summaryrefslogtreecommitdiffstats
path: root/drivers/input/keyboard/gpio_keys_polled.c
blob: f2142de789e76a44cc1fc316b90ef66a6fe46c0a (plain)
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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
/*
 *  Driver for buttons on GPIO lines not capable of generating interrupts
 *
 *  Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org>
 *  Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com>
 *
 *  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/slab.h>
#include <linux/input.h>
#include <linux/input-polldev.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/gpio_keys.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>

#define DRV_NAME	"gpio-keys-polled"

struct gpio_keys_button_data {
	int last_state;
	int count;
	int threshold;
	int can_sleep;
};

struct gpio_keys_polled_dev {
	struct input_polled_dev *poll_dev;
	struct device *dev;
	const struct gpio_keys_platform_data *pdata;
	struct gpio_keys_button_data data[0];
};

static void gpio_keys_polled_check_state(struct input_dev *input,
					 struct gpio_keys_button *button,
					 struct gpio_keys_button_data *bdata)
{
	int state;

	if (bdata->can_sleep)
		state = !!gpio_get_value_cansleep(button->gpio);
	else
		state = !!gpio_get_value(button->gpio);

	if (state != bdata->last_state) {
		unsigned int type = button->type ?: EV_KEY;

		input_event(input, type, button->code,
			    !!(state ^ button->active_low));
		input_sync(input);
		bdata->count = 0;
		bdata->last_state = state;
	}
}

static void gpio_keys_polled_poll(struct input_polled_dev *dev)
{
	struct gpio_keys_polled_dev *bdev = dev->private;
	const struct gpio_keys_platform_data *pdata = bdev->pdata;
	struct input_dev *input = dev->input;
	int i;

	for (i = 0; i < pdata->nbuttons; i++) {
		struct gpio_keys_button_data *bdata = &bdev->data[i];

		if (bdata->count < bdata->threshold)
			bdata->count++;
		else
			gpio_keys_polled_check_state(input, &pdata->buttons[i],
						     bdata);
	}
}

static void gpio_keys_polled_open(struct input_polled_dev *dev)
{
	struct gpio_keys_polled_dev *bdev = dev->private;
	const struct gpio_keys_platform_data *pdata = bdev->pdata;

	if (pdata->enable)
		pdata->enable(bdev->dev);
}

static void gpio_keys_polled_close(struct input_polled_dev *dev)
{
	struct gpio_keys_polled_dev *bdev = dev->private;
	const struct gpio_keys_platform_data *pdata = bdev->pdata;

	if (pdata->disable)
		pdata->disable(bdev->dev);
}

#ifdef CONFIG_OF
static struct gpio_keys_platform_data * __devinit
gpio_keys_polled_get_devtree_pdata(struct device *dev)
{
	struct device_node *node, *pp;
	struct gpio_keys_platform_data *pdata;
	struct gpio_keys_button *button;
	int error;
	int nbuttons;
	int i;

	node = dev->of_node;
	if (!node)
		return NULL;

	nbuttons = of_get_child_count(node);
	if (nbuttons == 0)
		return NULL;

	pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
			GFP_KERNEL);
	if (!pdata) {
		error = -ENOMEM;
		goto err_out;
	}

	pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
	pdata->nbuttons = nbuttons;

	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
	of_property_read_u32(node, "poll-interval", &pdata->poll_interval);

	i = 0;
	for_each_child_of_node(node, pp) {
		enum of_gpio_flags flags;

		if (!of_find_property(pp, "gpios", NULL)) {
			pdata->nbuttons--;
			dev_warn(dev, "Found button without gpios\n");
			continue;
		}

		button = &pdata->buttons[i++];

		button->gpio = of_get_gpio_flags(pp, 0, &flags);
		button->active_low = flags & OF_GPIO_ACTIVE_LOW;

		if (of_property_read_u32(pp, "linux,code", &button->code)) {
			dev_err(dev, "Button without keycode: 0x%x\n",
				button->gpio);
			error = -EINVAL;
			goto err_free_pdata;
		}

		button->desc = of_get_property(pp, "label", NULL);

		if (of_property_read_u32(pp, "linux,input-type", &button->type))
			button->type = EV_KEY;

		button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);

		if (of_property_read_u32(pp, "debounce-interval",
					 &button->debounce_interval))
			button->debounce_interval = 5;
	}

	if (pdata->nbuttons == 0) {
		error = -EINVAL;
		goto err_free_pdata;
	}

	return pdata;

err_free_pdata:
	kfree(pdata);
err_out:
	return ERR_PTR(error);
}

static struct of_device_id gpio_keys_polled_of_match[] = {
	{ .compatible = "gpio-keys-polled", },
	{ },
};
MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);

