drivers/usb/misc/yurex.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for Meywa-Denki & KAYAC YUREX
   4  *
   5  * Copyright (C) 2010 Tomoki Sekiyama (tomoki.sekiyama@gmail.com)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/errno.h>
  10 #include <linux/slab.h>
  11 #include <linux/module.h>
  12 #include <linux/kref.h>
  13 #include <linux/mutex.h>
  14 #include <linux/uaccess.h>
  15 #include <linux/usb.h>
  16 #include <linux/hid.h>
  17
  18 #define DRIVER_AUTHOR "Tomoki Sekiyama"
  19 #define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX"
  20
  21 #define YUREX_VENDOR_ID         0x0c45
  22 #define YUREX_PRODUCT_ID        0x1010
  23
  24 #define CMD_ACK         '!'
  25 #define CMD_ANIMATE     'A'
  26 #define CMD_COUNT       'C'
  27 #define CMD_LED         'L'
  28 #define CMD_READ        'R'
  29 #define CMD_SET         'S'
  30 #define CMD_VERSION     'V'
  31 #define CMD_EOF         0x0d
  32 #define CMD_PADDING     0xff
  33
  34 #define YUREX_BUF_SIZE          8
  35 #define YUREX_WRITE_TIMEOUT     (HZ*2)
  36
  37 /* table of devices that work with this driver */
  38 static struct usb_device_id yurex_table[] = {
  39         { USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
  40         { }                                     /* Terminating entry */
  41 };
  42 MODULE_DEVICE_TABLE(usb, yurex_table);
  43
  44 #ifdef CONFIG_USB_DYNAMIC_MINORS
  45 #define YUREX_MINOR_BASE        0
  46 #else
  47 #define YUREX_MINOR_BASE        192
  48 #endif
  49
  50 /* Structure to hold all of our device specific stuff */
  51 struct usb_yurex {
  52         struct usb_device       *udev;
  53         struct usb_interface    *interface;
  54         __u8                    int_in_endpointAddr;
  55         struct urb              *urb;           /* URB for interrupt in */
  56         unsigned char           *int_buffer;    /* buffer for intterupt in */
  57         struct urb              *cntl_urb;      /* URB for control msg */
  58         struct usb_ctrlrequest  *cntl_req;      /* req for control msg */
  59         unsigned char           *cntl_buffer;   /* buffer for control msg */
  60
  61         struct kref             kref;
  62         struct mutex            io_mutex;
  63         unsigned long           disconnected:1;
  64         struct fasync_struct    *async_queue;
  65         wait_queue_head_t       waitq;
  66
  67         spinlock_t              lock;
  68         __s64                   bbu;            /* BBU from device */
  69 };
  70 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
  71
  72 static struct usb_driver yurex_driver;
  73 static const struct file_operations yurex_fops;
  74
  75
  76 static void yurex_control_callback(struct urb *urb)
  77 {
  78         struct usb_yurex *dev = urb->context;
  79         int status = urb->status;
  80
  81         if (status) {
  82                 dev_err(&urb->dev->dev, "%s - control failed: %d\n",
  83                         __func__, status);
  84                 wake_up_interruptible(&dev->waitq);
  85                 return;
  86         }
  87         /* on success, sender woken up by CMD_ACK int in, or timeout */
  88 }
  89
  90 static void yurex_delete(struct kref *kref)
  91 {
  92         struct usb_yurex *dev = to_yurex_dev(kref);
  93
  94         dev_dbg(&dev->interface->dev, "%s\n", __func__);
  95
  96         if (dev->cntl_urb) {
  97                 usb_kill_urb(dev->cntl_urb);
  98                 kfree(dev->cntl_req);
  99                 usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 100                                 dev->cntl_buffer, dev->cntl_urb->transfer_dma);
 101                 usb_free_urb(dev->cntl_urb);
 102         }
 103         if (dev->urb) {
 104                 usb_kill_urb(dev->urb);
 105                 usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 106                                 dev->int_buffer, dev->urb->transfer_dma);
 107                 usb_free_urb(dev->urb);
 108         }
 109         usb_put_intf(dev->interface);
 110         usb_put_dev(dev->udev);
 111         kfree(dev);
 112 }
 113
 114 /*
 115  * usb class driver info in order to get a minor number from the usb core,
 116  * and to have the device registered with the driver core
 117  */
 118 static struct usb_class_driver yurex_class = {
 119         .name =         "yurex%d",
 120         .fops =         &yurex_fops,
 121         .minor_base =   YUREX_MINOR_BASE,
 122 };
 123
 124 static void yurex_interrupt(struct urb *urb)
 125 {
 126         struct usb_yurex *dev = urb->context;
 127         unsigned char *buf = dev->int_buffer;
 128         int status = urb->status;
 129         unsigned long flags;
