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                 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         usb_put_dev(dev->udev);
 101         if (dev->cntl_urb) {
 102                 usb_kill_urb(dev->cntl_urb);
 103                 kfree(dev->cntl_req);
 104                 if (dev->cntl_buffer)
 105                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 106                                 dev->cntl_buffer, dev->cntl_urb->transfer_dma);
 107                 usb_free_urb(dev->cntl_urb);
 108         }
 109         if (dev->urb) {
 110                 usb_kill_urb(dev->urb);
 111                 if (dev->int_buffer)
 112                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 113                                 dev->int_buffer, dev->urb->transfer_dma);
 114                 usb_free_urb(dev->urb);
 115         }
 116         kfree(dev);
 117 }
 118
 119 /*
 120  * usb class driver info in order to get a minor number from the usb core,
 121  * and to have the device registered with the driver core
 122  */
 123 static struct usb_class_driver yurex_class = {
 124         .name =         "yurex%d",
 125         .fops =         &yurex_fops,
 126         .minor_base =   YUREX_MINOR_BASE,
 127 };
 128
 129 static void yurex_interrupt(struct urb *urb)
 130 {
 131         struct usb_yurex *dev = urb->context;
 132         unsigned char *buf = dev->int_buffer;
 133         int status = urb->status;
 134         unsigned long flags;
 135         int retval, i;
 136
 137         switch (status) {
 138         case 0: /*success*/
 139                 break;
 140         case -EOVERFLOW:
 141                 dev_err(&dev->interface->dev,
 142                         "%s - overflow with length %d, actual length is %d\n",
 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                 dev_err(&dev->interface->dev,
 152                         "%s - unknown status received: %d\n", __func__, status);
 153                 goto exit;
 154         }
 155
 156         /* handle received message */
 157         switch (buf[0]) {
 158         case CMD_COUNT:
 159         case CMD_READ:
 160                 if (buf[6] == CMD_EOF) {
 161                         spin_lock_irqsave(&dev->lock, flags);
 162                         dev->bbu = 0;
 163                         for (i = 1; i < 6; i++) {
 164                                 dev->bbu += buf[i];
 165                                 if (i != 5)
 166                                         dev->bbu <<= 8;
 167                         }
 168                         dev_dbg(&dev->interface->dev, "%s count: %lld\n",
 169                                 __func__, dev->bbu);
 170                         spin_unlock_irqrestore(&dev->lock, flags);
 171
 172                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 173                 }
 174                 else
 175                         dev_dbg(&dev->interface->dev,
 176                                 "data format error - no EOF\n");
 177                 break;
 178         case CMD_ACK:
 179                 dev_dbg(&dev->interface->dev, "%s ack: %c\n",
 180                         __func__, buf[1]);
 181                 wake_up_interruptible(&dev->waitq);
 182                 break;
 183         }
 184
 185 exit:
 186         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 187         if (retval) {
 188                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
 189                         __func__, retval);
 190         }
 191 }
 192
 193 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 194 {
 195         struct usb_yurex *dev;
 196         struct usb_host_interface *iface_desc;
 197         struct usb_endpoint_descriptor *endpoint;
 198         int retval = -ENOMEM;
 199         int i;
 200         DEFINE_WAIT(wait);
 201
 202         /* allocate memory for our device state and initialize it */
 203         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 204         if (!dev) {
 205                 dev_err(&interface->dev, "Out of memory\n");
 206                 goto error;
 207         }
 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 = interface;
 215
 216         /* set up the endpoint information */
 217         iface_desc = interface->cur_altsetting;
 218         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 219                 endpoint = &iface_desc->endpoint[i].desc;
 220
 221                 if (usb_endpoint_is_int_in(endpoint)) {
 222                         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 223                         break;
 224                 }
 225         }
 226         if (!dev->int_in_endpointAddr) {
 227                 retval = -ENODEV;
 228                 dev_err(&interface->dev, "Could not find endpoints\n");
 229                 goto error;
 230         }
 231
 232
 233         /* allocate control URB */
 234         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 235         if (!dev->cntl_urb) {
 236                 dev_err(&interface->dev, "Could not allocate control URB\n");
 237                 goto error;
 238         }
 239
 240         /* allocate buffer for control req */
 241         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 242         if (!dev->cntl_req) {
 243                 dev_err(&interface->dev, "Could not allocate cntl_req\n");
 244                 goto error;
 245         }
 246
 247         /* allocate buffer for control msg */
