Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[zen-stable.git] / drivers / tty / serial / 8250.c
blobb4129f53fb1b1c7a6fe5d18e7fd2ed8097fcdfda
1 /*
2 * Driver for 8250/16550-type serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright (C) 2001 Russell King.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * A note about mapbase / membase
15 * mapbase is the physical address of the IO port.
16 * membase is an 'ioremapped' cookie.
19 #if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
20 #define SUPPORT_SYSRQ
21 #endif
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/sysrq.h>
29 #include <linux/delay.h>
30 #include <linux/platform_device.h>
31 #include <linux/tty.h>
32 #include <linux/ratelimit.h>
33 #include <linux/tty_flip.h>
34 #include <linux/serial_reg.h>
35 #include <linux/serial_core.h>
36 #include <linux/serial.h>
37 #include <linux/serial_8250.h>
38 #include <linux/nmi.h>
39 #include <linux/mutex.h>
40 #include <linux/slab.h>
42 #include <asm/io.h>
43 #include <asm/irq.h>
45 #include "8250.h"
47 #ifdef CONFIG_SPARC
48 #include "suncore.h"
49 #endif
52 * Configuration:
53 * share_irqs - whether we pass IRQF_SHARED to request_irq(). This option
54 * is unsafe when used on edge-triggered interrupts.
56 static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
58 static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
60 static struct uart_driver serial8250_reg;
62 static int serial_index(struct uart_port *port)
64 return (serial8250_reg.minor - 64) + port->line;
67 static unsigned int skip_txen_test; /* force skip of txen test at init time */
70 * Debugging.
72 #if 0
73 #define DEBUG_AUTOCONF(fmt...) printk(fmt)
74 #else
75 #define DEBUG_AUTOCONF(fmt...) do { } while (0)
76 #endif
78 #if 0
79 #define DEBUG_INTR(fmt...) printk(fmt)
80 #else
81 #define DEBUG_INTR(fmt...) do { } while (0)
82 #endif
84 #define PASS_LIMIT 256
86 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
90 * We default to IRQ0 for the "no irq" hack. Some
91 * machine types want others as well - they're free
92 * to redefine this in their header file.
94 #define is_real_interrupt(irq) ((irq) != 0)
96 #ifdef CONFIG_SERIAL_8250_DETECT_IRQ
97 #define CONFIG_SERIAL_DETECT_IRQ 1
98 #endif
99 #ifdef CONFIG_SERIAL_8250_MANY_PORTS
100 #define CONFIG_SERIAL_MANY_PORTS 1
101 #endif
104 * HUB6 is always on. This will be removed once the header
105 * files have been cleaned.
107 #define CONFIG_HUB6 1
109 #include <asm/serial.h>
111 * SERIAL_PORT_DFNS tells us about built-in ports that have no
112 * standard enumeration mechanism. Platforms that can find all
113 * serial ports via mechanisms like ACPI or PCI need not supply it.
115 #ifndef SERIAL_PORT_DFNS
116 #define SERIAL_PORT_DFNS
117 #endif
119 static const struct old_serial_port old_serial_port[] = {
120 SERIAL_PORT_DFNS /* defined in asm/serial.h */
123 #define UART_NR CONFIG_SERIAL_8250_NR_UARTS
125 #ifdef CONFIG_SERIAL_8250_RSA
127 #define PORT_RSA_MAX 4
128 static unsigned long probe_rsa[PORT_RSA_MAX];
129 static unsigned int probe_rsa_count;
130 #endif /* CONFIG_SERIAL_8250_RSA */
132 struct uart_8250_port {
133 struct uart_port port;
134 struct timer_list timer; /* "no irq" timer */
135 struct list_head list; /* ports on this IRQ */
136 unsigned short capabilities; /* port capabilities */
137 unsigned short bugs; /* port bugs */
138 unsigned int tx_loadsz; /* transmit fifo load size */
139 unsigned char acr;
140 unsigned char ier;
141 unsigned char lcr;
142 unsigned char mcr;
143 unsigned char mcr_mask; /* mask of user bits */
144 unsigned char mcr_force; /* mask of forced bits */
145 unsigned char cur_iotype; /* Running I/O type */
148 * Some bits in registers are cleared on a read, so they must
149 * be saved whenever the register is read but the bits will not
150 * be immediately processed.
152 #define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
153 unsigned char lsr_saved_flags;
154 #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
155 unsigned char msr_saved_flags;
158 struct irq_info {
159 struct hlist_node node;
160 int irq;
161 spinlock_t lock; /* Protects list not the hash */
162 struct list_head *head;
165 #define NR_IRQ_HASH 32 /* Can be adjusted later */
166 static struct hlist_head irq_lists[NR_IRQ_HASH];
167 static DEFINE_MUTEX(hash_mutex); /* Used to walk the hash */
170 * Here we define the default xmit fifo size used for each type of UART.
172 static const struct serial8250_config uart_config[] = {
173 [PORT_UNKNOWN] = {
174 .name = "unknown",
175 .fifo_size = 1,
176 .tx_loadsz = 1,
178 [PORT_8250] = {
179 .name = "8250",
180 .fifo_size = 1,
181 .tx_loadsz = 1,
183 [PORT_16450] = {
184 .name = "16450",
185 .fifo_size = 1,
186 .tx_loadsz = 1,
188 [PORT_16550] = {
189 .name = "16550",
190 .fifo_size = 1,
191 .tx_loadsz = 1,
193 [PORT_16550A] = {
194 .name = "16550A",
195 .fifo_size = 16,
196 .tx_loadsz = 16,
197 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
198 .flags = UART_CAP_FIFO,
200 [PORT_CIRRUS] = {
201 .name = "Cirrus",
202 .fifo_size = 1,
203 .tx_loadsz = 1,
205 [PORT_16650] = {
206 .name = "ST16650",
207 .fifo_size = 1,
208 .tx_loadsz = 1,
209 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
211 [PORT_16650V2] = {
212 .name = "ST16650V2",
213 .fifo_size = 32,
214 .tx_loadsz = 16,
215 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
216 UART_FCR_T_TRIG_00,
217 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
219 [PORT_16750] = {
220 .name = "TI16750",
221 .fifo_size = 64,
222 .tx_loadsz = 64,
223 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
224 UART_FCR7_64BYTE,
225 .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
227 [PORT_STARTECH] = {
228 .name = "Startech",
229 .fifo_size = 1,
230 .tx_loadsz = 1,
232 [PORT_16C950] = {
233 .name = "16C950/954",
234 .fifo_size = 128,
235 .tx_loadsz = 128,
236 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
237 /* UART_CAP_EFR breaks billionon CF bluetooth card. */
238 .flags = UART_CAP_FIFO | UART_CAP_SLEEP,
240 [PORT_16654] = {
241 .name = "ST16654",
242 .fifo_size = 64,
243 .tx_loadsz = 32,
244 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
245 UART_FCR_T_TRIG_10,
246 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
248 [PORT_16850] = {
249 .name = "XR16850",
250 .fifo_size = 128,
251 .tx_loadsz = 128,
252 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
253 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
255 [PORT_RSA] = {
256 .name = "RSA",
257 .fifo_size = 2048,
258 .tx_loadsz = 2048,
259 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
260 .flags = UART_CAP_FIFO,
262 [PORT_NS16550A] = {
263 .name = "NS16550A",
264 .fifo_size = 16,
265 .tx_loadsz = 16,
266 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
267 .flags = UART_CAP_FIFO | UART_NATSEMI,
269 [PORT_XSCALE] = {
270 .name = "XScale",
271 .fifo_size = 32,
272 .tx_loadsz = 32,
273 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
274 .flags = UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
276 [PORT_RM9000] = {
277 .name = "RM9000",
278 .fifo_size = 16,
279 .tx_loadsz = 16,
280 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
281 .flags = UART_CAP_FIFO,
283 [PORT_OCTEON] = {
284 .name = "OCTEON",
285 .fifo_size = 64,
286 .tx_loadsz = 64,
287 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
288 .flags = UART_CAP_FIFO,
290 [PORT_AR7] = {
291 .name = "AR7",
292 .fifo_size = 16,
293 .tx_loadsz = 16,
294 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
295 .flags = UART_CAP_FIFO | UART_CAP_AFE,
297 [PORT_U6_16550A] = {
298 .name = "U6_16550A",
299 .fifo_size = 64,
300 .tx_loadsz = 64,
301 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
302 .flags = UART_CAP_FIFO | UART_CAP_AFE,
304 [PORT_TEGRA] = {
305 .name = "Tegra",
306 .fifo_size = 32,
307 .tx_loadsz = 8,
308 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
309 UART_FCR_T_TRIG_01,
310 .flags = UART_CAP_FIFO | UART_CAP_RTOIE,
314 #if defined(CONFIG_MIPS_ALCHEMY)
316 /* Au1x00 UART hardware has a weird register layout */
317 static const u8 au_io_in_map[] = {
318 [UART_RX] = 0,
319 [UART_IER] = 2,
320 [UART_IIR] = 3,
321 [UART_LCR] = 5,
322 [UART_MCR] = 6,
323 [UART_LSR] = 7,
324 [UART_MSR] = 8,
327 static const u8 au_io_out_map[] = {
328 [UART_TX] = 1,
329 [UART_IER] = 2,
330 [UART_FCR] = 4,
331 [UART_LCR] = 5,
332 [UART_MCR] = 6,
335 /* sane hardware needs no mapping */
336 static inline int map_8250_in_reg(struct uart_port *p, int offset)
338 if (p->iotype != UPIO_AU)
339 return offset;
340 return au_io_in_map[offset];
343 static inline int map_8250_out_reg(struct uart_port *p, int offset)
345 if (p->iotype != UPIO_AU)
346 return offset;
347 return au_io_out_map[offset];
350 #elif defined(CONFIG_SERIAL_8250_RM9K)
352 static const u8
353 regmap_in[8] = {
354 [UART_RX] = 0x00,
355 [UART_IER] = 0x0c,
356 [UART_IIR] = 0x14,
357 [UART_LCR] = 0x1c,
358 [UART_MCR] = 0x20,
359 [UART_LSR] = 0x24,
360 [UART_MSR] = 0x28,
361 [UART_SCR] = 0x2c
363 regmap_out[8] = {
364 [UART_TX] = 0x04,
365 [UART_IER] = 0x0c,
366 [UART_FCR] = 0x18,
367 [UART_LCR] = 0x1c,
368 [UART_MCR] = 0x20,
369 [UART_LSR] = 0x24,
370 [UART_MSR] = 0x28,
371 [UART_SCR] = 0x2c
374 static inline int map_8250_in_reg(struct uart_port *p, int offset)
376 if (p->iotype != UPIO_RM9000)
377 return offset;
378 return regmap_in[offset];
381 static inline int map_8250_out_reg(struct uart_port *p, int offset)
383 if (p->iotype != UPIO_RM9000)
384 return offset;
385 return regmap_out[offset];
388 #else
390 /* sane hardware needs no mapping */
391 #define map_8250_in_reg(up, offset) (offset)
392 #define map_8250_out_reg(up, offset) (offset)
394 #endif
396 static unsigned int hub6_serial_in(struct uart_port *p, int offset)
398 offset = map_8250_in_reg(p, offset) << p->regshift;
399 outb(p->hub6 - 1 + offset, p->iobase);
400 return inb(p->iobase + 1);
403 static void hub6_serial_out(struct uart_port *p, int offset, int value)
405 offset = map_8250_out_reg(p, offset) << p->regshift;
406 outb(p->hub6 - 1 + offset, p->iobase);
407 outb(value, p->iobase + 1);
410 static unsigned int mem_serial_in(struct uart_port *p, int offset)
412 offset = map_8250_in_reg(p, offset) << p->regshift;
413 return readb(p->membase + offset);
416 static void mem_serial_out(struct uart_port *p, int offset, int value)
418 offset = map_8250_out_reg(p, offset) << p->regshift;
419 writeb(value, p->membase + offset);
422 static void mem32_serial_out(struct uart_port *p, int offset, int value)
424 offset = map_8250_out_reg(p, offset) << p->regshift;
425 writel(value, p->membase + offset);
428 static unsigned int mem32_serial_in(struct uart_port *p, int offset)
430 offset = map_8250_in_reg(p, offset) << p->regshift;
431 return readl(p->membase + offset);
434 static unsigned int au_serial_in(struct uart_port *p, int offset)
436 offset = map_8250_in_reg(p, offset) << p->regshift;
437 return __raw_readl(p->membase + offset);
440 static void au_serial_out(struct uart_port *p, int offset, int value)
442 offset = map_8250_out_reg(p, offset) << p->regshift;
443 __raw_writel(value, p->membase + offset);
446 static unsigned int tsi_serial_in(struct uart_port *p, int offset)
448 unsigned int tmp;
449 offset = map_8250_in_reg(p, offset) << p->regshift;
450 if (offset == UART_IIR) {
451 tmp = readl(p->membase + (UART_IIR & ~3));
452 return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
453 } else
454 return readb(p->membase + offset);
457 static void tsi_serial_out(struct uart_port *p, int offset, int value)
459 offset = map_8250_out_reg(p, offset) << p->regshift;
460 if (!((offset == UART_IER) && (value & UART_IER_UUE)))
461 writeb(value, p->membase + offset);
464 /* Save the LCR value so it can be re-written when a Busy Detect IRQ occurs. */
465 static inline void dwapb_save_out_value(struct uart_port *p, int offset,
