Commit | Line | Data |
---|---|---|
206f5f2f SA |
1 | /* |
2 | * Roccat driver for Linux | |
3 | * | |
4 | * Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net> | |
5 | */ | |
6 | ||
7 | /* | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the Free | |
10 | * Software Foundation; either version 2 of the License, or (at your option) | |
11 | * any later version. | |
12 | */ | |
13 | ||
14 | /* | |
15 | * Module roccat is a char device used to report special events of roccat | |
16 | * hardware to userland. These events include requests for on-screen-display of | |
17 | * profile or dpi settings or requests for execution of macro sequences that are | |
18 | * not stored in device. The information in these events depends on hid device | |
19 | * implementation and contains data that is not available in a single hid event | |
20 | * or else hidraw could have been used. | |
21 | * It is inspired by hidraw, but uses only one circular buffer for all readers. | |
22 | */ | |
23 | ||
4291ee30 JP |
24 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
25 | ||
206f5f2f SA |
26 | #include <linux/cdev.h> |
27 | #include <linux/poll.h> | |
28 | #include <linux/sched.h> | |
5dc0c983 | 29 | #include <linux/hid-roccat.h> |
206f5f2f SA |
30 | |
31 | #define ROCCAT_FIRST_MINOR 0 | |
32 | #define ROCCAT_MAX_DEVICES 8 | |
33 | ||
34 | /* should be a power of 2 for performance reason */ | |
35 | #define ROCCAT_CBUF_SIZE 16 | |
36 | ||
37 | struct roccat_report { | |
38 | uint8_t *value; | |
206f5f2f SA |
39 | }; |
40 | ||
41 | struct roccat_device { | |
42 | unsigned int minor; | |
8211e460 | 43 | int report_size; |
206f5f2f SA |
44 | int open; |
45 | int exist; | |
46 | wait_queue_head_t wait; | |
47 | struct device *dev; | |
48 | struct hid_device *hid; | |
49 | struct list_head readers; | |
50 | /* protects modifications of readers list */ | |
51 | struct mutex readers_lock; | |
52 | ||
53 | /* | |
54 | * circular_buffer has one writer and multiple readers with their own | |
55 | * read pointers | |
56 | */ | |
57 | struct roccat_report cbuf[ROCCAT_CBUF_SIZE]; | |
58 | int cbuf_end; | |
59 | struct mutex cbuf_lock; | |
60 | }; | |
61 | ||
62 | struct roccat_reader { | |
63 | struct list_head node; | |
64 | struct roccat_device *device; | |
65 | int cbuf_start; | |
66 | }; | |
67 | ||
68 | static int roccat_major; | |
206f5f2f SA |
69 | static struct cdev roccat_cdev; |
70 | ||
71 | static struct roccat_device *devices[ROCCAT_MAX_DEVICES]; | |
72 | /* protects modifications of devices array */ | |
73 | static DEFINE_MUTEX(devices_lock); | |
74 | ||
75 | static ssize_t roccat_read(struct file *file, char __user *buffer, | |
76 | size_t count, loff_t *ppos) | |
77 | { | |
78 | struct roccat_reader *reader = file->private_data; | |
79 | struct roccat_device *device = reader->device; | |
80 | struct roccat_report *report; | |
81 | ssize_t retval = 0, len; | |
82 | DECLARE_WAITQUEUE(wait, current); | |
83 | ||
84 | mutex_lock(&device->cbuf_lock); | |
85 | ||
86 | /* no data? */ | |
87 | if (reader->cbuf_start == device->cbuf_end) { | |
88 | add_wait_queue(&device->wait, &wait); | |
89 | set_current_state(TASK_INTERRUPTIBLE); | |
90 | ||
91 | /* wait for data */ | |
92 | while (reader->cbuf_start == device->cbuf_end) { | |
93 | if (file->f_flags & O_NONBLOCK) { | |
94 | retval = -EAGAIN; | |
95 | break; | |
96 | } | |
97 | if (signal_pending(current)) { | |
98 | retval = -ERESTARTSYS; | |
99 | break; | |
100 | } | |
101 | if (!device->exist) { | |
102 | retval = -EIO; | |
103 | break; | |
104 | } | |
105 | ||
106 | mutex_unlock(&device->cbuf_lock); | |
107 | schedule(); | |
108 | mutex_lock(&device->cbuf_lock); | |
109 | set_current_state(TASK_INTERRUPTIBLE); | |
110 | } | |
111 | ||
