ia64/linux-2.6.18-xen.hg

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

linux/blktap2: reduce TLB flush scope

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

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
2 * dz.c: Serial port driver for DECStations equiped
3 * with the DZ chipset.
4 *
5 * Copyright (C) 1998 Olivier A. D. Lebaillif
6 *
7 * Email: olivier.lebaillif@ifrsys.com
8 *
9 * [31-AUG-98] triemer
10 * Changed IRQ to use Harald's dec internals interrupts.h
11 * removed base_addr code - moving address assignment to setup.c
12 * Changed name of dz_init to rs_init to be consistent with tc code
13 * [13-NOV-98] triemer fixed code to receive characters
14 * after patches by harald to irq code.
15 * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
16 * field from "current" - somewhere between 2.1.121 and 2.1.131
17 Qua Jun 27 15:02:26 BRT 2001
18 * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups
19 *
20 * Parts (C) 1999 David Airlie, airlied@linux.ie
21 * [07-SEP-99] Bugfixes
22 *
23 * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
24 * Converted to new serial core
25 */
27 #undef DEBUG_DZ
29 #include <linux/module.h>
30 #include <linux/interrupt.h>
31 #include <linux/init.h>
32 #include <linux/console.h>
33 #include <linux/tty.h>
34 #include <linux/tty_flip.h>
35 #include <linux/serial_core.h>
36 #include <linux/serial.h>
38 #include <asm/bootinfo.h>
39 #include <asm/dec/interrupts.h>
40 #include <asm/dec/kn01.h>
41 #include <asm/dec/kn02.h>
42 #include <asm/dec/machtype.h>
43 #include <asm/dec/prom.h>
44 #include <asm/irq.h>
45 #include <asm/system.h>
46 #include <asm/uaccess.h>
48 #define CONSOLE_LINE (3) /* for definition of struct console */
50 #include "dz.h"
52 #define DZ_INTR_DEBUG 1
54 static char *dz_name = "DECstation DZ serial driver version ";
55 static char *dz_version = "1.02";
57 struct dz_port {
58 struct uart_port port;
59 unsigned int cflag;
60 };
62 static struct dz_port dz_ports[DZ_NB_PORT];
64 #ifdef DEBUG_DZ
65 /*
66 * debugging code to send out chars via prom
67 */
68 static void debug_console(const char *s, int count)
69 {
70 unsigned i;
72 for (i = 0; i < count; i++) {
73 if (*s == 10)
74 prom_printf("%c", 13);
75 prom_printf("%c", *s++);
76 }
77 }
78 #endif
80 /*
81 * ------------------------------------------------------------
82 * dz_in () and dz_out ()
83 *
84 * These routines are used to access the registers of the DZ
85 * chip, hiding relocation differences between implementation.
86 * ------------------------------------------------------------
87 */
89 static inline unsigned short dz_in(struct dz_port *dport, unsigned offset)
90 {
91 volatile unsigned short *addr =
92 (volatile unsigned short *) (dport->port.membase + offset);
93 return *addr;
94 }
96 static inline void dz_out(struct dz_port *dport, unsigned offset,
97 unsigned short value)
98 {
99 volatile unsigned short *addr =
100 (volatile unsigned short *) (dport->port.membase + offset);
101 *addr = value;
102 }
104 /*
105 * ------------------------------------------------------------
106 * rs_stop () and rs_start ()
107 *
108 * These routines are called before setting or resetting
109 * tty->stopped. They enable or disable transmitter interrupts,
110 * as necessary.
