From 99209ff2c535981889eaff40660c845683a885d6 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Thu, 7 May 2020 16:59:03 +0100
Subject: [PATCH] media: Add a pixel format for MIPI packed 12bit luma
 only.

This is the format used by monochrome 12bit image sensors.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 .../userspace-api/media/v4l/pixfmt-y12p.rst   | 45 +++++++++++++++++++
 .../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, 48 insertions(+)
 create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-y12p.rst

--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/pixfmt-y12p.rst
@@ -0,0 +1,45 @@
+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _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.
+
+**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)
+
--- 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
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1314,6 +1314,7 @@ static void v4l_fill_fmtdesc(struct v4l2
 	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;
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -595,6 +595,7 @@ 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 */
