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