drivers/usb/serial/ir-usb.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * USB IR Dongle driver
   4  *
   5  *      Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
   6  *      Copyright (C) 2002      Gary Brubaker (xavyer@ix.netcom.com)
   7  *      Copyright (C) 2010      Johan Hovold (jhovold@gmail.com)
   8  *
   9  * This driver allows a USB IrDA device to be used as a "dumb" serial device.
  10  * This can be useful if you do not have access to a full IrDA stack on the
  11  * other side of the connection.  If you do have an IrDA stack on both devices,
  12  * please use the usb-irda driver, as it contains the proper error checking and
  13  * other goodness of a full IrDA stack.
  14  *
  15  * Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
  16  * was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
  17  * <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
  18  *
  19  * See Documentation/usb/usb-serial.rst for more information on using this
  20  * driver
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/errno.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/tty.h>
  28 #include <linux/tty_driver.h>
  29 #include <linux/tty_flip.h>
  30 #include <linux/module.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/usb.h>
  34 #include <linux/usb/serial.h>
  35 #include <linux/usb/irda.h>
  36
  37 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
  38 #define DRIVER_DESC "USB IR Dongle driver"
  39
  40 /* if overridden by the user, then use their value for the size of the read and
  41  * write urbs */
  42 static int buffer_size;
  43
  44 /* if overridden by the user, then use the specified number of XBOFs */
  45 static int xbof = -1;
  46
  47 static int  ir_startup (struct usb_serial *serial);
  48 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
  49                 const unsigned char *buf, int count);
  50 static int ir_write_room(struct tty_struct *tty);
  51 static void ir_write_bulk_callback(struct urb *urb);
  52 static void ir_process_read_urb(struct urb *urb);
  53 static void ir_set_termios(struct tty_struct *tty,
  54                 struct usb_serial_port *port, struct ktermios *old_termios);
  55
  56 /* Not that this lot means you can only have one per system */
  57 static u8 ir_baud;
  58 static u8 ir_xbof;
  59 static u8 ir_add_bof;
  60
  61 static const struct usb_device_id ir_id_table[] = {
  62         { USB_DEVICE(0x050f, 0x0180) },         /* KC Technology, KC-180 */
  63         { USB_DEVICE(0x08e9, 0x0100) },         /* XTNDAccess */
  64         { USB_DEVICE(0x09c4, 0x0011) },         /* ACTiSys ACT-IR2000U */
  65         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
  66         { }                                     /* Terminating entry */
  67 };
  68
  69 MODULE_DEVICE_TABLE(usb, ir_id_table);
  70
  71 static struct usb_serial_driver ir_device = {
  72         .driver = {
  73                 .owner  = THIS_MODULE,
  74                 .name   = "ir-usb",
  75         },
  76         .description            = "IR Dongle",
  77         .id_table               = ir_id_table,
  78         .num_ports              = 1,
  79         .num_bulk_in            = 1,
  80         .num_bulk_out           = 1,
  81         .set_termios            = ir_set_termios,
  82         .attach                 = ir_startup,
  83         .write                  = ir_write,
  84         .write_room             = ir_write_room,
  85         .write_bulk_callback    = ir_write_bulk_callback,
  86         .process_read_urb       = ir_process_read_urb,
  87 };
  88
  89 static struct usb_serial_driver * const serial_drivers[] = {
  90         &ir_device, NULL
  91 };
  92
  93 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
  94                                             struct usb_irda_cs_descriptor *desc)
  95 {
  96         struct device *dev = &serial->dev->dev;
  97
  98         dev_dbg(dev, "bLength=%x\n", desc->bLength);
  99         dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
 100         dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
 101         dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
 102         dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
 103         dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
 104         dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
 105         dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
