rfkill: preserve state across suspend
[safe/jmp/linux-2.6] / net / rfkill / rfkill.c
index dd1c3f1..5ad411d 100644 (file)
@@ -37,14 +37,21 @@ MODULE_DESCRIPTION("RF switch support");
 MODULE_LICENSE("GPL");
 
 static LIST_HEAD(rfkill_list); /* list of registered rf switches */
-static DEFINE_MUTEX(rfkill_mutex);
+static DEFINE_MUTEX(rfkill_global_mutex);
 
-static unsigned int rfkill_default_state = RFKILL_STATE_ON;
+static unsigned int rfkill_default_state = RFKILL_STATE_UNBLOCKED;
 module_param_named(default_state, rfkill_default_state, uint, 0444);
 MODULE_PARM_DESC(default_state,
                 "Default initial state for all radio types, 0 = radio off");
 
-static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
+struct rfkill_gsw_state {
+       enum rfkill_state current_state;
+       enum rfkill_state default_state;
+};
+
+static struct rfkill_gsw_state rfkill_global_states[RFKILL_TYPE_MAX];
+static unsigned long rfkill_states_lockdflt[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
+static bool rfkill_epo_lock_active;
 
 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
 
@@ -70,6 +77,7 @@ static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
  */
 int register_rfkill_notifier(struct notifier_block *nb)
 {
+       BUG_ON(!nb);
        return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
@@ -85,6 +93,7 @@ EXPORT_SYMBOL_GPL(register_rfkill_notifier);
  */
 int unregister_rfkill_notifier(struct notifier_block *nb)
 {
+       BUG_ON(!nb);
        return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
@@ -98,15 +107,26 @@ static void rfkill_led_trigger(struct rfkill *rfkill,
 
        if (!led->name)
                return;
-       if (state == RFKILL_STATE_OFF)
+       if (state != RFKILL_STATE_UNBLOCKED)
                led_trigger_event(led, LED_OFF);
        else
                led_trigger_event(led, LED_FULL);
 #endif /* CONFIG_RFKILL_LEDS */
 }
 
+#ifdef CONFIG_RFKILL_LEDS
+static void rfkill_led_trigger_activate(struct led_classdev *led)
+{
+       struct rfkill *rfkill = container_of(led->trigger,
+                       struct rfkill, led_trigger);
+
+       rfkill_led_trigger(rfkill, rfkill->state);
+}
+#endif /* CONFIG_RFKILL_LEDS */
+
 static void notify_rfkill_state_change(struct rfkill *rfkill)
 {
+       rfkill_led_trigger(rfkill, rfkill->state);
        blocking_notifier_call_chain(&rfkill_notifier_list,
                        RFKILL_STATE_CHANGED,
                        rfkill);
@@ -128,6 +148,31 @@ static void update_rfkill_state(struct rfkill *rfkill)
        }
 }
 
+/**
+ * rfkill_toggle_radio - wrapper for toggle_radio hook
+ * @rfkill: the rfkill struct to use
+ * @force: calls toggle_radio even if cache says it is not needed,
+ *     and also makes sure notifications of the state will be
+ *     sent even if it didn't change
+ * @state: the new state to call toggle_radio() with
+ *
+ * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
+ * calls and handling all the red tape such as issuing notifications
+ * if the call is successful.
+ *
+ * Suspended devices are not touched at all, and -EAGAIN is returned.
+ *
+ * Note that the @force parameter cannot override a (possibly cached)
+ * state of RFKILL_STATE_HARD_BLOCKED.  Any device making use of
+ * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
+ * rfkill_force_state(), so the cache either is bypassed or valid.
+ *
+ * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
+ * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
+ * give the driver a hint that it should double-BLOCK the transmitter.
+ *
+ * Caller must have acquired rfkill->mutex.
+ */
 static int rfkill_toggle_radio(struct rfkill *rfkill,
                                enum rfkill_state state,
                                int force)
@@ -135,53 +180,198 @@ static int rfkill_toggle_radio(struct rfkill *rfkill,
        int retval = 0;
        enum rfkill_state oldstate, newstate;
 
+       if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
+               return -EBUSY;
+
        oldstate = rfkill->state;
 
        if (rfkill->get_state && !force &&
            !rfkill->get_state(rfkill->data, &newstate))
                rfkill->state = newstate;
 
