Commit | Line | Data |
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0dcd8073 DT |
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 | #include <linux/jiffies.h> | |
5a0e3ad6 | 12 | #include <linux/slab.h> |
0dcd8073 DT |
13 | #include <linux/mutex.h> |
14 | #include <linux/input-polldev.h> | |
15 | ||
36bd52a4 EP |
16 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); |
17 | MODULE_DESCRIPTION("Generic implementation of a polled input device"); | |
18 | MODULE_LICENSE("GPL v2"); | |
19 | MODULE_VERSION("0.1"); | |
20 | ||
0dcd8073 DT |
21 | static DEFINE_MUTEX(polldev_mutex); |
22 | static int polldev_users; | |
23 | static struct workqueue_struct *polldev_wq; | |
24 | ||
25 | static int input_polldev_start_workqueue(void) | |
26 | { | |
27 | int retval; | |
28 | ||
29 | retval = mutex_lock_interruptible(&polldev_mutex); | |
30 | if (retval) | |
31 | return retval; | |
32 | ||
33 | if (!polldev_users) { | |
34 | polldev_wq = create_singlethread_workqueue("ipolldevd"); | |
35 | if (!polldev_wq) { | |
36 | printk(KERN_ERR "input-polldev: failed to create " | |
37 | "ipolldevd workqueue\n"); | |
38 | retval = -ENOMEM; | |
39 | goto out; | |
40 | } | |
41 | } | |
42 | ||
43 | polldev_users++; | |
44 | ||
45 | out: | |
46 | mutex_unlock(&polldev_mutex); | |
47 | return retval; | |
48 | } | |
49 | ||
50 | static void input_polldev_stop_workqueue(void) | |
51 | { | |
52 | mutex_lock(&polldev_mutex); | |
53 | ||
54 | if (!--polldev_users) | |
55 | destroy_workqueue(polldev_wq); | |
56 | ||
57 | mutex_unlock(&polldev_mutex); | |
58 | } | |
59 | ||
dad725d0 | 60 | static void input_polldev_queue_work(struct input_polled_dev *dev) |
0dcd8073 | 61 | { |
374766bc | 62 | unsigned long delay; |
0dcd8073 | 63 | |
374766bc SH |
64 | delay = msecs_to_jiffies(dev->poll_interval); |
65 | if (delay >= HZ) | |
66 | delay = round_jiffies_relative(delay); | |
67 | ||
68 | queue_delayed_work(polldev_wq, &dev->work, delay); | |
0dcd8073 DT |
69 | } |
70 | ||
dad725d0 SO |
71 | static void input_polled_device_work(struct work_struct *work) |
72 | { | |
73 | struct input_polled_dev *dev = | |
74 | container_of(work, struct input_polled_dev, work.work); | |
75 | ||
76 | dev->poll(dev); | |
77 | input_polldev_queue_work(dev); | |
78 | } | |
79 | ||
0dcd8073 DT |
80 | static int input_open_polled_device(struct input_dev *input) |
81 | { | |
3797fec1 | 82 | struct input_polled_dev *dev = input_get_drvdata(input); |
0dcd8073 DT |
83 | int error; |
84 | ||
85 | error = input_polldev_start_workqueue(); | |
86 | if (error) | |
87 | return error; | |
88 | ||
b0aba1e6 SO |
89 | if (dev->open) |
90 | dev->open(dev); | |
0dcd8073 | 91 | |
11bb4cc7 SO |
92 | /* Only start polling if polling is enabled */ |
93 | if (dev->poll_interval > 0) | |
94 | queue_delayed_work(polldev_wq, &dev->work, 0); | |
0dcd8073 DT |
95 | |
96 | return 0; | |
97 | } | |
98 | ||
99 | static void input_close_polled_device(struct input_dev *input) | |
100 | { | |
3797fec1 | 101 | struct input_polled_dev *dev = input_get_drvdata(input); |
0dcd8073 | 102 | |
374766bc | 103 | cancel_delayed_work_sync(&dev->work); |
d9c4f846 SO |
104 | /* |
105 | * Clean up work struct to remove references to the workqueue. | |
106 | * It may be destroyed by the next call. This causes problems | |
107 | * at next device open-close in case of poll_interval == 0. | |
