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.txt 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_open(struct tty_struct *tty, struct usb_serial_port *port);
  49 static int ir_prepare_write_buffer(struct usb_serial_port *port,
  50                                                 void *dest, size_t size);
  51 static void ir_process_read_urb(struct urb *urb);
  52 static void ir_set_termios(struct tty_struct *tty,
  53                 struct usb_serial_port *port, struct ktermios *old_termios);
  54
  55 /* Not that this lot means you can only have one per system */
  56 static u8 ir_baud;
  57 static u8 ir_xbof;
  58 static u8 ir_add_bof;
  59
  60 static const struct usb_device_id ir_id_table[] = {
  61         { USB_DEVICE(0x050f, 0x0180) },         /* KC Technology, KC-180 */
  62         { USB_DEVICE(0x08e9, 0x0100) },         /* XTNDAccess */
  63         { USB_DEVICE(0x09c4, 0x0011) },         /* ACTiSys ACT-IR2000U */
  64         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
  65         { }                                     /* Terminating entry */
  66 };
  67
  68 MODULE_DEVICE_TABLE(usb, ir_id_table);
  69
  70 static struct usb_serial_driver ir_device = {
  71         .driver = {
  72                 .owner  = THIS_MODULE,
  73                 .name   = "ir-usb",
  74         },
  75         .description            = "IR Dongle",
  76         .id_table               = ir_id_table,
  77         .num_ports              = 1,
  78         .set_termios            = ir_set_termios,
  79         .attach                 = ir_startup,
  80         .open                   = ir_open,
  81         .prepare_write_buffer   = ir_prepare_write_buffer,
  82         .process_read_urb       = ir_process_read_urb,
  83 };
  84
  85 static struct usb_serial_driver * const serial_drivers[] = {
  86         &ir_device, NULL
  87 };
  88
  89 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
  90                                             struct usb_irda_cs_descriptor *desc)
  91 {
  92         struct device *dev = &serial->dev->dev;
  93
  94         dev_dbg(dev, "bLength=%x\n", desc->bLength);
  95         dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
  96         dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
  97         dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
  98         dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
  99         dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
 100         dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
 101         dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
 102         dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
 103         dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
 104 }
 105
 106 /*------------------------------------------------------------------*/
 107 /*
 108  * Function irda_usb_find_class_desc(dev, ifnum)
 109  *
 110  *    Returns instance of IrDA class descriptor, or NULL if not found
 111  *
 112  * The class descriptor is some extra info that IrDA USB devices will
 113  * offer to us, describing their IrDA characteristics. We will use that in
 114  * irda_usb_init_qos()
 115  *
 116  * Based on the same function in drivers/net/irda/irda-usb.c
 117  */
 118 static struct usb_irda_cs_descriptor *
 119 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
 120 {
 121         struct usb_device *dev = serial->dev;
 122         struct usb_irda_cs_descriptor *desc;
 123         int ret;
 124
 125         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 126         if (!desc)
 127                 return NULL;
 128
 129         ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 130                         USB_REQ_CS_IRDA_GET_CLASS_DESC,
 131                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 132                         0, ifnum, desc, sizeof(*desc), 1000);
 133
 134         dev_dbg(&serial->dev->dev, "%s -  ret=%d\n", __func__, ret);
 135         if (ret < (int)sizeof(*desc)) {
 136                 dev_dbg(&serial->dev->dev,
 137                         "%s - class descriptor read %s (%d)\n", __func__,
 138                         (ret < 0) ? "failed" : "too short", ret);
 139                 goto error;
 140         }
 141         if (desc->bDescriptorType != USB_DT_CS_IRDA) {
 142                 dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
 143                         __func__);
 144                 goto error;
 145         }
 146
 147         irda_usb_dump_class_desc(serial, desc);
 148         return desc;
 149
 150 error:
 151         kfree(desc);
 152         return NULL;
 153 }
 154
 155 static u8 ir_xbof_change(u8 xbof)
 156 {
 157         u8 result;
