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; 500 501 serial8250_init_port(up); 502 if (!base_ops) 503 base_ops = up->port.ops; 504 up->port.ops = &univ8250_port_ops; 505 506 timer_setup(&up->timer, serial8250_timeout, 0); 507 508 up->ops = &univ8250_driver_ops; 509 510 if (IS_ENABLED(CONFIG_ALPHA_JENSEN) || 511 (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen())) 512 up->port.set_mctrl = alpha_jensen_set_mctrl; 513 514 serial8250_set_defaults(up); 515 516 return up; 517 } 518 519 static void __init serial8250_isa_init_ports(void) 520 { 521 struct uart_8250_port *up; 522 static int first = 1; 523 int i, irqflag = 0; 524 525 if (!first) 526 return; 527 first = 0; 528 529 if (nr_uarts > UART_NR) 530 nr_uarts = UART_NR; 531 532 /* 533 * Set up initial isa ports based on nr_uart module param, or else 534 * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not 535 * need to increase nr_uarts when setting up the initial isa ports. 536 */ 537 for (i = 0; i < nr_uarts; i++) 538 serial8250_setup_port(i); 539 540 /* chain base port ops to support Remote Supervisor Adapter */ 541 univ8250_port_ops = *base_ops; 542 univ8250_rsa_support(&univ8250_port_ops); 543 544 if (share_irqs) 545 irqflag = IRQF_SHARED; 546 547 for (i = 0, up = serial8250_ports; 548 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; 549 i++, up++) { 550 struct uart_port *port = &up->port; 551 552 port->iobase = old_serial_port[i].port; 553 port->irq = irq_canonicalize(old_serial_port[i].irq); 554 port->irqflags = 0; 555 port->uartclk = old_serial_port[i].baud_base * 16; 556 port->flags = old_serial_port[i].flags; 557 port->hub6 = 0; 558 port->membase = old_serial_port[i].iomem_base; 559 port->iotype = old_serial_port[i].io_type; 560 port->regshift = old_serial_port[i].iomem_reg_shift; 561 562 port->irqflags |= irqflag; 563 if (serial8250_isa_config != NULL) 564 serial8250_isa_config(i, &up->port, &up->capabilities); 565 } 566 } 567 568 static void __init 569 serial8250_register_ports(struct uart_driver *drv, struct device *dev) 570 { 571 int i; 572 573 for (i = 0; i < nr_uarts; i++) { 574 struct uart_8250_port *up = &serial8250_ports[i]; 575 576 if (up->port.type == PORT_8250_CIR) 577 continue; 578 579 if (up->port.dev) 580 continue; 581 582 up->port.dev = dev; 583 584 if (uart_console_registered(&up->port)) 585 pm_runtime_get_sync(up->port.dev); 586 587 serial8250_apply_quirks(up); 588 uart_add_one_port(drv, &up->port); 589 } 590 } 591 592 #ifdef CONFIG_SERIAL_8250_CONSOLE 593 594 static void univ8250_console_write(struct console *co, const char *s, 595 unsigned int count) 596 { 597 struct uart_8250_port *up = &serial8250_ports[co->index]; 598 599 serial8250_console_write(up, s, count); 600 } 601 602 static int univ8250_console_setup(struct console *co, char *options) 603 { 604 struct uart_8250_port *up; 605 struct uart_port *port; 606 int retval, i; 607 608 /* 609 * Check whether an invalid uart number has been specified, and 610 * if so, search for the first available port that does have 611 * console support. 612 */ 613 if (co->index >= UART_NR) 614 co->index = 0; 615 616 /* 617 * If the console is past the initial isa ports, init more ports up to 618 * co->index as needed and increment nr_uarts accordingly. 