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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/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};
244
245static int __init gpio_keys_polled_init(void)
246{
247 return platform_driver_register(&gpio_keys_polled_driver);
248}
249
250static void __exit gpio_keys_polled_exit(void)
251{
252 platform_driver_unregister(&gpio_keys_polled_driver);
253}
254
255module_init(gpio_keys_polled_init);
256module_exit(gpio_keys_polled_exit);
257
258MODULE_LICENSE("GPL v2");
259MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
260MODULE_DESCRIPTION("Polled GPIO Buttons driver");
261MODULE_ALIAS("platform:" DRV_NAME);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for buttons on GPIO lines not capable of generating interrupts
4 *
5 * Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org>
6 * Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com>
7 *
8 * This file was based on: /drivers/input/misc/cobalt_btns.c
9 * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
10 *
11 * also was based on: /drivers/input/keyboard/gpio_keys.c
12 * Copyright 2005 Phil Blundell
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/input.h>
19#include <linux/input-polldev.h>
20#include <linux/ioport.h>
21#include <linux/platform_device.h>
22#include <linux/gpio.h>
23#include <linux/gpio/consumer.h>
24#include <linux/gpio_keys.h>
25#include <linux/property.h>
26
27#define DRV_NAME "gpio-keys-polled"
28
29struct gpio_keys_button_data {
30 struct gpio_desc *gpiod;
31 int last_state;
32 int count;
33 int threshold;
34};
35
36struct gpio_keys_polled_dev {
37 struct input_polled_dev *poll_dev;
38 struct device *dev;
39 const struct gpio_keys_platform_data *pdata;
40 unsigned long rel_axis_seen[BITS_TO_LONGS(REL_CNT)];
41 unsigned long abs_axis_seen[BITS_TO_LONGS(ABS_CNT)];
42 struct gpio_keys_button_data data[0];
43};
44
45static void gpio_keys_button_event(struct input_polled_dev *dev,
46 const struct gpio_keys_button *button,
47 int state)
48{
49 struct gpio_keys_polled_dev *bdev = dev->private;
50 struct input_dev *input = dev->input;
51 unsigned int type = button->type ?: EV_KEY;
52
53 if (type == EV_REL) {
54 if (state) {
55 input_event(input, type, button->code, button->value);
56 __set_bit(button->code, bdev->rel_axis_seen);
57 }
58 } else if (type == EV_ABS) {
59 if (state) {
60 input_event(input, type, button->code, button->value);
61 __set_bit(button->code, bdev->abs_axis_seen);
62 }
63 } else {
64 input_event(input, type, button->code, state);
65 input_sync(input);
66 }
67}
68
69static void gpio_keys_polled_check_state(struct input_polled_dev *dev,
70 const struct gpio_keys_button *button,
71 struct gpio_keys_button_data *bdata)
72{
73 int state;
74
75 state = gpiod_get_value_cansleep(bdata->gpiod);
76 if (state < 0) {
77 dev_err(dev->input->dev.parent,
78 "failed to get gpio state: %d\n", state);
79 } else {
80 gpio_keys_button_event(dev, button, state);
81
82 if (state != bdata->last_state) {
83 bdata->count = 0;
84 bdata->last_state = state;
85 }
86 }
87}
88
89static void gpio_keys_polled_poll(struct input_polled_dev *dev)
90{
91 struct gpio_keys_polled_dev *bdev = dev->private;
92 const struct gpio_keys_platform_data *pdata = bdev->pdata;
93 struct input_dev *input = dev->input;
94 int i;
95
96 memset(bdev->rel_axis_seen, 0, sizeof(bdev->rel_axis_seen));
97 memset(bdev->abs_axis_seen, 0, sizeof(bdev->abs_axis_seen));
98
99 for (i = 0; i < pdata->nbuttons; i++) {
100 struct gpio_keys_button_data *bdata = &bdev->data[i];
101
102 if (bdata->count < bdata->threshold) {
103 bdata->count++;
104 gpio_keys_button_event(dev, &pdata->buttons[i],
105 bdata->last_state);
106 } else {
107 gpio_keys_polled_check_state(dev, &pdata->buttons[i],
108 bdata);
109 }
110 }
