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                 .owner =        THIS_MODULE,
  70                 .name =         "belkin",
  71         },
  72         .description =          "Belkin / Peracom / GoHubs USB Serial Adapter",
  73         .id_table =             id_table,
  74         .num_ports =            1,
  75         .open =                 belkin_sa_open,
  76         .close =                belkin_sa_close,
  77         .read_int_callback =    belkin_sa_read_int_callback,
  78         .process_read_urb =     belkin_sa_process_read_urb,
  79         .set_termios =          belkin_sa_set_termios,
  80         .break_ctl =            belkin_sa_break_ctl,
  81         .tiocmget =             belkin_sa_tiocmget,
  82         .tiocmset =             belkin_sa_tiocmset,
  83         .port_probe =           belkin_sa_port_probe,
  84         .port_remove =          belkin_sa_port_remove,
  85 };
  86
  87 static struct usb_serial_driver * const serial_drivers[] = {
  88         &belkin_device, NULL
  89 };
  90
  91 struct belkin_sa_private {
  92         spinlock_t              lock;
  93         unsigned long           control_state;
  94         unsigned char           last_lsr;
  95         unsigned char           last_msr;
  96         int                     bad_flow_control;
  97 };
  98
  99
 100 /*
 101  * ***************************************************************************
 102  * Belkin USB Serial Adapter F5U103 specific driver functions
 103  * ***************************************************************************
 104  */
 105
 106 #define WDR_TIMEOUT 5000 /* default urb timeout */
 107
 108 /* assumes that struct usb_serial *serial is available */
 109 #define BSA_USB_CMD(c, v) usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), \
 110                                             (c), BELKIN_SA_SET_REQUEST_TYPE, \
 111                                             (v), 0, NULL, 0, WDR_TIMEOUT)
 112
 113 static int belkin_sa_port_probe(struct usb_serial_port *port)
 114 {
 115         struct usb_device *dev = port->serial->dev;
 116         struct belkin_sa_private *priv;
 117
 118         priv = kmalloc(sizeof(struct belkin_sa_private), GFP_KERNEL);
 119         if (!priv)
 120                 return -ENOMEM;
 121
 122         spin_lock_init(&priv->lock);
 123         priv->control_state = 0;
 124         priv->last_lsr = 0;
 125         priv->last_msr = 0;
 126         /* see comments at top of file */
 127         priv->bad_flow_control =
 128                 (le16_to_cpu(dev->descriptor.bcdDevice) <= 0x0206) ? 1 : 0;
 129         dev_info(&dev->dev, "bcdDevice: %04x, bfc: %d\n",
 130                                         le16_to_cpu(dev->descriptor.bcdDevice),
 131                                         priv->bad_flow_control);
 132
 133         usb_set_serial_port_data(port, priv);
 134
 135         return 0;
 136 }
 137
 138 static void belkin_sa_port_remove(struct usb_serial_port *port)
 139 {
 140         struct belkin_sa_private *priv;
 141
 142         priv = usb_get_serial_port_data(port);
 143         kfree(priv);
 144 }
 145
 146 static int belkin_sa_open(struct tty_struct *tty,
 147                                         struct usb_serial_port *port)
 148 {
 149         int retval;
 150
 151         retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 152         if (retval) {
 153                 dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
 154                 return retval;
 155         }
 156
 157         retval = usb_serial_generic_open(tty, port);
 158         if (retval)
 159                 usb_kill_urb(port->interrupt_in_urb);
 160
 161         return retval;
 162 }
 163
 164 static void belkin_sa_close(struct usb_serial_port *port)
 165 {
 166         usb_serial_generic_close(port);
 167         usb_kill_urb(port->interrupt_in_urb);
 168 }
 169
 170 static void belkin_sa_read_int_callback(struct urb *urb)
 171 {
 172         struct usb_serial_port *port = urb->context;
 173         struct belkin_sa_private *priv;
 174         unsigned char *data = urb->transfer_buffer;
 175         int retval;
 176         int status = urb->status;
 177         unsigned long flags;
 178
 179         switch (status) {
 180         case 0:
 181                 /* success */
 182                 break;
 183         case -ECONNRESET:
