1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Driver core for serial ports 4 * 5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. 6 * 7 * Copyright 1999 ARM Limited 8 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. 9 */ 10 #include <linux/module.h> 11 #include <linux/tty.h> 12 #include <linux/tty_flip.h> 13 #include <linux/slab.h> 14 #include <linux/sched/signal.h> 15 #include <linux/init.h> 16 #include <linux/console.h> 17 #include <linux/gpio/consumer.h> 18 #include <linux/kernel.h> 19 #include <linux/of.h> 20 #include <linux/pm_runtime.h> 21 #include <linux/proc_fs.h> 22 #include <linux/seq_file.h> 23 #include <linux/device.h> 24 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */ 25 #include <linux/serial_core.h> 26 #include <linux/sysrq.h> 27 #include <linux/delay.h> 28 #include <linux/mutex.h> 29 #include <linux/math64.h> 30 #include <linux/security.h> 31 32 #include <linux/irq.h> 33 #include <linux/uaccess.h> 34 35 #include "serial_base.h" 36 37 /* 38 * This is used to lock changes in serial line configuration. 39 */ 40 static DEFINE_MUTEX(port_mutex); 41 42 /* 43 * lockdep: port->lock is initialized in two places, but we 44 * want only one lock-class: 45 */ 46 static struct lock_class_key port_lock_key; 47 48 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) 49 50 /* 51 * Max time with active RTS before/after data is sent. 52 */ 53 #define RS485_MAX_RTS_DELAY 100 /* msecs */ 54 55 static void uart_change_pm(struct uart_state *state, 56 enum uart_pm_state pm_state); 57 58 static void uart_port_shutdown(struct tty_port *port); 59 60 static int uart_dcd_enabled(struct uart_port *uport) 61 { 62 return !!(uport->status & UPSTAT_DCD_ENABLE); 63 } 64 65 static inline struct uart_port *uart_port_ref(struct uart_state *state) 66 { 67 if (atomic_add_unless(&state->refcount, 1, 0)) 68 return state->uart_port; 69 return NULL; 70 } 71 72 static inline void uart_port_deref(struct uart_port *uport) 73 { 74 if (atomic_dec_and_test(&uport->state->refcount)) 75 wake_up(&uport->state->remove_wait); 76 } 77 78 #define uart_port_lock(state, flags) \ 79 ({ \ 80 struct uart_port *__uport = uart_port_ref(state); \ 81 if (__uport) \ 82 uart_port_lock_irqsave(__uport, &flags); \ 83 __uport; \ 84 }) 85 86 #define uart_port_unlock(uport, flags) \ 87 ({ \ 88 struct uart_port *__uport = uport; \ 89 if (__uport) { \ 90 uart_port_unlock_irqrestore(__uport, flags); \ 91 uart_port_deref(__uport); \ 92 } \ 93 }) 94 95 static inline struct uart_port *uart_port_check(struct uart_state *state) 96 { 97 lockdep_assert_held(&state->port.mutex); 98 return state->uart_port; 99 } 100 101 /** 102 * uart_write_wakeup - schedule write processing 103 * @port: port to be processed 104 * 105 * This routine is used by the interrupt handler to schedule processing in the 106 * software interrupt portion of the driver. A driver is expected to call this 107 * function when the number of characters in the transmit buffer have dropped 108 * below a threshold. 109 * 110 * Locking: @port->lock should be held 111 */ 112 void uart_write_wakeup(struct uart_port *port) 113 { 114 struct uart_state *state = port->state; 115 /* 116 * This means you called this function _after_ the port was 117 * closed. No cookie for you. 118 */ 119 BUG_ON(!state); 120 tty_port_tty_wakeup(&state->port); 121 } 122 EXPORT_SYMBOL(uart_write_wakeup); 123 124 static void uart_stop(struct tty_struct *tty) 125 { 126 struct uart_state *state = tty->driver_data; 127 struct uart_port *port; 128 unsigned long flags; 129 130 port = uart_port_lock(state, flags); 131 if (port) 132 port->ops->stop_tx(port); 133 uart_port_unlock(port, flags); 134 } 135 136 static void __uart_start(struct uart_state *state) 137 { 138 struct uart_port *port = state->uart_port; 139 struct serial_port_device *port_dev; 140 int err; 141 142 if (!port || port->flags & UPF_DEAD || uart_tx_stopped(port)) 143 return; 144 145 port_dev = port->port_dev; 146 147 /* Increment the runtime PM usage count for the active check below */ 148 err = pm_runtime_get(&port_dev->dev); 149 if (err < 0 && err != -EINPROGRESS) { 150 pm_runtime_put_noidle(&port_dev->dev); 151 return; 152 } 153 154 /* 155 * Start TX if enabled, and kick runtime PM. If the device is not 156 * enabled, serial_port_runtime_resume() calls start_tx() again 157 * after enabling the device. 158 */ 159 if (!pm_runtime_enabled(port->dev) || pm_runtime_active(&port_dev->dev)) 160 port->ops->start_tx(port); 161 pm_runtime_mark_last_busy(&port_dev->dev); 162 pm_runtime_put_autosuspend(&port_dev->dev); 163 } 164 165 static void uart_start(struct tty_struct *tty) 166 { 167 struct uart_state *state = tty->driver_data; 168 struct uart_port *port; 169 unsigned long flags; 170 171 port = uart_port_lock(state, flags); 172 __uart_start(state); 173 uart_port_unlock(port, flags); 174 } 175 176 static void 177 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) 178 { 179 unsigned long flags; 180 unsigned int old; 181 182 uart_port_lock_irqsave(port, &flags); 183 old = port->mctrl; 184 port->mctrl = (old & ~clear) | set; 185 if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED)) 186 port->ops->set_mctrl(port, port->mctrl); 187 uart_port_unlock_irqrestore(port, flags); 188 } 189 190 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0) 191 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear) 192 193 static void uart_port_dtr_rts(struct uart_port *uport, bool active) 194 { 195 if (active) 196 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 197 else 198 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 199 } 200 201 /* Caller holds port mutex */ 202 static void uart_change_line_settings(struct tty_struct *tty, struct uart_state *state, 203 const struct ktermios *old_termios) 204 { 205 struct uart_port *uport = uart_port_check(state); 206 struct ktermios *termios; 207 bool old_hw_stopped; 208 209 /* 210 * If we have no tty, termios, or the port does not exist, 211 * then we can't set the parameters for this port. 212 */ 213 if (!tty || uport->type == PORT_UNKNOWN) 214 return; 215 216 termios = &tty->termios; 217 uport->ops->set_termios(uport, termios, old_termios); 218 219 /* 220 * Set modem status enables based on termios cflag 221 */ 222 uart_port_lock_irq(uport); 223 if (termios->c_cflag & CRTSCTS) 224 uport->status |= UPSTAT_CTS_ENABLE; 225 else 226 uport->status &= ~UPSTAT_CTS_ENABLE; 227 228 if (termios->c_cflag & CLOCAL) 229 uport->status &= ~UPSTAT_DCD_ENABLE; 230 else 231 uport->status |= UPSTAT_DCD_ENABLE; 232 233 /* reset sw-assisted CTS flow control based on (possibly) new mode */ 234 old_hw_stopped = uport->hw_stopped; 235 uport->hw_stopped = uart_softcts_mode(uport) && 236 !(uport->ops->get_mctrl(uport) & TIOCM_CTS); 237 if (uport->hw_stopped != old_hw_stopped) { 238 if (!old_hw_stopped) 239 uport->ops->stop_tx(uport); 240 else 241 __uart_start(state); 242 } 243 uart_port_unlock_irq(uport); 244 } 245 246 /* 247 * Startup the port. This will be called once per open. All calls 248 * will be serialised by the per-port mutex. 249 */ 250 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, 251 bool init_hw) 252 { 253 struct uart_port *uport = uart_port_check(state); 254 unsigned long flags; 255 unsigned long page; 256 int retval = 0; 257 258 if (uport->type == PORT_UNKNOWN) 259 return 1; 260 261 /* 262 * Make sure the device is in D0 state. 263 */ 264 uart_change_pm(state, UART_PM_STATE_ON); 265 266 /* 267 * Initialise and allocate the transmit and temporary 268 * buffer. 269 */ 270 page = get_zeroed_page(GFP_KERNEL); 271 if (!page) 272 return -ENOMEM; 273 274 uart_port_lock(state, flags); 275 if (!state->xmit.buf) { 276 state->xmit.buf = (unsigned char *) page; 277 uart_circ_clear(&state->xmit); 278 uart_port_unlock(uport, flags); 279 } else { 280 uart_port_unlock(uport, flags); 281 /* 282 * Do not free() the page under the port lock, see 283 * uart_shutdown(). 284 */ 285 free_page(page); 286 } 287 288 retval = uport->ops->startup(uport); 289 if (retval == 0) { 290 if (uart_console(uport) && uport->cons->cflag) { 291 tty->termios.c_cflag = uport->cons->cflag; 292 tty->termios.c_ispeed = uport->cons->ispeed; 293 tty->termios.c_ospeed = uport->cons->ospeed; 294 uport->cons->cflag = 0; 295 uport->cons->ispeed = 0; 296 uport->cons->ospeed = 0; 297 } 298 /* 299 * Initialise the hardware port settings. 300 */ 301 uart_change_line_settings(tty, state, NULL); 302 303 /* 304 * Setup the RTS and DTR signals once the 305 * port is open and ready to respond. 306 */ 307 if (init_hw && C_BAUD(tty)) 308 uart_port_dtr_rts(uport, true); 309 } 310 311 /* 312 * This is to allow setserial on this port. People may want to set 313 * port/irq/type and then reconfigure the port properly if it failed 314 * now. 315 */ 316 if (retval && capable(CAP_SYS_ADMIN)) 317 return 1; 318 319 return retval; 320 } 321 322 static int uart_startup(struct tty_struct *tty, struct uart_state *state, 323 bool init_hw) 324 { 325 struct tty_port *port = &state->port; 326 struct uart_port *uport; 327 int retval; 328 329 if (tty_port_initialized(port)) 330 goto out_base_port_startup; 331 332 retval = uart_port_startup(tty, state, init_hw); 333 if (retval) { 334 set_bit(TTY_IO_ERROR, &tty->flags); 335 return retval; 336 } 337 338 out_base_port_startup: 339 uport = uart_port_check(state); 340 if (!uport) 341 return -EIO; 342 343 serial_base_port_startup(uport); 344 345 return 0; 346 } 347 348 /* 349 * This routine will shutdown a serial port; interrupts are disabled, and 350 * DTR is dropped if the hangup on close termio flag is on. Calls to 351 * uart_shutdown are serialised by the per-port semaphore. 352 * 353 * uport == NULL if uart_port has already been removed 354 */ 355 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) 356 { 357 struct uart_port *uport = uart_port_check(state); 358 struct tty_port *port = &state->port; 359 unsigned long flags; 360 char *xmit_buf = NULL; 361 362 /* 363 * Set the TTY IO error marker 364 */ 365 if (tty) 366 set_bit(TTY_IO_ERROR, &tty->flags); 367 368 if (uport) 369 serial_base_port_shutdown(uport); 370 371 if (tty_port_initialized(port)) { 372 tty_port_set_initialized(port, false); 373 374 /* 375 * Turn off DTR and RTS early. 376 */ 377 if (uport && uart_console(uport) && tty) { 378 uport->cons->cflag = tty->termios.c_cflag; 379 uport->cons->ispeed = tty->termios.c_ispeed; 380 uport->cons->ospeed = tty->termios.c_ospeed; 381 } 382 383 if (!tty || C_HUPCL(tty)) 384 uart_port_dtr_rts(uport, false); 385 386 uart_port_shutdown(port); 387 } 388 389 /* 390 * It's possible for shutdown to be called after suspend if we get 391 * a DCD drop (hangup) at just the right time. Clear suspended bit so 392 * we don't try to resume a port that has been shutdown. 393 */ 394 tty_port_set_suspended(port, false); 395 396 /* 397 * Do not free() the transmit buffer page under the port lock since 398 * this can create various circular locking scenarios. For instance, 399 * console driver may need to allocate/free a debug object, which 400 * can endup in printk() recursion. 401 */ 402 uart_port_lock(state, flags); 403 xmit_buf = state->xmit.buf; 404 state->xmit.buf = NULL; 405 uart_port_unlock(uport, flags); 406 407 free_page((unsigned long)xmit_buf); 408 } 409 410 /** 411 * uart_update_timeout - update per-port frame timing information 412 * @port: uart_port structure describing the port 413 * @cflag: termios cflag value 414 * @baud: speed of the port 415 * 416 * Set the @port frame timing information from which the FIFO timeout value is 417 * derived. The @cflag value should reflect the actual hardware settings as 418 * number of bits, parity, stop bits and baud rate is taken into account here. 419 * 420 * Locking: caller is expected to take @port->lock 421 */ 422 void 423 uart_update_timeout(struct uart_port *port, unsigned int cflag, 424 unsigned int baud) 425 { 426 u64 temp = tty_get_frame_size(cflag); 427 428 temp *= NSEC_PER_SEC; 429 port->frame_time = (unsigned int)DIV64_U64_ROUND_UP(temp, baud); 430 } 431 EXPORT_SYMBOL(uart_update_timeout); 432 433 /** 434 * uart_get_baud_rate - return baud rate for a particular port 435 * @port: uart_port structure describing the port in question. 436 * @termios: desired termios settings 437 * @old: old termios (or %NULL) 438 * @min: minimum acceptable baud rate 439 * @max: maximum acceptable baud rate 440 * 441 * Decode the termios structure into a numeric baud rate, taking account of the 442 * magic 38400 baud rate (with spd_* flags), and mapping the %B0 rate to 9600 443 * baud. 444 * 445 * If the new baud rate is invalid, try the @old termios setting. If it's still 446 * invalid, we try 9600 baud. If that is also invalid 0 is returned. 447 * 448 * The @termios structure is updated to reflect the baud rate we're actually 449 * going to be using. Don't do this for the case where B0 is requested ("hang 450 * up"). 