drivers/usb/serial/kl5kusb105.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * KLSI KL5KUSB105 chip RS232 converter driver
   4  *
   5  *   Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
   6  *   Copyright (C) 2001 Utz-Uwe Haus <haus@uuhaus.de>
   7  *
   8  * All information about the device was acquired using SniffUSB ans snoopUSB
   9  * on Windows98.
  10  * It was written out of frustration with the PalmConnect USB Serial adapter
  11  * sold by Palm Inc.
  12  * Neither Palm, nor their contractor (MCCI) or their supplier (KLSI) provided
  13  * information that was not already available.
  14  *
  15  * It seems that KLSI bought some silicon-design information from ScanLogic,
  16  * whose SL11R processor is at the core of the KL5KUSB chipset from KLSI.
  17  * KLSI has firmware available for their devices; it is probable that the
  18  * firmware differs from that used by KLSI in their products. If you have an
  19  * original KLSI device and can provide some information on it, I would be
  20  * most interested in adding support for it here. If you have any information
  21  * on the protocol used (or find errors in my reverse-engineered stuff), please
  22  * let me know.
  23  *
  24  * The code was only tested with a PalmConnect USB adapter; if you
  25  * are adventurous, try it with any KLSI-based device and let me know how it
  26  * breaks so that I can fix it!
  27  */
  28
  29 /* TODO:
  30  *      check modem line signals
  31  *      implement handshaking or decide that we do not support it
  32  */
  33
  34 #include <linux/kernel.h>
  35 #include <linux/errno.h>
  36 #include <linux/slab.h>
  37 #include <linux/tty.h>
  38 #include <linux/tty_driver.h>
  39 #include <linux/tty_flip.h>
  40 #include <linux/module.h>
  41 #include <linux/uaccess.h>
  42 #include <asm/unaligned.h>
  43 #include <linux/usb.h>
  44 #include <linux/usb/serial.h>
  45 #include "kl5kusb105.h"
  46
  47 #define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
  48 #define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
  49
  50
  51 /*
  52  * Function prototypes
  53  */
  54 static int klsi_105_port_probe(struct usb_serial_port *port);
  55 static void klsi_105_port_remove(struct usb_serial_port *port);
  56 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
  57 static void klsi_105_close(struct usb_serial_port *port);
  58 static void klsi_105_set_termios(struct tty_struct *tty,
  59                         struct usb_serial_port *port, struct ktermios *old);
  60 static int  klsi_105_tiocmget(struct tty_struct *tty);
  61 static void klsi_105_process_read_urb(struct urb *urb);
  62 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
  63                                                 void *dest, size_t size);
  64
  65 /*
  66  * All of the device info needed for the KLSI converters.
  67  */
  68 static const struct usb_device_id id_table[] = {
  69         { USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
  70         { }             /* Terminating entry */
  71 };
  72
  73 MODULE_DEVICE_TABLE(usb, id_table);
  74
  75 static struct usb_serial_driver kl5kusb105d_device = {
  76         .driver = {
  77                 .owner =        THIS_MODULE,
  78                 .name =         "kl5kusb105d",
  79         },
  80         .description =          "KL5KUSB105D / PalmConnect",
  81         .id_table =             id_table,
  82         .num_ports =            1,
  83         .bulk_out_size =        64,
  84         .open =                 klsi_105_open,
  85         .close =                klsi_105_close,
  86         .set_termios =          klsi_105_set_termios,
  87         .tiocmget =             klsi_105_tiocmget,
  88         .port_probe =           klsi_105_port_probe,
  89         .port_remove =          klsi_105_port_remove,
  90         .throttle =             usb_serial_generic_throttle,
  91         .unthrottle =           usb_serial_generic_unthrottle,
  92         .process_read_urb =     klsi_105_process_read_urb,
  93         .prepare_write_buffer = klsi_105_prepare_write_buffer,
  94 };
  95
  96 static struct usb_serial_driver * const serial_drivers[] = {
  97         &kl5kusb105d_device, NULL
  98 };
  99
 100 struct klsi_105_port_settings {
 101         u8      pktlen;         /* always 5, it seems */
 102         u8      baudrate;
 103         u8      databits;
 104         u8      unknown1;
 105         u8      unknown2;
 106 };
 107
 108 struct klsi_105_private {
 109         struct klsi_105_port_settings   cfg;
 110         unsigned long                   line_state; /* modem line settings */
 111         spinlock_t                      lock;
 112 };
 113
 114
 115 /*
 116  * Handle vendor specific USB requests
 117  */
 118
 119
 120 #define KLSI_TIMEOUT     5000 /* default urb timeout */
 121
 122 static int klsi_105_chg_port_settings(struct usb_serial_port *port,
 123                                       struct klsi_105_port_settings *settings)
 124 {
 125         int rc;
 126
 127         rc = usb_control_msg_send(port->serial->dev,
 128                                   0,
 129                                   KL5KUSB105A_SIO_SET_DATA,
 130                                   USB_TYPE_VENDOR | USB_DIR_OUT |
 131                                   USB_RECIP_INTERFACE,
 132                                   0, /* value */
 133                                   0, /* index */
 134                                   settings,
 135                                   sizeof(struct klsi_105_port_settings),
 136                                   KLSI_TIMEOUT,
 137                                   GFP_KERNEL);
 138         if (rc)
 139                 dev_err(&port->dev,
 140                         "Change port settings failed (error = %d)\n", rc);
 141
 142         dev_dbg(&port->dev,
 143                 "pktlen %u, baudrate 0x%02x, databits %u, u1 %u, u2 %u\n",
 144                 settings->pktlen, settings->baudrate, settings->databits,
 145                 settings->unknown1, settings->unknown2);
 146
 147         return rc;
 148 }
 149
 150 /*
 151  * Read line control via vendor command and return result through
 152  * the state pointer.
 153  */
 154 static int klsi_105_get_line_state(struct usb_serial_port *port,
 155                                    unsigned long *state)
 156 {
 157         u16 status;
 158         int rc;
 159
 160         rc = usb_control_msg_recv(port->serial->dev, 0,
 161                                   KL5KUSB105A_SIO_POLL,
 162                                   USB_TYPE_VENDOR | USB_DIR_IN,
 163                                   0, /* value */
 164                                   0, /* index */
 165                                   &status, sizeof(status),
 166                                   10000,
 167                                   GFP_KERNEL);
 168         if (rc) {
 169                 dev_err(&port->dev, "reading line status failed: %d\n", rc);
 170                 return rc;
 171         }
 172
 173         le16_to_cpus(&status);
 174
 175         dev_dbg(&port->dev, "read status %04x\n", status);
 176
 177         *state = ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0) |
 178                  ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0);
 179
 180         return 0;
 181 }
 182
 183
 184 /*
 185  * Driver's tty interface functions
 186  */
 187
 188 static int klsi_105_port_probe(struct usb_serial_port *port)
 189 {
 190         struct klsi_105_private *priv;
 191
 192         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 193         if (!priv)
 194                 return -ENOMEM;
 195
 196         /* set initial values for control structures */
 197         priv->cfg.pktlen    = 5;
 198         priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
 199         priv->cfg.databits  = kl5kusb105a_dtb_8;
 200         priv->cfg.unknown1  = 0;
 201         priv->cfg.unknown2  = 1;
 202
 203         priv->line_state    = 0;
 204
 205         spin_lock_init(&priv->lock);
 206
 207         usb_set_serial_port_data(port, priv);
 208
 209         return 0;
 210 }
 211
 212 static void klsi_105_port_remove(struct usb_serial_port *port)
 213 {
 214         struct klsi_105_private *priv;
 215
 216         priv = usb_get_serial_port_data(port);
 217         kfree(priv);
 218 }
 219
 220 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 221 {
 222         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 223         int retval = 0;
 224         int rc;
 225         unsigned long line_state;
 226         struct klsi_105_port_settings cfg;
 227         unsigned long flags;
 228
 229         /* Do a defined restart:
 230          * Set up sane default baud rate and send the 'READ_ON'
 231          * vendor command.
 232          * FIXME: set modem line control (how?)
 233          * Then read the modem line control and store values in
 234          * priv->line_state.
