Root/
1 | /* |
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) 2004-2006 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/interrupt.h> |
41 | #include <linux/tty.h> |
42 | #include <linux/serial.h> |
43 | #include <linux/console.h> |
44 | #include <linux/module.h> |
45 | #include <linux/sysrq.h> |
46 | #include <linux/circ_buf.h> |
47 | #include <linux/serial_reg.h> |
48 | #include <linux/delay.h> /* for mdelay */ |
49 | #include <linux/miscdevice.h> |
50 | #include <linux/serial_core.h> |
51 | |
52 | #include <asm/io.h> |
53 | #include <asm/sn/simulator.h> |
54 | #include <asm/sn/sn_sal.h> |
55 | |
56 | /* number of characters we can transmit to the SAL console at a time */ |
57 | #define SN_SAL_MAX_CHARS 120 |
58 | |
59 | /* 64K, when we're asynch, it must be at least printk's LOG_BUF_LEN to |
60 | * avoid losing chars, (always has to be a power of 2) */ |
61 | #define SN_SAL_BUFFER_SIZE (64 * (1 << 10)) |
62 | |
63 | #define SN_SAL_UART_FIFO_DEPTH 16 |
64 | #define SN_SAL_UART_FIFO_SPEED_CPS (9600/10) |
65 | |
66 | /* sn_transmit_chars() calling args */ |
67 | #define TRANSMIT_BUFFERED 0 |
68 | #define TRANSMIT_RAW 1 |
69 | |
70 | /* To use dynamic numbers only and not use the assigned major and minor, |
71 | * define the following.. */ |
72 | /* #define USE_DYNAMIC_MINOR 1 *//* use dynamic minor number */ |
73 | #define USE_DYNAMIC_MINOR 0 /* Don't rely on misc_register dynamic minor */ |
74 | |
75 | /* Device name we're using */ |
76 | #define DEVICE_NAME "ttySG" |
77 | #define DEVICE_NAME_DYNAMIC "ttySG0" /* need full name for misc_register */ |
78 | /* The major/minor we are using, ignored for USE_DYNAMIC_MINOR */ |
79 | #define DEVICE_MAJOR 204 |
80 | #define DEVICE_MINOR 40 |
81 | |
82 | #ifdef CONFIG_MAGIC_SYSRQ |
83 | static char sysrq_serial_str[] = "\eSYS"; |
84 | static char *sysrq_serial_ptr = sysrq_serial_str; |
85 | static unsigned long sysrq_requested; |
86 | #endif /* CONFIG_MAGIC_SYSRQ */ |
87 | |
88 | /* |
89 | * Port definition - this kinda drives it all |
90 | */ |
91 | struct sn_cons_port { |
92 | struct timer_list sc_timer; |
93 | struct uart_port sc_port; |
94 | struct sn_sal_ops { |
95 | int (*sal_puts_raw) (const char *s, int len); |
96 | int (*sal_puts) (const char *s, int len); |
97 | int (*sal_getc) (void); |
98 | int (*sal_input_pending) (void); |
99 | void (*sal_wakeup_transmit) (struct sn_cons_port *, int); |
100 | } *sc_ops; |
101 | unsigned long sc_interrupt_timeout; |
102 | int sc_is_asynch; |
103 | }; |
104 | |
105 | static struct sn_cons_port sal_console_port; |
106 | static int sn_process_input; |
107 | |
108 | /* Only used if USE_DYNAMIC_MINOR is set to 1 */ |
109 | static struct miscdevice misc; /* used with misc_register for dynamic */ |
110 | |
111 | extern void early_sn_setup(void); |
112 | |
113 | #undef DEBUG |
114 | #ifdef DEBUG |
115 | static int sn_debug_printf(const char *fmt, ...); |
116 | #define DPRINTF(x...) sn_debug_printf(x) |
117 | #else |
118 | #define DPRINTF(x...) do { } while (0) |
119 | #endif |
120 | |
121 | /* Prototypes */ |
122 | static int snt_hw_puts_raw(const char *, int); |
123 | static int snt_hw_puts_buffered(const char *, int); |
124 | static int snt_poll_getc(void); |
125 | static int snt_poll_input_pending(void); |
126 | static int snt_intr_getc(void); |
127 | static int snt_intr_input_pending(void); |
128 | static void sn_transmit_chars(struct sn_cons_port *, int); |
129 | |
130 | /* A table for polling: |
131 | */ |
132 | static struct sn_sal_ops poll_ops = { |
133 | .sal_puts_raw = snt_hw_puts_raw, |
134 | .sal_puts = snt_hw_puts_raw, |
135 | .sal_getc = snt_poll_getc, |
136 | .sal_input_pending = snt_poll_input_pending |
137 | }; |
138 | |
139 | /* A table for interrupts enabled */ |
140 | static struct sn_sal_ops intr_ops = { |
141 | .sal_puts_raw = snt_hw_puts_raw, |
142 | .sal_puts = snt_hw_puts_buffered, |
143 | .sal_getc = snt_intr_getc, |
144 | .sal_input_pending = snt_intr_input_pending, |
145 | .sal_wakeup_transmit = sn_transmit_chars |
146 | }; |
147 | |
148 | /* the console does output in two distinctly different ways: |
149 | * synchronous (raw) and asynchronous (buffered). initally, early_printk |
150 | * does synchronous output. any data written goes directly to the SAL |
151 | * to be output (incidentally, it is internally buffered by the SAL) |
152 | * after interrupts and timers are initialized and available for use, |