 130         int retval, i;
 131
 132         switch (status) {
 133         case 0: /*success*/
 134                 break;
 135         /* The device is terminated or messed up, give up */
 136         case -EOVERFLOW:
 137                 dev_err(&dev->interface->dev,
 138                         "%s - overflow with length %d, actual length is %d\n",
 139                         __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
 140         case -ECONNRESET:
 141         case -ENOENT:
 142         case -ESHUTDOWN:
 143         case -EILSEQ:
 144         case -EPROTO:
 145         case -ETIME:
 146                 return;
 147         default:
 148                 dev_err(&dev->interface->dev,
 149                         "%s - unknown status received: %d\n", __func__, status);
 150                 return;
 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                         dev_dbg(&dev->interface->dev, "%s count: %lld\n",
 166                                 __func__, dev->bbu);
 167                         spin_unlock_irqrestore(&dev->lock, flags);
 168
 169                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 170                 }
 171                 else
 172                         dev_dbg(&dev->interface->dev,
 173                                 "data format error - no EOF\n");
 174                 break;
 175         case CMD_ACK:
 176                 dev_dbg(&dev->interface->dev, "%s ack: %c\n",
 177                         __func__, buf[1]);
 178                 wake_up_interruptible(&dev->waitq);
 179                 break;
 180         }
 181
 182         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 183         if (retval) {
 184                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
 185                         __func__, retval);
 186         }
 187 }
 188
 189 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 190 {
 191         struct usb_yurex *dev;
 192         struct usb_host_interface *iface_desc;
 193         struct usb_endpoint_descriptor *endpoint;
 194         int retval = -ENOMEM;
 195         DEFINE_WAIT(wait);
 196         int res;
 197
 198         /* allocate memory for our device state and initialize it */
 199         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 200         if (!dev)
 201                 goto error;
 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 = usb_get_intf(interface);
 209
 210         /* set up the endpoint information */
 211         iface_desc = interface->cur_altsetting;
 212         res = usb_find_int_in_endpoint(iface_desc, &endpoint);
 213         if (res) {
 214                 dev_err(&interface->dev, "Could not find endpoints\n");
 215                 retval = res;
 216                 goto error;
 217         }
 218
 219         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 220
 221         /* allocate control URB */
 222         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 223         if (!dev->cntl_urb)
 224                 goto error;
 225
 226         /* allocate buffer for control req */
 227         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 228         if (!dev->cntl_req)
 229                 goto error;
 230
 231         /* allocate buffer for control msg */
 232         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 233                                               GFP_KERNEL,
 234                                               &dev->cntl_urb->transfer_dma);
 235         if (!dev->cntl_buffer) {
 236                 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
 237                 goto error;
 238         }
 239
 240         /* configure control URB */
 241         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 242                                       USB_RECIP_INTERFACE;
 243         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 244         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 245         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 246         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 247
 248         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 249                              usb_sndctrlpipe(dev->udev, 0),
 250                              (void *)dev->cntl_req, dev->cntl_buffer,
 251                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 252         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 253
 254
 255         /* allocate interrupt URB */
 256         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 257         if (!dev->urb)
 258                 goto error;
 259
 260         /* allocate buffer for interrupt in */
