[PATCH v4 02/10] media: Add Y012 video format

[Ming Qian]

Y012 is a luma-only formats with 12-bits per pixel,
expanded to 16bits.
Data in the 12 high bits, zeros in the 4 low bits,
arranged in little endian order.

Signed-off-by: Ming Qian <ming.qian@xxxxxxx>
---
 .../userspace-api/media/v4l/pixfmt-yuv-luma.rst   | 15 +++++++++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c              |  1 +
 include/uapi/linux/videodev2.h                    |  1 +
 3 files changed, 17 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst
index 62078a01de76..7888151f2cd4 100644
--- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst
+++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst
@@ -103,6 +103,17 @@ are often referred to as greyscale formats.
       - ...
       - ...
 
+    * .. _V4L2-PIX-FMT-Y012:
+
+      - ``V4L2_PIX_FMT_Y012``
+      - 'Y012'
+
+      - Y'\ :sub:`0`\ [3:0] `0000`
+      - Y'\ :sub:`0`\ [11:4]
+      - ...
+      - ...
+      - ...
+
     * .. _V4L2-PIX-FMT-Y14:
 
       - ``V4L2_PIX_FMT_Y14``
@@ -146,3 +157,7 @@ are often referred to as greyscale formats.
     than 16 bits. For example, 10 bits per pixel uses values in the range 0 to
     1023. For the IPU3_Y10 format 25 pixels are packed into 32 bytes, which
     leaves the 6 most significant bits of the last byte padded with 0.
+
+    For Y012 and Y12 formats, Y012 place its data in the 12 high bits, with
+    padding zeros in the 4 low bits, in contrast to Y12 format, which have
+    its padding located in the most significant bits of the 16 bit word.
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 6489b67babfa..2cb485643562 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1307,6 +1307,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_PIX_FMT_Y6:		descr = "6-bit Greyscale"; break;
 	case V4L2_PIX_FMT_Y10:		descr = "10-bit Greyscale"; break;
 	case V4L2_PIX_FMT_Y12:		descr = "12-bit Greyscale"; break;
+	case V4L2_PIX_FMT_Y012:		descr = "12-bit Greyscale"; break;
 	case V4L2_PIX_FMT_Y14:		descr = "14-bit Greyscale"; break;
 	case V4L2_PIX_FMT_Y16:		descr = "16-bit Greyscale"; break;
 	case V4L2_PIX_FMT_Y16_BE:	descr = "16-bit Greyscale BE"; break;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index f83a9d1210fb..db06d4c4f008 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -586,6 +586,7 @@ struct v4l2_pix_format {
 #define V4L2_PIX_FMT_Y6      v4l2_fourcc('Y', '0', '6', ' ') /*  6  Greyscale     */
 #define V4L2_PIX_FMT_Y10     v4l2_fourcc('Y', '1', '0', ' ') /* 10  Greyscale     */
 #define V4L2_PIX_FMT_Y12     v4l2_fourcc('Y', '1', '2', ' ') /* 12  Greyscale     */
+#define V4L2_PIX_FMT_Y012    v4l2_fourcc('Y', '0', '1', '2') /* 12  Greyscale     */
 #define V4L2_PIX_FMT_Y14     v4l2_fourcc('Y', '1', '4', ' ') /* 14  Greyscale     */
 #define V4L2_PIX_FMT_Y16     v4l2_fourcc('Y', '1', '6', ' ') /* 16  Greyscale     */
 #define V4L2_PIX_FMT_Y16_BE  v4l2_fourcc_be('Y', '1', '6', ' ') /* 16  Greyscale BE  */
-- 
2.38.1