466 int value)
468 struct uart_8250_port *up =
469 container_of(p, struct uart_8250_port, port);
471 if (offset == UART_LCR)
472 up->lcr = value;
475 /* Read the IER to ensure any interrupt is cleared before returning from ISR. */
476 static inline void dwapb_check_clear_ier(struct uart_port *p, int offset)
478 if (offset == UART_TX || offset == UART_IER)
479 p->serial_in(p, UART_IER);
482 static void dwapb_serial_out(struct uart_port *p, int offset, int value)
484 int save_offset = offset;
485 offset = map_8250_out_reg(p, offset) << p->regshift;
486 dwapb_save_out_value(p, save_offset, value);
487 writeb(value, p->membase + offset);
488 dwapb_check_clear_ier(p, save_offset);
491 static void dwapb32_serial_out(struct uart_port *p, int offset, int value)
493 int save_offset = offset;
494 offset = map_8250_out_reg(p, offset) << p->regshift;
495 dwapb_save_out_value(p, save_offset, value);
496 writel(value, p->membase + offset);
497 dwapb_check_clear_ier(p, save_offset);
500 static unsigned int io_serial_in(struct uart_port *p, int offset)
502 offset = map_8250_in_reg(p, offset) << p->regshift;
503 return inb(p->iobase + offset);
506 static void io_serial_out(struct uart_port *p, int offset, int value)
508 offset = map_8250_out_reg(p, offset) << p->regshift;
509 outb(value, p->iobase + offset);
512 static void set_io_from_upio(struct uart_port *p)
514 struct uart_8250_port *up =
515 container_of(p, struct uart_8250_port, port);
516 switch (p->iotype) {
517 case UPIO_HUB6:
518 p->serial_in = hub6_serial_in;
519 p->serial_out = hub6_serial_out;
520 break;
522 case UPIO_MEM:
523 p->serial_in = mem_serial_in;
524 p->serial_out = mem_serial_out;
525 break;
527 case UPIO_RM9000:
528 case UPIO_MEM32:
529 p->serial_in = mem32_serial_in;
530 p->serial_out = mem32_serial_out;
531 break;
533 case UPIO_AU:
534 p->serial_in = au_serial_in;
535 p->serial_out = au_serial_out;
536 break;
538 case UPIO_TSI:
539 p->serial_in = tsi_serial_in;
540 p->serial_out = tsi_serial_out;
541 break;
543 case UPIO_DWAPB:
544 p->serial_in = mem_serial_in;
545 p->serial_out = dwapb_serial_out;
546 break;
548 case UPIO_DWAPB32:
549 p->serial_in = mem32_serial_in;
550 p->serial_out = dwapb32_serial_out;
551 break;
553 default:
554 p->serial_in = io_serial_in;
555 p->serial_out = io_serial_out;
556 break;
558 /* Remember loaded iotype */
559 up->cur_iotype = p->iotype;
562 static void
563 serial_out_sync(struct uart_8250_port *up, int offset, int value)
565 struct uart_port *p = &up->port;
566 switch (p->iotype) {
567 case UPIO_MEM:
568 case UPIO_MEM32:
569 case UPIO_AU:
570 case UPIO_DWAPB:
571 case UPIO_DWAPB32:
572 p->serial_out(p, offset, value);
573 p->serial_in(p, UART_LCR); /* safe, no side-effects */
574 break;
575 default:
576 p->serial_out(p, offset, value);
580 #define serial_in(up, offset) \
581 (up->port.serial_in(&(up)->port, (offset)))
582 #define serial_out(up, offset, value) \
583 (up->port.serial_out(&(up)->port, (offset), (value)))
585 * We used to support using pause I/O for certain machines. We
586 * haven't supported this for a while, but just in case it's badly
587 * needed for certain old 386 machines, I've left these #define's
588 * in....
590 #define serial_inp(up, offset) serial_in(up, offset)
591 #define serial_outp(up, offset, value) serial_out(up, offset, value)
593 /* Uart divisor latch read */
594 static inline int _serial_dl_read(struct uart_8250_port *up)
596 return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
599 /* Uart divisor latch write */
600 static inline void _serial_dl_write(struct uart_8250_port *up, int value)
602 serial_outp(up, UART_DLL, value & 0xff);
603 serial_outp(up, UART_DLM, value >> 8 & 0xff);
606 #if defined(CONFIG_MIPS_ALCHEMY)
607 /* Au1x00 haven't got a standard divisor latch */
608 static int serial_dl_read(struct uart_8250_port *up)
610 if (up->port.iotype == UPIO_AU)
611 return __raw_readl(up->port.membase + 0x28);
612 else
613 return _serial_dl_read(up);
616 static void serial_dl_write(struct uart_8250_port *up, int value)
618 if (up->port.iotype == UPIO_AU)
619 __raw_writel(value, up->port.membase + 0x28);
620 else
621 _serial_dl_write(up, value);
623 #elif defined(CONFIG_SERIAL_8250_RM9K)
624 static int serial_dl_read(struct uart_8250_port *up)
626 return (up->port.iotype == UPIO_RM9000) ?
627 (((__raw_readl(up->port.membase + 0x10) << 8) |
628 (__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) :
629 _serial_dl_read(up);
632 static void serial_dl_write(struct uart_8250_port *up, int value)
634 if (up->port.iotype == UPIO_RM9000) {
635 __raw_writel(value, up->port.membase + 0x08);
636 __raw_writel(value >> 8, up->port.membase + 0x10);
637 } else {
638 _serial_dl_write(up, value);
641 #else
642 #define serial_dl_read(up) _serial_dl_read(up)
643 #define serial_dl_write(up, value) _serial_dl_write(up, value)
644 #endif
647 * For the 16C950
649 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
651 serial_out(up, UART_SCR, offset);
652 serial_out(up, UART_ICR, value);
655 static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
657 unsigned int value;
659 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
660 serial_out(up, UART_SCR, offset);
661 value = serial_in(up, UART_ICR);
662 serial_icr_write(up, UART_ACR, up->acr);
664 return value;
668 * FIFO support.
670 static void serial8250_clear_fifos(struct uart_8250_port *p)
672 if (p->capabilities & UART_CAP_FIFO) {
673 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
674 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
675 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
676 serial_outp(p, UART_FCR, 0);
681 * IER sleep support. UARTs which have EFRs need the "extended
682 * capability" bit enabled. Note that on XR16C850s, we need to
683 * reset LCR to write to IER.
685 static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
687 if (p->capabilities & UART_CAP_SLEEP) {
688 if (p->capabilities & UART_CAP_EFR) {
689 serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
690 serial_outp(p, UART_EFR, UART_EFR_ECB);
691 serial_outp(p, UART_LCR, 0);
693 serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
694 if (p->capabilities & UART_CAP_EFR) {
695 serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
696 serial_outp(p, UART_EFR, 0);
697 serial_outp(p, UART_LCR, 0);
702 #ifdef CONFIG_SERIAL_8250_RSA
704 * Attempts to turn on the RSA FIFO. Returns zero on failure.
705 * We set the port uart clock rate if we succeed.
707 static int __enable_rsa(struct uart_8250_port *up)
709 unsigned char mode;
710 int result;
712 mode = serial_inp(up, UART_RSA_MSR);
713 result = mode & UART_RSA_MSR_FIFO;
715 if (!result) {
716 serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
717 mode = serial_inp(up, UART_RSA_MSR);
718 result = mode & UART_RSA_MSR_FIFO;
721 if (result)
722 up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
724 return result;
727 static void enable_rsa(struct uart_8250_port *up)
729 if (up->port.type == PORT_RSA) {
730 if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
731 spin_lock_irq(&up->port.lock);
732 __enable_rsa(up);
733 spin_unlock_irq(&up->port.lock);
735 if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
736 serial_outp(up, UART_RSA_FRR, 0);
741 * Attempts to turn off the RSA FIFO. Returns zero on failure.
742 * It is unknown why interrupts were disabled in here. However,
743 * the caller is expected to preserve this behaviour by grabbing
744 * the spinlock before calling this function.
746 static void disable_rsa(struct uart_8250_port *up)
748 unsigned char mode;
749 int result;
751 if (up->port.type == PORT_RSA &&
752 up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
753 spin_lock_irq(&up->port.lock);
755 mode = serial_inp(up, UART_RSA_MSR);
756 result = !(mode & UART_RSA_MSR_FIFO);
758 if (!result) {
759 serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
760 mode = serial_inp(up, UART_RSA_MSR);
761 result = !(mode & UART_RSA_MSR_FIFO);
764 if (result)
765 up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
766 spin_unlock_irq(&up->port.lock);
769 #endif /* CONFIG_SERIAL_8250_RSA */
772 * This is a quickie test to see how big the FIFO is.
773 * It doesn't work at all the time, more's the pity.
775 static int size_fifo(struct uart_8250_port *up)
777 unsigned char old_fcr, old_mcr, old_lcr;
778 unsigned short old_dl;
779 int count;
781 old_lcr = serial_inp(up, UART_LCR);
782 serial_outp(up, UART_LCR, 0);
783 old_fcr = serial_inp(up, UART_FCR);
784 old_mcr = serial_inp(up, UART_MCR);
785 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
786 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
787 serial_outp(up, UART_MCR, UART_MCR_LOOP);
788 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
789 old_dl = serial_dl_read(up);
790 serial_dl_write(up, 0x0001);
791 serial_outp(up, UART_LCR, 0x03);
792 for (count = 0; count < 256; count++)
793 serial_outp(up, UART_TX, count);
794 mdelay(20);/* FIXME - schedule_timeout */
795 for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
796 (count < 256); count++)
797 serial_inp(up, UART_RX);
798 serial_outp(up, UART_FCR, old_fcr);
799 serial_outp(up, UART_MCR, old_mcr);
800 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
801 serial_dl_write(up, old_dl);
802 serial_outp(up, UART_LCR, old_lcr);
804 return count;
808 * Read UART ID using the divisor method - set DLL and DLM to zero
809 * and the revision will be in DLL and device type in DLM. We
810 * preserve the device state across this.
812 static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
814 unsigned char old_dll, old_dlm, old_lcr;
815 unsigned int id;
817 old_lcr = serial_inp(p, UART_LCR);
818 serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_A);
820 old_dll = serial_inp(p, UART_DLL);
821 old_dlm = serial_inp(p, UART_DLM);
823 serial_outp(p, UART_DLL, 0);
824 serial_outp(p, UART_DLM, 0);
826 id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
828 serial_outp(p, UART_DLL, old_dll);
829 serial_outp(p, UART_DLM, old_dlm);
830 serial_outp(p, UART_LCR, old_lcr);
832 return id;
836 * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
837 * When this function is called we know it is at least a StarTech
838 * 16650 V2, but it might be one of several StarTech UARTs, or one of
839 * its clones. (We treat the broken original StarTech 16650 V1 as a
840 * 16550, and why not? Startech doesn't seem to even acknowledge its
841 * existence.)
843 * What evil have men's minds wrought...
845 static void autoconfig_has_efr(struct uart_8250_port *up)
847 unsigned int id1, id2, id3, rev;
850 * Everything with an EFR has SLEEP
852 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
855 * First we check to see if it's an Oxford Semiconductor UART.
857 * If we have to do this here because some non-National
858 * Semiconductor clone chips lock up if you try writing to the
859 * LSR register (which serial_icr_read does)
863 * Check for Oxford Semiconductor 16C950.
865 * EFR [4] must be set else this test fails.
867 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
868 * claims that it's needed for 952 dual UART's (which are not
869 * recommended for new designs).
871 up->acr = 0;
872 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
873 serial_out(up, UART_EFR, UART_EFR_ECB);
874 serial_out(up, UART_LCR, 0x00);
875 id1 = serial_icr_read(up, UART_ID1);
876 id2 = serial_icr_read(up, UART_ID2);
877 id3 = serial_icr_read(up, UART_ID3);
878 rev = serial_icr_read(up, UART_REV);
880 DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
882 if (id1 == 0x16 && id2 == 0xC9 &&
883 (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
884 up->port.type = PORT_16C950;
887 * Enable work around for the Oxford Semiconductor 952 rev B
888 * chip which causes it to seriously miscalculate baud rates
889 * when DLL is 0.