 184         case -ENOENT:
 185         case -ESHUTDOWN:
 186                 /* this urb is terminated, clean up */
 187                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
 188                         __func__, status);
 189                 return;
 190         default:
 191                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
 192                         __func__, status);
 193                 goto exit;
 194         }
 195
 196         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
 197
 198         /* Handle known interrupt data */
 199         /* ignore data[0] and data[1] */
 200
 201         priv = usb_get_serial_port_data(port);
 202         spin_lock_irqsave(&priv->lock, flags);
 203         priv->last_msr = data[BELKIN_SA_MSR_INDEX];
 204
 205         /* Record Control Line states */
 206         if (priv->last_msr & BELKIN_SA_MSR_DSR)
 207                 priv->control_state |= TIOCM_DSR;
 208         else
 209                 priv->control_state &= ~TIOCM_DSR;
 210
 211         if (priv->last_msr & BELKIN_SA_MSR_CTS)
 212                 priv->control_state |= TIOCM_CTS;
 213         else
 214                 priv->control_state &= ~TIOCM_CTS;
 215
 216         if (priv->last_msr & BELKIN_SA_MSR_RI)
 217                 priv->control_state |= TIOCM_RI;
 218         else
 219                 priv->control_state &= ~TIOCM_RI;
 220
 221         if (priv->last_msr & BELKIN_SA_MSR_CD)
 222                 priv->control_state |= TIOCM_CD;
 223         else
 224                 priv->control_state &= ~TIOCM_CD;
 225
 226         priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
 227         spin_unlock_irqrestore(&priv->lock, flags);
 228 exit:
 229         retval = usb_submit_urb(urb, GFP_ATOMIC);
 230         if (retval)
 231                 dev_err(&port->dev, "%s - usb_submit_urb failed with "
 232                         "result %d\n", __func__, retval);
 233 }
 234
 235 static void belkin_sa_process_read_urb(struct urb *urb)
 236 {
 237         struct usb_serial_port *port = urb->context;
 238         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 239         unsigned char *data = urb->transfer_buffer;
 240         unsigned long flags;
 241         unsigned char status;
 242         char tty_flag;
 243
 244         /* Update line status */
 245         tty_flag = TTY_NORMAL;
 246
 247         spin_lock_irqsave(&priv->lock, flags);
 248         status = priv->last_lsr;
 249         priv->last_lsr &= ~BELKIN_SA_LSR_ERR;
 250         spin_unlock_irqrestore(&priv->lock, flags);
 251
 252         if (!urb->actual_length)
 253                 return;
 254
 255         if (status & BELKIN_SA_LSR_ERR) {
 256                 /* Break takes precedence over parity, which takes precedence
 257                  * over framing errors. */
 258                 if (status & BELKIN_SA_LSR_BI)
 259                         tty_flag = TTY_BREAK;
 260                 else if (status & BELKIN_SA_LSR_PE)
 261                         tty_flag = TTY_PARITY;
 262                 else if (status & BELKIN_SA_LSR_FE)
 263                         tty_flag = TTY_FRAME;
 264                 dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
 265
 266                 /* Overrun is special, not associated with a char. */
 267                 if (status & BELKIN_SA_LSR_OE)
 268                         tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 269         }
 270
 271         tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
 272                                                         urb->actual_length);
 273         tty_flip_buffer_push(&port->port);
 274 }
 275
 276 static void belkin_sa_set_termios(struct tty_struct *tty,
 277                                   struct usb_serial_port *port,
 278                                   const 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                 urb_value = BELKIN_SA_DATA_BITS(tty_get_char_size(cflag));
 362                 if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
 363                         dev_err(&port->dev, "Set data bits error\n");
 364         }
 365
 366         /* set the number of stop bits */
 367         if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 368                 urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
 369                                                 : BELKIN_SA_STOP_BITS(1);
