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         struct fasync_struct    *async_queue;
  64         wait_queue_head_t       waitq;
  65
  66         spinlock_t              lock;
  67         __s64                   bbu;            /* BBU from device */
  68 };
  69 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
  70
  71 static struct usb_driver yurex_driver;
  72 static const struct file_operations yurex_fops;
  73
  74
  75 static void yurex_control_callback(struct urb *urb)
  76 {
  77         struct usb_yurex *dev = urb->context;
  78         int status = urb->status;
  79
  80         if (status) {
  81                 dev_err(&urb->dev->dev, "%s - control failed: %d\n",
  82                         __func__, status);
  83                 wake_up_interruptible(&dev->waitq);
  84                 return;
  85         }
  86         /* on success, sender woken up by CMD_ACK int in, or timeout */
  87 }
  88
  89 static void yurex_delete(struct kref *kref)
  90 {
  91         struct usb_yurex *dev = to_yurex_dev(kref);
  92
  93         dev_dbg(&dev->interface->dev, "%s\n", __func__);
  94
  95         usb_put_dev(dev->udev);
  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         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         case -EOVERFLOW:
 136                 dev_err(&dev->interface->dev,
 137                         "%s - overflow with length %d, actual length is %d\n",
 138                         __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
 139         case -ECONNRESET:
 140         case -ENOENT:
 141         case -ESHUTDOWN:
 142         case -EILSEQ:
 143                 /* The device is terminated, clean up */
 144                 return;
 145         default:
 146                 dev_err(&dev->interface->dev,
 147                         "%s - unknown status received: %d\n", __func__, status);
 148                 goto exit;
 149         }
 150
 151         /* handle received message */
 152         switch (buf[0]) {
 153         case CMD_COUNT:
 154         case CMD_READ:
 155                 if (buf[6] == CMD_EOF) {
 156                         spin_lock_irqsave(&dev->lock, flags);
 157                         dev->bbu = 0;
 158                         for (i = 1; i < 6; i++) {
 159                                 dev->bbu += buf[i];
 160                                 if (i != 5)
 161                                         dev->bbu <<= 8;
 162                         }
 163                         dev_dbg(&dev->interface->dev, "%s count: %lld\n",
 164                                 __func__, dev->bbu);
 165                         spin_unlock_irqrestore(&dev->lock, flags);
 166
 167                         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 168                 }
 169                 else
 170                         dev_dbg(&dev->interface->dev,
 171                                 "data format error - no EOF\n");
 172                 break;
 173         case CMD_ACK:
 174                 dev_dbg(&dev->interface->dev, "%s ack: %c\n",
 175                         __func__, buf[1]);
 176                 wake_up_interruptible(&dev->waitq);
 177                 break;
 178         }
 179
 180 exit:
 181         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 182         if (retval) {
 183                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
 184                         __func__, retval);
 185         }
 186 }
 187
 188 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
 189 {
 190         struct usb_yurex *dev;
 191         struct usb_host_interface *iface_desc;
 192         struct usb_endpoint_descriptor *endpoint;
 193         int retval = -ENOMEM;
 194         DEFINE_WAIT(wait);
 195         int res;
 196
 197         /* allocate memory for our device state and initialize it */
 198         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 199         if (!dev)
 200                 goto error;
 201         kref_init(&dev->kref);
 202         mutex_init(&dev->io_mutex);
 203         spin_lock_init(&dev->lock);
 204         init_waitqueue_head(&dev->waitq);
 205
 206         dev->udev = usb_get_dev(interface_to_usbdev(interface));
 207         dev->interface = interface;
 208
 209         /* set up the endpoint information */
 210         iface_desc = interface->cur_altsetting;
 211         res = usb_find_int_in_endpoint(iface_desc, &endpoint);
 212         if (res) {
 213                 dev_err(&interface->dev, "Could not find endpoints\n");
 214                 retval = res;
 215                 goto error;
 216         }
 217
 218         dev->int_in_endpointAddr = endpoint->bEndpointAddress;
 219
 220         /* allocate control URB */
 221         dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
 222         if (!dev->cntl_urb)
 223                 goto error;
 224
 225         /* allocate buffer for control req */
 226         dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
 227         if (!dev->cntl_req)
 228                 goto error;
 229
 230         /* allocate buffer for control msg */
 231         dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 232                                               GFP_KERNEL,
