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cfq-iosched: limit coop preemption
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / serial / 8250.c
blobb1ae774016f12b5271ed4d90dc3150838f1415d6
1 /*
2 * linux/drivers/char/8250.c
3 *
4 * Driver for 8250/16550-type serial ports
5 *
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 *
8 * Copyright (C) 2001 Russell King.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * A note about mapbase / membase
16 *
17 * mapbase is the physical address of the IO port.
18 * membase is an 'ioremapped' cookie.
19 */
20
21 #if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
22 #define SUPPORT_SYSRQ
23 #endif
24
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/ioport.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/sysrq.h>
31 #include <linux/delay.h>
32 #include <linux/platform_device.h>
33 #include <linux/tty.h>
34 #include <linux/tty_flip.h>
35 #include <linux/serial_reg.h>
36 #include <linux/serial_core.h>
37 #include <linux/serial.h>
38 #include <linux/serial_8250.h>
39 #include <linux/nmi.h>
40 #include <linux/mutex.h>
41
42 #include <asm/io.h>
43 #include <asm/irq.h>
44
45 #include "8250.h"
46
47 #ifdef CONFIG_SPARC
48 #include "suncore.h"
49 #endif
50
51 /*
52 * Configuration:
53 * share_irqs - whether we pass IRQF_SHARED to request_irq(). This option
54 * is unsafe when used on edge-triggered interrupts.
55 */
56 static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
57
58 static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
59
60 static struct uart_driver serial8250_reg;
61
62 static int serial_index(struct uart_port *port)
63 {
64 return (serial8250_reg.minor - 64) + port->line;
65 }
66
67 static unsigned int skip_txen_test; /* force skip of txen test at init time */
68
69 /*
70 * Debugging.
71 */
72 #if 0
73 #define DEBUG_AUTOCONF(fmt...) printk(fmt)
74 #else
75 #define DEBUG_AUTOCONF(fmt...) do { } while (0)
76 #endif
77
78 #if 0
79 #define DEBUG_INTR(fmt...) printk(fmt)
80 #else
81 #define DEBUG_INTR(fmt...) do { } while (0)
82 #endif
83
84 #define PASS_LIMIT 256
85
86 /*
87 * We default to IRQ0 for the "no irq" hack. Some
88 * machine types want others as well - they're free
89 * to redefine this in their header file.
90 */
91 #define is_real_interrupt(irq) ((irq) != 0)
92
93 #ifdef CONFIG_SERIAL_8250_DETECT_IRQ
94 #define CONFIG_SERIAL_DETECT_IRQ 1
95 #endif
96 #ifdef CONFIG_SERIAL_8250_MANY_PORTS
97 #define CONFIG_SERIAL_MANY_PORTS 1
98 #endif
99
100 /*
101 * HUB6 is always on. This will be removed once the header
102 * files have been cleaned.
103 */
104 #define CONFIG_HUB6 1
105
106 #include <asm/serial.h>
107 /*
108 * SERIAL_PORT_DFNS tells us about built-in ports that have no
109 * standard enumeration mechanism. Platforms that can find all
110 * serial ports via mechanisms like ACPI or PCI need not supply it.
111 */
112 #ifndef SERIAL_PORT_DFNS
113 #define SERIAL_PORT_DFNS
114 #endif
115
116 static const struct old_serial_port old_serial_port[] = {
117 SERIAL_PORT_DFNS /* defined in asm/serial.h */
118 };
119
120 #define UART_NR CONFIG_SERIAL_8250_NR_UARTS
121
122 #ifdef CONFIG_SERIAL_8250_RSA
123
124 #define PORT_RSA_MAX 4
125 static unsigned long probe_rsa[PORT_RSA_MAX];
126 static unsigned int probe_rsa_count;
127 #endif /* CONFIG_SERIAL_8250_RSA */
128
129 struct uart_8250_port {
130 struct uart_port port;
131 struct timer_list timer; /* "no irq" timer */
132 struct list_head list; /* ports on this IRQ */
133 unsigned short capabilities; /* port capabilities */
134 unsigned short bugs; /* port bugs */
135 unsigned int tx_loadsz; /* transmit fifo load size */
136 unsigned char acr;
137 unsigned char ier;
138 unsigned char lcr;
139 unsigned char mcr;
140 unsigned char mcr_mask; /* mask of user bits */
141 unsigned char mcr_force; /* mask of forced bits */
142 unsigned char cur_iotype; /* Running I/O type */
143
144 /*
145 * Some bits in registers are cleared on a read, so they must
146 * be saved whenever the register is read but the bits will not
147 * be immediately processed.
148 */
149 #define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
150 unsigned char lsr_saved_flags;
151 #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
152 unsigned char msr_saved_flags;
153
154 /*
155 * We provide a per-port pm hook.
156 */
157 void (*pm)(struct uart_port *port,
158 unsigned int state, unsigned int old);
159 };
160
161 struct irq_info {
162 struct hlist_node node;
163 int irq;
164 spinlock_t lock; /* Protects list not the hash */
165 struct list_head *head;
166 };
167
168 #define NR_IRQ_HASH 32 /* Can be adjusted later */
169 static struct hlist_head irq_lists[NR_IRQ_HASH];
170 static DEFINE_MUTEX(hash_mutex); /* Used to walk the hash */
171
172 /*
173 * Here we define the default xmit fifo size used for each type of UART.
174 */
175 static const struct serial8250_config uart_config[] = {
176 [PORT_UNKNOWN] = {
177 .name = "unknown",
178 .fifo_size = 1,
179 .tx_loadsz = 1,
180 },
181 [PORT_8250] = {
182 .name = "8250",
183 .fifo_size = 1,
184 .tx_loadsz = 1,
185 },
186 [PORT_16450] = {
187 .name = "16450",
188 .fifo_size = 1,
189 .tx_loadsz = 1,
190 },
191 [PORT_16550] = {
192 .name = "16550",
193 .fifo_size = 1,
194 .tx_loadsz = 1,
195 },
196 [PORT_16550A] = {
197 .name = "16550A",
198 .fifo_size = 16,
199 .tx_loadsz = 16,
200 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
201 .flags = UART_CAP_FIFO,
202 },
203 [PORT_CIRRUS] = {
204 .name = "Cirrus",
205 .fifo_size = 1,
206 .tx_loadsz = 1,
207 },
208 [PORT_16650] = {
209 .name = "ST16650",
210 .fifo_size = 1,
211 .tx_loadsz = 1,
212 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
213 },
214 [PORT_16650V2] = {
215 .name = "ST16650V2",
216 .fifo_size = 32,
217 .tx_loadsz = 16,
218 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
219 UART_FCR_T_TRIG_00,
220 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
221 },
222 [PORT_16750] = {
223 .name = "TI16750",
224 .fifo_size = 64,
225 .tx_loadsz = 64,
226 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
227 UART_FCR7_64BYTE,
228 .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
229 },
230 [PORT_STARTECH] = {
231 .name = "Startech",
232 .fifo_size = 1,
233 .tx_loadsz = 1,
234 },
235 [PORT_16C950] = {
236 .name = "16C950/954",
237 .fifo_size = 128,
238 .tx_loadsz = 128,
239 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
240 .flags = UART_CAP_FIFO,
241 },
242 [PORT_16654] = {
243 .name = "ST16654",
244 .fifo_size = 64,
245 .tx_loadsz = 32,
246 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
247 UART_FCR_T_TRIG_10,
248 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
249 },
250 [PORT_16850] = {
251 .name = "XR16850",
252 .fifo_size = 128,
253 .tx_loadsz = 128,
254 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
255 .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
256 },
257 [PORT_RSA] = {
258 .name = "RSA",
259 .fifo_size = 2048,
260 .tx_loadsz = 2048,
261 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
262 .flags = UART_CAP_FIFO,
263 },
264 [PORT_NS16550A] = {
265 .name = "NS16550A",
266 .fifo_size = 16,
267 .tx_loadsz = 16,
268 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
269 .flags = UART_CAP_FIFO | UART_NATSEMI,
270 },
271 [PORT_XSCALE] = {
272 .name = "XScale",
273 .fifo_size = 32,
274 .tx_loadsz = 32,
275 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
276 .flags = UART_CAP_FIFO | UART_CAP_UUE,
277 },
278 [PORT_RM9000] = {
279 .name = "RM9000",
280 .fifo_size = 16,
281 .tx_loadsz = 16,
282 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
283 .flags = UART_CAP_FIFO,
284 },
285 [PORT_OCTEON] = {
286 .name = "OCTEON",
287 .fifo_size = 64,
288 .tx_loadsz = 64,
289 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
290 .flags = UART_CAP_FIFO,
291 },
292 [PORT_AR7] = {
293 .name = "AR7",
294 .fifo_size = 16,
295 .tx_loadsz = 16,
296 .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
297 .flags = UART_CAP_FIFO | UART_CAP_AFE,
298 },
299 };
300
301 #if defined (CONFIG_SERIAL_8250_AU1X00)
302
303 /* Au1x00 UART hardware has a weird register layout */
304 static const u8 au_io_in_map[] = {
305 [UART_RX] = 0,
306 [UART_IER] = 2,
307 [UART_IIR] = 3,
308 [UART_LCR] = 5,
309 [UART_MCR] = 6,
310 [UART_LSR] = 7,
311 [UART_MSR] = 8,
312 };
313
314 static const u8 au_io_out_map[] = {
315 [UART_TX] = 1,
316 [UART_IER] = 2,
317 [UART_FCR] = 4,
318 [UART_LCR] = 5,
319 [UART_MCR] = 6,
320 };
321
322 /* sane hardware needs no mapping */
323 static inline int map_8250_in_reg(struct uart_port *p, int offset)
324 {
325 if (p->iotype != UPIO_AU)
326 return offset;
327 return au_io_in_map[offset];
328 }
329
330 static inline int map_8250_out_reg(struct uart_port *p, int offset)
331 {
332 if (p->iotype != UPIO_AU)
333 return offset;
334 return au_io_out_map[offset];
335 }
336
337 #elif defined(CONFIG_SERIAL_8250_RM9K)
338
339 static const u8
340 regmap_in[8] = {
341 [UART_RX] = 0x00,
342 [UART_IER] = 0x0c,
343 [UART_IIR] = 0x14,
344 [UART_LCR] = 0x1c,
345 [UART_MCR] = 0x20,
346 [UART_LSR] = 0x24,
347 [UART_MSR] = 0x28,
348 [UART_SCR] = 0x2c
349 },
350 regmap_out[8] = {
351 [UART_TX] = 0x04,
352 [UART_IER] = 0x0c,
353 [UART_FCR] = 0x18,
354 [UART_LCR] = 0x1c,
355 [UART_MCR] = 0x20,
356 [UART_LSR] = 0x24,
357 [UART_MSR] = 0x28,
358 [UART_SCR] = 0x2c
359 };
360
361 static inline int map_8250_in_reg(struct uart_port *p, int offset)
362 {
363 if (p->iotype != UPIO_RM9000)
364 return offset;
365 return regmap_in[offset];
366 }
367
368 static inline int map_8250_out_reg(struct uart_port *p, int offset)
369 {
370 if (p->iotype != UPIO_RM9000)
371 return offset;
372 return regmap_out[offset];
373 }
374
375 #else
376
377 /* sane hardware needs no mapping */
378 #define map_8250_in_reg(up, offset) (offset)
379 #define map_8250_out_reg(up, offset) (offset)
380
381 #endif
382
383 static unsigned int hub6_serial_in(struct uart_port *p, int offset)
384 {
385 offset = map_8250_in_reg(p, offset) << p->regshift;
386 outb(p->hub6 - 1 + offset, p->iobase);
387 return inb(p->iobase + 1);
388 }
389
390 static void hub6_serial_out(struct uart_port *p, int offset, int value)
391 {
392 offset = map_8250_out_reg(p, offset) << p->regshift;
393 outb(p->hub6 - 1 + offset, p->iobase);
394 outb(value, p->iobase + 1);
395 }
396
397 static unsigned int mem_serial_in(struct uart_port *p, int offset)
398 {
399 offset = map_8250_in_reg(p, offset) << p->regshift;
400 return readb(p->membase + offset);
401 }
402
403 static void mem_serial_out(struct uart_port *p, int offset, int value)
404 {
405 offset = map_8250_out_reg(p, offset) << p->regshift;
406 writeb(value, p->membase + offset);
407 }
408
409 static void mem32_serial_out(struct uart_port *p, int offset, int value)
410 {
411 offset = map_8250_out_reg(p, offset) << p->regshift;
412 writel(value, p->membase + offset);
413 }
414
415 static unsigned int mem32_serial_in(struct uart_port *p, int offset)
416 {
417 offset = map_8250_in_reg(p, offset) << p->regshift;
418 return readl(p->membase + offset);
419 }
420
421 #ifdef CONFIG_SERIAL_8250_AU1X00
422 static unsigned int au_serial_in(struct uart_port *p, int offset)
423 {
424 offset = map_8250_in_reg(p, offset) << p->regshift;
425 return __raw_readl(p->membase + offset);
426 }
427
428 static void au_serial_out(struct uart_port *p, int offset, int value)
429 {
430 offset = map_8250_out_reg(p, offset) << p->regshift;
431 __raw_writel(value, p->membase + offset);
432 }
433 #endif
434
435 static unsigned int tsi_serial_in(struct uart_port *p, int offset)
436 {
437 unsigned int tmp;
438 offset = map_8250_in_reg(p, offset) << p->regshift;
439 if (offset == UART_IIR) {
440 tmp = readl(p->membase + (UART_IIR & ~3));
441 return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
442 } else
443 return readb(p->membase + offset);
444 }
445
446 static void tsi_serial_out(struct uart_port *p, int offset, int value)
447 {
448 offset = map_8250_out_reg(p, offset) << p->regshift;
449 if (!((offset == UART_IER) && (value & UART_IER_UUE)))
450 writeb(value, p->membase + offset);
451 }
452
453 static void dwapb_serial_out(struct uart_port *p, int offset, int value)
454 {
455 int save_offset = offset;
456 offset = map_8250_out_reg(p, offset) << p->regshift;
457 /* Save the LCR value so it can be re-written when a
458 * Busy Detect interrupt occurs. */
459 if (save_offset == UART_LCR) {
460 struct uart_8250_port *up = (struct uart_8250_port *)p;
461 up->lcr = value;
462 }
463 writeb(value, p->membase + offset);
464 /* Read the IER to ensure any interrupt is cleared before
465 * returning from ISR. */
466 if (save_offset == UART_TX || save_offset == UART_IER)
467 value = p->serial_in(p, UART_IER);
468 }
469
470 static unsigned int io_serial_in(struct uart_port *p, int offset)
471 {
472 offset = map_8250_in_reg(p, offset) << p->regshift;
473 return inb(p->iobase + offset);
474 }
475
476 static void io_serial_out(struct uart_port *p, int offset, int value)
477 {
478 offset = map_8250_out_reg(p, offset) << p->regshift;
479 outb(value, p->iobase + offset);
480 }
481
482 static void set_io_from_upio(struct uart_port *p)
483 {
484 struct uart_8250_port *up = (struct uart_8250_port *)p;
485 switch (p->iotype) {
486 case UPIO_HUB6:
487 p->serial_in = hub6_serial_in;
488 p->serial_out = hub6_serial_out;
489 break;
490
491 case UPIO_MEM:
492 p->serial_in = mem_serial_in;
493 p->serial_out = mem_serial_out;
494 break;
495
496 case UPIO_RM9000:
497 case UPIO_MEM32:
498 p->serial_in = mem32_serial_in;
499 p->serial_out = mem32_serial_out;
500 break;
501
502 #ifdef CONFIG_SERIAL_8250_AU1X00
503 case UPIO_AU:
504 p->serial_in = au_serial_in;
505 p->serial_out = au_serial_out;
506 break;
507 #endif
508 case UPIO_TSI:
509 p->serial_in = tsi_serial_in;
510 p->serial_out = tsi_serial_out;
511 break;
512
513 case UPIO_DWAPB:
514 p->serial_in = mem_serial_in;
515 p->serial_out = dwapb_serial_out;
516 break;
517
518 default:
519 p->serial_in = io_serial_in;
520 p->serial_out = io_serial_out;
521 break;
522 }
523 /* Remember loaded iotype */
524 up->cur_iotype = p->iotype;
525 }
526
527 static void
528 serial_out_sync(struct uart_8250_port *up, int offset, int value)
529 {
530 struct uart_port *p = &up->port;
531 switch (p->iotype) {
532 case UPIO_MEM:
533 case UPIO_MEM32:
534 #ifdef CONFIG_SERIAL_8250_AU1X00
535 case UPIO_AU:
536 #endif
537 case UPIO_DWAPB:
538 p->serial_out(p, offset, value);
539 p->serial_in(p, UART_LCR); /* safe, no side-effects */
540 break;
541 default:
542 p->serial_out(p, offset, value);
543 }
544 }
545
546 #define serial_in(up, offset) \
547 (up->port.serial_in(&(up)->port, (offset)))
548 #define serial_out(up, offset, value) \
549 (up->port.serial_out(&(up)->port, (offset), (value)))
550 /*
551 * We used to support using pause I/O for certain machines. We
552 * haven't supported this for a while, but just in case it's badly
553 * needed for certain old 386 machines, I've left these #define's
554 * in....