451 * 452 * Locking: caller dependent 453 */ 454 unsigned int 455 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 456 const struct ktermios *old, unsigned int min, unsigned int max) 457 { 458 unsigned int try; 459 unsigned int baud; 460 unsigned int altbaud; 461 int hung_up = 0; 462 upf_t flags = port->flags & UPF_SPD_MASK; 463 464 switch (flags) { 465 case UPF_SPD_HI: 466 altbaud = 57600; 467 break; 468 case UPF_SPD_VHI: 469 altbaud = 115200; 470 break; 471 case UPF_SPD_SHI: 472 altbaud = 230400; 473 break; 474 case UPF_SPD_WARP: 475 altbaud = 460800; 476 break; 477 default: 478 altbaud = 38400; 479 break; 480 } 481 482 for (try = 0; try < 2; try++) { 483 baud = tty_termios_baud_rate(termios); 484 485 /* 486 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge... 487 * Die! Die! Die! 488 */ 489 if (try == 0 && baud == 38400) 490 baud = altbaud; 491 492 /* 493 * Special case: B0 rate. 494 */ 495 if (baud == 0) { 496 hung_up = 1; 497 baud = 9600; 498 } 499 500 if (baud >= min && baud <= max) 501 return baud; 502 503 /* 504 * Oops, the quotient was zero. Try again with 505 * the old baud rate if possible. 506 */ 507 termios->c_cflag &= ~CBAUD; 508 if (old) { 509 baud = tty_termios_baud_rate(old); 510 if (!hung_up) 511 tty_termios_encode_baud_rate(termios, 512 baud, baud); 513 old = NULL; 514 continue; 515 } 516 517 /* 518 * As a last resort, if the range cannot be met then clip to 519 * the nearest chip supported rate. 520 */ 521 if (!hung_up) { 522 if (baud <= min) 523 tty_termios_encode_baud_rate(termios, 524 min + 1, min + 1); 525 else 526 tty_termios_encode_baud_rate(termios, 527 max - 1, max - 1); 528 } 529 } 530 return 0; 531 } 532 EXPORT_SYMBOL(uart_get_baud_rate); 533 534 /** 535 * uart_get_divisor - return uart clock divisor 536 * @port: uart_port structure describing the port 537 * @baud: desired baud rate 538 * 539 * Calculate the divisor (baud_base / baud) for the specified @baud, 540 * appropriately rounded. 541 * 542 * If 38400 baud and custom divisor is selected, return the custom divisor 543 * instead. 544 * 545 * Locking: caller dependent 546 */ 547 unsigned int 548 uart_get_divisor(struct uart_port *port, unsigned int baud) 549 { 550 unsigned int quot; 551 552 /* 553 * Old custom speed handling. 554 */ 555 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) 556 quot = port->custom_divisor; 557 else 558 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud); 559 560 return quot; 561 } 562 EXPORT_SYMBOL(uart_get_divisor); 563 564 static int uart_put_char(struct tty_struct *tty, u8 c) 565 { 566 struct uart_state *state = tty->driver_data; 567 struct uart_port *port; 568 struct circ_buf *circ; 569 unsigned long flags; 570 int ret = 0; 571 572 circ = &state->xmit; 573 port = uart_port_lock(state, flags); 574 if (!circ->buf) { 575 uart_port_unlock(port, flags); 576 return 0; 577 } 578 579 if (port && uart_circ_chars_free(circ) != 0) { 580 circ->buf[circ->head] = c; 581 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); 582 ret = 1; 583 } 584 uart_port_unlock(port, flags); 585 return ret; 586 } 587 588 static void uart_flush_chars(struct tty_struct *tty) 589 { 590 uart_start(tty); 591 } 592 593 static ssize_t uart_write(struct tty_struct *tty, const u8 *buf, size_t count) 594 { 595 struct uart_state *state = tty->driver_data; 596 struct uart_port *port; 597 struct circ_buf *circ; 598 unsigned long flags; 599 int c, ret = 0; 600 601 /* 602 * This means you called this function _after_ the port was 603 * closed. No cookie for you. 604 */ 605 if (WARN_ON(!state)) 606 return -EL3HLT; 607 608 port = uart_port_lock(state, flags); 609 circ = &state->xmit; 610 if (!circ->buf) { 611 uart_port_unlock(port, flags); 612 return 0; 613 } 614 615 while (port) { 616 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); 617 if (count < c) 618 c = count; 619 if (c <= 0) 620 break; 621 memcpy(circ->buf + circ->head, buf, c); 622 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); 623 buf += c; 624 count -= c; 625 ret += c; 626 } 627 628 __uart_start(state); 629 uart_port_unlock(port, flags); 630 return ret; 631 } 632 633 static unsigned int uart_write_room(struct tty_struct *tty) 634 { 635 struct uart_state *state = tty->driver_data; 636 struct uart_port *port; 637 unsigned long flags; 638 unsigned int ret; 639 640 port = uart_port_lock(state, flags); 641 ret = uart_circ_chars_free(&state->xmit); 642 uart_port_unlock(port, flags); 643 return ret; 644 } 645 646 static unsigned int uart_chars_in_buffer(struct tty_struct *tty) 647 { 648 struct uart_state *state = tty->driver_data; 649 struct uart_port *port; 650 unsigned long flags; 651 unsigned int ret; 652 653 port = uart_port_lock(state, flags); 654 ret = uart_circ_chars_pending(&state->xmit); 655 uart_port_unlock(port, flags); 656 return ret; 657 } 658 659 static void uart_flush_buffer(struct tty_struct *tty) 660 { 661 struct uart_state *state = tty->driver_data; 662 struct uart_port *port; 663 unsigned long flags; 664 665 /* 666 * This means you called this function _after_ the port was 667 * closed. No cookie for you. 668 */ 669 if (WARN_ON(!state)) 670 return; 671 672 pr_debug("uart_flush_buffer(%d) called\n", tty->index); 673 674 port = uart_port_lock(state, flags); 675 if (!port) 676 return; 677 uart_circ_clear(&state->xmit); 678 if (port->ops->flush_buffer) 679 port->ops->flush_buffer(port); 680 uart_port_unlock(port, flags); 681 tty_port_tty_wakeup(&state->port); 682 } 683 684 /* 685 * This function performs low-level write of high-priority XON/XOFF 686 * character and accounting for it. 687 * 688 * Requires uart_port to implement .serial_out(). 689 */ 690 void uart_xchar_out(struct uart_port *uport, int offset) 691 { 692 serial_port_out(uport, offset, uport->x_char); 693 uport->icount.tx++; 694 uport->x_char = 0; 695 } 696 EXPORT_SYMBOL_GPL(uart_xchar_out); 697 698 /* 699 * This function is used to send a high-priority XON/XOFF character to 700 * the device 701 */ 702 static void uart_send_xchar(struct tty_struct *tty, u8 ch) 703 { 704 struct uart_state *state = tty->driver_data; 705 struct uart_port *port; 706 unsigned long flags; 707 708 port = uart_port_ref(state); 709 if (!port) 710 return; 711 712 if (port->ops->send_xchar) 713 port->ops->send_xchar(port, ch); 714 else { 715 uart_port_lock_irqsave(port, &flags); 716 port->x_char = ch; 717 if (ch) 718 port->ops->start_tx(port); 719 uart_port_unlock_irqrestore(port, flags); 720 } 721 uart_port_deref(port); 722 } 723 724 static void uart_throttle(struct tty_struct *tty) 725 { 726 struct uart_state *state = tty->driver_data; 727 upstat_t mask = UPSTAT_SYNC_FIFO; 728 struct uart_port *port; 729 730 port = uart_port_ref(state); 731 if (!port) 732 return; 733 734 if (I_IXOFF(tty)) 735 mask |= UPSTAT_AUTOXOFF; 736 if (C_CRTSCTS(tty)) 737 mask |= UPSTAT_AUTORTS; 738 739 if (port->status & mask) { 740 port->ops->throttle(port); 741 mask &= ~port->status; 742 } 743 744 if (mask & UPSTAT_AUTORTS) 745 uart_clear_mctrl(port, TIOCM_RTS); 746 747 if (mask & UPSTAT_AUTOXOFF) 748 uart_send_xchar(tty, STOP_CHAR(tty)); 749 750 uart_port_deref(port); 751 } 752 753 static void uart_unthrottle(struct tty_struct *tty) 754 { 755 struct uart_state *state = tty->driver_data; 756 upstat_t mask = UPSTAT_SYNC_FIFO; 757 struct uart_port *port; 758 759 port = uart_port_ref(state); 760 if (!port) 761 return; 762 763 if (I_IXOFF(tty)) 764 mask |= UPSTAT_AUTOXOFF; 765 if (C_CRTSCTS(tty)) 766 mask |= UPSTAT_AUTORTS; 767 768 if (port->status & mask) { 769 port->ops->unthrottle(port); 770 mask &= ~port->status; 771 } 772 773 if (mask & UPSTAT_AUTORTS) 774 uart_set_mctrl(port, TIOCM_RTS); 775 776 if (mask & UPSTAT_AUTOXOFF) 777 uart_send_xchar(tty, START_CHAR(tty)); 778 779 uart_port_deref(port); 780 } 781 782 static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo) 783 { 784 struct uart_state *state = container_of(port, struct uart_state, port); 785 struct uart_port *uport; 786 int ret = -ENODEV; 787 788 /* Initialize structure in case we error out later to prevent any stack info leakage. */ 789 *retinfo = (struct serial_struct){}; 790 791 /* 792 * Ensure the state we copy is consistent and no hardware changes 793 * occur as we go 794 */ 795 mutex_lock(&port->mutex); 796 uport = uart_port_check(state); 797 if (!uport) 798 goto out; 799 800 retinfo->type = uport->type; 801 retinfo->line = uport->line; 802 retinfo->port = uport->iobase; 803 if (HIGH_BITS_OFFSET) 804 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET; 805 retinfo->irq = uport->irq; 806 retinfo->flags = (__force int)uport->flags; 807 retinfo->xmit_fifo_size = uport->fifosize; 808 retinfo->baud_base = uport->uartclk / 16; 809 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10; 810 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 811 ASYNC_CLOSING_WAIT_NONE : 812 jiffies_to_msecs(port->closing_wait) / 10; 813 retinfo->custom_divisor = uport->custom_divisor; 814 retinfo->hub6 = uport->hub6; 815 retinfo->io_type = uport->iotype; 816 retinfo->iomem_reg_shift = uport->regshift; 817 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase; 818 819 ret = 0; 820 out: 821 mutex_unlock(&port->mutex); 822 return ret; 823 } 824 825 static int uart_get_info_user(struct tty_struct *tty, 826 struct serial_struct *ss) 827 { 828 struct uart_state *state = tty->driver_data; 829 struct tty_port *port = &state->port; 830 831 return uart_get_info(port, ss) < 0 ? -EIO : 0; 832 } 833 834 static int uart_set_info(struct tty_struct *tty, struct tty_port *port, 835 struct uart_state *state, 836 struct serial_struct *new_info) 837 { 838 struct uart_port *uport = uart_port_check(state); 839 unsigned long new_port; 840 unsigned int change_irq, change_port, closing_wait; 841 unsigned int old_custom_divisor, close_delay; 842 upf_t old_flags, new_flags; 843 int retval = 0; 844 845 if (!uport) 846 return -EIO; 847 848 new_port = new_info->port; 849 if (HIGH_BITS_OFFSET) 850 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET; 851 852 new_info->irq = irq_canonicalize(new_info->irq); 853 close_delay = msecs_to_jiffies(new_info->close_delay * 10); 854 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 855 ASYNC_CLOSING_WAIT_NONE : 856 msecs_to_jiffies(new_info->closing_wait * 10); 857 858 859 change_irq = !(uport->flags & UPF_FIXED_PORT) 860 && new_info->irq != uport->irq; 861 862 /* 863 * Since changing the 'type' of the port changes its resource 864 * allocations, we should treat type changes the same as 865 * IO port changes. 866 */ 867 change_port = !(uport->flags & UPF_FIXED_PORT) 868 && (new_port != uport->iobase || 869 (unsigned long)new_info->iomem_base != uport->mapbase || 870 new_info->hub6 != uport->hub6 || 871 new_info->io_type != uport->iotype || 872 new_info->iomem_reg_shift != uport->regshift || 873 new_info->type != uport->type); 874 875 old_flags = uport->flags; 876 new_flags = (__force upf_t)new_info->flags; 877 old_custom_divisor = uport->custom_divisor; 878 879 if (!capable(CAP_SYS_ADMIN)) { 880 retval = -EPERM; 881 if (change_irq || change_port || 882 (new_info->baud_base != uport->uartclk / 16) || 883 (close_delay != port->close_delay) || 884 (closing_wait != port->closing_wait) || 885 (new_info->xmit_fifo_size && 886 new_info->xmit_fifo_size != uport->fifosize) || 887 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) 888 goto exit; 889 uport->flags = ((uport->flags & ~UPF_USR_MASK) | 890 (new_flags & UPF_USR_MASK)); 891 uport->custom_divisor = new_info->custom_divisor; 892 goto check_and_exit; 893 } 894 895 if (change_irq || change_port) { 896 retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); 897 if (retval) 898 goto exit; 899 } 900 901 /* 902 * Ask the low level driver to verify the settings. 903 */ 904 if (uport->ops->verify_port) 905 retval = uport->ops->verify_port(uport, new_info); 906 907 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) || 908 (new_info->baud_base < 9600)) 909 retval = -EINVAL; 910 911 if (retval) 912 goto exit; 913 914 if (change_port || change_irq) { 915 retval = -EBUSY; 916 917 /* 918 * Make sure that we are the sole user of this port. 919 */ 920 if (tty_port_users(port) > 1) 921 goto exit; 922 923 /* 924 * We need to shutdown the serial port at the old 925 * port/type/irq combination. 926 */ 927 uart_shutdown(tty, state); 928 } 929 930 if (change_port) { 931 unsigned long old_iobase, old_mapbase; 932 unsigned int old_type, old_iotype, old_hub6, old_shift; 933 934 old_iobase = uport->iobase; 935 old_mapbase = uport->mapbase; 936 old_type = uport->type; 937 old_hub6 = uport->hub6; 938 old_iotype = uport->iotype; 939 old_shift = uport->regshift; 940 941 /* 942 * Free and release old regions 943 */ 944 if (old_type != PORT_UNKNOWN && uport->ops->release_port) 945 uport->ops->release_port(uport); 946 947 uport->iobase = new_port; 948 uport->type = new_info->type; 949 uport->hub6 = new_info->hub6; 950 uport->iotype = new_info->io_type; 951 uport->regshift = new_info->iomem_reg_shift; 952 uport->mapbase = (unsigned long)new_info->iomem_base; 953 954 /* 955 * Claim and map the new regions 956 */ 957 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) { 958 retval = uport->ops->request_port(uport); 959 } else { 960 /* Always success - Jean II */ 961 retval = 0; 962 } 963 964 /* 965 * If we fail to request resources for the 966 * new port, try to restore the old settings. 967 */ 968 if (retval) { 969 uport->iobase = old_iobase; 970 uport->type = old_type; 971 uport->hub6 = old_hub6; 972 uport->iotype = old_iotype; 973 uport->regshift = old_shift; 974 uport->mapbase = old_mapbase; 975 976 if (old_type != PORT_UNKNOWN) { 977 retval = uport->ops->request_port(uport); 978 /* 979 * If we failed to restore the old settings, 980 * we fail like this. 981 */ 982 if (retval) 983 uport->type = PORT_UNKNOWN; 984 985 /* 986 * We failed anyway. 