[TG3]: Set minimal hw interrupt mitigation.
[linux-2.6/verdex.git] / drivers / serial / dz.c
blob97824eeeafae51bdeb93cda017b21e223b7c8c9e
1 /*
2 * dz.c: Serial port driver for DECStations equiped
3 * with the DZ chipset.
5 * Copyright (C) 1998 Olivier A. D. Lebaillif
6 *
7 * Email: olivier.lebaillif@ifrsys.com
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
20 * Parts (C) 1999 David Airlie, airlied@linux.ie
21 * [07-SEP-99] Bugfixes
23 * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
24 * Converted to new serial core
27 #undef DEBUG_DZ
29 #include <linux/config.h>
30 #include <linux/module.h>
31 #include <linux/interrupt.h>
32 #include <linux/init.h>
33 #include <linux/console.h>
34 #include <linux/tty.h>
35 #include <linux/tty_flip.h>
36 #include <linux/serial_core.h>
37 #include <linux/serial.h>
39 #include <asm/bootinfo.h>
40 #include <asm/dec/interrupts.h>
41 #include <asm/dec/kn01.h>
42 #include <asm/dec/kn02.h>
43 #include <asm/dec/machtype.h>
44 #include <asm/dec/prom.h>
45 #include <asm/irq.h>
46 #include <asm/system.h>
47 #include <asm/uaccess.h>
49 #define CONSOLE_LINE (3) /* for definition of struct console */
51 #include "dz.h"
53 #define DZ_INTR_DEBUG 1
55 static char *dz_name = "DECstation DZ serial driver version ";
56 static char *dz_version = "1.02";
58 struct dz_port {
59 struct uart_port port;
60 unsigned int cflag;
63 static struct dz_port dz_ports[DZ_NB_PORT];
65 #ifdef DEBUG_DZ
67 * debugging code to send out chars via prom
69 static void debug_console(const char *s, int count)
71 unsigned i;
73 for (i = 0; i < count; i++) {
74 if (*s == 10)
75 prom_printf("%c", 13);
76 prom_printf("%c", *s++);
79 #endif
82 * ------------------------------------------------------------
83 * dz_in () and dz_out ()
85 * These routines are used to access the registers of the DZ
86 * chip, hiding relocation differences between implementation.
87 * ------------------------------------------------------------
90 static inline unsigned short dz_in(struct dz_port *dport, unsigned offset)
92 volatile unsigned short *addr =
93 (volatile unsigned short *) (dport->port.membase + offset);
94 return *addr;
97 static inline void dz_out(struct dz_port *dport, unsigned offset,
98 unsigned short value)
100 volatile unsigned short *addr =
101 (volatile unsigned short *) (dport->port.membase + offset);
102 *addr = value;
106 * ------------------------------------------------------------
107 * rs_stop () and rs_start ()
109 * These routines are called before setting or resetting
110 * tty->stopped. They enable or disable transmitter interrupts,
111 * as necessary.
112 * ------------------------------------------------------------
115 static void dz_stop_tx(struct uart_port *uport, unsigned int tty_stop)
117 struct dz_port *dport = (struct dz_port *)uport;
118 unsigned short tmp, mask = 1 << dport->port.line;
119 unsigned long flags;
121 spin_lock_irqsave(&dport->port.lock, flags);
122 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
123 tmp &= ~mask; /* clear the TX flag */
124 dz_out(dport, DZ_TCR, tmp);
125 spin_unlock_irqrestore(&dport->port.lock, flags);
128 static void dz_start_tx(struct uart_port *uport, unsigned int tty_start)
130 struct dz_port *dport = (struct dz_port *)uport;
131 unsigned short tmp, mask = 1 << dport->port.line;
132 unsigned long flags;
134 spin_lock_irqsave(&dport->port.lock, flags);
135 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
136 tmp |= mask; /* set the TX flag */
137 dz_out(dport, DZ_TCR, tmp);
138 spin_unlock_irqrestore(&dport->port.lock, flags);
141 static void dz_stop_rx(struct uart_port *uport)
143 struct dz_port *dport = (struct dz_port *)uport;
144 unsigned long flags;
146 spin_lock_irqsave(&dport->port.lock, flags);
147 dport->cflag &= ~DZ_CREAD;
148 dz_out(dport, DZ_LPR, dport->cflag);
149 spin_unlock_irqrestore(&dport->port.lock, flags);
152 static void dz_enable_ms(struct uart_port *port)
154 /* nothing to do */
158 * ------------------------------------------------------------
159 * Here starts the interrupt handling routines. All of the
160 * following subroutines are declared as inline and are folded
161 * into dz_interrupt. They were separated out for readability's
162 * sake.