555 */
556 #define serial_inp(up, offset) serial_in(up, offset)
557 #define serial_outp(up, offset, value) serial_out(up, offset, value)
558
559 /* Uart divisor latch read */
560 static inline int _serial_dl_read(struct uart_8250_port *up)
561 {
562 return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
563 }
564
565 /* Uart divisor latch write */
566 static inline void _serial_dl_write(struct uart_8250_port *up, int value)
567 {
568 serial_outp(up, UART_DLL, value & 0xff);
569 serial_outp(up, UART_DLM, value >> 8 & 0xff);
570 }
571
572 #if defined(CONFIG_SERIAL_8250_AU1X00)
573 /* Au1x00 haven't got a standard divisor latch */
574 static int serial_dl_read(struct uart_8250_port *up)
575 {
576 if (up->port.iotype == UPIO_AU)
577 return __raw_readl(up->port.membase + 0x28);
578 else
579 return _serial_dl_read(up);
580 }
581
582 static void serial_dl_write(struct uart_8250_port *up, int value)
583 {
584 if (up->port.iotype == UPIO_AU)
585 __raw_writel(value, up->port.membase + 0x28);
586 else
587 _serial_dl_write(up, value);
588 }
589 #elif defined(CONFIG_SERIAL_8250_RM9K)
590 static int serial_dl_read(struct uart_8250_port *up)
591 {
592 return (up->port.iotype == UPIO_RM9000) ?
593 (((__raw_readl(up->port.membase + 0x10) << 8) |
594 (__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) :
595 _serial_dl_read(up);
596 }
597
598 static void serial_dl_write(struct uart_8250_port *up, int value)
599 {
600 if (up->port.iotype == UPIO_RM9000) {
601 __raw_writel(value, up->port.membase + 0x08);
602 __raw_writel(value >> 8, up->port.membase + 0x10);
603 } else {
604 _serial_dl_write(up, value);
605 }
606 }
607 #else
608 #define serial_dl_read(up) _serial_dl_read(up)
609 #define serial_dl_write(up, value) _serial_dl_write(up, value)
610 #endif
611
612 /*
613 * For the 16C950
614 */
615 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
616 {
617 serial_out(up, UART_SCR, offset);
618 serial_out(up, UART_ICR, value);
619 }
620
621 static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
622 {
623 unsigned int value;
624
625 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
626 serial_out(up, UART_SCR, offset);
627 value = serial_in(up, UART_ICR);
628 serial_icr_write(up, UART_ACR, up->acr);
629
630 return value;
631 }
632
633 /*
634 * FIFO support.
635 */
636 static void serial8250_clear_fifos(struct uart_8250_port *p)
637 {
638 if (p->capabilities & UART_CAP_FIFO) {
639 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
640 serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
641 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
642 serial_outp(p, UART_FCR, 0);
643 }
644 }
645
646 /*
647 * IER sleep support. UARTs which have EFRs need the "extended
648 * capability" bit enabled. Note that on XR16C850s, we need to
649 * reset LCR to write to IER.
650 */
651 static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
652 {
653 if (p->capabilities & UART_CAP_SLEEP) {
654 if (p->capabilities & UART_CAP_EFR) {
655 serial_outp(p, UART_LCR, 0xBF);
656 serial_outp(p, UART_EFR, UART_EFR_ECB);
657 serial_outp(p, UART_LCR, 0);
658 }
659 serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
660 if (p->capabilities & UART_CAP_EFR) {
661 serial_outp(p, UART_LCR, 0xBF);
662 serial_outp(p, UART_EFR, 0);
663 serial_outp(p, UART_LCR, 0);
664 }
665 }
666 }
667
668 #ifdef CONFIG_SERIAL_8250_RSA
669 /*
670 * Attempts to turn on the RSA FIFO. Returns zero on failure.
671 * We set the port uart clock rate if we succeed.
672 */
673 static int __enable_rsa(struct uart_8250_port *up)
674 {
675 unsigned char mode;
676 int result;
677
678 mode = serial_inp(up, UART_RSA_MSR);
679 result = mode & UART_RSA_MSR_FIFO;
680
681 if (!result) {
682 serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
683 mode = serial_inp(up, UART_RSA_MSR);
684 result = mode & UART_RSA_MSR_FIFO;
685 }
686
687 if (result)
688 up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
689
690 return result;
691 }
692
693 static void enable_rsa(struct uart_8250_port *up)
694 {
695 if (up->port.type == PORT_RSA) {
696 if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
697 spin_lock_irq(&up->port.lock);
698 __enable_rsa(up);
699 spin_unlock_irq(&up->port.lock);
700 }
701 if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
702 serial_outp(up, UART_RSA_FRR, 0);
703 }
704 }
705
706 /*
707 * Attempts to turn off the RSA FIFO. Returns zero on failure.
708 * It is unknown why interrupts were disabled in here. However,
709 * the caller is expected to preserve this behaviour by grabbing
710 * the spinlock before calling this function.
711 */
712 static void disable_rsa(struct uart_8250_port *up)
713 {
714 unsigned char mode;
715 int result;
716
717 if (up->port.type == PORT_RSA &&
718 up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
719 spin_lock_irq(&up->port.lock);
720
721 mode = serial_inp(up, UART_RSA_MSR);
722 result = !(mode & UART_RSA_MSR_FIFO);
723
724 if (!result) {
725 serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
726 mode = serial_inp(up, UART_RSA_MSR);
727 result = !(mode & UART_RSA_MSR_FIFO);
728 }
729
730 if (result)
731 up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
732 spin_unlock_irq(&up->port.lock);
733 }
734 }
735 #endif /* CONFIG_SERIAL_8250_RSA */
736
737 /*
738 * This is a quickie test to see how big the FIFO is.
739 * It doesn't work at all the time, more's the pity.
740 */
741 static int size_fifo(struct uart_8250_port *up)
742 {
743 unsigned char old_fcr, old_mcr, old_lcr;
744 unsigned short old_dl;
745 int count;
746
747 old_lcr = serial_inp(up, UART_LCR);
748 serial_outp(up, UART_LCR, 0);
749 old_fcr = serial_inp(up, UART_FCR);
750 old_mcr = serial_inp(up, UART_MCR);
751 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
752 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
753 serial_outp(up, UART_MCR, UART_MCR_LOOP);
754 serial_outp(up, UART_LCR, UART_LCR_DLAB);
755 old_dl = serial_dl_read(up);
756 serial_dl_write(up, 0x0001);
757 serial_outp(up, UART_LCR, 0x03);
758 for (count = 0; count < 256; count++)
759 serial_outp(up, UART_TX, count);
760 mdelay(20);/* FIXME - schedule_timeout */
761 for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
762 (count < 256); count++)
763 serial_inp(up, UART_RX);
764 serial_outp(up, UART_FCR, old_fcr);
765 serial_outp(up, UART_MCR, old_mcr);
766 serial_outp(up, UART_LCR, UART_LCR_DLAB);
767 serial_dl_write(up, old_dl);
768 serial_outp(up, UART_LCR, old_lcr);
769
770 return count;
771 }
772
773 /*
774 * Read UART ID using the divisor method - set DLL and DLM to zero
775 * and the revision will be in DLL and device type in DLM. We
776 * preserve the device state across this.
777 */
778 static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
779 {
780 unsigned char old_dll, old_dlm, old_lcr;
781 unsigned int id;
782
783 old_lcr = serial_inp(p, UART_LCR);
784 serial_outp(p, UART_LCR, UART_LCR_DLAB);
785
786 old_dll = serial_inp(p, UART_DLL);
787 old_dlm = serial_inp(p, UART_DLM);
788
789 serial_outp(p, UART_DLL, 0);
790 serial_outp(p, UART_DLM, 0);
791
792 id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
793
794 serial_outp(p, UART_DLL, old_dll);
795 serial_outp(p, UART_DLM, old_dlm);
796 serial_outp(p, UART_LCR, old_lcr);
797
798 return id;
799 }
800
801 /*
802 * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
803 * When this function is called we know it is at least a StarTech
804 * 16650 V2, but it might be one of several StarTech UARTs, or one of
805 * its clones. (We treat the broken original StarTech 16650 V1 as a
806 * 16550, and why not? Startech doesn't seem to even acknowledge its
807 * existence.)
808 *
809 * What evil have men's minds wrought...
810 */
811 static void autoconfig_has_efr(struct uart_8250_port *up)
812 {
813 unsigned int id1, id2, id3, rev;
814
815 /*
816 * Everything with an EFR has SLEEP
817 */
818 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
819
820 /*
821 * First we check to see if it's an Oxford Semiconductor UART.
822 *
823 * If we have to do this here because some non-National
824 * Semiconductor clone chips lock up if you try writing to the
825 * LSR register (which serial_icr_read does)
826 */
827
828 /*
829 * Check for Oxford Semiconductor 16C950.
830 *
831 * EFR [4] must be set else this test fails.
832 *
833 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
834 * claims that it's needed for 952 dual UART's (which are not
835 * recommended for new designs).
836 */
837 up->acr = 0;
838 serial_out(up, UART_LCR, 0xBF);
839 serial_out(up, UART_EFR, UART_EFR_ECB);
840 serial_out(up, UART_LCR, 0x00);
841 id1 = serial_icr_read(up, UART_ID1);
842 id2 = serial_icr_read(up, UART_ID2);
843 id3 = serial_icr_read(up, UART_ID3);
844 rev = serial_icr_read(up, UART_REV);
845
846 DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
847
848 if (id1 == 0x16 && id2 == 0xC9 &&
849 (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
850 up->port.type = PORT_16C950;
851
852 /*
853 * Enable work around for the Oxford Semiconductor 952 rev B
854 * chip which causes it to seriously miscalculate baud rates
855 * when DLL is 0.
