ia64/linux-2.6.18-xen.hg

view drivers/serial/8250.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
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 */
23 #if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
24 #define SUPPORT_SYSRQ
25 #endif
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>
33 #include <linux/delay.h>
34 #include <linux/platform_device.h>
35 #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>
41 #include <linux/nmi.h>
42 #include <linux/mutex.h>
44 #include <asm/io.h>
45 #include <asm/irq.h>
47 #include "8250.h"
49 /*
50 * Configuration:
51 * share_irqs - whether we pass IRQF_SHARED to request_irq(). This option
52 * is unsafe when used on edge-triggered interrupts.
53 */
54 static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
56 static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
58 /*
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
67 #if 0
68 #define DEBUG_INTR(fmt...) printk(fmt)
69 #else
70 #define DEBUG_INTR(fmt...) do { } while (0)
71 #endif
73 #define PASS_LIMIT 256
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)
82 #ifdef CONFIG_SERIAL_8250_DETECT_IRQ
83 #define CONFIG_SERIAL_DETECT_IRQ 1
84 #endif
85 #ifdef CONFIG_SERIAL_8250_MANY_PORTS
86 #define CONFIG_SERIAL_MANY_PORTS 1
87 #endif
89 /*
90 * HUB6 is always on. This will be removed once the header
91 * files have been cleaned.
92 */
93 #define CONFIG_HUB6 1
95 #include <asm/serial.h>
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
106 static const struct old_serial_port old_serial_port[] = {
107 SERIAL_PORT_DFNS /* defined in asm/serial.h */
108 };
110 #define UART_NR CONFIG_SERIAL_8250_NR_UARTS
112 #ifdef CONFIG_SERIAL_8250_RSA
114 #define PORT_RSA_MAX 4
115 static unsigned long probe_rsa[PORT_RSA_MAX];
116 static unsigned int probe_rsa_count;
117 #endif /* CONFIG_SERIAL_8250_RSA */
119 struct 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 */
123 unsigned short capabilities; /* port capabilities */
124 unsigned short bugs; /* port bugs */
125 unsigned int tx_loadsz; /* transmit fifo load size */
126 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;
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 };
141 struct irq_info {
142 spinlock_t lock;
143 struct list_head *head;
144 };
146 static struct irq_info irq_lists[NR_IRQS];
148 /*
149 * Here we define the default xmit fifo size used for each type of UART.
150 */
151 static 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 };
256 #ifdef CONFIG_SERIAL_8250_AU1X00
258 /* Au1x00 UART hardware has a weird register layout */
259 static 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 };
269 static 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 };
277 /* sane hardware needs no mapping */
278 static 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 }
285 static 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 }
292 #else
294 /* sane hardware needs no mapping */
295 #define map_8250_in_reg(up, offset) (offset)
296 #define map_8250_out_reg(up, offset) (offset)
298 #endif
300 static unsigned int serial_in(struct uart_8250_port *up, int offset)
301 {
302 unsigned int tmp;
303 offset = map_8250_in_reg(up, offset) << up->port.regshift;
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);
310 case UPIO_MEM:
311 return readb(up->port.membase + offset);
313 case UPIO_MEM32:
314 return readl(up->port.membase + offset);
316 #ifdef CONFIG_SERIAL_8250_AU1X00
317 case UPIO_AU:
318 return __raw_readl(up->port.membase + offset);
319 #endif
321 case UPIO_TSI:
322 if (offset == UART_IIR) {
323 tmp = readl((u32 *)(up->port.membase + UART_RX));
324 return (cpu_to_le32(tmp) >> 8) & 0xff;
325 } else
326 return readb(up->port.membase + offset);
328 default:
329 return inb(up->port.iobase + offset);
330 }
331 }
333 static void
334 serial_out(struct uart_8250_port *up, int offset, int value)
335 {
336 offset = map_8250_out_reg(up, offset) << up->port.regshift;
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;
344 case UPIO_MEM:
345 writeb(value, up->port.membase + offset);
346 break;
348 case UPIO_MEM32:
349 writel(value, up->port.membase + offset);
350 break;
352 #ifdef CONFIG_SERIAL_8250_AU1X00
353 case UPIO_AU:
354 __raw_writel(value, up->port.membase + offset);
355 break;
356 #endif
357 case UPIO_TSI:
358 if (!((offset == UART_IER) && (value & UART_IER_UUE)))
359 writeb(value, up->port.membase + offset);
360 break;
362 default:
363 outb(value, up->port.iobase + offset);
364 }
365 }
367 /*
368 * We used to support using pause I/O for certain machines. We
369 * haven't supported this for a while, but just in case it's badly
370 * needed for certain old 386 machines, I've left these #define's
371 * in....
372 */
373 #define serial_inp(up, offset) serial_in(up, offset)
374 #define serial_outp(up, offset, value) serial_out(up, offset, value)
376 /* Uart divisor latch read */
377 static inline int _serial_dl_read(struct uart_8250_port *up)
378 {
379 return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
380 }
382 /* Uart divisor latch write */
383 static inline void _serial_dl_write(struct uart_8250_port *up, int value)
384 {
385 serial_outp(up, UART_DLL, value & 0xff);
386 serial_outp(up, UART_DLM, value >> 8 & 0xff);
387 }
389 #ifdef CONFIG_SERIAL_8250_AU1X00
390 /* Au1x00 haven't got a standard divisor latch */
391 static int serial_dl_read(struct uart_8250_port *up)
392 {
393 if (up->port.iotype == UPIO_AU)
394 return __raw_readl(up->port.membase + 0x28);
395 else
396 return _serial_dl_read(up);
397 }
399 static void serial_dl_write(struct uart_8250_port *up, int value)
400 {
401 if (up->port.iotype == UPIO_AU)
402 __raw_writel(value, up->port.membase + 0x28);
403 else
404 _serial_dl_write(up, value);
405 }
406 #else
407 #define serial_dl_read(up) _serial_dl_read(up)
408 #define serial_dl_write(up, value) _serial_dl_write(up, value)
409 #endif
411 /*
412 * For the 16C950
413 */
414 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
415 {
416 serial_out(up, UART_SCR, offset);
417 serial_out(up, UART_ICR, value);
418 }
420 static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
421 {
422 unsigned int value;
424 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
425 serial_out(up, UART_SCR, offset);
426 value = serial_in(up, UART_ICR);
427 serial_icr_write(up, UART_ACR, up->acr);
429 return value;
430 }
432 /*
433 * FIFO support.
434 */
435 static inline void serial8250_clear_fifos(struct uart_8250_port *p)
436 {
437 if (p->capabilities & UART_CAP_FIFO) {
438 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
439 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
440 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
441 serial_outp(p, UART_FCR, 0);
442 }
443 }
445 /*
446 * IER sleep support. UARTs which have EFRs need the "extended
447 * capability" bit enabled. Note that on XR16C850s, we need to
448 * reset LCR to write to IER.
449 */
450 static inline void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
451 {
452 if (p->capabilities & UART_CAP_SLEEP) {
453 if (p->capabilities & UART_CAP_EFR) {
454 serial_outp(p, UART_LCR, 0xBF);
455 serial_outp(p, UART_EFR, UART_EFR_ECB);
456 serial_outp(p, UART_LCR, 0);
457 }
458 serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
459 if (p->capabilities & UART_CAP_EFR) {
460 serial_outp(p, UART_LCR, 0xBF);
461 serial_outp(p, UART_EFR, 0);
462 serial_outp(p, UART_LCR, 0);
463 }
464 }
465 }
467 #ifdef CONFIG_SERIAL_8250_RSA
468 /*
469 * Attempts to turn on the RSA FIFO. Returns zero on failure.
470 * We set the port uart clock rate if we succeed.
471 */
472 static int __enable_rsa(struct uart_8250_port *up)
473 {
474 unsigned char mode;
475 int result;
477 mode = serial_inp(up, UART_RSA_MSR);
478 result = mode & UART_RSA_MSR_FIFO;
480 if (!result) {
481 serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
482 mode = serial_inp(up, UART_RSA_MSR);
483 result = mode & UART_RSA_MSR_FIFO;
484 }
486 if (result)
487 up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
489 return result;
490 }
492 static void enable_rsa(struct uart_8250_port *up)
493 {
494 if (up->port.type == PORT_RSA) {
495 if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
496 spin_lock_irq(&up->port.lock);
497 __enable_rsa(up);
498 spin_unlock_irq(&up->port.lock);
499 }
500 if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
501 serial_outp(up, UART_RSA_FRR, 0);
502 }
503 }
505 /*
506 * Attempts to turn off the RSA FIFO. Returns zero on failure.
507 * It is unknown why interrupts were disabled in here. However,
508 * the caller is expected to preserve this behaviour by grabbing
509 * the spinlock before calling this function.
510 */
511 static void disable_rsa(struct uart_8250_port *up)
512 {
513 unsigned char mode;
514 int result;
516 if (up->port.type == PORT_RSA &&
517 up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
518 spin_lock_irq(&up->port.lock);
520 mode = serial_inp(up, UART_RSA_MSR);
521 result = !(mode & UART_RSA_MSR_FIFO);
523 if (!result) {
524 serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
525 mode = serial_inp(up, UART_RSA_MSR);
526 result = !(mode & UART_RSA_MSR_FIFO);
527 }
529 if (result)
530 up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
531 spin_unlock_irq(&up->port.lock);
532 }
533 }
534 #endif /* CONFIG_SERIAL_8250_RSA */
536 /*
537 * This is a quickie test to see how big the FIFO is.
538 * It doesn't work at all the time, more's the pity.
