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/hid.h> 32 #include <linux/mutex.h> 33 #include <linux/smp_lock.h> 34 35 #include <linux/hidraw.h> 36 37 static int hidraw_major; 38 static struct cdev hidraw_cdev; 39 static struct class *hidraw_class; 40 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; 41 static DEFINE_MUTEX(minors_lock); 42 43 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) 44 { 45 struct hidraw_list *list = file->private_data; 46 int ret = 0, len; 47 char *report; 48 DECLARE_WAITQUEUE(wait, current); 49 50 while (ret == 0) { 51 52 mutex_lock(&list->read_mutex); 53 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 report = list->buffer[list->tail].value; 87 len = list->buffer[list->tail].len > count ? 88 count : list->buffer[list->tail].len; 89 90 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) { 91 ret = -EFAULT; 92 goto out; 93 } 94 ret += len; 95 96 kfree(list->buffer[list->tail].value); 97 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); 98 } 99 out: 100 mutex_unlock(&list->read_mutex); 101 return ret; 102 } 103 104 /* the first byte is expected to be a report number */ 105 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 106 { 107 unsigned int minor = iminor(file->f_path.dentry->d_inode); 108 /* FIXME: What stops hidraw_table going NULL */ 109 struct hid_device *dev = hidraw_table[minor]->hid; 110 __u8 *buf; 111 int ret = 0; 112 113 if (!dev->hid_output_raw_report) 114 return -ENODEV; 115 116 if (count > HID_MAX_BUFFER_SIZE) { 117 printk(KERN_WARNING "hidraw: pid %d passed too large report\n", 118 task_pid_nr(current)); 119 return -EINVAL; 120 } 121 122 if (count < 2) { 123 printk(KERN_WARNING "hidraw: pid %d passed too short report\n", 124 task_pid_nr(current)); 125 return -EINVAL; 126 } 127 128 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); 129 if (!buf) 130 return -ENOMEM; 131 132 if (copy_from_user(buf, buffer, count)) { 133 ret = -EFAULT; 134 goto out; 135 } 136 137 ret = dev->hid_output_raw_report(dev, buf, count); 138 out: 139 kfree(buf); 140 return ret; 141 } 142 143 static unsigned int hidraw_poll(struct file *file, poll_table *wait) 144 { 145 struct hidraw_list *list = file->private_data; 146 147 poll_wait(file, &list->hidraw->wait, wait); 148 if (list->head != list->tail) 149 return POLLIN | POLLRDNORM; 150 if (!list->hidraw->exist) 151 return POLLERR | POLLHUP; 152 return 0; 153 } 154 155 static int hidraw_open(struct inode *inode, struct file *file) 156 { 157 unsigned int minor = iminor(inode); 158 struct hidraw *dev; 159 struct hidraw_list *list; 160 int err = 0; 161 162 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) { 163 err = -ENOMEM; 164 goto out; 165 } 166 167 lock_kernel(); 168 mutex_lock(&minors_lock); 169 if (!hidraw_table[minor]) { 170 printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", 171 minor); 172 kfree(list); 173 err = -ENODEV; 174 goto out_unlock; 175 } 176 177 list->hidraw = hidraw_table[minor]; 178 mutex_init(&list->read_mutex); 179 list_add_tail(&list->node, &hidraw_table[minor]->list); 180 file->private_data = list; 181 182 dev = hidraw_table[minor]; 183 if (!dev->open++) { 184 if (dev->hid->ll_driver->power) { 185 err = dev->hid->ll_driver->power(dev->hid, PM_HINT_FULLON); 186 if (err < 0) 187 goto out_unlock; 188 } 189 err = dev->hid->ll_driver->open(dev->hid); 190 if (err < 0) { 191 if (dev->hid->ll_driver->power) 192 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); 193 dev->open--; 194 } 195 } 196 197 out_unlock: 198 mutex_unlock(&minors_lock); 199 unlock_kernel(); 200 out: 201 return err; 202 203 } 204 205 static int hidraw_release(struct inode * inode, struct file * file) 206 { 207 unsigned int minor = iminor(inode); 208 struct hidraw *dev; 209 struct hidraw_list *list = file->private_data; 210 211 if (!hidraw_table[minor]) { 212 printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", 213 minor); 214 return -ENODEV; 215 } 216 217 list_del(&list->node); 218 dev = hidraw_table[minor]; 219 if (!