[CPUFREQ] Fix the p4-clockmod N60 errata workaround.
[linux-2.6/mini2440.git] / drivers / serial / dz.c
blobba5541de673b1706079fc28e5423612e556f8006
1 /*
2 * dz.c: Serial port driver for DECStations equiped
3 * with the DZ chipset.
5 * Copyright (C) 1998 Olivier A. D. Lebaillif
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)
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)
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;
220 icount->rx++;
222 /* keep track of the statistics */
223 if (status & (DZ_OERR | DZ_FERR | DZ_PERR)) {
224 if (status & DZ_PERR) /* parity error */
225 icount->parity++;
226 else if (status & DZ_FERR) /* frame error */
227 icount->frame++;
228 if (status & DZ_OERR) /* overrun error */
229 icount->overrun++;
231 /* check to see if we should ignore the character
232 and mask off conditions that should be ignored
235 if (status & dport->port.ignore_status_mask) {
236 if (++ignore > 100)
237 break;
238 goto ignore_char;
240 /* mask off the error conditions we want to ignore */
241 tmp = status & dport->port.read_status_mask;
243 if (tmp & DZ_PERR) {
244 flag = TTY_PARITY;
245 #ifdef DEBUG_DZ
246 debug_console("PERR\n", 5);
247 #endif
248 } else if (tmp & DZ_FERR) {
249 flag = TTY_FRAME;
250 #ifdef DEBUG_DZ
251 debug_console("FERR\n", 5);
252 #endif
254 if (tmp & DZ_OERR) {
255 #ifdef DEBUG_DZ
256 debug_console("OERR\n", 5);
257 #endif
258 tty_insert_flip_char(tty, ch, flag);
259 ch = 0;
260 flag = TTY_OVERRUN;
263 tty_insert_flip_char(tty, ch, flag);
264 ignore_char:
266 } while (status & DZ_DVAL);
268 if (tty)
269 tty_flip_buffer_push(tty);
273 * ------------------------------------------------------------
274 * transmit_char ()
276 * This routine deals with outputs to any lines.
277 * ------------------------------------------------------------
279 static inline void dz_transmit_chars(struct dz_port *dport)
281 struct circ_buf *xmit = &dport->port.info->xmit;
282 unsigned char tmp;
284 if (dport->port.x_char) { /* XON/XOFF chars */
285 dz_out(dport, DZ_TDR, dport->port.x_char);
286 dport->port.icount.tx++;
287 dport->port.x_char = 0;
288 return;
290 /* if nothing to do or stopped or hardware stopped */
291 if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
292 dz_stop_tx(&dport->port);
293 return;
297 * if something to do ... (rember the dz has no output fifo so we go
298 * one char at a time :-<
300 tmp = xmit->buf[xmit->tail];
301 xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
302 dz_out(dport, DZ_TDR, tmp);
303 dport->port.icount.tx++;
305 if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
306 uart_write_wakeup(&dport->port);
308 /* Are we done */
309 if (uart_circ_empty(xmit))
310 dz_stop_tx(&dport->port);
314 * ------------------------------------------------------------
315 * check_modem_status ()
317 * Only valid for the MODEM line duh !
318 * ------------------------------------------------------------
320 static inline void check_modem_status(struct dz_port *dport)
322 unsigned short status;
324 /* if not ne modem line just return */
325 if (dport->port.line != DZ_MODEM)
326 return;
328 status = dz_in(dport, DZ_MSR);
330 /* it's easy, since DSR2 is the only bit in the register */
331 if (status)
332 dport->port.icount.dsr++;
336 * ------------------------------------------------------------
337 * dz_interrupt ()
339 * this is the main interrupt routine for the DZ chip.
340 * It deals with the multiple ports.
341 * ------------------------------------------------------------
343 static irqreturn_t dz_interrupt(int irq, void *dev, struct pt_regs *regs)
345 struct dz_port *dport;
346 unsigned short status;
348 /* get the reason why we just got an irq */
349 status = dz_in((struct dz_port *)dev, DZ_CSR);
350 dport = &dz_ports[LINE(status)];
352 if (status & DZ_RDONE)
353 dz_receive_chars(dport);
355 if (status & DZ_TRDY)
356 dz_transmit_chars(dport);
358 /* FIXME: what about check modem status??? --rmk */
360 return IRQ_HANDLED;
364 * -------------------------------------------------------------------
365 * Here ends the DZ interrupt routines.