539 */
540 static int size_fifo(struct uart_8250_port *up)
541 {
542 unsigned char old_fcr, old_mcr, old_lcr;
543 unsigned short old_dl;
544 int count;
546 old_lcr = serial_inp(up, UART_LCR);
547 serial_outp(up, UART_LCR, 0);
548 old_fcr = serial_inp(up, UART_FCR);
549 old_mcr = serial_inp(up, UART_MCR);
550 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
551 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
552 serial_outp(up, UART_MCR, UART_MCR_LOOP);
553 serial_outp(up, UART_LCR, UART_LCR_DLAB);
554 old_dl = serial_dl_read(up);
555 serial_dl_write(up, 0x0001);
556 serial_outp(up, UART_LCR, 0x03);
557 for (count = 0; count < 256; count++)
558 serial_outp(up, UART_TX, count);
559 mdelay(20);/* FIXME - schedule_timeout */
560 for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
561 (count < 256); count++)
562 serial_inp(up, UART_RX);
563 serial_outp(up, UART_FCR, old_fcr);
564 serial_outp(up, UART_MCR, old_mcr);
565 serial_outp(up, UART_LCR, UART_LCR_DLAB);
566 serial_dl_write(up, old_dl);
567 serial_outp(up, UART_LCR, old_lcr);
569 return count;
570 }
572 /*
573 * Read UART ID using the divisor method - set DLL and DLM to zero
574 * and the revision will be in DLL and device type in DLM. We
575 * preserve the device state across this.
576 */
577 static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
578 {
579 unsigned char old_dll, old_dlm, old_lcr;
580 unsigned int id;
582 old_lcr = serial_inp(p, UART_LCR);
583 serial_outp(p, UART_LCR, UART_LCR_DLAB);
585 old_dll = serial_inp(p, UART_DLL);
586 old_dlm = serial_inp(p, UART_DLM);
588 serial_outp(p, UART_DLL, 0);
589 serial_outp(p, UART_DLM, 0);
591 id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
593 serial_outp(p, UART_DLL, old_dll);
594 serial_outp(p, UART_DLM, old_dlm);
595 serial_outp(p, UART_LCR, old_lcr);
597 return id;
598 }
600 /*
601 * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
602 * When this function is called we know it is at least a StarTech
603 * 16650 V2, but it might be one of several StarTech UARTs, or one of
604 * its clones. (We treat the broken original StarTech 16650 V1 as a
605 * 16550, and why not? Startech doesn't seem to even acknowledge its
606 * existence.)
607 *
608 * What evil have men's minds wrought...
609 */
610 static void autoconfig_has_efr(struct uart_8250_port *up)
611 {
612 unsigned int id1, id2, id3, rev;
614 /*
615 * Everything with an EFR has SLEEP
616 */
617 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
619 /*
620 * First we check to see if it's an Oxford Semiconductor UART.
621 *
622 * If we have to do this here because some non-National
623 * Semiconductor clone chips lock up if you try writing to the
624 * LSR register (which serial_icr_read does)
625 */
627 /*
628 * Check for Oxford Semiconductor 16C950.
629 *
630 * EFR [4] must be set else this test fails.
631 *
632 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
633 * claims that it's needed for 952 dual UART's (which are not
634 * recommended for new designs).
635 */
636 up->acr = 0;
637 serial_out(up, UART_LCR, 0xBF);
638 serial_out(up, UART_EFR, UART_EFR_ECB);
639 serial_out(up, UART_LCR, 0x00);
640 id1 = serial_icr_read(up, UART_ID1);
641 id2 = serial_icr_read(up, UART_ID2);
642 id3 = serial_icr_read(up, UART_ID3);
643 rev = serial_icr_read(up, UART_REV);
645 DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
647 if (id1 == 0x16 && id2 == 0xC9 &&
648 (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
649 up->port.type = PORT_16C950;
651 /*
652 * Enable work around for the Oxford Semiconductor 952 rev B
653 * chip which causes it to seriously miscalculate baud rates
654 * when DLL is 0.
655 */
656 if (id3 == 0x52 && rev == 0x01)
657 up->bugs |= UART_BUG_QUOT;
658 return;
659 }
661 /*
662 * We check for a XR16C850 by setting DLL and DLM to 0, and then
663 * reading back DLL and DLM. The chip type depends on the DLM
664 * value read back:
665 * 0x10 - XR16C850 and the DLL contains the chip revision.
666 * 0x12 - XR16C2850.
667 * 0x14 - XR16C854.
668 */
669 id1 = autoconfig_read_divisor_id(up);
670 DEBUG_AUTOCONF("850id=%04x ", id1);
672 id2 = id1 >> 8;
673 if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
674 up->port.type = PORT_16850;
675 return;
676 }
678 /*
679 * It wasn't an XR16C850.
680 *
681 * We distinguish between the '654 and the '650 by counting
682 * how many bytes are in the FIFO. I'm using this for now,
683 * since that's the technique that was sent to me in the
684 * serial driver update, but I'm not convinced this works.
685 * I've had problems doing this in the past. -TYT
686 */
687 if (size_fifo(up) == 64)
688 up->port.type = PORT_16654;
689 else
690 up->port.type = PORT_16650V2;
691 }
693 /*
694 * We detected a chip without a FIFO. Only two fall into
695 * this category - the original 8250 and the 16450. The
696 * 16450 has a scratch register (accessible with LCR=0)
697 */
698 static void autoconfig_8250(struct uart_8250_port *up)
699 {
700 unsigned char scratch, status1, status2;
702 up->port.type = PORT_8250;
704 scratch = serial_in(up, UART_SCR);
705 serial_outp(up, UART_SCR, 0xa5);
706 status1 = serial_in(up, UART_SCR);
707 serial_outp(up, UART_SCR, 0x5a);
708 status2 = serial_in(up, UART_SCR);
709 serial_outp(up, UART_SCR, scratch);
711 if (status1 == 0xa5 && status2 == 0x5a)
712 up->port.type = PORT_16450;
713 }
715 static int broken_efr(struct uart_8250_port *up)
716 {
717 /*
718 * Exar ST16C2550 "A2" devices incorrectly detect as
719 * having an EFR, and report an ID of 0x0201. See
720 * http://www.exar.com/info.php?pdf=dan180_oct2004.pdf
721 */
722 if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
723 return 1;
725 return 0;
726 }
728 /*
729 * We know that the chip has FIFOs. Does it have an EFR? The
730 * EFR is located in the same register position as the IIR and
731 * we know the top two bits of the IIR are currently set. The
732 * EFR should contain zero. Try to read the EFR.
733 */
734 static void autoconfig_16550a(struct uart_8250_port *up)
735 {
736 unsigned char status1, status2;
737 unsigned int iersave;
739 up->port.type = PORT_16550A;
740 up->capabilities |= UART_CAP_FIFO;
742 /*
743 * Check for presence of the EFR when DLAB is set.
744 * Only ST16C650V1 UARTs pass this test.
745 */
746 serial_outp(up, UART_LCR, UART_LCR_DLAB);
747 if (serial_in(up, UART_EFR) == 0) {
748 serial_outp(up, UART_EFR, 0xA8);
749 if (serial_in(up, UART_EFR) != 0) {
750 DEBUG_AUTOCONF("EFRv1 ");
751 up->port.type = PORT_16650;
752 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
753 } else {
754 DEBUG_AUTOCONF("Motorola 8xxx DUART ");
755 }
756 serial_outp(up, UART_EFR, 0);
757 return;
758 }
760 /*
761 * Maybe it requires 0xbf to be written to the LCR.
762 * (other ST16C650V2 UARTs, TI16C752A, etc)
763 */
764 serial_outp(up, UART_LCR, 0xBF);
765 if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
766 DEBUG_AUTOCONF("EFRv2 ");
767 autoconfig_has_efr(up);
768 return;
769 }
771 /*
772 * Check for a National Semiconductor SuperIO chip.
773 * Attempt to switch to bank 2, read the value of the LOOP bit
774 * from EXCR1. Switch back to bank 0, change it in MCR. Then
775 * switch back to bank 2, read it from EXCR1 again and check
776 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
777 */
778 serial_outp(up, UART_LCR, 0);
779 status1 = serial_in(up, UART_MCR);
780 serial_outp(up, UART_LCR, 0xE0);
781 status2 = serial_in(up, 0x02); /* EXCR1 */
783 if (!((status2 ^ status1) & UART_MCR_LOOP)) {
784 serial_outp(up, UART_LCR, 0);
785 serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
786 serial_outp(up, UART_LCR, 0xE0);
787 status2 = serial_in(up, 0x02); /* EXCR1 */
788 serial_outp(up, UART_LCR, 0);
789 serial_outp(up, UART_MCR, status1);
791 if ((status2 ^ status1) & UART_MCR_LOOP) {
792 unsigned short quot;
794 serial_outp(up, UART_LCR, 0xE0);
796 quot = serial_dl_read(up);
797 quot <<= 3;
799 status1 = serial_in(up, 0x04); /* EXCR1 */
800 status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
801 status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
802 serial_outp(up, 0x04, status1);
804 serial_dl_write(up, quot);
806 serial_outp(up, UART_LCR, 0);
808 up->port.uartclk = 921600*16;
809 up->port.type = PORT_NS16550A;
810 up->capabilities |= UART_NATSEMI;
811 return;
812 }
813 }
815 /*
816 * No EFR. Try to detect a TI16750, which only sets bit 5 of
817 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
818 * Try setting it with and without DLAB set. Cheap clones
819 * set bit 5 without DLAB set.
820 */
821 serial_outp(up, UART_LCR, 0);
822 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
823 status1 = serial_in(up, UART_IIR) >> 5;
824 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
825 serial_outp(up, UART_LCR, UART_LCR_DLAB);
826 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
827 status2 = serial_in(up, UART_IIR) >> 5;
828 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
829 serial_outp(up, UART_LCR, 0);
831 DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
833 if (status1 == 6 && status2 == 7) {
834 up->port.type = PORT_16750;
835 up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
836 return;
837 }
839 /*
840 * Try writing and reading the UART_IER_UUE bit (b6).