153 | * the console init code switches to asynchronous output. this is |
154 | * also the earliest opportunity to begin polling for console input. |
155 | * after console initialization, console output and tty (serial port) |
156 | * output is buffered and sent to the SAL asynchronously (either by |
157 | * timer callback or by UART interrupt) */ |
158 | |
159 | /* routines for running the console in polling mode */ |
160 | |
161 | /** |
162 | * snt_poll_getc - Get a character from the console in polling mode |
163 | * |
164 | */ |
165 | static int snt_poll_getc(void) |
166 | { |
167 | int ch; |
168 | |
169 | ia64_sn_console_getc(&ch); |
170 | return ch; |
171 | } |
172 | |
173 | /** |
174 | * snt_poll_input_pending - Check if any input is waiting - polling mode. |
175 | * |
176 | */ |
177 | static int snt_poll_input_pending(void) |
178 | { |
179 | int status, input; |
180 | |
181 | status = ia64_sn_console_check(&input); |
182 | return !status && input; |
183 | } |
184 | |
185 | /* routines for an interrupt driven console (normal) */ |
186 | |
187 | /** |
188 | * snt_intr_getc - Get a character from the console, interrupt mode |
189 | * |
190 | */ |
191 | static int snt_intr_getc(void) |
192 | { |
193 | return ia64_sn_console_readc(); |
194 | } |
195 | |
196 | /** |
197 | * snt_intr_input_pending - Check if input is pending, interrupt mode |
198 | * |
199 | */ |
200 | static int snt_intr_input_pending(void) |
201 | { |
202 | return ia64_sn_console_intr_status() & SAL_CONSOLE_INTR_RECV; |
203 | } |
204 | |
205 | /* these functions are polled and interrupt */ |
206 | |
207 | /** |
208 | * snt_hw_puts_raw - Send raw string to the console, polled or interrupt mode |
209 | * @s: String |
210 | * @len: Length |
211 | * |
212 | */ |
213 | static int snt_hw_puts_raw(const char *s, int len) |
214 | { |
215 | /* this will call the PROM and not return until this is done */ |
216 | return ia64_sn_console_putb(s, len); |
217 | } |
218 | |
219 | /** |
220 | * snt_hw_puts_buffered - Send string to console, polled or interrupt mode |
221 | * @s: String |
222 | * @len: Length |
223 | * |
224 | */ |
225 | static int snt_hw_puts_buffered(const char *s, int len) |
226 | { |
227 | /* queue data to the PROM */ |
228 | return ia64_sn_console_xmit_chars((char *)s, len); |
229 | } |
230 | |
231 | /* uart interface structs |
232 | * These functions are associated with the uart_port that the serial core |
233 | * infrastructure calls. |
234 | * |
235 | * Note: Due to how the console works, many routines are no-ops. |
236 | */ |
237 | |
238 | /** |
239 | * snp_type - What type of console are we? |
240 | * @port: Port to operate with (we ignore since we only have one port) |
241 | * |
242 | */ |
243 | static const char *snp_type(struct uart_port *port) |
244 | { |
245 | return ("SGI SN L1"); |
246 | } |
247 | |
248 | /** |
249 | * snp_tx_empty - Is the transmitter empty? We pretend we're always empty |
250 | * @port: Port to operate on (we ignore since we only have one port) |
251 | * |
252 | */ |
253 | static unsigned int snp_tx_empty(struct uart_port *port) |
254 | { |
255 | return 1; |
256 | } |
257 | |
258 | /** |
259 | * snp_stop_tx - stop the transmitter - no-op for us |
260 | * @port: Port to operat eon - we ignore - no-op function |
261 | * |
262 | */ |
263 | static void snp_stop_tx(struct uart_port *port) |
264 | { |
265 | } |
266 | |
267 | /** |
268 | * snp_release_port - Free i/o and resources for port - no-op for us |
269 | * @port: Port to operate on - we ignore - no-op function |
270 | * |
271 | */ |
272 | static void snp_release_port(struct uart_port *port) |
273 | { |
274 | } |
275 | |
276 | /** |
277 | * snp_enable_ms - Force modem status interrupts on - no-op for us |
278 | * @port: Port to operate on - we ignore - no-op function |
279 | * |
280 | */ |
281 | static void snp_enable_ms(struct uart_port *port) |
282 | { |
283 | } |
284 | |
285 | /** |
286 | * snp_shutdown - shut down the port - free irq and disable - no-op for us |
287 | * @port: Port to shut down - we ignore |
288 | * |
289 | */ |
290 | static void snp_shutdown(struct uart_port *port) |
291 | { |
292 | } |
293 | |
294 | /** |
295 | * snp_set_mctrl - set control lines (dtr, rts, etc) - no-op for our console |
296 | * @port: Port to operate on - we ignore |
297 | * @mctrl: Lines to set/unset - we ignore |
298 | * |
299 | */ |
300 | static void snp_set_mctrl(struct uart_port *port, unsigned int mctrl) |
301 | { |
302 | } |
303 | |
304 | /** |