111 * ------------------------------------------------------------
112 */
114 static void dz_stop_tx(struct uart_port *uport)
115 {
116 struct dz_port *dport = (struct dz_port *)uport;
117 unsigned short tmp, mask = 1 << dport->port.line;
118 unsigned long flags;
120 spin_lock_irqsave(&dport->port.lock, flags);
121 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
122 tmp &= ~mask; /* clear the TX flag */
123 dz_out(dport, DZ_TCR, tmp);
124 spin_unlock_irqrestore(&dport->port.lock, flags);
125 }
127 static void dz_start_tx(struct uart_port *uport)
128 {
129 struct dz_port *dport = (struct dz_port *)uport;
130 unsigned short tmp, mask = 1 << dport->port.line;
131 unsigned long flags;
133 spin_lock_irqsave(&dport->port.lock, flags);
134 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
135 tmp |= mask; /* set the TX flag */
136 dz_out(dport, DZ_TCR, tmp);
137 spin_unlock_irqrestore(&dport->port.lock, flags);
138 }
140 static void dz_stop_rx(struct uart_port *uport)
141 {
142 struct dz_port *dport = (struct dz_port *)uport;
143 unsigned long flags;
145 spin_lock_irqsave(&dport->port.lock, flags);
146 dport->cflag &= ~DZ_CREAD;
147 dz_out(dport, DZ_LPR, dport->cflag);
148 spin_unlock_irqrestore(&dport->port.lock, flags);
149 }
151 static void dz_enable_ms(struct uart_port *port)
152 {
153 /* nothing to do */
154 }
156 /*
157 * ------------------------------------------------------------
158 * Here starts the interrupt handling routines. All of the
159 * following subroutines are declared as inline and are folded
160 * into dz_interrupt. They were separated out for readability's
161 * sake.
162 *
163 * Note: rs_interrupt() is a "fast" interrupt, which means that it
164 * runs with interrupts turned off. People who may want to modify
165 * rs_interrupt() should try to keep the interrupt handler as fast as
166 * possible. After you are done making modifications, it is not a bad
167 * idea to do:
168 *
169 * make drivers/serial/dz.s
170 *
171 * and look at the resulting assemble code in dz.s.
172 *
173 * ------------------------------------------------------------
174 */
176 /*
177 * ------------------------------------------------------------
178 * receive_char ()
179 *
180 * This routine deals with inputs from any lines.
181 * ------------------------------------------------------------
182 */
183 static inline void dz_receive_chars(struct dz_port *dport)
184 {
185 struct tty_struct *tty = NULL;
186 struct uart_icount *icount;
187 int ignore = 0;
188 unsigned short status, tmp;
189 unsigned char ch, flag;
191 /* this code is going to be a problem...
192 the call to tty_flip_buffer is going to need
193 to be rethought...
194 */
195 do {
196 status = dz_in(dport, DZ_RBUF);
198 /* punt so we don't get duplicate characters */
199 if (!(status & DZ_DVAL))
200 goto ignore_char;
203 ch = UCHAR(status); /* grab the char */
204 flag = TTY_NORMAL;
206 #if 0
207 if (info->is_console) {
208 if (ch == 0)
209 return; /* it's a break ... */
210 }
211 #endif
213 tty = dport->port.info->tty;/* now tty points to the proper dev */
214 icount = &dport->port.icount;
216 if (!tty)
217 break;
219 icount->rx++;
221 /* keep track of the statistics */
222 if (status & (DZ_OERR | DZ_FERR | DZ_PERR)) {
223 if (status & DZ_PERR) /* parity error */
224 icount->parity++;
225 else if (status & DZ_FERR) /* frame error */
226 icount->frame++;
227 if (status & DZ_OERR) /* overrun error */
228 icount->overrun++;
230 /* check to see if we should ignore the character
231 and mask off conditions that should be ignored
232 */
234 if (status & dport->port.ignore_status_mask) {
235 if (++ignore > 100)
236 break;
237 goto ignore_char;
238 }
239 /* mask off the error conditions we want to ignore */
240 tmp = status & dport->port.read_status_mask;
242 if (tmp & DZ_PERR) {
243 flag = TTY_PARITY;
244 #ifdef DEBUG_DZ
245 debug_console("PERR\n", 5);
246 #endif
247 } else if (tmp & DZ_FERR) {
248 flag = TTY_FRAME;
249 #ifdef DEBUG_DZ
250 debug_console("FERR\n", 5);
251 #endif
252 }
253 if (tmp & DZ_OERR) {
254 #ifdef DEBUG_DZ
255 debug_console("OERR\n", 5);
256 #endif
257 tty_insert_flip_char(tty, ch, flag);
258 ch = 0;
259 flag = TTY_OVERRUN;
260 }
261 }
262 tty_insert_flip_char(tty, ch, flag);
263 ignore_char:
264 ;
265 } while (status & DZ_DVAL);
267 if (tty)
268 tty_flip_buffer_push(tty);
269 }
271 /*
272 * ------------------------------------------------------------
273 * transmit_char ()
274 *
275 * This routine deals with outputs to any lines.
