Hi Hans

Thanks for the detailed review.

On Mon, 9 Aug 2021 at 17:16, Hans Verkuil [off-list ref] wrote:

On 15/07/2021 11:24, dillon.minfei@gmail.com wrote:

quoted

From: Dillon Min <redacted>

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 <redacted>
---
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``

Please mention the control type as well.

OK, how about change to
``V4L2_CID_DMA2D_R2M_MODE (boolean)``

quoted

+-------------------------
+    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``

Ditto.

I will remove this item in v3, turn to use your suggestion (add
V4L2_COLORFX_SET_COLOR_ARGB to V4L2_CID_COLORFX)

quoted

+-------------------------------
+    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:

Here you mention RGB only,

quoted

+
+    31 .. 24    23 .. 16  15 .. 8     7 .. 0
+    ALPHA[7:0]  RED[7:0]  GREEN[7:0]  BLUE[7:0]

but here you also mention Alpha. So which is it?

Anyway this will be removed in v3, give a short explanation about it,
The DMA2D_OCOLR register contains alpha value for m2m-pfc-blend mode,
which defines the alpha channel of the output color. it's not used for R2M.

sorry for confusion.

See also my review of patch 9/9.

quoted

I'm getting some warnings building this doc:

Documentation/media/userspace-api/drivers/stm32-uapi.rst:4: WARNING: Title underline too short.

STM32 Chrom-Art 2D Graphics Accelerator unit (DMA2D) driver
================================================
Documentation/media/userspace-api/drivers/stm32-uapi.rst:9: WARNING: Title underline too short.

``V4L2_CID_DMA2D_R2M_MODE``
-------------------------

OK, will be fixed in v3.

Regards,

        Hans

Thanks and Best Regards
Dillon