media: v4l: Add 32-bit packed YUV formats

The formats added in this patch include:
 V4L2_PIX_FMT_AYUV32
 V4L2_PIX_FMT_XYUV32
 V4L2_PIX_FMT_VUYA32
 V4L2_PIX_FMT_VUYX32

These formats enable the trasmission of alpha channel data to other
drivers and userspace applications in addition to YUV data. For
example, buffers generated by drivers in one of these formats
can be used by the Weston compositor to display as a texture or
flipped directly onto the overlay planes with the help of a DRM
driver.
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/media/uapi/v4l/pixfmt-packed-yuv.rst

@@ -190,6 +190,170 @@ component of each pixel in one 16 or 32 bit word.
       - Cr\ :sub:`2`
       - Cr\ :sub:`1`
       - Cr\ :sub:`0`
+      -
+    * .. _V4L2-PIX-FMT-AYUV32:
+
+      - ``V4L2_PIX_FMT_AYUV32``
+      - 'AYUV'
+
+      - a\ :sub:`7`
+      - a\ :sub:`6`
+      - a\ :sub:`5`
+      - a\ :sub:`4`
+      - a\ :sub:`3`
+      - a\ :sub:`2`
+      - a\ :sub:`1`
+      - a\ :sub:`0`
+
+      - Y'\ :sub:`7`
+      - Y'\ :sub:`6`
+      - Y'\ :sub:`5`
+      - Y'\ :sub:`4`
+      - Y'\ :sub:`3`
+      - Y'\ :sub:`2`
+      - Y'\ :sub:`1`
+      - Y'\ :sub:`0`
+
+      - Cb\ :sub:`7`
+      - Cb\ :sub:`6`
+      - Cb\ :sub:`5`
+      - Cb\ :sub:`4`
+      - Cb\ :sub:`3`
+      - Cb\ :sub:`2`
+      - Cb\ :sub:`1`
+      - Cb\ :sub:`0`
+
+      - Cr\ :sub:`7`
+      - Cr\ :sub:`6`
+      - Cr\ :sub:`5`
+      - Cr\ :sub:`4`
+      - Cr\ :sub:`3`
+      - Cr\ :sub:`2`
+      - Cr\ :sub:`1`
+      - Cr\ :sub:`0`
+      -
+    * .. _V4L2-PIX-FMT-XYUV32:
+
+      - ``V4L2_PIX_FMT_XYUV32``
+      - 'XYUV'
+
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+
+      - Y'\ :sub:`7`
+      - Y'\ :sub:`6`
+      - Y'\ :sub:`5`
+      - Y'\ :sub:`4`
+      - Y'\ :sub:`3`
+      - Y'\ :sub:`2`
+      - Y'\ :sub:`1`
+      - Y'\ :sub:`0`
+
+      - Cb\ :sub:`7`
+      - Cb\ :sub:`6`
+      - Cb\ :sub:`5`
+      - Cb\ :sub:`4`
+      - Cb\ :sub:`3`
+      - Cb\ :sub:`2`
+      - Cb\ :sub:`1`
+      - Cb\ :sub:`0`
+
+      - Cr\ :sub:`7`
+      - Cr\ :sub:`6`
+      - Cr\ :sub:`5`
+      - Cr\ :sub:`4`
+      - Cr\ :sub:`3`
+      - Cr\ :sub:`2`
+      - Cr\ :sub:`1`
+      - Cr\ :sub:`0`
+      -
+    * .. _V4L2-PIX-FMT-VUYA32:
+
+      - ``V4L2_PIX_FMT_VUYA32``
+      - 'VUYA'
+
+      - Cr\ :sub:`7`
+      - Cr\ :sub:`6`
+      - Cr\ :sub:`5`
+      - Cr\ :sub:`4`
+      - Cr\ :sub:`3`
+      - Cr\ :sub:`2`
+      - Cr\ :sub:`1`
+      - Cr\ :sub:`0`
+
+      - Cb\ :sub:`7`
+      - Cb\ :sub:`6`
+      - Cb\ :sub:`5`
+      - Cb\ :sub:`4`
+      - Cb\ :sub:`3`
+      - Cb\ :sub:`2`
+      - Cb\ :sub:`1`
+      - Cb\ :sub:`0`
+
+      - Y'\ :sub:`7`
+      - Y'\ :sub:`6`
+      - Y'\ :sub:`5`
+      - Y'\ :sub:`4`
+      - Y'\ :sub:`3`
+      - Y'\ :sub:`2`
+      - Y'\ :sub:`1`
+      - Y'\ :sub:`0`
+
+      - a\ :sub:`7`
+      - a\ :sub:`6`
+      - a\ :sub:`5`
+      - a\ :sub:`4`
+      - a\ :sub:`3`
+      - a\ :sub:`2`
+      - a\ :sub:`1`
+      - a\ :sub:`0`
+      -
+    * .. _V4L2-PIX-FMT-VUYX32:
+
+      - ``V4L2_PIX_FMT_VUYX32``
+      - 'VUYX'
+
+      - Cr\ :sub:`7`
+      - Cr\ :sub:`6`
+      - Cr\ :sub:`5`
+      - Cr\ :sub:`4`
+      - Cr\ :sub:`3`
+      - Cr\ :sub:`2`
+      - Cr\ :sub:`1`
+      - Cr\ :sub:`0`
+
+      - Cb\ :sub:`7`
+      - Cb\ :sub:`6`
+      - Cb\ :sub:`5`
+      - Cb\ :sub:`4`
+      - Cb\ :sub:`3`
+      - Cb\ :sub:`2`
+      - Cb\ :sub:`1`
+      - Cb\ :sub:`0`
+
+      - Y'\ :sub:`7`
+      - Y'\ :sub:`6`
+      - Y'\ :sub:`5`
+      - Y'\ :sub:`4`
+      - Y'\ :sub:`3`
+      - Y'\ :sub:`2`
+      - Y'\ :sub:`1`
+      - Y'\ :sub:`0`
+
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
 
