push-switch.c
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/*
* Generic push-switch framework
*
* Copyright (C) 2006 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <asm/push-switch.h>
#define DRV_NAME "push-switch"
#define DRV_VERSION "0.1.1"
static ssize_t switch_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct push_switch_platform_info *psw_info = dev->platform_data;
return sprintf(buf, "%s\n", psw_info->name);
}
static DEVICE_ATTR(switch, S_IRUGO, switch_show, NULL);
static void switch_timer(unsigned long data)
{
struct push_switch *psw = (struct push_switch *)data;
schedule_work(&psw->work);
}
static void switch_work_handler(struct work_struct *work)
{
struct push_switch *psw = container_of(work, struct push_switch, work);
struct platform_device *pdev = psw->pdev;
psw->state = 0;
kobject_uevent(&pdev->dev.kobj, KOBJ_CHANGE);
}
static int switch_drv_probe(struct platform_device *pdev)
{
struct push_switch_platform_info *psw_info;
struct push_switch *psw;
int ret, irq;
psw = kzalloc(sizeof(struct push_switch), GFP_KERNEL);
if (unlikely(!psw))
return -ENOMEM;
irq = platform_get_irq(pdev, 0);
if (unlikely(irq < 0)) {
ret = -ENODEV;
goto err;
}
psw_info = pdev->dev.platform_data;
BUG_ON(!psw_info);
ret = request_irq(irq, psw_info->irq_handler,
psw_info->irq_flags,
psw_info->name ? psw_info->name : DRV_NAME, pdev);
if (unlikely(ret < 0))
goto err;
if (psw_info->name) {
ret = device_create_file(&pdev->dev, &dev_attr_switch);
if (unlikely(ret)) {
dev_err(&pdev->dev, "Failed creating device attrs\n");
ret = -EINVAL;
goto err_irq;
}
}
INIT_WORK(&psw->work, switch_work_handler);
init_timer(&psw->debounce);
psw->debounce.function = switch_timer;
psw->debounce.data = (unsigned long)psw;
/* Workqueue API brain-damage */
psw->pdev = pdev;
platform_set_drvdata(pdev, psw);
return 0;
err_irq:
free_irq(irq, pdev);
err:
kfree(psw);
return ret;
}
static int switch_drv_remove(struct platform_device *pdev)
{
struct push_switch *psw = platform_get_drvdata(pdev);
struct push_switch_platform_info *psw_info = pdev->dev.platform_data;
int irq = platform_get_irq(pdev, 0);
if (psw_info->name)
device_remove_file(&pdev->dev, &dev_attr_switch);
platform_set_drvdata(pdev, NULL);
flush_work(&psw->work);
del_timer_sync(&psw->debounce);
free_irq(irq, pdev);
kfree(psw);
return 0;
}
static struct platform_driver switch_driver = {
.probe = switch_drv_probe,
.remove = switch_drv_remove,
.driver = {
.name = DRV_NAME,
},
};
static int __init switch_init(void)
{
printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
return platform_driver_register(&switch_driver);
}
static void __exit switch_exit(void)
{
platform_driver_unregister(&switch_driver);
}
module_init(switch_init);
module_exit(switch_exit);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("Paul Mundt");
MODULE_LICENSE("GPL v2");