891 if (id3 == 0x52 && rev == 0x01)
892 up->bugs |= UART_BUG_QUOT;
893 return;
897 * We check for a XR16C850 by setting DLL and DLM to 0, and then
898 * reading back DLL and DLM. The chip type depends on the DLM
899 * value read back:
900 * 0x10 - XR16C850 and the DLL contains the chip revision.
901 * 0x12 - XR16C2850.
902 * 0x14 - XR16C854.
904 id1 = autoconfig_read_divisor_id(up);
905 DEBUG_AUTOCONF("850id=%04x ", id1);
907 id2 = id1 >> 8;
908 if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
909 up->port.type = PORT_16850;
910 return;
914 * It wasn't an XR16C850.
916 * We distinguish between the '654 and the '650 by counting
917 * how many bytes are in the FIFO. I'm using this for now,
918 * since that's the technique that was sent to me in the
919 * serial driver update, but I'm not convinced this works.
920 * I've had problems doing this in the past. -TYT
922 if (size_fifo(up) == 64)
923 up->port.type = PORT_16654;
924 else
925 up->port.type = PORT_16650V2;
929 * We detected a chip without a FIFO. Only two fall into
930 * this category - the original 8250 and the 16450. The
931 * 16450 has a scratch register (accessible with LCR=0)
933 static void autoconfig_8250(struct uart_8250_port *up)
935 unsigned char scratch, status1, status2;
937 up->port.type = PORT_8250;
939 scratch = serial_in(up, UART_SCR);
940 serial_outp(up, UART_SCR, 0xa5);
941 status1 = serial_in(up, UART_SCR);
942 serial_outp(up, UART_SCR, 0x5a);
943 status2 = serial_in(up, UART_SCR);
944 serial_outp(up, UART_SCR, scratch);
946 if (status1 == 0xa5 && status2 == 0x5a)
947 up->port.type = PORT_16450;
950 static int broken_efr(struct uart_8250_port *up)
953 * Exar ST16C2550 "A2" devices incorrectly detect as
954 * having an EFR, and report an ID of 0x0201. See
955 * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html
957 if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
958 return 1;
960 return 0;
963 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
965 unsigned char status;
967 status = serial_in(up, 0x04); /* EXCR2 */
968 #define PRESL(x) ((x) & 0x30)
969 if (PRESL(status) == 0x10) {
970 /* already in high speed mode */
971 return 0;
972 } else {
973 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
974 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
975 serial_outp(up, 0x04, status);
977 return 1;
981 * We know that the chip has FIFOs. Does it have an EFR? The
982 * EFR is located in the same register position as the IIR and
983 * we know the top two bits of the IIR are currently set. The
984 * EFR should contain zero. Try to read the EFR.
986 static void autoconfig_16550a(struct uart_8250_port *up)
988 unsigned char status1, status2;
989 unsigned int iersave;
991 up->port.type = PORT_16550A;
992 up->capabilities |= UART_CAP_FIFO;
995 * Check for presence of the EFR when DLAB is set.
996 * Only ST16C650V1 UARTs pass this test.
998 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
999 if (serial_in(up, UART_EFR) == 0) {
1000 serial_outp(up, UART_EFR, 0xA8);
1001 if (serial_in(up, UART_EFR) != 0) {
1002 DEBUG_AUTOCONF("EFRv1 ");
1003 up->port.type = PORT_16650;
1004 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
1005 } else {
1006 DEBUG_AUTOCONF("Motorola 8xxx DUART ");
1008 serial_outp(up, UART_EFR, 0);
1009 return;
1013 * Maybe it requires 0xbf to be written to the LCR.
1014 * (other ST16C650V2 UARTs, TI16C752A, etc)
1016 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
1017 if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
1018 DEBUG_AUTOCONF("EFRv2 ");
1019 autoconfig_has_efr(up);
1020 return;
1024 * Check for a National Semiconductor SuperIO chip.
1025 * Attempt to switch to bank 2, read the value of the LOOP bit
1026 * from EXCR1. Switch back to bank 0, change it in MCR. Then
1027 * switch back to bank 2, read it from EXCR1 again and check
1028 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
1030 serial_outp(up, UART_LCR, 0);
1031 status1 = serial_in(up, UART_MCR);
1032 serial_outp(up, UART_LCR, 0xE0);
1033 status2 = serial_in(up, 0x02); /* EXCR1 */
1035 if (!((status2 ^ status1) & UART_MCR_LOOP)) {
1036 serial_outp(up, UART_LCR, 0);
1037 serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
1038 serial_outp(up, UART_LCR, 0xE0);
1039 status2 = serial_in(up, 0x02); /* EXCR1 */
1040 serial_outp(up, UART_LCR, 0);
1041 serial_outp(up, UART_MCR, status1);
1043 if ((status2 ^ status1) & UART_MCR_LOOP) {
1044 unsigned short quot;
1046 serial_outp(up, UART_LCR, 0xE0);
1048 quot = serial_dl_read(up);
1049 quot <<= 3;
1051 if (ns16550a_goto_highspeed(up))
1052 serial_dl_write(up, quot);
1054 serial_outp(up, UART_LCR, 0);
1056 up->port.uartclk = 921600*16;
1057 up->port.type = PORT_NS16550A;
1058 up->capabilities |= UART_NATSEMI;
1059 return;
1064 * No EFR. Try to detect a TI16750, which only sets bit 5 of
1065 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
1066 * Try setting it with and without DLAB set. Cheap clones
1067 * set bit 5 without DLAB set.
1069 serial_outp(up, UART_LCR, 0);
1070 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1071 status1 = serial_in(up, UART_IIR) >> 5;
1072 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1073 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
1074 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1075 status2 = serial_in(up, UART_IIR) >> 5;
1076 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1077 serial_outp(up, UART_LCR, 0);
1079 DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
1081 if (status1 == 6 && status2 == 7) {
1082 up->port.type = PORT_16750;
1083 up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
1084 return;
1088 * Try writing and reading the UART_IER_UUE bit (b6).
1089 * If it works, this is probably one of the Xscale platform's
1090 * internal UARTs.
1091 * We're going to explicitly set the UUE bit to 0 before
1092 * trying to write and read a 1 just to make sure it's not
1093 * already a 1 and maybe locked there before we even start start.
1095 iersave = serial_in(up, UART_IER);
1096 serial_outp(up, UART_IER, iersave & ~UART_IER_UUE);
1097 if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
1099 * OK it's in a known zero state, try writing and reading
1100 * without disturbing the current state of the other bits.
1102 serial_outp(up, UART_IER, iersave | UART_IER_UUE);
1103 if (serial_in(up, UART_IER) & UART_IER_UUE) {
1105 * It's an Xscale.
1106 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
1108 DEBUG_AUTOCONF("Xscale ");
1109 up->port.type = PORT_XSCALE;
1110 up->capabilities |= UART_CAP_UUE;
1111 return;
1113 } else {
1115 * If we got here we couldn't force the IER_UUE bit to 0.
1116 * Log it and continue.
1118 DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
1120 serial_outp(up, UART_IER, iersave);
1123 * We distinguish between 16550A and U6 16550A by counting
1124 * how many bytes are in the FIFO.
1126 if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
1127 up->port.type = PORT_U6_16550A;
1128 up->capabilities |= UART_CAP_AFE;
1133 * This routine is called by rs_init() to initialize a specific serial
1134 * port. It determines what type of UART chip this serial port is
1135 * using: 8250, 16450, 16550, 16550A. The important question is
1136 * whether or not this UART is a 16550A or not, since this will
1137 * determine whether or not we can use its FIFO features or not.
1139 static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
1141 unsigned char status1, scratch, scratch2, scratch3;
1142 unsigned char save_lcr, save_mcr;
1143 unsigned long flags;
1145 if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
1146 return;
1148 DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
1149 serial_index(&up->port), up->port.iobase, up->port.membase);
1152 * We really do need global IRQs disabled here - we're going to
1153 * be frobbing the chips IRQ enable register to see if it exists.
1155 spin_lock_irqsave(&up->port.lock, flags);
1157 up->capabilities = 0;
1158 up->bugs = 0;
1160 if (!(up->port.flags & UPF_BUGGY_UART)) {
1162 * Do a simple existence test first; if we fail this,
1163 * there's no point trying anything else.
1165 * 0x80 is used as a nonsense port to prevent against
1166 * false positives due to ISA bus float. The
1167 * assumption is that 0x80 is a non-existent port;
1168 * which should be safe since include/asm/io.h also
1169 * makes this assumption.
1171 * Note: this is safe as long as MCR bit 4 is clear
1172 * and the device is in "PC" mode.
1174 scratch = serial_inp(up, UART_IER);
1175 serial_outp(up, UART_IER, 0);
1176 #ifdef __i386__
1177 outb(0xff, 0x080);
1178 #endif
1180 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
1181 * 16C754B) allow only to modify them if an EFR bit is set.
1183 scratch2 = serial_inp(up, UART_IER) & 0x0f;
1184 serial_outp(up, UART_IER, 0x0F);
1185 #ifdef __i386__
1186 outb(0, 0x080);
1187 #endif
1188 scratch3 = serial_inp(up, UART_IER) & 0x0f;
1189 serial_outp(up, UART_IER, scratch);
1190 if (scratch2 != 0 || scratch3 != 0x0F) {
1192 * We failed; there's nothing here
1194 DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
1195 scratch2, scratch3);
1196 goto out;
1200 save_mcr = serial_in(up, UART_MCR);
1201 save_lcr = serial_in(up, UART_LCR);
1204 * Check to see if a UART is really there. Certain broken
1205 * internal modems based on the Rockwell chipset fail this
1206 * test, because they apparently don't implement the loopback
1207 * test mode. So this test is skipped on the COM 1 through
1208 * COM 4 ports. This *should* be safe, since no board
1209 * manufacturer would be stupid enough to design a board
1210 * that conflicts with COM 1-4 --- we hope!
1212 if (!(up->port.flags & UPF_SKIP_TEST)) {
1213 serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
1214 status1 = serial_inp(up, UART_MSR) & 0xF0;
1215 serial_outp(up, UART_MCR, save_mcr);
1216 if (status1 != 0x90) {
1217 DEBUG_AUTOCONF("LOOP test failed (%02x) ",
1218 status1);
1219 goto out;
1224 * We're pretty sure there's a port here. Lets find out what
1225 * type of port it is. The IIR top two bits allows us to find
1226 * out if it's 8250 or 16450, 16550, 16550A or later. This
1227 * determines what we test for next.
1229 * We also initialise the EFR (if any) to zero for later. The
1230 * EFR occupies the same register location as the FCR and IIR.
1232 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
1233 serial_outp(up, UART_EFR, 0);
1234 serial_outp(up, UART_LCR, 0);
1236 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1237 scratch = serial_in(up, UART_IIR) >> 6;
1239 DEBUG_AUTOCONF("iir=%d ", scratch);
1241 switch (scratch) {
1242 case 0:
1243 autoconfig_8250(up);
1244 break;
1245 case 1:
1246 up->port.type = PORT_UNKNOWN;
1247 break;
1248 case 2:
1249 up->port.type = PORT_16550;
1250 break;
1251 case 3:
1252 autoconfig_16550a(up);
1253 break;
1256 #ifdef CONFIG_SERIAL_8250_RSA
1258 * Only probe for RSA ports if we got the region.
1260 if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
1261 int i;
1263 for (i = 0 ; i < probe_rsa_count; ++i) {
1264 if (probe_rsa[i] == up->port.iobase &&
1265 __enable_rsa(up)) {
1266 up->port.type = PORT_RSA;
1267 break;
1271 #endif
1273 serial_outp(up, UART_LCR, save_lcr);
1275 if (up->capabilities != uart_config[up->port.type].flags) {
1276 printk(KERN_WARNING
1277 "ttyS%d: detected caps %08x should be %08x\n",
1278 serial_index(&up->port), up->capabilities,
1279 uart_config[up->port.type].flags);
1282 up->port.fifosize = uart_config[up->port.type].fifo_size;
1283 up->capabilities = uart_config[up->port.type].flags;
1284 up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
1286 if (up->port.type == PORT_UNKNOWN)
1287 goto out;
1290 * Reset the UART.