305 | * snp_get_mctrl - get contorl line info, we just return a static value |
306 | * @port: port to operate on - we only have one port so we ignore this |
307 | * |
308 | */ |
309 | static unsigned int snp_get_mctrl(struct uart_port *port) |
310 | { |
311 | return TIOCM_CAR | TIOCM_RNG | TIOCM_DSR | TIOCM_CTS; |
312 | } |
313 | |
314 | /** |
315 | * snp_stop_rx - Stop the receiver - we ignor ethis |
316 | * @port: Port to operate on - we ignore |
317 | * |
318 | */ |
319 | static void snp_stop_rx(struct uart_port *port) |
320 | { |
321 | } |
322 | |
323 | /** |
324 | * snp_start_tx - Start transmitter |
325 | * @port: Port to operate on |
326 | * |
327 | */ |
328 | static void snp_start_tx(struct uart_port *port) |
329 | { |
330 | if (sal_console_port.sc_ops->sal_wakeup_transmit) |
331 | sal_console_port.sc_ops->sal_wakeup_transmit(&sal_console_port, |
332 | TRANSMIT_BUFFERED); |
333 | |
334 | } |
335 | |
336 | /** |
337 | * snp_break_ctl - handle breaks - ignored by us |
338 | * @port: Port to operate on |
339 | * @break_state: Break state |
340 | * |
341 | */ |
342 | static void snp_break_ctl(struct uart_port *port, int break_state) |
343 | { |
344 | } |
345 | |
346 | /** |
347 | * snp_startup - Start up the serial port - always return 0 (We're always on) |
348 | * @port: Port to operate on |
349 | * |
350 | */ |
351 | static int snp_startup(struct uart_port *port) |
352 | { |
353 | return 0; |
354 | } |
355 | |
356 | /** |
357 | * snp_set_termios - set termios stuff - we ignore these |
358 | * @port: port to operate on |
359 | * @termios: New settings |
360 | * @termios: Old |
361 | * |
362 | */ |
363 | static void |
364 | snp_set_termios(struct uart_port *port, struct ktermios *termios, |
365 | struct ktermios *old) |
366 | { |
367 | } |
368 | |
369 | /** |
370 | * snp_request_port - allocate resources for port - ignored by us |
371 | * @port: port to operate on |
372 | * |
373 | */ |
374 | static int snp_request_port(struct uart_port *port) |
375 | { |
376 | return 0; |
377 | } |
378 | |
379 | /** |
380 | * snp_config_port - allocate resources, set up - we ignore, we're always on |
381 | * @port: Port to operate on |
382 | * @flags: flags used for port setup |
383 | * |
384 | */ |
385 | static void snp_config_port(struct uart_port *port, int flags) |
386 | { |
387 | } |
388 | |
389 | /* Associate the uart functions above - given to serial core */ |
390 | |
391 | static struct uart_ops sn_console_ops = { |
392 | .tx_empty = snp_tx_empty, |
393 | .set_mctrl = snp_set_mctrl, |
394 | .get_mctrl = snp_get_mctrl, |
395 | .stop_tx = snp_stop_tx, |
396 | .start_tx = snp_start_tx, |
397 | .stop_rx = snp_stop_rx, |
398 | .enable_ms = snp_enable_ms, |
399 | .break_ctl = snp_break_ctl, |
400 | .startup = snp_startup, |
401 | .shutdown = snp_shutdown, |
402 | .set_termios = snp_set_termios, |
403 | .pm = NULL, |
404 | .type = snp_type, |
405 | .release_port = snp_release_port, |
406 | .request_port = snp_request_port, |
407 | .config_port = snp_config_port, |
408 | .verify_port = NULL, |
409 | }; |
410 | |
411 | /* End of uart struct functions and defines */ |
412 | |
413 | #ifdef DEBUG |
414 | |
415 | /** |
416 | * sn_debug_printf - close to hardware debugging printf |
417 | * @fmt: printf format |
418 | * |
419 | * This is as "close to the metal" as we can get, used when the driver |
420 | * itself may be broken. |
421 | * |
422 | */ |
423 | static int sn_debug_printf(const char *fmt, ...) |
424 | { |
425 | static char printk_buf[1024]; |
426 | int printed_len; |
427 | va_list args; |
428 | |
429 | va_start(args, fmt); |
430 | printed_len = vsnprintf(printk_buf, sizeof(printk_buf), fmt, args); |
431 | |
432 | if (!sal_console_port.sc_ops) { |
433 | sal_console_port.sc_ops = &poll_ops; |
434 | early_sn_setup(); |
435 | } |
436 | sal_console_port.sc_ops->sal_puts_raw(printk_buf, printed_len); |
437 | |
438 | va_end(args); |
439 | return printed_len; |
440 | } |
441 | #endif /* DEBUG */ |
442 | |
443 | /* |
444 | * Interrupt handling routines. |
445 | */ |
446 | |
447 | /** |
448 | * sn_receive_chars - Grab characters, pass them to tty layer |
449 | * @port: Port to operate on |
450 | * @flags: irq flags |
451 | * |
452 | * Note: If we're not registered with the serial core infrastructure yet, |
453 | * we don't try to send characters to it... |
454 | * |
455 | */ |
456 | static void |
457 | sn_receive_chars(struct sn_cons_port *port, unsigned long flags) |
