Re: [PATCH v4] media: i2c: imx334: support lower bandwidth mode

[Sakari Ailus <sakari.ailus@iki.fi>]

Hi Shravan,

On Mon, Sep 26, 2022 at 11:32:31AM +0000, Shravan.Chippa@microchip.com wrote:
> 
> 
> > -----Original Message-----
> > From: Sakari Ailus <sakari.ailus@iki.fi>
> > Sent: 20 September 2022 05:44 PM
> > To: shravan Chippa - I35088 <Shravan.Chippa@microchip.com>
> > Cc: paul.j.murphy@intel.com; daniele.alessandrelli@intel.com;
> > mchehab@kernel.org; linux-media@vger.kernel.org; linux-
> > kernel@vger.kernel.org; Conor Dooley - M52691
> > <Conor.Dooley@microchip.com>; Battu Prakash Reddy - I30399
> > <Prakash.Battu@microchip.com>
> > Subject: Re: [PATCH v4] media: i2c: imx334: support lower bandwidth mode
> > 
> > [Some people who received this message don't often get email from
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> > 
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the
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This looks like a mail system problem.

> > 
> > Hi Shravan,
> > 
> > Thanks for the patch.
> > 
> > On Tue, Sep 20, 2022 at 10:40:23AM +0530, shravan kumar wrote:
> > > From: Shravan Chippa <shravan.chippa@microchip.com>
> > >
> > > Some platforms may not be capable of supporting the bandwidth required
> > > for 12 bit or 3840x2160 resolutions.
> > >
> > > Add support for dynamically selecting 10 bit and 1920x1080 resolutions
> > > while leaving the existing configuration as default
> > >
> > > CC: Conor Dooley <conor.dooley@microchip.com>
> > > Signed-off-by: Prakash Battu <Prakash.Battu@microchip.com>
> > > Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
> > > ---
> > >
> > > V3 -> V4
> > > - Make the 12 bit and 3840x2160 as default
> > > - Set bus code SRGGB12 if set format fails
> > >
> > > V2 -> V3
> > > - Fixed the warning reported by kernel test robot
> > >
> > > V1 -> V2
> > > - Addressed the review comment given by Jacopo Mondi,
> > >   Which has bug in imx334_enum_frame_size() loop function,
> > > - Renamed array codes[] to imx334_mbus_codes[]
> > > - Modified supported_modes[] to get higher resolution first
> > >
> > > ---
> > >  drivers/media/i2c/imx334.c | 302
> > > +++++++++++++++++++++++++++++++++----
> > >  1 file changed, 276 insertions(+), 26 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/imx334.c b/drivers/media/i2c/imx334.c
> > > index 062125501788..df2f1821569e 100644
> > > --- a/drivers/media/i2c/imx334.c
> > > +++ b/drivers/media/i2c/imx334.c
> > > @@ -79,7 +79,6 @@ struct imx334_reg_list {
> > >   * struct imx334_mode - imx334 sensor mode structure
> > >   * @width: Frame width
> > >   * @height: Frame height
> > > - * @code: Format code
> > >   * @hblank: Horizontal blanking in lines
> > >   * @vblank: Vertical blanking in lines
> > >   * @vblank_min: Minimal vertical blanking in lines @@ -91,7 +90,6 @@
> > > struct imx334_reg_list {  struct imx334_mode {
> > >       u32 width;
> > >       u32 height;
> > > -     u32 code;
> > >       u32 hblank;
> > >       u32 vblank;
> > >       u32 vblank_min;
> > > @@ -119,6 +117,7 @@ struct imx334_mode {
> > >   * @vblank: Vertical blanking in lines
> > >   * @cur_mode: Pointer to current selected sensor mode
> > >   * @mutex: Mutex for serializing sensor controls
> > > + * @cur_code: current selected format code
> > >   * @streaming: Flag indicating streaming state
> > >   */
> > >  struct imx334 {
> > > @@ -140,6 +139,7 @@ struct imx334 {
> > >       u32 vblank;
> > >       const struct imx334_mode *cur_mode;
> > >       struct mutex mutex;
