projects/linux·blob v5.5-rc2 · refs

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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 <[email protected]>");
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);