1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Universal/legacy driver for 8250/16550-type serial ports 4 * 5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. 6 * 7 * Copyright (C) 2001 Russell King. 8 * 9 * Supports: ISA-compatible 8250/16550 ports 10 * PNP 8250/16550 ports 11 * early_serial_setup() ports 12 * userspace-configurable "phantom" ports 13 * "serial8250" platform devices 14 * serial8250_register_8250_port() ports 15 */ 16 17 #include <linux/acpi.h> 18 #include <linux/module.h> 19 #include <linux/moduleparam.h> 20 #include <linux/ioport.h> 21 #include <linux/init.h> 22 #include <linux/console.h> 23 #include <linux/sysrq.h> 24 #include <linux/delay.h> 25 #include <linux/platform_device.h> 26 #include <linux/pm_runtime.h> 27 #include <linux/tty.h> 28 #include <linux/ratelimit.h> 29 #include <linux/tty_flip.h> 30 #include <linux/serial.h> 31 #include <linux/serial_8250.h> 32 #include <linux/nmi.h> 33 #include <linux/mutex.h> 34 #include <linux/slab.h> 35 #include <linux/string_helpers.h> 36 #include <linux/uaccess.h> 37 #include <linux/io.h> 38 #ifdef CONFIG_SPARC 39 #include <linux/sunserialcore.h> 40 #endif 41 42 #include <asm/irq.h> 43 44 #include "8250.h" 45 46 /* 47 * Configuration: 48 * share_irqs - whether we pass IRQF_SHARED to request_irq(). This option 49 * is unsafe when used on edge-triggered interrupts. 50 */ 51 static unsigned int share_irqs = SERIAL8250_SHARE_IRQS; 52 53 static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS; 54 55 static struct uart_driver serial8250_reg; 56 57 static unsigned int skip_txen_test; /* force skip of txen test at init time */ 58 59 #define PASS_LIMIT 512 60 61 #include <asm/serial.h> 62 /* 63 * SERIAL_PORT_DFNS tells us about built-in ports that have no 64 * standard enumeration mechanism. Platforms that can find all 65 * serial ports via mechanisms like ACPI or PCI need not supply it. 66 */ 67 #ifndef SERIAL_PORT_DFNS 68 #define SERIAL_PORT_DFNS 69 #endif 70 71 static const struct old_serial_port old_serial_port[] = { 72 SERIAL_PORT_DFNS /* defined in asm/serial.h */ 73 }; 74 75 #define UART_NR CONFIG_SERIAL_8250_NR_UARTS 76 77 #ifdef CONFIG_SERIAL_8250_RSA 78 79 #define PORT_RSA_MAX 4 80 static unsigned long probe_rsa[PORT_RSA_MAX]; 81 static unsigned int probe_rsa_count; 82 #endif /* CONFIG_SERIAL_8250_RSA */ 83 84 struct irq_info { 85 struct hlist_node node; 86 int irq; 87 spinlock_t lock; /* Protects list not the hash */ 88 struct list_head *head; 89 }; 90 91 #define NR_IRQ_HASH 32 /* Can be adjusted later */ 92 static struct hlist_head irq_lists[NR_IRQ_HASH]; 93 static DEFINE_MUTEX(hash_mutex); /* Used to walk the hash */ 94 95 /* 96 * This is the serial driver's interrupt routine. 97 * 98 * Arjan thinks the old way was overly complex, so it got simplified. 99 * Alan disagrees, saying that need the complexity to handle the weird 100 * nature of ISA shared interrupts. (This is a special exception.) 101 * 102 * In order to handle ISA shared interrupts properly, we need to check 103 * that all ports have been serviced, and therefore the ISA interrupt 104 * line has been de-asserted. 105 * 106 * This means we need to loop through all ports. checking that they 107 * don't have an interrupt pending. 108 */ 109 static irqreturn_t serial8250_interrupt(int irq, void *dev_id) 110 { 111 struct irq_info *i = dev_id; 112 struct list_head *l, *end = NULL; 113 int pass_counter = 0, handled = 0; 114 115 pr_debug("%s(%d): start\n", __func__, irq); 116 117 spin_lock(&i->lock); 118 119 l = i->head; 120 do { 121 struct uart_8250_port *up; 122 struct uart_port *port; 123 124 up = list_entry(l, struct uart_8250_port, list); 125 port = &up->port; 126 127 if (port->handle_irq(port)) { 128 handled = 1; 129 end = NULL; 130 } else if (end == NULL) 131 end = l; 132 133 l = l->next; 134 135 if (l == i->head && pass_counter++ > PASS_LIMIT) 136 break; 137 } while (l != end); 138 139 spin_unlock(&i->lock); 140 141 pr_debug("%s(%d): end\n", __func__, irq); 142 143 return IRQ_RETVAL(handled); 144 } 145 146 /* 147 * To support ISA shared interrupts, we need to have one interrupt 148 * handler that ensures that the IRQ line has been deasserted 149 * before returning. Failing to do this will result in the IRQ 150 * line being stuck active, and, since ISA irqs are edge triggered, 151 * no more IRQs will be seen. 152 */ 153 static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up) 154 { 155 spin_lock_irq(&i->lock); 156 157 if (!list_empty(i->head)) { 158 if (i->head == &up->list) 159 i->head = i->head->next; 160 list_del(&up->list); 161 } else { 162 BUG_ON(i->head != &up->list); 163 i->head = NULL; 164 } 165 spin_unlock_irq(&i->lock); 166 /* List empty so throw away the hash node */ 167 if (i->head == NULL) { 168 hlist_del(&i->node); 169 kfree(i); 170 } 171 } 172 173 static int