841 * If it works, this is probably one of the Xscale platform's
842 * internal UARTs.
843 * We're going to explicitly set the UUE bit to 0 before
844 * trying to write and read a 1 just to make sure it's not
845 * already a 1 and maybe locked there before we even start start.
846 */
847 iersave = serial_in(up, UART_IER);
848 serial_outp(up, UART_IER, iersave & ~UART_IER_UUE);
849 if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
850 /*
851 * OK it's in a known zero state, try writing and reading
852 * without disturbing the current state of the other bits.
853 */
854 serial_outp(up, UART_IER, iersave | UART_IER_UUE);
855 if (serial_in(up, UART_IER) & UART_IER_UUE) {
856 /*
857 * It's an Xscale.
858 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
859 */
860 DEBUG_AUTOCONF("Xscale ");
861 up->port.type = PORT_XSCALE;
862 up->capabilities |= UART_CAP_UUE;
863 return;
864 }
865 } else {
866 /*
867 * If we got here we couldn't force the IER_UUE bit to 0.
868 * Log it and continue.
869 */
870 DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
871 }
872 serial_outp(up, UART_IER, iersave);
873 }
875 /*
876 * This routine is called by rs_init() to initialize a specific serial
877 * port. It determines what type of UART chip this serial port is
878 * using: 8250, 16450, 16550, 16550A. The important question is
879 * whether or not this UART is a 16550A or not, since this will
880 * determine whether or not we can use its FIFO features or not.
881 */
882 static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
883 {
884 unsigned char status1, scratch, scratch2, scratch3;
885 unsigned char save_lcr, save_mcr;
886 unsigned long flags;
888 if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
889 return;
891 DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04x, 0x%p): ",
892 up->port.line, up->port.iobase, up->port.membase);
894 /*
895 * We really do need global IRQs disabled here - we're going to
896 * be frobbing the chips IRQ enable register to see if it exists.
897 */
898 spin_lock_irqsave(&up->port.lock, flags);
899 // save_flags(flags); cli();
901 up->capabilities = 0;
902 up->bugs = 0;
904 if (!(up->port.flags & UPF_BUGGY_UART)) {
905 /*
906 * Do a simple existence test first; if we fail this,
907 * there's no point trying anything else.
908 *
909 * 0x80 is used as a nonsense port to prevent against
910 * false positives due to ISA bus float. The
911 * assumption is that 0x80 is a non-existent port;
912 * which should be safe since include/asm/io.h also
913 * makes this assumption.
914 *
915 * Note: this is safe as long as MCR bit 4 is clear
916 * and the device is in "PC" mode.
917 */
918 scratch = serial_inp(up, UART_IER);
919 serial_outp(up, UART_IER, 0);
920 #ifdef __i386__
921 outb(0xff, 0x080);
922 #endif
923 scratch2 = serial_inp(up, UART_IER);
924 serial_outp(up, UART_IER, 0x0F);
925 #ifdef __i386__
926 outb(0, 0x080);
927 #endif
928 scratch3 = serial_inp(up, UART_IER);
929 serial_outp(up, UART_IER, scratch);
930 if (scratch2 != 0 || scratch3 != 0x0F) {
931 /*
932 * We failed; there's nothing here
933 */
934 DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
935 scratch2, scratch3);
936 goto out;
937 }
938 }
940 save_mcr = serial_in(up, UART_MCR);
941 save_lcr = serial_in(up, UART_LCR);
943 /*
944 * Check to see if a UART is really there. Certain broken
945 * internal modems based on the Rockwell chipset fail this
946 * test, because they apparently don't implement the loopback
947 * test mode. So this test is skipped on the COM 1 through
948 * COM 4 ports. This *should* be safe, since no board
949 * manufacturer would be stupid enough to design a board
950 * that conflicts with COM 1-4 --- we hope!
951 */
952 if (!(up->port.flags & UPF_SKIP_TEST)) {
953 serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
954 status1 = serial_inp(up, UART_MSR) & 0xF0;
955 serial_outp(up, UART_MCR, save_mcr);
956 if (status1 != 0x90) {
957 DEBUG_AUTOCONF("LOOP test failed (%02x) ",
958 status1);
959 goto out;
960 }
961 }
963 /*
964 * We're pretty sure there's a port here. Lets find out what
965 * type of port it is. The IIR top two bits allows us to find
966 * out if it's 8250 or 16450, 16550, 16550A or later. This
967 * determines what we test for next.
968 *
969 * We also initialise the EFR (if any) to zero for later. The
970 * EFR occupies the same register location as the FCR and IIR.
971 */
972 serial_outp(up, UART_LCR, 0xBF);
973 serial_outp(up, UART_EFR, 0);
974 serial_outp(up, UART_LCR, 0);
976 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
977 scratch = serial_in(up, UART_IIR) >> 6;
979 DEBUG_AUTOCONF("iir=%d ", scratch);
981 switch (scratch) {
982 case 0:
983 autoconfig_8250(up);
984 break;
985 case 1:
986 up->port.type = PORT_UNKNOWN;
987 break;
988 case 2:
989 up->port.type = PORT_16550;
990 break;
991 case 3:
992 autoconfig_16550a(up);
993 break;
994 }
996 #ifdef CONFIG_SERIAL_8250_RSA
997 /*
998 * Only probe for RSA ports if we got the region.
999 */
1000 if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
1001 int i;
1003 for (i = 0 ; i < probe_rsa_count; ++i) {
1004 if (probe_rsa[i] == up->port.iobase &&
1005 __enable_rsa(up)) {
1006 up->port.type = PORT_RSA;
1007 break;
1011 #endif
1013 #ifdef CONFIG_SERIAL_8250_AU1X00
1014 /* if access method is AU, it is a 16550 with a quirk */
1015 if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
1016 up->bugs |= UART_BUG_NOMSR;
1017 #endif
1019 serial_outp(up, UART_LCR, save_lcr);
1021 if (up->capabilities != uart_config[up->port.type].flags) {
1022 printk(KERN_WARNING
1023 "ttyS%d: detected caps %08x should be %08x\n",
1024 up->port.line, up->capabilities,
1025 uart_config[up->port.type].flags);
1028 up->port.fifosize = uart_config[up->port.type].fifo_size;
1029 up->capabilities = uart_config[up->port.type].flags;
1030 up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
1032 if (up->port.type == PORT_UNKNOWN)
1033 goto out;
1035 /*
1036 * Reset the UART.
1037 */
1038 #ifdef CONFIG_SERIAL_8250_RSA
1039 if (up->port.type == PORT_RSA)
1040 serial_outp(up, UART_RSA_FRR, 0);
1041 #endif
1042 serial_outp(up, UART_MCR, save_mcr);
1043 serial8250_clear_fifos(up);
1044 (void)serial_in(up, UART_RX);
1045 if (up->capabilities & UART_CAP_UUE)
1046 serial_outp(up, UART_IER, UART_IER_UUE);
1047 else
1048 serial_outp(up, UART_IER, 0);
1050 out:
1051 spin_unlock_irqrestore(&up->port.lock, flags);
1052 // restore_flags(flags);
1053 DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
1056 static void autoconfig_irq(struct uart_8250_port *up)
1058 unsigned char save_mcr, save_ier;
1059 unsigned char save_ICP = 0;
1060 unsigned int ICP = 0;
1061 unsigned long irqs;
1062 int irq;
1064 if (up->port.flags & UPF_FOURPORT) {
1065 ICP = (up->port.iobase & 0xfe0) | 0x1f;
1066 save_ICP = inb_p(ICP);
1067 outb_p(0x80, ICP);
1068 (void) inb_p(ICP);
1071 /* forget possible initially masked and pending IRQ */
1072 probe_irq_off(probe_irq_on());
1073 save_mcr = serial_inp(up, UART_MCR);
1074 save_ier = serial_inp(up, UART_IER);
1075 serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
1077 irqs = probe_irq_on();
1078 serial_outp(up, UART_MCR, 0);
1079 udelay (10);
1080 if (up->port.flags & UPF_FOURPORT) {
1081 serial_outp(up, UART_MCR,
1082 UART_MCR_DTR | UART_MCR_RTS);
1083 } else {
1084 serial_outp(up, UART_MCR,
1085 UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
1087 serial_outp(up, UART_IER, 0x0f); /* enable all intrs */
1088 (void)serial_inp(up, UART_LSR);
1089 (void)serial_inp(up, UART_RX);
1090 (void)serial_inp(up, UART_IIR);
1091 (void)serial_inp(up, UART_MSR);
1092 serial_outp(up, UART_TX, 0xFF);
1093 udelay (20);
1094 irq = probe_irq_off(irqs);
1096 serial_outp(up, UART_MCR, save_mcr);
1097 serial_outp(up, UART_IER, save_ier);
1099 if (up->port.flags & UPF_FOURPORT)
1100 outb_p(save_ICP, ICP);
1102 up->port.irq = (irq > 0) ? irq : 0;
1105 static inline void __stop_tx(struct uart_8250_port *p)
1107 if (p->ier & UART_IER_THRI) {
1108 p->ier &= ~UART_IER_THRI;
1109 serial_out(p, UART_IER, p->ier);
1113 static void serial8250_stop_tx(struct uart_port *port)
1115 struct uart_8250_port *up = (struct uart_8250_port *)port;
1117 __stop_tx(up);
1119 /*
1120 * We really want to stop the transmitter from sending.
