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                 kfree(dev->cntl_req);
 103                 if (dev->cntl_buffer)
 104                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 105                                 dev->cntl_buffer, dev->cntl_urb->transfer_dma);
 106                 usb_free_urb(dev->cntl_urb);
 107         }
 108         if (dev->urb) {
 109                 usb_kill_urb(dev->urb);
 110                 if (dev->int_buffer)
 111                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 112                                 dev->int_buffer, dev->urb->transfer_dma);
 113                 usb_free_urb(dev->urb);
 114         }
 115         kfree(dev);
 116 }
 117
 118 /*
 119  * usb class driver info in order to get a minor number from the usb core,
 120  * and to have the device registered with the driver core
 121  */
 122 static struct usb_class_driver yurex_class = {
 123         .name =         "yurex%d",
 124         .fops =         &yurex_fops,
 125         .minor_base =   YUREX_MINOR_BASE,
 126 };
 127
 128 static void yurex_interrupt(struct urb *urb)
 129 {
 130         struct usb_yurex *dev = urb->context;
 131         unsigned char *buf = dev->int_buffer;
 132         int status = urb->status;
 133         unsigned long flags;
 134         int retval, i;
 135
 136         switch (status) {
 137         case 0: /*success*/
 138                 break;
 139         case -EOVERFLOW:
 140                 err("%s - overflow with length %d, actual length is %d",
 141                     __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
 142         case -ECONNRESET:
 143         case -ENOENT:
 144         case -ESHUTDOWN:
 145         case -EILSEQ:
 146                 /* The device is terminated, clean up */
 147                 return;
 148         default:
 149                 err("%s - unknown status received: %d", __func__, status);
 150                 goto exit;
 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                         dbg("%s count: %lld", __func__, dev->bbu);
 166                         spin_unlock_irqrestore(&dev->lock, flags);
 167
 168                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 169                 }
 170                 else
 171                         dbg("data format error - no EOF");
 172                 break;
 173         case CMD_ACK:
 174                 dbg("%s ack: %c", __func__, buf[1]);
 175                 wake_up_interruptible(&dev->waitq);
 176                 break;
 177         }
 178
 179 exit:
 180         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 181         if (retval) {
 182                 err("%s - usb_submit_urb failed: %d",
 183                         __func__, retval);
 184         }
 185 }
 186
 187 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 188 {
 189         struct usb_yurex *dev;
 190         struct usb_host_interface *iface_desc;
 191         struct usb_endpoint_descriptor *endpoint;
 192         int retval = -ENOMEM;
 193         int i;
 194         DEFINE_WAIT(wait);
 195
 196         /* allocate memory for our device state and initialize it */
 197         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 198         if (!dev) {
 199                 err("Out of memory");
 200                 goto error;
 201         }
 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 = interface;
 209
 210         /* set up the endpoint information */
 211         iface_desc = interface->cur_altsetting;
 212         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 213                 endpoint = &iface_desc->endpoint[i].desc;
 214
 215                 if (usb_endpoint_is_int_in(endpoint)) {
 216                         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 217                         break;
 218                 }
 219         }
 220         if (!dev->int_in_endpointAddr) {
 221                 retval = -ENODEV;
 222                 err("Could not find endpoints");
 223                 goto error;
 224         }
 225
 226
 227         /* allocate control URB */
 228         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 229         if (!dev->cntl_urb) {
 230                 err("Could not allocate control URB");
 231                 goto error;
 232         }
 233
 234         /* allocate buffer for control req */
 235         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 236         if (!dev->cntl_req) {
 237                 err("Could not allocate cntl_req");
 238                 goto error;
 239         }
 240
 241         /* allocate buffer for control msg */
 242         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 243                                               GFP_KERNEL,
 244                                               &dev->cntl_urb->transfer_dma);
 245         if (!dev->cntl_buffer) {
 246                 err("Could not allocate cntl_buffer");
 247                 goto error;
 248         }
 249
 250         /* configure control URB */
 251         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 252                                       USB_RECIP_INTERFACE;