serial_link_irq_chain(struct uart_8250_port *up) 174 { 175 struct hlist_head *h; 176 struct irq_info *i; 177 int ret; 178 179 mutex_lock(&hash_mutex); 180 181 h = &irq_lists[up->port.irq % NR_IRQ_HASH]; 182 183 hlist_for_each_entry(i, h, node) 184 if (i->irq == up->port.irq) 185 break; 186 187 if (i == NULL) { 188 i = kzalloc(sizeof(struct irq_info), GFP_KERNEL); 189 if (i == NULL) { 190 mutex_unlock(&hash_mutex); 191 return -ENOMEM; 192 } 193 spin_lock_init(&i->lock); 194 i->irq = up->port.irq; 195 hlist_add_head(&i->node, h); 196 } 197 mutex_unlock(&hash_mutex); 198 199 spin_lock_irq(&i->lock); 200 201 if (i->head) { 202 list_add(&up->list, i->head); 203 spin_unlock_irq(&i->lock); 204 205 ret = 0; 206 } else { 207 INIT_LIST_HEAD(&up->list); 208 i->head = &up->list; 209 spin_unlock_irq(&i->lock); 210 ret = request_irq(up->port.irq, serial8250_interrupt, 211 up->port.irqflags, up->port.name, i); 212 if (ret < 0) 213 serial_do_unlink(i, up); 214 } 215 216 return ret; 217 } 218 219 static void serial_unlink_irq_chain(struct uart_8250_port *up) 220 { 221 struct irq_info *i; 222 struct hlist_head *h; 223 224 mutex_lock(&hash_mutex); 225 226 h = &irq_lists[up->port.irq % NR_IRQ_HASH]; 227 228 hlist_for_each_entry(i, h, node) 229 if (i->irq == up->port.irq) 230 break; 231 232 BUG_ON(i == NULL); 233 BUG_ON(i->head == NULL); 234 235 if (list_empty(i->head)) 236 free_irq(up->port.irq, i); 237 238 serial_do_unlink(i, up); 239 mutex_unlock(&hash_mutex); 240 } 241 242 /* 243 * This function is used to handle ports that do not have an 244 * interrupt. This doesn't work very well for 16450's, but gives 245 * barely passable results for a 16550A. (Although at the expense 246 * of much CPU overhead). 247 */ 248 static void serial8250_timeout(struct timer_list *t) 249 { 250 struct uart_8250_port *up = from_timer(up, t, timer); 251 252 up->port.handle_irq(&up->port); 253 mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port)); 254 } 255 256 static void serial8250_backup_timeout(struct timer_list *t) 257 { 258 struct uart_8250_port *up = from_timer(up, t, timer); 259 unsigned int iir, ier = 0, lsr; 260 unsigned long flags; 261 262 spin_lock_irqsave(&up->port.lock, flags); 263 264 /* 265 * Must disable interrupts or else we risk racing with the interrupt 266 * based handler. 267 */ 268 if (up->port.irq) { 269 ier = serial_in(up, UART_IER); 270 serial_out(up, UART_IER, 0); 271 } 272 273 iir = serial_in(up, UART_IIR); 274 275 /* 276 * This should be a safe test for anyone who doesn't trust the 277 * IIR bits on their UART, but it's specifically designed for 278 * the "Diva" UART used on the management processor on many HP 279 * ia64 and parisc boxes. 280 */ 281 lsr = serial_lsr_in(up); 282 if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) && 283 (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) && 284 (lsr & UART_LSR_THRE)) { 285 iir &= ~(UART_IIR_ID | UART_IIR_NO_INT); 286 iir |= UART_IIR_THRI; 287 } 288 289 if (!(iir & UART_IIR_NO_INT)) 290 serial8250_tx_chars(up); 291 292 if (up->port.irq) 293 serial_out(up, UART_IER, ier); 294 295 spin_unlock_irqrestore(&up->port.lock, flags); 296 297 /* Standard timer interval plus 0.2s to keep the port running */ 298 mod_timer(&up->timer, 299 jiffies + uart_poll_timeout(&up->port) + HZ / 5); 300 } 301 302 static void univ8250_setup_timer(struct uart_8250_port *up) 303 { 304 struct uart_port *port = &up->port; 305 306 /* 307 * The above check will only give an accurate result the first time 308 * the port is opened so this value needs to be preserved. 309 */ 310 if (up->bugs & UART_BUG_THRE) { 311 pr_debug("%s - using backup timer\n", port->name); 312 313 up->timer.function = serial8250_backup_timeout; 314 mod_timer(&up->timer, jiffies + 315 uart_poll_timeout(port) + HZ / 5); 316 } 317 318 /* 319 * If the "interrupt" for this port doesn't correspond with any 320 * hardware interrupt, we use a timer-based system. The original 321 * driver used to do this with IRQ0. 322 */ 323 if (!port->irq) 324 mod_timer(&up->timer, jiffies + uart_poll_timeout(port)); 325 } 326 327 static int univ8250_setup_irq(struct uart_8250_port *up) 328 { 329 struct uart_port *port = &up->port; 330 331 if (port->irq) 332 return serial_link_irq_chain(up); 333 334 return 0; 335 } 336 337 static void univ8250_release_irq(struct uart_8250_port *up) 338 { 339 struct uart_port *port = &up->port; 340 341 del_timer_sync(&up->timer); 342 up->timer.function = serial8250_timeout; 343 if (port->irq) 344 serial_unlink_irq_chain(up); 345 } 346 347 #ifdef CONFIG_SERIAL_8250_RSA 348 static int serial8250_request_rsa_resource(struct uart_8250_port *up) 349 { 350 unsigned long start = UART_RSA_BASE << up->port.regshift; 351 unsigned int size = 8 << up->port.regshift; 352 struct uart_port *port = &up->port; 353 int ret = -EINVAL; 354 