Commit 81898671 authored by Jonathan Corbet's avatar Jonathan Corbet Committed by Mauro Carvalho Chehab
Browse files

V4L/DVB: ov7670: Wire up V4L2_CID_GAIN and V4L2_CID_AUTOGAIN 



Allow applications to play with the gain settings.

Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 2bf7de48

drivers/media/video/ov7670.c

+73 −0
Original line number Diff line number Diff line
@@ -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;

}