blob: 313f9df24a2de97426df92de3c439af9d07dda91 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * C-Brick Serial Port (and console) driver for SGI Altix machines.
3 *
4 * This driver is NOT suitable for talking to the l1-controller for
5 * anything other than 'console activities' --- please use the l1
6 * driver for that.
7 *
8 *
9 * Copyright (c) 2004-2005 Silicon Graphics, Inc. All Rights Reserved.
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of version 2 of the GNU General Public License
13 * as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it would be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
18 *
19 * Further, this software is distributed without any warranty that it is
20 * free of the rightful claim of any third person regarding infringement
21 * or the like. Any license provided herein, whether implied or
22 * otherwise, applies only to this software file. Patent licenses, if
23 * any, provided herein do not apply to combinations of this program with
24 * other software, or any other product whatsoever.
25 *
26 * You should have received a copy of the GNU General Public
27 * License along with this program; if not, write the Free Software
28 * Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
29 *
30 * Contact information: Silicon Graphics, Inc., 1500 Crittenden Lane,
31 * Mountain View, CA 94043, or:
32 *
33 * http://www.sgi.com
34 *
35 * For further information regarding this notice, see:
36 *
37 * http://oss.sgi.com/projects/GenInfo/NoticeExplan
38 */
39
40#include <linux/config.h>
41#include <linux/interrupt.h>
42#include <linux/tty.h>
43#include <linux/serial.h>
44#include <linux/console.h>
45#include <linux/module.h>
46#include <linux/sysrq.h>
47#include <linux/circ_buf.h>
48#include <linux/serial_reg.h>
49#include <linux/delay.h> /* for mdelay */
50#include <linux/miscdevice.h>
51#include <linux/serial_core.h>
52
53#include <asm/io.h>
54#include <asm/sn/simulator.h>
55#include <asm/sn/sn_sal.h>
56
57/* number of characters we can transmit to the SAL console at a time */
58#define SN_SAL_MAX_CHARS 120
59
60/* 64K, when we're asynch, it must be at least printk's LOG_BUF_LEN to
61 * avoid losing chars, (always has to be a power of 2) */
62#define SN_SAL_BUFFER_SIZE (64 * (1 << 10))
63
64#define SN_SAL_UART_FIFO_DEPTH 16
65#define SN_SAL_UART_FIFO_SPEED_CPS 9600/10
66
67/* sn_transmit_chars() calling args */
68#define TRANSMIT_BUFFERED 0
69#define TRANSMIT_RAW 1
70
71/* To use dynamic numbers only and not use the assigned major and minor,
72 * define the following.. */
73 /* #define USE_DYNAMIC_MINOR 1 *//* use dynamic minor number */
74#define USE_DYNAMIC_MINOR 0 /* Don't rely on misc_register dynamic minor */
75
76/* Device name we're using */
77#define DEVICE_NAME "ttySG"
78#define DEVICE_NAME_DYNAMIC "ttySG0" /* need full name for misc_register */
79/* The major/minor we are using, ignored for USE_DYNAMIC_MINOR */
80#define DEVICE_MAJOR 204
81#define DEVICE_MINOR 40
82
83#ifdef CONFIG_MAGIC_SYSRQ
84static char sysrq_serial_str[] = "\eSYS";
85static char *sysrq_serial_ptr = sysrq_serial_str;
86static unsigned long sysrq_requested;
87#endif /* CONFIG_MAGIC_SYSRQ */
88
89/*
90 * Port definition - this kinda drives it all
91 */
92struct sn_cons_port {
93 struct timer_list sc_timer;
94 struct uart_port sc_port;
95 struct sn_sal_ops {
96 int (*sal_puts_raw) (const char *s, int len);
97 int (*sal_puts) (const char *s, int len);
98 int (*sal_getc) (void);
99 int (*sal_input_pending) (void);
100 void (*sal_wakeup_transmit) (struct sn_cons_port *, int);
101 } *sc_ops;
102 unsigned long sc_interrupt_timeout;
103 int sc_is_asynch;
104};
105
106static struct sn_cons_port sal_console_port;
107static int sn_process_input;
108
109/* Only used if USE_DYNAMIC_MINOR is set to 1 */
110static struct miscdevice misc; /* used with misc_register for dynamic */
111
112extern void early_sn_setup(void);
113
114#undef DEBUG
115#ifdef DEBUG
116static int sn_debug_printf(const char *fmt, ...);
117#define DPRINTF(x...) sn_debug_printf(x)
118#else
119#define DPRINTF(x...) do { } while (0)
120#endif
121
122/* Prototypes */
123static int snt_hw_puts_raw(const char *, int);
124static int snt_hw_puts_buffered(const char *, int);
125static int snt_poll_getc(void);
126static int snt_poll_input_pending(void);
127static int snt_intr_getc(void);
128static int snt_intr_input_pending(void);
129static void sn_transmit_chars(struct sn_cons_port *, int);
130
131/* A table for polling:
132 */
133static struct sn_sal_ops poll_ops = {
134 .sal_puts_raw = snt_hw_puts_raw,
135 .sal_puts = snt_hw_puts_raw,
136 .sal_getc = snt_poll_getc,
137 .sal_input_pending = snt_poll_input_pending
138};
139
140/* A table for interrupts enabled */
141static struct sn_sal_ops intr_ops = {
142 .sal_puts_raw = snt_hw_puts_raw,
143 .sal_puts = snt_hw_puts_buffered,
144 .sal_getc = snt_intr_getc,
145 .sal_input_pending = snt_intr_input_pending,
146 .sal_wakeup_transmit = sn_transmit_chars
147};
148
149/* the console does output in two distinctly different ways:
150 * synchronous (raw) and asynchronous (buffered). initally, early_printk
151 * does synchronous output. any data written goes directly to the SAL
152 * to be output (incidentally, it is internally buffered by the SAL)
153 * after interrupts and timers are initialized and available for use,
154 * the console init code switches to asynchronous output. this is
155 * also the earliest opportunity to begin polling for console input.