1121 */
1122 if (up->port.type == PORT_16C950) {
1123 up->acr |= UART_ACR_TXDIS;
1124 serial_icr_write(up, UART_ACR, up->acr);
1128 static void transmit_chars(struct uart_8250_port *up);
1130 static void serial8250_start_tx(struct uart_port *port)
1132 struct uart_8250_port *up = (struct uart_8250_port *)port;
1134 if (!(up->ier & UART_IER_THRI)) {
1135 up->ier |= UART_IER_THRI;
1136 serial_out(up, UART_IER, up->ier);
1138 if (up->bugs & UART_BUG_TXEN) {
1139 unsigned char lsr, iir;
1140 lsr = serial_in(up, UART_LSR);
1141 iir = serial_in(up, UART_IIR);
1142 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
1143 transmit_chars(up);
1147 /*
1148 * Re-enable the transmitter if we disabled it.
1149 */
1150 if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
1151 up->acr &= ~UART_ACR_TXDIS;
1152 serial_icr_write(up, UART_ACR, up->acr);
1156 static void serial8250_stop_rx(struct uart_port *port)
1158 struct uart_8250_port *up = (struct uart_8250_port *)port;
1160 up->ier &= ~UART_IER_RLSI;
1161 up->port.read_status_mask &= ~UART_LSR_DR;
1162 serial_out(up, UART_IER, up->ier);
1165 static void serial8250_enable_ms(struct uart_port *port)
1167 struct uart_8250_port *up = (struct uart_8250_port *)port;
1169 /* no MSR capabilities */
1170 if (up->bugs & UART_BUG_NOMSR)
1171 return;
1173 up->ier |= UART_IER_MSI;
1174 serial_out(up, UART_IER, up->ier);
1177 static void
1178 receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs)
1180 struct tty_struct *tty = up->port.info->tty;
1181 unsigned char ch, lsr = *status;
1182 int max_count = 256;
1183 char flag;
1185 do {
1186 ch = serial_inp(up, UART_RX);
1187 flag = TTY_NORMAL;
1188 up->port.icount.rx++;
1190 #ifdef CONFIG_SERIAL_8250_CONSOLE
1191 /*
1192 * Recover the break flag from console xmit
1193 */
1194 if (up->port.line == up->port.cons->index) {
1195 lsr |= up->lsr_break_flag;
1196 up->lsr_break_flag = 0;
1198 #endif
1200 if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE |
1201 UART_LSR_FE | UART_LSR_OE))) {
1202 /*
1203 * For statistics only
1204 */
1205 if (lsr & UART_LSR_BI) {
1206 lsr &= ~(UART_LSR_FE | UART_LSR_PE);
1207 up->port.icount.brk++;
1208 /*
1209 * We do the SysRQ and SAK checking
1210 * here because otherwise the break
1211 * may get masked by ignore_status_mask
1212 * or read_status_mask.
1213 */
1214 if (uart_handle_break(&up->port))
1215 goto ignore_char;
1216 } else if (lsr & UART_LSR_PE)
1217 up->port.icount.parity++;
1218 else if (lsr & UART_LSR_FE)
1219 up->port.icount.frame++;
1220 if (lsr & UART_LSR_OE)
1221 up->port.icount.overrun++;
1223 /*
1224 * Mask off conditions which should be ignored.
1225 */
1226 lsr &= up->port.read_status_mask;
1228 if (lsr & UART_LSR_BI) {
1229 DEBUG_INTR("handling break....");
1230 flag = TTY_BREAK;
1231 } else if (lsr & UART_LSR_PE)
1232 flag = TTY_PARITY;
1233 else if (lsr & UART_LSR_FE)
1234 flag = TTY_FRAME;
1236 if (uart_handle_sysrq_char(&up->port, ch, regs))
1237 goto ignore_char;
1239 uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
1241 ignore_char:
1242 lsr = serial_inp(up, UART_LSR);
1243 } while ((lsr & UART_LSR_DR) && (max_count-- > 0));
1244 spin_unlock(&up->port.lock);
1245 tty_flip_buffer_push(tty);
1246 spin_lock(&up->port.lock);
1247 *status = lsr;
1250 static void transmit_chars(struct uart_8250_port *up)
1252 struct circ_buf *xmit = &up->port.info->xmit;
1253 int count;
1255 if (up->port.x_char) {
1256 serial_outp(up, UART_TX, up->port.x_char);
1257 up->port.icount.tx++;
1258 up->port.x_char = 0;
1259 return;
1261 if (uart_tx_stopped(&up->port)) {
1262 serial8250_stop_tx(&up->port);
1263 return;
1265 if (uart_circ_empty(xmit)) {
1266 __stop_tx(up);
1267 return;
1270 count = up->tx_loadsz;
1271 do {
1272 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
1273 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1274 up->port.icount.tx++;
1275 if (uart_circ_empty(xmit))
1276 break;
1277 } while (--count > 0);
1279 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1280 uart_write_wakeup(&up->port);
1282 DEBUG_INTR("THRE...");
1284 if (uart_circ_empty(xmit))
1285 __stop_tx(up);
1288 static unsigned int check_modem_status(struct uart_8250_port *up)
1290 unsigned int status = serial_in(up, UART_MSR);
1292 if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI) {
1293 if (status & UART_MSR_TERI)
1294 up->port.icount.rng++;
1295 if (status & UART_MSR_DDSR)
1296 up->port.icount.dsr++;
1297 if (status & UART_MSR_DDCD)
1298 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
1299 if (status & UART_MSR_DCTS)
1300 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
1302 wake_up_interruptible(&up->port.info->delta_msr_wait);
1305 return status;
1308 /*
1309 * This handles the interrupt from one port.
1310 */
1311 static inline void
1312 serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs)
1314 unsigned int status;
1316 spin_lock(&up->port.lock);
1318 status = serial_inp(up, UART_LSR);
1320 DEBUG_INTR("status = %x...", status);
1322 if (status & UART_LSR_DR)
1323 receive_chars(up, &status, regs);
1324 check_modem_status(up);
1325 if (status & UART_LSR_THRE)
1326 transmit_chars(up);
1328 spin_unlock(&up->port.lock);
1331 /*
1332 * This is the serial driver's interrupt routine.
1334 * Arjan thinks the old way was overly complex, so it got simplified.
1335 * Alan disagrees, saying that need the complexity to handle the weird
1336 * nature of ISA shared interrupts. (This is a special exception.)
1338 * In order to handle ISA shared interrupts properly, we need to check
1339 * that all ports have been serviced, and therefore the ISA interrupt
1340 * line has been de-asserted.
1342 * This means we need to loop through all ports. checking that they
1343 * don't have an interrupt pending.
1344 */
1345 static irqreturn_t serial8250_interrupt(int irq, void *dev_id, struct pt_regs *regs)
1347 struct irq_info *i = dev_id;
1348 struct list_head *l, *end = NULL;
1349 int pass_counter = 0, handled = 0;
1351 DEBUG_INTR("serial8250_interrupt(%d)...", irq);
1353 spin_lock(&i->lock);
1355 l = i->head;
1356 do {
1357 struct uart_8250_port *up;
1358 unsigned int iir;
1360 up = list_entry(l, struct uart_8250_port, list);
1362 iir = serial_in(up, UART_IIR);
1363 if (!(iir & UART_IIR_NO_INT)) {
1364 serial8250_handle_port(up, regs);
1366 handled = 1;
1368 end = NULL;
1369 } else if (end == NULL)
1370 end = l;
1372 l = l->next;
1374 if (l == i->head && pass_counter++ > PASS_LIMIT) {
1375 /* If we hit this, we're dead. */
1376 printk(KERN_ERR "serial8250: too much work for "
1377 "irq%d\n", irq);
1378 break;
1380 } while (l != end);
1382 spin_unlock(&i->lock);
1384 DEBUG_INTR("end.\n");
1386 return IRQ_RETVAL(handled);
1389 /*
1390 * To support ISA shared interrupts, we need to have one interrupt
1391 * handler that ensures that the IRQ line has been deasserted
1392 * before returning. Failing to do this will result in the IRQ
1393 * line being stuck active, and, since ISA irqs are edge triggered,
1394 * no more IRQs will be seen.
1395 */
1396 static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
1398 spin_lock_irq(&i->lock);
1400 if (!list_empty(i->head)) {
1401 if (i->head == &up->list)
1402 i->head = i->head->next;
1403 list_del(&up->list);
1404 } else {
1405 BUG_ON(i->head != &up->list);
1406 i->head = NULL;
1409 spin_unlock_irq(&i->lock);
1412 static int serial_link_irq_chain(struct uart_8250_port *up)
1414 struct irq_info *i = irq_lists + up->port.irq;
1415 int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
1417 spin_lock_irq(&i->lock);
1419 if (i->head) {
1420 list_add(&up->list, i->head);
1421 spin_unlock_irq(&i->lock);
1423 ret = 0;
1424 } else {
1425 INIT_LIST_HEAD(&up->list);
1426 i->head = &up->list;
1427 spin_unlock_irq(&i->lock);
1429 ret = request_irq(up->port.irq, serial8250_interrupt,
1430 irq_flags, "serial", i);
1431 if (ret < 0)
1432 serial_do_unlink(i, up);
1435 return ret;
1438 static void serial_unlink_irq_chain(struct uart_8250_port *up)
1440 struct irq_info *i = irq_lists + up->port.irq;
1442 BUG_ON(i->head == NULL);
1444 if (list_empty(i->head))
1445 free_irq(up->port.irq, i);
1447 serial_do_unlink(i, up);
1450 /*
1451 * This function is used to handle ports that do not have an
1452 * interrupt. This doesn't work very well for 16450's, but gives
1453 * barely passable results for a 16550A. (Although at the expense
1454 * of much CPU overhead).