366 * -------------------------------------------------------------------
369 static unsigned int dz_get_mctrl(struct uart_port *uport)
371 struct dz_port *dport = (struct dz_port *)uport;
372 unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
374 if (dport->port.line == DZ_MODEM) {
376 * CHECKME: This is a guess from the other code... --rmk
378 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
379 mctrl &= ~TIOCM_DSR;
382 return mctrl;
385 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
387 struct dz_port *dport = (struct dz_port *)uport;
388 unsigned short tmp;
390 if (dport->port.line == DZ_MODEM) {
391 tmp = dz_in(dport, DZ_TCR);
392 if (mctrl & TIOCM_DTR)
393 tmp &= ~DZ_MODEM_DTR;
394 else
395 tmp |= DZ_MODEM_DTR;
396 dz_out(dport, DZ_TCR, tmp);
401 * -------------------------------------------------------------------
402 * startup ()
404 * various initialization tasks
405 * -------------------------------------------------------------------
407 static int dz_startup(struct uart_port *uport)
409 struct dz_port *dport = (struct dz_port *)uport;
410 unsigned long flags;
411 unsigned short tmp;
413 /* The dz lines for the mouse/keyboard must be
414 * opened using their respective drivers.
416 if ((dport->port.line == DZ_KEYBOARD) ||
417 (dport->port.line == DZ_MOUSE))
418 return -ENODEV;
420 spin_lock_irqsave(&dport->port.lock, flags);
422 /* enable the interrupt and the scanning */
423 tmp = dz_in(dport, DZ_CSR);
424 tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
425 dz_out(dport, DZ_CSR, tmp);
427 spin_unlock_irqrestore(&dport->port.lock, flags);
429 return 0;
433 * -------------------------------------------------------------------
434 * shutdown ()
436 * This routine will shutdown a serial port; interrupts are disabled, and
437 * DTR is dropped if the hangup on close termio flag is on.
438 * -------------------------------------------------------------------
440 static void dz_shutdown(struct uart_port *uport)
442 dz_stop_tx(uport);
446 * get_lsr_info - get line status register info
448 * Purpose: Let user call ioctl() to get info when the UART physically
449 * is emptied. On bus types like RS485, the transmitter must
450 * release the bus after transmitting. This must be done when
451 * the transmit shift register is empty, not be done when the
452 * transmit holding register is empty. This functionality
453 * allows an RS485 driver to be written in user space.
455 static unsigned int dz_tx_empty(struct uart_port *uport)
457 struct dz_port *dport = (struct dz_port *)uport;
458 unsigned short status = dz_in(dport, DZ_LPR);
460 /* FIXME: this appears to be obviously broken --rmk. */
461 return status ? TIOCSER_TEMT : 0;
464 static void dz_break_ctl(struct uart_port *uport, int break_state)
466 struct dz_port *dport = (struct dz_port *)uport;
467 unsigned long flags;
468 unsigned short tmp, mask = 1 << uport->line;
470 spin_lock_irqsave(&uport->lock, flags);
471 tmp = dz_in(dport, DZ_TCR);
472 if (break_state)
473 tmp |= mask;
474 else
475 tmp &= ~mask;
476 dz_out(dport, DZ_TCR, tmp);
477 spin_unlock_irqrestore(&uport->lock, flags);
480 static void dz_set_termios(struct uart_port *uport, struct termios *termios,
481 struct termios *old_termios)
483 struct dz_port *dport = (struct dz_port *)uport;
484 unsigned long flags;
485 unsigned int cflag, baud;
487 cflag = dport->port.line;
489 switch (termios->c_cflag & CSIZE) {
490 case CS5:
491 cflag |= DZ_CS5;
492 break;
493 case CS6:
494 cflag |= DZ_CS6;
495 break;
496 case CS7:
497 cflag |= DZ_CS7;
498 break;
499 case CS8:
500 default:
501 cflag |= DZ_CS8;
504 if (termios->c_cflag & CSTOPB)
505 cflag |= DZ_CSTOPB;
506 if (termios->c_cflag & PARENB)
507 cflag |= DZ_PARENB;
508 if (termios->c_cflag & PARODD)
509 cflag |= DZ_PARODD;
511 baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
512 switch (baud) {
513 case 50:
