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 39static int hidraw_major; 40static struct cdev hidraw_cdev; 41static struct class *hidraw_class; 42static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; 43static DEFINE_MUTEX(minors_lock); 44 45static 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 } 98out: 99 mutex_unlock(&list->read_mutex); 100 return ret; 101} 102 103/* the first byte is expected to be a report number */ 104static 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); 151out_free: 152 kfree(buf); 153out: 154 mutex_unlock(&minors_lock); 155 return ret; 156} 157 158static 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 170static 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 209out_unlock: 210 mutex_unlock(&minors_lock); 211out: 212 return err; 213 214} 215 216static 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; 221 222 if (!hidraw_table[minor]) 223 return -ENODEV; 224 225 list_del(&list->node); 226 dev = hidraw_table[minor]; 227 if (!--dev->open) { 228 if (list->hidraw->exist) { 229 if (dev->hid->ll_driver->power) 230 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); 231 dev->hid->ll_driver->close(dev->hid); 232 } else { 233 kfree(list->hidraw); 234 } 235 } 236 237 kfree(list); 238 239 return 0; 240} 241 242static long hidraw_ioctl(struct file *file, unsigned int cmd, 243 unsigned long arg) 244{ 245 struct inode *inode = file->f_path.dentry->d_inode; 246 unsigned int minor = iminor(inode); 247 long ret = 0; 248 struct hidraw *dev; 249 void __user *user_arg = (void __user*) arg; 250 251 mutex_lock(&minors_lock); 252 dev = hidraw_table[minor]; 253 if (!dev) { 254 ret = -ENODEV; 255 goto out; 256 } 257 258 switch (cmd) { 259 case HIDIOCGRDESCSIZE: 260 if (put_user(dev->hid->rsize, (int __user *)arg)) 261 ret = -EFAULT; 262 break; 263 264 case HIDIOCGRDESC: 265 { 266 __u32 len; 267 268 if (get_user(len, (int __user *)arg)) 269 ret = -EFAULT; 270 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) 271 ret = -EINVAL; 272 else if (copy_to_user(user_arg + offsetof( 273 struct hidraw_report_descriptor, 274 value[0]), 275 dev->hid->rdesc, 276 min(dev->hid->rsize, len))) 277 ret = -EFAULT; 278 break; 279 } 280 case HIDIOCGRAWINFO: 281 { 282 struct hidraw_devinfo dinfo; 283 284 dinfo.bustype = dev->hid->bus; 285 dinfo.vendor = dev->hid->vendor; 286 dinfo.product = dev->hid->product; 287 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) 288 ret = -EFAULT; 289 break; 290 } 291 default: 292 { 293 struct hid_device *hid = dev->hid; 294 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) { 295 ret = -EINVAL; 296 break; 297 } 298 299 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { 300 int len; 301 if (!hid->name) { 302 ret = 0; 303 break; 304 } 305 len = strlen(hid->name) + 1; 306 if (len > _IOC_SIZE(cmd)) 307 len = _IOC_SIZE(cmd); 308 ret = copy_to_user(user_arg, hid->name, len) ? 309 -EFAULT : len; 310 break; 311 } 312 313 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { 314 int len; 315 if (!hid->phys) { 316 ret = 0; 317 break; 318 } 319 len = strlen(hid->phys) + 1; 320 if (len > _IOC_SIZE(cmd)) 321 len = _IOC_SIZE(cmd); 322 ret = copy_to_user(user_arg, hid->phys, len) ? 323 -EFAULT : len; 324 break; 325 } 326 } 327 328 ret = -ENOTTY; 329 } 330out: 331 mutex_unlock(&minors_lock); 332 return ret; 333} 334 335static const struct file_operations hidraw_ops = { 336 .owner = THIS_MODULE, 337 .read = hidraw_read, 338 .write = hidraw_write, 339 .poll = hidraw_poll, 340 .open = hidraw_open, 341 .release = hidraw_release, 342 .unlocked_ioctl = hidraw_ioctl, 343}; 344 345void hidraw_report_event(struct hid_device *hid, u8 *data, int len) 346{ 347 struct hidraw *dev = hid->hidraw; 348 struct hidraw_list *list; 349 350 list_for_each_entry(list, &dev->list, node) { 351 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC); 352 list->buffer[list->head].len = len; 353 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); 354 kill_fasync(&list->fasync, SIGIO, POLL_IN); 355 } 356 357 wake_up_interruptible(&dev->wait); 358} 359EXPORT_SYMBOL_GPL(hidraw_report_event); 360 361int hidraw_connect(struct hid_device *hid) 362{ 363 int minor, result; 364 struct hidraw *dev; 365 366 /* we accept any HID device, no matter the applications */ 367 368 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL); 369 if (!dev) 370 return -ENOMEM; 371 372 result = -EINVAL; 373 374 mutex_lock(&minors_lock); 375 376 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { 377 if (hidraw_table[minor]) 378 continue; 379 hidraw_table[minor] = dev; 380 result = 0; 381 break; 382 } 383 384 if (result) { 385 mutex_unlock(&minors_lock); 386 kfree(dev); 387 goto out; 388 } 389 390 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor), 391 NULL, "%s%d", "hidraw", minor); 392 393 if (IS_ERR(dev->dev)) { 394 hidraw_table[minor] = NULL; 395 mutex_unlock(&minors_lock); 396 result = PTR_ERR(dev->dev); 397 kfree(dev); 398 goto out; 399 } 400 401 mutex_unlock(&minors_lock); 402 init_waitqueue_head(&dev->wait); 403 INIT_LIST_HEAD(&dev->list); 404 405 dev->hid = hid; 406 dev->minor = minor; 407 408 dev->exist = 1; 409 hid->hidraw = dev; 410 411out: 412 return result; 413 414} 415EXPORT_SYMBOL_GPL(hidraw_connect); 416 417void hidraw_disconnect(struct hid_device *hid) 418{ 419 struct hidraw *hidraw = hid->hidraw; 420 421 hidraw->exist = 0; 422 423 mutex_lock(&minors_lock); 424 hidraw_table[hidraw->minor] = NULL; 425 mutex_unlock(&minors_lock); 426 427 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor)); 428 429 if (hidraw->open) { 430 hid->ll_driver->close(hid); 431 wake_up_interruptible(&hidraw->wait); 432 } else { 433 kfree(hidraw); 434 } 435} 436EXPORT_SYMBOL_GPL(hidraw_disconnect); 437 438int __init hidraw_init(void) 439{ 440 int result; 441 dev_t dev_id; 442 443 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, 444 HIDRAW_MAX_DEVICES, "hidraw"); 445 446 hidraw_major = MAJOR(dev_id); 447 448 if (result < 0) { 449 printk(KERN_WARNING "hidraw: can't get major number\n"); 450 result = 0; 451 goto out; 452 } 453 454 hidraw_class = class_create(THIS_MODULE, "hidraw"); 455 if (IS_ERR(hidraw_class)) { 456 result = PTR_ERR(hidraw_class); 457 unregister_chrdev(hidraw_major, "hidraw"); 458 goto out; 459 } 460 461 cdev_init(&hidraw_cdev, &hidraw_ops); 462 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); 463out: 464 return result; 465} 466 467void hidraw_exit(void) 468{ 469 dev_t dev_id = MKDEV(hidraw_major, 0); 470 471 cdev_del(&hidraw_cdev); 472 class_destroy(hidraw_class); 473 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); 474 475} 476