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 = from_timer(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(sizeof(struct push_switch), GFP_KERNEL);
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 int 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	return 0;
111}
112
113static struct platform_driver switch_driver = {
114	.probe		= switch_drv_probe,
115	.remove		= switch_drv_remove,
116	.driver		= {
117		.name	= DRV_NAME,
118	},
119};
120
121static int __init switch_init(void)
122{
123	printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
124	return platform_driver_register(&switch_driver);
125}
126
127static void __exit switch_exit(void)
128{
129	platform_driver_unregister(&switch_driver);
130}
131module_init(switch_init);
132module_exit(switch_exit);
133
134MODULE_VERSION(DRV_VERSION);
135MODULE_AUTHOR("Paul Mundt");
136MODULE_LICENSE("GPL v2");
137