| 1 | /* |
| 2 | * HID raw devices, giving access to raw HID events. |
| 3 | * |
| 4 | * In comparison to hiddev, this device does not process the |
| 5 | * hid events at all (no parsing, no lookups). This lets applications |
| 6 | * to work on raw hid events as they want to, and avoids a need to |
| 7 | * use a transport-specific userspace libhid/libusb libraries. |
| 8 | * |
| 9 | * Copyright (c) 2007-2014 Jiri Kosina |
| 10 | */ |
| 11 | |
| 12 | /* |
| 13 | * This program is free software; you can redistribute it and/or modify it |
| 14 | * under the terms and conditions of the GNU General Public License, |
| 15 | * version 2, as published by the Free Software Foundation. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License along with |
| 18 | * this program; if not, write to the Free Software Foundation, Inc., |
| 19 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | */ |
| 21 | |
| 22 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 23 | |
| 24 | #include <linux/fs.h> |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/errno.h> |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/init.h> |
| 29 | #include <linux/cdev.h> |
| 30 | #include <linux/poll.h> |
| 31 | #include <linux/device.h> |
| 32 | #include <linux/major.h> |
| 33 | #include <linux/slab.h> |
| 34 | #include <linux/hid.h> |
| 35 | #include <linux/mutex.h> |
| 36 | #include <linux/sched.h> |
| 37 | |
| 38 | #include <linux/hidraw.h> |
| 39 | |
| 40 | static int hidraw_major; |
| 41 | static struct cdev hidraw_cdev; |
| 42 | static struct class *hidraw_class; |
| 43 | static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; |
| 44 | static DEFINE_MUTEX(minors_lock); |
| 45 | |
| 46 | static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) |
| 47 | { |
| 48 | struct hidraw_list *list = file->private_data; |
| 49 | int ret = 0, len; |
| 50 | DECLARE_WAITQUEUE(wait, current); |
| 51 | |
| 52 | mutex_lock(&list->read_mutex); |
| 53 | |
| 54 | while (ret == 0) { |
| 55 | if (list->head == list->tail) { |
| 56 | add_wait_queue(&list->hidraw->wait, &wait); |
| 57 | set_current_state(TASK_INTERRUPTIBLE); |
| 58 | |
| 59 | while (list->head == list->tail) { |
| 60 | if (signal_pending(current)) { |
| 61 | ret = -ERESTARTSYS; |
| 62 | break; |
| 63 | } |
| 64 | if (!list->hidraw->exist) { |
| 65 | ret = -EIO; |
| 66 | break; |
| 67 | } |
| 68 | if (file->f_flags & O_NONBLOCK) { |
| 69 | ret = -EAGAIN; |
| 70 | break; |
| 71 | } |
| 72 | |
| 73 | /* allow O_NONBLOCK to work well from other threads */ |
| 74 | mutex_unlock(&list->read_mutex); |
| 75 | schedule(); |
| 76 | mutex_lock(&list->read_mutex); |
| 77 | set_current_state(TASK_INTERRUPTIBLE); |
| 78 | } |
| 79 | |
| 80 | set_current_state(TASK_RUNNING); |
| 81 | remove_wait_queue(&list->hidraw->wait, &wait); |
| 82 | } |
| 83 | |
| 84 | if (ret) |
| 85 | goto out; |
| 86 | |
| 87 | len = list->buffer[list->tail].len > count ? |
| 88 | count : list->buffer[list->tail].len; |
| 89 | |
| 90 | if (list->buffer[list->tail].value) { |
| 91 | if (copy_to_user(buffer, list->buffer[list->tail].value, len)) { |
| 92 | ret = -EFAULT; |
| 93 | goto out; |
| 94 | } |
| 95 | ret = len; |
| 96 | } |
