diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h index c0cab7d37828..98667becdee4 100644 --- a/include/linux/rfkill.h +++ b/include/linux/rfkill.h @@ -117,4 +117,11 @@ static inline char *rfkill_get_led_name(struct rfkill *rfkill) #endif } +/* rfkill notification chain */ +#define RFKILL_STATE_CHANGED 0x0001 /* state of a normal rfkill + switch has changed */ + +int register_rfkill_notifier(struct notifier_block *nb); +int unregister_rfkill_notifier(struct notifier_block *nb); + #endif /* RFKILL_H */ diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c index fb566902030a..a561e350a70a 100644 --- a/net/rfkill/rfkill.c +++ b/net/rfkill/rfkill.c @@ -46,6 +46,49 @@ MODULE_PARM_DESC(default_state, static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX]; +static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list); + + +/** + * register_rfkill_notifier - Add notifier to rfkill notifier chain + * @nb: pointer to the new entry to add to the chain + * + * See blocking_notifier_chain_register() for return value and further + * observations. + * + * Adds a notifier to the rfkill notifier chain. The chain will be + * called with a pointer to the relevant rfkill structure as a parameter, + * refer to include/linux/rfkill.h for the possible events. + * + * Notifiers added to this chain are to always return NOTIFY_DONE. This + * chain is a blocking notifier chain: notifiers can sleep. + * + * Calls to this chain may have been done through a workqueue. One must + * assume unordered asynchronous behaviour, there is no way to know if + * actions related to the event that generated the notification have been + * carried out already. + */ +int register_rfkill_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&rfkill_notifier_list, nb); +} +EXPORT_SYMBOL_GPL(register_rfkill_notifier); + +/** + * unregister_rfkill_notifier - remove notifier from rfkill notifier chain + * @nb: pointer to the entry to remove from the chain + * + * See blocking_notifier_chain_unregister() for return value and further + * observations. + * + * Removes a notifier from the rfkill notifier chain. + */ +int unregister_rfkill_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb); +} +EXPORT_SYMBOL_GPL(unregister_rfkill_notifier); + static void rfkill_led_trigger(struct rfkill *rfkill, enum rfkill_state state) @@ -62,14 +105,25 @@ static void rfkill_led_trigger(struct rfkill *rfkill, #endif /* CONFIG_RFKILL_LEDS */ } +static void notify_rfkill_state_change(struct rfkill *rfkill) +{ + blocking_notifier_call_chain(&rfkill_notifier_list, + RFKILL_STATE_CHANGED, + rfkill); +} + static void update_rfkill_state(struct rfkill *rfkill) { - enum rfkill_state newstate; + enum rfkill_state newstate, oldstate; if (rfkill->get_state) { mutex_lock(&rfkill->mutex); - if (!rfkill->get_state(rfkill->data, &newstate)) + if (!rfkill->get_state(rfkill->data, &newstate)) { + oldstate = rfkill->state; rfkill->state = newstate; + if (oldstate != newstate) + notify_rfkill_state_change(rfkill); + } mutex_unlock(&rfkill->mutex); } } @@ -93,8 +147,10 @@ static int rfkill_toggle_radio(struct rfkill *rfkill, rfkill->state = state; } - if (force || rfkill->state != oldstate) + if (force || rfkill->state != oldstate) { rfkill_led_trigger(rfkill, rfkill->state); + notify_rfkill_state_change(rfkill); + } return retval; } @@ -139,12 +195,20 @@ EXPORT_SYMBOL(rfkill_switch_all); */ int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state) { + enum rfkill_state oldstate; + if (state != RFKILL_STATE_OFF && state != RFKILL_STATE_ON) return -EINVAL; mutex_lock(&rfkill->mutex); + + oldstate = rfkill->state; rfkill->state = state; + + if (state != oldstate) + notify_rfkill_state_change(rfkill); + mutex_unlock(&rfkill->mutex); return 0;