355 switch (port->iotype) { 356 case UPIO_HUB6: 357 case UPIO_PORT: 358 start += port->iobase; 359 if (request_region(start, size, "serial-rsa")) 360 ret = 0; 361 else 362 ret = -EBUSY; 363 break; 364 } 365 366 return ret; 367 } 368 369 static void serial8250_release_rsa_resource(struct uart_8250_port *up) 370 { 371 unsigned long offset = UART_RSA_BASE << up->port.regshift; 372 unsigned int size = 8 << up->port.regshift; 373 struct uart_port *port = &up->port; 374 375 switch (port->iotype) { 376 case UPIO_HUB6: 377 case UPIO_PORT: 378 release_region(port->iobase + offset, size); 379 break; 380 } 381 } 382 #endif 383 384 static const struct uart_ops *base_ops; 385 static struct uart_ops univ8250_port_ops; 386 387 static const struct uart_8250_ops univ8250_driver_ops = { 388 .setup_irq = univ8250_setup_irq, 389 .release_irq = univ8250_release_irq, 390 .setup_timer = univ8250_setup_timer, 391 }; 392 393 static struct uart_8250_port serial8250_ports[UART_NR]; 394 395 /** 396 * serial8250_get_port - retrieve struct uart_8250_port 397 * @line: serial line number 398 * 399 * This function retrieves struct uart_8250_port for the specific line. 400 * This struct *must* *not* be used to perform a 8250 or serial core operation 401 * which is not accessible otherwise. Its only purpose is to make the struct 402 * accessible to the runtime-pm callbacks for context suspend/restore. 403 * The lock assumption made here is none because runtime-pm suspend/resume 404 * callbacks should not be invoked if there is any operation performed on the 405 * port. 406 */ 407 struct uart_8250_port *serial8250_get_port(int line) 408 { 409 return &serial8250_ports[line]; 410 } 411 EXPORT_SYMBOL_GPL(serial8250_get_port); 412 413 static void (*serial8250_isa_config)(int port, struct uart_port *up, 414 u32 *capabilities); 415 416 void serial8250_set_isa_configurator( 417 void (*v)(int port, struct uart_port *up, u32 *capabilities)) 418 { 419 serial8250_isa_config = v; 420 } 421 EXPORT_SYMBOL(serial8250_set_isa_configurator); 422 423 #ifdef CONFIG_SERIAL_8250_RSA 424 425 static void univ8250_config_port(struct uart_port *port, int flags) 426 { 427 struct uart_8250_port *up = up_to_u8250p(port); 428 429 up->probe &= ~UART_PROBE_RSA; 430 if (port->type == PORT_RSA) { 431 if (serial8250_request_rsa_resource(up) == 0) 432 up->probe |= UART_PROBE_RSA; 433 } else if (flags & UART_CONFIG_TYPE) { 434 int i; 435 436 for (i = 0; i < probe_rsa_count; i++) { 437 if (probe_rsa[i] == up->port.iobase) { 438 if (serial8250_request_rsa_resource(up) == 0) 439 up->probe |= UART_PROBE_RSA; 440 break; 441 } 442 } 443 } 444 445 base_ops->config_port(port, flags); 446 447 if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA) 448 serial8250_release_rsa_resource(up); 449 } 450 451 static int univ8250_request_port(struct uart_port *port) 452 { 453 struct uart_8250_port *up = up_to_u8250p(port); 454 int ret; 455 456 ret = base_ops->request_port(port); 457 if (ret == 0 && port->type == PORT_RSA) { 458 ret = serial8250_request_rsa_resource(up); 459 if (ret < 0) 460 base_ops->release_port(port); 461 } 462 463 return ret; 464 } 465 466 static void univ8250_release_port(struct uart_port *port) 467 { 468 struct uart_8250_port *up = up_to_u8250p(port); 469 470 if (port->type == PORT_RSA) 471 serial8250_release_rsa_resource(up); 472 base_ops->release_port(port); 473 } 474 475 static void univ8250_rsa_support(struct uart_ops *ops) 476 { 477 ops->config_port = univ8250_config_port; 478 ops->request_port = univ8250_request_port; 479 ops->release_port = univ8250_release_port; 480 } 481 482 #else 483 #define univ8250_rsa_support(x) do { } while (0) 484 #endif /* CONFIG_SERIAL_8250_RSA */ 485 486 static inline void serial8250_apply_quirks(struct uart_8250_port *up) 487 { 488 up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0; 489 } 490 491 static struct uart_8250_port *serial8250_setup_port(int index) 492 { 493 struct uart_8250_port *up; 494 495 if (index >= UART_NR) 496 return NULL; 497 498 up = &serial8250_ports[index]; 499 up->port.line = index; 500 up->port.port_id = index; 501 502 serial8250_init_port(up); 503 if (!base_ops) 504 base_ops = up->port.ops; 505 up->port.ops = &univ8250_port_ops; 506 507 timer_setup(&up->timer, serial8250_timeout, 0); 508 509 up->ops = &univ8250_driver_ops; 510 511 if (IS_ENABLED(CONFIG_ALPHA_JENSEN) || 512 (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen())) 513 up->port.set_mctrl = alpha_jensen_set_mctrl; 514 515 serial8250_set_defaults(up); 516 517 return up; 518 } 519 520 static void __init serial8250_isa_init_ports(void) 521 { 522 struct uart_8250_port *up; 523 static int first = 1; 524 int i, irqflag = 0; 525 526 if (!first) 527 return; 528 first = 0; 529 530 if (nr_uarts > UART_NR) 531 nr_uarts = UART_NR; 532 533 /* 534 * Set up initial isa ports based on nr_uart module param, or else 535 * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not 536 * need to increase nr_uarts when setting up the initial isa ports. 