Messages in this thread | | | Subject | Re: [PATCH v2 1/5] media: mt9p031: Add support for 8 bit and 10 bit formats | From | Stefan Riedmüller <> | Date | Mon, 5 Oct 2020 11:31:59 +0200 |
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Hi Laurent,
On 02.10.20 01:53, Laurent Pinchart wrote: > Hi Stefan, > > On Thu, Oct 01, 2020 at 11:07:00AM +0200, Stefan Riedmüller wrote: >> On 30.09.20 13:42, Laurent Pinchart wrote: >>> On Wed, Sep 30, 2020 at 12:51:29PM +0200, Stefan Riedmueller wrote: >>>> From: Christian Hemp <c.hemp@phytec.de> >>>> >>>> Aside from 12 bit monochrome or color format the sensor implicitly >>>> supports 10 and 8 bit formats as well by simply dropping the >>>> corresponding LSBs. >>> >>> That's not how it should work though. If you set the format on >>> MEDIA_BUS_FMT_SGRBG8_1X8 through the pipeline for instance, you will end >>> up capturing the 8 LSB, not the 8 MSB. >>> >>> What's your use case for this ? >> >> I use this sensor in combination with an i.MX 6 and i.MX 6UL. When the >> sensor is connected with 12 bit (or 10 bit on the i.MX 6UL) and I set >> MEDIA_BUS_FMT_SGRBG8_1X8 through the pipeline the CSI interface drops the >> unused 4 LSB (or 2 LSB on the i.MX 6UL) so I get the 8 MSB from my 12 bit >> sensor. > > Is that the PIXEL_BIT bit in CSI_CSICR1 for the i.MX6UL ? If so I think > this should be handled in the imx7-media-csi driver. You could set the > format to MEDIA_BUS_FMT_SGRBG10_1X10 on the sink pad of the CSI and to > MEDIA_BUS_FMT_SGRBG8_1X8 on the source pad to configure this. I don't > think the sensor driver should be involved, otherwise we'd have to patch > all sensor drivers. From a sensor point of view, it outputs 12-bit > Bayer, not 8-bit.
Ah, I had it wrong. What you say makes total sense. I will take another look at it and also try to work your suggestion from below in.
Thanks, Stefan
> > Now there's a caveat. When used with the i.MX6UL, I assume you connected > D[11:2] of the sensor to D[9:0] of the i.MX6UL, right ? The i.MX6UL > doesn't support 12-bit inputs, so it should accept > MEDIA_BUS_FMT_SGRBG12_1X12 on its sink pad. In this case, as D[1:0] of > the sensor are left unconnected, I think you should set data-shift to 2 > and bus-width to 10 in DT on the sensor side. The MT9P031 driver should > parse that, and output MEDIA_BUS_FMT_SGRBG10_1X10 instead of > MEDIA_BUS_FMT_SGRBG12_1X12 in that case. > >> Does this clarify things? Maybe the description in the commit message is not >> accurate enough or did I get something wrong? >> >>>> Signed-off-by: Christian Hemp <c.hemp@phytec.de> >>>> [jlu@pengutronix.de: simplified by dropping v4l2_colorspace handling] >>>> Signed-off-by: Jan Luebbe <jlu@pengutronix.de> >>>> Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de> >>>> --- >>>> Changes in v2: >>>> - Use unsigned int for num_fmts and loop variable in find_datafmt >>>> - Remove superfluous const qualifier from find_datafmt >>>> --- >>>> drivers/media/i2c/mt9p031.c | 50 +++++++++++++++++++++++++++++-------- >>>> 1 file changed, 40 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c >>>> index dc23b9ed510a..2e6671ef877c 100644 >>>> --- a/drivers/media/i2c/mt9p031.c >>>> +++ b/drivers/media/i2c/mt9p031.c >>>> @@ -116,6 +116,18 @@ enum mt9p031_model { >>>> MT9P031_MODEL_MONOCHROME, >>>> }; >>>> >>>> +static