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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic implementation of a polled input device
4
5 * Copyright (c) 2007 Dmitry Torokhov
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/jiffies.h>
11#include <linux/slab.h>
12#include <linux/mutex.h>
13#include <linux/workqueue.h>
14#include <linux/module.h>
15#include <linux/input-polldev.h>
16
17MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
18MODULE_DESCRIPTION("Generic implementation of a polled input device");
19MODULE_LICENSE("GPL v2");
20
21static void input_polldev_queue_work(struct input_polled_dev *dev)
22{
23 unsigned long delay;
24
25 delay = msecs_to_jiffies(dev->poll_interval);
26 if (delay >= HZ)
27 delay = round_jiffies_relative(delay);
28
29 queue_delayed_work(system_freezable_wq, &dev->work, delay);
30}
31
32static void input_polled_device_work(struct work_struct *work)
33{
34 struct input_polled_dev *dev =
35 container_of(work, struct input_polled_dev, work.work);
36
37 dev->poll(dev);
38 input_polldev_queue_work(dev);
39}
40
41static int input_open_polled_device(struct input_dev *input)
42{
43 struct input_polled_dev *dev = input_get_drvdata(input);
44
45 if (dev->open)
46 dev->open(dev);
47
48 /* Only start polling if polling is enabled */
49 if (dev->poll_interval > 0) {
50 dev->poll(dev);
51 input_polldev_queue_work(dev);
52 }
53
54 return 0;
55}
56
57static void input_close_polled_device(struct input_dev *input)
58{
59 struct input_polled_dev *dev = input_get_drvdata(input);
60
61 cancel_delayed_work_sync(&dev->work);
62
63 if (dev->close)
64 dev->close(dev);
65}
66
67/* SYSFS interface */
68
69static ssize_t input_polldev_get_poll(struct device *dev,
70 struct device_attribute *attr, char *buf)
71{
72 struct input_polled_dev *polldev = dev_get_drvdata(dev);
73
74 return sprintf(buf, "%d\n", polldev->poll_interval);
75}
76
77static ssize_t input_polldev_set_poll(struct device *dev,
78 struct device_attribute *attr, const char *buf,
79 size_t count)
80{
81 struct input_polled_dev *polldev = dev_get_drvdata(dev);
82 struct input_dev *input = polldev->input;
83 unsigned int interval;
84 int err;
85
86 err = kstrtouint(buf, 0, &interval);
87 if (err)
88 return err;
89
90 if (interval < polldev->poll_interval_min)
91 return -EINVAL;
92
93 if (interval > polldev->poll_interval_max)
94 return -EINVAL;
95
96 mutex_lock(&input->mutex);
97
98 polldev->poll_interval = interval;
99
100 if (input->users) {
101 cancel_delayed_work_sync(&polldev->work);
102 if (polldev->poll_interval > 0)
103 input_polldev_queue_work(polldev);
104 }
105
106 mutex_unlock(&input->mutex);
107
108 return count;
109}
110
111static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll,
112 input_polldev_set_poll);
113
114
115static ssize_t input_polldev_get_max(struct device *dev,
116 struct device_attribute *attr, char *buf)
117{
118 struct input_polled_dev *polldev = dev_get_drvdata(dev);
119
120 return sprintf(buf, "%d\n", polldev->poll_interval_max);
121}
122
123static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);
124
125static ssize_t input_polldev_get_min(struct device *dev,
126 struct device_attribute *attr, char *buf)
127{
128 struct input_polled_dev *polldev = dev_get_drvdata(dev);
129
130 return sprintf(buf, "%d\n", polldev->poll_interval_min);
131}
132
133static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);
134
135static struct attribute *sysfs_attrs[] = {
136 &dev_attr_poll.attr,
137 &dev_attr_max.attr,
138 &dev_attr_min.attr,
139 NULL
140};
141
142static struct attribute_group input_polldev_attribute_group = {
143 .attrs = sysfs_attrs
144};
145
146static const struct attribute_group *input_polldev_attribute_groups[] = {
147 &input_polldev_attribute_group,
148 NULL
149};
150
151/**
152 * input_allocate_polled_device - allocate memory for polled device
153 *
154 * The function allocates memory for a polled device and also
155 * for an input device associated with this polled device.
