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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/drivers/char/8250.c
3 *
4 * Driver for 8250/16550-type serial ports
5 *
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 *
8 * Copyright (C) 2001 Russell King.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * $Id: 8250.c,v 1.90 2002/07/28 10:03:27 rmk Exp $
16 *
17 * A note about mapbase / membase
18 *
19 * mapbase is the physical address of the IO port.
20 * membase is an 'ioremapped' cookie.
21 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
24#define SUPPORT_SYSRQ
25#endif
26
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/ioport.h>
30#include <linux/init.h>
31#include <linux/console.h>
32#include <linux/sysrq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/delay.h>
Russell Kingd052d1b2005-10-29 19:07:23 +010034#include <linux/platform_device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/tty.h>
36#include <linux/tty_flip.h>
37#include <linux/serial_reg.h>
38#include <linux/serial_core.h>
39#include <linux/serial.h>
40#include <linux/serial_8250.h>
Andrew Morton78512ec2005-11-07 00:59:13 -080041#include <linux/nmi.h>
Arjan van de Venf392ecf2006-01-12 18:44:32 +000042#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
44#include <asm/io.h>
45#include <asm/irq.h>
46
47#include "8250.h"
48
49/*
50 * Configuration:
Thomas Gleixner40663cc2006-07-01 19:29:43 -070051 * share_irqs - whether we pass IRQF_SHARED to request_irq(). This option
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 * is unsafe when used on edge-triggered interrupts.
53 */
Adrian Bunk408b6642005-05-01 08:59:29 -070054static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Dave Jonesa61c2d72006-01-07 23:18:19 +000056static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
57
Linus Torvalds1da177e2005-04-16 15:20:36 -070058/*
59 * Debugging.
60 */
61#if 0
62#define DEBUG_AUTOCONF(fmt...) printk(fmt)
63#else
64#define DEBUG_AUTOCONF(fmt...) do { } while (0)
65#endif
66
67#if 0
68#define DEBUG_INTR(fmt...) printk(fmt)
69#else
70#define DEBUG_INTR(fmt...) do { } while (0)
71#endif
72
73#define PASS_LIMIT 256
74
75/*
76 * We default to IRQ0 for the "no irq" hack. Some
77 * machine types want others as well - they're free
78 * to redefine this in their header file.
79 */
80#define is_real_interrupt(irq) ((irq) != 0)
81
Linus Torvalds1da177e2005-04-16 15:20:36 -070082#ifdef CONFIG_SERIAL_8250_DETECT_IRQ
83#define CONFIG_SERIAL_DETECT_IRQ 1
84#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#ifdef CONFIG_SERIAL_8250_MANY_PORTS
86#define CONFIG_SERIAL_MANY_PORTS 1
87#endif
88
89/*
90 * HUB6 is always on. This will be removed once the header
91 * files have been cleaned.
92 */
93#define CONFIG_HUB6 1
94
95#include <asm/serial.h>
96
97/*
98 * SERIAL_PORT_DFNS tells us about built-in ports that have no
99 * standard enumeration mechanism. Platforms that can find all
100 * serial ports via mechanisms like ACPI or PCI need not supply it.
101 */
102#ifndef SERIAL_PORT_DFNS
103#define SERIAL_PORT_DFNS
104#endif
105
Arjan van de Vencb3592b2005-11-28 21:04:11 +0000106static const struct old_serial_port old_serial_port[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 SERIAL_PORT_DFNS /* defined in asm/serial.h */
108};
109
Russell King026d02a2005-06-29 18:45:19 +0100110#define UART_NR CONFIG_SERIAL_8250_NR_UARTS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
112#ifdef CONFIG_SERIAL_8250_RSA
113
114#define PORT_RSA_MAX 4
115static unsigned long probe_rsa[PORT_RSA_MAX];
116static unsigned int probe_rsa_count;
117#endif /* CONFIG_SERIAL_8250_RSA */
118
119struct uart_8250_port {
120 struct uart_port port;
121 struct timer_list timer; /* "no irq" timer */
122 struct list_head list; /* ports on this IRQ */
Russell King4ba5e352005-06-23 10:43:04 +0100123 unsigned short capabilities; /* port capabilities */
124 unsigned short bugs; /* port bugs */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 unsigned int tx_loadsz; /* transmit fifo load size */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 unsigned char acr;
127 unsigned char ier;
128 unsigned char lcr;
129 unsigned char mcr;
130 unsigned char mcr_mask; /* mask of user bits */
131 unsigned char mcr_force; /* mask of forced bits */
132 unsigned char lsr_break_flag;
133
134 /*
135 * We provide a per-port pm hook.
136 */
137 void (*pm)(struct uart_port *port,
138 unsigned int state, unsigned int old);
139};
140
141struct irq_info {
142 spinlock_t lock;
143 struct list_head *head;
144};
145
146static struct irq_info irq_lists[NR_IRQS];
147
148/*
149 * Here we define the default xmit fifo size used for each type of UART.
150 */
151static const struct serial8250_config uart_config[] = {
152 [PORT_UNKNOWN] = {
153 .name = "unknown",
154 .fifo_size = 1,
155 .tx_loadsz = 1,
156 },
157 [PORT_8250] = {
158 .name = "8250",
159 .fifo_size = 1,
160 .tx_loadsz = 1,
161 },
162 [PORT_16450] = {
163 .name = "16450",
164 .fifo_size = 1,
165 .tx_loadsz = 1,
166 },
167 [PORT_16550] = {
168 .name = "16550",
169 .fifo_size = 1,
170 .tx_loadsz = 1,
171 },
172 [PORT_16550A] = {
173 .name = "16550A",
174 .fifo_size = 16,
175 .tx_loadsz = 16,
176 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
177 .flags = UART_CAP_FIFO,
178 },
179 [PORT_CIRRUS] = {
180 .name = "Cirrus",
181 .fifo_size = 1,
182 .tx_loadsz = 1,
183 },
184 [PORT_16650] = {
185 .name = "ST16650",
186 .fifo_size = 1,
187 .tx_loadsz = 1,
188 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
189 },
190 [PORT_16650V2] = {
191 .name = "ST16650V2",
192 .fifo_size = 32,
193 .tx_loadsz = 16,
194 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
195 UART_FCR_T_TRIG_00,
196 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
197 },
198 [PORT_16750] = {
199 .name = "TI16750",
200 .fifo_size = 64,
201 .tx_loadsz = 64,
202 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
203 UART_FCR7_64BYTE,
204 .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
205 },
206 [PORT_STARTECH] = {
207 .name = "Startech",
208 .fifo_size = 1,
209 .tx_loadsz = 1,
210 },
211 [PORT_16C950] = {
212 .name = "16C950/954",
213 .fifo_size = 128,
214 .tx_loadsz = 128,
215 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
216 .flags = UART_CAP_FIFO,
217 },
218 [PORT_16654] = {
219 .name = "ST16654",
220 .fifo_size = 64,
221 .tx_loadsz = 32,
222 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
223 UART_FCR_T_TRIG_10,
224 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
225 },
226 [PORT_16850] = {
227 .name = "XR16850",
228 .fifo_size = 128,
229 .tx_loadsz = 128,
230 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
231 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
232 },
233 [PORT_RSA] = {
234 .name = "RSA",
235 .fifo_size = 2048,
236 .tx_loadsz = 2048,
237 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
238 .flags = UART_CAP_FIFO,
239 },
240 [PORT_NS16550A] = {
241 .name = "NS16550A",
242 .fifo_size = 16,
243 .tx_loadsz = 16,
244 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
245 .flags = UART_CAP_FIFO | UART_NATSEMI,
246 },
247 [PORT_XSCALE] = {
248 .name = "XScale",
249 .fifo_size = 32,
250 .tx_loadsz = 32,
251 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
252 .flags = UART_CAP_FIFO | UART_CAP_UUE,
253 },
254};
255
Pantelis Antoniou21c614a2005-11-06 09:07:03 +0000256#ifdef CONFIG_SERIAL_8250_AU1X00
257
258/* Au1x00 UART hardware has a weird register layout */
259static const u8 au_io_in_map[] = {
260 [UART_RX] = 0,
261 [UART_IER] = 2,
262 [UART_IIR] = 3,
263 [UART_LCR] = 5,
264 [UART_MCR] = 6,
265 [UART_LSR] = 7,
266 [UART_MSR] = 8,
267};
268
269static const u8 au_io_out_map[] = {
270 [UART_TX] = 1,
271 [UART_IER] = 2,
272 [UART_FCR] = 4,
273 [UART_LCR] = 5,
274 [UART_MCR] = 6,
275};
276
277/* sane hardware needs no mapping */
278static inline int map_8250_in_reg(struct uart_8250_port *up, int offset)
279{
280 if (up->port.iotype != UPIO_AU)
281 return offset;
282 return au_io_in_map[offset];
283}
284
285static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
286{
287 if (up->port.iotype != UPIO_AU)
288 return offset;
289 return au_io_out_map[offset];
290}
291
292#else
293
294/* sane hardware needs no mapping */
295#define map_8250_in_reg(up, offset) (offset)
296#define map_8250_out_reg(up, offset) (offset)
297
298#endif
299
Russell Kingea8874d2006-01-04 19:43:24 +0000300static unsigned int serial_in(struct uart_8250_port *up, int offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
Zang Roy-r619113be91ec2006-06-30 02:29:58 -0700302 unsigned int tmp;
Pantelis Antoniou21c614a2005-11-06 09:07:03 +0000303 offset = map_8250_in_reg(up, offset) << up->port.regshift;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
305 switch (up->port.iotype) {
306 case UPIO_HUB6:
307 outb(up->port.hub6 - 1 + offset, up->port.iobase);
308 return inb(up->port.iobase + 1);
309
310 case UPIO_MEM:
311 return readb(up->port.membase + offset);
312
313 case UPIO_MEM32:
314 return readl(up->port.membase + offset);
315
Pantelis Antoniou21c614a2005-11-06 09:07:03 +0000316#ifdef CONFIG_SERIAL_8250_AU1X00
317 case UPIO_AU:
318 return __raw_readl(up->port.membase + offset);
319#endif
320
Zang Roy-r619113be91ec2006-06-30 02:29:58 -0700321 case UPIO_TSI:
322 if (offset == UART_IIR) {
Al Viro9e84b602006-09-23 01:39:45 +0100323 tmp = readl(up->port.membase + (UART_IIR & ~3));
324 return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
Zang Roy-r619113be91ec2006-06-30 02:29:58 -0700325 } else
326 return readb(up->port.membase + offset);
327
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 default:
329 return inb(up->port.iobase + offset);
330 }
331}
332
Russell Kingea8874d2006-01-04 19:43:24 +0000333static void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334serial_out(struct uart_8250_port *up, int offset, int value)
335{
Pantelis Antoniou21c614a2005-11-06 09:07:03 +0000336 offset = map_8250_out_reg(up, offset) << up->port.regshift;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
338 switch (up->port.iotype) {
339 case UPIO_HUB6:
340 outb(up->port.hub6 - 1 + offset, up->port.iobase);
341 outb(value, up->port.iobase + 1);
342 break;
343
344 case UPIO_MEM:
345 writeb(value, up->port.membase + offset);
346 break;
347
348 case UPIO_MEM32:
349 writel(value, up->port.membase + offset);
350 break;
351
Pantelis Antoniou21c614a2005-11-06 09:07:03 +0000352#ifdef CONFIG_SERIAL_8250_AU1X00
353 case UPIO_AU:
354 __raw_writel(value, up->port.membase + offset);
355 break;
356#endif
Zang Roy-r619113be91ec2006-06-30 02:29:58 -0700357 case UPIO_TSI:
358 if (!((offset == UART_IER) && (value & UART_IER_UUE)))
359 writeb(value, up->port.membase + offset);
360 break;
Pantelis Antoniou21c614a2005-11-06 09:07:03 +0000361
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 default:
363 outb(value, up->port.iobase + offset);
364 }
365}
366
Alex Williamson40b36da2007-02-14 00:33:04 -0800367static void
368serial_out_sync(struct uart_8250_port *up, int offset, int value)
369{
370 switch (up->port.iotype) {
371 case UPIO_MEM:
372 case UPIO_MEM32:
373#ifdef CONFIG_SERIAL_8250_AU1X00
374 case UPIO_AU:
375#endif
376 serial_out(up, offset, value);
377 serial_in(up, UART_LCR); /* safe, no side-effects */
378 break;
379 default:
380 serial_out(up, offset, value);
381 }
382}
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384/*
385 * We used to support using pause I/O for certain machines. We
386 * haven't supported this for a while, but just in case it's badly
387 * needed for certain old 386 machines, I've left these #define's
388 * in....