> > > +     u32 cur_code;
> > >       bool streaming;
> > >  };
> > >
> > > @@ -147,6 +147,169 @@ static const s64 link_freq[] = {
> > >       IMX334_LINK_FREQ,
> > >  };
> > >
> > > +/* Sensor mode registers */
> > > +static const struct imx334_reg mode_1920x1080_regs[] = {
> > > +     {0x3000, 0x01},
> > > +     {0x3018, 0x04},
> > > +     {0x3030, 0xCA},
> > > +     {0x3031, 0x08},
> > > +     {0x3032, 0x00},
> > > +     {0x3034, 0x4C},
> > > +     {0x3035, 0x04},
> > > +     {0x302C, 0xF0},
> > > +     {0x302D, 0x03},
> > > +     {0x302E, 0x80},
> > > +     {0x302F, 0x07},
> > > +     {0x3074, 0xCC},
> > > +     {0x3075, 0x02},
> > > +     {0x308E, 0xCD},
> > > +     {0x308F, 0x02},
> > > +     {0x3076, 0x38},
> > > +     {0x3077, 0x04},
> > > +     {0x3090, 0x38},
> > > +     {0x3091, 0x04},
> > > +     {0x3308, 0x38},
> > > +     {0x3309, 0x04},
> > > +     {0x30C6, 0x00},
> > > +     {0x30C7, 0x00},
> > > +     {0x30CE, 0x00},
> > > +     {0x30CF, 0x00},
> > > +     {0x30D8, 0x18},
> > > +     {0x30D9, 0x0A},
> > > +     {0x304C, 0x00},
> > > +     {0x304E, 0x00},
> > > +     {0x304F, 0x00},
> > > +     {0x3050, 0x00},
> > > +     {0x30B6, 0x00},
> > > +     {0x30B7, 0x00},
> > > +     {0x3116, 0x08},
> > > +     {0x3117, 0x00},
> > > +     {0x31A0, 0x20},
> > > +     {0x31A1, 0x0F},
> > > +     {0x300C, 0x3B},
> > > +     {0x300D, 0x29},
> > > +     {0x314C, 0x29},
> > > +     {0x314D, 0x01},
> > > +     {0x315A, 0x0A},
> > > +     {0x3168, 0xA0},
> > > +     {0x316A, 0x7E},
> > > +     {0x319E, 0x02},
> > > +     {0x3199, 0x00},
> > > +     {0x319D, 0x00},
> > > +     {0x31DD, 0x03},
> > > +     {0x3300, 0x00},
> > > +     {0x341C, 0xFF},
> > > +     {0x341D, 0x01},
> > > +     {0x3A01, 0x03},
> > > +     {0x3A18, 0x7F},
> > > +     {0x3A19, 0x00},
> > > +     {0x3A1A, 0x37},
> > > +     {0x3A1B, 0x00},
> > > +     {0x3A1C, 0x37},
> > > +     {0x3A1D, 0x00},
> > > +     {0x3A1E, 0xF7},
> > > +     {0x3A1F, 0x00},
> > > +     {0x3A20, 0x3F},
> > > +     {0x3A21, 0x00},
> > > +     {0x3A20, 0x6F},
> > > +     {0x3A21, 0x00},
> > > +     {0x3A20, 0x3F},
> > > +     {0x3A21, 0x00},
> > > +     {0x3A20, 0x5F},
> > > +     {0x3A21, 0x00},
> > > +     {0x3A20, 0x2F},
> > > +     {0x3A21, 0x00},
> > > +     {0x3078, 0x02},
> > > +     {0x3079, 0x00},
> > > +     {0x307A, 0x00},
> > > +     {0x307B, 0x00},
> > > +     {0x3080, 0x02},
> > > +     {0x3081, 0x00},
> > > +     {0x3082, 0x00},
> > > +     {0x3083, 0x00},
> > > +     {0x3088, 0x02},
> > > +     {0x3094, 0x00},
> > > +     {0x3095, 0x00},
> > > +     {0x3096, 0x00},
> > > +     {0x309B, 0x02},
> > > +     {0x309C, 0x00},
> > > +     {0x309D, 0x00},
> > > +     {0x309E, 0x00},
> > > +     {0x30A4, 0x00},
> > > +     {0x30A5, 0x00},
> > > +     {0x3288, 0x21},
> > > +     {0x328A, 0x02},
> > > +     {0x3414, 0x05},
> > > +     {0x3416, 0x18},
> > > +     {0x35AC, 0x0E},
> > > +     {0x3648, 0x01},
> > > +     {0x364A, 0x04},
> > > +     {0x364C, 0x04},
> > > +     {0x3678, 0x01},
> > > +     {0x367C, 0x31},
> > > +     {0x367E, 0x31},
> > > +     {0x3708, 0x02},
> > > +     {0x3714, 0x01},
> > > +     {0x3715, 0x02},
> > > +     {0x3716, 0x02},
> > > +     {0x3717, 0x02},
> > > +     {0x371C, 0x3D},
> > > +     {0x371D, 0x3F},
> > > +     {0x372C, 0x00},
> > > +     {0x372D, 0x00},
> > > +     {0x372E, 0x46},
> > > +     {0x372F, 0x00},
> > > +     {0x3730, 0x89},
> > > +     {0x3731, 0x00},
> > > +     {0x3732, 0x08},
> > > +     {0x3733, 0x01},
> > > +     {0x3734, 0xFE},
> > > +     {0x3735, 0x05},
> > > +     {0x375D, 0x00},