458 | { |
459 | int ch; |
460 | struct tty_struct *tty; |
461 | |
462 | if (!port) { |
463 | printk(KERN_ERR "sn_receive_chars - port NULL so can't receieve\n"); |
464 | return; |
465 | } |
466 | |
467 | if (!port->sc_ops) { |
468 | printk(KERN_ERR "sn_receive_chars - port->sc_ops NULL so can't receieve\n"); |
469 | return; |
470 | } |
471 | |
472 | if (port->sc_port.state) { |
473 | /* The serial_core stuffs are initilized, use them */ |
474 | tty = port->sc_port.state->port.tty; |
475 | } |
476 | else { |
477 | /* Not registered yet - can't pass to tty layer. */ |
478 | tty = NULL; |
479 | } |
480 | |
481 | while (port->sc_ops->sal_input_pending()) { |
482 | ch = port->sc_ops->sal_getc(); |
483 | if (ch < 0) { |
484 | printk(KERN_ERR "sn_console: An error occured while " |
485 | "obtaining data from the console (0x%0x)\n", ch); |
486 | break; |
487 | } |
488 | #ifdef CONFIG_MAGIC_SYSRQ |
489 | if (sysrq_requested) { |
490 | unsigned long sysrq_timeout = sysrq_requested + HZ*5; |
491 | |
492 | sysrq_requested = 0; |
493 | if (ch && time_before(jiffies, sysrq_timeout)) { |
494 | spin_unlock_irqrestore(&port->sc_port.lock, flags); |
495 | handle_sysrq(ch, NULL); |
496 | spin_lock_irqsave(&port->sc_port.lock, flags); |
497 | /* ignore actual sysrq command char */ |
498 | continue; |
499 | } |
500 | } |
501 | if (ch == *sysrq_serial_ptr) { |
502 | if (!(*++sysrq_serial_ptr)) { |
503 | sysrq_requested = jiffies; |
504 | sysrq_serial_ptr = sysrq_serial_str; |
505 | } |
506 | /* |
507 | * ignore the whole sysrq string except for the |
508 | * leading escape |
509 | */ |
510 | if (ch != '\e') |
511 | continue; |
512 | } |
513 | else |
514 | sysrq_serial_ptr = sysrq_serial_str; |
515 | #endif /* CONFIG_MAGIC_SYSRQ */ |
516 | |
517 | /* record the character to pass up to the tty layer */ |
518 | if (tty) { |
519 | if(tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0) |
520 | break; |
521 | } |
522 | port->sc_port.icount.rx++; |
523 | } |
524 | |
525 | if (tty) |
526 | tty_flip_buffer_push(tty); |
527 | } |
528 | |
529 | /** |
530 | * sn_transmit_chars - grab characters from serial core, send off |
531 | * @port: Port to operate on |
532 | * @raw: Transmit raw or buffered |
533 | * |
534 | * Note: If we're early, before we're registered with serial core, the |
535 | * writes are going through sn_sal_console_write because that's how |
536 | * register_console has been set up. We currently could have asynch |
537 | * polls calling this function due to sn_sal_switch_to_asynch but we can |
538 | * ignore them until we register with the serial core stuffs. |
539 | * |
540 | */ |
541 | static void sn_transmit_chars(struct sn_cons_port *port, int raw) |
542 | { |
543 | int xmit_count, tail, head, loops, ii; |
544 | int result; |
545 | char *start; |
546 | struct circ_buf *xmit; |
547 | |
548 | if (!port) |
549 | return; |
550 | |
551 | BUG_ON(!port->sc_is_asynch); |
552 | |
553 | if (port->sc_port.state) { |
554 | /* We're initilized, using serial core infrastructure */ |
555 | xmit = &port->sc_port.state->xmit; |
556 | } else { |
557 | /* Probably sn_sal_switch_to_asynch has been run but serial core isn't |
558 | * initilized yet. Just return. Writes are going through |
559 | * sn_sal_console_write (due to register_console) at this time. |
560 | */ |
561 | return; |
562 | } |
563 | |
564 | if (uart_circ_empty(xmit) || uart_tx_stopped(&port->sc_port)) { |
565 | /* Nothing to do. */ |
566 | ia64_sn_console_intr_disable(SAL_CONSOLE_INTR_XMIT); |
567 | return; |
568 | } |
569 | |
570 | head = xmit->head; |
571 | tail = xmit->tail; |
572 | start = &xmit->buf[tail]; |
573 | |
574 | /* twice around gets the tail to the end of the buffer and |
575 | * then to the head, if needed */ |
576 | loops = (head < tail) ? 2 : 1; |
577 | |
578 | for (ii = 0; ii < loops; ii++) { |
579 | xmit_count = (head < tail) ? |
580 | (UART_XMIT_SIZE - tail) : (head - tail); |
581 | |
582 | if (xmit_count > 0) { |
583 | if (raw == TRANSMIT_RAW) |
584 | result = |
585 | port->sc_ops->sal_puts_raw(start, |
586 | xmit_count); |
587 | else |
588 | result = |
589 | port->sc_ops->sal_puts(start, xmit_count); |
590 | #ifdef DEBUG |
591 | if (!result) |
592 | DPRINTF("`"); |
593 | #endif |
594 | if (result > 0) { |
595 | xmit_count -= result; |
596 | port->sc_port.icount.tx += result; |
597 | tail += result; |
598 | tail &= UART_XMIT_SIZE - 1; |
599 | xmit->tail = tail; |
600 | start = &xmit->buf[tail]; |