+       switch (state) {
+       case RFKILL_STATE_HARD_BLOCKED:
+               /* typically happens when refreshing hardware state,
+                * such as on resume */
+               state = RFKILL_STATE_SOFT_BLOCKED;
+               break;
+       case RFKILL_STATE_UNBLOCKED:
+               /* force can't override this, only rfkill_force_state() can */
+               if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
+                       return -EPERM;
+               break;
+       case RFKILL_STATE_SOFT_BLOCKED:
+               /* nothing to do, we want to give drivers the hint to double
+                * BLOCK even a transmitter that is already in state
+                * RFKILL_STATE_HARD_BLOCKED */
+               break;
+       default:
+               WARN(1, KERN_WARNING
+                       "rfkill: illegal state %d passed as parameter "
+                       "to rfkill_toggle_radio\n", state);
+               return -EINVAL;
+       }
+
        if (force || state != rfkill->state) {
                retval = rfkill->toggle_radio(rfkill->data, state);
-               if (!retval)
+               /* never allow a HARD->SOFT downgrade! */
+               if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
                        rfkill->state = state;
        }
 
-       if (force || rfkill->state != oldstate) {
-               rfkill_led_trigger(rfkill, rfkill->state);
+       if (force || rfkill->state != oldstate)
                notify_rfkill_state_change(rfkill);
-       }
 
        return retval;
 }
 
 /**
- * rfkill_switch_all - Toggle state of all switches of given type
- * @type: type of interfaces to be affeceted
+ * __rfkill_switch_all - Toggle state of all switches of given type
+ * @type: type of interfaces to be affected
  * @state: the new state
  *
- * This function toggles state of all switches of given type unless
- * a specific switch is claimed by userspace in which case it is
- * left alone.
+ * This function toggles the state of all switches of given type,
+ * unless a specific switch is claimed by userspace (in which case,
+ * that switch is left alone) or suspended.
+ *
+ * Caller must have acquired rfkill_global_mutex.
  */
-void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
+static void __rfkill_switch_all(const enum rfkill_type type,
+                               const enum rfkill_state state)
 {
        struct rfkill *rfkill;
 
-       mutex_lock(&rfkill_mutex);
-
-       rfkill_states[type] = state;
+       if (WARN((state >= RFKILL_STATE_MAX || type >= RFKILL_TYPE_MAX),
+                       KERN_WARNING
+                       "rfkill: illegal state %d or type %d "
+                       "passed as parameter to __rfkill_switch_all\n",
+                       state, type))
+               return;
 
+       rfkill_global_states[type].current_state = state;
        list_for_each_entry(rfkill, &rfkill_list, node) {
-               if ((!rfkill->user_claim) && (rfkill->type == type))
+               if ((!rfkill->user_claim) && (rfkill->type == type)) {
+                       mutex_lock(&rfkill->mutex);
                        rfkill_toggle_radio(rfkill, state, 0);
+                       mutex_unlock(&rfkill->mutex);
+               }
        }
+}
 
-       mutex_unlock(&rfkill_mutex);
+/**
+ * rfkill_switch_all - Toggle state of all switches of given type
+ * @type: type of interfaces to be affected
+ * @state: the new state
+ *
+ * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
+ * Please refer to __rfkill_switch_all() for details.
+ *
+ * Does nothing if the EPO lock is active.
+ */
+void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
+{
+       mutex_lock(&rfkill_global_mutex);
+       if (!rfkill_epo_lock_active)
+               __rfkill_switch_all(type, state);
+       mutex_unlock(&rfkill_global_mutex);
 }
 EXPORT_SYMBOL(rfkill_switch_all);
 