856 */
857 if (id3 == 0x52 && rev == 0x01)
858 up->bugs |= UART_BUG_QUOT;
859 return;
860 }
861
862 /*
863 * We check for a XR16C850 by setting DLL and DLM to 0, and then
864 * reading back DLL and DLM. The chip type depends on the DLM
865 * value read back:
866 * 0x10 - XR16C850 and the DLL contains the chip revision.
867 * 0x12 - XR16C2850.
868 * 0x14 - XR16C854.
869 */
870 id1 = autoconfig_read_divisor_id(up);
871 DEBUG_AUTOCONF("850id=%04x ", id1);
872
873 id2 = id1 >> 8;
874 if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
875 up->port.type = PORT_16850;
876 return;
877 }
878
879 /*
880 * It wasn't an XR16C850.
881 *
882 * We distinguish between the '654 and the '650 by counting
883 * how many bytes are in the FIFO. I'm using this for now,
884 * since that's the technique that was sent to me in the
885 * serial driver update, but I'm not convinced this works.
886 * I've had problems doing this in the past. -TYT
887 */
888 if (size_fifo(up) == 64)
889 up->port.type = PORT_16654;
890 else
891 up->port.type = PORT_16650V2;
892 }
893
894 /*
895 * We detected a chip without a FIFO. Only two fall into
896 * this category - the original 8250 and the 16450. The
897 * 16450 has a scratch register (accessible with LCR=0)
898 */
899 static void autoconfig_8250(struct uart_8250_port *up)
900 {
901 unsigned char scratch, status1, status2;
902
903 up->port.type = PORT_8250;
904
905 scratch = serial_in(up, UART_SCR);
906 serial_outp(up, UART_SCR, 0xa5);
907 status1 = serial_in(up, UART_SCR);
908 serial_outp(up, UART_SCR, 0x5a);
909 status2 = serial_in(up, UART_SCR);
910 serial_outp(up, UART_SCR, scratch);
911
912 if (status1 == 0xa5 && status2 == 0x5a)
913 up->port.type = PORT_16450;
914 }
915
916 static int broken_efr(struct uart_8250_port *up)
917 {
918 /*
919 * Exar ST16C2550 "A2" devices incorrectly detect as
920 * having an EFR, and report an ID of 0x0201. See
921 * http://www.exar.com/info.php?pdf=dan180_oct2004.pdf
922 */
923 if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
924 return 1;
925
926 return 0;
927 }
928
929 /*
930 * We know that the chip has FIFOs. Does it have an EFR? The
931 * EFR is located in the same register position as the IIR and
932 * we know the top two bits of the IIR are currently set. The
933 * EFR should contain zero. Try to read the EFR.
934 */
935 static void autoconfig_16550a(struct uart_8250_port *up)
936 {
937 unsigned char status1, status2;
938 unsigned int iersave;
939
940 up->port.type = PORT_16550A;
941 up->capabilities |= UART_CAP_FIFO;
942
943 /*
944 * Check for presence of the EFR when DLAB is set.
945 * Only ST16C650V1 UARTs pass this test.
946 */
947 serial_outp(up, UART_LCR, UART_LCR_DLAB);
948 if (serial_in(up, UART_EFR) == 0) {
949 serial_outp(up, UART_EFR, 0xA8);
950 if (serial_in(up, UART_EFR) != 0) {
951 DEBUG_AUTOCONF("EFRv1 ");
952 up->port.type = PORT_16650;
953 up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
954 } else {
955 DEBUG_AUTOCONF("Motorola 8xxx DUART ");
956 }
957 serial_outp(up, UART_EFR, 0);
958 return;
959 }
960
961 /*
962 * Maybe it requires 0xbf to be written to the LCR.
963 * (other ST16C650V2 UARTs, TI16C752A, etc)
964 */
965 serial_outp(up, UART_LCR, 0xBF);
966 if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
967 DEBUG_AUTOCONF("EFRv2 ");
968 autoconfig_has_efr(up);
969 return;
970 }
971
972 /*
973 * Check for a National Semiconductor SuperIO chip.
974 * Attempt to switch to bank 2, read the value of the LOOP bit
975 * from EXCR1. Switch back to bank 0, change it in MCR. Then
976 * switch back to bank 2, read it from EXCR1 again and check
977 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
978 */
979 serial_outp(up, UART_LCR, 0);
980 status1 = serial_in(up, UART_MCR);
981 serial_outp(up, UART_LCR, 0xE0);
982 status2 = serial_in(up, 0x02); /* EXCR1 */
983
984 if (!((status2 ^ status1) & UART_MCR_LOOP)) {
985 serial_outp(up, UART_LCR, 0);
986 serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
987 serial_outp(up, UART_LCR, 0xE0);
988 status2 = serial_in(up, 0x02); /* EXCR1 */
989 serial_outp(up, UART_LCR, 0);
990 serial_outp(up, UART_MCR, status1);
991
992 if ((status2 ^ status1) & UART_MCR_LOOP) {
993 unsigned short quot;
994
995 serial_outp(up, UART_LCR, 0xE0);
996
997 quot = serial_dl_read(up);
998 quot <<= 3;
999
1000 status1 = serial_in(up, 0x04); /* EXCR2 */
1001 status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
1002 status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
1003 serial_outp(up, 0x04, status1);
1004
1005 serial_dl_write(up, quot);
1006
1007 serial_outp(up, UART_LCR, 0);
1008
1009 up->port.uartclk = 921600*16;
1010 up->port.type = PORT_NS16550A;
1011 up->capabilities |= UART_NATSEMI;
1012 return;
1013 }
1014 }
1015
1016 /*
1017 * No EFR. Try to detect a TI16750, which only sets bit 5 of
1018 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
1019 * Try setting it with and without DLAB set. Cheap clones
1020 * set bit 5 without DLAB set.
1021 */
1022 serial_outp(up, UART_LCR, 0);
1023 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1024 status1 = serial_in(up, UART_IIR) >> 5;
1025 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1026 serial_outp(up, UART_LCR, UART_LCR_DLAB);
1027 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1028 status2 = serial_in(up, UART_IIR) >> 5;
1029 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1030 serial_outp(up, UART_LCR, 0);
1031
1032 DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
1033
1034 if (status1 == 6 && status2 == 7) {
1035 up->port.type = PORT_16750;
1036 up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
1037 return;
1038 }
1039
1040 /*
1041 * Try writing and reading the UART_IER_UUE bit (b6).
1042 * If it works, this is probably one of the Xscale platform's
1043 * internal UARTs.
1044 * We're going to explicitly set the UUE bit to 0 before
1045 * trying to write and read a 1 just to make sure it's not
1046 * already a 1 and maybe locked there before we even start start.
1047 */
1048 iersave = serial_in(up, UART_IER);
1049 serial_outp(up, UART_IER, iersave & ~UART_IER_UUE);
1050 if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
1051 /*
1052 * OK it's in a known zero state, try writing and reading
1053 * without disturbing the current state of the other bits.
1054 */
1055 serial_outp(up, UART_IER, iersave | UART_IER_UUE);
1056 if (serial_in(up, UART_IER) & UART_IER_UUE) {
1057 /*
1058 * It's an Xscale.
1059 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
1060 */
1061 DEBUG_AUTOCONF("Xscale ");
1062 up->port.type = PORT_XSCALE;
1063 up->capabilities |= UART_CAP_UUE;
1064 return;
1065 }
1066 } else {
1067 /*
1068 * If we got here we couldn't force the IER_UUE bit to 0.
1069 * Log it and continue.
1070 */
1071 DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
1072 }
1073 serial_outp(up, UART_IER, iersave);
1074 }
1075
1076 /*
1077 * This routine is called by rs_init() to initialize a specific serial
1078 * port. It determines what type of UART chip this serial port is
1079 * using: 8250, 16450, 16550, 16550A. The important question is
1080 * whether or not this UART is a 16550A or not, since this will
1081 * determine whether or not we can use its FIFO features or not.
1082 */
1083 static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
1084 {
1085 unsigned char status1, scratch, scratch2, scratch3;
1086 unsigned char save_lcr, save_mcr;
1087 unsigned long flags;
1088
1089 if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
1090 return;
1091
1092 DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04x, 0x%p): ",
1093 serial_index(&up->port), up->port.iobase, up->port.membase);
1094
1095 /*
1096 * We really do need global IRQs disabled here - we're going to
1097 * be frobbing the chips IRQ enable register to see if it exists.
1098 */
1099 spin_lock_irqsave(&up->port.lock, flags);
1100
1101 up->capabilities = 0;
1102 up->bugs = 0;
1103
1104 if (!(up->port.flags & UPF_BUGGY_UART)) {
1105 /*
1106 * Do a simple existence test first; if we fail this,
1107 * there's no point trying anything else.
1108 *
1109 * 0x80 is used as a nonsense port to prevent against
1110 * false positives due to ISA bus float. The
1111 * assumption is that 0x80 is a non-existent port;
1112 * which should be safe since include/asm/io.h also
1113 * makes this assumption.
1114 *
1115 * Note: this is safe as long as MCR bit 4 is clear
1116 * and the device is in "PC" mode.
1117 */
1118 scratch = serial_inp(up, UART_IER);
1119 serial_outp(up, UART_IER, 0);
1120 #ifdef __i386__
1121 outb(0xff, 0x080);
1122 #endif
1123 /*
1124 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
1125 * 16C754B) allow only to modify them if an EFR bit is set.
1126 */
1127 scratch2 = serial_inp(up, UART_IER) & 0x0f;
1128 serial_outp(up, UART_IER, 0x0F);
1129 #ifdef __i386__
1130 outb(0, 0x080);
1131 #endif
1132 scratch3 = serial_inp(up, UART_IER) & 0x0f;
1133 serial_outp(up, UART_IER, scratch);
1134 if (scratch2 != 0 || scratch3 != 0x0F) {
1135 /*
1136 * We failed; there's nothing here
1137 */
1138 DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
1139 scratch2, scratch3);
1140 goto out;
1141 }
1142 }
1143
1144 save_mcr = serial_in(up, UART_MCR);
1145 save_lcr = serial_in(up, UART_LCR);
1146
1147 /*
1148 * Check to see if a UART is really there. Certain broken
1149 * internal modems based on the Rockwell chipset fail this
1150 * test, because they apparently don't implement the loopback
1151 * test mode. So this test is skipped on the COM 1 through
1152 * COM 4 ports. This *should* be safe, since no board
1153 * manufacturer would be stupid enough to design a board
1154 * that conflicts with COM 1-4 --- we hope!
1155 */
1156 if (!(up->port.flags & UPF_SKIP_TEST)) {
1157 serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
1158 status1 = serial_inp(up, UART_MSR) & 0xF0;
1159 serial_outp(up, UART_MCR, save_mcr);
1160 if (status1 != 0x90) {
1161 DEBUG_AUTOCONF("LOOP test failed (%02x) ",
1162 status1);
1163 goto out;
1164 }
1165 }
1166
1167 /*
1168 * We're pretty sure there's a port here. Lets find out what
1169 * type of port it is. The IIR top two bits allows us to find
1170 * out if it's 8250 or 16450, 16550, 16550A or later. This
1171 * determines what we test for next.
1172 *
1173 * We also initialise the EFR (if any) to zero for later. The
1174 * EFR occupies the same register location as the FCR and IIR.
1175 */
1176 serial_outp(up, UART_LCR, 0xBF);
1177 serial_outp(up, UART_EFR, 0);
1178 serial_outp(up, UART_LCR, 0);
1179
1180 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1181 scratch = serial_in(up, UART_IIR) >> 6;
1182
1183 DEBUG_AUTOCONF("iir=%d ", scratch);
1184
1185 switch (scratch) {
1186 case 0:
1187 autoconfig_8250(up);
1188 break;
1189 case 1:
1190 up->port.type = PORT_UNKNOWN;
1191 break;
1192 case 2:
1193 up->port.type = PORT_16550;
1194 break;
1195 case 3:
1196 autoconfig_16550a(up);
1197 break;
1198 }
1199
1200 #ifdef CONFIG_SERIAL_8250_RSA
1201 /*
1202 * Only probe for RSA ports if we got the region.
1203 */
1204 if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
1205 int i;
1206
1207 for (i = 0 ; i < probe_rsa_count; ++i) {
1208 if (probe_rsa[i] == up->port.iobase &&
1209 __enable_rsa(up)) {
1210 up->port.type = PORT_RSA;
1211 break;
1212 }
1213 }
1214 }
1215 #endif
1216
1217 #ifdef CONFIG_SERIAL_8250_AU1X00
1218 /* if access method is AU, it is a 16550 with a quirk */
1219 if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
1220 up->bugs |= UART_BUG_NOMSR;
1221 #endif
1222
1223 serial_outp(up, UART_LCR, save_lcr);
1224
1225 if (up->capabilities != uart_config[up->port.type].flags) {
1226 printk(KERN_WARNING
1227 "ttyS%d: detected caps %08x should be %08x\n",
1228 serial_index(&up->port), up->capabilities,
1229 uart_config[up->port.type].flags);
1230 }
1231
1232 up->port.fifosize = uart_config[up->port.type].fifo_size;
1233 up->capabilities = uart_config[up->port.type].flags;
1234 up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
1235
1236 if (up->port.type == PORT_UNKNOWN)
1237 goto out;
1238
1239 /*
1240 * Reset the UART.