111
112 for_each_set_bit(i, input->relbit, REL_CNT) {
113 if (!test_bit(i, bdev->rel_axis_seen))
114 input_event(input, EV_REL, i, 0);
115 }
116
117 for_each_set_bit(i, input->absbit, ABS_CNT) {
118 if (!test_bit(i, bdev->abs_axis_seen))
119 input_event(input, EV_ABS, i, 0);
120 }
121
122 input_sync(input);
123}
124
125static void gpio_keys_polled_open(struct input_polled_dev *dev)
126{
127 struct gpio_keys_polled_dev *bdev = dev->private;
128 const struct gpio_keys_platform_data *pdata = bdev->pdata;
129
130 if (pdata->enable)
131 pdata->enable(bdev->dev);
132}
133
134static void gpio_keys_polled_close(struct input_polled_dev *dev)
135{
136 struct gpio_keys_polled_dev *bdev = dev->private;
137 const struct gpio_keys_platform_data *pdata = bdev->pdata;
138
139 if (pdata->disable)
140 pdata->disable(bdev->dev);
141}
142
143static struct gpio_keys_platform_data *
144gpio_keys_polled_get_devtree_pdata(struct device *dev)
145{
146 struct gpio_keys_platform_data *pdata;
147 struct gpio_keys_button *button;
148 struct fwnode_handle *child;
149 int nbuttons;
150
151 nbuttons = device_get_child_node_count(dev);
152 if (nbuttons == 0)
153 return ERR_PTR(-EINVAL);
154
155 pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * sizeof(*button),
156 GFP_KERNEL);
157 if (!pdata)
158 return ERR_PTR(-ENOMEM);
159
160 button = (struct gpio_keys_button *)(pdata + 1);
161
162 pdata->buttons = button;
163 pdata->nbuttons = nbuttons;
164
165 pdata->rep = device_property_present(dev, "autorepeat");
166 device_property_read_u32(dev, "poll-interval", &pdata->poll_interval);
167
168 device_property_read_string(dev, "label", &pdata->name);
169
170 device_for_each_child_node(dev, child) {
171 if (fwnode_property_read_u32(child, "linux,code",
172 &button->code)) {
173 dev_err(dev, "button without keycode\n");
174 fwnode_handle_put(child);
175 return ERR_PTR(-EINVAL);
176 }
177
178 fwnode_property_read_string(child, "label", &button->desc);
179
180 if (fwnode_property_read_u32(child, "linux,input-type",
181 &button->type))
182 button->type = EV_KEY;
183
184 if (fwnode_property_read_u32(child, "linux,input-value",
185 (u32 *)&button->value))
186 button->value = 1;
187
188 button->wakeup =
189 fwnode_property_read_bool(child, "wakeup-source") ||
190 /* legacy name */
191 fwnode_property_read_bool(child, "gpio-key,wakeup");
192
193 if (fwnode_property_read_u32(child, "debounce-interval",
194 &button->debounce_interval))
195 button->debounce_interval = 5;
196
197 button++;
198 }
199
200 return pdata;
201}
202
203static void gpio_keys_polled_set_abs_params(struct input_dev *input,
204 const struct gpio_keys_platform_data *pdata, unsigned int code)
205{
206 int i, min = 0, max = 0;
207
208 for (i = 0; i < pdata->nbuttons; i++) {
209 const struct gpio_keys_button *button = &pdata->buttons[i];
210
211 if (button->type != EV_ABS || button->code != code)
212 continue;
213
214 if (button->value < min)
215 min = button->value;
216 if (button->value > max)
217 max = button->value;
218 }
219
220 input_set_abs_params(input, code, min, max, 0, 0);
221}
222
223static const struct of_device_id gpio_keys_polled_of_match[] = {
224 { .compatible = "gpio-keys-polled", },
225 { },
226};
227MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
228
229static int gpio_keys_polled_probe(struct platform_device *pdev)
230{
231 struct device *dev = &pdev->dev;
232 struct fwnode_handle *child = NULL;
233 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
234 struct gpio_keys_polled_dev *bdev;
235 struct input_polled_dev *poll_dev;
236 struct input_dev *input;
237 int error;
238 int i;
239
240 if (!pdata) {
241 pdata = gpio_keys_polled_get_devtree_pdata(dev);
242 if (IS_ERR(pdata))
243 return PTR_ERR(pdata);
244 }
245
246 if (!pdata->poll_interval) {
