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