514 cflag |= DZ_B50;
515 break;
516 case 75:
517 cflag |= DZ_B75;
518 break;
519 case 110:
520 cflag |= DZ_B110;
521 break;
522 case 134:
523 cflag |= DZ_B134;
524 break;
525 case 150:
526 cflag |= DZ_B150;
527 break;
528 case 300:
529 cflag |= DZ_B300;
530 break;
531 case 600:
532 cflag |= DZ_B600;
533 break;
534 case 1200:
535 cflag |= DZ_B1200;
536 break;
537 case 1800:
538 cflag |= DZ_B1800;
539 break;
540 case 2000:
541 cflag |= DZ_B2000;
542 break;
543 case 2400:
544 cflag |= DZ_B2400;
545 break;
546 case 3600:
547 cflag |= DZ_B3600;
548 break;
549 case 4800:
550 cflag |= DZ_B4800;
551 break;
552 case 7200:
553 cflag |= DZ_B7200;
554 break;
555 case 9600:
556 default:
557 cflag |= DZ_B9600;
560 if (termios->c_cflag & CREAD)
561 cflag |= DZ_RXENAB;
563 spin_lock_irqsave(&dport->port.lock, flags);
565 dz_out(dport, DZ_LPR, cflag);
566 dport->cflag = cflag;
568 /* setup accept flag */
569 dport->port.read_status_mask = DZ_OERR;
570 if (termios->c_iflag & INPCK)
571 dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
573 /* characters to ignore */
574 uport->ignore_status_mask = 0;
575 if (termios->c_iflag & IGNPAR)
576 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
578 spin_unlock_irqrestore(&dport->port.lock, flags);
581 static const char *dz_type(struct uart_port *port)
583 return "DZ";
586 static void dz_release_port(struct uart_port *port)
588 /* nothing to do */
591 static int dz_request_port(struct uart_port *port)
593 return 0;
596 static void dz_config_port(struct uart_port *port, int flags)
598 if (flags & UART_CONFIG_TYPE)
599 port->type = PORT_DZ;
603 * verify the new serial_struct (for TIOCSSERIAL).
605 static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
607 int ret = 0;
608 if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
609 ret = -EINVAL;
610 if (ser->irq != port->irq)
611 ret = -EINVAL;
612 return ret;
615 static struct uart_ops dz_ops = {
616 .tx_empty = dz_tx_empty,
617 .get_mctrl = dz_get_mctrl,
618 .set_mctrl = dz_set_mctrl,
619 .stop_tx = dz_stop_tx,
620 .start_tx = dz_start_tx,
621 .stop_rx = dz_stop_rx,
622 .enable_ms = dz_enable_ms,
623 .break_ctl = dz_break_ctl,
624 .startup = dz_startup,
625 .shutdown = dz_shutdown,
626 .set_termios = dz_set_termios,
627 .type = dz_type,
628 .release_port = dz_release_port,
629 .request_port = dz_request_port,
630 .config_port = dz_config_port,
631 .verify_port = dz_verify_port,
634 static void __init dz_init_ports(void)
636 static int first = 1;
637 struct dz_port *dport;
638 unsigned long base;
639 int i;
641 if (!first)
642 return;
643 first = 0;
645 if (mips_machtype == MACH_DS23100 ||
646 mips_machtype == MACH_DS5100)
647 base = CKSEG1ADDR(KN01_SLOT_BASE + KN01_DZ11);
648 else
649 base = CKSEG1ADDR(KN02_SLOT_BASE + KN02_DZ11);
651 for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
652 spin_lock_init(&dport->port.lock);
653 dport->port.membase = (char *) base;
654 dport->port.iotype = UPIO_PORT;
655 dport->port.irq = dec_interrupt[DEC_IRQ_DZ11];
656 dport->port.line = i;
657 dport->port.fifosize = 1;
658 dport->port.ops = &dz_ops;
659 dport->port.flags = UPF_BOOT_AUTOCONF;
663 static void dz_reset(struct dz_port *dport)
665 dz_out(dport, DZ_CSR, DZ_CLR);
667 while (dz_in(dport, DZ_CSR) & DZ_CLR);
668 /* FIXME: cpu_relax? */
670 iob();
672 /* enable scanning */
673 dz_out(dport, DZ_CSR, DZ_MSE);
676 #ifdef CONFIG_SERIAL_DZ_CONSOLE
677 static void dz_console_put_char(struct dz_port *dport, unsigned char ch)
679 unsigned long flags;
680 int loops = 2500;
681 unsigned short tmp = 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 */
692 /* Actually transmit the character. */
693 dz_out(dport, DZ_TDR, tmp);
695 spin_unlock_irqrestore(&dport->port.lock, flags);
698 * -------------------------------------------------------------------
699 * dz_console_print ()
701 * dz_console_print is registered for printk.
702 * The console must be locked when we get here.
703 * -------------------------------------------------------------------
705 static void dz_console_print(struct console *cons,
706 const char *str,
707 unsigned int count)
709 struct dz_port *dport = &dz_ports[CONSOLE_LINE];
710 #ifdef DEBUG_DZ
711 prom_printf((char *) str);
712 #endif
713 while (count--) {
714 if (*str == '\n')
715 dz_console_put_char(dport, '\r');
716 dz_console_put_char(dport, *str++);
720 static int __init dz_console_setup(struct console *co, char *options)
722 struct dz_port *dport = &dz_ports[CONSOLE_LINE];
723 int baud = 9600;
724 int bits = 8;
725 int parity = 'n';
726 int flow = 'n';
727 int ret;
728 unsigned short mask, tmp;
730 if (options)
731 uart_parse_options(options, &baud, &parity, &bits, &flow);
733 dz_reset(dport);
735 ret = uart_set_options(&dport->port, co, baud, parity, bits, flow);
736 if (ret == 0) {
737 mask = 1 << dport->port.line;
738 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
739 if (!(tmp & mask)) {
740 tmp |= mask; /* set the TX flag */
741 dz_out(dport, DZ_TCR, tmp);
745 return ret;
748 static struct console dz_sercons =
750 .name = "ttyS",
751 .write = dz_console_print,
752 .device = uart_console_device,
753 .setup = dz_console_setup,
754 .flags = CON_CONSDEV | CON_PRINTBUFFER,
755 .index = CONSOLE_LINE,
758 void __init dz_serial_console_init(void)
760 dz_init_ports();
762 register_console(&dz_sercons);
765 #define SERIAL_DZ_CONSOLE &dz_sercons
766 #else
767 #define SERIAL_DZ_CONSOLE NULL
768 #endif /* CONFIG_SERIAL_DZ_CONSOLE */
770 static struct uart_driver dz_reg = {
771 .owner = THIS_MODULE,
772 .driver_name = "serial",
773 #ifdef CONFIG_DEVFS
774 .dev_name = "tts/%d",
775 #else
776 .dev_name = "ttyS%d",
777 #endif
778 .major = TTY_MAJOR,
779 .minor = 64,
780 .nr = DZ_NB_PORT,
781 .cons = SERIAL_DZ_CONSOLE,
784 int __init dz_init(void)
786 unsigned long flags;
787 int ret, i;
789 printk("%s%s\n", dz_name, dz_version);
791 dz_init_ports();
793 save_flags(flags);
794 cli();
796 #ifndef CONFIG_SERIAL_DZ_CONSOLE
797 /* reset the chip */
798 dz_reset(&dz_ports[0]);
799 #endif
801 /* order matters here... the trick is that flags
802 is updated... in request_irq - to immediatedly obliterate
803 it is unwise. */
804 restore_flags(flags);
806 if (request_irq(dz_ports[0].port.irq, dz_interrupt,
807 SA_INTERRUPT, "DZ", &dz_ports[0]))
808 panic("Unable to register DZ interrupt");
810 ret = uart_register_driver(&dz_reg);
811 if (ret != 0)
812 return ret;
814 for (i = 0; i < DZ_NB_PORT; i++)
815 uart_add_one_port(&dz_reg, &dz_ports[i].port);
817 return ret;
820 MODULE_DESCRIPTION("DECstation DZ serial driver");
821 MODULE_LICENSE("GPL");