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/*
Copyright (C) 2006 Ivo van Doorn
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/timer.h>
#include <linux/rfkill.h>
#include <asm/atomic.h>
MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
MODULE_VERSION("1.0");
MODULE_DESCRIPTION("RF button support");
MODULE_LICENSE("GPL");
/*
* List of all registered buttons.
*/
static struct list_head rfkill_list;
static spinlock_t rfkill_list_lock;
/*
* Polling timer, poll_delay and use count.
*/
static struct timer_list poll_timer;
static atomic_t poll_required;
static void rfkill_toggle_radio(int new_status)
{
struct list_head *entry;
struct rfkill *rfkill;
/*
* Go through the list of all radio's to toggle the radio state.
*/
list_for_each(entry, &rfkill_list) {
rfkill = list_entry(entry, struct rfkill, entry);
rfkill->current_status = new_status;
/*
* If the input_device has been opened
* all radio events should be send to user space.
*/
if (rfkill->input_dev->users) {
input_report_key(rfkill->input_dev,
KEY_RFKILL, new_status);
input_sync(rfkill->input_dev);
continue;
}
/*
* If the hardware does not toggle the radio status automaticly,
* we should take care of it.
*/
if (new_status && rfkill->enable_radio)
rfkill->enable_radio(rfkill->data);
else if (!new_status && rfkill->disable_radio)
rfkill->disable_radio(rfkill->data);
}
}
static void rfkill_poll_button(unsigned long data)
{
struct list_head *entry;
struct rfkill *rfkill;
int status;
spin_lock(&rfkill_list_lock);
list_for_each(entry, &rfkill_list) {
rfkill = list_entry(entry, struct rfkill, entry);
if (!rfkill->poll)
continue;
status = !!rfkill->poll(rfkill->data);
if (status != rfkill->current_status) {
rfkill_toggle_radio(status);
break;
}
}
spin_unlock(&rfkill_list_lock);
/*
* Check if polling is still required.
*/
if (atomic_read(&poll_required)) {
poll_timer.expires = jiffies + RFKILL_POLL_DELAY;
add_timer(&poll_timer);
}
}
void rfkill_button_event(struct rfkill *rfkill, int status)
{
if (status != rfkill->current_status) {
spin_lock(&rfkill_list_lock);
rfkill_toggle_radio(status);
spin_unlock(&rfkill_list_lock);
}
}
EXPORT_SYMBOL(rfkill_button_event);
int rfkill_add_device(struct rfkill *rfkill)
{
int status;
/*
* Allocate, initialize and register input device.
*/
rfkill->input_dev = input_allocate_device();
if (!rfkill->input_dev) {
printk(KERN_ERR "Failed to allocate input device %s.\n",
rfkill->dev_name);
return -ENOMEM;
}
rfkill->input_dev->name = "Radio button";
rfkill->input_dev->phys = rfkill->dev_name;
rfkill->input_dev->id.bustype = BUS_HOST;
set_bit(KEY_RFKILL, rfkill->input_dev->keybit);
status = input_register_device(rfkill->input_dev);
if (status) {
printk(KERN_ERR "Failed to register input device %s.\n",
rfkill->dev_name);
input_free_device(rfkill->input_dev);
return status;
}
INIT_LIST_HEAD(&rfkill->entry);
spin_lock(&rfkill_list_lock);
list_add(&rfkill->entry, &rfkill_list);
spin_unlock(&rfkill_list_lock);
/*
* If polling is required the poll_required counter should be
* increased. If it was previously 0 we should start the polling timer.
*/
if (rfkill->poll) {
if (!atomic_read(&poll_required)) {
poll_timer.expires = jiffies + RFKILL_POLL_DELAY;
add_timer(&poll_timer);
}
atomic_inc(&poll_required);
}
return 0;
}
EXPORT_SYMBOL(rfkill_add_device);
void rfkill_del_device(struct rfkill *rfkill)
{
spin_lock(&rfkill_list_lock);
/*
* Check if this button required polling and if this
* was the last button that required polling.
*/
if (rfkill->poll && atomic_dec_and_test(&poll_required))
del_timer(&poll_timer);
list_del(&rfkill->entry);
spin_unlock(&rfkill_list_lock);
}
EXPORT_SYMBOL(rfkill_del_device);
static int __init radiobtn_init(void)
{
printk(KERN_INFO "Loading rfkill driver.\n");
INIT_LIST_HEAD(&rfkill_list);
spin_lock_init(&rfkill_list_lock);
init_timer(&poll_timer);
poll_timer.function = rfkill_poll_button;
poll_timer.data = 0;
atomic_set(&poll_required, 0);
return 0;
}
static void __exit radiobtn_exit(void)
{
printk(KERN_INFO "Unloading rfkill driver.\n");
}
module_init(radiobtn_init);
module_exit(radiobtn_exit);
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