 233                                               &dev->cntl_urb->transfer_dma);
 234         if (!dev->cntl_buffer) {
 235                 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
 236                 goto error;
 237         }
 238
 239         /* configure control URB */
 240         dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
 241                                       USB_RECIP_INTERFACE;
 242         dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
 243         dev->cntl_req->wValue   = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
 244         dev->cntl_req->wIndex   = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
 245         dev->cntl_req->wLength  = cpu_to_le16(YUREX_BUF_SIZE);
 246
 247         usb_fill_control_urb(dev->cntl_urb, dev->udev,
 248                              usb_sndctrlpipe(dev->udev, 0),
 249                              (void *)dev->cntl_req, dev->cntl_buffer,
 250                              YUREX_BUF_SIZE, yurex_control_callback, dev);
 251         dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 252
 253
 254         /* allocate interrupt URB */
 255         dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 256         if (!dev->urb)
 257                 goto error;
 258
 259         /* allocate buffer for interrupt in */
 260         dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
 261                                         GFP_KERNEL, &dev->urb->transfer_dma);
 262         if (!dev->int_buffer) {
 263                 dev_err(&interface->dev, "Could not allocate int_buffer\n");
 264                 goto error;
 265         }
 266
 267         /* configure interrupt URB */
 268         usb_fill_int_urb(dev->urb, dev->udev,
 269                          usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
 270                          dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 271                          dev, 1);
 272         dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 273         if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 274                 retval = -EIO;
 275                 dev_err(&interface->dev, "Could not submitting URB\n");
 276                 goto error;
 277         }
 278
 279         /* save our data pointer in this interface device */
 280         usb_set_intfdata(interface, dev);
 281         dev->bbu = -1;
 282
 283         /* we can register the device now, as it is ready */
 284         retval = usb_register_dev(interface, &yurex_class);
 285         if (retval) {
 286                 dev_err(&interface->dev,
 287                         "Not able to get a minor for this device.\n");
 288                 usb_set_intfdata(interface, NULL);
 289                 goto error;
 290         }
 291
 292         dev_info(&interface->dev,
 293                  "USB YUREX device now attached to Yurex #%d\n",
 294                  interface->minor);
 295
 296         return 0;
 297
 298 error:
 299         if (dev)
 300                 /* this frees allocated memory */
 301                 kref_put(&dev->kref, yurex_delete);
 302         return retval;
 303 }
 304
 305 static void yurex_disconnect(struct usb_interface *interface)
 306 {
 307         struct usb_yurex *dev;
 308         int minor = interface->minor;
 309
 310         dev = usb_get_intfdata(interface);
 311         usb_set_intfdata(interface, NULL);
 312
 313         /* give back our minor */
 314         usb_deregister_dev(interface, &yurex_class);
 315
 316         /* prevent more I/O from starting */
 317         mutex_lock(&dev->io_mutex);
 318         dev->interface = NULL;
 319         mutex_unlock(&dev->io_mutex);
 320
 321         /* wakeup waiters */
 322         kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
 323         wake_up_interruptible(&dev->waitq);
 324
 325         /* decrement our usage count */
 326         kref_put(&dev->kref, yurex_delete);
 327
 328         dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
 329 }
 330
 331 static struct usb_driver yurex_driver = {
 332         .name =         "yurex",
 333         .probe =        yurex_probe,
 334         .disconnect =   yurex_disconnect,
 335         .id_table =     yurex_table,
 336 };
 337
 338
 339 static int yurex_fasync(int fd, struct file *file, int on)
 340 {
 341         struct usb_yurex *dev;
 342
 343         dev = file->private_data;
 344         return fasync_helper(fd, file, on, &dev->async_queue);
 345 }
 346
 347 static int yurex_open(struct inode *inode, struct file *file)
 348 {
 349         struct usb_yurex *dev;
 350         struct usb_interface *interface;
 351         int subminor;
 352         int retval = 0;
 353
 354         subminor = iminor(inode);
 355
 356         interface = usb_find_interface(&yurex_driver, subminor);
 357         if (!interface) {
 358                 printk(KERN_ERR "%s - error, can't find device for minor %d",
 359                        __func__, subminor);
 360                 retval = -ENODEV;
 361                 goto exit;
 362         }
 363
 364         dev = usb_get_intfdata(interface);
 365         if (!dev) {
 366                 retval = -ENODEV;
 367                 goto exit;
 368         }
 369
 370         /* increment our usage count for the device */
