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