 253         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 254         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 255         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 256         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 257
 258         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 259                              usb_sndctrlpipe(dev->udev, 0),
 260                              (void *)dev->cntl_req, dev->cntl_buffer,
 261                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 262         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 263
 264
 265         /* allocate interrupt URB */
 266         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 267         if (!dev->urb) {
 268                 err("Could not allocate URB");
 269                 goto error;
 270         }
 271
 272         /* allocate buffer for interrupt in */
 273         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 274                                         GFP_KERNEL, &dev->urb->transfer_dma);
 275         if (!dev->int_buffer) {
 276                 err("Could not allocate int_buffer");
 277                 goto error;
 278         }
 279
 280         /* configure interrupt URB */
 281         usb_fill_int_urb(dev->urb, dev->udev,
 282                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 283                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 284                          dev, 1);
 285         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 286         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 287                 retval = -EIO;
 288                 err("Could not submitting URB");
 289                 goto error;
 290         }
 291
 292         /* save our data pointer in this interface device */
 293         usb_set_intfdata(interface, dev);
 294
 295         /* we can register the device now, as it is ready */
 296         retval = usb_register_dev(interface, &yurex_class);
 297         if (retval) {
 298                 err("Not able to get a minor for this device.");
 299                 usb_set_intfdata(interface, NULL);
 300                 goto error;
 301         }
 302
 303         dev->bbu = -1;
 304
 305         dev_info(&interface->dev,
 306                  "USB YUREX device now attached to Yurex #%d\n",
 307                  interface->minor);
 308
 309         return 0;
 310
 311 error:
 312         if (dev)
 313                 /* this frees allocated memory */
 314                 kref_put(&dev->kref, yurex_delete);
 315         return retval;
 316 }
 317
 318 static void yurex_disconnect(struct usb_interface *interface)
 319 {
 320         struct usb_yurex *dev;
 321         int minor = interface->minor;
 322
 323         dev = usb_get_intfdata(interface);
 324         usb_set_intfdata(interface, NULL);
 325
 326         /* give back our minor */
 327         usb_deregister_dev(interface, &yurex_class);
 328
 329         /* prevent more I/O from starting */
 330         mutex_lock(&dev->io_mutex);
 331         dev->interface = NULL;
 332         mutex_unlock(&dev->io_mutex);
 333
 334         /* wakeup waiters */
 335         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 336         wake_up_interruptible(&dev->waitq);
 337
 338         /* decrement our usage count */
 339         kref_put(&dev->kref, yurex_delete);
 340
 341         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 342 }
 343
 344 static struct usb_driver yurex_driver = {
 345         .name =         "yurex",
 346         .probe =        yurex_probe,
 347         .disconnect =   yurex_disconnect,
 348         .id_table =     yurex_table,
 349 };
 350
 351
 352 static int yurex_fasync(int fd, struct file *file, int on)
 353 {
 354         struct usb_yurex *dev;
 355
 356         dev = (struct usb_yurex *)file->private_data;
 357         return fasync_helper(fd, file, on, &dev->async_queue);
 358 }
 359
 360 static int yurex_open(struct inode *inode, struct file *file)
 361 {
 362         struct usb_yurex *dev;
 363         struct usb_interface *interface;
 364         int subminor;
 365         int retval = 0;
 366
 367         subminor = iminor(inode);
 368
 369         interface = usb_find_interface(&yurex_driver, subminor);
 370         if (!interface) {
 371                 err("%s - error, can't find device for minor %d",
 372                     __func__, subminor);
 373                 retval = -ENODEV;
 374                 goto exit;
 375         }
 376
 377         dev = usb_get_intfdata(interface);
 378         if (!dev) {
 379                 retval = -ENODEV;
 380                 goto exit;
 381         }
 382
 383         /* increment our usage count for the device */
 384         kref_get(&dev->kref);
 385
 386         /* save our object in the file's private structure */
 387         mutex_lock(&dev->io_mutex);
 388         file->private_data = dev;
 389         mutex_unlock(&dev->io_mutex);
 390
 391 exit:
 392         return retval;
 393 }
 394
 395 static int yurex_release(struct inode *inode, struct file *file)
 396 {
 397         struct usb_yurex *dev;
 398
 399         dev = (struct usb_yurex *)file->private_data;
 400         if (dev == NULL)
 401                 return -ENODEV;
 402
 403         yurex_fasync(-1, file, 0);
 404