 .. raw:: latex
 
@@ -202,4 +366,8 @@ component of each pixel in one 16 or 32 bit word.
     #) The value of a = alpha bits is undefined when reading from the driver,
        ignored when writing to the driver, except when alpha blending has
        been negotiated for a :ref:`Video Overlay <overlay>` or
-       :ref:`Video Output Overlay <osd>`.
+       :ref:`Video Output Overlay <osd>` for the formats Y444, YUV555 and
+       YUV4. However, for formats AYUV32 and VUYA32, the alpha component is
+       expected to contain a meaningful value that can be used by drivers
+       and applications. And, the formats XYUV32 and VUYX32 contain undefined
+       alpha values that must be ignored by all applications and drivers.

drivers/media/v4l2-core/v4l2-ioctl.c

@@ -1220,6 +1220,10 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_PIX_FMT_YUV555:	descr = "16-bit A/XYUV 1-5-5-5"; break;
 	case V4L2_PIX_FMT_YUV565:	descr = "16-bit YUV 5-6-5"; break;
 	case V4L2_PIX_FMT_YUV32:	descr = "32-bit A/XYUV 8-8-8-8"; break;
+	case V4L2_PIX_FMT_AYUV32:	descr = "32-bit AYUV 8-8-8-8"; break;
+	case V4L2_PIX_FMT_XYUV32:	descr = "32-bit XYUV 8-8-8-8"; break;
+	case V4L2_PIX_FMT_VUYA32:	descr = "32-bit VUYA 8-8-8-8"; break;
+	case V4L2_PIX_FMT_VUYX32:	descr = "32-bit VUYX 8-8-8-8"; break;
 	case V4L2_PIX_FMT_YUV410:	descr = "Planar YUV 4:1:0"; break;
 	case V4L2_PIX_FMT_YUV420:	descr = "Planar YUV 4:2:0"; break;
 	case V4L2_PIX_FMT_HI240:	descr = "8-bit Dithered RGB (BTTV)"; break;

include/uapi/linux/videodev2.h

@@ -562,6 +562,10 @@ struct v4l2_pix_format {
 #define V4L2_PIX_FMT_YUV555  v4l2_fourcc('Y', 'U', 'V', 'O') /* 16  YUV-5-5-5     */
 #define V4L2_PIX_FMT_YUV565  v4l2_fourcc('Y', 'U', 'V', 'P') /* 16  YUV-5-6-5     */
 #define V4L2_PIX_FMT_YUV32   v4l2_fourcc('Y', 'U', 'V', '4') /* 32  YUV-8-8-8-8   */
+#define V4L2_PIX_FMT_AYUV32  v4l2_fourcc('A', 'Y', 'U', 'V') /* 32  AYUV-8-8-8-8  */
+#define V4L2_PIX_FMT_XYUV32  v4l2_fourcc('X', 'Y', 'U', 'V') /* 32  XYUV-8-8-8-8  */
+#define V4L2_PIX_FMT_VUYA32  v4l2_fourcc('V', 'U', 'Y', 'A') /* 32  VUYA-8-8-8-8  */
+#define V4L2_PIX_FMT_VUYX32  v4l2_fourcc('V', 'U', 'Y', 'X') /* 32  VUYX-8-8-8-8  */
 #define V4L2_PIX_FMT_HI240   v4l2_fourcc('H', 'I', '2', '4') /*  8  8-bit color   */
 #define V4L2_PIX_FMT_HM12    v4l2_fourcc('H', 'M', '1', '2') /*  8  YUV 4:2:0 16x16 macroblocks */
 #define V4L2_PIX_FMT_M420    v4l2_fourcc('M', '4', '2', '0') /* 12  YUV 4:2:0 2 lines y, 1 line uv interleaved */