601 | } |
602 | } |
603 | } |
604 | |
605 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) |
606 | uart_write_wakeup(&port->sc_port); |
607 | |
608 | if (uart_circ_empty(xmit)) |
609 | snp_stop_tx(&port->sc_port); /* no-op for us */ |
610 | } |
611 | |
612 | /** |
613 | * sn_sal_interrupt - Handle console interrupts |
614 | * @irq: irq #, useful for debug statements |
615 | * @dev_id: our pointer to our port (sn_cons_port which contains the uart port) |
616 | * |
617 | */ |
618 | static irqreturn_t sn_sal_interrupt(int irq, void *dev_id) |
619 | { |
620 | struct sn_cons_port *port = (struct sn_cons_port *)dev_id; |
621 | unsigned long flags; |
622 | int status = ia64_sn_console_intr_status(); |
623 | |
624 | if (!port) |
625 | return IRQ_NONE; |
626 | |
627 | spin_lock_irqsave(&port->sc_port.lock, flags); |
628 | if (status & SAL_CONSOLE_INTR_RECV) { |
629 | sn_receive_chars(port, flags); |
630 | } |
631 | if (status & SAL_CONSOLE_INTR_XMIT) { |
632 | sn_transmit_chars(port, TRANSMIT_BUFFERED); |
633 | } |
634 | spin_unlock_irqrestore(&port->sc_port.lock, flags); |
635 | return IRQ_HANDLED; |
636 | } |
637 | |
638 | /** |
639 | * sn_sal_timer_poll - this function handles polled console mode |
640 | * @data: A pointer to our sn_cons_port (which contains the uart port) |
641 | * |
642 | * data is the pointer that init_timer will store for us. This function is |
643 | * associated with init_timer to see if there is any console traffic. |
644 | * Obviously not used in interrupt mode |
645 | * |
646 | */ |
647 | static void sn_sal_timer_poll(unsigned long data) |
648 | { |
649 | struct sn_cons_port *port = (struct sn_cons_port *)data; |
650 | unsigned long flags; |
651 | |
652 | if (!port) |
653 | return; |
654 | |
655 | if (!port->sc_port.irq) { |
656 | spin_lock_irqsave(&port->sc_port.lock, flags); |
657 | if (sn_process_input) |
658 | sn_receive_chars(port, flags); |
659 | sn_transmit_chars(port, TRANSMIT_RAW); |
660 | spin_unlock_irqrestore(&port->sc_port.lock, flags); |
661 | mod_timer(&port->sc_timer, |
662 | jiffies + port->sc_interrupt_timeout); |
663 | } |
664 | } |
665 | |
666 | /* |
667 | * Boot-time initialization code |
668 | */ |
669 | |
670 | /** |
671 | * sn_sal_switch_to_asynch - Switch to async mode (as opposed to synch) |
672 | * @port: Our sn_cons_port (which contains the uart port) |
673 | * |
674 | * So this is used by sn_sal_serial_console_init (early on, before we're |
675 | * registered with serial core). It's also used by sn_sal_module_init |
676 | * right after we've registered with serial core. The later only happens |
677 | * if we didn't already come through here via sn_sal_serial_console_init. |
678 | * |
679 | */ |
680 | static void __init sn_sal_switch_to_asynch(struct sn_cons_port *port) |
681 | { |
682 | unsigned long flags; |
683 | |
684 | if (!port) |
685 | return; |
686 | |
687 | DPRINTF("sn_console: about to switch to asynchronous console\n"); |
688 | |
689 | /* without early_printk, we may be invoked late enough to race |
690 | * with other cpus doing console IO at this point, however |
691 | * console interrupts will never be enabled */ |
692 | spin_lock_irqsave(&port->sc_port.lock, flags); |
693 | |
694 | /* early_printk invocation may have done this for us */ |
695 | if (!port->sc_ops) |
696 | port->sc_ops = &poll_ops; |
697 | |
698 | /* we can't turn on the console interrupt (as request_irq |
699 | * calls kmalloc, which isn't set up yet), so we rely on a |
700 | * timer to poll for input and push data from the console |
701 | * buffer. |
702 | */ |
703 | init_timer(&port->sc_timer); |
704 | port->sc_timer.function = sn_sal_timer_poll; |
705 | port->sc_timer.data = (unsigned long)port; |
706 | |
707 | if (IS_RUNNING_ON_SIMULATOR()) |
708 | port->sc_interrupt_timeout = 6; |
709 | else { |
710 | /* 960cps / 16 char FIFO = 60HZ |
711 | * HZ / (SN_SAL_FIFO_SPEED_CPS / SN_SAL_FIFO_DEPTH) */ |
712 | port->sc_interrupt_timeout = |
713 | HZ * SN_SAL_UART_FIFO_DEPTH / SN_SAL_UART_FIFO_SPEED_CPS; |
714 | } |
715 | mod_timer(&port->sc_timer, jiffies + port->sc_interrupt_timeout); |
716 | |
717 | port->sc_is_asynch = 1; |
718 | spin_unlock_irqrestore(&port->sc_port.lock, flags); |
719 | } |
720 | |
721 | /** |
722 | * sn_sal_switch_to_interrupts - Switch to interrupt driven mode |
723 | * @port: Our sn_cons_port (which contains the uart port) |
724 | * |
725 | * In sn_sal_module_init, after we're registered with serial core and |
