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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/*
* Driver for buttons on GPIO lines not capable of generating interrupts
*
* Copyright (C) 2007,2008 Gabor Juhos <juhosg at openwrt.org>
*
* This file was based on: /drivers/input/misc/cobalt_btns.c
* Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* also was based on: /drivers/input/keyboard/gpio_keys.c
* 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/input-polldev.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/gpio_buttons.h>
#include <asm/gpio.h>
#define DRV_NAME "gpio-buttons"
#define DRV_VERSION "0.1.1"
#define PFX DRV_NAME ": "
struct gpio_buttons_dev {
struct input_polled_dev *poll_dev;
struct gpio_buttons_platform_data *pdata;
};
static void gpio_buttons_poll(struct input_polled_dev *dev)
{
struct gpio_buttons_dev *bdev = dev->private;
struct gpio_buttons_platform_data *pdata = bdev->pdata;
struct input_dev *input = dev->input;
int i;
for (i = 0; i < bdev->pdata->nbuttons; i++) {
struct gpio_button *button = &pdata->buttons[i];
unsigned int type = button->type ?: EV_KEY;
int state;
state = gpio_get_value(button->gpio) ? 1 : 0;
state ^= button->active_low;
if (state) {
button->count++;
} else {
if (button->count >= button->threshold) {
input_event(input, type, button->code, 1);
input_sync(input);
}
button->count = 0;
}
if (button->count == button->threshold) {
input_event(input, type, button->code, 0);
input_sync(input);
}
}
}
static int __devinit gpio_buttons_probe(struct platform_device *pdev)
{
struct gpio_buttons_platform_data *pdata = pdev->dev.platform_data;
struct gpio_buttons_dev *bdev;
struct input_polled_dev *poll_dev;
struct input_dev *input;
int error, i;
if (!pdata)
return -ENXIO;
bdev = kzalloc(sizeof(*bdev), GFP_KERNEL);
if (!bdev) {
printk(KERN_ERR DRV_NAME "no memory for device\n");
return -ENOMEM;
}
poll_dev = input_allocate_polled_device();
if (!poll_dev) {
printk(KERN_ERR DRV_NAME "no memory for polled device\n");
error = -ENOMEM;
goto err_free_bdev;
}
poll_dev->private = bdev;
poll_dev->poll = gpio_buttons_poll;
poll_dev->poll_interval = pdata->poll_interval;
input = poll_dev->input;
input->evbit[0] = BIT(EV_KEY);
input->name = pdev->name;
input->phys = "gpio-buttons/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++) {
struct gpio_button *button = &pdata->buttons[i];
unsigned int gpio = button->gpio;
unsigned int type = button->type ?: EV_KEY;
error = gpio_request(gpio, button->desc ?
button->desc : DRV_NAME);
if (error) {
printk(KERN_ERR PFX "unable to claim gpio %u, "
"error %d\n", gpio, error);
goto err_free_gpio;
}
error = gpio_direction_input(gpio);
if (error) {
printk(KERN_ERR PFX "unable to set direction on "
"gpio %u, error %d\n", gpio, error);
goto err_free_gpio;
}
input_set_capability(input, type, button->code);
button->count = 0;
}
bdev->poll_dev = poll_dev;
bdev->pdata = pdata;
platform_set_drvdata(pdev, bdev);
error = input_register_polled_device(poll_dev);
if (error) {
printk(KERN_ERR PFX "unable to register polled device, "
"error %d\n", error);
goto err_free_gpio;
}
return 0;
err_free_gpio:
for (i = i - 1; i >= 0; i--)
gpio_free(pdata->buttons[i].gpio);
input_free_polled_device(poll_dev);
err_free_bdev:
kfree(bdev);
platform_set_drvdata(pdev, NULL);
return error;
}
static int __devexit gpio_buttons_remove(struct platform_device *pdev)
{
struct gpio_buttons_dev *bdev = platform_get_drvdata(pdev);
struct gpio_buttons_platform_data *pdata = bdev->pdata;
int i;
input_unregister_polled_device(bdev->poll_dev);
for (i = 0; i < pdata->nbuttons; i++)
gpio_free(pdata->buttons[i].gpio);
input_free_polled_device(bdev->poll_dev);
kfree(bdev);
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct platform_driver gpio_buttons_driver = {
.probe = gpio_buttons_probe,
.remove = __devexit_p(gpio_buttons_remove),
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
};
static int __init gpio_buttons_init(void)
{
printk(KERN_INFO DRV_NAME " driver version " DRV_VERSION "\n");
return platform_driver_register(&gpio_buttons_driver);
}
static void __exit gpio_buttons_exit(void)
{
platform_driver_unregister(&gpio_buttons_driver);
}
module_init(gpio_buttons_init);
module_exit(gpio_buttons_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
MODULE_VERSION(DRV_VERSION);
MODULE_DESCRIPTION("Polled buttons driver for CPU GPIOs");
|
