8250.c 83.6 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
/*
 *  Driver for 8250/16550-type serial ports
 *
 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
 *
 *  Copyright (C) 2001 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * A note about mapbase / membase
 *
 *  mapbase is the physical address of the IO port.
 *  membase is an 'ioremapped' cookie.
 */

#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
30
#include <linux/platform_device.h>
L
Linus Torvalds 已提交
31
#include <linux/tty.h>
32
#include <linux/ratelimit.h>
L
Linus Torvalds 已提交
33 34 35 36 37
#include <linux/tty_flip.h>
#include <linux/serial_reg.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
38
#include <linux/nmi.h>
39
#include <linux/mutex.h>
40
#include <linux/slab.h>
L
Linus Torvalds 已提交
41 42 43 44 45 46

#include <asm/io.h>
#include <asm/irq.h>

#include "8250.h"

47
#ifdef CONFIG_SPARC
C
Cong Wang 已提交
48
#include "../suncore.h"
49 50
#endif

L
Linus Torvalds 已提交
51 52
/*
 * Configuration:
53
 *   share_irqs - whether we pass IRQF_SHARED to request_irq().  This option
L
Linus Torvalds 已提交
54 55
 *                is unsafe when used on edge-triggered interrupts.
 */
A
Adrian Bunk 已提交
56
static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
L
Linus Torvalds 已提交
57

58 59
static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;

60 61 62 63 64 65 66
static struct uart_driver serial8250_reg;

static int serial_index(struct uart_port *port)
{
	return (serial8250_reg.minor - 64) + port->line;
}

67 68
static unsigned int skip_txen_test; /* force skip of txen test at init time */

L
Linus Torvalds 已提交
69 70 71 72 73 74 75 76 77 78 79 80 81 82 83
/*
 * Debugging.
 */
#if 0
#define DEBUG_AUTOCONF(fmt...)	printk(fmt)
#else
#define DEBUG_AUTOCONF(fmt...)	do { } while (0)
#endif

#if 0
#define DEBUG_INTR(fmt...)	printk(fmt)
#else
#define DEBUG_INTR(fmt...)	do { } while (0)
#endif

J
Jiri Slaby 已提交
84
#define PASS_LIMIT	512
L
Linus Torvalds 已提交
85

86 87 88
#define BOTH_EMPTY 	(UART_LSR_TEMT | UART_LSR_THRE)


L
Linus Torvalds 已提交
89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108
/*
 * We default to IRQ0 for the "no irq" hack.   Some
 * machine types want others as well - they're free
 * to redefine this in their header file.
 */
#define is_real_interrupt(irq)	((irq) != 0)

#ifdef CONFIG_SERIAL_8250_DETECT_IRQ
#define CONFIG_SERIAL_DETECT_IRQ 1
#endif
#ifdef CONFIG_SERIAL_8250_MANY_PORTS
#define CONFIG_SERIAL_MANY_PORTS 1
#endif

/*
 * HUB6 is always on.  This will be removed once the header
 * files have been cleaned.
 */
#define CONFIG_HUB6 1

109
#include <asm/serial.h>
L
Linus Torvalds 已提交
110 111 112 113 114 115 116 117 118
/*
 * SERIAL_PORT_DFNS tells us about built-in ports that have no
 * standard enumeration mechanism.   Platforms that can find all
 * serial ports via mechanisms like ACPI or PCI need not supply it.
 */
#ifndef SERIAL_PORT_DFNS
#define SERIAL_PORT_DFNS
#endif

119
static const struct old_serial_port old_serial_port[] = {
L
Linus Torvalds 已提交
120 121 122
	SERIAL_PORT_DFNS /* defined in asm/serial.h */
};

123
#define UART_NR	CONFIG_SERIAL_8250_NR_UARTS
L
Linus Torvalds 已提交
124 125 126 127 128 129 130 131 132

#ifdef CONFIG_SERIAL_8250_RSA

#define PORT_RSA_MAX 4
static unsigned long probe_rsa[PORT_RSA_MAX];
static unsigned int probe_rsa_count;
#endif /* CONFIG_SERIAL_8250_RSA  */

struct irq_info {
A
Alan Cox 已提交
133 134 135
	struct			hlist_node node;
	int			irq;
	spinlock_t		lock;	/* Protects list not the hash */
L
Linus Torvalds 已提交
136 137 138
	struct list_head	*head;
};

A
Alan Cox 已提交
139 140 141
#define NR_IRQ_HASH		32	/* Can be adjusted later */
static struct hlist_head irq_lists[NR_IRQ_HASH];
static DEFINE_MUTEX(hash_mutex);	/* Used to walk the hash */
L
Linus Torvalds 已提交
142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210

/*
 * Here we define the default xmit fifo size used for each type of UART.
 */
static const struct serial8250_config uart_config[] = {
	[PORT_UNKNOWN] = {
		.name		= "unknown",
		.fifo_size	= 1,
		.tx_loadsz	= 1,
	},
	[PORT_8250] = {
		.name		= "8250",
		.fifo_size	= 1,
		.tx_loadsz	= 1,
	},
	[PORT_16450] = {
		.name		= "16450",
		.fifo_size	= 1,
		.tx_loadsz	= 1,
	},
	[PORT_16550] = {
		.name		= "16550",
		.fifo_size	= 1,
		.tx_loadsz	= 1,
	},
	[PORT_16550A] = {
		.name		= "16550A",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
		.flags		= UART_CAP_FIFO,
	},
	[PORT_CIRRUS] = {
		.name		= "Cirrus",
		.fifo_size	= 1,
		.tx_loadsz	= 1,
	},
	[PORT_16650] = {
		.name		= "ST16650",
		.fifo_size	= 1,
		.tx_loadsz	= 1,
		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
	},
	[PORT_16650V2] = {
		.name		= "ST16650V2",
		.fifo_size	= 32,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
				  UART_FCR_T_TRIG_00,
		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
	},
	[PORT_16750] = {
		.name		= "TI16750",
		.fifo_size	= 64,
		.tx_loadsz	= 64,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
				  UART_FCR7_64BYTE,
		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
	},
	[PORT_STARTECH] = {
		.name		= "Startech",
		.fifo_size	= 1,
		.tx_loadsz	= 1,
	},
	[PORT_16C950] = {
		.name		= "16C950/954",
		.fifo_size	= 128,
		.tx_loadsz	= 128,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
211 212
		/* UART_CAP_EFR breaks billionon CF bluetooth card. */
		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
L
Linus Torvalds 已提交
213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247
	},
	[PORT_16654] = {
		.name		= "ST16654",
		.fifo_size	= 64,
		.tx_loadsz	= 32,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
				  UART_FCR_T_TRIG_10,
		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
	},
	[PORT_16850] = {
		.name		= "XR16850",
		.fifo_size	= 128,
		.tx_loadsz	= 128,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
	},
	[PORT_RSA] = {
		.name		= "RSA",
		.fifo_size	= 2048,
		.tx_loadsz	= 2048,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
		.flags		= UART_CAP_FIFO,
	},
	[PORT_NS16550A] = {
		.name		= "NS16550A",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
		.flags		= UART_CAP_FIFO | UART_NATSEMI,
	},
	[PORT_XSCALE] = {
		.name		= "XScale",
		.fifo_size	= 32,
		.tx_loadsz	= 32,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
248
		.flags		= UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
L
Linus Torvalds 已提交
249
	},
T
Thomas Koeller 已提交
250 251 252 253 254
	[PORT_RM9000] = {
		.name		= "RM9000",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
255 256 257 258 259 260 261
		.flags		= UART_CAP_FIFO,
	},
	[PORT_OCTEON] = {
		.name		= "OCTEON",
		.fifo_size	= 64,
		.tx_loadsz	= 64,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
T
Thomas Koeller 已提交
262 263
		.flags		= UART_CAP_FIFO,
	},
264 265 266 267 268 269 270
	[PORT_AR7] = {
		.name		= "AR7",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
	},
271 272 273 274 275 276 277
	[PORT_U6_16550A] = {
		.name		= "U6_16550A",
		.fifo_size	= 64,
		.tx_loadsz	= 64,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
	},
278 279 280 281 282 283 284 285
	[PORT_TEGRA] = {
		.name		= "Tegra",
		.fifo_size	= 32,
		.tx_loadsz	= 8,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
				  UART_FCR_T_TRIG_01,
		.flags		= UART_CAP_FIFO | UART_CAP_RTOIE,
	},
286 287 288 289 290 291 292
	[PORT_XR17D15X] = {
		.name		= "XR17D15X",
		.fifo_size	= 64,
		.tx_loadsz	= 64,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
		.flags		= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR,
	},
L
Linus Torvalds 已提交
293 294
};

295
#if defined(CONFIG_MIPS_ALCHEMY)
296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316

/* Au1x00 UART hardware has a weird register layout */
static const u8 au_io_in_map[] = {
	[UART_RX]  = 0,
	[UART_IER] = 2,
	[UART_IIR] = 3,
	[UART_LCR] = 5,
	[UART_MCR] = 6,
	[UART_LSR] = 7,
	[UART_MSR] = 8,
};

static const u8 au_io_out_map[] = {
	[UART_TX]  = 1,
	[UART_IER] = 2,
	[UART_FCR] = 4,
	[UART_LCR] = 5,
	[UART_MCR] = 6,
};

/* sane hardware needs no mapping */
317
static inline int map_8250_in_reg(struct uart_port *p, int offset)
318
{
319
	if (p->iotype != UPIO_AU)
320 321 322 323
		return offset;
	return au_io_in_map[offset];
}

324
static inline int map_8250_out_reg(struct uart_port *p, int offset)
325
{
326
	if (p->iotype != UPIO_AU)
327 328 329 330
		return offset;
	return au_io_out_map[offset];
}

A
Alan Cox 已提交
331
#elif defined(CONFIG_SERIAL_8250_RM9K)
T
Thomas Koeller 已提交
332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354

static const u8
	regmap_in[8] = {
		[UART_RX]	= 0x00,
		[UART_IER]	= 0x0c,
		[UART_IIR]	= 0x14,
		[UART_LCR]	= 0x1c,
		[UART_MCR]	= 0x20,
		[UART_LSR]	= 0x24,
		[UART_MSR]	= 0x28,
		[UART_SCR]	= 0x2c
	},
	regmap_out[8] = {
		[UART_TX] 	= 0x04,
		[UART_IER]	= 0x0c,
		[UART_FCR]	= 0x18,
		[UART_LCR]	= 0x1c,
		[UART_MCR]	= 0x20,
		[UART_LSR]	= 0x24,
		[UART_MSR]	= 0x28,
		[UART_SCR]	= 0x2c
	};

355
static inline int map_8250_in_reg(struct uart_port *p, int offset)
T
Thomas Koeller 已提交
356
{
357
	if (p->iotype != UPIO_RM9000)
T
Thomas Koeller 已提交
358 359 360 361
		return offset;
	return regmap_in[offset];
}

362
static inline int map_8250_out_reg(struct uart_port *p, int offset)
T
Thomas Koeller 已提交
363
{
364
	if (p->iotype != UPIO_RM9000)
T
Thomas Koeller 已提交
365 366 367 368
		return offset;
	return regmap_out[offset];
}

369 370 371 372 373 374 375 376
#else

/* sane hardware needs no mapping */
#define map_8250_in_reg(up, offset) (offset)
#define map_8250_out_reg(up, offset) (offset)

#endif

377
static unsigned int hub6_serial_in(struct uart_port *p, int offset)
L
Linus Torvalds 已提交
378
{
379 380 381 382
	offset = map_8250_in_reg(p, offset) << p->regshift;
	outb(p->hub6 - 1 + offset, p->iobase);
	return inb(p->iobase + 1);
}
L
Linus Torvalds 已提交
383

384 385 386 387 388 389
static void hub6_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	outb(p->hub6 - 1 + offset, p->iobase);
	outb(value, p->iobase + 1);
}
L
Linus Torvalds 已提交
390

391 392 393 394 395
static unsigned int mem_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return readb(p->membase + offset);
}
L
Linus Torvalds 已提交
396

397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413
static void mem_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	writeb(value, p->membase + offset);
}

static void mem32_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	writel(value, p->membase + offset);
}

static unsigned int mem32_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return readl(p->membase + offset);
}
L
Linus Torvalds 已提交
414

415 416 417 418 419 420 421 422 423 424 425
static unsigned int au_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return __raw_readl(p->membase + offset);
}

static void au_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	__raw_writel(value, p->membase + offset);
}
426

427 428 429 430 431 432 433 434 435 436 437 438
static unsigned int io_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return inb(p->iobase + offset);
}

static void io_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	outb(value, p->iobase + offset);
}

439 440
static int serial8250_default_handle_irq(struct uart_port *port);

441 442
static void set_io_from_upio(struct uart_port *p)
{
443 444
	struct uart_8250_port *up =
		container_of(p, struct uart_8250_port, port);
445
	switch (p->iotype) {
L
Linus Torvalds 已提交
446
	case UPIO_HUB6:
447 448
		p->serial_in = hub6_serial_in;
		p->serial_out = hub6_serial_out;
L
Linus Torvalds 已提交
449 450 451
		break;

	case UPIO_MEM:
452 453
		p->serial_in = mem_serial_in;
		p->serial_out = mem_serial_out;
L
Linus Torvalds 已提交
454 455
		break;

T
Thomas Koeller 已提交
456
	case UPIO_RM9000:
L
Linus Torvalds 已提交
457
	case UPIO_MEM32:
458 459
		p->serial_in = mem32_serial_in;
		p->serial_out = mem32_serial_out;
L
Linus Torvalds 已提交
460 461
		break;

462
	case UPIO_AU:
463 464
		p->serial_in = au_serial_in;
		p->serial_out = au_serial_out;
465
		break;
466

L
Linus Torvalds 已提交
467
	default:
468 469 470
		p->serial_in = io_serial_in;
		p->serial_out = io_serial_out;
		break;
L
Linus Torvalds 已提交
471
	}
A
Alan Cox 已提交
472 473
	/* Remember loaded iotype */
	up->cur_iotype = p->iotype;
474
	p->handle_irq = serial8250_default_handle_irq;
L
Linus Torvalds 已提交
475 476
}

