Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
206f5f2f SA |
2 | /* |
3 | * Roccat driver for Linux | |
4 | * | |
5 | * Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net> | |
6 | */ | |
7 | ||
8 | /* | |
206f5f2f SA |
9 | */ |
10 | ||
11 | /* | |
12 | * Module roccat is a char device used to report special events of roccat | |
13 | * hardware to userland. These events include requests for on-screen-display of | |
14 | * profile or dpi settings or requests for execution of macro sequences that are | |
15 | * not stored in device. The information in these events depends on hid device | |
16 | * implementation and contains data that is not available in a single hid event | |
17 | * or else hidraw could have been used. | |
18 | * It is inspired by hidraw, but uses only one circular buffer for all readers. | |
19 | */ | |
20 | ||
4291ee30 JP |
21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
22 | ||
206f5f2f SA |
23 | #include <linux/cdev.h> |
24 | #include <linux/poll.h> | |
174cd4b1 | 25 | #include <linux/sched/signal.h> |
5dc0c983 | 26 | #include <linux/hid-roccat.h> |
8f86a2c3 | 27 | #include <linux/module.h> |
206f5f2f SA |
28 | |
29 | #define ROCCAT_FIRST_MINOR 0 | |
30 | #define ROCCAT_MAX_DEVICES 8 | |
31 | ||
32 | /* should be a power of 2 for performance reason */ | |
33 | #define ROCCAT_CBUF_SIZE 16 | |
34 | ||
35 | struct roccat_report { | |
36 | uint8_t *value; | |
206f5f2f SA |
37 | }; |
38 | ||
39 | struct roccat_device { | |
40 | unsigned int minor; | |
8211e460 | 41 | int report_size; |
206f5f2f SA |
42 | int open; |
43 | int exist; | |
44 | wait_queue_head_t wait; | |
45 | struct device *dev; | |
46 | struct hid_device *hid; | |
47 | struct list_head readers; | |
48 | /* protects modifications of readers list */ | |
49 | struct mutex readers_lock; | |
50 | ||
51 | /* | |
52 | * circular_buffer has one writer and multiple readers with their own | |
53 | * read pointers | |
54 | */ | |
55 | struct roccat_report cbuf[ROCCAT_CBUF_SIZE]; | |
56 | int cbuf_end; | |
57 | struct mutex cbuf_lock; | |
58 | }; | |
59 | ||
60 | struct roccat_reader { | |
61 | struct list_head node; | |
62 | struct roccat_device *device; | |
63 | int cbuf_start; | |
64 | }; | |
65 | ||
66 | static int roccat_major; | |
206f5f2f SA |
67 | static struct cdev roccat_cdev; |
68 | ||
69 | static struct roccat_device *devices[ROCCAT_MAX_DEVICES]; | |
70 | /* protects modifications of devices array */ | |
71 | static DEFINE_MUTEX(devices_lock); | |
72 | ||
73 | static ssize_t roccat_read(struct file *file, char __user *buffer, | |
74 | size_t count, loff_t *ppos) | |
75 | { | |
76 | struct roccat_reader *reader = file->private_data; | |
77 | struct roccat_device *device = reader->device; | |
78 | struct roccat_report *report; | |
79 | ssize_t retval = 0, len; | |
80 | DECLARE_WAITQUEUE(wait, current); | |
81 | ||
82 | mutex_lock(&device->cbuf_lock); | |
83 | ||
84 | /* no data? */ | |
85 | if (reader->cbuf_start == device->cbuf_end) { | |
86 | add_wait_queue(&device->wait, &wait); | |
87 | set_current_state(TASK_INTERRUPTIBLE); | |
88 | ||
89 | /* wait for data */ | |
90 | while (reader->cbuf_start == device->cbuf_end) { | |
91 | if (file->f_flags & O_NONBLOCK) { | |
92 | retval = -EAGAIN; | |
93 | break; | |
94 | } | |
95 | if (signal_pending(current)) { | |
96 | retval = -ERESTARTSYS; | |
97 | break; | |
98 | } | |
99 | if (!device->exist) { | |
100 | retval = -EIO; | |
101 | break; | |
102 | } | |
103 | ||
104 | mutex_unlock(&device->cbuf_lock); | |
105 | schedule(); | |
106 | mutex_lock(&device->cbuf_lock); | |
107 | set_current_state(TASK_INTERRUPTIBLE); | |
108 | } | |
109 | ||
110 | set_current_state(TASK_RUNNING); | |
111 | remove_wait_queue(&device->wait, &wait); | |
112 | } | |
113 | ||
114 | /* here we either have data or a reason to return if retval is set */ | |
115 | if (retval) | |
