drivers/usb/misc/yurex.c

   1 /*
   2  * Driver for Meywa-Denki & KAYAC YUREX
   3  *
   4  * Copyright (C) 2010 Tomoki Sekiyama (tomoki.sekiyama@gmail.com)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/init.h>
  15 #include <linux/slab.h>
  16 #include <linux/module.h>
  17 #include <linux/kref.h>
  18 #include <linux/mutex.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/usb.h>
  21 #include <linux/hid.h>
  22
  23 #define DRIVER_AUTHOR "Tomoki Sekiyama"
  24 #define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX"
  25
  26 #define YUREX_VENDOR_ID         0x0c45
  27 #define YUREX_PRODUCT_ID        0x1010
  28
  29 #define CMD_ACK         '!'
  30 #define CMD_ANIMATE     'A'
  31 #define CMD_COUNT       'C'
  32 #define CMD_LED         'L'
  33 #define CMD_READ        'R'
  34 #define CMD_SET         'S'
  35 #define CMD_VERSION     'V'
  36 #define CMD_EOF         0x0d
  37 #define CMD_PADDING     0xff
  38
  39 #define YUREX_BUF_SIZE          8
  40 #define YUREX_WRITE_TIMEOUT     (HZ*2)
  41
  42 /* table of devices that work with this driver */
  43 static struct usb_device_id yurex_table[] = {
  44         { USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
  45         { }                                     /* Terminating entry */
  46 };
  47 MODULE_DEVICE_TABLE(usb, yurex_table);
  48
  49 #ifdef CONFIG_USB_DYNAMIC_MINORS
  50 #define YUREX_MINOR_BASE        0
  51 #else
  52 #define YUREX_MINOR_BASE        192
  53 #endif
  54
  55 /* Structure to hold all of our device specific stuff */
  56 struct usb_yurex {
  57         struct usb_device       *udev;
  58         struct usb_interface    *interface;
  59         __u8                    int_in_endpointAddr;
  60         struct urb              *urb;           /* URB for interrupt in */
  61         unsigned char           *int_buffer;    /* buffer for intterupt in */
  62         struct urb              *cntl_urb;      /* URB for control msg */
  63         struct usb_ctrlrequest  *cntl_req;      /* req for control msg */
  64         unsigned char           *cntl_buffer;   /* buffer for control msg */
  65
  66         struct kref             kref;
  67         struct mutex            io_mutex;
  68         struct fasync_struct    *async_queue;
  69         wait_queue_head_t       waitq;
  70
  71         spinlock_t              lock;
  72         __s64                   bbu;            /* BBU from device */
  73 };
  74 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
  75
  76 static struct usb_driver yurex_driver;
  77 static const struct file_operations yurex_fops;
  78
  79
  80 static void yurex_control_callback(struct urb *urb)
  81 {
  82         struct usb_yurex *dev = urb->context;
  83         int status = urb->status;
  84
  85         if (status) {
  86                 err("%s - control failed: %d\n", __func__, status);
  87                 wake_up_interruptible(&dev->waitq);
  88                 return;
  89         }
  90         /* on success, sender woken up by CMD_ACK int in, or timeout */
  91 }
  92
  93 static void yurex_delete(struct kref *kref)
  94 {
  95         struct usb_yurex *dev = to_yurex_dev(kref);
  96
  97         dbg("yurex_delete");
  98
  99         usb_put_dev(dev->udev);
 100         if (dev->cntl_urb) {
 101                 usb_kill_urb(dev->cntl_urb);
 102                 if (dev->cntl_req)
 103                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 104                                 dev->cntl_req, dev->cntl_urb->setup_dma);
 105                 if (dev->cntl_buffer)
 106                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 107                                 dev->cntl_buffer, dev->cntl_urb->transfer_dma);
 108                 usb_free_urb(dev->cntl_urb);
 109         }
 110         if (dev->urb) {
 111                 usb_kill_urb(dev->urb);
 112                 if (dev->int_buffer)
 113                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 114                                 dev->int_buffer, dev->urb->transfer_dma);
 115                 usb_free_urb(dev->urb);
 116         }
 117         kfree(dev);
 118 }
 119
 120 /*
 121  * usb class driver info in order to get a minor number from the usb core,
 122  * and to have the device registered with the driver core
 123  */
 124 static struct usb_class_driver yurex_class = {
 125         .name =         "yurex%d",
 126         .fops =         &yurex_fops,
 127         .minor_base =   YUREX_MINOR_BASE,
 128 };
 129
 130 static void yurex_interrupt(struct urb *urb)
 131 {
 132         struct usb_yurex *dev = urb->context;
 133         unsigned char *buf = dev->int_buffer;
 134         int status = urb->status;
 135         unsigned long flags;
 136         int retval, i;
 137
 138         switch (status) {
 139         case 0: /*success*/
 140                 break;
 141         case -EOVERFLOW:
 142                 err("%s - overflow with length %d, actual length is %d",
