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135 lines · 2.9 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Generic push-switch framework
4 *
5 * Copyright (C) 2006 Paul Mundt
6 */
7#include <linux/init.h>
8#include <linux/slab.h>
9#include <linux/module.h>
10#include <linux/interrupt.h>
11#include <linux/platform_device.h>
12#include <asm/push-switch.h>
13
14#define DRV_NAME "push-switch"
15#define DRV_VERSION "0.1.1"
16
17static ssize_t switch_show(struct device *dev,
18 struct device_attribute *attr,
19 char *buf)
20{
21 struct push_switch_platform_info *psw_info = dev->platform_data;
22 return sprintf(buf, "%s\n", psw_info->name);
23}
24static DEVICE_ATTR_RO(switch);
25
26static void switch_timer(struct timer_list *t)
27{
28 struct push_switch *psw = timer_container_of(psw, t, debounce);
29
30 schedule_work(&psw->work);
31}
32
33static void switch_work_handler(struct work_struct *work)
34{
35 struct push_switch *psw = container_of(work, struct push_switch, work);
36 struct platform_device *pdev = psw->pdev;
37
38 psw->state = 0;
39
40 kobject_uevent(&pdev->dev.kobj, KOBJ_CHANGE);
41}
42
43static int switch_drv_probe(struct platform_device *pdev)
44{
45 struct push_switch_platform_info *psw_info;
46 struct push_switch *psw;
47 int ret, irq;
48
49 psw = kzalloc_obj(struct push_switch);
50 if (unlikely(!psw))
51 return -ENOMEM;
52
53 irq = platform_get_irq(pdev, 0);
54 if (unlikely(irq < 0)) {
55 ret = -ENODEV;
56 goto err;
57 }
58
59 psw_info = pdev->dev.platform_data;
60 BUG_ON(!psw_info);
61
62 ret = request_irq(irq, psw_info->irq_handler,
63 psw_info->irq_flags,
64 psw_info->name ? psw_info->name : DRV_NAME, pdev);
65 if (unlikely(ret < 0))
66 goto err;
67
68 if (psw_info->name) {
69 ret = device_create_file(&pdev->dev, &dev_attr_switch);
70 if (unlikely(ret)) {
71 dev_err(&pdev->dev, "Failed creating device attrs\n");
72 ret = -EINVAL;
73 goto err_irq;
74 }
75 }
76
77 INIT_WORK(&psw->work, switch_work_handler);
78 timer_setup(&psw->debounce, switch_timer, 0);
79
80 /* Workqueue API brain-damage */
81 psw->pdev = pdev;
82
83 platform_set_drvdata(pdev, psw);
84
85 return 0;
86
87err_irq:
88 free_irq(irq, pdev);
89err:
90 kfree(psw);
91 return ret;
92}
93
94static void switch_drv_remove(struct platform_device *pdev)
95{
96 struct push_switch *psw = platform_get_drvdata(pdev);
97 struct push_switch_platform_info *psw_info = pdev->dev.platform_data;
98 int irq = platform_get_irq(pdev, 0);
99
100 if (psw_info->name)
101 device_remove_file(&pdev->dev, &dev_attr_switch);
102
103 platform_set_drvdata(pdev, NULL);
104 timer_shutdown_sync(&psw->debounce);
105 flush_work(&psw->work);
106 free_irq(irq, pdev);
107
108 kfree(psw);
109}
110
111static struct platform_driver switch_driver = {
112 .probe = switch_drv_probe,
113 .remove = switch_drv_remove,
114 .driver = {
115 .name = DRV_NAME,
116 },
117};
118
119static int __init switch_init(void)
120{
121 printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
122 return platform_driver_register(&switch_driver);
123}
124
125static void __exit switch_exit(void)
126{
127 platform_driver_unregister(&switch_driver);
128}
129module_init(switch_init);
130module_exit(switch_exit);
131
132MODULE_VERSION(DRV_VERSION);
133MODULE_AUTHOR("Paul Mundt");
134MODULE_DESCRIPTION("Generic push-switch framework");
135MODULE_LICENSE("GPL v2");