 /**
+ * rfkill_epo - emergency power off all transmitters
+ *
+ * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
+ * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
+ *
+ * The global state before the EPO is saved and can be restored later
+ * using rfkill_restore_states().
+ */
+void rfkill_epo(void)
+{
+       struct rfkill *rfkill;
+       int i;
+
+       mutex_lock(&rfkill_global_mutex);
+
+       rfkill_epo_lock_active = true;
+       list_for_each_entry(rfkill, &rfkill_list, node) {
+               mutex_lock(&rfkill->mutex);
+               rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
+               mutex_unlock(&rfkill->mutex);
+       }
+       for (i = 0; i < RFKILL_TYPE_MAX; i++) {
+               rfkill_global_states[i].default_state =
+                               rfkill_global_states[i].current_state;
+               rfkill_global_states[i].current_state =
+                               RFKILL_STATE_SOFT_BLOCKED;
+       }
+       mutex_unlock(&rfkill_global_mutex);
+}
+EXPORT_SYMBOL_GPL(rfkill_epo);
+
+/**
+ * rfkill_restore_states - restore global states
+ *
+ * Restore (and sync switches to) the global state from the
+ * states in rfkill_default_states.  This can undo the effects of
+ * a call to rfkill_epo().
+ */
+void rfkill_restore_states(void)
+{
+       int i;
+
+       mutex_lock(&rfkill_global_mutex);
+
+       rfkill_epo_lock_active = false;
+       for (i = 0; i < RFKILL_TYPE_MAX; i++)
+               __rfkill_switch_all(i, rfkill_global_states[i].default_state);
+       mutex_unlock(&rfkill_global_mutex);
+}
+EXPORT_SYMBOL_GPL(rfkill_restore_states);
+
+/**
+ * rfkill_remove_epo_lock - unlock state changes
+ *
+ * Used by rfkill-input manually unlock state changes, when
+ * the EPO switch is deactivated.
+ */
+void rfkill_remove_epo_lock(void)
+{
+       mutex_lock(&rfkill_global_mutex);
+       rfkill_epo_lock_active = false;
+       mutex_unlock(&rfkill_global_mutex);
+}
+EXPORT_SYMBOL_GPL(rfkill_remove_epo_lock);
+
+/**
+ * rfkill_is_epo_lock_active - returns true EPO is active
+ *
+ * Returns 0 (false) if there is NOT an active EPO contidion,
+ * and 1 (true) if there is an active EPO contition, which
+ * locks all radios in one of the BLOCKED states.
+ *
+ * Can be called in atomic context.
+ */
+bool rfkill_is_epo_lock_active(void)
+{
+       return rfkill_epo_lock_active;
+}
+EXPORT_SYMBOL_GPL(rfkill_is_epo_lock_active);
+
+/**
+ * rfkill_get_global_state - returns global state for a type
+ * @type: the type to get the global state of
+ *
+ * Returns the current global state for a given wireless
+ * device type.
+ */
+enum rfkill_state rfkill_get_global_state(const enum rfkill_type type)
+{
+       return rfkill_global_states[type].current_state;
+}
+EXPORT_SYMBOL_GPL(rfkill_get_global_state);
+
+/**
  * rfkill_force_state - Force the internal rfkill radio state
  * @rfkill: pointer to the rfkill class to modify.
  * @state: the current radio state the class should be forced to.
@@ -191,14 +381,22 @@ EXPORT_SYMBOL(rfkill_switch_all);
  * a notification by the firmware/hardware of the current *real*
  * state of the radio rfkill switch.
  *
- * It may not be called from an atomic context.
+ * Devices which are subject to external changes on their rfkill
+ * state (such as those caused by a hardware rfkill line) MUST
+ * have their driver arrange to call rfkill_force_state() as soon
+ * as possible after such a change.
+ *
+ * This function may not be called from an atomic context.
  */
 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 {
        enum rfkill_state oldstate;
 
-       if (state != RFKILL_STATE_OFF &&
-           state != RFKILL_STATE_ON)
+       BUG_ON(!rfkill);
+       if (WARN((state >= RFKILL_STATE_MAX),
+                       KERN_WARNING
+                       "rfkill: illegal state %d passed as parameter "
+                       "to rfkill_force_state\n", state))
                return -EINVAL;
 
        mutex_lock(&rfkill->mutex);
@@ -266,17 +464,30 @@ static ssize_t rfkill_state_store(struct device *dev,
                                  const char *buf, size_t count)
 {
        struct rfkill *rfkill = to_rfkill(dev);
-       unsigned int state = simple_strtoul(buf, NULL, 0);
+       unsigned long state;
        int error;
 
        if (!capable(CAP_NET_ADMIN))
                return -EPERM;
 
-       if (mutex_lock_interruptible(&rfkill->mutex))
-               return -ERESTARTSYS;
-       error = rfkill_toggle_radio(rfkill,
-                       state ? RFKILL_STATE_ON : RFKILL_STATE_OFF,
-                       0);
+       error = strict_strtoul(buf, 0, &state);
+       if (error)
+               return error;
+
+       /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
+       if (state != RFKILL_STATE_UNBLOCKED &&
+           state != RFKILL_STATE_SOFT_BLOCKED)
+               return -EINVAL;
+
+       error = mutex_lock_killable(&rfkill->mutex);
+       if (error)
+               return error;
+
+       if (!rfkill_epo_lock_active)
+               error = rfkill_toggle_radio(rfkill, state, 0);
+       else
+               error = -EPERM;
+
        mutex_unlock(&rfkill->mutex);
 
        return error ? error : count;
@@ -288,7 +499,7 @@ static ssize_t rfkill_claim_show(struct device *dev,
 {
        struct rfkill *rfkill = to_rfkill(dev);
 
