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