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 dev = hidraw_table[minor]->hid; 113 114 if (!dev->hid_output_raw_report) { 115 ret = -ENODEV; 116 goto out; 117 } 118 119 if (count > HID_MAX_BUFFER_SIZE) { 120 printk(KERN_WARNING "hidraw: pid %d passed too large report\n", 121 task_pid_nr(current)); 122 ret = -EINVAL; 123 goto out; 124 } 125 126 if (count < 2) { 127 printk(KERN_WARNING "hidraw: pid %d passed too short report\n", 128 task_pid_nr(current)); 129 ret = -EINVAL; 130 goto out; 131 } 132 133 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); 134 if (!buf) { 135 ret = -ENOMEM; 136 goto out; 137 } 138 139 if (copy_from_user(buf, buffer, count)) { 140 ret = -EFAULT; 141 goto out_free; 142 } 143 144 ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT); 145 out_free: 146 kfree(buf); 147 out: 148 mutex_unlock(&minors_lock); 149 return ret; 150 } 151 152 static unsigned int hidraw_poll(struct file *file, poll_table *wait) 153 { 154 struct hidraw_list *list = file->private_data; 155 156 poll_wait(file, &list->hidraw->wait, wait); 157 if (list->head != list->tail) 158 return POLLIN | POLLRDNORM; 159 if (!list->hidraw->exist) 160 return POLLERR | POLLHUP; 161 return 0; 162 } 163 164 static int hidraw_open(struct inode *inode, struct file *file) 165 { 166 unsigned int minor = iminor(inode); 167 struct hidraw *dev; 168 struct hidraw_list *list; 169 int err = 0; 170 171 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) { 172 err = -ENOMEM; 173 goto out; 174 } 175 176 mutex_lock(&minors_lock); 177 if (!hidraw_table[minor]) { 178 kfree(list); 179 err = -ENODEV; 180 goto out_unlock; 181 } 182 183 list->hidraw = hidraw_table[minor]; 184 mutex_init(&list->read_mutex); 185 list_add_tail(&list->node, &hidraw_table[minor]->list); 186 file->private_data = list; 187 188 dev = hidraw_table[minor]; 189 if (!dev->open++) { 190 if (dev->hid->ll_driver->power) { 191 err = dev->hid->ll_driver->power(dev->hid, PM_HINT_FULLON); 192 if (err < 0) 193 goto out_unlock; 194 } 195 err = dev->hid->ll_driver->open(dev->hid); 196 if (err < 0) { 197 if (dev->hid->ll_driver->power) 198 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); 199 dev->open--; 200 } 201 } 202 203 out_unlock: 204 mutex_unlock(&minors_lock); 205 out: 206 return err; 207 208 } 209 210 static int hidraw_release(struct inode * inode, struct file * file) 211 { 212 unsigned int minor = iminor(inode); 213 struct hidraw *dev; 214 struct hidraw_list *list = file->private_data; 215 216 if (!hidraw_table[minor]) 217 return -ENODEV; 218 219 list_del(&list->node); 220 dev = hidraw_table[minor]; 221 if (!--dev->open) { 222 if (list->hidraw->exist) { 223 if (dev->hid->ll_driver->power) 224 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); 225 dev->hid->ll_driver->close(dev->hid); 226 } else { 227 kfree(list->hidraw); 228 } 229 } 230 231 kfree(list); 232 233 return 0; 234 } 235 236 static long hidraw_ioctl(struct file *file, unsigned int cmd, 237 unsigned long arg) 238 { 239 struct inode *inode = file->f_path.dentry->d_inode; 240 unsigned int minor = iminor(inode); 241 long ret = 0; 242 struct hidraw *dev; 243 void __user *user_arg = (void __user*) arg; 244 245 mutex_lock(&minors_lock); 246 dev = hidraw_table[minor]; 247 248 switch (cmd) { 249 case HIDIOCGRDESCSIZE: 250 if (put_user(dev->hid->rsize, (int __user *)arg)) 251 ret = -EFAULT; 252 break; 253 254 case HIDIOCGRDESC: 255 { 256 __u32 len; 257 258 if (get_user(len, (int __user *)arg)) 259 ret = -EFAULT; 260 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) 261 ret = -EINVAL; 262 else if (copy_to_user(user_arg + offsetof( 263 struct hidraw_report_descriptor, 264 value[0]), 265 dev->hid->rdesc, 266 min(dev->hid->rsize, len))) 267 ret = -EFAULT; 268 break; 269 } 270 case HIDIOCGRAWINFO: 271 { 272 struct hidraw_devinfo dinfo; 273 274 dinfo.bustype = dev->hid->bus; 275 dinfo.vendor = dev->hid->vendor; 276 dinfo.product = dev->hid->product; 277 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) 278 ret = -EFAULT; 279 break; 280 } 281 default: 282 { 283 struct hid_device *hid = dev->hid; 284 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) { 285 ret = -EINVAL; 286 break; 287 } 288 289 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { 290 int len; 291 if (!hid->name) { 292 ret = 0; 293 break; 294 } 295 len = strlen(hid->name) + 1; 296 if (len > _IOC_SIZE(cmd)) 297 len = _IOC_SIZE(cmd); 298 ret = copy_to_user(user_arg, hid->name, len) ? 