generic: update gpio_buttons driver
[openwrt/svn-archive/archive.git] / target / linux / generic / files / drivers / input / misc / gpio_buttons.c
1 /*
2 * Driver for buttons on GPIO lines not capable of generating interrupts
3 *
4 * Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org>
5 * Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com>
6 *
7 * This file was based on: /drivers/input/misc/cobalt_btns.c
8 * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
9 *
10 * also was based on: /drivers/input/keyboard/gpio_keys.c
11 * Copyright 2005 Phil Blundell
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
16 *
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <linux/input.h>
24 #include <linux/input-polldev.h>
25 #include <linux/ioport.h>
26 #include <linux/platform_device.h>
27 #include <linux/gpio.h>
28 #include <linux/gpio_buttons.h>
29
30 #define DRV_NAME "gpio-buttons"
31
32 struct gpio_button_data {
33 int last_state;
34 int count;
35 int can_sleep;
36 };
37
38 struct gpio_buttons_dev {
39 struct input_polled_dev *poll_dev;
40 struct gpio_buttons_platform_data *pdata;
41 struct gpio_button_data *data;
42 };
43
44 static void gpio_buttons_check_state(struct input_dev *input,
45 struct gpio_button *button,
46 struct gpio_button_data *bdata)
47 {
48 int state;
49
50 if (bdata->can_sleep)
51 state = !!gpio_get_value_cansleep(button->gpio);
52 else
53 state = !!gpio_get_value(button->gpio);
54
55 if (state != bdata->last_state) {
56 unsigned int type = button->type ?: EV_KEY;
57
58 input_event(input, type, button->code,
59 !!(state ^ button->active_low));
60 input_sync(input);
61 bdata->count = 0;
62 bdata->last_state = state;
63 }
64 }
65
66 static void gpio_buttons_poll(struct input_polled_dev *dev)
67 {
68 struct gpio_buttons_dev *bdev = dev->private;
69 struct gpio_buttons_platform_data *pdata = bdev->pdata;
70 struct input_dev *input = dev->input;
71 int i;
72
73 for (i = 0; i < bdev->pdata->nbuttons; i++) {
74 struct gpio_button *button = &pdata->buttons[i];
75 struct gpio_button_data *bdata = &bdev->data[i];
76
77 if (bdata->count < button->threshold)
78 bdata->count++;
79 else
80 gpio_buttons_check_state(input, button, bdata);
81
82 }
83 }
84
85 static int __devinit gpio_buttons_probe(struct platform_device *pdev)
86 {
87 struct gpio_buttons_platform_data *pdata = pdev->dev.platform_data;
88 struct device *dev = &pdev->dev;
89 struct gpio_buttons_dev *bdev;
90 struct input_polled_dev *poll_dev;
91 struct input_dev *input;
92 int error;
93 int i;
94
95 if (!pdata)
96 return -ENXIO;
97
98 bdev = kzalloc(sizeof(struct gpio_buttons_dev) +
99 pdata->nbuttons * sizeof(struct gpio_button_data),
100 GFP_KERNEL);
101 if (!bdev) {
102 dev_err(dev, "no memory for private data\n");
103 return -ENOMEM;
104 }
105
106 bdev->data = (struct gpio_button_data *) &bdev[1];
107
108 poll_dev = input_allocate_polled_device();
109 if (!poll_dev) {
110 dev_err(dev, "no memory for polled device\n");
111 error = -ENOMEM;
112 goto err_free_bdev;
113 }
114
115 poll_dev->private = bdev;
116 poll_dev->poll = gpio_buttons_poll;
117 poll_dev->poll_interval = pdata->poll_interval;
118
119 input = poll_dev->input;
120
121 input->evbit[0] = BIT(EV_KEY);
122 input->name = pdev->name;
123 input->phys = "gpio-buttons/input0";
124 input->dev.parent = &pdev->dev;
125
126 input->id.bustype = BUS_HOST;
127 input->id.vendor = 0x0001;
128 input->id.product = 0x0001;
129 input->id.version = 0x0100;
130
131 for (i = 0; i < pdata->nbuttons; i++) {
132 struct gpio_button *button = &pdata->buttons[i];
133 unsigned int gpio = button->gpio;
134 unsigned int type = button->type ?: EV_KEY;
135
136 error = gpio_request(gpio,
137 button->desc ? button->desc : DRV_NAME);
138 if (error) {
139 dev_err(dev, "unable to claim gpio %u, err=%d\n",
140 gpio, error);
141 goto err_free_gpio;
142 }
143
144 error = gpio_direction_input(gpio);
145 if (error) {
146 dev_err(dev,
147 "unable to set direction on gpio %u, err=%d\n",
148 gpio, error);
149 goto err_free_gpio;
150 }
151
152 bdev->data[i].can_sleep = gpio_cansleep(gpio);
153 bdev->data[i].last_state = -1;
154
155 input_set_capability(input, type, button->code);
156 }
157
158 bdev->poll_dev = poll_dev;
159 bdev->pdata = pdata;
160 platform_set_drvdata(pdev, bdev);
161
162 error = input_register_polled_device(poll_dev);
163 if (error) {
164 dev_err(dev, "unable to register polled device, err=%d\n",
165 error);
166 goto err_free_gpio;
167 }
168
169 /* report initial state of the buttons */
170 for (i = 0; i < pdata->nbuttons; i++)
171 gpio_buttons_check_state(input, &pdata->buttons[i],
172 &bdev->data[i]);
173
174 return 0;
175
176 err_free_gpio:
177 for (i = i - 1; i >= 0; i--)
178 gpio_free(pdata->buttons[i].gpio);
179
180 input_free_polled_device(poll_dev);
181
182 err_free_bdev:
183 kfree(bdev);
184
185 platform_set_drvdata(pdev, NULL);
186 return error;
187 }
188
189 static int __devexit gpio_buttons_remove(struct platform_device *pdev)
190 {
191 struct gpio_buttons_dev *bdev = platform_get_drvdata(pdev);
192 struct gpio_buttons_platform_data *pdata = bdev->pdata;
193 int i;
194
195 input_unregister_polled_device(bdev->poll_dev);
196
197 for (i = 0; i < pdata->nbuttons; i++)
198 gpio_free(pdata->buttons[i].gpio);
199
200 input_free_polled_device(bdev->poll_dev);
201
202 kfree(bdev);
203 platform_set_drvdata(pdev, NULL);
204
205 return 0;
206 }
207
208 static struct platform_driver gpio_buttons_driver = {
209 .probe = gpio_buttons_probe,
210 .remove = __devexit_p(gpio_buttons_remove),
211 .driver = {
212 .name = DRV_NAME,
213 .owner = THIS_MODULE,
214 },
215 };
216
217 static int __init gpio_buttons_init(void)
218 {
219 return platform_driver_register(&gpio_buttons_driver);
220 }
221
222 static void __exit gpio_buttons_exit(void)
223 {
224 platform_driver_unregister(&gpio_buttons_driver);
225 }
226
227 module_init(gpio_buttons_init);
228 module_exit(gpio_buttons_exit);
229
230 MODULE_LICENSE("GPL v2");
231 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
232 MODULE_DESCRIPTION("Polled GPIO Buttons driver");