116 | goto exit_unlock; | |
117 | ||
118 | report = &device->cbuf[reader->cbuf_start]; | |
119 | /* | |
120 | * If report is larger than requested amount of data, rest of report | |
121 | * is lost! | |
122 | */ | |
8211e460 | 123 | len = device->report_size > count ? count : device->report_size; |
206f5f2f SA |
124 | |
125 | if (copy_to_user(buffer, report->value, len)) { | |
126 | retval = -EFAULT; | |
127 | goto exit_unlock; | |
128 | } | |
129 | retval += len; | |
130 | reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE; | |
131 | ||
132 | exit_unlock: | |
133 | mutex_unlock(&device->cbuf_lock); | |
134 | return retval; | |
135 | } | |
136 | ||
afc9a42b | 137 | static __poll_t roccat_poll(struct file *file, poll_table *wait) |
206f5f2f SA |
138 | { |
139 | struct roccat_reader *reader = file->private_data; | |
140 | poll_wait(file, &reader->device->wait, wait); | |
141 | if (reader->cbuf_start != reader->device->cbuf_end) | |
a9a08845 | 142 | return EPOLLIN | EPOLLRDNORM; |
206f5f2f | 143 | if (!reader->device->exist) |
a9a08845 | 144 | return EPOLLERR | EPOLLHUP; |
206f5f2f SA |
145 | return 0; |
146 | } | |
147 | ||
148 | static int roccat_open(struct inode *inode, struct file *file) | |
149 | { | |
150 | unsigned int minor = iminor(inode); | |
151 | struct roccat_reader *reader; | |
152 | struct roccat_device *device; | |
153 | int error = 0; | |
154 | ||
155 | reader = kzalloc(sizeof(struct roccat_reader), GFP_KERNEL); | |
156 | if (!reader) | |
157 | return -ENOMEM; | |
158 | ||
159 | mutex_lock(&devices_lock); | |
160 | ||
161 | device = devices[minor]; | |
162 | ||
206f5f2f | 163 | if (!device) { |
4291ee30 | 164 | pr_emerg("roccat device with minor %d doesn't exist\n", minor); |
206f5f2f | 165 | error = -ENODEV; |
8052ee5f | 166 | goto exit_err_devices; |
206f5f2f SA |
167 | } |
168 | ||
8052ee5f JL |
169 | mutex_lock(&device->readers_lock); |
170 | ||
206f5f2f SA |
171 | if (!device->open++) { |
172 | /* power on device on adding first reader */ | |
5bea7660 DT |
173 | error = hid_hw_power(device->hid, PM_HINT_FULLON); |
174 | if (error < 0) { | |
175 | --device->open; | |
8052ee5f | 176 | goto exit_err_readers; |
206f5f2f | 177 | } |
5bea7660 DT |
178 | |
179 | error = hid_hw_open(device->hid); | |
206f5f2f | 180 | if (error < 0) { |
5bea7660 | 181 | hid_hw_power(device->hid, PM_HINT_NORMAL); |
206f5f2f | 182 | --device->open; |
8052ee5f | 183 | goto exit_err_readers; |
206f5f2f SA |
184 | } |
185 | } | |
186 | ||
187 | reader->device = device; | |
188 | /* new reader doesn't get old events */ | |
189 | reader->cbuf_start = device->cbuf_end; | |
190 | ||
191 | list_add_tail(&reader->node, &device->readers); | |
192 | file->private_data = reader; | |
193 | ||
8052ee5f | 194 | exit_err_readers: |
206f5f2f | 195 | mutex_unlock(&device->readers_lock); |
8052ee5f | 196 | exit_err_devices: |
206f5f2f | 197 | mutex_unlock(&devices_lock); |
8052ee5f JL |
198 | if (error) |
199 | kfree(reader); | |
206f5f2f SA |
200 | return error; |
201 | } | |
202 | ||
203 | static int roccat_release(struct inode *inode, struct file *file) | |
204 | { | |
205 | unsigned int minor = iminor(inode); | |
206 | struct roccat_reader *reader = file->private_data; | |
207 | struct roccat_device *device; | |
208 | ||
209 | mutex_lock(&devices_lock); | |
210 | ||
211 | device = devices[minor]; | |
212 | if (!device) { | |
213 | mutex_unlock(&devices_lock); | |
4291ee30 | 214 | pr_emerg("roccat device with minor %d doesn't exist\n", minor); |
206f5f2f SA |
215 | return -ENODEV; |
216 | } | |
217 | ||
218 | mutex_lock(&device->readers_lock); | |
219 | list_del(&reader->node); | |
220 | mutex_unlock(&device->readers_lock); | |
221 | kfree(reader); | |
222 | ||
223 | if (!--device->open) { | |
224 | /* removing last reader */ | |
225 | if (device->exist) { | |
5bea7660 DT |
226 | hid_hw_power(device->hid, PM_HINT_NORMAL); |