389 */
390#define serial_inp(up, offset) serial_in(up, offset)
391#define serial_outp(up, offset, value) serial_out(up, offset, value)
392
Jon Anders Haugumb32b19b2006-04-30 11:20:56 +0100393/* Uart divisor latch read */
394static inline int _serial_dl_read(struct uart_8250_port *up)
395{
396 return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
397}
398
399/* Uart divisor latch write */
400static inline void _serial_dl_write(struct uart_8250_port *up, int value)
401{
402 serial_outp(up, UART_DLL, value & 0xff);
403 serial_outp(up, UART_DLM, value >> 8 & 0xff);
404}
405
406#ifdef CONFIG_SERIAL_8250_AU1X00
407/* Au1x00 haven't got a standard divisor latch */
408static int serial_dl_read(struct uart_8250_port *up)
409{
410 if (up->port.iotype == UPIO_AU)
411 return __raw_readl(up->port.membase + 0x28);
412 else
413 return _serial_dl_read(up);
414}
415
416static void serial_dl_write(struct uart_8250_port *up, int value)
417{
418 if (up->port.iotype == UPIO_AU)
419 __raw_writel(value, up->port.membase + 0x28);
420 else
421 _serial_dl_write(up, value);
422}
423#else
424#define serial_dl_read(up) _serial_dl_read(up)
425#define serial_dl_write(up, value) _serial_dl_write(up, value)
426#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
428/*
429 * For the 16C950
430 */
431static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
432{
433 serial_out(up, UART_SCR, offset);
434 serial_out(up, UART_ICR, value);
435}
436
437static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
438{
439 unsigned int value;
440
441 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
442 serial_out(up, UART_SCR, offset);
443 value = serial_in(up, UART_ICR);
444 serial_icr_write(up, UART_ACR, up->acr);
445
446 return value;
447}
448
449/*
450 * FIFO support.
451 */
452static inline void serial8250_clear_fifos(struct uart_8250_port *p)
453{
454 if (p->capabilities & UART_CAP_FIFO) {
455 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
456 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
457 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
458 serial_outp(p, UART_FCR, 0);
459 }
460}
461
462/*
463 * IER sleep support. UARTs which have EFRs need the "extended
464 * capability" bit enabled. Note that on XR16C850s, we need to
465 * reset LCR to write to IER.
466 */
467static inline void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
468{
469 if (p->capabilities & UART_CAP_SLEEP) {
470 if (p->capabilities & UART_CAP_EFR) {
471 serial_outp(p, UART_LCR, 0xBF);
472 serial_outp(p, UART_EFR, UART_EFR_ECB);
473 serial_outp(p, UART_LCR, 0);
474 }
475 serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
476 if (p->capabilities & UART_CAP_EFR) {
477 serial_outp(p, UART_LCR, 0xBF);
478 serial_outp(p, UART_EFR, 0);
479 serial_outp(p, UART_LCR, 0);
480 }
481 }
482}
483
484#ifdef CONFIG_SERIAL_8250_RSA
485/*
486 * Attempts to turn on the RSA FIFO. Returns zero on failure.
487 * We set the port uart clock rate if we succeed.
488 */
489static int __enable_rsa(struct uart_8250_port *up)
490{
491 unsigned char mode;
492 int result;
493
494 mode = serial_inp(up, UART_RSA_MSR);
495 result = mode & UART_RSA_MSR_FIFO;
496
497 if (!result) {
498 serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
499 mode = serial_inp(up, UART_RSA_MSR);
500 result = mode & UART_RSA_MSR_FIFO;
501 }
502
503 if (result)
504 up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
505
506 return result;
507}
508
509static void enable_rsa(struct uart_8250_port *up)
510{
511 if (up->port.type == PORT_RSA) {
512 if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
513 spin_lock_irq(&up->port.lock);
514 __enable_rsa(up);
515 spin_unlock_irq(&up->port.lock);
516 }
517 if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
518 serial_outp(up, UART_RSA_FRR, 0);
519 }
520}
521
522/*
523 * Attempts to turn off the RSA FIFO. Returns zero on failure.
524 * It is unknown why interrupts were disabled in here. However,
525 * the caller is expected to preserve this behaviour by grabbing
526 * the spinlock before calling this function.
527 */
528static void disable_rsa(struct uart_8250_port *up)
529{
530 unsigned char mode;
531 int result;
532
533 if (up->port.type == PORT_RSA &&
534 up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
535 spin_lock_irq(&up->port.lock);
536
537 mode = serial_inp(up, UART_RSA_MSR);
538 result = !(mode & UART_RSA_MSR_FIFO);
539
540 if (!result) {
541 serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
542 mode = serial_inp(up, UART_RSA_MSR);
543 result = !(mode & UART_RSA_MSR_FIFO);
544 }
545
546 if (result)
547 up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
548 spin_unlock_irq(&up->port.lock);
549 }
550}
551#endif /* CONFIG_SERIAL_8250_RSA */
552
553/*
554 * This is a quickie test to see how big the FIFO is.
555 * It doesn't work at all the time, more's the pity.
556 */
557static int size_fifo(struct uart_8250_port *up)
558{
Jon Anders Haugumb32b19b2006-04-30 11:20:56 +0100559 unsigned char old_fcr, old_mcr, old_lcr;
560 unsigned short old_dl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 int count;
562
563 old_lcr = serial_inp(up, UART_LCR);
564 serial_outp(up, UART_LCR, 0);
565 old_fcr = serial_inp(up, UART_FCR);
566 old_mcr = serial_inp(up, UART_MCR);
567 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
568 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
569 serial_outp(up, UART_MCR, UART_MCR_LOOP);
570 serial_outp(up, UART_LCR, UART_LCR_DLAB);
Jon Anders Haugumb32b19b2006-04-30 11:20:56 +0100571 old_dl = serial_dl_read(up);
572 serial_dl_write(up, 0x0001);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 serial_outp(up, UART_LCR, 0x03);
574 for (count = 0; count < 256; count++)
575 serial_outp(up, UART_TX, count);
576 mdelay(20);/* FIXME - schedule_timeout */
577 for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
578 (count < 256); count++)
579 serial_inp(up, UART_RX);
580 serial_outp(up, UART_FCR, old_fcr);
581 serial_outp(up, UART_MCR, old_mcr);
582 serial_outp(up, UART_LCR, UART_LCR_DLAB);
Jon Anders Haugumb32b19b2006-04-30 11:20:56 +0100583 serial_dl_write(up, old_dl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 serial_outp(up, UART_LCR, old_lcr);
585
586 return count;
587}
588
589/*
590 * Read UART ID using the divisor method - set DLL and DLM to zero
591 * and the revision will be in DLL and device type in DLM. We
592 * preserve the device state across this.
593 */
594static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
595{
596 unsigned char old_dll, old_dlm, old_lcr;
597 unsigned int id;
598
599 old_lcr = serial_inp(p, UART_LCR);
600 serial_outp(p, UART_LCR, UART_LCR_DLAB);
601
602 old_dll = serial_inp(p, UART_DLL);
603 old_dlm = serial_inp(p, UART_DLM);
604
605 serial_outp(p, UART_DLL, 0);
606 serial_outp(p, UART_DLM, 0);
607
608 id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
609
610 serial_outp(p, UART_DLL, old_dll);
611 serial_outp(p, UART_DLM, old_dlm);
612 serial_outp(p, UART_LCR, old_lcr);
613
614 return id;
615}
616
617/*
618 * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
619 * When this function is called we know it is at least a StarTech
620 * 16650 V2, but it might be one of several StarTech UARTs, or one of
621 * its clones. (We treat the broken original StarTech 16650 V1 as a
622 * 16550, and why not? Startech doesn't seem to even acknowledge its
623 * existence.)
624 *
625 * What evil have men's minds wrought...
626 */
627static void autoconfig_has_efr(struct uart_8250_port *up)
628{
629 unsigned int id1, id2, id3, rev;
630
631 /*
632 * Everything with an EFR has SLEEP
633 */
634 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
635
636 /*
637 * First we check to see if it's an Oxford Semiconductor UART.
638 *
639 * If we have to do this here because some non-National
640 * Semiconductor clone chips lock up if you try writing to the
641 * LSR register (which serial_icr_read does)
642 */
643
644 /*
645 * Check for Oxford Semiconductor 16C950.
646 *
647 * EFR [4] must be set else this test fails.
648 *
649 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
650 * claims that it's needed for 952 dual UART's (which are not
651 * recommended for new designs).
652 */
653 up->acr = 0;
654 serial_out(up, UART_LCR, 0xBF);
655 serial_out(up, UART_EFR, UART_EFR_ECB);
656 serial_out(up, UART_LCR, 0x00);
657 id1 = serial_icr_read(up, UART_ID1);
658 id2 = serial_icr_read(up, UART_ID2);
659 id3 = serial_icr_read(up, UART_ID3);
660 rev = serial_icr_read(up, UART_REV);
661
662 DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
663
664 if (id1 == 0x16 && id2 == 0xC9 &&
665 (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
666 up->port.type = PORT_16C950;
Russell King4ba5e352005-06-23 10:43:04 +0100667
668 /*
669 * Enable work around for the Oxford Semiconductor 952 rev B
670 * chip which causes it to seriously miscalculate baud rates
671 * when DLL is 0.
672 */
673 if (id3 == 0x52 && rev == 0x01)
674 up->bugs |= UART_BUG_QUOT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 return;
676 }
677
678 /*
679 * We check for a XR16C850 by setting DLL and DLM to 0, and then
680 * reading back DLL and DLM. The chip type depends on the DLM
681 * value read back:
682 * 0x10 - XR16C850 and the DLL contains the chip revision.
683 * 0x12 - XR16C2850.
684 * 0x14 - XR16C854.
685 */
686 id1 = autoconfig_read_divisor_id(up);
687 DEBUG_AUTOCONF("850id=%04x ", id1);
688
689 id2 = id1 >> 8;
690 if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 up->port.type = PORT_16850;
692 return;
693 }
694
695 /*
696 * It wasn't an XR16C850.
697 *
698 * We distinguish between the '654 and the '650 by counting
699 * how many bytes are in the FIFO. I'm using this for now,
700 * since that's the technique that was sent to me in the
701 * serial driver update, but I'm not convinced this works.
702 * I've had problems doing this in the past. -TYT
703 */
704 if (size_fifo(up) == 64)
705 up->port.type = PORT_16654;
706 else
707 up->port.type = PORT_16650V2;
708}
709
710/*
711 * We detected a chip without a FIFO. Only two fall into
712 * this category - the original 8250 and the 16450. The
713 * 16450 has a scratch register (accessible with LCR=0)
714 */
715static void autoconfig_8250(struct uart_8250_port *up)
716{
717 unsigned char scratch, status1, status2;
718
719 up->port.type = PORT_8250;
720
721 scratch = serial_in(up, UART_SCR);
722 serial_outp(up, UART_SCR, 0xa5);
723 status1 = serial_in(up, UART_SCR);
724 serial_outp(up, UART_SCR, 0x5a);
725 status2 = serial_in(up, UART_SCR);
726 serial_outp(up, UART_SCR, scratch);
727
728 if (status1 == 0xa5 && status2 == 0x5a)
729 up->port.type = PORT_16450;
730}
731
732static int broken_efr(struct uart_8250_port *up)
733{
734 /*
735 * Exar ST16C2550 "A2" devices incorrectly detect as
736 * having an EFR, and report an ID of 0x0201. See
737 * http://www.exar.com/info.php?pdf=dan180_oct2004.pdf
738 */
739 if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
740 return 1;
741
742 return 0;
743}
744
745/*
746 * We know that the chip has FIFOs. Does it have an EFR? The
747 * EFR is located in the same register position as the IIR and
748 * we know the top two bits of the IIR are currently set. The
749 * EFR should contain zero. Try to read the EFR.
750 */
751static void autoconfig_16550a(struct uart_8250_port *up)
752{
753 unsigned char status1, status2;
754 unsigned int iersave;
755
756 up->port.type = PORT_16550A;
757 up->capabilities |= UART_CAP_FIFO;
758
759 /*
760 * Check for presence of the EFR when DLAB is set.
761 * Only ST16C650V1 UARTs pass this test.
762 */
763 serial_outp(up, UART_LCR, UART_LCR_DLAB);
764 if (serial_in(up, UART_EFR) == 0) {
765 serial_outp(up, UART_EFR, 0xA8);
766 if (serial_in(up, UART_EFR) != 0) {
767 DEBUG_AUTOCONF("EFRv1 ");
768 up->port.type = PORT_16650;
769 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
770 } else {
771 DEBUG_AUTOCONF("Motorola 8xxx DUART ");
772 }
773 serial_outp(up, UART_EFR, 0);
774 return;
775 }
776
777 /*
778 * Maybe it requires 0xbf to be written to the LCR.