A
Alex Williamson 已提交
477 478 479
static void
serial_out_sync(struct uart_8250_port *up, int offset, int value)
{
480 481
	struct uart_port *p = &up->port;
	switch (p->iotype) {
A
Alex Williamson 已提交
482 483 484
	case UPIO_MEM:
	case UPIO_MEM32:
	case UPIO_AU:
485 486
		p->serial_out(p, offset, value);
		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
A
Alex Williamson 已提交
487 488
		break;
	default:
489
		p->serial_out(p, offset, value);
A
Alex Williamson 已提交
490 491 492
	}
}

493 494 495 496
#define serial_in(up, offset)		\
	(up->port.serial_in(&(up)->port, (offset)))
#define serial_out(up, offset, value)	\
	(up->port.serial_out(&(up)->port, (offset), (value)))
L
Linus Torvalds 已提交
497 498 499 500 501 502 503 504 505
/*
 * We used to support using pause I/O for certain machines.  We
 * haven't supported this for a while, but just in case it's badly
 * needed for certain old 386 machines, I've left these #define's
 * in....
 */
#define serial_inp(up, offset)		serial_in(up, offset)
#define serial_outp(up, offset, value)	serial_out(up, offset, value)

506 507 508 509 510 511 512 513 514 515 516 517 518
/* Uart divisor latch read */
static inline int _serial_dl_read(struct uart_8250_port *up)
{
	return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
}

/* Uart divisor latch write */
static inline void _serial_dl_write(struct uart_8250_port *up, int value)
{
	serial_outp(up, UART_DLL, value & 0xff);
	serial_outp(up, UART_DLM, value >> 8 & 0xff);
}

519
#if defined(CONFIG_MIPS_ALCHEMY)
520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535
/* Au1x00 haven't got a standard divisor latch */
static int serial_dl_read(struct uart_8250_port *up)
{
	if (up->port.iotype == UPIO_AU)
		return __raw_readl(up->port.membase + 0x28);
	else
		return _serial_dl_read(up);
}

static void serial_dl_write(struct uart_8250_port *up, int value)
{
	if (up->port.iotype == UPIO_AU)
		__raw_writel(value, up->port.membase + 0x28);
	else
		_serial_dl_write(up, value);
}
A
Alan Cox 已提交
536
#elif defined(CONFIG_SERIAL_8250_RM9K)
T
Thomas Koeller 已提交
537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553
static int serial_dl_read(struct uart_8250_port *up)
{
	return	(up->port.iotype == UPIO_RM9000) ?
		(((__raw_readl(up->port.membase + 0x10) << 8) |
		(__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) :
		_serial_dl_read(up);
}

static void serial_dl_write(struct uart_8250_port *up, int value)
{
	if (up->port.iotype == UPIO_RM9000) {
		__raw_writel(value, up->port.membase + 0x08);
		__raw_writel(value >> 8, up->port.membase + 0x10);
	} else {
		_serial_dl_write(up, value);
	}
}
554 555 556 557
#else
#define serial_dl_read(up) _serial_dl_read(up)
#define serial_dl_write(up, value) _serial_dl_write(up, value)
#endif
L
Linus Torvalds 已提交
558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582

/*
 * For the 16C950
 */
static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
{
	serial_out(up, UART_SCR, offset);
	serial_out(up, UART_ICR, value);
}

static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
{
	unsigned int value;

	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
	serial_out(up, UART_SCR, offset);
	value = serial_in(up, UART_ICR);
	serial_icr_write(up, UART_ACR, up->acr);

	return value;
}

/*
 * FIFO support.
 */
583
static void serial8250_clear_fifos(struct uart_8250_port *p)
L
Linus Torvalds 已提交
584 585 586 587 588 589 590 591 592 593 594 595 596 597
{
	if (p->capabilities & UART_CAP_FIFO) {
		serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
		serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
			       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
		serial_outp(p, UART_FCR, 0);
	}
}

/*
 * IER sleep support.  UARTs which have EFRs need the "extended
 * capability" bit enabled.  Note that on XR16C850s, we need to
 * reset LCR to write to IER.
 */
598
static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
L
Linus Torvalds 已提交
599 600 601
{
	if (p->capabilities & UART_CAP_SLEEP) {
		if (p->capabilities & UART_CAP_EFR) {
602
			serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
603 604 605 606 607
			serial_outp(p, UART_EFR, UART_EFR_ECB);
			serial_outp(p, UART_LCR, 0);
		}
		serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
		if (p->capabilities & UART_CAP_EFR) {
608
			serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689
			serial_outp(p, UART_EFR, 0);
			serial_outp(p, UART_LCR, 0);
		}
	}
}

#ifdef CONFIG_SERIAL_8250_RSA
/*
 * Attempts to turn on the RSA FIFO.  Returns zero on failure.
 * We set the port uart clock rate if we succeed.
 */
static int __enable_rsa(struct uart_8250_port *up)
{
	unsigned char mode;
	int result;

	mode = serial_inp(up, UART_RSA_MSR);
	result = mode & UART_RSA_MSR_FIFO;

	if (!result) {
		serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
		mode = serial_inp(up, UART_RSA_MSR);
		result = mode & UART_RSA_MSR_FIFO;
	}

	if (result)
		up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;

	return result;
}

static void enable_rsa(struct uart_8250_port *up)
{
	if (up->port.type == PORT_RSA) {
		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
			spin_lock_irq(&up->port.lock);
			__enable_rsa(up);
			spin_unlock_irq(&up->port.lock);
		}
		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
			serial_outp(up, UART_RSA_FRR, 0);
	}
}

/*
 * Attempts to turn off the RSA FIFO.  Returns zero on failure.
 * It is unknown why interrupts were disabled in here.  However,
 * the caller is expected to preserve this behaviour by grabbing
 * the spinlock before calling this function.
 */
static void disable_rsa(struct uart_8250_port *up)
{
	unsigned char mode;
	int result;

	if (up->port.type == PORT_RSA &&
	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
		spin_lock_irq(&up->port.lock);

		mode = serial_inp(up, UART_RSA_MSR);
		result = !(mode & UART_RSA_MSR_FIFO);

		if (!result) {
			serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
			mode = serial_inp(up, UART_RSA_MSR);
			result = !(mode & UART_RSA_MSR_FIFO);
		}

		if (result)
			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
		spin_unlock_irq(&up->port.lock);
	}
}
#endif /* CONFIG_SERIAL_8250_RSA */

/*
 * This is a quickie test to see how big the FIFO is.
 * It doesn't work at all the time, more's the pity.
 */
static int size_fifo(struct uart_8250_port *up)
{
690 691
	unsigned char old_fcr, old_mcr, old_lcr;
	unsigned short old_dl;
L
Linus Torvalds 已提交
692 693 694 695 696 697 698 699 700
	int count;

	old_lcr = serial_inp(up, UART_LCR);
	serial_outp(up, UART_LCR, 0);
	old_fcr = serial_inp(up, UART_FCR);
	old_mcr = serial_inp(up, UART_MCR);
	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
		    UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
	serial_outp(up, UART_MCR, UART_MCR_LOOP);
701
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
702 703
	old_dl = serial_dl_read(up);
	serial_dl_write(up, 0x0001);
L
Linus Torvalds 已提交
704 705 706 707 708 709 710 711 712
	serial_outp(up, UART_LCR, 0x03);
	for (count = 0; count < 256; count++)
		serial_outp(up, UART_TX, count);
	mdelay(20);/* FIXME - schedule_timeout */
	for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
	     (count < 256); count++)
		serial_inp(up, UART_RX);
	serial_outp(up, UART_FCR, old_fcr);
	serial_outp(up, UART_MCR, old_mcr);
713
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
714
	serial_dl_write(up, old_dl);
L
Linus Torvalds 已提交
715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730
	serial_outp(up, UART_LCR, old_lcr);

	return count;
}

/*
 * Read UART ID using the divisor method - set DLL and DLM to zero
 * and the revision will be in DLL and device type in DLM.  We
 * preserve the device state across this.
 */
static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
{
	unsigned char old_dll, old_dlm, old_lcr;
	unsigned int id;

	old_lcr = serial_inp(p, UART_LCR);
731
	serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_A);
L
Linus Torvalds 已提交
732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754

	old_dll = serial_inp(p, UART_DLL);
	old_dlm = serial_inp(p, UART_DLM);

	serial_outp(p, UART_DLL, 0);
	serial_outp(p, UART_DLM, 0);

	id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;

	serial_outp(p, UART_DLL, old_dll);
	serial_outp(p, UART_DLM, old_dlm);
	serial_outp(p, UART_LCR, old_lcr);

	return id;
}

/*
 * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
 * When this function is called we know it is at least a StarTech
 * 16650 V2, but it might be one of several StarTech UARTs, or one of
 * its clones.  (We treat the broken original StarTech 16650 V1 as a
 * 16550, and why not?  Startech doesn't seem to even acknowledge its
 * existence.)
T
Thomas Koeller 已提交
755
 *
L
Linus Torvalds 已提交
756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784
 * What evil have men's minds wrought...
 */
static void autoconfig_has_efr(struct uart_8250_port *up)
{
	unsigned int id1, id2, id3, rev;

	/*
	 * Everything with an EFR has SLEEP
	 */
	up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;

	/*
	 * First we check to see if it's an Oxford Semiconductor UART.
	 *
	 * If we have to do this here because some non-National
	 * Semiconductor clone chips lock up if you try writing to the
	 * LSR register (which serial_icr_read does)
	 */

	/*
	 * Check for Oxford Semiconductor 16C950.
	 *
	 * EFR [4] must be set else this test fails.
	 *
	 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
	 * claims that it's needed for 952 dual UART's (which are not
	 * recommended for new designs).
	 */
	up->acr = 0;
785
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
786 787 788 789 790 791 792 793 794 795 796 797
	serial_out(up, UART_EFR, UART_EFR_ECB);
	serial_out(up, UART_LCR, 0x00);
	id1 = serial_icr_read(up, UART_ID1);
	id2 = serial_icr_read(up, UART_ID2);
	id3 = serial_icr_read(up, UART_ID3);
	rev = serial_icr_read(up, UART_REV);

	DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);

	if (id1 == 0x16 && id2 == 0xC9 &&
	    (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
		up->port.type = PORT_16C950;
798 799 800 801 802 803 804 805

		/*
		 * Enable work around for the Oxford Semiconductor 952 rev B
		 * chip which causes it to seriously miscalculate baud rates
		 * when DLL is 0.
		 */
		if (id3 == 0x52 && rev == 0x01)
			up->bugs |= UART_BUG_QUOT;
L
Linus Torvalds 已提交
806 807
		return;
	}
T
Thomas Koeller 已提交
808

L
Linus Torvalds 已提交
809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867
	/*
	 * We check for a XR16C850 by setting DLL and DLM to 0, and then
	 * reading back DLL and DLM.  The chip type depends on the DLM
	 * value read back:
	 *  0x10 - XR16C850 and the DLL contains the chip revision.
	 *  0x12 - XR16C2850.
	 *  0x14 - XR16C854.
	 */
	id1 = autoconfig_read_divisor_id(up);
	DEBUG_AUTOCONF("850id=%04x ", id1);

	id2 = id1 >> 8;
	if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
		up->port.type = PORT_16850;
		return;
	}

	/*
	 * It wasn't an XR16C850.
	 *
	 * We distinguish between the '654 and the '650 by counting
	 * how many bytes are in the FIFO.  I'm using this for now,
	 * since that's the technique that was sent to me in the
	 * serial driver update, but I'm not convinced this works.
	 * I've had problems doing this in the past.  -TYT
	 */
	if (size_fifo(up) == 64)
		up->port.type = PORT_16654;
	else
		up->port.type = PORT_16650V2;
}

/*
 * We detected a chip without a FIFO.  Only two fall into
 * this category - the original 8250 and the 16450.  The
 * 16450 has a scratch register (accessible with LCR=0)
 */
static void autoconfig_8250(struct uart_8250_port *up)
{
	unsigned char scratch, status1, status2;

	up->port.type = PORT_8250;

	scratch = serial_in(up, UART_SCR);
	serial_outp(up, UART_SCR, 0xa5);
	status1 = serial_in(up, UART_SCR);
	serial_outp(up, UART_SCR, 0x5a);
	status2 = serial_in(up, UART_SCR);
	serial_outp(up, UART_SCR, scratch);

	if (status1 == 0xa5 && status2 == 0x5a)
		up->port.type = PORT_16450;
}

static int broken_efr(struct uart_8250_port *up)
{
	/*
	 * Exar ST16C2550 "A2" devices incorrectly detect as
	 * having an EFR, and report an ID of 0x0201.  See
868
	 * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html 
L
Linus Torvalds 已提交
869 870 871 872 873 874 875
	 */
	if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
		return 1;

	return 0;
}

876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892
static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
{
	unsigned char status;

	status = serial_in(up, 0x04); /* EXCR2 */
#define PRESL(x) ((x) & 0x30)
	if (PRESL(status) == 0x10) {
		/* already in high speed mode */
		return 0;
	} else {
		status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
		status |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
		serial_outp(up, 0x04, status);
	}
	return 1;
}

L
Linus Torvalds 已提交
893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910
/*
 * We know that the chip has FIFOs.  Does it have an EFR?  The
 * EFR is located in the same register position as the IIR and
 * we know the top two bits of the IIR are currently set.  The
 * EFR should contain zero.  Try to read the EFR.
 */
static void autoconfig_16550a(struct uart_8250_port *up)
{
	unsigned char status1, status2;
	unsigned int iersave;

	up->port.type = PORT_16550A;
	up->capabilities |= UART_CAP_FIFO;

	/*
	 * Check for presence of the EFR when DLAB is set.
	 * Only ST16C650V1 UARTs pass this test.
	 */
911
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
L
Linus Torvalds 已提交
912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928
	if (serial_in(up, UART_EFR) == 0) {
		serial_outp(up, UART_EFR, 0xA8);
		if (serial_in(up, UART_EFR) != 0) {
			DEBUG_AUTOCONF("EFRv1 ");
			up->port.type = PORT_16650;
			up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
		} else {
			DEBUG_AUTOCONF("Motorola 8xxx DUART ");
		}
		serial_outp(up, UART_EFR, 0);
		return;
	}

	/*
	 * Maybe it requires 0xbf to be written to the LCR.
	 * (other ST16C650V2 UARTs, TI16C752A, etc)
	 */
929
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956
	if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
		DEBUG_AUTOCONF("EFRv2 ");
		autoconfig_has_efr(up);
		return;
	}