112 | set_current_state(TASK_RUNNING); | |
113 | remove_wait_queue(&device->wait, &wait); | |
114 | } | |
115 | ||
116 | /* here we either have data or a reason to return if retval is set */ | |
117 | if (retval) | |
118 | goto exit_unlock; | |
119 | ||
120 | report = &device->cbuf[reader->cbuf_start]; | |
121 | /* | |
122 | * If report is larger than requested amount of data, rest of report | |
123 | * is lost! | |
124 | */ | |
8211e460 | 125 | len = device->report_size > count ? count : device->report_size; |
206f5f2f SA |
126 | |
127 | if (copy_to_user(buffer, report->value, len)) { | |
128 | retval = -EFAULT; | |
129 | goto exit_unlock; | |
130 | } | |
131 | retval += len; | |
132 | reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE; | |
133 | ||
134 | exit_unlock: | |
135 | mutex_unlock(&device->cbuf_lock); | |
136 | return retval; | |
137 | } | |
138 | ||
139 | static unsigned int roccat_poll(struct file *file, poll_table *wait) | |
140 | { | |
141 | struct roccat_reader *reader = file->private_data; | |
142 | poll_wait(file, &reader->device->wait, wait); | |
143 | if (reader->cbuf_start != reader->device->cbuf_end) | |
144 | return POLLIN | POLLRDNORM; | |
145 | if (!reader->device->exist) | |
146 | return POLLERR | POLLHUP; | |
147 | return 0; | |
148 | } | |
149 | ||
150 | static int roccat_open(struct inode *inode, struct file *file) | |
151 | { | |
152 | unsigned int minor = iminor(inode); | |
153 | struct roccat_reader *reader; | |
154 | struct roccat_device *device; | |
155 | int error = 0; | |
156 | ||
157 | reader = kzalloc(sizeof(struct roccat_reader), GFP_KERNEL); | |
158 | if (!reader) | |
159 | return -ENOMEM; | |
160 | ||
161 | mutex_lock(&devices_lock); | |
162 | ||
163 | device = devices[minor]; | |
164 | ||
165 | mutex_lock(&device->readers_lock); | |
166 | ||
167 | if (!device) { | |
4291ee30 | 168 | pr_emerg("roccat device with minor %d doesn't exist\n", minor); |
206f5f2f | 169 | error = -ENODEV; |
dfe5c7b7 | 170 | goto exit_err; |
206f5f2f SA |
171 | } |
172 | ||
173 | if (!device->open++) { | |
174 | /* power on device on adding first reader */ | |
5bea7660 DT |
175 | error = hid_hw_power(device->hid, PM_HINT_FULLON); |
176 | if (error < 0) { | |
177 | --device->open; | |
178 | goto exit_err; | |
206f5f2f | 179 | } |
5bea7660 DT |
180 | |
181 | error = hid_hw_open(device->hid); | |
206f5f2f | 182 | if (error < 0) { |
5bea7660 | 183 | hid_hw_power(device->hid, PM_HINT_NORMAL); |
206f5f2f | 184 | --device->open; |
dfe5c7b7 | 185 | goto exit_err; |
206f5f2f SA |
186 | } |
187 | } | |
188 | ||
189 | reader->device = device; | |
190 | /* new reader doesn't get old events */ | |
191 | reader->cbuf_start = device->cbuf_end; | |
192 | ||
193 | list_add_tail(&reader->node, &device->readers); | |
194 | file->private_data = reader; | |
195 | ||
196 | exit_unlock: | |
197 | mutex_unlock(&device->readers_lock); | |
198 | mutex_unlock(&devices_lock); | |
199 | return error; | |
dfe5c7b7 JL |
200 | exit_err: |
201 | kfree(reader); | |
202 | goto exit_unlock; | |
206f5f2f SA |
203 | } |
204 | ||
205 | static int roccat_release(struct inode *inode, struct file *file) | |
206 | { | |
207 | unsigned int minor = iminor(inode); | |
208 | struct roccat_reader *reader = file->private_data; | |
209 | struct roccat_device *device; | |
210 | ||
211 | mutex_lock(&devices_lock); | |
212 | ||
213 | device = devices[minor]; | |
214 | if (!device) { | |
215 | mutex_unlock(&devices_lock); | |
4291ee30 | 216 | pr_emerg("roccat device with minor %d doesn't exist\n", minor); |
206f5f2f SA |
217 | return -ENODEV; |
218 | } | |
219 | ||
220 | mutex_lock(&device->readers_lock); | |
221 | list_del(&reader->node); | |
222 | mutex_unlock(&device->readers_lock); | |
