blob: 10b05ceee8ae679782274195d8e0748b3bdcc897 [file] [log] [blame]
/*
* 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_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");
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)
{
#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;
}
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.
*/
void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
{
struct rfkill *rfkill;
mutex_lock(&rfkill_mutex);
rfkill_states[type] = 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);
}
}
mutex_unlock(&rfkill_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_mutex and rfkill->mutex.
*/
void rfkill_epo(void)
{
struct rfkill *rfkill;
mutex_lock(&rfkill_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);
}
mutex_unlock(&rfkill_mutex);
}
EXPORT_SYMBOL_GPL(rfkill_epo);
/**
* 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;
if (state != RFKILL_STATE_SOFT_BLOCKED &&
state != RFKILL_STATE_UNBLOCKED &&
state != RFKILL_STATE_HARD_BLOCKED)
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 int state = simple_strtoul(buf, NULL, 0);
int error;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
/* 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);
bool claim = !!simple_strtoul(buf, NULL, 0);
int error;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (rfkill->user_claim_unsupported)
return -EOPNOTSUPP;
/*
* Take the global lock to make sure the kernel is not in
* the middle of rfkill_switch_all
*/
error = mutex_lock_interruptible(&rfkill_mutex);
if (error)
return error;
if (rfkill->user_claim != claim) {
if (!claim) {
mutex_lock(&rfkill->mutex);
rfkill_toggle_radio(rfkill,
rfkill_states[rfkill->type],
0);
mutex_unlock(&rfkill->mutex);
}
rfkill->user_claim = claim;
}
mutex_unlock(&rfkill_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)
{
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_SOFT_BLOCKED);
mutex_unlock(&rfkill->mutex);
}
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_add_switch(struct rfkill *rfkill)
{
mutex_lock(&rfkill_mutex);
rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
list_add_tail(&rfkill->node, &rfkill_list);
mutex_unlock(&rfkill_mutex);
return 0;
}
static void rfkill_remove_switch(struct rfkill *rfkill)
{
mutex_lock(&rfkill_mutex);
list_del_init(&rfkill->node);
mutex_unlock(&rfkill_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 *rfkill_allocate(struct device *parent, enum rfkill_type type)
{
struct rfkill *rfkill;
struct device *dev;
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 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)
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)
{
device_del(&rfkill->dev);
rfkill_remove_switch(rfkill);
rfkill_led_trigger_unregister(rfkill);
put_device(&rfkill->dev);
}
EXPORT_SYMBOL(rfkill_unregister);
/*
* 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 < ARRAY_SIZE(rfkill_states); i++)
rfkill_states[i] = 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);