987 */ 988 retval = -EBUSY; 989 } 990 991 /* Added to return the correct error -Ram Gupta */ 992 goto exit; 993 } 994 } 995 996 if (change_irq) 997 uport->irq = new_info->irq; 998 if (!(uport->flags & UPF_FIXED_PORT)) 999 uport->uartclk = new_info->baud_base * 16; 1000 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) | 1001 (new_flags & UPF_CHANGE_MASK); 1002 uport->custom_divisor = new_info->custom_divisor; 1003 port->close_delay = close_delay; 1004 port->closing_wait = closing_wait; 1005 if (new_info->xmit_fifo_size) 1006 uport->fifosize = new_info->xmit_fifo_size; 1007 1008 check_and_exit: 1009 retval = 0; 1010 if (uport->type == PORT_UNKNOWN) 1011 goto exit; 1012 if (tty_port_initialized(port)) { 1013 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) || 1014 old_custom_divisor != uport->custom_divisor) { 1015 /* 1016 * If they're setting up a custom divisor or speed, 1017 * instead of clearing it, then bitch about it. 1018 */ 1019 if (uport->flags & UPF_SPD_MASK) { 1020 dev_notice_ratelimited(uport->dev, 1021 "%s sets custom speed on %s. This is deprecated.\n", 1022 current->comm, 1023 tty_name(port->tty)); 1024 } 1025 uart_change_line_settings(tty, state, NULL); 1026 } 1027 } else { 1028 retval = uart_startup(tty, state, true); 1029 if (retval == 0) 1030 tty_port_set_initialized(port, true); 1031 if (retval > 0) 1032 retval = 0; 1033 } 1034 exit: 1035 return retval; 1036 } 1037 1038 static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss) 1039 { 1040 struct uart_state *state = tty->driver_data; 1041 struct tty_port *port = &state->port; 1042 int retval; 1043 1044 down_write(&tty->termios_rwsem); 1045 /* 1046 * This semaphore protects port->count. It is also 1047 * very useful to prevent opens. Also, take the 1048 * port configuration semaphore to make sure that a 1049 * module insertion/removal doesn't change anything 1050 * under us. 1051 */ 1052 mutex_lock(&port->mutex); 1053 retval = uart_set_info(tty, port, state, ss); 1054 mutex_unlock(&port->mutex); 1055 up_write(&tty->termios_rwsem); 1056 return retval; 1057 } 1058 1059 /** 1060 * uart_get_lsr_info - get line status register info 1061 * @tty: tty associated with the UART 1062 * @state: UART being queried 1063 * @value: returned modem value 1064 */ 1065 static int uart_get_lsr_info(struct tty_struct *tty, 1066 struct uart_state *state, unsigned int __user *value) 1067 { 1068 struct uart_port *uport = uart_port_check(state); 1069 unsigned int result; 1070 1071 result = uport->ops->tx_empty(uport); 1072 1073 /* 1074 * If we're about to load something into the transmit 1075 * register, we'll pretend the transmitter isn't empty to 1076 * avoid a race condition (depending on when the transmit 1077 * interrupt happens). 1078 */ 1079 if (uport->x_char || 1080 ((uart_circ_chars_pending(&state->xmit) > 0) && 1081 !uart_tx_stopped(uport))) 1082 result &= ~TIOCSER_TEMT; 1083 1084 return put_user(result, value); 1085 } 1086 1087 static int uart_tiocmget(struct tty_struct *tty) 1088 { 1089 struct uart_state *state = tty->driver_data; 1090 struct tty_port *port = &state->port; 1091 struct uart_port *uport; 1092 int result = -EIO; 1093 1094 mutex_lock(&port->mutex); 1095 uport = uart_port_check(state); 1096 if (!uport) 1097 goto out; 1098 1099 if (!tty_io_error(tty)) { 1100 uart_port_lock_irq(uport); 1101 result = uport->mctrl; 1102 result |= uport->ops->get_mctrl(uport); 1103 uart_port_unlock_irq(uport); 1104 } 1105 out: 1106 mutex_unlock(&port->mutex); 1107 return result; 1108 } 1109 1110 static int 1111 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) 1112 { 1113 struct uart_state *state = tty->driver_data; 1114 struct tty_port *port = &state->port; 1115 struct uart_port *uport; 1116 int ret = -EIO; 1117 1118 mutex_lock(&port->mutex); 1119 uport = uart_port_check(state); 1120 if (!uport) 1121 goto out; 1122 1123 if (!tty_io_error(tty)) { 1124 uart_update_mctrl(uport, set, clear); 1125 ret = 0; 1126 } 1127 out: 1128 mutex_unlock(&port->mutex); 1129 return ret; 1130 } 1131 1132 static int uart_break_ctl(struct tty_struct *tty, int break_state) 1133 { 1134 struct uart_state *state = tty->driver_data; 1135 struct tty_port *port = &state->port; 1136 struct uart_port *uport; 1137 int ret = -EIO; 1138 1139 mutex_lock(&port->mutex); 1140 uport = uart_port_check(state); 1141 if (!uport) 1142 goto out; 1143 1144 if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl) 1145 uport->ops->break_ctl(uport, break_state); 1146 ret = 0; 1147 out: 1148 mutex_unlock(&port->mutex); 1149 return ret; 1150 } 1151 1152 static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state) 1153 { 1154 struct tty_port *port = &state->port; 1155 struct uart_port *uport; 1156 int flags, ret; 1157 1158 if (!capable(CAP_SYS_ADMIN)) 1159 return -EPERM; 1160 1161 /* 1162 * Take the per-port semaphore. This prevents count from 1163 * changing, and hence any extra opens of the port while 1164 * we're auto-configuring. 1165 */ 1166 if (mutex_lock_interruptible(&port->mutex)) 1167 return -ERESTARTSYS; 1168 1169 uport = uart_port_check(state); 1170 if (!uport) { 1171 ret = -EIO; 1172 goto out; 1173 } 1174 1175 ret = -EBUSY; 1176 if (tty_port_users(port) == 1) { 1177 uart_shutdown(tty, state); 1178 1179 /* 1180 * If we already have a port type configured, 1181 * we must release its resources. 1182 */ 1183 if (uport->type != PORT_UNKNOWN && uport->ops->release_port) 1184 uport->ops->release_port(uport); 1185 1186 flags = UART_CONFIG_TYPE; 1187 if (uport->flags & UPF_AUTO_IRQ) 1188 flags |= UART_CONFIG_IRQ; 1189 1190 /* 1191 * This will claim the ports resources if 1192 * a port is found. 1193 */ 1194 uport->ops->config_port(uport, flags); 1195 1196 ret = uart_startup(tty, state, true); 1197 if (ret == 0) 1198 tty_port_set_initialized(port, true); 1199 if (ret > 0) 1200 ret = 0; 1201 } 1202 out: 1203 mutex_unlock(&port->mutex); 1204 return ret; 1205 } 1206 1207 static void uart_enable_ms(struct uart_port *uport) 1208 { 1209 /* 1210 * Force modem status interrupts on 1211 */ 1212 if (uport->ops->enable_ms) 1213 uport->ops->enable_ms(uport); 1214 } 1215 1216 /* 1217 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change 1218 * - mask passed in arg for lines of interest 1219 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) 1220 * Caller should use TIOCGICOUNT to see which one it was 1221 * 1222 * FIXME: This wants extracting into a common all driver implementation 1223 * of TIOCMWAIT using tty_port. 1224 */ 1225 static int uart_wait_modem_status(struct uart_state *state, unsigned long arg) 1226 { 1227 struct uart_port *uport; 1228 struct tty_port *port = &state->port; 1229 DECLARE_WAITQUEUE(wait, current); 1230 struct uart_icount cprev, cnow; 1231 int ret; 1232 1233 /* 1234 * note the counters on entry 1235 */ 1236 uport = uart_port_ref(state); 1237 if (!uport) 1238 return -EIO; 1239 uart_port_lock_irq(uport); 1240 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); 1241 uart_enable_ms(uport); 1242 uart_port_unlock_irq(uport); 1243 1244 add_wait_queue(&port->delta_msr_wait, &wait); 1245 for (;;) { 1246 uart_port_lock_irq(uport); 1247 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); 1248 uart_port_unlock_irq(uport); 1249 1250 set_current_state(TASK_INTERRUPTIBLE); 1251 1252 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || 1253 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || 1254 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || 1255 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { 1256 ret = 0; 1257 break; 1258 } 1259 1260 schedule(); 1261 1262 /* see if a signal did it */ 1263 if (signal_pending(current)) { 1264 ret = -ERESTARTSYS; 1265 break; 1266 } 1267 1268 cprev = cnow; 1269 } 1270 __set_current_state(TASK_RUNNING); 1271 remove_wait_queue(&port->delta_msr_wait, &wait); 1272 uart_port_deref(uport); 1273 1274 return ret; 1275 } 1276 1277 /* 1278 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS) 1279 * Return: write counters to the user passed counter struct 1280 * NB: both 1->0 and 0->1 transitions are counted except for 1281 * RI where only 0->1 is counted. 1282 */ 1283 static int uart_get_icount(struct tty_struct *tty, 1284 struct serial_icounter_struct *icount) 1285 { 1286 struct uart_state *state = tty->driver_data; 1287 struct uart_icount cnow; 1288 struct uart_port *uport; 1289 1290 uport = uart_port_ref(state); 1291 if (!uport) 1292 return -EIO; 1293 uart_port_lock_irq(uport); 1294 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); 1295 uart_port_unlock_irq(uport); 1296 uart_port_deref(uport); 1297 1298 icount->cts = cnow.cts; 1299 icount->dsr = cnow.dsr; 1300 icount->rng = cnow.rng; 1301 icount->dcd = cnow.dcd; 1302 icount->rx = cnow.rx; 1303 icount->tx = cnow.tx; 1304 icount->frame = cnow.frame; 1305 icount->overrun = cnow.overrun; 1306 icount->parity = cnow.parity; 1307 icount->brk = cnow.brk; 1308 icount->buf_overrun = cnow.buf_overrun; 1309 1310 return 0; 1311 } 1312 1313 #define SER_RS485_LEGACY_FLAGS (SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \ 1314 SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \ 1315 SER_RS485_TERMINATE_BUS) 1316 1317 static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *rs485) 1318 { 1319 u32 flags = rs485->flags; 1320 1321 /* Don't return -EINVAL for unsupported legacy flags */ 1322 flags &= ~SER_RS485_LEGACY_FLAGS; 1323 1324 /* 1325 * For any bit outside of the legacy ones that is not supported by 1326 * the driver, return -EINVAL. 1327 */ 1328 if (flags & ~port->rs485_supported.flags) 1329 return -EINVAL; 1330 1331 /* Asking for address w/o addressing mode? */ 1332 if (!(rs485->flags & SER_RS485_ADDRB) && 1333 (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST))) 1334 return -EINVAL; 1335 1336 /* Address given but not enabled? */ 1337 if (!(rs485->flags & SER_RS485_ADDR_RECV) && rs485->addr_recv) 1338 return -EINVAL; 1339 if (!(rs485->flags & SER_RS485_ADDR_DEST) && rs485->addr_dest) 1340 return -EINVAL; 1341 1342 return 0; 1343 } 1344 1345 static void uart_sanitize_serial_rs485_delays(struct uart_port *port, 1346 struct serial_rs485 *rs485) 1347 { 1348 if (!port->rs485_supported.delay_rts_before_send) { 1349 if (rs485->delay_rts_before_send) { 1350 dev_warn_ratelimited(port->dev, 1351 "%s (%d): RTS delay before sending not supported\n", 1352 port->name, port->line); 1353 } 1354 rs485->delay_rts_before_send = 0; 1355 } else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) { 1356 rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY; 1357 dev_warn_ratelimited(port->dev, 1358 "%s (%d): RTS delay before sending clamped to %u ms\n", 1359 port->name, port->line, rs485->delay_rts_before_send); 1360 } 1361 1362 if (!port->rs485_supported.delay_rts_after_send) { 1363 if (rs485->delay_rts_after_send) { 1364 dev_warn_ratelimited(port->dev, 1365 "%s (%d): RTS delay after sending not supported\n", 1366 port->name, port->line); 1367 } 1368 rs485->delay_rts_after_send = 0; 1369 } else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) { 1370 rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY; 1371 dev_warn_ratelimited(port->dev, 1372 "%s (%d): RTS delay after sending clamped to %u ms\n", 1373 port->name, port->line, rs485->delay_rts_after_send); 1374 } 1375 } 1376 1377 static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485) 1378 { 1379 u32 supported_flags = port->rs485_supported.flags; 1380 1381 if (!(rs485->flags & SER_RS485_ENABLED)) { 1382 memset(rs485, 0, sizeof(*rs485)); 1383 return; 1384 } 1385 1386 /* Clear other RS485 flags but SER_RS485_TERMINATE_BUS and return if enabling RS422 */ 1387 if (rs485->flags & SER_RS485_MODE_RS422) { 1388 rs485->flags &= (SER_RS485_ENABLED | SER_RS485_MODE_RS422 | SER_RS485_TERMINATE_BUS); 1389 return; 1390 } 1391 1392 rs485->flags &= supported_flags; 1393 1394 /* Pick sane settings if the user hasn't */ 1395 if (!(rs485->flags & SER_RS485_RTS_ON_SEND) == 1396 !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) { 1397 if (supported_flags & SER_RS485_RTS_ON_SEND) { 1398 rs485->flags |= SER_RS485_RTS_ON_SEND; 1399 rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; 1400 1401 dev_warn_ratelimited(port->dev, 1402 "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n", 1403 port->name, port->line); 1404 } else { 1405 rs485->flags |= SER_RS485_RTS_AFTER_SEND; 1406 rs485->flags &= ~SER_RS485_RTS_ON_SEND; 1407 1408 dev_warn_ratelimited(port->dev, 1409 "%s (%d): invalid RTS setting, using RTS_AFTER_SEND instead\n", 1410 port->name, port->line); 1411 } 1412 } 1413 1414 uart_sanitize_serial_rs485_delays(port, rs485); 1415 1416 /* Return clean padding area to userspace */ 1417 memset(rs485->padding0, 0, sizeof(rs485->padding0)); 1418 memset(rs485->padding1, 0, sizeof(rs485->padding1)); 1419 } 1420 1421 static void uart_set_rs485_termination(struct uart_port *port, 1422 const struct serial_rs485 *rs485) 1423 { 1424 if (!(rs485->flags & SER_RS485_ENABLED)) 1425 return; 1426 1427 gpiod_set_value_cansleep(port->rs485_term_gpio, 1428 !!(rs485->flags & SER_RS485_TERMINATE_BUS)); 1429 } 1430 1431 static void uart_set_rs485_rx_during_tx(struct uart_port *port, 1432 const struct serial_rs485 *rs485) 1433 { 1434 if (!(rs485->flags & SER_RS485_ENABLED)) 1435 return; 1436 1437 gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 1438 !!(rs485->flags & SER_RS485_RX_DURING_TX)); 1439 } 1440 1441 static int uart_rs485_config(struct uart_port *port) 1442 { 1443 struct serial_rs485 *rs485 = &port->rs485; 1444 unsigned long flags; 1445 int ret; 1446 1447 if (!