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