Hi Dave, On Thu, Oct 06, 2022 at 12:33:01PM +0100, Dave Stevenson wrote: > Hi Jacopo. > > On Thu, 6 Oct 2022 at 10:41, Jacopo Mondi <jacopo@xxxxxxxxxx> wrote: > > > > Hi Dave > > > > On Wed, Oct 05, 2022 at 04:28:05PM +0100, Dave Stevenson wrote: > > > There's no reason why HBLANK has to be read-only as it > > > only changes the TIMING_HTS register in the sensor. > > > > > > Remove the READ_ONLY flag, and add the relevant handling > > > for it. > > > > > > The minimum value also varies based on whether continuous clock > > > mode is being used or not, so allow hblank_min to depend on > > > that. > > > > Interesting, do you know why they're different and why the continous > > version is smaller ? > > Dropping from HS to LP-11 and back to HS for non-continuous mode takes > a minimum amount of time, so the time per line on the MIPI bus is > increased. Whilst there is a FIFO between the pixel array and MIPI > block, having to expend that time on the MIPI side means that the FIFO > can overflow. > > I haven't found this behaviour documented, but I was trying to work > out the difference between this driver and our downstream driver [1] > in max frame rate. The default value for TIMING_HTS of 0x2d8 (doubled > to 1456 pixels) didn't work with this mainline driver, and it used > 0x2fd (1530 pixels). The CSI clock mode turned out to be the > difference. > The minimum HTS has therefore been left alone for non-continuous clock > mode, and the lower setting added for continuous clock. > Makes sense! Thanks for the explanation Please add my tag to v2 Reviewed-by: Jacopo Mondi <jacopo@xxxxxxxxxx> Thanks j > Dave > > [1] https://github.com/raspberrypi/linux/blob/rpi-5.15.y/drivers/media/i2c/ov9281.c > based on https://github.com/rockchip-linux/kernel/blob/develop-4.4/drivers/media/i2c/ov9281.c > > > > > > > Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> > > > --- > > > drivers/media/i2c/ov9282.c | 34 +++++++++++++++++++++------------- > > > 1 file changed, 21 insertions(+), 13 deletions(-) > > > > > > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c > > > index 12cbe401fd78..8e86aa7e4b2a 100644 > > > --- a/drivers/media/i2c/ov9282.c > > > +++ b/drivers/media/i2c/ov9282.c > > > @@ -22,6 +22,9 @@ > > > #define OV9282_MODE_STANDBY 0x00 > > > #define OV9282_MODE_STREAMING 0x01 > > > > > > +#define OV9282_REG_TIMING_HTS 0x380c > > > +#define OV9282_TIMING_HTS_MAX 0x7fff > > > + > > > /* Lines per frame */ > > > #define OV9282_REG_LPFR 0x380e > > > > > > @@ -99,7 +102,8 @@ struct ov9282_reg_list { > > > * struct ov9282_mode - ov9282 sensor mode structure > > > * @width: Frame width > > > * @height: Frame height > > > - * @hblank: Horizontal blanking in lines > > > + * @hblank_min: Minimum horizontal blanking in lines for non-continuous[0] and > > > + * continuous[1] clock modes > > > * @vblank: Vertical blanking in lines > > > * @vblank_min: Minimum vertical blanking in lines > > > * @vblank_max: Maximum vertical blanking in lines > > > @@ -109,7 +113,7 @@ struct ov9282_reg_list { > > > struct ov9282_mode { > > > u32 width; > > > u32 height; > > > - u32 hblank; > > > + u32 hblank_min[2]; > > > u32 vblank; > > > u32 vblank_min; > > > u32 vblank_max; > > > @@ -249,8 +253,6 @@ static const struct ov9282_reg mode_1280x720_regs[] = { > > > {0x3809, 0x00}, > > > {0x380a, 0x02}, > > > {0x380b, 0xd0}, > > > - {0x380c, 0x02}, > > > - {0x380d, 0xfd}, > > > {0x3810, 0x00}, > > > {0x3811, 0x08}, > > > {0x3812, 0x00}, > > > @@ -273,7 +275,7 @@ static const struct ov9282_mode supported_modes[] = { > > > { > > > .width = 1280, > > > .height = 720, > > > - .hblank = 250, > > > + .hblank_min = { 250, 176 }, > > > .vblank = 1022, > > > .vblank_min = 41, > > > .vblank_max = 51540, > > > @@ -399,15 +401,17 @@ static int ov9282_write_regs(struct ov9282 *ov9282, > > > static int ov9282_update_controls(struct ov9282 *ov9282, > > > const struct ov9282_mode *mode) > > > { > > > + u32 hblank_min; > > > int ret; > > > > > > ret = __v4l2_ctrl_s_ctrl(ov9282->link_freq_ctrl, mode->link_freq_idx); > > > if (ret) > > > return ret; > > > > > > - ret = __v4l2_ctrl_s_ctrl(ov9282->hblank_ctrl, mode->hblank); > > > - if (ret) > > > - return ret; > > > + hblank_min = mode->hblank_min[ov9282->noncontinuous_clock ? 0 : 1]; > > > + ret = __v4l2_ctrl_modify_range(ov9282->hblank_ctrl, hblank_min, > > > + OV9282_TIMING_HTS_MAX - mode->width, 1, > > > + hblank_min); > > > > > > return __v4l2_ctrl_modify_range(ov9282->vblank_ctrl, mode->vblank_min, > > > mode->vblank_max, 1, mode->vblank); > > > @@ -539,6 +543,10 @@ static int ov9282_set_ctrl(struct v4l2_ctrl *ctrl) > > > case V4L2_CID_VFLIP: > > > ret = ov9282_set_ctrl_vflip(ov9282, ctrl->val); > > > break; > > > + case V4L2_CID_HBLANK: > > > + ret = ov9282_write_reg(ov9282, OV9282_REG_TIMING_HTS, 2, > > > + (ctrl->val + ov9282->cur_mode->width) >> 1); > > > + break; > > > default: > > > dev_err(ov9282->dev, "Invalid control %d", ctrl->id); > > > ret = -EINVAL; > > > @@ -1033,6 +1041,7 @@ static int ov9282_init_controls(struct ov9282 *ov9282) > > > struct v4l2_ctrl_handler *ctrl_hdlr = &ov9282->ctrl_handler; > > > const struct ov9282_mode *mode = ov9282->cur_mode; > > > struct v4l2_fwnode_device_properties props; > > > + u32 hblank_min; > > > u32 lpfr; > > > int ret; > > > > > > @@ -1091,14 +1100,13 @@ static int ov9282_init_controls(struct ov9282 *ov9282) > > > if (ov9282->link_freq_ctrl) > > > ov9282->link_freq_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY; > > > > > > + hblank_min = mode->hblank_min[ov9282->noncontinuous_clock ? 0 : 1]; > > > ov9282->hblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr, > > > &ov9282_ctrl_ops, > > > V4L2_CID_HBLANK, > > > - OV9282_REG_MIN, > > > - OV9282_REG_MAX, > > > - 1, mode->hblank); > > > - if (ov9282->hblank_ctrl) > > > - ov9282->hblank_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY; > > > + hblank_min, > > > + OV9282_TIMING_HTS_MAX - mode->width, > > > + 1, hblank_min); > > > > > > ret = v4l2_fwnode_device_parse(ov9282->dev, &props); > > > if (!ret) { > > > -- > > > 2.34.1 > > >