(rs485->flags & SER_RS485_ENABLED)) 1448 return 0; 1449 1450 uart_sanitize_serial_rs485(port, rs485); 1451 uart_set_rs485_termination(port, rs485); 1452 uart_set_rs485_rx_during_tx(port, rs485); 1453 1454 uart_port_lock_irqsave(port, &flags); 1455 ret = port->rs485_config(port, NULL, rs485); 1456 uart_port_unlock_irqrestore(port, flags); 1457 if (ret) { 1458 memset(rs485, 0, sizeof(*rs485)); 1459 /* unset GPIOs */ 1460 gpiod_set_value_cansleep(port->rs485_term_gpio, 0); 1461 gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 0); 1462 } 1463 1464 return ret; 1465 } 1466 1467 static int uart_get_rs485_config(struct uart_port *port, 1468 struct serial_rs485 __user *rs485) 1469 { 1470 unsigned long flags; 1471 struct serial_rs485 aux; 1472 1473 uart_port_lock_irqsave(port, &flags); 1474 aux = port->rs485; 1475 uart_port_unlock_irqrestore(port, flags); 1476 1477 if (copy_to_user(rs485, &aux, sizeof(aux))) 1478 return -EFAULT; 1479 1480 return 0; 1481 } 1482 1483 static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port, 1484 struct serial_rs485 __user *rs485_user) 1485 { 1486 struct serial_rs485 rs485; 1487 int ret; 1488 unsigned long flags; 1489 1490 if (!(port->rs485_supported.flags & SER_RS485_ENABLED)) 1491 return -ENOTTY; 1492 1493 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) 1494 return -EFAULT; 1495 1496 ret = uart_check_rs485_flags(port, &rs485); 1497 if (ret) 1498 return ret; 1499 uart_sanitize_serial_rs485(port, &rs485); 1500 uart_set_rs485_termination(port, &rs485); 1501 uart_set_rs485_rx_during_tx(port, &rs485); 1502 1503 uart_port_lock_irqsave(port, &flags); 1504 ret = port->rs485_config(port, &tty->termios, &rs485); 1505 if (!ret) { 1506 port->rs485 = rs485; 1507 1508 /* Reset RTS and other mctrl lines when disabling RS485 */ 1509 if (!(rs485.flags & SER_RS485_ENABLED)) 1510 port->ops->set_mctrl(port, port->mctrl); 1511 } 1512 uart_port_unlock_irqrestore(port, flags); 1513 if (ret) { 1514 /* restore old GPIO settings */ 1515 gpiod_set_value_cansleep(port->rs485_term_gpio, 1516 !!(port->rs485.flags & SER_RS485_TERMINATE_BUS)); 1517 gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 1518 !!(port->rs485.flags & SER_RS485_RX_DURING_TX)); 1519 return ret; 1520 } 1521 1522 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485))) 1523 return -EFAULT; 1524 1525 return 0; 1526 } 1527 1528 static int uart_get_iso7816_config(struct uart_port *port, 1529 struct serial_iso7816 __user *iso7816) 1530 { 1531 unsigned long flags; 1532 struct serial_iso7816 aux; 1533 1534 if (!port->iso7816_config) 1535 return -ENOTTY; 1536 1537 uart_port_lock_irqsave(port, &flags); 1538 aux = port->iso7816; 1539 uart_port_unlock_irqrestore(port, flags); 1540 1541 if (copy_to_user(iso7816, &aux, sizeof(aux))) 1542 return -EFAULT; 1543 1544 return 0; 1545 } 1546 1547 static int uart_set_iso7816_config(struct uart_port *port, 1548 struct serial_iso7816 __user *iso7816_user) 1549 { 1550 struct serial_iso7816 iso7816; 1551 int i, ret; 1552 unsigned long flags; 1553 1554 if (!port->iso7816_config) 1555 return -ENOTTY; 1556 1557 if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user))) 1558 return -EFAULT; 1559 1560 /* 1561 * There are 5 words reserved for future use. Check that userspace 1562 * doesn't put stuff in there to prevent breakages in the future. 1563 */ 1564 for (i = 0; i < ARRAY_SIZE(iso7816.reserved); i++) 1565 if (iso7816.reserved[i]) 1566 return -EINVAL; 1567 1568 uart_port_lock_irqsave(port, &flags); 1569 ret = port->iso7816_config(port, &iso7816); 1570 uart_port_unlock_irqrestore(port, flags); 1571 if (ret) 1572 return ret; 1573 1574 if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816))) 1575 return -EFAULT; 1576 1577 return 0; 1578 } 1579 1580 /* 1581 * Called via sys_ioctl. We can use spin_lock_irq() here. 1582 */ 1583 static int 1584 uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) 1585 { 1586 struct uart_state *state = tty->driver_data; 1587 struct tty_port *port = &state->port; 1588 struct uart_port *uport; 1589 void __user *uarg = (void __user *)arg; 1590 int ret = -ENOIOCTLCMD; 1591 1592 1593 /* 1594 * These ioctls don't rely on the hardware to be present. 1595 */ 1596 switch (cmd) { 1597 case TIOCSERCONFIG: 1598 down_write(&tty->termios_rwsem); 1599 ret = uart_do_autoconfig(tty, state); 1600 up_write(&tty->termios_rwsem); 1601 break; 1602 } 1603 1604 if (ret != -ENOIOCTLCMD) 1605 goto out; 1606 1607 if (tty_io_error(tty)) { 1608 ret = -EIO; 1609 goto out; 1610 } 1611 1612 /* 1613 * The following should only be used when hardware is present. 1614 */ 1615 switch (cmd) { 1616 case TIOCMIWAIT: 1617 ret = uart_wait_modem_status(state, arg); 1618 break; 1619 } 1620 1621 if (ret != -ENOIOCTLCMD) 1622 goto out; 1623 1624 /* rs485_config requires more locking than others */ 1625 if (cmd == TIOCSRS485) 1626 down_write(&tty->termios_rwsem); 1627 1628 mutex_lock(&port->mutex); 1629 uport = uart_port_check(state); 1630 1631 if (!uport || tty_io_error(tty)) { 1632 ret = -EIO; 1633 goto out_up; 1634 } 1635 1636 /* 1637 * All these rely on hardware being present and need to be 1638 * protected against the tty being hung up. 1639 */ 1640 1641 switch (cmd) { 1642 case TIOCSERGETLSR: /* Get line status register */ 1643 ret = uart_get_lsr_info(tty, state, uarg); 1644 break; 1645 1646 case TIOCGRS485: 1647 ret = uart_get_rs485_config(uport, uarg); 1648 break; 1649 1650 case TIOCSRS485: 1651 ret = uart_set_rs485_config(tty, uport, uarg); 1652 break; 1653 1654 case TIOCSISO7816: 1655 ret = uart_set_iso7816_config(state->uart_port, uarg); 1656 break; 1657 1658 case TIOCGISO7816: 1659 ret = uart_get_iso7816_config(state->uart_port, uarg); 1660 break; 1661 default: 1662 if (uport->ops->ioctl) 1663 ret = uport->ops->ioctl(uport, cmd, arg); 1664 break; 1665 } 1666 out_up: 1667 mutex_unlock(&port->mutex); 1668 if (cmd == TIOCSRS485) 1669 up_write(&tty->termios_rwsem); 1670 out: 1671 return ret; 1672 } 1673 1674 static void uart_set_ldisc(struct tty_struct *tty) 1675 { 1676 struct uart_state *state = tty->driver_data; 1677 struct uart_port *uport; 1678 struct tty_port *port = &state->port; 1679 1680 if (!tty_port_initialized(port)) 1681 return; 1682 1683 mutex_lock(&state->port.mutex); 1684 uport = uart_port_check(state); 1685 if (uport && uport->ops->set_ldisc) 1686 uport->ops->set_ldisc(uport, &tty->termios); 1687 mutex_unlock(&state->port.mutex); 1688 } 1689 1690 static void uart_set_termios(struct tty_struct *tty, 1691 const struct ktermios *old_termios) 1692 { 1693 struct uart_state *state = tty->driver_data; 1694 struct uart_port *uport; 1695 unsigned int cflag = tty->termios.c_cflag; 1696 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; 1697 bool sw_changed = false; 1698 1699 mutex_lock(&state->port.mutex); 1700 uport = uart_port_check(state); 1701 if (!uport) 1702 goto out; 1703 1704 /* 1705 * Drivers doing software flow control also need to know 1706 * about changes to these input settings. 1707 */ 1708 if (uport->flags & UPF_SOFT_FLOW) { 1709 iflag_mask |= IXANY|IXON|IXOFF; 1710 sw_changed = 1711 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] || 1712 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP]; 1713 } 1714 1715 /* 1716 * These are the bits that are used to setup various 1717 * flags in the low level driver. We can ignore the Bfoo 1718 * bits in c_cflag; c_[io]speed will always be set 1719 * appropriately by set_termios() in tty_ioctl.c 1720 */ 1721 if ((cflag ^ old_termios->c_cflag) == 0 && 1722 tty->termios.c_ospeed == old_termios->c_ospeed && 1723 tty->termios.c_ispeed == old_termios->c_ispeed && 1724 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && 1725 !sw_changed) { 1726 goto out; 1727 } 1728 1729 uart_change_line_settings(tty, state, old_termios); 1730 /* reload cflag from termios; port driver may have overridden flags */ 1731 cflag = tty->termios.c_cflag; 1732 1733 /* Handle transition to B0 status */ 1734 if (((old_termios->c_cflag & CBAUD) != B0) && ((cflag & CBAUD) == B0)) 1735 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR); 1736 /* Handle transition away from B0 status */ 1737 else if (((old_termios->c_cflag & CBAUD) == B0) && ((cflag & CBAUD) != B0)) { 1738 unsigned int mask = TIOCM_DTR; 1739 1740 if (!(cflag & CRTSCTS) || !tty_throttled(tty)) 1741 mask |= TIOCM_RTS; 1742 uart_set_mctrl(uport, mask); 1743 } 1744 out: 1745 mutex_unlock(&state->port.mutex); 1746 } 1747 1748 /* 1749 * Calls to uart_close() are serialised via the tty_lock in 1750 * drivers/tty/tty_io.c:tty_release() 1751 * drivers/tty/tty_io.c:do_tty_hangup() 1752 */ 1753 static void uart_close(struct tty_struct *tty, struct file *filp) 1754 { 1755 struct uart_state *state = tty->driver_data; 1756 1757 if (!state) { 1758 struct uart_driver *drv = tty->driver->driver_state; 1759 struct tty_port *port; 1760 1761 state = drv->state + tty->index; 1762 port = &state->port; 1763 spin_lock_irq(&port->lock); 1764 --port->count; 1765 spin_unlock_irq(&port->lock); 1766 return; 1767 } 1768 1769 pr_debug("uart_close(%d) called\n", tty->index); 1770 1771 tty_port_close(tty->port, tty, filp); 1772 } 1773 1774 static void uart_tty_port_shutdown(struct tty_port *port) 1775 { 1776 struct uart_state *state = container_of(port, struct uart_state, port); 1777 struct uart_port *uport = uart_port_check(state); 1778 char *buf; 1779 1780 /* 1781 * At this point, we stop accepting input. To do this, we 1782 * disable the receive line status interrupts. 1783 */ 1784 if (WARN(!uport, "detached port still initialized!\n")) 1785 return; 1786 1787 uart_port_lock_irq(uport); 1788 uport->ops->stop_rx(uport); 1789 uart_port_unlock_irq(uport); 1790 1791 serial_base_port_shutdown(uport); 1792 uart_port_shutdown(port); 1793 1794 /* 1795 * It's possible for shutdown to be called after suspend if we get 1796 * a DCD drop (hangup) at just the right time. Clear suspended bit so 1797 * we don't try to resume a port that has been shutdown. 1798 */ 1799 tty_port_set_suspended(port, false); 1800 1801 /* 1802 * Free the transmit buffer. 1803 */ 1804 uart_port_lock_irq(uport); 1805 uart_circ_clear(&state->xmit); 1806 buf = state->xmit.buf; 1807 state->xmit.buf = NULL; 1808 uart_port_unlock_irq(uport); 1809 1810 free_page((unsigned long)buf); 1811 1812 uart_change_pm(state, UART_PM_STATE_OFF); 1813 } 1814 1815 static void uart_wait_until_sent(struct tty_struct *tty, int timeout) 1816 { 1817 struct uart_state *state = tty->driver_data; 1818 struct uart_port *port; 1819 unsigned long char_time, expire, fifo_timeout; 1820 1821 port = uart_port_ref(state); 1822 if (!port) 1823 return; 1824 1825 if (port->type == PORT_UNKNOWN || port->fifosize == 0) { 1826 uart_port_deref(port); 1827 return; 1828 } 1829 1830 /* 1831 * Set the check interval to be 1/5 of the estimated time to 1832 * send a single character, and make it at least 1. The check 1833 * interval should also be less than the timeout. 1834 * 1835 * Note: we have to use pretty tight timings here to satisfy 1836 * the NIST-PCTS. 1837 */ 1838 char_time = max(nsecs_to_jiffies(port->frame_time / 5), 1UL); 1839 1840 if (timeout && timeout < char_time) 1841 char_time = timeout; 1842 1843 if (!uart_cts_enabled(port)) { 1844 /* 1845 * If the transmitter hasn't cleared in twice the approximate 1846 * amount of time to send the entire FIFO, it probably won't 1847 * ever clear. This assumes the UART isn't doing flow 1848 * control, which is currently the case. Hence, if it ever 1849 * takes longer than FIFO timeout, this is probably due to a 1850 * UART bug of some kind. So, we clamp the timeout parameter at 1851 * 2 * FIFO timeout. 1852 */ 1853 fifo_timeout = uart_fifo_timeout(port); 1854 if (timeout == 0 || timeout > 2 * fifo_timeout) 1855 timeout = 2 * fifo_timeout; 1856 } 1857 1858 expire = jiffies + timeout; 1859 1860 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n", 1861 port->line, jiffies, expire); 1862 1863 /* 1864 * Check whether the transmitter is empty every 'char_time'. 1865 * 'timeout' / 'expire' give us the maximum amount of time 1866 * we wait. 1867 */ 1868 while (!port->ops->tx_empty(port)) { 1869 msleep_interruptible(jiffies_to_msecs(char_time)); 1870 if (signal_pending(current)) 1871 break; 1872 if (timeout && time_after(jiffies, expire)) 1873 break; 1874 } 1875 uart_port_deref(port); 1876 } 1877 1878 /* 1879 * Calls to uart_hangup() are serialised by the tty_lock in 1880 * drivers/tty/tty_io.c:do_tty_hangup() 1881 * This runs from a workqueue and can sleep for a _short_ time only. 1882 */ 1883 static void uart_hangup(struct tty_struct *tty) 1884 { 1885 struct uart_state *state = tty->driver_data; 1886 struct tty_port *port = &state->port; 1887 struct uart_port *uport; 1888 unsigned long flags; 1889 1890 pr_debug("uart_hangup(%d)\n", tty->index); 1891 1892 mutex_lock(&port->mutex); 1893 uport = uart_port_check(state); 1894 WARN(!uport, "hangup of detached port!