1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Driver for Meywa-Denki & KAYAC YUREX 4 * 5 * Copyright (C) 2010 Tomoki Sekiyama (tomoki.sekiyama@gmail.com) 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/errno.h> 10 #include <linux/slab.h> 11 #include <linux/module.h> 12 #include <linux/kref.h> 13 #include <linux/mutex.h> 14 #include <linux/uaccess.h> 15 #include <linux/usb.h> 16 #include <linux/hid.h> 17 18 #define DRIVER_AUTHOR "Tomoki Sekiyama" 19 #define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX" 20 21 #define YUREX_VENDOR_ID 0x0c45 22 #define YUREX_PRODUCT_ID 0x1010 23 24 #define CMD_ACK '!' 25 #define CMD_ANIMATE 'A' 26 #define CMD_COUNT 'C' 27 #define CMD_LED 'L' 28 #define CMD_READ 'R' 29 #define CMD_SET 'S' 30 #define CMD_VERSION 'V' 31 #define CMD_EOF 0x0d 32 #define CMD_PADDING 0xff 33 34 #define YUREX_BUF_SIZE 8 35 #define YUREX_WRITE_TIMEOUT (HZ*2) 36 37 #define MAX_S64_STRLEN 20 /* {-}922337203685477580{7,8} */ 38 39 /* table of devices that work with this driver */ 40 static struct usb_device_id yurex_table[] = { 41 { USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) }, 42 { } /* Terminating entry */ 43 }; 44 MODULE_DEVICE_TABLE(usb, yurex_table); 45 46 #ifdef CONFIG_USB_DYNAMIC_MINORS 47 #define YUREX_MINOR_BASE 0 48 #else 49 #define YUREX_MINOR_BASE 192 50 #endif 51 52 /* Structure to hold all of our device specific stuff */ 53 struct usb_yurex { 54 struct usb_device *udev; 55 struct usb_interface *interface; 56 __u8 int_in_endpointAddr; 57 struct urb *urb; /* URB for interrupt in */ 58 unsigned char *int_buffer; /* buffer for intterupt in */ 59 struct urb *cntl_urb; /* URB for control msg */ 60 struct usb_ctrlrequest *cntl_req; /* req for control msg */ 61 unsigned char *cntl_buffer; /* buffer for control msg */ 62 63 struct kref kref; 64 struct mutex io_mutex; 65 unsigned long disconnected:1; 66 struct fasync_struct *async_queue; 67 wait_queue_head_t waitq; 68 69 spinlock_t lock; 70 __s64 bbu; /* BBU from device */ 71 }; 72 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref) 73 74 static struct usb_driver yurex_driver; 75 static const struct file_operations yurex_fops; 76 77 78 static void yurex_control_callback(struct urb *urb) 79 { 80 struct usb_yurex *dev = urb->context; 81 int status = urb->status; 82 83 if (status) { 84 dev_err(&urb->dev->dev, "%s - control failed: %d\n", 85 __func__, status); 86 wake_up_interruptible(&dev->waitq); 87 return; 88 } 89 /* on success, sender woken up by CMD_ACK int in, or timeout */ 90 } 91 92 static void yurex_delete(struct kref *kref) 93 { 94 struct usb_yurex *dev = to_yurex_dev(kref); 95 96 dev_dbg(&dev->interface->dev, "%s\n", __func__); 97 98 if (dev->cntl_urb) { 99 usb_kill_urb(dev->cntl_urb); 100 kfree(dev->cntl_req); 101 usb_free_coherent(dev->udev, YUREX_BUF_SIZE, 102 dev->cntl_buffer, dev->cntl_urb->transfer_dma); 103 usb_free_urb(dev->cntl_urb); 104 } 105 if (dev->urb) { 106 usb_kill_urb(dev->urb); 107 usb_free_coherent(dev->udev, YUREX_BUF_SIZE, 108 dev->int_buffer, dev->urb->transfer_dma); 109 usb_free_urb(dev->urb); 110 } 111 usb_put_intf(dev->interface); 112 usb_put_dev(dev->udev); 113 kfree(dev); 114 } 115 116 /* 117 * usb class driver info in order to get a minor number from the usb core, 118 * and to have the device registered with the driver core 119 */ 120 static struct usb_class_driver yurex_class = { 121 .name = "yurex%d", 122 .fops = &yurex_fops, 123 .minor_base = YUREX_MINOR_BASE, 124 }; 125 126 static void yurex_interrupt(struct urb *urb) 127 { 128 struct usb_yurex *dev = urb->context; 129 unsigned char *buf = dev->int_buffer; 130 int status = urb->status; 131 unsigned long flags; 132 int retval, i; 133 134 switch (status) { 135 case 0: /*success*/ 136 break; 137 /* The device is terminated or messed up, give up */ 138 case -EOVERFLOW: 139 dev_err(&dev->interface->dev, 140 "%s - overflow with length %d, actual length is %d\n", 141 __func__, YUREX_BUF_SIZE, dev->urb->actual_length); 142 return; 143 case -ECONNRESET: 144 case -ENOENT: 145 case -ESHUTDOWN: 146 case -EILSEQ: 147 case -EPROTO: 148 case -ETIME: 149 return; 150 default: 151 dev_err(&dev->interface->dev, 152 "%s - unknown status received: %d\n", __func__, status); 153 return; 154 } 155 156 /* handle received message */ 157 switch (buf[0]) { 158 case CMD_COUNT: 159 case CMD_READ: 160 if (buf[6] == CMD_EOF) { 161 spin_lock_irqsave(&dev->lock, flags); 162 dev->bbu = 0; 163 for (i = 1; i < 6; i++) { 164 dev->bbu += buf[i]; 165 if (i != 5) 166 dev->bbu <<= 8; 167 } 168 dev_dbg(&dev->interface->dev, "%s count: %lld\n", 169 __func__, dev->bbu); 170 spin_unlock_irqrestore(&dev->lock, flags); 171 172 kill_fasync(&dev->async_queue, SIGIO, POLL_IN); 173 } 174 else 175 dev_dbg(&dev->interface->dev, 176 "data format error - no EOF\n"); 177 break; 178 case CMD_ACK: 179 dev_dbg(&dev->interface->dev, "%s ack: %c\n", 180 __func__, buf[1]); 181 wake_up_interruptible(&dev->waitq); 182 break; 183 } 184 185 retval = usb_submit_urb(dev->urb, GFP_ATOMIC); 186 if (retval) { 187 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n", 188 __func__, retval); 189 } 190 } 191 192 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id) 193 { 194 struct usb_yurex *dev; 195 struct usb_host_interface *iface_desc; 196 struct usb_endpoint_descriptor *endpoint; 197 int retval = -ENOMEM; 198 DEFINE_WAIT(wait); 199 int res; 200 201 /* allocate memory for our device state and initialize it */ 202 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 203 if (!dev) 204 goto error; 205 kref_init(&dev->kref); 206 mutex_init(&dev->io_mutex); 207 spin_lock_init(&dev->lock); 208 init_waitqueue_head(&dev->waitq); 209 210 dev->udev = usb_get_dev(interface_to_usbdev(interface)); 211 dev->interface = usb_get_intf(interface); 212 213 /* set up the endpoint information */ 214 iface_desc = interface->cur_altsetting; 215 res = usb_find_int_in_endpoint(iface_desc, &endpoint); 216 if (res) { 217 dev_err(&interface->dev, "Could not find endpoints\n"); 218 retval = res; 219 goto error; 220 } 221 222 dev->int_in_endpointAddr = endpoint->bEndpointAddress; 223 224 /* allocate control URB */ 225 dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL); 226 if (!dev->cntl_urb) 227 goto error; 228 229 /* allocate buffer for control req */ 230 dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL); 231 if (!dev->cntl_req) 232 goto error; 233 234 /* allocate buffer for control msg */ 235 dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE, 236 GFP_KERNEL, 237 &dev->cntl_urb->transfer_dma); 238 if (!dev->cntl_buffer) { 239 dev_err(&interface->dev, "Could not allocate cntl_buffer\n"); 240 goto error; 241 } 242 243 /* configure control URB */ 244 dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS | 245 USB_RECIP_INTERFACE; 246 dev->cntl_req->bRequest = HID_REQ_SET_REPORT; 247 dev->cntl_req->wValue = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8); 248 dev->cntl_req->wIndex = cpu_to_le16(iface_desc->desc.bInterfaceNumber); 249 dev->cntl_req->wLength = cpu_to_le16(YUREX_BUF_SIZE); 250 251 usb_fill_control_urb(dev->cntl_urb, dev->udev, 252 usb_sndctrlpipe(dev->udev, 0), 253 (void *)dev->cntl_req, dev->cntl_buffer, 254 YUREX_BUF_SIZE, yurex_control_callback, dev); 255 dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 256 257 258 /* allocate interrupt URB */ 259 dev->urb = usb_alloc_urb(0, GFP_KERNEL); 260 if (!dev->urb) 261 goto error; 262 263 /* allocate buffer for interrupt in */ 264 dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE, 265 GFP_KERNEL, &dev->urb->transfer_dma); 266 if (!dev->int_buffer) { 267 dev_err(&interface->dev, "Could not allocate int_buffer\n"); 268 goto error; 269 } 270 271 /* configure interrupt URB */ 272 usb_fill_int_urb(dev->urb, dev->udev, 273 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr), 274 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt, 275 dev, 1); 276 dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 277 if (usb_submit_urb(dev->urb, GFP_KERNEL)) { 278 retval = -EIO; 279 dev_err(&interface->dev, "Could not submitting URB\n"); 280 goto error; 281 } 282 283 /* save our data pointer in this interface device */ 284 usb_set_intfdata(interface, dev); 285 dev->bbu = -1; 286 287 /* we can register the device now, as it is ready */ 288 retval = usb_register_dev(interface, &yurex_class); 289 if (retval) { 290 dev_err(&interface->dev, 291 "Not able to get a minor for this device.\n"); 292 usb_set_intfdata(interface, NULL); 293 goto error; 294 } 295 296 dev_info(&interface->dev, 297 "USB YUREX device now attached to Yurex #%d\n", 298 interface->minor); 299 300 return 0; 301 302 error: 303 if (dev) 304 /* this frees allocated memory */ 305 kref_put(&dev->kref, yurex_delete); 306 return retval; 307 } 308 309 static void yurex_disconnect(struct usb_interface *interface) 310 { 311 struct usb_yurex *dev; 312 int minor = interface->minor; 313 314 dev = usb_get_intfdata(interface); 315 usb_set_intfdata(interface, NULL); 316 317 /* give back our minor */ 318 usb_deregister_dev(interface, &yurex_class); 319 320 /* prevent more I/O from starting */ 321 usb_poison_urb(dev->urb); 322 usb_poison_urb(dev->cntl_urb); 323 mutex_lock(&dev->io_mutex); 324 dev->disconnected = 1; 325 mutex_unlock(&dev->io_mutex); 326 327 /* wakeup waiters */ 328 kill_fasync(&dev->async_queue, SIGIO, POLL_IN); 329 wake_up_interruptible(&dev->waitq); 330 331 /* decrement our usage count */ 332 kref_put(&dev->kref, yurex_delete); 333 334 dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor); 335 } 336 337 static struct usb_driver yurex_driver = { 338 .name = "yurex", 339 .probe = yurex_probe, 340 .disconnect = yurex_disconnect, 341 .id_table = yurex_table, 342 }; 343 344 345 static int yurex_fasync(int fd, struct file *file, int on) 346 { 347 struct usb_yurex *dev; 348 349 dev = file->private_data; 350 return fasync_helper(fd, file, on, &dev->async_queue); 351 } 352 353 static int yurex_open(struct inode *inode, struct file *file) 354 { 355 struct usb_yurex *dev; 356 struct usb_interface *interface; 357 int subminor; 358 int retval = 0; 359 360 subminor = iminor(inode); 361 362 interface = usb_find_interface(&yurex_driver, subminor); 363 if (!interface) { 364 printk(KERN_ERR "%s - error, can't find device for minor %d", 365 __func__, subminor); 366 retval = -ENODEV; 367 goto exit; 368 } 369 370 dev = usb_get_intfdata(interface); 371 if (!dev) { 372 retval = -ENODEV; 373 goto exit; 374 } 375 376 /* increment our usage count for the device */ 377 kref_get(&dev->kref); 378 379 /* save our object in the file's private structure */ 380 mutex_lock(&dev->io_mutex); 381 file->private_data = dev; 382 mutex_unlock(&dev->io_mutex); 383 384 exit: 385 return retval; 386 } 387 388 static int yurex_release(struct inode *inode, struct file *file) 389 { 390 struct usb_yurex *dev; 391 392 dev = file->private_data; 393 if (dev == NULL) 394 