1292 #ifdef CONFIG_SERIAL_8250_RSA
1293 if (up->port.type == PORT_RSA)
1294 serial_outp(up, UART_RSA_FRR, 0);
1295 #endif
1296 serial_outp(up, UART_MCR, save_mcr);
1297 serial8250_clear_fifos(up);
1298 serial_in(up, UART_RX);
1299 if (up->capabilities & UART_CAP_UUE)
1300 serial_outp(up, UART_IER, UART_IER_UUE);
1301 else
1302 serial_outp(up, UART_IER, 0);
1304 out:
1305 spin_unlock_irqrestore(&up->port.lock, flags);
1306 DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
1309 static void autoconfig_irq(struct uart_8250_port *up)
1311 unsigned char save_mcr, save_ier;
1312 unsigned char save_ICP = 0;
1313 unsigned int ICP = 0;
1314 unsigned long irqs;
1315 int irq;
1317 if (up->port.flags & UPF_FOURPORT) {
1318 ICP = (up->port.iobase & 0xfe0) | 0x1f;
1319 save_ICP = inb_p(ICP);
1320 outb_p(0x80, ICP);
1321 (void) inb_p(ICP);
1324 /* forget possible initially masked and pending IRQ */
1325 probe_irq_off(probe_irq_on());
1326 save_mcr = serial_inp(up, UART_MCR);
1327 save_ier = serial_inp(up, UART_IER);
1328 serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
1330 irqs = probe_irq_on();
1331 serial_outp(up, UART_MCR, 0);
1332 udelay(10);
1333 if (up->port.flags & UPF_FOURPORT) {
1334 serial_outp(up, UART_MCR,
1335 UART_MCR_DTR | UART_MCR_RTS);
1336 } else {
1337 serial_outp(up, UART_MCR,
1338 UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
1340 serial_outp(up, UART_IER, 0x0f); /* enable all intrs */
1341 (void)serial_inp(up, UART_LSR);
1342 (void)serial_inp(up, UART_RX);
1343 (void)serial_inp(up, UART_IIR);
1344 (void)serial_inp(up, UART_MSR);
1345 serial_outp(up, UART_TX, 0xFF);
1346 udelay(20);
1347 irq = probe_irq_off(irqs);
1349 serial_outp(up, UART_MCR, save_mcr);
1350 serial_outp(up, UART_IER, save_ier);
1352 if (up->port.flags & UPF_FOURPORT)
1353 outb_p(save_ICP, ICP);
1355 up->port.irq = (irq > 0) ? irq : 0;
1358 static inline void __stop_tx(struct uart_8250_port *p)
1360 if (p->ier & UART_IER_THRI) {
1361 p->ier &= ~UART_IER_THRI;
1362 serial_out(p, UART_IER, p->ier);
1366 static void serial8250_stop_tx(struct uart_port *port)
1368 struct uart_8250_port *up =
1369 container_of(port, struct uart_8250_port, port);
1371 __stop_tx(up);
1374 * We really want to stop the transmitter from sending.
1376 if (up->port.type == PORT_16C950) {
1377 up->acr |= UART_ACR_TXDIS;
1378 serial_icr_write(up, UART_ACR, up->acr);
1382 static void transmit_chars(struct uart_8250_port *up);
1384 static void serial8250_start_tx(struct uart_port *port)
1386 struct uart_8250_port *up =
1387 container_of(port, struct uart_8250_port, port);
1389 if (!(up->ier & UART_IER_THRI)) {
1390 up->ier |= UART_IER_THRI;
1391 serial_out(up, UART_IER, up->ier);
1393 if (up->bugs & UART_BUG_TXEN) {
1394 unsigned char lsr;
1395 lsr = serial_in(up, UART_LSR);
1396 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1397 if ((up->port.type == PORT_RM9000) ?
1398 (lsr & UART_LSR_THRE) :
1399 (lsr & UART_LSR_TEMT))
1400 transmit_chars(up);
1405 * Re-enable the transmitter if we disabled it.
1407 if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
1408 up->acr &= ~UART_ACR_TXDIS;
1409 serial_icr_write(up, UART_ACR, up->acr);
1413 static void serial8250_stop_rx(struct uart_port *port)
1415 struct uart_8250_port *up =
1416 container_of(port, struct uart_8250_port, port);
1418 up->ier &= ~UART_IER_RLSI;
1419 up->port.read_status_mask &= ~UART_LSR_DR;
1420 serial_out(up, UART_IER, up->ier);
1423 static void serial8250_enable_ms(struct uart_port *port)
1425 struct uart_8250_port *up =
1426 container_of(port, struct uart_8250_port, port);
1428 /* no MSR capabilities */
1429 if (up->bugs & UART_BUG_NOMSR)
1430 return;
1432 up->ier |= UART_IER_MSI;
1433 serial_out(up, UART_IER, up->ier);
1437 * Clear the Tegra rx fifo after a break
1439 * FIXME: This needs to become a port specific callback once we have a
1440 * framework for this
1442 static void clear_rx_fifo(struct uart_8250_port *up)
1444 unsigned int status, tmout = 10000;
1445 do {
1446 status = serial_in(up, UART_LSR);
1447 if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
1448 status = serial_in(up, UART_RX);
1449 else
1450 break;
1451 if (--tmout == 0)
1452 break;
1453 udelay(1);
1454 } while (1);
1457 static void
1458 receive_chars(struct uart_8250_port *up, unsigned int *status)
1460 struct tty_struct *tty = up->port.state->port.tty;
1461 unsigned char ch, lsr = *status;
1462 int max_count = 256;
1463 char flag;
1465 do {
1466 if (likely(lsr & UART_LSR_DR))
1467 ch = serial_inp(up, UART_RX);
1468 else
1470 * Intel 82571 has a Serial Over Lan device that will
1471 * set UART_LSR_BI without setting UART_LSR_DR when
1472 * it receives a break. To avoid reading from the
1473 * receive buffer without UART_LSR_DR bit set, we
1474 * just force the read character to be 0
1476 ch = 0;
1478 flag = TTY_NORMAL;
1479 up->port.icount.rx++;
1481 lsr |= up->lsr_saved_flags;
1482 up->lsr_saved_flags = 0;
1484 if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
1486 * For statistics only
1488 if (lsr & UART_LSR_BI) {
1489 lsr &= ~(UART_LSR_FE | UART_LSR_PE);
1490 up->port.icount.brk++;
1492 * If tegra port then clear the rx fifo to
1493 * accept another break/character.
1495 if (up->port.type == PORT_TEGRA)
1496 clear_rx_fifo(up);
1499 * We do the SysRQ and SAK checking
1500 * here because otherwise the break
1501 * may get masked by ignore_status_mask
1502 * or read_status_mask.
1504 if (uart_handle_break(&up->port))
1505 goto ignore_char;
1506 } else if (lsr & UART_LSR_PE)
1507 up->port.icount.parity++;
1508 else if (lsr & UART_LSR_FE)
1509 up->port.icount.frame++;
1510 if (lsr & UART_LSR_OE)
1511 up->port.icount.overrun++;
1514 * Mask off conditions which should be ignored.
1516 lsr &= up->port.read_status_mask;
1518 if (lsr & UART_LSR_BI) {
1519 DEBUG_INTR("handling break....");
1520 flag = TTY_BREAK;
1521 } else if (lsr & UART_LSR_PE)
1522 flag = TTY_PARITY;
1523 else if (lsr & UART_LSR_FE)
1524 flag = TTY_FRAME;
1526 if (uart_handle_sysrq_char(&up->port, ch))
1527 goto ignore_char;
1529 uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
1531 ignore_char:
1532 lsr = serial_inp(up, UART_LSR);
1533 } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
1534 spin_unlock(&up->port.lock);
1535 tty_flip_buffer_push(tty);
1536 spin_lock(&up->port.lock);
1537 *status = lsr;
1540 static void transmit_chars(struct uart_8250_port *up)
1542 struct circ_buf *xmit = &up->port.state->xmit;
1543 int count;
1545 if (up->port.x_char) {
1546 serial_outp(up, UART_TX, up->port.x_char);
1547 up->port.icount.tx++;
1548 up->port.x_char = 0;
1549 return;
1551 if (uart_tx_stopped(&up->port)) {
1552 serial8250_stop_tx(&up->port);
1553 return;
1555 if (uart_circ_empty(xmit)) {
1556 __stop_tx(up);
1557 return;
1560 count = up->tx_loadsz;
1561 do {
1562 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
1563 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1564 up->port.icount.tx++;
1565 if (uart_circ_empty(xmit))
1566 break;
1567 } while (--count > 0);
1569 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1570 uart_write_wakeup(&up->port);
1572 DEBUG_INTR("THRE...");
1574 if (uart_circ_empty(xmit))
1575 __stop_tx(up);
1578 static unsigned int check_modem_status(struct uart_8250_port *up)
1580 unsigned int status = serial_in(up, UART_MSR);
1582 status |= up->msr_saved_flags;
1583 up->msr_saved_flags = 0;
1584 if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
1585 up->port.state != NULL) {
1586 if (status & UART_MSR_TERI)
1587 up->port.icount.rng++;
1588 if (status & UART_MSR_DDSR)
1589 up->port.icount.dsr++;
1590 if (status & UART_MSR_DDCD)
1591 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
1592 if (status & UART_MSR_DCTS)
1593 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
1595 wake_up_interruptible(&up->port.state->port.delta_msr_wait);
1598 return status;
1602 * This handles the interrupt from one port.
1604 static void serial8250_handle_port(struct uart_8250_port *up)
1606 unsigned int status;
1607 unsigned long flags;
1609 spin_lock_irqsave(&up->port.lock, flags);
1611 status = serial_inp(up, UART_LSR);
1613 DEBUG_INTR("status = %x...", status);
1615 if (status & (UART_LSR_DR | UART_LSR_BI))
1616 receive_chars(up, &status);
1617 check_modem_status(up);
1618 if (status & UART_LSR_THRE)
1619 transmit_chars(up);
1621 spin_unlock_irqrestore(&up->port.lock, flags);
1625 * This is the serial driver's interrupt routine.
1627 * Arjan thinks the old way was overly complex, so it got simplified.
1628 * Alan disagrees, saying that need the complexity to handle the weird
1629 * nature of ISA shared interrupts. (This is a special exception.)
1631 * In order to handle ISA shared interrupts properly, we need to check
1632 * that all ports have been serviced, and therefore the ISA interrupt
1633 * line has been de-asserted.
1635 * This means we need to loop through all ports. checking that they
1636 * don't have an interrupt pending.
1638 static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
1640 struct irq_info *i = dev_id;
1641 struct list_head *l, *end = NULL;
1642 int pass_counter = 0, handled = 0;
1644 DEBUG_INTR("serial8250_interrupt(%d)...", irq);
1646 spin_lock(&i->lock);
1648 l = i->head;
1649 do {
1650 struct uart_8250_port *up;
1651 unsigned int iir;
1653 up = list_entry(l, struct uart_8250_port, list);
1655 iir = serial_in(up, UART_IIR);
1656 if (!(iir & UART_IIR_NO_INT)) {
1657 serial8250_handle_port(up);
1659 handled = 1;
1661 end = NULL;
1662 } else if ((up->port.iotype == UPIO_DWAPB ||
1663 up->port.iotype == UPIO_DWAPB32) &&
1664 (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
1665 /* The DesignWare APB UART has an Busy Detect (0x07)
1666 * interrupt meaning an LCR write attempt occurred while the
1667 * UART was busy. The interrupt must be cleared by reading
1668 * the UART status register (USR) and the LCR re-written. */
1669 unsigned int status;
1670 status = *(volatile u32 *)up->port.private_data;
1671 serial_out(up, UART_LCR, up->lcr);
1673 handled = 1;
1675 end = NULL;
1676 } else if (end == NULL)
1677 end = l;
1679 l = l->next;
1681 if (l == i->head && pass_counter++ > PASS_LIMIT) {
1682 /* If we hit this, we're dead. */
1683 printk_ratelimited(KERN_ERR
1684 "serial8250: too much work for irq%d\n", irq);
1685 break;
1687 } while (l != end);
1689 spin_unlock(&i->lock);
1691 DEBUG_INTR("end.\n");
1693 return IRQ_RETVAL(handled);
1697 * To support ISA shared interrupts, we need to have one interrupt
1698 * handler that ensures that the IRQ line has been deasserted
1699 * before returning. Failing to do this will result in the IRQ
1700 * line being stuck active, and, since ISA irqs are edge triggered,
1701 * no more IRQs will be seen.