	/*
	 * Check for a National Semiconductor SuperIO chip.
	 * Attempt to switch to bank 2, read the value of the LOOP bit
	 * from EXCR1. Switch back to bank 0, change it in MCR. Then
	 * switch back to bank 2, read it from EXCR1 again and check
	 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
	 */
	serial_outp(up, UART_LCR, 0);
	status1 = serial_in(up, UART_MCR);
	serial_outp(up, UART_LCR, 0xE0);
	status2 = serial_in(up, 0x02); /* EXCR1 */

	if (!((status2 ^ status1) & UART_MCR_LOOP)) {
		serial_outp(up, UART_LCR, 0);
		serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
		serial_outp(up, UART_LCR, 0xE0);
		status2 = serial_in(up, 0x02); /* EXCR1 */
		serial_outp(up, UART_LCR, 0);
		serial_outp(up, UART_MCR, status1);

		if ((status2 ^ status1) & UART_MCR_LOOP) {
957 958
			unsigned short quot;

L
Linus Torvalds 已提交
959
			serial_outp(up, UART_LCR, 0xE0);
960

961
			quot = serial_dl_read(up);
962 963
			quot <<= 3;

964 965
			if (ns16550a_goto_highspeed(up))
				serial_dl_write(up, quot);
966

L
Linus Torvalds 已提交
967 968
			serial_outp(up, UART_LCR, 0);

969
			up->port.uartclk = 921600*16;
L
Linus Torvalds 已提交
970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985
			up->port.type = PORT_NS16550A;
			up->capabilities |= UART_NATSEMI;
			return;
		}
	}

	/*
	 * No EFR.  Try to detect a TI16750, which only sets bit 5 of
	 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
	 * Try setting it with and without DLAB set.  Cheap clones
	 * set bit 5 without DLAB set.
	 */
	serial_outp(up, UART_LCR, 0);
	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
	status1 = serial_in(up, UART_IIR) >> 5;
	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
986
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
L
Linus Torvalds 已提交
987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022
	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
	status2 = serial_in(up, UART_IIR) >> 5;
	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
	serial_outp(up, UART_LCR, 0);

	DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);

	if (status1 == 6 && status2 == 7) {
		up->port.type = PORT_16750;
		up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
		return;
	}

	/*
	 * Try writing and reading the UART_IER_UUE bit (b6).
	 * If it works, this is probably one of the Xscale platform's
	 * internal UARTs.
	 * We're going to explicitly set the UUE bit to 0 before
	 * trying to write and read a 1 just to make sure it's not
	 * already a 1 and maybe locked there before we even start start.
	 */
	iersave = serial_in(up, UART_IER);
	serial_outp(up, UART_IER, iersave & ~UART_IER_UUE);
	if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
		/*
		 * OK it's in a known zero state, try writing and reading
		 * without disturbing the current state of the other bits.
		 */
		serial_outp(up, UART_IER, iersave | UART_IER_UUE);
		if (serial_in(up, UART_IER) & UART_IER_UUE) {
			/*
			 * It's an Xscale.
			 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
			 */
			DEBUG_AUTOCONF("Xscale ");
			up->port.type = PORT_XSCALE;
1023
			up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE;
L
Linus Torvalds 已提交
1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
			return;
		}
	} else {
		/*
		 * If we got here we couldn't force the IER_UUE bit to 0.
		 * Log it and continue.
		 */
		DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
	}
	serial_outp(up, UART_IER, iersave);
1034

1035 1036 1037 1038 1039 1040 1041 1042
	/*
	 * Exar uarts have EFR in a weird location
	 */
	if (up->port.flags & UPF_EXAR_EFR) {
		up->port.type = PORT_XR17D15X;
		up->capabilities |= UART_CAP_AFE | UART_CAP_EFR;
	}

1043 1044 1045 1046 1047 1048 1049 1050
	/*
	 * We distinguish between 16550A and U6 16550A by counting
	 * how many bytes are in the FIFO.
	 */
	if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
		up->port.type = PORT_U6_16550A;
		up->capabilities |= UART_CAP_AFE;
	}
L
Linus Torvalds 已提交
1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068
}

/*
 * This routine is called by rs_init() to initialize a specific serial
 * port.  It determines what type of UART chip this serial port is
 * using: 8250, 16450, 16550, 16550A.  The important question is
 * whether or not this UART is a 16550A or not, since this will
 * determine whether or not we can use its FIFO features or not.
 */
static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
{
	unsigned char status1, scratch, scratch2, scratch3;
	unsigned char save_lcr, save_mcr;
	unsigned long flags;

	if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
		return;

1069
	DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
1070
		       serial_index(&up->port), up->port.iobase, up->port.membase);
L
Linus Torvalds 已提交
1071 1072 1073 1074 1075 1076 1077 1078

	/*
	 * We really do need global IRQs disabled here - we're going to
	 * be frobbing the chips IRQ enable register to see if it exists.
	 */
	spin_lock_irqsave(&up->port.lock, flags);

	up->capabilities = 0;
1079
	up->bugs = 0;
L
Linus Torvalds 已提交
1080 1081 1082 1083 1084

	if (!(up->port.flags & UPF_BUGGY_UART)) {
		/*
		 * Do a simple existence test first; if we fail this,
		 * there's no point trying anything else.
T
Thomas Koeller 已提交
1085
		 *
L
Linus Torvalds 已提交
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
		 * 0x80 is used as a nonsense port to prevent against
		 * false positives due to ISA bus float.  The
		 * assumption is that 0x80 is a non-existent port;
		 * which should be safe since include/asm/io.h also
		 * makes this assumption.
		 *
		 * Note: this is safe as long as MCR bit 4 is clear
		 * and the device is in "PC" mode.
		 */
		scratch = serial_inp(up, UART_IER);
		serial_outp(up, UART_IER, 0);
#ifdef __i386__
		outb(0xff, 0x080);
#endif
1100 1101 1102 1103 1104
		/*
		 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
		 * 16C754B) allow only to modify them if an EFR bit is set.
		 */
		scratch2 = serial_inp(up, UART_IER) & 0x0f;
L
Linus Torvalds 已提交
1105 1106 1107 1108
		serial_outp(up, UART_IER, 0x0F);
#ifdef __i386__
		outb(0, 0x080);
#endif
1109
		scratch3 = serial_inp(up, UART_IER) & 0x0f;
L
Linus Torvalds 已提交
1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
		serial_outp(up, UART_IER, scratch);
		if (scratch2 != 0 || scratch3 != 0x0F) {
			/*
			 * We failed; there's nothing here
			 */
			DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
				       scratch2, scratch3);
			goto out;
		}
	}

	save_mcr = serial_in(up, UART_MCR);
	save_lcr = serial_in(up, UART_LCR);

T
Thomas Koeller 已提交
1124
	/*
L
Linus Torvalds 已提交
1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146
	 * Check to see if a UART is really there.  Certain broken
	 * internal modems based on the Rockwell chipset fail this
	 * test, because they apparently don't implement the loopback
	 * test mode.  So this test is skipped on the COM 1 through
	 * COM 4 ports.  This *should* be safe, since no board
	 * manufacturer would be stupid enough to design a board
	 * that conflicts with COM 1-4 --- we hope!
	 */
	if (!(up->port.flags & UPF_SKIP_TEST)) {
		serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
		status1 = serial_inp(up, UART_MSR) & 0xF0;
		serial_outp(up, UART_MCR, save_mcr);
		if (status1 != 0x90) {
			DEBUG_AUTOCONF("LOOP test failed (%02x) ",
				       status1);
			goto out;
		}
	}

	/*
	 * We're pretty sure there's a port here.  Lets find out what
	 * type of port it is.  The IIR top two bits allows us to find
R
Russell King 已提交
1147
	 * out if it's 8250 or 16450, 16550, 16550A or later.  This
L
Linus Torvalds 已提交
1148 1149 1150 1151 1152
	 * determines what we test for next.
	 *
	 * We also initialise the EFR (if any) to zero for later.  The
	 * EFR occupies the same register location as the FCR and IIR.
	 */
1153
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192
	serial_outp(up, UART_EFR, 0);
	serial_outp(up, UART_LCR, 0);

	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
	scratch = serial_in(up, UART_IIR) >> 6;

	DEBUG_AUTOCONF("iir=%d ", scratch);

	switch (scratch) {
	case 0:
		autoconfig_8250(up);
		break;
	case 1:
		up->port.type = PORT_UNKNOWN;
		break;
	case 2:
		up->port.type = PORT_16550;
		break;
	case 3:
		autoconfig_16550a(up);
		break;
	}

#ifdef CONFIG_SERIAL_8250_RSA
	/*
	 * Only probe for RSA ports if we got the region.
	 */
	if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
		int i;

		for (i = 0 ; i < probe_rsa_count; ++i) {
			if (probe_rsa[i] == up->port.iobase &&
			    __enable_rsa(up)) {
				up->port.type = PORT_RSA;
				break;
			}
		}
	}
#endif
1193

L
Linus Torvalds 已提交
1194 1195 1196 1197 1198
	serial_outp(up, UART_LCR, save_lcr);

	if (up->capabilities != uart_config[up->port.type].flags) {
		printk(KERN_WARNING
		       "ttyS%d: detected caps %08x should be %08x\n",
1199 1200
		       serial_index(&up->port), up->capabilities,
		       uart_config[up->port.type].flags);
L
Linus Torvalds 已提交
1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218
	}

	up->port.fifosize = uart_config[up->port.type].fifo_size;
	up->capabilities = uart_config[up->port.type].flags;
	up->tx_loadsz = uart_config[up->port.type].tx_loadsz;

	if (up->port.type == PORT_UNKNOWN)
		goto out;

	/*
	 * Reset the UART.
	 */
#ifdef CONFIG_SERIAL_8250_RSA
	if (up->port.type == PORT_RSA)
		serial_outp(up, UART_RSA_FRR, 0);
#endif
	serial_outp(up, UART_MCR, save_mcr);
	serial8250_clear_fifos(up);
A
Alex Williamson 已提交
1219
	serial_in(up, UART_RX);
1220 1221 1222 1223
	if (up->capabilities & UART_CAP_UUE)
		serial_outp(up, UART_IER, UART_IER_UUE);
	else
		serial_outp(up, UART_IER, 0);
L
Linus Torvalds 已提交
1224

T
Thomas Koeller 已提交
1225
 out:
L
Linus Torvalds 已提交
1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249
	spin_unlock_irqrestore(&up->port.lock, flags);
	DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
}

static void autoconfig_irq(struct uart_8250_port *up)
{
	unsigned char save_mcr, save_ier;
	unsigned char save_ICP = 0;
	unsigned int ICP = 0;
	unsigned long irqs;
	int irq;

	if (up->port.flags & UPF_FOURPORT) {
		ICP = (up->port.iobase & 0xfe0) | 0x1f;
		save_ICP = inb_p(ICP);
		outb_p(0x80, ICP);
		(void) inb_p(ICP);
	}

	/* forget possible initially masked and pending IRQ */
	probe_irq_off(probe_irq_on());
	save_mcr = serial_inp(up, UART_MCR);
	save_ier = serial_inp(up, UART_IER);
	serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
T
Thomas Koeller 已提交
1250

L
Linus Torvalds 已提交
1251 1252
	irqs = probe_irq_on();
	serial_outp(up, UART_MCR, 0);
A
Alan Cox 已提交
1253 1254
	udelay(10);
	if (up->port.flags & UPF_FOURPORT) {
L
Linus Torvalds 已提交
1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266
		serial_outp(up, UART_MCR,
			    UART_MCR_DTR | UART_MCR_RTS);
	} else {
		serial_outp(up, UART_MCR,
			    UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
	}
	serial_outp(up, UART_IER, 0x0f);	/* enable all intrs */
	(void)serial_inp(up, UART_LSR);
	(void)serial_inp(up, UART_RX);
	(void)serial_inp(up, UART_IIR);
	(void)serial_inp(up, UART_MSR);
	serial_outp(up, UART_TX, 0xFF);
A
Alan Cox 已提交
1267
	udelay(20);
L
Linus Torvalds 已提交
1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278
	irq = probe_irq_off(irqs);

	serial_outp(up, UART_MCR, save_mcr);
	serial_outp(up, UART_IER, save_ier);

	if (up->port.flags & UPF_FOURPORT)
		outb_p(save_ICP, ICP);

	up->port.irq = (irq > 0) ? irq : 0;
}

1279 1280 1281 1282 1283 1284 1285 1286
static inline void __stop_tx(struct uart_8250_port *p)
{
	if (p->ier & UART_IER_THRI) {
		p->ier &= ~UART_IER_THRI;
		serial_out(p, UART_IER, p->ier);
	}
}

1287
static void serial8250_stop_tx(struct uart_port *port)
L
Linus Torvalds 已提交
1288
{
1289 1290
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1291

1292
	__stop_tx(up);
L
Linus Torvalds 已提交
1293 1294

	/*
1295
	 * We really want to stop the transmitter from sending.
L
Linus Torvalds 已提交
1296
	 */
1297
	if (up->port.type == PORT_16C950) {
L
Linus Torvalds 已提交
1298 1299 1300 1301 1302
		up->acr |= UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

1303
static void serial8250_start_tx(struct uart_port *port)
L
Linus Torvalds 已提交
1304
{
1305 1306
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1307 1308 1309 1310

	if (!(up->ier & UART_IER_THRI)) {
		up->ier |= UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
1311

1312
		if (up->bugs & UART_BUG_TXEN) {
1313
			unsigned char lsr;
1314
			lsr = serial_in(up, UART_LSR);
1315
			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
T
Thomas Koeller 已提交
1316
			if ((up->port.type == PORT_RM9000) ?
1317 1318
				(lsr & UART_LSR_THRE) :
				(lsr & UART_LSR_TEMT))
1319
				serial8250_tx_chars(up);
1320
		}
L
Linus Torvalds 已提交
1321
	}
1322