\n"); 1895 1896 if (tty_port_active(port)) { 1897 uart_flush_buffer(tty); 1898 uart_shutdown(tty, state); 1899 spin_lock_irqsave(&port->lock, flags); 1900 port->count = 0; 1901 spin_unlock_irqrestore(&port->lock, flags); 1902 tty_port_set_active(port, false); 1903 tty_port_tty_set(port, NULL); 1904 if (uport && !uart_console(uport)) 1905 uart_change_pm(state, UART_PM_STATE_OFF); 1906 wake_up_interruptible(&port->open_wait); 1907 wake_up_interruptible(&port->delta_msr_wait); 1908 } 1909 mutex_unlock(&port->mutex); 1910 } 1911 1912 /* uport == NULL if uart_port has already been removed */ 1913 static void uart_port_shutdown(struct tty_port *port) 1914 { 1915 struct uart_state *state = container_of(port, struct uart_state, port); 1916 struct uart_port *uport = uart_port_check(state); 1917 1918 /* 1919 * clear delta_msr_wait queue to avoid mem leaks: we may free 1920 * the irq here so the queue might never be woken up. Note 1921 * that we won't end up waiting on delta_msr_wait again since 1922 * any outstanding file descriptors should be pointing at 1923 * hung_up_tty_fops now. 1924 */ 1925 wake_up_interruptible(&port->delta_msr_wait); 1926 1927 if (uport) { 1928 /* Free the IRQ and disable the port. */ 1929 uport->ops->shutdown(uport); 1930 1931 /* Ensure that the IRQ handler isn't running on another CPU. */ 1932 synchronize_irq(uport->irq); 1933 } 1934 } 1935 1936 static bool uart_carrier_raised(struct tty_port *port) 1937 { 1938 struct uart_state *state = container_of(port, struct uart_state, port); 1939 struct uart_port *uport; 1940 int mctrl; 1941 1942 uport = uart_port_ref(state); 1943 /* 1944 * Should never observe uport == NULL since checks for hangup should 1945 * abort the tty_port_block_til_ready() loop before checking for carrier 1946 * raised -- but report carrier raised if it does anyway so open will 1947 * continue and not sleep 1948 */ 1949 if (WARN_ON(!uport)) 1950 return true; 1951 uart_port_lock_irq(uport); 1952 uart_enable_ms(uport); 1953 mctrl = uport->ops->get_mctrl(uport); 1954 uart_port_unlock_irq(uport); 1955 uart_port_deref(uport); 1956 1957 return mctrl & TIOCM_CAR; 1958 } 1959 1960 static void uart_dtr_rts(struct tty_port *port, bool active) 1961 { 1962 struct uart_state *state = container_of(port, struct uart_state, port); 1963 struct uart_port *uport; 1964 1965 uport = uart_port_ref(state); 1966 if (!uport) 1967 return; 1968 uart_port_dtr_rts(uport, active); 1969 uart_port_deref(uport); 1970 } 1971 1972 static int uart_install(struct tty_driver *driver, struct tty_struct *tty) 1973 { 1974 struct uart_driver *drv = driver->driver_state; 1975 struct uart_state *state = drv->state + tty->index; 1976 1977 tty->driver_data = state; 1978 1979 return tty_standard_install(driver, tty); 1980 } 1981 1982 /* 1983 * Calls to uart_open are serialised by the tty_lock in 1984 * drivers/tty/tty_io.c:tty_open() 1985 * Note that if this fails, then uart_close() _will_ be called. 1986 * 1987 * In time, we want to scrap the "opening nonpresent ports" 1988 * behaviour and implement an alternative way for setserial 1989 * to set base addresses/ports/types. This will allow us to 1990 * get rid of a certain amount of extra tests. 1991 */ 1992 static int uart_open(struct tty_struct *tty, struct file *filp) 1993 { 1994 struct uart_state *state = tty->driver_data; 1995 int retval; 1996 1997 retval = tty_port_open(&state->port, tty, filp); 1998 if (retval > 0) 1999 retval = 0; 2000 2001 return retval; 2002 } 2003 2004 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty) 2005 { 2006 struct uart_state *state = container_of(port, struct uart_state, port); 2007 struct uart_port *uport; 2008 int ret; 2009 2010 uport = uart_port_check(state); 2011 if (!uport || uport->flags & UPF_DEAD) 2012 return -ENXIO; 2013 2014 /* 2015 * Start up the serial port. 2016 */ 2017 ret = uart_startup(tty, state, false); 2018 if (ret > 0) 2019 tty_port_set_active(port, true); 2020 2021 return ret; 2022 } 2023 2024 static const char *uart_type(struct uart_port *port) 2025 { 2026 const char *str = NULL; 2027 2028 if (port->ops->type) 2029 str = port->ops->type(port); 2030 2031 if (!str) 2032 str = "unknown"; 2033 2034 return str; 2035 } 2036 2037 #ifdef CONFIG_PROC_FS 2038 2039 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) 2040 { 2041 struct uart_state *state = drv->state + i; 2042 struct tty_port *port = &state->port; 2043 enum uart_pm_state pm_state; 2044 struct uart_port *uport; 2045 char stat_buf[32]; 2046 unsigned int status; 2047 int mmio; 2048 2049 mutex_lock(&port->mutex); 2050 uport = uart_port_check(state); 2051 if (!uport) 2052 goto out; 2053 2054 mmio = uport->iotype >= UPIO_MEM; 2055 seq_printf(m, "%d: uart:%s %s%08llX irq:%d", 2056 uport->line, uart_type(uport), 2057 mmio ? "mmio:0x" : "port:", 2058 mmio ? (unsigned long long)uport->mapbase 2059 : (unsigned long long)uport->iobase, 2060 uport->irq); 2061 2062 if (uport->type == PORT_UNKNOWN) { 2063 seq_putc(m, '\n'); 2064 goto out; 2065 } 2066 2067 if (capable(CAP_SYS_ADMIN)) { 2068 pm_state = state->pm_state; 2069 if (pm_state != UART_PM_STATE_ON) 2070 uart_change_pm(state, UART_PM_STATE_ON); 2071 uart_port_lock_irq(uport); 2072 status = uport->ops->get_mctrl(uport); 2073 uart_port_unlock_irq(uport); 2074 if (pm_state != UART_PM_STATE_ON) 2075 uart_change_pm(state, pm_state); 2076 2077 seq_printf(m, " tx:%d rx:%d", 2078 uport->icount.tx, uport->icount.rx); 2079 if (uport->icount.frame) 2080 seq_printf(m, " fe:%d", uport->icount.frame); 2081 if (uport->icount.parity) 2082 seq_printf(m, " pe:%d", uport->icount.parity); 2083 if (uport->icount.brk) 2084 seq_printf(m, " brk:%d", uport->icount.brk); 2085 if (uport->icount.overrun) 2086 seq_printf(m, " oe:%d", uport->icount.overrun); 2087 if (uport->icount.buf_overrun) 2088 seq_printf(m, " bo:%d", uport->icount.buf_overrun); 2089 2090 #define INFOBIT(bit, str) \ 2091 if (uport->mctrl & (bit)) \ 2092 strncat(stat_buf, (str), sizeof(stat_buf) - \ 2093 strlen(stat_buf) - 2) 2094 #define STATBIT(bit, str) \ 2095 if (status & (bit)) \ 2096 strncat(stat_buf, (str), sizeof(stat_buf) - \ 2097 strlen(stat_buf) - 2) 2098 2099 stat_buf[0] = '\0'; 2100 stat_buf[1] = '\0'; 2101 INFOBIT(TIOCM_RTS, "|RTS"); 2102 STATBIT(TIOCM_CTS, "|CTS"); 2103 INFOBIT(TIOCM_DTR, "|DTR"); 2104 STATBIT(TIOCM_DSR, "|DSR"); 2105 STATBIT(TIOCM_CAR, "|CD"); 2106 STATBIT(TIOCM_RNG, "|RI"); 2107 if (stat_buf[0]) 2108 stat_buf[0] = ' '; 2109 2110 seq_puts(m, stat_buf); 2111 } 2112 seq_putc(m, '\n'); 2113 #undef STATBIT 2114 #undef INFOBIT 2115 out: 2116 mutex_unlock(&port->mutex); 2117 } 2118 2119 static int uart_proc_show(struct seq_file *m, void *v) 2120 { 2121 struct tty_driver *ttydrv = m->private; 2122 struct uart_driver *drv = ttydrv->driver_state; 2123 int i; 2124 2125 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", ""); 2126 for (i = 0; i < drv->nr; i++) 2127 uart_line_info(m, drv, i); 2128 return 0; 2129 } 2130 #endif 2131 2132 static void uart_port_spin_lock_init(struct uart_port *port) 2133 { 2134 spin_lock_init(&port->lock); 2135 lockdep_set_class(&port->lock, &port_lock_key); 2136 } 2137 2138 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) 2139 /** 2140 * uart_console_write - write a console message to a serial port 2141 * @port: the port to write the message 2142 * @s: array of characters 2143 * @count: number of characters in string to write 2144 * @putchar: function to write character to port 2145 */ 2146 void uart_console_write(struct uart_port *port, const char *s, 2147 unsigned int count, 2148 void (*putchar)(struct uart_port *, unsigned char)) 2149 { 2150 unsigned int i; 2151 2152 for (i = 0; i < count; i++, s++) { 2153 if (*s == '\n') 2154 putchar(port, '\r'); 2155 putchar(port, *s); 2156 } 2157 } 2158 EXPORT_SYMBOL_GPL(uart_console_write); 2159 2160 /** 2161 * uart_get_console - get uart port for console 2162 * @ports: ports to search in 2163 * @nr: number of @ports 2164 * @co: console to search for 2165 * Returns: uart_port for the console @co 2166 * 2167 * Check whether an invalid uart number has been specified (as @co->index), and 2168 * if so, search for the first available port that does have console support. 2169 */ 2170 struct uart_port * __init 2171 uart_get_console(struct uart_port *ports, int nr, struct console *co) 2172 { 2173 int idx = co->index; 2174 2175 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 && 2176 ports[idx].membase == NULL)) 2177 for (idx = 0; idx < nr; idx++) 2178 if (ports[idx].iobase != 0 || 2179 ports[idx].membase != NULL) 2180 break; 2181 2182 co->index = idx; 2183 2184 return ports + idx; 2185 } 2186 2187 /** 2188 * uart_parse_earlycon - Parse earlycon options 2189 * @p: ptr to 2nd field (ie., just beyond '<name>,') 2190 * @iotype: ptr for decoded iotype (out) 2191 * @addr: ptr for decoded mapbase/iobase (out) 2192 * @options: ptr for <options> field; %NULL if not present (out) 2193 * 2194 * Decodes earlycon kernel command line parameters of the form: 2195 * * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> 2196 * * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> 2197 * 2198 * The optional form: 2199 * * earlycon=<name>,0x<addr>,<options> 2200 * * console=<name>,0x<addr>,<options> 2201 * 2202 * is also accepted; the returned @iotype will be %UPIO_MEM. 2203 * 2204 * Returns: 0 on success or -%EINVAL on failure 2205 */ 2206 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, 2207 char **options) 2208 { 2209 if (strncmp(p, "mmio,", 5) == 0) { 2210 *iotype = UPIO_MEM; 2211 p += 5; 2212 } else if (strncmp(p, "mmio16,", 7) == 0) { 2213 *iotype = UPIO_MEM16; 2214 p += 7; 2215 } else if (strncmp(p, "mmio32,", 7) == 0) { 2216 *iotype = UPIO_MEM32; 2217 p += 7; 2218 } else if (strncmp(p, "mmio32be,", 9) == 0) { 2219 *iotype = UPIO_MEM32BE; 2220 p += 9; 2221 } else if (strncmp(p, "mmio32native,", 13) == 0) { 2222 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ? 2223 UPIO_MEM32BE : UPIO_MEM32; 2224 p += 13; 2225 } else if (strncmp(p, "io,", 3) == 0) { 2226 *iotype = UPIO_PORT; 2227 p += 3; 2228 } else if (strncmp(p, "0x", 2) == 0) { 2229 *iotype = UPIO_MEM; 2230 } else { 2231 return -EINVAL; 2232 } 2233 2234 /* 2235 * Before you replace it with kstrtoull(), think about options separator 2236 * (',') it will not tolerate 2237 */ 2238 *addr = simple_strtoull(p, NULL, 0); 2239 p = strchr(p, ','); 2240 if (p) 2241 p++; 2242 2243 *options = p; 2244 return 0; 2245 } 2246 EXPORT_SYMBOL_GPL(uart_parse_earlycon); 2247 2248 /** 2249 * uart_parse_options - Parse serial port baud/parity/bits/flow control. 2250 * @options: pointer to option string 2251 * @baud: pointer to an 'int' variable for the baud rate. 2252 * @parity: pointer to an 'int' variable for the parity. 2253 * @bits: pointer to an 'int' variable for the number of data bits. 2254 * @flow: pointer to an 'int' variable for the flow control character. 2255 * 2256 * uart_parse_options() decodes a string containing the serial console 2257 * options. The format of the string is <baud><parity><bits><flow>, 2258 * eg: 115200n8r 2259 */ 2260 void 2261 uart_parse_options(const char *options, int *baud, int *parity, 2262 int *bits, int *flow) 2263 { 2264 const char *s = options; 2265 2266 *baud = simple_strtoul(s, NULL, 10); 2267 while (*s >= '0' && *s <= '9') 2268 s++; 2269 if (*s) 2270 *parity = *s++; 2271 if (*s) 2272 *bits = *s++ - '0'; 2273 if (*s) 2274 *flow = *s; 2275 } 2276 EXPORT_SYMBOL_GPL(uart_parse_options); 2277 2278 /** 2279 * uart_set_options - setup the serial console parameters 2280 * @port: pointer to the serial ports uart_port structure 2281 * @co: console pointer 2282 * @baud: baud rate 2283 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) 2284 * @bits: number of data bits 2285 * @flow: flow control character - 'r' (rts) 2286 * 2287 * Locking: Caller must hold console_list_lock in order to serialize 2288 * early initialization of the serial-console lock. 2289 */ 2290 int 2291 uart_set_options(struct uart_port *port, struct console *co, 2292 int baud, int parity, int bits, int flow) 2293 { 2294 struct ktermios termios; 2295 static struct ktermios dummy; 2296 2297 /* 2298 * Ensure that the serial-console lock is initialised early. 2299 * 2300 * Note that the console-registered check is needed because 2301 * kgdboc can call uart_set_options() for an already registered 2302 * console via tty_find_polling_driver() and uart_poll_init(). 2303 */ 2304 if (!uart_console_registered_locked(port) && !port->console_reinit) 2305 uart_port_spin_lock_init(port); 2306 2307 memset(&termios, 0, sizeof(struct ktermios)); 2308 2309 termios.c_cflag |= CREAD | HUPCL | CLOCAL; 2310 tty_termios_encode_baud_rate(&termios, baud, baud); 2311 2312 if (bits == 7) 2313 termios.c_cflag |= CS7; 2314 else 2315 termios.c_cflag |= CS8; 2316 2317 switch (parity) { 2318 case 'o': case 'O': 2319 termios.c_cflag |= PARODD; 2320 fallthrough; 2321 case 'e': case 'E': 2322 termios.c_cflag |= PARENB; 2323 break; 2324 } 2325 2326 if (flow == 'r') 2327 termios.c_cflag |= CRTSCTS; 2328 2329 /* 2330 * some uarts on other side don't support no flow control. 