Re: [PATCH 03/11] media: i2c: ov5640: Fix minimum gain to 1.0x

[Jacopo Mondi <jacopo.mondi@ideasonboard.com>]

On Fri, May 01, 2026 at 04:39:05PM +0100, Kieran Bingham wrote:
> Adjust the Analogue Gain control to only provide a minimum gain of 1.0,
> and ensure that this is the default value rather than '0' which is
> invalid.
>
> Requesting an Analogue gain of 0 would result in a black frame, and when
> the sensor is over exposed the Exposure should be reduced instead.
>
> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> ---
>  drivers/media/i2c/ov5640.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index b5e529ea662b..0dc4f4272d05 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -3484,7 +3484,7 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
>  	ctrls->auto_gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_AUTOGAIN,
>  					     0, 1, 1, 1);
>  	ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_ANALOGUE_GAIN,
> -					0, 1023, 1, 0);
> +					16, 1023, 1, 16);

Again the register is not documented, but it is said that 0xff = x32
which suggests Q6.4 hence 16 should be x1.0

Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

>
>  	ctrls->saturation = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_SATURATION,
>  					      0, 255, 1, 64);
>
> --
> 2.52.0
>
>