1703 static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
1705 spin_lock_irq(&i->lock);
1707 if (!list_empty(i->head)) {
1708 if (i->head == &up->list)
1709 i->head = i->head->next;
1710 list_del(&up->list);
1711 } else {
1712 BUG_ON(i->head != &up->list);
1713 i->head = NULL;
1715 spin_unlock_irq(&i->lock);
1716 /* List empty so throw away the hash node */
1717 if (i->head == NULL) {
1718 hlist_del(&i->node);
1719 kfree(i);
1723 static int serial_link_irq_chain(struct uart_8250_port *up)
1725 struct hlist_head *h;
1726 struct hlist_node *n;
1727 struct irq_info *i;
1728 int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
1730 mutex_lock(&hash_mutex);
1732 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1734 hlist_for_each(n, h) {
1735 i = hlist_entry(n, struct irq_info, node);
1736 if (i->irq == up->port.irq)
1737 break;
1740 if (n == NULL) {
1741 i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
1742 if (i == NULL) {
1743 mutex_unlock(&hash_mutex);
1744 return -ENOMEM;
1746 spin_lock_init(&i->lock);
1747 i->irq = up->port.irq;
1748 hlist_add_head(&i->node, h);
1750 mutex_unlock(&hash_mutex);
1752 spin_lock_irq(&i->lock);
1754 if (i->head) {
1755 list_add(&up->list, i->head);
1756 spin_unlock_irq(&i->lock);
1758 ret = 0;
1759 } else {
1760 INIT_LIST_HEAD(&up->list);
1761 i->head = &up->list;
1762 spin_unlock_irq(&i->lock);
1763 irq_flags |= up->port.irqflags;
1764 ret = request_irq(up->port.irq, serial8250_interrupt,
1765 irq_flags, "serial", i);
1766 if (ret < 0)
1767 serial_do_unlink(i, up);
1770 return ret;
1773 static void serial_unlink_irq_chain(struct uart_8250_port *up)
1775 struct irq_info *i;
1776 struct hlist_node *n;
1777 struct hlist_head *h;
1779 mutex_lock(&hash_mutex);
1781 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1783 hlist_for_each(n, h) {
1784 i = hlist_entry(n, struct irq_info, node);
1785 if (i->irq == up->port.irq)
1786 break;
1789 BUG_ON(n == NULL);
1790 BUG_ON(i->head == NULL);
1792 if (list_empty(i->head))
1793 free_irq(up->port.irq, i);
1795 serial_do_unlink(i, up);
1796 mutex_unlock(&hash_mutex);
1800 * This function is used to handle ports that do not have an
1801 * interrupt. This doesn't work very well for 16450's, but gives
1802 * barely passable results for a 16550A. (Although at the expense
1803 * of much CPU overhead).
1805 static void serial8250_timeout(unsigned long data)
1807 struct uart_8250_port *up = (struct uart_8250_port *)data;
1808 unsigned int iir;
1810 iir = serial_in(up, UART_IIR);
1811 if (!(iir & UART_IIR_NO_INT))
1812 serial8250_handle_port(up);
1813 mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
1816 static void serial8250_backup_timeout(unsigned long data)
1818 struct uart_8250_port *up = (struct uart_8250_port *)data;
1819 unsigned int iir, ier = 0, lsr;
1820 unsigned long flags;
1823 * Must disable interrupts or else we risk racing with the interrupt
1824 * based handler.
1826 if (is_real_interrupt(up->port.irq)) {
1827 ier = serial_in(up, UART_IER);
1828 serial_out(up, UART_IER, 0);
1831 iir = serial_in(up, UART_IIR);
1834 * This should be a safe test for anyone who doesn't trust the
1835 * IIR bits on their UART, but it's specifically designed for
1836 * the "Diva" UART used on the management processor on many HP
1837 * ia64 and parisc boxes.
1839 spin_lock_irqsave(&up->port.lock, flags);
1840 lsr = serial_in(up, UART_LSR);
1841 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1842 spin_unlock_irqrestore(&up->port.lock, flags);
1843 if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
1844 (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
1845 (lsr & UART_LSR_THRE)) {
1846 iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
1847 iir |= UART_IIR_THRI;
1850 if (!(iir & UART_IIR_NO_INT))
1851 serial8250_handle_port(up);
1853 if (is_real_interrupt(up->port.irq))
1854 serial_out(up, UART_IER, ier);
1856 /* Standard timer interval plus 0.2s to keep the port running */
1857 mod_timer(&up->timer,
1858 jiffies + uart_poll_timeout(&up->port) + HZ / 5);
1861 static unsigned int serial8250_tx_empty(struct uart_port *port)
1863 struct uart_8250_port *up =
1864 container_of(port, struct uart_8250_port, port);
1865 unsigned long flags;
1866 unsigned int lsr;
1868 spin_lock_irqsave(&up->port.lock, flags);
1869 lsr = serial_in(up, UART_LSR);
1870 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1871 spin_unlock_irqrestore(&up->port.lock, flags);
1873 return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
1876 static unsigned int serial8250_get_mctrl(struct uart_port *port)
1878 struct uart_8250_port *up =
1879 container_of(port, struct uart_8250_port, port);
1880 unsigned int status;
1881 unsigned int ret;
1883 status = check_modem_status(up);
1885 ret = 0;
1886 if (status & UART_MSR_DCD)
1887 ret |= TIOCM_CAR;
1888 if (status & UART_MSR_RI)
1889 ret |= TIOCM_RNG;
1890 if (status & UART_MSR_DSR)
1891 ret |= TIOCM_DSR;
1892 if (status & UART_MSR_CTS)
1893 ret |= TIOCM_CTS;
1894 return ret;
1897 static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
1899 struct uart_8250_port *up =
1900 container_of(port, struct uart_8250_port, port);
1901 unsigned char mcr = 0;
1903 if (mctrl & TIOCM_RTS)
1904 mcr |= UART_MCR_RTS;
1905 if (mctrl & TIOCM_DTR)
1906 mcr |= UART_MCR_DTR;
1907 if (mctrl & TIOCM_OUT1)
1908 mcr |= UART_MCR_OUT1;
1909 if (mctrl & TIOCM_OUT2)
1910 mcr |= UART_MCR_OUT2;
1911 if (mctrl & TIOCM_LOOP)
1912 mcr |= UART_MCR_LOOP;
1914 mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
1916 serial_out(up, UART_MCR, mcr);
1919 static void serial8250_break_ctl(struct uart_port *port, int break_state)
1921 struct uart_8250_port *up =
1922 container_of(port, struct uart_8250_port, port);
1923 unsigned long flags;
1925 spin_lock_irqsave(&up->port.lock, flags);
1926 if (break_state == -1)
1927 up->lcr |= UART_LCR_SBC;
1928 else
1929 up->lcr &= ~UART_LCR_SBC;
1930 serial_out(up, UART_LCR, up->lcr);
1931 spin_unlock_irqrestore(&up->port.lock, flags);
1935 * Wait for transmitter & holding register to empty
1937 static void wait_for_xmitr(struct uart_8250_port *up, int bits)
1939 unsigned int status, tmout = 10000;
1941 /* Wait up to 10ms for the character(s) to be sent. */
1942 for (;;) {
1943 status = serial_in(up, UART_LSR);
1945 up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
1947 if ((status & bits) == bits)
1948 break;
1949 if (--tmout == 0)
1950 break;
1951 udelay(1);
1954 /* Wait up to 1s for flow control if necessary */
1955 if (up->port.flags & UPF_CONS_FLOW) {
1956 unsigned int tmout;
1957 for (tmout = 1000000; tmout; tmout--) {
1958 unsigned int msr = serial_in(up, UART_MSR);
1959 up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
1960 if (msr & UART_MSR_CTS)
1961 break;
1962 udelay(1);
1963 touch_nmi_watchdog();
1968 #ifdef CONFIG_CONSOLE_POLL
1970 * Console polling routines for writing and reading from the uart while
1971 * in an interrupt or debug context.
1974 static int serial8250_get_poll_char(struct uart_port *port)
1976 struct uart_8250_port *up =
1977 container_of(port, struct uart_8250_port, port);
1978 unsigned char lsr = serial_inp(up, UART_LSR);
1980 if (!(lsr & UART_LSR_DR))
1981 return NO_POLL_CHAR;
1983 return serial_inp(up, UART_RX);
1987 static void serial8250_put_poll_char(struct uart_port *port,
1988 unsigned char c)
1990 unsigned int ier;
1991 struct uart_8250_port *up =
1992 container_of(port, struct uart_8250_port, port);
1995 * First save the IER then disable the interrupts
1997 ier = serial_in(up, UART_IER);
1998 if (up->capabilities & UART_CAP_UUE)
1999 serial_out(up, UART_IER, UART_IER_UUE);
2000 else
2001 serial_out(up, UART_IER, 0);
2003 wait_for_xmitr(up, BOTH_EMPTY);
2005 * Send the character out.
2006 * If a LF, also do CR...
2008 serial_out(up, UART_TX, c);
2009 if (c == 10) {
2010 wait_for_xmitr(up, BOTH_EMPTY);
2011 serial_out(up, UART_TX, 13);
2015 * Finally, wait for transmitter to become empty
2016 * and restore the IER
2018 wait_for_xmitr(up, BOTH_EMPTY);
2019 serial_out(up, UART_IER, ier);
2022 #endif /* CONFIG_CONSOLE_POLL */
2024 static int serial8250_startup(struct uart_port *port)
2026 struct uart_8250_port *up =
2027 container_of(port, struct uart_8250_port, port);
2028 unsigned long flags;
2029 unsigned char lsr, iir;
2030 int retval;
2032 up->port.fifosize = uart_config[up->port.type].fifo_size;
2033 up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
2034 up->capabilities = uart_config[up->port.type].flags;
2035 up->mcr = 0;
2037 if (up->port.iotype != up->cur_iotype)
2038 set_io_from_upio(port);
2040 if (up->port.type == PORT_16C950) {
2041 /* Wake up and initialize UART */
2042 up->acr = 0;
2043 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
2044 serial_outp(up, UART_EFR, UART_EFR_ECB);
2045 serial_outp(up, UART_IER, 0);
2046 serial_outp(up, UART_LCR, 0);
2047 serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
2048 serial_outp(up, UART_LCR, 0xBF);
2049 serial_outp(up, UART_EFR, UART_EFR_ECB);
2050 serial_outp(up, UART_LCR, 0);
2053 #ifdef CONFIG_SERIAL_8250_RSA
2055 * If this is an RSA port, see if we can kick it up to the
2056 * higher speed clock.
2058 enable_rsa(up);
2059 #endif
2062 * Clear the FIFO buffers and disable them.
2063 * (they will be reenabled in set_termios())
2065 serial8250_clear_fifos(up);
2068 * Clear the interrupt registers.
2070 (void) serial_inp(up, UART_LSR);
2071 (void) serial_inp(up, UART_RX);
2072 (void) serial_inp(up, UART_IIR);
2073 (void) serial_inp(up, UART_MSR);
2076 * At this point, there's no way the LSR could still be 0xff;
2077 * if it is, then bail out, because there's likely no UART
2078 * here.
2080 if (!(up->port.flags & UPF_BUGGY_UART) &&
2081 (serial_inp(up, UART_LSR) == 0xff)) {
2082 printk(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
2083 serial_index(&up->port));
2084 return -ENODEV;
2088 * For a XR16C850, we need to set the trigger levels
2090 if (up->port.type == PORT_16850) {
2091 unsigned char fctr;
2093 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
2095 fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
2096 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
2097 serial_outp(up, UART_TRG, UART_TRG_96);
2098 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
2099 serial_outp(up, UART_TRG, UART_TRG_96);
2101 serial_outp(up, UART_LCR, 0);
2104 if (is_real_interrupt(up->port.irq)) {
2105 unsigned char iir1;
2107 * Test for UARTs that do not reassert THRE when the
2108 * transmitter is idle and the interrupt has already
2109 * been cleared. Real 16550s should always reassert
2110 * this interrupt whenever the transmitter is idle and
2111 * the interrupt is enabled. Delays are necessary to
2112 * allow register changes to become visible.
2114 spin_lock_irqsave(&up->port.lock, flags);
2115 if (up->port.irqflags & IRQF_SHARED)
2116 disable_irq_nosync(up->port.irq);
2118 wait_for_xmitr(up, UART_LSR_THRE);
2119 serial_out_sync(up, UART_IER, UART_IER_THRI);
2120 udelay(1); /* allow THRE to set */
2121 iir1 = serial_in(up, UART_IIR);
2122 serial_out(up, UART_IER, 0);
2123 serial_out_sync(up, UART_IER, UART_IER_THRI);
2124 udelay(1); /* allow a working UART time to re-assert THRE */
2125 iir = serial_in(up, UART_IIR);
2126 serial_out(up, UART_IER, 0);
2128 if (up->port.irqflags & IRQF_SHARED)
2129 enable_irq(up->port.irq);
2130 spin_unlock_irqrestore(&up->port.lock, flags);
2133 * If the interrupt is not reasserted, setup a timer to
2134 * kick the UART on a regular basis.
2136 if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
2137 up->bugs |= UART_BUG_THRE;
2138 pr_debug("ttyS%d - using backup timer\n",
2139 serial_index(port));
2144 * The above check will only give an accurate result the first time
2145 * the port is opened so this value needs to be preserved.
2147 if (up->bugs & UART_BUG_THRE) {
2148 up->timer.function = serial8250_backup_timeout;
2149 up->timer.data = (unsigned long)up;
2150 mod_timer(&up->timer, jiffies +
2151 uart_poll_timeout(port) + HZ / 5);
2155 * If the "interrupt" for this port doesn't correspond with any
2156 * hardware interrupt, we use a timer-based system. The original
2157 * driver used to do this with IRQ0.