537 */ 538 for (i = 0; i < nr_uarts; i++) 539 serial8250_setup_port(i); 540 541 /* chain base port ops to support Remote Supervisor Adapter */ 542 univ8250_port_ops = *base_ops; 543 univ8250_rsa_support(&univ8250_port_ops); 544 545 if (share_irqs) 546 irqflag = IRQF_SHARED; 547 548 for (i = 0, up = serial8250_ports; 549 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; 550 i++, up++) { 551 struct uart_port *port = &up->port; 552 553 port->iobase = old_serial_port[i].port; 554 port->irq = irq_canonicalize(old_serial_port[i].irq); 555 port->irqflags = 0; 556 port->uartclk = old_serial_port[i].baud_base * 16; 557 port->flags = old_serial_port[i].flags; 558 port->hub6 = 0; 559 port->membase = old_serial_port[i].iomem_base; 560 port->iotype = old_serial_port[i].io_type; 561 port->regshift = old_serial_port[i].iomem_reg_shift; 562 563 port->irqflags |= irqflag; 564 if (serial8250_isa_config != NULL) 565 serial8250_isa_config(i, &up->port, &up->capabilities); 566 } 567 } 568 569 static void __init 570 serial8250_register_ports(struct uart_driver *drv, struct device *dev) 571 { 572 int i; 573 574 for (i = 0; i < nr_uarts; i++) { 575 struct uart_8250_port *up = &serial8250_ports[i]; 576 577 if (up->port.type == PORT_8250_CIR) 578 continue; 579 580 if (up->port.dev) 581 continue; 582 583 up->port.dev = dev; 584 585 if (uart_console_registered(&up->port)) 586 pm_runtime_get_sync(up->port.dev); 587 588 serial8250_apply_quirks(up); 589 uart_add_one_port(drv, &up->port); 590 } 591 } 592 593 #ifdef CONFIG_SERIAL_8250_CONSOLE 594 595 static void univ8250_console_write(struct console *co, const char *s, 596 unsigned int count) 597 { 598 struct uart_8250_port *up = &serial8250_ports[co->index]; 599 600 serial8250_console_write(up, s, count); 601 } 602 603 static int univ8250_console_setup(struct console *co, char *options) 604 { 605 struct uart_8250_port *up; 606 struct uart_port *port; 607 int retval, i; 608 609 /* 610 * Check whether an invalid uart number has been specified, and 611 * if so, search for the first available port that does have 612 * console support. 613 */ 614 if (co->index >= UART_NR) 615 co->index = 0; 616 617 /* 618 * If the console is past the initial isa ports, init more ports up to 619 * co->index as needed and increment nr_uarts accordingly. 620 */ 621 for (i = nr_uarts; i <= co->index; i++) { 622 up = serial8250_setup_port(i); 623 if (!up) 624 return -ENODEV; 625 nr_uarts++; 626 } 627 628 port = &serial8250_ports[co->index].port; 629 /* link port to console */ 630 port->cons = co; 631 632 retval = serial8250_console_setup(port, options, false); 633 if (retval != 0) 634 port->cons = NULL; 635 return retval; 636 } 637 638 static int univ8250_console_exit(struct console *co) 639 { 640 struct uart_port *port; 641 642 port = &serial8250_ports[co->index].port; 643 return serial8250_console_exit(port); 644 } 645 646 /** 647 * univ8250_console_match - non-standard console matching 648 * @co: registering console 649 * @name: name from console command line 650 * @idx: index from console command line 651 * @options: ptr to option string from console command line 652 * 653 * Only attempts to match console command lines of the form: 654 * console=uart[8250],io|mmio|mmio16|mmio32,<addr>[,<options>] 655 * console=uart[8250],0x<addr>[,<options>] 656 * This form is used to register an initial earlycon boot console and 657 * replace it with the serial8250_console at 8250 driver init. 658 * 659 * Performs console setup for a match (as required by interface) 660 * If no <options> are specified, then assume the h/w is already setup. 661 * 662 * Returns 0 if console matches; otherwise non-zero to use default matching 663 */ 664 static int univ8250_console_match(struct console *co, char *name, int idx, 665 char *options) 666 { 667 char match[] = "uart"; /* 8250-specific earlycon name */ 668 unsigned char iotype; 669 resource_size_t addr; 670 int i; 671 672 if (strncmp(name, match, 4) != 0) 673 return -ENODEV; 674 675 if (uart_parse_earlycon(options, &iotype, &addr, &options)) 676 return -ENODEV; 677 678 /* try to match the port specified on the command line */ 679 for (i = 0; i < nr_uarts; i++) { 680 struct uart_port *port = &serial8250_ports[i].port; 681 682 if (port->iotype != iotype) 683 continue; 684 if ((iotype == UPIO_MEM || iotype == UPIO_MEM16 || 685 iotype == UPIO_MEM32 || iotype == UPIO_MEM32BE) 686 && (port->mapbase != addr)) 687 continue; 688 if (iotype == UPIO_PORT && port->iobase != addr) 689 continue; 690 691 co->index = i; 692 port->cons = co; 693 return serial8250_console_setup(port, options, true); 694 } 695 696 return -ENODEV; 697 } 698 699 