> > > +     {0x375E, 0x00},
> > > +     {0x375F, 0x61},
> > > +     {0x3760, 0x06},
> > > +     {0x3768, 0x1B},
> > > +     {0x3769, 0x1B},
> > > +     {0x376A, 0x1A},
> > > +     {0x376B, 0x19},
> > > +     {0x376C, 0x18},
> > > +     {0x376D, 0x14},
> > > +     {0x376E, 0x0F},
> > > +     {0x3776, 0x00},
> > > +     {0x3777, 0x00},
> > > +     {0x3778, 0x46},
> > > +     {0x3779, 0x00},
> > > +     {0x377A, 0x08},
> > > +     {0x377B, 0x01},
> > > +     {0x377C, 0x45},
> > > +     {0x377D, 0x01},
> > > +     {0x377E, 0x23},
> > > +     {0x377F, 0x02},
> > > +     {0x3780, 0xD9},
> > > +     {0x3781, 0x03},
> > > +     {0x3782, 0xF5},
> > > +     {0x3783, 0x06},
> > > +     {0x3784, 0xA5},
> > > +     {0x3788, 0x0F},
> > > +     {0x378A, 0xD9},
> > > +     {0x378B, 0x03},
> > > +     {0x378C, 0xEB},
> > > +     {0x378D, 0x05},
> > > +     {0x378E, 0x87},
> > > +     {0x378F, 0x06},
> > > +     {0x3790, 0xF5},
> > > +     {0x3792, 0x43},
> > > +     {0x3794, 0x7A},
> > > +     {0x3796, 0xA1},
> > > +     {0x37B0, 0x37},
> > > +     {0x3E04, 0x0E},
> > > +     {0x30E8, 0x50},
> > > +     {0x30E9, 0x00},
> > > +     {0x3E04, 0x0E},
> > > +     {0x3002, 0x00},
> > > +};
> > > +
> > >  /* Sensor mode registers */
> > >  static const struct imx334_reg mode_3840x2160_regs[] = {
> > >       {0x3000, 0x01},
> > > @@ -243,20 +406,56 @@ static const struct imx334_reg
> > mode_3840x2160_regs[] = {
> > >       {0x3a00, 0x01},
> > >  };
> > >
> > > +static const struct imx334_reg raw10_framefmt_regs[] = {
> > > +     {0x3050, 0x00},
> > > +     {0x319D, 0x00},
> > > +     {0x341C, 0xFF},
> > > +     {0x341D, 0x01},
> > > +};
> > > +
> > > +static const struct imx334_reg raw12_framefmt_regs[] = {
> > > +     {0x3050, 0x01},
> > > +     {0x319D, 0x01},
> > > +     {0x341C, 0x47},
> > > +     {0x341D, 0x00},
> > > +};
> > > +
> > > +/*
> > > + * The supported BUS formats.
> > > + */
> > > +static const u32 imx334_mbus_codes[] = {
> > > +     MEDIA_BUS_FMT_SRGGB12_1X12,
> > > +     MEDIA_BUS_FMT_SRGGB10_1X10,
> > > +};
> > > +
> > >  /* Supported sensor mode configurations */ -static const struct
> > > imx334_mode supported_mode = {
> > > -     .width = 3840,
> > > -     .height = 2160,
> > > -     .hblank = 560,
> > > -     .vblank = 2340,
> > > -     .vblank_min = 90,
> > > -     .vblank_max = 132840,
> > > -     .pclk = 594000000,
> > > -     .link_freq_idx = 0,
> > > -     .code = MEDIA_BUS_FMT_SRGGB12_1X12,
> > > -     .reg_list = {
> > > -             .num_of_regs = ARRAY_SIZE(mode_3840x2160_regs),
> > > -             .regs = mode_3840x2160_regs,
> > > +static const struct imx334_mode supported_modes[] = {
> > > +     {
> > > +             .width = 3840,
> > > +             .height = 2160,
> > > +             .hblank = 560,
> > > +             .vblank = 2340,
> > > +             .vblank_min = 90,
> > > +             .vblank_max = 132840,
> > > +             .pclk = 594000000,
> > > +             .link_freq_idx = 0,
> > > +             .reg_list = {
> > > +                     .num_of_regs = ARRAY_SIZE(mode_3840x2160_regs),
> > > +                     .regs = mode_3840x2160_regs,
> > > +             },
> > > +     }, {
> > > +             .width = 1920,
> > > +             .height = 1080,
> > > +             .hblank = 560,
> > > +             .vblank = 1170,
> > > +             .vblank_min = 90,
> > > +             .vblank_max = 132840,
> > > +             .pclk = 594000000,
> > > +             .link_freq_idx = 0,
> > > +             .reg_list = {
> > > +                     .num_of_regs = ARRAY_SIZE(mode_1920x1080_regs),
