drivers/usb/serial/ir-usb.c

   1 /*
   2  * USB IR Dongle driver
   3  *
   4  *      Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
   5  *      Copyright (C) 2002      Gary Brubaker (xavyer@ix.netcom.com)
   6  *      Copyright (C) 2010      Johan Hovold (jhovold@gmail.com)
   7  *
   8  *      This program is free software; you can redistribute it and/or modify
   9  *      it under the terms of the GNU General Public License as published by
  10  *      the Free Software Foundation; either version 2 of the License, or
  11  *      (at your option) any later version.
  12  *
  13  * This driver allows a USB IrDA device to be used as a "dumb" serial device.
  14  * This can be useful if you do not have access to a full IrDA stack on the
  15  * other side of the connection.  If you do have an IrDA stack on both devices,
  16  * please use the usb-irda driver, as it contains the proper error checking and
  17  * other goodness of a full IrDA stack.
  18  *
  19  * Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
  20  * was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
  21  * <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
  22  *
  23  * See Documentation/usb/usb-serial.txt for more information on using this
  24  * driver
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/errno.h>
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/tty.h>
  32 #include <linux/tty_driver.h>
  33 #include <linux/tty_flip.h>
  34 #include <linux/module.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/usb.h>
  38 #include <linux/usb/serial.h>
  39 #include <linux/usb/irda.h>
  40
  41 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
  42 #define DRIVER_DESC "USB IR Dongle driver"
  43
  44 /* if overridden by the user, then use their value for the size of the read and
  45  * write urbs */
  46 static int buffer_size;
  47
  48 /* if overridden by the user, then use the specified number of XBOFs */
  49 static int xbof = -1;
  50
  51 static int  ir_startup (struct usb_serial *serial);
  52 static int  ir_open(struct tty_struct *tty, struct usb_serial_port *port);
  53 static int ir_prepare_write_buffer(struct usb_serial_port *port,
  54                                                 void *dest, size_t size);
  55 static void ir_process_read_urb(struct urb *urb);
  56 static void ir_set_termios(struct tty_struct *tty,
  57                 struct usb_serial_port *port, struct ktermios *old_termios);
  58
  59 /* Not that this lot means you can only have one per system */
  60 static u8 ir_baud;
  61 static u8 ir_xbof;
  62 static u8 ir_add_bof;
  63
  64 static const struct usb_device_id ir_id_table[] = {
  65         { USB_DEVICE(0x050f, 0x0180) },         /* KC Technology, KC-180 */
  66         { USB_DEVICE(0x08e9, 0x0100) },         /* XTNDAccess */
  67         { USB_DEVICE(0x09c4, 0x0011) },         /* ACTiSys ACT-IR2000U */
  68         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
  69         { }                                     /* Terminating entry */
  70 };
  71
  72 MODULE_DEVICE_TABLE(usb, ir_id_table);
  73
  74 static struct usb_serial_driver ir_device = {
  75         .driver = {
  76                 .owner  = THIS_MODULE,
  77                 .name   = "ir-usb",
  78         },
  79         .description            = "IR Dongle",
  80         .id_table               = ir_id_table,
  81         .num_ports              = 1,
  82         .set_termios            = ir_set_termios,
  83         .attach                 = ir_startup,
  84         .open                   = ir_open,
  85         .prepare_write_buffer   = ir_prepare_write_buffer,
  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 < 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
 201         irda_desc = irda_usb_find_class_desc(serial, 0);
 202         if (!irda_desc) {
 203                 dev_err(&serial->dev->dev,
 204                         "IRDA class descriptor not found, device not bound\n");
 205                 return -ENODEV;
 206         }
 207
 208         dev_dbg(&serial->dev->dev,
 209                 "%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
 210                 __func__,
 211                 (irda_desc->wBaudRate & USB_IRDA_BR_2400) ? " 2400" : "",
 212                 (irda_desc->wBaudRate & USB_IRDA_BR_9600) ? " 9600" : "",
 213                 (irda_desc->wBaudRate & USB_IRDA_BR_19200) ? " 19200" : "",
