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                 if (dev->cntl_buffer)
 100                         usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 101                                 dev->cntl_buffer, dev->cntl_urb->transfer_dma);
 102                 usb_free_urb(dev->cntl_urb);
 103         }
 104         if (dev->urb) {
 105                 usb_kill_urb(dev->urb);
 106                 if (dev->int_buffer)
 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         case -ECONNRESET:
 143         case -ENOENT:
 144         case -ESHUTDOWN:
 145         case -EILSEQ:
 146         case -EPROTO:
 147         case -ETIME:
 148                 return;
 149         default:
 150                 dev_err(&dev->interface->dev,
 151                         "%s - unknown status received: %d\n", __func__, status);
 152                 return;
 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         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 185         if (retval) {
 186                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
 187                         __func__, retval);
 188         }
 189 }
 190
 191 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 192 {
 193         struct usb_yurex *dev;
 194         struct usb_host_interface *iface_desc;
 195         struct usb_endpoint_descriptor *endpoint;
 196         int retval = -ENOMEM;
 197         DEFINE_WAIT(wait);
 198         int res;
 199
 200         /* allocate memory for our device state and initialize it */
 201         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 202         if (!dev)
 203                 goto error;
 204         kref_init(&dev->kref);
 205         mutex_init(&dev->io_mutex);
 206         spin_lock_init(&dev->lock);
 207         init_waitqueue_head(&dev->waitq);
 208
 209         dev->udev = usb_get_dev(interface_to_usbdev(interface));
 210         dev->interface = usb_get_intf(interface);
 211
 212         /* set up the endpoint information */
 213         iface_desc = interface->cur_altsetting;
 214         res = usb_find_int_in_endpoint(iface_desc, &endpoint);
 215         if (res) {
 216                 dev_err(&interface->dev, "Could not find endpoints\n");
 217                 retval = res;
 218                 goto error;
 219         }
 220
 221         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 222
 223         /* allocate control URB */
 224         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 225         if (!dev->cntl_urb)
 226                 goto error;
 227
 228         /* allocate buffer for control req */
 229         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 230         if (!dev->cntl_req)
 231                 goto error;
 232
 233         /* allocate buffer for control msg */
 234         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 235                                               GFP_KERNEL,
 236                                               &dev->cntl_urb->transfer_dma);
 237         if (!dev->cntl_buffer) {
 238                 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
 239                 goto error;
 240         }
 241
 242         /* configure control URB */
 243         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 244                                       USB_RECIP_INTERFACE;
 245         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 246         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 247         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 248         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 249
 250         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 251                              usb_sndctrlpipe(dev->udev, 0),
 252                              (void *)dev->cntl_req, dev->cntl_buffer,
 253                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 254         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 255
 256
 257         /* allocate interrupt URB */
 258         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 259         if (!dev->urb)
 260                 goto error;
 261
 262         /* allocate buffer for interrupt in */
 263         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 264                                         GFP_KERNEL, &dev->urb->transfer_dma);
 265         if (!dev->int_buffer) {
 266                 dev_err(&interface->dev, "Could not allocate int_buffer\n");
 267                 goto error;
 268         }
 269
 270         /* configure interrupt URB */
 271         usb_fill_int_urb(dev->urb, dev->udev,
 272                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 273                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 274                          dev, 1);
 275         dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 276         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 277                 retval = -EIO;
 278                 dev_err(&interface->dev, "Could not submitting URB\n");
 279                 goto error;
 280         }
 281
 282         /* save our data pointer in this interface device */
 283         usb_set_intfdata(interface, dev);
 284         dev->bbu = -1;
 285
 286         /* we can register the device now, as it is ready */
 287         retval = usb_register_dev(interface, &yurex_class);
 288         if (retval) {
 289                 dev_err(&interface->dev,
 290                         "Not able to get a minor for this device.\n");
 291                 usb_set_intfdata(interface, NULL);
 292                 goto error;
 293         }
 294
 295         dev_info(&interface->dev,
 296                  "USB YUREX device now attached to Yurex #%d\n",
 297                  interface->minor);
 298
 299         return 0;
 300
 301 error:
 302         if (dev)
 303                 /* this frees allocated memory */
 304                 kref_put(&dev->kref, yurex_delete);
 305         return retval;
 306 }
 307
 308 static void yurex_disconnect(struct usb_interface *interface)
 309 {
 310         struct usb_yurex *dev;
 311         int minor = interface->minor;
 312
 313         dev = usb_get_intfdata(interface);
 314         usb_set_intfdata(interface, NULL);
 315
 316         /* give back our minor */
 317         usb_deregister_dev(interface, &yurex_class);
 318
 319         /* prevent more I/O from starting */
 320         usb_poison_urb(dev->urb);
 321         usb_poison_urb(dev->cntl_urb);
 322         mutex_lock(&dev->io_mutex);
 323         dev->disconnected = 1;
 324         mutex_unlock(&dev->io_mutex);
 325
 326         /* wakeup waiters */
