Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/sh/drivers/push-switch.c
26424 views
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


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


26
static 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


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


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


94
static 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


111
static struct platform_driver switch_driver = {

112
	.probe		= switch_drv_probe,

113
	.remove		= switch_drv_remove,

114
	.driver		= {

115
		.name	= DRV_NAME,

116
	},

117
};

118


119
static 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


125
static void __exit switch_exit(void)

126
{

127
	platform_driver_unregister(&switch_driver);

128
}

129
module_init(switch_init);

130
module_exit(switch_exit);

131


132
MODULE_VERSION(DRV_VERSION);

133
MODULE_AUTHOR("Paul Mundt");

134
MODULE_DESCRIPTION("Generic push-switch framework");

135
MODULE_LICENSE("GPL v2");

136


137