1From 81471d8195f3da907205ec7384bccfe9c8f846fd Mon Sep 17 00:00:00 2001
2From: "vicent.chi" <vicent.chi@rock-chips.com>
3Date: Thu, 31 Oct 2019 11:46:12 +0800
4Subject: [PATCH 3/7] libv4l: add V4L2_MEMORY_DMABUF memory support
5
6Signed-off-by: vicent.chi <vicent.chi@rock-chips.com>
7---
8 lib/libv4l2/libv4l2-priv.h |  1 +
9 lib/libv4l2/libv4l2.c      | 23 +++++++++++++++++++++--
10 2 files changed, 22 insertions(+), 2 deletions(-)
11
12diff --git a/lib/libv4l2/libv4l2-priv.h b/lib/libv4l2/libv4l2-priv.h
13index 1924c91..30dd1bc 100644
14--- a/lib/libv4l2/libv4l2-priv.h
15+++ b/lib/libv4l2/libv4l2-priv.h
16@@ -104,6 +104,7 @@ struct v4l2_dev_info {
17 	void *plugin_library;
18 	void *dev_ops_priv;
19 	const struct libv4l_dev_ops *dev_ops;
20+	int has_dmabuf_memory;
21 };
22
23 /* From v4l2-plugin.c */
24diff --git a/lib/libv4l2/libv4l2.c b/lib/libv4l2/libv4l2.c
25index 0c02bec..0b17888 100644
26--- a/lib/libv4l2/libv4l2.c
27+++ b/lib/libv4l2/libv4l2.c
28@@ -543,7 +543,7 @@ static int v4l2_deactivate_read_stream(int index)
29
30 static int v4l2_needs_conversion(int index)
31 {
32-	if (devices[index].convert == NULL)
33+	if (devices[index].convert == NULL || devices[index].has_dmabuf_memory)
34 		return 0;
35
36 	return v4lconvert_needs_conversion(devices[index].convert,
37@@ -1305,12 +1305,18 @@ no_capture_request:
38 		struct v4l2_requestbuffers *req = arg;
39
40 		/* IMPROVEME (maybe?) add support for userptr's? */
41-		if (req->memory != V4L2_MEMORY_MMAP) {
42+		if (req->memory != V4L2_MEMORY_MMAP && req->memory != V4L2_MEMORY_DMABUF) {
43 			errno = EINVAL;
44 			result = -1;
45 			break;
46 		}
47
48+		if (req->memory == V4L2_MEMORY_DMABUF) {
49+			devices[index].has_dmabuf_memory = 1;
50+			V4L2_LOG("memory type is V4L2_MEMORY_DMABUF, "
51+			         "buf conversion and mmap emulation are disabled\n");
52+		}
53+
54 		result = v4l2_check_buffer_change_ok(index);
55 		if (result)
56 			break;
57@@ -1563,6 +1569,14 @@ ssize_t v4l2_read(int fd, void *dest, size_t n)
58 		goto leave;
59 	}
60
61+	if (!(devices[index].flags & V4L2_USE_READ_FOR_READ) &&
62+	    devices[index].has_dmabuf_memory) {
63+		V4L2_PERROR("memory type is V4L2_MEMORY_DMABUF, "
64+		            "no support v4l2 read\n");
65+		errno = EINVAL;
66+		return -1;
67+	}
68+
69 	/* Since we need to do conversion try to use mmap (streaming) mode under
70 	   the hood as that safes a memcpy for each frame read.
71
72@@ -1627,6 +1641,7 @@ void *v4l2_mmap(void *start, size_t length, int prot, int flags, int fd,
73 	void *result;
74
75 	index = v4l2_get_index(fd);
76+
77 	if (index != -1 && devices[index].dev_ops->mmap) {
78 		pthread_mutex_lock(&devices[index].stream_lock);
79 		result = devices[index].dev_ops->mmap(
80@@ -1637,6 +1652,10 @@ void *v4l2_mmap(void *start, size_t length, int prot, int flags, int fd,
81 		return result;
82 	}
83
84+        if (index != -1 && devices[index].has_dmabuf_memory) {
85+                return (void *)SYS_MMAP(start, length, prot, flags, fd, offset);
86+        }
87+
88 	if (index == -1 ||
89 			/* Check if the mmap data matches our answer to QUERY_BUF. If it doesn't,
90 			   let the kernel handle it (to allow for mmap-based non capture use) */
91--
922.20.1
93
94