164 * Note: rs_interrupt() is a "fast" interrupt, which means that it
165 * runs with interrupts turned off. People who may want to modify
166 * rs_interrupt() should try to keep the interrupt handler as fast as
167 * possible. After you are done making modifications, it is not a bad
168 * idea to do:
170 * make drivers/serial/dz.s
172 * and look at the resulting assemble code in dz.s.
174 * ------------------------------------------------------------
178 * ------------------------------------------------------------
179 * receive_char ()
181 * This routine deals with inputs from any lines.
182 * ------------------------------------------------------------
184 static inline void dz_receive_chars(struct dz_port *dport)
186 struct tty_struct *tty = NULL;
187 struct uart_icount *icount;
188 int ignore = 0;
189 unsigned short status, tmp;
190 unsigned char ch, flag;
192 /* this code is going to be a problem...
193 the call to tty_flip_buffer is going to need
194 to be rethought...
196 do {
197 status = dz_in(dport, DZ_RBUF);
199 /* punt so we don't get duplicate characters */
200 if (!(status & DZ_DVAL))
201 goto ignore_char;
204 ch = UCHAR(status); /* grab the char */
205 flag = TTY_NORMAL;
207 #if 0
208 if (info->is_console) {
209 if (ch == 0)
210 return; /* it's a break ... */
212 #endif
214 tty = dport->port.info->tty;/* now tty points to the proper dev */
215 icount = &dport->port.icount;
217 if (!tty)
218 break;
219 if (tty->flip.count >= TTY_FLIPBUF_SIZE)
220 break;
222 icount->rx++;
224 /* keep track of the statistics */
225 if (status & (DZ_OERR | DZ_FERR | DZ_PERR)) {
226 if (status & DZ_PERR) /* parity error */
227 icount->parity++;
228 else if (status & DZ_FERR) /* frame error */
229 icount->frame++;
230 if (status & DZ_OERR) /* overrun error */
231 icount->overrun++;
233 /* check to see if we should ignore the character
234 and mask off conditions that should be ignored
237 if (status & dport->port.ignore_status_mask) {
238 if (++ignore > 100)
239 break;
240 goto ignore_char;
242 /* mask off the error conditions we want to ignore */
243 tmp = status & dport->port.read_status_mask;
245 if (tmp & DZ_PERR) {
246 flag = TTY_PARITY;
247 #ifdef DEBUG_DZ
248 debug_console("PERR\n", 5);
249 #endif
250 } else if (tmp & DZ_FERR) {
251 flag = TTY_FRAME;
252 #ifdef DEBUG_DZ
253 debug_console("FERR\n", 5);
254 #endif
256 if (tmp & DZ_OERR) {
257 #ifdef DEBUG_DZ
258 debug_console("OERR\n", 5);
259 #endif
260 tty_insert_flip_char(tty, ch, flag);
261 ch = 0;
262 flag = TTY_OVERRUN;
265 tty_insert_flip_char(tty, ch, flag);
266 ignore_char:
267 } while (status & DZ_DVAL);
269 if (tty)
270 tty_flip_buffer_push(tty);
274 * ------------------------------------------------------------
275 * transmit_char ()
277 * This routine deals with outputs to any lines.
278 * ------------------------------------------------------------
280 static inline void dz_transmit_chars(struct dz_port *dport)
282 struct circ_buf *xmit = &dport->port.info->xmit;
283 unsigned char tmp;
285 if (dport->port.x_char) { /* XON/XOFF chars */
286 dz_out(dport, DZ_TDR, dport->port.x_char);
287 dport->port.icount.tx++;
288 dport->port.x_char = 0;
289 return;
291 /* if nothing to do or stopped or hardware stopped */
292 if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
293 dz_stop_tx(&dport->port, 0);
294 return;
298 * if something to do ... (rember the dz has no output fifo so we go
299 * one char at a time :-<
301 tmp = xmit->buf[xmit->tail];
302 xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
303 dz_out(dport, DZ_TDR, tmp);
304 dport->port.icount.tx++;
306 if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
307 uart_write_wakeup(&dport->port);
309 /* Are we done */
310 if (uart_circ_empty(xmit))
311 dz_stop_tx(&dport->port, 0);
315 * ------------------------------------------------------------
316 * check_modem_status ()
318 * Only valid for the MODEM line duh !