 261         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 262                                         GFP_KERNEL, &dev->urb->transfer_dma);
 263         if (!dev->int_buffer) {
 264                 dev_err(&interface->dev, "Could not allocate int_buffer\n");
 265                 goto error;
 266         }
 267
 268         /* configure interrupt URB */
 269         usb_fill_int_urb(dev->urb, dev->udev,
 270                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 271                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 272                          dev, 1);
 273         dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 274         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 275                 retval = -EIO;
 276                 dev_err(&interface->dev, "Could not submitting URB\n");
 277                 goto error;
 278         }
 279
 280         /* save our data pointer in this interface device */
 281         usb_set_intfdata(interface, dev);
 282         dev->bbu = -1;
 283
 284         /* we can register the device now, as it is ready */
 285         retval = usb_register_dev(interface, &yurex_class);
 286         if (retval) {
 287                 dev_err(&interface->dev,
 288                         "Not able to get a minor for this device.\n");
 289                 usb_set_intfdata(interface, NULL);
 290                 goto error;
 291         }
 292
 293         dev_info(&interface->dev,
 294                  "USB YUREX device now attached to Yurex #%d\n",
 295                  interface->minor);
 296
 297         return 0;
 298
 299 error:
 300         if (dev)
 301                 /* this frees allocated memory */
 302                 kref_put(&dev->kref, yurex_delete);
 303         return retval;
 304 }
 305
 306 static void yurex_disconnect(struct usb_interface *interface)
 307 {
 308         struct usb_yurex *dev;
 309         int minor = interface->minor;
 310
 311         dev = usb_get_intfdata(interface);
 312         usb_set_intfdata(interface, NULL);
 313
 314         /* give back our minor */
 315         usb_deregister_dev(interface, &yurex_class);
 316
 317         /* prevent more I/O from starting */
 318         usb_poison_urb(dev->urb);
 319         usb_poison_urb(dev->cntl_urb);
 320         mutex_lock(&dev->io_mutex);
 321         dev->disconnected = 1;
 322         mutex_unlock(&dev->io_mutex);
 323
 324         /* wakeup waiters */
 325         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 326         wake_up_interruptible(&dev->waitq);
 327
 328         /* decrement our usage count */
 329         kref_put(&dev->kref, yurex_delete);
 330
 331         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 332 }
 333
 334 static struct usb_driver yurex_driver = {
 335         .name =         "yurex",
 336         .probe =        yurex_probe,
 337         .disconnect =   yurex_disconnect,
 338         .id_table =     yurex_table,
 339 };
 340
 341
 342 static int yurex_fasync(int fd, struct file *file, int on)
 343 {
 344         struct usb_yurex *dev;
 345
 346         dev = file->private_data;
 347         return fasync_helper(fd, file, on, &dev->async_queue);
 348 }
 349
 350 static int yurex_open(struct inode *inode, struct file *file)
 351 {
 352         struct usb_yurex *dev;
 353         struct usb_interface *interface;
 354         int subminor;
 355         int retval = 0;
 356
 357         subminor = iminor(inode);
 358
 359         interface = usb_find_interface(&yurex_driver, subminor);
 360         if (!interface) {
 361                 printk(KERN_ERR "%s - error, can't find device for minor %d",
 362                        __func__, subminor);
 363                 retval = -ENODEV;
 364                 goto exit;
 365         }
 366
 367         dev = usb_get_intfdata(interface);
 368         if (!dev) {
 369                 retval = -ENODEV;
 370                 goto exit;
 371         }
 372
 373         /* increment our usage count for the device */
 374         kref_get(&dev->kref);
 375
 376         /* save our object in the file's private structure */
 377         mutex_lock(&dev->io_mutex);
 378         file->private_data = dev;
 379         mutex_unlock(&dev->io_mutex);
 380
 381 exit:
 382         return retval;
 383 }
 384
 385 static int yurex_release(struct inode *inode, struct file *file)
 386 {
 387         struct usb_yurex *dev;
 388
 389         dev = file->private_data;
 390         if (dev == NULL)
 391                 return -ENODEV;
 392
 393         /* decrement the count on our device */
 394         kref_put(&dev->kref, yurex_delete);
 395         return 0;
 396 }
 397
 398 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
