[PATCH v4 25/29] media: v4l2-subdev: Move subdev client capabilities into a new struct

Sakari Ailus
2026-04-08T15:40:29Z

Add struct v4l2_subdev_client_info to hold sub-device client capability
bits that used to be stored in the client_caps field of struct
v4l2_subdev_fh. The intent is to enable passing this struct to sub-device
pad operation callbacks for capability information. The main reason why
this is a new struct instead of a u64 field is that modifying the callback
arguments requires touching almost every sub-device driver and that is
desirable to avoid in the future, should more than the client capability bits
need to be known to the callbacks.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mirela Rabulea <mirela.rabulea@nxp.com>
---
drivers/media/v4l2-core/v4l2-subdev.c | 8 ++++----
include/media/v4l2-subdev.h | 12 ++++++++++--
2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 40b28e070726..eaa408832c6b 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -612,7 +612,7 @@ subdev_ioctl_get_state(struct v4l2_subdev *sd, struct v4l2_subdev_fh *subdev_fh,
case VIDIOC_SUBDEV_S_FRAME_INTERVAL: {
struct v4l2_subdev_frame_interval *fi = arg;

- if (!(subdev_fh->client_caps &
+ if (!(subdev_fh->ci.client_caps &
V4L2_SUBDEV_CLIENT_CAP_INTERVAL_USES_WHICH))
fi->which = V4L2_SUBDEV_FORMAT_ACTIVE;

@@ -652,7 +652,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh);
bool ro_subdev = test_bit(V4L2_FL_SUBDEV_RO_DEVNODE, &vdev->flags);
bool streams_subdev = sd->flags & V4L2_SUBDEV_FL_STREAMS;
- bool client_supports_streams = subdev_fh->client_caps &
+ bool client_supports_streams = subdev_fh->ci.client_caps &
V4L2_SUBDEV_CLIENT_CAP_STREAMS;
int rval;

@@ -1119,7 +1119,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
case VIDIOC_SUBDEV_G_CLIENT_CAP: {
struct v4l2_subdev_client_capability *client_cap = arg;

- client_cap->capabilities = subdev_fh->client_caps;
+ client_cap->capabilities = subdev_fh->ci.client_caps;

return 0;
}
@@ -1139,7 +1139,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
client_cap->capabilities &= (V4L2_SUBDEV_CLIENT_CAP_STREAMS |
V4L2_SUBDEV_CLIENT_CAP_INTERVAL_USES_WHICH);

- subdev_fh->client_caps = client_cap->capabilities;
+ subdev_fh->ci.client_caps = client_cap->capabilities;

return 0;
}
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 93b672edd08e..e0861acc638d 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -734,6 +734,14 @@ struct v4l2_subdev_state {
struct v4l2_subdev_stream_configs stream_configs;
};

+/**
+ * struct v4l2_subdev_client_info - Sub-device client information
+ * @client_caps: bitmask of ``V4L2_SUBDEV_CLIENT_CAP_*``
+ */
+struct v4l2_subdev_client_info {
+ u64 client_caps;
+};
+
/**
* struct v4l2_subdev_pad_ops - v4l2-subdev pad level operations
*
@@ -1129,14 +1137,14 @@ struct v4l2_subdev {
* @vfh: pointer to &struct v4l2_fh
* @state: pointer to &struct v4l2_subdev_state
* @owner: module pointer to the owner of this file handle
- * @client_caps: bitmask of ``V4L2_SUBDEV_CLIENT_CAP_*``
+ * @ci: sub-device client info related to this file handle
*/
struct v4l2_subdev_fh {
struct v4l2_fh vfh;
struct module *owner;
#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
struct v4l2_subdev_state *state;
- u64 client_caps;
+ struct v4l2_subdev_client_info ci;
#endif
};

--
2.47.3