 143                     __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
 144         case -ECONNRESET:
 145         case -ENOENT:
 146         case -ESHUTDOWN:
 147         case -EILSEQ:
 148                 /* The device is terminated, clean up */
 149                 return;
 150         default:
 151                 err("%s - unknown status received: %d", __func__, status);
 152                 goto exit;
 153         }
 154
 155         /* handle received message */
 156         switch (buf[0]) {
 157         case CMD_COUNT:
 158         case CMD_READ:
 159                 if (buf[6] == CMD_EOF) {
 160                         spin_lock_irqsave(&dev->lock, flags);
 161                         dev->bbu = 0;
 162                         for (i = 1; i < 6; i++) {
 163                                 dev->bbu += buf[i];
 164                                 if (i != 5)
 165                                         dev->bbu <<= 8;
 166                         }
 167                         dbg("%s count: %lld", __func__, dev->bbu);
 168                         spin_unlock_irqrestore(&dev->lock, flags);
 169
 170                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 171                 }
 172                 else
 173                         dbg("data format error - no EOF");
 174                 break;
 175         case CMD_ACK:
 176                 dbg("%s ack: %c", __func__, buf[1]);
 177                 wake_up_interruptible(&dev->waitq);
 178                 break;
 179         }
 180
 181 exit:
 182         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 183         if (retval) {
 184                 err("%s - usb_submit_urb failed: %d",
 185                         __func__, retval);
 186         }
 187 }
 188
 189 static 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         int i;
 196         DEFINE_WAIT(wait);
 197
 198         /* allocate memory for our device state and initialize it */
 199         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 200         if (!dev) {
 201                 err("Out of memory");
 202                 goto error;
 203         }
 204         kref_init(&dev->kref);
 205         mutex_init(&dev->io_mutex);
 206         spin_lock_init(&dev->lock);
 207         init_waitqueue_head(&dev->waitq);
 208
 209         dev->udev = usb_get_dev(interface_to_usbdev(interface));
 210         dev->interface = interface;
 211
 212         /* set up the endpoint information */
 213         iface_desc = interface->cur_altsetting;
 214         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 215                 endpoint = &iface_desc->endpoint[i].desc;
 216
 217                 if (usb_endpoint_is_int_in(endpoint)) {
 218                         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 219                         break;
 220                 }
 221         }
 222         if (!dev->int_in_endpointAddr) {
 223                 retval = -ENODEV;
 224                 err("Could not find endpoints");
 225                 goto error;
 226         }
 227
 228
 229         /* allocate control URB */
 230         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 231         if (!dev->cntl_urb) {
 232                 err("Could not allocate control URB");
 233                 goto error;
 234         }
 235
 236         /* allocate buffer for control req */
 237         dev->cntl_req = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 238                                            GFP_KERNEL,
 239                                            &dev->cntl_urb->setup_dma);
 240         if (!dev->cntl_req) {
 241                 err("Could not allocate cntl_req");
 242                 goto error;
 243         }
 244
 245         /* allocate buffer for control msg */
 246         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 247                                               GFP_KERNEL,
 248                                               &dev->cntl_urb->transfer_dma);
 249         if (!dev->cntl_buffer) {
 250                 err("Could not allocate cntl_buffer");
 251                 goto error;
 252         }
 253
 254         /* configure control URB */
 255         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 256                                       USB_RECIP_INTERFACE;
 257         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 258         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 259         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 260         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 261
 262         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 263                              usb_sndctrlpipe(dev->udev, 0),
 264                              (void *)dev->cntl_req, dev->cntl_buffer,
 265                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 266         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 267
 268
 269         /* allocate interrupt URB */