1241 */
1242 #ifdef CONFIG_SERIAL_8250_RSA
1243 if (up->port.type == PORT_RSA)
1244 serial_outp(up, UART_RSA_FRR, 0);
1245 #endif
1246 serial_outp(up, UART_MCR, save_mcr);
1247 serial8250_clear_fifos(up);
1248 serial_in(up, UART_RX);
1249 if (up->capabilities & UART_CAP_UUE)
1250 serial_outp(up, UART_IER, UART_IER_UUE);
1251 else
1252 serial_outp(up, UART_IER, 0);
1253
1254 out:
1255 spin_unlock_irqrestore(&up->port.lock, flags);
1256 DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
1257 }
1258
1259 static void autoconfig_irq(struct uart_8250_port *up)
1260 {
1261 unsigned char save_mcr, save_ier;
1262 unsigned char save_ICP = 0;
1263 unsigned int ICP = 0;
1264 unsigned long irqs;
1265 int irq;
1266
1267 if (up->port.flags & UPF_FOURPORT) {
1268 ICP = (up->port.iobase & 0xfe0) | 0x1f;
1269 save_ICP = inb_p(ICP);
1270 outb_p(0x80, ICP);
1271 (void) inb_p(ICP);
1272 }
1273
1274 /* forget possible initially masked and pending IRQ */
1275 probe_irq_off(probe_irq_on());
1276 save_mcr = serial_inp(up, UART_MCR);
1277 save_ier = serial_inp(up, UART_IER);
1278 serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
1279
1280 irqs = probe_irq_on();
1281 serial_outp(up, UART_MCR, 0);
1282 udelay(10);
1283 if (up->port.flags & UPF_FOURPORT) {
1284 serial_outp(up, UART_MCR,
1285 UART_MCR_DTR | UART_MCR_RTS);
1286 } else {
1287 serial_outp(up, UART_MCR,
1288 UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
1289 }
1290 serial_outp(up, UART_IER, 0x0f); /* enable all intrs */
1291 (void)serial_inp(up, UART_LSR);
1292 (void)serial_inp(up, UART_RX);
1293 (void)serial_inp(up, UART_IIR);
1294 (void)serial_inp(up, UART_MSR);
1295 serial_outp(up, UART_TX, 0xFF);
1296 udelay(20);
1297 irq = probe_irq_off(irqs);
1298
1299 serial_outp(up, UART_MCR, save_mcr);
1300 serial_outp(up, UART_IER, save_ier);
1301
1302 if (up->port.flags & UPF_FOURPORT)
1303 outb_p(save_ICP, ICP);
1304
1305 up->port.irq = (irq > 0) ? irq : 0;
1306 }
1307
1308 static inline void __stop_tx(struct uart_8250_port *p)
1309 {
1310 if (p->ier & UART_IER_THRI) {
1311 p->ier &= ~UART_IER_THRI;
1312 serial_out(p, UART_IER, p->ier);
1313 }
1314 }
1315
1316 static void serial8250_stop_tx(struct uart_port *port)
1317 {
1318 struct uart_8250_port *up = (struct uart_8250_port *)port;
1319
1320 __stop_tx(up);
1321
1322 /*
1323 * We really want to stop the transmitter from sending.
1324 */
1325 if (up->port.type == PORT_16C950) {
1326 up->acr |= UART_ACR_TXDIS;
1327 serial_icr_write(up, UART_ACR, up->acr);
1328 }
1329 }
1330
1331 static void transmit_chars(struct uart_8250_port *up);
1332
1333 static void serial8250_start_tx(struct uart_port *port)
1334 {
1335 struct uart_8250_port *up = (struct uart_8250_port *)port;
1336
1337 if (!(up->ier & UART_IER_THRI)) {
1338 up->ier |= UART_IER_THRI;
1339 serial_out(up, UART_IER, up->ier);
1340
1341 if (up->bugs & UART_BUG_TXEN) {
1342 unsigned char lsr, iir;
1343 lsr = serial_in(up, UART_LSR);
1344 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1345 iir = serial_in(up, UART_IIR) & 0x0f;
1346 if ((up->port.type == PORT_RM9000) ?
1347 (lsr & UART_LSR_THRE &&
1348 (iir == UART_IIR_NO_INT || iir == UART_IIR_THRI)) :
1349 (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT))
1350 transmit_chars(up);
1351 }
1352 }
1353
1354 /*
1355 * Re-enable the transmitter if we disabled it.
1356 */
1357 if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
1358 up->acr &= ~UART_ACR_TXDIS;
1359 serial_icr_write(up, UART_ACR, up->acr);
1360 }
1361 }
1362
1363 static void serial8250_stop_rx(struct uart_port *port)
1364 {
1365 struct uart_8250_port *up = (struct uart_8250_port *)port;
1366
1367 up->ier &= ~UART_IER_RLSI;
1368 up->port.read_status_mask &= ~UART_LSR_DR;
1369 serial_out(up, UART_IER, up->ier);
1370 }
1371
1372 static void serial8250_enable_ms(struct uart_port *port)
1373 {
1374 struct uart_8250_port *up = (struct uart_8250_port *)port;
1375
1376 /* no MSR capabilities */
1377 if (up->bugs & UART_BUG_NOMSR)
1378 return;
1379
1380 up->ier |= UART_IER_MSI;
1381 serial_out(up, UART_IER, up->ier);
1382 }
1383
1384 static void
1385 receive_chars(struct uart_8250_port *up, unsigned int *status)
1386 {
1387 struct tty_struct *tty = up->port.state->port.tty;
1388 unsigned char ch, lsr = *status;
1389 int max_count = 256;
1390 char flag;
1391
1392 do {
1393 if (likely(lsr & UART_LSR_DR))
1394 ch = serial_inp(up, UART_RX);
1395 else
1396 /*
1397 * Intel 82571 has a Serial Over Lan device that will
1398 * set UART_LSR_BI without setting UART_LSR_DR when
1399 * it receives a break. To avoid reading from the
1400 * receive buffer without UART_LSR_DR bit set, we
1401 * just force the read character to be 0
1402 */
1403 ch = 0;
1404
1405 flag = TTY_NORMAL;
1406 up->port.icount.rx++;
1407
1408 lsr |= up->lsr_saved_flags;
1409 up->lsr_saved_flags = 0;
1410
1411 if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
1412 /*
1413 * For statistics only
1414 */
1415 if (lsr & UART_LSR_BI) {
1416 lsr &= ~(UART_LSR_FE | UART_LSR_PE);
1417 up->port.icount.brk++;
1418 /*
1419 * We do the SysRQ and SAK checking
1420 * here because otherwise the break
1421 * may get masked by ignore_status_mask
1422 * or read_status_mask.
1423 */
1424 if (uart_handle_break(&up->port))
1425 goto ignore_char;
1426 } else if (lsr & UART_LSR_PE)
1427 up->port.icount.parity++;
1428 else if (lsr & UART_LSR_FE)
1429 up->port.icount.frame++;
1430 if (lsr & UART_LSR_OE)
1431 up->port.icount.overrun++;
1432
1433 /*
1434 * Mask off conditions which should be ignored.
1435 */
1436 lsr &= up->port.read_status_mask;
1437
1438 if (lsr & UART_LSR_BI) {
1439 DEBUG_INTR("handling break....");
1440 flag = TTY_BREAK;
1441 } else if (lsr & UART_LSR_PE)
1442 flag = TTY_PARITY;
1443 else if (lsr & UART_LSR_FE)
1444 flag = TTY_FRAME;
1445 }
1446 if (uart_handle_sysrq_char(&up->port, ch))
1447 goto ignore_char;
1448
1449 uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
1450
1451 ignore_char:
1452 lsr = serial_inp(up, UART_LSR);
1453 } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
1454 spin_unlock(&up->port.lock);
1455 tty_flip_buffer_push(tty);
1456 spin_lock(&up->port.lock);
1457 *status = lsr;
1458 }
1459
1460 static void transmit_chars(struct uart_8250_port *up)
1461 {
1462 struct circ_buf *xmit = &up->port.state->xmit;
1463 int count;
1464
1465 if (up->port.x_char) {
1466 serial_outp(up, UART_TX, up->port.x_char);
1467 up->port.icount.tx++;
1468 up->port.x_char = 0;
1469 return;
1470 }
1471 if (uart_tx_stopped(&up->port)) {
1472 serial8250_stop_tx(&up->port);
1473 return;
1474 }
1475 if (uart_circ_empty(xmit)) {
1476 __stop_tx(up);
1477 return;
1478 }
1479
1480 count = up->tx_loadsz;
1481 do {
1482 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
1483 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1484 up->port.icount.tx++;
1485 if (uart_circ_empty(xmit))
1486 break;
1487 } while (--count > 0);
1488
1489 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1490 uart_write_wakeup(&up->port);
1491
1492 DEBUG_INTR("THRE...");
1493
1494 if (uart_circ_empty(xmit))
1495 __stop_tx(up);
1496 }
1497
1498 static unsigned int check_modem_status(struct uart_8250_port *up)
1499 {
1500 unsigned int status = serial_in(up, UART_MSR);
1501
1502 status |= up->msr_saved_flags;
1503 up->msr_saved_flags = 0;
1504 if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
1505 up->port.state != NULL) {
1506 if (status & UART_MSR_TERI)
1507 up->port.icount.rng++;
1508 if (status & UART_MSR_DDSR)
1509 up->port.icount.dsr++;
1510 if (status & UART_MSR_DDCD)
1511 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
1512 if (status & UART_MSR_DCTS)
1513 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
1514
1515 wake_up_interruptible(&up->port.state->port.delta_msr_wait);
1516 }
1517
1518 return status;
1519 }
1520
1521 /*
1522 * This handles the interrupt from one port.
1523 */
1524 static void serial8250_handle_port(struct uart_8250_port *up)
1525 {
1526 unsigned int status;
1527 unsigned long flags;
1528
1529 spin_lock_irqsave(&up->port.lock, flags);
1530
1531 status = serial_inp(up, UART_LSR);
1532
1533 DEBUG_INTR("status = %x...", status);
1534
1535 if (status & (UART_LSR_DR | UART_LSR_BI))
1536 receive_chars(up, &status);
1537 check_modem_status(up);
1538 if (status & UART_LSR_THRE)
1539 transmit_chars(up);
1540
1541 spin_unlock_irqrestore(&up->port.lock, flags);
1542 }
1543
1544 /*
1545 * This is the serial driver's interrupt routine.
1546 *
1547 * Arjan thinks the old way was overly complex, so it got simplified.
1548 * Alan disagrees, saying that need the complexity to handle the weird
1549 * nature of ISA shared interrupts. (This is a special exception.)
1550 *
1551 * In order to handle ISA shared interrupts properly, we need to check
1552 * that all ports have been serviced, and therefore the ISA interrupt
1553 * line has been de-asserted.
1554 *
1555 * This means we need to loop through all ports. checking that they
1556 * don't have an interrupt pending.
1557 */
1558 static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
1559 {
1560 struct irq_info *i = dev_id;
1561 struct list_head *l, *end = NULL;
1562 int pass_counter = 0, handled = 0;
1563
1564 DEBUG_INTR("serial8250_interrupt(%d)...", irq);
1565
1566 spin_lock(&i->lock);
1567
1568 l = i->head;
1569 do {
1570 struct uart_8250_port *up;
1571 unsigned int iir;
1572
1573 up = list_entry(l, struct uart_8250_port, list);
1574
1575 iir = serial_in(up, UART_IIR);
1576 if (!(iir & UART_IIR_NO_INT)) {
1577 serial8250_handle_port(up);
1578
1579 handled = 1;
1580
1581 end = NULL;
1582 } else if (up->port.iotype == UPIO_DWAPB &&
1583 (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
1584 /* The DesignWare APB UART has an Busy Detect (0x07)
1585 * interrupt meaning an LCR write attempt occured while the
1586 * UART was busy. The interrupt must be cleared by reading
1587 * the UART status register (USR) and the LCR re-written. */
1588 unsigned int status;
1589 status = *(volatile u32 *)up->port.private_data;
1590 serial_out(up, UART_LCR, up->lcr);
1591
1592 handled = 1;
1593
1594 end = NULL;
1595 } else if (end == NULL)
1596 end = l;
1597
1598 l = l->next;
1599
1600 if (l == i->head && pass_counter++ > PASS_LIMIT) {
1601 /* If we hit this, we're dead. */
1602 printk(KERN_ERR "serial8250: too much work for "
1603 "irq%d\n", irq);
1604 break;
1605 }
1606 } while (l != end);
1607
1608 spin_unlock(&i->lock);
1609
1610 DEBUG_INTR("end.\n");
1611
1612 return IRQ_RETVAL(handled);
1613 }
1614
1615 /*
1616 * To support ISA shared interrupts, we need to have one interrupt
1617 * handler that ensures that the IRQ line has been deasserted
1618 * before returning. Failing to do this will result in the IRQ
1619 * line being stuck active, and, since ISA irqs are edge triggered,
1620 * no more IRQs will be seen.