276 * ------------------------------------------------------------
277 */
278 static inline void dz_transmit_chars(struct dz_port *dport)
279 {
280 struct circ_buf *xmit = &dport->port.info->xmit;
281 unsigned char tmp;
283 if (dport->port.x_char) { /* XON/XOFF chars */
284 dz_out(dport, DZ_TDR, dport->port.x_char);
285 dport->port.icount.tx++;
286 dport->port.x_char = 0;
287 return;
288 }
289 /* if nothing to do or stopped or hardware stopped */
290 if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
291 dz_stop_tx(&dport->port);
292 return;
293 }
295 /*
296 * if something to do ... (rember the dz has no output fifo so we go
297 * one char at a time :-<
298 */
299 tmp = xmit->buf[xmit->tail];
300 xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
301 dz_out(dport, DZ_TDR, tmp);
302 dport->port.icount.tx++;
304 if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
305 uart_write_wakeup(&dport->port);
307 /* Are we done */
308 if (uart_circ_empty(xmit))
309 dz_stop_tx(&dport->port);
310 }
312 /*
313 * ------------------------------------------------------------
314 * check_modem_status ()
315 *
316 * Only valid for the MODEM line duh !
317 * ------------------------------------------------------------
318 */
319 static inline void check_modem_status(struct dz_port *dport)
320 {
321 unsigned short status;
323 /* if not ne modem line just return */
324 if (dport->port.line != DZ_MODEM)
325 return;
327 status = dz_in(dport, DZ_MSR);
329 /* it's easy, since DSR2 is the only bit in the register */
330 if (status)
331 dport->port.icount.dsr++;
332 }
334 /*
335 * ------------------------------------------------------------
336 * dz_interrupt ()
337 *
338 * this is the main interrupt routine for the DZ chip.
339 * It deals with the multiple ports.
340 * ------------------------------------------------------------
341 */
342 static irqreturn_t dz_interrupt(int irq, void *dev, struct pt_regs *regs)
343 {
344 struct dz_port *dport;
345 unsigned short status;
347 /* get the reason why we just got an irq */
348 status = dz_in((struct dz_port *)dev, DZ_CSR);
349 dport = &dz_ports[LINE(status)];
351 if (status & DZ_RDONE)
352 dz_receive_chars(dport);
354 if (status & DZ_TRDY)
355 dz_transmit_chars(dport);
357 /* FIXME: what about check modem status??? --rmk */
359 return IRQ_HANDLED;
360 }
362 /*
363 * -------------------------------------------------------------------
364 * Here ends the DZ interrupt routines.
365 * -------------------------------------------------------------------
366 */
368 static unsigned int dz_get_mctrl(struct uart_port *uport)
369 {
370 struct dz_port *dport = (struct dz_port *)uport;
371 unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
373 if (dport->port.line == DZ_MODEM) {
374 /*
375 * CHECKME: This is a guess from the other code... --rmk
376 */
377 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
378 mctrl &= ~TIOCM_DSR;
379 }
381 return mctrl;
382 }
384 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
385 {
386 struct dz_port *dport = (struct dz_port *)uport;
387 unsigned short tmp;
389 if (dport->port.line == DZ_MODEM) {
390 tmp = dz_in(dport, DZ_TCR);
391 if (mctrl & TIOCM_DTR)
392 tmp &= ~DZ_MODEM_DTR;
393 else
394 tmp |= DZ_MODEM_DTR;
395 dz_out(dport, DZ_TCR, tmp);
396 }
397 }
399 /*
400 * -------------------------------------------------------------------
401 * startup ()
402 *
403 * various initialization tasks
404 * -------------------------------------------------------------------
405 */
406 static int dz_startup(struct uart_port *uport)
407 {
408 struct dz_port *dport = (struct dz_port *)uport;
409 unsigned long flags;
410 unsigned short tmp;
412 /* The dz lines for the mouse/keyboard must be
413 * opened using their respective drivers.
