[PATCH 10/11] media: v4l2: Add callback for show_fdinfo

Detlev Casanova
2026-02-12T16:24:26Z

Allow v4l2 drivers to add information in the fdinfo file matching the
opened /dev/videoX file.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
drivers/media/v4l2-core/v4l2-dev.c | 10 ++++++++++
include/media/v4l2-dev.h | 1 +
2 files changed, 11 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index 10a126e50c1c..29c04f5f4c59 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -481,6 +481,15 @@ static int v4l2_release(struct inode *inode, struct file *filp)
return ret;
}

+/* Override for the show_fdinfo function */
+static void v4l2_show_fdinfo(struct seq_file *m, struct file *filp)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (vdev->fops->show_fdinfo)
+ vdev->fops->show_fdinfo(m, filp);
+}
+
static const struct file_operations v4l2_fops = {
.owner = THIS_MODULE,
.read = v4l2_read,
@@ -494,6 +503,7 @@ static const struct file_operations v4l2_fops = {
#endif
.release = v4l2_release,
.poll = v4l2_poll,
+ .show_fdinfo = v4l2_show_fdinfo,
};

/**
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 2e0f6d2e6a78..1635ab186f21 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -212,6 +212,7 @@ struct v4l2_file_operations {
int (*mmap) (struct file *, struct vm_area_struct *);
int (*open) (struct file *);
int (*release) (struct file *);
+ void (*show_fdinfo)(struct seq_file *, struct file *);
};

/*
--
2.53.0