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
switch_show(struct device * dev,struct device_attribute * attr,char * buf)17 static 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 }
24 static DEVICE_ATTR_RO(switch);
25
switch_timer(struct timer_list * t)26 static 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
switch_work_handler(struct work_struct * work)33 static 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
switch_drv_probe(struct platform_device * pdev)43 static 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
87 err_irq:
88 free_irq(irq, pdev);
89 err:
90 kfree(psw);
91 return ret;
92 }
93
switch_drv_remove(struct platform_device * pdev)94 static 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
113 static struct platform_driver switch_driver = {
114 .probe = switch_drv_probe,
115 .remove = switch_drv_remove,
116 .driver = {
117 .name = DRV_NAME,
118 },
119 };
120
switch_init(void)121 static 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
switch_exit(void)127 static void __exit switch_exit(void)
128 {
129 platform_driver_unregister(&switch_driver);
130 }
131 module_init(switch_init);
132 module_exit(switch_exit);
133
134 MODULE_VERSION(DRV_VERSION);
135 MODULE_AUTHOR("Paul Mundt");
136 MODULE_LICENSE("GPL v2");
137