156 */
157struct input_polled_dev *input_allocate_polled_device(void)
158{
159 struct input_polled_dev *dev;
160
161 dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
162 if (!dev)
163 return NULL;
164
165 dev->input = input_allocate_device();
166 if (!dev->input) {
167 kfree(dev);
168 return NULL;
169 }
170
171 return dev;
172}
173EXPORT_SYMBOL(input_allocate_polled_device);
174
175struct input_polled_devres {
176 struct input_polled_dev *polldev;
177};
178
179static int devm_input_polldev_match(struct device *dev, void *res, void *data)
180{
181 struct input_polled_devres *devres = res;
182
183 return devres->polldev == data;
184}
185
186static void devm_input_polldev_release(struct device *dev, void *res)
187{
188 struct input_polled_devres *devres = res;
189 struct input_polled_dev *polldev = devres->polldev;
190
191 dev_dbg(dev, "%s: dropping reference/freeing %s\n",
192 __func__, dev_name(&polldev->input->dev));
193
194 input_put_device(polldev->input);
195 kfree(polldev);
196}
197
198static void devm_input_polldev_unregister(struct device *dev, void *res)
199{
200 struct input_polled_devres *devres = res;
201 struct input_polled_dev *polldev = devres->polldev;
202
203 dev_dbg(dev, "%s: unregistering device %s\n",
204 __func__, dev_name(&polldev->input->dev));
205 input_unregister_device(polldev->input);
206
207 /*
208 * Note that we are still holding extra reference to the input
209 * device so it will stick around until devm_input_polldev_release()
210 * is called.
211 */
212}
213
214/**
215 * devm_input_allocate_polled_device - allocate managed polled device
216 * @dev: device owning the polled device being created
217 *
218 * Returns prepared &struct input_polled_dev or %NULL.
219 *
220 * Managed polled input devices do not need to be explicitly unregistered
221 * or freed as it will be done automatically when owner device unbinds
222 * from * its driver (or binding fails). Once such managed polled device
223 * is allocated, it is ready to be set up and registered in the same
224 * fashion as regular polled input devices (using
225 * input_register_polled_device() function).
226 *
227 * If you want to manually unregister and free such managed polled devices,
228 * it can be still done by calling input_unregister_polled_device() and
229 * input_free_polled_device(), although it is rarely needed.
230 *
231 * NOTE: the owner device is set up as parent of input device and users
232 * should not override it.
233 */
234struct input_polled_dev *devm_input_allocate_polled_device(struct device *dev)
235{
236 struct input_polled_dev *polldev;
237 struct input_polled_devres *devres;
238
239 devres = devres_alloc(devm_input_polldev_release, sizeof(*devres),
240 GFP_KERNEL);
241 if (!devres)
242 return NULL;
243
244 polldev = input_allocate_polled_device();
245 if (!polldev) {
246 devres_free(devres);
247 return NULL;
248 }
249
250 polldev->input->dev.parent = dev;
251 polldev->devres_managed = true;
252
253 devres->polldev = polldev;
254 devres_add(dev, devres);
255
256 return polldev;
257}
258EXPORT_SYMBOL(devm_input_allocate_polled_device);
259
260/**
261 * input_free_polled_device - free memory allocated for polled device
262 * @dev: device to free
263 *
264 * The function frees memory allocated for polling device and drops
265 * reference to the associated input device.
266 */
267void input_free_polled_device(struct input_polled_dev *dev)
268{
269 if (dev) {
270 if (dev->devres_managed)
271 WARN_ON(devres_destroy(dev->input->dev.parent,
272 devm_input_polldev_release,
273 devm_input_polldev_match,
274 dev));
275 input_put_device(dev->input);
276 kfree(dev);
277 }
278}
279EXPORT_SYMBOL(input_free_polled_device);
280
281/**
282 * input_register_polled_device - register polled device
283 * @dev: device to register
284 *
285 * The function registers previously initialized polled input device
286 * with input layer. The device should be allocated with call to
287 * input_allocate_polled_device(). Callers should also set up poll()
288 * method and set up capabilities (id, name, phys, bits) of the
289 * corresponding input_dev structure.