726 | * the port is added, this function is called to switch us to interrupt |
727 | * mode. We were previously in asynch/polling mode (using init_timer). |
728 | * |
729 | * We attempt to switch to interrupt mode here by calling |
730 | * request_irq. If that works out, we enable receive interrupts. |
731 | */ |
732 | static void __init sn_sal_switch_to_interrupts(struct sn_cons_port *port) |
733 | { |
734 | unsigned long flags; |
735 | |
736 | if (port) { |
737 | DPRINTF("sn_console: switching to interrupt driven console\n"); |
738 | |
739 | if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt, |
740 | IRQF_DISABLED | IRQF_SHARED, |
741 | "SAL console driver", port) >= 0) { |
742 | spin_lock_irqsave(&port->sc_port.lock, flags); |
743 | port->sc_port.irq = SGI_UART_VECTOR; |
744 | port->sc_ops = &intr_ops; |
745 | |
746 | /* turn on receive interrupts */ |
747 | ia64_sn_console_intr_enable(SAL_CONSOLE_INTR_RECV); |
748 | spin_unlock_irqrestore(&port->sc_port.lock, flags); |
749 | } |
750 | else { |
751 | printk(KERN_INFO |
752 | "sn_console: console proceeding in polled mode\n"); |
753 | } |
754 | } |
755 | } |
756 | |
757 | /* |
758 | * Kernel console definitions |
759 | */ |
760 | |
761 | static void sn_sal_console_write(struct console *, const char *, unsigned); |
762 | static int sn_sal_console_setup(struct console *, char *); |
763 | static struct uart_driver sal_console_uart; |
764 | extern struct tty_driver *uart_console_device(struct console *, int *); |
765 | |
766 | static struct console sal_console = { |
767 | .name = DEVICE_NAME, |
768 | .write = sn_sal_console_write, |
769 | .device = uart_console_device, |
770 | .setup = sn_sal_console_setup, |
771 | .index = -1, /* unspecified */ |
772 | .data = &sal_console_uart, |
773 | }; |
774 | |
775 | #define SAL_CONSOLE &sal_console |
776 | |
777 | static struct uart_driver sal_console_uart = { |
778 | .owner = THIS_MODULE, |
779 | .driver_name = "sn_console", |
780 | .dev_name = DEVICE_NAME, |
781 | .major = 0, /* major/minor set at registration time per USE_DYNAMIC_MINOR */ |
782 | .minor = 0, |
783 | .nr = 1, /* one port */ |
784 | .cons = SAL_CONSOLE, |
785 | }; |
786 | |
787 | /** |
788 | * sn_sal_module_init - When the kernel loads us, get us rolling w/ serial core |
789 | * |
790 | * Before this is called, we've been printing kernel messages in a special |
791 | * early mode not making use of the serial core infrastructure. When our |
792 | * driver is loaded for real, we register the driver and port with serial |
793 | * core and try to enable interrupt driven mode. |
794 | * |
795 | */ |
796 | static int __init sn_sal_module_init(void) |
797 | { |
798 | int retval; |
799 | |
800 | if (!ia64_platform_is("sn2")) |
801 | return 0; |
802 | |
803 | printk(KERN_INFO "sn_console: Console driver init\n"); |
804 | |
805 | if (USE_DYNAMIC_MINOR == 1) { |
806 | misc.minor = MISC_DYNAMIC_MINOR; |
807 | misc.name = DEVICE_NAME_DYNAMIC; |
808 | retval = misc_register(&misc); |
809 | if (retval != 0) { |
810 | printk(KERN_WARNING "Failed to register console " |
811 | "device using misc_register.\n"); |
812 | return -ENODEV; |
813 | } |
814 | sal_console_uart.major = MISC_MAJOR; |
815 | sal_console_uart.minor = misc.minor; |
816 | } else { |
817 | sal_console_uart.major = DEVICE_MAJOR; |
818 | sal_console_uart.minor = DEVICE_MINOR; |
819 | } |
820 | |
821 | /* We register the driver and the port before switching to interrupts |
822 | * or async above so the proper uart structures are populated */ |
823 | |
824 | if (uart_register_driver(&sal_console_uart) < 0) { |
825 | printk |
826 | ("ERROR sn_sal_module_init failed uart_register_driver, line %d\n", |
827 | __LINE__); |
828 | return -ENODEV; |
829 | } |
830 | |
831 | spin_lock_init(&sal_console_port.sc_port.lock); |
832 | |
833 | /* Setup the port struct with the minimum needed */ |
834 | sal_console_port.sc_port.membase = (char *)1; /* just needs to be non-zero */ |
835 | sal_console_port.sc_port.type = PORT_16550A; |
836 | sal_console_port.sc_port.fifosize = SN_SAL_MAX_CHARS; |
837 | sal_console_port.sc_port.ops = &sn_console_ops; |
838 | sal_console_port.sc_port.line = 0; |
839 | |
840 | if (uart_add_one_port(&sal_console_uart, &sal_console_port.sc_port) < 0) { |
841 | /* error - not sure what I'd do - so I'll do nothing */ |
842 | printk(KERN_ERR "%s: unable to add port\n", __func__); |
843 | } |
844 | |
845 | /* when this driver is compiled in, the console initialization |