619 */ 620 for (i = nr_uarts; i <= co->index; i++) { 621 up = serial8250_setup_port(i); 622 if (!up) 623 return -ENODEV; 624 nr_uarts++; 625 } 626 627 port = &serial8250_ports[co->index].port; 628 /* link port to console */ 629 port->cons = co; 630 631 retval = serial8250_console_setup(port, options, false); 632 if (retval != 0) 633 port->cons = NULL; 634 return retval; 635 } 636 637 static int univ8250_console_exit(struct console *co) 638 { 639 struct uart_port *port; 640 641 port = &serial8250_ports[co->index].port; 642 return serial8250_console_exit(port); 643 } 644 645 /** 646 * univ8250_console_match - non-standard console matching 647 * @co: registering console 648 * @name: name from console command line 649 * @idx: index from console command line 650 * @options: ptr to option string from console command line 651 * 652 * Only attempts to match console command lines of the form: 653 * console=uart[8250],io|mmio|mmio16|mmio32,<addr>[,<options>] 654 * console=uart[8250],0x<addr>[,<options>] 655 * This form is used to register an initial earlycon boot console and 656 * replace it with the serial8250_console at 8250 driver init. 657 * 658 * Performs console setup for a match (as required by interface) 659 * If no <options> are specified, then assume the h/w is already setup. 660 * 661 * Returns 0 if console matches; otherwise non-zero to use default matching 662 */ 663 static int univ8250_console_match(struct console *co, char *name, int idx, 664 char *options) 665 { 666 char match[] = "uart"; /* 8250-specific earlycon name */ 667 unsigned char iotype; 668 resource_size_t addr; 669 int i; 670 671 if (strncmp(name, match, 4) != 0) 672 return -ENODEV; 673 674 if (uart_parse_earlycon(options, &iotype, &addr, &options)) 675 return -ENODEV; 676 677 /* try to match the port specified on the command line */ 678 for (i = 0; i < nr_uarts; i++) { 679 struct uart_port *port = &serial8250_ports[i].port; 680 681 if (port->iotype != iotype) 682 continue; 683 if ((iotype == UPIO_MEM || iotype == UPIO_MEM16 || 684 iotype == UPIO_MEM32 || iotype == UPIO_MEM32BE) 685 && (port->mapbase != addr)) 686 continue; 687 if (iotype == UPIO_PORT && port->iobase != addr) 688 continue; 689 690 co->index = i; 691 port->cons = co; 692 return serial8250_console_setup(port, options, true); 693 } 694 695 return -ENODEV; 696 } 697 698 static struct console univ8250_console = { 699 .name = "ttyS", 700 .write = univ8250_console_write, 701 .device = uart_console_device, 702 .setup = univ8250_console_setup, 703 .exit = univ8250_console_exit, 704 .match = univ8250_console_match, 705 .flags = CON_PRINTBUFFER | CON_ANYTIME, 706 .index = -1, 707 .data = &serial8250_reg, 708 }; 709 710 static int __init univ8250_console_init(void) 711 { 712 if (nr_uarts == 0) 713 return -ENODEV; 714 715 serial8250_isa_init_ports(); 716 register_console(&univ8250_console); 717 return 0; 718 } 719 console_initcall(univ8250_console_init); 720 721 #define SERIAL8250_CONSOLE (&univ8250_console) 722 #else 723 #define SERIAL8250_CONSOLE NULL 724 #endif 725 726 static struct uart_driver serial8250_reg = { 727 .owner = THIS_MODULE, 728 .driver_name = "serial", 729 .dev_name = "ttyS", 730 .major = TTY_MAJOR, 731 .minor = 64, 732 .cons = SERIAL8250_CONSOLE, 733 }; 734 735 /* 736 * early_serial_setup - early registration for 8250 ports 737 * 738 * Setup an 8250 port structure prior to console initialisation. Use 739 * after console initialisation will cause undefined behaviour. 