156 * after console initialization, console output and tty (serial port)
157 * output is buffered and sent to the SAL asynchronously (either by
158 * timer callback or by UART interrupt) */
159
160/* routines for running the console in polling mode */
161
162/**
163 * snt_poll_getc - Get a character from the console in polling mode
164 *
165 */
166static int snt_poll_getc(void)
167{
168 int ch;
169
170 ia64_sn_console_getc(&ch);
171 return ch;
172}
173
174/**
175 * snt_poll_input_pending - Check if any input is waiting - polling mode.
176 *
177 */
178static int snt_poll_input_pending(void)
179{
180 int status, input;
181
182 status = ia64_sn_console_check(&input);
183 return !status && input;
184}
185
186/* routines for an interrupt driven console (normal) */
187
188/**
189 * snt_intr_getc - Get a character from the console, interrupt mode
190 *
191 */
192static int snt_intr_getc(void)
193{
194 return ia64_sn_console_readc();
195}
196
197/**
198 * snt_intr_input_pending - Check if input is pending, interrupt mode
199 *
200 */
201static int snt_intr_input_pending(void)
202{
203 return ia64_sn_console_intr_status() & SAL_CONSOLE_INTR_RECV;
204}
205
206/* these functions are polled and interrupt */
207
208/**
209 * snt_hw_puts_raw - Send raw string to the console, polled or interrupt mode
210 * @s: String
211 * @len: Length
212 *
213 */
214static int snt_hw_puts_raw(const char *s, int len)
215{
216 /* this will call the PROM and not return until this is done */
217 return ia64_sn_console_putb(s, len);
218}
219
220/**
221 * snt_hw_puts_buffered - Send string to console, polled or interrupt mode
222 * @s: String
223 * @len: Length
224 *
225 */
226static int snt_hw_puts_buffered(const char *s, int len)
227{
228 /* queue data to the PROM */
229 return ia64_sn_console_xmit_chars((char *)s, len);
230}
231
232/* uart interface structs
233 * These functions are associated with the uart_port that the serial core
234 * infrastructure calls.
235 *
236 * Note: Due to how the console works, many routines are no-ops.
237 */
238
239/**
240 * snp_type - What type of console are we?