 270         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 271         if (!dev->urb) {
 272                 err("Could not allocate URB");
 273                 goto error;
 274         }
 275
 276         /* allocate buffer for interrupt in */
 277         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 278                                         GFP_KERNEL, &dev->urb->transfer_dma);
 279         if (!dev->int_buffer) {
 280                 err("Could not allocate int_buffer");
 281                 goto error;
 282         }
 283
 284         /* configure interrupt URB */
 285         usb_fill_int_urb(dev->urb, dev->udev,
 286                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 287                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 288                          dev, 1);
 289         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 290         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 291                 retval = -EIO;
 292                 err("Could not submitting URB");
 293                 goto error;
 294         }
 295
 296         /* save our data pointer in this interface device */
 297         usb_set_intfdata(interface, dev);
 298
 299         /* we can register the device now, as it is ready */
 300         retval = usb_register_dev(interface, &yurex_class);
 301         if (retval) {
 302                 err("Not able to get a minor for this device.");
 303                 usb_set_intfdata(interface, NULL);
 304                 goto error;
 305         }
 306
 307         dev->bbu = -1;
 308
 309         dev_info(&interface->dev,
 310                  "USB YUREX device now attached to Yurex #%d\n",
 311                  interface->minor);
 312
 313         return 0;
 314
 315 error:
 316         if (dev)
 317                 /* this frees allocated memory */
 318                 kref_put(&dev->kref, yurex_delete);
 319         return retval;
 320 }
 321
 322 static void yurex_disconnect(struct usb_interface *interface)
 323 {
 324         struct usb_yurex *dev;
 325         int minor = interface->minor;
 326
 327         dev = usb_get_intfdata(interface);
 328         usb_set_intfdata(interface, NULL);
 329
 330         /* give back our minor */
 331         usb_deregister_dev(interface, &yurex_class);
 332
 333         /* prevent more I/O from starting */
 334         mutex_lock(&dev->io_mutex);
 335         dev->interface = NULL;
 336         mutex_unlock(&dev->io_mutex);
 337
 338         /* wakeup waiters */
 339         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 340         wake_up_interruptible(&dev->waitq);
 341
 342         /* decrement our usage count */
 343         kref_put(&dev->kref, yurex_delete);
 344
 345         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 346 }
 347
 348 static struct usb_driver yurex_driver = {
 349         .name =         "yurex",
 350         .probe =        yurex_probe,
 351         .disconnect =   yurex_disconnect,
 352         .id_table =     yurex_table,
 353 };
 354
 355
 356 static int yurex_fasync(int fd, struct file *file, int on)
 357 {
 358         struct usb_yurex *dev;
 359
 360         dev = (struct usb_yurex *)file->private_data;
 361         return fasync_helper(fd, file, on, &dev->async_queue);
 362 }
 363
 364 static int yurex_open(struct inode *inode, struct file *file)
 365 {
 366         struct usb_yurex *dev;
 367         struct usb_interface *interface;
 368         int subminor;
 369         int retval = 0;
 370
 371         subminor = iminor(inode);
 372
 373         interface = usb_find_interface(&yurex_driver, subminor);
 374         if (!interface) {
 375                 err("%s - error, can't find device for minor %d",
 376                     __func__, subminor);
 377                 retval = -ENODEV;
 378                 goto exit;
 379         }
 380
 381         dev = usb_get_intfdata(interface);
 382         if (!dev) {
 383                 retval = -ENODEV;
 384                 goto exit;
 385         }
 386
 387         /* increment our usage count for the device */
 388         kref_get(&dev->kref);
 389
 390         /* save our object in the file's private structure */
 391         mutex_lock(&dev->io_mutex);
 392         file->private_data = dev;
 393         mutex_unlock(&dev->io_mutex);
 394
 395 exit:
 396         return retval;
 397 }
 398
 399 static int yurex_release(struct inode *inode, struct file *file)
 400 {
 401         struct usb_yurex *dev;
 402
 403         dev = (struct usb_yurex *)file->private_data;
 404         if (dev == NULL)
 405                 return -ENODEV;
 406
 407         yurex_fasync(-1, file, 0);
 408
 409         /* decrement the count on our device */
 410         kref_put(&dev->kref, yurex_delete);
 411         return 0;
 412 }
 413
 414 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
 415 {
 416         struct usb_yurex *dev;
 417         int retval = 0;
 418         int bytes_read = 0;
