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
  20 static 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 }
  27 static DEVICE_ATTR_RO(switch);
  28
  29 static void switch_timer(struct timer_list *t)
  30 {
  31         struct push_switch *psw = from_timer(psw, t, debounce);
  32
  33         schedule_work(&psw->work);
  34 }
  35
  36 static 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
  46 static 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         timer_setup(&psw->debounce, switch_timer, 0);
  82
  83         /* Workqueue API brain-damage */
  84         psw->pdev = pdev;
  85
  86         platform_set_drvdata(pdev, psw);
  87
  88         return 0;
  89
  90 err_irq:
  91         free_irq(irq, pdev);
  92 err:
  93         kfree(psw);
  94         return ret;
  95 }
  96
  97 static int switch_drv_remove(struct platform_device *pdev)
  98 {
  99         struct push_switch *psw = platform_get_drvdata(pdev);
 100         struct push_switch_platform_info *psw_info = pdev->dev.platform_data;
 101         int irq = platform_get_irq(pdev, 0);
 102
 103         if (psw_info->name)
 104                 device_remove_file(&pdev->dev, &dev_attr_switch);
 105
 106         platform_set_drvdata(pdev, NULL);
 107         flush_work(&psw->work);
 108         del_timer_sync(&psw->debounce);
 109         free_irq(irq, pdev);
 110
 111         kfree(psw);
 112
 113         return 0;
 114 }
 115
 116 static struct platform_driver switch_driver = {
 117         .probe          = switch_drv_probe,
 118         .remove         = switch_drv_remove,
 119         .driver         = {
 120                 .name   = DRV_NAME,
 121         },
 122 };
 123
 124 static int __init switch_init(void)
 125 {
 126         printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
 127         return platform_driver_register(&switch_driver);
 128 }
 129
 130 static void __exit switch_exit(void)
 131 {
 132         platform_driver_unregister(&switch_driver);
 133 }
 134 module_init(switch_init);
 135 module_exit(switch_exit);
 136
 137 MODULE_VERSION(DRV_VERSION);
 138 MODULE_AUTHOR("Paul Mundt");
 139 MODULE_LICENSE("GPL v2");