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)
  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->urb) {
 101                 usb_kill_urb(dev->urb);
 102                 if (dev->int_buffer)
 103                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 104                                 dev->int_buffer, dev->urb->transfer_dma);
 105                 usb_free_urb(dev->urb);
 106         }
 107         kfree(dev);
 108 }
 109
 110 /*
 111  * usb class driver info in order to get a minor number from the usb core,
 112  * and to have the device registered with the driver core
 113  */
 114 static struct usb_class_driver yurex_class = {
 115         .name =         "yurex%d",
 116         .fops =         &yurex_fops,
 117         .minor_base =   YUREX_MINOR_BASE,
 118 };
 119
 120 static void yurex_interrupt(struct urb *urb)
 121 {
 122         struct usb_yurex *dev = urb->context;
 123         unsigned char *buf = dev->int_buffer;
 124         int status = urb->status;
 125         unsigned long flags;
 126         int retval, i;
 127
 128         switch (status) {
 129         case 0: /*success*/
 130                 break;
 131         case -EOVERFLOW:
 132                 err("%s - overflow with length %d, actual length is %d",
 133                     __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
 134         case -ECONNRESET:
 135         case -ENOENT:
 136         case -ESHUTDOWN:
 137         case -EILSEQ:
 138                 /* The device is terminated, clean up */
 139                 return;
 140         default:
 141                 err("%s - unknown status received: %d", __func__, status);
 142                 goto exit;
 143         }
 144
 145         /* handle received message */
 146         switch (buf[0]) {
 147         case CMD_COUNT:
 148         case CMD_READ:
 149                 if (buf[6] == CMD_EOF) {
 150                         spin_lock_irqsave(&dev->lock, flags);
 151                         dev->bbu = 0;
 152                         for (i = 1; i < 6; i++) {
 153                                 dev->bbu += buf[i];
 154                                 if (i != 5)
 155                                         dev->bbu <<= 8;
 156                         }
 157                         dbg("%s count: %lld", __func__, dev->bbu);
 158                         spin_unlock_irqrestore(&dev->lock, flags);
 159
 160                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 161                 }
 162                 else
 163                         dbg("data format error - no EOF");
 164                 break;
 165         case CMD_ACK:
 166                 dbg("%s ack: %c", __func__, buf[1]);
 167                 wake_up_interruptible(&dev->waitq);
 168                 break;
 169         }
 170
 171 exit:
 172         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 173         if (retval) {
 174                 err("%s - usb_submit_urb failed: %d",
 175                         __func__, retval);
 176         }
 177 }
 178
 179 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 180 {
 181         struct usb_yurex *dev;
 182         struct usb_host_interface *iface_desc;
 183         struct usb_endpoint_descriptor *endpoint;
 184         int retval = -ENOMEM;
 185         int i;
 186         DEFINE_WAIT(wait);
 187
 188         /* allocate memory for our device state and initialize it */
 189         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 190         if (!dev) {
 191                 err("Out of memory");
 192                 goto error;
 193         }
 194         kref_init(&dev->kref);
 195         mutex_init(&dev->io_mutex);
 196         spin_lock_init(&dev->lock);
 197         init_waitqueue_head(&dev->waitq);
 198
 199         dev->udev = usb_get_dev(interface_to_usbdev(interface));
 200         dev->interface = interface;
 201
 202         /* set up the endpoint information */
 203         iface_desc = interface->cur_altsetting;
 204         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 205                 endpoint = &iface_desc->endpoint[i].desc;
 206
 207                 if (usb_endpoint_is_int_in(endpoint)) {
 208                         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 209                         break;
 210                 }
 211         }
 212         if (!dev->int_in_endpointAddr) {
 213                 retval = -ENODEV;
 214                 err("Could not find endpoints");
 215                 goto error;
 216         }
 217
 218
 219         /* allocate control URB */
 220         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 221         if (!dev->cntl_urb) {
 222                 err("Could not allocate control URB");
 223                 goto error;
 224         }
 225
 226         /* allocate buffer for control req */
 227         dev->cntl_req = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 228                                            GFP_KERNEL,
 229                                            &dev->cntl_urb->setup_dma);
 230         if (!dev->cntl_req) {
 231                 err("Could not allocate cntl_req");
 232                 goto error;