L
Linus Torvalds 已提交
1323
	/*
1324
	 * Re-enable the transmitter if we disabled it.
L
Linus Torvalds 已提交
1325
	 */
1326
	if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
L
Linus Torvalds 已提交
1327 1328 1329 1330 1331 1332 1333
		up->acr &= ~UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

static void serial8250_stop_rx(struct uart_port *port)
{
1334 1335
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1336 1337 1338 1339 1340 1341 1342 1343

	up->ier &= ~UART_IER_RLSI;
	up->port.read_status_mask &= ~UART_LSR_DR;
	serial_out(up, UART_IER, up->ier);
}

static void serial8250_enable_ms(struct uart_port *port)
{
1344 1345
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1346

1347 1348 1349 1350
	/* no MSR capabilities */
	if (up->bugs & UART_BUG_NOMSR)
		return;

L
Linus Torvalds 已提交
1351 1352 1353 1354
	up->ier |= UART_IER_MSI;
	serial_out(up, UART_IER, up->ier);
}

1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375
/*
 * Clear the Tegra rx fifo after a break
 *
 * FIXME: This needs to become a port specific callback once we have a
 * framework for this
 */
static void clear_rx_fifo(struct uart_8250_port *up)
{
	unsigned int status, tmout = 10000;
	do {
		status = serial_in(up, UART_LSR);
		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
			status = serial_in(up, UART_RX);
		else
			break;
		if (--tmout == 0)
			break;
		udelay(1);
	} while (1);
}

1376
/*
1377
 * serial8250_rx_chars: processes according to the passed in LSR
1378 1379 1380
 * value, and returns the remaining LSR bits not handled
 * by this Rx routine.
 */
1381 1382
unsigned char
serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
L
Linus Torvalds 已提交
1383
{
A
Alan Cox 已提交
1384
	struct tty_struct *tty = up->port.state->port.tty;
1385
	unsigned char ch;
L
Linus Torvalds 已提交
1386 1387 1388 1389
	int max_count = 256;
	char flag;

	do {
1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401
		if (likely(lsr & UART_LSR_DR))
			ch = serial_inp(up, UART_RX);
		else
			/*
			 * Intel 82571 has a Serial Over Lan device that will
			 * set UART_LSR_BI without setting UART_LSR_DR when
			 * it receives a break. To avoid reading from the
			 * receive buffer without UART_LSR_DR bit set, we
			 * just force the read character to be 0
			 */
			ch = 0;

L
Linus Torvalds 已提交
1402 1403 1404
		flag = TTY_NORMAL;
		up->port.icount.rx++;

1405 1406
		lsr |= up->lsr_saved_flags;
		up->lsr_saved_flags = 0;
L
Linus Torvalds 已提交
1407

1408
		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
L
Linus Torvalds 已提交
1409 1410 1411 1412 1413 1414
			/*
			 * For statistics only
			 */
			if (lsr & UART_LSR_BI) {
				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
				up->port.icount.brk++;
1415 1416 1417 1418 1419 1420 1421
				/*
				 * If tegra port then clear the rx fifo to
				 * accept another break/character.
				 */
				if (up->port.type == PORT_TEGRA)
					clear_rx_fifo(up);

L
Linus Torvalds 已提交
1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437
				/*
				 * We do the SysRQ and SAK checking
				 * here because otherwise the break
				 * may get masked by ignore_status_mask
				 * or read_status_mask.
				 */
				if (uart_handle_break(&up->port))
					goto ignore_char;
			} else if (lsr & UART_LSR_PE)
				up->port.icount.parity++;
			else if (lsr & UART_LSR_FE)
				up->port.icount.frame++;
			if (lsr & UART_LSR_OE)
				up->port.icount.overrun++;

			/*
1438
			 * Mask off conditions which should be ignored.
L
Linus Torvalds 已提交
1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449
			 */
			lsr &= up->port.read_status_mask;

			if (lsr & UART_LSR_BI) {
				DEBUG_INTR("handling break....");
				flag = TTY_BREAK;
			} else if (lsr & UART_LSR_PE)
				flag = TTY_PARITY;
			else if (lsr & UART_LSR_FE)
				flag = TTY_FRAME;
		}
1450
		if (uart_handle_sysrq_char(&up->port, ch))
L
Linus Torvalds 已提交
1451
			goto ignore_char;
1452 1453 1454

		uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);

A
Alan Cox 已提交
1455
ignore_char:
L
Linus Torvalds 已提交
1456
		lsr = serial_inp(up, UART_LSR);
1457
	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
L
Linus Torvalds 已提交
1458 1459 1460
	spin_unlock(&up->port.lock);
	tty_flip_buffer_push(tty);
	spin_lock(&up->port.lock);
1461
	return lsr;
L
Linus Torvalds 已提交
1462
}
1463
EXPORT_SYMBOL_GPL(serial8250_rx_chars);
L
Linus Torvalds 已提交
1464

1465
void serial8250_tx_chars(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1466
{
A
Alan Cox 已提交
1467
	struct circ_buf *xmit = &up->port.state->xmit;
L
Linus Torvalds 已提交
1468 1469 1470 1471 1472 1473 1474 1475
	int count;

	if (up->port.x_char) {
		serial_outp(up, UART_TX, up->port.x_char);
		up->port.icount.tx++;
		up->port.x_char = 0;
		return;
	}
1476 1477 1478 1479 1480
	if (uart_tx_stopped(&up->port)) {
		serial8250_stop_tx(&up->port);
		return;
	}
	if (uart_circ_empty(xmit)) {
1481
		__stop_tx(up);
L
Linus Torvalds 已提交
1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499
		return;
	}

	count = up->tx_loadsz;
	do {
		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		up->port.icount.tx++;
		if (uart_circ_empty(xmit))
			break;
	} while (--count > 0);

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(&up->port);

	DEBUG_INTR("THRE...");

	if (uart_circ_empty(xmit))
1500
		__stop_tx(up);
L
Linus Torvalds 已提交
1501
}
1502
EXPORT_SYMBOL_GPL(serial8250_tx_chars);
L
Linus Torvalds 已提交
1503

1504
unsigned int serial8250_modem_status(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1505
{
1506 1507
	unsigned int status = serial_in(up, UART_MSR);

1508 1509
	status |= up->msr_saved_flags;
	up->msr_saved_flags = 0;
1510
	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
A
Alan Cox 已提交
1511
	    up->port.state != NULL) {
1512 1513 1514 1515 1516 1517 1518 1519 1520
		if (status & UART_MSR_TERI)
			up->port.icount.rng++;
		if (status & UART_MSR_DDSR)
			up->port.icount.dsr++;
		if (status & UART_MSR_DDCD)
			uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
		if (status & UART_MSR_DCTS)
			uart_handle_cts_change(&up->port, status & UART_MSR_CTS);

1521
		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
1522
	}
L
Linus Torvalds 已提交
1523

1524
	return status;
L
Linus Torvalds 已提交
1525
}
1526
EXPORT_SYMBOL_GPL(serial8250_modem_status);
L
Linus Torvalds 已提交
1527 1528 1529 1530

/*
 * This handles the interrupt from one port.
 */
1531
int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
L
Linus Torvalds 已提交
1532
{
1533
	unsigned char status;
1534
	unsigned long flags;
1535 1536 1537 1538 1539
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);

	if (iir & UART_IIR_NO_INT)
		return 0;
1540

1541
	spin_lock_irqsave(&up->port.lock, flags);
1542 1543

	status = serial_inp(up, UART_LSR);
L
Linus Torvalds 已提交
1544 1545 1546

	DEBUG_INTR("status = %x...", status);

1547
	if (status & (UART_LSR_DR | UART_LSR_BI))
1548 1549
		status = serial8250_rx_chars(up, status);
	serial8250_modem_status(up);
L
Linus Torvalds 已提交
1550
	if (status & UART_LSR_THRE)
1551
		serial8250_tx_chars(up);
1552

1553
	spin_unlock_irqrestore(&up->port.lock, flags);
1554
	return 1;
1555
}
1556
EXPORT_SYMBOL_GPL(serial8250_handle_irq);
1557 1558 1559 1560 1561 1562 1563 1564 1565 1566

static int serial8250_default_handle_irq(struct uart_port *port)
{
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
	unsigned int iir = serial_in(up, UART_IIR);

	return serial8250_handle_irq(port, iir);
}

L
Linus Torvalds 已提交
1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580
/*
 * This is the serial driver's interrupt routine.
 *
 * Arjan thinks the old way was overly complex, so it got simplified.
 * Alan disagrees, saying that need the complexity to handle the weird
 * nature of ISA shared interrupts.  (This is a special exception.)
 *
 * In order to handle ISA shared interrupts properly, we need to check
 * that all ports have been serviced, and therefore the ISA interrupt
 * line has been de-asserted.
 *
 * This means we need to loop through all ports. checking that they
 * don't have an interrupt pending.
 */
1581
static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
L
Linus Torvalds 已提交
1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593
{
	struct irq_info *i = dev_id;
	struct list_head *l, *end = NULL;
	int pass_counter = 0, handled = 0;

	DEBUG_INTR("serial8250_interrupt(%d)...", irq);

	spin_lock(&i->lock);

	l = i->head;
	do {
		struct uart_8250_port *up;
1594
		struct uart_port *port;
1595
		bool skip;
L
Linus Torvalds 已提交
1596 1597

		up = list_entry(l, struct uart_8250_port, list);
1598
		port = &up->port;
1599
		skip = pass_counter && up->port.flags & UPF_IIR_ONCE;
L
Linus Torvalds 已提交
1600

1601
		if (!skip && port->handle_irq(port)) {
L
Linus Torvalds 已提交
1602 1603 1604 1605 1606 1607 1608 1609 1610
			handled = 1;
			end = NULL;
		} else if (end == NULL)
			end = l;

		l = l->next;

		if (l == i->head && pass_counter++ > PASS_LIMIT) {
			/* If we hit this, we're dead. */
1611 1612
			printk_ratelimited(KERN_ERR
				"serial8250: too much work for irq%d\n", irq);
L
Linus Torvalds 已提交
1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643
			break;
		}
	} while (l != end);

	spin_unlock(&i->lock);

	DEBUG_INTR("end.\n");

	return IRQ_RETVAL(handled);
}

/*
 * To support ISA shared interrupts, we need to have one interrupt
 * handler that ensures that the IRQ line has been deasserted
 * before returning.  Failing to do this will result in the IRQ
 * line being stuck active, and, since ISA irqs are edge triggered,
 * no more IRQs will be seen.
 */
static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
{
	spin_lock_irq(&i->lock);

	if (!list_empty(i->head)) {
		if (i->head == &up->list)
			i->head = i->head->next;
		list_del(&up->list);
	} else {
		BUG_ON(i->head != &up->list);
		i->head = NULL;
	}
	spin_unlock_irq(&i->lock);
A
Alan Cox 已提交
1644 1645 1646 1647 1648
	/* List empty so throw away the hash node */
	if (i->head == NULL) {
		hlist_del(&i->node);
		kfree(i);
	}
L
Linus Torvalds 已提交
1649 1650 1651 1652
}

static int serial_link_irq_chain(struct uart_8250_port *up)
{
A
Alan Cox 已提交
1653 1654 1655
	struct hlist_head *h;
	struct hlist_node *n;
	struct irq_info *i;
1656
	int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
L
Linus Torvalds 已提交
1657

A
Alan Cox 已提交
1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
	mutex_lock(&hash_mutex);

	h = &irq_lists[up->port.irq % NR_IRQ_HASH];

	hlist_for_each(n, h) {
		i = hlist_entry(n, struct irq_info, node);
		if (i->irq == up->port.irq)
			break;
	}

	if (n == NULL) {
		i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
		if (i == NULL) {
			mutex_unlock(&hash_mutex);
			return -ENOMEM;
		}
		spin_lock_init(&i->lock);
		i->irq = up->port.irq;
		hlist_add_head(&i->node, h);
	}
	mutex_unlock(&hash_mutex);

L
Linus Torvalds 已提交
1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690
	spin_lock_irq(&i->lock);

	if (i->head) {
		list_add(&up->list, i->head);
		spin_unlock_irq(&i->lock);

		ret = 0;
	} else {
		INIT_LIST_HEAD(&up->list);
		i->head = &up->list;
		spin_unlock_irq(&i->lock);
1691
		irq_flags |= up->port.irqflags;
L
Linus Torvalds 已提交
1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702
		ret = request_irq(up->port.irq, serial8250_interrupt,
				  irq_flags, "serial", i);
		if (ret < 0)
			serial_do_unlink(i, up);
	}

	return ret;
}

static void serial_unlink_irq_chain(struct uart_8250_port *up)
{
A
Alan Cox 已提交
1703 1704 1705
	struct irq_info *i;
	struct hlist_node *n;
	struct hlist_head *h;
L
Linus Torvalds 已提交
1706

A
Alan Cox 已提交
1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717
	mutex_lock(&hash_mutex);

	h = &irq_lists[up->port.irq % NR_IRQ_HASH];

	hlist_for_each(n, h) {
		i = hlist_entry(n, struct irq_info, node);
		if (i->irq == up->port.irq)
			break;
	}

	BUG_ON(n == NULL);
L
Linus Torvalds 已提交
1718 1719 1720 1721 1722 1723
	BUG_ON(i->head == NULL);

	if (list_empty(i->head))
		free_irq(up->port.irq, i);

	serial_do_unlink(i, up);
A
Alan Cox 已提交
1724
	mutex_unlock(&hash_mutex);
L
Linus Torvalds 已提交
1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736
}

/*
 * This function is used to handle ports that do not have an
 * interrupt.  This doesn't work very well for 16450's, but gives
 * barely passable results for a 16550A.  (Although at the expense
 * of much CPU overhead).
 */
static void serial8250_timeout(unsigned long data)
{
	struct uart_8250_port *up = (struct uart_8250_port *)data;

1737
	up->port.handle_irq(&up->port);
1738
	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
A
Alex Williamson 已提交
1739 1740 1741 1742 1743
}

static void serial8250_backup_timeout(unsigned long data)
{
	struct uart_8250_port *up = (struct uart_8250_port *)data;
1744 1745
	unsigned int iir, ier = 0, lsr;
	unsigned long flags;
A
Alex Williamson 已提交
1746

1747 1748
	spin_lock_irqsave(&up->port.lock, flags);

A
Alex Williamson 已提交
1749 1750 1751 1752 1753 1754 1755 1756
	/*
	 * Must disable interrupts or else we risk racing with the interrupt
	 * based handler.
	 */
	if (is_real_interrupt(up->port.irq)) {
		ier = serial_in(up, UART_IER);
		serial_out(up, UART_IER, 0);
	}
L
Linus Torvalds 已提交
1757