| 97 | |
| 98 | kfree(list->buffer[list->tail].value); |
| 99 | list->buffer[list->tail].value = NULL; |
| 100 | list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); |
| 101 | } |
| 102 | out: |
| 103 | mutex_unlock(&list->read_mutex); |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * The first byte of the report buffer is expected to be a report number. |
| 109 | * |
| 110 | * This function is to be called with the minors_lock mutex held. |
| 111 | */ |
| 112 | static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type) |
| 113 | { |
| 114 | unsigned int minor = iminor(file_inode(file)); |
| 115 | struct hid_device *dev; |
| 116 | __u8 *buf; |
| 117 | int ret = 0; |
| 118 | |
| 119 | if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { |
| 120 | ret = -ENODEV; |
| 121 | goto out; |
| 122 | } |
| 123 | |
| 124 | dev = hidraw_table[minor]->hid; |
| 125 | |
| 126 | |
| 127 | if (count > HID_MAX_BUFFER_SIZE) { |
| 128 | hid_warn(dev, "pid %d passed too large report\n", |
| 129 | task_pid_nr(current)); |
| 130 | ret = -EINVAL; |
| 131 | goto out; |
| 132 | } |
| 133 | |
| 134 | if (count < 2) { |
| 135 | hid_warn(dev, "pid %d passed too short report\n", |
| 136 | task_pid_nr(current)); |
| 137 | ret = -EINVAL; |
| 138 | goto out; |
| 139 | } |
| 140 | |
| 141 | buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); |
| 142 | if (!buf) { |
| 143 | ret = -ENOMEM; |
| 144 | goto out; |
| 145 | } |
| 146 | |
| 147 | if (copy_from_user(buf, buffer, count)) { |
| 148 | ret = -EFAULT; |
| 149 | goto out_free; |
| 150 | } |
| 151 | |
| 152 | if ((report_type == HID_OUTPUT_REPORT) && |
| 153 | !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) { |
| 154 | ret = hid_hw_output_report(dev, buf, count); |
| 155 | /* |
| 156 | * compatibility with old implementation of USB-HID and I2C-HID: |
| 157 | * if the device does not support receiving output reports, |
| 158 | * on an interrupt endpoint, fallback to SET_REPORT HID command. |
| 159 | */ |
| 160 | if (ret != -ENOSYS) |
| 161 | goto out_free; |
| 162 | } |
| 163 | |
| 164 | ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type, |
| 165 | HID_REQ_SET_REPORT); |
| 166 | |
| 167 | out_free: |
| 168 | kfree(buf); |
| 169 | out: |
| 170 | return ret; |
| 171 | } |
| 172 | |
| 173 | static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) |
| 174 | { |
| 175 | ssize_t ret; |
| 176 | mutex_lock(&minors_lock); |
| 177 | ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT); |
| 178 | mutex_unlock(&minors_lock); |
| 179 | return ret; |
| 180 | } |
| 181 | |
| 182 | |
| 183 | /* |
| 184 | * This function performs a Get_Report transfer over the control endpoint |
| 185 | * per section 7.2.1 of the HID specification, version 1.1. The first byte |
| 186 | * of buffer is the report number to request, or 0x0 if the defice does not |
| 187 | * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT |
| 188 | * or HID_INPUT_REPORT. |
| 189 | * |
| 190 | * This function is to be called with the minors_lock mutex held. |
| 191 | */ |
| 192 | static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type) |
| 193 | { |
| 194 | unsigned int minor = iminor(file_inode(file)); |
