atm: propagate signal changes via notifier

Add notifier chain for changes in atm_dev.

Clients like br2684 will call register_atmdevice_notifier() to be notified of
changes. Drivers will call atm_dev_signal_change() to notify clients like
br2684 of the change.

On DSL and ATM devices it's usefull to have a know if you have a carrier
signal. netdevice LOWER_UP changes can be propagated to userspace via netlink
monitor.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
index 817b237..f6481da 100644
--- a/include/linux/atmdev.h
+++ b/include/linux/atmdev.h
@@ -431,6 +431,14 @@ struct atm_dev *atm_dev_register(const char *type,const struct atmdev_ops *ops,
     int number,unsigned long *flags); /* number == -1: pick first available */
 struct atm_dev *atm_dev_lookup(int number);
 void atm_dev_deregister(struct atm_dev *dev);
+
+/* atm_dev_signal_change
+ *
+ * Propagate lower layer signal change in atm_dev->signal to netdevice.
+ * The event will be sent via a notifier call chain.
+ */
+void atm_dev_signal_change(struct atm_dev *dev, char signal);
+
 void vcc_insert_socket(struct sock *sk);
 
 
@@ -510,6 +518,15 @@ void register_atm_ioctl(struct atm_ioctl *);
  */
 void deregister_atm_ioctl(struct atm_ioctl *);
 
+
+/* register_atmdevice_notifier - register atm_dev notify events
+ *
+ * Clients like br2684 will register notify events
+ * Currently we notify of signal found/lost
+ */
+int register_atmdevice_notifier(struct notifier_block *nb);
+void unregister_atmdevice_notifier(struct notifier_block *nb);
+
 #endif /* __KERNEL__ */
 
 #endif