290 */
291int input_register_polled_device(struct input_polled_dev *dev)
292{
293 struct input_polled_devres *devres = NULL;
294 struct input_dev *input = dev->input;
295 int error;
296
297 if (dev->devres_managed) {
298 devres = devres_alloc(devm_input_polldev_unregister,
299 sizeof(*devres), GFP_KERNEL);
300 if (!devres)
301 return -ENOMEM;
302
303 devres->polldev = dev;
304 }
305
306 input_set_drvdata(input, dev);
307 INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
308
309 if (!dev->poll_interval)
310 dev->poll_interval = 500;
311 if (!dev->poll_interval_max)
312 dev->poll_interval_max = dev->poll_interval;
313
314 input->open = input_open_polled_device;
315 input->close = input_close_polled_device;
316
317 input->dev.groups = input_polldev_attribute_groups;
318
319 error = input_register_device(input);
320 if (error) {
321 devres_free(devres);
322 return error;
323 }
324
325 /*
326 * Take extra reference to the underlying input device so
327 * that it survives call to input_unregister_polled_device()
328 * and is deleted only after input_free_polled_device()
329 * has been invoked. This is needed to ease task of freeing
330 * sparse keymaps.
331 */
332 input_get_device(input);
333
334 if (dev->devres_managed) {
335 dev_dbg(input->dev.parent, "%s: registering %s with devres.\n",
336 __func__, dev_name(&input->dev));
337 devres_add(input->dev.parent, devres);
338 }
339
340 return 0;
341}
342EXPORT_SYMBOL(input_register_polled_device);
343
344/**
345 * input_unregister_polled_device - unregister polled device
346 * @dev: device to unregister
347 *
348 * The function unregisters previously registered polled input
349 * device from input layer. Polling is stopped and device is
350 * ready to be freed with call to input_free_polled_device().
351 */
352void input_unregister_polled_device(struct input_polled_dev *dev)
353{
354 if (dev->devres_managed)
355 WARN_ON(devres_destroy(dev->input->dev.parent,
356 devm_input_polldev_unregister,
357 devm_input_polldev_match,
358 dev));
359
360 input_unregister_device(dev->input);
361}
362EXPORT_SYMBOL(input_unregister_polled_device);
1/*
2 * Generic implementation of a polled input device
3
4 * Copyright (c) 2007 Dmitry Torokhov
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/jiffies.h>
14#include <linux/slab.h>
15#include <linux/mutex.h>
16#include <linux/workqueue.h>
17#include <linux/module.h>
18#include <linux/input-polldev.h>
19
20MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
21MODULE_DESCRIPTION("Generic implementation of a polled input device");
22MODULE_LICENSE("GPL v2");
23MODULE_VERSION("0.1");
24
25static void input_polldev_queue_work(struct input_polled_dev *dev)
26{
27 unsigned long delay;
28
29 delay = msecs_to_jiffies(dev->poll_interval);
30 if (delay >= HZ)
31 delay = round_jiffies_relative(delay);
32
33 queue_delayed_work(system_freezable_wq, &dev->work, delay);
34}
35
36static void input_polled_device_work(struct work_struct *work)
37{
38 struct input_polled_dev *dev =
39 container_of(work, struct input_polled_dev, work.work);
40
41 dev->poll(dev);
42 input_polldev_queue_work(dev);
43}
44
45static int input_open_polled_device(struct input_dev *input)
46{
47 struct input_polled_dev *dev = input_get_drvdata(input);
48
49 if (dev->open)
50 dev->open(dev);
51
52 /* Only start polling if polling is enabled */
53 if (dev->poll_interval > 0) {
54 dev->poll(dev);
55 input_polldev_queue_work(dev);
56 }
57
58 return 0;
59}
60
61static void input_close_polled_device(struct input_dev *input)
62{
63 struct input_polled_dev *dev = input_get_drvdata(input);
64
65 cancel_delayed_work_sync(&dev->work);
66
67 if (dev->close)
68 dev->close(dev);
69}
70
71/* SYSFS interface */
72
73static ssize_t input_polldev_get_poll(struct device *dev,
74 struct device_attribute *attr, char *buf)
75{
76 struct input_polled_dev *polldev = dev_get_drvdata(dev);
77
78 return sprintf(buf, "%d\n", polldev->poll_interval);
79}
80
81static ssize_t input_polldev_set_poll(struct device *dev,
82 struct device_attribute *attr, const char *buf,
83 size_t count)
84{
85 struct input_polled_dev *polldev = dev_get_drvdata(dev);
86 struct input_dev *input = polldev->input;
87 unsigned int interval;
88 int err;
89
90 err = kstrtouint(buf, 0, &interval);
91 if (err)
92 return err;
93
94 if (interval < polldev->poll_interval_min)
95 return -EINVAL;
96
97 if (interval > polldev->poll_interval_max)
