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                 return;
 141         case -ECONNRESET:
 142         case -ENOENT:
 143         case -ESHUTDOWN:
 144         case -EILSEQ:
 145         case -EPROTO:
 146         case -ETIME:
 147                 return;
 148         default:
 149                 dev_err(&dev->interface->dev,
 150                         "%s - unknown status received: %d\n", __func__, status);
 151                 return;
 152         }
 153
 154         /* handle received message */
 155         switch (buf[0]) {
 156         case CMD_COUNT:
 157         case CMD_READ:
 158                 if (buf[6] == CMD_EOF) {
 159                         spin_lock_irqsave(&dev->lock, flags);
 160                         dev->bbu = 0;
 161                         for (i = 1; i < 6; i++) {
 162                                 dev->bbu += buf[i];
 163                                 if (i != 5)
 164                                         dev->bbu <<= 8;
 165                         }
 166                         dev_dbg(&dev->interface->dev, "%s count: %lld\n",
 167                                 __func__, dev->bbu);
 168                         spin_unlock_irqrestore(&dev->lock, flags);
 169
 170                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 171                 }
 172                 else
 173                         dev_dbg(&dev->interface->dev,
 174                                 "data format error - no EOF\n");
 175                 break;
 176         case CMD_ACK:
 177                 dev_dbg(&dev->interface->dev, "%s ack: %c\n",
 178                         __func__, buf[1]);
 179                 wake_up_interruptible(&dev->waitq);
 180                 break;
 181         }
 182
 183         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 184         if (retval) {
 185                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
 186                         __func__, retval);
 187         }
 188 }
 189
 190 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 191 {
 192         struct usb_yurex *dev;
 193         struct usb_host_interface *iface_desc;
 194         struct usb_endpoint_descriptor *endpoint;
 195         int retval = -ENOMEM;
 196         DEFINE_WAIT(wait);
 197         int res;
 198
 199         /* allocate memory for our device state and initialize it */
 200         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 201         if (!dev)
 202                 goto error;
 203         kref_init(&dev->kref);
 204         mutex_init(&dev->io_mutex);
 205         spin_lock_init(&dev->lock);
 206         init_waitqueue_head(&dev->waitq);
 207
 208         dev->udev = usb_get_dev(interface_to_usbdev(interface));
 209         dev->interface = usb_get_intf(interface);
 210
 211         /* set up the endpoint information */
 212         iface_desc = interface->cur_altsetting;
 213         res = usb_find_int_in_endpoint(iface_desc, &endpoint);
 214         if (res) {
 215                 dev_err(&interface->dev, "Could not find endpoints\n");
 216                 retval = res;
 217                 goto error;
 218         }
 219
 220         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 221
 222         /* allocate control URB */
 223         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 224         if (!dev->cntl_urb)
 225                 goto error;
 226
 227         /* allocate buffer for control req */
 228         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 229         if (!dev->cntl_req)
 230                 goto error;
 231
 232         /* allocate buffer for control msg */
 233         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 234                                               GFP_KERNEL,
 235                                               &dev->cntl_urb->transfer_dma);
 236         if (!dev->cntl_buffer) {
 237                 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
 238                 goto error;
 239         }
 240
 241         /* configure control URB */
 242         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 243                                       USB_RECIP_INTERFACE;
 244         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 245         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 246         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 247         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 248
 249         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 250                              usb_sndctrlpipe(dev->udev, 0),
 251                              (void *)dev->cntl_req, dev->cntl_buffer,
 252                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 253         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 254
 255