A
Alex Williamson 已提交
1758 1759 1760 1761 1762 1763 1764 1765
	iir = serial_in(up, UART_IIR);

	/*
	 * This should be a safe test for anyone who doesn't trust the
	 * IIR bits on their UART, but it's specifically designed for
	 * the "Diva" UART used on the management processor on many HP
	 * ia64 and parisc boxes.
	 */
1766 1767
	lsr = serial_in(up, UART_LSR);
	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
A
Alex Williamson 已提交
1768
	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
A
Alan Cox 已提交
1769
	    (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
1770
	    (lsr & UART_LSR_THRE)) {
A
Alex Williamson 已提交
1771 1772 1773 1774 1775
		iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
		iir |= UART_IIR_THRI;
	}

	if (!(iir & UART_IIR_NO_INT))
1776
		serial8250_tx_chars(up);
A
Alex Williamson 已提交
1777 1778 1779 1780

	if (is_real_interrupt(up->port.irq))
		serial_out(up, UART_IER, ier);

1781 1782
	spin_unlock_irqrestore(&up->port.lock, flags);

A
Alex Williamson 已提交
1783
	/* Standard timer interval plus 0.2s to keep the port running */
A
Alan Cox 已提交
1784
	mod_timer(&up->timer,
1785
		jiffies + uart_poll_timeout(&up->port) + HZ / 5);
L
Linus Torvalds 已提交
1786 1787 1788 1789
}

static unsigned int serial8250_tx_empty(struct uart_port *port)
{
1790 1791
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1792
	unsigned long flags;
1793
	unsigned int lsr;
L
Linus Torvalds 已提交
1794 1795

	spin_lock_irqsave(&up->port.lock, flags);
1796 1797
	lsr = serial_in(up, UART_LSR);
	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
L
Linus Torvalds 已提交
1798 1799
	spin_unlock_irqrestore(&up->port.lock, flags);

1800
	return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
L
Linus Torvalds 已提交
1801 1802 1803 1804
}

static unsigned int serial8250_get_mctrl(struct uart_port *port)
{
1805 1806
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
1807
	unsigned int status;
L
Linus Torvalds 已提交
1808 1809
	unsigned int ret;

1810
	status = serial8250_modem_status(up);
L
Linus Torvalds 已提交
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825

	ret = 0;
	if (status & UART_MSR_DCD)
		ret |= TIOCM_CAR;
	if (status & UART_MSR_RI)
		ret |= TIOCM_RNG;
	if (status & UART_MSR_DSR)
		ret |= TIOCM_DSR;
	if (status & UART_MSR_CTS)
		ret |= TIOCM_CTS;
	return ret;
}

static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
1826 1827
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847
	unsigned char mcr = 0;

	if (mctrl & TIOCM_RTS)
		mcr |= UART_MCR_RTS;
	if (mctrl & TIOCM_DTR)
		mcr |= UART_MCR_DTR;
	if (mctrl & TIOCM_OUT1)
		mcr |= UART_MCR_OUT1;
	if (mctrl & TIOCM_OUT2)
		mcr |= UART_MCR_OUT2;
	if (mctrl & TIOCM_LOOP)
		mcr |= UART_MCR_LOOP;

	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;

	serial_out(up, UART_MCR, mcr);
}

static void serial8250_break_ctl(struct uart_port *port, int break_state)
{
1848 1849
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860
	unsigned long flags;

	spin_lock_irqsave(&up->port.lock, flags);
	if (break_state == -1)
		up->lcr |= UART_LCR_SBC;
	else
		up->lcr &= ~UART_LCR_SBC;
	serial_out(up, UART_LCR, up->lcr);
	spin_unlock_irqrestore(&up->port.lock, flags);
}

A
Alex Williamson 已提交
1861 1862 1863
/*
 *	Wait for transmitter & holding register to empty
 */
1864
static void wait_for_xmitr(struct uart_8250_port *up, int bits)
A
Alex Williamson 已提交
1865 1866 1867 1868
{
	unsigned int status, tmout = 10000;

	/* Wait up to 10ms for the character(s) to be sent. */
1869
	for (;;) {
A
Alex Williamson 已提交
1870 1871
		status = serial_in(up, UART_LSR);

1872
		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
A
Alex Williamson 已提交
1873

1874 1875
		if ((status & bits) == bits)
			break;
A
Alex Williamson 已提交
1876 1877 1878
		if (--tmout == 0)
			break;
		udelay(1);
1879
	}
A
Alex Williamson 已提交
1880 1881 1882

	/* Wait up to 1s for flow control if necessary */
	if (up->port.flags & UPF_CONS_FLOW) {
1883 1884 1885 1886 1887 1888
		unsigned int tmout;
		for (tmout = 1000000; tmout; tmout--) {
			unsigned int msr = serial_in(up, UART_MSR);
			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
			if (msr & UART_MSR_CTS)
				break;
A
Alex Williamson 已提交
1889 1890 1891 1892 1893 1894
			udelay(1);
			touch_nmi_watchdog();
		}
	}
}

J
Jason Wessel 已提交
1895 1896 1897 1898 1899 1900 1901 1902
#ifdef CONFIG_CONSOLE_POLL
/*
 * Console polling routines for writing and reading from the uart while
 * in an interrupt or debug context.
 */

static int serial8250_get_poll_char(struct uart_port *port)
{
1903 1904
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
J
Jason Wessel 已提交
1905 1906
	unsigned char lsr = serial_inp(up, UART_LSR);

1907 1908
	if (!(lsr & UART_LSR_DR))
		return NO_POLL_CHAR;
J
Jason Wessel 已提交
1909 1910 1911 1912 1913 1914 1915 1916 1917

	return serial_inp(up, UART_RX);
}


static void serial8250_put_poll_char(struct uart_port *port,
			 unsigned char c)
{
	unsigned int ier;
1918 1919
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
J
Jason Wessel 已提交
1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950

	/*
	 *	First save the IER then disable the interrupts
	 */
	ier = serial_in(up, UART_IER);
	if (up->capabilities & UART_CAP_UUE)
		serial_out(up, UART_IER, UART_IER_UUE);
	else
		serial_out(up, UART_IER, 0);

	wait_for_xmitr(up, BOTH_EMPTY);
	/*
	 *	Send the character out.
	 *	If a LF, also do CR...
	 */
	serial_out(up, UART_TX, c);
	if (c == 10) {
		wait_for_xmitr(up, BOTH_EMPTY);
		serial_out(up, UART_TX, 13);
	}

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the IER
	 */
	wait_for_xmitr(up, BOTH_EMPTY);
	serial_out(up, UART_IER, ier);
}

#endif /* CONFIG_CONSOLE_POLL */

L
Linus Torvalds 已提交
1951 1952
static int serial8250_startup(struct uart_port *port)
{
1953 1954
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1955
	unsigned long flags;
1956
	unsigned char lsr, iir;
L
Linus Torvalds 已提交
1957 1958
	int retval;

O
Ondrej Puzman 已提交
1959 1960
	up->port.fifosize = uart_config[up->port.type].fifo_size;
	up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
L
Linus Torvalds 已提交
1961 1962 1963
	up->capabilities = uart_config[up->port.type].flags;
	up->mcr = 0;

A
Alan Cox 已提交
1964 1965 1966
	if (up->port.iotype != up->cur_iotype)
		set_io_from_upio(port);

L
Linus Torvalds 已提交
1967 1968 1969
	if (up->port.type == PORT_16C950) {
		/* Wake up and initialize UART */
		up->acr = 0;
1970
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
1971 1972 1973 1974
		serial_outp(up, UART_EFR, UART_EFR_ECB);
		serial_outp(up, UART_IER, 0);
		serial_outp(up, UART_LCR, 0);
		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
1975
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
		serial_outp(up, UART_EFR, UART_EFR_ECB);
		serial_outp(up, UART_LCR, 0);
	}

#ifdef CONFIG_SERIAL_8250_RSA
	/*
	 * If this is an RSA port, see if we can kick it up to the
	 * higher speed clock.
	 */
	enable_rsa(up);
#endif

	/*
	 * Clear the FIFO buffers and disable them.
A
Alexey Dobriyan 已提交
1990
	 * (they will be reenabled in set_termios())
L
Linus Torvalds 已提交
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
	 */
	serial8250_clear_fifos(up);

	/*
	 * Clear the interrupt registers.
	 */
	(void) serial_inp(up, UART_LSR);
	(void) serial_inp(up, UART_RX);
	(void) serial_inp(up, UART_IIR);
	(void) serial_inp(up, UART_MSR);

	/*
	 * At this point, there's no way the LSR could still be 0xff;
	 * if it is, then bail out, because there's likely no UART
	 * here.
	 */
	if (!(up->port.flags & UPF_BUGGY_UART) &&
	    (serial_inp(up, UART_LSR) == 0xff)) {
2009 2010
		printk_ratelimited(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
				   serial_index(&up->port));
L
Linus Torvalds 已提交
2011 2012 2013 2014 2015 2016 2017 2018 2019
		return -ENODEV;
	}

	/*
	 * For a XR16C850, we need to set the trigger levels
	 */
	if (up->port.type == PORT_16850) {
		unsigned char fctr;

2020
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
2021 2022 2023 2024 2025 2026 2027 2028 2029 2030

		fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
		serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
		serial_outp(up, UART_TRG, UART_TRG_96);
		serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
		serial_outp(up, UART_TRG, UART_TRG_96);

		serial_outp(up, UART_LCR, 0);
	}

A
Alex Williamson 已提交
2031
	if (is_real_interrupt(up->port.irq)) {
2032
		unsigned char iir1;
A
Alex Williamson 已提交
2033 2034 2035 2036 2037 2038 2039 2040
		/*
		 * Test for UARTs that do not reassert THRE when the
		 * transmitter is idle and the interrupt has already
		 * been cleared.  Real 16550s should always reassert
		 * this interrupt whenever the transmitter is idle and
		 * the interrupt is enabled.  Delays are necessary to
		 * allow register changes to become visible.
		 */
B
Borislav Petkov 已提交
2041
		spin_lock_irqsave(&up->port.lock, flags);
2042
		if (up->port.irqflags & IRQF_SHARED)
2043
			disable_irq_nosync(up->port.irq);
A
Alex Williamson 已提交
2044 2045 2046 2047

		wait_for_xmitr(up, UART_LSR_THRE);
		serial_out_sync(up, UART_IER, UART_IER_THRI);
		udelay(1); /* allow THRE to set */
2048
		iir1 = serial_in(up, UART_IIR);
A
Alex Williamson 已提交
2049 2050 2051 2052 2053 2054
		serial_out(up, UART_IER, 0);
		serial_out_sync(up, UART_IER, UART_IER_THRI);
		udelay(1); /* allow a working UART time to re-assert THRE */
		iir = serial_in(up, UART_IIR);
		serial_out(up, UART_IER, 0);

2055
		if (up->port.irqflags & IRQF_SHARED)
2056
			enable_irq(up->port.irq);
B
Borislav Petkov 已提交
2057
		spin_unlock_irqrestore(&up->port.lock, flags);
A
Alex Williamson 已提交
2058 2059 2060 2061 2062

		/*
		 * If the interrupt is not reasserted, setup a timer to
		 * kick the UART on a regular basis.
		 */
2063
		if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
2064
			up->bugs |= UART_BUG_THRE;
2065 2066
			pr_debug("ttyS%d - using backup timer\n",
				 serial_index(port));
A
Alex Williamson 已提交
2067 2068 2069
		}
	}

2070 2071 2072 2073 2074 2075 2076 2077
	/*
	 * The above check will only give an accurate result the first time
	 * the port is opened so this value needs to be preserved.
	 */
	if (up->bugs & UART_BUG_THRE) {
		up->timer.function = serial8250_backup_timeout;
		up->timer.data = (unsigned long)up;
		mod_timer(&up->timer, jiffies +
2078
			uart_poll_timeout(port) + HZ / 5);
2079 2080
	}

L
Linus Torvalds 已提交
2081 2082 2083 2084 2085 2086 2087
	/*
	 * If the "interrupt" for this port doesn't correspond with any
	 * hardware interrupt, we use a timer-based system.  The original
	 * driver used to do this with IRQ0.
	 */
	if (!is_real_interrupt(up->port.irq)) {
		up->timer.data = (unsigned long)up;
2088
		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
L
Linus Torvalds 已提交
2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111
	} else {
		retval = serial_link_irq_chain(up);
		if (retval)
			return retval;
	}

	/*
	 * Now, initialize the UART
	 */
	serial_outp(up, UART_LCR, UART_LCR_WLEN8);

	spin_lock_irqsave(&up->port.lock, flags);
	if (up->port.flags & UPF_FOURPORT) {
		if (!is_real_interrupt(up->port.irq))
			up->port.mctrl |= TIOCM_OUT1;
	} else
		/*
		 * Most PC uarts need OUT2 raised to enable interrupts.
		 */
		if (is_real_interrupt(up->port.irq))
			up->port.mctrl |= TIOCM_OUT2;

	serial8250_set_mctrl(&up->port, up->port.mctrl);
2112

2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123
	/* Serial over Lan (SoL) hack:
	   Intel 8257x Gigabit ethernet chips have a
	   16550 emulation, to be used for Serial Over Lan.
	   Those chips take a longer time than a normal
	   serial device to signalize that a transmission
	   data was queued. Due to that, the above test generally
	   fails. One solution would be to delay the reading of
	   iir. However, this is not reliable, since the timeout
	   is variable. So, let's just don't test if we receive
	   TX irq. This way, we'll never enable UART_BUG_TXEN.
	 */
2124
	if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST)
2125 2126
		goto dont_test_tx_en;

2127 2128 2129 2130 2131 2132 2133 2134 2135 2136
	/*
	 * Do a quick test to see if we receive an
	 * interrupt when we enable the TX irq.
	 */
	serial_outp(up, UART_IER, UART_IER_THRI);
	lsr = serial_in(up, UART_LSR);
	iir = serial_in(up, UART_IIR);
	serial_outp(up, UART_IER, 0);

	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
2137 2138
		if (!(up->bugs & UART_BUG_TXEN)) {
			up->bugs |= UART_BUG_TXEN;
2139
			pr_debug("ttyS%d - enabling bad tx status workarounds\n",
2140
				 serial_index(port));
2141 2142
		}
	} else {
2143
		up->bugs &= ~UART_BUG_TXEN;
2144 2145
	}

