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   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(switch, S_IRUGO, switch_show, NULL);
  28
  29 static void switch_timer(unsigned long data)
  30 {
  31         struct push_switch *psw = (struct push_switch *)data;
  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                           IRQF_DISABLED | 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
  93 err_irq:
  94         free_irq(irq, pdev);
  95 err:
  96         kfree(psw);
  97         return ret;
  98 }
  99
 100 static 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_scheduled_work();
 111         del_timer_sync(&psw->debounce);
 112         free_irq(irq, pdev);
 113
 114         kfree(psw);
 115
 116         return 0;
 117 }
 118
 119 static struct platform_driver switch_driver = {
 120         .probe          = switch_drv_probe,
 121         .remove         = switch_drv_remove,
 122         .driver         = {
 123                 .name   = DRV_NAME,
 124         },
 125 };
 126
 127 static 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
 133 static void __exit switch_exit(void)
 134 {
 135         platform_driver_unregister(&switch_driver);
 136 }
 137 module_init(switch_init);
 138 module_exit(switch_exit);
 139
 140 MODULE_VERSION(DRV_VERSION);
 141 MODULE_AUTHOR("Paul Mundt");
 142 MODULE_LICENSE("GPL v2");