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         struct fasync_struct    *async_queue;
  68         wait_queue_head_t       waitq;
  69
  70         spinlock_t              lock;
  71         __s64                   bbu;            /* BBU from device */
  72 };
  73 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
  74
  75 static struct usb_driver yurex_driver;
  76 static const struct file_operations yurex_fops;
  77
  78
  79 static void yurex_control_callback(struct urb *urb)
  80 {
  81         struct usb_yurex *dev = urb->context;
  82         int status = urb->status;
  83
  84         if (status) {
  85                 dev_err(&urb->dev->dev, "%s - control failed: %d\n",
  86                         __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         dev_dbg(&dev->interface->dev, "%s\n", __func__);
  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                 dev_err(&dev->interface->dev,
 141                         "%s - overflow with length %d, actual length is %d\n",
 142                         __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
 143         case -ECONNRESET:
 144         case -ENOENT:
 145         case -ESHUTDOWN:
 146         case -EILSEQ:
 147                 /* The device is terminated, clean up */
 148                 return;
 149         default:
 150                 dev_err(&dev->interface->dev,
 151                         "%s - unknown status received: %d\n", __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                         dev_dbg(&dev->interface->dev, "%s count: %lld\n",
 168                                 __func__, dev->bbu);
 169                         spin_unlock_irqrestore(&dev->lock, flags);
 170
 171                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 172                 }
 173                 else
 174                         dev_dbg(&dev->interface->dev,
 175                                 "data format error - no EOF\n");
 176                 break;
 177         case CMD_ACK:
 178                 dev_dbg(&dev->interface->dev, "%s ack: %c\n",
 179                         __func__, buf[1]);
 180                 wake_up_interruptible(&dev->waitq);
 181                 break;
 182         }
 183
 184 exit:
 185         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 186         if (retval) {
 187                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
 188                         __func__, retval);
 189         }
 190 }
 191
 192 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 193 {
 194         struct usb_yurex *dev;
 195         struct usb_host_interface *iface_desc;
 196         struct usb_endpoint_descriptor *endpoint;
 197         int retval = -ENOMEM;
 198         int i;
 199         DEFINE_WAIT(wait);
 200
 201         /* allocate memory for our device state and initialize it */
 202         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 203         if (!dev)
 204                 goto error;
 205         kref_init(&dev->kref);
 206         mutex_init(&dev->io_mutex);
 207         spin_lock_init(&dev->lock);
 208         init_waitqueue_head(&dev->waitq);
 209
 210         dev->udev = usb_get_dev(interface_to_usbdev(interface));
 211         dev->interface = interface;
 212
 213         /* set up the endpoint information */
 214         iface_desc = interface->cur_altsetting;
 215         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 216                 endpoint = &iface_desc->endpoint[i].desc;
 217
 218                 if (usb_endpoint_is_int_in(endpoint)) {
 219                         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 220                         break;
 221                 }
 222         }
 223         if (!dev->int_in_endpointAddr) {
 224                 retval = -ENODEV;
 225                 dev_err(&interface->dev, "Could not find endpoints\n");
 226                 goto error;
 227         }
 228
 229
 230         /* allocate control URB */
 231         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 232         if (!dev->cntl_urb)
 233                 goto error;
 234
 235         /* allocate buffer for control req */
 236         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 237         if (!dev->cntl_req)
 238                 goto error;
 239
 240         /* allocate buffer for control msg */
 241         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 242                                               GFP_KERNEL,
 243                                               &dev->cntl_urb->transfer_dma);
 244         if (!dev->cntl_buffer) {
 245                 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
 246                 goto error;
 247         }
 248
 249         /* configure control URB */
 250         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 251                                       USB_RECIP_INTERFACE;
