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 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 #include <linux/fs.h> 23 #include <linux/module.h> 24 #include <linux/errno.h> 25 #include <linux/kernel.h> 26 #include <linux/init.h> 27 #include <linux/cdev.h> 28 #include <linux/poll.h> 29 #include <linux/device.h> 30 #include <linux/major.h> 31 #include <linux/slab.h> 32 #include <linux/hid.h> 33 #include <linux/mutex.h> 34 #include <linux/sched.h> 35 #include <linux/smp_lock.h> 36 37 #include <linux/hidraw.h> 38 39 static int hidraw_major; 40 static struct cdev hidraw_cdev; 41 static struct class *hidraw_class; 42 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; 43 static DEFINE_MUTEX(minors_lock); 44 45 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) 46 { 47 struct hidraw_list *list = file->private_data; 48 int ret = 0, len; 49 DECLARE_WAITQUEUE(wait, current); 50 51 mutex_lock(&list->read_mutex); 52 53 while (ret == 0) { 54 if (list->head == list->tail) { 55 add_wait_queue(&list->hidraw->wait, &wait); 56 set_current_state(TASK_INTERRUPTIBLE); 57 58 while (list->head == list->tail) { 59 if (file->f_flags & O_NONBLOCK) { 60 ret = -EAGAIN; 61 break; 62 } 63 if (signal_pending(current)) { 64 ret = -ERESTARTSYS; 65 break; 66 } 67 if (!list->hidraw->exist) { 68 ret = -EIO; 69 break; 70 } 71 72 /* allow O_NONBLOCK to work well from other threads */ 73 mutex_unlock(&list->read_mutex); 74 schedule(); 75 mutex_lock(&list->read_mutex); 76 set_current_state(TASK_INTERRUPTIBLE); 77 } 78 79 set_current_state(TASK_RUNNING); 80 remove_wait_queue(&list->hidraw->wait, &wait); 81 } 82 83 if (ret) 84 goto out; 85 86 len = list->buffer[list->tail].len > count ? 87 count : list->buffer[list->tail].len; 88 89 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) { 90 ret = -EFAULT; 91 goto out; 92 } 93 ret += len; 94 95 kfree(list->buffer[list->tail].value); 96 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); 97 } 98 out: 99 mutex_unlock(&list->read_mutex); 100 return ret; 101 } 102 103 /* the first byte is expected to be a report number */ 104 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 105 { 106 unsigned int minor = iminor(file->f_path.dentry->d_inode); 107 struct hid_device *dev; 108 __u8 *buf; 109 int ret = 0; 110 111 mutex_lock(&minors_lock); 112 113 if (!hidraw_table[minor]) { 114 ret = -ENODEV; 115 goto out; 116 } 117 118 dev = hidraw_table[minor]->hid; 119 120 if (!dev->hid_output_raw_report) { 121 ret = -ENODEV; 122 goto out; 123 } 124 125 if (count > HID_MAX_BUFFER_SIZE) { 126 printk(KERN_WARNING "hidraw: pid %d passed too large report\n", 127 task_pid_nr(current)); 128 ret = -EINVAL; 129 goto out; 130 } 131 132 if (count < 2) { 133 printk(KERN_WARNING "hidraw: pid %d passed too short report\n", 134 task_pid_nr(current)); 135 ret = -EINVAL; 136 goto out; 137 } 138 139 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); 140 if (!buf) { 141 ret = -ENOMEM; 142 goto out; 143 } 144 145 if (copy_from_user(buf, buffer, count)) { 146 ret = -EFAULT; 147 goto out_free; 148 } 149 150 ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT); 151 out_free: 152 kfree(buf); 153 out: 154 mutex_unlock(&minors_lock); 155 return ret; 156 } 157 158 static unsigned int hidraw_poll(struct file *file, poll_table *wait) 159 { 160 struct hidraw_list *list = file->private_data; 161 162 poll_wait(file, &list->hidraw->wait, wait); 163 if (list->head != list->tail) 164 return POLLIN | POLLRDNORM; 165 if (!list->hidraw->exist) 166 return POLLERR | POLLHUP; 167 return 0; 168 } 169 170 static int