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 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_work(&psw->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"); 143