2159 if (!is_real_interrupt(up->port.irq)) {
2160 up->timer.data = (unsigned long)up;
2161 mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
2162 } else {
2163 retval = serial_link_irq_chain(up);
2164 if (retval)
2165 return retval;
2169 * Now, initialize the UART
2171 serial_outp(up, UART_LCR, UART_LCR_WLEN8);
2173 spin_lock_irqsave(&up->port.lock, flags);
2174 if (up->port.flags & UPF_FOURPORT) {
2175 if (!is_real_interrupt(up->port.irq))
2176 up->port.mctrl |= TIOCM_OUT1;
2177 } else
2179 * Most PC uarts need OUT2 raised to enable interrupts.
2181 if (is_real_interrupt(up->port.irq))
2182 up->port.mctrl |= TIOCM_OUT2;
2184 serial8250_set_mctrl(&up->port, up->port.mctrl);
2186 /* Serial over Lan (SoL) hack:
2187 Intel 8257x Gigabit ethernet chips have a
2188 16550 emulation, to be used for Serial Over Lan.
2189 Those chips take a longer time than a normal
2190 serial device to signalize that a transmission
2191 data was queued. Due to that, the above test generally
2192 fails. One solution would be to delay the reading of
2193 iir. However, this is not reliable, since the timeout
2194 is variable. So, let's just don't test if we receive
2195 TX irq. This way, we'll never enable UART_BUG_TXEN.
2197 if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST)
2198 goto dont_test_tx_en;
2201 * Do a quick test to see if we receive an
2202 * interrupt when we enable the TX irq.
2204 serial_outp(up, UART_IER, UART_IER_THRI);
2205 lsr = serial_in(up, UART_LSR);
2206 iir = serial_in(up, UART_IIR);
2207 serial_outp(up, UART_IER, 0);
2209 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
2210 if (!(up->bugs & UART_BUG_TXEN)) {
2211 up->bugs |= UART_BUG_TXEN;
2212 pr_debug("ttyS%d - enabling bad tx status workarounds\n",
2213 serial_index(port));
2215 } else {
2216 up->bugs &= ~UART_BUG_TXEN;
2219 dont_test_tx_en:
2220 spin_unlock_irqrestore(&up->port.lock, flags);
2223 * Clear the interrupt registers again for luck, and clear the
2224 * saved flags to avoid getting false values from polling
2225 * routines or the previous session.
2227 serial_inp(up, UART_LSR);
2228 serial_inp(up, UART_RX);
2229 serial_inp(up, UART_IIR);
2230 serial_inp(up, UART_MSR);
2231 up->lsr_saved_flags = 0;
2232 up->msr_saved_flags = 0;
2235 * Finally, enable interrupts. Note: Modem status interrupts
2236 * are set via set_termios(), which will be occurring imminently
2237 * anyway, so we don't enable them here.
2239 up->ier = UART_IER_RLSI | UART_IER_RDI;
2240 serial_outp(up, UART_IER, up->ier);
2242 if (up->port.flags & UPF_FOURPORT) {
2243 unsigned int icp;
2245 * Enable interrupts on the AST Fourport board
2247 icp = (up->port.iobase & 0xfe0) | 0x01f;
2248 outb_p(0x80, icp);
2249 (void) inb_p(icp);
2252 return 0;
2255 static void serial8250_shutdown(struct uart_port *port)
2257 struct uart_8250_port *up =
2258 container_of(port, struct uart_8250_port, port);
2259 unsigned long flags;
2262 * Disable interrupts from this port
2264 up->ier = 0;
2265 serial_outp(up, UART_IER, 0);
2267 spin_lock_irqsave(&up->port.lock, flags);
2268 if (up->port.flags & UPF_FOURPORT) {
2269 /* reset interrupts on the AST Fourport board */
2270 inb((up->port.iobase & 0xfe0) | 0x1f);
2271 up->port.mctrl |= TIOCM_OUT1;
2272 } else
2273 up->port.mctrl &= ~TIOCM_OUT2;
2275 serial8250_set_mctrl(&up->port, up->port.mctrl);
2276 spin_unlock_irqrestore(&up->port.lock, flags);
2279 * Disable break condition and FIFOs
2281 serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
2282 serial8250_clear_fifos(up);
2284 #ifdef CONFIG_SERIAL_8250_RSA
2286 * Reset the RSA board back to 115kbps compat mode.
2288 disable_rsa(up);
2289 #endif
2292 * Read data port to reset things, and then unlink from
2293 * the IRQ chain.
2295 (void) serial_in(up, UART_RX);
2297 del_timer_sync(&up->timer);
2298 up->timer.function = serial8250_timeout;
2299 if (is_real_interrupt(up->port.irq))
2300 serial_unlink_irq_chain(up);
2303 static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
2305 unsigned int quot;
2308 * Handle magic divisors for baud rates above baud_base on
2309 * SMSC SuperIO chips.
2311 if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2312 baud == (port->uartclk/4))
2313 quot = 0x8001;
2314 else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2315 baud == (port->uartclk/8))
2316 quot = 0x8002;
2317 else
2318 quot = uart_get_divisor(port, baud);
2320 return quot;
2323 void
2324 serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
2325 struct ktermios *old)
2327 struct uart_8250_port *up =
2328 container_of(port, struct uart_8250_port, port);
2329 unsigned char cval, fcr = 0;
2330 unsigned long flags;
2331 unsigned int baud, quot;
2333 switch (termios->c_cflag & CSIZE) {
2334 case CS5:
2335 cval = UART_LCR_WLEN5;
2336 break;
2337 case CS6:
2338 cval = UART_LCR_WLEN6;
2339 break;
2340 case CS7:
2341 cval = UART_LCR_WLEN7;
2342 break;
2343 default:
2344 case CS8:
2345 cval = UART_LCR_WLEN8;
2346 break;
2349 if (termios->c_cflag & CSTOPB)
2350 cval |= UART_LCR_STOP;
2351 if (termios->c_cflag & PARENB)
2352 cval |= UART_LCR_PARITY;
2353 if (!(termios->c_cflag & PARODD))
2354 cval |= UART_LCR_EPAR;
2355 #ifdef CMSPAR
2356 if (termios->c_cflag & CMSPAR)
2357 cval |= UART_LCR_SPAR;
2358 #endif
2361 * Ask the core to calculate the divisor for us.
2363 baud = uart_get_baud_rate(port, termios, old,
2364 port->uartclk / 16 / 0xffff,
2365 port->uartclk / 16);
2366 quot = serial8250_get_divisor(port, baud);
2369 * Oxford Semi 952 rev B workaround
2371 if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
2372 quot++;
2374 if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
2375 if (baud < 2400)
2376 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
2377 else
2378 fcr = uart_config[up->port.type].fcr;
2382 * MCR-based auto flow control. When AFE is enabled, RTS will be
2383 * deasserted when the receive FIFO contains more characters than
2384 * the trigger, or the MCR RTS bit is cleared. In the case where
2385 * the remote UART is not using CTS auto flow control, we must
2386 * have sufficient FIFO entries for the latency of the remote
2387 * UART to respond. IOW, at least 32 bytes of FIFO.
2389 if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
2390 up->mcr &= ~UART_MCR_AFE;
2391 if (termios->c_cflag & CRTSCTS)
2392 up->mcr |= UART_MCR_AFE;
2396 * Ok, we're now changing the port state. Do it with
2397 * interrupts disabled.
2399 spin_lock_irqsave(&up->port.lock, flags);
2402 * Update the per-port timeout.
2404 uart_update_timeout(port, termios->c_cflag, baud);
2406 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
2407 if (termios->c_iflag & INPCK)
2408 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
2409 if (termios->c_iflag & (BRKINT | PARMRK))
2410 up->port.read_status_mask |= UART_LSR_BI;
2413 * Characteres to ignore
2415 up->port.ignore_status_mask = 0;
2416 if (termios->c_iflag & IGNPAR)
2417 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
2418 if (termios->c_iflag & IGNBRK) {
2419 up->port.ignore_status_mask |= UART_LSR_BI;
2421 * If we're ignoring parity and break indicators,
2422 * ignore overruns too (for real raw support).
2424 if (termios->c_iflag & IGNPAR)
2425 up->port.ignore_status_mask |= UART_LSR_OE;
2429 * ignore all characters if CREAD is not set
2431 if ((termios->c_cflag & CREAD) == 0)
2432 up->port.ignore_status_mask |= UART_LSR_DR;
2435 * CTS flow control flag and modem status interrupts
2437 up->ier &= ~UART_IER_MSI;
2438 if (!(up->bugs & UART_BUG_NOMSR) &&
2439 UART_ENABLE_MS(&up->port, termios->c_cflag))
2440 up->ier |= UART_IER_MSI;
2441 if (up->capabilities & UART_CAP_UUE)
2442 up->ier |= UART_IER_UUE;
2443 if (up->capabilities & UART_CAP_RTOIE)
2444 up->ier |= UART_IER_RTOIE;
2446 serial_out(up, UART_IER, up->ier);
2448 if (up->capabilities & UART_CAP_EFR) {
2449 unsigned char efr = 0;
2451 * TI16C752/Startech hardware flow control. FIXME:
2452 * - TI16C752 requires control thresholds to be set.
2453 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
2455 if (termios->c_cflag & CRTSCTS)
2456 efr |= UART_EFR_CTS;
2458 serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
2459 serial_outp(up, UART_EFR, efr);
2462 #ifdef CONFIG_ARCH_OMAP
2463 /* Workaround to enable 115200 baud on OMAP1510 internal ports */
2464 if (cpu_is_omap1510() && is_omap_port(up)) {
2465 if (baud == 115200) {
2466 quot = 1;
2467 serial_out(up, UART_OMAP_OSC_12M_SEL, 1);
2468 } else
2469 serial_out(up, UART_OMAP_OSC_12M_SEL, 0);
2471 #endif
2473 if (up->capabilities & UART_NATSEMI) {
2474 /* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
2475 serial_outp(up, UART_LCR, 0xe0);
2476 } else {
2477 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
2480 serial_dl_write(up, quot);
2483 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
2484 * is written without DLAB set, this mode will be disabled.
2486 if (up->port.type == PORT_16750)
2487 serial_outp(up, UART_FCR, fcr);
2489 serial_outp(up, UART_LCR, cval); /* reset DLAB */
2490 up->lcr = cval; /* Save LCR */
2491 if (up->port.type != PORT_16750) {
2492 if (fcr & UART_FCR_ENABLE_FIFO) {
2493 /* emulated UARTs (Lucent Venus 167x) need two steps */
2494 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
2496 serial_outp(up, UART_FCR, fcr); /* set fcr */
2498 serial8250_set_mctrl(&up->port, up->port.mctrl);
2499 spin_unlock_irqrestore(&up->port.lock, flags);
2500 /* Don't rewrite B0 */
2501 if (tty_termios_baud_rate(termios))
2502 tty_termios_encode_baud_rate(termios, baud, baud);
2504 EXPORT_SYMBOL(serial8250_do_set_termios);
2506 static void
2507 serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
2508 struct ktermios *old)
2510 if (port->set_termios)
2511 port->set_termios(port, termios, old);
2512 else
2513 serial8250_do_set_termios(port, termios, old);
2516 static void
2517 serial8250_set_ldisc(struct uart_port *port, int new)
2519 if (new == N_PPS) {
2520 port->flags |= UPF_HARDPPS_CD;
2521 serial8250_enable_ms(port);
2522 } else
2523 port->flags &= ~UPF_HARDPPS_CD;
2527 void serial8250_do_pm(struct uart_port *port, unsigned int state,
2528 unsigned int oldstate)
2530 struct uart_8250_port *p =
2531 container_of(port, struct uart_8250_port, port);
2533 serial8250_set_sleep(p, state != 0);
2535 EXPORT_SYMBOL(serial8250_do_pm);
2537 static void
2538 serial8250_pm(struct uart_port *port, unsigned int state,
2539 unsigned int oldstate)
2541 if (port->pm)
2542 port->pm(port, state, oldstate);
2543 else
2544 serial8250_do_pm(port, state, oldstate);
2547 static unsigned int serial8250_port_size(struct uart_8250_port *pt)
2549 if (pt->port.iotype == UPIO_AU)
2550 return 0x1000;
2551 #ifdef CONFIG_ARCH_OMAP
2552 if (is_omap_port(pt))
2553 return 0x16 << pt->port.regshift;
2554 #endif
2555 return 8 << pt->port.regshift;
2559 * Resource handling.