1455 */
1456 static void serial8250_timeout(unsigned long data)
1458 struct uart_8250_port *up = (struct uart_8250_port *)data;
1459 unsigned int timeout;
1460 unsigned int iir;
1462 iir = serial_in(up, UART_IIR);
1463 if (!(iir & UART_IIR_NO_INT))
1464 serial8250_handle_port(up, NULL);
1466 timeout = up->port.timeout;
1467 timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
1468 mod_timer(&up->timer, jiffies + timeout);
1471 static unsigned int serial8250_tx_empty(struct uart_port *port)
1473 struct uart_8250_port *up = (struct uart_8250_port *)port;
1474 unsigned long flags;
1475 unsigned int ret;
1477 spin_lock_irqsave(&up->port.lock, flags);
1478 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
1479 spin_unlock_irqrestore(&up->port.lock, flags);
1481 return ret;
1484 static unsigned int serial8250_get_mctrl(struct uart_port *port)
1486 struct uart_8250_port *up = (struct uart_8250_port *)port;
1487 unsigned int status;
1488 unsigned int ret;
1490 status = check_modem_status(up);
1492 ret = 0;
1493 if (status & UART_MSR_DCD)
1494 ret |= TIOCM_CAR;
1495 if (status & UART_MSR_RI)
1496 ret |= TIOCM_RNG;
1497 if (status & UART_MSR_DSR)
1498 ret |= TIOCM_DSR;
1499 if (status & UART_MSR_CTS)
1500 ret |= TIOCM_CTS;
1501 return ret;
1504 static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
1506 struct uart_8250_port *up = (struct uart_8250_port *)port;
1507 unsigned char mcr = 0;
1509 if (mctrl & TIOCM_RTS)
1510 mcr |= UART_MCR_RTS;
1511 if (mctrl & TIOCM_DTR)
1512 mcr |= UART_MCR_DTR;
1513 if (mctrl & TIOCM_OUT1)
1514 mcr |= UART_MCR_OUT1;
1515 if (mctrl & TIOCM_OUT2)
1516 mcr |= UART_MCR_OUT2;
1517 if (mctrl & TIOCM_LOOP)
1518 mcr |= UART_MCR_LOOP;
1520 mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
1522 serial_out(up, UART_MCR, mcr);
1525 static void serial8250_break_ctl(struct uart_port *port, int break_state)
1527 struct uart_8250_port *up = (struct uart_8250_port *)port;
1528 unsigned long flags;
1530 spin_lock_irqsave(&up->port.lock, flags);
1531 if (break_state == -1)
1532 up->lcr |= UART_LCR_SBC;
1533 else
1534 up->lcr &= ~UART_LCR_SBC;
1535 serial_out(up, UART_LCR, up->lcr);
1536 spin_unlock_irqrestore(&up->port.lock, flags);
1539 static int serial8250_startup(struct uart_port *port)
1541 struct uart_8250_port *up = (struct uart_8250_port *)port;
1542 unsigned long flags;
1543 unsigned char lsr, iir;
1544 int retval;
1546 up->capabilities = uart_config[up->port.type].flags;
1547 up->mcr = 0;
1549 if (up->port.type == PORT_16C950) {
1550 /* Wake up and initialize UART */
1551 up->acr = 0;
1552 serial_outp(up, UART_LCR, 0xBF);
1553 serial_outp(up, UART_EFR, UART_EFR_ECB);
1554 serial_outp(up, UART_IER, 0);
1555 serial_outp(up, UART_LCR, 0);
1556 serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
1557 serial_outp(up, UART_LCR, 0xBF);
1558 serial_outp(up, UART_EFR, UART_EFR_ECB);
1559 serial_outp(up, UART_LCR, 0);
1562 #ifdef CONFIG_SERIAL_8250_RSA
1563 /*
1564 * If this is an RSA port, see if we can kick it up to the
1565 * higher speed clock.
1566 */
1567 enable_rsa(up);
1568 #endif
1570 /*
1571 * Clear the FIFO buffers and disable them.
1572 * (they will be reenabled in set_termios())
1573 */
1574 serial8250_clear_fifos(up);
1576 /*
1577 * Clear the interrupt registers.
1578 */
1579 (void) serial_inp(up, UART_LSR);
1580 (void) serial_inp(up, UART_RX);
1581 (void) serial_inp(up, UART_IIR);
1582 (void) serial_inp(up, UART_MSR);
1584 /*
1585 * At this point, there's no way the LSR could still be 0xff;
1586 * if it is, then bail out, because there's likely no UART
1587 * here.
1588 */
1589 if (!(up->port.flags & UPF_BUGGY_UART) &&
1590 (serial_inp(up, UART_LSR) == 0xff)) {
1591 printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
1592 return -ENODEV;
1595 /*
1596 * For a XR16C850, we need to set the trigger levels
1597 */
1598 if (up->port.type == PORT_16850) {
1599 unsigned char fctr;
1601 serial_outp(up, UART_LCR, 0xbf);
1603 fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
1604 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
1605 serial_outp(up, UART_TRG, UART_TRG_96);
1606 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
1607 serial_outp(up, UART_TRG, UART_TRG_96);
1609 serial_outp(up, UART_LCR, 0);
1612 /*
1613 * If the "interrupt" for this port doesn't correspond with any
1614 * hardware interrupt, we use a timer-based system. The original
1615 * driver used to do this with IRQ0.
1616 */
1617 if (!is_real_interrupt(up->port.irq)) {
1618 unsigned int timeout = up->port.timeout;
1620 timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
1622 up->timer.data = (unsigned long)up;
1623 mod_timer(&up->timer, jiffies + timeout);
1624 } else {
1625 retval = serial_link_irq_chain(up);
1626 if (retval)
1627 return retval;
1630 /*
1631 * Now, initialize the UART
1632 */
1633 serial_outp(up, UART_LCR, UART_LCR_WLEN8);
1635 spin_lock_irqsave(&up->port.lock, flags);
1636 if (up->port.flags & UPF_FOURPORT) {
1637 if (!is_real_interrupt(up->port.irq))
1638 up->port.mctrl |= TIOCM_OUT1;
1639 } else
1640 /*
1641 * Most PC uarts need OUT2 raised to enable interrupts.
1642 */
1643 if (is_real_interrupt(up->port.irq))
1644 up->port.mctrl |= TIOCM_OUT2;
1646 serial8250_set_mctrl(&up->port, up->port.mctrl);
1648 /*
1649 * Do a quick test to see if we receive an
1650 * interrupt when we enable the TX irq.
1651 */
1652 serial_outp(up, UART_IER, UART_IER_THRI);
1653 lsr = serial_in(up, UART_LSR);
1654 iir = serial_in(up, UART_IIR);
1655 serial_outp(up, UART_IER, 0);
1657 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
1658 if (!(up->bugs & UART_BUG_TXEN)) {
1659 up->bugs |= UART_BUG_TXEN;
1660 pr_debug("ttyS%d - enabling bad tx status workarounds\n",
1661 port->line);
1663 } else {
1664 up->bugs &= ~UART_BUG_TXEN;
1667 spin_unlock_irqrestore(&up->port.lock, flags);
1669 /*
1670 * Finally, enable interrupts. Note: Modem status interrupts
1671 * are set via set_termios(), which will be occurring imminently
1672 * anyway, so we don't enable them here.
1673 */
1674 up->ier = UART_IER_RLSI | UART_IER_RDI;
1675 serial_outp(up, UART_IER, up->ier);
1677 if (up->port.flags & UPF_FOURPORT) {
1678 unsigned int icp;
1679 /*
1680 * Enable interrupts on the AST Fourport board
1681 */
1682 icp = (up->port.iobase & 0xfe0) | 0x01f;
1683 outb_p(0x80, icp);
1684 (void) inb_p(icp);
1687 /*
1688 * And clear the interrupt registers again for luck.
1689 */
1690 (void) serial_inp(up, UART_LSR);
1691 (void) serial_inp(up, UART_RX);
1692 (void) serial_inp(up, UART_IIR);
1693 (void) serial_inp(up, UART_MSR);
1695 return 0;
1698 static void serial8250_shutdown(struct uart_port *port)
1700 struct uart_8250_port *up = (struct uart_8250_port *)port;
1701 unsigned long flags;
1703 /*
1704 * Disable interrupts from this port
1705 */
1706 up->ier = 0;
1707 serial_outp(up, UART_IER, 0);
1709 spin_lock_irqsave(&up->port.lock, flags);
1710 if (up->port.flags & UPF_FOURPORT) {
1711 /* reset interrupts on the AST Fourport board */
1712 inb((up->port.iobase & 0xfe0) | 0x1f);
1713 up->port.mctrl |= TIOCM_OUT1;
1714 } else
1715 up->port.mctrl &= ~TIOCM_OUT2;
1717 serial8250_set_mctrl(&up->port, up->port.mctrl);
1718 spin_unlock_irqrestore(&up->port.lock, flags);
1720 /*
1721 * Disable break condition and FIFOs
1722 */
1723 serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
1724 serial8250_clear_fifos(up);
1726 #ifdef CONFIG_SERIAL_8250_RSA
1727 /*
1728 * Reset the RSA board back to 115kbps compat mode.
1729 */
1730 disable_rsa(up);
1731 #endif
1733 /*
1734 * Read data port to reset things, and then unlink from
1735 * the IRQ chain.
1736 */
1737 (void) serial_in(up, UART_RX);
1739 if (!is_real_interrupt(up->port.irq))
1740 del_timer_sync(&up->timer);
1741 else
1742 serial_unlink_irq_chain(up);
1745 static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
1747 unsigned int quot;
1749 /*
1750 * Handle magic divisors for baud rates above baud_base on
1751 * SMSC SuperIO chips.
