[v6,7/8] utils/common: Set V4L2_SUBDEV_CLIENT_CAP_STREAMS for subdevs

Commit Message

Tomi Valkeinen July 20, 2023, 7:50 a.m. UTC

Use the new VIDIOC_SUBDEV_S_CLIENT_CAP ioctl to inform the kernel that
we support streams, and use the return values of
VIDIOC_SUBDEV_S_CLIENT_CAP and VIDIOC_SUBDEV_QUERYCAP to decide if the
entity supports streams.

Signed-off-by: Tomi Valkeinen <[e-mail]>
Reviewed-by: Laurent Pinchart <[e-mail]>
---
 utils/common/cv4l-helpers.h |  1 +
 utils/common/v4l-helpers.h  | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

Patch

diff --git a/utils/common/cv4l-helpers.h b/utils/common/cv4l-helpers.h
index 3cee372b..91a04146 100644
--- a/utils/common/cv4l-helpers.h
+++ b/utils/common/cv4l-helpers.h
@@ -82,6 +82,7 @@  public:
 	bool has_rw() const { return v4l_has_rw(this); }
 	bool has_streaming() const { return v4l_has_streaming(this); }
 	bool has_ext_pix_format() const { return v4l_has_ext_pix_format(this); }
+	bool has_streams() const { return have_streams; }
 
 	int querycap(v4l2_capability &cap, bool force = false)
 	{
diff --git a/utils/common/v4l-helpers.h b/utils/common/v4l-helpers.h
index c09cd987..f8e96d58 100644
--- a/utils/common/v4l-helpers.h
+++ b/utils/common/v4l-helpers.h
@@ -9,6 +9,7 @@ 
 #ifndef _V4L_HELPERS_H_
 #define _V4L_HELPERS_H_
 
+#include <linux/v4l2-subdev.h>
 #include <linux/videodev2.h>
 #include <string.h>
 #include <stdlib.h>
@@ -39,6 +40,7 @@  struct v4l_fd {
 	bool have_selection;
 	bool is_subdev;
 	bool is_media;
+	bool have_streams;
 
 	int (*open)(struct v4l_fd *f, const char *file, int oflag, ...);
 	int (*close)(struct v4l_fd *f);
@@ -507,6 +509,12 @@  static inline int v4l_open(struct v4l_fd *f, const char *devname, bool non_block
 
 static inline int v4l_subdev_s_fd(struct v4l_fd *f, int fd, const char *devname)
 {
+	struct v4l2_subdev_client_capability clientcap = {};
+	struct v4l2_subdev_capability subdevcap = {};
+	bool subdev_streams;
+	bool client_streams;
+	int ret;
+
 	if (f->fd >= 0)
 		f->close(f);
 
@@ -528,6 +536,16 @@  static inline int v4l_subdev_s_fd(struct v4l_fd *f, int fd, const char *devname)
 	f->have_next_ctrl = false;
 	f->have_selection = false;
 
+	ret = ioctl(f->fd, VIDIOC_SUBDEV_QUERYCAP, &subdevcap);
+	subdev_streams = !ret && (subdevcap.capabilities & V4L2_SUBDEV_CAP_STREAMS);
+
+	clientcap.capabilities = V4L2_SUBDEV_CLIENT_CAP_STREAMS;
+
+	ret = ioctl(f->fd, VIDIOC_SUBDEV_S_CLIENT_CAP, &clientcap);
+	client_streams = !ret && (clientcap.capabilities & V4L2_SUBDEV_CLIENT_CAP_STREAMS);
+
+	f->have_streams = subdev_streams && client_streams;
+
 	return f->fd;
 }