319 * ------------------------------------------------------------
321 static inline void check_modem_status(struct dz_port *dport)
323 unsigned short status;
325 /* if not ne modem line just return */
326 if (dport->port.line != DZ_MODEM)
327 return;
329 status = dz_in(dport, DZ_MSR);
331 /* it's easy, since DSR2 is the only bit in the register */
332 if (status)
333 dport->port.icount.dsr++;
337 * ------------------------------------------------------------
338 * dz_interrupt ()
340 * this is the main interrupt routine for the DZ chip.
341 * It deals with the multiple ports.
342 * ------------------------------------------------------------
344 static irqreturn_t dz_interrupt(int irq, void *dev, struct pt_regs *regs)
346 struct dz_port *dport;
347 unsigned short status;
349 /* get the reason why we just got an irq */
350 status = dz_in((struct dz_port *)dev, DZ_CSR);
351 dport = &dz_ports[LINE(status)];
353 if (status & DZ_RDONE)
354 dz_receive_chars(dport);
356 if (status & DZ_TRDY)
357 dz_transmit_chars(dport);
359 /* FIXME: what about check modem status??? --rmk */
361 return IRQ_HANDLED;
365 * -------------------------------------------------------------------
366 * Here ends the DZ interrupt routines.
367 * -------------------------------------------------------------------
370 static unsigned int dz_get_mctrl(struct uart_port *uport)
372 struct dz_port *dport = (struct dz_port *)uport;
373 unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
375 if (dport->port.line == DZ_MODEM) {
377 * CHECKME: This is a guess from the other code... --rmk
379 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
380 mctrl &= ~TIOCM_DSR;
383 return mctrl;
386 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
388 struct dz_port *dport = (struct dz_port *)uport;
389 unsigned short tmp;
391 if (dport->port.line == DZ_MODEM) {
392 tmp = dz_in(dport, DZ_TCR);
393 if (mctrl & TIOCM_DTR)
394 tmp &= ~DZ_MODEM_DTR;
395 else
396 tmp |= DZ_MODEM_DTR;
397 dz_out(dport, DZ_TCR, tmp);
402 * -------------------------------------------------------------------
403 * startup ()
405 * various initialization tasks
406 * -------------------------------------------------------------------
408 static int dz_startup(struct uart_port *uport)
410 struct dz_port *dport = (struct dz_port *)uport;
411 unsigned long flags;
412 unsigned short tmp;
414 /* The dz lines for the mouse/keyboard must be
415 * opened using their respective drivers.
417 if ((dport->port.line == DZ_KEYBOARD) ||
418 (dport->port.line == DZ_MOUSE))
419 return -ENODEV;
421 spin_lock_irqsave(&dport->port.lock, flags);
423 /* enable the interrupt and the scanning */
424 tmp = dz_in(dport, DZ_CSR);
425 tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
426 dz_out(dport, DZ_CSR, tmp);
428 spin_unlock_irqrestore(&dport->port.lock, flags);
430 return 0;
434 * -------------------------------------------------------------------
435 * shutdown ()
437 * This routine will shutdown a serial port; interrupts are disabled, and
438 * DTR is dropped if the hangup on close termio flag is on.
439 * -------------------------------------------------------------------
441 static void dz_shutdown(struct uart_port *uport)
443 dz_stop_tx(uport, 0);
447 * get_lsr_info - get line status register info
449 * Purpose: Let user call ioctl() to get info when the UART physically
450 * is emptied. On bus types like RS485, the transmitter must
451 * release the bus after transmitting. This must be done when
452 * the transmit shift register is empty, not be done when the
453 * transmit holding register is empty. This functionality
454 * allows an RS485 driver to be written in user space.