static struct console univ8250_console = { 700 .name = "ttyS", 701 .write = univ8250_console_write, 702 .device = uart_console_device, 703 .setup = univ8250_console_setup, 704 .exit = univ8250_console_exit, 705 .match = univ8250_console_match, 706 .flags = CON_PRINTBUFFER | CON_ANYTIME, 707 .index = -1, 708 .data = &serial8250_reg, 709 }; 710 711 static int __init univ8250_console_init(void) 712 { 713 if (nr_uarts == 0) 714 return -ENODEV; 715 716 serial8250_isa_init_ports(); 717 register_console(&univ8250_console); 718 return 0; 719 } 720 console_initcall(univ8250_console_init); 721 722 #define SERIAL8250_CONSOLE (&univ8250_console) 723 #else 724 #define SERIAL8250_CONSOLE NULL 725 #endif 726 727 static struct uart_driver serial8250_reg = { 728 .owner = THIS_MODULE, 729 .driver_name = "serial", 730 .dev_name = "ttyS", 731 .major = TTY_MAJOR, 732 .minor = 64, 733 .cons = SERIAL8250_CONSOLE, 734 }; 735 736 /* 737 * early_serial_setup - early registration for 8250 ports 738 * 739 * Setup an 8250 port structure prior to console initialisation. Use 740 * after console initialisation will cause undefined behaviour. 741 */ 742 int __init early_serial_setup(struct uart_port *port) 743 { 744 struct uart_port *p; 745 746 if (port->line >= ARRAY_SIZE(serial8250_ports) || nr_uarts == 0) 747 return -ENODEV; 748 749 serial8250_isa_init_ports(); 750 p = &serial8250_ports[port->line].port; 751 p->iobase = port->iobase; 752 p->membase = port->membase; 753 p->irq = port->irq; 754 p->irqflags = port->irqflags; 755 p->uartclk = port->uartclk; 756 p->fifosize = port->fifosize; 757 p->regshift = port->regshift; 758 p->iotype = port->iotype; 759 p->flags = port->flags; 760 p->mapbase = port->mapbase; 761 p->mapsize = port->mapsize; 762 p->private_data = port->private_data; 763 p->type = port->type; 764 p->line = port->line; 765 766 serial8250_set_defaults(up_to_u8250p(p)); 767 768 if (port->serial_in) 769 p->serial_in = port->serial_in; 770 if (port->serial_out) 771 p->serial_out = port->serial_out; 772 if (port->handle_irq) 773 p->handle_irq = port->handle_irq; 774 775 return 0; 776 } 777 778 /** 779 * serial8250_suspend_port - suspend one serial port 780 * @line: serial line number 781 * 782 * Suspend one serial port. 783 */ 784 void serial8250_suspend_port(int line) 785 { 786 struct uart_8250_port *up = &serial8250_ports[line]; 787 struct uart_port *port = &up->port; 788 789 if (!console_suspend_enabled && uart_console(port) && 790 port->type != PORT_8250) { 791 unsigned char canary = 0xa5; 792 793 serial_out(up, UART_SCR, canary); 794 if (serial_in(up, UART_SCR) == canary) 795 up->canary = canary; 796 } 797 798 uart_suspend_port(&serial8250_reg, port); 799 } 800 EXPORT_SYMBOL(serial8250_suspend_port); 801 802 /** 803 * serial8250_resume_port - resume one serial port 804 * @line: serial line number 805 * 806 * Resume one serial port. 807 */ 808 void serial8250_resume_port(int line) 809 { 810 struct uart_8250_port *up = &serial8250_ports[line]; 811 struct uart_port *port = &up->port; 812 813 up->canary = 0; 814 815 if (up->capabilities & UART_NATSEMI) { 816 /* Ensure it's still in high speed mode */ 817 serial_port_out(port, UART_LCR, 0xE0); 818 819 ns16550a_goto_highspeed(up); 820 821 serial_port_out(port, UART_LCR, 0); 822 port->uartclk = 921600*16; 823 } 824 uart_resume_port(&serial8250_reg, port); 825 } 826 EXPORT_SYMBOL(serial8250_resume_port); 827 828 /* 829 * Register a set of serial devices attached to a platform device. The 830 * list is terminated with a zero flags entry, which means we expect 831 * all entries to have at least UPF_BOOT_AUTOCONF set. 832 */ 833 static int serial8250_probe(struct platform_device *dev) 834 { 835 struct plat_serial8250_port *p = dev_get_platdata(&dev->dev); 836 struct uart_8250_port uart; 837 int ret, i, irqflag = 0; 838 839 memset(&uart, 0, sizeof(uart)); 840 841 if (share_irqs) 842 irqflag = IRQF_SHARED; 843 844 for (i = 0; p && p->flags != 0; p++, i++) { 845 uart.port.iobase = p->iobase; 846 uart.port.membase = p->membase; 847 uart.port.irq = p->irq; 848 uart.port.irqflags = p->irqflags; 849 uart.port.uartclk = p->uartclk; 850 uart.port.regshift = p->regshift; 851 uart.port.iotype = p->iotype; 852 uart.port.flags = p->flags; 853 uart.port.mapbase = p->mapbase; 854 uart.port.mapsize = p->mapsize; 855 uart.port.hub6 = p->hub6; 856 uart.port.has_sysrq = p->has_sysrq; 857 uart.port.private_data = p->private_data; 858 uart.port.type = p->type; 859 uart.bugs = p->bugs; 860 uart.port.serial_in = p->serial_in; 861 uart.port.serial_out = p->serial_out; 862 uart.dl_read = p->dl_read; 863 uart.dl_write = p->dl_write; 864 uart.port.handle_irq = p->handle_irq; 865 uart.port.handle_break = p->handle_break; 866 uart.port.set_termios = p->set_termios; 867 uart.port.set_ldisc = p->set_ldisc; 868 uart.port.get_mctrl = p->get_mctrl; 869 uart.port.pm = p->pm; 870 uart.port.dev = &dev->dev; 871 uart.port.irqflags |= irqflag; 872 ret = serial8250_register_8250_port(&uart); 873 if (ret < 0) { 874 dev_err(&dev->dev, "unable to register port at index %d " 875 "(IO%lx MEM%llx IRQ%d): %d\n", i, 876 p->iobase, (unsigned long long)p->mapbase, 877 p->irq, ret); 878 } 879 } 880 return 0; 881 } 882 883 /* 884 * Remove serial ports registered against a platform device. 