2561 static int serial8250_request_std_resource(struct uart_8250_port *up)
2563 unsigned int size = serial8250_port_size(up);
2564 int ret = 0;
2566 switch (up->port.iotype) {
2567 case UPIO_AU:
2568 case UPIO_TSI:
2569 case UPIO_MEM32:
2570 case UPIO_MEM:
2571 case UPIO_DWAPB:
2572 case UPIO_DWAPB32:
2573 if (!up->port.mapbase)
2574 break;
2576 if (!request_mem_region(up->port.mapbase, size, "serial")) {
2577 ret = -EBUSY;
2578 break;
2581 if (up->port.flags & UPF_IOREMAP) {
2582 up->port.membase = ioremap_nocache(up->port.mapbase,
2583 size);
2584 if (!up->port.membase) {
2585 release_mem_region(up->port.mapbase, size);
2586 ret = -ENOMEM;
2589 break;
2591 case UPIO_HUB6:
2592 case UPIO_PORT:
2593 if (!request_region(up->port.iobase, size, "serial"))
2594 ret = -EBUSY;
2595 break;
2597 return ret;
2600 static void serial8250_release_std_resource(struct uart_8250_port *up)
2602 unsigned int size = serial8250_port_size(up);
2604 switch (up->port.iotype) {
2605 case UPIO_AU:
2606 case UPIO_TSI:
2607 case UPIO_MEM32:
2608 case UPIO_MEM:
2609 case UPIO_DWAPB:
2610 case UPIO_DWAPB32:
2611 if (!up->port.mapbase)
2612 break;
2614 if (up->port.flags & UPF_IOREMAP) {
2615 iounmap(up->port.membase);
2616 up->port.membase = NULL;
2619 release_mem_region(up->port.mapbase, size);
2620 break;
2622 case UPIO_HUB6:
2623 case UPIO_PORT:
2624 release_region(up->port.iobase, size);
2625 break;
2629 static int serial8250_request_rsa_resource(struct uart_8250_port *up)
2631 unsigned long start = UART_RSA_BASE << up->port.regshift;
2632 unsigned int size = 8 << up->port.regshift;
2633 int ret = -EINVAL;
2635 switch (up->port.iotype) {
2636 case UPIO_HUB6:
2637 case UPIO_PORT:
2638 start += up->port.iobase;
2639 if (request_region(start, size, "serial-rsa"))
2640 ret = 0;
2641 else
2642 ret = -EBUSY;
2643 break;
2646 return ret;
2649 static void serial8250_release_rsa_resource(struct uart_8250_port *up)
2651 unsigned long offset = UART_RSA_BASE << up->port.regshift;
2652 unsigned int size = 8 << up->port.regshift;
2654 switch (up->port.iotype) {
2655 case UPIO_HUB6:
2656 case UPIO_PORT:
2657 release_region(up->port.iobase + offset, size);
2658 break;
2662 static void serial8250_release_port(struct uart_port *port)
2664 struct uart_8250_port *up =
2665 container_of(port, struct uart_8250_port, port);
2667 serial8250_release_std_resource(up);
2668 if (up->port.type == PORT_RSA)
2669 serial8250_release_rsa_resource(up);
2672 static int serial8250_request_port(struct uart_port *port)
2674 struct uart_8250_port *up =
2675 container_of(port, struct uart_8250_port, port);
2676 int ret = 0;
2678 ret = serial8250_request_std_resource(up);
2679 if (ret == 0 && up->port.type == PORT_RSA) {
2680 ret = serial8250_request_rsa_resource(up);
2681 if (ret < 0)
2682 serial8250_release_std_resource(up);
2685 return ret;
2688 static void serial8250_config_port(struct uart_port *port, int flags)
2690 struct uart_8250_port *up =
2691 container_of(port, struct uart_8250_port, port);
2692 int probeflags = PROBE_ANY;
2693 int ret;
2696 * Find the region that we can probe for. This in turn
2697 * tells us whether we can probe for the type of port.
2699 ret = serial8250_request_std_resource(up);
2700 if (ret < 0)
2701 return;
2703 ret = serial8250_request_rsa_resource(up);
2704 if (ret < 0)
2705 probeflags &= ~PROBE_RSA;
2707 if (up->port.iotype != up->cur_iotype)
2708 set_io_from_upio(port);
2710 if (flags & UART_CONFIG_TYPE)
2711 autoconfig(up, probeflags);
2713 /* if access method is AU, it is a 16550 with a quirk */
2714 if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
2715 up->bugs |= UART_BUG_NOMSR;
2717 if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
2718 autoconfig_irq(up);
2720 if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
2721 serial8250_release_rsa_resource(up);
2722 if (up->port.type == PORT_UNKNOWN)
2723 serial8250_release_std_resource(up);
2726 static int
2727 serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
2729 if (ser->irq >= nr_irqs || ser->irq < 0 ||
2730 ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
2731 ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
2732 ser->type == PORT_STARTECH)
2733 return -EINVAL;
2734 return 0;
2737 static const char *
2738 serial8250_type(struct uart_port *port)
2740 int type = port->type;
2742 if (type >= ARRAY_SIZE(uart_config))
2743 type = 0;
2744 return uart_config[type].name;
2747 static struct uart_ops serial8250_pops = {
2748 .tx_empty = serial8250_tx_empty,
2749 .set_mctrl = serial8250_set_mctrl,
2750 .get_mctrl = serial8250_get_mctrl,
2751 .stop_tx = serial8250_stop_tx,
2752 .start_tx = serial8250_start_tx,
2753 .stop_rx = serial8250_stop_rx,
2754 .enable_ms = serial8250_enable_ms,
2755 .break_ctl = serial8250_break_ctl,
2756 .startup = serial8250_startup,
2757 .shutdown = serial8250_shutdown,
2758 .set_termios = serial8250_set_termios,
2759 .set_ldisc = serial8250_set_ldisc,
2760 .pm = serial8250_pm,
2761 .type = serial8250_type,
2762 .release_port = serial8250_release_port,
2763 .request_port = serial8250_request_port,
2764 .config_port = serial8250_config_port,
2765 .verify_port = serial8250_verify_port,
2766 #ifdef CONFIG_CONSOLE_POLL
2767 .poll_get_char = serial8250_get_poll_char,
2768 .poll_put_char = serial8250_put_poll_char,
2769 #endif
2772 static struct uart_8250_port serial8250_ports[UART_NR];
2774 static void (*serial8250_isa_config)(int port, struct uart_port *up,
2775 unsigned short *capabilities);
2777 void serial8250_set_isa_configurator(
2778 void (*v)(int port, struct uart_port *up, unsigned short *capabilities))
2780 serial8250_isa_config = v;
2782 EXPORT_SYMBOL(serial8250_set_isa_configurator);
2784 static void __init serial8250_isa_init_ports(void)
2786 struct uart_8250_port *up;
2787 static int first = 1;
2788 int i, irqflag = 0;
2790 if (!first)
2791 return;
2792 first = 0;
2794 for (i = 0; i < nr_uarts; i++) {
2795 struct uart_8250_port *up = &serial8250_ports[i];
2797 up->port.line = i;
2798 spin_lock_init(&up->port.lock);
2800 init_timer(&up->timer);
2801 up->timer.function = serial8250_timeout;
2804 * ALPHA_KLUDGE_MCR needs to be killed.
2806 up->mcr_mask = ~ALPHA_KLUDGE_MCR;
2807 up->mcr_force = ALPHA_KLUDGE_MCR;
2809 up->port.ops = &serial8250_pops;
2812 if (share_irqs)
2813 irqflag = IRQF_SHARED;
2815 for (i = 0, up = serial8250_ports;
2816 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
2817 i++, up++) {
2818 up->port.iobase = old_serial_port[i].port;
2819 up->port.irq = irq_canonicalize(old_serial_port[i].irq);
2820 up->port.irqflags = old_serial_port[i].irqflags;
2821 up->port.uartclk = old_serial_port[i].baud_base * 16;
2822 up->port.flags = old_serial_port[i].flags;
2823 up->port.hub6 = old_serial_port[i].hub6;
2824 up->port.membase = old_serial_port[i].iomem_base;
2825 up->port.iotype = old_serial_port[i].io_type;
2826 up->port.regshift = old_serial_port[i].iomem_reg_shift;
2827 set_io_from_upio(&up->port);
2828 up->port.irqflags |= irqflag;
2829 if (serial8250_isa_config != NULL)
2830 serial8250_isa_config(i, &up->port, &up->capabilities);
2835 static void
2836 serial8250_init_fixed_type_port(struct uart_8250_port *up, unsigned int type)
2838 up->port.type = type;
2839 up->port.fifosize = uart_config[type].fifo_size;
2840 up->capabilities = uart_config[type].flags;
2841 up->tx_loadsz = uart_config[type].tx_loadsz;
2844 static void __init
2845 serial8250_register_ports(struct uart_driver *drv, struct device *dev)
2847 int i;
2849 for (i = 0; i < nr_uarts; i++) {
2850 struct uart_8250_port *up = &serial8250_ports[i];
2851 up->cur_iotype = 0xFF;
2854 serial8250_isa_init_ports();
2856 for (i = 0; i < nr_uarts; i++) {
2857 struct uart_8250_port *up = &serial8250_ports[i];
2859 up->port.dev = dev;
2861 if (up->port.flags & UPF_FIXED_TYPE)
2862 serial8250_init_fixed_type_port(up, up->port.type);
2864 uart_add_one_port(drv, &up->port);
2868 #ifdef CONFIG_SERIAL_8250_CONSOLE
2870 static void serial8250_console_putchar(struct uart_port *port, int ch)
2872 struct uart_8250_port *up =
2873 container_of(port, struct uart_8250_port, port);
2875 wait_for_xmitr(up, UART_LSR_THRE);
2876 serial_out(up, UART_TX, ch);
2880 * Print a string to the serial port trying not to disturb
2881 * any possible real use of the port...
2883 * The console_lock must be held when we get here.
2885 static void
2886 serial8250_console_write(struct console *co, const char *s, unsigned int count)
2888 struct uart_8250_port *up = &serial8250_ports[co->index];
2889 unsigned long flags;
2890 unsigned int ier;
2891 int locked = 1;
2893 touch_nmi_watchdog();
2895 local_irq_save(flags);
2896 if (up->port.sysrq) {
2897 /* serial8250_handle_port() already took the lock */
2898 locked = 0;
2899 } else if (oops_in_progress) {
2900 locked = spin_trylock(&up->port.lock);
2901 } else
2902 spin_lock(&up->port.lock);
2905 * First save the IER then disable the interrupts
2907 ier = serial_in(up, UART_IER);
2909 if (up->capabilities & UART_CAP_UUE)
2910 serial_out(up, UART_IER, UART_IER_UUE);
2911 else
2912 serial_out(up, UART_IER, 0);
2914 uart_console_write(&up->port, s, count, serial8250_console_putchar);
2917 * Finally, wait for transmitter to become empty
2918 * and restore the IER
2920 wait_for_xmitr(up, BOTH_EMPTY);
2921 serial_out(up, UART_IER, ier);
2924 * The receive handling will happen properly because the
2925 * receive ready bit will still be set; it is not cleared
2926 * on read. However, modem control will not, we must
2927 * call it if we have saved something in the saved flags
2928 * while processing with interrupts off.
2930 if (up->msr_saved_flags)
2931 check_modem_status(up);
2933 if (locked)
2934 spin_unlock(&up->port.lock);
2935 local_irq_restore(flags);
2938 static int __init serial8250_console_setup(struct console *co, char *options)
2940 struct uart_port *port;
2941 int baud = 9600;
2942 int bits = 8;
2943 int parity = 'n';
2944 int flow = 'n';
2947 * Check whether an invalid uart number has been specified, and
2948 * if so, search for the first available port that does have
2949 * console support.
2951 if (co->index >= nr_uarts)
2952 co->index = 0;
2953 port = &serial8250_ports[co->index].port;
2954 if (!port->iobase && !port->membase)
2955 return -ENODEV;
2957 if (options)
2958 uart_parse_options(options, &baud, &parity, &bits, &flow);
2960 return uart_set_options(port, co, baud, parity, bits, flow);
2963 static int serial8250_console_early_setup(void)
2965 return serial8250_find_port_for_earlycon();
2968 static struct console serial8250_console = {
2969 .name = "ttyS",
2970 .write = serial8250_console_write,
2971 .device = uart_console_device,
2972 .setup = serial8250_console_setup,
2973 .early_setup = serial8250_console_early_setup,
2974 .flags = CON_PRINTBUFFER | CON_ANYTIME,
2975 .index = -1,
2976 .data = &serial8250_reg,
2979 static int __init serial8250_console_init(void)
2981 if (nr_uarts > UART_NR)
2982 nr_uarts = UART_NR;
2984 serial8250_isa_init_ports();
2985 register_console(&serial8250_console);
2986 return 0;
2988 console_initcall(serial8250_console_init);
2990 int serial8250_find_port(struct uart_port *p)
2992 int line;
2993 struct uart_port *port;
2995 for (line = 0; line < nr_uarts; line++) {
2996 port = &serial8250_ports[line].port;
2997 if (uart_match_port(p, port))
2998 return line;
3000 return -ENODEV;
3003 #define SERIAL8250_CONSOLE &serial8250_console
3004 #else
3005 #define SERIAL8250_CONSOLE NULL
3006 #endif
3008 static struct uart_driver serial8250_reg = {
3009 .owner = THIS_MODULE,
3010 .driver_name = "serial",
3011 .dev_name = "ttyS",
3012 .major = TTY_MAJOR,
3013 .minor = 64,
3014 .cons = SERIAL8250_CONSOLE,
3018 * early_serial_setup - early registration for 8250 ports
3020 * Setup an 8250 port structure prior to console initialisation. Use
3021 * after console initialisation will cause undefined behaviour.
