tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_RO(switch);
28
29static 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
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 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
90err_irq:
91 free_irq(irq, pdev);
92err:
93 kfree(psw);
94 return ret;
95}
96
97static 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
116static struct platform_driver switch_driver = {
117 .probe = switch_drv_probe,
118 .remove = switch_drv_remove,
119 .driver = {
120 .name = DRV_NAME,
121 },
122};
123
124static 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
130static void __exit switch_exit(void)
131{
132 platform_driver_unregister(&switch_driver);
133}
134module_init(switch_init);
135module_exit(switch_exit);
136
137MODULE_VERSION(DRV_VERSION);
138MODULE_AUTHOR("Paul Mundt");
139MODULE_LICENSE("GPL v2");