[PATCH v12 6/9] media: uapi: Add a control for HANTRO driver

From: Benjamin Gaignard
Date: Wed May 26 2021 - 08:47:02 EST


The HEVC HANTRO driver needs to know the number of bits to skip at
the beginning of the slice header.
That is a hardware specific requirement so create a dedicated control
for this purpose.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
---
.../userspace-api/media/drivers/hantro.rst | 19 +++++++++++++++++++
.../userspace-api/media/drivers/index.rst | 1 +
include/media/hevc-ctrls.h | 13 +++++++++++++
3 files changed, 33 insertions(+)
create mode 100644 Documentation/userspace-api/media/drivers/hantro.rst

diff --git a/Documentation/userspace-api/media/drivers/hantro.rst b/Documentation/userspace-api/media/drivers/hantro.rst
new file mode 100644
index 000000000000..cd9754b4e005
--- /dev/null
+++ b/Documentation/userspace-api/media/drivers/hantro.rst
@@ -0,0 +1,19 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Hantro video decoder driver
+===========================
+
+The Hantro video decoder driver implements the following driver-specific controls:
+
+``V4L2_CID_HANTRO_HEVC_SLICE_HEADER_SKIP (integer)``
+ Specifies to Hantro HEVC video decoder driver the number of data (in bits) to
+ skip in the slice segment header.
+ If non-IDR, the bits to be skipped go from syntax element "pic_output_flag"
+ to before syntax element "slice_temporal_mvp_enabled_flag".
+ If IDR, the skipped bits are just "pic_output_flag"
+ (separate_colour_plane_flag is not supported).
+
+.. note::
+
+ This control is not yet part of the public kernel API and
+ it is expected to change.
diff --git a/Documentation/userspace-api/media/drivers/index.rst b/Documentation/userspace-api/media/drivers/index.rst
index 1a9038f5f9fa..12e3c512d718 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
+ hantro
imx-uapi
max2175
meye-uapi
diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
index e53666a1127f..dc964ff7cd29 100644
--- a/include/media/hevc-ctrls.h
+++ b/include/media/hevc-ctrls.h
@@ -225,4 +225,17 @@ struct v4l2_ctrl_hevc_decode_params {
__u64 flags;
};

+/* MPEG-class control IDs specific to the Hantro driver as defined by V4L2 */
+#define V4L2_CID_CODEC_HANTRO_BASE (V4L2_CTRL_CLASS_CODEC | 0x1200)
+/*
+ * V4L2_CID_HANTRO_HEVC_SLICE_HEADER_SKIP -
+ * the number of data (in bits) to skip in the
+ * slice segment header.
+ * If non-IDR, the bits to be skipped go from syntax element "pic_output_flag"
+ * to before syntax element "slice_temporal_mvp_enabled_flag".
+ * If IDR, the skipped bits are just "pic_output_flag"
+ * (separate_colour_plane_flag is not supported).
+ */
+#define V4L2_CID_HANTRO_HEVC_SLICE_HEADER_SKIP (V4L2_CID_CODEC_HANTRO_BASE + 0)
+
#endif
--
2.25.1