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 ([email protected])
   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 #define MAX_S64_STRLEN 20 /* {-}922337203685477580{7,8} */
  38
  39 /* table of devices that work with this driver */
  40 static struct usb_device_id yurex_table[] = {
  41         { USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
  42         { }                                     /* Terminating entry */
  43 };
  44 MODULE_DEVICE_TABLE(usb, yurex_table);
  45
  46 #ifdef CONFIG_USB_DYNAMIC_MINORS
  47 #define YUREX_MINOR_BASE        0
  48 #else
  49 #define YUREX_MINOR_BASE        192
  50 #endif
  51
  52 /* Structure to hold all of our device specific stuff */
  53 struct usb_yurex {
  54         struct usb_device       *udev;
  55         struct usb_interface    *interface;
  56         __u8                    int_in_endpointAddr;
  57         struct urb              *urb;           /* URB for interrupt in */
  58         unsigned char           *int_buffer;    /* buffer for intterupt in */
  59         struct urb              *cntl_urb;      /* URB for control msg */
  60         struct usb_ctrlrequest  *cntl_req;      /* req for control msg */
  61         unsigned char           *cntl_buffer;   /* buffer for control msg */
  62
  63         struct kref             kref;
  64         struct mutex            io_mutex;
  65         unsigned long           disconnected:1;
  66         struct fasync_struct    *async_queue;
  67         wait_queue_head_t       waitq;
  68
  69         spinlock_t              lock;
  70         __s64                   bbu;            /* BBU from device */
  71 };
  72 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
  73
  74 static struct usb_driver yurex_driver;
  75 static const struct file_operations yurex_fops;
  76
  77
  78 static void yurex_control_callback(struct urb *urb)
  79 {
  80         struct usb_yurex *dev = urb->context;
  81         int status = urb->status;
  82
  83         if (status) {
  84                 dev_err(&urb->dev->dev, "%s - control failed: %d\n",
  85                         __func__, status);
  86                 wake_up_interruptible(&dev->waitq);
  87                 return;
  88         }
  89         /* on success, sender woken up by CMD_ACK int in, or timeout */
  90 }
  91
  92 static void yurex_delete(struct kref *kref)
  93 {
  94         struct usb_yurex *dev = to_yurex_dev(kref);
  95
  96         dev_dbg(&dev->interface->dev, "%s\n", __func__);
  97
  98         if (dev->cntl_urb) {
  99                 usb_kill_urb(dev->cntl_urb);
 100                 kfree(dev->cntl_req);
 101                 usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 102                                 dev->cntl_buffer, dev->cntl_urb->transfer_dma);
 103                 usb_free_urb(dev->cntl_urb);
 104         }
 105         if (dev->urb) {
 106                 usb_kill_urb(dev->urb);
 107                 usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 108                                 dev->int_buffer, dev->urb->transfer_dma);
 109                 usb_free_urb(dev->urb);
 110         }
 111         usb_put_intf(dev->interface);
 112         usb_put_dev(dev->udev);
 113         kfree(dev);
 114 }
 115
 116 /*
 117  * usb class driver info in order to get a minor number from the usb core,
 118  * and to have the device registered with the driver core
 119  */
 120 static struct usb_class_driver yurex_class = {
 121         .name =         "yurex%d",
 122         .fops =         &yurex_fops,
 123         .minor_base =   YUREX_MINOR_BASE,
 124 };
 125
 126 static void yurex_interrupt(struct urb *urb)
 127 {
 128         struct usb_yurex *dev = urb->context;
 129         unsigned char *buf = dev->int_buffer;
 130         int status = urb->status;
 131         unsigned long flags;
 132         int retval, i;
 133
 134         switch (status) {
 135         case 0: /*success*/
 136                 break;
 137         /* The device is terminated or messed up, give up */
 138         case -EOVERFLOW:
 139                 dev_err(&dev->interface->dev,
 140                         "%s - overflow with length %d, actual length is %d\n",
 141                         __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
 142                 return;
 143         case -ECONNRESET:
 144         case -ENOENT:
 145         case -ESHUTDOWN:
 146         case -EILSEQ:
 147         case -EPROTO:
 148         case -ETIME:
 149                 return;
 150         default:
 151                 dev_err(&dev->interface->dev,
 152                         "%s - unknown status received: %d\n", __func__, status);
 153                 return;
 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         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         DEFINE_WAIT(wait);
 199         int res;
 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 = usb_get_intf(interface);
 212
 213         /* set up the endpoint information */