| 195 | struct hid_device *dev; |
| 196 | __u8 *buf; |
| 197 | int ret = 0, len; |
| 198 | unsigned char report_number; |
| 199 | |
| 200 | dev = hidraw_table[minor]->hid; |
| 201 | |
| 202 | if (!dev->ll_driver->raw_request) { |
| 203 | ret = -ENODEV; |
| 204 | goto out; |
| 205 | } |
| 206 | |
| 207 | if (count > HID_MAX_BUFFER_SIZE) { |
| 208 | printk(KERN_WARNING "hidraw: pid %d passed too large report\n", |
| 209 | task_pid_nr(current)); |
| 210 | ret = -EINVAL; |
| 211 | goto out; |
| 212 | } |
| 213 | |
| 214 | if (count < 2) { |
| 215 | printk(KERN_WARNING "hidraw: pid %d passed too short report\n", |
| 216 | task_pid_nr(current)); |
| 217 | ret = -EINVAL; |
| 218 | goto out; |
| 219 | } |
| 220 | |
| 221 | buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); |
| 222 | if (!buf) { |
| 223 | ret = -ENOMEM; |
| 224 | goto out; |
| 225 | } |
| 226 | |
| 227 | /* |
| 228 | * Read the first byte from the user. This is the report number, |
| 229 | * which is passed to hid_hw_raw_request(). |
| 230 | */ |
| 231 | if (copy_from_user(&report_number, buffer, 1)) { |
| 232 | ret = -EFAULT; |
| 233 | goto out_free; |
| 234 | } |
| 235 | |
| 236 | ret = hid_hw_raw_request(dev, report_number, buf, count, report_type, |
| 237 | HID_REQ_GET_REPORT); |
| 238 | |
| 239 | if (ret < 0) |
| 240 | goto out_free; |
| 241 | |
| 242 | len = (ret < count) ? ret : count; |
| 243 | |
| 244 | if (copy_to_user(buffer, buf, len)) { |
| 245 | ret = -EFAULT; |
| 246 | goto out_free; |
| 247 | } |
| 248 | |
| 249 | ret = len; |
| 250 | |
| 251 | out_free: |
| 252 | kfree(buf); |
| 253 | out: |
| 254 | return ret; |
| 255 | } |
| 256 | |
| 257 | static unsigned int hidraw_poll(struct file *file, poll_table *wait) |
| 258 | { |
| 259 | struct hidraw_list *list = file->private_data; |
| 260 | |
| 261 | poll_wait(file, &list->hidraw->wait, wait); |
| 262 | if (list->head != list->tail) |
| 263 | return POLLIN | POLLRDNORM; |
| 264 | if (!list->hidraw->exist) |
| 265 | return POLLERR | POLLHUP; |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | static int hidraw_open(struct inode *inode, struct file *file) |
| 270 | { |
| 271 | unsigned int minor = iminor(inode); |
| 272 | struct hidraw *dev; |
| 273 | struct hidraw_list *list; |
| 274 | unsigned long flags; |
| 275 | int err = 0; |
| 276 | |
| 277 | if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) { |
| 278 | err = -ENOMEM; |
| 279 | goto out; |
| 280 | } |
| 281 | |
| 282 | mutex_lock(&minors_lock); |
| 283 | if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { |
| 284 | err = -ENODEV; |
| 285 | goto out_unlock; |
| 286 | } |
| 287 | |
| 288 | dev = hidraw_table[minor]; |
| 289 | if (!dev->open++) { |
| 290 | err = hid_hw_power(dev->hid, PM_HINT_FULLON); |
| 291 | if (err < 0) { |
| 292 | dev->open--; |
| 293 | goto out_unlock; |
| 294 | } |
| 295 | |
| 296 | err = hid_hw_open(dev->hid); |
| 297 | if (err < 0) { |
| 298 | hid_hw_power(dev->hid, PM_HINT_NORMAL); |
| 299 | dev->open--; |
| 300 | goto out_unlock; |
| 301 | } |
| 302 | } |
| 303 | |
| 304 | list->hidraw = hidraw_table[minor]; |
| 305 | mutex_init(&list->read_mutex); |
| 306 | spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags); |
