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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
0dcd8073 DT |
2 | /* |
3 | * Generic implementation of a polled input device | |
4 | ||
5 | * Copyright (c) 2007 Dmitry Torokhov | |
0dcd8073 DT |
6 | */ |
7 | ||
da0c4901 JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
0dcd8073 | 10 | #include <linux/jiffies.h> |
5a0e3ad6 | 11 | #include <linux/slab.h> |
0dcd8073 | 12 | #include <linux/mutex.h> |
e490ebdc | 13 | #include <linux/workqueue.h> |
d2d8442d | 14 | #include <linux/module.h> |
0dcd8073 DT |
15 | #include <linux/input-polldev.h> |
16 | ||
36bd52a4 EP |
17 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); |
18 | MODULE_DESCRIPTION("Generic implementation of a polled input device"); | |
19 | MODULE_LICENSE("GPL v2"); | |
36bd52a4 | 20 | |
dad725d0 | 21 | static void input_polldev_queue_work(struct input_polled_dev *dev) |
0dcd8073 | 22 | { |
374766bc | 23 | unsigned long delay; |
0dcd8073 | 24 | |
374766bc SH |
25 | delay = msecs_to_jiffies(dev->poll_interval); |
26 | if (delay >= HZ) | |
27 | delay = round_jiffies_relative(delay); | |
28 | ||
e490ebdc | 29 | queue_delayed_work(system_freezable_wq, &dev->work, delay); |
0dcd8073 DT |
30 | } |
31 | ||
dad725d0 SO |
32 | static 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 | ||
0dcd8073 DT |
41 | static int input_open_polled_device(struct input_dev *input) |
42 | { | |
3797fec1 | 43 | struct input_polled_dev *dev = input_get_drvdata(input); |
0dcd8073 | 44 | |
b0aba1e6 SO |
45 | if (dev->open) |
46 | dev->open(dev); | |
0dcd8073 | 47 | |
11bb4cc7 | 48 | /* Only start polling if polling is enabled */ |
5e3e4eb1 DT |
49 | if (dev->poll_interval > 0) { |
50 | dev->poll(dev); | |
51 | input_polldev_queue_work(dev); | |
52 | } | |
0dcd8073 DT |
53 | |
54 | return 0; | |
55 | } | |
56 | ||
57 | static void input_close_polled_device(struct input_dev *input) | |
58 | { | |
3797fec1 | 59 | struct input_polled_dev *dev = input_get_drvdata(input); |
0dcd8073 | 60 | |
374766bc | 61 | cancel_delayed_work_sync(&dev->work); |
b0aba1e6 SO |
62 | |
63 | if (dev->close) | |
64 | dev->close(dev); | |
0dcd8073 DT |
65 | } |
66 | ||
dad725d0 SO |
67 | /* SYSFS interface */ |
68 | ||
69 | static 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 | ||
77 | static 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; | |
76496e7a JD |
83 | unsigned int interval; |
84 | int err; | |
dad725d0 | 85 | |
76496e7a JD |
86 | err = kstrtouint(buf, 0, &interval); |
87 | if (err) | |
88 | return err; | |
dad725d0 SO |
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 | ||
111 | static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll, | |
112 | input_polldev_set_poll); | |
113 | ||
114 | ||
115 | static 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 | ||
123 | static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL); | |
124 | ||
125 | static 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 | ||
133 | static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL); | |
134 | ||
135 | static struct attribute *sysfs_attrs[] = { | |
136 | &dev_attr_poll.attr, | |
137 | &dev_attr_max.attr, | |
138 | &dev_attr_min.attr, | |
139 | NULL | |
140 | }; | |
141 | ||
142 | static struct attribute_group input_polldev_attribute_group = { | |
143 | .attrs = sysfs_attrs | |
144 | }; | |
145 | ||
d1fefd5b DT |
146 | static const struct attribute_group *input_polldev_attribute_groups[] = { |
147 | &input_polldev_attribute_group, | |
148 | NULL | |
149 | }; | |
150 | ||
0dcd8073 | 151 | /** |
2546bcc2 | 152 | * input_allocate_polled_device - allocate memory for polled device |
0dcd8073 DT |
153 | * |
154 | * The function allocates memory for a polled device and also | |
155 | * for an input device associated with this polled device. | |
156 | */ | |
157 | struct 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 | } | |
173 | EXPORT_SYMBOL(input_allocate_polled_device); | |
174 | ||
bf1de976 DT |
175 | struct input_polled_devres { |
176 | struct input_polled_dev *polldev; | |
177 | }; | |
178 | ||
179 | static 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 | ||
186 | static 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 | ||
198 | static 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 | */ | |
234 | struct 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 | } | |
258 | EXPORT_SYMBOL(devm_input_allocate_polled_device); | |
259 | ||
0dcd8073 DT |
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 | |
36203c4f | 265 | * reference to the associated input device. |
0dcd8073 DT |
266 | */ |
267 | void input_free_polled_device(struct input_polled_dev *dev) | |
268 | { | |
269 | if (dev) { | |
bf1de976 DT |
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); | |
0dcd8073 DT |
276 | kfree(dev); |
277 | } | |
278 | } | |
279 | EXPORT_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 | |
2546bcc2 | 289 | * corresponding input_dev structure. |
0dcd8073 DT |
290 | */ |
291 | int input_register_polled_device(struct input_polled_dev *dev) | |
292 | { | |
bf1de976 | 293 | struct input_polled_devres *devres = NULL; |
0dcd8073 | 294 | struct input_dev *input = dev->input; |
dad725d0 | 295 | int error; |
0dcd8073 | 296 | |
bf1de976 DT |
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 | ||
3797fec1 | 306 | input_set_drvdata(input, dev); |
0dcd8073 | 307 | INIT_DELAYED_WORK(&dev->work, input_polled_device_work); |
d1fefd5b | 308 | |
0dcd8073 DT |
309 | if (!dev->poll_interval) |
310 | dev->poll_interval = 500; | |
dad725d0 SO |
311 | if (!dev->poll_interval_max) |
312 | dev->poll_interval_max = dev->poll_interval; | |
d1fefd5b | 313 | |
0dcd8073 DT |
314 | input->open = input_open_polled_device; |
315 | input->close = input_close_polled_device; | |
316 | ||
d1fefd5b DT |
317 | input->dev.groups = input_polldev_attribute_groups; |
318 | ||
dad725d0 | 319 | error = input_register_device(input); |
bf1de976 DT |
320 | if (error) { |
321 | devres_free(devres); | |
dad725d0 | 322 | return error; |
bf1de976 | 323 | } |
dad725d0 | 324 | |
36203c4f DT |
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 | ||
bf1de976 DT |
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 | ||
dad725d0 | 340 | return 0; |
0dcd8073 DT |
341 | } |
342 | EXPORT_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(). | |
0dcd8073 DT |
351 | */ |
352 | void input_unregister_polled_device(struct input_polled_dev *dev) | |
353 | { | |
bf1de976 DT |
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 | ||
0dcd8073 | 360 | input_unregister_device(dev->input); |
0dcd8073 DT |
361 | } |
362 | EXPORT_SYMBOL(input_unregister_polled_device); |