--dev->open) { 220 if (list->hidraw->exist) { 221 if (dev->hid->ll_driver->power) 222 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); 223 dev->hid->ll_driver->close(dev->hid); 224 } else { 225 kfree(list->hidraw); 226 } 227 } 228 229 kfree(list); 230 231 return 0; 232 } 233 234 static long hidraw_ioctl(struct file *file, unsigned int cmd, 235 unsigned long arg) 236 { 237 struct inode *inode = file->f_path.dentry->d_inode; 238 unsigned int minor = iminor(inode); 239 long ret = 0; 240 /* FIXME: What stops hidraw_table going NULL */ 241 struct hidraw *dev = hidraw_table[minor]; 242 void __user *user_arg = (void __user*) arg; 243 244 lock_kernel(); 245 switch (cmd) { 246 case HIDIOCGRDESCSIZE: 247 if (put_user(dev->hid->rsize, (int __user *)arg)) 248 ret = -EFAULT; 249 break; 250 251 case HIDIOCGRDESC: 252 { 253 __u32 len; 254 255 if (get_user(len, (int __user *)arg)) 256 ret = -EFAULT; 257 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) 258 ret = -EINVAL; 259 else if (copy_to_user(user_arg + offsetof( 260 struct hidraw_report_descriptor, 261 value[0]), 262 dev->hid->rdesc, 263 min(dev->hid->rsize, len))) 264 ret = -EFAULT; 265 break; 266 } 267 case HIDIOCGRAWINFO: 268 { 269 struct hidraw_devinfo dinfo; 270 271 dinfo.bustype = dev->hid->bus; 272 dinfo.vendor = dev->hid->vendor; 273 dinfo.product = dev->hid->product; 274 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) 275 ret = -EFAULT; 276 break; 277 } 278 default: 279 { 280 struct hid_device *hid = dev->hid; 281 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) { 282 ret = -EINVAL; 283 break; 284 } 285 286 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { 287 int len; 288 if (!hid->name) { 289 ret = 0; 290 break; 291 } 292 len = strlen(hid->name) + 1; 293 if (len > _IOC_SIZE(cmd)) 294 len = _IOC_SIZE(cmd); 295 ret = copy_to_user(user_arg, hid->name, len) ? 296 -EFAULT : len; 297 break; 298 } 299 300 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { 301 int len; 302 if (!hid->phys) { 303 ret = 0; 304 break; 305 } 306 len = strlen(hid->phys) + 1; 307 if (len > _IOC_SIZE(cmd)) 308 len = _IOC_SIZE(cmd); 309 ret = copy_to_user(user_arg, hid->phys, len) ? 310 -EFAULT : len; 311 break; 312 } 313 } 314 315 ret = -ENOTTY; 316 } 317 unlock_kernel(); 318 return ret; 319 } 320 321 static const struct file_operations hidraw_ops = { 322 .owner = THIS_MODULE, 323 .read = hidraw_read, 324 .write = hidraw_write, 325 .poll = hidraw_poll, 326 .open = hidraw_open, 327 .release = hidraw_release, 328 .unlocked_ioctl = hidraw_ioctl, 329 }; 330 331 void hidraw_report_event(struct hid_device *hid, u8 *data, int len) 332 { 333 struct hidraw *dev = hid->hidraw; 334 struct hidraw_list *list; 335 336 list_for_each_entry(list, &dev->list, node) { 337 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC); 338 list->buffer[list->head].len = len; 339 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); 340 kill_fasync(&list->fasync, SIGIO, POLL_IN); 341 } 342 343 wake_up_interruptible(&dev->wait); 344 } 345 EXPORT_SYMBOL_GPL(hidraw_report_event); 346 347 int hidraw_connect(struct hid_device *hid) 348 { 349 int minor, result; 350 struct hidraw *dev; 351 352 /* TODO currently we accept any HID device. This should later 353 * probably be fixed to accept only those devices which provide 354 * non-input applications 355 */ 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