return -ENODEV; 395 396 /* decrement the count on our device */ 397 kref_put(&dev->kref, yurex_delete); 398 return 0; 399 } 400 401 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count, 402 loff_t *ppos) 403 { 404 struct usb_yurex *dev; 405 int len = 0; 406 char in_buffer[MAX_S64_STRLEN]; 407 unsigned long flags; 408 409 dev = file->private_data; 410 411 mutex_lock(&dev->io_mutex); 412 if (dev->disconnected) { /* already disconnected */ 413 mutex_unlock(&dev->io_mutex); 414 return -ENODEV; 415 } 416 417 if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN)) { 418 mutex_unlock(&dev->io_mutex); 419 return -EIO; 420 } 421 422 spin_lock_irqsave(&dev->lock, flags); 423 scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu); 424 spin_unlock_irqrestore(&dev->lock, flags); 425 mutex_unlock(&dev->io_mutex); 426 427 return simple_read_from_buffer(buffer, count, ppos, in_buffer, len); 428 } 429 430 static ssize_t yurex_write(struct file *file, const char __user *user_buffer, 431 size_t count, loff_t *ppos) 432 { 433 struct usb_yurex *dev; 434 int i, set = 0, retval = 0; 435 char buffer[16 + 1]; 436 char *data = buffer; 437 unsigned long long c, c2 = 0; 438 signed long timeout = 0; 439 DEFINE_WAIT(wait); 440 441 count = min(sizeof(buffer) - 1, count); 442 dev = file->private_data; 443 444 /* verify that we actually have some data to write */ 445 if (count == 0) 446 goto error; 447 448 mutex_lock(&dev->io_mutex); 449 if (dev->disconnected) { /* already disconnected */ 450 mutex_unlock(&dev->io_mutex); 451 retval = -ENODEV; 452 goto error; 453 } 454 455 if (copy_from_user(buffer, user_buffer, count)) { 456 mutex_unlock(&dev->io_mutex); 457 retval = -EFAULT; 458 goto error; 459 } 460 buffer[count] = 0; 461 memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE); 462 463 switch (buffer[0]) { 464 case CMD_ANIMATE: 465 case CMD_LED: 466 dev->cntl_buffer[0] = buffer[0]; 467 dev->cntl_buffer[1] = buffer[1]; 468 dev->cntl_buffer[2] = CMD_EOF; 469 break; 470 case CMD_READ: 471 case CMD_VERSION: 472 dev->cntl_buffer[0] = buffer[0]; 473 dev->cntl_buffer[1] = 0x00; 474 dev->cntl_buffer[2] = CMD_EOF; 475 break; 476 case CMD_SET: 477 data++; 478 fallthrough; 479 case '0' ... '9': 480 set = 1; 481 c = c2 = simple_strtoull(data, NULL, 0); 482 dev->cntl_buffer[0] = CMD_SET; 483 for (i = 1; i < 6; i++) { 484 dev->cntl_buffer[i] = (c>>32) & 0xff; 485 c <<= 8; 486 } 487 buffer[6] = CMD_EOF; 488 break; 489 default: 490 mutex_unlock(&dev->io_mutex); 491 return -EINVAL; 492 } 493 494 /* send the data as the control msg */ 495 prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE); 496 dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__, 497 dev->cntl_buffer[0]); 498 retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC); 499 if (retval >= 0) 500 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT); 501 finish_wait(&dev->waitq, &wait); 502 503 /* make sure URB is idle after timeout or (spurious) CMD_ACK */ 504 usb_kill_urb(dev->cntl_urb); 505 506 mutex_unlock(&dev->io_mutex); 507 508 if (retval < 0) { 509 dev_err(&dev->interface->dev, 510 "%s - failed to send bulk msg, error %d\n", 511 __func__, retval); 512 goto error; 513 } 514 if (set && timeout) 515 dev->bbu = c2; 516 return timeout ? count : -EIO; 517 518 error: 519 return retval; 520 } 521 522 static const struct file_operations yurex_fops = { 523 .owner = THIS_MODULE, 524 .read = yurex_read, 525 .write = yurex_write, 526 .open = yurex_open, 527 .release = yurex_release, 528 .fasync = yurex_fasync, 529 .llseek = default_llseek, 530 }; 531 532 module_usb_driver(yurex_driver); 533 534 MODULE_LICENSE("GPL"); 535