1621 */
1622 static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
1623 {
1624 spin_lock_irq(&i->lock);
1625
1626 if (!list_empty(i->head)) {
1627 if (i->head == &up->list)
1628 i->head = i->head->next;
1629 list_del(&up->list);
1630 } else {
1631 BUG_ON(i->head != &up->list);
1632 i->head = NULL;
1633 }
1634 spin_unlock_irq(&i->lock);
1635 /* List empty so throw away the hash node */
1636 if (i->head == NULL) {
1637 hlist_del(&i->node);
1638 kfree(i);
1639 }
1640 }
1641
1642 static int serial_link_irq_chain(struct uart_8250_port *up)
1643 {
1644 struct hlist_head *h;
1645 struct hlist_node *n;
1646 struct irq_info *i;
1647 int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
1648
1649 mutex_lock(&hash_mutex);
1650
1651 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1652
1653 hlist_for_each(n, h) {
1654 i = hlist_entry(n, struct irq_info, node);
1655 if (i->irq == up->port.irq)
1656 break;
1657 }
1658
1659 if (n == NULL) {
1660 i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
1661 if (i == NULL) {
1662 mutex_unlock(&hash_mutex);
1663 return -ENOMEM;
1664 }
1665 spin_lock_init(&i->lock);
1666 i->irq = up->port.irq;
1667 hlist_add_head(&i->node, h);
1668 }
1669 mutex_unlock(&hash_mutex);
1670
1671 spin_lock_irq(&i->lock);
1672
1673 if (i->head) {
1674 list_add(&up->list, i->head);
1675 spin_unlock_irq(&i->lock);
1676
1677 ret = 0;
1678 } else {
1679 INIT_LIST_HEAD(&up->list);
1680 i->head = &up->list;
1681 spin_unlock_irq(&i->lock);
1682 irq_flags |= up->port.irqflags;
1683 ret = request_irq(up->port.irq, serial8250_interrupt,
1684 irq_flags, "serial", i);
1685 if (ret < 0)
1686 serial_do_unlink(i, up);
1687 }
1688
1689 return ret;
1690 }
1691
1692 static void serial_unlink_irq_chain(struct uart_8250_port *up)
1693 {
1694 struct irq_info *i;
1695 struct hlist_node *n;
1696 struct hlist_head *h;
1697
1698 mutex_lock(&hash_mutex);
1699
1700 h = &irq_lists[up->port.irq % NR_IRQ_HASH];
1701
1702 hlist_for_each(n, h) {
1703 i = hlist_entry(n, struct irq_info, node);
1704 if (i->irq == up->port.irq)
1705 break;
1706 }
1707
1708 BUG_ON(n == NULL);
1709 BUG_ON(i->head == NULL);
1710
1711 if (list_empty(i->head))
1712 free_irq(up->port.irq, i);
1713
1714 serial_do_unlink(i, up);
1715 mutex_unlock(&hash_mutex);
1716 }
1717
1718 /* Base timer interval for polling */
1719 static inline int poll_timeout(int timeout)
1720 {
1721 return timeout > 6 ? (timeout / 2 - 2) : 1;
1722 }
1723
1724 /*
1725 * This function is used to handle ports that do not have an
1726 * interrupt. This doesn't work very well for 16450's, but gives
1727 * barely passable results for a 16550A. (Although at the expense
1728 * of much CPU overhead).
1729 */
1730 static void serial8250_timeout(unsigned long data)
1731 {
1732 struct uart_8250_port *up = (struct uart_8250_port *)data;
1733 unsigned int iir;
1734
1735 iir = serial_in(up, UART_IIR);
1736 if (!(iir & UART_IIR_NO_INT))
1737 serial8250_handle_port(up);
1738 mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
1739 }
1740
1741 static void serial8250_backup_timeout(unsigned long data)
1742 {
1743 struct uart_8250_port *up = (struct uart_8250_port *)data;
1744 unsigned int iir, ier = 0, lsr;
1745 unsigned long flags;
1746
1747 /*
1748 * Must disable interrupts or else we risk racing with the interrupt
1749 * based handler.
1750 */
1751 if (is_real_interrupt(up->port.irq)) {
1752 ier = serial_in(up, UART_IER);
1753 serial_out(up, UART_IER, 0);
1754 }
1755
1756 iir = serial_in(up, UART_IIR);
1757
1758 /*
1759 * This should be a safe test for anyone who doesn't trust the
1760 * IIR bits on their UART, but it's specifically designed for
1761 * the "Diva" UART used on the management processor on many HP
1762 * ia64 and parisc boxes.
1763 */
1764 spin_lock_irqsave(&up->port.lock, flags);
1765 lsr = serial_in(up, UART_LSR);
1766 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1767 spin_unlock_irqrestore(&up->port.lock, flags);
1768 if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
1769 (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
1770 (lsr & UART_LSR_THRE)) {
1771 iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
1772 iir |= UART_IIR_THRI;
1773 }
1774
1775 if (!(iir & UART_IIR_NO_INT))
1776 serial8250_handle_port(up);
1777
1778 if (is_real_interrupt(up->port.irq))
1779 serial_out(up, UART_IER, ier);
1780
1781 /* Standard timer interval plus 0.2s to keep the port running */
1782 mod_timer(&up->timer,
1783 jiffies + poll_timeout(up->port.timeout) + HZ / 5);
1784 }
1785
1786 static unsigned int serial8250_tx_empty(struct uart_port *port)
1787 {
1788 struct uart_8250_port *up = (struct uart_8250_port *)port;
1789 unsigned long flags;
1790 unsigned int lsr;
1791
1792 spin_lock_irqsave(&up->port.lock, flags);
1793 lsr = serial_in(up, UART_LSR);
1794 up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
1795 spin_unlock_irqrestore(&up->port.lock, flags);
1796
1797 return lsr & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
1798 }
1799
1800 static unsigned int serial8250_get_mctrl(struct uart_port *port)
1801 {
1802 struct uart_8250_port *up = (struct uart_8250_port *)port;
1803 unsigned int status;
1804 unsigned int ret;
1805
1806 status = check_modem_status(up);
1807
1808 ret = 0;
1809 if (status & UART_MSR_DCD)
1810 ret |= TIOCM_CAR;
1811 if (status & UART_MSR_RI)
1812 ret |= TIOCM_RNG;
1813 if (status & UART_MSR_DSR)
1814 ret |= TIOCM_DSR;
1815 if (status & UART_MSR_CTS)
1816 ret |= TIOCM_CTS;
1817 return ret;
1818 }
1819
1820 static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
1821 {
1822 struct uart_8250_port *up = (struct uart_8250_port *)port;
1823 unsigned char mcr = 0;
1824
1825 if (mctrl & TIOCM_RTS)
1826 mcr |= UART_MCR_RTS;
1827 if (mctrl & TIOCM_DTR)
1828 mcr |= UART_MCR_DTR;
1829 if (mctrl & TIOCM_OUT1)
1830 mcr |= UART_MCR_OUT1;
1831 if (mctrl & TIOCM_OUT2)
1832 mcr |= UART_MCR_OUT2;
1833 if (mctrl & TIOCM_LOOP)
1834 mcr |= UART_MCR_LOOP;
1835
1836 mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
1837
1838 serial_out(up, UART_MCR, mcr);
1839 }
1840
1841 static void serial8250_break_ctl(struct uart_port *port, int break_state)
1842 {
1843 struct uart_8250_port *up = (struct uart_8250_port *)port;
1844 unsigned long flags;
1845
1846 spin_lock_irqsave(&up->port.lock, flags);
1847 if (break_state == -1)
1848 up->lcr |= UART_LCR_SBC;
1849 else
1850 up->lcr &= ~UART_LCR_SBC;
1851 serial_out(up, UART_LCR, up->lcr);
1852 spin_unlock_irqrestore(&up->port.lock, flags);
1853 }
1854
1855 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
1856
1857 /*
1858 * Wait for transmitter & holding register to empty
1859 */
1860 static void wait_for_xmitr(struct uart_8250_port *up, int bits)
1861 {
1862 unsigned int status, tmout = 10000;
1863
1864 /* Wait up to 10ms for the character(s) to be sent. */
1865 do {
1866 status = serial_in(up, UART_LSR);
1867
1868 up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
1869
1870 if (--tmout == 0)
1871 break;
1872 udelay(1);
1873 } while ((status & bits) != bits);
1874
1875 /* Wait up to 1s for flow control if necessary */
1876 if (up->port.flags & UPF_CONS_FLOW) {
1877 unsigned int tmout;
1878 for (tmout = 1000000; tmout; tmout--) {
1879 unsigned int msr = serial_in(up, UART_MSR);
1880 up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
1881 if (msr & UART_MSR_CTS)
1882 break;
1883 udelay(1);
1884 touch_nmi_watchdog();
1885 }
1886 }
1887 }
1888
1889 #ifdef CONFIG_CONSOLE_POLL
1890 /*
1891 * Console polling routines for writing and reading from the uart while
1892 * in an interrupt or debug context.
1893 */
1894
1895 static int serial8250_get_poll_char(struct uart_port *port)
1896 {
1897 struct uart_8250_port *up = (struct uart_8250_port *)port;
1898 unsigned char lsr = serial_inp(up, UART_LSR);
1899
1900 while (!(lsr & UART_LSR_DR))
1901 lsr = serial_inp(up, UART_LSR);
1902
1903 return serial_inp(up, UART_RX);
1904 }
1905
1906
1907 static void serial8250_put_poll_char(struct uart_port *port,
1908 unsigned char c)
1909 {
1910 unsigned int ier;
1911 struct uart_8250_port *up = (struct uart_8250_port *)port;
1912
1913 /*
1914 * First save the IER then disable the interrupts
1915 */
1916 ier = serial_in(up, UART_IER);
1917 if (up->capabilities & UART_CAP_UUE)
1918 serial_out(up, UART_IER, UART_IER_UUE);
1919 else
1920 serial_out(up, UART_IER, 0);
1921
1922 wait_for_xmitr(up, BOTH_EMPTY);
1923 /*
1924 * Send the character out.
1925 * If a LF, also do CR...
1926 */
1927 serial_out(up, UART_TX, c);
1928 if (c == 10) {
1929 wait_for_xmitr(up, BOTH_EMPTY);
1930 serial_out(up, UART_TX, 13);
1931 }
1932
1933 /*
1934 * Finally, wait for transmitter to become empty
1935 * and restore the IER
1936 */
1937 wait_for_xmitr(up, BOTH_EMPTY);
1938 serial_out(up, UART_IER, ier);
1939 }
1940
1941 #endif /* CONFIG_CONSOLE_POLL */
1942
1943 static int serial8250_startup(struct uart_port *port)
1944 {
1945 struct uart_8250_port *up = (struct uart_8250_port *)port;
1946 unsigned long flags;
1947 unsigned char lsr, iir;
1948 int retval;
1949
1950 up->capabilities = uart_config[up->port.type].flags;
1951 up->mcr = 0;
1952
1953 if (up->port.iotype != up->cur_iotype)
1954 set_io_from_upio(port);
1955
1956 if (up->port.type == PORT_16C950) {
1957 /* Wake up and initialize UART */
1958 up->acr = 0;
1959 serial_outp(up, UART_LCR, 0xBF);
1960 serial_outp(up, UART_EFR, UART_EFR_ECB);
1961 serial_outp(up, UART_IER, 0);
1962 serial_outp(up, UART_LCR, 0);
1963 serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
1964 serial_outp(up, UART_LCR, 0xBF);
1965 serial_outp(up, UART_EFR, UART_EFR_ECB);
1966 serial_outp(up, UART_LCR, 0);
1967 }
1968
1969 #ifdef CONFIG_SERIAL_8250_RSA
1970 /*
1971 * If this is an RSA port, see if we can kick it up to the
1972 * higher speed clock.
1973 */
1974 enable_rsa(up);
1975 #endif
1976
1977 /*
1978 * Clear the FIFO buffers and disable them.
1979 * (they will be reenabled in set_termios())
1980 */
1981 serial8250_clear_fifos(up);
1982
1983 /*
1984 * Clear the interrupt registers.
1985 */
1986 (void) serial_inp(up, UART_LSR);
1987 (void) serial_inp(up, UART_RX);
1988 (void) serial_inp(up, UART_IIR);
1989 (void) serial_inp(up, UART_MSR);
1990
1991 /*
1992 * At this point, there's no way the LSR could still be 0xff;
1993 * if it is, then bail out, because there's likely no UART
1994 * here.
1995 */
1996 if (!(up->port.flags & UPF_BUGGY_UART) &&
1997 (serial_inp(up, UART_LSR) == 0xff)) {
1998 printk(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
1999 serial_index(&up->port));
2000 return -ENODEV;
2001 }
2002
2003 /*
2004 * For a XR16C850, we need to set the trigger levels
2005 */
2006 if (up->port.type == PORT_16850) {
2007 unsigned char fctr;
2008
2009 serial_outp(up, UART_LCR, 0xbf);
2010
2011 fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
2012 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
2013 serial_outp(up, UART_TRG, UART_TRG_96);
2014 serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
2015 serial_outp(up, UART_TRG, UART_TRG_96);
2016
2017 serial_outp(up, UART_LCR, 0);
2018 }
2019
2020 if (is_real_interrupt(up->port.irq)) {
2021 unsigned char iir1;
2022 /*
2023 * Test for UARTs that do not reassert THRE when the
2024 * transmitter is idle and the interrupt has already
2025 * been cleared. Real 16550s should always reassert
2026 * this interrupt whenever the transmitter is idle and
2027 * the interrupt is enabled. Delays are necessary to
2028 * allow register changes to become visible.
2029 */
2030 spin_lock_irqsave(&up->port.lock, flags);
2031 if (up->port.irqflags & IRQF_SHARED)
2032 disable_irq_nosync(up->port.irq);
2033
2034 wait_for_xmitr(up, UART_LSR_THRE);
2035 serial_out_sync(up, UART_IER, UART_IER_THRI);
2036 udelay(1); /* allow THRE to set */
2037 iir1 = serial_in(up, UART_IIR);
2038 serial_out(up, UART_IER, 0);
2039 serial_out_sync(up, UART_IER, UART_IER_THRI);
2040 udelay(1); /* allow a working UART time to re-assert THRE */
2041 iir = serial_in(up, UART_IIR);
2042 serial_out(up, UART_IER, 0);
2043
2044 if (up->port.irqflags & IRQF_SHARED)
2045 enable_irq(up->port.irq);
2046 spin_unlock_irqrestore(&up->port.lock, flags);
2047
2048 /*
2049 * If the interrupt is not reasserted, setup a timer to
2050 * kick the UART on a regular basis.
