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 <[email protected]> > >> > >> 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. 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 <[email protected]> > >> [[email protected]: simplified by dropping v4l2_colorspace handling] > >> Signed-off-by: Jan Luebbe <[email protected]> > >> Signed-off-by: Stefan Riedmueller <[email protected]> > >> --- > >> 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; -- Regards, Laurent Pinchart
