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[v3,4/9] media: Documentation: dw100: Add user documentation for the DW100 driver

Message ID 20220308201038.48386-5-xavier.roumegue@oss.nxp.com (mailing list archive)
State New, archived
Headers show
Series i.MX8MP DW100 dewarper driver | expand

Commit Message

Xavier Roumegue (OSS) March 8, 2022, 8:10 p.m. UTC 
Add user documentation for the DW100 driver.

Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com>
---
 .../userspace-api/media/drivers/dw100.rst     | 23 +++++++++++++++++++
 .../userspace-api/media/drivers/index.rst     |  1 +
 2 files changed, 24 insertions(+)
 create mode 100644 Documentation/userspace-api/media/drivers/dw100.rst
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Patch

diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst
new file mode 100644
index 000000000000..4cd55c75628e
--- /dev/null
+++ b/Documentation/userspace-api/media/drivers/dw100.rst
@@ -0,0 +1,23 @@ 
+.. SPDX-License-Identifier: GPL-2.0
+
+DW100 dewarp driver
+===========================
+
+The Vivante DW100 Dewarp Processor IP core found on i.MX8MP SoC applies a
+programmable geometrical transformation on input image to correct distorsion
+introduced by lenses.
+
+The transformation function is exposed by the hardware as a grid map with 16x16
+pixel macroblocks indexed using X, Y vertex coordinates. Each x, y coordinate
+register uses 16 bits to record the coordinate address in UQ12.4 fixed point
+format.
+
+The dewarping map can be set from application through a dedicated v4l2 control.
+If not set or invalid, the driver computes an identity map prior to start the
+processing engine. The map is evaluated as invalid if the array size does not
+match the expected size inherited from the destination image resolution.
+
+More details on the DW100 hardware operations can be found in
+*chapter 13.15 DeWarp* of IMX8MP_ reference manuel.
+
+.. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM
diff --git a/Documentation/userspace-api/media/drivers/index.rst b/Documentation/userspace-api/media/drivers/index.rst
index 12e3c512d718..8826777321b0 100644
--- a/Documentation/userspace-api/media/drivers/index.rst
+++ b/Documentation/userspace-api/media/drivers/index.rst
@@ -33,6 +33,7 @@  For more details see the file COPYING in the source distribution of Linux.
 
 	ccs
 	cx2341x-uapi
+	dw100
         hantro
 	imx-uapi
 	max2175