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"); 485