2146
dont_test_tx_en:
L
Linus Torvalds 已提交
2147 2148
	spin_unlock_irqrestore(&up->port.lock, flags);

2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160
	/*
	 * Clear the interrupt registers again for luck, and clear the
	 * saved flags to avoid getting false values from polling
	 * routines or the previous session.
	 */
	serial_inp(up, UART_LSR);
	serial_inp(up, UART_RX);
	serial_inp(up, UART_IIR);
	serial_inp(up, UART_MSR);
	up->lsr_saved_flags = 0;
	up->msr_saved_flags = 0;

L
Linus Torvalds 已提交
2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183
	/*
	 * Finally, enable interrupts.  Note: Modem status interrupts
	 * are set via set_termios(), which will be occurring imminently
	 * anyway, so we don't enable them here.
	 */
	up->ier = UART_IER_RLSI | UART_IER_RDI;
	serial_outp(up, UART_IER, up->ier);

	if (up->port.flags & UPF_FOURPORT) {
		unsigned int icp;
		/*
		 * Enable interrupts on the AST Fourport board
		 */
		icp = (up->port.iobase & 0xfe0) | 0x01f;
		outb_p(0x80, icp);
		(void) inb_p(icp);
	}

	return 0;
}

static void serial8250_shutdown(struct uart_port *port)
{
2184 2185
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223
	unsigned long flags;

	/*
	 * Disable interrupts from this port
	 */
	up->ier = 0;
	serial_outp(up, UART_IER, 0);

	spin_lock_irqsave(&up->port.lock, flags);
	if (up->port.flags & UPF_FOURPORT) {
		/* reset interrupts on the AST Fourport board */
		inb((up->port.iobase & 0xfe0) | 0x1f);
		up->port.mctrl |= TIOCM_OUT1;
	} else
		up->port.mctrl &= ~TIOCM_OUT2;

	serial8250_set_mctrl(&up->port, up->port.mctrl);
	spin_unlock_irqrestore(&up->port.lock, flags);

	/*
	 * Disable break condition and FIFOs
	 */
	serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
	serial8250_clear_fifos(up);

#ifdef CONFIG_SERIAL_8250_RSA
	/*
	 * Reset the RSA board back to 115kbps compat mode.
	 */
	disable_rsa(up);
#endif

	/*
	 * Read data port to reset things, and then unlink from
	 * the IRQ chain.
	 */
	(void) serial_in(up, UART_RX);

A
Alex Williamson 已提交
2224 2225 2226
	del_timer_sync(&up->timer);
	up->timer.function = serial8250_timeout;
	if (is_real_interrupt(up->port.irq))
L
Linus Torvalds 已提交
2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249
		serial_unlink_irq_chain(up);
}

static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
{
	unsigned int quot;

	/*
	 * Handle magic divisors for baud rates above baud_base on
	 * SMSC SuperIO chips.
	 */
	if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
	    baud == (port->uartclk/4))
		quot = 0x8001;
	else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
		 baud == (port->uartclk/8))
		quot = 0x8002;
	else
		quot = uart_get_divisor(port, baud);

	return quot;
}

2250 2251 2252
void
serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
		          struct ktermios *old)
L
Linus Torvalds 已提交
2253
{
2254 2255
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2256 2257 2258 2259 2260 2261
	unsigned char cval, fcr = 0;
	unsigned long flags;
	unsigned int baud, quot;

	switch (termios->c_cflag & CSIZE) {
	case CS5:
2262
		cval = UART_LCR_WLEN5;
L
Linus Torvalds 已提交
2263 2264
		break;
	case CS6:
2265
		cval = UART_LCR_WLEN6;
L
Linus Torvalds 已提交
2266 2267
		break;
	case CS7:
2268
		cval = UART_LCR_WLEN7;
L
Linus Torvalds 已提交
2269 2270 2271
		break;
	default:
	case CS8:
2272
		cval = UART_LCR_WLEN8;
L
Linus Torvalds 已提交
2273 2274 2275 2276
		break;
	}

	if (termios->c_cflag & CSTOPB)
2277
		cval |= UART_LCR_STOP;
L
Linus Torvalds 已提交
2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289
	if (termios->c_cflag & PARENB)
		cval |= UART_LCR_PARITY;
	if (!(termios->c_cflag & PARODD))
		cval |= UART_LCR_EPAR;
#ifdef CMSPAR
	if (termios->c_cflag & CMSPAR)
		cval |= UART_LCR_SPAR;
#endif

	/*
	 * Ask the core to calculate the divisor for us.
	 */
2290 2291 2292
	baud = uart_get_baud_rate(port, termios, old,
				  port->uartclk / 16 / 0xffff,
				  port->uartclk / 16);
L
Linus Torvalds 已提交
2293 2294 2295
	quot = serial8250_get_divisor(port, baud);

	/*
2296
	 * Oxford Semi 952 rev B workaround
L
Linus Torvalds 已提交
2297
	 */
2298
	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
A
Alan Cox 已提交
2299
		quot++;
L
Linus Torvalds 已提交
2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363

	if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
		if (baud < 2400)
			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
		else
			fcr = uart_config[up->port.type].fcr;
	}

	/*
	 * MCR-based auto flow control.  When AFE is enabled, RTS will be
	 * deasserted when the receive FIFO contains more characters than
	 * the trigger, or the MCR RTS bit is cleared.  In the case where
	 * the remote UART is not using CTS auto flow control, we must
	 * have sufficient FIFO entries for the latency of the remote
	 * UART to respond.  IOW, at least 32 bytes of FIFO.
	 */
	if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
		up->mcr &= ~UART_MCR_AFE;
		if (termios->c_cflag & CRTSCTS)
			up->mcr |= UART_MCR_AFE;
	}

	/*
	 * Ok, we're now changing the port state.  Do it with
	 * interrupts disabled.
	 */
	spin_lock_irqsave(&up->port.lock, flags);

	/*
	 * Update the per-port timeout.
	 */
	uart_update_timeout(port, termios->c_cflag, baud);

	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
	if (termios->c_iflag & INPCK)
		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
	if (termios->c_iflag & (BRKINT | PARMRK))
		up->port.read_status_mask |= UART_LSR_BI;

	/*
	 * Characteres to ignore
	 */
	up->port.ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
	if (termios->c_iflag & IGNBRK) {
		up->port.ignore_status_mask |= UART_LSR_BI;
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns too (for real raw support).
		 */
		if (termios->c_iflag & IGNPAR)
			up->port.ignore_status_mask |= UART_LSR_OE;
	}

	/*
	 * ignore all characters if CREAD is not set
	 */
	if ((termios->c_cflag & CREAD) == 0)
		up->port.ignore_status_mask |= UART_LSR_DR;

	/*
	 * CTS flow control flag and modem status interrupts
	 */
2364
	up->ier &= ~UART_IER_MSI;
2365 2366
	if (!(up->bugs & UART_BUG_NOMSR) &&
			UART_ENABLE_MS(&up->port, termios->c_cflag))
L
Linus Torvalds 已提交
2367 2368
		up->ier |= UART_IER_MSI;
	if (up->capabilities & UART_CAP_UUE)
2369 2370 2371
		up->ier |= UART_IER_UUE;
	if (up->capabilities & UART_CAP_RTOIE)
		up->ier |= UART_IER_RTOIE;
L
Linus Torvalds 已提交
2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384

	serial_out(up, UART_IER, up->ier);

	if (up->capabilities & UART_CAP_EFR) {
		unsigned char efr = 0;
		/*
		 * TI16C752/Startech hardware flow control.  FIXME:
		 * - TI16C752 requires control thresholds to be set.
		 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
		 */
		if (termios->c_cflag & CRTSCTS)
			efr |= UART_EFR_CTS;

2385
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
2386 2387 2388 2389
		if (up->port.flags & UPF_EXAR_EFR)
			serial_outp(up, UART_XR_EFR, efr);
		else
			serial_outp(up, UART_EFR, efr);
L
Linus Torvalds 已提交
2390 2391
	}

2392
#ifdef CONFIG_ARCH_OMAP
2393
	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
2394
	if (cpu_is_omap1510() && is_omap_port(up)) {
2395 2396 2397 2398 2399 2400 2401 2402
		if (baud == 115200) {
			quot = 1;
			serial_out(up, UART_OMAP_OSC_12M_SEL, 1);
		} else
			serial_out(up, UART_OMAP_OSC_12M_SEL, 0);
	}
#endif

L
Linus Torvalds 已提交
2403 2404 2405 2406 2407 2408 2409
	if (up->capabilities & UART_NATSEMI) {
		/* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
		serial_outp(up, UART_LCR, 0xe0);
	} else {
		serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
	}

2410
	serial_dl_write(up, quot);
L
Linus Torvalds 已提交
2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429

	/*
	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
	 * is written without DLAB set, this mode will be disabled.
	 */
	if (up->port.type == PORT_16750)
		serial_outp(up, UART_FCR, fcr);

	serial_outp(up, UART_LCR, cval);		/* reset DLAB */
	up->lcr = cval;					/* Save LCR */
	if (up->port.type != PORT_16750) {
		if (fcr & UART_FCR_ENABLE_FIFO) {
			/* emulated UARTs (Lucent Venus 167x) need two steps */
			serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
		}
		serial_outp(up, UART_FCR, fcr);		/* set fcr */
	}
	serial8250_set_mctrl(&up->port, up->port.mctrl);
	spin_unlock_irqrestore(&up->port.lock, flags);
A
Alan Cox 已提交
2430 2431 2432
	/* Don't rewrite B0 */
	if (tty_termios_baud_rate(termios))
		tty_termios_encode_baud_rate(termios, baud, baud);
L
Linus Torvalds 已提交
2433
}
2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444
EXPORT_SYMBOL(serial8250_do_set_termios);

static void
serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
		       struct ktermios *old)
{
	if (port->set_termios)
		port->set_termios(port, termios, old);
	else
		serial8250_do_set_termios(port, termios, old);
}
L
Linus Torvalds 已提交
2445

2446
static void
A
Arnd Bergmann 已提交
2447
serial8250_set_ldisc(struct uart_port *port, int new)
2448
{
A
Arnd Bergmann 已提交
2449
	if (new == N_PPS) {
2450 2451 2452 2453 2454 2455
		port->flags |= UPF_HARDPPS_CD;
		serial8250_enable_ms(port);
	} else
		port->flags &= ~UPF_HARDPPS_CD;
}

2456 2457 2458

void serial8250_do_pm(struct uart_port *port, unsigned int state,
		      unsigned int oldstate)
L
Linus Torvalds 已提交
2459
{
2460 2461
	struct uart_8250_port *p =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2462 2463

	serial8250_set_sleep(p, state != 0);
2464 2465
}
EXPORT_SYMBOL(serial8250_do_pm);
L
Linus Torvalds 已提交
2466

2467 2468 2469 2470 2471 2472 2473 2474
static void
serial8250_pm(struct uart_port *port, unsigned int state,
	      unsigned int oldstate)
{
	if (port->pm)
		port->pm(port, state, oldstate);
	else
		serial8250_do_pm(port, state, oldstate);
L
Linus Torvalds 已提交
2475 2476
}

2477 2478 2479
static unsigned int serial8250_port_size(struct uart_8250_port *pt)
{
	if (pt->port.iotype == UPIO_AU)
2480
		return 0x1000;
2481 2482 2483 2484 2485 2486 2487
#ifdef CONFIG_ARCH_OMAP
	if (is_omap_port(pt))
		return 0x16 << pt->port.regshift;
#endif
	return 8 << pt->port.regshift;
}

L
Linus Torvalds 已提交
2488 2489 2490 2491 2492
/*
 * Resource handling.
 */
static int serial8250_request_std_resource(struct uart_8250_port *up)
{
2493
	unsigned int size = serial8250_port_size(up);
L
Linus Torvalds 已提交
2494 2495 2496
	int ret = 0;

	switch (up->port.iotype) {
2497
	case UPIO_AU:
2498 2499
	case UPIO_TSI:
	case UPIO_MEM32:
L
Linus Torvalds 已提交
2500 2501 2502 2503 2504 2505 2506 2507 2508 2509
	case UPIO_MEM:
		if (!up->port.mapbase)
			break;

		if (!request_mem_region(up->port.mapbase, size, "serial")) {
			ret = -EBUSY;
			break;
		}

		if (up->port.flags & UPF_IOREMAP) {
2510 2511
			up->port.membase = ioremap_nocache(up->port.mapbase,
									size);
L
Linus Torvalds 已提交
2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529
			if (!up->port.membase) {
				release_mem_region(up->port.mapbase, size);
				ret = -ENOMEM;
			}
		}
		break;

	case UPIO_HUB6:
	case UPIO_PORT:
		if (!request_region(up->port.iobase, size, "serial"))
			ret = -EBUSY;
		break;
	}
	return ret;
}

static void serial8250_release_std_resource(struct uart_8250_port *up)
{
2530
	unsigned int size = serial8250_port_size(up);
L
Linus Torvalds 已提交
2531 2532

	switch (up->port.iotype) {
2533
	case UPIO_AU:
2534 2535
	case UPIO_TSI:
	case UPIO_MEM32:
L
Linus Torvalds 已提交
2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558
	case UPIO_MEM:
		if (!up->port.mapbase)
			break;

		if (up->port.flags & UPF_IOREMAP) {
			iounmap(up->port.membase);
			up->port.membase = NULL;
		}

		release_mem_region(up->port.mapbase, size);
		break;

	case UPIO_HUB6:
	case UPIO_PORT:
		release_region(up->port.iobase, size);
		break;
	}
}

static int serial8250_request_rsa_resource(struct uart_8250_port *up)
{
	unsigned long start = UART_RSA_BASE << up->port.regshift;
	unsigned int size = 8 << up->port.regshift;
2559
	int ret = -EINVAL;
L
Linus Torvalds 已提交
2560 2561 2562 2563 2564

	switch (up->port.iotype) {
	case UPIO_HUB6:
	case UPIO_PORT:
		start += up->port.iobase;
2565 2566 2567
		if (request_region(start, size, "serial-rsa"))
			ret = 0;
		else
L
Linus Torvalds 已提交
2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589
			ret = -EBUSY;
		break;
	}

	return ret;
}

static void serial8250_release_rsa_resource(struct uart_8250_port *up)
{
	unsigned long offset = UART_RSA_BASE << up->port.regshift;
	unsigned int size = 8 << up->port.regshift;

	switch (up->port.iotype) {
	case UPIO_HUB6:
	case UPIO_PORT:
		release_region(up->port.iobase + offset, size);
		break;
	}
}

static void serial8250_release_port(struct uart_port *port)
{
2590 2591
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2592 2593 2594 2595 2596 2597 2598 2599

	serial8250_release_std_resource(up);
	if (up->port.type == PORT_RSA)
		serial8250_release_rsa_resource(up);
}

static int serial8250_request_port(struct uart_port *port)
{
2600 2601
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615
	int ret = 0;

	ret = serial8250_request_std_resource(up);
	if (ret == 0 && up->port.type == PORT_RSA) {
		ret = serial8250_request_rsa_resource(up);
		if (ret < 0)
			serial8250_release_std_resource(up);
	}

	return ret;
}

static void serial8250_config_port(struct uart_port *port, int flags)
{
2616 2617
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
	int probeflags = PROBE_ANY;
	int ret;