 256         /* allocate interrupt URB */
 257         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 258         if (!dev->urb)
 259                 goto error;
 260
 261         /* allocate buffer for interrupt in */
 262         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 263                                         GFP_KERNEL, &dev->urb->transfer_dma);
 264         if (!dev->int_buffer) {
 265                 dev_err(&interface->dev, "Could not allocate int_buffer\n");
 266                 goto error;
 267         }
 268
 269         /* configure interrupt URB */
 270         usb_fill_int_urb(dev->urb, dev->udev,
 271                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 272                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 273                          dev, 1);
 274         dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 275         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 276                 retval = -EIO;
 277                 dev_err(&interface->dev, "Could not submitting URB\n");
 278                 goto error;
 279         }
 280
 281         /* save our data pointer in this interface device */
 282         usb_set_intfdata(interface, dev);
 283         dev->bbu = -1;
 284
 285         /* we can register the device now, as it is ready */
 286         retval = usb_register_dev(interface, &yurex_class);
 287         if (retval) {
 288                 dev_err(&interface->dev,
 289                         "Not able to get a minor for this device.\n");
 290                 usb_set_intfdata(interface, NULL);
 291                 goto error;
 292         }
 293
 294         dev_info(&interface->dev,
 295                  "USB YUREX device now attached to Yurex #%d\n",
 296                  interface->minor);
 297
 298         return 0;
 299
 300 error:
 301         if (dev)
 302                 /* this frees allocated memory */
 303                 kref_put(&dev->kref, yurex_delete);
 304         return retval;
 305 }
 306
 307 static void yurex_disconnect(struct usb_interface *interface)
 308 {
 309         struct usb_yurex *dev;
 310         int minor = interface->minor;
 311
 312         dev = usb_get_intfdata(interface);
 313         usb_set_intfdata(interface, NULL);
 314
 315         /* give back our minor */
 316         usb_deregister_dev(interface, &yurex_class);
 317
 318         /* prevent more I/O from starting */
 319         usb_poison_urb(dev->urb);
 320         usb_poison_urb(dev->cntl_urb);
 321         mutex_lock(&dev->io_mutex);
 322         dev->disconnected = 1;
 323         mutex_unlock(&dev->io_mutex);
 324
 325         /* wakeup waiters */
 326         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 327         wake_up_interruptible(&dev->waitq);
 328
 329         /* decrement our usage count */
 330         kref_put(&dev->kref, yurex_delete);
 331
 332         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 333 }
 334
 335 static struct usb_driver yurex_driver = {
 336         .name =         "yurex",
 337         .probe =        yurex_probe,
 338         .disconnect =   yurex_disconnect,
 339         .id_table =     yurex_table,
 340 };
 341
 342
 343 static int yurex_fasync(int fd, struct file *file, int on)
 344 {
 345         struct usb_yurex *dev;
 346
 347         dev = file->private_data;
 348         return fasync_helper(fd, file, on, &dev->async_queue);
 349 }
 350
 351 static int yurex_open(struct inode *inode, struct file *file)
 352 {
 353         struct usb_yurex *dev;
 354         struct usb_interface *interface;
 355         int subminor;
 356         int retval = 0;
 357
 358         subminor = iminor(inode);
 359
 360         interface = usb_find_interface(&yurex_driver, subminor);
 361         if (!interface) {
 362                 printk(KERN_ERR "%s - error, can't find device for minor %d",
 363                        __func__, subminor);
 364                 retval = -ENODEV;
 365                 goto exit;
 366         }
 367
 368         dev = usb_get_intfdata(interface);
 369         if (!dev) {
 370                 retval = -ENODEV;
 371                 goto exit;
 372         }
 373
 374         /* increment our usage count for the device */
 375         kref_get(&dev->kref);
 376
 377         /* save our object in the file's private structure */
 378         mutex_lock(&dev->io_mutex);
 379         file->private_data = dev;
 380         mutex_unlock(&dev->io_mutex);
 381
 382 exit:
 383         return retval;
 384 }
 385
 386 static int yurex_release(struct inode *inode, struct file *file)
 387 {
 388         struct usb_yurex *dev;
 389
 390         dev = file->private_data;
 391         if (dev == NULL)
 392                 return -ENODEV;
 393
 394         /* decrement the count on our device */
 395         kref_put(&dev->kref, yurex_delete);
