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zs.c revision 1.13
      1 /*	$NetBSD: zs.c,v 1.13 1997/11/02 08:05:09 mycroft Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Gordon W. Ross.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Zilog Z8530 Dual UART driver (machine-dependent part)
     41  *
     42  * Runs two serial lines per chip using slave drivers.
     43  * Plain tty/async lines use the zs_async slave.
     44  *
     45  * Modified for NetBSD/mvme68k by Jason R. Thorpe <thorpej (at) NetBSD.ORG>
     46  */
     47 
     48 #include <sys/param.h>
     49 #include <sys/systm.h>
     50 #include <sys/conf.h>
     51 #include <sys/device.h>
     52 #include <sys/file.h>
     53 #include <sys/ioctl.h>
     54 #include <sys/kernel.h>
     55 #include <sys/proc.h>
     56 #include <sys/tty.h>
     57 #include <sys/time.h>
     58 #include <sys/syslog.h>
     59 
     60 #include <dev/cons.h>
     61 #include <dev/ic/z8530reg.h>
     62 #include <machine/z8530var.h>
     63 
     64 #include <machine/cpu.h>
     65 
     66 #include <mvme68k/dev/zsvar.h>
     67 
     68 /*
     69  * Some warts needed by z8530tty.c -
     70  * The default parity REALLY needs to be the same as the PROM uses,
     71  * or you can not see messages done with printf during boot-up...
     72  */
     73 int zs_def_cflag = (CREAD | CS8 | HUPCL);
     74 /* XXX Shouldn't hardcode the minor number... */
     75 int zs_major = 12;
     76 
     77 static u_long zs_sir;	/* software interrupt cookie */
     78 
     79 /* Flags from zscnprobe() */
     80 static int zs_hwflags[NZSC][2];
     81 
     82 /* Default speed for each channel */
     83 static int zs_defspeed[NZSC][2] = {
     84 	{ 9600, 	/* port 1 */
     85 	  9600 },	/* port 2 */
     86 	{ 9600, 	/* port 3 */
     87 	  9600 },	/* port 4 */
     88 };
     89 
     90 static struct zs_chanstate zs_conschan_store;
     91 static struct zs_chanstate *zs_conschan;
     92 
     93 u_char zs_init_reg[16] = {
     94 	0,	/* 0: CMD (reset, etc.) */
     95 	0,	/* 1: No interrupts yet. */
     96 	0x18 + ZSHARD_PRI,	/* IVECT */
     97 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
     98 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
     99 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
    100 	0,	/* 6: TXSYNC/SYNCLO */
    101 	0,	/* 7: RXSYNC/SYNCHI */
    102 	0,	/* 8: alias for data port */
    103 	ZSWR9_MASTER_IE,
    104 	0,	/*10: Misc. TX/RX control bits */
    105 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
    106 	14,	/*12: BAUDLO (default=9600) */
    107 	0,	/*13: BAUDHI (default=9600) */
    108 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
    109 	ZSWR15_BREAK_IE | ZSWR15_DCD_IE,
    110 };
    111 
    112 
    113 /****************************************************************
    114  * Autoconfig
    115  ****************************************************************/
    116 
    117 /* Definition of the driver for autoconfig. */
    118 static int	zsc_print __P((void *, const char *name));
    119 
    120 struct cfdriver zsc_cd = {
    121 	NULL, "zsc", DV_DULL
    122 };
    123 
    124 static int zs_get_speed __P((struct zs_chanstate *));
    125 
    126 
    127 /*
    128  * Configure children of an SCC.
    129  */
    130 void
    131 zs_config(zsc, chan_addr)
    132 	struct zsc_softc *zsc;
    133 	struct zschan *(*chan_addr) __P((int, int));
    134 {
    135 	struct zsc_attach_args zsc_args;
    136 	volatile struct zschan *zc;
    137 	struct zs_chanstate *cs;
    138 	int zsc_unit, channel, s;
    139 
    140 	zsc_unit = zsc->zsc_dev.dv_unit;
    141 	printf(": Zilog 8530 SCC\n");
    142 
    143 	/*
    144 	 * Initialize software state for each channel.
    145 	 */
    146 	for (channel = 0; channel < 2; channel++) {
    147 		zsc_args.channel = channel;
    148 		zsc_args.hwflags = zs_hwflags[zsc_unit][channel];
    149 		cs = &zsc->zsc_cs_store[channel];
    150 		zsc->zsc_cs[channel] = cs;
    151 
    152 		/*
    153 		 * If we're the console, copy the channel state, and
    154 		 * adjust the console channel pointer.
