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.rst 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 void 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,
  48                                   const struct ktermios *old_termios);
  49 static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
  50 static int  belkin_sa_tiocmget(struct tty_struct *tty);
  51 static int  belkin_sa_tiocmset(struct tty_struct *tty,
  52                                         unsigned int set, unsigned int clear);
  53
  54
  55 static const struct usb_device_id id_table[] = {
  56         { USB_DEVICE(BELKIN_SA_VID, BELKIN_SA_PID) },
  57         { USB_DEVICE(BELKIN_OLD_VID, BELKIN_OLD_PID) },
  58         { USB_DEVICE(PERACOM_VID, PERACOM_PID) },
  59         { USB_DEVICE(GOHUBS_VID, GOHUBS_PID) },
  60         { USB_DEVICE(GOHUBS_VID, HANDYLINK_PID) },
  61         { USB_DEVICE(BELKIN_DOCKSTATION_VID, BELKIN_DOCKSTATION_PID) },
  62         { }     /* Terminating entry */
  63 };
  64 MODULE_DEVICE_TABLE(usb, id_table);
  65
  66 /* All of the device info needed for the serial converters */
  67 static struct usb_serial_driver belkin_device = {
  68         .driver = {
  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 void 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
 145 static int belkin_sa_open(struct tty_struct *tty,
 146                                         struct usb_serial_port *port)
 147 {
 148         int retval;
 149
 150         retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 151         if (retval) {
 152                 dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
 153                 return retval;
 154         }
 155
 156         retval = usb_serial_generic_open(tty, port);
 157         if (retval)
 158                 usb_kill_urb(port->interrupt_in_urb);
 159
 160         return retval;
 161 }
 162
 163 static void belkin_sa_close(struct usb_serial_port *port)
 164 {
 165         usb_serial_generic_close(port);
 166         usb_kill_urb(port->interrupt_in_urb);
 167 }
 168
 169 static void belkin_sa_read_int_callback(struct urb *urb)
 170 {
 171         struct usb_serial_port *port = urb->context;
 172         struct belkin_sa_private *priv;
 173         unsigned char *data = urb->transfer_buffer;
 174         int retval;
 175         int status = urb->status;
 176         unsigned long flags;
 177
 178         switch (status) {
 179         case 0:
 180                 /* success */
 181                 break;
 182         case -ECONNRESET:
 183         case -ENOENT:
 184         case -ESHUTDOWN:
 185                 /* this urb is terminated, clean up */
 186                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
 187                         __func__, status);
 188                 return;
 189         default:
 190                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
 191                         __func__, status);
 192                 goto exit;
 193         }
 194
 195         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
 196
 197         /* Handle known interrupt data */
 198         /* ignore data[0] and data[1] */
 199
 200         priv = usb_get_serial_port_data(port);
 201         spin_lock_irqsave(&priv->lock, flags);
 202         priv->last_msr = data[BELKIN_SA_MSR_INDEX];
 203
 204         /* Record Control Line states */
 205         if (priv->last_msr & BELKIN_SA_MSR_DSR)
 206                 priv->control_state |= TIOCM_DSR;
 207         else
 208                 priv->control_state &= ~TIOCM_DSR;
 209
 210         if (priv->last_msr & BELKIN_SA_MSR_CTS)
 211                 priv->control_state |= TIOCM_CTS;
 212         else
 213                 priv->control_state &= ~TIOCM_CTS;
 214
 215         if (priv->last_msr & BELKIN_SA_MSR_RI)
 216                 priv->control_state |= TIOCM_RI;
 217         else
 218                 priv->control_state &= ~TIOCM_RI;
 219
 220         if (priv->last_msr & BELKIN_SA_MSR_CD)
 221                 priv->control_state |= TIOCM_CD;
 222         else
 223                 priv->control_state &= ~TIOCM_CD;
 224
 225         priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
 226         spin_unlock_irqrestore(&priv->lock, flags);
 227 exit:
 228         retval = usb_submit_urb(urb, GFP_ATOMIC);
 229         if (retval)
 230                 dev_err(&port->dev, "%s - usb_submit_urb failed with "
 231                         "result %d\n", __func__, retval);
 232 }
 233
 234 static void belkin_sa_process_read_urb(struct urb *urb)
 235 {
 236         struct usb_serial_port *port = urb->context;
 237         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 238         unsigned char *data = urb->transfer_buffer;
 239         unsigned long flags;
 240         unsigned char status;
 241         char tty_flag;
 242
 243         /* Update line status */
 244         tty_flag = TTY_NORMAL;
 245
 246         spin_lock_irqsave(&priv->lock, flags);
 247         status = priv->last_lsr;
 248         priv->last_lsr &= ~BELKIN_SA_LSR_ERR;
 249         spin_unlock_irqrestore(&priv->lock, flags);