 396         return 0;
 397 }
 398
 399 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
 400                           loff_t *ppos)
 401 {
 402         struct usb_yurex *dev;
 403         int len = 0;
 404         char in_buffer[20];
 405         unsigned long flags;
 406
 407         dev = file->private_data;
 408
 409         mutex_lock(&dev->io_mutex);
 410         if (dev->disconnected) {                /* already disconnected */
 411                 mutex_unlock(&dev->io_mutex);
 412                 return -ENODEV;
 413         }
 414
 415         spin_lock_irqsave(&dev->lock, flags);
 416         len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 417         spin_unlock_irqrestore(&dev->lock, flags);
 418         mutex_unlock(&dev->io_mutex);
 419
 420         if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
 421                 return -EIO;
 422
 423         return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
 424 }
 425
 426 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
 427                            size_t count, loff_t *ppos)
 428 {
 429         struct usb_yurex *dev;
 430         int i, set = 0, retval = 0;
 431         char buffer[16 + 1];
 432         char *data = buffer;
 433         unsigned long long c, c2 = 0;
 434         signed long timeout = 0;
 435         DEFINE_WAIT(wait);
 436
 437         count = min(sizeof(buffer) - 1, count);
 438         dev = file->private_data;
 439
 440         /* verify that we actually have some data to write */
 441         if (count == 0)
 442                 goto error;
 443
 444         mutex_lock(&dev->io_mutex);
 445         if (dev->disconnected) {                /* already disconnected */
 446                 mutex_unlock(&dev->io_mutex);
 447                 retval = -ENODEV;
 448                 goto error;
 449         }
 450
 451         if (copy_from_user(buffer, user_buffer, count)) {
 452                 mutex_unlock(&dev->io_mutex);
 453                 retval = -EFAULT;
 454                 goto error;
 455         }
 456         buffer[count] = 0;
 457         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 458
 459         switch (buffer[0]) {
 460         case CMD_ANIMATE:
 461         case CMD_LED:
 462                 dev->cntl_buffer[0] = buffer[0];
 463                 dev->cntl_buffer[1] = buffer[1];
 464                 dev->cntl_buffer[2] = CMD_EOF;
 465                 break;
 466         case CMD_READ:
 467         case CMD_VERSION:
 468                 dev->cntl_buffer[0] = buffer[0];
 469                 dev->cntl_buffer[1] = 0x00;
 470                 dev->cntl_buffer[2] = CMD_EOF;
 471                 break;
 472         case CMD_SET:
 473                 data++;
 474                 fallthrough;
 475         case '0' ... '9':
 476                 set = 1;
 477                 c = c2 = simple_strtoull(data, NULL, 0);
 478                 dev->cntl_buffer[0] = CMD_SET;
 479                 for (i = 1; i < 6; i++) {
 480                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 481                         c <<= 8;
 482                 }
 483                 buffer[6] = CMD_EOF;
 484                 break;
 485         default:
 486                 mutex_unlock(&dev->io_mutex);
 487                 return -EINVAL;
 488         }
 489
 490         /* send the data as the control msg */
 491         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 492         dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
 493                 dev->cntl_buffer[0]);
 494         retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC);
 495         if (retval >= 0)
 496                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 497         finish_wait(&dev->waitq, &wait);
 498
 499         /* make sure URB is idle after timeout or (spurious) CMD_ACK */
 500         usb_kill_urb(dev->cntl_urb);
 501
 502         mutex_unlock(&dev->io_mutex);
 503
 504         if (retval < 0) {
 505                 dev_err(&dev->interface->dev,
 506                         "%s - failed to send bulk msg, error %d\n",
 507                         __func__, retval);
 508                 goto error;
 509         }
 510         if (set && timeout)
 511                 dev->bbu = c2;
 512         return timeout ? count : -EIO;
 513
 514 error:
 515         return retval;
 516 }
 517
 518 static const struct file_operations yurex_fops = {
 519         .owner =        THIS_MODULE,
 520         .read =         yurex_read,
 521         .write =        yurex_write,
 522         .open =         yurex_open,
 523         .release =      yurex_release,
 524         .fasync =       yurex_fasync,
 525         .llseek =       default_llseek,
 526 };
 527
 528 module_usb_driver(yurex_driver);
 529
 530 MODULE_LICENSE("GPL");