885 */ 886 static int serial8250_remove(struct platform_device *dev) 887 { 888 int i; 889 890 for (i = 0; i < nr_uarts; i++) { 891 struct uart_8250_port *up = &serial8250_ports[i]; 892 893 if (up->port.dev == &dev->dev) 894 serial8250_unregister_port(i); 895 } 896 return 0; 897 } 898 899 static int serial8250_suspend(struct platform_device *dev, pm_message_t state) 900 { 901 int i; 902 903 for (i = 0; i < UART_NR; i++) { 904 struct uart_8250_port *up = &serial8250_ports[i]; 905 906 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) 907 uart_suspend_port(&serial8250_reg, &up->port); 908 } 909 910 return 0; 911 } 912 913 static int serial8250_resume(struct platform_device *dev) 914 { 915 int i; 916 917 for (i = 0; i < UART_NR; i++) { 918 struct uart_8250_port *up = &serial8250_ports[i]; 919 920 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) 921 serial8250_resume_port(i); 922 } 923 924 return 0; 925 } 926 927 static struct platform_driver serial8250_isa_driver = { 928 .probe = serial8250_probe, 929 .remove = serial8250_remove, 930 .suspend = serial8250_suspend, 931 .resume = serial8250_resume, 932 .driver = { 933 .name = "serial8250", 934 }, 935 }; 936 937 /* 938 * This "device" covers _all_ ISA 8250-compatible serial devices listed 939 * in the table in include/asm/serial.h 940 */ 941 static struct platform_device *serial8250_isa_devs; 942 943 /* 944 * serial8250_register_8250_port and serial8250_unregister_port allows for 945 * 16x50 serial ports to be configured at run-time, to support PCMCIA 946 * modems and PCI multiport cards. 947 */ 948 static DEFINE_MUTEX(serial_mutex); 949 950 static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_port *port) 951 { 952 int i; 953 954 /* 955 * First, find a port entry which matches. 956 */ 957 for (i = 0; i < nr_uarts; i++) 958 if (uart_match_port(&serial8250_ports[i].port, port)) 959 return &serial8250_ports[i]; 960 961 /* try line number first if still available */ 962 i = port->line; 963 if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN && 964 serial8250_ports[i].port.iobase == 0) 965 return &serial8250_ports[i]; 966 /* 967 * We didn't find a matching entry, so look for the first 968 * free entry. We look for one which hasn't been previously 969 * used (indicated by zero iobase). 970 */ 971 for (i = 0; i < nr_uarts; i++) 972 if (serial8250_ports[i].port.type == PORT_UNKNOWN && 973 serial8250_ports[i].port.iobase == 0) 974 return &serial8250_ports[i]; 975 976 /* 977 * That also failed. Last resort is to find any entry which 978 * doesn't have a real port associated with it. 979 */ 980 for (i = 0; i < nr_uarts; i++) 981 if (serial8250_ports[i].port.type == PORT_UNKNOWN) 982 return &serial8250_ports[i]; 983 984 return NULL; 985 } 986 987 static void serial_8250_overrun_backoff_work(struct work_struct *work) 988 { 989 struct uart_8250_port *up = 990 container_of(to_delayed_work(work), struct uart_8250_port, 991 overrun_backoff); 992 struct uart_port *port = &up->port; 993 unsigned long flags; 994 995 spin_lock_irqsave(&port->lock, flags); 996 up->ier |= UART_IER_RLSI | UART_IER_RDI; 997 up->port.read_status_mask |= UART_LSR_DR; 998 serial_out(up, UART_IER, up->ier); 999 spin_unlock_irqrestore(&port->lock, flags); 1000 } 1001 1002 /** 1003 * serial8250_register_8250_port - register a serial port 1004 * @up: serial port template 1005 * 1006 * Configure the serial port specified by the request. If the 1007 * port exists and is in use, it is hung up and unregistered 1008 * first. 1009 * 1010 * The port is then probed and if necessary the IRQ is autodetected 1011 * If this fails an error is returned. 1012 * 1013 * On success the port is ready to use and the line number is returned. 1014 */ 1015 int serial8250_register_8250_port(const struct uart_8250_port *up) 1016 { 1017 struct uart_8250_port *uart; 1018 int ret = -ENOSPC; 1019 1020 if (up->port.uartclk == 0) 1021 return -EINVAL; 1022 1023 mutex_lock(&serial_mutex); 1024 1025 uart = serial8250_find_match_or_unused(&up->port); 1026 if (!uart) { 1027 /* 1028 * If the port is past the initial isa ports, initialize a new 1029 * port and increment nr_uarts accordingly. 