98 return -EINVAL;
99
100 mutex_lock(&input->mutex);
101
102 polldev->poll_interval = interval;
103
104 if (input->users) {
105 cancel_delayed_work_sync(&polldev->work);
106 if (polldev->poll_interval > 0)
107 input_polldev_queue_work(polldev);
108 }
109
110 mutex_unlock(&input->mutex);
111
112 return count;
113}
114
115static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll,
116 input_polldev_set_poll);
117
118
119static ssize_t input_polldev_get_max(struct device *dev,
120 struct device_attribute *attr, char *buf)
121{
122 struct input_polled_dev *polldev = dev_get_drvdata(dev);
123
124 return sprintf(buf, "%d\n", polldev->poll_interval_max);
125}
126
127static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);
128
129static ssize_t input_polldev_get_min(struct device *dev,
130 struct device_attribute *attr, char *buf)
131{
132 struct input_polled_dev *polldev = dev_get_drvdata(dev);
133
134 return sprintf(buf, "%d\n", polldev->poll_interval_min);
135}
136
137static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);
138
139static struct attribute *sysfs_attrs[] = {
140 &dev_attr_poll.attr,
141 &dev_attr_max.attr,
142 &dev_attr_min.attr,
143 NULL
144};
145
146static struct attribute_group input_polldev_attribute_group = {
147 .attrs = sysfs_attrs
148};
149
150/**
151 * input_allocate_polled_device - allocate memory for polled device
152 *
153 * The function allocates memory for a polled device and also
154 * for an input device associated with this polled device.
155 */
156struct input_polled_dev *input_allocate_polled_device(void)
157{
158 struct input_polled_dev *dev;
159
160 dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
161 if (!dev)
162 return NULL;
163
164 dev->input = input_allocate_device();
165 if (!dev->input) {
166 kfree(dev);
167 return NULL;
168 }
169
170 return dev;
171}
172EXPORT_SYMBOL(input_allocate_polled_device);
173
174/**
175 * input_free_polled_device - free memory allocated for polled device
176 * @dev: device to free
177 *
178 * The function frees memory allocated for polling device and drops
179 * reference to the associated input device.
180 */
181void input_free_polled_device(struct input_polled_dev *dev)
182{
183 if (dev) {
184 input_free_device(dev->input);
185 kfree(dev);
186 }
187}
188EXPORT_SYMBOL(input_free_polled_device);
189
190/**
191 * input_register_polled_device - register polled device
192 * @dev: device to register
193 *
194 * The function registers previously initialized polled input device
195 * with input layer. The device should be allocated with call to
196 * input_allocate_polled_device(). Callers should also set up poll()
197 * method and set up capabilities (id, name, phys, bits) of the
198 * corresponding input_dev structure.
199 */
200int input_register_polled_device(struct input_polled_dev *dev)
201{
202 struct input_dev *input = dev->input;
203 int error;
204
205 input_set_drvdata(input, dev);
206 INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
207 if (!dev->poll_interval)
208 dev->poll_interval = 500;
209 if (!dev->poll_interval_max)
210 dev->poll_interval_max = dev->poll_interval;
211 input->open = input_open_polled_device;
212 input->close = input_close_polled_device;
213
214 error = input_register_device(input);
215 if (error)
216 return error;
217
218 error = sysfs_create_group(&input->dev.kobj,
219 &input_polldev_attribute_group);
220 if (error) {
221 input_unregister_device(input);
222 return error;
223 }
224
225 /*
226 * Take extra reference to the underlying input device so
227 * that it survives call to input_unregister_polled_device()
228 * and is deleted only after input_free_polled_device()
229 * has been invoked. This is needed to ease task of freeing
230 * sparse keymaps.
231 */
232 input_get_device(input);
233
234 return 0;
235}
236EXPORT_SYMBOL(input_register_polled_device);
237
238/**
239 * input_unregister_polled_device - unregister polled device
240 * @dev: device to unregister
241 *
242 * The function unregisters previously registered polled input
243 * device from input layer. Polling is stopped and device is
244 * ready to be freed with call to input_free_polled_device().
245 */
246void input_unregister_polled_device(struct input_polled_dev *dev)
247{
248 sysfs_remove_group(&dev->input->dev.kobj,
249 &input_polldev_attribute_group);
250
251 input_unregister_device(dev->input);
252}
253EXPORT_SYMBOL(input_unregister_polled_device);