241 * @port: Port to operate with (we ignore since we only have one port)
242 *
243 */
244static const char *snp_type(struct uart_port *port)
245{
246 return ("SGI SN L1");
247}
248
249/**
250 * snp_tx_empty - Is the transmitter empty? We pretend we're always empty
251 * @port: Port to operate on (we ignore since we only have one port)
252 *
253 */
254static unsigned int snp_tx_empty(struct uart_port *port)
255{
256 return 1;
257}
258
259/**
260 * snp_stop_tx - stop the transmitter - no-op for us
261 * @port: Port to operat eon - we ignore - no-op function
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 *
263 */
Russell Kingb129a8c2005-08-31 10:12:14 +0100264static void snp_stop_tx(struct uart_port *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265{
266}
267
268/**
269 * snp_release_port - Free i/o and resources for port - no-op for us
270 * @port: Port to operate on - we ignore - no-op function
271 *
272 */
273static void snp_release_port(struct uart_port *port)
274{
275}
276
277/**
278 * snp_enable_ms - Force modem status interrupts on - no-op for us
279 * @port: Port to operate on - we ignore - no-op function
280 *
281 */
282static void snp_enable_ms(struct uart_port *port)
283{
284}
285
286/**
287 * snp_shutdown - shut down the port - free irq and disable - no-op for us
288 * @port: Port to shut down - we ignore
289 *
290 */
291static void snp_shutdown(struct uart_port *port)
292{
293}
294
295/**
296 * snp_set_mctrl - set control lines (dtr, rts, etc) - no-op for our console
297 * @port: Port to operate on - we ignore
298 * @mctrl: Lines to set/unset - we ignore
299 *
300 */
301static void snp_set_mctrl(struct uart_port *port, unsigned int mctrl)
302{
303}
304
305/**
306 * snp_get_mctrl - get contorl line info, we just return a static value
307 * @port: port to operate on - we only have one port so we ignore this
308 *
309 */
310static unsigned int snp_get_mctrl(struct uart_port *port)
311{
312 return TIOCM_CAR | TIOCM_RNG | TIOCM_DSR | TIOCM_CTS;
313}
314
315/**
316 * snp_stop_rx - Stop the receiver - we ignor ethis
317 * @port: Port to operate on - we ignore
318 *
319 */
320static void snp_stop_rx(struct uart_port *port)
321{
322}
323
324/**
325 * snp_start_tx - Start transmitter
326 * @port: Port to operate on
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 *
328 */
Russell Kingb129a8c2005-08-31 10:12:14 +0100329static void snp_start_tx(struct uart_port *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330{
331 if (sal_console_port.sc_ops->sal_wakeup_transmit)
332 sal_console_port.sc_ops->sal_wakeup_transmit(&sal_console_port,
333 TRANSMIT_BUFFERED);
334
335}
336
337/**
338 * snp_break_ctl - handle breaks - ignored by us
339 * @port: Port to operate on
340 * @break_state: Break state
341 *
342 */
343static void snp_break_ctl(struct uart_port *port, int break_state)
344{
345}
346
347/**
348 * snp_startup - Start up the serial port - always return 0 (We're always on)
349 * @port: Port to operate on
350 *
351 */
352static int snp_startup(struct uart_port *port)
353{
354 return 0;
355}
356
357/**
358 * snp_set_termios - set termios stuff - we ignore these
359 * @port: port to operate on
360 * @termios: New settings
361 * @termios: Old
362 *
363 */
364static void
365snp_set_termios(struct uart_port *port, struct termios *termios,
366 struct termios *old)
367{
368}
369
370/**
371 * snp_request_port - allocate resources for port - ignored by us
372 * @port: port to operate on
373 *
374 */
375static int snp_request_port(struct uart_port *port)
376{
377 return 0;
378}
379
380/**
381 * snp_config_port - allocate resources, set up - we ignore, we're always on
382 * @port: Port to operate on
383 * @flags: flags used for port setup
384 *
385 */
386static void snp_config_port(struct uart_port *port, int flags)
387{
388}
389
390/* Associate the uart functions above - given to serial core */
391
392static struct uart_ops sn_console_ops = {
393 .tx_empty = snp_tx_empty,
394 .set_mctrl = snp_set_mctrl,
395 .get_mctrl = snp_get_mctrl,
396 .stop_tx = snp_stop_tx,
397 .start_tx = snp_start_tx,
398 .stop_rx = snp_stop_rx,
399 .enable_ms = snp_enable_ms,
400 .break_ctl = snp_break_ctl,
401 .startup = snp_startup,
402 .shutdown = snp_shutdown,
403 .set_termios = snp_set_termios,
404 .pm = NULL,
405 .type = snp_type,
406 .release_port = snp_release_port,
407 .request_port = snp_request_port,
408 .config_port = snp_config_port,
409 .verify_port = NULL,
410};
411
412/* End of uart struct functions and defines */
413
414#ifdef DEBUG
415
416/**
417 * sn_debug_printf - close to hardware debugging printf
418 * @fmt: printf format
419 *
420 * This is as "close to the metal" as we can get, used when the driver
421 * itself may be broken.
422 *
423 */
424static int sn_debug_printf(const char *fmt, ...)
425{
426 static char printk_buf[1024];
427 int printed_len;
428 va_list args;
429
430 va_start(args, fmt);
431 printed_len = vsnprintf(printk_buf, sizeof(printk_buf), fmt, args);
432
433 if (!sal_console_port.sc_ops) {
434 sal_console_port.sc_ops = &poll_ops;
435 early_sn_setup();
436 }
437 sal_console_port.sc_ops->sal_puts_raw(printk_buf, printed_len);
438
439 va_end(args);
440 return printed_len;
441}
442#endif /* DEBUG */
443
444/*
445 * Interrupt handling routines.
446 */
447
448/**
449 * sn_receive_chars - Grab characters, pass them to tty layer
450 * @port: Port to operate on
451 * @regs: Saved registers (needed by uart_handle_sysrq_char)
452 * @flags: irq flags
453 *
454 * Note: If we're not registered with the serial core infrastructure yet,
455 * we don't try to send characters to it...