 233         }
 234
 235         /* allocate buffer for control msg */
 236         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 237                                               GFP_KERNEL,
 238                                               &dev->cntl_urb->transfer_dma);
 239         if (!dev->cntl_buffer) {
 240                 err("Could not allocate cntl_buffer");
 241                 goto error;
 242         }
 243
 244         /* configure control URB */
 245         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 246                                       USB_RECIP_INTERFACE;
 247         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 248         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 249         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 250         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 251
 252         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 253                              usb_sndctrlpipe(dev->udev, 0),
 254                              (void *)dev->cntl_req, dev->cntl_buffer,
 255                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 256         dev->cntl_urb->transfer_flags   |= URB_NO_TRANSFER_DMA_MAP;
 257
 258
 259         /* allocate interrupt URB */
 260         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 261         if (!dev->urb) {
 262                 err("Could not allocate URB");
 263                 goto error;
 264         }
 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                 err("Could not allocate int_buffer");
 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         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 280                 retval = -EIO;
 281                 err("Could not submitting URB");
 282                 goto error;
 283         }
 284
 285         /* save our data pointer in this interface device */
 286         usb_set_intfdata(interface, dev);
 287
 288         /* we can register the device now, as it is ready */
 289         retval = usb_register_dev(interface, &yurex_class);
 290         if (retval) {
 291                 err("Not able to get a minor for this device.");
 292                 usb_set_intfdata(interface, NULL);
 293                 goto error;
 294         }
 295
 296         dev->bbu = -1;
 297
 298         dev_info(&interface->dev,
 299                  "USB Yurex device now attached to Yurex-%d¥n",
 300                  interface->minor);
 301
 302         return 0;
 303
 304 error:
 305         if (dev)
 306                 /* this frees allocated memory */
 307                 kref_put(&dev->kref, yurex_delete);
 308         return retval;
 309 }
 310
 311 static void yurex_disconnect(struct usb_interface *interface)
 312 {
 313         struct usb_yurex *dev;
 314         int minor = interface->minor;
 315
 316         dev = usb_get_intfdata(interface);
 317         usb_set_intfdata(interface, NULL);
 318
 319         /* give back our minor */
 320         usb_deregister_dev(interface, &yurex_class);
 321
 322         /* prevent more I/O from starting */
 323         mutex_lock(&dev->io_mutex);
 324         dev->interface = NULL;
 325         mutex_unlock(&dev->io_mutex);
 326
 327         /* wakeup waiters */
 328         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 329         wake_up_interruptible(&dev->waitq);
 330
 331         /* decrement our usage count */
 332         kref_put(&dev->kref, yurex_delete);
 333
 334         dev_info(&interface->dev, "USB Yurex #%d now disconnected", minor);
 335 }
 336
 337 static struct usb_driver yurex_driver = {
 338         .name =         "yurex",
 339         .probe =        yurex_probe,
 340         .disconnect =   yurex_disconnect,
 341         .id_table =     yurex_table,
 342 };
 343
 344
 345 static int yurex_fasync(int fd, struct file *file, int on)
 346 {
 347         struct usb_yurex *dev;
 348
 349         dev = (struct usb_yurex *)file->private_data;
 350         return fasync_helper(fd, file, on, &dev->async_queue);
 351 }
 352
 353 static int yurex_open(struct inode *inode, struct file *file)
 354 {
 355         struct usb_yurex *dev;
 356         struct usb_interface *interface;
 357         int subminor;
 358         int retval = 0;
 359
 360         subminor = iminor(inode);
 361
 362         interface = usb_find_interface(&yurex_driver, subminor);
 363         if (!interface) {
 364                 err("%s - error, can't find device for minor %d",
 365                     __func__, subminor);
 366                 retval = -ENODEV;
 367                 goto exit;
 368         }
 369
 370         dev = usb_get_intfdata(interface);
 371         if (!dev) {
 372                 retval = -ENODEV;
 373                 goto exit;
 374         }
 375
 376         /* increment our usage count for the device */
 377         kref_get(&dev->kref);
 378
 379         /* save our object in the file's private structure */
 380         mutex_lock(&dev->io_mutex);
 381         file->private_data = dev;
 382         mutex_unlock(&dev->io_mutex);
 383
 384 exit:
 385         return retval;
 386 }
 387
