LXR linux/arch/sh/drivers/push-switch.c

   1/*
   2 * Generic push-switch framework
   3 *
   4 * Copyright (C) 2006  Paul Mundt
   5 *
   6 * This file is subject to the terms and conditions of the GNU General Public
   7 * License.  See the file "COPYING" in the main directory of this archive
   8 * for more details.
   9 */
  10#include <linux/init.h>
  11#include <linux/slab.h>
  12#include <linux/module.h>
  13#include <linux/interrupt.h>
  14#include <linux/platform_device.h>
  15#include <asm/push-switch.h>
  16
  17#define DRV_NAME "push-switch"
  18#define DRV_VERSION "0.1.1"
  19
  20static ssize_t switch_show(struct device *dev,
  21                           struct device_attribute *attr,
  22                           char *buf)
  23{
  24        struct push_switch_platform_info *psw_info = dev->platform_data;
  25        return sprintf(buf, "%s\n", psw_info->name);
  26}
  27static DEVICE_ATTR(switch, S_IRUGO, switch_show, NULL);
  28
  29static void switch_timer(unsigned long data)
  30{
  31        struct push_switch *psw = (struct push_switch *)data;
  32
  33        schedule_work(&psw->work);
  34}
  35
  36static void switch_work_handler(struct work_struct *work)
  37{
  38        struct push_switch *psw = container_of(work, struct push_switch, work);
  39        struct platform_device *pdev = psw->pdev;
  40
  41        psw->state = 0;
  42
  43        kobject_uevent(&pdev->dev.kobj, KOBJ_CHANGE);
  44}
  45
  46static int switch_drv_probe(struct platform_device *pdev)
  47{
  48        struct push_switch_platform_info *psw_info;
  49        struct push_switch *psw;
  50        int ret, irq;
  51
  52        psw = kzalloc(sizeof(struct push_switch), GFP_KERNEL);
  53        if (unlikely(!psw))
  54                return -ENOMEM;
  55
  56        irq = platform_get_irq(pdev, 0);
  57        if (unlikely(irq < 0)) {
  58                ret = -ENODEV;
  59                goto err;
  60        }
  61
  62        psw_info = pdev->dev.platform_data;
  63        BUG_ON(!psw_info);
  64
  65        ret = request_irq(irq, psw_info->irq_handler,
  66                          psw_info->irq_flags,
  67                          psw_info->name ? psw_info->name : DRV_NAME, pdev);
  68        if (unlikely(ret < 0))
  69                goto err;
  70
  71        if (psw_info->name) {
  72                ret = device_create_file(&pdev->dev, &dev_attr_switch);
  73                if (unlikely(ret)) {
  74                        dev_err(&pdev->dev, "Failed creating device attrs\n");
  75                        ret = -EINVAL;
  76                        goto err_irq;
  77                }
  78        }
  79
  80        INIT_WORK(&psw->work, switch_work_handler);
  81        init_timer(&psw->debounce);
  82
  83        psw->debounce.function = switch_timer;
  84        psw->debounce.data = (unsigned long)psw;
  85
  86        /* Workqueue API brain-damage */
  87        psw->pdev = pdev;
  88
  89        platform_set_drvdata(pdev, psw);
  90
  91        return 0;
  92
  93err_irq:
  94        free_irq(irq, pdev);
  95err:
  96        kfree(psw);
  97        return ret;
  98}
  99
 100static int switch_drv_remove(struct platform_device *pdev)
 101{
 102        struct push_switch *psw = platform_get_drvdata(pdev);
 103        struct push_switch_platform_info *psw_info = pdev->dev.platform_data;
 104        int irq = platform_get_irq(pdev, 0);
 105
 106        if (psw_info->name)
 107                device_remove_file(&pdev->dev, &dev_attr_switch);
 108
 109        platform_set_drvdata(pdev, NULL);
 110        flush_work(&psw->work);
 111        del_timer_sync(&psw->debounce);
 112        free_irq(irq, pdev);
 113
 114        kfree(psw);
 115
 116        return 0;
 117}
 118
 119static struct platform_driver switch_driver = {
 120        .probe          = switch_drv_probe,
 121        .remove         = switch_drv_remove,
 122        .driver         = {
 123                .name   = DRV_NAME,
 124        },
 125};
 126
 127static int __init switch_init(void)
 128{
 129        printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
 130        return platform_driver_register(&switch_driver);
 131}
 132
 133static void __exit switch_exit(void)
 134{
 135        platform_driver_unregister(&switch_driver);
 136}
 137module_init(switch_init);
 138module_exit(switch_exit);
 139
 140MODULE_VERSION(DRV_VERSION);
 141MODULE_AUTHOR("Paul Mundt");
 142MODULE_LICENSE("GPL v2");
 143