456 *
457 */
458static void
459sn_receive_chars(struct sn_cons_port *port, struct pt_regs *regs,
460 unsigned long flags)
461{
462 int ch;
463 struct tty_struct *tty;
464
465 if (!port) {
466 printk(KERN_ERR "sn_receive_chars - port NULL so can't receieve\n");
467 return;
468 }
469
470 if (!port->sc_ops) {
471 printk(KERN_ERR "sn_receive_chars - port->sc_ops NULL so can't receieve\n");
472 return;
473 }
474
475 if (port->sc_port.info) {
476 /* The serial_core stuffs are initilized, use them */
477 tty = port->sc_port.info->tty;
478 }
479 else {
480 /* Not registered yet - can't pass to tty layer. */
481 tty = NULL;
482 }
483
484 while (port->sc_ops->sal_input_pending()) {
485 ch = port->sc_ops->sal_getc();
486 if (ch < 0) {
487 printk(KERN_ERR "sn_console: An error occured while "
488 "obtaining data from the console (0x%0x)\n", ch);
489 break;
490 }
491#ifdef CONFIG_MAGIC_SYSRQ
492 if (sysrq_requested) {
493 unsigned long sysrq_timeout = sysrq_requested + HZ*5;
494
495 sysrq_requested = 0;
496 if (ch && time_before(jiffies, sysrq_timeout)) {
497 spin_unlock_irqrestore(&port->sc_port.lock, flags);
498 handle_sysrq(ch, regs, NULL);
499 spin_lock_irqsave(&port->sc_port.lock, flags);
500 /* ignore actual sysrq command char */
501 continue;
502 }
503 }
504 if (ch == *sysrq_serial_ptr) {
505 if (!(*++sysrq_serial_ptr)) {
506 sysrq_requested = jiffies;
507 sysrq_serial_ptr = sysrq_serial_str;
508 }
509 /*
510 * ignore the whole sysrq string except for the
511 * leading escape
512 */
513 if (ch != '\e')
514 continue;
515 }
516 else
517 sysrq_serial_ptr = sysrq_serial_str;
518#endif /* CONFIG_MAGIC_SYSRQ */
519
520 /* record the character to pass up to the tty layer */
521 if (tty) {
522 *tty->flip.char_buf_ptr = ch;
523 *tty->flip.flag_buf_ptr = TTY_NORMAL;
524 tty->flip.char_buf_ptr++;
525 tty->flip.count++;
526 if (tty->flip.count == TTY_FLIPBUF_SIZE)
527 break;
528 }
529 port->sc_port.icount.rx++;
530 }
531
532 if (tty)
533 tty_flip_buffer_push(tty);
534}
535
536/**
537 * sn_transmit_chars - grab characters from serial core, send off
538 * @port: Port to operate on
539 * @raw: Transmit raw or buffered
540 *
541 * Note: If we're early, before we're registered with serial core, the
542 * writes are going through sn_sal_console_write because that's how
543 * register_console has been set up. We currently could have asynch
544 * polls calling this function due to sn_sal_switch_to_asynch but we can
545 * ignore them until we register with the serial core stuffs.
546 *
547 */
548static void sn_transmit_chars(struct sn_cons_port *port, int raw)
549{
550 int xmit_count, tail, head, loops, ii;
551 int result;
552 char *start;
553 struct circ_buf *xmit;
554
555 if (!port)
556 return;
557
558 BUG_ON(!port->sc_is_asynch);
559
560 if (port->sc_port.info) {
561 /* We're initilized, using serial core infrastructure */
562 xmit = &port->sc_port.info->xmit;
563 } else {
564 /* Probably sn_sal_switch_to_asynch has been run but serial core isn't
565 * initilized yet. Just return. Writes are going through
566 * sn_sal_console_write (due to register_console) at this time.
567 */
568 return;
569 }
570
571 if (uart_circ_empty(xmit) || uart_tx_stopped(&port->sc_port)) {
572 /* Nothing to do. */
Pat Gefre328007b2005-06-23 00:09:54 -0700573 ia64_sn_console_intr_disable(SAL_CONSOLE_INTR_XMIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 return;
575 }
576
577 head = xmit->head;
578 tail = xmit->tail;
579 start = &xmit->buf[tail];
580
581 /* twice around gets the tail to the end of the buffer and
582 * then to the head, if needed */
583 loops = (head < tail) ? 2 : 1;
584
585 for (ii = 0; ii < loops; ii++) {
586 xmit_count = (head < tail) ?