299 -EFAULT : len; 300 break; 301 } 302 303 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { 304 int len; 305 if (!hid->phys) { 306 ret = 0; 307 break; 308 } 309 len = strlen(hid->phys) + 1; 310 if (len > _IOC_SIZE(cmd)) 311 len = _IOC_SIZE(cmd); 312 ret = copy_to_user(user_arg, hid->phys, len) ? 313 -EFAULT : len; 314 break; 315 } 316 } 317 318 ret = -ENOTTY; 319 } 320 mutex_unlock(&minors_lock); 321 return ret; 322 } 323 324 static const struct file_operations hidraw_ops = { 325 .owner = THIS_MODULE, 326 .read = hidraw_read, 327 .write = hidraw_write, 328 .poll = hidraw_poll, 329 .open = hidraw_open, 330 .release = hidraw_release, 331 .unlocked_ioctl = hidraw_ioctl, 332 }; 333 334 void hidraw_report_event(struct hid_device *hid, u8 *data, int len) 335 { 336 struct hidraw *dev = hid->hidraw; 337 struct hidraw_list *list; 338 339 list_for_each_entry(list, &dev->list, node) { 340 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC); 341 list->buffer[list->head].len = len; 342 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); 343 kill_fasync(&list->fasync, SIGIO, POLL_IN); 344 } 345 346 wake_up_interruptible(&dev->wait); 347 } 348 EXPORT_SYMBOL_GPL(hidraw_report_event); 349 350 int hidraw_connect(struct hid_device *hid) 351 { 352 int minor, result; 353 struct hidraw *dev; 354 355 /* we accept any HID device, no matter the applications */ 356 357 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL); 358 if (!dev) 359 return -ENOMEM; 360 361 result = -EINVAL; 362 363 mutex_lock(&minors_lock); 364 365 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { 366 if (hidraw_table[minor]) 367 continue; 368 hidraw_table[minor] = dev; 369 result = 0; 370 break; 371 } 372 373 if (result) { 374 mutex_unlock(&minors_lock); 375 kfree(dev); 376 goto out; 377 } 378 379 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor), 380 NULL, "%s%d", "hidraw", minor); 381 382 if (IS_ERR(dev->dev)) { 383 hidraw_table[minor] = NULL; 384 mutex_unlock(&minors_lock); 385 result = PTR_ERR(dev->dev); 386 kfree(dev); 387 goto out; 388 } 389 390 mutex_unlock(&minors_lock); 391 init_waitqueue_head(&dev->wait); 392 INIT_LIST_HEAD(&dev->list); 393 394 dev->hid = hid; 395 dev->minor = minor; 396 397 dev->exist = 1; 398 hid->hidraw = dev; 399 400 out: 401 return result; 402 403 } 404 EXPORT_SYMBOL_GPL(hidraw_connect); 405 406 void hidraw_disconnect(struct hid_device *hid) 407 { 408 struct hidraw *hidraw = hid->hidraw; 409 410 hidraw->exist = 0; 411 412 mutex_lock(&minors_lock); 413 hidraw_table[hidraw->minor] = NULL; 414 mutex_unlock(&minors_lock); 415 416 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor)); 417 418 if (hidraw->open) { 419 hid->ll_driver->close(hid); 420 wake_up_interruptible(&hidraw->wait); 421 } else { 422 kfree(hidraw); 423 } 424 } 425 EXPORT_SYMBOL_GPL(hidraw_disconnect); 426 427 int __init hidraw_init(void) 428 { 429 int result; 430 dev_t dev_id; 431 432 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, 433 HIDRAW_MAX_DEVICES, "hidraw"); 434 435 hidraw_major = MAJOR(dev_id); 436 437 if (result < 0) { 438 printk(KERN_WARNING "hidraw: can't get major number\n"); 439 result = 0; 440 goto out; 441 } 442 443 hidraw_class = class_create(THIS_MODULE, "hidraw"); 444 if (IS_ERR(hidraw_class)) { 445 result = PTR_ERR(hidraw_class); 446 unregister_chrdev(hidraw_major, "hidraw"); 447 goto out; 448 } 449 450 cdev_init(&hidraw_cdev, &hidraw_ops); 451 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); 452 out: 453 return result; 454 } 455 456 void hidraw_exit(void) 457 { 458 dev_t dev_id = MKDEV(hidraw_major, 0); 459 460 cdev_del(&hidraw_cdev); 461 class_destroy(hidraw_class); 462 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); 463 464 } 465