 370                 if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
 371                                                         urb_value) < 0)
 372                         dev_err(&port->dev, "Set stop bits error\n");
 373         }
 374
 375         /* Set flow control */
 376         if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
 377                 ((cflag ^ old_cflag) & CRTSCTS)) {
 378                 urb_value = 0;
 379                 if ((iflag & IXOFF) || (iflag & IXON))
 380                         urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
 381                 else
 382                         urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
 383
 384                 if (cflag & CRTSCTS)
 385                         urb_value |=  (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
 386                 else
 387                         urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
 388
 389                 if (bad_flow_control)
 390                         urb_value &= ~(BELKIN_SA_FLOW_IRTS);
 391
 392                 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
 393                         dev_err(&port->dev, "Set flow control error\n");
 394         }
 395
 396         /* save off the modified port settings */
 397         spin_lock_irqsave(&priv->lock, flags);
 398         priv->control_state = control_state;
 399         spin_unlock_irqrestore(&priv->lock, flags);
 400 }
 401
 402 static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
 403 {
 404         struct usb_serial_port *port = tty->driver_data;
 405         struct usb_serial *serial = port->serial;
 406         int ret;
 407
 408         ret = BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0);
 409         if (ret < 0) {
 410                 dev_err(&port->dev, "Set break_ctl %d\n", break_state);
 411                 return ret;
 412         }
 413
 414         return 0;
 415 }
 416
 417 static int belkin_sa_tiocmget(struct tty_struct *tty)
 418 {
 419         struct usb_serial_port *port = tty->driver_data;
 420         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 421         unsigned long control_state;
 422         unsigned long flags;
 423
 424         spin_lock_irqsave(&priv->lock, flags);
 425         control_state = priv->control_state;
 426         spin_unlock_irqrestore(&priv->lock, flags);
 427
 428         return control_state;
 429 }
 430
 431 static int belkin_sa_tiocmset(struct tty_struct *tty,
 432                                unsigned int set, unsigned int clear)
 433 {
 434         struct usb_serial_port *port = tty->driver_data;
 435         struct usb_serial *serial = port->serial;
 436         struct belkin_sa_private *priv = usb_get_serial_port_data(port);
 437         unsigned long control_state;
 438         unsigned long flags;
 439         int retval;
 440         int rts = 0;
 441         int dtr = 0;
 442
 443         spin_lock_irqsave(&priv->lock, flags);
 444         control_state = priv->control_state;
 445
 446         if (set & TIOCM_RTS) {
 447                 control_state |= TIOCM_RTS;
 448                 rts = 1;
 449         }
 450         if (set & TIOCM_DTR) {
 451                 control_state |= TIOCM_DTR;
 452                 dtr = 1;
 453         }
 454         if (clear & TIOCM_RTS) {
 455                 control_state &= ~TIOCM_RTS;
 456                 rts = 0;
 457         }
 458         if (clear & TIOCM_DTR) {
 459                 control_state &= ~TIOCM_DTR;
 460                 dtr = 0;
 461         }
 462
 463         priv->control_state = control_state;
 464         spin_unlock_irqrestore(&priv->lock, flags);
 465
 466         retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
 467         if (retval < 0) {
 468                 dev_err(&port->dev, "Set RTS error %d\n", retval);
 469                 goto exit;
 470         }
 471
 472         retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
 473         if (retval < 0) {
 474                 dev_err(&port->dev, "Set DTR error %d\n", retval);
 475                 goto exit;
 476         }
 477 exit:
 478         return retval;
 479 }
 480
 481 module_usb_serial_driver(serial_drivers, id_table);
 482
 483 MODULE_AUTHOR(DRIVER_AUTHOR);
 484 MODULE_DESCRIPTION(DRIVER_DESC);
 485 MODULE_LICENSE("GPL");