-       return sprintf(buf, "%d", rfkill->user_claim);
+       return sprintf(buf, "%d\n", rfkill->user_claim);
 }
 
 static ssize_t rfkill_claim_store(struct device *dev,
@@ -296,34 +507,41 @@ static ssize_t rfkill_claim_store(struct device *dev,
                                  const char *buf, size_t count)
 {
        struct rfkill *rfkill = to_rfkill(dev);
-       bool claim = !!simple_strtoul(buf, NULL, 0);
+       unsigned long claim_tmp;
+       bool claim;
        int error;
 
        if (!capable(CAP_NET_ADMIN))
                return -EPERM;
 
+       if (rfkill->user_claim_unsupported)
+               return -EOPNOTSUPP;
+
+       error = strict_strtoul(buf, 0, &claim_tmp);
+       if (error)
+               return error;
+       claim = !!claim_tmp;
+
        /*
         * Take the global lock to make sure the kernel is not in
         * the middle of rfkill_switch_all
         */
-       error = mutex_lock_interruptible(&rfkill_mutex);
+       error = mutex_lock_killable(&rfkill_global_mutex);
        if (error)
                return error;
 
-       if (rfkill->user_claim_unsupported) {
-               error = -EOPNOTSUPP;
-               goto out_unlock;
-       }
        if (rfkill->user_claim != claim) {
-               if (!claim)
+               if (!claim && !rfkill_epo_lock_active) {
+                       mutex_lock(&rfkill->mutex);
                        rfkill_toggle_radio(rfkill,
-                                           rfkill_states[rfkill->type],
-                                           0);
+                                       rfkill_global_states[rfkill->type].current_state,
+                                       0);
+                       mutex_unlock(&rfkill->mutex);
+               }
                rfkill->user_claim = claim;
        }
 
-out_unlock:
-       mutex_unlock(&rfkill_mutex);
+       mutex_unlock(&rfkill_global_mutex);
 
        return error ? error : count;
 }
@@ -349,18 +567,12 @@ static int rfkill_suspend(struct device *dev, pm_message_t state)
 {
        struct rfkill *rfkill = to_rfkill(dev);
 
-       if (dev->power.power_state.event != state.event) {
-               if (state.event & PM_EVENT_SLEEP) {
-                       /* Stop transmitter, keep state, no notifies */
-                       update_rfkill_state(rfkill);
-
-                       mutex_lock(&rfkill->mutex);
-                       rfkill->toggle_radio(rfkill->data, RFKILL_STATE_OFF);
-                       mutex_unlock(&rfkill->mutex);
-               }
-
+       /* mark class device as suspended */
+       if (dev->power.power_state.event != state.event)
                dev->power.power_state = state;
-       }
+
+       /* store state for the resume handler */
+       rfkill->state_for_resume = rfkill->state;
 
        return 0;
 }
@@ -372,13 +584,23 @@ static int rfkill_resume(struct device *dev)
        if (dev->power.power_state.event != PM_EVENT_ON) {
                mutex_lock(&rfkill->mutex);
 
-               /* restore radio state AND notify everybody */
-               rfkill_toggle_radio(rfkill, rfkill->state, 1);
+               dev->power.power_state.event = PM_EVENT_ON;
+
+               /*
+                * If we are under EPO, kick transmitter offline,
+                * otherwise restore to pre-suspend state.
+                *
+                * Issue a notification in any case
+                */
+               rfkill_toggle_radio(rfkill,
+                               rfkill_epo_lock_active ?
+                                       RFKILL_STATE_SOFT_BLOCKED :
+                                       rfkill->state_for_resume,
+                               1);
 
                mutex_unlock(&rfkill->mutex);
        }
 
-       dev->power.power_state = PMSG_ON;
        return 0;
 }
 #else
@@ -433,27 +655,64 @@ static struct class rfkill_class = {
        .dev_uevent     = rfkill_dev_uevent,
 };
 