108 | */ | |
109 | INIT_DELAYED_WORK(&dev->work, dev->work.work.func); | |
0dcd8073 | 110 | input_polldev_stop_workqueue(); |
b0aba1e6 SO |
111 | |
112 | if (dev->close) | |
113 | dev->close(dev); | |
0dcd8073 DT |
114 | } |
115 | ||
dad725d0 SO |
116 | /* SYSFS interface */ |
117 | ||
118 | static ssize_t input_polldev_get_poll(struct device *dev, | |
119 | struct device_attribute *attr, char *buf) | |
120 | { | |
121 | struct input_polled_dev *polldev = dev_get_drvdata(dev); | |
122 | ||
123 | return sprintf(buf, "%d\n", polldev->poll_interval); | |
124 | } | |
125 | ||
126 | static ssize_t input_polldev_set_poll(struct device *dev, | |
127 | struct device_attribute *attr, const char *buf, | |
128 | size_t count) | |
129 | { | |
130 | struct input_polled_dev *polldev = dev_get_drvdata(dev); | |
131 | struct input_dev *input = polldev->input; | |
132 | unsigned long interval; | |
133 | ||
134 | if (strict_strtoul(buf, 0, &interval)) | |
135 | return -EINVAL; | |
136 | ||
137 | if (interval < polldev->poll_interval_min) | |
138 | return -EINVAL; | |
139 | ||
140 | if (interval > polldev->poll_interval_max) | |
141 | return -EINVAL; | |
142 | ||
143 | mutex_lock(&input->mutex); | |
144 | ||
145 | polldev->poll_interval = interval; | |
146 | ||
147 | if (input->users) { | |
148 | cancel_delayed_work_sync(&polldev->work); | |
149 | if (polldev->poll_interval > 0) | |
150 | input_polldev_queue_work(polldev); | |
151 | } | |
152 | ||
153 | mutex_unlock(&input->mutex); | |
154 | ||
155 | return count; | |
156 | } | |
157 | ||
158 | static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll, | |
159 | input_polldev_set_poll); | |
160 | ||
161 | ||
162 | static ssize_t input_polldev_get_max(struct device *dev, | |
163 | struct device_attribute *attr, char *buf) | |
164 | { | |
165 | struct input_polled_dev *polldev = dev_get_drvdata(dev); | |
166 | ||
167 | return sprintf(buf, "%d\n", polldev->poll_interval_max); | |
168 | } | |
169 | ||
170 | static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL); | |
171 | ||
172 | static ssize_t input_polldev_get_min(struct device *dev, | |
173 | struct device_attribute *attr, char *buf) | |
174 | { | |
175 | struct input_polled_dev *polldev = dev_get_drvdata(dev); | |
176 | ||
177 | return sprintf(buf, "%d\n", polldev->poll_interval_min); | |
178 | } | |
179 | ||
180 | static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL); | |
181 | ||
182 | static struct attribute *sysfs_attrs[] = { | |
183 | &dev_attr_poll.attr, | |
184 | &dev_attr_max.attr, | |
185 | &dev_attr_min.attr, | |
186 | NULL | |
187 | }; | |
188 | ||
189 | static struct attribute_group input_polldev_attribute_group = { | |
190 | .attrs = sysfs_attrs | |
191 | }; | |
192 | ||
0dcd8073 DT |
193 | /** |
194 | * input_allocate_polled_device - allocated memory polled device | |
195 | * | |
196 | * The function allocates memory for a polled device and also | |
197 | * for an input device associated with this polled device. | |
198 | */ | |
199 | struct input_polled_dev *input_allocate_polled_device(void) | |
200 | { | |
201 | struct input_polled_dev *dev; | |
202 | ||
203 | dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL); | |
204 | if (!dev) | |
205 | return NULL; | |
206 | ||
207 | dev->input = input_allocate_device(); | |
208 | if (!dev->input) { | |