#else

static inline struct gpio_keys_platform_data *
gpio_keys_polled_get_devtree_pdata(struct device *dev)
{
	return NULL;
}
#endif

static int __devinit gpio_keys_polled_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
	struct gpio_keys_polled_dev *bdev;
	struct input_polled_dev *poll_dev;
	struct input_dev *input;
	int error;
	int i;

	if (!pdata) {
		pdata = gpio_keys_polled_get_devtree_pdata(dev);
		if (IS_ERR(pdata))
			return PTR_ERR(pdata);
		if (!pdata) {
			dev_err(dev, "missing platform data\n");
			return -EINVAL;
		}
	}

	if (!pdata->poll_interval) {
		dev_err(dev, "missing poll_interval value\n");
		error = -EINVAL;
		goto err_free_pdata;
	}

	bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
		       pdata->nbuttons * sizeof(struct gpio_keys_button_data),
		       GFP_KERNEL);
	if (!bdev) {
		dev_err(dev, "no memory for private data\n");
		error = -ENOMEM;
		goto err_free_pdata;
	}

	poll_dev = input_allocate_polled_device();
	if (!poll_dev) {
		dev_err(dev, "no memory for polled device\n");
		error = -ENOMEM;
		goto err_free_bdev;
	}

	poll_dev->private = bdev;
	poll_dev->poll = gpio_keys_polled_poll;
	poll_dev->poll_interval = pdata->poll_interval;
	poll_dev->open = gpio_keys_polled_open;
	poll_dev->close = gpio_keys_polled_close;

	input = poll_dev->input;

	input->evbit[0] = BIT(EV_KEY);
	input->name = pdev->name;
	input->phys = DRV_NAME"/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_keys_button *button = &pdata->buttons[i];
		struct gpio_keys_button_data *bdata = &bdev->data[i];
		unsigned int gpio = button->gpio;
		unsigned int type = button->type ?: EV_KEY;

		if (button->wakeup) {
			dev_err(dev, DRV_NAME " does not support wakeup\n");
			error = -EINVAL;
			goto err_free_gpio;
		}

		error = gpio_request(gpio,
				     button->desc ? button->desc : DRV_NAME);
		if (error) {
			dev_err(dev, "unable to claim gpio %u, err=%d\n",
				gpio, error);
			goto err_free_gpio;
		}

		error = gpio_direction_input(gpio);
		if (error) {
			dev_err(dev,
				"unable to set direction on gpio %u, err=%d\n",
				gpio, error);
			goto err_free_gpio;
		}

		bdata->can_sleep = gpio_cansleep(gpio);
		bdata->last_state = -1;
		bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
						pdata->poll_interval);

		input_set_capability(input, type, button->code);
	}

	bdev->poll_dev = poll_dev;
	bdev->dev = dev;
	bdev->pdata = pdata;
	platform_set_drvdata(pdev, bdev);

	error = input_register_polled_device(poll_dev);
	if (error) {
		dev_err(dev, "unable to register polled device, err=%d\n",
			error);
		goto err_free_gpio;
	}

	/* report initial state of the buttons */
	for (i = 0; i < pdata->nbuttons; i++)
		gpio_keys_polled_check_state(input, &pdata->buttons[i],
					     &bdev->data[i]);

	return 0;

err_free_gpio:
	while (--i >= 0)
		gpio_free(pdata->buttons[i].gpio);

	input_free_polled_device(poll_dev);

err_free_bdev:
	kfree(bdev);
	platform_set_drvdata(pdev, NULL);

err_free_pdata:
	/* If we have no platform_data, we allocated pdata dynamically.  */
	if (!dev_get_platdata(&pdev->dev))
		kfree(pdata);

	return error;
}

static int __devexit gpio_keys_polled_remove(struct platform_device *pdev)
{
	struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
	const struct gpio_keys_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);

	/*
	 * If we had no platform_data, we allocated pdata dynamically and
	 * must free it here.
	 */
	if (!dev_get_platdata(&pdev->dev))
		kfree(pdata);

	kfree(bdev);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver gpio_keys_polled_driver = {
	.probe	= gpio_keys_polled_probe,
	.remove	= __devexit_p(gpio_keys_polled_remove),
	.driver	= {
		.name	= DRV_NAME,
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(gpio_keys_polled_of_match),
	},
};
module_platform_driver(gpio_keys_polled_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_DESCRIPTION("Polled GPIO Buttons driver");
MODULE_ALIAS("platform:" DRV_NAME);