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Diffstat (limited to 'net/rfkill/rfkill.c')
| -rw-r--r-- | net/rfkill/rfkill.c | 879 |
1 files changed, 879 insertions, 0 deletions
diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c new file mode 100644 index 0000000..25ba3bd --- /dev/null +++ b/net/rfkill/rfkill.c @@ -0,0 +1,879 @@ +/* + * Copyright (C) 2006 - 2007 Ivo van Doorn + * Copyright (C) 2007 Dmitry Torokhov + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the + * Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/workqueue.h> +#include <linux/capability.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/rfkill.h> + +/* Get declaration of rfkill_switch_all() to shut up sparse. */ +#include "rfkill-input.h" + + +MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>"); +MODULE_VERSION("1.0"); +MODULE_DESCRIPTION("RF switch support"); +MODULE_LICENSE("GPL"); + +static LIST_HEAD(rfkill_list); /* list of registered rf switches */ +static DEFINE_MUTEX(rfkill_global_mutex); + +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"); + +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 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) +{ + BUG_ON(!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) +{ + BUG_ON(!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) +{ +#ifdef CONFIG_RFKILL_LEDS + struct led_trigger *led = &rfkill->led_trigger; + + if (!led->name) + return; + 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); +} + +static void update_rfkill_state(struct rfkill *rfkill) +{ + enum rfkill_state newstate, oldstate; + + if (rfkill->get_state) { + mutex_lock(&rfkill->mutex); + 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); + } +} + +/** + * 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) +{ + 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); + /* never allow a HARD->SOFT downgrade! */ + if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED) + rfkill->state = 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 affected + * @state: the new state + * + * 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. + */ +static void __rfkill_switch_all(const enum rfkill_type type, + const enum rfkill_state state) +{ + struct rfkill *rfkill; + + 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)) { + mutex_lock(&rfkill->mutex); + rfkill_toggle_radio(rfkill, state, 0); + 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. + */ +void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state) +{ + mutex_lock(&rfkill_global_mutex); + __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); + + 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); + + 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_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. + * + * This function updates the internal state of the radio cached + * by the rfkill class. It should be used when the driver gets + * a notification by the firmware/hardware of the current *real* + * state of the radio rfkill switch. + * + * 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; + + 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); + + oldstate = rfkill->state; + rfkill->state = state; + + if (state != oldstate) + notify_rfkill_state_change(rfkill); + + mutex_unlock(&rfkill->mutex); + + return 0; +} +EXPORT_SYMBOL(rfkill_force_state); + +static ssize_t rfkill_name_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rfkill *rfkill = to_rfkill(dev); + + return sprintf(buf, "%s\n", rfkill->name); +} + +static const char *rfkill_get_type_str(enum rfkill_type type) +{ + switch (type) { + case RFKILL_TYPE_WLAN: + return "wlan"; + case RFKILL_TYPE_BLUETOOTH: + return "bluetooth"; + case RFKILL_TYPE_UWB: + return "ultrawideband"; + case RFKILL_TYPE_WIMAX: + return "wimax"; + case RFKILL_TYPE_WWAN: + return "wwan"; + default: + BUG(); + } +} + +static ssize_t rfkill_type_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rfkill *rfkill = to_rfkill(dev); + + return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type)); +} + +static ssize_t rfkill_state_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rfkill *rfkill = to_rfkill(dev); + + update_rfkill_state(rfkill); + return sprintf(buf, "%d\n", rfkill->state); +} + +static ssize_t rfkill_state_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct rfkill *rfkill = to_rfkill(dev); + unsigned long state; + int error; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + 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; + + if (mutex_lock_interruptible(&rfkill->mutex)) + return -ERESTARTSYS; + error = rfkill_toggle_radio(rfkill, state, 0); + mutex_unlock(&rfkill->mutex); + + return error ? error : count; +} + +static ssize_t rfkill_claim_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rfkill *rfkill = to_rfkill(dev); + + return sprintf(buf, "%d\n", rfkill->user_claim); +} + +static ssize_t rfkill_claim_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct rfkill *rfkill = to_rfkill(dev); + 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_global_mutex); + if (error) + return error; + + if (rfkill->user_claim != claim) { + if (!claim) { + mutex_lock(&rfkill->mutex); + rfkill_toggle_radio(rfkill, + rfkill_global_states[rfkill->type].current_state, + 0); + mutex_unlock(&rfkill->mutex); + } + rfkill->user_claim = claim; + } + + mutex_unlock(&rfkill_global_mutex); + + return error ? error : count; +} + +static struct device_attribute rfkill_dev_attrs[] = { + __ATTR(name, S_IRUGO, rfkill_name_show, NULL), + __ATTR(type, S_IRUGO, rfkill_type_show, NULL), + __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store), + __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store), + __ATTR_NULL +}; + +static void rfkill_release(struct device *dev) +{ + struct rfkill *rfkill = to_rfkill(dev); + + kfree(rfkill); + module_put(THIS_MODULE); +} + +#ifdef CONFIG_PM +static int rfkill_suspend(struct device *dev, pm_message_t state) +{ + /* mark class device as suspended */ + if (dev->power.power_state.event != state.event) + dev->power.power_state = state; + + return 0; +} + +static int rfkill_resume(struct device *dev) +{ + struct rfkill *rfkill = to_rfkill(dev); + + if (dev->power.power_state.event != PM_EVENT_ON) { + mutex_lock(&rfkill->mutex); + + dev->power.power_state.event = PM_EVENT_ON; + + /* restore radio state AND notify everybody */ + rfkill_toggle_radio(rfkill, rfkill->state, 1); + + mutex_unlock(&rfkill->mutex); + } + + return 0; +} +#else +#define rfkill_suspend NULL +#define rfkill_resume NULL +#endif + +static int rfkill_blocking_uevent_notifier(struct notifier_block *nb, + unsigned long eventid, + void *data) +{ + struct rfkill *rfkill = (struct rfkill *)data; + + switch (eventid) { + case RFKILL_STATE_CHANGED: + kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE); + break; + default: + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block rfkill_blocking_uevent_nb = { + .notifier_call = rfkill_blocking_uevent_notifier, + .priority = 0, +}; + +static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct rfkill *rfkill = to_rfkill(dev); + int error; + + error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name); + if (error) + return error; + error = add_uevent_var(env, "RFKILL_TYPE=%s", + rfkill_get_type_str(rfkill->type)); + if (error) + return error; + error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state); + return error; +} + +static struct class rfkill_class = { + .name = "rfkill", + .dev_release = rfkill_release, + .dev_attrs = rfkill_dev_attrs, + .suspend = rfkill_suspend, + .resume = rfkill_resume, + .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_global_mutex); + + error = rfkill_check_duplicity(rfkill); + if (error < 0) + goto unlock_out; + + 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_global_mutex); + list_del_init(&rfkill->node); + mutex_unlock(&rfkill_global_mutex); + + mutex_lock(&rfkill->mutex); + rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1); + mutex_unlock(&rfkill->mutex); +} + +/** + * rfkill_allocate - allocate memory for rfkill structure. + * @parent: device that has rf switch on it + * @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 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 * __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; + + mutex_init(&rfkill->mutex); + INIT_LIST_HEAD(&rfkill->node); + rfkill->type = type; + + dev = &rfkill->dev; + dev->class = &rfkill_class; + dev->parent = parent; + device_initialize(dev); + + __module_get(THIS_MODULE); + + return rfkill; +} +EXPORT_SYMBOL(rfkill_allocate); + +/** + * rfkill_free - Mark rfkill structure for deletion + * @rfkill: rfkill structure to be 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) +{ + if (rfkill) + put_device(&rfkill->dev); +} +EXPORT_SYMBOL(rfkill_free); + +static void rfkill_led_trigger_register(struct rfkill *rfkill) +{ +#ifdef CONFIG_RFKILL_LEDS + int error; + + if (!rfkill->led_trigger.name) + rfkill->led_trigger.name = rfkill->dev.bus_id; + 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; +#endif /* CONFIG_RFKILL_LEDS */ +} + +static void rfkill_led_trigger_unregister(struct rfkill *rfkill) +{ +#ifdef CONFIG_RFKILL_LEDS + if (rfkill->led_trigger.name) { + led_trigger_unregister(&rfkill->led_trigger); + rfkill->led_trigger.name = NULL; + } +#endif +} + +/** + * rfkill_register - Register a rfkill structure. + * @rfkill: rfkill structure to be registered + * + * This function should be called by the network driver when the rfkill + * structure needs to be registered. Immediately from registration the + * switch driver should be able to service calls to toggle_radio. + */ +int __must_check rfkill_register(struct rfkill *rfkill) +{ + static atomic_t rfkill_no = ATOMIC_INIT(0); + struct device *dev = &rfkill->dev; + int error; + + 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); + + rfkill_led_trigger_register(rfkill); + + error = rfkill_add_switch(rfkill); + if (error) { + rfkill_led_trigger_unregister(rfkill); + return error; + } + + error = device_add(dev); + if (error) { + rfkill_remove_switch(rfkill); + rfkill_led_trigger_unregister(rfkill); + return error; + } + + return 0; +} +EXPORT_SYMBOL(rfkill_register); + +/** + * rfkill_unregister - Unregister a rfkill structure. + * @rfkill: rfkill structure to be unregistered + * + * This function should be called by the network driver during device + * teardown to destroy rfkill structure. Note that rfkill_free() should + * _not_ be called after rfkill_unregister(). + */ +void rfkill_unregister(struct rfkill *rfkill) +{ + BUG_ON(!rfkill); + device_del(&rfkill->dev); + rfkill_remove_switch(rfkill); + rfkill_led_trigger_unregister(rfkill); + put_device(&rfkill->dev); +} +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; + error = 0; + } else + error = -EPERM; + + mutex_unlock(&rfkill_global_mutex); + return error; +} +EXPORT_SYMBOL_GPL(rfkill_set_default); + +/* + * Rfkill module initialization/deinitialization. + */ +static int __init rfkill_init(void) +{ + int error; + int i; + + /* 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 < RFKILL_TYPE_MAX; i++) + rfkill_global_states[i].default_state = rfkill_default_state; + + error = class_register(&rfkill_class); + if (error) { + printk(KERN_ERR "rfkill: unable to register rfkill class\n"); + return error; + } + + register_rfkill_notifier(&rfkill_blocking_uevent_nb); + + return 0; +} + +static void __exit rfkill_exit(void) +{ + unregister_rfkill_notifier(&rfkill_blocking_uevent_nb); + class_unregister(&rfkill_class); +} + +subsys_initcall(rfkill_init); +module_exit(rfkill_exit); |