209 | kfree(dev); | |
210 | return NULL; | |
211 | } | |
212 | ||
213 | return dev; | |
214 | } | |
215 | EXPORT_SYMBOL(input_allocate_polled_device); | |
216 | ||
217 | /** | |
218 | * input_free_polled_device - free memory allocated for polled device | |
219 | * @dev: device to free | |
220 | * | |
221 | * The function frees memory allocated for polling device and drops | |
36203c4f | 222 | * reference to the associated input device. |
0dcd8073 DT |
223 | */ |
224 | void input_free_polled_device(struct input_polled_dev *dev) | |
225 | { | |
226 | if (dev) { | |
227 | input_free_device(dev->input); | |
228 | kfree(dev); | |
229 | } | |
230 | } | |
231 | EXPORT_SYMBOL(input_free_polled_device); | |
232 | ||
233 | /** | |
234 | * input_register_polled_device - register polled device | |
235 | * @dev: device to register | |
236 | * | |
237 | * The function registers previously initialized polled input device | |
238 | * with input layer. The device should be allocated with call to | |
239 | * input_allocate_polled_device(). Callers should also set up poll() | |
240 | * method and set up capabilities (id, name, phys, bits) of the | |
241 | * corresponing input_dev structure. | |
242 | */ | |
243 | int input_register_polled_device(struct input_polled_dev *dev) | |
244 | { | |
245 | struct input_dev *input = dev->input; | |
dad725d0 | 246 | int error; |
0dcd8073 | 247 | |
3797fec1 | 248 | input_set_drvdata(input, dev); |
0dcd8073 DT |
249 | INIT_DELAYED_WORK(&dev->work, input_polled_device_work); |
250 | if (!dev->poll_interval) | |
251 | dev->poll_interval = 500; | |
dad725d0 SO |
252 | if (!dev->poll_interval_max) |
253 | dev->poll_interval_max = dev->poll_interval; | |
0dcd8073 DT |
254 | input->open = input_open_polled_device; |
255 | input->close = input_close_polled_device; | |
256 | ||
dad725d0 SO |
257 | error = input_register_device(input); |
258 | if (error) | |
259 | return error; | |
260 | ||
261 | error = sysfs_create_group(&input->dev.kobj, | |
262 | &input_polldev_attribute_group); | |
263 | if (error) { | |
264 | input_unregister_device(input); | |
265 | return error; | |
266 | } | |
267 | ||
36203c4f DT |
268 | /* |
269 | * Take extra reference to the underlying input device so | |
270 | * that it survives call to input_unregister_polled_device() | |
271 | * and is deleted only after input_free_polled_device() | |
272 | * has been invoked. This is needed to ease task of freeing | |
273 | * sparse keymaps. | |
274 | */ | |
275 | input_get_device(input); | |
276 | ||
dad725d0 | 277 | return 0; |
0dcd8073 DT |
278 | } |
279 | EXPORT_SYMBOL(input_register_polled_device); | |
280 | ||
281 | /** | |
282 | * input_unregister_polled_device - unregister polled device | |
283 | * @dev: device to unregister | |
284 | * | |
285 | * The function unregisters previously registered polled input | |
286 | * device from input layer. Polling is stopped and device is | |
287 | * ready to be freed with call to input_free_polled_device(). | |
0dcd8073 DT |
288 | */ |
289 | void input_unregister_polled_device(struct input_polled_dev *dev) | |
290 | { | |
dad725d0 SO |
291 | sysfs_remove_group(&dev->input->dev.kobj, |
292 | &input_polldev_attribute_group); | |
293 | ||
0dcd8073 | 294 | input_unregister_device(dev->input); |
0dcd8073 DT |
295 | } |
296 | EXPORT_SYMBOL(input_unregister_polled_device); | |
297 |