/* * 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 #include #include #include #include #include #include #include /* Get declaration of rfkill_switch_all() to shut up sparse. */ #include "rfkill-input.h" MODULE_AUTHOR("Ivo van Doorn "); 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);