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