> > > +                     .regs = mode_1920x1080_regs,
> > > +             },
> > >       },
> > >  };
> > >
> > > @@ -506,10 +705,10 @@ static int imx334_enum_mbus_code(struct
> > v4l2_subdev *sd,
> > >                                struct v4l2_subdev_state *sd_state,
> > >                                struct v4l2_subdev_mbus_code_enum
> > > *code)  {
> > > -     if (code->index > 0)
> > > +     if (code->index >= ARRAY_SIZE(imx334_mbus_codes))
> > >               return -EINVAL;
> > >
> > > -     code->code = supported_mode.code;
> > > +     code->code = imx334_mbus_codes[code->index];
> > >
> > >       return 0;
> > >  }
> > > @@ -526,15 +725,22 @@ static int imx334_enum_frame_size(struct
> > v4l2_subdev *sd,
> > >                                 struct v4l2_subdev_state *sd_state,
> > >                                 struct v4l2_subdev_frame_size_enum
> > > *fsize)  {
> > > -     if (fsize->index > 0)
> > > +     unsigned int i;
> > > +
> > > +     if (fsize->index >= ARRAY_SIZE(supported_modes))
> > >               return -EINVAL;
> > >
> > > -     if (fsize->code != supported_mode.code)
> > > +     for (i = 0; i < ARRAY_SIZE(imx334_mbus_codes); ++i) {
> > > +             if (imx334_mbus_codes[i] == fsize->code)
> > > +                     break;
> > > +     }
> > > +
> > > +     if (i == ARRAY_SIZE(imx334_mbus_codes))
> > >               return -EINVAL;
> > >
> > > -     fsize->min_width = supported_mode.width;
> > > +     fsize->min_width = supported_modes[fsize->index].width;
> > >       fsize->max_width = fsize->min_width;
> > > -     fsize->min_height = supported_mode.height;
> > > +     fsize->min_height = supported_modes[fsize->index].height;
> > >       fsize->max_height = fsize->min_height;
> > >
> > >       return 0;
> > > @@ -553,7 +759,7 @@ static void imx334_fill_pad_format(struct imx334
> > > *imx334,  {
> > >       fmt->format.width = mode->width;
> > >       fmt->format.height = mode->height;
> > > -     fmt->format.code = mode->code;
> > > +     fmt->format.code = imx334->cur_code;
> > >       fmt->format.field = V4L2_FIELD_NONE;
> > >       fmt->format.colorspace = V4L2_COLORSPACE_RAW;
> > >       fmt->format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT; @@ -591,6
> > > +797,21 @@ static int imx334_get_pad_format(struct v4l2_subdev *sd,
> > >       return 0;
> > >  }
> > >
> > > +static int imx334_get_format_code(struct imx334 *imx334, struct
> > > +v4l2_subdev_format *fmt) {
> > > +     unsigned int i;
> > > +
> > > +     for (i = 0; i < ARRAY_SIZE(imx334_mbus_codes); i++) {
> > > +             if (imx334_mbus_codes[i] == fmt->format.code)
> > 
> > If you return here, you can remove the check below.
> This function taken ref from imx219 driver.
> And suggested by given by Jacopo Mondi
> Change in v2
> > 
> > > +                     break;
> > > +     }
> > > +
> > > +     if (i >= ARRAY_SIZE(imx334_mbus_codes))
> > > +             i = 0;
> > > +
> > > +     return imx334_mbus_codes[i];
> > > +}
> > > +
> > >  /**
> > >   * imx334_set_pad_format() - Set subdevice pad format
> > >   * @sd: pointer to imx334 V4L2 sub-device structure @@ -609,7 +830,13
> > > @@ static int imx334_set_pad_format(struct v4l2_subdev *sd,
> > >
> > >       mutex_lock(&imx334->mutex);
> > >
> > > -     mode = &supported_mode;
> > > +     imx334->cur_code = imx334_get_format_code(imx334, fmt);
> > 
> > This should be done only for the active format.
> Are you expecting  if condiftion to check the current bus code with set_pad_fromat bus code?

