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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#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/slab.h>
21#include <linux/input.h>
22#include <linux/input-polldev.h>
23#include <linux/ioport.h>
24#include <linux/platform_device.h>
25#include <linux/gpio.h>
26#include <linux/gpio_keys.h>
27#include <linux/of.h>
28#include <linux/of_platform.h>
29#include <linux/of_gpio.h>
30
31#define DRV_NAME "gpio-keys-polled"
32
33struct gpio_keys_button_data {
34 int last_state;
35 int count;
36 int threshold;
37 int can_sleep;
38};
39
40struct gpio_keys_polled_dev {
41 struct input_polled_dev *poll_dev;
42 struct device *dev;
43 const struct gpio_keys_platform_data *pdata;
44 struct gpio_keys_button_data data[0];
45};
46
47static void gpio_keys_polled_check_state(struct input_dev *input,
48 struct gpio_keys_button *button,
49 struct gpio_keys_button_data *bdata)
50{
51 int state;
52
53 if (bdata->can_sleep)
54 state = !!gpio_get_value_cansleep(button->gpio);
55 else
56 state = !!gpio_get_value(button->gpio);
57
58 if (state != bdata->last_state) {
59 unsigned int type = button->type ?: EV_KEY;
60
61 input_event(input, type, button->code,
62 !!(state ^ button->active_low));
63 input_sync(input);
64 bdata->count = 0;
65 bdata->last_state = state;
66 }
67}
68
69static void gpio_keys_polled_poll(struct input_polled_dev *dev)
70{
71 struct gpio_keys_polled_dev *bdev = dev->private;
72 const struct gpio_keys_platform_data *pdata = bdev->pdata;
73 struct input_dev *input = dev->input;
74 int i;
75
76 for (i = 0; i < pdata->nbuttons; i++) {
77 struct gpio_keys_button_data *bdata = &bdev->data[i];
78
79 if (bdata->count < bdata->threshold)
80 bdata->count++;
81 else
82 gpio_keys_polled_check_state(input, &pdata->buttons[i],
83 bdata);
84 }
85}
86
87static void gpio_keys_polled_open(struct input_polled_dev *dev)
88{
89 struct gpio_keys_polled_dev *bdev = dev->private;
90 const struct gpio_keys_platform_data *pdata = bdev->pdata;
91
92 if (pdata->enable)
93 pdata->enable(bdev->dev);
94}
95
96static void gpio_keys_polled_close(struct input_polled_dev *dev)
97{
98 struct gpio_keys_polled_dev *bdev = dev->private;
99 const struct gpio_keys_platform_data *pdata = bdev->pdata;
100
101 if (pdata->disable)
102 pdata->disable(bdev->dev);
103}
104
105#ifdef CONFIG_OF
106static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct device *dev)
107{
108 struct device_node *node, *pp;
109 struct gpio_keys_platform_data *pdata;
110 struct gpio_keys_button *button;
111 int error;
112 int nbuttons;
113 int i;
114
115 node = dev->of_node;
116 if (!node)
117 return NULL;
118
119 nbuttons = of_get_child_count(node);
120 if (nbuttons == 0)
121 return NULL;
122
123 pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
124 GFP_KERNEL);
125 if (!pdata) {
126 error = -ENOMEM;
127 goto err_out;
128 }
129
130 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
131 pdata->nbuttons = nbuttons;
132
133 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
134 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
135
136 i = 0;
137 for_each_child_of_node(node, pp) {
138 int gpio;
139 enum of_gpio_flags flags;
140
141 if (!of_find_property(pp, "gpios", NULL)) {
142 pdata->nbuttons--;
143 dev_warn(dev, "Found button without gpios\n");
144 continue;
145 }
146
147 gpio = of_get_gpio_flags(pp, 0, &flags);
148 if (gpio < 0) {
149 error = gpio;
150 if (error != -EPROBE_DEFER)
151 dev_err(dev,
152 "Failed to get gpio flags, error: %d\n",
153 error);
154 goto err_free_pdata;
155 }
156
157 button = &pdata->buttons[i++];
158
159 button->gpio = gpio;
160 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
161
162 if (of_property_read_u32(pp, "linux,code", &button->code)) {
163 dev_err(dev, "Button without keycode: 0x%x\n",
164 button->gpio);
165 error = -EINVAL;
166 goto err_free_pdata;
167 }
168
169 button->desc = of_get_property(pp, "label", NULL);
170
171 if (of_property_read_u32(pp, "linux,input-type", &button->type))
172 button->type = EV_KEY;
173
174 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
175
176 if (of_property_read_u32(pp, "debounce-interval",
177 &button->debounce_interval))
178 button->debounce_interval = 5;
179 }
180
181 if (pdata->nbuttons == 0) {
182 error = -EINVAL;
183 goto err_free_pdata;
