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