 235          */
 236
 237         cfg.pktlen   = 5;
 238         cfg.baudrate = kl5kusb105a_sio_b9600;
 239         cfg.databits = kl5kusb105a_dtb_8;
 240         cfg.unknown1 = 0;
 241         cfg.unknown2 = 1;
 242         klsi_105_chg_port_settings(port, &cfg);
 243
 244         spin_lock_irqsave(&priv->lock, flags);
 245         priv->cfg.pktlen   = cfg.pktlen;
 246         priv->cfg.baudrate = cfg.baudrate;
 247         priv->cfg.databits = cfg.databits;
 248         priv->cfg.unknown1 = cfg.unknown1;
 249         priv->cfg.unknown2 = cfg.unknown2;
 250         spin_unlock_irqrestore(&priv->lock, flags);
 251
 252         /* READ_ON and urb submission */
 253         rc = usb_serial_generic_open(tty, port);
 254         if (rc)
 255                 return rc;
 256
 257         rc = usb_control_msg(port->serial->dev,
 258                              usb_sndctrlpipe(port->serial->dev, 0),
 259                              KL5KUSB105A_SIO_CONFIGURE,
 260                              USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
 261                              KL5KUSB105A_SIO_CONFIGURE_READ_ON,
 262                              0, /* index */
 263                              NULL,
 264                              0,
 265                              KLSI_TIMEOUT);
 266         if (rc < 0) {
 267                 dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
 268                 retval = rc;
 269                 goto err_generic_close;
 270         } else
 271                 dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
 272
 273         rc = klsi_105_get_line_state(port, &line_state);
 274         if (rc < 0) {
 275                 retval = rc;
 276                 goto err_disable_read;
 277         }
 278
 279         spin_lock_irqsave(&priv->lock, flags);
 280         priv->line_state = line_state;
 281         spin_unlock_irqrestore(&priv->lock, flags);
 282         dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__,
 283                         line_state);
 284
 285         return 0;
 286
 287 err_disable_read:
 288         usb_control_msg(port->serial->dev,
 289                              usb_sndctrlpipe(port->serial->dev, 0),
 290                              KL5KUSB105A_SIO_CONFIGURE,
 291                              USB_TYPE_VENDOR | USB_DIR_OUT,
 292                              KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
 293                              0, /* index */
 294                              NULL, 0,
 295                              KLSI_TIMEOUT);
 296 err_generic_close:
 297         usb_serial_generic_close(port);
 298
 299         return retval;
 300 }
 301
 302 static void klsi_105_close(struct usb_serial_port *port)
 303 {
 304         int rc;
 305
 306         /* send READ_OFF */
 307         rc = usb_control_msg(port->serial->dev,
 308                              usb_sndctrlpipe(port->serial->dev, 0),
 309                              KL5KUSB105A_SIO_CONFIGURE,
 310                              USB_TYPE_VENDOR | USB_DIR_OUT,
 311                              KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
 312                              0, /* index */
 313                              NULL, 0,
 314                              KLSI_TIMEOUT);
 315         if (rc < 0)
 316                 dev_err(&port->dev, "failed to disable read: %d\n", rc);
 317
 318         /* shutdown our bulk reads and writes */
 319         usb_serial_generic_close(port);
 320 }
 321
 322 /* We need to write a complete 64-byte data block and encode the
 323  * number actually sent in the first double-byte, LSB-order. That
 324  * leaves at most 62 bytes of payload.
 325  */
 326 #define KLSI_HDR_LEN            2
 327 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
 328                                                 void *dest, size_t size)
 329 {
 330         unsigned char *buf = dest;
 331         int count;
 332
 333         count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
 334                                                                 &port->lock);
 335         put_unaligned_le16(count, buf);
 336
 337         return count + KLSI_HDR_LEN;
 338 }
 339
 340 /* The data received is preceded by a length double-byte in LSB-first order.
 341  */
 342 static void klsi_105_process_read_urb(struct urb *urb)
 343 {
 344         struct usb_serial_port *port = urb->context;
 345         unsigned char *data = urb->transfer_buffer;
 346         unsigned len;
 347
 348         /* empty urbs seem to happen, we ignore them */
 349         if (!urb->actual_length)
 350                 return;
 351
 352         if (urb->actual_length <= KLSI_HDR_LEN) {
 353                 dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
 354                 return;
 355         }
 356
 357         len = get_unaligned_le16(data);
 358         if (len > urb->actual_length - KLSI_HDR_LEN) {
 359                 dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
 360                 len = urb->actual_length - KLSI_HDR_LEN;
 361         }
 362
 363         tty_insert_flip_string(&port->port, data + KLSI_HDR_LEN, len);
 364         tty_flip_buffer_push(&port->port);
 365 }
 366
 367 static void klsi_105_set_termios(struct tty_struct *tty,
 368                                  struct usb_serial_port *port,
 369                                  struct ktermios *old_termios)
 370 {
 371         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 372         struct device *dev = &port->dev;
 373         unsigned int iflag = tty->termios.c_iflag;
 374         unsigned int old_iflag = old_termios->c_iflag;
 375         unsigned int cflag = tty->termios.c_cflag;
 376         unsigned int old_cflag = old_termios->c_cflag;
 377         struct klsi_105_port_settings *cfg;
 378         unsigned long flags;
 379         speed_t baud;
 380
 381         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
 382         if (!cfg)
 383                 return;
 384
 385         /* lock while we are modifying the settings */
 386         spin_lock_irqsave(&priv->lock, flags);
 387
 388         /*
 389          * Update baud rate
 390          */
 391         baud = tty_get_baud_rate(tty);
 392
 393         switch (baud) {
 394         case 0: /* handled below */
 395                 break;
 396         case 1200:
 397                 priv->cfg.baudrate = kl5kusb105a_sio_b1200;
 398                 break;
 399         case 2400:
 400                 priv->cfg.baudrate = kl5kusb105a_sio_b2400;
 401                 break;
 402         case 4800:
 403                 priv->cfg.baudrate = kl5kusb105a_sio_b4800;
 404                 break;
 405         case 9600:
 406                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 407                 break;
 408         case 19200:
 409                 priv->cfg.baudrate = kl5kusb105a_sio_b19200;
 410                 break;
 411         case 38400:
 412                 priv->cfg.baudrate = kl5kusb105a_sio_b38400;
 413                 break;
 414         case 57600:
 415                 priv->cfg.baudrate = kl5kusb105a_sio_b57600;
 416                 break;
 417         case 115200:
 418                 priv->cfg.baudrate = kl5kusb105a_sio_b115200;
 419                 break;
 420         default:
 421                 dev_dbg(dev, "unsupported baudrate, using 9600\n");
 422                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 423                 baud = 9600;
 424                 break;
 425         }
 426
 427         /*
 428          * FIXME: implement B0 handling
 429          *
 430          * Maybe this should be simulated by sending read disable and read
 431          * enable messages?
 432          */
 433
 434         tty_encode_baud_rate(tty, baud, baud);
 435
 436         if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 437                 /* set the number of data bits */
 438                 switch (cflag & CSIZE) {
 439                 case CS5:
 440                         dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
 441                         spin_unlock_irqrestore(&priv->lock, flags);
 442                         goto err;
 443                 case CS6:
 444                         dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
 445                         spin_unlock_irqrestore(&priv->lock, flags);
 446                         goto err;
 447                 case CS7:
 448                         priv->cfg.databits = kl5kusb105a_dtb_7;
 449                         break;
 450                 case CS8:
 451                         priv->cfg.databits = kl5kusb105a_dtb_8;
 452                         break;
 453                 default:
 454                         dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
 455                         priv->cfg.databits = kl5kusb105a_dtb_8;
 456                         break;
 457                 }
 458         }
 459
 460         /*
 461          * Update line control register (LCR)
 462          */
 463         if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
 464             || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 465                 /* Not currently supported */
 466                 tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
 467         }
 468         /*
 469          * Set flow control: well, I do not really now how to handle DTR/RTS.
 470          * Just do what we have seen with SniffUSB on Win98.
 471          */
 472         if ((iflag & IXOFF) != (old_iflag & IXOFF)
 473             || (iflag & IXON) != (old_iflag & IXON)
 474             ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
 475                 /* Not currently supported */
 476                 tty->termios.c_cflag &= ~CRTSCTS;
 477         }
 478         memcpy(cfg, &priv->cfg, sizeof(*cfg));
 479         spin_unlock_irqrestore(&priv->lock, flags);
 480
 481         /* now commit changes to device */
 482         klsi_105_chg_port_settings(port, cfg);
 483 err:
 484         kfree(cfg);
 485 }
 486
 487 static int klsi_105_tiocmget(struct tty_struct *tty)
 488 {
 489         struct usb_serial_port *port = tty->driver_data;
 490         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 491         unsigned long flags;
 492         int rc;
 493         unsigned long line_state;
 494
 495         rc = klsi_105_get_line_state(port, &line_state);
 496         if (rc < 0) {
 497                 dev_err(&port->dev,
 498                         "Reading line control failed (error = %d)\n", rc);
 499                 /* better return value? EAGAIN? */
 500                 return rc;
 501         }
 502
 503         spin_lock_irqsave(&priv->lock, flags);
 504         priv->line_state = line_state;
 505         spin_unlock_irqrestore(&priv->lock, flags);
 506         dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
 507         return (int)line_state;
 508 }
 509
 510 module_usb_serial_driver(serial_drivers, id_table);
 511
 512 MODULE_AUTHOR(DRIVER_AUTHOR);
 513 MODULE_DESCRIPTION(DRIVER_DESC);
 514 MODULE_LICENSE("GPL");