| 307 | list_add_tail(&list->node, &hidraw_table[minor]->list); |
| 308 | spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags); |
| 309 | file->private_data = list; |
| 310 | out_unlock: |
| 311 | mutex_unlock(&minors_lock); |
| 312 | out: |
| 313 | if (err < 0) |
| 314 | kfree(list); |
| 315 | return err; |
| 316 | |
| 317 | } |
| 318 | |
| 319 | static int hidraw_fasync(int fd, struct file *file, int on) |
| 320 | { |
| 321 | struct hidraw_list *list = file->private_data; |
| 322 | |
| 323 | return fasync_helper(fd, file, on, &list->fasync); |
| 324 | } |
| 325 | |
| 326 | static void drop_ref(struct hidraw *hidraw, int exists_bit) |
| 327 | { |
| 328 | if (exists_bit) { |
| 329 | hidraw->exist = 0; |
| 330 | if (hidraw->open) { |
| 331 | hid_hw_close(hidraw->hid); |
| 332 | wake_up_interruptible(&hidraw->wait); |
| 333 | } |
| 334 | device_destroy(hidraw_class, |
| 335 | MKDEV(hidraw_major, hidraw->minor)); |
| 336 | } else { |
| 337 | --hidraw->open; |
| 338 | } |
| 339 | if (!hidraw->open) { |
| 340 | if (!hidraw->exist) { |
| 341 | hidraw_table[hidraw->minor] = NULL; |
| 342 | kfree(hidraw); |
| 343 | } else { |
| 344 | /* close device for last reader */ |
| 345 | hid_hw_power(hidraw->hid, PM_HINT_NORMAL); |
| 346 | hid_hw_close(hidraw->hid); |
| 347 | } |
| 348 | } |
| 349 | } |
| 350 | |
| 351 | static int hidraw_release(struct inode * inode, struct file * file) |
| 352 | { |
| 353 | unsigned int minor = iminor(inode); |
| 354 | struct hidraw_list *list = file->private_data; |
| 355 | unsigned long flags; |
| 356 | |
| 357 | mutex_lock(&minors_lock); |
| 358 | |
| 359 | spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags); |
| 360 | list_del(&list->node); |
| 361 | spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags); |
| 362 | kfree(list); |
| 363 | |
| 364 | drop_ref(hidraw_table[minor], 0); |
| 365 | |
| 366 | mutex_unlock(&minors_lock); |
| 367 | return 0; |
| 368 | } |
| 369 | |
| 370 | static long hidraw_ioctl(struct file *file, unsigned int cmd, |
| 371 | unsigned long arg) |
| 372 | { |
| 373 | struct inode *inode = file_inode(file); |
| 374 | unsigned int minor = iminor(inode); |
| 375 | long ret = 0; |
| 376 | struct hidraw *dev; |
| 377 | void __user *user_arg = (void __user*) arg; |
| 378 | |
| 379 | mutex_lock(&minors_lock); |
| 380 | dev = hidraw_table[minor]; |
| 381 | if (!dev) { |
| 382 | ret = -ENODEV; |
| 383 | goto out; |
| 384 | } |
| 385 | |
| 386 | switch (cmd) { |
| 387 | case HIDIOCGRDESCSIZE: |
| 388 | if (put_user(dev->hid->rsize, (int __user *)arg)) |
| 389 | ret = -EFAULT; |
| 390 | break; |
| 391 | |
| 392 | case HIDIOCGRDESC: |
| 393 | { |
| 394 | __u32 len; |
| 395 | |
| 396 | if (get_user(len, (int __user *)arg)) |
| 397 | ret = -EFAULT; |
| 398 | else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) |
| 399 | ret = -EINVAL; |
| 400 | else if (copy_to_user(user_arg + offsetof( |
| 401 | struct hidraw_report_descriptor, |
| 402 | value[0]), |
| 403 | dev->hid->rdesc, |
| 404 | min(dev->hid->rsize, len))) |
| 405 | ret = -EFAULT; |
| 406 | break; |
| 407 | } |
| 408 | case HIDIOCGRAWINFO: |
| 409 | { |
| 410 | struct hidraw_devinfo dinfo; |