2051 */
2052 if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
2053 up->bugs |= UART_BUG_THRE;
2054 pr_debug("ttyS%d - using backup timer\n",
2055 serial_index(port));
2056 }
2057 }
2058
2059 /*
2060 * The above check will only give an accurate result the first time
2061 * the port is opened so this value needs to be preserved.
2062 */
2063 if (up->bugs & UART_BUG_THRE) {
2064 up->timer.function = serial8250_backup_timeout;
2065 up->timer.data = (unsigned long)up;
2066 mod_timer(&up->timer, jiffies +
2067 poll_timeout(up->port.timeout) + HZ / 5);
2068 }
2069
2070 /*
2071 * If the "interrupt" for this port doesn't correspond with any
2072 * hardware interrupt, we use a timer-based system. The original
2073 * driver used to do this with IRQ0.
2074 */
2075 if (!is_real_interrupt(up->port.irq)) {
2076 up->timer.data = (unsigned long)up;
2077 mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
2078 } else {
2079 retval = serial_link_irq_chain(up);
2080 if (retval)
2081 return retval;
2082 }
2083
2084 /*
2085 * Now, initialize the UART
2086 */
2087 serial_outp(up, UART_LCR, UART_LCR_WLEN8);
2088
2089 spin_lock_irqsave(&up->port.lock, flags);
2090 if (up->port.flags & UPF_FOURPORT) {
2091 if (!is_real_interrupt(up->port.irq))
2092 up->port.mctrl |= TIOCM_OUT1;
2093 } else
2094 /*
2095 * Most PC uarts need OUT2 raised to enable interrupts.
2096 */
2097 if (is_real_interrupt(up->port.irq))
2098 up->port.mctrl |= TIOCM_OUT2;
2099
2100 serial8250_set_mctrl(&up->port, up->port.mctrl);
2101
2102 /* Serial over Lan (SoL) hack:
2103 Intel 8257x Gigabit ethernet chips have a
2104 16550 emulation, to be used for Serial Over Lan.
2105 Those chips take a longer time than a normal
2106 serial device to signalize that a transmission
2107 data was queued. Due to that, the above test generally
2108 fails. One solution would be to delay the reading of
2109 iir. However, this is not reliable, since the timeout
2110 is variable. So, let's just don't test if we receive
2111 TX irq. This way, we'll never enable UART_BUG_TXEN.
2112 */
2113 if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST)
2114 goto dont_test_tx_en;
2115
2116 /*
2117 * Do a quick test to see if we receive an
2118 * interrupt when we enable the TX irq.
2119 */
2120 serial_outp(up, UART_IER, UART_IER_THRI);
2121 lsr = serial_in(up, UART_LSR);
2122 iir = serial_in(up, UART_IIR);
2123 serial_outp(up, UART_IER, 0);
2124
2125 if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
2126 if (!(up->bugs & UART_BUG_TXEN)) {
2127 up->bugs |= UART_BUG_TXEN;
2128 pr_debug("ttyS%d - enabling bad tx status workarounds\n",
2129 serial_index(port));
2130 }
2131 } else {
2132 up->bugs &= ~UART_BUG_TXEN;
2133 }
2134
2135 dont_test_tx_en:
2136 spin_unlock_irqrestore(&up->port.lock, flags);
2137
2138 /*
2139 * Clear the interrupt registers again for luck, and clear the
2140 * saved flags to avoid getting false values from polling
2141 * routines or the previous session.
2142 */
2143 serial_inp(up, UART_LSR);
2144 serial_inp(up, UART_RX);
2145 serial_inp(up, UART_IIR);
2146 serial_inp(up, UART_MSR);
2147 up->lsr_saved_flags = 0;
2148 up->msr_saved_flags = 0;
2149
2150 /*
2151 * Finally, enable interrupts. Note: Modem status interrupts
2152 * are set via set_termios(), which will be occurring imminently
2153 * anyway, so we don't enable them here.
2154 */
2155 up->ier = UART_IER_RLSI | UART_IER_RDI;
2156 serial_outp(up, UART_IER, up->ier);
2157
2158 if (up->port.flags & UPF_FOURPORT) {
2159 unsigned int icp;
2160 /*
2161 * Enable interrupts on the AST Fourport board
2162 */
2163 icp = (up->port.iobase & 0xfe0) | 0x01f;
2164 outb_p(0x80, icp);
2165 (void) inb_p(icp);
2166 }
2167
2168 return 0;
2169 }
2170
2171 static void serial8250_shutdown(struct uart_port *port)
2172 {
2173 struct uart_8250_port *up = (struct uart_8250_port *)port;
2174 unsigned long flags;
2175
2176 /*
2177 * Disable interrupts from this port
2178 */
2179 up->ier = 0;
2180 serial_outp(up, UART_IER, 0);
2181
2182 spin_lock_irqsave(&up->port.lock, flags);
2183 if (up->port.flags & UPF_FOURPORT) {
2184 /* reset interrupts on the AST Fourport board */
2185 inb((up->port.iobase & 0xfe0) | 0x1f);
2186 up->port.mctrl |= TIOCM_OUT1;
2187 } else
2188 up->port.mctrl &= ~TIOCM_OUT2;
2189
2190 serial8250_set_mctrl(&up->port, up->port.mctrl);
2191 spin_unlock_irqrestore(&up->port.lock, flags);
2192
2193 /*
2194 * Disable break condition and FIFOs
2195 */
2196 serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
2197 serial8250_clear_fifos(up);
2198
2199 #ifdef CONFIG_SERIAL_8250_RSA
2200 /*
2201 * Reset the RSA board back to 115kbps compat mode.
2202 */
2203 disable_rsa(up);
2204 #endif
2205
2206 /*
2207 * Read data port to reset things, and then unlink from
2208 * the IRQ chain.
2209 */
2210 (void) serial_in(up, UART_RX);
2211
2212 del_timer_sync(&up->timer);
2213 up->timer.function = serial8250_timeout;
2214 if (is_real_interrupt(up->port.irq))
2215 serial_unlink_irq_chain(up);
2216 }
2217
2218 static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
2219 {
2220 unsigned int quot;
2221
2222 /*
2223 * Handle magic divisors for baud rates above baud_base on
2224 * SMSC SuperIO chips.
2225 */
2226 if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2227 baud == (port->uartclk/4))
2228 quot = 0x8001;
2229 else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
2230 baud == (port->uartclk/8))
2231 quot = 0x8002;
2232 else
2233 quot = uart_get_divisor(port, baud);
2234
2235 return quot;
2236 }
2237
2238 static void
2239 serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
2240 struct ktermios *old)
2241 {
2242 struct uart_8250_port *up = (struct uart_8250_port *)port;
2243 unsigned char cval, fcr = 0;
2244 unsigned long flags;
2245 unsigned int baud, quot;
2246
2247 switch (termios->c_cflag & CSIZE) {
2248 case CS5:
2249 cval = UART_LCR_WLEN5;
2250 break;
2251 case CS6:
2252 cval = UART_LCR_WLEN6;
2253 break;
2254 case CS7:
2255 cval = UART_LCR_WLEN7;
2256 break;
2257 default:
2258 case CS8:
2259 cval = UART_LCR_WLEN8;
2260 break;
2261 }
2262
2263 if (termios->c_cflag & CSTOPB)
2264 cval |= UART_LCR_STOP;
2265 if (termios->c_cflag & PARENB)
2266 cval |= UART_LCR_PARITY;
2267 if (!(termios->c_cflag & PARODD))
2268 cval |= UART_LCR_EPAR;
2269 #ifdef CMSPAR
2270 if (termios->c_cflag & CMSPAR)
2271 cval |= UART_LCR_SPAR;
2272 #endif
2273
2274 /*
2275 * Ask the core to calculate the divisor for us.
2276 */
2277 baud = uart_get_baud_rate(port, termios, old,
2278 port->uartclk / 16 / 0xffff,
2279 port->uartclk / 16);
2280 quot = serial8250_get_divisor(port, baud);
2281
2282 /*
2283 * Oxford Semi 952 rev B workaround
2284 */
2285 if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
2286 quot++;
2287
2288 if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
2289 if (baud < 2400)
2290 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
2291 else
2292 fcr = uart_config[up->port.type].fcr;
2293 }
2294
2295 /*
2296 * MCR-based auto flow control. When AFE is enabled, RTS will be
2297 * deasserted when the receive FIFO contains more characters than
2298 * the trigger, or the MCR RTS bit is cleared. In the case where
2299 * the remote UART is not using CTS auto flow control, we must
2300 * have sufficient FIFO entries for the latency of the remote
2301 * UART to respond. IOW, at least 32 bytes of FIFO.
2302 */
2303 if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
2304 up->mcr &= ~UART_MCR_AFE;
2305 if (termios->c_cflag & CRTSCTS)
2306 up->mcr |= UART_MCR_AFE;
2307 }
2308
2309 /*
2310 * Ok, we're now changing the port state. Do it with
2311 * interrupts disabled.
2312 */
2313 spin_lock_irqsave(&up->port.lock, flags);
2314
2315 /*
2316 * Update the per-port timeout.
2317 */
2318 uart_update_timeout(port, termios->c_cflag, baud);
2319
2320 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
2321 if (termios->c_iflag & INPCK)
2322 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
2323 if (termios->c_iflag & (BRKINT | PARMRK))
2324 up->port.read_status_mask |= UART_LSR_BI;
2325
2326 /*
2327 * Characteres to ignore
2328 */
2329 up->port.ignore_status_mask = 0;
2330 if (termios->c_iflag & IGNPAR)
2331 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
2332 if (termios->c_iflag & IGNBRK) {
2333 up->port.ignore_status_mask |= UART_LSR_BI;
2334 /*
2335 * If we're ignoring parity and break indicators,
2336 * ignore overruns too (for real raw support).
2337 */
2338 if (termios->c_iflag & IGNPAR)
2339 up->port.ignore_status_mask |= UART_LSR_OE;
2340 }
2341
2342 /*
2343 * ignore all characters if CREAD is not set
2344 */
2345 if ((termios->c_cflag & CREAD) == 0)
2346 up->port.ignore_status_mask |= UART_LSR_DR;
2347
2348 /*
2349 * CTS flow control flag and modem status interrupts
2350 */
2351 up->ier &= ~UART_IER_MSI;
2352 if (!(up->bugs & UART_BUG_NOMSR) &&
2353 UART_ENABLE_MS(&up->port, termios->c_cflag))
2354 up->ier |= UART_IER_MSI;
2355 if (up->capabilities & UART_CAP_UUE)
2356 up->ier |= UART_IER_UUE | UART_IER_RTOIE;
2357
2358 serial_out(up, UART_IER, up->ier);
2359
2360 if (up->capabilities & UART_CAP_EFR) {
2361 unsigned char efr = 0;
2362 /*
2363 * TI16C752/Startech hardware flow control. FIXME:
2364 * - TI16C752 requires control thresholds to be set.
2365 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
2366 */
2367 if (termios->c_cflag & CRTSCTS)
2368 efr |= UART_EFR_CTS;
2369
2370 serial_outp(up, UART_LCR, 0xBF);
2371 serial_outp(up, UART_EFR, efr);
2372 }
2373
2374 #ifdef CONFIG_ARCH_OMAP
2375 /* Workaround to enable 115200 baud on OMAP1510 internal ports */
2376 if (cpu_is_omap1510() && is_omap_port(up)) {
2377 if (baud == 115200) {
2378 quot = 1;
2379 serial_out(up, UART_OMAP_OSC_12M_SEL, 1);
2380 } else
2381 serial_out(up, UART_OMAP_OSC_12M_SEL, 0);
2382 }
2383 #endif
2384
2385 if (up->capabilities & UART_NATSEMI) {
2386 /* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
2387 serial_outp(up, UART_LCR, 0xe0);
2388 } else {
2389 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
2390 }
2391
2392 serial_dl_write(up, quot);
2393
2394 /*
2395 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
2396 * is written without DLAB set, this mode will be disabled.
2397 */
2398 if (up->port.type == PORT_16750)
2399 serial_outp(up, UART_FCR, fcr);
2400
2401 serial_outp(up, UART_LCR, cval); /* reset DLAB */
2402 up->lcr = cval; /* Save LCR */
2403 if (up->port.type != PORT_16750) {
2404 if (fcr & UART_FCR_ENABLE_FIFO) {
2405 /* emulated UARTs (Lucent Venus 167x) need two steps */
2406 serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
2407 }
2408 serial_outp(up, UART_FCR, fcr); /* set fcr */
2409 }
2410 serial8250_set_mctrl(&up->port, up->port.mctrl);
2411 spin_unlock_irqrestore(&up->port.lock, flags);
2412 /* Don't rewrite B0 */
2413 if (tty_termios_baud_rate(termios))
2414 tty_termios_encode_baud_rate(termios, baud, baud);
2415 }
2416
2417 static void
2418 serial8250_pm(struct uart_port *port, unsigned int state,
2419 unsigned int oldstate)
2420 {
2421 struct uart_8250_port *p = (struct uart_8250_port *)port;
2422
2423 serial8250_set_sleep(p, state != 0);
2424
2425 if (p->pm)
2426 p->pm(port, state, oldstate);
2427 }
2428
2429 static unsigned int serial8250_port_size(struct uart_8250_port *pt)
2430 {
2431 if (pt->port.iotype == UPIO_AU)
2432 return 0x100000;
2433 #ifdef CONFIG_ARCH_OMAP
2434 if (is_omap_port(pt))
2435 return 0x16 << pt->port.regshift;
2436 #endif
2437 return 8 << pt->port.regshift;
2438 }
2439
2440 /*
2441 * Resource handling.