184 }
185
186 return pdata;
187
188err_free_pdata:
189 kfree(pdata);
190err_out:
191 return ERR_PTR(error);
192}
193
194static struct of_device_id gpio_keys_polled_of_match[] = {
195 { .compatible = "gpio-keys-polled", },
196 { },
197};
198MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
199
200#else
201
202static inline struct gpio_keys_platform_data *
203gpio_keys_polled_get_devtree_pdata(struct device *dev)
204{
205 return NULL;
206}
207#endif
208
209static int gpio_keys_polled_probe(struct platform_device *pdev)
210{
211 struct device *dev = &pdev->dev;
212 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
213 struct gpio_keys_polled_dev *bdev;
214 struct input_polled_dev *poll_dev;
215 struct input_dev *input;
216 int error;
217 int i;
218
219 if (!pdata) {
220 pdata = gpio_keys_polled_get_devtree_pdata(dev);
221 if (IS_ERR(pdata))
222 return PTR_ERR(pdata);
223 if (!pdata) {
224 dev_err(dev, "missing platform data\n");
225 return -EINVAL;
226 }
227 }
228
229 if (!pdata->poll_interval) {
230 dev_err(dev, "missing poll_interval value\n");
231 error = -EINVAL;
232 goto err_free_pdata;
233 }
234
235 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
236 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
237 GFP_KERNEL);
238 if (!bdev) {
239 dev_err(dev, "no memory for private data\n");
240 error = -ENOMEM;
241 goto err_free_pdata;
242 }
243
244 poll_dev = input_allocate_polled_device();
245 if (!poll_dev) {
246 dev_err(dev, "no memory for polled device\n");
247 error = -ENOMEM;
248 goto err_free_bdev;
249 }
250
251 poll_dev->private = bdev;
252 poll_dev->poll = gpio_keys_polled_poll;
253 poll_dev->poll_interval = pdata->poll_interval;
254 poll_dev->open = gpio_keys_polled_open;
255 poll_dev->close = gpio_keys_polled_close;
256
257 input = poll_dev->input;
258
259 input->name = pdev->name;
260 input->phys = DRV_NAME"/input0";
261 input->dev.parent = &pdev->dev;
262
263 input->id.bustype = BUS_HOST;
264 input->id.vendor = 0x0001;
265 input->id.product = 0x0001;
266 input->id.version = 0x0100;
267
268 __set_bit(EV_KEY, input->evbit);
269 if (pdata->rep)
270 __set_bit(EV_REP, input->evbit);
271
272 for (i = 0; i < pdata->nbuttons; i++) {
273 struct gpio_keys_button *button = &pdata->buttons[i];
274 struct gpio_keys_button_data *bdata = &bdev->data[i];
275 unsigned int gpio = button->gpio;
276 unsigned int type = button->type ?: EV_KEY;
277
278 if (button->wakeup) {
279 dev_err(dev, DRV_NAME " does not support wakeup\n");
280 error = -EINVAL;
281 goto err_free_gpio;
282 }
283
284 error = gpio_request_one(gpio, GPIOF_IN,
285 button->desc ?: DRV_NAME);
286 if (error) {
287 dev_err(dev, "unable to claim gpio %u, err=%d\n",
288 gpio, error);
289 goto err_free_gpio;
290 }
291
292 bdata->can_sleep = gpio_cansleep(gpio);
293 bdata->last_state = -1;
294 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
295 pdata->poll_interval);
296
297 input_set_capability(input, type, button->code);
298 }
299
300 bdev->poll_dev = poll_dev;
301 bdev->dev = dev;
302 bdev->pdata = pdata;
303 platform_set_drvdata(pdev, bdev);
304
305 error = input_register_polled_device(poll_dev);
306 if (error) {
307 dev_err(dev, "unable to register polled device, err=%d\n",
308 error);
309 goto err_free_gpio;
310 }
311
312 /* report initial state of the buttons */
313 for (i = 0; i < pdata->nbuttons; i++)
314 gpio_keys_polled_check_state(input, &pdata->buttons[i],
315 &bdev->data[i]);
316
317 return 0;
318
319err_free_gpio:
320 while (--i >= 0)
321 gpio_free(pdata->buttons[i].gpio);
322
323 input_free_polled_device(poll_dev);
324
325err_free_bdev:
326 kfree(bdev);
327
328err_free_pdata:
329 /* If we have no platform_data, we allocated pdata dynamically. */
330 if (!dev_get_platdata(&pdev->dev))
331 kfree(pdata);
332
333 return error;
334}
335
336static int gpio_keys_polled_remove(struct platform_device *pdev)
337{
338 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
339 const struct gpio_keys_platform_data *pdata = bdev->pdata;
340 int i;
341
342 input_unregister_polled_device(bdev->poll_dev);
343
344 for (i = 0; i < pdata->nbuttons; i++)
345 gpio_free(pdata->buttons[i].gpio);
346
347 input_free_polled_device(bdev->poll_dev);
348
349 /*
350 * If we had no platform_data, we allocated pdata dynamically and
351 * must free it here.
