Re: [PATCH 10/19] media: i2c: ov4689: Make horizontal blanking configurable

Laurent Pinchart
2023-12-11T22:08:09Z

Hi Mikhail,

Thank you for the patch.

On Mon, Dec 11, 2023 at 08:50:13PM +0300, Mikhail Rudenko wrote:
> Make horizontal blanking configurable. To do so, set HTS register
> according to the requested horizontal blanking in ov4689_set_ctrl
> instead of the register table. Default HTS value is not changed by
> this patch. Minimal HTS value is found experimentally and corresponds
> to 90 fps framerate at minimum vertical blanking. Real HTS value is
> the register value multiplied by 4.
>
> Signed-off-by: Mikhail Rudenko <mike.rudenko@gmail.com>
> ---
> drivers/media/i2c/ov4689.c | 33 +++++++++++++++++++++------------
> 1 file changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/media/i2c/ov4689.c b/drivers/media/i2c/ov4689.c
> index 9fa06941a0e5..67d4004bdcfb 100644
> --- a/drivers/media/i2c/ov4689.c
> +++ b/drivers/media/i2c/ov4689.c
> @@ -30,7 +30,6 @@
> #define OV4689_REG_EXPOSURE CCI_REG24(0x3500)
> #define OV4689_EXPOSURE_MIN 4
> #define OV4689_EXPOSURE_STEP 1
> -#define OV4689_VTS_MAX 0x7fff
>
> #define OV4689_REG_GAIN CCI_REG16(0x3508)
> #define OV4689_GAIN_STEP 1
> @@ -41,6 +40,11 @@
> #define OV4689_TEST_PATTERN_DISABLE 0x0
>
> #define OV4689_REG_VTS CCI_REG16(0x380e)
> +#define OV4689_VTS_MAX 0x7fff
> +
> +#define OV4689_REG_HTS CCI_REG16(0x380c)
> +#define OV4689_HTS_DIVIDER 4
> +#define OV4689_HTS_MAX 0x7fff

Could you move this just before REG_VTS to keep registers sorted by
address ?

>
> #define OV4689_LANES 4
> #define OV4689_XVCLK_FREQ 24000000
> @@ -61,6 +65,7 @@ struct ov4689_mode {
> u32 width;
> u32 height;
> u32 hts_def;
> + u32 hts_min;
> u32 vts_def;
> u32 exp_def;
> u32 pixel_rate;
> @@ -104,7 +109,7 @@ struct ov4689_gain_range {
>
> /*
> * Xclk 24Mhz
> - * max_framerate 30fps
> + * max_framerate 90fps
> * mipi_datarate per lane 1008Mbps
> */
> static const struct cci_reg_sequence ov4689_2688x1520_regs[] = {
> @@ -175,8 +180,6 @@ static const struct cci_reg_sequence ov4689_2688x1520_regs[] = {
> /* Timing control */
> {CCI_REG8(0x3801), 0x08}, /* H_CROP_START_L h_crop_start[7:0] = 0x08 */
> {CCI_REG8(0x3805), 0x97}, /* H_CROP_END_L h_crop_end[7:0] = 0x97 */
> - {CCI_REG8(0x380c), 0x0a}, /* TIMING_HTS_H hts[14:8] = 0x0a */
> - {CCI_REG8(0x380d), 0x0e}, /* TIMING_HTS_L hts[7:0] = 0x0e */
> {CCI_REG8(0x3811), 0x08}, /* H_WIN_OFF_L h_win_off[7:0] = 0x08*/
> {CCI_REG8(0x3813), 0x04}, /* V_WIN_OFF_L v_win_off[7:0] = 0x04 */
> {CCI_REG8(0x3819), 0x01}, /* VSYNC_END_L vsync_end_point[7:0] = 0x01 */
> @@ -237,7 +240,8 @@ static const struct ov4689_mode supported_modes[] = {
> .crop_top = 8,
> .crop_left = 16,
> .exp_def = 1536,
> - .hts_def = 4 * 2574,
> + .hts_def = 10296,
> + .hts_min = 3432,
> .vts_def = 1554,
> .pixel_rate = 480000000,
> .reg_list = ov4689_2688x1520_regs,
> @@ -596,6 +600,11 @@ static int ov4689_set_ctrl(struct v4l2_ctrl *ctrl)
> case V4L2_CID_TEST_PATTERN:
> ret = ov4689_enable_test_pattern(ov4689, val);
> break;
> + case V4L2_CID_HBLANK:
> + cci_write(regmap, OV4689_REG_HTS,
> + (val + ov4689->cur_mode->width) /
> + OV4689_HTS_DIVIDER, &ret);
> + break;
> default:
> dev_warn(dev, "%s Unhandled id:0x%x, val:0x%x\n",
> __func__, ctrl->id, val);
> @@ -618,13 +627,13 @@ static int ov4689_initialize_controls(struct ov4689 *ov4689)
> struct v4l2_ctrl_handler *handler;
> const struct ov4689_mode *mode;
> s64 exposure_max, vblank_def;
> + s64 hblank_def, hblank_min;
> struct v4l2_ctrl *ctrl;
> - s64 h_blank_def;
> int ret;
>
> handler = &ov4689->ctrl_handler;
> mode = ov4689->cur_mode;
> - ret = v4l2_ctrl_handler_init(handler, 10);
> + ret = v4l2_ctrl_handler_init(handler, 11);

The HBLANK control already exists, you're only changing how it is
initialized. I see 8 controls being created by the driver directly,
plus 2 created by v4l2_ctrl_new_fwnode_properties(), so I think 10 is a
correct value here.

With these small issues addressed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> if (ret)
> return ret;
>
> @@ -636,11 +645,11 @@ static int ov4689_initialize_controls(struct ov4689 *ov4689)
> v4l2_ctrl_new_std(handler, NULL, V4L2_CID_PIXEL_RATE, 0,
> mode->pixel_rate, 1, mode->pixel_rate);
>
> - h_blank_def = mode->hts_def - mode->width;
> - ctrl = v4l2_ctrl_new_std(handler, NULL, V4L2_CID_HBLANK, h_blank_def,
> - h_blank_def, 1, h_blank_def);
> - if (ctrl)
> - ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> + hblank_def = mode->hts_def - mode->width;
> + hblank_min = mode->hts_min - mode->width;
> + v4l2_ctrl_new_std(handler, &ov4689_ctrl_ops, V4L2_CID_HBLANK,
> + hblank_min, OV4689_HTS_MAX - mode->width,
> + OV4689_HTS_DIVIDER, hblank_def);
>
> vblank_def = mode->vts_def - mode->height;
> v4l2_ctrl_new_std(handler, &ov4689_ctrl_ops, V4L2_CID_VBLANK,

--
Regards,

Laurent Pinchart