Re: [PATCH 08/13] media: i2c: imx214: Add vblank and hblank controls
From: André
Date: Sun Oct 06 2024 - 17:42:08 EST
Hi Dave,
Am Freitag, dem 13.09.2024 um 18:40 +0100 schrieb Dave Stevenson:
> On Thu, 12 Sept 2024 at 15:51, Dave Stevenson
> <dave.stevenson@xxxxxxxxxxxxxxx> wrote:
> >
> > Hi André & Ricardo
> >
> > On Thu, 12 Sept 2024 at 14:41, Ricardo Ribalda Delgado
> > <ribalda@xxxxxxxxxx> wrote:
> > >
> > > Hi
> > >
> > > Arent you missing some chage in enum_frame_interval?
> >
> > Raw sensors shouldn't be using [enum|set|get]_frame_interval at all
> > https://www.kernel.org/doc/html/latest/userspace-api/media/drivers/camera-sensor.html#frame-interval-configuration
> >
> > The question now is how to handle the backwards compatibility for
> > any userspace app that might be using this driver and expecting to
> > use the frame_interval calls.
> > Seeing as it only ever allowed a fixed value of 30fps, leaving it
> > as is with a comment as to why it is there would be reasonable in
> > my view.
Should the comment be added in this commit?
And what exactly should the comment say?
> >
> > > On Mon, Sep 2, 2024 at 11:53 PM André Apitzsch via B4 Relay
> > > <devnull+git.apitzsch.eu@xxxxxxxxxx> wrote:
> > > >
> > > > From: André Apitzsch <git@xxxxxxxxxxx>
> > > >
> > > > Add vblank control to allow changing the framerate /
> > > > higher exposure values.
> > > >
> > > > The vblank and hblank controls are needed for libcamera
> > > > support.
> > > >
> > > > While at it, fix the minimal exposure time according to the
> > > > datasheet.
> > > >
> > > > Signed-off-by: André Apitzsch <git@xxxxxxxxxxx>
> > > > ---
> > > > drivers/media/i2c/imx214.c | 112
> > > > ++++++++++++++++++++++++++++++++++++---------
> > > > 1 file changed, 91 insertions(+), 21 deletions(-)
> > > >
> > > > diff --git a/drivers/media/i2c/imx214.c
> > > > b/drivers/media/i2c/imx214.c
> > > > index 3b422cddbdce..9f5a57aebb86 100644
> > > > --- a/drivers/media/i2c/imx214.c
> > > > +++ b/drivers/media/i2c/imx214.c
> > > > @@ -34,11 +34,18 @@
> > > >
> > > > /* V-TIMING internal */
> > > > #define IMX214_REG_FRM_LENGTH_LINES CCI_REG16(0x0340)
> > > > +#define IMX214_VTS_MAX 0xffff
> > > > +
> > > > +#define IMX214_VBLANK_MIN 4
> > > > +
> > > > +/* HBLANK control - read only */
> > > > +#define IMX214_PPL_DEFAULT 5008
> > > >
> > > > /* Exposure control */
> > > > #define IMX214_REG_EXPOSURE CCI_REG16(0x0202)
> > > > -#define IMX214_EXPOSURE_MIN 0
> > > > -#define IMX214_EXPOSURE_MAX 3184
> > > > +#define IMX214_EXPOSURE_OFFSET 10
> > > > +#define IMX214_EXPOSURE_MIN 1
> > > > +#define IMX214_EXPOSURE_MAX (IMX214_VTS_MAX -
> > > > IMX214_EXPOSURE_OFFSET)
> > > > #define IMX214_EXPOSURE_STEP 1
> > > > #define IMX214_EXPOSURE_DEFAULT 3184
> > > > #define IMX214_REG_EXPOSURE_RATIO CCI_REG8(0x0222)
> > > > @@ -189,6 +196,8 @@ struct imx214 {
> > > > struct v4l2_ctrl_handler ctrls;
> > > > struct v4l2_ctrl *pixel_rate;
> > > > struct v4l2_ctrl *link_freq;
> > > > + struct v4l2_ctrl *vblank;
> > > > + struct v4l2_ctrl *hblank;
> > > > struct v4l2_ctrl *exposure;
> > > > struct v4l2_ctrl *unit_size;
> > > >
> > > > @@ -205,8 +214,6 @@ static const struct cci_reg_sequence
> > > > mode_4096x2304[] = {
> > > > { IMX214_REG_HDR_MODE, IMX214_HDR_MODE_OFF },
> > > > { IMX214_REG_HDR_RES_REDUCTION,