 388 static int yurex_release(struct inode *inode, struct file *file)
 389 {
 390         struct usb_yurex *dev;
 391
 392         dev = (struct usb_yurex *)file->private_data;
 393         if (dev == NULL)
 394                 return -ENODEV;
 395
 396         yurex_fasync(-1, file, 0);
 397
 398         /* decrement the count on our device */
 399         kref_put(&dev->kref, yurex_delete);
 400         return 0;
 401 }
 402
 403 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
 404 {
 405         struct usb_yurex *dev;
 406         int retval = 0;
 407         int bytes_read = 0;
 408         char in_buffer[20];
 409         unsigned long flags;
 410
 411         dev = (struct usb_yurex *)file->private_data;
 412
 413         mutex_lock(&dev->io_mutex);
 414         if (!dev->interface) {          /* already disconnected */
 415                 retval = -ENODEV;
 416                 goto exit;
 417         }
 418
 419         spin_lock_irqsave(&dev->lock, flags);
 420         bytes_read = snprintf(in_buffer, 20, "%lld¥n", dev->bbu);
 421         spin_unlock_irqrestore(&dev->lock, flags);
 422
 423         if (*ppos < bytes_read) {
 424                 if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
 425                         retval = -EFAULT;
 426                 else {
 427                         retval = bytes_read - *ppos;
 428                         *ppos += bytes_read;
 429                 }
 430         }
 431
 432 exit:
 433         mutex_unlock(&dev->io_mutex);
 434         return retval;
 435 }
 436
 437 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
 438 {
 439         struct usb_yurex *dev;
 440         int i, set = 0, retval = 0;
 441         char buffer[16];
 442         char *data = buffer;
 443         unsigned long long c, c2 = 0;
 444         signed long timeout = 0;
 445         DEFINE_WAIT(wait);
 446
 447         count = min(sizeof(buffer), count);
 448         dev = (struct usb_yurex *)file->private_data;
 449
 450         /* verify that we actually have some data to write */
 451         if (count == 0)
 452                 goto error;
 453
 454         mutex_lock(&dev->io_mutex);
 455         if (!dev->interface) {          /* alreaday disconnected */
 456                 mutex_unlock(&dev->io_mutex);
 457                 retval = -ENODEV;
 458                 goto error;
 459         }
 460
 461         if (copy_from_user(buffer, user_buffer, count)) {
 462                 mutex_unlock(&dev->io_mutex);
 463                 retval = -EFAULT;
 464                 goto error;
 465         }
 466         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 467
 468         switch (buffer[0]) {
 469         case CMD_ANIMATE:
 470         case CMD_LED:
 471                 dev->cntl_buffer[0] = buffer[0];
 472                 dev->cntl_buffer[1] = buffer[1];
 473                 dev->cntl_buffer[2] = CMD_EOF;
 474                 break;
 475         case CMD_READ:
 476         case CMD_VERSION:
 477                 dev->cntl_buffer[0] = buffer[0];
 478                 dev->cntl_buffer[1] = 0x00;
 479                 dev->cntl_buffer[2] = CMD_EOF;
 480                 break;
 481         case CMD_SET:
 482                 data++;
 483                 /* FALL THROUGH */
 484         case '0' ... '9':
 485                 set = 1;
 486                 c = c2 = simple_strtoull(data, NULL, 0);
 487                 dev->cntl_buffer[0] = CMD_SET;
 488                 for (i = 1; i < 6; i++) {
 489                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 490                         c <<= 8;
 491                 }
 492                 buffer[6] = CMD_EOF;
 493                 break;
 494         default:
 495                 mutex_unlock(&dev->io_mutex);
 496                 return -EINVAL;
 497         }
 498
 499         /* send the data as the control msg */
 500         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 501         dbg("%s - submit %c", __func__, dev->cntl_buffer[0]);
 502         retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
 503         if (retval >= 0)
 504                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 505         finish_wait(&dev->waitq, &wait);
 506
 507         mutex_unlock(&dev->io_mutex);
 508
 509         if (retval < 0) {
 510                 err("%s - failed to send bulk msg, error %d", __func__, retval);
 511                 goto error;
 512         }
 513         if (set && timeout)
 514                 dev->bbu = c2;
 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 };
 529
 530
 531 static int __init usb_yurex_init(void)
 532 {
 533         int result;
 534
 535         /* register this driver with the USB subsystem */
 536         result = usb_register(&yurex_driver);
 537         if (result)
 538                 err("usb_register failed. Error number %d", result);
 539
 540         return result;
 541 }
 542
 543 static void __exit usb_yurex_exit(void)
 544 {
 545         /* deregister this driver with the USB subsystem */
 546         usb_deregister(&yurex_driver);
 547 }
 548
 549 module_init(usb_yurex_init);
 550 module_exit(usb_yurex_exit);
 551
 552 MODULE_LICENSE("GPL");