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