const u32 mt9p031_color_fmts[] = { >>>> + MEDIA_BUS_FMT_SGRBG8_1X8, >>>> + MEDIA_BUS_FMT_SGRBG10_1X10, >>>> + MEDIA_BUS_FMT_SGRBG12_1X12, >>>> +}; >>>> + >>>> +static const u32 mt9p031_monochrome_fmts[] = { >>>> + MEDIA_BUS_FMT_Y8_1X8, >>>> + MEDIA_BUS_FMT_Y10_1X10, >>>> + MEDIA_BUS_FMT_Y12_1X12, >>>> +}; >>>> + >>>> struct mt9p031 { >>>> struct v4l2_subdev subdev; >>>> struct media_pad pad; >>>> @@ -138,6 +150,9 @@ struct mt9p031 { >>>> struct v4l2_ctrl *blc_auto; >>>> struct v4l2_ctrl *blc_offset; >>>> >>>> + const u32 *fmts; >>>> + unsigned int num_fmts; >>>> + >>>> /* Registers cache */ >>>> u16 output_control; >>>> u16 mode2; >>>> @@ -148,6 +163,17 @@ static struct mt9p031 *to_mt9p031(struct v4l2_subdev *sd) >>>> return container_of(sd, struct mt9p031, subdev); >>>> } >>>> >>>> +static u32 mt9p031_find_datafmt(struct mt9p031 *mt9p031, u32 code) >>>> +{ >>>> + unsigned int i; >>>> + >>>> + for (i = 0; i < mt9p031->num_fmts; i++) >>>> + if (mt9p031->fmts[i] == code) >>>> + return mt9p031->fmts[i]; >>>> + >>>> + return mt9p031->fmts[mt9p031->num_fmts-1]; >>>> +} >>>> + >>>> static int mt9p031_read(struct i2c_client *client, u8 reg) >>>> { >>>> return i2c_smbus_read_word_swapped(client, reg); >>>> @@ -476,10 +502,11 @@ static int mt9p031_enum_mbus_code(struct v4l2_subdev *subdev, >>>> { >>>> struct mt9p031 *mt9p031 = to_mt9p031(subdev); >>>> >>>> - if (code->pad || code->index) >>>> + if (code->pad || code->index >= mt9p031->num_fmts) >>>> return -EINVAL; >>>> >>>> - code->code = mt9p031->format.code; >>>> + code->code = mt9p031->fmts[code->index]; >>>> + >>>> return 0; >>>> } >>>> >>>> @@ -573,6 +600,8 @@ static int mt9p031_set_format(struct v4l2_subdev *subdev, >>>> __format->width = __crop->width / hratio; >>>> __format->height = __crop->height / vratio; >>>> >>>> + __format->code = mt9p031_find_datafmt(mt9p031, format->format.code); >>>> + >>>> format->format = *__format; >>>> >>>> return 0; >>>> @@ -951,10 +980,7 @@ static int mt9p031_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh) >>>> >>>> format = v4l2_subdev_get_try_format(subdev, fh->pad, 0); >>>> >>>> - if (mt9p031->model == MT9P031_MODEL_MONOCHROME) >>>> - format->code = MEDIA_BUS_FMT_Y12_1X12; >>>> - else >>>> - format->code = MEDIA_BUS_FMT_SGRBG12_1X12; >>>> + format->code = mt9p031_find_datafmt(mt9p031, 0); >>>> >>>> format->width = MT9P031_WINDOW_WIDTH_DEF; >>>> format->height = MT9P031_WINDOW_HEIGHT_DEF; >>>> @@ -1121,10 +1147,14 @@ static int mt9p031_probe(struct i2c_client *client, >>>> mt9p031->crop.left = MT9P031_COLUMN_START_DEF; >>>> mt9p031->crop.top = MT9P031_ROW_START_DEF; >>>> >>>> - if (mt9p031->model == MT9P031_MODEL_MONOCHROME) >>>> - mt9p031->format.code = MEDIA_BUS_FMT_Y12_1X12; >>>> - else >>>> - mt9p031->format.code = MEDIA_BUS_FMT_SGRBG12_1X12; >>>> + if (mt9p031->model == MT9P031_MODEL_MONOCHROME) { >>>> + mt9p031->fmts = mt9p031_monochrome_fmts; >>>> + mt9p031->num_fmts = ARRAY_SIZE(mt9p031_monochrome_fmts); >>>> + } else { >>>> + mt9p031->fmts = mt9p031_color_fmts; >>>> + mt9p031->num_fmts = ARRAY_SIZE(mt9p031_color_fmts); >>>> + } >>>> + mt9p031->format.code = mt9p031_find_datafmt(mt9p031, 0); >>>> >>>> mt9p031->format.width = MT9P031_WINDOW_WIDTH_DEF; >>>> mt9p031->format.height = MT9P031_WINDOW_HEIGHT_DEF; >
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