+static int rfkill_check_duplicity(const struct rfkill *rfkill)
+{
+       struct rfkill *p;
+       unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
+
+       memset(seen, 0, sizeof(seen));
+
+       list_for_each_entry(p, &rfkill_list, node) {
+               if (WARN((p == rfkill), KERN_WARNING
+                               "rfkill: illegal attempt to register "
+                               "an already registered rfkill struct\n"))
+                       return -EEXIST;
+               set_bit(p->type, seen);
+       }
+
+       /* 0: first switch of its kind */
+       return (test_bit(rfkill->type, seen)) ? 1 : 0;
+}
+
 static int rfkill_add_switch(struct rfkill *rfkill)
 {
        int error;
 
-       mutex_lock(&rfkill_mutex);
+       mutex_lock(&rfkill_global_mutex);
 
-       error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
-       if (!error)
-               list_add_tail(&rfkill->node, &rfkill_list);
+       error = rfkill_check_duplicity(rfkill);
+       if (error < 0)
+               goto unlock_out;
 
-       mutex_unlock(&rfkill_mutex);
+       if (!error) {
+               /* lock default after first use */
+               set_bit(rfkill->type, rfkill_states_lockdflt);
+               rfkill_global_states[rfkill->type].current_state =
+                       rfkill_global_states[rfkill->type].default_state;
+       }
+
+       rfkill_toggle_radio(rfkill,
+                           rfkill_global_states[rfkill->type].current_state,
+                           0);
+
+       list_add_tail(&rfkill->node, &rfkill_list);
+
+       error = 0;
+unlock_out:
+       mutex_unlock(&rfkill_global_mutex);
 
        return error;
 }
 
 static void rfkill_remove_switch(struct rfkill *rfkill)
 {
-       mutex_lock(&rfkill_mutex);
+       mutex_lock(&rfkill_global_mutex);
        list_del_init(&rfkill->node);
-       rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF, 1);
-       mutex_unlock(&rfkill_mutex);
+       mutex_unlock(&rfkill_global_mutex);
+
+       mutex_lock(&rfkill->mutex);
+       rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
+       mutex_unlock(&rfkill->mutex);
 }
 
 /**
@@ -462,17 +721,25 @@ static void rfkill_remove_switch(struct rfkill *rfkill)
  * @type: type of the switch (RFKILL_TYPE_*)
  *
  * This function should be called by the network driver when it needs
- * rfkill structure. Once the structure is allocated the driver shoud
- * finish its initialization by setting name, private data, enable_radio
+ * rfkill structure.  Once the structure is allocated the driver should
+ * finish its initialization by setting the name, private data, enable_radio
  * and disable_radio methods and then register it with rfkill_register().
+ *
  * NOTE: If registration fails the structure shoudl be freed by calling
  * rfkill_free() otherwise rfkill_unregister() should be used.
  */
-struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
+struct rfkill * __must_check rfkill_allocate(struct device *parent,
+                                            enum rfkill_type type)
 {
        struct rfkill *rfkill;
        struct device *dev;
 
+       if (WARN((type >= RFKILL_TYPE_MAX),
+                       KERN_WARNING
+                       "rfkill: illegal type %d passed as parameter "
+                       "to rfkill_allocate\n", type))
+               return NULL;
+
        rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
        if (!rfkill)
                return NULL;
@@ -496,7 +763,7 @@ EXPORT_SYMBOL(rfkill_allocate);
  * rfkill_free - Mark rfkill structure for deletion
  * @rfkill: rfkill structure to be destroyed
  *
- * Decrements reference count of rfkill structure so it is destroyed.
+ * Decrements reference count of the rfkill structure so it is destroyed.
  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
  */
 void rfkill_free(struct rfkill *rfkill)
@@ -511,7 +778,10 @@ static void rfkill_led_trigger_register(struct rfkill *rfkill)
 #ifdef CONFIG_RFKILL_LEDS
        int error;
 
-       rfkill->led_trigger.name = rfkill->dev.bus_id;
+       if (!rfkill->led_trigger.name)
+               rfkill->led_trigger.name = dev_name(&rfkill->dev);
+       if (!rfkill->led_trigger.activate)
+               rfkill->led_trigger.activate = rfkill_led_trigger_activate;
        error = led_trigger_register(&rfkill->led_trigger);
        if (error)
                rfkill->led_trigger.name = NULL;
@@ -521,8 +791,10 @@ static void rfkill_led_trigger_register(struct rfkill *rfkill)
 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 {
 #ifdef CONFIG_RFKILL_LEDS
-       if (rfkill->led_trigger.name)
+       if (rfkill->led_trigger.name) {
                led_trigger_unregister(&rfkill->led_trigger);
+               rfkill->led_trigger.name = NULL;
+       }
 #endif
 }
 