> > > > IMX214_HDR_RES_REDU_THROUGH },
> > > > { IMX214_REG_EXPOSURE_RATIO, 1 },
> > > > - { IMX214_REG_FRM_LENGTH_LINES, 3194 },
> > > > - { IMX214_REG_LINE_LENGTH_PCK, 5008 },
> > > > { IMX214_REG_X_ADD_STA, 56 },
> > > > { IMX214_REG_Y_ADD_STA, 408 },
> > > > { IMX214_REG_X_ADD_END, 4151 },
> > > > @@ -277,8 +284,6 @@ static const struct cci_reg_sequence
> > > > mode_1920x1080[] = {
> > > > { IMX214_REG_HDR_MODE, IMX214_HDR_MODE_OFF },
> > > > { IMX214_REG_HDR_RES_REDUCTION,
> > > > IMX214_HDR_RES_REDU_THROUGH },
> > > > { IMX214_REG_EXPOSURE_RATIO, 1 },
> > > > - { IMX214_REG_FRM_LENGTH_LINES, 3194 },
> > > > - { IMX214_REG_LINE_LENGTH_PCK, 5008 },
> > > > { IMX214_REG_X_ADD_STA, 1144 },
> > > > { IMX214_REG_Y_ADD_STA, 1020 },
> > > > { IMX214_REG_X_ADD_END, 3063 },
> > > > @@ -362,6 +367,7 @@ static const struct cci_reg_sequence
> > > > mode_table_common[] = {
> > > > { IMX214_REG_ORIENTATION, 0 },
> > > > { IMX214_REG_MASK_CORR_FRAMES, IMX214_CORR_FRAMES_MASK
> > > > },
> > > > { IMX214_REG_FAST_STANDBY_CTRL, 1 },
> > > > + { IMX214_REG_LINE_LENGTH_PCK, IMX214_PPL_DEFAULT },
> > > > { CCI_REG8(0x4550), 0x02 },
> > > > { CCI_REG8(0x4601), 0x00 },
> > > > { CCI_REG8(0x4642), 0x05 },
> > > > @@ -465,18 +471,24 @@ static const struct cci_reg_sequence
> > > > mode_table_common[] = {
> > > > static const struct imx214_mode {
> > > > u32 width;
> > > > u32 height;
> > > > +
> > > > + /* V-timing */
> > > > + unsigned int vts_def;
> > > > +
> > > > unsigned int num_of_regs;
> > > > const struct cci_reg_sequence *reg_table;
> > > > } imx214_modes[] = {
> > > > {
> > > > .width = 4096,
> > > > .height = 2304,
> > > > + .vts_def = 3194,
> > > > .num_of_regs = ARRAY_SIZE(mode_4096x2304),
> > > > .reg_table = mode_4096x2304,
> > > > },
> > > > {
> > > > .width = 1920,
> > > > .height = 1080,
> > > > + .vts_def = 3194,
> > > > .num_of_regs = ARRAY_SIZE(mode_1920x1080),
> > > > .reg_table = mode_1920x1080,
> > > > },
> > > > @@ -629,6 +641,37 @@ static int imx214_set_format(struct
> > > > v4l2_subdev *sd,
> > > > __crop->width = mode->width;
> > > > __crop->height = mode->height;
> > > >
> > > > + if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> > > > + int exposure_max;
> > > > + int exposure_def;
> > > > + int hblank;
> > > > +
> > > > + /* Update limits and set FPS to default */
> > > > + __v4l2_ctrl_modify_range(imx214->vblank,
> > > > IMX214_VBLANK_MIN,
> > > > + IMX214_VTS_MAX - mode-
> > > > >height, 1,
> > > > + mode->vts_def - mode-
> > > > >height);
> > > > + __v4l2_ctrl_s_ctrl(imx214->vblank,
> > > > + mode->vts_def - mode-
> > > > >height);
> > > > +
> > > > + /* Update max exposure while meeting expected
> > > > vblanking */
> > > > + exposure_max = mode->vts_def -
> > > > IMX214_EXPOSURE_OFFSET;
> > > > + exposure_def = (exposure_max <
> > > > IMX214_EXPOSURE_DEFAULT) ?
> > > > + exposure_max : IMX214_EXPOSURE_DEFAULT;
> > > > + __v4l2_ctrl_modify_range(imx214->exposure,
> > > > + imx214->exposure-
> > > > >minimum,
> > > > + exposure_max, imx214-
> > > > >exposure->step,
> > > > + exposure_def);
> > > > +
> > > > + /*
> > > > + * Currently PPL is fixed to
> > > > IMX214_PPL_DEFAULT, so hblank
> > > > + * depends on mode->width only, and is not
> > > > changeble in any
> > > > + * way other than changing the mode.
