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 void 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 void 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; 406 407 if (BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0) < 0) 408 dev_err(&port->dev, "Set break_ctl %d\n", break_state); 409 } 410 411 static int belkin_sa_tiocmget(struct tty_struct *tty) 412 { 413 struct usb_serial_port *port = tty->driver_data; 414 struct belkin_sa_private *priv = usb_get_serial_port_data(port); 415 unsigned long control_state; 416 unsigned long flags; 417 418 spin_lock_irqsave(&priv->lock, flags); 419 control_state = priv->control_state; 420 spin_unlock_irqrestore(&priv->lock, flags); 421 422 return control_state; 423 } 424 425 static int belkin_sa_tiocmset(struct tty_struct *tty, 426 unsigned int set, unsigned int clear) 427 { 428 struct usb_serial_port *port = tty->driver_data; 429 struct usb_serial *serial = port->serial; 430 struct belkin_sa_private *priv = usb_get_serial_port_data(port); 431 unsigned long control_state; 432 unsigned long flags; 433 int retval; 434 int rts = 0; 435 int dtr = 0; 436 437 spin_lock_irqsave(&priv->lock, flags); 438 control_state = priv->control_state; 439 440 if (set & TIOCM_RTS) { 441 control_state |= TIOCM_RTS; 442 rts = 1; 443 } 444 if (set & TIOCM_DTR) { 445 control_state |= TIOCM_DTR; 446 dtr = 1; 447 } 448 if (clear & TIOCM_RTS) { 449 control_state &= ~TIOCM_RTS; 450 rts = 0; 451 } 452 if (clear & TIOCM_DTR) { 453 control_state &= ~TIOCM_DTR; 454 dtr = 0; 455 } 456 457 priv->control_state = control_state; 458 spin_unlock_irqrestore(&priv->lock, flags); 459 460 retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts); 461 if (retval < 0) { 462 dev_err(&port->dev, "Set RTS error %d\n", retval); 463 goto exit; 464 } 465 466 retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr); 467 if (retval < 0) { 468 dev_err(&port->dev, "Set DTR error %d\n", retval); 469 goto exit; 470 } 471 exit: 472 return retval; 473 } 474 475 module_usb_serial_driver(serial_drivers, id_table); 476 477 MODULE_AUTHOR(DRIVER_AUTHOR); 478 MODULE_DESCRIPTION(DRIVER_DESC); 479 MODULE_LICENSE("GPL"); 480