[PATCH v2 7/9] media: docs: add doc for the stm32 dma2d driver

[dillon.minfei at gmail.com]

From: Dillon Min <dillon.minfei at gmail.com>

add stm32-uapi.rst for stm32's dma2d driver, explain the details of ioctl
V4L2_CID_DMA2D_R2M_MODE, V4L2_CID_DMA2D_R2M_COLOR.

Signed-off-by: Dillon Min <dillon.minfei at gmail.com>
---
v2: introduce the stm32-uapi.rst to explain the detail of dma2d's ioctl.

 .../userspace-api/media/drivers/index.rst          |  1 +
 .../userspace-api/media/drivers/stm32-uapi.rst     | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 Documentation/userspace-api/media/drivers/stm32-uapi.rst

diff --git a/Documentation/userspace-api/media/drivers/index.rst b/Documentation/userspace-api/media/drivers/index.rst
index 12e3c512d718..ce42915d48f4 100644
--- a/Documentation/userspace-api/media/drivers/index.rst
+++ b/Documentation/userspace-api/media/drivers/index.rst
@@ -38,4 +38,5 @@ For more details see the file COPYING in the source distribution of Linux.
 	max2175
 	meye-uapi
 	omap3isp-uapi
+	stm32-uapi
 	uvcvideo
diff --git a/Documentation/userspace-api/media/drivers/stm32-uapi.rst b/Documentation/userspace-api/media/drivers/stm32-uapi.rst
new file mode 100644
index 000000000000..d7a4f717387d
--- /dev/null
+++ b/Documentation/userspace-api/media/drivers/stm32-uapi.rst
@@ -0,0 +1,22 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+STM32 Chrom-Art 2D Graphics Accelerator unit (DMA2D) driver
+================================================
+
+The DMA2D driver implements the following driver-specific controls:
+
+``V4L2_CID_DMA2D_R2M_MODE``
+-------------------------
+    Enable/Disable the Register-To-Memory mode, filling a part or the
+    whole of a destination image with a specific color.
+
+    1 for enable, 0 for disable.
+
+``V4L2_CID_DMA2D_R2M_COLOR``
+-------------------------------
+    Set the color to fill a part or the whole of a destination image.
+    only used under Register-To-Memory mode, to set the DMA2D_OCOLR register
+    (RED, GREEN, BLUE) which is:
+
+    31 .. 24    23 .. 16  15 .. 8     7 .. 0
+    ALPHA[7:0]  RED[7:0]  GREEN[7:0]  BLUE[7:0]
-- 
2.7.4