456 static unsigned int dz_tx_empty(struct uart_port *uport)
458 struct dz_port *dport = (struct dz_port *)uport;
459 unsigned short status = dz_in(dport, DZ_LPR);
461 /* FIXME: this appears to be obviously broken --rmk. */
462 return status ? TIOCSER_TEMT : 0;
465 static void dz_break_ctl(struct uart_port *uport, int break_state)
467 struct dz_port *dport = (struct dz_port *)uport;
468 unsigned long flags;
469 unsigned short tmp, mask = 1 << uport->line;
471 spin_lock_irqsave(&uport->lock, flags);
472 tmp = dz_in(dport, DZ_TCR);
473 if (break_state)
474 tmp |= mask;
475 else
476 tmp &= ~mask;
477 dz_out(dport, DZ_TCR, tmp);
478 spin_unlock_irqrestore(&uport->lock, flags);
481 static void dz_set_termios(struct uart_port *uport, struct termios *termios,
482 struct termios *old_termios)
484 struct dz_port *dport = (struct dz_port *)uport;
485 unsigned long flags;
486 unsigned int cflag, baud;
488 cflag = dport->port.line;
490 switch (termios->c_cflag & CSIZE) {
491 case CS5:
492 cflag |= DZ_CS5;
493 break;
494 case CS6:
495 cflag |= DZ_CS6;
496 break;
497 case CS7:
498 cflag |= DZ_CS7;
499 break;
500 case CS8:
501 default:
502 cflag |= DZ_CS8;
505 if (termios->c_cflag & CSTOPB)
506 cflag |= DZ_CSTOPB;
507 if (termios->c_cflag & PARENB)
508 cflag |= DZ_PARENB;
509 if (termios->c_cflag & PARODD)
510 cflag |= DZ_PARODD;
512 baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
513 switch (baud) {
514 case 50:
515 cflag |= DZ_B50;
516 break;
517 case 75:
518 cflag |= DZ_B75;
519 break;
520 case 110:
521 cflag |= DZ_B110;
522 break;
523 case 134:
524 cflag |= DZ_B134;
525 break;
526 case 150:
527 cflag |= DZ_B150;
528 break;
529 case 300:
530 cflag |= DZ_B300;
531 break;
532 case 600:
533 cflag |= DZ_B600;
534 break;
535 case 1200:
536 cflag |= DZ_B1200;
537 break;
538 case 1800:
539 cflag |= DZ_B1800;
540 break;
541 case 2000:
542 cflag |= DZ_B2000;
543 break;
544 case 2400:
545 cflag |= DZ_B2400;
546 break;
547 case 3600:
548 cflag |= DZ_B3600;
549 break;
550 case 4800:
551 cflag |= DZ_B4800;
552 break;
553 case 7200:
554 cflag |= DZ_B7200;
555 break;
556 case 9600:
557 default:
558 cflag |= DZ_B9600;
561 if (termios->c_cflag & CREAD)
562 cflag |= DZ_RXENAB;
564 spin_lock_irqsave(&dport->port.lock, flags);
566 dz_out(dport, DZ_LPR, cflag);
567 dport->cflag = cflag;
569 /* setup accept flag */
570 dport->port.read_status_mask = DZ_OERR;
571 if (termios->c_iflag & INPCK)
572 dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
574 /* characters to ignore */
575 uport->ignore_status_mask = 0;
576 if (termios->c_iflag & IGNPAR)
577 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
579 spin_unlock_irqrestore(&dport->port.lock, flags);
582 static const char *dz_type(struct uart_port *port)
584 return "DZ";
587 static void dz_release_port(struct uart_port *port)
589 /* nothing to do */
592 static int dz_request_port(struct uart_port *port)
594 return 0;
597 static void dz_config_port(struct uart_port *port, int flags)
599 if (flags & UART_CONFIG_TYPE)
600 port->type = PORT_DZ;
604 * verify the new serial_struct (for TIOCSSERIAL).
606 static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
608 int ret = 0;
609 if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
610 ret = -EINVAL;
611 if (ser->irq != port->irq)
612 ret = -EINVAL;
613 return ret;
616 static struct uart_ops dz_ops = {
617 .tx_empty = dz_tx_empty,
618 .get_mctrl = dz_get_mctrl,
619 .set_mctrl = dz_set_mctrl,
620 .stop_tx = dz_stop_tx,
621 .start_tx = dz_start_tx,
622 .stop_rx = dz_stop_rx,
623 .enable_ms = dz_enable_ms,
624 .break_ctl = dz_break_ctl,
625 .startup = dz_startup,
626 .shutdown = dz_shutdown,
627 .set_termios = dz_set_termios,
628 .type = dz_type,
629 .release_port = dz_release_port,
630 .request_port = dz_request_port,
631 .config_port = dz_config_port,
632 .verify_port = dz_verify_port,
635 static void __init dz_init_ports(void)
637 static int first = 1;
638 struct dz_port *dport;
639 unsigned long base;
640 int i;
642 if (!first)
643 return;
644 first = 0;
646 if (mips_machtype == MACH_DS23100 ||
647 mips_machtype == MACH_DS5100)
648 base = (unsigned long) KN01_DZ11_BASE;
649 else
650 base = (unsigned long) KN02_DZ11_BASE;
652 for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
653 spin_lock_init(&dport->port.lock);
654 dport->port.membase = (char *) base;
655 dport->port.iotype = SERIAL_IO_PORT;
656 dport->port.irq = dec_interrupt[DEC_IRQ_DZ11];
657 dport->port.line = i;
658 dport->port.fifosize = 1;
659 dport->port.ops = &dz_ops;
660 dport->port.flags = UPF_BOOT_AUTOCONF;
664 static void dz_reset(struct dz_port *dport)
666 dz_out(dport, DZ_CSR, DZ_CLR);
668 while (dz_in(dport, DZ_CSR) & DZ_CLR);
669 /* FIXME: cpu_relax? */
671 iob();
673 /* enable scanning */
674 dz_out(dport, DZ_CSR, DZ_MSE);
677 #ifdef CONFIG_SERIAL_DZ_CONSOLE
678 static void dz_console_put_char(struct dz_port *dport, unsigned char ch)
680 unsigned long flags;
681 int loops = 2500;
682 unsigned short tmp = ch;
683 /* this code sends stuff out to serial device - spinning its
684 wheels and waiting. */
686 spin_lock_irqsave(&dport->port.lock, flags);
688 /* spin our wheels */
689 while (((dz_in(dport, DZ_CSR) & DZ_TRDY) != DZ_TRDY) && loops--)
690 /* FIXME: cpu_relax, udelay? --rmk */
693 /* Actually transmit the character. */
694 dz_out(dport, DZ_TDR, tmp);
696 spin_unlock_irqrestore(&dport->port.lock, flags);
699 * -------------------------------------------------------------------
700 * dz_console_print ()
702 * dz_console_print is registered for printk.