1030 */ 1031 uart = serial8250_setup_port(nr_uarts); 1032 if (!uart) 1033 goto unlock; 1034 nr_uarts++; 1035 } 1036 1037 if (uart->port.type != PORT_8250_CIR) { 1038 struct mctrl_gpios *gpios; 1039 1040 if (uart->port.dev) 1041 uart_remove_one_port(&serial8250_reg, &uart->port); 1042 1043 uart->port.ctrl_id = up->port.ctrl_id; 1044 uart->port.port_id = up->port.port_id; 1045 uart->port.iobase = up->port.iobase; 1046 uart->port.membase = up->port.membase; 1047 uart->port.irq = up->port.irq; 1048 uart->port.irqflags = up->port.irqflags; 1049 uart->port.uartclk = up->port.uartclk; 1050 uart->port.fifosize = up->port.fifosize; 1051 uart->port.regshift = up->port.regshift; 1052 uart->port.iotype = up->port.iotype; 1053 uart->port.flags = up->port.flags | UPF_BOOT_AUTOCONF; 1054 uart->bugs = up->bugs; 1055 uart->port.mapbase = up->port.mapbase; 1056 uart->port.mapsize = up->port.mapsize; 1057 uart->port.private_data = up->port.private_data; 1058 uart->tx_loadsz = up->tx_loadsz; 1059 uart->capabilities = up->capabilities; 1060 uart->port.throttle = up->port.throttle; 1061 uart->port.unthrottle = up->port.unthrottle; 1062 uart->port.rs485_config = up->port.rs485_config; 1063 uart->port.rs485_supported = up->port.rs485_supported; 1064 uart->port.rs485 = up->port.rs485; 1065 uart->rs485_start_tx = up->rs485_start_tx; 1066 uart->rs485_stop_tx = up->rs485_stop_tx; 1067 uart->lsr_save_mask = up->lsr_save_mask; 1068 uart->dma = up->dma; 1069 1070 /* Take tx_loadsz from fifosize if it wasn't set separately */ 1071 if (uart->port.fifosize && !uart->tx_loadsz) 1072 uart->tx_loadsz = uart->port.fifosize; 1073 1074 if (up->port.dev) { 1075 uart->port.dev = up->port.dev; 1076 ret = uart_get_rs485_mode(&uart->port); 1077 if (ret) 1078 goto err; 1079 } 1080 1081 if (up->port.flags & UPF_FIXED_TYPE) 1082 uart->port.type = up->port.type; 1083 1084 /* 1085 * Only call mctrl_gpio_init(), if the device has no ACPI 1086 * companion device 1087 */ 1088 if (!has_acpi_companion(uart->port.dev)) { 1089 gpios = mctrl_gpio_init(&uart->port, 0); 1090 if (IS_ERR(gpios)) { 1091 ret = PTR_ERR(gpios); 1092 goto err; 1093 } else { 1094 uart->gpios = gpios; 1095 } 1096 } 1097 1098 serial8250_set_defaults(uart); 1099 1100 /* Possibly override default I/O functions. */ 1101 if (up->port.serial_in) 1102 uart->port.serial_in = up->port.serial_in; 1103 if (up->port.serial_out) 1104 uart->port.serial_out = up->port.serial_out; 1105 if (up->port.handle_irq) 1106 uart->port.handle_irq = up->port.handle_irq; 1107 /* Possibly override set_termios call */ 1108 if (up->port.set_termios) 1109 uart->port.set_termios = up->port.set_termios; 1110 if (up->port.set_ldisc) 1111 uart->port.set_ldisc = up->port.set_ldisc; 1112 if (up->port.get_mctrl) 1113 uart->port.get_mctrl = up->port.get_mctrl; 1114 if (up->port.set_mctrl) 1115 uart->port.set_mctrl = up->port.set_mctrl; 1116 if (up->port.get_divisor) 1117 uart->port.get_divisor = up->port.get_divisor; 1118 if (up->port.set_divisor) 1119 uart->port.set_divisor = up->port.set_divisor; 1120 if (up->port.startup) 1121 uart->port.startup = up->port.startup; 1122 if (up->port.shutdown) 1123 uart->port.shutdown = up->port.shutdown; 1124 if (up->port.pm) 1125 uart->port.pm = up->port.pm; 1126 if (up->port.handle_break) 1127 uart->port.handle_break = up->port.handle_break; 1128 if (up->dl_read) 1129 uart->dl_read = up->dl_read; 1130 if (up->dl_write) 1131 uart->dl_write = up->dl_write; 1132 1133 if (uart->port.type != PORT_8250_CIR) { 1134 if (serial8250_isa_config != NULL) 1135 serial8250_isa_config(0, &uart->port, 1136 &uart->capabilities); 1137 1138 serial8250_apply_quirks(uart); 1139 ret = uart_add_one_port(&serial8250_reg, 1140 &uart->port); 1141 if (ret) 1142 goto err; 1143 1144 ret = uart->port.line; 1145 } else { 1146 dev_info(uart->port.dev, 1147 "skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n", 1148 uart->port.iobase, 1149 (unsigned long long)uart->port.mapbase, 1150 uart->port.irq); 1151 1152 ret = 0; 1153 } 1154 1155 if (!uart->lsr_save_mask) 1156 uart->lsr_save_mask = LSR_SAVE_FLAGS; /* Use default LSR mask */ 1157 1158 /* Initialise interrupt backoff work if required */ 1159 if (up->overrun_backoff_time_ms > 0) { 1160 uart->overrun_backoff_time_ms = 1161 up->overrun_backoff_time_ms; 1162 INIT_DELAYED_WORK(&uart->overrun_backoff, 1163 serial_8250_overrun_backoff_work); 1164 } else { 1165 uart->overrun_backoff_time_ms = 0; 1166 } 1167 } 1168 1169 unlock: 1170 mutex_unlock(&serial_mutex); 1171 1172 return ret; 1173 1174 err: 1175 uart->port.dev = NULL; 1176 mutex_unlock(&serial_mutex); 1177 return ret; 1178 } 1179 EXPORT_SYMBOL(serial8250_register_8250_port); 1180 1181 /** 1182 * serial8250_unregister_port - remove a 16x50 serial port at runtime 1183 * @line: serial line number 1184 * 1185 * Remove one serial port. This may not be called from interrupt 1186 * context. We hand the port back to the our control. 