 214         iface_desc = interface->cur_altsetting;
 215         res = usb_find_int_in_endpoint(iface_desc, &endpoint);
 216         if (res) {
 217                 dev_err(&interface->dev, "Could not find endpoints\n");
 218                 retval = res;
 219                 goto error;
 220         }
 221
 222         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 223
 224         /* allocate control URB */
 225         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 226         if (!dev->cntl_urb)
 227                 goto error;
 228
 229         /* allocate buffer for control req */
 230         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 231         if (!dev->cntl_req)
 232                 goto error;
 233
 234         /* allocate buffer for control msg */
 235         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 236                                               GFP_KERNEL,
 237                                               &dev->cntl_urb->transfer_dma);
 238         if (!dev->cntl_buffer) {
 239                 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
 240                 goto error;
 241         }
 242
 243         /* configure control URB */
 244         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 245                                       USB_RECIP_INTERFACE;
 246         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 247         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 248         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 249         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 250
 251         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 252                              usb_sndctrlpipe(dev->udev, 0),
 253                              (void *)dev->cntl_req, dev->cntl_buffer,
 254                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 255         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 256
 257
 258         /* allocate interrupt URB */
 259         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 260         if (!dev->urb)
 261                 goto error;
 262
 263         /* allocate buffer for interrupt in */
 264         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 265                                         GFP_KERNEL, &dev->urb->transfer_dma);
 266         if (!dev->int_buffer) {
 267                 dev_err(&interface->dev, "Could not allocate int_buffer\n");
 268                 goto error;
 269         }
 270
 271         /* configure interrupt URB */
 272         usb_fill_int_urb(dev->urb, dev->udev,
 273                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 274                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 275                          dev, 1);
 276         dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 277         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 278                 retval = -EIO;
 279                 dev_err(&interface->dev, "Could not submitting URB\n");
 280                 goto error;
 281         }
 282
 283         /* save our data pointer in this interface device */
 284         usb_set_intfdata(interface, dev);
 285         dev->bbu = -1;
 286
 287         /* we can register the device now, as it is ready */
 288         retval = usb_register_dev(interface, &yurex_class);
 289         if (retval) {
 290                 dev_err(&interface->dev,
 291                         "Not able to get a minor for this device.\n");
 292                 usb_set_intfdata(interface, NULL);
 293                 goto error;
 294         }
 295
 296         dev_info(&interface->dev,
 297                  "USB YUREX device now attached to Yurex #%d\n",
 298                  interface->minor);
 299
 300         return 0;
 301
 302 error:
 303         if (dev)
 304                 /* this frees allocated memory */
 305                 kref_put(&dev->kref, yurex_delete);
 306         return retval;
 307 }
 308
 309 static void yurex_disconnect(struct usb_interface *interface)
 310 {
 311         struct usb_yurex *dev;
 312         int minor = interface->minor;
 313
 314         dev = usb_get_intfdata(interface);
 315         usb_set_intfdata(interface, NULL);
 316
 317         /* give back our minor */
 318         usb_deregister_dev(interface, &yurex_class);
 319
 320         /* prevent more I/O from starting */
 321         usb_poison_urb(dev->urb);
 322         usb_poison_urb(dev->cntl_urb);
 323         mutex_lock(&dev->io_mutex);
 324         dev->disconnected = 1;
 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\n", 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 = 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                 printk(KERN_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 = file->private_data;
 393         if (dev == NULL)
 394                 return -ENODEV;
 395
 396         /* decrement the count on our device */
 397         kref_put(&dev->kref, yurex_delete);