 214                 (irda_desc->wBaudRate & USB_IRDA_BR_38400) ? " 38400" : "",
 215                 (irda_desc->wBaudRate & USB_IRDA_BR_57600) ? " 57600" : "",
 216                 (irda_desc->wBaudRate & USB_IRDA_BR_115200) ? " 115200" : "",
 217                 (irda_desc->wBaudRate & USB_IRDA_BR_576000) ? " 576000" : "",
 218                 (irda_desc->wBaudRate & USB_IRDA_BR_1152000) ? " 1152000" : "",
 219                 (irda_desc->wBaudRate & USB_IRDA_BR_4000000) ? " 4000000" : "");
 220
 221         switch (irda_desc->bmAdditionalBOFs) {
 222         case USB_IRDA_AB_48:
 223                 ir_add_bof = 48;
 224                 break;
 225         case USB_IRDA_AB_24:
 226                 ir_add_bof = 24;
 227                 break;
 228         case USB_IRDA_AB_12:
 229                 ir_add_bof = 12;
 230                 break;
 231         case USB_IRDA_AB_6:
 232                 ir_add_bof = 6;
 233                 break;
 234         case USB_IRDA_AB_3:
 235                 ir_add_bof = 3;
 236                 break;
 237         case USB_IRDA_AB_2:
 238                 ir_add_bof = 2;
 239                 break;
 240         case USB_IRDA_AB_1:
 241                 ir_add_bof = 1;
 242                 break;
 243         case USB_IRDA_AB_0:
 244                 ir_add_bof = 0;
 245                 break;
 246         default:
 247                 break;
 248         }
 249
 250         kfree(irda_desc);
 251
 252         return 0;
 253 }
 254
 255 static int ir_open(struct tty_struct *tty, struct usb_serial_port *port)
 256 {
 257         int i;
 258
 259         for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
 260                 port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET;
 261
 262         /* Start reading from the device */
 263         return usb_serial_generic_open(tty, port);
 264 }
 265
 266 static int ir_prepare_write_buffer(struct usb_serial_port *port,
 267                                                 void *dest, size_t size)
 268 {
 269         unsigned char *buf = dest;
 270         int count;
 271
 272         /*
 273          * The first byte of the packet we send to the device contains an
 274          * inbound header which indicates an additional number of BOFs and
 275          * a baud rate change.
 276          *
 277          * See section 5.4.2.2 of the USB IrDA spec.
 278          */
 279         *buf = ir_xbof | ir_baud;
 280
 281         count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1,
 282                                                                 &port->lock);
 283         return count + 1;
 284 }
 285
 286 static void ir_process_read_urb(struct urb *urb)
 287 {
 288         struct usb_serial_port *port = urb->context;
 289         unsigned char *data = urb->transfer_buffer;
 290         struct tty_struct *tty;
 291
 292         if (!urb->actual_length)
 293                 return;
 294         /*
 295          * The first byte of the packet we get from the device
 296          * contains a busy indicator and baud rate change.
 297          * See section 5.4.1.2 of the USB IrDA spec.
 298          */
 299         if (*data & 0x0f)
 300                 ir_baud = *data & 0x0f;
 301
 302         if (urb->actual_length == 1)
 303                 return;
 304
 305         tty = tty_port_tty_get(&port->port);
 306         if (!tty)
 307                 return;
 308         tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
 309         tty_flip_buffer_push(tty);
 310         tty_kref_put(tty);
 311 }
 312
 313 static void ir_set_termios_callback(struct urb *urb)
 314 {
 315         kfree(urb->transfer_buffer);
 316
 317         if (urb->status)
 318                 dev_dbg(&urb->dev->dev, "%s - non-zero urb status: %d\n",
 319                         __func__, urb->status);
 320 }
 321
 322 static void ir_set_termios(struct tty_struct *tty,
 323                 struct usb_serial_port *port, struct ktermios *old_termios)
 324 {
 325         struct urb *urb;
 326         unsigned char *transfer_buffer;
 327         int result;
 328         speed_t baud;
 329         int ir_baud;
 330
 331         baud = tty_get_baud_rate(tty);
 332
 333         /*
 334          * FIXME, we should compare the baud request against the
 335          * capability stated in the IR header that we got in the
 336          * startup function.
 337          */
 338
 339         switch (baud) {
 340         case 2400:
 341                 ir_baud = USB_IRDA_BR_2400;
 342                 break;
 343         case 9600:
 344                 ir_baud = USB_IRDA_BR_9600;
 345                 break;
 346         case 19200:
 347                 ir_baud = USB_IRDA_BR_19200;
 348                 break;
 349         case 38400:
 350                 ir_baud = USB_IRDA_BR_38400;
 351                 break;
 352         case 57600:
 353                 ir_baud = USB_IRDA_BR_57600;
 354                 break;
 355         case 115200:
 356                 ir_baud = USB_IRDA_BR_115200;
 357                 break;
 358         case 576000:
 359                 ir_baud = USB_IRDA_BR_576000;
 360                 break;
 361         case 1152000:
 362                 ir_baud = USB_IRDA_BR_1152000;
 363                 break;
 364         case 4000000:
 365                 ir_baud = USB_IRDA_BR_4000000;
 366                 break;
 367         default:
 368                 ir_baud = USB_IRDA_BR_9600;
 369                 baud = 9600;
 370         }
 371
 372         if (xbof == -1)
 373                 ir_xbof = ir_xbof_change(ir_add_bof);
 374         else
 375                 ir_xbof = ir_xbof_change(xbof) ;
 376
 377         /* Only speed changes are supported */
 378         tty_termios_copy_hw(&tty->termios, old_termios);
 379         tty_encode_baud_rate(tty, baud, baud);
 380
 381         /*
 382          * send the baud change out on an "empty" data packet
 383          */
 384         urb = usb_alloc_urb(0, GFP_KERNEL);
 385         if (!urb) {
 386                 dev_err(&port->dev, "%s - no more urbs\n", __func__);
 387                 return;
 388         }
 389         transfer_buffer = kmalloc(1, GFP_KERNEL);
 390         if (!transfer_buffer) {
 391                 dev_err(&port->dev, "%s - out of memory\n", __func__);
 392                 goto err_buf;
 393         }
 394
 395         *transfer_buffer = ir_xbof | ir_baud;
 396
 397         usb_fill_bulk_urb(
 398                 urb,
 399                 port->serial->dev,
 400                 usb_sndbulkpipe(port->serial->dev,
 401                         port->bulk_out_endpointAddress),
 402                 transfer_buffer,
 403                 1,
 404                 ir_set_termios_callback,
 405                 port);
 406
 407         urb->transfer_flags = URB_ZERO_PACKET;
 408
 409         result = usb_submit_urb(urb, GFP_KERNEL);
 410         if (result) {
 411                 dev_err(&port->dev, "%s - failed to submit urb: %d\n",
 412                                                         __func__, result);
 413                 goto err_subm;
 414         }
 415
 416         usb_free_urb(urb);
 417
 418         return;
 419 err_subm:
 420         kfree(transfer_buffer);
 421 err_buf:
 422         usb_free_urb(urb);
 423 }
 424
 425 static int __init ir_init(void)
 426 {
 427         if (buffer_size) {
 428                 ir_device.bulk_in_size = buffer_size;
 429                 ir_device.bulk_out_size = buffer_size;
 430         }
 431
 432         return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
 433 }
 434
 435 static void __exit ir_exit(void)
 436 {
 437         usb_serial_deregister_drivers(serial_drivers);
 438 }
 439
 440
 441 module_init(ir_init);
 442 module_exit(ir_exit);
 443
 444 MODULE_AUTHOR(DRIVER_AUTHOR);
 445 MODULE_DESCRIPTION(DRIVER_DESC);
 446 MODULE_LICENSE("GPL");
 447
 448 module_param(xbof, int, 0);
 449 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
 450 module_param(buffer_size, int, 0);
 451 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
 452