703 * The console must be locked when we get here.
704 * -------------------------------------------------------------------
706 static void dz_console_print(struct console *cons,
707 const char *str,
708 unsigned int count)
710 struct dz_port *dport = &dz_ports[CONSOLE_LINE];
711 #ifdef DEBUG_DZ
712 prom_printf((char *) str);
713 #endif
714 while (count--) {
715 if (*str == '\n')
716 dz_console_put_char(dport, '\r');
717 dz_console_put_char(dport, *str++);
721 static int __init dz_console_setup(struct console *co, char *options)
723 struct dz_port *dport = &dz_ports[CONSOLE_LINE];
724 int baud = 9600;
725 int bits = 8;
726 int parity = 'n';
727 int flow = 'n';
728 int ret;
729 unsigned short mask, tmp;
731 if (options)
732 uart_parse_options(options, &baud, &parity, &bits, &flow);
734 dz_reset(dport);
736 ret = uart_set_options(&dport->port, co, baud, parity, bits, flow);
737 if (ret == 0) {
738 mask = 1 << dport->port.line;
739 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
740 if (!(tmp & mask)) {
741 tmp |= mask; /* set the TX flag */
742 dz_out(dport, DZ_TCR, tmp);
746 return ret;
749 static struct console dz_sercons =
751 .name = "ttyS",
752 .write = dz_console_print,
753 .device = uart_console_device,
754 .setup = dz_console_setup,
755 .flags = CON_CONSDEV | CON_PRINTBUFFER,
756 .index = CONSOLE_LINE,
759 void __init dz_serial_console_init(void)
761 dz_init_ports();
763 register_console(&dz_sercons);
766 #define SERIAL_DZ_CONSOLE &dz_sercons
767 #else
768 #define SERIAL_DZ_CONSOLE NULL
769 #endif /* CONFIG_SERIAL_DZ_CONSOLE */
771 static struct uart_driver dz_reg = {
772 .owner = THIS_MODULE,
773 .driver_name = "serial",
774 #ifdef CONFIG_DEVFS
775 .dev_name = "tts/%d",
776 #else
777 .dev_name = "ttyS%d",
778 #endif
779 .major = TTY_MAJOR,
780 .minor = 64,
781 .nr = DZ_NB_PORT,
782 .cons = SERIAL_DZ_CONSOLE,
785 int __init dz_init(void)
787 unsigned long flags;
788 int ret, i;
790 printk("%s%s\n", dz_name, dz_version);
792 dz_init_ports();
794 save_flags(flags);
795 cli();
797 #ifndef CONFIG_SERIAL_DZ_CONSOLE
798 /* reset the chip */
799 dz_reset(&dz_ports[0]);
800 #endif
802 /* order matters here... the trick is that flags
803 is updated... in request_irq - to immediatedly obliterate
804 it is unwise. */
805 restore_flags(flags);
807 if (request_irq(dz_ports[0].port.irq, dz_interrupt,
808 SA_INTERRUPT, "DZ", &dz_ports[0]))
809 panic("Unable to register DZ interrupt");
811 ret = uart_register_driver(&dz_reg);
812 if (ret != 0)
813 return ret;
815 for (i = 0; i < DZ_NB_PORT; i++)
816 uart_add_one_port(&dz_reg, &dz_ports[i].port);
818 return ret;
821 MODULE_DESCRIPTION("DECstation DZ serial driver");
822 MODULE_LICENSE("GPL");