 252         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 253         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 254         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 255         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 256
 257         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 258                              usb_sndctrlpipe(dev->udev, 0),
 259                              (void *)dev->cntl_req, dev->cntl_buffer,
 260                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 261         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 262
 263
 264         /* allocate interrupt URB */
 265         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 266         if (!dev->urb)
 267                 goto error;
 268
 269         /* allocate buffer for interrupt in */
 270         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 271                                         GFP_KERNEL, &dev->urb->transfer_dma);
 272         if (!dev->int_buffer) {
 273                 dev_err(&interface->dev, "Could not allocate int_buffer\n");
 274                 goto error;
 275         }
 276
 277         /* configure interrupt URB */
 278         usb_fill_int_urb(dev->urb, dev->udev,
 279                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 280                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 281                          dev, 1);
 282         dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 283         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 284                 retval = -EIO;
 285                 dev_err(&interface->dev, "Could not submitting URB\n");
 286                 goto error;
 287         }
 288
 289         /* save our data pointer in this interface device */
 290         usb_set_intfdata(interface, dev);
 291         dev->bbu = -1;
 292
 293         /* we can register the device now, as it is ready */
 294         retval = usb_register_dev(interface, &yurex_class);
 295         if (retval) {
 296                 dev_err(&interface->dev,
 297                         "Not able to get a minor for this device.\n");
 298                 usb_set_intfdata(interface, NULL);
 299                 goto error;
 300         }
 301
 302         dev_info(&interface->dev,
 303                  "USB YUREX device now attached to Yurex #%d\n",
 304                  interface->minor);
 305
 306         return 0;
 307
 308 error:
 309         if (dev)
 310                 /* this frees allocated memory */
 311                 kref_put(&dev->kref, yurex_delete);
 312         return retval;
 313 }
 314
 315 static void yurex_disconnect(struct usb_interface *interface)
 316 {
 317         struct usb_yurex *dev;
 318         int minor = interface->minor;
 319
 320         dev = usb_get_intfdata(interface);
 321         usb_set_intfdata(interface, NULL);
 322
 323         /* give back our minor */
 324         usb_deregister_dev(interface, &yurex_class);
 325
 326         /* prevent more I/O from starting */
 327         mutex_lock(&dev->io_mutex);
 328         dev->interface = NULL;
 329         mutex_unlock(&dev->io_mutex);
 330
 331         /* wakeup waiters */
 332         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 333         wake_up_interruptible(&dev->waitq);
 334
 335         /* decrement our usage count */
 336         kref_put(&dev->kref, yurex_delete);
 337
 338         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 339 }
 340
 341 static struct usb_driver yurex_driver = {
 342         .name =         "yurex",
 343         .probe =        yurex_probe,
 344         .disconnect =   yurex_disconnect,
 345         .id_table =     yurex_table,
 346 };
 347
 348
 349 static int yurex_fasync(int fd, struct file *file, int on)
 350 {
 351         struct usb_yurex *dev;
 352
 353         dev = file->private_data;
 354         return fasync_helper(fd, file, on, &dev->async_queue);
 355 }
 356
 357 static int yurex_open(struct inode *inode, struct file *file)
 358 {
 359         struct usb_yurex *dev;
 360         struct usb_interface *interface;
 361         int subminor;
 362         int retval = 0;
 363
 364         subminor = iminor(inode);
 365
 366         interface = usb_find_interface(&yurex_driver, subminor);
 367         if (!interface) {
 368                 printk(KERN_ERR "%s - error, can't find device for minor %d",
 369                        __func__, subminor);
 370                 retval = -ENODEV;
 371                 goto exit;
 372         }
 373
 374         dev = usb_get_intfdata(interface);
 375         if (!dev) {
 376                 retval = -ENODEV;
 377                 goto exit;
 378         }
 379
 380         /* increment our usage count for the device */
 381         kref_get(&dev->kref);