846 | * will have already switched us into asynchronous operation |
847 | * before we get here through the module initcalls */ |
848 | if (!sal_console_port.sc_is_asynch) { |
849 | sn_sal_switch_to_asynch(&sal_console_port); |
850 | } |
851 | |
852 | /* at this point (module_init) we can try to turn on interrupts */ |
853 | if (!IS_RUNNING_ON_SIMULATOR()) { |
854 | sn_sal_switch_to_interrupts(&sal_console_port); |
855 | } |
856 | sn_process_input = 1; |
857 | return 0; |
858 | } |
859 | |
860 | /** |
861 | * sn_sal_module_exit - When we're unloaded, remove the driver/port |
862 | * |
863 | */ |
864 | static void __exit sn_sal_module_exit(void) |
865 | { |
866 | del_timer_sync(&sal_console_port.sc_timer); |
867 | uart_remove_one_port(&sal_console_uart, &sal_console_port.sc_port); |
868 | uart_unregister_driver(&sal_console_uart); |
869 | misc_deregister(&misc); |
870 | } |
871 | |
872 | module_init(sn_sal_module_init); |
873 | module_exit(sn_sal_module_exit); |
874 | |
875 | /** |
876 | * puts_raw_fixed - sn_sal_console_write helper for adding \r's as required |
877 | * @puts_raw : puts function to do the writing |
878 | * @s: input string |
879 | * @count: length |
880 | * |
881 | * We need a \r ahead of every \n for direct writes through |
882 | * ia64_sn_console_putb (what sal_puts_raw below actually does). |
883 | * |
884 | */ |
885 | |
886 | static void puts_raw_fixed(int (*puts_raw) (const char *s, int len), |
887 | const char *s, int count) |
888 | { |
889 | const char *s1; |
890 | |
891 | /* Output '\r' before each '\n' */ |
892 | while ((s1 = memchr(s, '\n', count)) != NULL) { |
893 | puts_raw(s, s1 - s); |
894 | puts_raw("\r\n", 2); |
895 | count -= s1 + 1 - s; |
896 | s = s1 + 1; |
897 | } |
898 | puts_raw(s, count); |
899 | } |
900 | |
901 | /** |
902 | * sn_sal_console_write - Print statements before serial core available |
903 | * @console: Console to operate on - we ignore since we have just one |
904 | * @s: String to send |
905 | * @count: length |
906 | * |
907 | * This is referenced in the console struct. It is used for early |
908 | * console printing before we register with serial core and for things |
909 | * such as kdb. The console_lock must be held when we get here. |
910 | * |
911 | * This function has some code for trying to print output even if the lock |
912 | * is held. We try to cover the case where a lock holder could have died. |
913 | * We don't use this special case code if we're not registered with serial |
914 | * core yet. After we're registered with serial core, the only time this |
915 | * function would be used is for high level kernel output like magic sys req, |
916 | * kdb, and printk's. |
917 | */ |
918 | static void |
919 | sn_sal_console_write(struct console *co, const char *s, unsigned count) |
920 | { |
921 | unsigned long flags = 0; |
922 | struct sn_cons_port *port = &sal_console_port; |
923 | static int stole_lock = 0; |
924 | |
925 | BUG_ON(!port->sc_is_asynch); |
926 | |
927 | /* We can't look at the xmit buffer if we're not registered with serial core |
928 | * yet. So only do the fancy recovery after registering |
929 | */ |
930 | if (!port->sc_port.state) { |
931 | /* Not yet registered with serial core - simple case */ |
932 | puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); |
933 | return; |
934 | } |
935 | |
936 | /* somebody really wants this output, might be an |
937 | * oops, kdb, panic, etc. make sure they get it. */ |
938 | if (spin_is_locked(&port->sc_port.lock)) { |
939 | int lhead = port->sc_port.state->xmit.head; |
940 | int ltail = port->sc_port.state->xmit.tail; |
941 | int counter, got_lock = 0; |
942 | |
943 | /* |
944 | * We attempt to determine if someone has died with the |
945 | * lock. We wait ~20 secs after the head and tail ptrs |
946 | * stop moving and assume the lock holder is not functional |
947 | * and plow ahead. If the lock is freed within the time out |
948 | * period we re-get the lock and go ahead normally. We also |
949 | * remember if we have plowed ahead so that we don't have |
950 | * to wait out the time out period again - the asumption |
951 | * is that we will time out again. |
952 | */ |
953 | |
954 | for (counter = 0; counter < 150; mdelay(125), counter++) { |
955 | if (!spin_is_locked(&port->sc_port.lock) |
956 | || stole_lock) { |
957 | if (!stole_lock) { |
958 | spin_lock_irqsave(&port->sc_port.lock, |
959 | flags); |