 158
 159         /* reference irda-usb.c */
 160         switch (xbof) {
 161         case 48:
 162                 result = 0x10;
 163                 break;
 164         case 28:
 165         case 24:
 166                 result = 0x20;
 167                 break;
 168         default:
 169         case 12:
 170                 result = 0x30;
 171                 break;
 172         case  5:
 173         case  6:
 174                 result = 0x40;
 175                 break;
 176         case  3:
 177                 result = 0x50;
 178                 break;
 179         case  2:
 180                 result = 0x60;
 181                 break;
 182         case  1:
 183                 result = 0x70;
 184                 break;
 185         case  0:
 186                 result = 0x80;
 187                 break;
 188         }
 189
 190         return(result);
 191 }
 192
 193 static int ir_startup(struct usb_serial *serial)
 194 {
 195         struct usb_irda_cs_descriptor *irda_desc;
 196         int rates;
 197
 198         irda_desc = irda_usb_find_class_desc(serial, 0);
 199         if (!irda_desc) {
 200                 dev_err(&serial->dev->dev,
 201                         "IRDA class descriptor not found, device not bound\n");
 202                 return -ENODEV;
 203         }
 204
 205         rates = le16_to_cpu(irda_desc->wBaudRate);
 206
 207         dev_dbg(&serial->dev->dev,
 208                 "%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
 209                 __func__,
 210                 (rates & USB_IRDA_BR_2400) ? " 2400" : "",
 211                 (rates & USB_IRDA_BR_9600) ? " 9600" : "",
 212                 (rates & USB_IRDA_BR_19200) ? " 19200" : "",
 213                 (rates & USB_IRDA_BR_38400) ? " 38400" : "",
 214                 (rates & USB_IRDA_BR_57600) ? " 57600" : "",
 215                 (rates & USB_IRDA_BR_115200) ? " 115200" : "",
 216                 (rates & USB_IRDA_BR_576000) ? " 576000" : "",
 217                 (rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
 218                 (rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
 219
 220         switch (irda_desc->bmAdditionalBOFs) {
 221         case USB_IRDA_AB_48:
 222                 ir_add_bof = 48;
 223                 break;
 224         case USB_IRDA_AB_24:
 225                 ir_add_bof = 24;
 226                 break;
 227         case USB_IRDA_AB_12:
 228                 ir_add_bof = 12;
 229                 break;
 230         case USB_IRDA_AB_6:
 231                 ir_add_bof = 6;
 232                 break;
 233         case USB_IRDA_AB_3:
 234                 ir_add_bof = 3;
 235                 break;
 236         case USB_IRDA_AB_2:
 237                 ir_add_bof = 2;
 238                 break;
 239         case USB_IRDA_AB_1:
 240                 ir_add_bof = 1;
 241                 break;
 242         case USB_IRDA_AB_0:
 243                 ir_add_bof = 0;
 244                 break;
 245         default:
 246                 break;
 247         }
 248
 249         kfree(irda_desc);
 250
 251         return 0;
 252 }
 253
 254 static int ir_open(struct tty_struct *tty, struct usb_serial_port *port)
 255 {
 256         int i;
 257
 258         for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
 259                 port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET;
 260
 261         /* Start reading from the device */
 262         return usb_serial_generic_open(tty, port);
 263 }
 264
 265 static int ir_prepare_write_buffer(struct usb_serial_port *port,
 266                                                 void *dest, size_t size)
 267 {
 268         unsigned char *buf = dest;
 269         int count;
 270
 271         /*
 272          * The first byte of the packet we send to the device contains an
 273          * inbound header which indicates an additional number of BOFs and
 274          * a baud rate change.
 275          *
 276          * See section 5.4.2.2 of the USB IrDA spec.
 277          */
 278         *buf = ir_xbof | ir_baud;
 279
 280         count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1,
 281                                                                 &port->lock);
 282         return count + 1;
 283 }
 284
 285 static void ir_process_read_urb(struct urb *urb)
 286 {
 287         struct usb_serial_port *port = urb->context;
 288         unsigned char *data = urb->transfer_buffer;
 289
 290         if (!urb->actual_length)
 291                 return;
 292         /*
 293          * The first byte of the packet we get from the device
 294          * contains a busy indicator and baud rate change.
 295          * See section 5.4.1.2 of the USB IrDA spec.