740 */ 741 int __init early_serial_setup(struct uart_port *port) 742 { 743 struct uart_port *p; 744 745 if (port->line >= ARRAY_SIZE(serial8250_ports) || nr_uarts == 0) 746 return -ENODEV; 747 748 serial8250_isa_init_ports(); 749 p = &serial8250_ports[port->line].port; 750 p->iobase = port->iobase; 751 p->membase = port->membase; 752 p->irq = port->irq; 753 p->irqflags = port->irqflags; 754 p->uartclk = port->uartclk; 755 p->fifosize = port->fifosize; 756 p->regshift = port->regshift; 757 p->iotype = port->iotype; 758 p->flags = port->flags; 759 p->mapbase = port->mapbase; 760 p->mapsize = port->mapsize; 761 p->private_data = port->private_data; 762 p->type = port->type; 763 p->line = port->line; 764 765 serial8250_set_defaults(up_to_u8250p(p)); 766 767 if (port->serial_in) 768 p->serial_in = port->serial_in; 769 if (port->serial_out) 770 p->serial_out = port->serial_out; 771 if (port->handle_irq) 772 p->handle_irq = port->handle_irq; 773 774 return 0; 775 } 776 777 /** 778 * serial8250_suspend_port - suspend one serial port 779 * @line: serial line number 780 * 781 * Suspend one serial port. 782 */ 783 void serial8250_suspend_port(int line) 784 { 785 struct uart_8250_port *up = &serial8250_ports[line]; 786 struct uart_port *port = &up->port; 787 788 if (!console_suspend_enabled && uart_console(port) && 789 port->type != PORT_8250) { 790 unsigned char canary = 0xa5; 791 792 serial_out(up, UART_SCR, canary); 793 if (serial_in(up, UART_SCR) == canary) 794 up->canary = canary; 795 } 796 797 uart_suspend_port(&serial8250_reg, port); 798 } 799 EXPORT_SYMBOL(serial8250_suspend_port); 800 801 /** 802 * serial8250_resume_port - resume one serial port 803 * @line: serial line number 804 * 805 * Resume one serial port. 806 */ 807 void serial8250_resume_port(int line) 808 { 809 struct uart_8250_port *up = &serial8250_ports[line]; 810 struct uart_port *port = &up->port; 811 812 up->canary = 0; 813 814 if (up->capabilities & UART_NATSEMI) { 815 /* Ensure it's still in high speed mode */ 816 serial_port_out(port, UART_LCR, 0xE0); 817 818 ns16550a_goto_highspeed(up); 819 820 serial_port_out(port, UART_LCR, 0); 821 port->uartclk = 921600*16; 822 } 823 uart_resume_port(&serial8250_reg, port); 824 } 825 EXPORT_SYMBOL(serial8250_resume_port); 826 827 /* 828 * Register a set of serial devices attached to a platform device. The 829 * list is terminated with a zero flags entry, which means we expect 830 * all entries to have at least UPF_BOOT_AUTOCONF set. 831 */ 832 static int serial8250_probe(struct platform_device *dev) 833 { 834 struct plat_serial8250_port *p = dev_get_platdata(&dev->dev); 835 struct uart_8250_port uart; 836 int ret, i, irqflag = 0; 837 838 memset(&uart, 0, sizeof(uart)); 839 840 if (share_irqs) 841 irqflag = IRQF_SHARED; 842 843 for (i = 0; p && p->flags != 0; p++, i++) { 844 uart.port.iobase = p->iobase; 845 uart.port.membase = p->membase; 846 uart.port.irq = p->irq; 847 uart.port.irqflags = p->irqflags; 848 uart.port.uartclk = p->uartclk; 849 uart.port.regshift = p->regshift; 850 uart.port.iotype = p->iotype; 851 uart.port.flags = p->flags; 852 uart.port.mapbase = p->mapbase; 853 uart.port.mapsize = p->mapsize; 854 uart.port.hub6 = p->hub6; 855 uart.port.has_sysrq = p->has_sysrq; 856 uart.port.private_data = p->private_data; 857 uart.port.type = p->type; 858 uart.bugs = p->bugs; 859 uart.port.serial_in = p->serial_in; 860 uart.port.serial_out = p->serial_out; 861 uart.dl_read = p->dl_read; 862 uart.dl_write = p->dl_write; 863 uart.port.handle_irq = p->handle_irq; 864 uart.port.handle_break = p->handle_break; 865 uart.port.set_termios = p->set_termios; 866 uart.port.set_ldisc = p->set_ldisc; 867 uart.port.get_mctrl = p->get_mctrl; 868 uart.port.pm = p->pm; 869 uart.port.dev = &dev->dev; 870 uart.port.irqflags |= irqflag; 871 ret = serial8250_register_8250_port(&uart); 872 if (ret < 0) { 873 dev_err(&dev->dev, "unable to register port at index %d " 874 "(IO%lx MEM%llx IRQ%d): %d\n", i, 875 p->iobase, (unsigned long long)p->mapbase, 876 p->irq, ret); 877 } 878 } 879 return 0; 880 } 881 882 /* 883 * Remove serial ports registered against a platform device. 