1752 */
1753 if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
1754 baud == (port->uartclk/4))
1755 quot = 0x8001;
1756 else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
1757 baud == (port->uartclk/8))
1758 quot = 0x8002;
1759 else
1760 quot = uart_get_divisor(port, baud);
1762 return quot;
1765 static void
1766 serial8250_set_termios(struct uart_port *port, struct termios *termios,
1767 struct termios *old)
1769 struct uart_8250_port *up = (struct uart_8250_port *)port;
1770 unsigned char cval, fcr = 0;
1771 unsigned long flags;
1772 unsigned int baud, quot;
1774 switch (termios->c_cflag & CSIZE) {
1775 case CS5:
1776 cval = UART_LCR_WLEN5;
1777 break;
1778 case CS6:
1779 cval = UART_LCR_WLEN6;
1780 break;
1781 case CS7:
1782 cval = UART_LCR_WLEN7;
1783 break;
1784 default:
1785 case CS8:
1786 cval = UART_LCR_WLEN8;
1787 break;
1790 if (termios->c_cflag & CSTOPB)
1791 cval |= UART_LCR_STOP;
1792 if (termios->c_cflag & PARENB)
1793 cval |= UART_LCR_PARITY;
1794 if (!(termios->c_cflag & PARODD))
1795 cval |= UART_LCR_EPAR;
1796 #ifdef CMSPAR
1797 if (termios->c_cflag & CMSPAR)
1798 cval |= UART_LCR_SPAR;
1799 #endif
1801 /*
1802 * Ask the core to calculate the divisor for us.
1803 */
1804 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
1805 quot = serial8250_get_divisor(port, baud);
1807 /*
1808 * Oxford Semi 952 rev B workaround
1809 */
1810 if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
1811 quot ++;
1813 if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
1814 if (baud < 2400)
1815 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
1816 else
1817 fcr = uart_config[up->port.type].fcr;
1820 /*
1821 * MCR-based auto flow control. When AFE is enabled, RTS will be
1822 * deasserted when the receive FIFO contains more characters than
1823 * the trigger, or the MCR RTS bit is cleared. In the case where
1824 * the remote UART is not using CTS auto flow control, we must
1825 * have sufficient FIFO entries for the latency of the remote
1826 * UART to respond. IOW, at least 32 bytes of FIFO.
1827 */
1828 if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
1829 up->mcr &= ~UART_MCR_AFE;
1830 if (termios->c_cflag & CRTSCTS)
1831 up->mcr |= UART_MCR_AFE;
1834 /*
1835 * Ok, we're now changing the port state. Do it with
1836 * interrupts disabled.
1837 */
1838 spin_lock_irqsave(&up->port.lock, flags);
1840 /*
1841 * Update the per-port timeout.
1842 */
1843 uart_update_timeout(port, termios->c_cflag, baud);
1845 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
1846 if (termios->c_iflag & INPCK)
1847 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
1848 if (termios->c_iflag & (BRKINT | PARMRK))
1849 up->port.read_status_mask |= UART_LSR_BI;
1851 /*
1852 * Characteres to ignore
1853 */
1854 up->port.ignore_status_mask = 0;
1855 if (termios->c_iflag & IGNPAR)
1856 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
1857 if (termios->c_iflag & IGNBRK) {
1858 up->port.ignore_status_mask |= UART_LSR_BI;
1859 /*
1860 * If we're ignoring parity and break indicators,
1861 * ignore overruns too (for real raw support).
1862 */
1863 if (termios->c_iflag & IGNPAR)
1864 up->port.ignore_status_mask |= UART_LSR_OE;
1867 /*
1868 * ignore all characters if CREAD is not set
1869 */
1870 if ((termios->c_cflag & CREAD) == 0)
1871 up->port.ignore_status_mask |= UART_LSR_DR;
1873 /*
1874 * CTS flow control flag and modem status interrupts
1875 */
1876 up->ier &= ~UART_IER_MSI;
1877 if (!(up->bugs & UART_BUG_NOMSR) &&
1878 UART_ENABLE_MS(&up->port, termios->c_cflag))
1879 up->ier |= UART_IER_MSI;
1880 if (up->capabilities & UART_CAP_UUE)
1881 up->ier |= UART_IER_UUE | UART_IER_RTOIE;
1883 serial_out(up, UART_IER, up->ier);
1885 if (up->capabilities & UART_CAP_EFR) {
1886 unsigned char efr = 0;
1887 /*
1888 * TI16C752/Startech hardware flow control. FIXME:
1889 * - TI16C752 requires control thresholds to be set.
1890 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
1891 */
1892 if (termios->c_cflag & CRTSCTS)
1893 efr |= UART_EFR_CTS;
1895 serial_outp(up, UART_LCR, 0xBF);
1896 serial_outp(up, UART_EFR, efr);
1899 if (up->capabilities & UART_NATSEMI) {
1900 /* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
1901 serial_outp(up, UART_LCR, 0xe0);
1902 } else {
1903 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
1906 serial_dl_write(up, quot);
1908 /*
1909 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
1910 * is written without DLAB set, this mode will be disabled.
1911 */
1912 if (up->port.type == PORT_16750)
1913 serial_outp(up, UART_FCR, fcr);
1915 serial_outp(up, UART_LCR, cval); /* reset DLAB */
1916 up->lcr = cval; /* Save LCR */
1917 if (up->port.type != PORT_16750) {
1918 if (fcr & UART_FCR_ENABLE_FIFO) {
1919 /* emulated UARTs (Lucent Venus 167x) need two steps */
1920 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1922 serial_outp(up, UART_FCR, fcr); /* set fcr */
1924 serial8250_set_mctrl(&up->port, up->port.mctrl);
1925 spin_unlock_irqrestore(&up->port.lock, flags);
1928 static void
1929 serial8250_pm(struct uart_port *port, unsigned int state,
1930 unsigned int oldstate)
1932 struct uart_8250_port *p = (struct uart_8250_port *)port;
1934 serial8250_set_sleep(p, state != 0);
1936 if (p->pm)
1937 p->pm(port, state, oldstate);
1940 /*
1941 * Resource handling.
1942 */
1943 static int serial8250_request_std_resource(struct uart_8250_port *up)
1945 unsigned int size = 8 << up->port.regshift;
1946 int ret = 0;
1948 switch (up->port.iotype) {
1949 case UPIO_AU:
1950 size = 0x100000;
1951 /* fall thru */
1952 case UPIO_MEM:
1953 if (!up->port.mapbase)
1954 break;
1956 if (!request_mem_region(up->port.mapbase, size, "serial")) {
1957 ret = -EBUSY;
1958 break;
1961 if (up->port.flags & UPF_IOREMAP) {
1962 up->port.membase = ioremap(up->port.mapbase, size);
1963 if (!up->port.membase) {
1964 release_mem_region(up->port.mapbase, size);
1965 ret = -ENOMEM;
1968 break;
1970 case UPIO_HUB6:
1971 case UPIO_PORT:
1972 if (!request_region(up->port.iobase, size, "serial"))
1973 ret = -EBUSY;
1974 break;
1976 return ret;
1979 static void serial8250_release_std_resource(struct uart_8250_port *up)
1981 unsigned int size = 8 << up->port.regshift;
1983 switch (up->port.iotype) {
1984 case UPIO_AU:
1985 size = 0x100000;
1986 /* fall thru */
1987 case UPIO_MEM:
1988 if (!up->port.mapbase)
1989 break;
1991 if (up->port.flags & UPF_IOREMAP) {
1992 iounmap(up->port.membase);
1993 up->port.membase = NULL;
1996 release_mem_region(up->port.mapbase, size);
1997 break;
1999 case UPIO_HUB6:
2000 case UPIO_PORT:
2001 release_region(up->port.iobase, size);
2002 break;
2006 static int serial8250_request_rsa_resource(struct uart_8250_port *up)
2008 unsigned long start = UART_RSA_BASE << up->port.regshift;
2009 unsigned int size = 8 << up->port.regshift;
2010 int ret = 0;
2012 switch (up->port.iotype) {
2013 case UPIO_MEM:
2014 ret = -EINVAL;
2015 break;
2017 case UPIO_HUB6:
2018 case UPIO_PORT:
2019 start += up->port.iobase;
2020 if (!request_region(start, size, "serial-rsa"))
2021 ret = -EBUSY;
2022 break;
2025 return ret;
2028 static void serial8250_release_rsa_resource(struct uart_8250_port *up)
2030 unsigned long offset = UART_RSA_BASE << up->port.regshift;
2031 unsigned int size = 8 << up->port.regshift;
2033 switch (up->port.iotype) {
2034 case UPIO_MEM:
2035 break;
2037 case UPIO_HUB6:
2038 case UPIO_PORT:
2039 release_region(up->port.iobase + offset, size);
2040 break;
2044 static void serial8250_release_port(struct uart_port *port)
2046 struct uart_8250_port *up = (struct uart_8250_port *)port;
2048 serial8250_release_std_resource(up);
2049 if (up->port.type == PORT_RSA)
2050 serial8250_release_rsa_resource(up);
2053 static int serial8250_request_port(struct uart_port *port)
2055 struct uart_8250_port *up = (struct uart_8250_port *)port;
2056 int ret = 0;
2058 ret = serial8250_request_std_resource(up);
2059 if (ret == 0 && up->port.type == PORT_RSA) {
2060 ret = serial8250_request_rsa_resource(up);
2061 if (ret < 0)
2062 serial8250_release_std_resource(up);
2065 return ret;
2068 static void serial8250_config_port(struct uart_port *port, int flags)
2070 struct uart_8250_port *up = (struct uart_8250_port *)port;
2071 int probeflags = PROBE_ANY;
2072 int ret;
2074 /*
2075 * Find the region that we can probe for. This in turn
2076 * tells us whether we can probe for the type of port.