	/*
	 * Find the region that we can probe for.  This in turn
	 * tells us whether we can probe for the type of port.
	 */
	ret = serial8250_request_std_resource(up);
	if (ret < 0)
		return;

	ret = serial8250_request_rsa_resource(up);
	if (ret < 0)
		probeflags &= ~PROBE_RSA;

A
Alan Cox 已提交
2633 2634 2635
	if (up->port.iotype != up->cur_iotype)
		set_io_from_upio(port);

L
Linus Torvalds 已提交
2636 2637
	if (flags & UART_CONFIG_TYPE)
		autoconfig(up, probeflags);
2638 2639 2640 2641 2642

	/* if access method is AU, it is a 16550 with a quirk */
	if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
		up->bugs |= UART_BUG_NOMSR;

L
Linus Torvalds 已提交
2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654
	if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
		autoconfig_irq(up);

	if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
		serial8250_release_rsa_resource(up);
	if (up->port.type == PORT_UNKNOWN)
		serial8250_release_std_resource(up);
}

static int
serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
{
Y
Yinghai Lu 已提交
2655
	if (ser->irq >= nr_irqs || ser->irq < 0 ||
L
Linus Torvalds 已提交
2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684
	    ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
	    ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
	    ser->type == PORT_STARTECH)
		return -EINVAL;
	return 0;
}

static const char *
serial8250_type(struct uart_port *port)
{
	int type = port->type;

	if (type >= ARRAY_SIZE(uart_config))
		type = 0;
	return uart_config[type].name;
}

static struct uart_ops serial8250_pops = {
	.tx_empty	= serial8250_tx_empty,
	.set_mctrl	= serial8250_set_mctrl,
	.get_mctrl	= serial8250_get_mctrl,
	.stop_tx	= serial8250_stop_tx,
	.start_tx	= serial8250_start_tx,
	.stop_rx	= serial8250_stop_rx,
	.enable_ms	= serial8250_enable_ms,
	.break_ctl	= serial8250_break_ctl,
	.startup	= serial8250_startup,
	.shutdown	= serial8250_shutdown,
	.set_termios	= serial8250_set_termios,
2685
	.set_ldisc	= serial8250_set_ldisc,
L
Linus Torvalds 已提交
2686 2687 2688 2689 2690 2691
	.pm		= serial8250_pm,
	.type		= serial8250_type,
	.release_port	= serial8250_release_port,
	.request_port	= serial8250_request_port,
	.config_port	= serial8250_config_port,
	.verify_port	= serial8250_verify_port,
J
Jason Wessel 已提交
2692 2693 2694 2695
#ifdef CONFIG_CONSOLE_POLL
	.poll_get_char = serial8250_get_poll_char,
	.poll_put_char = serial8250_put_poll_char,
#endif
L
Linus Torvalds 已提交
2696 2697 2698 2699
};

static struct uart_8250_port serial8250_ports[UART_NR];

2700 2701 2702 2703 2704 2705 2706 2707 2708 2709
static void (*serial8250_isa_config)(int port, struct uart_port *up,
	unsigned short *capabilities);

void serial8250_set_isa_configurator(
	void (*v)(int port, struct uart_port *up, unsigned short *capabilities))
{
	serial8250_isa_config = v;
}
EXPORT_SYMBOL(serial8250_set_isa_configurator);

L
Linus Torvalds 已提交
2710 2711 2712 2713
static void __init serial8250_isa_init_ports(void)
{
	struct uart_8250_port *up;
	static int first = 1;
2714
	int i, irqflag = 0;
L
Linus Torvalds 已提交
2715 2716 2717 2718 2719

	if (!first)
		return;
	first = 0;

2720
	for (i = 0; i < nr_uarts; i++) {
L
Linus Torvalds 已提交
2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737
		struct uart_8250_port *up = &serial8250_ports[i];

		up->port.line = i;
		spin_lock_init(&up->port.lock);

		init_timer(&up->timer);
		up->timer.function = serial8250_timeout;

		/*
		 * ALPHA_KLUDGE_MCR needs to be killed.
		 */
		up->mcr_mask = ~ALPHA_KLUDGE_MCR;
		up->mcr_force = ALPHA_KLUDGE_MCR;

		up->port.ops = &serial8250_pops;
	}

2738 2739 2740
	if (share_irqs)
		irqflag = IRQF_SHARED;

2741
	for (i = 0, up = serial8250_ports;
2742
	     i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
L
Linus Torvalds 已提交
2743 2744 2745
	     i++, up++) {
		up->port.iobase   = old_serial_port[i].port;
		up->port.irq      = irq_canonicalize(old_serial_port[i].irq);
2746
		up->port.irqflags = old_serial_port[i].irqflags;
L
Linus Torvalds 已提交
2747 2748 2749 2750 2751 2752
		up->port.uartclk  = old_serial_port[i].baud_base * 16;
		up->port.flags    = old_serial_port[i].flags;
		up->port.hub6     = old_serial_port[i].hub6;
		up->port.membase  = old_serial_port[i].iomem_base;
		up->port.iotype   = old_serial_port[i].io_type;
		up->port.regshift = old_serial_port[i].iomem_reg_shift;
2753
		set_io_from_upio(&up->port);
2754
		up->port.irqflags |= irqflag;
2755 2756 2757
		if (serial8250_isa_config != NULL)
			serial8250_isa_config(i, &up->port, &up->capabilities);

L
Linus Torvalds 已提交
2758 2759 2760
	}
}

2761 2762 2763 2764 2765 2766 2767 2768 2769
static void
serial8250_init_fixed_type_port(struct uart_8250_port *up, unsigned int type)
{
	up->port.type = type;
	up->port.fifosize = uart_config[type].fifo_size;
	up->capabilities = uart_config[type].flags;
	up->tx_loadsz = uart_config[type].tx_loadsz;
}

L
Linus Torvalds 已提交
2770 2771 2772 2773 2774
static void __init
serial8250_register_ports(struct uart_driver *drv, struct device *dev)
{
	int i;

A
Alan Cox 已提交
2775 2776 2777 2778 2779
	for (i = 0; i < nr_uarts; i++) {
		struct uart_8250_port *up = &serial8250_ports[i];
		up->cur_iotype = 0xFF;
	}

L
Linus Torvalds 已提交
2780 2781
	serial8250_isa_init_ports();

2782
	for (i = 0; i < nr_uarts; i++) {
L
Linus Torvalds 已提交
2783 2784 2785
		struct uart_8250_port *up = &serial8250_ports[i];

		up->port.dev = dev;
2786 2787 2788 2789

		if (up->port.flags & UPF_FIXED_TYPE)
			serial8250_init_fixed_type_port(up, up->port.type);

L
Linus Torvalds 已提交
2790 2791 2792 2793 2794 2795
		uart_add_one_port(drv, &up->port);
	}
}

#ifdef CONFIG_SERIAL_8250_CONSOLE

2796 2797
static void serial8250_console_putchar(struct uart_port *port, int ch)
{
2798 2799
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
2800 2801 2802 2803 2804

	wait_for_xmitr(up, UART_LSR_THRE);
	serial_out(up, UART_TX, ch);
}

L
Linus Torvalds 已提交
2805 2806 2807 2808 2809 2810 2811 2812 2813 2814
/*
 *	Print a string to the serial port trying not to disturb
 *	any possible real use of the port...
 *
 *	The console_lock must be held when we get here.
 */
static void
serial8250_console_write(struct console *co, const char *s, unsigned int count)
{
	struct uart_8250_port *up = &serial8250_ports[co->index];
2815
	unsigned long flags;
L
Linus Torvalds 已提交
2816
	unsigned int ier;
2817
	int locked = 1;
L
Linus Torvalds 已提交
2818

2819 2820
	touch_nmi_watchdog();

2821 2822
	local_irq_save(flags);
	if (up->port.sysrq) {
2823
		/* serial8250_handle_irq() already took the lock */
2824 2825 2826
		locked = 0;
	} else if (oops_in_progress) {
		locked = spin_trylock(&up->port.lock);
2827
	} else
2828
		spin_lock(&up->port.lock);
2829

L
Linus Torvalds 已提交
2830
	/*
R
Ralf Baechle 已提交
2831
	 *	First save the IER then disable the interrupts
L
Linus Torvalds 已提交
2832 2833 2834 2835 2836 2837 2838 2839
	 */
	ier = serial_in(up, UART_IER);

	if (up->capabilities & UART_CAP_UUE)
		serial_out(up, UART_IER, UART_IER_UUE);
	else
		serial_out(up, UART_IER, 0);

2840
	uart_console_write(&up->port, s, count, serial8250_console_putchar);
L
Linus Torvalds 已提交
2841 2842 2843 2844 2845

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the IER
	 */
A
Alan Cox 已提交
2846
	wait_for_xmitr(up, BOTH_EMPTY);
2847
	serial_out(up, UART_IER, ier);
2848

2849 2850 2851 2852 2853 2854 2855 2856
	/*
	 *	The receive handling will happen properly because the
	 *	receive ready bit will still be set; it is not cleared
	 *	on read.  However, modem control will not, we must
	 *	call it if we have saved something in the saved flags
	 *	while processing with interrupts off.
	 */
	if (up->msr_saved_flags)
2857
		serial8250_modem_status(up);
2858

2859
	if (locked)
2860 2861
		spin_unlock(&up->port.lock);
	local_irq_restore(flags);
L
Linus Torvalds 已提交
2862 2863
}

2864
static int __init serial8250_console_setup(struct console *co, char *options)
L
Linus Torvalds 已提交
2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876
{
	struct uart_port *port;
	int baud = 9600;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	/*
	 * Check whether an invalid uart number has been specified, and
	 * if so, search for the first available port that does have
	 * console support.
	 */
2877
	if (co->index >= nr_uarts)
L
Linus Torvalds 已提交
2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888
		co->index = 0;
	port = &serial8250_ports[co->index].port;
	if (!port->iobase && !port->membase)
		return -ENODEV;

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);

	return uart_set_options(port, co, baud, parity, bits, flow);
}

2889
static int serial8250_console_early_setup(void)
2890 2891 2892 2893
{
	return serial8250_find_port_for_earlycon();
}

L
Linus Torvalds 已提交
2894 2895 2896 2897 2898
static struct console serial8250_console = {
	.name		= "ttyS",
	.write		= serial8250_console_write,
	.device		= uart_console_device,
	.setup		= serial8250_console_setup,
2899
	.early_setup	= serial8250_console_early_setup,
2900
	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
L
Linus Torvalds 已提交
2901 2902 2903 2904 2905 2906
	.index		= -1,
	.data		= &serial8250_reg,
};

static int __init serial8250_console_init(void)
{
2907 2908 2909
	if (nr_uarts > UART_NR)
		nr_uarts = UART_NR;

L
Linus Torvalds 已提交
2910 2911 2912 2913 2914 2915
	serial8250_isa_init_ports();
	register_console(&serial8250_console);
	return 0;
}
console_initcall(serial8250_console_init);

2916
int serial8250_find_port(struct uart_port *p)
L
Linus Torvalds 已提交
2917 2918 2919 2920
{
	int line;
	struct uart_port *port;

2921
	for (line = 0; line < nr_uarts; line++) {
L
Linus Torvalds 已提交
2922
		port = &serial8250_ports[line].port;
2923
		if (uart_match_port(p, port))
L
Linus Torvalds 已提交
2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942
			return line;
	}
	return -ENODEV;
}

#define SERIAL8250_CONSOLE	&serial8250_console
#else
#define SERIAL8250_CONSOLE	NULL
#endif

static struct uart_driver serial8250_reg = {
	.owner			= THIS_MODULE,
	.driver_name		= "serial",
	.dev_name		= "ttyS",
	.major			= TTY_MAJOR,
	.minor			= 64,
	.cons			= SERIAL8250_CONSOLE,
};

2943 2944 2945 2946 2947 2948
/*
 * early_serial_setup - early registration for 8250 ports
 *
 * Setup an 8250 port structure prior to console initialisation.  Use
 * after console initialisation will cause undefined behaviour.
 */
L
Linus Torvalds 已提交
2949 2950
int __init early_serial_setup(struct uart_port *port)
{
D
David Daney 已提交
2951 2952
	struct uart_port *p;

L
Linus Torvalds 已提交
2953 2954 2955 2956
	if (port->line >= ARRAY_SIZE(serial8250_ports))
		return -ENODEV;

	serial8250_isa_init_ports();
D
David Daney 已提交
2957 2958 2959 2960
	p = &serial8250_ports[port->line].port;
	p->iobase       = port->iobase;
	p->membase      = port->membase;
	p->irq          = port->irq;
2961
	p->irqflags     = port->irqflags;
D
David Daney 已提交
2962 2963 2964 2965 2966 2967 2968
	p->uartclk      = port->uartclk;
	p->fifosize     = port->fifosize;
	p->regshift     = port->regshift;
	p->iotype       = port->iotype;
	p->flags        = port->flags;
	p->mapbase      = port->mapbase;
	p->private_data = port->private_data;
2969 2970
	p->type		= port->type;
	p->line		= port->line;
2971 2972 2973 2974 2975 2976

	set_io_from_upio(p);
	if (port->serial_in)
		p->serial_in = port->serial_in;
	if (port->serial_out)
		p->serial_out = port->serial_out;
2977 2978 2979 2980
	if (port->handle_irq)
		p->handle_irq = port->handle_irq;
	else
		p->handle_irq = serial8250_default_handle_irq;
2981