 296          */
 297         if (*data & 0x0f)
 298                 ir_baud = *data & 0x0f;
 299
 300         if (urb->actual_length == 1)
 301                 return;
 302
 303         tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
 304         tty_flip_buffer_push(&port->port);
 305 }
 306
 307 static void ir_set_termios_callback(struct urb *urb)
 308 {
 309         kfree(urb->transfer_buffer);
 310
 311         if (urb->status)
 312                 dev_dbg(&urb->dev->dev, "%s - non-zero urb status: %d\n",
 313                         __func__, urb->status);
 314 }
 315
 316 static void ir_set_termios(struct tty_struct *tty,
 317                 struct usb_serial_port *port, struct ktermios *old_termios)
 318 {
 319         struct urb *urb;
 320         unsigned char *transfer_buffer;
 321         int result;
 322         speed_t baud;
 323         int ir_baud;
 324
 325         baud = tty_get_baud_rate(tty);
 326
 327         /*
 328          * FIXME, we should compare the baud request against the
 329          * capability stated in the IR header that we got in the
 330          * startup function.
 331          */
 332
 333         switch (baud) {
 334         case 2400:
 335                 ir_baud = USB_IRDA_BR_2400;
 336                 break;
 337         case 9600:
 338                 ir_baud = USB_IRDA_BR_9600;
 339                 break;
 340         case 19200:
 341                 ir_baud = USB_IRDA_BR_19200;
 342                 break;
 343         case 38400:
 344                 ir_baud = USB_IRDA_BR_38400;
 345                 break;
 346         case 57600:
 347                 ir_baud = USB_IRDA_BR_57600;
 348                 break;
 349         case 115200:
 350                 ir_baud = USB_IRDA_BR_115200;
 351                 break;
 352         case 576000:
 353                 ir_baud = USB_IRDA_BR_576000;
 354                 break;
 355         case 1152000:
 356                 ir_baud = USB_IRDA_BR_1152000;
 357                 break;
 358         case 4000000:
 359                 ir_baud = USB_IRDA_BR_4000000;
 360                 break;
 361         default:
 362                 ir_baud = USB_IRDA_BR_9600;
 363                 baud = 9600;
 364         }
 365
 366         if (xbof == -1)
 367                 ir_xbof = ir_xbof_change(ir_add_bof);
 368         else
 369                 ir_xbof = ir_xbof_change(xbof) ;
 370
 371         /* Only speed changes are supported */
 372         tty_termios_copy_hw(&tty->termios, old_termios);
 373         tty_encode_baud_rate(tty, baud, baud);
 374
 375         /*
 376          * send the baud change out on an "empty" data packet
 377          */
 378         urb = usb_alloc_urb(0, GFP_KERNEL);
 379         if (!urb)
 380                 return;
 381
 382         transfer_buffer = kmalloc(1, GFP_KERNEL);
 383         if (!transfer_buffer)
 384                 goto err_buf;
 385
 386         *transfer_buffer = ir_xbof | ir_baud;
 387
 388         usb_fill_bulk_urb(
 389                 urb,
 390                 port->serial->dev,
 391                 usb_sndbulkpipe(port->serial->dev,
 392                         port->bulk_out_endpointAddress),
 393                 transfer_buffer,
 394                 1,
 395                 ir_set_termios_callback,
 396                 port);
 397
 398         urb->transfer_flags = URB_ZERO_PACKET;
 399
 400         result = usb_submit_urb(urb, GFP_KERNEL);
 401         if (result) {
 402                 dev_err(&port->dev, "%s - failed to submit urb: %d\n",
 403                                                         __func__, result);
 404                 goto err_subm;
 405         }
 406
 407         usb_free_urb(urb);
 408
 409         return;
 410 err_subm:
 411         kfree(transfer_buffer);
 412 err_buf:
 413         usb_free_urb(urb);
 414 }
 415
 416 static int __init ir_init(void)
 417 {
 418         if (buffer_size) {
 419                 ir_device.bulk_in_size = buffer_size;
 420                 ir_device.bulk_out_size = buffer_size;
 421         }
 422
 423         return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
 424 }
 425
 426 static void __exit ir_exit(void)
 427 {
 428         usb_serial_deregister_drivers(serial_drivers);
 429 }
 430
 431
 432 module_init(ir_init);
 433 module_exit(ir_exit);
 434
 435 MODULE_AUTHOR(DRIVER_AUTHOR);
 436 MODULE_DESCRIPTION(DRIVER_DESC);
 437 MODULE_LICENSE("GPL");
 438
 439 module_param(xbof, int, 0);
 440 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
 441 module_param(buffer_size, int, 0);
 442 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
 443