RE: [PATCH v3] media: i2c: imx334: support lower bandwidth mode

From: Shravan.Chippa
Date: Thu Sep 15 2022 - 03:33:55 EST



> -----Original Message-----
> From: Alessandrelli, Daniele <daniele.alessandrelli@xxxxxxxxx>
> Sent: 14 September 2022 09:49 PM
> To: Murphy, Paul J <paul.j.murphy@xxxxxxxxx>; mchehab@xxxxxxxxxx;
> shravan Chippa - I35088 <Shravan.Chippa@xxxxxxxxxxxxx>
> Cc: linux-media@xxxxxxxxxxxxxxx; Conor Dooley - M52691
> <Conor.Dooley@xxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; Battu
> Prakash Reddy - I30399 <Prakash.Battu@xxxxxxxxxxxxx>
> Subject: Re: [PATCH v3] media: i2c: imx334: support lower bandwidth mode
>
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
>
> On Tue, 2022-09-06 at 13:53 +0530, shravan kumar wrote:
> > > From: Shravan Chippa <shravan.chippa@xxxxxxxxxxxxx>
> > >
> > > 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@xxxxxxxxxxxxx>
> > > Signed-off-by: Prakash Battu <Prakash.Battu@xxxxxxxxxxxxx>
> > > Signed-off-by: Shravan Chippa <shravan.chippa@xxxxxxxxxxxxx>
>
> Thanks for the patch!
>
> > > ---
> > > [PATCH v3]
> > > Fix for warning Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > >
> > > [PATCH v2]
> > > Fixe for big Reported-by: Jacopo Mondi <jacopo@xxxxxxxxxx>
> > > -imx334_enum_frame_size() loop function
> > >
> > > Changes Suggested by: Jacopo Mondi <jacopo@xxxxxxxxxx>
> > > -renamed array codes[] --> imx334_mbus_codes[]
> > > -modified supported_modes[] to get higher resolution first
> > >
> > > ---
> > > drivers/media/i2c/imx334.c | 305
> +++++++++++++++++++++++++++++++++----
> > > 1 file changed, 279 insertions(+), 26 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/imx334.c b/drivers/media/i2c/imx334.c
> > > index 062125501788..920d407aaa2d 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_SRGGB10_1X10,
> > > + MEDIA_BUS_FMT_SRGGB12_1X12,
> > > +};
> > > +
> > > /* 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)
> > > + break;
> > > + }
> > > +
> > > + if (i >= ARRAY_SIZE(imx334_mbus_codes))
> > > + i = 0;
>
> If I understand the ultimate effect of this code correctly, we fallback
> to MEDIA_BUS_FMT_SRGGB10_1X10 if the specified format code is not
> supported, while before this change we were always using
> MEDIA_BUS_FMT_SRGGB10_1X12.
>
> Is this intended? Would it be better to leave the same behavior as the
> current driver?

If it fail to find th bus code then, I will try set SRGGB10_1X12 as default.

>
> > > +
> > > + return imx334_mbus_codes[i];
> > > +}
> > > +
> > > /**
> > > * imx334_set_pad_format() - Set subdevice pad format
> > > * @sd: pointer to imx334 V4L2 sub-device structure
> > > @@ -606,10 +827,19 @@ static int imx334_set_pad_format(struct
> v4l2_subdev *sd,
> > > struct imx334 *imx334 = to_imx334(sd);
> > > const struct imx334_mode *mode;
> > > int ret = 0;
> > > + u32 code;
> > >
> > > mutex_lock(&imx334->mutex);
> > >
> > > - mode = &supported_mode;
> > > + code = imx334_get_format_code(imx334, fmt);
>
> nitpick: you probably don't need the 'code' variable and can simply do:
>
> imx334->cur_code = imx334_get_format_code(imx334, fmt);
>
> > > +
> > > + imx334->cur_code = code;
> > > +
> > > + 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 +847,7 @@ 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) {
>
> This second 'if' is not used in any other driver. Is this some kind of
> optimization?
>
> If this function is called after probe() and imx334->cur_mode == mode,
> I think that imx334_update_controls() will not be called for the
> specified mode. I'm not sure if that's OK or not.

In probe function imx334_init_controls() will take the cur_mode value as default values.
May be we do not need to update the mode values until the mode changes

>
> > > ret = imx334_update_controls(imx334, mode);
> > > if (!ret)
> > > imx334->cur_mode = mode;
> > > @@ -642,11 +872,26 @@ 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[1], &fmt);
>
> The newly added mode is now used by this function instead of the old
> one. Not sure if this is intended or not.
>
> > >
> > > 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));
> > > +
> > > + case MEDIA_BUS_FMT_SRGGB12_1X12:
> > > + return imx334_write_regs(imx334, raw12_framefmt_regs,
> > > + ARRAY_SIZE(raw12_framefmt_regs));
> > > + }
> > > +
> > > + return -EINVAL;
> > > +}
> > > +
> > > /**
> > > * imx334_start_streaming() - Start sensor stream
> > > * @imx334: pointer to imx334 device
> > > @@ -667,6 +912,13 @@ static int imx334_start_streaming(struct imx334
> *imx334)
> > > return ret;
> > > }
> > >
> > > + ret = imx334_set_framefmt(imx334);
> > > + if (ret) {
> > > + dev_err(imx334->dev, "%s failed to set frame format: %d\n",
> > > + __func__, ret);
> > > + return ret;
> > > + }
> > > +
> > > /* Setup handler will write actual exposure and gain */
> > > ret = __v4l2_ctrl_handler_setup(imx334->sd.ctrl_handler);
> > > if (ret) {
> > > @@ -1037,7 +1289,8 @@ static int imx334_probe(struct i2c_client *client)
> > > }
> > >
> > > /* Set default mode to max resolution */
> > > - imx334->cur_mode = &supported_mode;
> > > + imx334->cur_mode = &supported_modes[0];
> > > + imx334->cur_code = imx334_mbus_codes[0];
>
> imx334_mbus_codes[0] is MEDIA_BUS_FMT_SRGGB10_1X10, which means
> that
> the default configuration will switch from 12 bits to 10 bits, despite
> the commit message saying that the default configuration will stay the
> same.
I will try to modify the default bus code to SRGGB10_1X12.

Thanks,
Shravan
>
> > > imx334->vblank = imx334->cur_mode->vblank;
> > >
> > > ret = imx334_init_controls(imx334);