1187 */ 1188 void serial8250_unregister_port(int line) 1189 { 1190 struct uart_8250_port *uart = &serial8250_ports[line]; 1191 1192 mutex_lock(&serial_mutex); 1193 1194 if (uart->em485) { 1195 unsigned long flags; 1196 1197 spin_lock_irqsave(&uart->port.lock, flags); 1198 serial8250_em485_destroy(uart); 1199 spin_unlock_irqrestore(&uart->port.lock, flags); 1200 } 1201 1202 uart_remove_one_port(&serial8250_reg, &uart->port); 1203 if (serial8250_isa_devs) { 1204 uart->port.flags &= ~UPF_BOOT_AUTOCONF; 1205 uart->port.type = PORT_UNKNOWN; 1206 uart->port.dev = &serial8250_isa_devs->dev; 1207 uart->port.port_id = line; 1208 uart->capabilities = 0; 1209 serial8250_init_port(uart); 1210 serial8250_apply_quirks(uart); 1211 uart_add_one_port(&serial8250_reg, &uart->port); 1212 } else { 1213 uart->port.dev = NULL; 1214 } 1215 mutex_unlock(&serial_mutex); 1216 } 1217 EXPORT_SYMBOL(serial8250_unregister_port); 1218 1219 static int __init serial8250_init(void) 1220 { 1221 int ret; 1222 1223 if (nr_uarts == 0) 1224 return -ENODEV; 1225 1226 serial8250_isa_init_ports(); 1227 1228 pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n", 1229 nr_uarts, str_enabled_disabled(share_irqs)); 1230 1231 #ifdef CONFIG_SPARC 1232 ret = sunserial_register_minors(&serial8250_reg, UART_NR); 1233 #else 1234 serial8250_reg.nr = UART_NR; 1235 ret = uart_register_driver(&serial8250_reg); 1236 #endif 1237 if (ret) 1238 goto out; 1239 1240 ret = serial8250_pnp_init(); 1241 if (ret) 1242 goto unreg_uart_drv; 1243 1244 serial8250_isa_devs = platform_device_alloc("serial8250", 1245 PLAT8250_DEV_LEGACY); 1246 if (!serial8250_isa_devs) { 1247 ret = -ENOMEM; 1248 goto unreg_pnp; 1249 } 1250 1251 ret = platform_device_add(serial8250_isa_devs); 1252 if (ret) 1253 goto put_dev; 1254 1255 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev); 1256 1257 ret = platform_driver_register(&serial8250_isa_driver); 1258 if (ret == 0) 1259 goto out; 1260 1261 platform_device_del(serial8250_isa_devs); 1262 put_dev: 1263 platform_device_put(serial8250_isa_devs); 1264 unreg_pnp: 1265 serial8250_pnp_exit(); 1266 unreg_uart_drv: 1267 #ifdef CONFIG_SPARC 1268 sunserial_unregister_minors(&serial8250_reg, UART_NR); 1269 #else 1270 uart_unregister_driver(&serial8250_reg); 1271 #endif 1272 out: 1273 return ret; 1274 } 1275 1276 static void __exit serial8250_exit(void) 1277 { 1278 struct platform_device *isa_dev = serial8250_isa_devs; 1279 1280 /* 1281 * This tells serial8250_unregister_port() not to re-register 1282 * the ports (thereby making serial8250_isa_driver permanently 1283 * in use.) 1284 */ 1285 serial8250_isa_devs = NULL; 1286 1287 platform_driver_unregister(&serial8250_isa_driver); 1288 platform_device_unregister(isa_dev); 1289 1290 serial8250_pnp_exit(); 1291 1292 #ifdef CONFIG_SPARC 1293 sunserial_unregister_minors(&serial8250_reg, UART_NR); 1294 #else 1295 uart_unregister_driver(&serial8250_reg); 1296 #endif 1297 } 1298 1299 module_init(serial8250_init); 1300 module_exit(serial8250_exit); 1301 1302 MODULE_LICENSE("GPL"); 1303 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver"); 1304 1305 module_param_hw(share_irqs, uint, other, 0644); 1306 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)"); 1307 1308 module_param(nr_uarts, uint, 0644); 1309 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")"); 1310 1311 module_param(skip_txen_test, uint, 0644); 1312 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time"); 1313 1314 #ifdef CONFIG_SERIAL_8250_RSA 1315 module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444); 1316 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA"); 1317 #endif 1318 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR); 1319 1320 #ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS 1321 #ifndef MODULE 1322 /* This module was renamed to 8250_core in 3.7. Keep the old "8250" name 1323 * working as well for the module options so we don't break people. We 1324 * need to keep the names identical and the convenient macros will happily 1325 * refuse to let us do that by failing the build with redefinition errors 1326 * of global variables. So we stick them inside a dummy function to avoid 1327 * those conflicts. The options still get parsed, and the redefined 1328 * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive. 1329 * 1330 * This is hacky. I'm sorry. 1331 */ 1332 static void __used s8250_options(void) 1333 { 1334 #undef MODULE_PARAM_PREFIX 1335 #define MODULE_PARAM_PREFIX "8250_core." 1336 1337 module_param_cb(share_irqs, ¶m_ops_uint, &share_irqs, 0644); 1338 module_param_cb(nr_uarts, ¶m_ops_uint, &nr_uarts, 0644); 1339 module_param_cb(skip_txen_test, ¶m_ops_uint, &skip_txen_test, 0644); 1340 #ifdef CONFIG_SERIAL_8250_RSA 1341 __module_param_call(MODULE_PARAM_PREFIX, probe_rsa, 1342 ¶m_array_ops, .arr = &__param_arr_probe_rsa, 1343 0444, -1, 0); 1344 #endif 1345 } 1346 #else 1347 MODULE_ALIAS("8250_core"); 1348 #endif 1349 #endif 1350