> > > > + */
> > > > + hblank = IMX214_PPL_DEFAULT - mode->width;
> > > > + __v4l2_ctrl_modify_range(imx214->hblank,
> > > > hblank, hblank, 1,
> > > > + hblank);
> > > > + }
> > > > +
> > > > return 0;
> > > > }
> > > >
> > > > @@ -678,8 +721,25 @@ static int imx214_set_ctrl(struct
> > > > v4l2_ctrl *ctrl)
> > > > {
> > > > struct imx214 *imx214 = container_of(ctrl->handler,
> > > > struct imx214,
> > > > ctrls);
> > > > + const struct v4l2_mbus_framefmt *format;
> > > > + struct v4l2_subdev_state *state;
> > > > int ret;
> > > >
> > > > + state = v4l2_subdev_get_locked_active_state(&imx214-
> > > > >sd);
> > > > + format = v4l2_subdev_state_get_format(state, 0);
> > > > +
> > > > + if (ctrl->id == V4L2_CID_VBLANK) {
> > > > + int exposure_max, exposure_def;
> > > > +
> > > > + /* Update max exposure while meeting expected
> > > > vblanking */
> > > > + exposure_max = format->height + ctrl->val -
> > > > IMX214_EXPOSURE_OFFSET;
> > > > + exposure_def = min(exposure_max,
> > > > IMX214_EXPOSURE_DEFAULT);
> > > > + __v4l2_ctrl_modify_range(imx214->exposure,
> > > > + imx214->exposure-
> > > > >minimum,
> > > > + exposure_max, imx214-
> > > > >exposure->step,
> > > > + exposure_def);
> > > > + }
> > > > +
> > > > /*
> > > > * Applying V4L2 control value only happens
> > > > * when power is up for streaming
> > > > @@ -691,7 +751,10 @@ static int imx214_set_ctrl(struct
> > > > v4l2_ctrl *ctrl)
> > > > case V4L2_CID_EXPOSURE:
> > > > cci_write(imx214->regmap, IMX214_REG_EXPOSURE,
> > > > ctrl->val, &ret);
> > > > break;
> > > > -
> > > > + case V4L2_CID_VBLANK:
> > > > + cci_write(imx214->regmap,
> > > > IMX214_REG_FRM_LENGTH_LINES,
> > > > + format->height + ctrl->val, &ret);
> >
> > My datasheet says this register is "set up in multiples of 2".
> > (LINE_LENGTH_PCK for HBLANK is "set in multiples of 8")
> >
> > I don't have one of these modules, but is that saying only
> > multiples
> > of 2 are permitted (in which case the step size for the control
> > needs
> > to reflect that), or that setting a value of N is interpreted by
> > the
> > hardware as 2N?
> > Do all the numbers with PIXEL_RATE work out correctly in the frame
> > rate calcs?
>
> Answering my own question, PIXEL_RATE looks dubious.
>
> The original code had LINE_LENGTH_PCK as 5008, and FRAME_LENGTH_LINES
> as 3194. If enum_frame_intervals is to be believed, then it delivered
> 30fps.
> 5008 * 3194 * 30 = 479,866,560 Pix/s.
>
> The driver defines IMX214_DEFAULT_LINK_FREQ 480000000, and then
> IMX214_DEFAULT_PIXEL_RATE ((IMX214_DEFAULT_LINK_FREQ * 8LL) / 10),
> which works out as 384MPix/s. (Presumably the 8 is 4 lanes and DDR,
> but it's not obvious)
>
> Parsing the PLL registers with the defined 24MHz input. We're in
> single PLL mode, so MIPI frequency is directly linked to pixel rate.
> VTCK ends up being 1200MHz, and VTPXCK and OPPXCK both are 120MHz.
> Section 5.3 "Frame rate calculation formula" says "Pixel rate
> [pixels/s] = VTPXCK [MHz] * 4", so 120 * 4 = 480MPix/s, which
> basically agrees with my number above.
>
> 3.1.4. MIPI global timing setting says "Output bitrate = OPPXCK * reg
> 0x113[7:0]", so 120MHz * 10, or 1200Mbit/s. That would be a link
> frequency of 600MHz due to DDR.
> That also matches to 480MPix/s * 10bpp / 4 lanes / 2 for DDR
>
> Registers 0x0820-0823 are meant to define the target CSI2 bitrate,
> and are set to 0x12c00000, or 314,572,800 decimal. I can't get that
> to square with the above.
>
>
> So my conclusion is that both PIXEL_RATE and LINK_FREQUENCY are
> wrong, however the relationship used to define them looks to be
> correct.
> Correct IMX214_DEFAULT_LINK_FREQ to 600MHz, and all should be good.
Will do that. Should it be done in this commit or in a separat one?
> However you almost certainly want to set IMX214_VBLANK_MIN to
> something significantly greater than 4.
Any recommendation for the new IMX214_VBLANK_MIN value?
Best regards,
André
>
> Dave
>
> > Reading the spec sheet that 30fps is the max frame rate at full res
> > (4096x2304), and the driver was setting a value of 3194 to this
> > register, I don't see it being interpreted as 2N. Then again having
> > VBLANK at 890 seems pretty high.