 106         dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
 107         dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
 108 }
 109
 110 /*------------------------------------------------------------------*/
 111 /*
 112  * Function irda_usb_find_class_desc(dev, ifnum)
 113  *
 114  *    Returns instance of IrDA class descriptor, or NULL if not found
 115  *
 116  * The class descriptor is some extra info that IrDA USB devices will
 117  * offer to us, describing their IrDA characteristics. We will use that in
 118  * irda_usb_init_qos()
 119  *
 120  * Based on the same function in drivers/net/irda/irda-usb.c
 121  */
 122 static struct usb_irda_cs_descriptor *
 123 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
 124 {
 125         struct usb_device *dev = serial->dev;
 126         struct usb_irda_cs_descriptor *desc;
 127         int ret;
 128
 129         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 130         if (!desc)
 131                 return NULL;
 132
 133         ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 134                         USB_REQ_CS_IRDA_GET_CLASS_DESC,
 135                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 136                         0, ifnum, desc, sizeof(*desc), 1000);
 137
 138         dev_dbg(&serial->dev->dev, "%s -  ret=%d\n", __func__, ret);
 139         if (ret < (int)sizeof(*desc)) {
 140                 dev_dbg(&serial->dev->dev,
 141                         "%s - class descriptor read %s (%d)\n", __func__,
 142                         (ret < 0) ? "failed" : "too short", ret);
 143                 goto error;
 144         }
 145         if (desc->bDescriptorType != USB_DT_CS_IRDA) {
 146                 dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
 147                         __func__);
 148                 goto error;
 149         }
 150
 151         irda_usb_dump_class_desc(serial, desc);
 152         return desc;
 153
 154 error:
 155         kfree(desc);
 156         return NULL;
 157 }
 158
 159 static u8 ir_xbof_change(u8 xbof)
 160 {
 161         u8 result;
 162
 163         /* reference irda-usb.c */
 164         switch (xbof) {
 165         case 48:
 166                 result = 0x10;
 167                 break;
 168         case 28:
 169         case 24:
 170                 result = 0x20;
 171                 break;
 172         default:
 173         case 12:
 174                 result = 0x30;
 175                 break;
 176         case  5:
 177         case  6:
 178                 result = 0x40;
 179                 break;
 180         case  3:
 181                 result = 0x50;
 182                 break;
 183         case  2:
 184                 result = 0x60;
 185                 break;
 186         case  1:
 187                 result = 0x70;
 188                 break;
 189         case  0:
 190                 result = 0x80;
 191                 break;
 192         }
 193
 194         return(result);
 195 }
 196
 197 static int ir_startup(struct usb_serial *serial)
 198 {
 199         struct usb_irda_cs_descriptor *irda_desc;
 200         int rates;
 201
 202         irda_desc = irda_usb_find_class_desc(serial, 0);
 203         if (!irda_desc) {
 204                 dev_err(&serial->dev->dev,
 205                         "IRDA class descriptor not found, device not bound\n");
 206                 return -ENODEV;
 207         }
 208
 209         rates = le16_to_cpu(irda_desc->wBaudRate);
 210
 211         dev_dbg(&serial->dev->dev,
 212                 "%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
 213                 __func__,
 214                 (rates & USB_IRDA_BR_2400) ? " 2400" : "",
 215                 (rates & USB_IRDA_BR_9600) ? " 9600" : "",
 216                 (rates & USB_IRDA_BR_19200) ? " 19200" : "",
 217                 (rates & USB_IRDA_BR_38400) ? " 38400" : "",
 218                 (rates & USB_IRDA_BR_57600) ? " 57600" : "",
 219                 (rates & USB_IRDA_BR_115200) ? " 115200" : "",
 220                 (rates & USB_IRDA_BR_576000) ? " 576000" : "",
 221                 (rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
 222                 (rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
 223
 224         switch (irda_desc->bmAdditionalBOFs) {
 225         case USB_IRDA_AB_48:
 226                 ir_add_bof = 48;
 227                 break;
 228         case USB_IRDA_AB_24:
