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