227 | hid_hw_close(device->hid); | |
206f5f2f SA |
228 | } else { |
229 | kfree(device); | |
230 | } | |
231 | } | |
232 | ||
233 | mutex_unlock(&devices_lock); | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | /* | |
239 | * roccat_report_event() - output data to readers | |
240 | * @minor: minor device number returned by roccat_connect() | |
241 | * @data: pointer to data | |
206f5f2f SA |
242 | * |
243 | * Return value is zero on success, a negative error code on failure. | |
244 | * | |
245 | * This is called from interrupt handler. | |
246 | */ | |
8211e460 | 247 | int roccat_report_event(int minor, u8 const *data) |
206f5f2f SA |
248 | { |
249 | struct roccat_device *device; | |
250 | struct roccat_reader *reader; | |
251 | struct roccat_report *report; | |
252 | uint8_t *new_value; | |
253 | ||
8211e460 SA |
254 | device = devices[minor]; |
255 | ||
256 | new_value = kmemdup(data, device->report_size, GFP_ATOMIC); | |
206f5f2f SA |
257 | if (!new_value) |
258 | return -ENOMEM; | |
259 | ||
206f5f2f SA |
260 | report = &device->cbuf[device->cbuf_end]; |
261 | ||
262 | /* passing NULL is safe */ | |
263 | kfree(report->value); | |
264 | ||
265 | report->value = new_value; | |
206f5f2f SA |
266 | device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE; |
267 | ||
268 | list_for_each_entry(reader, &device->readers, node) { | |
269 | /* | |
270 | * As we already inserted one element, the buffer can't be | |
271 | * empty. If start and end are equal, buffer is full and we | |
272 | * increase start, so that slow reader misses one event, but | |
273 | * gets the newer ones in the right order. | |
274 | */ | |
275 | if (reader->cbuf_start == device->cbuf_end) | |
276 | reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE; | |
277 | } | |
278 | ||
279 | wake_up_interruptible(&device->wait); | |
280 | return 0; | |
281 | } | |
282 | EXPORT_SYMBOL_GPL(roccat_report_event); | |
283 | ||
284 | /* | |
285 | * roccat_connect() - create a char device for special event output | |
5012aada SA |
286 | * @class: the class thats used to create the device. Meant to hold device |
287 | * specific sysfs attributes. | |
206f5f2f | 288 | * @hid: the hid device the char device should be connected to. |
02060045 | 289 | * @report_size: size of reports |
206f5f2f SA |
290 | * |
291 | * Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on | |
292 | * success, a negative error code on failure. | |
293 | */ | |
8211e460 | 294 | int roccat_connect(struct class *klass, struct hid_device *hid, int report_size) |
206f5f2f SA |
295 | { |
296 | unsigned int minor; | |
297 | struct roccat_device *device; | |
298 | int temp; | |
299 | ||
300 | device = kzalloc(sizeof(struct roccat_device), GFP_KERNEL); | |
301 | if (!device) | |
302 | return -ENOMEM; | |
303 | ||
304 | mutex_lock(&devices_lock); | |
305 | ||
306 | for (minor = 0; minor < ROCCAT_MAX_DEVICES; ++minor) { | |
307 | if (devices[minor]) | |
308 | continue; | |
309 | break; | |
310 | } | |
311 | ||
312 | if (minor < ROCCAT_MAX_DEVICES) { | |
313 | devices[minor] = device; | |
314 | } else { | |
315 | mutex_unlock(&devices_lock); | |
316 | kfree(device); | |
317 | return -EINVAL; | |
318 | } | |
319 | ||
5012aada | 320 | device->dev = device_create(klass, &hid->dev, |
206f5f2f SA |
321 | MKDEV(roccat_major, minor), NULL, |
322 | "%s%s%d", "roccat", hid->driver->name, minor); | |
323 | ||
324 | if (IS_ERR(device->dev)) { | |
325 | devices[minor] = NULL; | |
326 | mutex_unlock(&devices_lock); | |
327 | temp = PTR_ERR(device->dev); | |
328 | kfree(device); | |
329 | return temp; | |
330 | } | |
331 | ||
332 | mutex_unlock(&devices_lock); | |
333 | ||
334 | init_waitqueue_head(&device->wait); | |
335 | INIT_LIST_HEAD(&device->readers); | |
336 | mutex_init(&device->readers_lock); | |
337 | mutex_init(&device->cbuf_lock); | |
338 | device->minor = minor; | |