 398         return 0;
 399 }
 400
 401 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
 402                           loff_t *ppos)
 403 {
 404         struct usb_yurex *dev;
 405         int len = 0;
 406         char in_buffer[MAX_S64_STRLEN];
 407
 408         dev = file->private_data;
 409
 410         mutex_lock(&dev->io_mutex);
 411         if (dev->disconnected) {                /* already disconnected */
 412                 mutex_unlock(&dev->io_mutex);
 413                 return -ENODEV;
 414         }
 415
 416         if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN)) {
 417                 mutex_unlock(&dev->io_mutex);
 418                 return -EIO;
 419         }
 420
 421         spin_lock_irq(&dev->lock);
 422         scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu);
 423         spin_unlock_irq(&dev->lock);
 424         mutex_unlock(&dev->io_mutex);
 425
 426         return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
 427 }
 428
 429 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
 430                            size_t count, loff_t *ppos)
 431 {
 432         struct usb_yurex *dev;
 433         int i, set = 0, retval = 0;
 434         char buffer[16 + 1];
 435         char *data = buffer;
 436         unsigned long long c, c2 = 0;
 437         signed long timeout = 0;
 438         DEFINE_WAIT(wait);
 439
 440         count = min(sizeof(buffer) - 1, count);
 441         dev = file->private_data;
 442
 443         /* verify that we actually have some data to write */
 444         if (count == 0)
 445                 goto error;
 446
 447         mutex_lock(&dev->io_mutex);
 448         if (dev->disconnected) {                /* already disconnected */
 449                 mutex_unlock(&dev->io_mutex);
 450                 retval = -ENODEV;
 451                 goto error;
 452         }
 453
 454         if (copy_from_user(buffer, user_buffer, count)) {
 455                 mutex_unlock(&dev->io_mutex);
 456                 retval = -EFAULT;
 457                 goto error;
 458         }
 459         buffer[count] = 0;
 460         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 461
 462         switch (buffer[0]) {
 463         case CMD_ANIMATE:
 464         case CMD_LED:
 465                 dev->cntl_buffer[0] = buffer[0];
 466                 dev->cntl_buffer[1] = buffer[1];
 467                 dev->cntl_buffer[2] = CMD_EOF;
 468                 break;
 469         case CMD_READ:
 470         case CMD_VERSION:
 471                 dev->cntl_buffer[0] = buffer[0];
 472                 dev->cntl_buffer[1] = 0x00;
 473                 dev->cntl_buffer[2] = CMD_EOF;
 474                 break;
 475         case CMD_SET:
 476                 data++;
 477                 fallthrough;
 478         case '0' ... '9':
 479                 set = 1;
 480                 c = c2 = simple_strtoull(data, NULL, 0);
 481                 dev->cntl_buffer[0] = CMD_SET;
 482                 for (i = 1; i < 6; i++) {
 483                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 484                         c <<= 8;
 485                 }
 486                 buffer[6] = CMD_EOF;
 487                 break;
 488         default:
 489                 mutex_unlock(&dev->io_mutex);
 490                 return -EINVAL;
 491         }
 492
 493         /* send the data as the control msg */
 494         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 495         dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
 496                 dev->cntl_buffer[0]);
 497         retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC);
 498         if (retval >= 0)
 499                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 500         finish_wait(&dev->waitq, &wait);
 501
 502         /* make sure URB is idle after timeout or (spurious) CMD_ACK */
 503         usb_kill_urb(dev->cntl_urb);
 504
 505         mutex_unlock(&dev->io_mutex);
 506
 507         if (retval < 0) {
 508                 dev_err(&dev->interface->dev,
 509                         "%s - failed to send bulk msg, error %d\n",
 510                         __func__, retval);
 511                 goto error;
 512         }
 513         if (set && timeout) {
 514                 spin_lock_irq(&dev->lock);
 515                 dev->bbu = c2;
 516                 spin_unlock_irq(&dev->lock);
 517         }
 518         return timeout ? count : -EIO;
 519
 520 error:
 521         return retval;
 522 }
 523
 524 static const struct file_operations yurex_fops = {
 525         .owner =        THIS_MODULE,
 526         .read =         yurex_read,
 527         .write =        yurex_write,
 528         .open =         yurex_open,
 529         .release =      yurex_release,
 530         .fasync =       yurex_fasync,
 531         .llseek =       default_llseek,
 532 };
 533
 534 module_usb_driver(yurex_driver);
 535
 536 MODULE_DESCRIPTION("USB YUREX driver support");
 537 MODULE_LICENSE("GPL");