2442 */
2443 static int serial8250_request_std_resource(struct uart_8250_port *up)
2444 {
2445 unsigned int size = serial8250_port_size(up);
2446 int ret = 0;
2447
2448 switch (up->port.iotype) {
2449 case UPIO_AU:
2450 case UPIO_TSI:
2451 case UPIO_MEM32:
2452 case UPIO_MEM:
2453 case UPIO_DWAPB:
2454 if (!up->port.mapbase)
2455 break;
2456
2457 if (!request_mem_region(up->port.mapbase, size, "serial")) {
2458 ret = -EBUSY;
2459 break;
2460 }
2461
2462 if (up->port.flags & UPF_IOREMAP) {
2463 up->port.membase = ioremap_nocache(up->port.mapbase,
2464 size);
2465 if (!up->port.membase) {
2466 release_mem_region(up->port.mapbase, size);
2467 ret = -ENOMEM;
2468 }
2469 }
2470 break;
2471
2472 case UPIO_HUB6:
2473 case UPIO_PORT:
2474 if (!request_region(up->port.iobase, size, "serial"))
2475 ret = -EBUSY;
2476 break;
2477 }
2478 return ret;
2479 }
2480
2481 static void serial8250_release_std_resource(struct uart_8250_port *up)
2482 {
2483 unsigned int size = serial8250_port_size(up);
2484
2485 switch (up->port.iotype) {
2486 case UPIO_AU:
2487 case UPIO_TSI:
2488 case UPIO_MEM32:
2489 case UPIO_MEM:
2490 case UPIO_DWAPB:
2491 if (!up->port.mapbase)
2492 break;
2493
2494 if (up->port.flags & UPF_IOREMAP) {
2495 iounmap(up->port.membase);
2496 up->port.membase = NULL;
2497 }
2498
2499 release_mem_region(up->port.mapbase, size);
2500 break;
2501
2502 case UPIO_HUB6:
2503 case UPIO_PORT:
2504 release_region(up->port.iobase, size);
2505 break;
2506 }
2507 }
2508
2509 static int serial8250_request_rsa_resource(struct uart_8250_port *up)
2510 {
2511 unsigned long start = UART_RSA_BASE << up->port.regshift;
2512 unsigned int size = 8 << up->port.regshift;
2513 int ret = -EINVAL;
2514
2515 switch (up->port.iotype) {
2516 case UPIO_HUB6:
2517 case UPIO_PORT:
2518 start += up->port.iobase;
2519 if (request_region(start, size, "serial-rsa"))
2520 ret = 0;
2521 else
2522 ret = -EBUSY;
2523 break;
2524 }
2525
2526 return ret;
2527 }
2528
2529 static void serial8250_release_rsa_resource(struct uart_8250_port *up)
2530 {
2531 unsigned long offset = UART_RSA_BASE << up->port.regshift;
2532 unsigned int size = 8 << up->port.regshift;
2533
2534 switch (up->port.iotype) {
2535 case UPIO_HUB6:
2536 case UPIO_PORT:
2537 release_region(up->port.iobase + offset, size);
2538 break;
2539 }
2540 }
2541
2542 static void serial8250_release_port(struct uart_port *port)
2543 {
2544 struct uart_8250_port *up = (struct uart_8250_port *)port;
2545
2546 serial8250_release_std_resource(up);
2547 if (up->port.type == PORT_RSA)
2548 serial8250_release_rsa_resource(up);
2549 }
2550
2551 static int serial8250_request_port(struct uart_port *port)
2552 {
2553 struct uart_8250_port *up = (struct uart_8250_port *)port;
2554 int ret = 0;
2555
2556 ret = serial8250_request_std_resource(up);
2557 if (ret == 0 && up->port.type == PORT_RSA) {
2558 ret = serial8250_request_rsa_resource(up);
2559 if (ret < 0)
2560 serial8250_release_std_resource(up);
2561 }
2562
2563 return ret;
2564 }
2565
2566 static void serial8250_config_port(struct uart_port *port, int flags)
2567 {
2568 struct uart_8250_port *up = (struct uart_8250_port *)port;
2569 int probeflags = PROBE_ANY;
2570 int ret;
2571
2572 /*
2573 * Find the region that we can probe for. This in turn
2574 * tells us whether we can probe for the type of port.
2575 */
2576 ret = serial8250_request_std_resource(up);
2577 if (ret < 0)
2578 return;
2579
2580 ret = serial8250_request_rsa_resource(up);
2581 if (ret < 0)
2582 probeflags &= ~PROBE_RSA;
2583
2584 if (up->port.iotype != up->cur_iotype)
2585 set_io_from_upio(port);
2586
2587 if (flags & UART_CONFIG_TYPE)
2588 autoconfig(up, probeflags);
2589 if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
2590 autoconfig_irq(up);
2591
2592 if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
2593 serial8250_release_rsa_resource(up);
2594 if (up->port.type == PORT_UNKNOWN)
2595 serial8250_release_std_resource(up);
2596 }
2597
2598 static int
2599 serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
2600 {
2601 if (ser->irq >= nr_irqs || ser->irq < 0 ||
2602 ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
2603 ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
2604 ser->type == PORT_STARTECH)
2605 return -EINVAL;
2606 return 0;
2607 }
2608
2609 static const char *
2610 serial8250_type(struct uart_port *port)
2611 {
2612 int type = port->type;
2613
2614 if (type >= ARRAY_SIZE(uart_config))
2615 type = 0;
2616 return uart_config[type].name;
2617 }
2618
2619 static struct uart_ops serial8250_pops = {
2620 .tx_empty = serial8250_tx_empty,
2621 .set_mctrl = serial8250_set_mctrl,
2622 .get_mctrl = serial8250_get_mctrl,
2623 .stop_tx = serial8250_stop_tx,
2624 .start_tx = serial8250_start_tx,
2625 .stop_rx = serial8250_stop_rx,
2626 .enable_ms = serial8250_enable_ms,
2627 .break_ctl = serial8250_break_ctl,
2628 .startup = serial8250_startup,
2629 .shutdown = serial8250_shutdown,
2630 .set_termios = serial8250_set_termios,
2631 .pm = serial8250_pm,
2632 .type = serial8250_type,
2633 .release_port = serial8250_release_port,
2634 .request_port = serial8250_request_port,
2635 .config_port = serial8250_config_port,
2636 .verify_port = serial8250_verify_port,
2637 #ifdef CONFIG_CONSOLE_POLL
2638 .poll_get_char = serial8250_get_poll_char,
2639 .poll_put_char = serial8250_put_poll_char,
2640 #endif
2641 };
2642
2643 static struct uart_8250_port serial8250_ports[UART_NR];
2644
2645 static void __init serial8250_isa_init_ports(void)
2646 {
2647 struct uart_8250_port *up;
2648 static int first = 1;
2649 int i;
2650
2651 if (!first)
2652 return;
2653 first = 0;
2654
2655 for (i = 0; i < nr_uarts; i++) {
2656 struct uart_8250_port *up = &serial8250_ports[i];
2657
2658 up->port.line = i;
2659 spin_lock_init(&up->port.lock);
2660
2661 init_timer(&up->timer);
2662 up->timer.function = serial8250_timeout;
2663
2664 /*
2665 * ALPHA_KLUDGE_MCR needs to be killed.
2666 */
2667 up->mcr_mask = ~ALPHA_KLUDGE_MCR;
2668 up->mcr_force = ALPHA_KLUDGE_MCR;
2669
2670 up->port.ops = &serial8250_pops;
2671 }
2672
2673 for (i = 0, up = serial8250_ports;
2674 i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
2675 i++, up++) {
2676 up->port.iobase = old_serial_port[i].port;
2677 up->port.irq = irq_canonicalize(old_serial_port[i].irq);
2678 up->port.irqflags = old_serial_port[i].irqflags;
2679 up->port.uartclk = old_serial_port[i].baud_base * 16;
2680 up->port.flags = old_serial_port[i].flags;
2681 up->port.hub6 = old_serial_port[i].hub6;
2682 up->port.membase = old_serial_port[i].iomem_base;
2683 up->port.iotype = old_serial_port[i].io_type;
2684 up->port.regshift = old_serial_port[i].iomem_reg_shift;
2685 set_io_from_upio(&up->port);
2686 if (share_irqs)
2687 up->port.irqflags |= IRQF_SHARED;
2688 }
2689 }
2690
2691 static void __init
2692 serial8250_register_ports(struct uart_driver *drv, struct device *dev)
2693 {
2694 int i;
2695
2696 for (i = 0; i < nr_uarts; i++) {
2697 struct uart_8250_port *up = &serial8250_ports[i];
2698 up->cur_iotype = 0xFF;
2699 }
2700
2701 serial8250_isa_init_ports();
2702
2703 for (i = 0; i < nr_uarts; i++) {
2704 struct uart_8250_port *up = &serial8250_ports[i];
2705
2706 up->port.dev = dev;
2707 uart_add_one_port(drv, &up->port);
2708 }
2709 }
2710
2711 #ifdef CONFIG_SERIAL_8250_CONSOLE
2712
2713 static void serial8250_console_putchar(struct uart_port *port, int ch)
2714 {
2715 struct uart_8250_port *up = (struct uart_8250_port *)port;
2716
2717 wait_for_xmitr(up, UART_LSR_THRE);
2718 serial_out(up, UART_TX, ch);
2719 }
2720
2721 /*
2722 * Print a string to the serial port trying not to disturb
2723 * any possible real use of the port...
2724 *
2725 * The console_lock must be held when we get here.
2726 */
2727 static void
2728 serial8250_console_write(struct console *co, const char *s, unsigned int count)
2729 {
2730 struct uart_8250_port *up = &serial8250_ports[co->index];
2731 unsigned long flags;
2732 unsigned int ier;
2733 int locked = 1;
2734
2735 touch_nmi_watchdog();
2736
2737 local_irq_save(flags);
2738 if (up->port.sysrq) {
2739 /* serial8250_handle_port() already took the lock */
2740 locked = 0;
2741 } else if (oops_in_progress) {
2742 locked = spin_trylock(&up->port.lock);
2743 } else
2744 spin_lock(&up->port.lock);
2745
2746 /*
2747 * First save the IER then disable the interrupts
2748 */
2749 ier = serial_in(up, UART_IER);
2750
2751 if (up->capabilities & UART_CAP_UUE)
2752 serial_out(up, UART_IER, UART_IER_UUE);
2753 else
2754 serial_out(up, UART_IER, 0);
2755
2756 uart_console_write(&up->port, s, count, serial8250_console_putchar);
2757
2758 /*
2759 * Finally, wait for transmitter to become empty
2760 * and restore the IER
2761 */
2762 wait_for_xmitr(up, BOTH_EMPTY);
2763 serial_out(up, UART_IER, ier);
2764
2765 /*
2766 * The receive handling will happen properly because the
2767 * receive ready bit will still be set; it is not cleared
2768 * on read. However, modem control will not, we must
2769 * call it if we have saved something in the saved flags
2770 * while processing with interrupts off.
2771 */
2772 if (up->msr_saved_flags)
2773 check_modem_status(up);
2774
2775 if (locked)
2776 spin_unlock(&up->port.lock);
2777 local_irq_restore(flags);
2778 }
2779
2780 static int __init serial8250_console_setup(struct console *co, char *options)
2781 {
2782 struct uart_port *port;
2783 int baud = 9600;
2784 int bits = 8;
2785 int parity = 'n';
2786 int flow = 'n';
2787
2788 /*
2789 * Check whether an invalid uart number has been specified, and
2790 * if so, search for the first available port that does have
2791 * console support.
2792 */
2793 if (co->index >= nr_uarts)
2794 co->index = 0;
2795 port = &serial8250_ports[co->index].port;
2796 if (!port->iobase && !port->membase)
2797 return -ENODEV;
2798
2799 if (options)
2800 uart_parse_options(options, &baud, &parity, &bits, &flow);
2801
2802 return uart_set_options(port, co, baud, parity, bits, flow);
2803 }
2804
2805 static int serial8250_console_early_setup(void)
2806 {
2807 return serial8250_find_port_for_earlycon();
2808 }
2809
2810 static struct console serial8250_console = {
2811 .name = "ttyS",
2812 .write = serial8250_console_write,
2813 .device = uart_console_device,
2814 .setup = serial8250_console_setup,
2815 .early_setup = serial8250_console_early_setup,
2816 .flags = CON_PRINTBUFFER,
2817 .index = -1,
2818 .data = &serial8250_reg,
2819 };
2820
2821 static int __init serial8250_console_init(void)
2822 {
2823 if (nr_uarts > UART_NR)
2824 nr_uarts = UART_NR;
2825
2826 serial8250_isa_init_ports();
2827 register_console(&serial8250_console);
2828 return 0;
2829 }
2830 console_initcall(serial8250_console_init);
2831
2832 int serial8250_find_port(struct uart_port *p)
2833 {
2834 int line;
2835 struct uart_port *port;
2836
2837 for (line = 0; line < nr_uarts; line++) {
2838 port = &serial8250_ports[line].port;
2839 if (uart_match_port(p, port))
2840 return line;
2841 }
2842 return -ENODEV;
2843 }
2844
2845 #define SERIAL8250_CONSOLE &serial8250_console
2846 #else
2847 #define SERIAL8250_CONSOLE NULL
2848 #endif
2849
2850 static struct uart_driver serial8250_reg = {
2851 .owner = THIS_MODULE,
2852 .driver_name = "serial",
2853 .dev_name = "ttyS",
2854 .major = TTY_MAJOR,
2855 .minor = 64,
2856 .cons = SERIAL8250_CONSOLE,
2857 };
2858
2859 /*
2860 * early_serial_setup - early registration for 8250 ports
2861 *
2862 * Setup an 8250 port structure prior to console initialisation. Use
2863 * after console initialisation will cause undefined behaviour.
