[PATCH v3 1/5] media: v4l2: Add callback for show_fdinfo
From: Detlev Casanova <detlev.casanova@collabora.com>
Date: 2026-07-06 13:42:41
Also in:
linux-media, linux-rockchip, lkml
Subsystem:
media input infrastructure (v4l/dvb), the rest · Maintainers:
Mauro Carvalho Chehab, Linus Torvalds
Allow v4l2 drivers to add information in the fdinfo file matching the opened /dev/videoX file. The core prints the standard "v4l2-driver:" key with the driver name and then calls the driver's optional show_fdinfo callback, added to struct v4l2_file_operations, to let drivers append their own key:value pairs. 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 5516b2bbb08f..6de85de0fd76 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 *); }; /*
--
2.54.0