414 */
415 if ((dport->port.line == DZ_KEYBOARD) ||
416 (dport->port.line == DZ_MOUSE))
417 return -ENODEV;
419 spin_lock_irqsave(&dport->port.lock, flags);
421 /* enable the interrupt and the scanning */
422 tmp = dz_in(dport, DZ_CSR);
423 tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
424 dz_out(dport, DZ_CSR, tmp);
426 spin_unlock_irqrestore(&dport->port.lock, flags);
428 return 0;
429 }
431 /*
432 * -------------------------------------------------------------------
433 * shutdown ()
434 *
435 * This routine will shutdown a serial port; interrupts are disabled, and
436 * DTR is dropped if the hangup on close termio flag is on.
437 * -------------------------------------------------------------------
438 */
439 static void dz_shutdown(struct uart_port *uport)
440 {
441 dz_stop_tx(uport);
442 }
444 /*
445 * get_lsr_info - get line status register info
446 *
447 * Purpose: Let user call ioctl() to get info when the UART physically
448 * is emptied. On bus types like RS485, the transmitter must
449 * release the bus after transmitting. This must be done when
450 * the transmit shift register is empty, not be done when the
451 * transmit holding register is empty. This functionality
452 * allows an RS485 driver to be written in user space.
453 */
454 static unsigned int dz_tx_empty(struct uart_port *uport)
455 {
456 struct dz_port *dport = (struct dz_port *)uport;
457 unsigned short status = dz_in(dport, DZ_LPR);
459 /* FIXME: this appears to be obviously broken --rmk. */
460 return status ? TIOCSER_TEMT : 0;
461 }
463 static void dz_break_ctl(struct uart_port *uport, int break_state)
464 {
465 struct dz_port *dport = (struct dz_port *)uport;
466 unsigned long flags;
467 unsigned short tmp, mask = 1 << uport->line;
469 spin_lock_irqsave(&uport->lock, flags);
470 tmp = dz_in(dport, DZ_TCR);
471 if (break_state)
472 tmp |= mask;
473 else
474 tmp &= ~mask;
475 dz_out(dport, DZ_TCR, tmp);
476 spin_unlock_irqrestore(&uport->lock, flags);
477 }
479 static void dz_set_termios(struct uart_port *uport, struct termios *termios,
480 struct termios *old_termios)
481 {
482 struct dz_port *dport = (struct dz_port *)uport;
483 unsigned long flags;
484 unsigned int cflag, baud;
486 cflag = dport->port.line;
488 switch (termios->c_cflag & CSIZE) {
489 case CS5:
490 cflag |= DZ_CS5;
491 break;
492 case CS6:
493 cflag |= DZ_CS6;
494 break;
495 case CS7:
496 cflag |= DZ_CS7;
497 break;
498 case CS8:
499 default:
500 cflag |= DZ_CS8;
501 }
503 if (termios->c_cflag & CSTOPB)
504 cflag |= DZ_CSTOPB;
505 if (termios->c_cflag & PARENB)
506 cflag |= DZ_PARENB;
507 if (termios->c_cflag & PARODD)
508 cflag |= DZ_PARODD;
510 baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
511 switch (baud) {
512 case 50:
513 cflag |= DZ_B50;
514 break;
515 case 75:
516 cflag |= DZ_B75;
517 break;
518 case 110:
519 cflag |= DZ_B110;
520 break;
521 case 134:
522 cflag |= DZ_B134;
523 break;
524 case 150:
525 cflag |= DZ_B150;
526 break;
527 case 300:
528 cflag |= DZ_B300;
529 break;
530 case 600:
531 cflag |= DZ_B600;
532 break;
533 case 1200:
534 cflag |= DZ_B1200;
535 break;
536 case 1800:
537 cflag |= DZ_B1800;
538 break;
539 case 2000:
540 cflag |= DZ_B2000;
541 break;
542 case 2400:
543 cflag |= DZ_B2400;
544 break;
545 case 3600:
546 cflag |= DZ_B3600;
547 break;
548 case 4800:
549 cflag |= DZ_B4800;
550 break;
551 case 7200:
552 cflag |= DZ_B7200;
553 break;
554 case 9600:
555 default:
556 cflag |= DZ_B9600;
557 }
559 if (termios->c_cflag & CREAD)
560 cflag |= DZ_RXENAB;