| 411 | |
| 412 | dinfo.bustype = dev->hid->bus; |
| 413 | dinfo.vendor = dev->hid->vendor; |
| 414 | dinfo.product = dev->hid->product; |
| 415 | if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) |
| 416 | ret = -EFAULT; |
| 417 | break; |
| 418 | } |
| 419 | default: |
| 420 | { |
| 421 | struct hid_device *hid = dev->hid; |
| 422 | if (_IOC_TYPE(cmd) != 'H') { |
| 423 | ret = -EINVAL; |
| 424 | break; |
| 425 | } |
| 426 | |
| 427 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) { |
| 428 | int len = _IOC_SIZE(cmd); |
| 429 | ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT); |
| 430 | break; |
| 431 | } |
| 432 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) { |
| 433 | int len = _IOC_SIZE(cmd); |
| 434 | ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT); |
| 435 | break; |
| 436 | } |
| 437 | |
| 438 | /* Begin Read-only ioctls. */ |
| 439 | if (_IOC_DIR(cmd) != _IOC_READ) { |
| 440 | ret = -EINVAL; |
| 441 | break; |
| 442 | } |
| 443 | |
| 444 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { |
| 445 | int len = strlen(hid->name) + 1; |
| 446 | if (len > _IOC_SIZE(cmd)) |
| 447 | len = _IOC_SIZE(cmd); |
| 448 | ret = copy_to_user(user_arg, hid->name, len) ? |
| 449 | -EFAULT : len; |
| 450 | break; |
| 451 | } |
| 452 | |
| 453 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { |
| 454 | int len = strlen(hid->phys) + 1; |
| 455 | if (len > _IOC_SIZE(cmd)) |
| 456 | len = _IOC_SIZE(cmd); |
| 457 | ret = copy_to_user(user_arg, hid->phys, len) ? |
| 458 | -EFAULT : len; |
| 459 | break; |
| 460 | } |
| 461 | } |
| 462 | |
| 463 | ret = -ENOTTY; |
| 464 | } |
| 465 | out: |
| 466 | mutex_unlock(&minors_lock); |
| 467 | return ret; |
| 468 | } |
| 469 | |
| 470 | static const struct file_operations hidraw_ops = { |
| 471 | .owner = THIS_MODULE, |
| 472 | .read = hidraw_read, |
| 473 | .write = hidraw_write, |
| 474 | .poll = hidraw_poll, |
| 475 | .open = hidraw_open, |
| 476 | .release = hidraw_release, |
| 477 | .unlocked_ioctl = hidraw_ioctl, |
| 478 | .fasync = hidraw_fasync, |
| 479 | #ifdef CONFIG_COMPAT |
| 480 | .compat_ioctl = hidraw_ioctl, |
| 481 | #endif |
| 482 | .llseek = noop_llseek, |
| 483 | }; |
| 484 | |
| 485 | int hidraw_report_event(struct hid_device *hid, u8 *data, int len) |
| 486 | { |
| 487 | struct hidraw *dev = hid->hidraw; |
| 488 | struct hidraw_list *list; |
| 489 | int ret = 0; |
| 490 | unsigned long flags; |
| 491 | |
| 492 | spin_lock_irqsave(&dev->list_lock, flags); |
| 493 | list_for_each_entry(list, &dev->list, node) { |
| 494 | int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); |
| 495 | |
| 496 | if (new_head == list->tail) |
| 497 | continue; |
| 498 | |
| 499 | if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) { |
| 500 | ret = -ENOMEM; |
| 501 | break; |
| 502 | } |
| 503 | list->buffer[list->head].len = len; |
| 504 | list->head = new_head; |
| 505 | kill_fasync(&list->fasync, SIGIO, POLL_IN); |
| 506 | } |
| 507 | spin_unlock_irqrestore(&dev->list_lock, flags); |
| 508 | |
| 509 | wake_up_interruptible(&dev->wait); |
| 510 | return ret; |
| 511 | } |
| 512 | EXPORT_SYMBOL_GPL(hidraw_report_event); |
| 513 | |
