Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 84 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst
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+.. 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 the input image to correct distortion
+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.
+::
+
+                          Image width
+           <--------------------------------------->
+
+      ^    .-------.-------.-------.-------.-------.
+      |    | 16x16 |       |       |       |       |
+   I  |    | pixel |       |       |       |       |
+   m  |    | block |       |       |       |       |
+   a  |    .-------.-------.-------.-------.-------.
+   g  |    |       |       |       |       |       |
+   e  |    |       |       |       |       |       |
+      |    |       |       |       |       |       |
+   h  |    .-------.-------.-------.-------.-------.
+   e  |    |       |       |       |       |       |
+   i  |    |       |       |       |       |       |
+   g  |    |       |       |       |       |       |
+   h  |    .-------.-------.-------.-------.-------.
+   t  |    |       |       |       |       |       |
+      |    |       |       |       |       |       |
+      |    |       |       |       |       |       |
+      v    '-------'-------'-------'-------'-------'
+
+            Grid of Image Blocks for Dewarping Map
+
+
+Each x, y coordinate register uses 16 bits to record the coordinate address in
+an unsigned 12.4 fixed point format (UQ12.4).
+::
+
+    .----------------------.--------..----------------------.--------.
+    |         31~20        | 19~16  ||         15~4         |  3~0   |
+    |       (integer)      | (frac) ||       (integer)      | (frac) |
+    '----------------------'--------''----------------------'--------'
+    <-------------------------------><------------------------------->
+                Y coordinate                     X coordinate
+
+                           Remap Register Layout
+
+The dewarping map is set from applications using the
+V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP control. The control contains
+an array of u32 values storing (x, y) destination coordinates for each
+vertex of the grid. The x coordinate is stored in the 16 LSBs and the y
+coordinate in the 16 MSBs.
+
+The number of elements in the array must match the image size:
+
+.. code-block:: C
+
+    elems = (DIV_ROUND_UP(width, 16) + 1) * (DIV_ROUND_UP(height, 16) + 1);
+
+If the control has not been set by the application, the driver uses an identity
+map.
+
+More details on the DW100 hardware operations can be found in
+*chapter 13.15 DeWarp* of IMX8MP_ reference manual.
+
+The Vivante DW100 m2m driver implements the following driver-specific control:
+
+``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (__u32 array)``
+    Specifies to DW100 driver its dewarping map (aka LUT) blob as described in
+    *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32
+    dynamic array. The image is divided into many small 16x16 blocks. If the
+    width/height of the image is not divisible by 16, the size of the
+    rightmost/bottommost block is the remainder. The dewarping map only saves
+    the vertex coordinates of the block. The dewarping grid map is comprised of
+    vertex coordinates for x and y. Each x, y coordinate register uses 16 bits
+    (UQ12.4) to record the coordinate address, with the Y coordinate in the
+    upper bits and X in the lower bits. The driver modifies the dimensions of
+    this control when the sink format is changed, to reflect the new input
+    resolution.
+
+.. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM