drivers/usb/serial/belkin_sa.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Belkin USB Serial Adapter Driver
   4  *
   5  *  Copyright (C) 2000          William Greathouse (wgreathouse@smva.com)
   6  *  Copyright (C) 2000-2001     Greg Kroah-Hartman (greg@kroah.com)
   7  *  Copyright (C) 2010          Johan Hovold (jhovold@gmail.com)
   8  *
   9  *  This program is largely derived from work by the linux-usb group
  10  *  and associated source files.  Please see the usb/serial files for
  11  *  individual credits and copyrights.
  12  *
  13  * See Documentation/usb/usb-serial.txt for more information on using this
  14  * driver
  15  *
  16  * TODO:
  17  * -- Add true modem control line query capability.  Currently we track the
  18  *    states reported by the interrupt and the states we request.
  19  * -- Add support for flush commands
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/errno.h>
  24 #include <linux/slab.h>
  25 #include <linux/tty.h>
  26 #include <linux/tty_driver.h>
  27 #include <linux/tty_flip.h>
  28 #include <linux/module.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/usb.h>
  32 #include <linux/usb/serial.h>
  33 #include "belkin_sa.h"
  34
  35 #define DRIVER_AUTHOR "William Greathouse <wgreathouse@smva.com>"
  36 #define DRIVER_DESC "USB Belkin Serial converter driver"
  37
  38 /* function prototypes for a Belkin USB Serial Adapter F5U103 */
  39 static int belkin_sa_port_probe(struct usb_serial_port *port);
  40 static int belkin_sa_port_remove(struct usb_serial_port *port);
  41 static int  belkin_sa_open(struct tty_struct *tty,
  42                         struct usb_serial_port *port);
  43 static void belkin_sa_close(struct usb_serial_port *port);
  44 static void belkin_sa_read_int_callback(struct urb *urb);
  45 static void belkin_sa_process_read_urb(struct urb *urb);
  46 static void belkin_sa_set_termios(struct tty_struct *tty,
  47                         struct usb_serial_port *port, struct ktermios * old);
  48 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
  49 static int  belkin_sa_tiocmget(struct tty_struct *tty);
  50 static int  belkin_sa_tiocmset(struct tty_struct *tty,
  51                                         unsigned int set, unsigned int clear);
  52
  53
  54 static const struct usb_device_id id_table[] = {
  55         { USB_DEVICE(BELKIN_SA_VID, BELKIN_SA_PID) },
  56         { USB_DEVICE(BELKIN_OLD_VID, BELKIN_OLD_PID) },
  57         { USB_DEVICE(PERACOM_VID, PERACOM_PID) },
  58         { USB_DEVICE(GOHUBS_VID, GOHUBS_PID) },
  59         { USB_DEVICE(GOHUBS_VID, HANDYLINK_PID) },
  60         { USB_DEVICE(BELKIN_DOCKSTATION_VID, BELKIN_DOCKSTATION_PID) },
  61         { }     /* Terminating entry */
  62 };
  63 MODULE_DEVICE_TABLE(usb, id_table);
  64
  65 /* All of the device info needed for the serial converters */
  66 static struct usb_serial_driver belkin_device = {
  67         .driver = {
  68                 .owner =        THIS_MODULE,
  69                 .name =         "belkin",
  70         },
  71         .description =          "Belkin / Peracom / GoHubs USB Serial Adapter",
  72         .id_table =             id_table,
  73         .num_ports =            1,
  74         .open =                 belkin_sa_open,
  75         .close =                belkin_sa_close,
  76         .read_int_callback =    belkin_sa_read_int_callback,
  77         .process_read_urb =     belkin_sa_process_read_urb,
  78         .set_termios =          belkin_sa_set_termios,
  79         .break_ctl =            belkin_sa_break_ctl,
  80         .tiocmget =             belkin_sa_tiocmget,
  81         .tiocmset =             belkin_sa_tiocmset,
  82         .port_probe =           belkin_sa_port_probe,
  83         .port_remove =          belkin_sa_port_remove,
  84 };
  85
  86 static struct usb_serial_driver * const serial_drivers[] = {
  87         &belkin_device, NULL
  88 };
  89
  90 struct belkin_sa_private {
  91         spinlock_t              lock;
  92         unsigned long           control_state;
  93         unsigned char           last_lsr;
  94         unsigned char           last_msr;
  95         int                     bad_flow_control;
  96 };
  97
  98
  99 /*
 100  * ***************************************************************************
 101  * Belkin USB Serial Adapter F5U103 specific driver functions
 102  * ***************************************************************************
 103  */
 104
 105 #define WDR_TIMEOUT 5000 /* default urb timeout */
 106
 107 /* assumes that struct usb_serial *serial is available */
 108 #define BSA_USB_CMD(c, v) usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), \
 109                                             (c), BELKIN_SA_SET_REQUEST_TYPE, \
 110                                             (v), 0, NULL, 0, WDR_TIMEOUT)
 111
 112 static int belkin_sa_port_probe(struct usb_serial_port *port)
 113 {
 114         struct usb_device *dev = port->serial->dev;
 115         struct belkin_sa_private *priv;
 116
 117         priv = kmalloc(sizeof(struct belkin_sa_private), GFP_KERNEL);
 118         if (!priv)
 119                 return -ENOMEM;
 120
 121         spin_lock_init(&priv->lock);
 122         priv->control_state = 0;
 123         priv->last_lsr = 0;
 124         priv->last_msr = 0;
 125         /* see comments at top of file */
 126         priv->bad_flow_control =
 127                 (le16_to_cpu(dev->descriptor.bcdDevice) <= 0x0206) ? 1 : 0;
 128         dev_info(&dev->dev, "bcdDevice: %04x, bfc: %d\n",
 129                                         le16_to_cpu(dev->descriptor.bcdDevice),
 130                                         priv->bad_flow_control);
 131
 132         usb_set_serial_port_data(port, priv);
 133
 134         return 0;
 135 }
 136
 137 static int belkin_sa_port_remove(struct usb_serial_port *port)
 138 {
 139         struct belkin_sa_private *priv;
 140
 141         priv = usb_get_serial_port_data(port);
 142         kfree(priv);
 143
 144         return 0;
 145 }
 146
 147 static int belkin_sa_open(struct tty_struct *tty,
 148                                         struct usb_serial_port *port)
 149 {
 150         int retval;
 151
 152         retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 153         if (retval) {
 154                 dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
 155                 return retval;
 156         }
 157
 158         retval = usb_serial_generic_open(tty, port);
 159         if (retval)
 160                 usb_kill_urb(port->interrupt_in_urb);
 161
 162         return retval;
 163 }
 164
 165 static void belkin_sa_close(struct usb_serial_port *port)
 166 {
 167         usb_serial_generic_close(port);
 168         usb_kill_urb(port->interrupt_in_urb);
 169 }
 170
 171 static void belkin_sa_read_int_callback(struct urb *urb)
 172 {
 173         struct usb_serial_port *port = urb->context;
 174         struct belkin_sa_private *priv;
 175         unsigned char *data = urb->transfer_buffer;
 176         int retval;
 177         int status = urb->status;
 178         unsigned long flags;
 179
 180         switch (status) {
 181         case 0:
 182                 /* success */
 183                 break;
 184         case -ECONNRESET:
 185         case -ENOENT:
 186         case -ESHUTDOWN:
 187                 /* this urb is terminated, clean up */
 188                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
 189                         __func__, status);
 190                 return;
 191         default:
 192                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
 193                         __func__, status);
 194                 goto exit;
 195         }
 196
 197         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
 198
 199         /* Handle known interrupt data */
 200         /* ignore data[0] and data[1] */
 201
 202         priv = usb_get_serial_port_data(port);
 203         spin_lock_irqsave(&priv->lock, flags);
 204         priv->last_msr = data[BELKIN_SA_MSR_INDEX];
 205
 206         /* Record Control Line states */
 207         if (priv->last_msr & BELKIN_SA_MSR_DSR)
 208                 priv->control_state |= TIOCM_DSR;
 209         else
 210                 priv->control_state &= ~TIOCM_DSR;
 211
 212         if (priv->last_msr & BELKIN_SA_MSR_CTS)
 213                 priv->control_state |= TIOCM_CTS;
 214         else
 215                 priv->control_state &= ~TIOCM_CTS;
 216
 217         if (priv->last_msr & BELKIN_SA_MSR_RI)
 218                 priv->control_state |= TIOCM_RI;
 219         else
 220                 priv->control_state &= ~TIOCM_RI;
 221
 222         if (priv->last_msr & BELKIN_SA_MSR_CD)
 223                 priv->control_state |= TIOCM_CD;
 224         else
 225                 priv->control_state &= ~TIOCM_CD;
 226
 227         priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
 228         spin_unlock_irqrestore(&priv->lock, flags);
 229 exit:
 230         retval = usb_submit_urb(urb, GFP_ATOMIC);
 231         if (retval)
 232                 dev_err(&port->dev, "%s - usb_submit_urb failed with "
 233                         "result %d\n", __func__, retval);
 234 }
 235
 236 static void belkin_sa_process_read_urb(struct urb *urb)
 237 {
 238         struct usb_serial_port *port = urb->context;
 239         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 240         unsigned char *data = urb->transfer_buffer;
 241         unsigned long flags;
 242         unsigned char status;
 243         char tty_flag;
 244
 245         /* Update line status */
 246         tty_flag = TTY_NORMAL;
 247
 248         spin_lock_irqsave(&priv->lock, flags);
 249         status = priv->last_lsr;
 250         priv->last_lsr &= ~BELKIN_SA_LSR_ERR;
 251         spin_unlock_irqrestore(&priv->lock, flags);
 252
 253         if (!urb->actual_length)
 254                 return;
 255
 256         if (status & BELKIN_SA_LSR_ERR) {
 257                 /* Break takes precedence over parity, which takes precedence
 258                  * over framing errors. */
 259                 if (status & BELKIN_SA_LSR_BI)
 260                         tty_flag = TTY_BREAK;
 261                 else if (status & BELKIN_SA_LSR_PE)
 262                         tty_flag = TTY_PARITY;
 263                 else if (status & BELKIN_SA_LSR_FE)
 264                         tty_flag = TTY_FRAME;
 265                 dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
 266
 267                 /* Overrun is special, not associated with a char. */
 268                 if (status & BELKIN_SA_LSR_OE)
 269                         tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 270         }
 271
 272         tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
 273                                                         urb->actual_length);
 274         tty_flip_buffer_push(&port->port);
 275 }
 276
 277 static void belkin_sa_set_termios(struct tty_struct *tty,
 278                 struct usb_serial_port *port, struct ktermios *old_termios)
 279 {
 280         struct usb_serial *serial = port->serial;
 281         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 282         unsigned int iflag;
 283         unsigned int cflag;
 284         unsigned int old_iflag = 0;
 285         unsigned int old_cflag = 0;
 286         __u16 urb_value = 0; /* Will hold the new flags */
 287         unsigned long flags;
 288         unsigned long control_state;
 289         int bad_flow_control;
 290         speed_t baud;
 291         struct ktermios *termios = &tty->termios;
 292
 293         iflag = termios->c_iflag;
 294         cflag = termios->c_cflag;
 295
 296         termios->c_cflag &= ~CMSPAR;
 297
 298         /* get a local copy of the current port settings */
 299         spin_lock_irqsave(&priv->lock, flags);
 300         control_state = priv->control_state;
 301         bad_flow_control = priv->bad_flow_control;
 302         spin_unlock_irqrestore(&priv->lock, flags);
 303
 304         old_iflag = old_termios->c_iflag;
 305         old_cflag = old_termios->c_cflag;
 306
 307         /* Set the baud rate */
 308         if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
 309                 /* reassert DTR and (maybe) RTS on transition from B0 */
 310                 if ((old_cflag & CBAUD) == B0) {
 311                         control_state |= (TIOCM_DTR|TIOCM_RTS);
 312                         if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 1) < 0)
 313                                 dev_err(&port->dev, "Set DTR error\n");
 314                         /* don't set RTS if using hardware flow control */
 315                         if (!(old_cflag & CRTSCTS))
 316                                 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST
 317                                                                 , 1) < 0)
 318                                         dev_err(&port->dev, "Set RTS error\n");
 319                 }
 320         }
 321
 322         baud = tty_get_baud_rate(tty);
 323         if (baud) {
 324                 urb_value = BELKIN_SA_BAUD(baud);
 325                 /* Clip to maximum speed */
 326                 if (urb_value == 0)
 327                         urb_value = 1;
 328                 /* Turn it back into a resulting real baud rate */
 329                 baud = BELKIN_SA_BAUD(urb_value);
 330
 331                 /* Report the actual baud rate back to the caller */
 332                 tty_encode_baud_rate(tty, baud, baud);
 333                 if (BSA_USB_CMD(BELKIN_SA_SET_BAUDRATE_REQUEST, urb_value) < 0)
 334                         dev_err(&port->dev, "Set baudrate error\n");
 335         } else {
 336                 /* Disable flow control */
 337                 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST,
 338                                                 BELKIN_SA_FLOW_NONE) < 0)
 339                         dev_err(&port->dev, "Disable flowcontrol error\n");
 340                 /* Drop RTS and DTR */
 341                 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 342                 if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 0) < 0)
 343                         dev_err(&port->dev, "DTR LOW error\n");
 344                 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, 0) < 0)
 345                         dev_err(&port->dev, "RTS LOW error\n");
 346         }
 347
 348         /* set the parity */
 349         if ((cflag ^ old_cflag) & (PARENB | PARODD)) {
 350                 if (cflag & PARENB)
 351                         urb_value = (cflag & PARODD) ?  BELKIN_SA_PARITY_ODD
 352                                                 : BELKIN_SA_PARITY_EVEN;
 353                 else
 354                         urb_value = BELKIN_SA_PARITY_NONE;
 355                 if (BSA_USB_CMD(BELKIN_SA_SET_PARITY_REQUEST, urb_value) < 0)
 356                         dev_err(&port->dev, "Set parity error\n");
 357         }
 358
 359         /* set the number of data bits */
 360         if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 361                 switch (cflag & CSIZE) {
 362                 case CS5:
 363                         urb_value = BELKIN_SA_DATA_BITS(5);
 364                         break;
 365                 case CS6:
 366                         urb_value = BELKIN_SA_DATA_BITS(6);
 367                         break;
 368                 case CS7:
 369                         urb_value = BELKIN_SA_DATA_BITS(7);
 370                         break;
 371                 case CS8:
 372                         urb_value = BELKIN_SA_DATA_BITS(8);
 373                         break;
 374                 default:
 375                         dev_dbg(&port->dev,
 376                                 "CSIZE was not CS5-CS8, using default of 8\n");
 377                         urb_value = BELKIN_SA_DATA_BITS(8);
 378                         break;
 379                 }
 380                 if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
 381                         dev_err(&port->dev, "Set data bits error\n");
 382         }
 383
 384         /* set the number of stop bits */
 385         if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 386                 urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
 387                                                 : BELKIN_SA_STOP_BITS(1);
 388                 if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
 389                                                         urb_value) < 0)
 390                         dev_err(&port->dev, "Set stop bits error\n");
 391         }
 392
 393         /* Set flow control */
 394         if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
 395                 ((cflag ^ old_cflag) & CRTSCTS)) {
 396                 urb_value = 0;
 397                 if ((iflag & IXOFF) || (iflag & IXON))
 398                         urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
 399                 else
 400                         urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
 401
 402                 if (cflag & CRTSCTS)
 403                         urb_value |=  (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
 404                 else
 405                         urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
 406
 407                 if (bad_flow_control)
 408                         urb_value &= ~(BELKIN_SA_FLOW_IRTS);
 409
 410                 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
 411                         dev_err(&port->dev, "Set flow control error\n");
 412         }
 413
 414         /* save off the modified port settings */
 415         spin_lock_irqsave(&priv->lock, flags);
 416         priv->control_state = control_state;
 417         spin_unlock_irqrestore(&priv->lock, flags);
 418 }
 419
 420 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
 421 {
 422         struct usb_serial_port *port = tty->driver_data;
 423         struct usb_serial *serial = port->serial;
 424
 425         if (BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0) < 0)
 426                 dev_err(&port->dev, "Set break_ctl %d\n", break_state);
 427 }
 428
 429 static int belkin_sa_tiocmget(struct tty_struct *tty)
 430 {
 431         struct usb_serial_port *port = tty->driver_data;
 432         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 433         unsigned long control_state;
 434         unsigned long flags;
 435
 436         spin_lock_irqsave(&priv->lock, flags);
 437         control_state = priv->control_state;
 438         spin_unlock_irqrestore(&priv->lock, flags);
 439
 440         return control_state;
 441 }
 442
 443 static int belkin_sa_tiocmset(struct tty_struct *tty,
 444                                unsigned int set, unsigned int clear)
 445 {
 446         struct usb_serial_port *port = tty->driver_data;
 447         struct usb_serial *serial = port->serial;
 448         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 449         unsigned long control_state;
 450         unsigned long flags;
 451         int retval;
 452         int rts = 0;
 453         int dtr = 0;
 454
 455         spin_lock_irqsave(&priv->lock, flags);
 456         control_state = priv->control_state;
 457
 458         if (set & TIOCM_RTS) {
 459                 control_state |= TIOCM_RTS;
 460                 rts = 1;
 461         }
 462         if (set & TIOCM_DTR) {
 463                 control_state |= TIOCM_DTR;
 464                 dtr = 1;
 465         }
 466         if (clear & TIOCM_RTS) {
 467                 control_state &= ~TIOCM_RTS;
 468                 rts = 0;
 469         }
 470         if (clear & TIOCM_DTR) {
 471                 control_state &= ~TIOCM_DTR;
 472                 dtr = 0;
 473         }
 474
 475         priv->control_state = control_state;
 476         spin_unlock_irqrestore(&priv->lock, flags);
 477
 478         retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
 479         if (retval < 0) {
 480                 dev_err(&port->dev, "Set RTS error %d\n", retval);
 481                 goto exit;
 482         }
 483
 484         retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
 485         if (retval < 0) {
 486                 dev_err(&port->dev, "Set DTR error %d\n", retval);
 487                 goto exit;
 488         }
 489 exit:
 490         return retval;
 491 }
 492
 493 module_usb_serial_driver(serial_drivers, id_table);
 494
 495 MODULE_AUTHOR(DRIVER_AUTHOR);
 496 MODULE_DESCRIPTION(DRIVER_DESC);
 497 MODULE_LICENSE("GPL");