 248         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 249                                               GFP_KERNEL,
 250                                               &dev->cntl_urb->transfer_dma);
 251         if (!dev->cntl_buffer) {
 252                 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
 253                 goto error;
 254         }
 255
 256         /* configure control URB */
 257         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 258                                       USB_RECIP_INTERFACE;
 259         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 260         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 261         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 262         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 263
 264         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 265                              usb_sndctrlpipe(dev->udev, 0),
 266                              (void *)dev->cntl_req, dev->cntl_buffer,
 267                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 268         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 269
 270
 271         /* allocate interrupt URB */
 272         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 273         if (!dev->urb) {
 274                 dev_err(&interface->dev, "Could not allocate URB\n");
 275                 goto error;
 276         }
 277
 278         /* allocate buffer for interrupt in */
 279         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 280                                         GFP_KERNEL, &dev->urb->transfer_dma);
 281         if (!dev->int_buffer) {
 282                 dev_err(&interface->dev, "Could not allocate int_buffer\n");
 283                 goto error;
 284         }
 285
 286         /* configure interrupt URB */
 287         usb_fill_int_urb(dev->urb, dev->udev,
 288                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 289                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 290                          dev, 1);
 291         dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 292         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 293                 retval = -EIO;
 294                 dev_err(&interface->dev, "Could not submitting URB\n");
 295                 goto error;
 296         }
 297
 298         /* save our data pointer in this interface device */
 299         usb_set_intfdata(interface, dev);
 300
 301         /* we can register the device now, as it is ready */
 302         retval = usb_register_dev(interface, &yurex_class);
 303         if (retval) {
 304                 dev_err(&interface->dev,
 305                         "Not able to get a minor for this device.\n");
 306                 usb_set_intfdata(interface, NULL);
 307                 goto error;
 308         }
 309
 310         dev->bbu = -1;
 311
 312         dev_info(&interface->dev,
 313                  "USB YUREX device now attached to Yurex #%d\n",
 314                  interface->minor);
 315
 316         return 0;
 317
 318 error:
 319         if (dev)
 320                 /* this frees allocated memory */
 321                 kref_put(&dev->kref, yurex_delete);
 322         return retval;
 323 }
 324
 325 static void yurex_disconnect(struct usb_interface *interface)
 326 {
 327         struct usb_yurex *dev;
 328         int minor = interface->minor;
 329
 330         dev = usb_get_intfdata(interface);
 331         usb_set_intfdata(interface, NULL);
 332
 333         /* give back our minor */
 334         usb_deregister_dev(interface, &yurex_class);
 335
 336         /* prevent more I/O from starting */
 337         mutex_lock(&dev->io_mutex);
 338         dev->interface = NULL;
 339         mutex_unlock(&dev->io_mutex);
 340
 341         /* wakeup waiters */
 342         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 343         wake_up_interruptible(&dev->waitq);
 344
 345         /* decrement our usage count */
 346         kref_put(&dev->kref, yurex_delete);
 347
 348         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 349 }
 350
 351 static struct usb_driver yurex_driver = {
 352         .name =         "yurex",
 353         .probe =        yurex_probe,
 354         .disconnect =   yurex_disconnect,
 355         .id_table =     yurex_table,
 356 };
 357
 358
 359 static int yurex_fasync(int fd, struct file *file, int on)
 360 {
 361         struct usb_yurex *dev;
 362
 363         dev = (struct usb_yurex *)file->private_data;
 364         return fasync_helper(fd, file, on, &dev->async_queue);
 365 }
 366
 367 static int yurex_open(struct inode *inode, struct file *file)
 368 {
 369         struct usb_yurex *dev;
 370         struct usb_interface *interface;
 371         int subminor;
 372         int retval = 0;
 373
 374         subminor = iminor(inode);
 375
 376         interface = usb_find_interface(&yurex_driver, subminor);
 377         if (!interface) {
 378                 printk(KERN_ERR "%s - error, can't find device for minor %d",
 379                        __func__, subminor);
 380                 retval = -ENODEV;
 381                 goto exit;
 382         }
 383
 384         dev = usb_get_intfdata(interface);
 385         if (!dev) {
 386                 retval = -ENODEV;
 387                 goto exit;
 388         }
 389
 390         /* increment our usage count for the device */