Only assign the cur_code field when setting the active format.

> > 
> > > +
> > > +     mode = v4l2_find_nearest_size(supported_modes,
> > > +                                   ARRAY_SIZE(supported_modes),
> > > +                                   width, height,
> > > +                                   fmt->format.width,
> > > + fmt->format.height);
> > > +
> > >       imx334_fill_pad_format(imx334, mode, fmt);
> > >
> > >       if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) { @@ -617,7 +844,7
> > @@
> > > static int imx334_set_pad_format(struct v4l2_subdev *sd,
> > >
> > >               framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
> > >               *framefmt = fmt->format;
> > > -     } else {
> > > +     } else if (imx334->cur_mode != mode) {

The mbus code no longer defines the mode. I think you'll need to take this
into account (pixel rate and link frequency?).

> > >               ret = imx334_update_controls(imx334, mode);
> > >               if (!ret)
> > >                       imx334->cur_mode = mode; @@ -642,11 +869,26 @@
> > > static int imx334_init_pad_cfg(struct v4l2_subdev *sd,
> > >       struct v4l2_subdev_format fmt = { 0 };
> > >
> > >       fmt.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY :
> > V4L2_SUBDEV_FORMAT_ACTIVE;
> > > -     imx334_fill_pad_format(imx334, &supported_mode, &fmt);
> > > +     imx334_fill_pad_format(imx334, &supported_modes[0], &fmt);
> > >
> > >       return imx334_set_pad_format(sd, sd_state, &fmt);  }
> > >
> > > +static int imx334_set_framefmt(struct imx334 *imx334) {
> > > +     switch (imx334->cur_code) {
> > > +     case MEDIA_BUS_FMT_SRGGB10_1X10:
> > > +             return imx334_write_regs(imx334, raw10_framefmt_regs,
> > > +
> > > +ARRAY_SIZE(raw10_framefmt_regs));
> > 
> > Please align to immediately right of the opening parenthesis. Same below.
> > 
> > > +
> > > +     case MEDIA_BUS_FMT_SRGGB12_1X12:
> > > +             return imx334_write_regs(imx334, raw12_framefmt_regs,
> > > +
> > > + ARRAY_SIZE(raw12_framefmt_regs));
> > 
> > I think you'll also need changes to the pixel clock calculation.
> > 
> In this driver pixel clock read only variable.
> Pixel clock change maybe in different series.

Please address it in this patch.

Is the link frequency affected by this patch as well?

-- 
Kind regards,

Sakari Ailus