2864 */
2865 int __init early_serial_setup(struct uart_port *port)
2866 {
2867 struct uart_port *p;
2868
2869 if (port->line >= ARRAY_SIZE(serial8250_ports))
2870 return -ENODEV;
2871
2872 serial8250_isa_init_ports();
2873 p = &serial8250_ports[port->line].port;
2874 p->iobase = port->iobase;
2875 p->membase = port->membase;
2876 p->irq = port->irq;
2877 p->irqflags = port->irqflags;
2878 p->uartclk = port->uartclk;
2879 p->fifosize = port->fifosize;
2880 p->regshift = port->regshift;
2881 p->iotype = port->iotype;
2882 p->flags = port->flags;
2883 p->mapbase = port->mapbase;
2884 p->private_data = port->private_data;
2885 p->type = port->type;
2886 p->line = port->line;
2887
2888 set_io_from_upio(p);
2889 if (port->serial_in)
2890 p->serial_in = port->serial_in;
2891 if (port->serial_out)
2892 p->serial_out = port->serial_out;
2893
2894 return 0;
2895 }
2896
2897 /**
2898 * serial8250_suspend_port - suspend one serial port
2899 * @line: serial line number
2900 *
2901 * Suspend one serial port.
2902 */
2903 void serial8250_suspend_port(int line)
2904 {
2905 uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
2906 }
2907
2908 /**
2909 * serial8250_resume_port - resume one serial port
2910 * @line: serial line number
2911 *
2912 * Resume one serial port.
2913 */
2914 void serial8250_resume_port(int line)
2915 {
2916 struct uart_8250_port *up = &serial8250_ports[line];
2917
2918 if (up->capabilities & UART_NATSEMI) {
2919 unsigned char tmp;
2920
2921 /* Ensure it's still in high speed mode */
2922 serial_outp(up, UART_LCR, 0xE0);
2923
2924 tmp = serial_in(up, 0x04); /* EXCR2 */
2925 tmp &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
2926 tmp |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
2927 serial_outp(up, 0x04, tmp);
2928
2929 serial_outp(up, UART_LCR, 0);
2930 }
2931 uart_resume_port(&serial8250_reg, &up->port);
2932 }
2933
2934 /*
2935 * Register a set of serial devices attached to a platform device. The
2936 * list is terminated with a zero flags entry, which means we expect
2937 * all entries to have at least UPF_BOOT_AUTOCONF set.
2938 */
2939 static int __devinit serial8250_probe(struct platform_device *dev)
2940 {
2941 struct plat_serial8250_port *p = dev->dev.platform_data;
2942 struct uart_port port;
2943 int ret, i;
2944
2945 memset(&port, 0, sizeof(struct uart_port));
2946
2947 for (i = 0; p && p->flags != 0; p++, i++) {
2948 port.iobase = p->iobase;
2949 port.membase = p->membase;
2950 port.irq = p->irq;
2951 port.irqflags = p->irqflags;
2952 port.uartclk = p->uartclk;
2953 port.regshift = p->regshift;
2954 port.iotype = p->iotype;
2955 port.flags = p->flags;
2956 port.mapbase = p->mapbase;
2957 port.hub6 = p->hub6;
2958 port.private_data = p->private_data;
2959 port.type = p->type;
2960 port.serial_in = p->serial_in;
2961 port.serial_out = p->serial_out;
2962 port.dev = &dev->dev;
2963 if (share_irqs)
2964 port.irqflags |= IRQF_SHARED;
2965 ret = serial8250_register_port(&port);
2966 if (ret < 0) {
2967 dev_err(&dev->dev, "unable to register port at index %d "
2968 "(IO%lx MEM%llx IRQ%d): %d\n", i,
2969 p->iobase, (unsigned long long)p->mapbase,
2970 p->irq, ret);
2971 }
2972 }
2973 return 0;
2974 }
2975
2976 /*
2977 * Remove serial ports registered against a platform device.
2978 */
2979 static int __devexit serial8250_remove(struct platform_device *dev)
2980 {
2981 int i;
2982
2983 for (i = 0; i < nr_uarts; i++) {
2984 struct uart_8250_port *up = &serial8250_ports[i];
2985
2986 if (up->port.dev == &dev->dev)
2987 serial8250_unregister_port(i);
2988 }
2989 return 0;
2990 }
2991
2992 static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
2993 {
2994 int i;
2995
2996 for (i = 0; i < UART_NR; i++) {
2997 struct uart_8250_port *up = &serial8250_ports[i];
2998
2999 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3000 uart_suspend_port(&serial8250_reg, &up->port);
3001 }
3002
3003 return 0;
3004 }
3005
3006 static int serial8250_resume(struct platform_device *dev)
3007 {
3008 int i;
3009
3010 for (i = 0; i < UART_NR; i++) {
3011 struct uart_8250_port *up = &serial8250_ports[i];
3012
3013 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3014 serial8250_resume_port(i);
3015 }
3016
3017 return 0;
3018 }
3019
3020 static struct platform_driver serial8250_isa_driver = {
3021 .probe = serial8250_probe,
3022 .remove = __devexit_p(serial8250_remove),
3023 .suspend = serial8250_suspend,
3024 .resume = serial8250_resume,
3025 .driver = {
3026 .name = "serial8250",
3027 .owner = THIS_MODULE,
3028 },
3029 };
3030
3031 /*
3032 * This "device" covers _all_ ISA 8250-compatible serial devices listed
3033 * in the table in include/asm/serial.h
3034 */
3035 static struct platform_device *serial8250_isa_devs;
3036
3037 /*
3038 * serial8250_register_port and serial8250_unregister_port allows for
3039 * 16x50 serial ports to be configured at run-time, to support PCMCIA
3040 * modems and PCI multiport cards.
3041 */
3042 static DEFINE_MUTEX(serial_mutex);
3043
3044 static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
3045 {
3046 int i;
3047
3048 /*
3049 * First, find a port entry which matches.
3050 */
3051 for (i = 0; i < nr_uarts; i++)
3052 if (uart_match_port(&serial8250_ports[i].port, port))
3053 return &serial8250_ports[i];
3054
3055 /*
3056 * We didn't find a matching entry, so look for the first
3057 * free entry. We look for one which hasn't been previously
3058 * used (indicated by zero iobase).
3059 */
3060 for (i = 0; i < nr_uarts; i++)
3061 if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
3062 serial8250_ports[i].port.iobase == 0)
3063 return &serial8250_ports[i];
3064
3065 /*
3066 * That also failed. Last resort is to find any entry which
3067 * doesn't have a real port associated with it.
3068 */
3069 for (i = 0; i < nr_uarts; i++)
3070 if (serial8250_ports[i].port.type == PORT_UNKNOWN)
3071 return &serial8250_ports[i];
3072
3073 return NULL;
3074 }
3075
3076 /**
3077 * serial8250_register_port - register a serial port
3078 * @port: serial port template
3079 *
3080 * Configure the serial port specified by the request. If the
3081 * port exists and is in use, it is hung up and unregistered
3082 * first.
3083 *
3084 * The port is then probed and if necessary the IRQ is autodetected
3085 * If this fails an error is returned.
3086 *
3087 * On success the port is ready to use and the line number is returned.
3088 */
3089 int serial8250_register_port(struct uart_port *port)
3090 {
3091 struct uart_8250_port *uart;
3092 int ret = -ENOSPC;
3093
3094 if (port->uartclk == 0)
3095 return -EINVAL;
3096
3097 mutex_lock(&serial_mutex);
3098
3099 uart = serial8250_find_match_or_unused(port);
3100 if (uart) {
3101 uart_remove_one_port(&serial8250_reg, &uart->port);
3102
3103 uart->port.iobase = port->iobase;
3104 uart->port.membase = port->membase;
3105 uart->port.irq = port->irq;
3106 uart->port.irqflags = port->irqflags;
3107 uart->port.uartclk = port->uartclk;
3108 uart->port.fifosize = port->fifosize;
3109 uart->port.regshift = port->regshift;
3110 uart->port.iotype = port->iotype;
3111 uart->port.flags = port->flags | UPF_BOOT_AUTOCONF;
3112 uart->port.mapbase = port->mapbase;
3113 uart->port.private_data = port->private_data;
3114 if (port->dev)
3115 uart->port.dev = port->dev;
3116
3117 if (port->flags & UPF_FIXED_TYPE) {
3118 uart->port.type = port->type;
3119 uart->port.fifosize = uart_config[port->type].fifo_size;
3120 uart->capabilities = uart_config[port->type].flags;
3121 uart->tx_loadsz = uart_config[port->type].tx_loadsz;
3122 }
3123
3124 set_io_from_upio(&uart->port);
3125 /* Possibly override default I/O functions. */
3126 if (port->serial_in)
3127 uart->port.serial_in = port->serial_in;
3128 if (port->serial_out)
3129 uart->port.serial_out = port->serial_out;
3130
3131 ret = uart_add_one_port(&serial8250_reg, &uart->port);
3132 if (ret == 0)
3133 ret = uart->port.line;
3134 }
3135 mutex_unlock(&serial_mutex);
3136
3137 return ret;
3138 }
3139 EXPORT_SYMBOL(serial8250_register_port);
3140
3141 /**
3142 * serial8250_unregister_port - remove a 16x50 serial port at runtime
3143 * @line: serial line number
3144 *
3145 * Remove one serial port. This may not be called from interrupt
3146 * context. We hand the port back to the our control.
3147 */
3148 void serial8250_unregister_port(int line)
3149 {
3150 struct uart_8250_port *uart = &serial8250_ports[line];
3151
3152 mutex_lock(&serial_mutex);
3153 uart_remove_one_port(&serial8250_reg, &uart->port);
3154 if (serial8250_isa_devs) {
3155 uart->port.flags &= ~UPF_BOOT_AUTOCONF;
3156 uart->port.type = PORT_UNKNOWN;
3157 uart->port.dev = &serial8250_isa_devs->dev;
3158 uart_add_one_port(&serial8250_reg, &uart->port);
3159 } else {
3160 uart->port.dev = NULL;
3161 }
3162 mutex_unlock(&serial_mutex);
3163 }
3164 EXPORT_SYMBOL(serial8250_unregister_port);
3165
3166 static int __init serial8250_init(void)
3167 {
3168 int ret;
3169
3170 if (nr_uarts > UART_NR)
3171 nr_uarts = UART_NR;
3172
3173 printk(KERN_INFO "Serial: 8250/16550 driver, "
3174 "%d ports, IRQ sharing %sabled\n", nr_uarts,
3175 share_irqs ? "en" : "dis");
3176
3177 #ifdef CONFIG_SPARC
3178 ret = sunserial_register_minors(&serial8250_reg, UART_NR);
3179 #else
3180 serial8250_reg.nr = UART_NR;
3181 ret = uart_register_driver(&serial8250_reg);
3182 #endif
3183 if (ret)
3184 goto out;
3185
3186 serial8250_isa_devs = platform_device_alloc("serial8250",
3187 PLAT8250_DEV_LEGACY);
3188 if (!serial8250_isa_devs) {
3189 ret = -ENOMEM;
3190 goto unreg_uart_drv;
3191 }
3192
3193 ret = platform_device_add(serial8250_isa_devs);
3194 if (ret)
3195 goto put_dev;
3196
3197 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
3198
3199 ret = platform_driver_register(&serial8250_isa_driver);
3200 if (ret == 0)
3201 goto out;
3202
3203 platform_device_del(serial8250_isa_devs);
3204 put_dev:
3205 platform_device_put(serial8250_isa_devs);
3206 unreg_uart_drv:
3207 #ifdef CONFIG_SPARC
3208 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3209 #else
3210 uart_unregister_driver(&serial8250_reg);
3211 #endif
3212 out:
3213 return ret;
3214 }
3215
3216 static void __exit serial8250_exit(void)
3217 {
3218 struct platform_device *isa_dev = serial8250_isa_devs;
3219
3220 /*
3221 * This tells serial8250_unregister_port() not to re-register
3222 * the ports (thereby making serial8250_isa_driver permanently
3223 * in use.)
3224 */
3225 serial8250_isa_devs = NULL;
3226
3227 platform_driver_unregister(&serial8250_isa_driver);
3228 platform_device_unregister(isa_dev);
3229
3230 #ifdef CONFIG_SPARC
3231 sunserial_unregister_minors(&serial8250_reg, UART_NR);
3232 #else
3233 uart_unregister_driver(&serial8250_reg);
3234 #endif
3235 }
3236
3237 module_init(serial8250_init);
3238 module_exit(serial8250_exit);
3239
3240 EXPORT_SYMBOL(serial8250_suspend_port);
3241 EXPORT_SYMBOL(serial8250_resume_port);
3242
3243 MODULE_LICENSE("GPL");
3244 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
3245
3246 module_param(share_irqs, uint, 0644);
3247 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
3248 " (unsafe)");
3249
3250 module_param(nr_uarts, uint, 0644);
3251 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
3252
3253 module_param(skip_txen_test, uint, 0644);
3254 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
3255
3256 #ifdef CONFIG_SERIAL_8250_RSA
3257 module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
3258 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
3259 #endif
3260 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree