Hi Hans
another drive-by question
On Tue, Jun 27, 2023 at 03:18:25PM +0200, Hans de Goede wrote:
> The exposure control's max effective value is VTS - 8, set the control
> range to match this. Thas means that if/when a future commit makes VTS
> configurable as a control itself the exposure range needs to be
> updated dynamically to match the VTS value.
>
> The gain control goes from 0 - 1023, higher values wrap around to
> the lowest gain setting.
>
> Also stop setting 0 as default for both controls this leads to
> a totally black picture which is no good. This is esp. important
> for tests of the sensor driver without (userspace driven)
> auto exposure / gain.
I see the driver uses V4L2_CID_GAIN. Is this intentional or should
this be V4L2_CID_ANALOGUE_GAIN? As you're plumbing libcamera support
in, this is the control libcamera expects to use to control analogue
gain.
>
> Acked-by: Rui Miguel Silva <rmfrfs@xxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> drivers/media/i2c/ov2680.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/i2c/ov2680.c b/drivers/media/i2c/ov2680.c
> index 6591ce3b9244..e26a6487d421 100644
> --- a/drivers/media/i2c/ov2680.c
> +++ b/drivers/media/i2c/ov2680.c
> @@ -81,6 +81,9 @@
> /* If possible send 16 extra rows / lines to the ISP as padding */
> #define OV2680_END_MARGIN 16
>
> +/* Max exposure time is VTS - 8 */
> +#define OV2680_INTEGRATION_TIME_MARGIN 8
> +
> #define OV2680_DEFAULT_WIDTH 800
> #define OV2680_DEFAULT_HEIGHT 600
>
> @@ -823,6 +826,7 @@ static int ov2680_v4l2_register(struct ov2680_dev *sensor)
> const struct v4l2_ctrl_ops *ops = &ov2680_ctrl_ops;
> struct ov2680_ctrls *ctrls = &sensor->ctrls;
> struct v4l2_ctrl_handler *hdl = &ctrls->handler;
> + int exp_max = OV2680_LINES_PER_FRAME - OV2680_INTEGRATION_TIME_MARGIN;
> int ret = 0;
>
> v4l2_i2c_subdev_init(&sensor->sd, client, &ov2680_subdev_ops);
> @@ -849,9 +853,10 @@ static int ov2680_v4l2_register(struct ov2680_dev *sensor)
> 0, 0, test_pattern_menu);
>
> ctrls->exposure = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_EXPOSURE,
> - 0, 32767, 1, 0);
> + 0, exp_max, 1, exp_max);
>
> - ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_GAIN, 0, 2047, 1, 0);
> + ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_GAIN,
> + 0, 1023, 1, 250);
>
> if (hdl->error) {
> ret = hdl->error;
> --
> 2.41.0
>