779 * (other ST16C650V2 UARTs, TI16C752A, etc)
780 */
781 serial_outp(up, UART_LCR, 0xBF);
782 if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
783 DEBUG_AUTOCONF("EFRv2 ");
784 autoconfig_has_efr(up);
785 return;
786 }
787
788 /*
789 * Check for a National Semiconductor SuperIO chip.
790 * Attempt to switch to bank 2, read the value of the LOOP bit
791 * from EXCR1. Switch back to bank 0, change it in MCR. Then
792 * switch back to bank 2, read it from EXCR1 again and check
793 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 */
795 serial_outp(up, UART_LCR, 0);
796 status1 = serial_in(up, UART_MCR);
797 serial_outp(up, UART_LCR, 0xE0);
798 status2 = serial_in(up, 0x02); /* EXCR1 */
799
800 if (!((status2 ^ status1) & UART_MCR_LOOP)) {
801 serial_outp(up, UART_LCR, 0);
802 serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
803 serial_outp(up, UART_LCR, 0xE0);
804 status2 = serial_in(up, 0x02); /* EXCR1 */
805 serial_outp(up, UART_LCR, 0);
806 serial_outp(up, UART_MCR, status1);
807
808 if ((status2 ^ status1) & UART_MCR_LOOP) {
David Woodhouse857dde22005-05-21 15:52:23 +0100809 unsigned short quot;
810
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 serial_outp(up, UART_LCR, 0xE0);
David Woodhouse857dde22005-05-21 15:52:23 +0100812
Jon Anders Haugumb32b19b2006-04-30 11:20:56 +0100813 quot = serial_dl_read(up);
David Woodhouse857dde22005-05-21 15:52:23 +0100814 quot <<= 3;
815
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 status1 = serial_in(up, 0x04); /* EXCR1 */
817 status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
818 status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
819 serial_outp(up, 0x04, status1);
David Woodhouse857dde22005-05-21 15:52:23 +0100820
Jon Anders Haugumb32b19b2006-04-30 11:20:56 +0100821 serial_dl_write(up, quot);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822
David Woodhouse857dde22005-05-21 15:52:23 +0100823 serial_outp(up, UART_LCR, 0);
824
825 up->port.uartclk = 921600*16;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 up->port.type = PORT_NS16550A;
827 up->capabilities |= UART_NATSEMI;
828 return;
829 }
830 }
831
832 /*
833 * No EFR. Try to detect a TI16750, which only sets bit 5 of
834 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
835 * Try setting it with and without DLAB set. Cheap clones
836 * set bit 5 without DLAB set.
837 */
838 serial_outp(up, UART_LCR, 0);
839 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
840 status1 = serial_in(up, UART_IIR) >> 5;
841 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
842 serial_outp(up, UART_LCR, UART_LCR_DLAB);
843 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
844 status2 = serial_in(up, UART_IIR) >> 5;
845 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
846 serial_outp(up, UART_LCR, 0);
847
848 DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
849
850 if (status1 == 6 && status2 == 7) {
851 up->port.type = PORT_16750;
852 up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
853 return;
854 }
855
856 /*
857 * Try writing and reading the UART_IER_UUE bit (b6).
858 * If it works, this is probably one of the Xscale platform's
859 * internal UARTs.
860 * We're going to explicitly set the UUE bit to 0 before
861 * trying to write and read a 1 just to make sure it's not
862 * already a 1 and maybe locked there before we even start start.
863 */
864 iersave = serial_in(up, UART_IER);
865 serial_outp(up, UART_IER, iersave & ~UART_IER_UUE);
866 if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
867 /*
868 * OK it's in a known zero state, try writing and reading
869 * without disturbing the current state of the other bits.
870 */
871 serial_outp(up, UART_IER, iersave | UART_IER_UUE);
872 if (serial_in(up, UART_IER) & UART_IER_UUE) {
873 /*
874 * It's an Xscale.
875 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
876 */
877 DEBUG_AUTOCONF("Xscale ");
878 up->port.type = PORT_XSCALE;
879 up->capabilities |= UART_CAP_UUE;
880 return;
881 }
882 } else {
883 /*
884 * If we got here we couldn't force the IER_UUE bit to 0.
885 * Log it and continue.
886 */
887 DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
888 }
889 serial_outp(up, UART_IER, iersave);
890}
891
892/*
893 * This routine is called by rs_init() to initialize a specific serial
894 * port. It determines what type of UART chip this serial port is
895 * using: 8250, 16450, 16550, 16550A. The important question is
896 * whether or not this UART is a 16550A or not, since this will
897 * determine whether or not we can use its FIFO features or not.
898 */
899static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
900{
901 unsigned char status1, scratch, scratch2, scratch3;
902 unsigned char save_lcr, save_mcr;
903 unsigned long flags;
904
905 if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
906 return;
907
908 DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04x, 0x%p): ",
909 up->port.line, up->port.iobase, up->port.membase);
910
911 /*
912 * We really do need global IRQs disabled here - we're going to
913 * be frobbing the chips IRQ enable register to see if it exists.
914 */
915 spin_lock_irqsave(&up->port.lock, flags);
916// save_flags(flags); cli();
917
918 up->capabilities = 0;
Russell King4ba5e352005-06-23 10:43:04 +0100919 up->bugs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920
921 if (!(up->port.flags & UPF_BUGGY_UART)) {
922 /*
923 * Do a simple existence test first; if we fail this,
924 * there's no point trying anything else.
925 *
926 * 0x80 is used as a nonsense port to prevent against
927 * false positives due to ISA bus float. The
928 * assumption is that 0x80 is a non-existent port;
929 * which should be safe since include/asm/io.h also
930 * makes this assumption.
931 *
932 * Note: this is safe as long as MCR bit 4 is clear
933 * and the device is in "PC" mode.
934 */
935 scratch = serial_inp(up, UART_IER);
936 serial_outp(up, UART_IER, 0);
937#ifdef __i386__
938 outb(0xff, 0x080);
939#endif
Thomas Hoehn48212002007-02-10 01:46:05 -0800940 /*
941 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
942 * 16C754B) allow only to modify them if an EFR bit is set.
943 */
944 scratch2 = serial_inp(up, UART_IER) & 0x0f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 serial_outp(up, UART_IER, 0x0F);
946#ifdef __i386__
947 outb(0, 0x080);
948#endif
Thomas Hoehn48212002007-02-10 01:46:05 -0800949 scratch3 = serial_inp(up, UART_IER) & 0x0f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 serial_outp(up, UART_IER, scratch);
951 if (scratch2 != 0 || scratch3 != 0x0F) {
952 /*
953 * We failed; there's nothing here
954 */
955 DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
956 scratch2, scratch3);
957 goto out;
958 }
959 }
960
961 save_mcr = serial_in(up, UART_MCR);
962 save_lcr = serial_in(up, UART_LCR);
963
964 /*
965 * Check to see if a UART is really there. Certain broken
966 * internal modems based on the Rockwell chipset fail this
967 * test, because they apparently don't implement the loopback
968 * test mode. So this test is skipped on the COM 1 through
969 * COM 4 ports. This *should* be safe, since no board
970 * manufacturer would be stupid enough to design a board
971 * that conflicts with COM 1-4 --- we hope!
972 */
973 if (!(up->port.flags & UPF_SKIP_TEST)) {
974 serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
975 status1 = serial_inp(up, UART_MSR) & 0xF0;
976 serial_outp(up, UART_MCR, save_mcr);
977 if (status1 != 0x90) {
978 DEBUG_AUTOCONF("LOOP test failed (%02x) ",
979 status1);
980 goto out;
981 }
982 }
983
984 /*
985 * We're pretty sure there's a port here. Lets find out what
986 * type of port it is. The IIR top two bits allows us to find
Russell King6f0d6182005-09-09 16:17:58 +0100987 * out if it's 8250 or 16450, 16550, 16550A or later. This
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 * determines what we test for next.
989 *
990 * We also initialise the EFR (if any) to zero for later. The
991 * EFR occupies the same register location as the FCR and IIR.
992 */
993 serial_outp(up, UART_LCR, 0xBF);
994 serial_outp(up, UART_EFR, 0);
995 serial_outp(up, UART_LCR, 0);
996
997 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
998 scratch = serial_in(up, UART_IIR) >> 6;
999
1000 DEBUG_AUTOCONF("iir=%d ", scratch);
1001
1002 switch (scratch) {
1003 case 0:
1004 autoconfig_8250(up);
1005 break;
1006 case 1:
1007 up->port.type = PORT_UNKNOWN;
1008 break;
1009 case 2:
1010 up->port.type = PORT_16550;
1011 break;
1012 case 3:
1013 autoconfig_16550a(up);
1014 break;
1015 }
1016
1017#ifdef CONFIG_SERIAL_8250_RSA
1018 /*
1019 * Only probe for RSA ports if we got the region.
1020 */
1021 if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
1022 int i;
1023
1024 for (i = 0 ; i < probe_rsa_count; ++i) {
1025 if (probe_rsa[i] == up->port.iobase &&
1026 __enable_rsa(up)) {
1027 up->port.type = PORT_RSA;
1028 break;
1029 }
1030 }
1031 }
1032#endif
Pantelis Antoniou21c614a2005-11-06 09:07:03 +00001033
1034#ifdef CONFIG_SERIAL_8250_AU1X00
1035 /* if access method is AU, it is a 16550 with a quirk */
1036 if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
1037 up->bugs |= UART_BUG_NOMSR;
1038#endif
1039
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 serial_outp(up, UART_LCR, save_lcr);
1041
1042 if (up->capabilities != uart_config[up->port.type].flags) {
1043 printk(KERN_WARNING
1044 "ttyS%d: detected caps %08x should be %08x\n",
1045 up->port.line, up->capabilities,
1046 uart_config[up->port.type].flags);
1047 }
1048
1049 up->port.fifosize = uart_config[up->port.type].fifo_size;
1050 up->capabilities = uart_config[up->port.type].flags;
1051 up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
1052
1053 if (up->port.type == PORT_UNKNOWN)
1054 goto out;
1055
1056 /*
1057 * Reset the UART.