 327         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 328         wake_up_interruptible(&dev->waitq);
 329
 330         /* decrement our usage count */
 331         kref_put(&dev->kref, yurex_delete);
 332
 333         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 334 }
 335
 336 static struct usb_driver yurex_driver = {
 337         .name =         "yurex",
 338         .probe =        yurex_probe,
 339         .disconnect =   yurex_disconnect,
 340         .id_table =     yurex_table,
 341 };
 342
 343
 344 static int yurex_fasync(int fd, struct file *file, int on)
 345 {
 346         struct usb_yurex *dev;
 347
 348         dev = file->private_data;
 349         return fasync_helper(fd, file, on, &dev->async_queue);
 350 }
 351
 352 static int yurex_open(struct inode *inode, struct file *file)
 353 {
 354         struct usb_yurex *dev;
 355         struct usb_interface *interface;
 356         int subminor;
 357         int retval = 0;
 358
 359         subminor = iminor(inode);
 360
 361         interface = usb_find_interface(&yurex_driver, subminor);
 362         if (!interface) {
 363                 printk(KERN_ERR "%s - error, can't find device for minor %d",
 364                        __func__, subminor);
 365                 retval = -ENODEV;
 366                 goto exit;
 367         }
 368
 369         dev = usb_get_intfdata(interface);
 370         if (!dev) {
 371                 retval = -ENODEV;
 372                 goto exit;
 373         }
 374
 375         /* increment our usage count for the device */
 376         kref_get(&dev->kref);
 377
 378         /* save our object in the file's private structure */
 379         mutex_lock(&dev->io_mutex);
 380         file->private_data = dev;
 381         mutex_unlock(&dev->io_mutex);
 382
 383 exit:
 384         return retval;
 385 }
 386
 387 static int yurex_release(struct inode *inode, struct file *file)
 388 {
 389         struct usb_yurex *dev;
 390
 391         dev = file->private_data;
 392         if (dev == NULL)
 393                 return -ENODEV;
 394
 395         /* decrement the count on our device */
 396         kref_put(&dev->kref, yurex_delete);
 397         return 0;
 398 }
 399
 400 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
 401                           loff_t *ppos)
 402 {
 403         struct usb_yurex *dev;
 404         int len = 0;
 405         char in_buffer[20];
 406         unsigned long flags;
 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         spin_lock_irqsave(&dev->lock, flags);
 417         len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 418         spin_unlock_irqrestore(&dev->lock, flags);
 419         mutex_unlock(&dev->io_mutex);
 420
 421         if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
 422                 return -EIO;
 423
 424         return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
 425 }
 426
 427 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
 428                            size_t count, loff_t *ppos)
 429 {
 430         struct usb_yurex *dev;
 431         int i, set = 0, retval = 0;
 432         char buffer[16 + 1];
 433         char *data = buffer;
 434         unsigned long long c, c2 = 0;
 435         signed long timeout = 0;
 436         DEFINE_WAIT(wait);
 437
 438         count = min(sizeof(buffer) - 1, count);
 439         dev = file->private_data;
 440
 441         /* verify that we actually have some data to write */
 442         if (count == 0)
 443                 goto error;
 444
 445         mutex_lock(&dev->io_mutex);
 446         if (dev->disconnected) {                /* already disconnected */
 447                 mutex_unlock(&dev->io_mutex);
 448                 retval = -ENODEV;
 449                 goto error;
 450         }
 451
 452         if (copy_from_user(buffer, user_buffer, count)) {
 453                 mutex_unlock(&dev->io_mutex);
 454                 retval = -EFAULT;
 455                 goto error;
 456         }
 457         buffer[count] = 0;
 458         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 459
 460         switch (buffer[0]) {
 461         case CMD_ANIMATE:
 462         case CMD_LED:
 463                 dev->cntl_buffer[0] = buffer[0];
 464                 dev->cntl_buffer[1] = buffer[1];
 465                 dev->cntl_buffer[2] = CMD_EOF;
 466                 break;
 467         case CMD_READ:
 468         case CMD_VERSION:
 469                 dev->cntl_buffer[0] = buffer[0];
 470                 dev->cntl_buffer[1] = 0x00;
 471                 dev->cntl_buffer[2] = CMD_EOF;
 472                 break;
 473         case CMD_SET:
 474                 data++;
 475                 fallthrough;
 476         case '0' ... '9':
 477                 set = 1;
 478                 c = c2 = simple_strtoull(data, NULL, 0);
 479                 dev->cntl_buffer[0] = CMD_SET;
 480                 for (i = 1; i < 6; i++) {
 481                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 482                         c <<= 8;
 483                 }
 484                 buffer[6] = CMD_EOF;
 485                 break;
 486         default:
 487                 mutex_unlock(&dev->io_mutex);
 488                 return -EINVAL;
 489         }
 490
 491         /* send the data as the control msg */
 492         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 493         dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
 494                 dev->cntl_buffer[0]);
 495         retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
 496         if (retval >= 0)
 497                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 498         finish_wait(&dev->waitq, &wait);
 499
 500         mutex_unlock(&dev->io_mutex);
 501
 502         if (retval < 0) {
 503                 dev_err(&dev->interface->dev,
 504                         "%s - failed to send bulk msg, error %d\n",
 505                         __func__, retval);
 506                 goto error;
 507         }
 508         if (set && timeout)
 509                 dev->bbu = c2;
 510         return timeout ? count : -EIO;
 511
 512 error:
 513         return retval;
 514 }
 515
 516 static const struct file_operations yurex_fops = {
 517         .owner =        THIS_MODULE,
 518         .read =         yurex_read,
 519         .write =        yurex_write,
 520         .open =         yurex_open,
 521         .release =      yurex_release,
 522         .fasync =       yurex_fasync,
 523         .llseek =       default_llseek,
 524 };
 525
 526 module_usb_driver(yurex_driver);
 527
 528 MODULE_LICENSE("GPL");