hidraw_open(struct inode *inode, struct file *file) 171 { 172 unsigned int minor = iminor(inode); 173 struct hidraw *dev; 174 struct hidraw_list *list; 175 int err = 0; 176 177 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) { 178 err = -ENOMEM; 179 goto out; 180 } 181 182 mutex_lock(&minors_lock); 183 if (!hidraw_table[minor]) { 184 kfree(list); 185 err = -ENODEV; 186 goto out_unlock; 187 } 188 189 list->hidraw = hidraw_table[minor]; 190 mutex_init(&list->read_mutex); 191 list_add_tail(&list->node, &hidraw_table[minor]->list); 192 file->private_data = list; 193 194 dev = hidraw_table[minor]; 195 if (!dev->open++) { 196 if (dev->hid->ll_driver->power) { 197 err = dev->hid->ll_driver->power(dev->hid, PM_HINT_FULLON); 198 if (err < 0) 199 goto out_unlock; 200 } 201 err = dev->hid->ll_driver->open(dev->hid); 202 if (err < 0) { 203 if (dev->hid->ll_driver->power) 204 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); 205 dev->open--; 206 } 207 } 208 209 out_unlock: 210 mutex_unlock(&minors_lock); 211 out: 212 return err; 213 214 } 215 216 static int hidraw_release(struct inode * inode, struct file * file) 217 { 218 unsigned int minor = iminor(inode); 219 struct hidraw *dev; 220 struct hidraw_list *list = file->private_data; 221 int ret; 222 223 mutex_lock(&minors_lock); 224 if (!hidraw_table[minor]) { 225 ret = -ENODEV; 226 goto unlock; 227 } 228 229 list_del(&list->node); 230 dev = hidraw_table[minor]; 231 if (!--dev->open) { 232 if (list->hidraw->exist) { 233 if (dev->hid->ll_driver->power) 234 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); 235 dev->hid->ll_driver->close(dev->hid); 236 } else { 237 kfree(list->hidraw); 238 } 239 } 240 kfree(list); 241 ret = 0; 242 unlock: 243 mutex_unlock(&minors_lock); 244 245 return ret; 246 } 247 248 static long hidraw_ioctl(struct file *file, unsigned int cmd, 249 unsigned long arg) 250 { 251 struct inode *inode = file->f_path.dentry->d_inode; 252 unsigned int minor = iminor(inode); 253 long ret = 0; 254 struct hidraw *dev; 255 void __user *user_arg = (void __user*) arg; 256 257 mutex_lock(&minors_lock); 258 dev = hidraw_table[minor]; 259 if (!dev) { 260 ret = -ENODEV; 261 goto out; 262 } 263 264 switch (cmd) { 265 case HIDIOCGRDESCSIZE: 266 if (put_user(dev->hid->rsize, (int __user *)arg)) 267 ret = -EFAULT; 268 break; 269 270 case HIDIOCGRDESC: 271 { 272 __u32 len; 273 274 if (get_user(len, (int __user *)arg)) 275 ret = -EFAULT; 276 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) 277 ret = -EINVAL; 278 else if (copy_to_user(user_arg + offsetof( 279 struct hidraw_report_descriptor, 280 value[0]), 281 dev->hid->rdesc, 282 min(dev->hid->rsize, len))) 283 ret = -EFAULT; 284 break; 285 } 286 case HIDIOCGRAWINFO: 287 { 288 struct hidraw_devinfo dinfo; 289 290 dinfo.bustype = dev->hid->bus; 291 dinfo.vendor = dev->hid->vendor; 292 dinfo.product = dev->hid->product; 293 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) 294 ret = -EFAULT; 295 break; 296 } 297 default: 298 { 299 struct hid_device *hid = dev->hid; 300 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) { 301 ret = -EINVAL; 302 break; 303 } 304 305 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { 306 int len; 307 if (!hid->name) { 308 ret = 0; 309 break; 310 } 311 len = strlen(hid->name) + 1; 312 if (len > _IOC_SIZE(cmd)) 313 len = _IOC_SIZE(cmd); 314 ret = copy_to_user(user_arg, hid->name, len) ? 315 -EFAULT : len; 316 break; 317 } 318 319 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { 320 int len; 321 if (!hid->phys) { 322 ret = 0; 323 break; 324 } 325 len = strlen(hid->phys) + 1; 326 if (len > _IOC_SIZE(cmd)) 327 len = _IOC_SIZE(cmd); 328 ret = copy_to_user(user_arg, hid->phys, len) ? 