[PATCHv3,4/4] dvbdev: add /sys media_dev attr for DVB devices
Commit Message
For each DVB device node create a media_dev attribute in /sys
which contains the media device major and minor number.
It is not created if the CONFIG_MEDIA_CONTROLLER_DVB is not
defined or if there is no associated media device.
This makes it possible for applications like v4l2-compliance
to find the associated media controller of a DVB device.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
---
drivers/media/dvb-core/dvbdev.c | 45 +++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
@@ -452,6 +452,48 @@ static int dvb_register_media_device(struct dvb_device *dvbdev,
return 0;
}
+#if defined(CONFIG_MEDIA_CONTROLLER_DVB)
+static ssize_t media_dev_show(struct device *cd,
+ struct device_attribute *attr, char *buf)
+{
+ struct dvb_device *dvbdev = dev_get_drvdata(cd);
+ dev_t devt = media_device_devt(dvbdev->adapter->mdev);
+
+ buf[0] = '\0';
+ if (!devt)
+ return 0;
+ return sprintf(buf, "%u:%u\n", MAJOR(devt), MINOR(devt));
+}
+static DEVICE_ATTR_RO(media_dev);
+
+static umode_t dvb_device_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ struct dvb_device *dvbdev = dev_get_drvdata(kobj_to_dev(kobj));
+
+ if (attr == &dev_attr_media_dev.attr) {
+ if (!dvbdev->adapter->mdev)
+ return 0;
+ }
+ return attr->mode;
+}
+
+static struct attribute *dvb_device_attrs[] = {
+ &dev_attr_media_dev.attr,
+ NULL,
+};
+
+static const struct attribute_group dvb_device_group = {
+ .is_visible = dvb_device_attr_is_visible,
+ .attrs = dvb_device_attrs,
+};
+
+static const struct attribute_group *dvb_device_groups[] = {
+ &dvb_device_group,
+ NULL
+};
+#endif
+
int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
const struct dvb_device *template, void *priv,
enum dvb_device_type type, int demux_sink_pads)
@@ -1056,6 +1098,9 @@ static int __init init_dvbdev(void)
}
dvb_class->dev_uevent = dvb_uevent;
dvb_class->devnode = dvb_devnode;
+#if defined(CONFIG_MEDIA_CONTROLLER_DVB)
+ dvb_class->dev_groups = dvb_device_groups;
+#endif
return 0;
error: