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 unsigned 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,
  55                            const struct ktermios *old_termios);
  56
  57 /* Not that this lot means you can only have one per system */
  58 static u8 ir_baud;
  59 static u8 ir_xbof;
  60 static u8 ir_add_bof;
  61
  62 static const struct usb_device_id ir_id_table[] = {
  63         { USB_DEVICE(0x050f, 0x0180) },         /* KC Technology, KC-180 */
  64         { USB_DEVICE(0x08e9, 0x0100) },         /* XTNDAccess */
  65         { USB_DEVICE(0x09c4, 0x0011) },         /* ACTiSys ACT-IR2000U */
  66         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
  67         { }                                     /* Terminating entry */
  68 };
  69
  70 MODULE_DEVICE_TABLE(usb, ir_id_table);
  71
  72 static struct usb_serial_driver ir_device = {
  73         .driver = {
  74                 .owner  = THIS_MODULE,
  75                 .name   = "ir-usb",
  76         },
  77         .description            = "IR Dongle",
  78         .id_table               = ir_id_table,
  79         .num_ports              = 1,
  80         .num_bulk_in            = 1,
  81         .num_bulk_out           = 1,
  82         .set_termios            = ir_set_termios,
  83         .attach                 = ir_startup,
  84         .write                  = ir_write,
  85         .write_room             = ir_write_room,
  86         .write_bulk_callback    = ir_write_bulk_callback,
  87         .process_read_urb       = ir_process_read_urb,
  88 };
  89
  90 static struct usb_serial_driver * const serial_drivers[] = {
  91         &ir_device, NULL
  92 };
  93
  94 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
  95                                             struct usb_irda_cs_descriptor *desc)
  96 {
  97         struct device *dev = &serial->dev->dev;
  98
  99         dev_dbg(dev, "bLength=%x\n", desc->bLength);
 100         dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
 101         dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
 102         dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
 103         dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
 104         dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
 105         dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
 106         dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
 107         dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
 108         dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
 109 }
 110
 111 /*------------------------------------------------------------------*/
 112 /*
 113  * Function irda_usb_find_class_desc(dev, ifnum)
 114  *
 115  *    Returns instance of IrDA class descriptor, or NULL if not found
 116  *
 117  * The class descriptor is some extra info that IrDA USB devices will
 118  * offer to us, describing their IrDA characteristics. We will use that in
 119  * irda_usb_init_qos()
 120  *
 121  * Based on the same function in drivers/net/irda/irda-usb.c
 122  */
 123 static struct usb_irda_cs_descriptor *
 124 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
 125 {
 126         struct usb_device *dev = serial->dev;
 127         struct usb_irda_cs_descriptor *desc;
 128         int ret;
 129
 130         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 131         if (!desc)
 132                 return NULL;
 133
 134         ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 135                         USB_REQ_CS_IRDA_GET_CLASS_DESC,
 136                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 137                         0, ifnum, desc, sizeof(*desc), 1000);
 138
 139         dev_dbg(&serial->dev->dev, "%s -  ret=%d\n", __func__, ret);
 140         if (ret < (int)sizeof(*desc)) {
 141                 dev_dbg(&serial->dev->dev,
 142                         "%s - class descriptor read %s (%d)\n", __func__,
 143                         (ret < 0) ? "failed" : "too short", ret);
 144                 goto error;
 145         }
 146         if (desc->bDescriptorType != USB_DT_CS_IRDA) {
 147                 dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
 148                         __func__);
 149                 goto error;
 150         }
 151
 152         irda_usb_dump_class_desc(serial, desc);
 153         return desc;
 154
 155 error:
 156         kfree(desc);
 157         return NULL;
 158 }
 159
 160 static u8 ir_xbof_change(u8 xbof)
 161 {
 162         u8 result;
 163
 164         /* reference irda-usb.c */
 165         switch (xbof) {
 166         case 48:
 167                 result = 0x10;
 168                 break;
 169         case 28:
 170         case 24:
 171                 result = 0x20;
 172                 break;
 173         default:
 174         case 12:
 175                 result = 0x30;
 176                 break;
 177         case  5:
 178         case  6:
 179                 result = 0x40;
 180                 break;
 181         case  3:
 182                 result = 0x50;
 183                 break;
 184         case  2:
 185                 result = 0x60;
 186                 break;
 187         case  1:
 188                 result = 0x70;
 189                 break;
 190         case  0:
 191                 result = 0x80;
 192                 break;
 193         }
 194
 195         return(result);
 196 }
 197
 198 static int ir_startup(struct usb_serial *serial)
 199 {
 200         struct usb_irda_cs_descriptor *irda_desc;
 201         int rates;
 202
 203         irda_desc = irda_usb_find_class_desc(serial, 0);
 204         if (!irda_desc) {
 205                 dev_err(&serial->dev->dev,
 206                         "IRDA class descriptor not found, device not bound\n");
 207                 return -ENODEV;
 208         }
 209
 210         rates = le16_to_cpu(irda_desc->wBaudRate);
 211
 212         dev_dbg(&serial->dev->dev,
 213                 "%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
 214                 __func__,
 215                 (rates & USB_IRDA_BR_2400) ? " 2400" : "",
 216                 (rates & USB_IRDA_BR_9600) ? " 9600" : "",
 217                 (rates & USB_IRDA_BR_19200) ? " 19200" : "",
 218                 (rates & USB_IRDA_BR_38400) ? " 38400" : "",
 219                 (rates & USB_IRDA_BR_57600) ? " 57600" : "",
 220                 (rates & USB_IRDA_BR_115200) ? " 115200" : "",
 221                 (rates & USB_IRDA_BR_576000) ? " 576000" : "",
 222                 (rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
 223                 (rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
 224
 225         switch (irda_desc->bmAdditionalBOFs) {
 226         case USB_IRDA_AB_48:
 227                 ir_add_bof = 48;
 228                 break;
 229         case USB_IRDA_AB_24:
 230                 ir_add_bof = 24;
 231                 break;
 232         case USB_IRDA_AB_12:
 233                 ir_add_bof = 12;
 234                 break;
 235         case USB_IRDA_AB_6:
 236                 ir_add_bof = 6;
 237                 break;
 238         case USB_IRDA_AB_3:
 239                 ir_add_bof = 3;
 240                 break;
 241         case USB_IRDA_AB_2:
 242                 ir_add_bof = 2;
 243                 break;
 244         case USB_IRDA_AB_1:
 245                 ir_add_bof = 1;
 246                 break;
 247         case USB_IRDA_AB_0:
 248                 ir_add_bof = 0;
 249                 break;
 250         default:
 251                 break;
 252         }
 253
 254         kfree(irda_desc);
 255
 256         return 0;
 257 }
 258
 259 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
 260                 const unsigned char *buf, int count)
 261 {
 262         struct urb *urb = NULL;
 263         unsigned long flags;
 264         int ret;
 265
 266         if (port->bulk_out_size == 0)
 267                 return -EINVAL;
 268
 269         if (count == 0)
 270                 return 0;
 271
 272         count = min(count, port->bulk_out_size - 1);
 273
 274         spin_lock_irqsave(&port->lock, flags);
 275         if (__test_and_clear_bit(0, &port->write_urbs_free)) {
 276                 urb = port->write_urbs[0];
 277                 port->tx_bytes += count;
 278         }
 279         spin_unlock_irqrestore(&port->lock, flags);
 280
 281         if (!urb)
 282                 return 0;
 283
 284         /*
 285          * The first byte of the packet we send to the device contains an
 286          * outbound header which indicates an additional number of BOFs and
 287          * a baud rate change.
 288          *
 289          * See section 5.4.2.2 of the USB IrDA spec.
 290          */
 291         *(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
 292
 293         memcpy(urb->transfer_buffer + 1, buf, count);
 294
 295         urb->transfer_buffer_length = count + 1;
 296         urb->transfer_flags = URB_ZERO_PACKET;
 297
 298         ret = usb_submit_urb(urb, GFP_ATOMIC);
 299         if (ret) {
 300                 dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
 301
 302                 spin_lock_irqsave(&port->lock, flags);
 303                 __set_bit(0, &port->write_urbs_free);
 304                 port->tx_bytes -= count;
 305                 spin_unlock_irqrestore(&port->lock, flags);
 306
 307                 return ret;
 308         }
 309
 310         return count;
 311 }
 312
 313 static void ir_write_bulk_callback(struct urb *urb)
 314 {
 315         struct usb_serial_port *port = urb->context;
 316         int status = urb->status;
 317         unsigned long flags;
 318
 319         spin_lock_irqsave(&port->lock, flags);
 320         __set_bit(0, &port->write_urbs_free);
 321         port->tx_bytes -= urb->transfer_buffer_length - 1;
 322         spin_unlock_irqrestore(&port->lock, flags);
 323
 324         switch (status) {
 325         case 0:
 326                 break;
 327         case -ENOENT:
 328         case -ECONNRESET:
 329         case -ESHUTDOWN:
 330                 dev_dbg(&port->dev, "write urb stopped: %d\n", status);
 331                 return;
 332         case -EPIPE:
 333                 dev_err(&port->dev, "write urb stopped: %d\n", status);
 334                 return;
 335         default:
 336                 dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
 337                 break;
 338         }
 339
 340         usb_serial_port_softint(port);
 341 }
 342
 343 static unsigned int ir_write_room(struct tty_struct *tty)
 344 {
 345         struct usb_serial_port *port = tty->driver_data;
 346         unsigned int count = 0;
 347
 348         if (port->bulk_out_size == 0)
 349                 return 0;
 350
 351         if (test_bit(0, &port->write_urbs_free))
 352                 count = port->bulk_out_size - 1;
 353
 354         return count;
 355 }
 356
 357 static void ir_process_read_urb(struct urb *urb)
 358 {
 359         struct usb_serial_port *port = urb->context;
 360         unsigned char *data = urb->transfer_buffer;
 361
 362         if (!urb->actual_length)
 363                 return;
 364         /*
 365          * The first byte of the packet we get from the device
 366          * contains a busy indicator and baud rate change.
 367          * See section 5.4.1.2 of the USB IrDA spec.
 368          */
 369         if (*data & 0x0f)
 370                 ir_baud = *data & 0x0f;
 371
 372         if (urb->actual_length == 1)
 373                 return;
 374
 375         tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
 376         tty_flip_buffer_push(&port->port);
 377 }
 378
 379 static void ir_set_termios(struct tty_struct *tty,
 380                            struct usb_serial_port *port,
 381                            const struct ktermios *old_termios)
 382 {
 383         struct usb_device *udev = port->serial->dev;
 384         unsigned char *transfer_buffer;
 385         int actual_length;
 386         speed_t baud;
 387         int ir_baud;
 388         int ret;
 389
 390         baud = tty_get_baud_rate(tty);
 391
 392         /*
 393          * FIXME, we should compare the baud request against the
 394          * capability stated in the IR header that we got in the
 395          * startup function.
 396          */
 397
 398         switch (baud) {
 399         case 2400:
 400                 ir_baud = USB_IRDA_LS_2400;
 401                 break;
 402         case 9600:
 403                 ir_baud = USB_IRDA_LS_9600;
 404                 break;
 405         case 19200:
 406                 ir_baud = USB_IRDA_LS_19200;
 407                 break;
 408         case 38400:
 409                 ir_baud = USB_IRDA_LS_38400;
 410                 break;
 411         case 57600:
 412                 ir_baud = USB_IRDA_LS_57600;
 413                 break;
 414         case 115200:
 415                 ir_baud = USB_IRDA_LS_115200;
 416                 break;
 417         case 576000:
 418                 ir_baud = USB_IRDA_LS_576000;
 419                 break;
 420         case 1152000:
 421                 ir_baud = USB_IRDA_LS_1152000;
 422                 break;
 423         case 4000000:
 424                 ir_baud = USB_IRDA_LS_4000000;
 425                 break;
 426         default:
 427                 ir_baud = USB_IRDA_LS_9600;
 428                 baud = 9600;
 429         }
 430
 431         if (xbof == -1)
 432                 ir_xbof = ir_xbof_change(ir_add_bof);
 433         else
 434                 ir_xbof = ir_xbof_change(xbof) ;
 435
 436         /* Only speed changes are supported */
 437         tty_termios_copy_hw(&tty->termios, old_termios);
 438         tty_encode_baud_rate(tty, baud, baud);
 439
 440         /*
 441          * send the baud change out on an "empty" data packet
 442          */
 443         transfer_buffer = kmalloc(1, GFP_KERNEL);
 444         if (!transfer_buffer)
 445                 return;
 446
 447         *transfer_buffer = ir_xbof | ir_baud;
 448
 449         ret = usb_bulk_msg(udev,
 450                         usb_sndbulkpipe(udev, port->bulk_out_endpointAddress),
 451                         transfer_buffer, 1, &actual_length, 5000);
 452         if (ret || actual_length != 1) {
 453                 if (!ret)
 454                         ret = -EIO;
 455                 dev_err(&port->dev, "failed to change line speed: %d\n", ret);
 456         }
 457
 458         kfree(transfer_buffer);
 459 }
 460
 461 static int __init ir_init(void)
 462 {
 463         if (buffer_size) {
 464                 ir_device.bulk_in_size = buffer_size;
 465                 ir_device.bulk_out_size = buffer_size;
 466         }
 467
 468         return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
 469 }
 470
 471 static void __exit ir_exit(void)
 472 {
 473         usb_serial_deregister_drivers(serial_drivers);
 474 }
 475
 476
 477 module_init(ir_init);
 478 module_exit(ir_exit);
 479
 480 MODULE_AUTHOR(DRIVER_AUTHOR);
 481 MODULE_DESCRIPTION(DRIVER_DESC);
 482 MODULE_LICENSE("GPL");
 483
 484 module_param(xbof, int, 0);
 485 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
 486 module_param(buffer_size, int, 0);
 487 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
 488