Hello Xavier
On Thu, Feb 03, 2022 at 08:58:37AM +0100, Xavier Roumegue (OSS) wrote:
> Hello Jacopo,
>
> On 1/31/22 15:32, Jacopo Mondi wrote:
> > Add the VBLANK control which allows to select the duration of the
> > frame vertical blankings and allows to control the framerate.
> >
> > The VBLANK control also modifies the exposure time range, which cannot
> > exceed the maximum frame length.
> >
> > Signed-off-by: Jacopo Mondi <jacopo@xxxxxxxxxx>
> > ---
> > drivers/media/i2c/ov5640.c | 50 ++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 50 insertions(+)
> >
> > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> > index b2961e8e07c3..6eeb50724195 100644
> > --- a/drivers/media/i2c/ov5640.c
> > +++ b/drivers/media/i2c/ov5640.c
> > @@ -31,6 +31,10 @@
> > #define OV5640_LINK_RATE_MAX 490000000U
> > +/* FIXME: not documented. */
> > +#define OV5640_MIN_VBLANK 24
> > +#define OV5640_MAX_VTS 1968
> > +
> > #define OV5640_DEFAULT_SLAVE_ID 0x3c
> > #define OV5640_REG_SYS_RESET02 0x3002
> > @@ -267,6 +271,7 @@ struct ov5640_ctrls {
> > struct v4l2_ctrl *pixel_rate;
> > struct v4l2_ctrl *link_freq;
> > struct v4l2_ctrl *hblank;
> > + struct v4l2_ctrl *vblank;
> > struct {
> > struct v4l2_ctrl *auto_exp;
> > struct v4l2_ctrl *exposure;
> > @@ -2531,6 +2536,7 @@ static int ov5640_update_pixel_rate(struct ov5640_dev *sensor)
> > struct v4l2_mbus_framefmt *fmt = &sensor->fmt;
> > enum ov5640_pixel_rate_id pixel_rate_id = mode->pixel_rate;
> > u32 num_lanes = sensor->ep.bus.mipi_csi2.num_data_lanes;
> > + s64 exposure_val, exposure_max;
> > unsigned int hblank;
> > unsigned int i = 0;
> > u32 pixel_rate;
> > @@ -2586,6 +2592,20 @@ static int ov5640_update_pixel_rate(struct ov5640_dev *sensor)
> > __v4l2_ctrl_modify_range(sensor->ctrls.hblank,
> > hblank, hblank, 1, hblank);
> > + __v4l2_ctrl_modify_range(sensor->ctrls.vblank,
> > + OV5640_MIN_VBLANK,
> > + OV5640_MAX_VTS - mode->crop.height, 1,
> > + mode->vblank_def);
> > + __v4l2_ctrl_s_ctrl(sensor->ctrls.vblank, mode->vblank_def);
> > +
> > + exposure_max = mode->crop.height + mode->vblank_def - OV5640_MIN_VBLANK;
> > + exposure_val = clamp((s64)sensor->ctrls.exposure->val,
> > + (s64)sensor->ctrls.exposure->minimum,
> > + (s64)exposure_max);
> > + __v4l2_ctrl_modify_range(sensor->ctrls.exposure,
> > + sensor->ctrls.exposure->minimum,
> > + exposure_max, 1, exposure_val);
> > +
> > return 0;
> > }
> > @@ -2958,6 +2978,15 @@ static int ov5640_set_ctrl_vflip(struct ov5640_dev *sensor, int value)
> > (BIT(2) | BIT(1)) : 0);
> > }
> > +static int ov5640_set_ctrl_vblank(struct ov5640_dev *sensor, int value)
> > +{
> > + const struct ov5640_mode_info *mode = sensor->current_mode;
> > +
> > + /* Update the VTOT timing register value. */
> > + return ov5640_write_reg16(sensor, OV5640_REG_TIMING_VTS,
> > + mode->crop.height + value);
> > +}
> > +
> > static int ov5640_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
> > {
> > struct v4l2_subdev *sd = ctrl_to_sd(ctrl);
> > @@ -2988,10 +3017,22 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
> > {
> > struct v4l2_subdev *sd = ctrl_to_sd(ctrl);
> > struct ov5640_dev *sensor = to_ov5640_dev(sd);
> > + const struct ov5640_mode_info *mode = sensor->current_mode;
> > int ret;
> > /* v4l2_ctrl_lock() locks our own mutex */
> > + switch (ctrl->id) {
> > + case V4L2_CID_VBLANK:
> > + /* Update the exposure range to the newly programmed vblank. */
> > + unsigned int max = mode->crop.height + ctrl->val - OV5640_MIN_VBLANK;
> > +
> > + __v4l2_ctrl_modify_range(sensor->ctrls.exposure,
> > + sensor->ctrls.exposure->minimum,
> > + max, sensor->ctrls.exposure->step, max);
> > + break;
> > + }The kernel build reports the errors below with clang toolchain (LLVM=1):
>
> drivers/media/i2c/ov5640.c:3124:3: error: expected expression
> unsigned int max = mode->crop.height + ctrl->val -
> OV5640_MIN_VBLANK;
> ^
> drivers/media/i2c/ov5640.c:3128:7: error: use of undeclared identifier 'max'
> max, sensor->ctrls.exposure->step,
> max);
> ^
> drivers/media/i2c/ov5640.c:3128:42: error: use of undeclared identifier
> 'max'
> max, sensor->ctrls.exposure->step,
> max);
>
> ^
> 3 errors generated.
> make[3]: *** [scripts/Makefile.build:288: drivers/media/i2c/ov5640.o] Error
> 1
>
> Declaring the variable within a compound statement following the label
> (case), or moving the declaration after the switch fix the build.
> The former construct might be more aligned with kernel coding use (?).
>
> switch(...) {
> case ...: {
> unsigned int max = ...;
> ...
> }
> }
>
> or
>
> switch(...) {
> unsigned int max = 0;
> case ...:
> ...
> break;
Thanks, I didn't compile with clang :)
I'll go for the former, as you say it is more aligned with common
practices as far as I can tell.
Thanks
j
> }
>
> > +
> > /*
> > * If the device is not powered up by the host driver do
> > * not apply any controls to H/W at this time. Instead
> > @@ -3031,6 +3072,9 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
> > case V4L2_CID_VFLIP:
> > ret = ov5640_set_ctrl_vflip(sensor, ctrl->val);
> > break;
> > + case V4L2_CID_VBLANK:
> > + ret = ov5640_set_ctrl_vblank(sensor, ctrl->val);
> > + break;
> > default:
> > ret = -EINVAL;
> > break;
> > @@ -3050,6 +3094,7 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
> > const struct v4l2_ctrl_ops *ops = &ov5640_ctrl_ops;
> > struct ov5640_ctrls *ctrls = &sensor->ctrls;
> > struct v4l2_ctrl_handler *hdl = &ctrls->handler;
> > + unsigned int max_vblank;
> > unsigned int hblank;
> > int ret;
> > @@ -3073,6 +3118,11 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
> > ctrls->hblank = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_HBLANK, hblank,
> > hblank, 1, hblank);
> > + max_vblank = OV5640_MAX_VTS - mode->crop.height;
> > + ctrls->vblank = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_VBLANK,
> > + OV5640_MIN_VBLANK, max_vblank,
> > + 1, mode->vblank_def);
> > +
> > /* Auto/manual white balance */
> > ctrls->auto_wb = v4l2_ctrl_new_std(hdl, ops,
> > V4L2_CID_AUTO_WHITE_BALANCE,
> Regards,
> Xavier