562 spin_lock_irqsave(&dport->port.lock, flags);
564 dz_out(dport, DZ_LPR, cflag);
565 dport->cflag = cflag;
567 /* setup accept flag */
568 dport->port.read_status_mask = DZ_OERR;
569 if (termios->c_iflag & INPCK)
570 dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
572 /* characters to ignore */
573 uport->ignore_status_mask = 0;
574 if (termios->c_iflag & IGNPAR)
575 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
577 spin_unlock_irqrestore(&dport->port.lock, flags);
578 }
580 static const char *dz_type(struct uart_port *port)
581 {
582 return "DZ";
583 }
585 static void dz_release_port(struct uart_port *port)
586 {
587 /* nothing to do */
588 }
590 static int dz_request_port(struct uart_port *port)
591 {
592 return 0;
593 }
595 static void dz_config_port(struct uart_port *port, int flags)
596 {
597 if (flags & UART_CONFIG_TYPE)
598 port->type = PORT_DZ;
599 }
601 /*
602 * verify the new serial_struct (for TIOCSSERIAL).
603 */
604 static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
605 {
606 int ret = 0;
607 if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
608 ret = -EINVAL;
609 if (ser->irq != port->irq)
610 ret = -EINVAL;
611 return ret;
612 }
614 static struct uart_ops dz_ops = {
615 .tx_empty = dz_tx_empty,
616 .get_mctrl = dz_get_mctrl,
617 .set_mctrl = dz_set_mctrl,
618 .stop_tx = dz_stop_tx,
619 .start_tx = dz_start_tx,
620 .stop_rx = dz_stop_rx,
621 .enable_ms = dz_enable_ms,
622 .break_ctl = dz_break_ctl,
623 .startup = dz_startup,
624 .shutdown = dz_shutdown,
625 .set_termios = dz_set_termios,
626 .type = dz_type,
627 .release_port = dz_release_port,
628 .request_port = dz_request_port,
629 .config_port = dz_config_port,
630 .verify_port = dz_verify_port,
631 };
633 static void __init dz_init_ports(void)
634 {
635 static int first = 1;
636 struct dz_port *dport;
637 unsigned long base;
638 int i;
640 if (!first)
641 return;
642 first = 0;
644 if (mips_machtype == MACH_DS23100 ||
645 mips_machtype == MACH_DS5100)
646 base = CKSEG1ADDR(KN01_SLOT_BASE + KN01_DZ11);
647 else
648 base = CKSEG1ADDR(KN02_SLOT_BASE + KN02_DZ11);
650 for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
651 spin_lock_init(&dport->port.lock);
652 dport->port.membase = (char *) base;
653 dport->port.iotype = UPIO_PORT;
654 dport->port.irq = dec_interrupt[DEC_IRQ_DZ11];
655 dport->port.line = i;
656 dport->port.fifosize = 1;
657 dport->port.ops = &dz_ops;
658 dport->port.flags = UPF_BOOT_AUTOCONF;
659 }
660 }
662 static void dz_reset(struct dz_port *dport)
663 {
664 dz_out(dport, DZ_CSR, DZ_CLR);
666 while (dz_in(dport, DZ_CSR) & DZ_CLR);
667 /* FIXME: cpu_relax? */
669 iob();
671 /* enable scanning */
672 dz_out(dport, DZ_CSR, DZ_MSE);
673 }
675 #ifdef CONFIG_SERIAL_DZ_CONSOLE
676 static void dz_console_putchar(struct uart_port *uport, int ch)
677 {
678 struct dz_port *dport = (struct dz_port *)uport;
679 unsigned long flags;
680 int loops = 2500;
681 unsigned short tmp = (unsigned char)ch;
682 /* this code sends stuff out to serial device - spinning its
683 wheels and waiting. */
685 spin_lock_irqsave(&dport->port.lock, flags);
687 /* spin our wheels */
688 while (((dz_in(dport, DZ_CSR) & DZ_TRDY) != DZ_TRDY) && loops--)
689 /* FIXME: cpu_relax, udelay? --rmk */
690 ;
692 /* Actually transmit the character. */
693 dz_out(dport, DZ_TDR, tmp);
695 spin_unlock_irqrestore(&dport->port.lock, flags);
696 }
698 /*
699 * -------------------------------------------------------------------
700 * dz_console_print ()
701 *
702 * dz_console_print is registered for printk.