1058 */
1059#ifdef CONFIG_SERIAL_8250_RSA
1060 if (up->port.type == PORT_RSA)
1061 serial_outp(up, UART_RSA_FRR, 0);
1062#endif
1063 serial_outp(up, UART_MCR, save_mcr);
1064 serial8250_clear_fifos(up);
Alex Williamson40b36da2007-02-14 00:33:04 -08001065 serial_in(up, UART_RX);
Lennert Buytenhek5c8c7552005-11-12 21:58:05 +00001066 if (up->capabilities & UART_CAP_UUE)
1067 serial_outp(up, UART_IER, UART_IER_UUE);
1068 else
1069 serial_outp(up, UART_IER, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070
1071 out:
1072 spin_unlock_irqrestore(&up->port.lock, flags);
1073// restore_flags(flags);
1074 DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
1075}
1076
1077static void autoconfig_irq(struct uart_8250_port *up)
1078{
1079 unsigned char save_mcr, save_ier;
1080 unsigned char save_ICP = 0;
1081 unsigned int ICP = 0;
1082 unsigned long irqs;
1083 int irq;
1084
1085 if (up->port.flags & UPF_FOURPORT) {
1086 ICP = (up->port.iobase & 0xfe0) | 0x1f;
1087 save_ICP = inb_p(ICP);
1088 outb_p(0x80, ICP);
1089 (void) inb_p(ICP);
1090 }
1091
1092 /* forget possible initially masked and pending IRQ */
1093 probe_irq_off(probe_irq_on());
1094 save_mcr = serial_inp(up, UART_MCR);
1095 save_ier = serial_inp(up, UART_IER);
1096 serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
1097
1098 irqs = probe_irq_on();
1099 serial_outp(up, UART_MCR, 0);
1100 udelay (10);
1101 if (up->port.flags & UPF_FOURPORT) {
1102 serial_outp(up, UART_MCR,
1103 UART_MCR_DTR | UART_MCR_RTS);
1104 } else {
1105 serial_outp(up, UART_MCR,
1106 UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
1107 }
1108 serial_outp(up, UART_IER, 0x0f); /* enable all intrs */
1109 (void)serial_inp(up, UART_LSR);
1110 (void)serial_inp(up, UART_RX);
1111 (void)serial_inp(up, UART_IIR);
1112 (void)serial_inp(up, UART_MSR);
1113 serial_outp(up, UART_TX, 0xFF);
1114 udelay (20);
1115 irq = probe_irq_off(irqs);
1116
1117 serial_outp(up, UART_MCR, save_mcr);
1118 serial_outp(up, UART_IER, save_ier);
1119
1120 if (up->port.flags & UPF_FOURPORT)
1121 outb_p(save_ICP, ICP);
1122
1123 up->port.irq = (irq > 0) ? irq : 0;
1124}
1125
Russell Kinge763b902005-06-29 18:41:51 +01001126static inline void __stop_tx(struct uart_8250_port *p)
1127{
1128 if (p->ier & UART_IER_THRI) {
1129 p->ier &= ~UART_IER_THRI;
1130 serial_out(p, UART_IER, p->ier);
1131 }
1132}
1133
Russell Kingb129a8c2005-08-31 10:12:14 +01001134static void serial8250_stop_tx(struct uart_port *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135{
1136 struct uart_8250_port *up = (struct uart_8250_port *)port;
1137
Russell Kinge763b902005-06-29 18:41:51 +01001138 __stop_tx(up);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
1140 /*
Russell Kinge763b902005-06-29 18:41:51 +01001141 * We really want to stop the transmitter from sending.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 */
Russell Kinge763b902005-06-29 18:41:51 +01001143 if (up->port.type == PORT_16C950) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 up->acr |= UART_ACR_TXDIS;
1145 serial_icr_write(up, UART_ACR, up->acr);
1146 }
1147}
1148
Russell King55d3b282005-06-23 15:05:41 +01001149static void transmit_chars(struct uart_8250_port *up);
1150
Russell Kingb129a8c2005-08-31 10:12:14 +01001151static void serial8250_start_tx(struct uart_port *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152{
1153 struct uart_8250_port *up = (struct uart_8250_port *)port;
1154
1155 if (!(up->ier & UART_IER_THRI)) {
1156 up->ier |= UART_IER_THRI;
1157 serial_out(up, UART_IER, up->ier);
Russell King55d3b282005-06-23 15:05:41 +01001158
Russell King67f76542005-06-23 22:26:43 +01001159 if (up->bugs & UART_BUG_TXEN) {
Russell King55d3b282005-06-23 15:05:41 +01001160 unsigned char lsr, iir;
1161 lsr = serial_in(up, UART_LSR);
1162 iir = serial_in(up, UART_IIR);
1163 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
1164 transmit_chars(up);
1165 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 }
Russell Kinge763b902005-06-29 18:41:51 +01001167
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168 /*
Russell Kinge763b902005-06-29 18:41:51 +01001169 * Re-enable the transmitter if we disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 */
Russell Kinge763b902005-06-29 18:41:51 +01001171 if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 up->acr &= ~UART_ACR_TXDIS;
1173 serial_icr_write(up, UART_ACR, up->acr);
1174 }
1175}
1176
1177static void serial8250_stop_rx(struct uart_port *port)
1178{
1179 struct uart_8250_port *up = (struct uart_8250_port *)port;
1180
1181 up->ier &= ~UART_IER_RLSI;
1182 up->port.read_status_mask &= ~UART_LSR_DR;
1183 serial_out(up, UART_IER, up->ier);
1184}
1185
1186static void serial8250_enable_ms(struct uart_port *port)
1187{
1188 struct uart_8250_port *up = (struct uart_8250_port *)port;
1189
Pantelis Antoniou21c614a2005-11-06 09:07:03 +00001190 /* no MSR capabilities */
1191 if (up->bugs & UART_BUG_NOMSR)
1192 return;
1193
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 up->ier |= UART_IER_MSI;
1195 serial_out(up, UART_IER, up->ier);
1196}
1197
Russell Kingea8874d2006-01-04 19:43:24 +00001198static void
David Howells7d12e782006-10-05 14:55:46 +01001199receive_chars(struct uart_8250_port *up, int *status)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200{
1201 struct tty_struct *tty = up->port.info->tty;
1202 unsigned char ch, lsr = *status;
1203 int max_count = 256;
1204 char flag;
1205
1206 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207 ch = serial_inp(up, UART_RX);
1208 flag = TTY_NORMAL;
1209 up->port.icount.rx++;
1210
1211#ifdef CONFIG_SERIAL_8250_CONSOLE
1212 /*
1213 * Recover the break flag from console xmit
1214 */
1215 if (up->port.line == up->port.cons->index) {
1216 lsr |= up->lsr_break_flag;
1217 up->lsr_break_flag = 0;
1218 }
1219#endif
1220
1221 if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE |
1222 UART_LSR_FE | UART_LSR_OE))) {
1223 /*
1224 * For statistics only
1225 */
1226 if (lsr & UART_LSR_BI) {
1227 lsr &= ~(UART_LSR_FE | UART_LSR_PE);
1228 up->port.icount.brk++;
1229 /*
1230 * We do the SysRQ and SAK checking
1231 * here because otherwise the break
1232 * may get masked by ignore_status_mask
1233 * or read_status_mask.
1234 */
1235 if (uart_handle_break(&up->port))
1236 goto ignore_char;
1237 } else if (lsr & UART_LSR_PE)
1238 up->port.icount.parity++;
1239 else if (lsr & UART_LSR_FE)
1240 up->port.icount.frame++;
1241 if (lsr & UART_LSR_OE)
1242 up->port.icount.overrun++;
1243
1244 /*
Russell King23907eb2005-04-16 15:26:39 -07001245 * Mask off conditions which should be ignored.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 */
1247 lsr &= up->port.read_status_mask;
1248
1249 if (lsr & UART_LSR_BI) {
1250 DEBUG_INTR("handling break....");
1251 flag = TTY_BREAK;
1252 } else if (lsr & UART_LSR_PE)
1253 flag = TTY_PARITY;
1254 else if (lsr & UART_LSR_FE)
1255 flag = TTY_FRAME;
1256 }
David Howells7d12e782006-10-05 14:55:46 +01001257 if (uart_handle_sysrq_char(&up->port, ch))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 goto ignore_char;
Russell King05ab3012005-05-09 23:21:59 +01001259
1260 uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
1261
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 ignore_char:
1263 lsr = serial_inp(up, UART_LSR);
1264 } while ((lsr & UART_LSR_DR) && (max_count-- > 0));
1265 spin_unlock(&up->port.lock);
1266 tty_flip_buffer_push(tty);
1267 spin_lock(&up->port.lock);
1268 *status = lsr;
1269}
1270
Russell Kingea8874d2006-01-04 19:43:24 +00001271static void transmit_chars(struct uart_8250_port *up)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272{
1273 struct circ_buf *xmit = &up->port.info->xmit;
1274 int count;
1275
1276 if (up->port.x_char) {
1277 serial_outp(up, UART_TX, up->port.x_char);
1278 up->port.icount.tx++;
1279 up->port.x_char = 0;
1280 return;
1281 }
Russell Kingb129a8c2005-08-31 10:12:14 +01001282 if (uart_tx_stopped(&up->port)) {
1283 serial8250_stop_tx(&up->port);
1284 return;
1285 }
1286 if (uart_circ_empty(xmit)) {
Russell Kinge763b902005-06-29 18:41:51 +01001287 __stop_tx(up);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 return;
1289 }
1290
1291 count = up->tx_loadsz;
1292 do {
1293 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
1294 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1295 up->port.icount.tx++;
1296 if (uart_circ_empty(xmit))
1297 break;
1298 } while (--count > 0);
1299
1300 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1301 uart_write_wakeup(&up->port);
1302
1303 DEBUG_INTR("THRE...");
1304
1305 if (uart_circ_empty(xmit))
Russell Kinge763b902005-06-29 18:41:51 +01001306 __stop_tx(up);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307}
1308
Russell King2af7cd62006-01-04 16:55:09 +00001309static unsigned int check_modem_status(struct uart_8250_port *up)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310{
Russell King2af7cd62006-01-04 16:55:09 +00001311 unsigned int status = serial_in(up, UART_MSR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312
Russell King2af7cd62006-01-04 16:55:09 +00001313 if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI) {
1314 if (status & UART_MSR_TERI)
1315 up->port.icount.rng++;
1316 if (status & UART_MSR_DDSR)
1317 up->port.icount.dsr++;
1318 if (status & UART_MSR_DDCD)
1319 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
1320 if (status & UART_MSR_DCTS)
1321 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322
Russell King2af7cd62006-01-04 16:55:09 +00001323 wake_up_interruptible(&up->port.info->delta_msr_wait);
1324 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325
Russell King2af7cd62006-01-04 16:55:09 +00001326 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327}
1328
1329/*
1330 * This handles the interrupt from one port.
1331 */
1332static inline void
David Howells7d12e782006-10-05 14:55:46 +01001333serial8250_handle_port(struct uart_8250_port *up)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334{
Russell King45e24602006-01-04 19:19:06 +00001335 unsigned int status;
1336
1337 spin_lock(&up->port.lock);
1338
1339 status = serial_inp(up, UART_LSR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340
1341 DEBUG_INTR("status = %x...", status);
1342
1343 if (status & UART_LSR_DR)
David Howells7d12e782006-10-05 14:55:46 +01001344 receive_chars(up, &status);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 check_modem_status(up);
1346 if (status & UART_LSR_THRE)
1347 transmit_chars(up);
Russell King45e24602006-01-04 19:19:06 +00001348
1349 spin_unlock(&up->port.lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350}
1351
1352/*
1353 * This is the serial driver's interrupt routine.
1354 *
1355 * Arjan thinks the old way was overly complex, so it got simplified.
1356 * Alan disagrees, saying that need the complexity to handle the weird
1357 * nature of ISA shared interrupts. (This is a special exception.)
1358 *
1359 * In order to handle ISA shared interrupts properly, we need to check
1360 * that all ports have been serviced, and therefore the ISA interrupt
1361 * line has been de-asserted.
1362 *
1363 * This means we need to loop through all ports. checking that they
1364 * don't have an interrupt pending.
1365 */
David Howells7d12e782006-10-05 14:55:46 +01001366static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367{
1368 struct irq_info *i = dev_id;
1369 struct list_head *l, *end = NULL;
1370 int pass_counter = 0, handled = 0;
1371
1372 DEBUG_INTR("serial8250_interrupt(%d)...", irq);
1373
1374 spin_lock(&i->lock);
1375
1376 l = i->head;
1377 do {
1378 struct uart_8250_port *up;
1379 unsigned int iir;
1380
1381 up = list_entry(l, struct uart_8250_port, list);
1382
1383 iir = serial_in(up, UART_IIR);
1384 if (!(iir & UART_IIR_NO_INT)) {
David Howells7d12e782006-10-05 14:55:46 +01001385 serial8250_handle_port(up);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386
1387 handled = 1;
1388
1389 end = NULL;
1390 } else if (end == NULL)
1391 end = l;
1392
1393 l = l->next;
1394
1395 if (l == i->head && pass_counter++ > PASS_LIMIT) {
1396 /* If we hit this, we're dead. */
1397 printk(KERN_ERR "serial8250: too much work for "
1398 "irq%d\n", irq);
1399 break;
1400 }
1401 } while (l != end);
1402
1403 spin_unlock(&i->lock);
1404
1405 DEBUG_INTR("end.\n");
1406
1407 return IRQ_RETVAL(handled);
1408}
1409
1410/*
1411 * To support ISA shared interrupts, we need to have one interrupt
1412 * handler that ensures that the IRQ line has been deasserted
1413 * before returning. Failing to do this will result in the IRQ
1414 * line being stuck active, and, since ISA irqs are edge triggered,
1415 * no more IRQs will be seen.
1416 */
1417static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
1418{
1419 spin_lock_irq(&i->lock);
1420
1421 if (!list_empty(i->head)) {
1422 if (i->head == &up->list)
1423 i->head = i->head->next;
1424 list_del(&up->list);
1425 } else {
1426 BUG_ON(i->head != &up->list);
1427 i->head = NULL;
1428 }
1429
1430 spin_unlock_irq(&i->lock);
1431}
1432
1433static int serial_link_irq_chain(struct uart_8250_port *up)
1434{
1435 struct irq_info *i = irq_lists + up->port.irq;
Thomas Gleixner40663cc2006-07-01 19:29:43 -07001436 int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001437
1438 spin_lock_irq(&i->lock);
1439
1440 if (i->head) {
1441 list_add(&up->list, i->head);
1442 spin_unlock_irq(&i->lock);
1443
1444 ret = 0;
1445 } else {
1446 INIT_LIST_HEAD(&up->list);
1447 i->head = &up->list;
1448 spin_unlock_irq(&i->lock);
1449
1450 ret = request_irq(up->port.irq, serial8250_interrupt,
1451 irq_flags, "serial", i);
1452 if (ret < 0)
1453 serial_do_unlink(i, up);
1454 }
1455
1456 return ret;
1457}
1458
1459static void serial_unlink_irq_chain(struct uart_8250_port *up)
1460{
1461 struct irq_info *i = irq_lists + up->port.irq;
1462
1463 BUG_ON(i->head == NULL);
1464
1465 if (list_empty(i->head))
1466 free_irq(up->port.irq, i);
1467
1468 serial_do_unlink(i, up);
1469}
1470
Alex Williamson40b36da2007-02-14 00:33:04 -08001471/* Base timer interval for polling */
1472static inline int poll_timeout(int timeout)
1473{
1474 return timeout > 6 ? (timeout / 2 - 2) : 1;
1475}
1476
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477/*
1478 * This function is used to handle ports that do not have an
1479 * interrupt. This doesn't work very well for 16450's, but gives
1480 * barely passable results for a 16550A. (Although at the expense
1481 * of much CPU overhead).