247 dev_err(dev, "missing poll_interval value\n");
248 return -EINVAL;
249 }
250
251 bdev = devm_kzalloc(dev, struct_size(bdev, data, pdata->nbuttons),
252 GFP_KERNEL);
253 if (!bdev) {
254 dev_err(dev, "no memory for private data\n");
255 return -ENOMEM;
256 }
257
258 poll_dev = devm_input_allocate_polled_device(dev);
259 if (!poll_dev) {
260 dev_err(dev, "no memory for polled device\n");
261 return -ENOMEM;
262 }
263
264 poll_dev->private = bdev;
265 poll_dev->poll = gpio_keys_polled_poll;
266 poll_dev->poll_interval = pdata->poll_interval;
267 poll_dev->open = gpio_keys_polled_open;
268 poll_dev->close = gpio_keys_polled_close;
269
270 input = poll_dev->input;
271
272 input->name = pdata->name ?: pdev->name;
273 input->phys = DRV_NAME"/input0";
274
275 input->id.bustype = BUS_HOST;
276 input->id.vendor = 0x0001;
277 input->id.product = 0x0001;
278 input->id.version = 0x0100;
279
280 __set_bit(EV_KEY, input->evbit);
281 if (pdata->rep)
282 __set_bit(EV_REP, input->evbit);
283
284 for (i = 0; i < pdata->nbuttons; i++) {
285 const struct gpio_keys_button *button = &pdata->buttons[i];
286 struct gpio_keys_button_data *bdata = &bdev->data[i];
287 unsigned int type = button->type ?: EV_KEY;
288
289 if (button->wakeup) {
290 dev_err(dev, DRV_NAME " does not support wakeup\n");
291 fwnode_handle_put(child);
292 return -EINVAL;
293 }
294
295 if (!dev_get_platdata(dev)) {
296 /* No legacy static platform data */
297 child = device_get_next_child_node(dev, child);
298 if (!child) {
299 dev_err(dev, "missing child device node\n");
300 return -EINVAL;
301 }
302
303 bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev,
304 NULL, child,
305 GPIOD_IN,
306 button->desc);
307 if (IS_ERR(bdata->gpiod)) {
308 error = PTR_ERR(bdata->gpiod);
309 if (error != -EPROBE_DEFER)
310 dev_err(dev,
311 "failed to get gpio: %d\n",
312 error);
313 fwnode_handle_put(child);
314 return error;
315 }
316 } else if (gpio_is_valid(button->gpio)) {
317 /*
318 * Legacy GPIO number so request the GPIO here and
319 * convert it to descriptor.
320 */
321 unsigned flags = GPIOF_IN;
322
323 if (button->active_low)
324 flags |= GPIOF_ACTIVE_LOW;
325
326 error = devm_gpio_request_one(dev, button->gpio,
327 flags, button->desc ? : DRV_NAME);
328 if (error) {
329 dev_err(dev,
330 "unable to claim gpio %u, err=%d\n",
331 button->gpio, error);
332 return error;
333 }
334
335 bdata->gpiod = gpio_to_desc(button->gpio);
336 if (!bdata->gpiod) {
337 dev_err(dev,
338 "unable to convert gpio %u to descriptor\n",
339 button->gpio);
340 return -EINVAL;
341 }
342 }
343
344 bdata->last_state = -1;
345 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
346 pdata->poll_interval);
347
348 input_set_capability(input, type, button->code);
349 if (type == EV_ABS)
350 gpio_keys_polled_set_abs_params(input, pdata,
351 button->code);
352 }
353
354 fwnode_handle_put(child);
355
356 bdev->poll_dev = poll_dev;
357 bdev->dev = dev;
358 bdev->pdata = pdata;
359
360 error = input_register_polled_device(poll_dev);
361 if (error) {
362 dev_err(dev, "unable to register polled device, err=%d\n",
363 error);
364 return error;
365 }
366
367 /* report initial state of the buttons */
368 for (i = 0; i < pdata->nbuttons; i++)
369 gpio_keys_polled_check_state(poll_dev, &pdata->buttons[i],
370 &bdev->data[i]);
371
372 input_sync(input);
373
374 return 0;
375}
376
377static struct platform_driver gpio_keys_polled_driver = {
378 .probe = gpio_keys_polled_probe,
379 .driver = {
380 .name = DRV_NAME,
381 .of_match_table = gpio_keys_polled_of_match,
382 },
383};
384module_platform_driver(gpio_keys_polled_driver);
385
386MODULE_LICENSE("GPL v2");
387MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
388MODULE_DESCRIPTION("Polled GPIO Buttons driver");
389MODULE_ALIAS("platform:" DRV_NAME);