aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/keyboard/gpio_keys.c
blob: 71771ba6123085f36bed1788c1132530613b46ad (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/*
 * Driver for keys on GPIO lines capable of generating interrupts.
 *
 * Copyright 2005 Phil Blundell
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/version.h>

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/irq.h>

#include <asm/gpio.h>
#include <asm/arch/hardware.h>

#include <asm/hardware/gpio_keys.h>

static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
{
	int i;
	struct platform_device *pdev = dev_id;
	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
	struct input_dev *input = platform_get_drvdata(pdev);

	for (i = 0; i < pdata->nbuttons; i++) {
		int gpio = pdata->buttons[i].gpio;
		if (irq == gpio_to_irq(gpio)) {
			int state = (gpio_get_value(gpio) ? 1 : 0) ^ (pdata->buttons[i].active_low);

			input_report_key(input, pdata->buttons[i].keycode, state);
			input_sync(input);
		}
	}

	return IRQ_HANDLED;
}

static int __devinit gpio_keys_probe(struct platform_device *pdev)
{
	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
	struct input_dev *input;
	int i, error;

	input = input_allocate_device();
	if (!input)
		return -ENOMEM;

	platform_set_drvdata(pdev, input);

	input->evbit[0] = BIT(EV_KEY);

	input->name = pdev->name;
	input->phys = "gpio-keys/input0";
	input->dev.parent = &pdev->dev;

	input->id.bustype = BUS_HOST;
	input->id.vendor = 0x0001;
	input->id.product = 0x0001;
	input->id.version = 0x0100;

	for (i = 0; i < pdata->nbuttons; i++) {
		int code = pdata->buttons[i].keycode;
		int irq = gpio_to_irq(pdata->buttons[i].gpio);

		set_irq_type(irq, IRQ_TYPE_EDGE_BOTH);
		error = request_irq(irq, gpio_keys_isr, IRQF_SAMPLE_RANDOM,
				     pdata->buttons[i].desc ? pdata->buttons[i].desc : "gpio_keys",
				     pdev);
		if (error) {
			printk(KERN_ERR "gpio-keys: unable to claim irq %d; error %d\n",
				irq, error);
			goto fail;
		}
		set_bit(code, input->keybit);
	}

	error = input_register_device(input);
	if (error) {
		printk(KERN_ERR "Unable to register gpio-keys input device\n");
		goto fail;
	}

	return 0;

 fail:
	for (i = i - 1; i >= 0; i--)
		free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);

	input_free_device(input);

	return error;
}

static int __devexit gpio_keys_remove(struct platform_device *pdev)
{
	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
	struct input_dev *input = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < pdata->nbuttons; i++) {
		int irq = gpio_to_irq(pdata->buttons[i].gpio);
		free_irq(irq, pdev);
	}

	input_unregister_device(input);

	return 0;
}

struct platform_driver gpio_keys_device_driver = {
	.probe		= gpio_keys_probe,
	.remove		= __devexit_p(gpio_keys_remove),
	.driver		= {
		.name	= "gpio-keys",
	}
};

static int __init gpio_keys_init(void)
{
	return platform_driver_register(&gpio_keys_device_driver);
}

static void __exit gpio_keys_exit(void)
{
	platform_driver_unregister(&gpio_keys_device_driver);
}

module_init(gpio_keys_init);
module_exit(gpio_keys_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");