2331 * So we set * DTR in host uart to make them happy 2332 */ 2333 port->mctrl |= TIOCM_DTR; 2334 2335 port->ops->set_termios(port, &termios, &dummy); 2336 /* 2337 * Allow the setting of the UART parameters with a NULL console 2338 * too: 2339 */ 2340 if (co) { 2341 co->cflag = termios.c_cflag; 2342 co->ispeed = termios.c_ispeed; 2343 co->ospeed = termios.c_ospeed; 2344 } 2345 2346 return 0; 2347 } 2348 EXPORT_SYMBOL_GPL(uart_set_options); 2349 #endif /* CONFIG_SERIAL_CORE_CONSOLE */ 2350 2351 /** 2352 * uart_change_pm - set power state of the port 2353 * 2354 * @state: port descriptor 2355 * @pm_state: new state 2356 * 2357 * Locking: port->mutex has to be held 2358 */ 2359 static void uart_change_pm(struct uart_state *state, 2360 enum uart_pm_state pm_state) 2361 { 2362 struct uart_port *port = uart_port_check(state); 2363 2364 if (state->pm_state != pm_state) { 2365 if (port && port->ops->pm) 2366 port->ops->pm(port, pm_state, state->pm_state); 2367 state->pm_state = pm_state; 2368 } 2369 } 2370 2371 struct uart_match { 2372 struct uart_port *port; 2373 struct uart_driver *driver; 2374 }; 2375 2376 static int serial_match_port(struct device *dev, void *data) 2377 { 2378 struct uart_match *match = data; 2379 struct tty_driver *tty_drv = match->driver->tty_driver; 2380 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) + 2381 match->port->line; 2382 2383 return dev->devt == devt; /* Actually, only one tty per port */ 2384 } 2385 2386 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) 2387 { 2388 struct uart_state *state = drv->state + uport->line; 2389 struct tty_port *port = &state->port; 2390 struct device *tty_dev; 2391 struct uart_match match = {uport, drv}; 2392 2393 mutex_lock(&port->mutex); 2394 2395 tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port); 2396 if (tty_dev && device_may_wakeup(tty_dev)) { 2397 enable_irq_wake(uport->irq); 2398 put_device(tty_dev); 2399 mutex_unlock(&port->mutex); 2400 return 0; 2401 } 2402 put_device(tty_dev); 2403 2404 /* 2405 * Nothing to do if the console is not suspending 2406 * except stop_rx to prevent any asynchronous data 2407 * over RX line. However ensure that we will be 2408 * able to Re-start_rx later. 2409 */ 2410 if (!console_suspend_enabled && uart_console(uport)) { 2411 if (uport->ops->start_rx) { 2412 uart_port_lock_irq(uport); 2413 uport->ops->stop_rx(uport); 2414 uart_port_unlock_irq(uport); 2415 } 2416 goto unlock; 2417 } 2418 2419 uport->suspended = 1; 2420 2421 if (tty_port_initialized(port)) { 2422 const struct uart_ops *ops = uport->ops; 2423 int tries; 2424 unsigned int mctrl; 2425 2426 tty_port_set_suspended(port, true); 2427 tty_port_set_initialized(port, false); 2428 2429 uart_port_lock_irq(uport); 2430 ops->stop_tx(uport); 2431 if (!(uport->rs485.flags & SER_RS485_ENABLED)) 2432 ops->set_mctrl(uport, 0); 2433 /* save mctrl so it can be restored on resume */ 2434 mctrl = uport->mctrl; 2435 uport->mctrl = 0; 2436 ops->stop_rx(uport); 2437 uart_port_unlock_irq(uport); 2438 2439 /* 2440 * Wait for the transmitter to empty. 2441 */ 2442 for (tries = 3; !ops->tx_empty(uport) && tries; tries--) 2443 msleep(10); 2444 if (!tries) 2445 dev_err(uport->dev, "%s: Unable to drain transmitter\n", 2446 uport->name); 2447 2448 ops->shutdown(uport); 2449 uport->mctrl = mctrl; 2450 } 2451 2452 /* 2453 * Disable the console device before suspending. 2454 */ 2455 if (uart_console(uport)) 2456 console_stop(uport->cons); 2457 2458 uart_change_pm(state, UART_PM_STATE_OFF); 2459 unlock: 2460 mutex_unlock(&port->mutex); 2461 2462 return 0; 2463 } 2464 EXPORT_SYMBOL(uart_suspend_port); 2465 2466 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) 2467 { 2468 struct uart_state *state = drv->state + uport->line; 2469 struct tty_port *port = &state->port; 2470 struct device *tty_dev; 2471 struct uart_match match = {uport, drv}; 2472 struct ktermios termios; 2473 2474 mutex_lock(&port->mutex); 2475 2476 tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port); 2477 if (!uport->suspended && device_may_wakeup(tty_dev)) { 2478 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq)))) 2479 disable_irq_wake(uport->irq); 2480 put_device(tty_dev); 2481 mutex_unlock(&port->mutex); 2482 return 0; 2483 } 2484 put_device(tty_dev); 2485 uport->suspended = 0; 2486 2487 /* 2488 * Re-enable the console device after suspending. 2489 */ 2490 if (uart_console(uport)) { 2491 /* 2492 * First try to use the console cflag setting. 2493 */ 2494 memset(&termios, 0, sizeof(struct ktermios)); 2495 termios.c_cflag = uport->cons->cflag; 2496 termios.c_ispeed = uport->cons->ispeed; 2497 termios.c_ospeed = uport->cons->ospeed; 2498 2499 /* 2500 * If that's unset, use the tty termios setting. 2501 */ 2502 if (port->tty && termios.c_cflag == 0) 2503 termios = port->tty->termios; 2504 2505 if (console_suspend_enabled) 2506 uart_change_pm(state, UART_PM_STATE_ON); 2507 uport->ops->set_termios(uport, &termios, NULL); 2508 if (!console_suspend_enabled && uport->ops->start_rx) { 2509 uart_port_lock_irq(uport); 2510 uport->ops->start_rx(uport); 2511 uart_port_unlock_irq(uport); 2512 } 2513 if (console_suspend_enabled) 2514 console_start(uport->cons); 2515 } 2516 2517 if (tty_port_suspended(port)) { 2518 const struct uart_ops *ops = uport->ops; 2519 int ret; 2520 2521 uart_change_pm(state, UART_PM_STATE_ON); 2522 uart_port_lock_irq(uport); 2523 if (!(uport->rs485.flags & SER_RS485_ENABLED)) 2524 ops->set_mctrl(uport, 0); 2525 uart_port_unlock_irq(uport); 2526 if (console_suspend_enabled || !uart_console(uport)) { 2527 /* Protected by port mutex for now */ 2528 struct tty_struct *tty = port->tty; 2529 2530 ret = ops->startup(uport); 2531 if (ret == 0) { 2532 if (tty) 2533 uart_change_line_settings(tty, state, NULL); 2534 uart_rs485_config(uport); 2535 uart_port_lock_irq(uport); 2536 if (!(uport->rs485.flags & SER_RS485_ENABLED)) 2537 ops->set_mctrl(uport, uport->mctrl); 2538 ops->start_tx(uport); 2539 uart_port_unlock_irq(uport); 2540 tty_port_set_initialized(port, true); 2541 } else { 2542 /* 2543 * Failed to resume - maybe hardware went away? 2544 * Clear the "initialized" flag so we won't try 2545 * to call the low level drivers shutdown method. 2546 */ 2547 uart_shutdown(tty, state); 2548 } 2549 } 2550 2551 tty_port_set_suspended(port, false); 2552 } 2553 2554 mutex_unlock(&port->mutex); 2555 2556 return 0; 2557 } 2558 EXPORT_SYMBOL(uart_resume_port); 2559 2560 static inline void 2561 uart_report_port(struct uart_driver *drv, struct uart_port *port) 2562 { 2563 char address[64]; 2564 2565 switch (port->iotype) { 2566 case UPIO_PORT: 2567 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase); 2568 break; 2569 case UPIO_HUB6: 2570 snprintf(address, sizeof(address), 2571 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6); 2572 break; 2573 case UPIO_MEM: 2574 case UPIO_MEM16: 2575 case UPIO_MEM32: 2576 case UPIO_MEM32BE: 2577 case UPIO_AU: 2578 case UPIO_TSI: 2579 snprintf(address, sizeof(address), 2580 "MMIO 0x%llx", (unsigned long long)port->mapbase); 2581 break; 2582 default: 2583 strscpy(address, "*unknown*", sizeof(address)); 2584 break; 2585 } 2586 2587 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n", 2588 port->dev ? dev_name(port->dev) : "", 2589 port->dev ? ": " : "", 2590 port->name, 2591 address, port->irq, port->uartclk / 16, uart_type(port)); 2592 2593 /* The magic multiplier feature is a bit obscure, so report it too. */ 2594 if (port->flags & UPF_MAGIC_MULTIPLIER) 2595 pr_info("%s%s%s extra baud rates supported: %d, %d", 2596 port->dev ? dev_name(port->dev) : "", 2597 port->dev ? ": " : "", 2598 port->name, 2599 port->uartclk / 8, port->uartclk / 4); 2600 } 2601 2602 static void 2603 uart_configure_port(struct uart_driver *drv, struct uart_state *state, 2604 struct uart_port *port) 2605 { 2606 unsigned int flags; 2607 2608 /* 2609 * If there isn't a port here, don't do anything further. 2610 */ 2611 if (!port->iobase && !port->mapbase && !port->membase) 2612 return; 2613 2614 /* 2615 * Now do the auto configuration stuff. Note that config_port 2616 * is expected to claim the resources and map the port for us. 2617 */ 2618 flags = 0; 2619 if (port->flags & UPF_AUTO_IRQ) 2620 flags |= UART_CONFIG_IRQ; 2621 if (port->flags & UPF_BOOT_AUTOCONF) { 2622 if (!(port->flags & UPF_FIXED_TYPE)) { 2623 port->type = PORT_UNKNOWN; 2624 flags |= UART_CONFIG_TYPE; 2625 } 2626 /* Synchronize with possible boot console. */ 2627 if (uart_console(port)) 2628 console_lock(); 2629 port->ops->config_port(port, flags); 2630 if (uart_console(port)) 2631 console_unlock(); 2632 } 2633 2634 if (port->type != PORT_UNKNOWN) { 2635 unsigned long flags; 2636 2637 uart_report_port(drv, port); 2638 2639 /* Synchronize with possible boot console. */ 2640 if (uart_console(port)) 2641 console_lock(); 2642 2643 /* Power up port for set_mctrl() */ 2644 uart_change_pm(state, UART_PM_STATE_ON); 2645 2646 /* 2647 * Ensure that the modem control lines are de-activated. 2648 * keep the DTR setting that is set in uart_set_options() 2649 * We probably don't need a spinlock around this, but 2650 */ 2651 uart_port_lock_irqsave(port, &flags); 2652 port->mctrl &= TIOCM_DTR; 2653 if (!(port->rs485.flags & SER_RS485_ENABLED)) 2654 port->ops->set_mctrl(port, port->mctrl); 2655 uart_port_unlock_irqrestore(port, flags); 2656 2657 uart_rs485_config(port); 2658 2659 if (uart_console(port)) 2660 console_unlock(); 2661 2662 /* 2663 * If this driver supports console, and it hasn't been 2664 * successfully registered yet, try to re-register it. 2665 * It may be that the port was not available. 2666 */ 2667 if (port->cons && !console_is_registered(port->cons)) 2668 register_console(port->cons); 2669 2670 /* 2671 * Power down all ports by default, except the 2672 * console if we have one. 2673 */ 2674 if (!uart_console(port)) 2675 uart_change_pm(state, UART_PM_STATE_OFF); 2676 } 2677 } 2678 2679 #ifdef CONFIG_CONSOLE_POLL 2680 2681 static int uart_poll_init(struct tty_driver *driver, int line, char *options) 2682 { 2683 struct uart_driver *drv = driver->driver_state; 2684 struct uart_state *state = drv->state + line; 2685 enum uart_pm_state pm_state; 2686 struct tty_port *tport; 2687 struct uart_port *port; 2688 int baud = 9600; 2689 int bits = 8; 2690 int parity = 'n'; 2691 int flow = 'n'; 2692 int ret = 0; 2693 2694 tport = &state->port; 2695 mutex_lock(&tport->mutex); 2696 2697 port = uart_port_check(state); 2698 if (!port || port->type == PORT_UNKNOWN || 2699 !(port->ops->poll_get_char && port->ops->poll_put_char)) { 2700 ret = -1; 2701 goto out; 2702 } 2703 2704 pm_state = state->pm_state; 2705 uart_change_pm(state, UART_PM_STATE_ON); 2706 2707 if (port->ops->poll_init) { 2708 /* 2709 * We don't set initialized as we only initialized the hw, 2710 * e.g. state->xmit is still uninitialized. 2711 */ 2712 if (!tty_port_initialized(tport)) 2713 ret = port->ops->poll_init(port); 2714 } 2715 2716 if (!ret && options) { 2717 uart_parse_options(options, &baud, &parity, &bits, &flow); 2718 console_list_lock(); 2719 ret = uart_set_options(port, NULL, baud, parity, bits, flow); 2720 console_list_unlock(); 2721 } 2722 out: 2723 if (ret) 2724 uart_change_pm(state, pm_state); 2725 mutex_unlock(&tport->mutex); 2726 return ret; 2727 } 2728 2729 static int uart_poll_get_char(struct tty_driver *driver, int line) 2730 { 2731 struct uart_driver *drv = driver->driver_state; 2732 struct uart_state *state = drv->state + line; 2733 struct uart_port *port; 2734 int ret = -1; 2735 2736 port = uart_port_ref(state); 2737 if (port) { 2738 ret = port->ops->poll_get_char(port); 2739 uart_port_deref(port); 2740 } 2741 2742 return ret; 2743 } 2744 2745 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) 2746 { 2747 struct uart_driver *drv = driver->driver_state; 2748 struct uart_state *state = drv->state + line; 2749 struct uart_port *port; 2750 2751 port = uart_port_ref(state); 2752 if (!port) 2753 return; 2754 2755 if (ch == '\n') 2756 port->ops->poll_put_char(port, '\r'); 2757 port->ops->poll_put_char(port, ch); 2758 uart_port_deref(port); 2759 } 2760 #endif 2761 2762 static const struct tty_operations uart_ops = { 2763 .install = uart_install, 2764 .open = uart_open, 2765 .close = uart_close, 2766 .write = uart_write, 2767 .put_char = uart_put_char, 2768 .flush_chars = uart_flush_chars, 2769 .write_room = uart_write_room, 2770 .chars_in_buffer= uart_chars_in_buffer, 2771 .flush_buffer = uart_flush_buffer, 2772 .ioctl = uart_ioctl, 2773 .throttle = uart_throttle, 2774 .unthrottle = uart_unthrottle, 2775 .send_xchar = uart_send_xchar, 2776 .set_termios = uart_set_termios, 2777 .set_ldisc = uart_set_ldisc, 2778 .stop = uart_stop, 2779 .start = uart_start, 2780 .hangup = uart_hangup, 2781 .break_ctl = uart_break_ctl, 2782 .wait_until_sent= uart_wait_until_sent, 2783 #ifdef CONFIG_PROC_FS 2784 .proc_show = uart_proc_show, 2785 #endif 2786 .tiocmget = uart_tiocmget, 2787 .tiocmset = uart_tiocmset, 2788 .set_serial = uart_set_info_user, 2789 .get_serial = uart_get_info_user, 2790 .get_icount = uart_get_icount, 2791 #ifdef CONFIG_CONSOLE_POLL 2792 .poll_init = uart_poll_init, 2793 .poll_get_char = uart_poll_get_char, 2794 .poll_put_char = uart_poll_put_char, 2795 #endif 2796 }; 2797 2798 static const struct tty_port_operations uart_port_ops = { 2799 .carrier_raised = uart_carrier_raised, 2800 .dtr_rts = uart_dtr_rts, 2801 .activate = uart_port_activate, 2802 .shutdown = uart_tty_port_shutdown, 2803 }; 2804 2805 /** 2806 * uart_register_driver - register a driver with the uart core layer 2807 * @drv: low level driver structure 2808 * 2809 * Register a uart driver with the core driver. We in turn register with the 2810 * tty layer, and initialise the core driver per-port state. 2811 * 2812 * We have a proc file in /proc/tty/driver which is named after the normal 2813 * driver. 2814 * 2815 * @drv->port should be %NULL, and the per-port structures should be registered 2816 * using uart_add_one_port() after this call has succeeded. 