Re: [PATCH v2 4/9] media: uapi: Add a control for HANTRO driver

From: Benjamin Gaignard
Date: Mon Feb 22 2021 - 11:31:49 EST



Le 22/02/2021 à 17:16, John Cox a écrit :
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
that this purpose.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
---
include/uapi/linux/hantro-v4l2-controls.h | 20 ++++++++++++++++++++
include/uapi/linux/v4l2-controls.h | 5 +++++
2 files changed, 25 insertions(+)
create mode 100644 include/uapi/linux/hantro-v4l2-controls.h

diff --git a/include/uapi/linux/hantro-v4l2-controls.h b/include/uapi/linux/hantro-v4l2-controls.h
new file mode 100644
index 000000000000..30b1999b7af3
--- /dev/null
+++ b/include/uapi/linux/hantro-v4l2-controls.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+#ifndef __UAPI_HANTRO_V4L2_CONYTROLS_H__
+#define __UAPI_HANTRO_V4L2_CONYTROLS_H__
+
+#include <linux/v4l2-controls.h>
+#include <media/hevc-ctrls.h>
+
+#define V4L2_CID_HANTRO_HEVC_EXTRA_DECODE_PARAMS (V4L2_CID_USER_HANTRO_BASE + 0)
+
+/**
+ * struct hantro_hevc_extra_decode_params - extra decode parameters for hantro driver
+ * @hevc_hdr_skip_lenght: header first bits offset
+ */
+struct hantro_hevc_extra_decode_params {
+ __u32 hevc_hdr_skip_lenght;
+ __u8 padding[4];
+};
Can you clarify how hevc_hdr_skip_length differs from
v4l2_ctrl_hevc_slice_params.data_bit_offset? At first sight they would
appear to be very similar.

hevc_hdr_skip_length is the difference between the start positions of 2 nals.
v4l2_ctrl_hevc_slice_params.data_bit_offset is the offset of the data in the nal.


Benjamin


Regards

John Cox

+#endif
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 039c0d7add1b..ced7486c7f46 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -209,6 +209,11 @@ enum v4l2_colorfx {
* We reserve 128 controls for this driver.
*/
#define V4L2_CID_USER_CCS_BASE (V4L2_CID_USER_BASE + 0x10f0)
+/*
+ * The base for HANTRO driver controls.
+ * We reserve 32 controls for this driver.
+ */
+#define V4L2_CID_USER_HANTRO_BASE (V4L2_CID_USER_BASE + 0x1170)

/* MPEG-class control IDs */
/* The MPEG controls are applicable to all codec controls