 391         kref_get(&dev->kref);
 392
 393         /* save our object in the file's private structure */
 394         mutex_lock(&dev->io_mutex);
 395         file->private_data = dev;
 396         mutex_unlock(&dev->io_mutex);
 397
 398 exit:
 399         return retval;
 400 }
 401
 402 static int yurex_release(struct inode *inode, struct file *file)
 403 {
 404         struct usb_yurex *dev;
 405
 406         dev = (struct usb_yurex *)file->private_data;
 407         if (dev == NULL)
 408                 return -ENODEV;
 409
 410         yurex_fasync(-1, file, 0);
 411
 412         /* decrement the count on our device */
 413         kref_put(&dev->kref, yurex_delete);
 414         return 0;
 415 }
 416
 417 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
 418 {
 419         struct usb_yurex *dev;
 420         int retval = 0;
 421         int bytes_read = 0;
 422         char in_buffer[20];
 423         unsigned long flags;
 424
 425         dev = (struct usb_yurex *)file->private_data;
 426
 427         mutex_lock(&dev->io_mutex);
 428         if (!dev->interface) {          /* already disconnected */
 429                 retval = -ENODEV;
 430                 goto exit;
 431         }
 432
 433         spin_lock_irqsave(&dev->lock, flags);
 434         bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 435         spin_unlock_irqrestore(&dev->lock, flags);
 436
 437         if (*ppos < bytes_read) {
 438                 if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
 439                         retval = -EFAULT;
 440                 else {
 441                         retval = bytes_read - *ppos;
 442                         *ppos += bytes_read;
 443                 }
 444         }
 445
 446 exit:
 447         mutex_unlock(&dev->io_mutex);
 448         return retval;
 449 }
 450
 451 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
 452 {
 453         struct usb_yurex *dev;
 454         int i, set = 0, retval = 0;
 455         char buffer[16];
 456         char *data = buffer;
 457         unsigned long long c, c2 = 0;
 458         signed long timeout = 0;
 459         DEFINE_WAIT(wait);
 460
 461         count = min(sizeof(buffer), count);
 462         dev = (struct usb_yurex *)file->private_data;
 463
 464         /* verify that we actually have some data to write */
 465         if (count == 0)
 466                 goto error;
 467
 468         mutex_lock(&dev->io_mutex);
 469         if (!dev->interface) {          /* alreaday disconnected */
 470                 mutex_unlock(&dev->io_mutex);
 471                 retval = -ENODEV;
 472                 goto error;
 473         }
 474
 475         if (copy_from_user(buffer, user_buffer, count)) {
 476                 mutex_unlock(&dev->io_mutex);
 477                 retval = -EFAULT;
 478                 goto error;
 479         }
 480         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 481
 482         switch (buffer[0]) {
 483         case CMD_ANIMATE:
 484         case CMD_LED:
 485                 dev->cntl_buffer[0] = buffer[0];
 486                 dev->cntl_buffer[1] = buffer[1];
 487                 dev->cntl_buffer[2] = CMD_EOF;
 488                 break;
 489         case CMD_READ:
 490         case CMD_VERSION:
 491                 dev->cntl_buffer[0] = buffer[0];
 492                 dev->cntl_buffer[1] = 0x00;
 493                 dev->cntl_buffer[2] = CMD_EOF;
 494                 break;
 495         case CMD_SET:
 496                 data++;
 497                 /* FALL THROUGH */
 498         case '0' ... '9':
 499                 set = 1;
 500                 c = c2 = simple_strtoull(data, NULL, 0);
 501                 dev->cntl_buffer[0] = CMD_SET;
 502                 for (i = 1; i < 6; i++) {
 503                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 504                         c <<= 8;
 505                 }
 506                 buffer[6] = CMD_EOF;
 507                 break;
 508         default:
 509                 mutex_unlock(&dev->io_mutex);
 510                 return -EINVAL;
 511         }
 512
 513         /* send the data as the control msg */
 514         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 515         dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
 516                 dev->cntl_buffer[0]);
 517         retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
 518         if (retval >= 0)
 519                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 520         finish_wait(&dev->waitq, &wait);
 521
 522         mutex_unlock(&dev->io_mutex);
 523
 524         if (retval < 0) {
 525                 dev_err(&dev->interface->dev,
 526                         "%s - failed to send bulk msg, error %d\n",
 527                         __func__, retval);
 528                 goto error;
 529         }
 530         if (set && timeout)
 531                 dev->bbu = c2;
 532         return timeout ? count : -EIO;
 533
 534 error:
 535         return retval;
 536 }
 537
 538 static const struct file_operations yurex_fops = {
 539         .owner =        THIS_MODULE,
 540         .read =         yurex_read,
 541         .write =        yurex_write,
 542         .open =         yurex_open,
 543         .release =      yurex_release,
 544         .fasync =       yurex_fasync,
 545         .llseek =       default_llseek,
 546 };
 547
 548 module_usb_driver(yurex_driver);
 549
 550 MODULE_LICENSE("GPL");