> >
> > > > + break;
> > > > default:
> > > > ret = -EINVAL;
> > > > }
> > > > @@ -714,8 +777,11 @@ static int imx214_ctrls_init(struct imx214
> > > > *imx214)
> > > > .width = 1120,
> > > > .height = 1120,
> > > > };
> > > > + const struct imx214_mode *mode = &imx214_modes[0];
> > > > struct v4l2_fwnode_device_properties props;
> > > > struct v4l2_ctrl_handler *ctrl_hdlr;
> > > > + int exposure_max, exposure_def;
> > > > + int hblank;
> > > > int ret;
> > > >
> > > > ret = v4l2_fwnode_device_parse(imx214->dev, &props);
> > > > @@ -723,7 +789,7 @@ static int imx214_ctrls_init(struct imx214
> > > > *imx214)
> > > > return ret;
> > > >
> > > > ctrl_hdlr = &imx214->ctrls;
> > > > - ret = v4l2_ctrl_handler_init(&imx214->ctrls, 6);
> > > > + ret = v4l2_ctrl_handler_init(&imx214->ctrls, 8);
> > > > if (ret)
> > > > return ret;
> > > >
> > > > @@ -739,22 +805,26 @@ static int imx214_ctrls_init(struct
> > > > imx214 *imx214)
> > > > if (imx214->link_freq)
> > > > imx214->link_freq->flags |=
> > > > V4L2_CTRL_FLAG_READ_ONLY;
> > > >
> > > > - /*
> > > > - * WARNING!
> > > > - * Values obtained reverse engineering blobs and/or
> > > > devices.
> > > > - * Ranges and functionality might be wrong.
> > > > - *
> > > > - * Sony, please release some register set documentation
> > > > for the
> > > > - * device.
> > > > - *
> > > > - * Yours sincerely, Ricardo.
> > > > - */
> > >
> > > I would like to keep this comment until there is a public
> > > document available.
> >
> > I suspect you'll be waiting forever for a document to be officially
> > released.
> >
> > I have a datasheet for IMX214, and I believe Kieran and Jacopo do
> > too.
> > Which specific values do you wish to be verified?
> >
> > >
> > > > + /* Initial vblank/hblank/exposure parameters based on
> > > > current mode */
> > > > + imx214->vblank = v4l2_ctrl_new_std(ctrl_hdlr,
> > > > &imx214_ctrl_ops,
> > > > + V4L2_CID_VBLANK,
> > > > IMX214_VBLANK_MIN,
> >
> > IMX214_VBLANK_MIN being 4 feels plausible, but pretty low.
> > I read the datasheet to say there are 4 embedded data lines per
> > image.
> > Seeing as you have STATS data output enabled as well that makes 5
> > lines of non-image data per frame, but you're only adding blanking
> > time for 4 lines.
> >
> > As noted above, I think you've also increased the max frame rate
> > significantly above that quoted by Sony. Has that been actually
> > exercised and confirmed to function correctly?
> >
> > Dave
> >
> > > > + IMX214_VTS_MAX -
> > > > mode->height, 1,
> > > > + mode->vts_def -
> > > > mode->height);
> > > > +
> > > > + hblank = IMX214_PPL_DEFAULT - mode->width;
> > > > + imx214->hblank = v4l2_ctrl_new_std(ctrl_hdlr,
> > > > &imx214_ctrl_ops,
> > > > + V4L2_CID_HBLANK,
> > > > hblank, hblank,
> > > > + 1, hblank);
> > > > + if (imx214->hblank)
> > > > + imx214->hblank->flags |=
> > > > V4L2_CTRL_FLAG_READ_ONLY;
> > > > +
> > > > + exposure_max = mode->vts_def - IMX214_EXPOSURE_OFFSET;
> > > > + exposure_def = min(exposure_max,
> > > > IMX214_EXPOSURE_DEFAULT);
> > > > imx214->exposure = v4l2_ctrl_new_std(ctrl_hdlr,
> > > > &imx214_ctrl_ops,
> > > > V4L2_CID_EXPOSURE,
> > > > -
> > > > IMX214_EXPOSURE_MIN,
> > > > -
> > > > IMX214_EXPOSURE_MAX,
> > > > +
> > > > IMX214_EXPOSURE_MIN, exposure_max,
> > > >
> > > > IMX214_EXPOSURE_STEP,
> > > > -
> > > > IMX214_EXPOSURE_DEFAULT);
> > > > + exposure_def);
> > > >
> > > > imx214->unit_size =
> > > > v4l2_ctrl_new_std_compound(ctrl_hdlr,
> > > > NULL,
> > > >
> > > > --
> > > > 2.46.0
> > > >
> > > >
> > >