1482 */
1483static void serial8250_timeout(unsigned long data)
1484{
1485 struct uart_8250_port *up = (struct uart_8250_port *)data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486 unsigned int iir;
1487
1488 iir = serial_in(up, UART_IIR);
Russell King45e24602006-01-04 19:19:06 +00001489 if (!(iir & UART_IIR_NO_INT))
David Howells7d12e782006-10-05 14:55:46 +01001490 serial8250_handle_port(up);
Alex Williamson40b36da2007-02-14 00:33:04 -08001491 mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
1492}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001493
Alex Williamson40b36da2007-02-14 00:33:04 -08001494static void serial8250_backup_timeout(unsigned long data)
1495{
1496 struct uart_8250_port *up = (struct uart_8250_port *)data;
1497 unsigned int iir, ier = 0;
1498
1499 /*
1500 * Must disable interrupts or else we risk racing with the interrupt
1501 * based handler.
1502 */
1503 if (is_real_interrupt(up->port.irq)) {
1504 ier = serial_in(up, UART_IER);
1505 serial_out(up, UART_IER, 0);
1506 }
1507
1508 iir = serial_in(up, UART_IIR);
1509
1510 /*
1511 * This should be a safe test for anyone who doesn't trust the
1512 * IIR bits on their UART, but it's specifically designed for
1513 * the "Diva" UART used on the management processor on many HP
1514 * ia64 and parisc boxes.
1515 */
1516 if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
1517 (!uart_circ_empty(&up->port.info->xmit) || up->port.x_char) &&
1518 (serial_in(up, UART_LSR) & UART_LSR_THRE)) {
1519 iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
1520 iir |= UART_IIR_THRI;
1521 }
1522
1523 if (!(iir & UART_IIR_NO_INT))
1524 serial8250_handle_port(up);
1525
1526 if (is_real_interrupt(up->port.irq))
1527 serial_out(up, UART_IER, ier);
1528
1529 /* Standard timer interval plus 0.2s to keep the port running */
1530 mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout) + HZ/5);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531}
1532
1533static unsigned int serial8250_tx_empty(struct uart_port *port)
1534{
1535 struct uart_8250_port *up = (struct uart_8250_port *)port;
1536 unsigned long flags;
1537 unsigned int ret;
1538
1539 spin_lock_irqsave(&up->port.lock, flags);
1540 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
1541 spin_unlock_irqrestore(&up->port.lock, flags);
1542
1543 return ret;
1544}
1545
1546static unsigned int serial8250_get_mctrl(struct uart_port *port)
1547{
1548 struct uart_8250_port *up = (struct uart_8250_port *)port;
Russell King2af7cd62006-01-04 16:55:09 +00001549 unsigned int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001550 unsigned int ret;
1551
Russell King2af7cd62006-01-04 16:55:09 +00001552 status = check_modem_status(up);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553
1554 ret = 0;
1555 if (status & UART_MSR_DCD)
1556 ret |= TIOCM_CAR;
1557 if (status & UART_MSR_RI)
1558 ret |= TIOCM_RNG;
1559 if (status & UART_MSR_DSR)
1560 ret |= TIOCM_DSR;
1561 if (status & UART_MSR_CTS)
1562 ret |= TIOCM_CTS;
1563 return ret;
1564}
1565
1566static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
1567{
1568 struct uart_8250_port *up = (struct uart_8250_port *)port;
1569 unsigned char mcr = 0;
1570
1571 if (mctrl & TIOCM_RTS)
1572 mcr |= UART_MCR_RTS;
1573 if (mctrl & TIOCM_DTR)
1574 mcr |= UART_MCR_DTR;
1575 if (mctrl & TIOCM_OUT1)
1576 mcr |= UART_MCR_OUT1;
1577 if (mctrl & TIOCM_OUT2)
1578 mcr |= UART_MCR_OUT2;
1579 if (mctrl & TIOCM_LOOP)
1580 mcr |= UART_MCR_LOOP;
1581
1582 mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
1583
1584 serial_out(up, UART_MCR, mcr);
1585}
1586
1587static void serial8250_break_ctl(struct uart_port *port, int break_state)
1588{
1589 struct uart_8250_port *up = (struct uart_8250_port *)port;
1590 unsigned long flags;
1591
1592 spin_lock_irqsave(&up->port.lock, flags);
1593 if (break_state == -1)
1594 up->lcr |= UART_LCR_SBC;
1595 else
1596 up->lcr &= ~UART_LCR_SBC;
1597 serial_out(up, UART_LCR, up->lcr);
1598 spin_unlock_irqrestore(&up->port.lock, flags);
1599}
1600
Alex Williamson40b36da2007-02-14 00:33:04 -08001601#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
1602
1603/*
1604 * Wait for transmitter & holding register to empty
1605 */
1606static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
1607{
1608 unsigned int status, tmout = 10000;
1609
1610 /* Wait up to 10ms for the character(s) to be sent. */
1611 do {
1612 status = serial_in(up, UART_LSR);
1613
1614 if (status & UART_LSR_BI)
1615 up->lsr_break_flag = UART_LSR_BI;
1616
1617 if (--tmout == 0)
1618 break;
1619 udelay(1);
1620 } while ((status & bits) != bits);
1621
1622 /* Wait up to 1s for flow control if necessary */
1623 if (up->port.flags & UPF_CONS_FLOW) {
1624 tmout = 1000000;
1625 while (!(serial_in(up, UART_MSR) & UART_MSR_CTS) && --tmout) {
1626 udelay(1);
1627 touch_nmi_watchdog();
1628 }
1629 }
1630}
1631
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632static int serial8250_startup(struct uart_port *port)
1633{
1634 struct uart_8250_port *up = (struct uart_8250_port *)port;
1635 unsigned long flags;
Russell King55d3b282005-06-23 15:05:41 +01001636 unsigned char lsr, iir;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 int retval;
1638
1639 up->capabilities = uart_config[up->port.type].flags;
1640 up->mcr = 0;
1641
1642 if (up->port.type == PORT_16C950) {
1643 /* Wake up and initialize UART */
1644 up->acr = 0;
1645 serial_outp(up, UART_LCR, 0xBF);
1646 serial_outp(up, UART_EFR, UART_EFR_ECB);
1647 serial_outp(up, UART_IER, 0);
1648 serial_outp(up, UART_LCR, 0);
1649 serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
1650 serial_outp(up, UART_LCR, 0xBF);
1651 serial_outp(up, UART_EFR, UART_EFR_ECB);
1652 serial_outp(up, UART_LCR, 0);
1653 }
1654
1655#ifdef CONFIG_SERIAL_8250_RSA
1656 /*
1657 * If this is an RSA port, see if we can kick it up to the
1658 * higher speed clock.
1659 */
1660 enable_rsa(up);
1661#endif
1662
1663 /*
1664 * Clear the FIFO buffers and disable them.
Alexey Dobriyan7f927fc2006-03-28 01:56:53 -08001665 * (they will be reenabled in set_termios())
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666 */
1667 serial8250_clear_fifos(up);
1668
1669 /*
1670 * Clear the interrupt registers.
1671 */
1672 (void) serial_inp(up, UART_LSR);
1673 (void) serial_inp(up, UART_RX);
1674 (void) serial_inp(up, UART_IIR);
1675 (void) serial_inp(up, UART_MSR);
1676
1677 /*
1678 * At this point, there's no way the LSR could still be 0xff;
1679 * if it is, then bail out, because there's likely no UART
1680 * here.
1681 */
1682 if (!(up->port.flags & UPF_BUGGY_UART) &&
1683 (serial_inp(up, UART_LSR) == 0xff)) {
1684 printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
1685 return -ENODEV;
1686 }
1687
1688 /*
1689 * For a XR16C850, we need to set the trigger levels
1690 */
1691 if (up->port.type == PORT_16850) {
1692 unsigned char fctr;
1693
1694 serial_outp(up, UART_LCR, 0xbf);
1695
1696 fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
1697 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
1698 serial_outp(up, UART_TRG, UART_TRG_96);
1699 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
1700 serial_outp(up, UART_TRG, UART_TRG_96);
1701
1702 serial_outp(up, UART_LCR, 0);
1703 }
1704
Alex Williamson40b36da2007-02-14 00:33:04 -08001705 if (is_real_interrupt(up->port.irq)) {
1706 /*
1707 * Test for UARTs that do not reassert THRE when the
1708 * transmitter is idle and the interrupt has already
1709 * been cleared. Real 16550s should always reassert
1710 * this interrupt whenever the transmitter is idle and
1711 * the interrupt is enabled. Delays are necessary to
1712 * allow register changes to become visible.
1713 */
1714 spin_lock_irqsave(&up->port.lock, flags);
1715
1716 wait_for_xmitr(up, UART_LSR_THRE);
1717 serial_out_sync(up, UART_IER, UART_IER_THRI);
1718 udelay(1); /* allow THRE to set */
1719 serial_in(up, UART_IIR);
1720 serial_out(up, UART_IER, 0);
1721 serial_out_sync(up, UART_IER, UART_IER_THRI);
1722 udelay(1); /* allow a working UART time to re-assert THRE */
1723 iir = serial_in(up, UART_IIR);
1724 serial_out(up, UART_IER, 0);
1725
1726 spin_unlock_irqrestore(&up->port.lock, flags);
1727
1728 /*
1729 * If the interrupt is not reasserted, setup a timer to
1730 * kick the UART on a regular basis.
1731 */
1732 if (iir & UART_IIR_NO_INT) {
1733 pr_debug("ttyS%d - using backup timer\n", port->line);
1734 up->timer.function = serial8250_backup_timeout;
1735 up->timer.data = (unsigned long)up;
1736 mod_timer(&up->timer, jiffies +
1737 poll_timeout(up->port.timeout) + HZ/5);
1738 }
1739 }
1740
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 /*
1742 * If the "interrupt" for this port doesn't correspond with any
1743 * hardware interrupt, we use a timer-based system. The original
1744 * driver used to do this with IRQ0.
1745 */
1746 if (!is_real_interrupt(up->port.irq)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001747 up->timer.data = (unsigned long)up;
Alex Williamson40b36da2007-02-14 00:33:04 -08001748 mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001749 } else {
1750 retval = serial_link_irq_chain(up);
1751 if (retval)
1752 return retval;
1753 }
1754
1755 /*
1756 * Now, initialize the UART
1757 */
1758 serial_outp(up, UART_LCR, UART_LCR_WLEN8);
1759
1760 spin_lock_irqsave(&up->port.lock, flags);
1761 if (up->port.flags & UPF_FOURPORT) {
1762 if (!is_real_interrupt(up->port.irq))
1763 up->port.mctrl |= TIOCM_OUT1;
1764 } else
1765 /*
1766 * Most PC uarts need OUT2 raised to enable interrupts.
1767 */
1768 if (is_real_interrupt(up->port.irq))
1769 up->port.mctrl |= TIOCM_OUT2;
1770
1771 serial8250_set_mctrl(&up->port, up->port.mctrl);
Russell King55d3b282005-06-23 15:05:41 +01001772
1773 /*
1774 * Do a quick test to see if we receive an
1775 * interrupt when we enable the TX irq.
1776 */
1777 serial_outp(up, UART_IER, UART_IER_THRI);
1778 lsr = serial_in(up, UART_LSR);
1779 iir = serial_in(up, UART_IIR);
1780 serial_outp(up, UART_IER, 0);
1781
1782 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
Russell King67f76542005-06-23 22:26:43 +01001783 if (!(up->bugs & UART_BUG_TXEN)) {
1784 up->bugs |= UART_BUG_TXEN;
Russell King55d3b282005-06-23 15:05:41 +01001785 pr_debug("ttyS%d - enabling bad tx status workarounds\n",
1786 port->line);
1787 }
1788 } else {
Russell King67f76542005-06-23 22:26:43 +01001789 up->bugs &= ~UART_BUG_TXEN;
Russell King55d3b282005-06-23 15:05:41 +01001790 }
1791
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792 spin_unlock_irqrestore(&up->port.lock, flags);
1793
1794 /*
1795 * Finally, enable interrupts. Note: Modem status interrupts
1796 * are set via set_termios(), which will be occurring imminently
1797 * anyway, so we don't enable them here.