587 (UART_XMIT_SIZE - tail) : (head - tail);
588
589 if (xmit_count > 0) {
590 if (raw == TRANSMIT_RAW)
591 result =
592 port->sc_ops->sal_puts_raw(start,
593 xmit_count);
594 else
595 result =
596 port->sc_ops->sal_puts(start, xmit_count);
597#ifdef DEBUG
598 if (!result)
599 DPRINTF("`");
600#endif
601 if (result > 0) {
602 xmit_count -= result;
603 port->sc_port.icount.tx += result;
604 tail += result;
605 tail &= UART_XMIT_SIZE - 1;
606 xmit->tail = tail;
607 start = &xmit->buf[tail];
608 }
609 }
610 }
611
612 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
613 uart_write_wakeup(&port->sc_port);
614
615 if (uart_circ_empty(xmit))
Russell Kingb129a8c2005-08-31 10:12:14 +0100616 snp_stop_tx(&port->sc_port); /* no-op for us */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617}
618
619/**
620 * sn_sal_interrupt - Handle console interrupts
621 * @irq: irq #, useful for debug statements
622 * @dev_id: our pointer to our port (sn_cons_port which contains the uart port)
623 * @regs: Saved registers, used by sn_receive_chars for uart_handle_sysrq_char
624 *
625 */
626static irqreturn_t sn_sal_interrupt(int irq, void *dev_id, struct pt_regs *regs)
627{
628 struct sn_cons_port *port = (struct sn_cons_port *)dev_id;
629 unsigned long flags;
630 int status = ia64_sn_console_intr_status();
631
632 if (!port)
633 return IRQ_NONE;
634
635 spin_lock_irqsave(&port->sc_port.lock, flags);
636 if (status & SAL_CONSOLE_INTR_RECV) {
637 sn_receive_chars(port, regs, flags);
638 }
639 if (status & SAL_CONSOLE_INTR_XMIT) {
640 sn_transmit_chars(port, TRANSMIT_BUFFERED);
641 }
642 spin_unlock_irqrestore(&port->sc_port.lock, flags);
643 return IRQ_HANDLED;
644}
645
646/**
647 * sn_sal_connect_interrupt - Request interrupt, handled by sn_sal_interrupt
648 * @port: Our sn_cons_port (which contains the uart port)
649 *
650 * returns the console irq if interrupt is successfully registered, else 0
651 *
652 */
653static int sn_sal_connect_interrupt(struct sn_cons_port *port)
654{
655 if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt,
656 SA_INTERRUPT | SA_SHIRQ,
657 "SAL console driver", port) >= 0) {
658 return SGI_UART_VECTOR;
659 }
660
661 printk(KERN_INFO "sn_console: console proceeding in polled mode\n");
662 return 0;
663}
664
665/**
666 * sn_sal_timer_poll - this function handles polled console mode
667 * @data: A pointer to our sn_cons_port (which contains the uart port)
668 *
669 * data is the pointer that init_timer will store for us. This function is
670 * associated with init_timer to see if there is any console traffic.
671 * Obviously not used in interrupt mode
672 *
673 */
674static void sn_sal_timer_poll(unsigned long data)
675{
676 struct sn_cons_port *port = (struct sn_cons_port *)data;
677 unsigned long flags;
678
679 if (!port)
680 return;
681
682 if (!port->sc_port.irq) {
683 spin_lock_irqsave(&port->sc_port.lock, flags);
684 if (sn_process_input)
685 sn_receive_chars(port, NULL, flags);
686 sn_transmit_chars(port, TRANSMIT_RAW);
687 spin_unlock_irqrestore(&port->sc_port.lock, flags);
688 mod_timer(&port->sc_timer,
689 jiffies + port->sc_interrupt_timeout);
690 }
691}
692
693/*
694 * Boot-time initialization code
695 */
696
697/**
698 * sn_sal_switch_to_asynch - Switch to async mode (as opposed to synch)
699 * @port: Our sn_cons_port (which contains the uart port)
700 *
701 * So this is used by sn_sal_serial_console_init (early on, before we're
702 * registered with serial core). It's also used by sn_sal_module_init
703 * right after we've registered with serial core. The later only happens
704 * if we didn't already come through here via sn_sal_serial_console_init.
705 *
706 */
707static void __init sn_sal_switch_to_asynch(struct sn_cons_port *port)
708{
709 unsigned long flags;
710
711 if (!port)
712 return;
713
714 DPRINTF("sn_console: about to switch to asynchronous console\n");
715
716 /* without early_printk, we may be invoked late enough to race
717 * with other cpus doing console IO at this point, however
718 * console interrupts will never be enabled */
719 spin_lock_irqsave(&port->sc_port.lock, flags);
720
721 /* early_printk invocation may have done this for us */
722 if (!port->sc_ops)
723 port->sc_ops = &poll_ops;
724
725 /* we can't turn on the console interrupt (as request_irq
726 * calls kmalloc, which isn't set up yet), so we rely on a
727 * timer to poll for input and push data from the console
728 * buffer.