884 */ 885 static int serial8250_remove(struct platform_device *dev) 886 { 887 int i; 888 889 for (i = 0; i < nr_uarts; i++) { 890 struct uart_8250_port *up = &serial8250_ports[i]; 891 892 if (up->port.dev == &dev->dev) 893 serial8250_unregister_port(i); 894 } 895 return 0; 896 } 897 898 static int serial8250_suspend(struct platform_device *dev, pm_message_t state) 899 { 900 int i; 901 902 for (i = 0; i < UART_NR; i++) { 903 struct uart_8250_port *up = &serial8250_ports[i]; 904 905 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) 906 uart_suspend_port(&serial8250_reg, &up->port); 907 } 908 909 return 0; 910 } 911 912 static int serial8250_resume(struct platform_device *dev) 913 { 914 int i; 915 916 for (i = 0; i < UART_NR; i++) { 917 struct uart_8250_port *up = &serial8250_ports[i]; 918 919 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) 920 serial8250_resume_port(i); 921 } 922 923 return 0; 924 } 925 926 static struct platform_driver serial8250_isa_driver = { 927 .probe = serial8250_probe, 928 .remove = serial8250_remove, 929 .suspend = serial8250_suspend, 930 .resume = serial8250_resume, 931 .driver = { 932 .name = "serial8250", 933 }, 934 }; 935 936 /* 937 * This "device" covers _all_ ISA 8250-compatible serial devices listed 938 * in the table in include/asm/serial.h 939 */ 940 static struct platform_device *serial8250_isa_devs; 941 942 /* 943 * serial8250_register_8250_port and serial8250_unregister_port allows for 944 * 16x50 serial ports to be configured at run-time, to support PCMCIA 945 * modems and PCI multiport cards. 946 */ 947 static DEFINE_MUTEX(serial_mutex); 948 949 static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_port *port) 950 { 951 int i; 952 953 /* 954 * First, find a port entry which matches. 955 */ 956 for (i = 0; i < nr_uarts; i++) 957 if (uart_match_port(&serial8250_ports[i].port, port)) 958 return &serial8250_ports[i]; 959 960 /* try line number first if still available */ 961 i = port->line; 962 if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN && 963 serial8250_ports[i].port.iobase == 0) 964 return &serial8250_ports[i]; 965 /* 966 * We didn't find a matching entry, so look for the first 967 * free entry. We look for one which hasn't been previously 968 * used (indicated by zero iobase). 969 */ 970 for (i = 0; i < nr_uarts; i++) 971 if (serial8250_ports[i].port.type == PORT_UNKNOWN && 972 serial8250_ports[i].port.iobase == 0) 973 return &serial8250_ports[i]; 974 975 /* 976 * That also failed. Last resort is to find any entry which 977 * doesn't have a real port associated with it. 978 */ 979 for (i = 0; i < nr_uarts; i++) 980 if (serial8250_ports[i].port.type == PORT_UNKNOWN) 981 return &serial8250_ports[i]; 982 983 return NULL; 984 } 985 986 static void serial_8250_overrun_backoff_work(struct work_struct *work) 987 { 988 struct uart_8250_port *up = 989 container_of(to_delayed_work(work), struct uart_8250_port, 990 overrun_backoff); 991 struct uart_port *port = &up->port; 992 unsigned long flags; 993 994 spin_lock_irqsave(&port->lock, flags); 995 up->ier |= UART_IER_RLSI | UART_IER_RDI; 996 up->port.read_status_mask |= UART_LSR_DR; 997 serial_out(up, UART_IER, up->ier); 998 spin_unlock_irqrestore(&port->lock, flags); 999 } 1000 1001 /** 1002 * serial8250_register_8250_port - register a serial port 1003 * @up: serial port template 1004 * 1005 * Configure the serial port specified by the request. If the 1006 * port exists and is in use, it is hung up and unregistered 1007 * first. 