2077 */
2078 ret = serial8250_request_std_resource(up);
2079 if (ret < 0)
2080 return;
2082 ret = serial8250_request_rsa_resource(up);
2083 if (ret < 0)
2084 probeflags &= ~PROBE_RSA;
2086 if (flags & UART_CONFIG_TYPE)
2087 autoconfig(up, probeflags);
2088 if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
2089 autoconfig_irq(up);
2091 if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
2092 serial8250_release_rsa_resource(up);
2093 if (up->port.type == PORT_UNKNOWN)
2094 serial8250_release_std_resource(up);
2097 static int
2098 serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
2100 if (ser->irq >= NR_IRQS || ser->irq < 0 ||
2101 ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
2102 ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
2103 ser->type == PORT_STARTECH)
2104 return -EINVAL;
2105 return 0;
2108 static const char *
2109 serial8250_type(struct uart_port *port)
2111 int type = port->type;
2113 if (type >= ARRAY_SIZE(uart_config))
2114 type = 0;
2115 return uart_config[type].name;
2118 static struct uart_ops serial8250_pops = {
2119 .tx_empty = serial8250_tx_empty,
2120 .set_mctrl = serial8250_set_mctrl,
2121 .get_mctrl = serial8250_get_mctrl,
2122 .stop_tx = serial8250_stop_tx,
2123 .start_tx = serial8250_start_tx,
2124 .stop_rx = serial8250_stop_rx,
2125 .enable_ms = serial8250_enable_ms,
2126 .break_ctl = serial8250_break_ctl,
2127 .startup = serial8250_startup,
2128 .shutdown = serial8250_shutdown,
2129 .set_termios = serial8250_set_termios,
2130 .pm = serial8250_pm,
2131 .type = serial8250_type,
2132 .release_port = serial8250_release_port,
2133 .request_port = serial8250_request_port,
2134 .config_port = serial8250_config_port,
2135 .verify_port = serial8250_verify_port,
2136 };
2138 static struct uart_8250_port serial8250_ports[UART_NR];
2140 static void __init serial8250_isa_init_ports(void)
2142 struct uart_8250_port *up;
2143 static int first = 1;
2144 int i;
2146 if (!first)
2147 return;
2148 first = 0;
2150 for (i = 0; i < nr_uarts; i++) {
2151 struct uart_8250_port *up = &serial8250_ports[i];
2153 up->port.line = i;
2154 spin_lock_init(&up->port.lock);
2156 init_timer(&up->timer);
2157 up->timer.function = serial8250_timeout;
2159 /*
2160 * ALPHA_KLUDGE_MCR needs to be killed.
2161 */
2162 up->mcr_mask = ~ALPHA_KLUDGE_MCR;
2163 up->mcr_force = ALPHA_KLUDGE_MCR;
2165 up->port.ops = &serial8250_pops;
2168 for (i = 0, up = serial8250_ports;
2169 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
2170 i++, up++) {
2171 up->port.iobase = old_serial_port[i].port;
2172 up->port.irq = irq_canonicalize(old_serial_port[i].irq);
2173 up->port.uartclk = old_serial_port[i].baud_base * 16;
2174 up->port.flags = old_serial_port[i].flags;
2175 up->port.hub6 = old_serial_port[i].hub6;
2176 up->port.membase = old_serial_port[i].iomem_base;
2177 up->port.iotype = old_serial_port[i].io_type;
2178 up->port.regshift = old_serial_port[i].iomem_reg_shift;
2179 if (share_irqs)
2180 up->port.flags |= UPF_SHARE_IRQ;
2184 static void __init
2185 serial8250_register_ports(struct uart_driver *drv, struct device *dev)
2187 int i;
2189 serial8250_isa_init_ports();
2191 for (i = 0; i < nr_uarts; i++) {
2192 struct uart_8250_port *up = &serial8250_ports[i];
2194 up->port.dev = dev;
2195 uart_add_one_port(drv, &up->port);
2199 #ifdef CONFIG_SERIAL_8250_CONSOLE
2201 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
2203 /*
2204 * Wait for transmitter & holding register to empty
2205 */
2206 static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
2208 unsigned int status, tmout = 10000;
2210 /* Wait up to 10ms for the character(s) to be sent. */
2211 do {
2212 status = serial_in(up, UART_LSR);
2214 if (status & UART_LSR_BI)
2215 up->lsr_break_flag = UART_LSR_BI;
2217 if (--tmout == 0)
2218 break;
2219 udelay(1);
2220 } while ((status & bits) != bits);
2222 /* Wait up to 1s for flow control if necessary */
2223 if (up->port.flags & UPF_CONS_FLOW) {
2224 tmout = 1000000;
2225 while (--tmout &&
2226 ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
2227 udelay(1);
2231 static void serial8250_console_putchar(struct uart_port *port, int ch)
2233 struct uart_8250_port *up = (struct uart_8250_port *)port;
2235 wait_for_xmitr(up, UART_LSR_THRE);
2236 serial_out(up, UART_TX, ch);
2239 /*
2240 * Print a string to the serial port trying not to disturb
2241 * any possible real use of the port...
2243 * The console_lock must be held when we get here.
2244 */
2245 static void
2246 serial8250_console_write(struct console *co, const char *s, unsigned int count)
2248 struct uart_8250_port *up = &serial8250_ports[co->index];
2249 unsigned long flags;
2250 unsigned int ier;
2251 int locked = 1;
2253 touch_nmi_watchdog();
2255 local_irq_save(flags);
2256 if (up->port.sysrq) {
2257 /* serial8250_handle_port() already took the lock */
2258 locked = 0;
2259 } else if (oops_in_progress) {
2260 locked = spin_trylock(&up->port.lock);
2261 } else
2262 spin_lock(&up->port.lock);
2264 /*
2265 * First save the IER then disable the interrupts
2266 */
2267 ier = serial_in(up, UART_IER);
2269 if (up->capabilities & UART_CAP_UUE)
2270 serial_out(up, UART_IER, UART_IER_UUE);
2271 else
2272 serial_out(up, UART_IER, 0);
2274 uart_console_write(&up->port, s, count, serial8250_console_putchar);
2276 /*
2277 * Finally, wait for transmitter to become empty
2278 * and restore the IER
2279 */
2280 wait_for_xmitr(up, BOTH_EMPTY);
2281 serial_out(up, UART_IER, ier);
2283 if (locked)
2284 spin_unlock(&up->port.lock);
2285 local_irq_restore(flags);
2288 static int serial8250_console_setup(struct console *co, char *options)
2290 struct uart_port *port;
2291 int baud = 9600;
2292 int bits = 8;
2293 int parity = 'n';
2294 int flow = 'n';
2296 /*
2297 * Check whether an invalid uart number has been specified, and
2298 * if so, search for the first available port that does have
2299 * console support.
2300 */
2301 if (co->index >= nr_uarts)
2302 co->index = 0;
2303 port = &serial8250_ports[co->index].port;
2304 if (!port->iobase && !port->membase)
2305 return -ENODEV;
2307 if (options)
2308 uart_parse_options(options, &baud, &parity, &bits, &flow);
2310 return uart_set_options(port, co, baud, parity, bits, flow);
2313 static struct uart_driver serial8250_reg;
2314 static struct console serial8250_console = {
2315 .name = "ttyS",
2316 .write = serial8250_console_write,
2317 .device = uart_console_device,
2318 .setup = serial8250_console_setup,
2319 .flags = CON_PRINTBUFFER,
2320 .index = -1,
2321 .data = &serial8250_reg,
2322 };
2324 static int __init serial8250_console_init(void)
2326 serial8250_isa_init_ports();
2327 register_console(&serial8250_console);
2328 return 0;
2330 console_initcall(serial8250_console_init);
2332 static int __init find_port(struct uart_port *p)
2334 int line;
2335 struct uart_port *port;
2337 for (line = 0; line < nr_uarts; line++) {
2338 port = &serial8250_ports[line].port;
2339 if (uart_match_port(p, port))
2340 return line;
2342 return -ENODEV;
2345 int __init serial8250_start_console(struct uart_port *port, char *options)
2347 int line;
2349 line = find_port(port);
2350 if (line < 0)
2351 return -ENODEV;
2353 add_preferred_console("ttyS", line, options);
2354 printk("Adding console on ttyS%d at %s 0x%lx (options '%s')\n",
2355 line, port->iotype == UPIO_MEM ? "MMIO" : "I/O port",
2356 port->iotype == UPIO_MEM ? (unsigned long) port->mapbase :
2357 (unsigned long) port->iobase, options);
2358 if (!(serial8250_console.flags & CON_ENABLED)) {
2359 serial8250_console.flags &= ~CON_PRINTBUFFER;
2360 register_console(&serial8250_console);
2362 return line;
2365 #define SERIAL8250_CONSOLE &serial8250_console
2366 #else
2367 #define SERIAL8250_CONSOLE NULL
2368 #endif
2370 static struct uart_driver serial8250_reg = {
2371 .owner = THIS_MODULE,
2372 .driver_name = "serial",
2373 .dev_name = "ttyS",
2374 .major = TTY_MAJOR,
2375 .minor = 64,
2376 .nr = UART_NR,
2377 .cons = SERIAL8250_CONSOLE,
2378 };
2380 /*
2381 * early_serial_setup - early registration for 8250 ports
2383 * Setup an 8250 port structure prior to console initialisation. Use
2384 * after console initialisation will cause undefined behaviour.