960 | got_lock = 1; |
961 | } |
962 | break; |
963 | } else { |
964 | /* still locked */ |
965 | if ((lhead != port->sc_port.state->xmit.head) |
966 | || (ltail != |
967 | port->sc_port.state->xmit.tail)) { |
968 | lhead = |
969 | port->sc_port.state->xmit.head; |
970 | ltail = |
971 | port->sc_port.state->xmit.tail; |
972 | counter = 0; |
973 | } |
974 | } |
975 | } |
976 | /* flush anything in the serial core xmit buffer, raw */ |
977 | sn_transmit_chars(port, 1); |
978 | if (got_lock) { |
979 | spin_unlock_irqrestore(&port->sc_port.lock, flags); |
980 | stole_lock = 0; |
981 | } else { |
982 | /* fell thru */ |
983 | stole_lock = 1; |
984 | } |
985 | puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); |
986 | } else { |
987 | stole_lock = 0; |
988 | spin_lock_irqsave(&port->sc_port.lock, flags); |
989 | sn_transmit_chars(port, 1); |
990 | spin_unlock_irqrestore(&port->sc_port.lock, flags); |
991 | |
992 | puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); |
993 | } |
994 | } |
995 | |
996 | |
997 | /** |
998 | * sn_sal_console_setup - Set up console for early printing |
999 | * @co: Console to work with |
1000 | * @options: Options to set |
1001 | * |
1002 | * Altix console doesn't do anything with baud rates, etc, anyway. |
1003 | * |
1004 | * This isn't required since not providing the setup function in the |
1005 | * console struct is ok. However, other patches like KDB plop something |
1006 | * here so providing it is easier. |
1007 | * |
1008 | */ |
1009 | static int sn_sal_console_setup(struct console *co, char *options) |
1010 | { |
1011 | return 0; |
1012 | } |
1013 | |
1014 | /** |
1015 | * sn_sal_console_write_early - simple early output routine |
1016 | * @co - console struct |
1017 | * @s - string to print |
1018 | * @count - count |
1019 | * |
1020 | * Simple function to provide early output, before even |
1021 | * sn_sal_serial_console_init is called. Referenced in the |
1022 | * console struct registerd in sn_serial_console_early_setup. |
1023 | * |
1024 | */ |
1025 | static void __init |
1026 | sn_sal_console_write_early(struct console *co, const char *s, unsigned count) |
1027 | { |
1028 | puts_raw_fixed(sal_console_port.sc_ops->sal_puts_raw, s, count); |
1029 | } |
1030 | |
1031 | /* Used for very early console printing - again, before |
1032 | * sn_sal_serial_console_init is run */ |
1033 | static struct console sal_console_early __initdata = { |
1034 | .name = "sn_sal", |
1035 | .write = sn_sal_console_write_early, |
1036 | .flags = CON_PRINTBUFFER, |
1037 | .index = -1, |
1038 | }; |
1039 | |
1040 | /** |
1041 | * sn_serial_console_early_setup - Sets up early console output support |
1042 | * |
1043 | * Register a console early on... This is for output before even |
1044 | * sn_sal_serial_cosnole_init is called. This function is called from |
1045 | * setup.c. This allows us to do really early polled writes. When |
1046 | * sn_sal_serial_console_init is called, this console is unregistered |
1047 | * and a new one registered. |
1048 | */ |
1049 | int __init sn_serial_console_early_setup(void) |
1050 | { |
1051 | if (!ia64_platform_is("sn2")) |
1052 | return -1; |
1053 | |
1054 | sal_console_port.sc_ops = &poll_ops; |
1055 | spin_lock_init(&sal_console_port.sc_port.lock); |
1056 | early_sn_setup(); /* Find SAL entry points */ |
1057 | register_console(&sal_console_early); |
1058 | |
1059 | return 0; |
1060 | } |
1061 | |
1062 | /** |
1063 | * sn_sal_serial_console_init - Early console output - set up for register |
1064 | * |
1065 | * This function is called when regular console init happens. Because we |
1066 | * support even earlier console output with sn_serial_console_early_setup |
1067 | * (called from setup.c directly), this function unregisters the really |
1068 | * early console. |
1069 | * |
1070 | * Note: Even if setup.c doesn't register sal_console_early, unregistering |
1071 | * it here doesn't hurt anything. |
1072 | * |
1073 | */ |
1074 | static int __init sn_sal_serial_console_init(void) |
1075 | { |
1076 | if (ia64_platform_is("sn2")) { |
1077 | sn_sal_switch_to_asynch(&sal_console_port); |
1078 | DPRINTF("sn_sal_serial_console_init : register console\n"); |
1079 | register_console(&sal_console); |
1080 | unregister_console(&sal_console_early); |
1081 | } |
1082 | return 0; |
1083 | } |
1084 | |
1085 | console_initcall(sn_sal_serial_console_init); |
1086 |
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