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