329 -EFAULT : len; 330 break; 331 } 332 } 333 334 ret = -ENOTTY; 335 } 336 out: 337 mutex_unlock(&minors_lock); 338 return ret; 339 } 340 341 static const struct file_operations hidraw_ops = { 342 .owner = THIS_MODULE, 343 .read = hidraw_read, 344 .write = hidraw_write, 345 .poll = hidraw_poll, 346 .open = hidraw_open, 347 .release = hidraw_release, 348 .unlocked_ioctl = hidraw_ioctl, 349 .llseek = noop_llseek, 350 }; 351 352 void hidraw_report_event(struct hid_device *hid, u8 *data, int len) 353 { 354 struct hidraw *dev = hid->hidraw; 355 struct hidraw_list *list; 356 357 list_for_each_entry(list, &dev->list, node) { 358 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC); 359 list->buffer[list->head].len = len; 360 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); 361 kill_fasync(&list->fasync, SIGIO, POLL_IN); 362 } 363 364 wake_up_interruptible(&dev->wait); 365 } 366 EXPORT_SYMBOL_GPL(hidraw_report_event); 367 368 int hidraw_connect(struct hid_device *hid) 369 { 370 int minor, result; 371 struct hidraw *dev; 372 373 /* we accept any HID device, no matter the applications */ 374 375 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL); 376 if (!dev) 377 return -ENOMEM; 378 379 result = -EINVAL; 380 381 mutex_lock(&minors_lock); 382 383 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { 384 if (hidraw_table[minor]) 385 continue; 386 hidraw_table[minor] = dev; 387 result = 0; 388 break; 389 } 390 391 if (result) { 392 mutex_unlock(&minors_lock); 393 kfree(dev); 394 goto out; 395 } 396 397 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor), 398 NULL, "%s%d", "hidraw", minor); 399 400 if (IS_ERR(dev->dev)) { 401 hidraw_table[minor] = NULL; 402 mutex_unlock(&minors_lock); 403 result = PTR_ERR(dev->dev); 404 kfree(dev); 405 goto out; 406 } 407 408 mutex_unlock(&minors_lock); 409 init_waitqueue_head(&dev->wait); 410 INIT_LIST_HEAD(&dev->list); 411 412 dev->hid = hid; 413 dev->minor = minor; 414 415 dev->exist = 1; 416 hid->hidraw = dev; 417 418 out: 419 return result; 420 421 } 422 EXPORT_SYMBOL_GPL(hidraw_connect); 423 424 void hidraw_disconnect(struct hid_device *hid) 425 { 426 struct hidraw *hidraw = hid->hidraw; 427 428 hidraw->exist = 0; 429 430 mutex_lock(&minors_lock); 431 hidraw_table[hidraw->minor] = NULL; 432 mutex_unlock(&minors_lock); 433 434 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor)); 435 436 if (hidraw->open) { 437 hid->ll_driver->close(hid); 438 wake_up_interruptible(&hidraw->wait); 439 } else { 440 kfree(hidraw); 441 } 442 } 443 EXPORT_SYMBOL_GPL(hidraw_disconnect); 444 445 int __init hidraw_init(void) 446 { 447 int result; 448 dev_t dev_id; 449 450 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, 451 HIDRAW_MAX_DEVICES, "hidraw"); 452 453 hidraw_major = MAJOR(dev_id); 454 455 if (result < 0) { 456 printk(KERN_WARNING "hidraw: can't get major number\n"); 457 result = 0; 458 goto out; 459 } 460 461 hidraw_class = class_create(THIS_MODULE, "hidraw"); 462 if (IS_ERR(hidraw_class)) { 463 result = PTR_ERR(hidraw_class); 464 unregister_chrdev(hidraw_major, "hidraw"); 465 goto out; 466 } 467 468 cdev_init(&hidraw_cdev, &hidraw_ops); 469 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); 470 out: 471 return result; 472 } 473 474 void hidraw_exit(void) 475 { 476 dev_t dev_id = MKDEV(hidraw_major, 0); 477 478 cdev_del(&hidraw_cdev); 479 class_destroy(hidraw_class); 480 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); 481 482 } 483