Le vendredi 09 février 2024 à 17:48 +0100, Jacopo Mondi a écrit :
> From: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
>
> This is the format used by monochrome 12bit image sensors.
>
> Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> Signed-off-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>
> ---
> .../userspace-api/media/v4l/pixfmt-y12p.rst | 38 +++++++++++++++++++
> .../userspace-api/media/v4l/yuv-formats.rst | 1 +
> drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
> include/uapi/linux/videodev2.h | 1 +
> 4 files changed, 41 insertions(+)
> create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-y12p.rst
>
> diff --git a/Documentation/userspace-api/media/v4l/pixfmt-y12p.rst b/Documentation/userspace-api/media/v4l/pixfmt-y12p.rst
> new file mode 100644
> index 000000000000..b2eb4a72724d
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/pixfmt-y12p.rst
> @@ -0,0 +1,38 @@
> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> +
> +.. _V4L2-PIX-FMT-Y12P:
> +
> +******************************
> +V4L2_PIX_FMT_Y12P ('Y12P')
> +******************************
> +
> +Grey-scale image as a MIPI RAW12 packed array
> +
> +
> +Description
> +===========
> +
> +This is a packed grey-scale image format with a depth of 12 bits per
> +pixel. Two consecutive pixels are packed into 3 bytes. The first 2 bytes
> +contain the 8 high order bits of the pixels, and the 3rd byte contains the 4
> +least significants bits of each pixel, in the same order.
This is an interesting arrangement, which make me feel that Y12P is perhaps bit
too generic ? Perhaps something like:
V4L2_PIX_FMT_Y12_MIPI
That being said, I don't mind if you reserve the nice and short name for the
first occurrence of such format in 20 years (it might equally be the last). Will
they do the same for Y10, by storing 4 bytes of higher 8bit of 4 pixels, and
packing the remaining lower 2 bits packed in the fif bytes ? Cause for this one,
we'd have confusion, since CODEC usually just place all the bits in order over 5
bytes here (which have its own issues of course).
> +
> +**Byte Order.**
> +Each cell is one byte.
> +
> +.. tabularcolumns:: |p{2.2cm}|p{1.2cm}|p{1.2cm}|p{3.1cm}|
> +
> +
> +.. flat-table::
> + :header-rows: 0
> + :stub-columns: 0
> + :widths: 2 1 1 1
> +
> +
> + - - start + 0:
> + - Y'\ :sub:`00high`
> + - Y'\ :sub:`01high`
> + - Y'\ :sub:`01low`\ (bits 7--4)
> +
> + Y'\ :sub:`00low`\ (bits 3--0)
> +
> diff --git a/Documentation/userspace-api/media/v4l/yuv-formats.rst b/Documentation/userspace-api/media/v4l/yuv-formats.rst
> index 24b34cdfa6fe..7c9ccfdd94cd 100644
> --- a/Documentation/userspace-api/media/v4l/yuv-formats.rst
> +++ b/Documentation/userspace-api/media/v4l/yuv-formats.rst
> @@ -267,6 +267,7 @@ image.
> pixfmt-packed-yuv
> pixfmt-yuv-planar
> pixfmt-yuv-luma
> + pixfmt-y12p
> pixfmt-y8i
> pixfmt-y12i
> pixfmt-uv8
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 33076af4dfdb..483498c55899 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1311,6 +1311,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> case V4L2_PIX_FMT_Y16_BE: descr = "16-bit Greyscale BE"; break;
> case V4L2_PIX_FMT_Y10BPACK: descr = "10-bit Greyscale (Packed)"; break;
> case V4L2_PIX_FMT_Y10P: descr = "10-bit Greyscale (MIPI Packed)"; break;
> + case V4L2_PIX_FMT_Y12P: descr = "12-bit Greyscale (MIPI Packed)"; break;
> case V4L2_PIX_FMT_IPU3_Y10: descr = "10-bit greyscale (IPU3 Packed)"; break;
> case V4L2_PIX_FMT_Y8I: descr = "Interleaved 8-bit Greyscale"; break;
> case V4L2_PIX_FMT_Y12I: descr = "Interleaved 12-bit Greyscale"; break;
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index a8015e5e7fa4..11ebf9b22ccb 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -598,6 +598,7 @@ struct v4l2_pix_format {
> /* Grey bit-packed formats */
> #define V4L2_PIX_FMT_Y10BPACK v4l2_fourcc('Y', '1', '0', 'B') /* 10 Greyscale bit-packed */
> #define V4L2_PIX_FMT_Y10P v4l2_fourcc('Y', '1', '0', 'P') /* 10 Greyscale, MIPI RAW10 packed */
> +#define V4L2_PIX_FMT_Y12P v4l2_fourcc('Y', '1', '2', 'P') /* 12 Greyscale, MIPI RAW12 packed */
> #define V4L2_PIX_FMT_IPU3_Y10 v4l2_fourcc('i', 'p', '3', 'y') /* IPU3 packed 10-bit greyscale */
>
> /* Palette formats */