223 | kfree(reader); | |
224 | ||
225 | if (!--device->open) { | |
226 | /* removing last reader */ | |
227 | if (device->exist) { | |
5bea7660 DT |
228 | hid_hw_power(device->hid, PM_HINT_NORMAL); |
229 | hid_hw_close(device->hid); | |
206f5f2f SA |
230 | } else { |
231 | kfree(device); | |
232 | } | |
233 | } | |
234 | ||
235 | mutex_unlock(&devices_lock); | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
240 | /* | |
241 | * roccat_report_event() - output data to readers | |
242 | * @minor: minor device number returned by roccat_connect() | |
243 | * @data: pointer to data | |
244 | * @len: size of data | |
245 | * | |
246 | * Return value is zero on success, a negative error code on failure. | |
247 | * | |
248 | * This is called from interrupt handler. | |
249 | */ | |
8211e460 | 250 | int roccat_report_event(int minor, u8 const *data) |
206f5f2f SA |
251 | { |
252 | struct roccat_device *device; | |
253 | struct roccat_reader *reader; | |
254 | struct roccat_report *report; | |
255 | uint8_t *new_value; | |
256 | ||
8211e460 SA |
257 | device = devices[minor]; |
258 | ||
259 | new_value = kmemdup(data, device->report_size, GFP_ATOMIC); | |
206f5f2f SA |
260 | if (!new_value) |
261 | return -ENOMEM; | |
262 | ||
206f5f2f SA |
263 | report = &device->cbuf[device->cbuf_end]; |
264 | ||
265 | /* passing NULL is safe */ | |
266 | kfree(report->value); | |
267 | ||
268 | report->value = new_value; | |
206f5f2f SA |
269 | device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE; |
270 | ||
271 | list_for_each_entry(reader, &device->readers, node) { | |
272 | /* | |
273 | * As we already inserted one element, the buffer can't be | |
274 | * empty. If start and end are equal, buffer is full and we | |
275 | * increase start, so that slow reader misses one event, but | |
276 | * gets the newer ones in the right order. | |
277 | */ | |
278 | if (reader->cbuf_start == device->cbuf_end) | |
279 | reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE; | |
280 | } | |
281 | ||
282 | wake_up_interruptible(&device->wait); | |
283 | return 0; | |
284 | } | |
285 | EXPORT_SYMBOL_GPL(roccat_report_event); | |
286 | ||
287 | /* | |
288 | * roccat_connect() - create a char device for special event output | |
5012aada SA |
289 | * @class: the class thats used to create the device. Meant to hold device |
290 | * specific sysfs attributes. | |
206f5f2f SA |
291 | * @hid: the hid device the char device should be connected to. |
292 | * | |
293 | * Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on | |
294 | * success, a negative error code on failure. | |
295 | */ | |
8211e460 | 296 | int roccat_connect(struct class *klass, struct hid_device *hid, int report_size) |
206f5f2f SA |
297 | { |
298 | unsigned int minor; | |
299 | struct roccat_device *device; | |
300 | int temp; | |
301 | ||
302 | device = kzalloc(sizeof(struct roccat_device), GFP_KERNEL); | |
303 | if (!device) | |
304 | return -ENOMEM; | |
305 | ||
306 | mutex_lock(&devices_lock); | |
307 | ||
308 | for (minor = 0; minor < ROCCAT_MAX_DEVICES; ++minor) { | |
309 | if (devices[minor]) | |
310 | continue; | |
311 | break; | |
312 | } | |
313 | ||
314 | if (minor < ROCCAT_MAX_DEVICES) { | |
315 | devices[minor] = device; | |
316 | } else { | |
317 | mutex_unlock(&devices_lock); | |
318 | kfree(device); | |
319 | return -EINVAL; | |
320 | } | |
321 | ||
5012aada | 322 | device->dev = device_create(klass, &hid->dev, |
206f5f2f SA |
323 | MKDEV(roccat_major, minor), NULL, |
324 | "%s%s%d", "roccat", hid->driver->name, minor); | |
325 | ||
326 | if (IS_ERR(device->dev)) { | |
327 | devices[minor] = NULL; | |
328 | mutex_unlock(&devices_lock); | |
329 | temp = PTR_ERR(device->dev); | |
330 | kfree(device); | |
331 | return temp; | |