1008 * 1009 * The port is then probed and if necessary the IRQ is autodetected 1010 * If this fails an error is returned. 1011 * 1012 * On success the port is ready to use and the line number is returned. 1013 */ 1014 int serial8250_register_8250_port(const struct uart_8250_port *up) 1015 { 1016 struct uart_8250_port *uart; 1017 int ret = -ENOSPC; 1018 1019 if (up->port.uartclk == 0) 1020 return -EINVAL; 1021 1022 mutex_lock(&serial_mutex); 1023 1024 uart = serial8250_find_match_or_unused(&up->port); 1025 if (!uart) { 1026 /* 1027 * If the port is past the initial isa ports, initialize a new 1028 * port and increment nr_uarts accordingly. 1029 */ 1030 uart = serial8250_setup_port(nr_uarts); 1031 if (!uart) 1032 goto unlock; 1033 nr_uarts++; 1034 } 1035 1036 if (uart->port.type != PORT_8250_CIR) { 1037 struct mctrl_gpios *gpios; 1038 1039 if (uart->port.dev) 1040 uart_remove_one_port(&serial8250_reg, &uart->port); 1041 1042 uart->port.ctrl_id = up->port.ctrl_id; 1043 uart->port.iobase = up->port.iobase; 1044 uart->port.membase = up->port.membase; 1045 uart->port.irq = up->port.irq; 1046 uart->port.irqflags = up->port.irqflags; 1047 uart->port.uartclk = up->port.uartclk; 1048 uart->port.fifosize = up->port.fifosize; 1049 uart->port.regshift = up->port.regshift; 1050 uart->port.iotype = up->port.iotype; 1051 uart->port.flags = up->port.flags | UPF_BOOT_AUTOCONF; 1052 uart->bugs = up->bugs; 1053 uart->port.mapbase = up->port.mapbase; 1054 uart->port.mapsize = up->port.mapsize; 1055 uart->port.private_data = up->port.private_data; 1056 uart->tx_loadsz = up->tx_loadsz; 1057 uart->capabilities = up->capabilities; 1058 uart->port.throttle = up->port.throttle; 1059 uart->port.unthrottle = up->port.unthrottle; 1060 uart->port.rs485_config = up->port.rs485_config; 1061 uart->port.rs485_supported = up->port.rs485_supported; 1062 uart->port.rs485 = up->port.rs485; 1063 uart->rs485_start_tx = up->rs485_start_tx; 1064 uart->rs485_stop_tx = up->rs485_stop_tx; 1065 uart->lsr_save_mask = up->lsr_save_mask; 1066 uart->dma = up->dma; 1067 1068 /* Take tx_loadsz from fifosize if it wasn't set separately */ 1069 if (uart->port.fifosize && !uart->tx_loadsz) 1070 uart->tx_loadsz = uart->port.fifosize; 1071 1072 if (up->port.dev) { 1073 uart->port.dev = up->port.dev; 1074 ret = uart_get_rs485_mode(&uart->port); 1075 if (ret) 1076 goto err; 1077 } 1078 1079 if (up->port.flags & UPF_FIXED_TYPE) 1080 uart->port.type = up->port.type; 1081 1082 /* 1083 * Only call mctrl_gpio_init(), if the device has no ACPI 1084 * companion device 1085 */ 1086 if (!has_acpi_companion(uart->port.dev)) { 1087 gpios = mctrl_gpio_init(&uart->port, 0); 1088 if (IS_ERR(gpios)) { 1089 ret = PTR_ERR(gpios); 1090 goto err; 1091 } else { 1092 uart->gpios = gpios; 1093 } 1094 } 1095 1096 serial8250_set_defaults(uart); 1097 1098 /* Possibly override default I/O functions. */ 1099 if (up->port.serial_in) 1100 uart->port.serial_in = up->port.serial_in; 1101 if (up->port.serial_out) 1102 uart->port.serial_out = up->port.serial_out; 1103 if (up->port.handle_irq) 1104 uart->port.handle_irq = up->port.handle_irq; 1105 /* Possibly override set_termios call */ 1106 if (up->port.set_termios) 1107 uart->port.set_termios = up->port.set_termios; 1108 if (up->port.set_ldisc) 1109 uart->port.set_ldisc = up->port.set_ldisc; 1110 if (up->port.get_mctrl) 