352 */
353 if (!dev_get_platdata(&pdev->dev))
354 kfree(pdata);
355
356 kfree(bdev);
357
358 return 0;
359}
360
361static struct platform_driver gpio_keys_polled_driver = {
362 .probe = gpio_keys_polled_probe,
363 .remove = gpio_keys_polled_remove,
364 .driver = {
365 .name = DRV_NAME,
366 .owner = THIS_MODULE,
367 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
368 },
369};
370module_platform_driver(gpio_keys_polled_driver);
371
372MODULE_LICENSE("GPL v2");
373MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
374MODULE_DESCRIPTION("Polled GPIO Buttons driver");
375MODULE_ALIAS("platform:" DRV_NAME);
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#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/slab.h>
22#include <linux/input.h>
23#include <linux/input-polldev.h>
24#include <linux/ioport.h>
25#include <linux/platform_device.h>
26#include <linux/gpio.h>
27#include <linux/gpio_keys.h>
28
29#define DRV_NAME "gpio-keys-polled"
30
31struct gpio_keys_button_data {
32 int last_state;
33 int count;
34 int threshold;
35 int can_sleep;
36};
37
38struct gpio_keys_polled_dev {
39 struct input_polled_dev *poll_dev;
40 struct device *dev;
41 struct gpio_keys_platform_data *pdata;
42 struct gpio_keys_button_data data[0];
43};
44
45static void gpio_keys_polled_check_state(struct input_dev *input,
46 struct gpio_keys_button *button,
47 struct gpio_keys_button_data *bdata)
48{
49 int state;
50
51 if (bdata->can_sleep)
52 state = !!gpio_get_value_cansleep(button->gpio);
53 else
54 state = !!gpio_get_value(button->gpio);
55
56 if (state != bdata->last_state) {
57 unsigned int type = button->type ?: EV_KEY;
58
59 input_event(input, type, button->code,
60 !!(state ^ button->active_low));
61 input_sync(input);
62 bdata->count = 0;
63 bdata->last_state = state;
64 }
65}
66
67static void gpio_keys_polled_poll(struct input_polled_dev *dev)
68{
69 struct gpio_keys_polled_dev *bdev = dev->private;
70 struct gpio_keys_platform_data *pdata = bdev->pdata;
71 struct input_dev *input = dev->input;
72 int i;
73
74 for (i = 0; i < bdev->pdata->nbuttons; i++) {
75 struct gpio_keys_button_data *bdata = &bdev->data[i];
76
77 if (bdata->count < bdata->threshold)
78 bdata->count++;
79 else
80 gpio_keys_polled_check_state(input, &pdata->buttons[i],
81 bdata);
82 }
83}
84
85static void gpio_keys_polled_open(struct input_polled_dev *dev)
86{
87 struct gpio_keys_polled_dev *bdev = dev->private;
88 struct gpio_keys_platform_data *pdata = bdev->pdata;
89
90 if (pdata->enable)
91 pdata->enable(bdev->dev);
92}
93
94static void gpio_keys_polled_close(struct input_polled_dev *dev)
95{
96 struct gpio_keys_polled_dev *bdev = dev->private;
97 struct gpio_keys_platform_data *pdata = bdev->pdata;
98
99 if (pdata->disable)
100 pdata->disable(bdev->dev);
101}
102
103static int __devinit gpio_keys_polled_probe(struct platform_device *pdev)
104{
105 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
106 struct device *dev = &pdev->dev;
107 struct gpio_keys_polled_dev *bdev;
108 struct input_polled_dev *poll_dev;
109 struct input_dev *input;
110 int error;
111 int i;
112
113 if (!pdata || !pdata->poll_interval)
114 return -EINVAL;
115
116 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
117 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
118 GFP_KERNEL);
119 if (!bdev) {
120 dev_err(dev, "no memory for private data\n");
121 return -ENOMEM;