 419         char in_buffer[20];
 420         unsigned long flags;
 421
 422         dev = (struct usb_yurex *)file->private_data;
 423
 424         mutex_lock(&dev->io_mutex);
 425         if (!dev->interface) {          /* already disconnected */
 426                 retval = -ENODEV;
 427                 goto exit;
 428         }
 429
 430         spin_lock_irqsave(&dev->lock, flags);
 431         bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 432         spin_unlock_irqrestore(&dev->lock, flags);
 433
 434         if (*ppos < bytes_read) {
 435                 if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
 436                         retval = -EFAULT;
 437                 else {
 438                         retval = bytes_read - *ppos;
 439                         *ppos += bytes_read;
 440                 }
 441         }
 442
 443 exit:
 444         mutex_unlock(&dev->io_mutex);
 445         return retval;
 446 }
 447
 448 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
 449 {
 450         struct usb_yurex *dev;
 451         int i, set = 0, retval = 0;
 452         char buffer[16];
 453         char *data = buffer;
 454         unsigned long long c, c2 = 0;
 455         signed long timeout = 0;
 456         DEFINE_WAIT(wait);
 457
 458         count = min(sizeof(buffer), count);
 459         dev = (struct usb_yurex *)file->private_data;
 460
 461         /* verify that we actually have some data to write */
 462         if (count == 0)
 463                 goto error;
 464
 465         mutex_lock(&dev->io_mutex);
 466         if (!dev->interface) {          /* alreaday disconnected */
 467                 mutex_unlock(&dev->io_mutex);
 468                 retval = -ENODEV;
 469                 goto error;
 470         }
 471
 472         if (copy_from_user(buffer, user_buffer, count)) {
 473                 mutex_unlock(&dev->io_mutex);
 474                 retval = -EFAULT;
 475                 goto error;
 476         }
 477         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 478
 479         switch (buffer[0]) {
 480         case CMD_ANIMATE:
 481         case CMD_LED:
 482                 dev->cntl_buffer[0] = buffer[0];
 483                 dev->cntl_buffer[1] = buffer[1];
 484                 dev->cntl_buffer[2] = CMD_EOF;
 485                 break;
 486         case CMD_READ:
 487         case CMD_VERSION:
 488                 dev->cntl_buffer[0] = buffer[0];
 489                 dev->cntl_buffer[1] = 0x00;
 490                 dev->cntl_buffer[2] = CMD_EOF;
 491                 break;
 492         case CMD_SET:
 493                 data++;
 494                 /* FALL THROUGH */
 495         case '0' ... '9':
 496                 set = 1;
 497                 c = c2 = simple_strtoull(data, NULL, 0);
 498                 dev->cntl_buffer[0] = CMD_SET;
 499                 for (i = 1; i < 6; i++) {
 500                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 501                         c <<= 8;
 502                 }
 503                 buffer[6] = CMD_EOF;
 504                 break;
 505         default:
 506                 mutex_unlock(&dev->io_mutex);
 507                 return -EINVAL;
 508         }
 509
 510         /* send the data as the control msg */
 511         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 512         dbg("%s - submit %c", __func__, dev->cntl_buffer[0]);
 513         retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
 514         if (retval >= 0)
 515                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 516         finish_wait(&dev->waitq, &wait);
 517
 518         mutex_unlock(&dev->io_mutex);
 519
 520         if (retval < 0) {
 521                 err("%s - failed to send bulk msg, error %d", __func__, retval);
 522                 goto error;
 523         }
 524         if (set && timeout)
 525                 dev->bbu = c2;
 526         return timeout ? count : -EIO;
 527
 528 error:
 529         return retval;
 530 }
 531
 532 static const struct file_operations yurex_fops = {
 533         .owner =        THIS_MODULE,
 534         .read =         yurex_read,
 535         .write =        yurex_write,
 536         .open =         yurex_open,
 537         .release =      yurex_release,
 538         .fasync =       yurex_fasync,
 539         .llseek =       default_llseek,
 540 };
 541
 542
 543 static int __init usb_yurex_init(void)
 544 {
 545         int result;
 546
 547         /* register this driver with the USB subsystem */
 548         result = usb_register(&yurex_driver);
 549         if (result)
 550                 err("usb_register failed. Error number %d", result);
 551
 552         return result;
 553 }
 554
 555 static void __exit usb_yurex_exit(void)
 556 {
 557         /* deregister this driver with the USB subsystem */
 558         usb_deregister(&yurex_driver);
 559 }
 560
 561 module_init(usb_yurex_init);
 562 module_exit(usb_yurex_exit);
 563
 564 MODULE_LICENSE("GPL");