729 */
730 init_timer(&port->sc_timer);
731 port->sc_timer.function = sn_sal_timer_poll;
732 port->sc_timer.data = (unsigned long)port;
733
734 if (IS_RUNNING_ON_SIMULATOR())
735 port->sc_interrupt_timeout = 6;
736 else {
737 /* 960cps / 16 char FIFO = 60HZ
738 * HZ / (SN_SAL_FIFO_SPEED_CPS / SN_SAL_FIFO_DEPTH) */
739 port->sc_interrupt_timeout =
740 HZ * SN_SAL_UART_FIFO_DEPTH / SN_SAL_UART_FIFO_SPEED_CPS;
741 }
742 mod_timer(&port->sc_timer, jiffies + port->sc_interrupt_timeout);
743
744 port->sc_is_asynch = 1;
745 spin_unlock_irqrestore(&port->sc_port.lock, flags);
746}
747
748/**
749 * sn_sal_switch_to_interrupts - Switch to interrupt driven mode
750 * @port: Our sn_cons_port (which contains the uart port)
751 *
752 * In sn_sal_module_init, after we're registered with serial core and
753 * the port is added, this function is called to switch us to interrupt
754 * mode. We were previously in asynch/polling mode (using init_timer).
755 *
756 * We attempt to switch to interrupt mode here by calling
757 * sn_sal_connect_interrupt. If that works out, we enable receive interrupts.
758 */
759static void __init sn_sal_switch_to_interrupts(struct sn_cons_port *port)
760{
761 int irq;
762 unsigned long flags;
763
764 if (!port)
765 return;
766
767 DPRINTF("sn_console: switching to interrupt driven console\n");
768
769 spin_lock_irqsave(&port->sc_port.lock, flags);
770
771 irq = sn_sal_connect_interrupt(port);
772
773 if (irq) {
774 port->sc_port.irq = irq;
775 port->sc_ops = &intr_ops;
776
777 /* turn on receive interrupts */
778 ia64_sn_console_intr_enable(SAL_CONSOLE_INTR_RECV);
779 }
780 spin_unlock_irqrestore(&port->sc_port.lock, flags);
781}
782
783/*
784 * Kernel console definitions
785 */
786
787static void sn_sal_console_write(struct console *, const char *, unsigned);
788static int __init sn_sal_console_setup(struct console *, char *);
Andreas Schwab434498d2005-05-01 08:59:12 -0700789static struct uart_driver sal_console_uart;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790extern struct tty_driver *uart_console_device(struct console *, int *);
791
792static struct console sal_console = {
793 .name = DEVICE_NAME,
794 .write = sn_sal_console_write,
795 .device = uart_console_device,
796 .setup = sn_sal_console_setup,
797 .index = -1, /* unspecified */
798 .data = &sal_console_uart,
799};
800
801#define SAL_CONSOLE &sal_console
802
Andreas Schwab434498d2005-05-01 08:59:12 -0700803static struct uart_driver sal_console_uart = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 .owner = THIS_MODULE,
805 .driver_name = "sn_console",
806 .dev_name = DEVICE_NAME,
807 .major = 0, /* major/minor set at registration time per USE_DYNAMIC_MINOR */
808 .minor = 0,
809 .nr = 1, /* one port */
810 .cons = SAL_CONSOLE,
811};
812
813/**
814 * sn_sal_module_init - When the kernel loads us, get us rolling w/ serial core
815 *
816 * Before this is called, we've been printing kernel messages in a special
817 * early mode not making use of the serial core infrastructure. When our
818 * driver is loaded for real, we register the driver and port with serial
819 * core and try to enable interrupt driven mode.