2817 * 2818 * Locking: none, Interrupts: enabled 2819 */ 2820 int uart_register_driver(struct uart_driver *drv) 2821 { 2822 struct tty_driver *normal; 2823 int i, retval = -ENOMEM; 2824 2825 BUG_ON(drv->state); 2826 2827 /* 2828 * Maybe we should be using a slab cache for this, especially if 2829 * we have a large number of ports to handle. 2830 */ 2831 drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL); 2832 if (!drv->state) 2833 goto out; 2834 2835 normal = tty_alloc_driver(drv->nr, TTY_DRIVER_REAL_RAW | 2836 TTY_DRIVER_DYNAMIC_DEV); 2837 if (IS_ERR(normal)) { 2838 retval = PTR_ERR(normal); 2839 goto out_kfree; 2840 } 2841 2842 drv->tty_driver = normal; 2843 2844 normal->driver_name = drv->driver_name; 2845 normal->name = drv->dev_name; 2846 normal->major = drv->major; 2847 normal->minor_start = drv->minor; 2848 normal->type = TTY_DRIVER_TYPE_SERIAL; 2849 normal->subtype = SERIAL_TYPE_NORMAL; 2850 normal->init_termios = tty_std_termios; 2851 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; 2852 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; 2853 normal->driver_state = drv; 2854 tty_set_operations(normal, &uart_ops); 2855 2856 /* 2857 * Initialise the UART state(s). 2858 */ 2859 for (i = 0; i < drv->nr; i++) { 2860 struct uart_state *state = drv->state + i; 2861 struct tty_port *port = &state->port; 2862 2863 tty_port_init(port); 2864 port->ops = &uart_port_ops; 2865 } 2866 2867 retval = tty_register_driver(normal); 2868 if (retval >= 0) 2869 return retval; 2870 2871 for (i = 0; i < drv->nr; i++) 2872 tty_port_destroy(&drv->state[i].port); 2873 tty_driver_kref_put(normal); 2874 out_kfree: 2875 kfree(drv->state); 2876 out: 2877 return retval; 2878 } 2879 EXPORT_SYMBOL(uart_register_driver); 2880 2881 /** 2882 * uart_unregister_driver - remove a driver from the uart core layer 2883 * @drv: low level driver structure 2884 * 2885 * Remove all references to a driver from the core driver. The low level 2886 * driver must have removed all its ports via the uart_remove_one_port() if it 2887 * registered them with uart_add_one_port(). (I.e. @drv->port is %NULL.) 2888 * 2889 * Locking: none, Interrupts: enabled 2890 */ 2891 void uart_unregister_driver(struct uart_driver *drv) 2892 { 2893 struct tty_driver *p = drv->tty_driver; 2894 unsigned int i; 2895 2896 tty_unregister_driver(p); 2897 tty_driver_kref_put(p); 2898 for (i = 0; i < drv->nr; i++) 2899 tty_port_destroy(&drv->state[i].port); 2900 kfree(drv->state); 2901 drv->state = NULL; 2902 drv->tty_driver = NULL; 2903 } 2904 EXPORT_SYMBOL(uart_unregister_driver); 2905 2906 struct tty_driver *uart_console_device(struct console *co, int *index) 2907 { 2908 struct uart_driver *p = co->data; 2909 *index = co->index; 2910 return p->tty_driver; 2911 } 2912 EXPORT_SYMBOL_GPL(uart_console_device); 2913 2914 static ssize_t uartclk_show(struct device *dev, 2915 struct device_attribute *attr, char *buf) 2916 { 2917 struct serial_struct tmp; 2918 struct tty_port *port = dev_get_drvdata(dev); 2919 2920 uart_get_info(port, &tmp); 2921 return sprintf(buf, "%d\n", tmp.baud_base * 16); 2922 } 2923 2924 static ssize_t type_show(struct device *dev, 2925 struct device_attribute *attr, char *buf) 2926 { 2927 struct serial_struct tmp; 2928 struct tty_port *port = dev_get_drvdata(dev); 2929 2930 uart_get_info(port, &tmp); 2931 return sprintf(buf, "%d\n", tmp.type); 2932 } 2933 2934 static ssize_t line_show(struct device *dev, 2935 struct device_attribute *attr, char *buf) 2936 { 2937 struct serial_struct tmp; 2938 struct tty_port *port = dev_get_drvdata(dev); 2939 2940 uart_get_info(port, &tmp); 2941 return sprintf(buf, "%d\n", tmp.line); 2942 } 2943 2944 static ssize_t port_show(struct device *dev, 2945 struct device_attribute *attr, char *buf) 2946 { 2947 struct serial_struct tmp; 2948 struct tty_port *port = dev_get_drvdata(dev); 2949 unsigned long ioaddr; 2950 2951 uart_get_info(port, &tmp); 2952 ioaddr = tmp.port; 2953 if (HIGH_BITS_OFFSET) 2954 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET; 2955 return sprintf(buf, "0x%lX\n", ioaddr); 2956 } 2957 2958 static ssize_t irq_show(struct device *dev, 2959 struct device_attribute *attr, char *buf) 2960 { 2961 struct serial_struct tmp; 2962 struct tty_port *port = dev_get_drvdata(dev); 2963 2964 uart_get_info(port, &tmp); 2965 return sprintf(buf, "%d\n", tmp.irq); 2966 } 2967 2968 static ssize_t flags_show(struct device *dev, 2969 struct device_attribute *attr, char *buf) 2970 { 2971 struct serial_struct tmp; 2972 struct tty_port *port = dev_get_drvdata(dev); 2973 2974 uart_get_info(port, &tmp); 2975 return sprintf(buf, "0x%X\n", tmp.flags); 2976 } 2977 2978 static ssize_t xmit_fifo_size_show(struct device *dev, 2979 struct device_attribute *attr, char *buf) 2980 { 2981 struct serial_struct tmp; 2982 struct tty_port *port = dev_get_drvdata(dev); 2983 2984 uart_get_info(port, &tmp); 2985 return sprintf(buf, "%d\n", tmp.xmit_fifo_size); 2986 } 2987 2988 static ssize_t close_delay_show(struct device *dev, 2989 struct device_attribute *attr, char *buf) 2990 { 2991 struct serial_struct tmp; 2992 struct tty_port *port = dev_get_drvdata(dev); 2993 2994 uart_get_info(port, &tmp); 2995 return sprintf(buf, "%d\n", tmp.close_delay); 2996 } 2997 2998 static ssize_t closing_wait_show(struct device *dev, 2999 struct device_attribute *attr, char *buf) 3000 { 3001 struct serial_struct tmp; 3002 struct tty_port *port = dev_get_drvdata(dev); 3003 3004 uart_get_info(port, &tmp); 3005 return sprintf(buf, "%d\n", tmp.closing_wait); 3006 } 3007 3008 static ssize_t custom_divisor_show(struct device *dev, 3009 struct device_attribute *attr, char *buf) 3010 { 3011 struct serial_struct tmp; 3012 struct tty_port *port = dev_get_drvdata(dev); 3013 3014 uart_get_info(port, &tmp); 3015 return sprintf(buf, "%d\n", tmp.custom_divisor); 3016 } 3017 3018 static ssize_t io_type_show(struct device *dev, 3019 struct device_attribute *attr, char *buf) 3020 { 3021 struct serial_struct tmp; 3022 struct tty_port *port = dev_get_drvdata(dev); 3023 3024 uart_get_info(port, &tmp); 3025 return sprintf(buf, "%d\n", tmp.io_type); 3026 } 3027 3028 static ssize_t iomem_base_show(struct device *dev, 3029 struct device_attribute *attr, char *buf) 3030 { 3031 struct serial_struct tmp; 3032 struct tty_port *port = dev_get_drvdata(dev); 3033 3034 uart_get_info(port, &tmp); 3035 return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base); 3036 } 3037 3038 static ssize_t iomem_reg_shift_show(struct device *dev, 3039 struct device_attribute *attr, char *buf) 3040 { 3041 struct serial_struct tmp; 3042 struct tty_port *port = dev_get_drvdata(dev); 3043 3044 uart_get_info(port, &tmp); 3045 return sprintf(buf, "%d\n", tmp.iomem_reg_shift); 3046 } 3047 3048 static ssize_t console_show(struct device *dev, 3049 struct device_attribute *attr, char *buf) 3050 { 3051 struct tty_port *port = dev_get_drvdata(dev); 3052 struct uart_state *state = container_of(port, struct uart_state, port); 3053 struct uart_port *uport; 3054 bool console = false; 3055 3056 mutex_lock(&port->mutex); 3057 uport = uart_port_check(state); 3058 if (uport) 3059 console = uart_console_registered(uport); 3060 mutex_unlock(&port->mutex); 3061 3062 return sprintf(buf, "%c\n", console ? 'Y' : 'N'); 3063 } 3064 3065 static ssize_t console_store(struct device *dev, 3066 struct device_attribute *attr, const char *buf, size_t count) 3067 { 3068 struct tty_port *port = dev_get_drvdata(dev); 3069 struct uart_state *state = container_of(port, struct uart_state, port); 3070 struct uart_port *uport; 3071 bool oldconsole, newconsole; 3072 int ret; 3073 3074 ret = kstrtobool(buf, &newconsole); 3075 if (ret) 3076 return ret; 3077 3078 mutex_lock(&port->mutex); 3079 uport = uart_port_check(state); 3080 if (uport) { 3081 oldconsole = uart_console_registered(uport); 3082 if (oldconsole && !newconsole) { 3083 ret = unregister_console(uport->cons); 3084 } else if (!oldconsole && newconsole) { 3085 if (uart_console(uport)) { 3086 uport->console_reinit = 1; 3087 register_console(uport->cons); 3088 } else { 3089 ret = -ENOENT; 3090 } 3091 } 3092 } else { 3093 ret = -ENXIO; 3094 } 3095 mutex_unlock(&port->mutex); 3096 3097 return ret < 0 ? ret : count; 3098 } 3099 3100 static DEVICE_ATTR_RO(uartclk); 3101 static DEVICE_ATTR_RO(type); 3102 static DEVICE_ATTR_RO(line); 3103 static DEVICE_ATTR_RO(port); 3104 static DEVICE_ATTR_RO(irq); 3105 static DEVICE_ATTR_RO(flags); 3106 static DEVICE_ATTR_RO(xmit_fifo_size); 3107 static DEVICE_ATTR_RO(close_delay); 3108 static DEVICE_ATTR_RO(closing_wait); 3109 static DEVICE_ATTR_RO(custom_divisor); 3110 static DEVICE_ATTR_RO(io_type); 3111 static DEVICE_ATTR_RO(iomem_base); 3112 static DEVICE_ATTR_RO(iomem_reg_shift); 3113 static DEVICE_ATTR_RW(console); 3114 3115 static struct attribute *tty_dev_attrs[] = { 3116 &dev_attr_uartclk.attr, 3117 &dev_attr_type.attr, 3118 &dev_attr_line.attr, 3119 &dev_attr_port.attr, 3120 &dev_attr_irq.attr, 3121 &dev_attr_flags.attr, 3122 &dev_attr_xmit_fifo_size.attr, 3123 &dev_attr_close_delay.attr, 3124 &dev_attr_closing_wait.attr, 3125 &dev_attr_custom_divisor.attr, 3126 &dev_attr_io_type.attr, 3127 &dev_attr_iomem_base.attr, 3128 &dev_attr_iomem_reg_shift.attr, 3129 &dev_attr_console.attr, 3130 NULL 3131 }; 3132 3133 static const struct attribute_group tty_dev_attr_group = { 3134 .attrs = tty_dev_attrs, 3135 }; 3136 3137 /** 3138 * serial_core_add_one_port - attach a driver-defined port structure 3139 * @drv: pointer to the uart low level driver structure for this port 3140 * @uport: uart port structure to use for this port. 3141 * 3142 * Context: task context, might sleep 3143 * 3144 * This allows the driver @drv to register its own uart_port structure with the 3145 * core driver. The main purpose is to allow the low level uart drivers to 3146 * expand uart_port, rather than having yet more levels of structures. 3147 * Caller must hold port_mutex. 3148 */ 3149 static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *uport) 3150 { 3151 struct uart_state *state; 3152 struct tty_port *port; 3153 int ret = 0; 3154 struct device *tty_dev; 3155 int num_groups; 3156 3157 if (uport->line >= drv->nr) 3158 return -EINVAL; 3159 3160 state = drv->state + uport->line; 3161 port = &state->port; 3162 3163 mutex_lock(&port->mutex); 3164 if (state->uart_port) { 3165 ret = -EINVAL; 3166 goto out; 3167 } 3168 3169 /* Link the port to the driver state table and vice versa */ 3170 atomic_set(&state->refcount, 1); 3171 init_waitqueue_head(&state->remove_wait); 3172 state->uart_port = uport; 3173 uport->state = state; 3174 3175 state->pm_state = UART_PM_STATE_UNDEFINED; 3176 uport->cons = drv->cons; 3177 uport->minor = drv->tty_driver->minor_start + uport->line; 3178 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name, 3179 drv->tty_driver->name_base + uport->line); 3180 if (!uport->name) { 3181 ret = -ENOMEM; 3182 goto out; 3183 } 3184 3185 /* 3186 * If this port is in use as a console then the spinlock is already 3187 * initialised. 3188 */ 3189 if (!uart_console_registered(uport)) 3190 uart_port_spin_lock_init(uport); 3191 3192 if (uport->cons && uport->dev) 3193 of_console_check(uport->dev->of_node, uport->cons->name, uport->line); 3194 3195 tty_port_link_device(port, drv->tty_driver, uport->line); 3196 uart_configure_port(drv, state, uport); 3197 3198 port->console = uart_console(uport); 3199 3200 num_groups = 2; 3201 if (uport->attr_group) 3202 num_groups++; 3203 3204 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups), 3205 GFP_KERNEL); 3206 if (!uport->tty_groups) { 3207 ret = -ENOMEM; 3208 goto out; 3209 } 3210 uport->tty_groups[0] = &tty_dev_attr_group; 3211 if (uport->attr_group) 3212 uport->tty_groups[1] = uport->attr_group; 3213 3214 /* 3215 * Register the port whether it's detected or not. This allows 3216 * setserial to be used to alter this port's parameters. 3217 */ 3218 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver, 3219 uport->line, uport->dev, &uport->port_dev->dev, port, 3220 uport->tty_groups); 3221 if (!IS_ERR(tty_dev)) { 3222 device_set_wakeup_capable(tty_dev, 1); 3223 } else { 3224 dev_err(uport->dev, "Cannot register tty device on line %d\n", 3225 uport->line); 3226 } 3227 3228 out: 3229 mutex_unlock(&port->mutex); 3230 3231 return ret; 3232 } 3233 3234 /** 3235 * serial_core_remove_one_port - detach a driver defined port structure 3236 * @drv: pointer to the uart low level driver structure for this port 3237 * @uport: uart port structure for this port 3238 * 3239 * Context: task context, might sleep 3240 * 3241 * This unhooks (and hangs up) the specified port structure from the core 3242 * driver. No further calls will be made to the low-level code for this port. 3243 * Caller must hold port_mutex. 3244 */ 3245 static void serial_core_remove_one_port(struct uart_driver *drv, 3246 struct uart_port *uport) 3247 { 3248 struct uart_state *state = drv->state + uport->line; 3249 struct tty_port *port = &state->port; 3250 struct uart_port *uart_port; 3251 struct tty_struct *tty; 3252 3253 mutex_lock(&port->mutex); 3254 uart_port = uart_port_check(state); 3255 if (uart_port != uport) 3256 dev_alert(uport->dev, "Removing wrong port: %p != %p\n", 3257 uart_port, uport); 3258 3259 if (!uart_port) { 3260 mutex_unlock(&port->mutex); 3261 return; 3262 } 3263 mutex_unlock(&port->mutex); 3264 3265 /* 3266 * Remove the devices from the tty layer 3267 */ 3268 tty_port_unregister_device(port, drv->tty_driver, uport->line); 3269 3270 tty = tty_port_tty_get(port); 3271 if (tty) { 3272 tty_vhangup(port->tty); 3273 tty_kref_put(tty); 3274 } 3275 3276 /* 3277 * If the port is used as a console, unregister it 3278 */ 3279 if (uart_console(uport)) 3280 unregister_console(uport->cons); 3281 3282 /* 3283 * Free the port IO and memory resources, if any. 3284 */ 3285 if (uport->type != PORT_UNKNOWN && uport->ops->release_port) 3286 uport->ops->release_port(uport); 3287 kfree(uport->tty_groups); 3288 kfree(uport->name); 3289 3290 /* 3291 * Indicate that there isn't a port here anymore. 