 382
 383         /* save our object in the file's private structure */
 384         mutex_lock(&dev->io_mutex);
 385         file->private_data = dev;
 386         mutex_unlock(&dev->io_mutex);
 387
 388 exit:
 389         return retval;
 390 }
 391
 392 static int yurex_release(struct inode *inode, struct file *file)
 393 {
 394         struct usb_yurex *dev;
 395
 396         dev = file->private_data;
 397         if (dev == NULL)
 398                 return -ENODEV;
 399
 400         /* decrement the count on our device */
 401         kref_put(&dev->kref, yurex_delete);
 402         return 0;
 403 }
 404
 405 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
 406                           loff_t *ppos)
 407 {
 408         struct usb_yurex *dev;
 409         int retval = 0;
 410         int bytes_read = 0;
 411         char in_buffer[20];
 412         unsigned long flags;
 413
 414         dev = file->private_data;
 415
 416         mutex_lock(&dev->io_mutex);
 417         if (!dev->interface) {          /* already disconnected */
 418                 retval = -ENODEV;
 419                 goto exit;
 420         }
 421
 422         spin_lock_irqsave(&dev->lock, flags);
 423         bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 424         spin_unlock_irqrestore(&dev->lock, flags);
 425
 426         if (*ppos < bytes_read) {
 427                 if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
 428                         retval = -EFAULT;
 429                 else {
 430                         retval = bytes_read - *ppos;
 431                         *ppos += bytes_read;
 432                 }
 433         }
 434
 435 exit:
 436         mutex_unlock(&dev->io_mutex);
 437         return retval;
 438 }
 439
 440 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
 441                            size_t count, loff_t *ppos)
 442 {
 443         struct usb_yurex *dev;
 444         int i, set = 0, retval = 0;
 445         char buffer[16];
 446         char *data = buffer;
 447         unsigned long long c, c2 = 0;
 448         signed long timeout = 0;
 449         DEFINE_WAIT(wait);
 450
 451         count = min(sizeof(buffer), count);
 452         dev = file->private_data;
 453
 454         /* verify that we actually have some data to write */
 455         if (count == 0)
 456                 goto error;
 457
 458         mutex_lock(&dev->io_mutex);
 459         if (!dev->interface) {          /* already disconnected */
 460                 mutex_unlock(&dev->io_mutex);
 461                 retval = -ENODEV;
 462                 goto error;
 463         }
 464
 465         if (copy_from_user(buffer, user_buffer, count)) {
 466                 mutex_unlock(&dev->io_mutex);
 467                 retval = -EFAULT;
 468                 goto error;
 469         }
 470         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 471
 472         switch (buffer[0]) {
 473         case CMD_ANIMATE:
 474         case CMD_LED:
 475                 dev->cntl_buffer[0] = buffer[0];
 476                 dev->cntl_buffer[1] = buffer[1];
 477                 dev->cntl_buffer[2] = CMD_EOF;
 478                 break;
 479         case CMD_READ:
 480         case CMD_VERSION:
 481                 dev->cntl_buffer[0] = buffer[0];
 482                 dev->cntl_buffer[1] = 0x00;
 483                 dev->cntl_buffer[2] = CMD_EOF;
 484                 break;
 485         case CMD_SET:
 486                 data++;
 487                 /* FALL THROUGH */
 488         case '0' ... '9':
 489                 set = 1;
 490                 c = c2 = simple_strtoull(data, NULL, 0);
 491                 dev->cntl_buffer[0] = CMD_SET;
 492                 for (i = 1; i < 6; i++) {
 493                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 494                         c <<= 8;
 495                 }
 496                 buffer[6] = CMD_EOF;
 497                 break;
 498         default:
 499                 mutex_unlock(&dev->io_mutex);
 500                 return -EINVAL;
 501         }
 502
 503         /* send the data as the control msg */
 504         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 505         dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
 506                 dev->cntl_buffer[0]);
 507         retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
 508         if (retval >= 0)
 509                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 510         finish_wait(&dev->waitq, &wait);
 511
 512         mutex_unlock(&dev->io_mutex);
 513
 514         if (retval < 0) {
 515                 dev_err(&dev->interface->dev,
 516                         "%s - failed to send bulk msg, error %d\n",
 517                         __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 module_usb_driver(yurex_driver);
 539
 540 MODULE_LICENSE("GPL");