339 | device->hid = hid; | |
340 | device->exist = 1; | |
341 | device->cbuf_end = 0; | |
8211e460 | 342 | device->report_size = report_size; |
206f5f2f SA |
343 | |
344 | return minor; | |
345 | } | |
346 | EXPORT_SYMBOL_GPL(roccat_connect); | |
347 | ||
348 | /* roccat_disconnect() - remove char device from hid device | |
349 | * @minor: the minor device number returned by roccat_connect() | |
350 | */ | |
351 | void roccat_disconnect(int minor) | |
352 | { | |
353 | struct roccat_device *device; | |
354 | ||
355 | mutex_lock(&devices_lock); | |
356 | device = devices[minor]; | |
206f5f2f SA |
357 | mutex_unlock(&devices_lock); |
358 | ||
359 | device->exist = 0; /* TODO exist maybe not needed */ | |
360 | ||
5012aada | 361 | device_destroy(device->dev->class, MKDEV(roccat_major, minor)); |
206f5f2f | 362 | |
e6fa47af SA |
363 | mutex_lock(&devices_lock); |
364 | devices[minor] = NULL; | |
365 | mutex_unlock(&devices_lock); | |
a0be10c2 | 366 | |
206f5f2f | 367 | if (device->open) { |
5bea7660 | 368 | hid_hw_close(device->hid); |
206f5f2f SA |
369 | wake_up_interruptible(&device->wait); |
370 | } else { | |
371 | kfree(device); | |
372 | } | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(roccat_disconnect); | |
375 | ||
8211e460 SA |
376 | static long roccat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
377 | { | |
496ad9aa | 378 | struct inode *inode = file_inode(file); |
8211e460 SA |
379 | struct roccat_device *device; |
380 | unsigned int minor = iminor(inode); | |
381 | long retval = 0; | |
382 | ||
383 | mutex_lock(&devices_lock); | |
384 | ||
385 | device = devices[minor]; | |
386 | if (!device) { | |
387 | retval = -ENODEV; | |
388 | goto out; | |
389 | } | |
390 | ||
391 | switch (cmd) { | |
392 | case ROCCATIOCGREPSIZE: | |
393 | if (put_user(device->report_size, (int __user *)arg)) | |
394 | retval = -EFAULT; | |
395 | break; | |
396 | default: | |
397 | retval = -ENOTTY; | |
398 | } | |
399 | out: | |
400 | mutex_unlock(&devices_lock); | |
401 | return retval; | |
402 | } | |
403 | ||
206f5f2f SA |
404 | static const struct file_operations roccat_ops = { |
405 | .owner = THIS_MODULE, | |
406 | .read = roccat_read, | |
407 | .poll = roccat_poll, | |
408 | .open = roccat_open, | |
409 | .release = roccat_release, | |
6038f373 | 410 | .llseek = noop_llseek, |
8211e460 | 411 | .unlocked_ioctl = roccat_ioctl, |
206f5f2f SA |
412 | }; |
413 | ||
414 | static int __init roccat_init(void) | |
415 | { | |
416 | int retval; | |
417 | dev_t dev_id; | |
418 | ||
419 | retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR, | |
420 | ROCCAT_MAX_DEVICES, "roccat"); | |
206f5f2f | 421 | if (retval < 0) { |
4291ee30 | 422 | pr_warn("can't get major number\n"); |
a0be10c2 | 423 | goto error; |
206f5f2f SA |
424 | } |
425 | ||
85d08340 DC |
426 | roccat_major = MAJOR(dev_id); |
427 | ||
206f5f2f | 428 | cdev_init(&roccat_cdev, &roccat_ops); |
a0be10c2 | 429 | retval = cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES); |
206f5f2f | 430 | |
a0be10c2 MR |
431 | if (retval < 0) { |
432 | pr_warn("cannot add cdev\n"); | |
433 | goto cleanup_alloc_chrdev_region; | |
434 | } | |
206f5f2f | 435 | return 0; |
a0be10c2 MR |
436 | |
437 | ||
438 | cleanup_alloc_chrdev_region: | |
439 | unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES); | |
440 | error: | |
441 | return retval; | |
206f5f2f SA |
442 | } |
443 | ||
444 | static void __exit roccat_exit(void) | |
445 | { | |
446 | dev_t dev_id = MKDEV(roccat_major, 0); | |
447 | ||
448 | cdev_del(&roccat_cdev); | |
206f5f2f SA |
449 | unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES); |
450 | } | |
451 | ||
452 | module_init(roccat_init); | |
453 | module_exit(roccat_exit); | |
454 | ||
455 | MODULE_AUTHOR("Stefan Achatz"); | |
456 | MODULE_DESCRIPTION("USB Roccat char device"); | |
457 | MODULE_LICENSE("GPL v2"); |