 229                 ir_add_bof = 24;
 230                 break;
 231         case USB_IRDA_AB_12:
 232                 ir_add_bof = 12;
 233                 break;
 234         case USB_IRDA_AB_6:
 235                 ir_add_bof = 6;
 236                 break;
 237         case USB_IRDA_AB_3:
 238                 ir_add_bof = 3;
 239                 break;
 240         case USB_IRDA_AB_2:
 241                 ir_add_bof = 2;
 242                 break;
 243         case USB_IRDA_AB_1:
 244                 ir_add_bof = 1;
 245                 break;
 246         case USB_IRDA_AB_0:
 247                 ir_add_bof = 0;
 248                 break;
 249         default:
 250                 break;
 251         }
 252
 253         kfree(irda_desc);
 254
 255         return 0;
 256 }
 257
 258 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
 259                 const unsigned char *buf, int count)
 260 {
 261         struct urb *urb = NULL;
 262         unsigned long flags;
 263         int ret;
 264
 265         if (port->bulk_out_size == 0)
 266                 return -EINVAL;
 267
 268         if (count == 0)
 269                 return 0;
 270
 271         count = min(count, port->bulk_out_size - 1);
 272
 273         spin_lock_irqsave(&port->lock, flags);
 274         if (__test_and_clear_bit(0, &port->write_urbs_free)) {
 275                 urb = port->write_urbs[0];
 276                 port->tx_bytes += count;
 277         }
 278         spin_unlock_irqrestore(&port->lock, flags);
 279
 280         if (!urb)
 281                 return 0;
 282
 283         /*
 284          * The first byte of the packet we send to the device contains an
 285          * outbound header which indicates an additional number of BOFs and
 286          * a baud rate change.
 287          *
 288          * See section 5.4.2.2 of the USB IrDA spec.
 289          */
 290         *(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
 291
 292         memcpy(urb->transfer_buffer + 1, buf, count);
 293
 294         urb->transfer_buffer_length = count + 1;
 295         urb->transfer_flags = URB_ZERO_PACKET;
 296
 297         ret = usb_submit_urb(urb, GFP_ATOMIC);
 298         if (ret) {
 299                 dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
 300
 301                 spin_lock_irqsave(&port->lock, flags);
 302                 __set_bit(0, &port->write_urbs_free);
 303                 port->tx_bytes -= count;
 304                 spin_unlock_irqrestore(&port->lock, flags);
 305
 306                 return ret;
 307         }
 308
 309         return count;
 310 }
 311
 312 static void ir_write_bulk_callback(struct urb *urb)
 313 {
 314         struct usb_serial_port *port = urb->context;
 315         int status = urb->status;
 316         unsigned long flags;
 317
 318         spin_lock_irqsave(&port->lock, flags);
 319         __set_bit(0, &port->write_urbs_free);
 320         port->tx_bytes -= urb->transfer_buffer_length - 1;
 321         spin_unlock_irqrestore(&port->lock, flags);
 322
 323         switch (status) {
 324         case 0:
 325                 break;
 326         case -ENOENT:
 327         case -ECONNRESET:
 328         case -ESHUTDOWN:
 329                 dev_dbg(&port->dev, "write urb stopped: %d\n", status);
 330                 return;
 331         case -EPIPE:
 332                 dev_err(&port->dev, "write urb stopped: %d\n", status);
 333                 return;
 334         default:
 335                 dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
 336                 break;
 337         }
 338
 339         usb_serial_port_softint(port);
 340 }
 341
 342 static int ir_write_room(struct tty_struct *tty)
 343 {
 344         struct usb_serial_port *port = tty->driver_data;
 345         int count = 0;
 346
 347         if (port->bulk_out_size == 0)
 348                 return 0;
 349
 350         if (test_bit(0, &port->write_urbs_free))
 351                 count = port->bulk_out_size - 1;
 352
 353         return count;
 354 }
 355
 356 static void ir_process_read_urb(struct urb *urb)
 357 {
 358         struct usb_serial_port *port = urb->context;
 359         unsigned char *data = urb->transfer_buffer;
 360
 361         if (!urb->actual_length)
 362                 return;
 363         /*
 364          * The first byte of the packet we get from the device
 365          * contains a busy indicator and baud rate change.
 366          * See section 5.4.1.2 of the USB IrDA spec.
 367          */
 368         if (*data & 0x0f)
 369                 ir_baud = *data & 0x0f;
 370
 371         if (urb->actual_length == 1)
 372                 return;
 373
 374         tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
 375         tty_flip_buffer_push(&port->port);
 376 }
 377
 378 static void ir_set_termios(struct tty_struct *tty,
 379                 struct usb_serial_port *port, struct ktermios *old_termios)
 380 {
 381         struct usb_device *udev = port->serial->dev;
 382         unsigned char *transfer_buffer;
 383         int actual_length;
 384         speed_t baud;
 385         int ir_baud;
 386         int ret;
 387
 388         baud = tty_get_baud_rate(tty);
 389
 390         /*
 391          * FIXME, we should compare the baud request against the
 392          * capability stated in the IR header that we got in the
 393          * startup function.
 394          */
 395
 396         switch (baud) {
 397         case 2400:
 398                 ir_baud = USB_IRDA_LS_2400;
 399                 break;
 400         case 9600:
 401                 ir_baud = USB_IRDA_LS_9600;
 402                 break;
 403         case 19200:
 404                 ir_baud = USB_IRDA_LS_19200;
 405                 break;
 406         case 38400:
 407                 ir_baud = USB_IRDA_LS_38400;
 408                 break;
 409         case 57600:
 410                 ir_baud = USB_IRDA_LS_57600;
 411                 break;
 412         case 115200:
 413                 ir_baud = USB_IRDA_LS_115200;
 414                 break;
 415         case 576000:
 416                 ir_baud = USB_IRDA_LS_576000;
 417                 break;
 418         case 1152000:
 419                 ir_baud = USB_IRDA_LS_1152000;
 420                 break;
 421         case 4000000:
 422                 ir_baud = USB_IRDA_LS_4000000;
 423                 break;
 424         default:
 425                 ir_baud = USB_IRDA_LS_9600;
 426                 baud = 9600;
 427         }
 428
 429         if (xbof == -1)
 430                 ir_xbof = ir_xbof_change(ir_add_bof);
 431         else
 432                 ir_xbof = ir_xbof_change(xbof) ;
 433
 434         /* Only speed changes are supported */
 435         tty_termios_copy_hw(&tty->termios, old_termios);
 436         tty_encode_baud_rate(tty, baud, baud);
 437
 438         /*
 439          * send the baud change out on an "empty" data packet
 440          */
 441         transfer_buffer = kmalloc(1, GFP_KERNEL);
 442         if (!transfer_buffer)
 443                 return;
 444
 445         *transfer_buffer = ir_xbof | ir_baud;
 446
 447         ret = usb_bulk_msg(udev,
 448                         usb_sndbulkpipe(udev, port->bulk_out_endpointAddress),
 449                         transfer_buffer, 1, &actual_length, 5000);
 450         if (ret || actual_length != 1) {
 451                 if (!ret)
 452                         ret = -EIO;
 453                 dev_err(&port->dev, "failed to change line speed: %d\n", ret);
 454         }
 455
 456         kfree(transfer_buffer);
 457 }
 458
 459 static int __init ir_init(void)
 460 {
 461         if (buffer_size) {
 462                 ir_device.bulk_in_size = buffer_size;
 463                 ir_device.bulk_out_size = buffer_size;
 464         }
 465
 466         return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
 467 }
 468
 469 static void __exit ir_exit(void)
 470 {
 471         usb_serial_deregister_drivers(serial_drivers);
 472 }
 473
 474
 475 module_init(ir_init);
 476 module_exit(ir_exit);
 477
 478 MODULE_AUTHOR(DRIVER_AUTHOR);
 479 MODULE_DESCRIPTION(DRIVER_DESC);
 480 MODULE_LICENSE("GPL");
 481
 482 module_param(xbof, int, 0);
 483 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
 484 module_param(buffer_size, int, 0);
 485 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
 486