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Dmitry Torokhov0dcd8072007-04-29 23:42:45 -04001/*
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
Joe Perchesda0c4902010-11-29 23:33:07 -080011#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040013#include <linux/jiffies.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040015#include <linux/mutex.h>
Dmitry Torokhove490ebd2011-04-27 23:20:16 -070016#include <linux/workqueue.h>
Paul Gortmakerd2d84422011-07-03 13:53:48 -040017#include <linux/module.h>
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040018#include <linux/input-polldev.h>
19
Eric Piel36bd52a2007-05-22 23:28:03 -040020MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
21MODULE_DESCRIPTION("Generic implementation of a polled input device");
22MODULE_LICENSE("GPL v2");
23MODULE_VERSION("0.1");
24
Samu Onkalodad725d2009-11-13 21:13:22 -080025static void input_polldev_queue_work(struct input_polled_dev *dev)
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040026{
Stephen Hemminger374766b2007-11-21 14:03:37 -050027 unsigned long delay;
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040028
Stephen Hemminger374766b2007-11-21 14:03:37 -050029 delay = msecs_to_jiffies(dev->poll_interval);
30 if (delay >= HZ)
31 delay = round_jiffies_relative(delay);
32
Dmitry Torokhove490ebd2011-04-27 23:20:16 -070033 queue_delayed_work(system_freezable_wq, &dev->work, delay);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040034}
35
Samu Onkalodad725d2009-11-13 21:13:22 -080036static 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
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040045static int input_open_polled_device(struct input_dev *input)
46{
Dmitry Torokhov3797fec2008-04-02 00:41:00 -040047 struct input_polled_dev *dev = input_get_drvdata(input);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040048
Samu Onkalob0aba1e2009-10-18 00:38:57 -070049 if (dev->open)
50 dev->open(dev);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040051
Samu Onkalo11bb4cc2009-11-23 10:01:33 -080052 /* Only start polling if polling is enabled */
Dmitry Torokhov5e3e4eb2011-08-02 22:22:46 -070053 if (dev->poll_interval > 0) {
54 dev->poll(dev);
55 input_polldev_queue_work(dev);
56 }
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040057
58 return 0;
59}
60
61static void input_close_polled_device(struct input_dev *input)
62{
Dmitry Torokhov3797fec2008-04-02 00:41:00 -040063 struct input_polled_dev *dev = input_get_drvdata(input);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040064
Stephen Hemminger374766b2007-11-21 14:03:37 -050065 cancel_delayed_work_sync(&dev->work);
Samu Onkalob0aba1e2009-10-18 00:38:57 -070066
67 if (dev->close)
68 dev->close(dev);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -040069}
70
Samu Onkalodad725d2009-11-13 21:13:22 -080071/* 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;
JJ Ding76496e72011-11-09 10:20:14 -080087 unsigned int interval;
88 int err;
Samu Onkalodad725d2009-11-13 21:13:22 -080089
JJ Ding76496e72011-11-09 10:20:14 -080090 err = kstrtouint(buf, 0, &interval);
91 if (err)
92 return err;
Samu Onkalodad725d2009-11-13 21:13:22 -080093
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
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700150static const struct attribute_group *input_polldev_attribute_groups[] = {
151 &input_polldev_attribute_group,
152 NULL
153};
154
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400155/**
Dmitry Torokhov2546bcc2011-01-31 21:06:34 -0800156 * input_allocate_polled_device - allocate memory for polled device
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400157 *
158 * The function allocates memory for a polled device and also
159 * for an input device associated with this polled device.
160 */
161struct input_polled_dev *input_allocate_polled_device(void)
162{
163 struct input_polled_dev *dev;
164
165 dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
166 if (!dev)
167 return NULL;
168
169 dev->input = input_allocate_device();
170 if (!dev->input) {
171 kfree(dev);
172 return NULL;
173 }
174
175 return dev;
176}
177EXPORT_SYMBOL(input_allocate_polled_device);
178
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700179struct input_polled_devres {
180 struct input_polled_dev *polldev;
181};
182
183static int devm_input_polldev_match(struct device *dev, void *res, void *data)
184{
185 struct input_polled_devres *devres = res;
186
187 return devres->polldev == data;
188}
189
190static void devm_input_polldev_release(struct device *dev, void *res)
191{
192 struct input_polled_devres *devres = res;
193 struct input_polled_dev *polldev = devres->polldev;
194
195 dev_dbg(dev, "%s: dropping reference/freeing %s\n",
196 __func__, dev_name(&polldev->input->dev));
197
198 input_put_device(polldev->input);
199 kfree(polldev);
200}
201
202static void devm_input_polldev_unregister(struct device *dev, void *res)
203{
204 struct input_polled_devres *devres = res;
205 struct input_polled_dev *polldev = devres->polldev;
206
207 dev_dbg(dev, "%s: unregistering device %s\n",
208 __func__, dev_name(&polldev->input->dev));
209 input_unregister_device(polldev->input);
210
211 /*
212 * Note that we are still holding extra reference to the input
213 * device so it will stick around until devm_input_polldev_release()
214 * is called.
215 */
216}
217
218/**
219 * devm_input_allocate_polled_device - allocate managed polled device
220 * @dev: device owning the polled device being created
221 *
222 * Returns prepared &struct input_polled_dev or %NULL.