 250
 251         if (!urb->actual_length)
 252                 return;
 253
 254         if (status & BELKIN_SA_LSR_ERR) {
 255                 /* Break takes precedence over parity, which takes precedence
 256                  * over framing errors. */
 257                 if (status & BELKIN_SA_LSR_BI)
 258                         tty_flag = TTY_BREAK;
 259                 else if (status & BELKIN_SA_LSR_PE)
 260                         tty_flag = TTY_PARITY;
 261                 else if (status & BELKIN_SA_LSR_FE)
 262                         tty_flag = TTY_FRAME;
 263                 dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
 264
 265                 /* Overrun is special, not associated with a char. */
 266                 if (status & BELKIN_SA_LSR_OE)
 267                         tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 268         }
 269
 270         tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
 271                                                         urb->actual_length);
 272         tty_flip_buffer_push(&port->port);
 273 }
 274
 275 static void belkin_sa_set_termios(struct tty_struct *tty,
 276                                   struct usb_serial_port *port,
 277                                   const struct ktermios *old_termios)
 278 {
 279         struct usb_serial *serial = port->serial;
 280         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 281         unsigned int iflag;
 282         unsigned int cflag;
 283         unsigned int old_iflag = 0;
 284         unsigned int old_cflag = 0;
 285         __u16 urb_value = 0; /* Will hold the new flags */
 286         unsigned long flags;
 287         unsigned long control_state;
 288         int bad_flow_control;
 289         speed_t baud;
 290         struct ktermios *termios = &tty->termios;
 291
 292         iflag = termios->c_iflag;
 293         cflag = termios->c_cflag;
 294
 295         termios->c_cflag &= ~CMSPAR;
 296
 297         /* get a local copy of the current port settings */
 298         spin_lock_irqsave(&priv->lock, flags);
 299         control_state = priv->control_state;
 300         bad_flow_control = priv->bad_flow_control;
 301         spin_unlock_irqrestore(&priv->lock, flags);
 302
 303         old_iflag = old_termios->c_iflag;
 304         old_cflag = old_termios->c_cflag;
 305
 306         /* Set the baud rate */
 307         if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
 308                 /* reassert DTR and (maybe) RTS on transition from B0 */
 309                 if ((old_cflag & CBAUD) == B0) {
 310                         control_state |= (TIOCM_DTR|TIOCM_RTS);
 311                         if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 1) < 0)
 312                                 dev_err(&port->dev, "Set DTR error\n");
 313                         /* don't set RTS if using hardware flow control */
 314                         if (!(old_cflag & CRTSCTS))
 315                                 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST
 316                                                                 , 1) < 0)
 317                                         dev_err(&port->dev, "Set RTS error\n");
 318                 }
 319         }
 320
 321         baud = tty_get_baud_rate(tty);
 322         if (baud) {
 323                 urb_value = BELKIN_SA_BAUD(baud);
 324                 /* Clip to maximum speed */
 325                 if (urb_value == 0)
 326                         urb_value = 1;
 327                 /* Turn it back into a resulting real baud rate */
 328                 baud = BELKIN_SA_BAUD(urb_value);
 329
 330                 /* Report the actual baud rate back to the caller */
 331                 tty_encode_baud_rate(tty, baud, baud);
 332                 if (BSA_USB_CMD(BELKIN_SA_SET_BAUDRATE_REQUEST, urb_value) < 0)
 333                         dev_err(&port->dev, "Set baudrate error\n");
 334         } else {
 335                 /* Disable flow control */
 336                 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST,
 337                                                 BELKIN_SA_FLOW_NONE) < 0)
 338                         dev_err(&port->dev, "Disable flowcontrol error\n");
 339                 /* Drop RTS and DTR */
 340                 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 341                 if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 0) < 0)
 342                         dev_err(&port->dev, "DTR LOW error\n");
 343                 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, 0) < 0)
 344                         dev_err(&port->dev, "RTS LOW error\n");
 345         }
 346
 347         /* set the parity */
 348         if ((cflag ^ old_cflag) & (PARENB | PARODD)) {
 349                 if (cflag & PARENB)
 350                         urb_value = (cflag & PARODD) ?  BELKIN_SA_PARITY_ODD
 351                                                 : BELKIN_SA_PARITY_EVEN;
 352                 else
 353                         urb_value = BELKIN_SA_PARITY_NONE;