1111 uart->port.get_mctrl = up->port.get_mctrl; 1112 if (up->port.set_mctrl) 1113 uart->port.set_mctrl = up->port.set_mctrl; 1114 if (up->port.get_divisor) 1115 uart->port.get_divisor = up->port.get_divisor; 1116 if (up->port.set_divisor) 1117 uart->port.set_divisor = up->port.set_divisor; 1118 if (up->port.startup) 1119 uart->port.startup = up->port.startup; 1120 if (up->port.shutdown) 1121 uart->port.shutdown = up->port.shutdown; 1122 if (up->port.pm) 1123 uart->port.pm = up->port.pm; 1124 if (up->port.handle_break) 1125 uart->port.handle_break = up->port.handle_break; 1126 if (up->dl_read) 1127 uart->dl_read = up->dl_read; 1128 if (up->dl_write) 1129 uart->dl_write = up->dl_write; 1130 1131 if (uart->port.type != PORT_8250_CIR) { 1132 if (serial8250_isa_config != NULL) 1133 serial8250_isa_config(0, &uart->port, 1134 &uart->capabilities); 1135 1136 serial8250_apply_quirks(uart); 1137 ret = uart_add_one_port(&serial8250_reg, 1138 &uart->port); 1139 if (ret) 1140 goto err; 1141 1142 ret = uart->port.line; 1143 } else { 1144 dev_info(uart->port.dev, 1145 "skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n", 1146 uart->port.iobase, 1147 (unsigned long long)uart->port.mapbase, 1148 uart->port.irq); 1149 1150 ret = 0; 1151 } 1152 1153 if (!uart->lsr_save_mask) 1154 uart->lsr_save_mask = LSR_SAVE_FLAGS; /* Use default LSR mask */ 1155 1156 /* Initialise interrupt backoff work if required */ 1157 if (up->overrun_backoff_time_ms > 0) { 1158 uart->overrun_backoff_time_ms = 1159 up->overrun_backoff_time_ms; 1160 INIT_DELAYED_WORK(&uart->overrun_backoff, 1161 serial_8250_overrun_backoff_work); 1162 } else { 1163 uart->overrun_backoff_time_ms = 0; 1164 } 1165 } 1166 1167 unlock: 1168 mutex_unlock(&serial_mutex); 1169 1170 return ret; 1171 1172 err: 1173 uart->port.dev = NULL; 1174 mutex_unlock(&serial_mutex); 1175 return ret; 1176 } 1177 EXPORT_SYMBOL(serial8250_register_8250_port); 1178 1179 /** 1180 * serial8250_unregister_port - remove a 16x50 serial port at runtime 1181 * @line: serial line number 1182 * 1183 * Remove one serial port. This may not be called from interrupt 1184 * context. We hand the port back to the our control. 1185 */ 1186 void serial8250_unregister_port(int line) 1187 { 1188 struct uart_8250_port *uart = &serial8250_ports[line]; 1189 1190 mutex_lock(&serial_mutex); 1191 1192 if (uart->em485) { 1193 unsigned long flags; 1194 1195 spin_lock_irqsave(&uart->port.lock, flags); 1196 serial8250_em485_destroy(uart); 1197 spin_unlock_irqrestore(&uart->port.lock, flags); 1198 } 1199 1200 uart_remove_one_port(&serial8250_reg, &uart->port); 1201 if (serial8250_isa_devs) { 1202 uart->port.flags &= ~UPF_BOOT_AUTOCONF; 1203 uart->port.type = PORT_UNKNOWN; 1204 uart->port.dev = &serial8250_isa_devs->dev; 1205 uart->capabilities = 0; 1206 serial8250_init_port(uart); 1207 serial8250_apply_quirks(uart); 1208 uart_add_one_port(&serial8250_reg, &uart->port); 1209 } else { 1210 uart->port.dev = NULL; 1211 } 1212 mutex_unlock(&serial_mutex); 1213 } 1214 EXPORT_SYMBOL(serial8250_unregister_port); 1215 1216 static int __init serial8250_init(void) 1217 { 1218 int ret; 1219 1220 if (nr_uarts == 0) 1221 return -ENODEV; 1222 1223 serial8250_isa_init_ports(); 1224 1225 pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n", 1226 nr_uarts, str_enabled_disabled(share_irqs)); 1227 1228 #ifdef CONFIG_SPARC 1229 ret = sunserial_register_minors(&serial8250_reg, UART_NR); 1230 #else 1231 serial8250_reg.nr = UART_NR; 1232 ret = uart_register_driver(&serial8250_reg); 1233 #endif 1234 if (ret) 1235 goto out; 1236 1237 ret = serial8250_pnp_init(); 1238 if (ret) 1239 goto unreg_uart_drv; 1240 1241 serial8250_isa_devs = platform_device_alloc("serial8250", 1242 PLAT8250_DEV_LEGACY); 1243 if (!serial8250_isa_devs) { 1244 ret = -ENOMEM; 1245 goto unreg_pnp; 1246 } 1247 1248 ret = platform_device_add(serial8250_isa_devs); 1249 if (ret) 1250 goto put_dev; 1251 1252 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev); 1253 1254 ret = platform_driver_register(&serial8250_isa_driver); 1255 if (ret == 0) 1256 goto out; 1257 1258 platform_device_del(serial8250_isa_devs); 1259 put_dev: 1260 platform_device_put(serial8250_isa_devs); 1261 unreg_pnp: 1262 serial8250_pnp_exit(); 1263 unreg_uart_drv: 1264 #ifdef CONFIG_SPARC 1265 sunserial_unregister_minors(&serial8250_reg, UART_NR); 1266 #else 1267 uart_unregister_driver(&serial8250_reg); 1268 #endif 1269 out: 1270 return ret; 1271 } 1272 1273 static void __exit serial8250_exit(void) 1274 { 1275 struct platform_device *isa_dev = serial8250_isa_devs; 1276 1277 /* 1278 * This tells serial8250_unregister_port() not to re-register 1279 * the ports (thereby making serial8250_isa_driver permanently 1280 * in use.) 1281 */ 1282 serial8250_isa_devs = NULL; 1283 1284 platform_driver_unregister(&serial8250_isa_driver); 1285 platform_device_unregister(isa_dev); 1286 1287 serial8250_pnp_exit(); 1288 1289 #ifdef CONFIG_SPARC 1290 sunserial_unregister_minors(&serial8250_reg, UART_NR); 1291 #else 1292 uart_unregister_driver(&serial8250_reg); 1293 #endif 1294 } 1295 1296 module_init(serial8250_init); 1297 module_exit(serial8250_exit); 1298 1299 MODULE_LICENSE("GPL"); 1300 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver"); 1301 1302 module_param_hw(share_irqs, uint, other, 0644); 1303 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)"); 1304 1305 module_param(nr_uarts, uint, 0644); 1306 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")"); 1307 1308 module_param(skip_txen_test, uint, 0644); 1309 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time"); 1310 1311 #ifdef CONFIG_SERIAL_8250_RSA 1312 module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444); 1313 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA"); 1314 #endif 1315 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR); 1316 1317 #ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS 1318 #ifndef MODULE 1319 /* This module was renamed to 8250_core in 3.7. Keep the old "8250" name 1320 * working as well for the module options so we don't break people. We 1321 * need to keep the names identical and the convenient macros will happily 1322 * refuse to let us do that by failing the build with redefinition errors 1323 * of global variables. So we stick them inside a dummy function to avoid 1324 * those conflicts. The options still get parsed, and the redefined 1325 * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive. 1326 * 1327 * This is hacky. I'm sorry. 1328 */ 1329 static void __used s8250_options(void) 1330 { 1331 #undef MODULE_PARAM_PREFIX 1332 #define MODULE_PARAM_PREFIX "8250_core." 1333 1334 module_param_cb(share_irqs, ¶m_ops_uint, &share_irqs, 0644); 1335 module_param_cb(nr_uarts, ¶m_ops_uint, &nr_uarts, 0644); 1336 module_param_cb(skip_txen_test, ¶m_ops_uint, &skip_txen_test, 0644); 1337 #ifdef CONFIG_SERIAL_8250_RSA 1338 __module_param_call(MODULE_PARAM_PREFIX, probe_rsa, 1339 ¶m_array_ops, .arr = &__param_arr_probe_rsa, 1340 0444, -1, 0); 1341 #endif 1342 } 1343 #else 1344 MODULE_ALIAS("8250_core"); 1345 #endif 1346 #endif 1347