3023 int __init early_serial_setup(struct uart_port *port)
3025 struct uart_port *p;
3027 if (port->line >= ARRAY_SIZE(serial8250_ports))
3028 return -ENODEV;
3030 serial8250_isa_init_ports();
3031 p = &serial8250_ports[port->line].port;
3032 p->iobase = port->iobase;
3033 p->membase = port->membase;
3034 p->irq = port->irq;
3035 p->irqflags = port->irqflags;
3036 p->uartclk = port->uartclk;
3037 p->fifosize = port->fifosize;
3038 p->regshift = port->regshift;
3039 p->iotype = port->iotype;
3040 p->flags = port->flags;
3041 p->mapbase = port->mapbase;
3042 p->private_data = port->private_data;
3043 p->type = port->type;
3044 p->line = port->line;
3046 set_io_from_upio(p);
3047 if (port->serial_in)
3048 p->serial_in = port->serial_in;
3049 if (port->serial_out)
3050 p->serial_out = port->serial_out;
3052 return 0;
3056 * serial8250_suspend_port - suspend one serial port
3057 * @line: serial line number
3059 * Suspend one serial port.
3061 void serial8250_suspend_port(int line)
3063 uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
3067 * serial8250_resume_port - resume one serial port
3068 * @line: serial line number
3070 * Resume one serial port.
3072 void serial8250_resume_port(int line)
3074 struct uart_8250_port *up = &serial8250_ports[line];
3076 if (up->capabilities & UART_NATSEMI) {
3077 /* Ensure it's still in high speed mode */
3078 serial_outp(up, UART_LCR, 0xE0);
3080 ns16550a_goto_highspeed(up);
3082 serial_outp(up, UART_LCR, 0);
3083 up->port.uartclk = 921600*16;
3085 uart_resume_port(&serial8250_reg, &up->port);
3089 * Register a set of serial devices attached to a platform device. The
3090 * list is terminated with a zero flags entry, which means we expect
3091 * all entries to have at least UPF_BOOT_AUTOCONF set.
3093 static int __devinit serial8250_probe(struct platform_device *dev)
3095 struct plat_serial8250_port *p = dev->dev.platform_data;
3096 struct uart_port port;
3097 int ret, i, irqflag = 0;
3099 memset(&port, 0, sizeof(struct uart_port));
3101 if (share_irqs)
3102 irqflag = IRQF_SHARED;
3104 for (i = 0; p && p->flags != 0; p++, i++) {
3105 port.iobase = p->iobase;
3106 port.membase = p->membase;
3107 port.irq = p->irq;
3108 port.irqflags = p->irqflags;
3109 port.uartclk = p->uartclk;
3110 port.regshift = p->regshift;
3111 port.iotype = p->iotype;
3112 port.flags = p->flags;
3113 port.mapbase = p->mapbase;
3114 port.hub6 = p->hub6;
3115 port.private_data = p->private_data;
3116 port.type = p->type;
3117 port.serial_in = p->serial_in;
3118 port.serial_out = p->serial_out;
3119 port.set_termios = p->set_termios;
3120 port.pm = p->pm;
3121 port.dev = &dev->dev;
3122 port.irqflags |= irqflag;
3123 ret = serial8250_register_port(&port);
3124 if (ret < 0) {
3125 dev_err(&dev->dev, "unable to register port at index %d "
3126 "(IO%lx MEM%llx IRQ%d): %d\n", i,
3127 p->iobase, (unsigned long long)p->mapbase,
3128 p->irq, ret);
3131 return 0;
3135 * Remove serial ports registered against a platform device.
3137 static int __devexit serial8250_remove(struct platform_device *dev)
3139 int i;
3141 for (i = 0; i < nr_uarts; i++) {
3142 struct uart_8250_port *up = &serial8250_ports[i];
3144 if (up->port.dev == &dev->dev)
3145 serial8250_unregister_port(i);
3147 return 0;
3150 static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
3152 int i;
3154 for (i = 0; i < UART_NR; i++) {
3155 struct uart_8250_port *up = &serial8250_ports[i];
3157 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3158 uart_suspend_port(&serial8250_reg, &up->port);
3161 return 0;
3164 static int serial8250_resume(struct platform_device *dev)
3166 int i;
3168 for (i = 0; i < UART_NR; i++) {
3169 struct uart_8250_port *up = &serial8250_ports[i];
3171 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3172 serial8250_resume_port(i);
3175 return 0;
3178 static struct platform_driver serial8250_isa_driver = {
3179 .probe = serial8250_probe,
3180 .remove = __devexit_p(serial8250_remove),
3181 .suspend = serial8250_suspend,
3182 .resume = serial8250_resume,
3183 .driver = {
3184 .name = "serial8250",
3185 .owner = THIS_MODULE,
3190 * This "device" covers _all_ ISA 8250-compatible serial devices listed
3191 * in the table in include/asm/serial.h
3193 static struct platform_device *serial8250_isa_devs;
3196 * serial8250_register_port and serial8250_unregister_port allows for
3197 * 16x50 serial ports to be configured at run-time, to support PCMCIA
3198 * modems and PCI multiport cards.
3200 static DEFINE_MUTEX(serial_mutex);
3202 static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
3204 int i;
3207 * First, find a port entry which matches.
3209 for (i = 0; i < nr_uarts; i++)
3210 if (uart_match_port(&serial8250_ports[i].port, port))
3211 return &serial8250_ports[i];
3214 * We didn't find a matching entry, so look for the first
3215 * free entry. We look for one which hasn't been previously
3216 * used (indicated by zero iobase).
3218 for (i = 0; i < nr_uarts; i++)
3219 if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
3220 serial8250_ports[i].port.iobase == 0)
3221 return &serial8250_ports[i];
3224 * That also failed. Last resort is to find any entry which
3225 * doesn't have a real port associated with it.
3227 for (i = 0; i < nr_uarts; i++)
3228 if (serial8250_ports[i].port.type == PORT_UNKNOWN)
3229 return &serial8250_ports[i];
3231 return NULL;
3235 * serial8250_register_port - register a serial port
3236 * @port: serial port template
3238 * Configure the serial port specified by the request. If the
3239 * port exists and is in use, it is hung up and unregistered
3240 * first.
3242 * The port is then probed and if necessary the IRQ is autodetected
3243 * If this fails an error is returned.
3245 * On success the port is ready to use and the line number is returned.
3247 int serial8250_register_port(struct uart_port *port)
3249 struct uart_8250_port *uart;
3250 int ret = -ENOSPC;
3252 if (port->uartclk == 0)
3253 return -EINVAL;
3255 mutex_lock(&serial_mutex);
3257 uart = serial8250_find_match_or_unused(port);
3258 if (uart) {
3259 uart_remove_one_port(&serial8250_reg, &uart->port);
3261 uart->port.iobase = port->iobase;
3262 uart->port.membase = port->membase;
3263 uart->port.irq = port->irq;
3264 uart->port.irqflags = port->irqflags;
3265 uart->port.uartclk = port->uartclk;
3266 uart->port.fifosize = port->fifosize;
3267 uart->port.regshift = port->regshift;
3268 uart->port.iotype = port->iotype;
3269 uart->port.flags = port->flags | UPF_BOOT_AUTOCONF;
3270 uart->port.mapbase = port->mapbase;
3271 uart->port.private_data = port->private_data;
3272 if (port->dev)
3273 uart->port.dev = port->dev;
3275 if (port->flags & UPF_FIXED_TYPE)
3276 serial8250_init_fixed_type_port(uart, port->type);
3278 set_io_from_upio(&uart->port);
3279 /* Possibly override default I/O functions. */
3280 if (port->serial_in)
3281 uart->port.serial_in = port->serial_in;
3282 if (port->serial_out)
3283 uart->port.serial_out = port->serial_out;
3284 /* Possibly override set_termios call */
3285 if (port->set_termios)
3286 uart->port.set_termios = port->set_termios;
3287 if (port->pm)
3288 uart->port.pm = port->pm;
3290 if (serial8250_isa_config != NULL)
3291 serial8250_isa_config(0, &uart->port,
3292 &uart->capabilities);
3294 ret = uart_add_one_port(&serial8250_reg, &uart->port);
3295 if (ret == 0)
3296 ret = uart->port.line;
3298 mutex_unlock(&serial_mutex);
3300 return ret;
3302 EXPORT_SYMBOL(serial8250_register_port);
3305 * serial8250_unregister_port - remove a 16x50 serial port at runtime
3306 * @line: serial line number
3308 * Remove one serial port. This may not be called from interrupt
3309 * context. We hand the port back to the our control.
3311 void serial8250_unregister_port(int line)
3313 struct uart_8250_port *uart = &serial8250_ports[line];
3315 mutex_lock(&serial_mutex);
3316 uart_remove_one_port(&serial8250_reg, &uart->port);
3317 if (serial8250_isa_devs) {
3318 uart->port.flags &= ~UPF_BOOT_AUTOCONF;
3319 uart->port.type = PORT_UNKNOWN;
3320 uart->port.dev = &serial8250_isa_devs->dev;
3321 uart->capabilities = uart_config[uart->port.type].flags;
3322 uart_add_one_port(&serial8250_reg, &uart->port);
3323 } else {
3324 uart->port.dev = NULL;
3326 mutex_unlock(&serial_mutex);
3328 EXPORT_SYMBOL(serial8250_unregister_port);
3330 static int __init serial8250_init(void)
3332 int ret;
3334 if (nr_uarts > UART_NR)
3335 nr_uarts = UART_NR;
3337 printk(KERN_INFO "Serial: 8250/16550 driver, "
3338 "%d ports, IRQ sharing %sabled\n", nr_uarts,
3339 share_irqs ? "en" : "dis");
3341 #ifdef CONFIG_SPARC
3342 ret = sunserial_register_minors(&serial8250_reg, UART_NR);
3343 #else
3344 serial8250_reg.nr = UART_NR;
3345 ret = uart_register_driver(&serial8250_reg);
3346 #endif
3347 if (ret)
3348 goto out;
3350 serial8250_isa_devs = platform_device_alloc("serial8250",
3351 PLAT8250_DEV_LEGACY);
3352 if (!serial8250_isa_devs) {
3353 ret = -ENOMEM;
3354 goto unreg_uart_drv;
3357 ret = platform_device_add(serial8250_isa_devs);
3358 if (ret)
3359 goto put_dev;
3361 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
3363 ret = platform_driver_register(&serial8250_isa_driver);
3364 if (ret == 0)
3365 goto out;
3367 platform_device_del(serial8250_isa_devs);
3368 put_dev:
3369 platform_device_put(serial8250_isa_devs);
3370 unreg_uart_drv:
3371 #ifdef CONFIG_SPARC
3372 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3373 #else
3374 uart_unregister_driver(&serial8250_reg);
3375 #endif
3376 out:
3377 return ret;
3380 static void __exit serial8250_exit(void)
3382 struct platform_device *isa_dev = serial8250_isa_devs;
3385 * This tells serial8250_unregister_port() not to re-register
3386 * the ports (thereby making serial8250_isa_driver permanently
3387 * in use.)
3389 serial8250_isa_devs = NULL;
3391 platform_driver_unregister(&serial8250_isa_driver);
3392 platform_device_unregister(isa_dev);
3394 #ifdef CONFIG_SPARC
3395 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3396 #else
3397 uart_unregister_driver(&serial8250_reg);
3398 #endif
3401 module_init(serial8250_init);
3402 module_exit(serial8250_exit);
3404 EXPORT_SYMBOL(serial8250_suspend_port);
3405 EXPORT_SYMBOL(serial8250_resume_port);
3407 MODULE_LICENSE("GPL");
3408 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
3410 module_param(share_irqs, uint, 0644);
3411 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
3412 " (unsafe)");
3414 module_param(nr_uarts, uint, 0644);
3415 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
3417 module_param(skip_txen_test, uint, 0644);
3418 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
3420 #ifdef CONFIG_SERIAL_8250_RSA
3421 module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
3422 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
3423 #endif
3424 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);