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
switch_show(struct device * dev,struct device_attribute * attr,char * buf)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
switch_timer(unsigned long data)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
switch_work_handler(struct work_struct * work)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
switch_drv_probe(struct platform_device * pdev)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
switch_drv_remove(struct platform_device * pdev)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_sync(&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
switch_init(void)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
switch_exit(void)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