2385 */
2386 int __init early_serial_setup(struct uart_port *port)
2388 if (port->line >= ARRAY_SIZE(serial8250_ports))
2389 return -ENODEV;
2391 serial8250_isa_init_ports();
2392 serial8250_ports[port->line].port = *port;
2393 serial8250_ports[port->line].port.ops = &serial8250_pops;
2394 return 0;
2397 /**
2398 * serial8250_suspend_port - suspend one serial port
2399 * @line: serial line number
2400 * @level: the level of port suspension, as per uart_suspend_port
2402 * Suspend one serial port.
2403 */
2404 void serial8250_suspend_port(int line)
2406 uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
2409 /**
2410 * serial8250_resume_port - resume one serial port
2411 * @line: serial line number
2412 * @level: the level of port resumption, as per uart_resume_port
2414 * Resume one serial port.
2415 */
2416 void serial8250_resume_port(int line)
2418 uart_resume_port(&serial8250_reg, &serial8250_ports[line].port);
2421 /*
2422 * Register a set of serial devices attached to a platform device. The
2423 * list is terminated with a zero flags entry, which means we expect
2424 * all entries to have at least UPF_BOOT_AUTOCONF set.
2425 */
2426 static int __devinit serial8250_probe(struct platform_device *dev)
2428 struct plat_serial8250_port *p = dev->dev.platform_data;
2429 struct uart_port port;
2430 int ret, i;
2432 memset(&port, 0, sizeof(struct uart_port));
2434 for (i = 0; p && p->flags != 0; p++, i++) {
2435 port.iobase = p->iobase;
2436 port.membase = p->membase;
2437 port.irq = p->irq;
2438 port.uartclk = p->uartclk;
2439 port.regshift = p->regshift;
2440 port.iotype = p->iotype;
2441 port.flags = p->flags;
2442 port.mapbase = p->mapbase;
2443 port.hub6 = p->hub6;
2444 port.dev = &dev->dev;
2445 if (share_irqs)
2446 port.flags |= UPF_SHARE_IRQ;
2447 ret = serial8250_register_port(&port);
2448 if (ret < 0) {
2449 dev_err(&dev->dev, "unable to register port at index %d "
2450 "(IO%lx MEM%lx IRQ%d): %d\n", i,
2451 p->iobase, p->mapbase, p->irq, ret);
2454 return 0;
2457 /*
2458 * Remove serial ports registered against a platform device.
2459 */
2460 static int __devexit serial8250_remove(struct platform_device *dev)
2462 int i;
2464 for (i = 0; i < nr_uarts; i++) {
2465 struct uart_8250_port *up = &serial8250_ports[i];
2467 if (up->port.dev == &dev->dev)
2468 serial8250_unregister_port(i);
2470 return 0;
2473 static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
2475 int i;
2477 for (i = 0; i < UART_NR; i++) {
2478 struct uart_8250_port *up = &serial8250_ports[i];
2480 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
2481 uart_suspend_port(&serial8250_reg, &up->port);
2484 return 0;
2487 static int serial8250_resume(struct platform_device *dev)
2489 int i;
2491 for (i = 0; i < UART_NR; i++) {
2492 struct uart_8250_port *up = &serial8250_ports[i];
2494 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
2495 uart_resume_port(&serial8250_reg, &up->port);
2498 return 0;
2501 static struct platform_driver serial8250_isa_driver = {
2502 .probe = serial8250_probe,
2503 .remove = __devexit_p(serial8250_remove),
2504 .suspend = serial8250_suspend,
2505 .resume = serial8250_resume,
2506 .driver = {
2507 .name = "serial8250",
2508 .owner = THIS_MODULE,
2509 },
2510 };
2512 /*
2513 * This "device" covers _all_ ISA 8250-compatible serial devices listed
2514 * in the table in include/asm/serial.h
2515 */
2516 static struct platform_device *serial8250_isa_devs;
2518 /*
2519 * serial8250_register_port and serial8250_unregister_port allows for
2520 * 16x50 serial ports to be configured at run-time, to support PCMCIA
2521 * modems and PCI multiport cards.
2522 */
2523 static DEFINE_MUTEX(serial_mutex);
2525 static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
2527 int i;
2529 /*
2530 * First, find a port entry which matches.
2531 */
2532 for (i = 0; i < nr_uarts; i++)
2533 if (uart_match_port(&serial8250_ports[i].port, port))
2534 return &serial8250_ports[i];
2536 /*
2537 * We didn't find a matching entry, so look for the first
2538 * free entry. We look for one which hasn't been previously
2539 * used (indicated by zero iobase).
2540 */
2541 for (i = 0; i < nr_uarts; i++)
2542 if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
2543 serial8250_ports[i].port.iobase == 0)
2544 return &serial8250_ports[i];
2546 /*
2547 * That also failed. Last resort is to find any entry which
2548 * doesn't have a real port associated with it.
2549 */
2550 for (i = 0; i < nr_uarts; i++)
2551 if (serial8250_ports[i].port.type == PORT_UNKNOWN)
2552 return &serial8250_ports[i];
2554 return NULL;
2557 /**
2558 * serial8250_register_port - register a serial port
2559 * @port: serial port template
2561 * Configure the serial port specified by the request. If the
2562 * port exists and is in use, it is hung up and unregistered
2563 * first.
2565 * The port is then probed and if necessary the IRQ is autodetected
2566 * If this fails an error is returned.
2568 * On success the port is ready to use and the line number is returned.
2569 */
2570 int serial8250_register_port(struct uart_port *port)
2572 struct uart_8250_port *uart;
2573 int ret = -ENOSPC;
2575 if (port->uartclk == 0)
2576 return -EINVAL;
2578 mutex_lock(&serial_mutex);
2580 uart = serial8250_find_match_or_unused(port);
2581 if (uart) {
2582 uart_remove_one_port(&serial8250_reg, &uart->port);
2584 uart->port.iobase = port->iobase;
2585 uart->port.membase = port->membase;
2586 uart->port.irq = port->irq;
2587 uart->port.uartclk = port->uartclk;
2588 uart->port.fifosize = port->fifosize;
2589 uart->port.regshift = port->regshift;
2590 uart->port.iotype = port->iotype;
2591 uart->port.flags = port->flags | UPF_BOOT_AUTOCONF;
2592 uart->port.mapbase = port->mapbase;
2593 if (port->dev)
2594 uart->port.dev = port->dev;
2596 ret = uart_add_one_port(&serial8250_reg, &uart->port);
2597 if (ret == 0)
2598 ret = uart->port.line;
2600 mutex_unlock(&serial_mutex);
2602 return ret;
2604 EXPORT_SYMBOL(serial8250_register_port);
2606 /**
2607 * serial8250_unregister_port - remove a 16x50 serial port at runtime
2608 * @line: serial line number
2610 * Remove one serial port. This may not be called from interrupt
2611 * context. We hand the port back to the our control.
2612 */
2613 void serial8250_unregister_port(int line)
2615 struct uart_8250_port *uart = &serial8250_ports[line];
2617 mutex_lock(&serial_mutex);
2618 uart_remove_one_port(&serial8250_reg, &uart->port);
2619 if (serial8250_isa_devs) {
2620 uart->port.flags &= ~UPF_BOOT_AUTOCONF;
2621 uart->port.type = PORT_UNKNOWN;
2622 uart->port.dev = &serial8250_isa_devs->dev;
2623 uart_add_one_port(&serial8250_reg, &uart->port);
2624 } else {
2625 uart->port.dev = NULL;
2627 mutex_unlock(&serial_mutex);
2629 EXPORT_SYMBOL(serial8250_unregister_port);
2631 static int __init serial8250_init(void)
2633 int ret, i;
2635 if (nr_uarts > UART_NR)
2636 nr_uarts = UART_NR;
2638 printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ "
2639 "%d ports, IRQ sharing %sabled\n", nr_uarts,
2640 share_irqs ? "en" : "dis");
2642 for (i = 0; i < NR_IRQS; i++)
2643 spin_lock_init(&irq_lists[i].lock);
2645 ret = uart_register_driver(&serial8250_reg);
2646 if (ret)
2647 goto out;
2649 serial8250_isa_devs = platform_device_alloc("serial8250",
2650 PLAT8250_DEV_LEGACY);
2651 if (!serial8250_isa_devs) {
2652 ret = -ENOMEM;
2653 goto unreg_uart_drv;
2656 ret = platform_device_add(serial8250_isa_devs);
2657 if (ret)
2658 goto put_dev;
2660 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
2662 ret = platform_driver_register(&serial8250_isa_driver);
2663 if (ret == 0)
2664 goto out;
2666 platform_device_del(serial8250_isa_devs);
2667 put_dev:
2668 platform_device_put(serial8250_isa_devs);
2669 unreg_uart_drv:
2670 uart_unregister_driver(&serial8250_reg);
2671 out:
2672 return ret;
2675 static void __exit serial8250_exit(void)
2677 struct platform_device *isa_dev = serial8250_isa_devs;
2679 /*
2680 * This tells serial8250_unregister_port() not to re-register
2681 * the ports (thereby making serial8250_isa_driver permanently
2682 * in use.)
2683 */
2684 serial8250_isa_devs = NULL;
2686 platform_driver_unregister(&serial8250_isa_driver);
2687 platform_device_unregister(isa_dev);
2689 uart_unregister_driver(&serial8250_reg);
2692 module_init(serial8250_init);
2693 module_exit(serial8250_exit);
2695 EXPORT_SYMBOL(serial8250_suspend_port);
2696 EXPORT_SYMBOL(serial8250_resume_port);
2698 MODULE_LICENSE("GPL");
2699 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver $Revision: 1.90 $");
2701 module_param(share_irqs, uint, 0644);
2702 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
2703 " (unsafe)");
2705 module_param(nr_uarts, uint, 0644);
2706 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
2708 #ifdef CONFIG_SERIAL_8250_RSA
2709 module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
2710 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
2711 #endif
2712 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);