 399                           loff_t *ppos)
 400 {
 401         struct usb_yurex *dev;
 402         int len = 0;
 403         char in_buffer[20];
 404         unsigned long flags;
 405
 406         dev = file->private_data;
 407
 408         mutex_lock(&dev->io_mutex);
 409         if (dev->disconnected) {                /* already disconnected */
 410                 mutex_unlock(&dev->io_mutex);
 411                 return -ENODEV;
 412         }
 413
 414         spin_lock_irqsave(&dev->lock, flags);
 415         len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 416         spin_unlock_irqrestore(&dev->lock, flags);
 417         mutex_unlock(&dev->io_mutex);
 418
 419         if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
 420                 return -EIO;
 421
 422         return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
 423 }
 424
 425 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
 426                            size_t count, loff_t *ppos)
 427 {
 428         struct usb_yurex *dev;
 429         int i, set = 0, retval = 0;
 430         char buffer[16 + 1];
 431         char *data = buffer;
 432         unsigned long long c, c2 = 0;
 433         signed long timeout = 0;
 434         DEFINE_WAIT(wait);
 435
 436         count = min(sizeof(buffer) - 1, count);
 437         dev = file->private_data;
 438
 439         /* verify that we actually have some data to write */
 440         if (count == 0)
 441                 goto error;
 442
 443         mutex_lock(&dev->io_mutex);
 444         if (dev->disconnected) {                /* already disconnected */
 445                 mutex_unlock(&dev->io_mutex);
 446                 retval = -ENODEV;
 447                 goto error;
 448         }
 449
 450         if (copy_from_user(buffer, user_buffer, count)) {
 451                 mutex_unlock(&dev->io_mutex);
 452                 retval = -EFAULT;
 453                 goto error;
 454         }
 455         buffer[count] = 0;
 456         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 457
 458         switch (buffer[0]) {
 459         case CMD_ANIMATE:
 460         case CMD_LED:
 461                 dev->cntl_buffer[0] = buffer[0];
 462                 dev->cntl_buffer[1] = buffer[1];
 463                 dev->cntl_buffer[2] = CMD_EOF;
 464                 break;
 465         case CMD_READ:
 466         case CMD_VERSION:
 467                 dev->cntl_buffer[0] = buffer[0];
 468                 dev->cntl_buffer[1] = 0x00;
 469                 dev->cntl_buffer[2] = CMD_EOF;
 470                 break;
 471         case CMD_SET:
 472                 data++;
 473                 fallthrough;
 474         case '0' ... '9':
 475                 set = 1;
 476                 c = c2 = simple_strtoull(data, NULL, 0);
 477                 dev->cntl_buffer[0] = CMD_SET;
 478                 for (i = 1; i < 6; i++) {
 479                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 480                         c <<= 8;
 481                 }
 482                 buffer[6] = CMD_EOF;
 483                 break;
 484         default:
 485                 mutex_unlock(&dev->io_mutex);
 486                 return -EINVAL;
 487         }
 488
 489         /* send the data as the control msg */
 490         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 491         dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
 492                 dev->cntl_buffer[0]);
 493         retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC);
 494         if (retval >= 0)
 495                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 496         finish_wait(&dev->waitq, &wait);
 497
 498         /* make sure URB is idle after timeout or (spurious) CMD_ACK */
 499         usb_kill_urb(dev->cntl_urb);
 500
 501         mutex_unlock(&dev->io_mutex);
 502
 503         if (retval < 0) {
 504                 dev_err(&dev->interface->dev,
 505                         "%s - failed to send bulk msg, error %d\n",
 506                         __func__, retval);
 507                 goto error;
 508         }
 509         if (set && timeout)
 510                 dev->bbu = c2;
 511         return timeout ? count : -EIO;
 512
 513 error:
 514         return retval;
 515 }
 516
 517 static const struct file_operations yurex_fops = {
 518         .owner =        THIS_MODULE,
 519         .read =         yurex_read,
 520         .write =        yurex_write,
 521         .open =         yurex_open,
 522         .release =      yurex_release,
 523         .fasync =       yurex_fasync,
 524         .llseek =       default_llseek,
 525 };
 526
 527 module_usb_driver(yurex_driver);
 528
 529 MODULE_LICENSE("GPL");