1798 */
1799 up->ier = UART_IER_RLSI | UART_IER_RDI;
1800 serial_outp(up, UART_IER, up->ier);
1801
1802 if (up->port.flags & UPF_FOURPORT) {
1803 unsigned int icp;
1804 /*
1805 * Enable interrupts on the AST Fourport board
1806 */
1807 icp = (up->port.iobase & 0xfe0) | 0x01f;
1808 outb_p(0x80, icp);
1809 (void) inb_p(icp);
1810 }
1811
1812 /*
1813 * And clear the interrupt registers again for luck.
1814 */
1815 (void) serial_inp(up, UART_LSR);
1816 (void) serial_inp(up, UART_RX);
1817 (void) serial_inp(up, UART_IIR);
1818 (void) serial_inp(up, UART_MSR);
1819
1820 return 0;
1821}
1822
1823static void serial8250_shutdown(struct uart_port *port)
1824{
1825 struct uart_8250_port *up = (struct uart_8250_port *)port;
1826 unsigned long flags;
1827
1828 /*
1829 * Disable interrupts from this port
1830 */
1831 up->ier = 0;
1832 serial_outp(up, UART_IER, 0);
1833
1834 spin_lock_irqsave(&up->port.lock, flags);
1835 if (up->port.flags & UPF_FOURPORT) {
1836 /* reset interrupts on the AST Fourport board */
1837 inb((up->port.iobase & 0xfe0) | 0x1f);
1838 up->port.mctrl |= TIOCM_OUT1;
1839 } else
1840 up->port.mctrl &= ~TIOCM_OUT2;
1841
1842 serial8250_set_mctrl(&up->port, up->port.mctrl);
1843 spin_unlock_irqrestore(&up->port.lock, flags);
1844
1845 /*
1846 * Disable break condition and FIFOs
1847 */
1848 serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
1849 serial8250_clear_fifos(up);
1850
1851#ifdef CONFIG_SERIAL_8250_RSA
1852 /*
1853 * Reset the RSA board back to 115kbps compat mode.
1854 */
1855 disable_rsa(up);
1856#endif
1857
1858 /*
1859 * Read data port to reset things, and then unlink from
1860 * the IRQ chain.
1861 */
1862 (void) serial_in(up, UART_RX);
1863
Alex Williamson40b36da2007-02-14 00:33:04 -08001864 del_timer_sync(&up->timer);
1865 up->timer.function = serial8250_timeout;
1866 if (is_real_interrupt(up->port.irq))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001867 serial_unlink_irq_chain(up);
1868}
1869
1870static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
1871{
1872 unsigned int quot;
1873
1874 /*
1875 * Handle magic divisors for baud rates above baud_base on
1876 * SMSC SuperIO chips.
1877 */
1878 if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
1879 baud == (port->uartclk/4))
1880 quot = 0x8001;
1881 else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
1882 baud == (port->uartclk/8))
1883 quot = 0x8002;
1884 else
1885 quot = uart_get_divisor(port, baud);
1886
1887 return quot;
1888}
1889
1890static void
Alan Cox606d0992006-12-08 02:38:45 -08001891serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
1892 struct ktermios *old)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893{
1894 struct uart_8250_port *up = (struct uart_8250_port *)port;
1895 unsigned char cval, fcr = 0;
1896 unsigned long flags;
1897 unsigned int baud, quot;
1898
1899 switch (termios->c_cflag & CSIZE) {
1900 case CS5:
Russell King0a8b80c52005-06-24 19:48:22 +01001901 cval = UART_LCR_WLEN5;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001902 break;
1903 case CS6:
Russell King0a8b80c52005-06-24 19:48:22 +01001904 cval = UART_LCR_WLEN6;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001905 break;
1906 case CS7:
Russell King0a8b80c52005-06-24 19:48:22 +01001907 cval = UART_LCR_WLEN7;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001908 break;
1909 default:
1910 case CS8:
Russell King0a8b80c52005-06-24 19:48:22 +01001911 cval = UART_LCR_WLEN8;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001912 break;
1913 }
1914
1915 if (termios->c_cflag & CSTOPB)
Russell King0a8b80c52005-06-24 19:48:22 +01001916 cval |= UART_LCR_STOP;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001917 if (termios->c_cflag & PARENB)
1918 cval |= UART_LCR_PARITY;
1919 if (!(termios->c_cflag & PARODD))
1920 cval |= UART_LCR_EPAR;
1921#ifdef CMSPAR
1922 if (termios->c_cflag & CMSPAR)
1923 cval |= UART_LCR_SPAR;
1924#endif
1925
1926 /*
1927 * Ask the core to calculate the divisor for us.
1928 */
1929 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
1930 quot = serial8250_get_divisor(port, baud);
1931
1932 /*
Russell King4ba5e352005-06-23 10:43:04 +01001933 * Oxford Semi 952 rev B workaround
Linus Torvalds1da177e2005-04-16 15:20:36 -07001934 */
Russell King4ba5e352005-06-23 10:43:04 +01001935 if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001936 quot ++;
1937
1938 if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
1939 if (baud < 2400)
1940 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
1941 else
1942 fcr = uart_config[up->port.type].fcr;
1943 }
1944
1945 /*
1946 * MCR-based auto flow control. When AFE is enabled, RTS will be
1947 * deasserted when the receive FIFO contains more characters than
1948 * the trigger, or the MCR RTS bit is cleared. In the case where
1949 * the remote UART is not using CTS auto flow control, we must
1950 * have sufficient FIFO entries for the latency of the remote
1951 * UART to respond. IOW, at least 32 bytes of FIFO.
1952 */
1953 if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
1954 up->mcr &= ~UART_MCR_AFE;
1955 if (termios->c_cflag & CRTSCTS)
1956 up->mcr |= UART_MCR_AFE;
1957 }
1958
1959 /*
1960 * Ok, we're now changing the port state. Do it with
1961 * interrupts disabled.
1962 */
1963 spin_lock_irqsave(&up->port.lock, flags);
1964
1965 /*
1966 * Update the per-port timeout.
1967 */
1968 uart_update_timeout(port, termios->c_cflag, baud);
1969
1970 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
1971 if (termios->c_iflag & INPCK)
1972 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
1973 if (termios->c_iflag & (BRKINT | PARMRK))
1974 up->port.read_status_mask |= UART_LSR_BI;
1975
1976 /*
1977 * Characteres to ignore
1978 */
1979 up->port.ignore_status_mask = 0;
1980 if (termios->c_iflag & IGNPAR)
1981 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
1982 if (termios->c_iflag & IGNBRK) {
1983 up->port.ignore_status_mask |= UART_LSR_BI;
1984 /*
1985 * If we're ignoring parity and break indicators,
1986 * ignore overruns too (for real raw support).
1987 */
1988 if (termios->c_iflag & IGNPAR)
1989 up->port.ignore_status_mask |= UART_LSR_OE;
1990 }
1991
1992 /*
1993 * ignore all characters if CREAD is not set
1994 */
1995 if ((termios->c_cflag & CREAD) == 0)
1996 up->port.ignore_status_mask |= UART_LSR_DR;
1997
1998 /*
1999 * CTS flow control flag and modem status interrupts
2000 */
2001 up->ier &= ~UART_IER_MSI;
Pantelis Antoniou21c614a2005-11-06 09:07:03 +00002002 if (!(up->bugs & UART_BUG_NOMSR) &&
2003 UART_ENABLE_MS(&up->port, termios->c_cflag))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004 up->ier |= UART_IER_MSI;
2005 if (up->capabilities & UART_CAP_UUE)
2006 up->ier |= UART_IER_UUE | UART_IER_RTOIE;
2007
2008 serial_out(up, UART_IER, up->ier);
2009
2010 if (up->capabilities & UART_CAP_EFR) {
2011 unsigned char efr = 0;
2012 /*
2013 * TI16C752/Startech hardware flow control. FIXME:
2014 * - TI16C752 requires control thresholds to be set.
2015 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
2016 */
2017 if (termios->c_cflag & CRTSCTS)
2018 efr |= UART_EFR_CTS;
2019
2020 serial_outp(up, UART_LCR, 0xBF);
2021 serial_outp(up, UART_EFR, efr);
2022 }
2023
Jonathan McDowell255341c2006-08-14 23:05:32 -07002024#ifdef CONFIG_ARCH_OMAP15XX
2025 /* Workaround to enable 115200 baud on OMAP1510 internal ports */
2026 if (cpu_is_omap1510() && is_omap_port((unsigned int)up->port.membase)) {
2027 if (baud == 115200) {
2028 quot = 1;
2029 serial_out(up, UART_OMAP_OSC_12M_SEL, 1);
2030 } else
2031 serial_out(up, UART_OMAP_OSC_12M_SEL, 0);
2032 }
2033#endif
2034
Linus Torvalds1da177e2005-04-16 15:20:36 -07002035 if (up->capabilities & UART_NATSEMI) {
2036 /* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
2037 serial_outp(up, UART_LCR, 0xe0);
2038 } else {
2039 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
2040 }
2041
Jon Anders Haugumb32b19b2006-04-30 11:20:56 +01002042 serial_dl_write(up, quot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002043
2044 /*
2045 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
2046 * is written without DLAB set, this mode will be disabled.
2047 */
2048 if (up->port.type == PORT_16750)
2049 serial_outp(up, UART_FCR, fcr);
2050
2051 serial_outp(up, UART_LCR, cval); /* reset DLAB */
2052 up->lcr = cval; /* Save LCR */
2053 if (up->port.type != PORT_16750) {
2054 if (fcr & UART_FCR_ENABLE_FIFO) {
2055 /* emulated UARTs (Lucent Venus 167x) need two steps */
2056 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
2057 }
2058 serial_outp(up, UART_FCR, fcr); /* set fcr */
2059 }
2060 serial8250_set_mctrl(&up->port, up->port.mctrl);
2061 spin_unlock_irqrestore(&up->port.lock, flags);
2062}
2063
2064static void
2065serial8250_pm(struct uart_port *port, unsigned int state,
2066 unsigned int oldstate)
2067{
2068 struct uart_8250_port *p = (struct uart_8250_port *)port;
2069
2070 serial8250_set_sleep(p, state != 0);
2071
2072 if (p->pm)
2073 p->pm(port, state, oldstate);
2074}
2075
2076/*
2077 * Resource handling.
2078 */
2079static int serial8250_request_std_resource(struct uart_8250_port *up)
2080{
2081 unsigned int size = 8 << up->port.regshift;
2082 int ret = 0;
2083
2084 switch (up->port.iotype) {
Sergei Shtylyov85835f42006-04-30 11:15:58 +01002085 case UPIO_AU:
2086 size = 0x100000;
2087 /* fall thru */
Sergei Shtylyov0b30d662006-09-09 22:23:56 +04002088 case UPIO_TSI:
2089 case UPIO_MEM32:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002090 case UPIO_MEM:
2091 if (!up->port.mapbase)
2092 break;
2093
2094 if (!request_mem_region(up->port.mapbase, size, "serial")) {
2095 ret = -EBUSY;
2096 break;
2097 }
2098
2099 if (up->port.flags & UPF_IOREMAP) {
2100 up->port.membase = ioremap(up->port.mapbase, size);
2101 if (!up->port.membase) {
2102 release_mem_region(up->port.mapbase, size);
2103 ret = -ENOMEM;
2104 }
2105 }
2106 break;
2107
2108 case UPIO_HUB6:
2109 case UPIO_PORT:
2110 if (!request_region(up->port.iobase, size, "serial"))
2111 ret = -EBUSY;
2112 break;
2113 }
2114 return ret;
2115}
2116
2117static void serial8250_release_std_resource(struct uart_8250_port *up)
2118{
2119 unsigned int size = 8 << up->port.regshift;
2120
2121 switch (up->port.iotype) {
Sergei Shtylyov85835f42006-04-30 11:15:58 +01002122 case UPIO_AU:
2123 size = 0x100000;
2124 /* fall thru */
Sergei Shtylyov0b30d662006-09-09 22:23:56 +04002125 case UPIO_TSI:
2126 case UPIO_MEM32:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127 case UPIO_MEM:
2128 if (!up->port.mapbase)
2129 break;
2130
2131 if (up->port.flags & UPF_IOREMAP) {
2132 iounmap(up->port.membase);
2133 up->port.membase = NULL;
2134 }
2135
2136 release_mem_region(up->port.mapbase, size);
2137 break;
2138
2139 case UPIO_HUB6:
2140 case UPIO_PORT:
2141 release_region(up->port.iobase, size);
2142 break;
2143 }
2144}
2145
2146static int serial8250_request_rsa_resource(struct uart_8250_port *up)
2147{
2148 unsigned long start = UART_RSA_BASE << up->port.regshift;
2149 unsigned int size = 8 << up->port.regshift;
Sergei Shtylyov0b30d662006-09-09 22:23:56 +04002150 int ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002151
2152 switch (up->port.iotype) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002153 case UPIO_HUB6:
2154 case UPIO_PORT:
2155 start += up->port.iobase;
Sergei Shtylyov0b30d662006-09-09 22:23:56 +04002156 if (request_region(start, size, "serial-rsa"))
2157 ret = 0;
2158 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002159 ret = -EBUSY;
2160 break;
2161 }
2162
2163 return ret;
2164}
2165
2166static void serial8250_release_rsa_resource(struct uart_8250_port *up)
2167{
2168 unsigned long offset = UART_RSA_BASE << up->port.regshift;
2169 unsigned int size = 8 << up->port.regshift;
2170
2171 switch (up->port.iotype) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002172 case UPIO_HUB6:
2173 case UPIO_PORT:
2174 release_region(up->port.iobase + offset, size);
2175 break;
2176 }
2177}
2178
2179static void serial8250_release_port(struct uart_port *port)
2180{
2181 struct uart_8250_port *up = (struct uart_8250_port *)port;
2182
2183 serial8250_release_std_resource(up);
2184 if (up->port.type == PORT_RSA)
2185 serial8250_release_rsa_resource(up);
2186}
2187
2188static int serial8250_request_port(struct uart_port *port)
2189{
2190 struct uart_8250_port *up = (struct uart_8250_port *)port;
2191 int ret = 0;
2192
2193 ret = serial8250_request_std_resource(up);
2194 if (ret == 0 && up->port.type == PORT_RSA) {
2195 ret = serial8250_request_rsa_resource(up);
2196 if (ret < 0)
2197 serial8250_release_std_resource(up);
2198 }
2199
2200 return ret;
2201}
2202
2203static void serial8250_config_port(struct uart_port *port, int flags)
2204{
2205 struct uart_8250_port *up = (struct uart_8250_port *)port;
2206 int probeflags = PROBE_ANY;
2207 int ret;
2208
2209 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002210 * Find the region that we can probe for. This in turn
2211 * tells us whether we can probe for the type of port.