820 *
821 */
822static int __init sn_sal_module_init(void)
823{
824 int retval;
825
826 if (!ia64_platform_is("sn2"))
827 return -ENODEV;
828
829 printk(KERN_INFO "sn_console: Console driver init\n");
830
831 if (USE_DYNAMIC_MINOR == 1) {
832 misc.minor = MISC_DYNAMIC_MINOR;
833 misc.name = DEVICE_NAME_DYNAMIC;
834 retval = misc_register(&misc);
835 if (retval != 0) {
836 printk
837 ("Failed to register console device using misc_register.\n");
838 return -ENODEV;
839 }
840 sal_console_uart.major = MISC_MAJOR;
841 sal_console_uart.minor = misc.minor;
842 } else {
843 sal_console_uart.major = DEVICE_MAJOR;
844 sal_console_uart.minor = DEVICE_MINOR;
845 }
846
847 /* We register the driver and the port before switching to interrupts
848 * or async above so the proper uart structures are populated */
849
850 if (uart_register_driver(&sal_console_uart) < 0) {
851 printk
852 ("ERROR sn_sal_module_init failed uart_register_driver, line %d\n",
853 __LINE__);
854 return -ENODEV;
855 }
856
857 spin_lock_init(&sal_console_port.sc_port.lock);
858
859 /* Setup the port struct with the minimum needed */
860 sal_console_port.sc_port.membase = (char *)1; /* just needs to be non-zero */
861 sal_console_port.sc_port.type = PORT_16550A;
862 sal_console_port.sc_port.fifosize = SN_SAL_MAX_CHARS;
863 sal_console_port.sc_port.ops = &sn_console_ops;
864 sal_console_port.sc_port.line = 0;
865
866 if (uart_add_one_port(&sal_console_uart, &sal_console_port.sc_port) < 0) {
867 /* error - not sure what I'd do - so I'll do nothing */
868 printk(KERN_ERR "%s: unable to add port\n", __FUNCTION__);
869 }
870
871 /* when this driver is compiled in, the console initialization
872 * will have already switched us into asynchronous operation
873 * before we get here through the module initcalls */
874 if (!sal_console_port.sc_is_asynch) {
875 sn_sal_switch_to_asynch(&sal_console_port);
876 }
877
878 /* at this point (module_init) we can try to turn on interrupts */
879 if (!IS_RUNNING_ON_SIMULATOR()) {
880 sn_sal_switch_to_interrupts(&sal_console_port);
881 }
882 sn_process_input = 1;
883 return 0;
884}
885
886/**
887 * sn_sal_module_exit - When we're unloaded, remove the driver/port
888 *
889 */
890static void __exit sn_sal_module_exit(void)
891{
892 del_timer_sync(&sal_console_port.sc_timer);
893 uart_remove_one_port(&sal_console_uart, &sal_console_port.sc_port);
894 uart_unregister_driver(&sal_console_uart);
895 misc_deregister(&misc);
896}
897
898module_init(sn_sal_module_init);
899module_exit(sn_sal_module_exit);
900
901/**
902 * puts_raw_fixed - sn_sal_console_write helper for adding \r's as required
903 * @puts_raw : puts function to do the writing
904 * @s: input string
905 * @count: length
906 *
907 * We need a \r ahead of every \n for direct writes through
908 * ia64_sn_console_putb (what sal_puts_raw below actually does).
909 *
910 */
911
912static void puts_raw_fixed(int (*puts_raw) (const char *s, int len),
913 const char *s, int count)
914{
915 const char *s1;
916
917 /* Output '\r' before each '\n' */
918 while ((s1 = memchr(s, '\n', count)) != NULL) {
919 puts_raw(s, s1 - s);
920 puts_raw("\r\n", 2);
921 count -= s1 + 1 - s;
922 s = s1 + 1;
923 }
924 puts_raw(s, count);
925}
926
927/**
928 * sn_sal_console_write - Print statements before serial core available
929 * @console: Console to operate on - we ignore since we have just one
930 * @s: String to send
931 * @count: length
932 *
933 * This is referenced in the console struct. It is used for early
934 * console printing before we register with serial core and for things
935 * such as kdb. The console_lock must be held when we get here.
936 *
937 * This function has some code for trying to print output even if the lock
938 * is held. We try to cover the case where a lock holder could have died.
939 * We don't use this special case code if we're not registered with serial
940 * core yet. After we're registered with serial core, the only time this
941 * function would be used is for high level kernel output like magic sys req,
942 * kdb, and printk's.
943 */
944static void
945sn_sal_console_write(struct console *co, const char *s, unsigned count)
946{
947 unsigned long flags = 0;
948 struct sn_cons_port *port = &sal_console_port;
949#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
950 static int stole_lock = 0;
951#endif
952
953 BUG_ON(!port->sc_is_asynch);
954
955 /* We can't look at the xmit buffer if we're not registered with serial core
956 * yet. So only do the fancy recovery after registering
957 */
958 if (port->sc_port.info) {
959
960 /* somebody really wants this output, might be an
961 * oops, kdb, panic, etc. make sure they get it. */
962#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
963 if (spin_is_locked(&port->sc_port.lock)) {
964 int lhead = port->sc_port.info->xmit.head;
965 int ltail = port->sc_port.info->xmit.tail;
966 int counter, got_lock = 0;
967
968 /*
969 * We attempt to determine if someone has died with the
970 * lock. We wait ~20 secs after the head and tail ptrs
971 * stop moving and assume the lock holder is not functional
972 * and plow ahead. If the lock is freed within the time out
973 * period we re-get the lock and go ahead normally. We also
974 * remember if we have plowed ahead so that we don't have
975 * to wait out the time out period again - the asumption
976 * is that we will time out again.