223 *
224 * Managed polled input devices do not need to be explicitly unregistered
225 * or freed as it will be done automatically when owner device unbinds
226 * from * its driver (or binding fails). Once such managed polled device
227 * is allocated, it is ready to be set up and registered in the same
228 * fashion as regular polled input devices (using
229 * input_register_polled_device() function).
230 *
231 * If you want to manually unregister and free such managed polled devices,
232 * it can be still done by calling input_unregister_polled_device() and
233 * input_free_polled_device(), although it is rarely needed.
234 *
235 * NOTE: the owner device is set up as parent of input device and users
236 * should not override it.
237 */
238struct input_polled_dev *devm_input_allocate_polled_device(struct device *dev)
239{
240 struct input_polled_dev *polldev;
241 struct input_polled_devres *devres;
242
243 devres = devres_alloc(devm_input_polldev_release, sizeof(*devres),
244 GFP_KERNEL);
245 if (!devres)
246 return NULL;
247
248 polldev = input_allocate_polled_device();
249 if (!polldev) {
250 devres_free(devres);
251 return NULL;
252 }
253
254 polldev->input->dev.parent = dev;
255 polldev->devres_managed = true;
256
257 devres->polldev = polldev;
258 devres_add(dev, devres);
259
260 return polldev;
261}
262EXPORT_SYMBOL(devm_input_allocate_polled_device);
263
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400264/**
265 * input_free_polled_device - free memory allocated for polled device
266 * @dev: device to free
267 *
268 * The function frees memory allocated for polling device and drops
Dmitry Torokhov36203c42009-12-04 10:22:23 -0800269 * reference to the associated input device.
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400270 */
271void input_free_polled_device(struct input_polled_dev *dev)
272{
273 if (dev) {
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700274 if (dev->devres_managed)
275 WARN_ON(devres_destroy(dev->input->dev.parent,
276 devm_input_polldev_release,
277 devm_input_polldev_match,
278 dev));
279 input_put_device(dev->input);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400280 kfree(dev);
281 }
282}
283EXPORT_SYMBOL(input_free_polled_device);
284
285/**
286 * input_register_polled_device - register polled device
287 * @dev: device to register
288 *
289 * The function registers previously initialized polled input device
290 * with input layer. The device should be allocated with call to
291 * input_allocate_polled_device(). Callers should also set up poll()
292 * method and set up capabilities (id, name, phys, bits) of the
Dmitry Torokhov2546bcc2011-01-31 21:06:34 -0800293 * corresponding input_dev structure.
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400294 */
295int input_register_polled_device(struct input_polled_dev *dev)
296{
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700297 struct input_polled_devres *devres = NULL;
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400298 struct input_dev *input = dev->input;
Samu Onkalodad725d2009-11-13 21:13:22 -0800299 int error;
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400300
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700301 if (dev->devres_managed) {
302 devres = devres_alloc(devm_input_polldev_unregister,
303 sizeof(*devres), GFP_KERNEL);
304 if (!devres)
305 return -ENOMEM;
306
307 devres->polldev = dev;
308 }
309
Dmitry Torokhov3797fec2008-04-02 00:41:00 -0400310 input_set_drvdata(input, dev);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400311 INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700312
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400313 if (!dev->poll_interval)
314 dev->poll_interval = 500;
Samu Onkalodad725d2009-11-13 21:13:22 -0800315 if (!dev->poll_interval_max)
316 dev->poll_interval_max = dev->poll_interval;
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700317
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400318 input->open = input_open_polled_device;
319 input->close = input_close_polled_device;
320
Dmitry Torokhovd1fefd52014-04-28 13:16:00 -0700321 input->dev.groups = input_polldev_attribute_groups;
322
Samu Onkalodad725d2009-11-13 21:13:22 -0800323 error = input_register_device(input);
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700324 if (error) {
325 devres_free(devres);
Samu Onkalodad725d2009-11-13 21:13:22 -0800326 return error;
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700327 }
Samu Onkalodad725d2009-11-13 21:13:22 -0800328
Dmitry Torokhov36203c42009-12-04 10:22:23 -0800329 /*
330 * Take extra reference to the underlying input device so
331 * that it survives call to input_unregister_polled_device()
332 * and is deleted only after input_free_polled_device()
333 * has been invoked. This is needed to ease task of freeing
334 * sparse keymaps.
335 */
336 input_get_device(input);
337
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700338 if (dev->devres_managed) {
339 dev_dbg(input->dev.parent, "%s: registering %s with devres.\n",
340 __func__, dev_name(&input->dev));
341 devres_add(input->dev.parent, devres);
342 }
343
Samu Onkalodad725d2009-11-13 21:13:22 -0800344 return 0;
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400345}
346EXPORT_SYMBOL(input_register_polled_device);
347
348/**
349 * input_unregister_polled_device - unregister polled device
350 * @dev: device to unregister
351 *
352 * The function unregisters previously registered polled input
353 * device from input layer. Polling is stopped and device is
354 * ready to be freed with call to input_free_polled_device().
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400355 */
356void input_unregister_polled_device(struct input_polled_dev *dev)
357{
Dmitry Torokhovbf1de972014-04-28 10:49:51 -0700358 if (dev->devres_managed)
359 WARN_ON(devres_destroy(dev->input->dev.parent,
360 devm_input_polldev_unregister,
361 devm_input_polldev_match,
362 dev));
363
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400364 input_unregister_device(dev->input);
Dmitry Torokhov0dcd8072007-04-29 23:42:45 -0400365}
366EXPORT_SYMBOL(input_unregister_polled_device);