2212 */
2213 ret = serial8250_request_std_resource(up);
2214 if (ret < 0)
2215 return;
2216
2217 ret = serial8250_request_rsa_resource(up);
2218 if (ret < 0)
2219 probeflags &= ~PROBE_RSA;
2220
2221 if (flags & UART_CONFIG_TYPE)
2222 autoconfig(up, probeflags);
2223 if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
2224 autoconfig_irq(up);
2225
2226 if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
2227 serial8250_release_rsa_resource(up);
2228 if (up->port.type == PORT_UNKNOWN)
2229 serial8250_release_std_resource(up);
2230}
2231
2232static int
2233serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
2234{
2235 if (ser->irq >= NR_IRQS || ser->irq < 0 ||
2236 ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
2237 ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
2238 ser->type == PORT_STARTECH)
2239 return -EINVAL;
2240 return 0;
2241}
2242
2243static const char *
2244serial8250_type(struct uart_port *port)
2245{
2246 int type = port->type;
2247
2248 if (type >= ARRAY_SIZE(uart_config))
2249 type = 0;
2250 return uart_config[type].name;
2251}
2252
2253static struct uart_ops serial8250_pops = {
2254 .tx_empty = serial8250_tx_empty,
2255 .set_mctrl = serial8250_set_mctrl,
2256 .get_mctrl = serial8250_get_mctrl,
2257 .stop_tx = serial8250_stop_tx,
2258 .start_tx = serial8250_start_tx,
2259 .stop_rx = serial8250_stop_rx,
2260 .enable_ms = serial8250_enable_ms,
2261 .break_ctl = serial8250_break_ctl,
2262 .startup = serial8250_startup,
2263 .shutdown = serial8250_shutdown,
2264 .set_termios = serial8250_set_termios,
2265 .pm = serial8250_pm,
2266 .type = serial8250_type,
2267 .release_port = serial8250_release_port,
2268 .request_port = serial8250_request_port,
2269 .config_port = serial8250_config_port,
2270 .verify_port = serial8250_verify_port,
2271};
2272
2273static struct uart_8250_port serial8250_ports[UART_NR];
2274
2275static void __init serial8250_isa_init_ports(void)
2276{
2277 struct uart_8250_port *up;
2278 static int first = 1;
2279 int i;
2280
2281 if (!first)
2282 return;
2283 first = 0;
2284
Dave Jonesa61c2d72006-01-07 23:18:19 +00002285 for (i = 0; i < nr_uarts; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002286 struct uart_8250_port *up = &serial8250_ports[i];
2287
2288 up->port.line = i;
2289 spin_lock_init(&up->port.lock);
2290
2291 init_timer(&up->timer);
2292 up->timer.function = serial8250_timeout;
2293
2294 /*
2295 * ALPHA_KLUDGE_MCR needs to be killed.
2296 */
2297 up->mcr_mask = ~ALPHA_KLUDGE_MCR;
2298 up->mcr_force = ALPHA_KLUDGE_MCR;
2299
2300 up->port.ops = &serial8250_pops;
2301 }
2302
Russell King44454bc2005-06-30 22:41:22 +01002303 for (i = 0, up = serial8250_ports;
Dave Jonesa61c2d72006-01-07 23:18:19 +00002304 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002305 i++, up++) {
2306 up->port.iobase = old_serial_port[i].port;
2307 up->port.irq = irq_canonicalize(old_serial_port[i].irq);
2308 up->port.uartclk = old_serial_port[i].baud_base * 16;
2309 up->port.flags = old_serial_port[i].flags;
2310 up->port.hub6 = old_serial_port[i].hub6;
2311 up->port.membase = old_serial_port[i].iomem_base;
2312 up->port.iotype = old_serial_port[i].io_type;
2313 up->port.regshift = old_serial_port[i].iomem_reg_shift;
2314 if (share_irqs)
2315 up->port.flags |= UPF_SHARE_IRQ;
2316 }
2317}
2318
2319static void __init
2320serial8250_register_ports(struct uart_driver *drv, struct device *dev)
2321{
2322 int i;
2323
2324 serial8250_isa_init_ports();
2325
Dave Jonesa61c2d72006-01-07 23:18:19 +00002326 for (i = 0; i < nr_uarts; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002327 struct uart_8250_port *up = &serial8250_ports[i];
2328
2329 up->port.dev = dev;
2330 uart_add_one_port(drv, &up->port);
2331 }
2332}
2333
2334#ifdef CONFIG_SERIAL_8250_CONSOLE
2335
Russell Kingd3587882006-03-20 20:00:09 +00002336static void serial8250_console_putchar(struct uart_port *port, int ch)
2337{
2338 struct uart_8250_port *up = (struct uart_8250_port *)port;
2339
2340 wait_for_xmitr(up, UART_LSR_THRE);
2341 serial_out(up, UART_TX, ch);
2342}
2343
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344/*
2345 * Print a string to the serial port trying not to disturb
2346 * any possible real use of the port...
2347 *
2348 * The console_lock must be held when we get here.
2349 */
2350static void
2351serial8250_console_write(struct console *co, const char *s, unsigned int count)
2352{
2353 struct uart_8250_port *up = &serial8250_ports[co->index];
Russell Kingd8a5a8d2006-05-02 16:04:29 +01002354 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002355 unsigned int ier;
Russell Kingd8a5a8d2006-05-02 16:04:29 +01002356 int locked = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002357
Andrew Morton78512ec2005-11-07 00:59:13 -08002358 touch_nmi_watchdog();
2359
Andrew Morton68aa2c02006-06-30 02:29:59 -07002360 local_irq_save(flags);
2361 if (up->port.sysrq) {
2362 /* serial8250_handle_port() already took the lock */
2363 locked = 0;
2364 } else if (oops_in_progress) {
2365 locked = spin_trylock(&up->port.lock);
Russell Kingd8a5a8d2006-05-02 16:04:29 +01002366 } else
Andrew Morton68aa2c02006-06-30 02:29:59 -07002367 spin_lock(&up->port.lock);
Russell Kingd8a5a8d2006-05-02 16:04:29 +01002368
Linus Torvalds1da177e2005-04-16 15:20:36 -07002369 /*
Ralf Baechledc7bf132006-02-15 09:59:47 +00002370 * First save the IER then disable the interrupts
Linus Torvalds1da177e2005-04-16 15:20:36 -07002371 */
2372 ier = serial_in(up, UART_IER);
2373
2374 if (up->capabilities & UART_CAP_UUE)
2375 serial_out(up, UART_IER, UART_IER_UUE);
2376 else
2377 serial_out(up, UART_IER, 0);
2378
Russell Kingd3587882006-03-20 20:00:09 +00002379 uart_console_write(&up->port, s, count, serial8250_console_putchar);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002380
2381 /*
2382 * Finally, wait for transmitter to become empty
2383 * and restore the IER
2384 */
Alan Coxf91a3712006-01-21 14:59:12 +00002385 wait_for_xmitr(up, BOTH_EMPTY);
Russell Kinga88d75b2006-04-30 11:30:15 +01002386 serial_out(up, UART_IER, ier);
Russell Kingd8a5a8d2006-05-02 16:04:29 +01002387
2388 if (locked)
Andrew Morton68aa2c02006-06-30 02:29:59 -07002389 spin_unlock(&up->port.lock);
2390 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002391}
2392
Vivek Goyal118c0ac2007-01-11 01:52:44 +01002393static int __init serial8250_console_setup(struct console *co, char *options)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002394{
2395 struct uart_port *port;
2396 int baud = 9600;
2397 int bits = 8;
2398 int parity = 'n';
2399 int flow = 'n';
2400
2401 /*
2402 * Check whether an invalid uart number has been specified, and
2403 * if so, search for the first available port that does have
2404 * console support.
2405 */
Dave Jonesa61c2d72006-01-07 23:18:19 +00002406 if (co->index >= nr_uarts)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002407 co->index = 0;
2408 port = &serial8250_ports[co->index].port;
2409 if (!port->iobase && !port->membase)
2410 return -ENODEV;
2411
2412 if (options)
2413 uart_parse_options(options, &baud, &parity, &bits, &flow);
2414
2415 return uart_set_options(port, co, baud, parity, bits, flow);
2416}
2417
2418static struct uart_driver serial8250_reg;
2419static struct console serial8250_console = {
2420 .name = "ttyS",
2421 .write = serial8250_console_write,
2422 .device = uart_console_device,
2423 .setup = serial8250_console_setup,
2424 .flags = CON_PRINTBUFFER,
2425 .index = -1,
2426 .data = &serial8250_reg,
2427};
2428
2429static int __init serial8250_console_init(void)
2430{
2431 serial8250_isa_init_ports();
2432 register_console(&serial8250_console);
2433 return 0;
2434}
2435console_initcall(serial8250_console_init);
2436
2437static int __init find_port(struct uart_port *p)
2438{
2439 int line;
2440 struct uart_port *port;
2441
Dave Jonesa61c2d72006-01-07 23:18:19 +00002442 for (line = 0; line < nr_uarts; line++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002443 port = &serial8250_ports[line].port;
Russell King50aec3b2006-01-04 18:13:03 +00002444 if (uart_match_port(p, port))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002445 return line;
2446 }
2447 return -ENODEV;
2448}
2449
2450int __init serial8250_start_console(struct uart_port *port, char *options)
2451{
2452 int line;
2453
2454 line = find_port(port);
2455 if (line < 0)
2456 return -ENODEV;
2457
2458 add_preferred_console("ttyS", line, options);
2459 printk("Adding console on ttyS%d at %s 0x%lx (options '%s')\n",
2460 line, port->iotype == UPIO_MEM ? "MMIO" : "I/O port",
2461 port->iotype == UPIO_MEM ? (unsigned long) port->mapbase :
2462 (unsigned long) port->iobase, options);
2463 if (!(serial8250_console.flags & CON_ENABLED)) {
2464 serial8250_console.flags &= ~CON_PRINTBUFFER;
2465 register_console(&serial8250_console);
2466 }
2467 return line;
2468}
2469
2470#define SERIAL8250_CONSOLE &serial8250_console
2471#else
2472#define SERIAL8250_CONSOLE NULL
2473#endif
2474
2475static struct uart_driver serial8250_reg = {
2476 .owner = THIS_MODULE,
2477 .driver_name = "serial",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002478 .dev_name = "ttyS",
2479 .major = TTY_MAJOR,
2480 .minor = 64,
2481 .nr = UART_NR,
2482 .cons = SERIAL8250_CONSOLE,
2483};
2484
Russell Kingd856c662006-02-23 10:22:13 +00002485/*
2486 * early_serial_setup - early registration for 8250 ports
2487 *
2488 * Setup an 8250 port structure prior to console initialisation. Use
2489 * after console initialisation will cause undefined behaviour.