| 514 | int hidraw_connect(struct hid_device *hid) |
| 515 | { |
| 516 | int minor, result; |
| 517 | struct hidraw *dev; |
| 518 | |
| 519 | /* we accept any HID device, all applications */ |
| 520 | |
| 521 | dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL); |
| 522 | if (!dev) |
| 523 | return -ENOMEM; |
| 524 | |
| 525 | result = -EINVAL; |
| 526 | |
| 527 | mutex_lock(&minors_lock); |
| 528 | |
| 529 | for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { |
| 530 | if (hidraw_table[minor]) |
| 531 | continue; |
| 532 | hidraw_table[minor] = dev; |
| 533 | result = 0; |
| 534 | break; |
| 535 | } |
| 536 | |
| 537 | if (result) { |
| 538 | mutex_unlock(&minors_lock); |
| 539 | kfree(dev); |
| 540 | goto out; |
| 541 | } |
| 542 | |
| 543 | dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor), |
| 544 | NULL, "%s%d", "hidraw", minor); |
| 545 | |
| 546 | if (IS_ERR(dev->dev)) { |
| 547 | hidraw_table[minor] = NULL; |
| 548 | mutex_unlock(&minors_lock); |
| 549 | result = PTR_ERR(dev->dev); |
| 550 | kfree(dev); |
| 551 | goto out; |
| 552 | } |
| 553 | |
| 554 | init_waitqueue_head(&dev->wait); |
| 555 | spin_lock_init(&dev->list_lock); |
| 556 | INIT_LIST_HEAD(&dev->list); |
| 557 | |
| 558 | dev->hid = hid; |
| 559 | dev->minor = minor; |
| 560 | |
| 561 | dev->exist = 1; |
| 562 | hid->hidraw = dev; |
| 563 | |
| 564 | mutex_unlock(&minors_lock); |
| 565 | out: |
| 566 | return result; |
| 567 | |
| 568 | } |
| 569 | EXPORT_SYMBOL_GPL(hidraw_connect); |
| 570 | |
| 571 | void hidraw_disconnect(struct hid_device *hid) |
| 572 | { |
| 573 | struct hidraw *hidraw = hid->hidraw; |
| 574 | |
| 575 | mutex_lock(&minors_lock); |
| 576 | |
| 577 | drop_ref(hidraw, 1); |
| 578 | |
| 579 | mutex_unlock(&minors_lock); |
| 580 | } |
| 581 | EXPORT_SYMBOL_GPL(hidraw_disconnect); |
| 582 | |
| 583 | int __init hidraw_init(void) |
| 584 | { |
| 585 | int result; |
| 586 | dev_t dev_id; |
| 587 | |
| 588 | result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, |
| 589 | HIDRAW_MAX_DEVICES, "hidraw"); |
| 590 | |
| 591 | hidraw_major = MAJOR(dev_id); |
| 592 | |
| 593 | if (result < 0) { |
| 594 | pr_warn("can't get major number\n"); |
| 595 | goto out; |
| 596 | } |
| 597 | |
| 598 | hidraw_class = class_create(THIS_MODULE, "hidraw"); |
| 599 | if (IS_ERR(hidraw_class)) { |
| 600 | result = PTR_ERR(hidraw_class); |
| 601 | goto error_cdev; |
| 602 | } |
| 603 | |
| 604 | cdev_init(&hidraw_cdev, &hidraw_ops); |
| 605 | result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); |
| 606 | if (result < 0) |
| 607 | goto error_class; |
| 608 | |
| 609 | printk(KERN_INFO "hidraw: raw HID events driver (C) Jiri Kosina\n"); |
| 610 | out: |
| 611 | return result; |
| 612 | |
| 613 | error_class: |
| 614 | class_destroy(hidraw_class); |
| 615 | error_cdev: |
| 616 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); |
| 617 | goto out; |
| 618 | } |
| 619 | |
| 620 | void hidraw_exit(void) |
| 621 | { |
| 622 | dev_t dev_id = MKDEV(hidraw_major, 0); |
| 623 | |
| 624 | cdev_del(&hidraw_cdev); |
| 625 | class_destroy(hidraw_class); |
| 626 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); |
| 627 | |
| 628 | } |