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