aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.19/950-0690-media-videodev2.h-add-new-capabilities-for-buffer-ty.patch
blob: ffe6237bcebe920025e76a64ebab8d9f428c94c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
From ebd995296afa99a5c53f164e595f7a6d41d32a01 Mon Sep 17 00:00:00 2001
From: Hans Verkuil <hansverk@cisco.com>
Date: Thu, 23 Aug 2018 09:56:22 -0400
Subject: [PATCH 690/806] media: videodev2.h: add new capabilities for buffer
 types

Upstream commit f35f5d72e70e6b91389eb98fcabf43b79f40587f

VIDIOC_REQBUFS and VIDIOC_CREATE_BUFFERS will return capabilities
telling userspace what the given buffer type is capable of.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 .../media/uapi/v4l/vidioc-create-bufs.rst     | 14 ++++++-
 .../media/uapi/v4l/vidioc-reqbufs.rst         | 42 ++++++++++++++++++-
 include/uapi/linux/videodev2.h                | 13 +++++-
 3 files changed, 65 insertions(+), 4 deletions(-)

--- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
@@ -102,7 +102,19 @@ than the number requested.
       - ``format``
       - Filled in by the application, preserved by the driver.
     * - __u32
-      - ``reserved``\ [8]
+      - ``capabilities``
+      - Set by the driver. If 0, then the driver doesn't support
+        capabilities. In that case all you know is that the driver is
+	guaranteed to support ``V4L2_MEMORY_MMAP`` and *might* support
+	other :c:type:`v4l2_memory` types. It will not support any others
+	capabilities. See :ref:`here <v4l2-buf-capabilities>` for a list of the
+	capabilities.
+
+	If you want to just query the capabilities without making any
+	other changes, then set ``count`` to 0, ``memory`` to
+	``V4L2_MEMORY_MMAP`` and ``format.type`` to the buffer type.
+    * - __u32
+      - ``reserved``\ [7]
       - A place holder for future extensions. Drivers and applications
 	must set the array to zero.
 
--- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
@@ -88,10 +88,50 @@ any DMA in progress, an implicit
 	``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See
 	:c:type:`v4l2_memory`.
     * - __u32
-      - ``reserved``\ [2]
+      - ``capabilities``
+      - Set by the driver. If 0, then the driver doesn't support
+        capabilities. In that case all you know is that the driver is
+	guaranteed to support ``V4L2_MEMORY_MMAP`` and *might* support
+	other :c:type:`v4l2_memory` types. It will not support any others
+	capabilities.
+
+	If you want to query the capabilities with a minimum of side-effects,
+	then this can be called with ``count`` set to 0, ``memory`` set to
+	``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will
+	free any previously allocated buffers, so this is typically something
+	that will be done at the start of the application.
+    * - __u32
+      - ``reserved``\ [1]
       - A place holder for future extensions. Drivers and applications
 	must set the array to zero.
 
+.. tabularcolumns:: |p{6.1cm}|p{2.2cm}|p{8.7cm}|
+
+.. _v4l2-buf-capabilities:
+.. _V4L2-BUF-CAP-SUPPORTS-MMAP:
+.. _V4L2-BUF-CAP-SUPPORTS-USERPTR:
+.. _V4L2-BUF-CAP-SUPPORTS-DMABUF:
+.. _V4L2-BUF-CAP-SUPPORTS-REQUESTS:
+
+.. cssclass:: longtable
+
+.. flat-table:: V4L2 Buffer Capabilities Flags
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       3 1 4
+
+    * - ``V4L2_BUF_CAP_SUPPORTS_MMAP``
+      - 0x00000001
+      - This buffer type supports the ``V4L2_MEMORY_MMAP`` streaming mode.
+    * - ``V4L2_BUF_CAP_SUPPORTS_USERPTR``
+      - 0x00000002
+      - This buffer type supports the ``V4L2_MEMORY_USERPTR`` streaming mode.
+    * - ``V4L2_BUF_CAP_SUPPORTS_DMABUF``
+      - 0x00000004
+      - This buffer type supports the ``V4L2_MEMORY_DMABUF`` streaming mode.
+    * - ``V4L2_BUF_CAP_SUPPORTS_REQUESTS``
+      - 0x00000008
+      - This buffer type supports :ref:`requests <media-request-api>`.
 
 Return Value
 ============
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -872,9 +872,16 @@ struct v4l2_requestbuffers {
 	__u32			count;
 	__u32			type;		/* enum v4l2_buf_type */
 	__u32			memory;		/* enum v4l2_memory */
-	__u32			reserved[2];
+	__u32			capabilities;
+	__u32			reserved[1];
 };
 
+/* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
+#define V4L2_BUF_CAP_SUPPORTS_MMAP	(1 << 0)
+#define V4L2_BUF_CAP_SUPPORTS_USERPTR	(1 << 1)
+#define V4L2_BUF_CAP_SUPPORTS_DMABUF	(1 << 2)
+#define V4L2_BUF_CAP_SUPPORTS_REQUESTS	(1 << 3)
+
 /**
  * struct v4l2_plane - plane info for multi-planar buffers
  * @bytesused:		number of bytes occupied by data in the plane (payload)
@@ -2318,6 +2325,7 @@ struct v4l2_dbg_chip_info {
  *		return: number of created buffers
  * @memory:	enum v4l2_memory; buffer memory type
  * @format:	frame format, for which buffers are requested
+ * @capabilities: capabilities of this buffer type.
  * @reserved:	future extensions
  */
 struct v4l2_create_buffers {
@@ -2325,7 +2333,8 @@ struct v4l2_create_buffers {
 	__u32			count;
 	__u32			memory;
 	struct v4l2_format	format;
-	__u32			reserved[8];
+	__u32			capabilities;
+	__u32			reserved[7];
 };
 
 /*