain; + return ret; +} + +static int ov7670_s_gain(struct v4l2_subdev *sd, int value) +{ + int ret; + unsigned char com8; + + ret = ov7670_write(sd, REG_GAIN, value & 0xff); + /* Have to turn off AGC as well */ + if (ret == 0) { + ret = ov7670_read(sd, REG_COM8, &com8); + ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC); + } + return ret; +} + +/* + * Tweak autogain. + */ +static int ov7670_g_autogain(struct v4l2_subdev *sd, __s32 *value) +{ + int ret; + unsigned char com8; + + ret = ov7670_read(sd, REG_COM8, &com8); + *value = (com8 & COM8_AGC) != 0; + return ret; +} + +static int ov7670_s_autogain(struct v4l2_subdev *sd, int value) +{ + int ret; + unsigned char com8; + + ret = ov7670_read(sd, REG_COM8, &com8); + if (ret == 0) { + if (value) + com8 |= COM8_AGC; + else + com8 &= ~COM8_AGC; + ret = ov7670_write(sd, REG_COM8, com8); + } + return ret; +} + + + static int ov7670_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc) { @@ -1147,6 +1208,10 @@ static int ov7670_queryctrl(struct v4l2_subdev *sd, return v4l2_ctrl_query_fill(qc, 0, 256, 1, 128); case V4L2_CID_HUE: return v4l2_ctrl_query_fill(qc, -180, 180, 5, 0); + case V4L2_CID_GAIN: + return v4l2_ctrl_query_fill(qc, 0, 255, 1, 128); + case V4L2_CID_AUTOGAIN: + return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1); } return -EINVAL; } @@ -1166,6 +1231,10 @@ static int ov7670_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl) return ov7670_g_vflip(sd, &ctrl->value); case V4L2_CID_HFLIP: return ov7670_g_hflip(sd, &ctrl->value); + case V4L2_CID_GAIN: + return ov7670_g_gain(sd, &ctrl->value); + case V4L2_CID_AUTOGAIN: + return ov7670_g_autogain(sd, &ctrl->value); } return -EINVAL; } @@ -1185,6 +1254,10 @@ static int ov7670_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl) return ov7670_s_vflip(sd, ctrl->value); case V4L2_CID_HFLIP: return ov7670_s_hflip(sd, ctrl->value); + case V4L2_CID_GAIN: + return ov7670_s_gain(sd, ctrl->value); + case V4L2_CID_AUTOGAIN: + return ov7670_s_autogain(sd, ctrl->value); } return -EINVAL; } -- 2.39.2