 405         /* decrement the count on our device */
 406         kref_put(&dev->kref, yurex_delete);
 407         return 0;
 408 }
 409
 410 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
 411 {
 412         struct usb_yurex *dev;
 413         int retval = 0;
 414         int bytes_read = 0;
 415         char in_buffer[20];
 416         unsigned long flags;
 417
 418         dev = (struct usb_yurex *)file->private_data;
 419
 420         mutex_lock(&dev->io_mutex);
 421         if (!dev->interface) {          /* already disconnected */
 422                 retval = -ENODEV;
 423                 goto exit;
 424         }
 425
 426         spin_lock_irqsave(&dev->lock, flags);
 427         bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 428         spin_unlock_irqrestore(&dev->lock, flags);
 429
 430         if (*ppos < bytes_read) {
 431                 if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
 432                         retval = -EFAULT;
 433                 else {
 434                         retval = bytes_read - *ppos;
 435                         *ppos += bytes_read;
 436                 }
 437         }
 438
 439 exit:
 440         mutex_unlock(&dev->io_mutex);
 441         return retval;
 442 }
 443
 444 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
 445 {
 446         struct usb_yurex *dev;
 447         int i, set = 0, retval = 0;
 448         char buffer[16];
 449         char *data = buffer;
 450         unsigned long long c, c2 = 0;
 451         signed long timeout = 0;
 452         DEFINE_WAIT(wait);
 453
 454         count = min(sizeof(buffer), count);
 455         dev = (struct usb_yurex *)file->private_data;
 456
 457         /* verify that we actually have some data to write */
 458         if (count == 0)
 459                 goto error;
 460
 461         mutex_lock(&dev->io_mutex);
 462         if (!dev->interface) {          /* alreaday disconnected */
 463                 mutex_unlock(&dev->io_mutex);
 464                 retval = -ENODEV;
 465                 goto error;
 466         }
 467
 468         if (copy_from_user(buffer, user_buffer, count)) {
 469                 mutex_unlock(&dev->io_mutex);
 470                 retval = -EFAULT;
 471                 goto error;
 472         }
 473         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 474
 475         switch (buffer[0]) {
 476         case CMD_ANIMATE:
 477         case CMD_LED:
 478                 dev->cntl_buffer[0] = buffer[0];
 479                 dev->cntl_buffer[1] = buffer[1];
 480                 dev->cntl_buffer[2] = CMD_EOF;
 481                 break;
 482         case CMD_READ:
 483         case CMD_VERSION:
 484                 dev->cntl_buffer[0] = buffer[0];
 485                 dev->cntl_buffer[1] = 0x00;
 486                 dev->cntl_buffer[2] = CMD_EOF;
 487                 break;
 488         case CMD_SET:
 489                 data++;
 490                 /* FALL THROUGH */
 491         case '0' ... '9':
 492                 set = 1;
 493                 c = c2 = simple_strtoull(data, NULL, 0);
 494                 dev->cntl_buffer[0] = CMD_SET;
 495                 for (i = 1; i < 6; i++) {
 496                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 497                         c <<= 8;
 498                 }
 499                 buffer[6] = CMD_EOF;
 500                 break;
 501         default:
 502                 mutex_unlock(&dev->io_mutex);
 503                 return -EINVAL;
 504         }
 505
 506         /* send the data as the control msg */
 507         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 508         dbg("%s - submit %c", __func__, dev->cntl_buffer[0]);
 509         retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
 510         if (retval >= 0)
 511                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 512         finish_wait(&dev->waitq, &wait);
 513
 514         mutex_unlock(&dev->io_mutex);
 515
 516         if (retval < 0) {
 517                 err("%s - failed to send bulk msg, error %d", __func__, retval);
 518                 goto error;
 519         }
 520         if (set && timeout)
 521                 dev->bbu = c2;
 522         return timeout ? count : -EIO;
 523
 524 error:
 525         return retval;
 526 }
 527
 528 static const struct file_operations yurex_fops = {
 529         .owner =        THIS_MODULE,
 530         .read =         yurex_read,
 531         .write =        yurex_write,
 532         .open =         yurex_open,
 533         .release =      yurex_release,
 534         .fasync =       yurex_fasync,
 535         .llseek =       default_llseek,
 536 };
 537
 538
 539 static int __init usb_yurex_init(void)
 540 {
 541         int result;
 542
 543         /* register this driver with the USB subsystem */
 544         result = usb_register(&yurex_driver);
 545         if (result)
 546                 err("usb_register failed. Error number %d", result);
 547
 548         return result;
 549 }
 550
 551 static void __exit usb_yurex_exit(void)
 552 {
 553         /* deregister this driver with the USB subsystem */
 554         usb_deregister(&yurex_driver);
 555 }
 556
 557 module_init(usb_yurex_init);
 558 module_exit(usb_yurex_exit);
 559
 560 MODULE_LICENSE("GPL");