[libcamera-devel] [PATCH v2] v4l2: V4L2CameraProxy: Add support for DMABUF buffer I/O in REQBUF ioctl

[Vedant Paranjape]

To support importing DMABUF, we need to reqbufs with DMABUF mode.

This patch enables using V4L2_MEMORY_DMABUF as one of the memory types
in vidioc_reqbuf to initialise DMA Buffer I/O

Bug: https://bugs.libcamera.org/show_bug.cgi?id=89

Signed-off-by: Vedant Paranjape <vedantparanjape160201 at gmail.com>
---
 src/v4l2/v4l2_camera_proxy.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index f194e06345b7..49db766d9f9d 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -160,7 +160,8 @@ bool V4L2CameraProxy::validateBufferType(uint32_t type)
 
 bool V4L2CameraProxy::validateMemoryType(uint32_t memory)
 {
-	return memory == V4L2_MEMORY_MMAP;
+	return (memory == V4L2_MEMORY_MMAP) ||
+	       (memory == V4L2_MEMORY_DMABUF);
 }
 
 void V4L2CameraProxy::setFmtFromConfig(const StreamConfiguration &streamConfig)
@@ -468,7 +469,8 @@ int V4L2CameraProxy::vidioc_reqbufs(V4L2CameraFile *file, struct v4l2_requestbuf
 	if (!hasOwnership(file) && owner_)
 		return -EBUSY;
 
-	arg->capabilities = V4L2_BUF_CAP_SUPPORTS_MMAP;
+	arg->capabilities = V4L2_BUF_CAP_SUPPORTS_MMAP |
+			    V4L2_BUF_CAP_SUPPORTS_DMABUF;
 	memset(arg->reserved, 0, sizeof(arg->reserved));
 
 	if (arg->count == 0) {
@@ -511,7 +513,7 @@ int V4L2CameraProxy::vidioc_reqbufs(V4L2CameraFile *file, struct v4l2_requestbuf
 		struct v4l2_buffer buf = {};
 		buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 		buf.length = v4l2PixFormat_.sizeimage;
-		buf.memory = V4L2_MEMORY_MMAP;
+		buf.memory = arg->memory;
 		buf.m.offset = i * v4l2PixFormat_.sizeimage;
 		buf.index = i;
 		buf.flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
-- 
2.25.1