122 }
123
124 poll_dev = input_allocate_polled_device();
125 if (!poll_dev) {
126 dev_err(dev, "no memory for polled device\n");
127 error = -ENOMEM;
128 goto err_free_bdev;
129 }
130
131 poll_dev->private = bdev;
132 poll_dev->poll = gpio_keys_polled_poll;
133 poll_dev->poll_interval = pdata->poll_interval;
134 poll_dev->open = gpio_keys_polled_open;
135 poll_dev->close = gpio_keys_polled_close;
136
137 input = poll_dev->input;
138
139 input->evbit[0] = BIT(EV_KEY);
140 input->name = pdev->name;
141 input->phys = DRV_NAME"/input0";
142 input->dev.parent = &pdev->dev;
143
144 input->id.bustype = BUS_HOST;
145 input->id.vendor = 0x0001;
146 input->id.product = 0x0001;
147 input->id.version = 0x0100;
148
149 for (i = 0; i < pdata->nbuttons; i++) {
150 struct gpio_keys_button *button = &pdata->buttons[i];
151 struct gpio_keys_button_data *bdata = &bdev->data[i];
152 unsigned int gpio = button->gpio;
153 unsigned int type = button->type ?: EV_KEY;
154
155 if (button->wakeup) {
156 dev_err(dev, DRV_NAME " does not support wakeup\n");
157 error = -EINVAL;
158 goto err_free_gpio;
159 }
160
161 error = gpio_request(gpio,
162 button->desc ? button->desc : DRV_NAME);
163 if (error) {
164 dev_err(dev, "unable to claim gpio %u, err=%d\n",
165 gpio, error);
166 goto err_free_gpio;
167 }
168
169 error = gpio_direction_input(gpio);
170 if (error) {
171 dev_err(dev,
172 "unable to set direction on gpio %u, err=%d\n",
173 gpio, error);
174 goto err_free_gpio;
175 }
176
177 bdata->can_sleep = gpio_cansleep(gpio);
178 bdata->last_state = -1;
179 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
180 pdata->poll_interval);
181
182 input_set_capability(input, type, button->code);
183 }
184
185 bdev->poll_dev = poll_dev;
186 bdev->dev = dev;
187 bdev->pdata = pdata;
188 platform_set_drvdata(pdev, bdev);
189
190 error = input_register_polled_device(poll_dev);
191 if (error) {
192 dev_err(dev, "unable to register polled device, err=%d\n",
193 error);
194 goto err_free_gpio;
195 }
196
197 /* report initial state of the buttons */
198 for (i = 0; i < pdata->nbuttons; i++)
199 gpio_keys_polled_check_state(input, &pdata->buttons[i],
200 &bdev->data[i]);
201
202 return 0;
203
204err_free_gpio:
205 while (--i >= 0)
206 gpio_free(pdata->buttons[i].gpio);
207
208 input_free_polled_device(poll_dev);
209
210err_free_bdev:
211 kfree(bdev);
212
213 platform_set_drvdata(pdev, NULL);
214 return error;
215}
216
217static int __devexit gpio_keys_polled_remove(struct platform_device *pdev)
218{
219 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
220 struct gpio_keys_platform_data *pdata = bdev->pdata;
221 int i;
222
223 input_unregister_polled_device(bdev->poll_dev);
224
225 for (i = 0; i < pdata->nbuttons; i++)
226 gpio_free(pdata->buttons[i].gpio);
227
228 input_free_polled_device(bdev->poll_dev);
229
230 kfree(bdev);
231 platform_set_drvdata(pdev, NULL);
232
233 return 0;
234}
235
236static struct platform_driver gpio_keys_polled_driver = {
237 .probe = gpio_keys_polled_probe,
238 .remove = __devexit_p(gpio_keys_polled_remove),
239 .driver = {
240 .name = DRV_NAME,
241 .owner = THIS_MODULE,
242 },
243};
244module_platform_driver(gpio_keys_polled_driver);
245
246MODULE_LICENSE("GPL v2");
247MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
248MODULE_DESCRIPTION("Polled GPIO Buttons driver");
249MODULE_ALIAS("platform:" DRV_NAME);