path: root/net/rfkill/core.c

/*
 * Copyright (C) 2006 - 2007 Ivo van Doorn
 * Copyright (C) 2007 Dmitry Torokhov
 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
 *
 * 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>
#include <linux/spinlock.h>
#include <linux/miscdevice.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/fs.h>

#include "rfkill.h"

#define POLL_INTERVAL		(5 * HZ)

#define RFKILL_BLOCK_HW		BIT(0)
#define RFKILL_BLOCK_SW		BIT(1)
#define RFKILL_BLOCK_SW_PREV	BIT(2)
#define RFKILL_BLOCK_ANY	(RFKILL_BLOCK_HW |\
				 RFKILL_BLOCK_SW |\
				 RFKILL_BLOCK_SW_PREV)
#define RFKILL_BLOCK_SW_SETCALL	BIT(31)

struct rfkill {
	spinlock_t		lock;

	const char		*name;
	enum rfkill_type	type;

	unsigned long		state;

	u32			idx;

	bool			registered;
	bool			suspended;
	bool			persistent;

	const struct rfkill_ops	*ops;
	void			*data;

#ifdef CONFIG_RFKILL_LEDS
	struct led_trigger	led_trigger;
	const char		*ledtrigname;
#endif

	struct device		dev;
	struct list_head	node;

	struct delayed_work	poll_work;
	struct work_struct	uevent_work;
	struct work_struct	sync_work;
};
#define to_rfkill(d)	container_of(d, struct rfkill, dev)

struct rfkill_int_event {
	struct list_head	list;
	struct rfkill_event	ev;
};

struct rfkill_data {
	struct list_head	list;
	struct list_head	events;
	struct mutex		mtx;
	wait_queue_head_t	read_wait;
	bool			input_handler;
};


MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
MODULE_DESCRIPTION("RF switch support");
MODULE_LICENSE("GPL");


/*
 * The locking here should be made much smarter, we currently have
 * a bit of a stupid situation because drivers might want to register
 * the rfkill struct under their own lock, and take this lock during
 * rfkill method calls -- which will cause an AB-BA deadlock situation.
 *
 * To fix that, we need to rework this code here to be mostly lock-free
 * and only use the mutex for list manipulations, not to protect the
 * various other global variables. Then we can avoid holding the mutex
 * around driver operations, and all is happy.
 */
static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
static DEFINE_MUTEX(rfkill_global_mutex);
static LIST_HEAD(rfkill_fds);	/* list of open fds of /dev/rfkill */

static unsigned int rfkill_default_state = 1;
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 struct {
	bool cur, sav;
} rfkill_global_states[NUM_RFKILL_TYPES];

static bool rfkill_epo_lock_active;


#ifdef CONFIG_RFKILL_LEDS
static void rfkill_led_trigger_event(struct rfkill *rfkill)
{
	struct led_trigger *trigger;

	if (!rfkill->registered)
		return;

	trigger = &rfkill->led_trigger;

	if (rfkill->state & RFKILL_BLOCK_ANY)
		led_trigger_event(trigger, LED_OFF);
	else
		led_trigger_event(trigger, LED_FULL);
}

static void rfkill_led_trigger_activate(struct led_classdev *led)
{
	struct rfkill *rfkill;

	rfkill = container_of(led->trigger, struct rfkill, led_trigger);

	rfkill_led_trigger_event(rfkill);
}

const char *rfkill_get_led_trigger_name(struct rfkill *rfkill)
{
	<