 371         kref_get(&dev->kref);
 372
 373         /* save our object in the file's private structure */
 374         mutex_lock(&dev->io_mutex);
 375         file->private_data = dev;
 376         mutex_unlock(&dev->io_mutex);
 377
 378 exit:
 379         return retval;
 380 }
 381
 382 static int yurex_release(struct inode *inode, struct file *file)
 383 {
 384         struct usb_yurex *dev;
 385
 386         dev = file->private_data;
 387         if (dev == NULL)
 388                 return -ENODEV;
 389
 390         /* decrement the count on our device */
 391         kref_put(&dev->kref, yurex_delete);
 392         return 0;
 393 }
 394
 395 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
 396                           loff_t *ppos)
 397 {
 398         struct usb_yurex *dev;
 399         int len = 0;
 400         char in_buffer[20];
 401         unsigned long flags;
 402
 403         dev = file->private_data;
 404
 405         mutex_lock(&dev->io_mutex);
 406         if (!dev->interface) {          /* already disconnected */
 407                 mutex_unlock(&dev->io_mutex);
 408                 return -ENODEV;
 409         }
 410
 411         spin_lock_irqsave(&dev->lock, flags);
 412         len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 413         spin_unlock_irqrestore(&dev->lock, flags);
 414         mutex_unlock(&dev->io_mutex);
 415
 416         if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
 417                 return -EIO;
 418
 419         return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
 420 }
 421
 422 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
 423                            size_t count, loff_t *ppos)
 424 {
 425         struct usb_yurex *dev;
 426         int i, set = 0, retval = 0;
 427         char buffer[16 + 1];
 428         char *data = buffer;
 429         unsigned long long c, c2 = 0;
 430         signed long timeout = 0;
 431         DEFINE_WAIT(wait);
 432
 433         count = min(sizeof(buffer) - 1, count);
 434         dev = file->private_data;
 435
 436         /* verify that we actually have some data to write */
 437         if (count == 0)
 438                 goto error;
 439
 440         mutex_lock(&dev->io_mutex);
 441         if (!dev->interface) {          /* already disconnected */
 442                 mutex_unlock(&dev->io_mutex);
 443                 retval = -ENODEV;
 444                 goto error;
 445         }
 446
 447         if (copy_from_user(buffer, user_buffer, count)) {
 448                 mutex_unlock(&dev->io_mutex);
 449                 retval = -EFAULT;
 450                 goto error;
 451         }
 452         buffer[count] = 0;
 453         memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
 454
 455         switch (buffer[0]) {
 456         case CMD_ANIMATE:
 457         case CMD_LED:
 458                 dev->cntl_buffer[0] = buffer[0];
 459                 dev->cntl_buffer[1] = buffer[1];
 460                 dev->cntl_buffer[2] = CMD_EOF;
 461                 break;
 462         case CMD_READ:
 463         case CMD_VERSION:
 464                 dev->cntl_buffer[0] = buffer[0];
 465                 dev->cntl_buffer[1] = 0x00;
 466                 dev->cntl_buffer[2] = CMD_EOF;
 467                 break;
 468         case CMD_SET:
 469                 data++;
 470                 /* FALL THROUGH */
 471         case '0' ... '9':
 472                 set = 1;
 473                 c = c2 = simple_strtoull(data, NULL, 0);
 474                 dev->cntl_buffer[0] = CMD_SET;
 475                 for (i = 1; i < 6; i++) {
 476                         dev->cntl_buffer[i] = (c>>32) & 0xff;
 477                         c <<= 8;
 478                 }
 479                 buffer[6] = CMD_EOF;
 480                 break;
 481         default:
 482                 mutex_unlock(&dev->io_mutex);
 483                 return -EINVAL;
 484         }
 485
 486         /* send the data as the control msg */
 487         prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
 488         dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
 489                 dev->cntl_buffer[0]);
 490         retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
 491         if (retval >= 0)
 492                 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 493         finish_wait(&dev->waitq, &wait);
 494
 495         mutex_unlock(&dev->io_mutex);
 496
 497         if (retval < 0) {
 498                 dev_err(&dev->interface->dev,
 499                         "%s - failed to send bulk msg, error %d\n",
 500                         __func__, retval);
 501                 goto error;
 502         }
 503         if (set && timeout)
 504                 dev->bbu = c2;
 505         return timeout ? count : -EIO;
 506
 507 error:
 508         return retval;
 509 }
 510
 511 static const struct file_operations yurex_fops = {
 512         .owner =        THIS_MODULE,
 513         .read =         yurex_read,
 514         .write =        yurex_write,
 515         .open =         yurex_open,
 516         .release =      yurex_release,
 517         .fasync =       yurex_fasync,
 518         .llseek =       default_llseek,
 519 };
 520
 521 module_usb_driver(yurex_driver);
 522
 523 MODULE_LICENSE("GPL");