2490 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002491int __init early_serial_setup(struct uart_port *port)
2492{
2493 if (port->line >= ARRAY_SIZE(serial8250_ports))
2494 return -ENODEV;
2495
2496 serial8250_isa_init_ports();
2497 serial8250_ports[port->line].port = *port;
2498 serial8250_ports[port->line].port.ops = &serial8250_pops;
2499 return 0;
2500}
2501
2502/**
2503 * serial8250_suspend_port - suspend one serial port
2504 * @line: serial line number
Linus Torvalds1da177e2005-04-16 15:20:36 -07002505 *
2506 * Suspend one serial port.
2507 */
2508void serial8250_suspend_port(int line)
2509{
2510 uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
2511}
2512
2513/**
2514 * serial8250_resume_port - resume one serial port
2515 * @line: serial line number
Linus Torvalds1da177e2005-04-16 15:20:36 -07002516 *
2517 * Resume one serial port.
2518 */
2519void serial8250_resume_port(int line)
2520{
2521 uart_resume_port(&serial8250_reg, &serial8250_ports[line].port);
2522}
2523
2524/*
2525 * Register a set of serial devices attached to a platform device. The
2526 * list is terminated with a zero flags entry, which means we expect
2527 * all entries to have at least UPF_BOOT_AUTOCONF set.
2528 */
Russell King3ae5eae2005-11-09 22:32:44 +00002529static int __devinit serial8250_probe(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002530{
Russell King3ae5eae2005-11-09 22:32:44 +00002531 struct plat_serial8250_port *p = dev->dev.platform_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002532 struct uart_port port;
Russell Kingec9f47c2005-06-27 11:12:54 +01002533 int ret, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002534
2535 memset(&port, 0, sizeof(struct uart_port));
2536
Russell Kingec9f47c2005-06-27 11:12:54 +01002537 for (i = 0; p && p->flags != 0; p++, i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 port.iobase = p->iobase;
2539 port.membase = p->membase;
2540 port.irq = p->irq;
2541 port.uartclk = p->uartclk;
2542 port.regshift = p->regshift;
2543 port.iotype = p->iotype;
2544 port.flags = p->flags;
2545 port.mapbase = p->mapbase;
Russell Kingec9f47c2005-06-27 11:12:54 +01002546 port.hub6 = p->hub6;
Russell King3ae5eae2005-11-09 22:32:44 +00002547 port.dev = &dev->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002548 if (share_irqs)
2549 port.flags |= UPF_SHARE_IRQ;
Russell Kingec9f47c2005-06-27 11:12:54 +01002550 ret = serial8250_register_port(&port);
2551 if (ret < 0) {
Russell King3ae5eae2005-11-09 22:32:44 +00002552 dev_err(&dev->dev, "unable to register port at index %d "
Russell Kingec9f47c2005-06-27 11:12:54 +01002553 "(IO%lx MEM%lx IRQ%d): %d\n", i,
2554 p->iobase, p->mapbase, p->irq, ret);
2555 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002556 }
2557 return 0;
2558}
2559
2560/*
2561 * Remove serial ports registered against a platform device.
2562 */
Russell King3ae5eae2005-11-09 22:32:44 +00002563static int __devexit serial8250_remove(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002564{
2565 int i;
2566
Dave Jonesa61c2d72006-01-07 23:18:19 +00002567 for (i = 0; i < nr_uarts; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002568 struct uart_8250_port *up = &serial8250_ports[i];
2569
Russell King3ae5eae2005-11-09 22:32:44 +00002570 if (up->port.dev == &dev->dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002571 serial8250_unregister_port(i);
2572 }
2573 return 0;
2574}
2575
Russell King3ae5eae2005-11-09 22:32:44 +00002576static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002577{
2578 int i;
2579
Linus Torvalds1da177e2005-04-16 15:20:36 -07002580 for (i = 0; i < UART_NR; i++) {
2581 struct uart_8250_port *up = &serial8250_ports[i];
2582
Russell King3ae5eae2005-11-09 22:32:44 +00002583 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002584 uart_suspend_port(&serial8250_reg, &up->port);
2585 }
2586
2587 return 0;
2588}
2589
Russell King3ae5eae2005-11-09 22:32:44 +00002590static int serial8250_resume(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002591{
2592 int i;
2593
Linus Torvalds1da177e2005-04-16 15:20:36 -07002594 for (i = 0; i < UART_NR; i++) {
2595 struct uart_8250_port *up = &serial8250_ports[i];
2596
Russell King3ae5eae2005-11-09 22:32:44 +00002597 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002598 uart_resume_port(&serial8250_reg, &up->port);
2599 }
2600
2601 return 0;
2602}
2603
Russell King3ae5eae2005-11-09 22:32:44 +00002604static struct platform_driver serial8250_isa_driver = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002605 .probe = serial8250_probe,
2606 .remove = __devexit_p(serial8250_remove),
2607 .suspend = serial8250_suspend,
2608 .resume = serial8250_resume,
Russell King3ae5eae2005-11-09 22:32:44 +00002609 .driver = {
2610 .name = "serial8250",
Dmitry Torokhov7493a312006-01-13 22:06:43 +00002611 .owner = THIS_MODULE,
Russell King3ae5eae2005-11-09 22:32:44 +00002612 },
Linus Torvalds1da177e2005-04-16 15:20:36 -07002613};
2614
2615/*
2616 * This "device" covers _all_ ISA 8250-compatible serial devices listed
2617 * in the table in include/asm/serial.h
2618 */
2619static struct platform_device *serial8250_isa_devs;
2620
2621/*
2622 * serial8250_register_port and serial8250_unregister_port allows for
2623 * 16x50 serial ports to be configured at run-time, to support PCMCIA
2624 * modems and PCI multiport cards.
2625 */
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002626static DEFINE_MUTEX(serial_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002627
2628static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
2629{
2630 int i;
2631
2632 /*
2633 * First, find a port entry which matches.
2634 */
Dave Jonesa61c2d72006-01-07 23:18:19 +00002635 for (i = 0; i < nr_uarts; i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002636 if (uart_match_port(&serial8250_ports[i].port, port))
2637 return &serial8250_ports[i];
2638
2639 /*
2640 * We didn't find a matching entry, so look for the first
2641 * free entry. We look for one which hasn't been previously
2642 * used (indicated by zero iobase).
2643 */
Dave Jonesa61c2d72006-01-07 23:18:19 +00002644 for (i = 0; i < nr_uarts; i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002645 if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
2646 serial8250_ports[i].port.iobase == 0)
2647 return &serial8250_ports[i];
2648
2649 /*
2650 * That also failed. Last resort is to find any entry which
2651 * doesn't have a real port associated with it.
2652 */
Dave Jonesa61c2d72006-01-07 23:18:19 +00002653 for (i = 0; i < nr_uarts; i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002654 if (serial8250_ports[i].port.type == PORT_UNKNOWN)
2655 return &serial8250_ports[i];
2656
2657 return NULL;
2658}
2659
2660/**
2661 * serial8250_register_port - register a serial port
2662 * @port: serial port template
2663 *
2664 * Configure the serial port specified by the request. If the
2665 * port exists and is in use, it is hung up and unregistered
2666 * first.
2667 *
2668 * The port is then probed and if necessary the IRQ is autodetected
2669 * If this fails an error is returned.
2670 *
2671 * On success the port is ready to use and the line number is returned.
2672 */
2673int serial8250_register_port(struct uart_port *port)
2674{
2675 struct uart_8250_port *uart;
2676 int ret = -ENOSPC;
2677
2678 if (port->uartclk == 0)
2679 return -EINVAL;
2680
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002681 mutex_lock(&serial_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002682
2683 uart = serial8250_find_match_or_unused(port);
2684 if (uart) {
2685 uart_remove_one_port(&serial8250_reg, &uart->port);
2686
2687 uart->port.iobase = port->iobase;
2688 uart->port.membase = port->membase;
2689 uart->port.irq = port->irq;
2690 uart->port.uartclk = port->uartclk;
2691 uart->port.fifosize = port->fifosize;
2692 uart->port.regshift = port->regshift;
2693 uart->port.iotype = port->iotype;
2694 uart->port.flags = port->flags | UPF_BOOT_AUTOCONF;
2695 uart->port.mapbase = port->mapbase;
2696 if (port->dev)
2697 uart->port.dev = port->dev;
2698
2699 ret = uart_add_one_port(&serial8250_reg, &uart->port);
2700 if (ret == 0)
2701 ret = uart->port.line;
2702 }
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002703 mutex_unlock(&serial_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002704
2705 return ret;
2706}
2707EXPORT_SYMBOL(serial8250_register_port);
2708
2709/**
2710 * serial8250_unregister_port - remove a 16x50 serial port at runtime
2711 * @line: serial line number
2712 *
2713 * Remove one serial port. This may not be called from interrupt
2714 * context. We hand the port back to the our control.
2715 */
2716void serial8250_unregister_port(int line)
2717{
2718 struct uart_8250_port *uart = &serial8250_ports[line];
2719
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002720 mutex_lock(&serial_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002721 uart_remove_one_port(&serial8250_reg, &uart->port);
2722 if (serial8250_isa_devs) {
2723 uart->port.flags &= ~UPF_BOOT_AUTOCONF;
2724 uart->port.type = PORT_UNKNOWN;
2725 uart->port.dev = &serial8250_isa_devs->dev;
2726 uart_add_one_port(&serial8250_reg, &uart->port);
2727 } else {
2728 uart->port.dev = NULL;
2729 }
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002730 mutex_unlock(&serial_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002731}
2732EXPORT_SYMBOL(serial8250_unregister_port);
2733
2734static int __init serial8250_init(void)
2735{
2736 int ret, i;
2737
Dave Jonesa61c2d72006-01-07 23:18:19 +00002738 if (nr_uarts > UART_NR)
2739 nr_uarts = UART_NR;
2740
Linus Torvalds1da177e2005-04-16 15:20:36 -07002741 printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ "
Dave Jonesa61c2d72006-01-07 23:18:19 +00002742 "%d ports, IRQ sharing %sabled\n", nr_uarts,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002743 share_irqs ? "en" : "dis");
2744
2745 for (i = 0; i < NR_IRQS; i++)
2746 spin_lock_init(&irq_lists[i].lock);
2747
2748 ret = uart_register_driver(&serial8250_reg);
2749 if (ret)
2750 goto out;
2751
Dmitry Torokhov7493a312006-01-13 22:06:43 +00002752 serial8250_isa_devs = platform_device_alloc("serial8250",
2753 PLAT8250_DEV_LEGACY);
2754 if (!serial8250_isa_devs) {
2755 ret = -ENOMEM;
Russell Kingbc965a72006-01-18 09:54:29 +00002756 goto unreg_uart_drv;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002757 }
2758
Dmitry Torokhov7493a312006-01-13 22:06:43 +00002759 ret = platform_device_add(serial8250_isa_devs);
2760 if (ret)
2761 goto put_dev;
2762
Linus Torvalds1da177e2005-04-16 15:20:36 -07002763 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
2764
Russell Kingbc965a72006-01-18 09:54:29 +00002765 ret = platform_driver_register(&serial8250_isa_driver);
2766 if (ret == 0)
2767 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002768
Russell Kingbc965a72006-01-18 09:54:29 +00002769 platform_device_del(serial8250_isa_devs);
Dmitry Torokhov7493a312006-01-13 22:06:43 +00002770 put_dev:
2771 platform_device_put(serial8250_isa_devs);
Dmitry Torokhov7493a312006-01-13 22:06:43 +00002772 unreg_uart_drv:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002773 uart_unregister_driver(&serial8250_reg);
2774 out:
2775 return ret;
2776}
2777
2778static void __exit serial8250_exit(void)
2779{
2780 struct platform_device *isa_dev = serial8250_isa_devs;
2781
2782 /*
2783 * This tells serial8250_unregister_port() not to re-register
2784 * the ports (thereby making serial8250_isa_driver permanently
2785 * in use.)
2786 */
2787 serial8250_isa_devs = NULL;
2788
Russell King3ae5eae2005-11-09 22:32:44 +00002789 platform_driver_unregister(&serial8250_isa_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002790 platform_device_unregister(isa_dev);
2791
2792 uart_unregister_driver(&serial8250_reg);
2793}
2794
2795module_init(serial8250_init);
2796module_exit(serial8250_exit);
2797
2798EXPORT_SYMBOL(serial8250_suspend_port);
2799EXPORT_SYMBOL(serial8250_resume_port);
2800
2801MODULE_LICENSE("GPL");
2802MODULE_DESCRIPTION("Generic 8250/16x50 serial driver $Revision: 1.90 $");
2803
2804module_param(share_irqs, uint, 0644);
2805MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
2806 " (unsafe)");
2807
Dave Jonesa61c2d72006-01-07 23:18:19 +00002808module_param(nr_uarts, uint, 0644);
2809MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
2810
Linus Torvalds1da177e2005-04-16 15:20:36 -07002811#ifdef CONFIG_SERIAL_8250_RSA
2812module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
2813MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
2814#endif
2815MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);