 354                 if (BSA_USB_CMD(BELKIN_SA_SET_PARITY_REQUEST, urb_value) < 0)
 355                         dev_err(&port->dev, "Set parity error\n");
 356         }
 357
 358         /* set the number of data bits */
 359         if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 360                 urb_value = BELKIN_SA_DATA_BITS(tty_get_char_size(cflag));
 361                 if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
 362                         dev_err(&port->dev, "Set data bits error\n");
 363         }
 364
 365         /* set the number of stop bits */
 366         if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 367                 urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
 368                                                 : BELKIN_SA_STOP_BITS(1);
 369                 if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
 370                                                         urb_value) < 0)
 371                         dev_err(&port->dev, "Set stop bits error\n");
 372         }
 373
 374         /* Set flow control */
 375         if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
 376                 ((cflag ^ old_cflag) & CRTSCTS)) {
 377                 urb_value = 0;
 378                 if ((iflag & IXOFF) || (iflag & IXON))
 379                         urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
 380                 else
 381                         urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
 382
 383                 if (cflag & CRTSCTS)
 384                         urb_value |=  (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
 385                 else
 386                         urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
 387
 388                 if (bad_flow_control)
 389                         urb_value &= ~(BELKIN_SA_FLOW_IRTS);
 390
 391                 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
 392                         dev_err(&port->dev, "Set flow control error\n");
 393         }
 394
 395         /* save off the modified port settings */
 396         spin_lock_irqsave(&priv->lock, flags);
 397         priv->control_state = control_state;
 398         spin_unlock_irqrestore(&priv->lock, flags);
 399 }
 400
 401 static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
 402 {
 403         struct usb_serial_port *port = tty->driver_data;
 404         struct usb_serial *serial = port->serial;
 405         int ret;
 406
 407         ret = BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0);
 408         if (ret < 0) {
 409                 dev_err(&port->dev, "Set break_ctl %d\n", break_state);
 410                 return ret;
 411         }
 412
 413         return 0;
 414 }
 415
 416 static int belkin_sa_tiocmget(struct tty_struct *tty)
 417 {
 418         struct usb_serial_port *port = tty->driver_data;
 419         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 420         unsigned long control_state;
 421         unsigned long flags;
 422
 423         spin_lock_irqsave(&priv->lock, flags);
 424         control_state = priv->control_state;
 425         spin_unlock_irqrestore(&priv->lock, flags);
 426
 427         return control_state;
 428 }
 429
 430 static int belkin_sa_tiocmset(struct tty_struct *tty,
 431                                unsigned int set, unsigned int clear)
 432 {
 433         struct usb_serial_port *port = tty->driver_data;
 434         struct usb_serial *serial = port->serial;
 435         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 436         unsigned long control_state;
 437         unsigned long flags;
 438         int retval;
 439         int rts = 0;
 440         int dtr = 0;
 441
 442         spin_lock_irqsave(&priv->lock, flags);
 443         control_state = priv->control_state;
 444
 445         if (set & TIOCM_RTS) {
 446                 control_state |= TIOCM_RTS;
 447                 rts = 1;
 448         }
 449         if (set & TIOCM_DTR) {
 450                 control_state |= TIOCM_DTR;
 451                 dtr = 1;
 452         }
 453         if (clear & TIOCM_RTS) {
 454                 control_state &= ~TIOCM_RTS;
 455                 rts = 0;
 456         }
 457         if (clear & TIOCM_DTR) {
 458                 control_state &= ~TIOCM_DTR;
 459                 dtr = 0;
 460         }
 461
 462         priv->control_state = control_state;
 463         spin_unlock_irqrestore(&priv->lock, flags);
 464
 465         retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
 466         if (retval < 0) {
 467                 dev_err(&port->dev, "Set RTS error %d\n", retval);
 468                 goto exit;
 469         }
 470
 471         retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
 472         if (retval < 0) {
 473                 dev_err(&port->dev, "Set DTR error %d\n", retval);
 474                 goto exit;
 475         }
 476 exit:
 477         return retval;
 478 }
 479
 480 module_usb_serial_driver(serial_drivers, id_table);
 481
 482 MODULE_AUTHOR(DRIVER_AUTHOR);
 483 MODULE_DESCRIPTION(DRIVER_DESC);
 484 MODULE_LICENSE("GPL");