L
Linus Torvalds 已提交
2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003
	return 0;
}

/**
 *	serial8250_suspend_port - suspend one serial port
 *	@line:  serial line number
 *
 *	Suspend one serial port.
 */
void serial8250_suspend_port(int line)
{
	uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
}

/**
 *	serial8250_resume_port - resume one serial port
 *	@line:  serial line number
 *
 *	Resume one serial port.
 */
void serial8250_resume_port(int line)
{
3004 3005 3006 3007 3008 3009
	struct uart_8250_port *up = &serial8250_ports[line];

	if (up->capabilities & UART_NATSEMI) {
		/* Ensure it's still in high speed mode */
		serial_outp(up, UART_LCR, 0xE0);

3010
		ns16550a_goto_highspeed(up);
3011 3012

		serial_outp(up, UART_LCR, 0);
3013
		up->port.uartclk = 921600*16;
3014 3015
	}
	uart_resume_port(&serial8250_reg, &up->port);
L
Linus Torvalds 已提交
3016 3017 3018 3019 3020 3021 3022
}

/*
 * Register a set of serial devices attached to a platform device.  The
 * list is terminated with a zero flags entry, which means we expect
 * all entries to have at least UPF_BOOT_AUTOCONF set.
 */
3023
static int __devinit serial8250_probe(struct platform_device *dev)
L
Linus Torvalds 已提交
3024
{
3025
	struct plat_serial8250_port *p = dev->dev.platform_data;
L
Linus Torvalds 已提交
3026
	struct uart_port port;
3027
	int ret, i, irqflag = 0;
L
Linus Torvalds 已提交
3028 3029 3030

	memset(&port, 0, sizeof(struct uart_port));

3031 3032 3033
	if (share_irqs)
		irqflag = IRQF_SHARED;

3034
	for (i = 0; p && p->flags != 0; p++, i++) {
3035 3036 3037
		port.iobase		= p->iobase;
		port.membase		= p->membase;
		port.irq		= p->irq;
3038
		port.irqflags		= p->irqflags;
3039 3040 3041 3042 3043 3044 3045
		port.uartclk		= p->uartclk;
		port.regshift		= p->regshift;
		port.iotype		= p->iotype;
		port.flags		= p->flags;
		port.mapbase		= p->mapbase;
		port.hub6		= p->hub6;
		port.private_data	= p->private_data;
3046
		port.type		= p->type;
3047 3048
		port.serial_in		= p->serial_in;
		port.serial_out		= p->serial_out;
3049
		port.handle_irq		= p->handle_irq;
3050
		port.set_termios	= p->set_termios;
3051
		port.pm			= p->pm;
3052
		port.dev		= &dev->dev;
3053
		port.irqflags		|= irqflag;
3054 3055
		ret = serial8250_register_port(&port);
		if (ret < 0) {
3056
			dev_err(&dev->dev, "unable to register port at index %d "
3057 3058 3059
				"(IO%lx MEM%llx IRQ%d): %d\n", i,
				p->iobase, (unsigned long long)p->mapbase,
				p->irq, ret);
3060
		}
L
Linus Torvalds 已提交
3061 3062 3063 3064 3065 3066 3067
	}
	return 0;
}

/*
 * Remove serial ports registered against a platform device.
 */
3068
static int __devexit serial8250_remove(struct platform_device *dev)
L
Linus Torvalds 已提交
3069 3070 3071
{
	int i;

3072
	for (i = 0; i < nr_uarts; i++) {
L
Linus Torvalds 已提交
3073 3074
		struct uart_8250_port *up = &serial8250_ports[i];

3075
		if (up->port.dev == &dev->dev)
L
Linus Torvalds 已提交
3076 3077 3078 3079 3080
			serial8250_unregister_port(i);
	}
	return 0;
}

3081
static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
L
Linus Torvalds 已提交
3082 3083 3084 3085 3086 3087
{
	int i;

	for (i = 0; i < UART_NR; i++) {
		struct uart_8250_port *up = &serial8250_ports[i];

3088
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
L
Linus Torvalds 已提交
3089 3090 3091 3092 3093 3094
			uart_suspend_port(&serial8250_reg, &up->port);
	}

	return 0;
}

3095
static int serial8250_resume(struct platform_device *dev)
L
Linus Torvalds 已提交
3096 3097 3098 3099 3100 3101
{
	int i;

	for (i = 0; i < UART_NR; i++) {
		struct uart_8250_port *up = &serial8250_ports[i];

3102
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3103
			serial8250_resume_port(i);
L
Linus Torvalds 已提交
3104 3105 3106 3107 3108
	}

	return 0;
}

3109
static struct platform_driver serial8250_isa_driver = {
L
Linus Torvalds 已提交
3110 3111 3112 3113
	.probe		= serial8250_probe,
	.remove		= __devexit_p(serial8250_remove),
	.suspend	= serial8250_suspend,
	.resume		= serial8250_resume,
3114 3115
	.driver		= {
		.name	= "serial8250",
3116
		.owner	= THIS_MODULE,
3117
	},
L
Linus Torvalds 已提交
3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130
};

/*
 * This "device" covers _all_ ISA 8250-compatible serial devices listed
 * in the table in include/asm/serial.h
 */
static struct platform_device *serial8250_isa_devs;

/*
 * serial8250_register_port and serial8250_unregister_port allows for
 * 16x50 serial ports to be configured at run-time, to support PCMCIA
 * modems and PCI multiport cards.
 */
3131
static DEFINE_MUTEX(serial_mutex);
L
Linus Torvalds 已提交
3132 3133 3134 3135 3136 3137 3138 3139

static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
{
	int i;

	/*
	 * First, find a port entry which matches.
	 */
3140
	for (i = 0; i < nr_uarts; i++)
L
Linus Torvalds 已提交
3141 3142 3143 3144 3145 3146 3147 3148
		if (uart_match_port(&serial8250_ports[i].port, port))
			return &serial8250_ports[i];

	/*
	 * We didn't find a matching entry, so look for the first
	 * free entry.  We look for one which hasn't been previously
	 * used (indicated by zero iobase).
	 */
3149
	for (i = 0; i < nr_uarts; i++)
L
Linus Torvalds 已提交
3150 3151 3152 3153 3154 3155 3156 3157
		if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
		    serial8250_ports[i].port.iobase == 0)
			return &serial8250_ports[i];

	/*
	 * That also failed.  Last resort is to find any entry which
	 * doesn't have a real port associated with it.
	 */
3158
	for (i = 0; i < nr_uarts; i++)
L
Linus Torvalds 已提交
3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185
		if (serial8250_ports[i].port.type == PORT_UNKNOWN)
			return &serial8250_ports[i];

	return NULL;
}

/**
 *	serial8250_register_port - register a serial port
 *	@port: serial port template
 *
 *	Configure the serial port specified by the request. If the
 *	port exists and is in use, it is hung up and unregistered
 *	first.
 *
 *	The port is then probed and if necessary the IRQ is autodetected
 *	If this fails an error is returned.
 *
 *	On success the port is ready to use and the line number is returned.
 */
int serial8250_register_port(struct uart_port *port)
{
	struct uart_8250_port *uart;
	int ret = -ENOSPC;

	if (port->uartclk == 0)
		return -EINVAL;

3186
	mutex_lock(&serial_mutex);
L
Linus Torvalds 已提交
3187 3188 3189 3190 3191

	uart = serial8250_find_match_or_unused(port);
	if (uart) {
		uart_remove_one_port(&serial8250_reg, &uart->port);

3192 3193 3194
		uart->port.iobase       = port->iobase;
		uart->port.membase      = port->membase;
		uart->port.irq          = port->irq;
3195
		uart->port.irqflags     = port->irqflags;
3196 3197 3198 3199 3200 3201 3202
		uart->port.uartclk      = port->uartclk;
		uart->port.fifosize     = port->fifosize;
		uart->port.regshift     = port->regshift;
		uart->port.iotype       = port->iotype;
		uart->port.flags        = port->flags | UPF_BOOT_AUTOCONF;
		uart->port.mapbase      = port->mapbase;
		uart->port.private_data = port->private_data;
L
Linus Torvalds 已提交
3203 3204
		if (port->dev)
			uart->port.dev = port->dev;
3205

3206 3207
		if (port->flags & UPF_FIXED_TYPE)
			serial8250_init_fixed_type_port(uart, port->type);
3208

3209 3210 3211 3212 3213 3214
		set_io_from_upio(&uart->port);
		/* Possibly override default I/O functions.  */
		if (port->serial_in)
			uart->port.serial_in = port->serial_in;
		if (port->serial_out)
			uart->port.serial_out = port->serial_out;
3215 3216
		if (port->handle_irq)
			uart->port.handle_irq = port->handle_irq;
3217 3218 3219
		/*  Possibly override set_termios call */
		if (port->set_termios)
			uart->port.set_termios = port->set_termios;
3220 3221
		if (port->pm)
			uart->port.pm = port->pm;
L
Linus Torvalds 已提交
3222

3223 3224 3225 3226
		if (serial8250_isa_config != NULL)
			serial8250_isa_config(0, &uart->port,
					&uart->capabilities);

L
Linus Torvalds 已提交
3227 3228 3229 3230
		ret = uart_add_one_port(&serial8250_reg, &uart->port);
		if (ret == 0)
			ret = uart->port.line;
	}
3231
	mutex_unlock(&serial_mutex);
L
Linus Torvalds 已提交
3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247

	return ret;
}
EXPORT_SYMBOL(serial8250_register_port);

/**
 *	serial8250_unregister_port - remove a 16x50 serial port at runtime
 *	@line: serial line number
 *
 *	Remove one serial port.  This may not be called from interrupt
 *	context.  We hand the port back to the our control.
 */
void serial8250_unregister_port(int line)
{
	struct uart_8250_port *uart = &serial8250_ports[line];

3248
	mutex_lock(&serial_mutex);
L
Linus Torvalds 已提交
3249 3250 3251 3252 3253
	uart_remove_one_port(&serial8250_reg, &uart->port);
	if (serial8250_isa_devs) {
		uart->port.flags &= ~UPF_BOOT_AUTOCONF;
		uart->port.type = PORT_UNKNOWN;
		uart->port.dev = &serial8250_isa_devs->dev;
3254
		uart->capabilities = uart_config[uart->port.type].flags;
L
Linus Torvalds 已提交
3255 3256 3257 3258
		uart_add_one_port(&serial8250_reg, &uart->port);
	} else {
		uart->port.dev = NULL;
	}
3259
	mutex_unlock(&serial_mutex);
L
Linus Torvalds 已提交
3260 3261 3262 3263 3264
}
EXPORT_SYMBOL(serial8250_unregister_port);

static int __init serial8250_init(void)
{
A
Alan Cox 已提交
3265
	int ret;
L
Linus Torvalds 已提交
3266

3267 3268 3269
	if (nr_uarts > UART_NR)
		nr_uarts = UART_NR;

3270
	printk(KERN_INFO "Serial: 8250/16550 driver, "
3271
		"%d ports, IRQ sharing %sabled\n", nr_uarts,
L
Linus Torvalds 已提交
3272 3273
		share_irqs ? "en" : "dis");

3274 3275 3276 3277
#ifdef CONFIG_SPARC
	ret = sunserial_register_minors(&serial8250_reg, UART_NR);
#else
	serial8250_reg.nr = UART_NR;
L
Linus Torvalds 已提交
3278
	ret = uart_register_driver(&serial8250_reg);
3279
#endif
L
Linus Torvalds 已提交
3280 3281 3282
	if (ret)
		goto out;

3283 3284 3285 3286
	serial8250_isa_devs = platform_device_alloc("serial8250",
						    PLAT8250_DEV_LEGACY);
	if (!serial8250_isa_devs) {
		ret = -ENOMEM;
3287
		goto unreg_uart_drv;
L
Linus Torvalds 已提交
3288 3289
	}

3290 3291 3292 3293
	ret = platform_device_add(serial8250_isa_devs);
	if (ret)
		goto put_dev;

L
Linus Torvalds 已提交
3294 3295
	serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);

3296 3297 3298
	ret = platform_driver_register(&serial8250_isa_driver);
	if (ret == 0)
		goto out;
L
Linus Torvalds 已提交
3299

3300
	platform_device_del(serial8250_isa_devs);
A
Alan Cox 已提交
3301
put_dev:
3302
	platform_device_put(serial8250_isa_devs);
A
Alan Cox 已提交
3303
unreg_uart_drv:
3304 3305 3306
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
L
Linus Torvalds 已提交
3307
	uart_unregister_driver(&serial8250_reg);
3308
#endif
A
Alan Cox 已提交
3309
out:
L
Linus Torvalds 已提交
3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323
	return ret;
}

static void __exit serial8250_exit(void)
{
	struct platform_device *isa_dev = serial8250_isa_devs;

	/*
	 * This tells serial8250_unregister_port() not to re-register
	 * the ports (thereby making serial8250_isa_driver permanently
	 * in use.)
	 */
	serial8250_isa_devs = NULL;

3324
	platform_driver_unregister(&serial8250_isa_driver);
L
Linus Torvalds 已提交
3325 3326
	platform_device_unregister(isa_dev);

3327 3328 3329
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
L
Linus Torvalds 已提交
3330
	uart_unregister_driver(&serial8250_reg);
3331
#endif
L
Linus Torvalds 已提交
3332 3333 3334 3335 3336 3337 3338 3339 3340
}

module_init(serial8250_init);
module_exit(serial8250_exit);

EXPORT_SYMBOL(serial8250_suspend_port);
EXPORT_SYMBOL(serial8250_resume_port);

MODULE_LICENSE("GPL");
3341
MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
L
Linus Torvalds 已提交
3342 3343 3344 3345 3346

module_param(share_irqs, uint, 0644);
MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
	" (unsafe)");

3347 3348 3349
module_param(nr_uarts, uint, 0644);
MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");

3350 3351 3352
module_param(skip_txen_test, uint, 0644);
MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");

L
Linus Torvalds 已提交
3353 3354 3355 3356 3357
#ifdef CONFIG_SERIAL_8250_RSA
module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
#endif
MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);