1/*
2 * Driver for keys on GPIO lines capable of generating interrupts.
3 *
4 * Copyright 2005 Phil Blundell
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/module.h>
12#include <linux/version.h>
13
14#include <linux/init.h>
15#include <linux/fs.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/sched.h>
19#include <linux/pm.h>
20#include <linux/sysctl.h>
21#include <linux/proc_fs.h>
22#include <linux/delay.h>
23#include <linux/platform_device.h>
24#include <linux/input.h>
25#include <linux/irq.h>
26#include <linux/gpio_keys.h>
27
28#include <asm/gpio.h>
29
30static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
31{
32	int i;
33	struct platform_device *pdev = dev_id;
34	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
35	struct input_dev *input = platform_get_drvdata(pdev);
36
37	for (i = 0; i < pdata->nbuttons; i++) {
38		struct gpio_keys_button *button = &pdata->buttons[i];
39		int gpio = button->gpio;
40
41		if (irq == gpio_to_irq(gpio)) {
42			unsigned int type = button->type ?: EV_KEY;
43			int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;
44
45			input_event(input, type, button->code, !!state);
46			input_sync(input);
47		}
48	}
49
50	return IRQ_HANDLED;
51}
52
53static int __devinit gpio_keys_probe(struct platform_device *pdev)
54{
55	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
56	struct input_dev *input;
57	int i, error;
58
59	input = input_allocate_device();
60	if (!input)
61		return -ENOMEM;
62
63	platform_set_drvdata(pdev, input);
64
65	input->evbit[0] = BIT(EV_KEY);
66
67	input->name = pdev->name;
68	input->phys = "gpio-keys/input0";
69	input->dev.parent = &pdev->dev;
70
71	input->id.bustype = BUS_HOST;
72	input->id.vendor = 0x0001;
73	input->id.product = 0x0001;
74	input->id.version = 0x0100;
75
76	for (i = 0; i < pdata->nbuttons; i++) {
77		struct gpio_keys_button *button = &pdata->buttons[i];
78		int irq = gpio_to_irq(button->gpio);
79		unsigned int type = button->type ?: EV_KEY;
80
81		set_irq_type(irq, IRQ_TYPE_EDGE_BOTH);
82		error = request_irq(irq, gpio_keys_isr, IRQF_SAMPLE_RANDOM,
83				     button->desc ? button->desc : "gpio_keys",
84				     pdev);
85		if (error) {
86			printk(KERN_ERR "gpio-keys: unable to claim irq %d; error %d\n",
87				irq, error);
88			goto fail;
89		}
90
91		input_set_capability(input, type, button->code);
92	}
93
94	error = input_register_device(input);
95	if (error) {
96		printk(KERN_ERR "Unable to register gpio-keys input device\n");
97		goto fail;
98	}
99
100	return 0;
101
102 fail:
103	for (i = i - 1; i >= 0; i--)
104		free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
105
106	input_free_device(input);
107
108	return error;
109}
110
111static int __devexit gpio_keys_remove(struct platform_device *pdev)
112{
113	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
114	struct input_dev *input = platform_get_drvdata(pdev);
115	int i;
116
117	for (i = 0; i < pdata->nbuttons; i++) {
118		int irq = gpio_to_irq(pdata->buttons[i].gpio);
119		free_irq(irq, pdev);
120	}
121
122	input_unregister_device(input);
123
124	return 0;
125}
126
127struct platform_driver gpio_keys_device_driver = {
128	.probe		= gpio_keys_probe,
129	.remove		= __devexit_p(gpio_keys_remove),
130	.driver		= {
131		.name	= "gpio-keys",
132	}
133};
134
135static int __init gpio_keys_init(void)
136{
137	return platform_driver_register(&gpio_keys_device_driver);
138}
139
140static void __exit gpio_keys_exit(void)
141{
142	platform_driver_unregister(&gpio_keys_device_driver);
143}
144
145module_init(gpio_keys_init);
146module_exit(gpio_keys_exit);
147
148MODULE_LICENSE("GPL");
149MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
150MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
151