703 * The console must be locked when we get here.
704 * -------------------------------------------------------------------
705 */
706 static void dz_console_print(struct console *cons,
707 const char *str,
708 unsigned int count)
709 {
710 struct dz_port *dport = &dz_ports[CONSOLE_LINE];
711 #ifdef DEBUG_DZ
712 prom_printf((char *) str);
713 #endif
714 uart_console_write(&dport->port, str, count, dz_console_putchar);
715 }
717 static int __init dz_console_setup(struct console *co, char *options)
718 {
719 struct dz_port *dport = &dz_ports[CONSOLE_LINE];
720 int baud = 9600;
721 int bits = 8;
722 int parity = 'n';
723 int flow = 'n';
724 int ret;
725 unsigned short mask, tmp;
727 if (options)
728 uart_parse_options(options, &baud, &parity, &bits, &flow);
730 dz_reset(dport);
732 ret = uart_set_options(&dport->port, co, baud, parity, bits, flow);
733 if (ret == 0) {
734 mask = 1 << dport->port.line;
735 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
736 if (!(tmp & mask)) {
737 tmp |= mask; /* set the TX flag */
738 dz_out(dport, DZ_TCR, tmp);
739 }
740 }
742 return ret;
743 }
745 static struct console dz_sercons =
746 {
747 .name = "ttyS",
748 .write = dz_console_print,
749 .device = uart_console_device,
750 .setup = dz_console_setup,
751 .flags = CON_CONSDEV | CON_PRINTBUFFER,
752 .index = CONSOLE_LINE,
753 };
755 void __init dz_serial_console_init(void)
756 {
757 dz_init_ports();
759 register_console(&dz_sercons);
760 }
762 #define SERIAL_DZ_CONSOLE &dz_sercons
763 #else
764 #define SERIAL_DZ_CONSOLE NULL
765 #endif /* CONFIG_SERIAL_DZ_CONSOLE */
767 static struct uart_driver dz_reg = {
768 .owner = THIS_MODULE,
769 .driver_name = "serial",
770 .dev_name = "ttyS%d",
771 .major = TTY_MAJOR,
772 .minor = 64,
773 .nr = DZ_NB_PORT,
774 .cons = SERIAL_DZ_CONSOLE,
775 };
777 int __init dz_init(void)
778 {
779 unsigned long flags;
780 int ret, i;
782 printk("%s%s\n", dz_name, dz_version);
784 dz_init_ports();
786 save_flags(flags);
787 cli();
789 #ifndef CONFIG_SERIAL_DZ_CONSOLE
790 /* reset the chip */
791 dz_reset(&dz_ports[0]);
792 #endif
794 /* order matters here... the trick is that flags
795 is updated... in request_irq - to immediatedly obliterate
796 it is unwise. */
797 restore_flags(flags);
799 if (request_irq(dz_ports[0].port.irq, dz_interrupt,
800 IRQF_DISABLED, "DZ", &dz_ports[0]))
801 panic("Unable to register DZ interrupt");
803 ret = uart_register_driver(&dz_reg);
804 if (ret != 0)
805 return ret;
807 for (i = 0; i < DZ_NB_PORT; i++)
808 uart_add_one_port(&dz_reg, &dz_ports[i].port);
810 return ret;
811 }
813 MODULE_DESCRIPTION("DECstation DZ serial driver");
814 MODULE_LICENSE("GPL");