@@ -534,19 +806,21 @@ static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
  * structure needs to be registered. Immediately from registration the
  * switch driver should be able to service calls to toggle_radio.
  */
-int rfkill_register(struct rfkill *rfkill)
+int __must_check rfkill_register(struct rfkill *rfkill)
 {
        static atomic_t rfkill_no = ATOMIC_INIT(0);
        struct device *dev = &rfkill->dev;
        int error;
 
-       if (!rfkill->toggle_radio)
-               return -EINVAL;
-       if (rfkill->type >= RFKILL_TYPE_MAX)
+       if (WARN((!rfkill || !rfkill->toggle_radio ||
+                       rfkill->type >= RFKILL_TYPE_MAX ||
+                       rfkill->state >= RFKILL_STATE_MAX),
+                       KERN_WARNING
+                       "rfkill: attempt to register a "
+                       "badly initialized rfkill struct\n"))
                return -EINVAL;
 
-       snprintf(dev->bus_id, sizeof(dev->bus_id),
-                "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
+       dev_set_name(dev, "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 
        rfkill_led_trigger_register(rfkill);
 
@@ -558,8 +832,8 @@ int rfkill_register(struct rfkill *rfkill)
 
        error = device_add(dev);
        if (error) {
-               rfkill_led_trigger_unregister(rfkill);
                rfkill_remove_switch(rfkill);
+               rfkill_led_trigger_unregister(rfkill);
                return error;
        }
 
@@ -577,6 +851,7 @@ EXPORT_SYMBOL(rfkill_register);
  */
 void rfkill_unregister(struct rfkill *rfkill)
 {
+       BUG_ON(!rfkill);
        device_del(&rfkill->dev);
        rfkill_remove_switch(rfkill);
        rfkill_led_trigger_unregister(rfkill);
@@ -584,6 +859,57 @@ void rfkill_unregister(struct rfkill *rfkill)
 }
 EXPORT_SYMBOL(rfkill_unregister);
 
+/**
+ * rfkill_set_default - set initial value for a switch type
+ * @type - the type of switch to set the default state of
+ * @state - the new default state for that group of switches
+ *
+ * Sets the initial state rfkill should use for a given type.
+ * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
+ * and RFKILL_STATE_UNBLOCKED.
+ *
+ * This function is meant to be used by platform drivers for platforms
+ * that can save switch state across power down/reboot.
+ *
+ * The default state for each switch type can be changed exactly once.
+ * After a switch of that type is registered, the default state cannot
+ * be changed anymore.  This guards against multiple drivers it the
+ * same platform trying to set the initial switch default state, which
+ * is not allowed.
+ *
+ * Returns -EPERM if the state has already been set once or is in use,
+ * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
+ * if this function returns -EPERM.
+ *
+ * Returns 0 if the new default state was set, or an error if it
+ * could not be set.
+ */
+int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
+{
+       int error;
+
+       if (WARN((type >= RFKILL_TYPE_MAX ||
+                       (state != RFKILL_STATE_SOFT_BLOCKED &&
+                        state != RFKILL_STATE_UNBLOCKED)),
+                       KERN_WARNING
+                       "rfkill: illegal state %d or type %d passed as "
+                       "parameter to rfkill_set_default\n", state, type))
+               return -EINVAL;
+
+       mutex_lock(&rfkill_global_mutex);
+
+       if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
+               rfkill_global_states[type].default_state = state;
+               rfkill_global_states[type].current_state = state;
+               error = 0;
+       } else
+               error = -EPERM;
+
+       mutex_unlock(&rfkill_global_mutex);
+       return error;
+}
+EXPORT_SYMBOL_GPL(rfkill_set_default);
+
 /*
  * Rfkill module initialization/deinitialization.
  */
@@ -592,12 +918,13 @@ static int __init rfkill_init(void)
        int error;
        int i;
 
-       if (rfkill_default_state != RFKILL_STATE_OFF &&
-           rfkill_default_state != RFKILL_STATE_ON)
+       /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
+       if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
+           rfkill_default_state != RFKILL_STATE_UNBLOCKED)
                return -EINVAL;
 
-       for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
-               rfkill_states[i] = rfkill_default_state;
+       for (i = 0; i < RFKILL_TYPE_MAX; i++)
+               rfkill_global_states[i].default_state = rfkill_default_state;
 
        error = class_register(&rfkill_class);
        if (error) {