3292 */ 3293 uport->type = PORT_UNKNOWN; 3294 uport->port_dev = NULL; 3295 3296 mutex_lock(&port->mutex); 3297 WARN_ON(atomic_dec_return(&state->refcount) < 0); 3298 wait_event(state->remove_wait, !atomic_read(&state->refcount)); 3299 state->uart_port = NULL; 3300 mutex_unlock(&port->mutex); 3301 } 3302 3303 /** 3304 * uart_match_port - are the two ports equivalent? 3305 * @port1: first port 3306 * @port2: second port 3307 * 3308 * This utility function can be used to determine whether two uart_port 3309 * structures describe the same port. 3310 */ 3311 bool uart_match_port(const struct uart_port *port1, 3312 const struct uart_port *port2) 3313 { 3314 if (port1->iotype != port2->iotype) 3315 return false; 3316 3317 switch (port1->iotype) { 3318 case UPIO_PORT: 3319 return port1->iobase == port2->iobase; 3320 case UPIO_HUB6: 3321 return port1->iobase == port2->iobase && 3322 port1->hub6 == port2->hub6; 3323 case UPIO_MEM: 3324 case UPIO_MEM16: 3325 case UPIO_MEM32: 3326 case UPIO_MEM32BE: 3327 case UPIO_AU: 3328 case UPIO_TSI: 3329 return port1->mapbase == port2->mapbase; 3330 } 3331 3332 return false; 3333 } 3334 EXPORT_SYMBOL(uart_match_port); 3335 3336 static struct serial_ctrl_device * 3337 serial_core_get_ctrl_dev(struct serial_port_device *port_dev) 3338 { 3339 struct device *dev = &port_dev->dev; 3340 3341 return to_serial_base_ctrl_device(dev->parent); 3342 } 3343 3344 /* 3345 * Find a registered serial core controller device if one exists. Returns 3346 * the first device matching the ctrl_id. Caller must hold port_mutex. 3347 */ 3348 static struct serial_ctrl_device *serial_core_ctrl_find(struct uart_driver *drv, 3349 struct device *phys_dev, 3350 int ctrl_id) 3351 { 3352 struct uart_state *state; 3353 int i; 3354 3355 lockdep_assert_held(&port_mutex); 3356 3357 for (i = 0; i < drv->nr; i++) { 3358 state = drv->state + i; 3359 if (!state->uart_port || !state->uart_port->port_dev) 3360 continue; 3361 3362 if (state->uart_port->dev == phys_dev && 3363 state->uart_port->ctrl_id == ctrl_id) 3364 return serial_core_get_ctrl_dev(state->uart_port->port_dev); 3365 } 3366 3367 return NULL; 3368 } 3369 3370 static struct serial_ctrl_device *serial_core_ctrl_device_add(struct uart_port *port) 3371 { 3372 return serial_base_ctrl_add(port, port->dev); 3373 } 3374 3375 static int serial_core_port_device_add(struct serial_ctrl_device *ctrl_dev, 3376 struct uart_port *port) 3377 { 3378 struct serial_port_device *port_dev; 3379 3380 port_dev = serial_base_port_add(port, ctrl_dev); 3381 if (IS_ERR(port_dev)) 3382 return PTR_ERR(port_dev); 3383 3384 port->port_dev = port_dev; 3385 3386 return 0; 3387 } 3388 3389 /* 3390 * Initialize a serial core port device, and a controller device if needed. 3391 */ 3392 int serial_core_register_port(struct uart_driver *drv, struct uart_port *port) 3393 { 3394 struct serial_ctrl_device *ctrl_dev, *new_ctrl_dev = NULL; 3395 int ret; 3396 3397 mutex_lock(&port_mutex); 3398 3399 /* 3400 * Prevent serial_port_runtime_resume() from trying to use the port 3401 * until serial_core_add_one_port() has completed 3402 */ 3403 port->flags |= UPF_DEAD; 3404 3405 /* Inititalize a serial core controller device if needed */ 3406 ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id); 3407 if (!ctrl_dev) { 3408 new_ctrl_dev = serial_core_ctrl_device_add(port); 3409 if (IS_ERR(new_ctrl_dev)) { 3410 ret = PTR_ERR(new_ctrl_dev); 3411 goto err_unlock; 3412 } 3413 ctrl_dev = new_ctrl_dev; 3414 } 3415 3416 /* 3417 * Initialize a serial core port device. Tag the port dead to prevent 3418 * serial_port_runtime_resume() trying to do anything until port has 3419 * been registered. It gets cleared by serial_core_add_one_port(). 3420 */ 3421 ret = serial_core_port_device_add(ctrl_dev, port); 3422 if (ret) 3423 goto err_unregister_ctrl_dev; 3424 3425 ret = serial_core_add_one_port(drv, port); 3426 if (ret) 3427 goto err_unregister_port_dev; 3428 3429 port->flags &= ~UPF_DEAD; 3430 3431 mutex_unlock(&port_mutex); 3432 3433 return 0; 3434 3435 err_unregister_port_dev: 3436 serial_base_port_device_remove(port->port_dev); 3437 3438 err_unregister_ctrl_dev: 3439 serial_base_ctrl_device_remove(new_ctrl_dev); 3440 3441 err_unlock: 3442 mutex_unlock(&port_mutex); 3443 3444 return ret; 3445 } 3446 3447 /* 3448 * Removes a serial core port device, and the related serial core controller 3449 * device if the last instance. 3450 */ 3451 void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port) 3452 { 3453 struct device *phys_dev = port->dev; 3454 struct serial_port_device *port_dev = port->port_dev; 3455 struct serial_ctrl_device *ctrl_dev = serial_core_get_ctrl_dev(port_dev); 3456 int ctrl_id = port->ctrl_id; 3457 3458 mutex_lock(&port_mutex); 3459 3460 port->flags |= UPF_DEAD; 3461 3462 serial_core_remove_one_port(drv, port); 3463 3464 /* Note that struct uart_port *port is no longer valid at this point */ 3465 serial_base_port_device_remove(port_dev); 3466 3467 /* Drop the serial core controller device if no ports are using it */ 3468 if (!serial_core_ctrl_find(drv, phys_dev, ctrl_id)) 3469 serial_base_ctrl_device_remove(ctrl_dev); 3470 3471 mutex_unlock(&port_mutex); 3472 } 3473 3474 /** 3475 * uart_handle_dcd_change - handle a change of carrier detect state 3476 * @uport: uart_port structure for the open port 3477 * @active: new carrier detect status 3478 * 3479 * Caller must hold uport->lock. 3480 */ 3481 void uart_handle_dcd_change(struct uart_port *uport, bool active) 3482 { 3483 struct tty_port *port = &uport->state->port; 3484 struct tty_struct *tty = port->tty; 3485 struct tty_ldisc *ld; 3486 3487 lockdep_assert_held_once(&uport->lock); 3488 3489 if (tty) { 3490 ld = tty_ldisc_ref(tty); 3491 if (ld) { 3492 if (ld->ops->dcd_change) 3493 ld->ops->dcd_change(tty, active); 3494 tty_ldisc_deref(ld); 3495 } 3496 } 3497 3498 uport->icount.dcd++; 3499 3500 if (uart_dcd_enabled(uport)) { 3501 if (active) 3502 wake_up_interruptible(&port->open_wait); 3503 else if (tty) 3504 tty_hangup(tty); 3505 } 3506 } 3507 EXPORT_SYMBOL_GPL(uart_handle_dcd_change); 3508 3509 /** 3510 * uart_handle_cts_change - handle a change of clear-to-send state 3511 * @uport: uart_port structure for the open port 3512 * @active: new clear-to-send status 3513 * 3514 * Caller must hold uport->lock. 3515 */ 3516 void uart_handle_cts_change(struct uart_port *uport, bool active) 3517 { 3518 lockdep_assert_held_once(&uport->lock); 3519 3520 uport->icount.cts++; 3521 3522 if (uart_softcts_mode(uport)) { 3523 if (uport->hw_stopped) { 3524 if (active) { 3525 uport->hw_stopped = false; 3526 uport->ops->start_tx(uport); 3527 uart_write_wakeup(uport); 3528 } 3529 } else { 3530 if (!active) { 3531 uport->hw_stopped = true; 3532 uport->ops->stop_tx(uport); 3533 } 3534 } 3535 3536 } 3537 } 3538 EXPORT_SYMBOL_GPL(uart_handle_cts_change); 3539 3540 /** 3541 * uart_insert_char - push a char to the uart layer 3542 * 3543 * User is responsible to call tty_flip_buffer_push when they are done with 3544 * insertion. 3545 * 3546 * @port: corresponding port 3547 * @status: state of the serial port RX buffer (LSR for 8250) 3548 * @overrun: mask of overrun bits in @status 3549 * @ch: character to push 3550 * @flag: flag for the character (see TTY_NORMAL and friends) 3551 */ 3552 void uart_insert_char(struct uart_port *port, unsigned int status, 3553 unsigned int overrun, u8 ch, u8 flag) 3554 { 3555 struct tty_port *tport = &port->state->port; 3556 3557 if ((status & port->ignore_status_mask & ~overrun) == 0) 3558 if (tty_insert_flip_char(tport, ch, flag) == 0) 3559 ++port->icount.buf_overrun; 3560 3561 /* 3562 * Overrun is special. Since it's reported immediately, 3563 * it doesn't affect the current character. 3564 */ 3565 if (status & ~port->ignore_status_mask & overrun) 3566 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0) 3567 ++port->icount.buf_overrun; 3568 } 3569 EXPORT_SYMBOL_GPL(uart_insert_char); 3570 3571 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL 3572 static const u8 sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE; 3573 3574 static void uart_sysrq_on(struct work_struct *w) 3575 { 3576 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); 3577 3578 sysrq_toggle_support(1); 3579 pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n", 3580 sysrq_toggle_seq_len, sysrq_toggle_seq); 3581 } 3582 static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on); 3583 3584 /** 3585 * uart_try_toggle_sysrq - Enables SysRq from serial line 3586 * @port: uart_port structure where char(s) after BREAK met 3587 * @ch: new character in the sequence after received BREAK 3588 * 3589 * Enables magic SysRq when the required sequence is met on port 3590 * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE). 3591 * 3592 * Returns: %false if @ch is out of enabling sequence and should be 3593 * handled some other way, %true if @ch was consumed. 3594 */ 3595 bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch) 3596 { 3597 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); 3598 3599 if (!sysrq_toggle_seq_len) 3600 return false; 3601 3602 BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX); 3603 if (sysrq_toggle_seq[port->sysrq_seq] != ch) { 3604 port->sysrq_seq = 0; 3605 return false; 3606 } 3607 3608 if (++port->sysrq_seq < sysrq_toggle_seq_len) { 3609 port->sysrq = jiffies + SYSRQ_TIMEOUT; 3610 return true; 3611 } 3612 3613 schedule_work(&sysrq_enable_work); 3614 3615 port->sysrq = 0; 3616 return true; 3617 } 3618 EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq); 3619 #endif 3620 3621 /** 3622 * uart_get_rs485_mode() - retrieve rs485 properties for given uart 3623 * @port: uart device's target port 3624 * 3625 * This function implements the device tree binding described in 3626 * Documentation/devicetree/bindings/serial/rs485.txt. 3627 */ 3628 int uart_get_rs485_mode(struct uart_port *port) 3629 { 3630 struct serial_rs485 *rs485conf = &port->rs485; 3631 struct device *dev = port->dev; 3632 enum gpiod_flags dflags; 3633 struct gpio_desc *desc; 3634 u32 rs485_delay[2]; 3635 int ret; 3636 3637 if (!(port->rs485_supported.flags & SER_RS485_ENABLED)) 3638 return 0; 3639 3640 ret = device_property_read_u32_array(dev, "rs485-rts-delay", 3641 rs485_delay, 2); 3642 if (!ret) { 3643 rs485conf->delay_rts_before_send = rs485_delay[0]; 3644 rs485conf->delay_rts_after_send = rs485_delay[1]; 3645 } else { 3646 rs485conf->delay_rts_before_send = 0; 3647 rs485conf->delay_rts_after_send = 0; 3648 } 3649 3650 uart_sanitize_serial_rs485_delays(port, rs485conf); 3651 3652 /* 3653 * Clear full-duplex and enabled flags, set RTS polarity to active high 3654 * to get to a defined state with the following properties: 3655 */ 3656 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED | 3657 SER_RS485_TERMINATE_BUS | 3658 SER_RS485_RTS_AFTER_SEND); 3659 rs485conf->flags |= SER_RS485_RTS_ON_SEND; 3660 3661 if (device_property_read_bool(dev, "rs485-rx-during-tx")) 3662 rs485conf->flags |= SER_RS485_RX_DURING_TX; 3663 3664 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time")) 3665 rs485conf->flags |= SER_RS485_ENABLED; 3666 3667 if (device_property_read_bool(dev, "rs485-rts-active-low")) { 3668 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; 3669 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; 3670 } 3671 3672 /* 3673 * Disabling termination by default is the safe choice: Else if many 3674 * bus participants enable it, no communication is possible at all. 3675 * Works fine for short cables and users may enable for longer cables. 3676 */ 3677 desc = devm_gpiod_get_optional(dev, "rs485-term", GPIOD_OUT_LOW); 3678 if (IS_ERR(desc)) 3679 return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-term-gpios\n"); 3680 port->rs485_term_gpio = desc; 3681 if (port->rs485_term_gpio) 3682 port->rs485_supported.flags |= SER_RS485_TERMINATE_BUS; 3683 3684 dflags = (rs485conf->flags & SER_RS485_RX_DURING_TX) ? 3685 GPIOD_OUT_HIGH : GPIOD_OUT_LOW; 3686 desc = devm_gpiod_get_optional(dev, "rs485-rx-during-tx", dflags); 3687 if (IS_ERR(desc)) 3688 return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-rx-during-tx-gpios\n"); 3689 port->rs485_rx_during_tx_gpio = desc; 3690 if (port->rs485_rx_during_tx_gpio) 3691 port->rs485_supported.flags |= SER_RS485_RX_DURING_TX; 3692 3693 return 0; 3694 } 3695 EXPORT_SYMBOL_GPL(uart_get_rs485_mode); 3696 3697 /* Compile-time assertions for serial_rs485 layout */ 3698 static_assert(offsetof(struct serial_rs485, padding) == 3699 (offsetof(struct serial_rs485, delay_rts_after_send) + sizeof(__u32))); 3700 static_assert(offsetof(struct serial_rs485, padding1) == 3701 offsetof(struct serial_rs485, padding[1])); 3702 static_assert((offsetof(struct serial_rs485, padding[4]) + sizeof(__u32)) == 3703 sizeof(struct serial_rs485)); 3704 3705 MODULE_DESCRIPTION("Serial driver core"); 3706 MODULE_LICENSE("GPL"); 3707