332 | } | |
333 | ||
334 | mutex_unlock(&devices_lock); | |
335 | ||
336 | init_waitqueue_head(&device->wait); | |
337 | INIT_LIST_HEAD(&device->readers); | |
338 | mutex_init(&device->readers_lock); | |
339 | mutex_init(&device->cbuf_lock); | |
340 | device->minor = minor; | |
341 | device->hid = hid; | |
342 | device->exist = 1; | |
343 | device->cbuf_end = 0; | |
8211e460 | 344 | device->report_size = report_size; |
206f5f2f SA |
345 | |
346 | return minor; | |
347 | } | |
348 | EXPORT_SYMBOL_GPL(roccat_connect); | |
349 | ||
350 | /* roccat_disconnect() - remove char device from hid device | |
351 | * @minor: the minor device number returned by roccat_connect() | |
352 | */ | |
353 | void roccat_disconnect(int minor) | |
354 | { | |
355 | struct roccat_device *device; | |
356 | ||
357 | mutex_lock(&devices_lock); | |
358 | device = devices[minor]; | |
206f5f2f SA |
359 | mutex_unlock(&devices_lock); |
360 | ||
361 | device->exist = 0; /* TODO exist maybe not needed */ | |
362 | ||
5012aada | 363 | device_destroy(device->dev->class, MKDEV(roccat_major, minor)); |
206f5f2f | 364 | |
e6fa47af SA |
365 | mutex_lock(&devices_lock); |
366 | devices[minor] = NULL; | |
367 | mutex_unlock(&devices_lock); | |
368 | ||
206f5f2f | 369 | if (device->open) { |
5bea7660 | 370 | hid_hw_close(device->hid); |
206f5f2f SA |
371 | wake_up_interruptible(&device->wait); |
372 | } else { | |
373 | kfree(device); | |
374 | } | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(roccat_disconnect); | |
377 | ||
8211e460 SA |
378 | static long roccat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
379 | { | |
380 | struct inode *inode = file->f_path.dentry->d_inode; | |
381 | struct roccat_device *device; | |
382 | unsigned int minor = iminor(inode); | |
383 | long retval = 0; | |
384 | ||
385 | mutex_lock(&devices_lock); | |
386 | ||
387 | device = devices[minor]; | |
388 | if (!device) { | |
389 | retval = -ENODEV; | |
390 | goto out; | |
391 | } | |
392 | ||
393 | switch (cmd) { | |
394 | case ROCCATIOCGREPSIZE: | |
395 | if (put_user(device->report_size, (int __user *)arg)) | |
396 | retval = -EFAULT; | |
397 | break; | |
398 | default: | |
399 | retval = -ENOTTY; | |
400 | } | |
401 | out: | |
402 | mutex_unlock(&devices_lock); | |
403 | return retval; | |
404 | } | |
405 | ||
206f5f2f SA |
406 | static const struct file_operations roccat_ops = { |
407 | .owner = THIS_MODULE, | |
408 | .read = roccat_read, | |
409 | .poll = roccat_poll, | |
410 | .open = roccat_open, | |
411 | .release = roccat_release, | |
6038f373 | 412 | .llseek = noop_llseek, |
8211e460 | 413 | .unlocked_ioctl = roccat_ioctl, |
206f5f2f SA |
414 | }; |
415 | ||
416 | static int __init roccat_init(void) | |
417 | { | |
418 | int retval; | |
419 | dev_t dev_id; | |
420 | ||
421 | retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR, | |
422 | ROCCAT_MAX_DEVICES, "roccat"); | |
423 | ||
424 | roccat_major = MAJOR(dev_id); | |
425 | ||
426 | if (retval < 0) { | |
4291ee30 | 427 | pr_warn("can't get major number\n"); |
206f5f2f SA |
428 | return retval; |
429 | } | |
430 | ||
206f5f2f SA |
431 | cdev_init(&roccat_cdev, &roccat_ops); |
432 | cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES); | |
433 | ||
434 | return 0; | |
435 | } | |
436 | ||
437 | static void __exit roccat_exit(void) | |
438 | { | |
439 | dev_t dev_id = MKDEV(roccat_major, 0); | |
440 | ||
441 | cdev_del(&roccat_cdev); | |
206f5f2f SA |
442 | unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES); |
443 | } | |
444 | ||
445 | module_init(roccat_init); | |
446 | module_exit(roccat_exit); | |
447 | ||
448 | MODULE_AUTHOR("Stefan Achatz"); | |
449 | MODULE_DESCRIPTION("USB Roccat char device"); | |
450 | MODULE_LICENSE("GPL v2"); |