977 */
978
979 for (counter = 0; counter < 150; mdelay(125), counter++) {
980 if (!spin_is_locked(&port->sc_port.lock)
981 || stole_lock) {
982 if (!stole_lock) {
983 spin_lock_irqsave(&port->
984 sc_port.lock,
985 flags);
986 got_lock = 1;
987 }
988 break;
989 } else {
990 /* still locked */
991 if ((lhead !=
992 port->sc_port.info->xmit.head)
993 || (ltail !=
994 port->sc_port.info->xmit.
995 tail)) {
996 lhead =
997 port->sc_port.info->xmit.
998 head;
999 ltail =
1000 port->sc_port.info->xmit.
1001 tail;
1002 counter = 0;
1003 }
1004 }
1005 }
1006 /* flush anything in the serial core xmit buffer, raw */
1007 sn_transmit_chars(port, 1);
1008 if (got_lock) {
1009 spin_unlock_irqrestore(&port->sc_port.lock,
1010 flags);
1011 stole_lock = 0;
1012 } else {
1013 /* fell thru */
1014 stole_lock = 1;
1015 }
1016 puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count);
1017 } else {
1018 stole_lock = 0;
1019#endif
1020 spin_lock_irqsave(&port->sc_port.lock, flags);
1021 sn_transmit_chars(port, 1);
1022 spin_unlock_irqrestore(&port->sc_port.lock, flags);
1023
1024 puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count);
1025#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
1026 }
1027#endif
1028 }
1029 else {
1030 /* Not yet registered with serial core - simple case */
1031 puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count);
1032 }
1033}
1034
1035
1036/**
1037 * sn_sal_console_setup - Set up console for early printing
1038 * @co: Console to work with
1039 * @options: Options to set
1040 *
1041 * Altix console doesn't do anything with baud rates, etc, anyway.
1042 *
1043 * This isn't required since not providing the setup function in the
1044 * console struct is ok. However, other patches like KDB plop something
1045 * here so providing it is easier.
1046 *
1047 */
1048static int __init sn_sal_console_setup(struct console *co, char *options)
1049{
1050 return 0;
1051}
1052
1053/**
1054 * sn_sal_console_write_early - simple early output routine
1055 * @co - console struct
1056 * @s - string to print
1057 * @count - count
1058 *
1059 * Simple function to provide early output, before even
1060 * sn_sal_serial_console_init is called. Referenced in the
1061 * console struct registerd in sn_serial_console_early_setup.
1062 *
1063 */
1064static void __init
1065sn_sal_console_write_early(struct console *co, const char *s, unsigned count)
1066{
1067 puts_raw_fixed(sal_console_port.sc_ops->sal_puts_raw, s, count);
1068}
1069
1070/* Used for very early console printing - again, before
1071 * sn_sal_serial_console_init is run */
1072static struct console sal_console_early __initdata = {
1073 .name = "sn_sal",
1074 .write = sn_sal_console_write_early,
1075 .flags = CON_PRINTBUFFER,
1076 .index = -1,
1077};
1078
1079/**
1080 * sn_serial_console_early_setup - Sets up early console output support
1081 *
1082 * Register a console early on... This is for output before even
1083 * sn_sal_serial_cosnole_init is called. This function is called from
1084 * setup.c. This allows us to do really early polled writes. When
1085 * sn_sal_serial_console_init is called, this console is unregistered
1086 * and a new one registered.
1087 */
1088int __init sn_serial_console_early_setup(void)
1089{
1090 if (!ia64_platform_is("sn2"))
1091 return -1;
1092
1093 sal_console_port.sc_ops = &poll_ops;
Keith Owens71841b82005-07-30 17:52:00 -07001094 spin_lock_init(&sal_console_port.sc_port.lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 early_sn_setup(); /* Find SAL entry points */
1096 register_console(&sal_console_early);
1097
1098 return 0;
1099}
1100
1101/**
1102 * sn_sal_serial_console_init - Early console output - set up for register
1103 *
1104 * This function is called when regular console init happens. Because we
1105 * support even earlier console output with sn_serial_console_early_setup
1106 * (called from setup.c directly), this function unregisters the really
1107 * early console.
1108 *
1109 * Note: Even if setup.c doesn't register sal_console_early, unregistering
1110 * it here doesn't hurt anything.
1111 *
1112 */
1113static int __init sn_sal_serial_console_init(void)
1114{
1115 if (ia64_platform_is("sn2")) {
1116 sn_sal_switch_to_asynch(&sal_console_port);
1117 DPRINTF("sn_sal_serial_console_init : register console\n");
1118 register_console(&sal_console);
1119 unregister_console(&sal_console_early);
1120 }
1121 return 0;
1122}
1123
1124console_initcall(sn_sal_serial_console_init);