    155 		 */
    156 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE) {
    157 			bcopy(zs_conschan, cs, sizeof(struct zs_chanstate));
    158 			zs_conschan = cs;
    159 		} else {
    160 			zc = (*chan_addr)(zsc_unit, channel);
    161 			cs->cs_reg_csr  = &zc->zc_csr;
    162 			cs->cs_reg_data = &zc->zc_data;
    163 			bcopy(zs_init_reg, cs->cs_creg, 16);
    164 			bcopy(zs_init_reg, cs->cs_preg, 16);
    165 			cs->cs_defspeed = zs_defspeed[zsc_unit][channel];
    166 		}
    167 		cs->cs_defcflag = zs_def_cflag;
    168 
    169 		/* Make these correspond to cs_defcflag (-crtscts) */
    170 		cs->cs_rr0_dcd = ZSRR0_DCD;
    171 		cs->cs_rr0_cts = 0;
    172 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    173 		cs->cs_wr5_rts = 0;
    174 
    175 		cs->cs_channel = channel;
    176 		cs->cs_private = NULL;
    177 		cs->cs_ops = &zsops_null;
    178 		cs->cs_brg_clk = PCLK / 16;
    179 
    180 		/*
    181 		 * Clear the master interrupt enable.
    182 		 * The INTENA is common to both channels,
    183 		 * so just do it on the A channel.
    184 		 */
    185 		if (channel == 0) {
    186 			zs_write_reg(cs, 9, 0);
    187 		}
    188 
    189 		/*
    190 		 * Look for a child driver for this channel.
    191 		 * The child attach will setup the hardware.
    192 		 */
    193 		if (!config_found(&zsc->zsc_dev, (void *)&zsc_args, zsc_print)) {
    194 			/* No sub-driver.  Just reset it. */
    195 			u_char reset = (channel == 0) ?
    196 				ZSWR9_A_RESET : ZSWR9_B_RESET;
    197 			s = splzs();
    198 			zs_write_reg(cs,  9, reset);
    199 			splx(s);
    200 		}
    201 	}
    202 
    203 	/*
    204 	 * Allocate a software interrupt cookie.  Note that the argument
    205 	 * "zsc" is never actually used in the software interrupt
    206 	 * handler.
    207 	 */
    208 	if (zs_sir == 0)
    209 		zs_sir = allocate_sir(zssoft, zsc);
    210 }
    211 
    212 static int
    213 zsc_print(aux, name)
    214 	void *aux;
    215 	const char *name;
    216 {
    217 	struct zsc_attach_args *args = aux;
    218 
    219 	if (name != NULL)
    220 		printf("%s: ", name);
    221 
    222 	if (args->channel != -1)
    223 		printf(" channel %d", args->channel);
    224 
    225 	return UNCONF;
    226 }
    227 
    228 static int zssoftpending;
    229 
    230 /*
    231  * Our ZS chips all share a common, autovectored interrupt,
    232  * so we have to look at all of them on each interrupt.
    233  */
    234 int
    235 zshard(arg)
    236 	void *arg;
    237 {
    238 	register struct zsc_softc *zsc;
    239 	register int unit, rval;
    240 
    241 	rval = 0;
    242 	for (unit = 0; unit < zsc_cd.cd_ndevs; unit++) {
    243 		zsc = zsc_cd.cd_devs[unit];
    244 		if (zsc == NULL)
    245 			continue;
    246 		rval |= zsc_intr_hard(zsc);
    247 		if ((zsc->zsc_cs[0]->cs_softreq) ||
    248 			(zsc->zsc_cs[1]->cs_softreq))
    249 		{
    250 			/* zsc_req_softint(zsc); */
    251 			/* We are at splzs here, so no need to lock. */
    252 			if (zssoftpending == 0) {
    253 				zssoftpending = zs_sir;
    254 				setsoftint(zs_sir);
    255 			}
    256 		}
    257 	}
    258 	return (rval);
    259 }
    260 
    261 /*
    262  * Similar scheme as for zshard (look at all of them)
    263  */
    264 int
    265 zssoft(arg)
    266 	void *arg;
    267 {
    268 	register struct zsc_softc *zsc;
    269 	register int unit;
    270 
    271 	/* This is not the only ISR on this IPL. */
    272 	if (zssoftpending == 0)
    273 		return (0);
    274 
    275 	/*
    276 	 * The soft intr. bit will be set by zshard only if
    277 	 * the variable zssoftpending is zero.
    278 	 */
    279 	zssoftpending = 0;
    280 
    281 	for (unit = 0; unit < zsc_cd.cd_ndevs; ++unit) {
    282 		zsc = zsc_cd.cd_devs[unit];
    283 		if (zsc == NULL)
    284 			continue;
    285 		(void) zsc_intr_soft(zsc);
    286 	}
    287 	return (1);
    288 }
    289 
    290 
    291 /*
    292  * Compute the current baud rate given a ZSCC channel.
    293  */
    294 static int
    295 zs_get_speed(cs)
    296 	struct zs_chanstate *cs;
    297 {
    298 	int tconst;
    299 
    300 	tconst = zs_read_reg(cs, 12);
    301 	tconst |= zs_read_reg(cs, 13) << 8;
    302 	return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
    303 }
    304 
    305 /*
    306  * MD functions for setting the baud rate and control modes.
    307  */
    308 int
    309 zs_set_speed(cs, bps)
    310 	struct zs_chanstate *cs;
    311 	int bps;	/* bits per second */
    312 {
    313 	int tconst, real_bps;
    314 
    315 	if (bps == 0)
    316 		return (0);
    317 
    318 #ifdef	DIAGNOSTIC
    319 	if (cs->cs_brg_clk == 0)
    320 		panic("zs_set_speed");
    321 #endif
    322 
    323 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
    324 	if (tconst < 0)
    325 		return (EINVAL);
    326 
    327 	/* Convert back to make sure we can do it. */
    328 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
    329 
    330 	/* XXX - Allow some tolerance here? */
    331 	if (real_bps != bps)
    332 		return (EINVAL);
    333 
    334 	cs->cs_preg[12] = tconst;
    335 	cs->cs_preg[13] = tconst >> 8;
    336 
    337 	/* Caller will stuff the pending registers. */
    338 	return (0);
    339 }
    340 
    341 int
    342 zs_set_modes(cs, cflag)
    343 	struct zs_chanstate *cs;
    344 	int cflag;	/* bits per second */
    345 {
    346 	int s;
    347 
    348 	/*
    349 	 * Output hardware flow control on the chip is horrendous:
    350 	 * if carrier detect drops, the receiver is disabled, and if
    351 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
    352 	 * Therefore, NEVER set the HFC bit, and instead use the
    353 	 * status interrupt to detect CTS changes.
    354 	 */
    355 	s = splzs();
    356 	if ((cflag & (CLOCAL | MDMBUF)) != 0)
    357 		cs->cs_rr0_dcd = 0;
    358 	else
    359 		cs->cs_rr0_dcd = ZSRR0_DCD;
    360 	if ((cflag & CRTSCTS) != 0) {
    361 		cs->cs_wr5_dtr = ZSWR5_DTR;
    362 		cs->cs_wr5_rts = ZSWR5_RTS;
    363 		cs->cs_rr0_cts = ZSRR0_CTS;
    364 	} else if ((cflag & MDMBUF) != 0) {
    365 		cs->cs_wr5_dtr = 0;
    366 		cs->cs_wr5_rts = ZSWR5_DTR;
    367 		cs->cs_rr0_cts = ZSRR0_DCD;
    368 	} else {
    369 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    370 		cs->cs_wr5_rts = 0;
    371 		cs->cs_rr0_cts = 0;
    372 	}
    373 	splx(s);
    374 
    375 	/* Caller will stuff the pending registers. */
    376 	return (0);
    377 }
    378 
    379 
    380 /*
    381  * Read or write the chip with suitable delays.
    382  */
    383 
    384 u_char
    385 zs_read_reg(cs, reg)
    386 	struct zs_chanstate *cs;
    387 	u_char reg;
    388 {
    389 	u_char val;
    390 
    391 	*cs->cs_reg_csr = reg;
    392 	ZS_DELAY();
    393 	val = *cs->cs_reg_csr;
    394 	ZS_DELAY();
    395 	return val;
    396 }
    397 
    398 void
    399 zs_write_reg(cs, reg, val)
    400 	struct zs_chanstate *cs;
    401 	u_char reg, val;
    402 {
    403 	*cs->cs_reg_csr = reg;
    404 	ZS_DELAY();
    405 	*cs->cs_reg_csr = val;
    406 	ZS_DELAY();
    407 }
    408 
    409 u_char zs_read_csr(cs)
    410 	struct zs_chanstate *cs;
    411 {
    412 	register u_char val;
    413 
    414 	val = *cs->cs_reg_csr;
    415 	ZS_DELAY();
    416 	return val;
    417 }
    418 
    419 void  zs_write_csr(cs, val)
    420 	struct zs_chanstate *cs;
    421 	u_char val;
    422 {
    423 	*cs->cs_reg_csr = val;
    424 	ZS_DELAY();
    425 }
    426 
    427 u_char zs_read_data(cs)
    428 	struct zs_chanstate *cs;
    429 {
    430 	register u_char val;
    431 
    432 	val = *cs->cs_reg_data;
    433 	ZS_DELAY();
    434 	return val;
    435 }
    436 
    437 void  zs_write_data(cs, val)
    438 	struct zs_chanstate *cs;
    439 	u_char val;
    440 {
    441 	*cs->cs_reg_data = val;
    442 	ZS_DELAY();
    443 }
    444 
    445 /****************************************************************
    446  * Console support functions (MVME specific!)
    447  ****************************************************************/
    448 
    449 /*
    450  * Polled input char.
    451  */
    452 int
    453 zs_getc(arg)
    454 	void *arg;
    455 {
    456 	register struct zs_chanstate *cs = arg;
    457 	register int s, c, rr0, stat;
    458 
    459 	s = splhigh();
    460  top:
    461 	/* Wait for a character to arrive. */
    462 	do {
    463 		rr0 = *cs->cs_reg_csr;
    464 		ZS_DELAY();
    465 	} while ((rr0 & ZSRR0_RX_READY) == 0);
    466 
    467 	/* Read error register. */
    468 	stat = zs_read_reg(cs, 1) & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE);
    469 	if (stat) {
    470 		zs_write_csr(cs, ZSM_RESET_ERR);
    471 		goto top;
    472 	}
    473 
    474 	/* Read character. */
    475 	c = *cs->cs_reg_data;
    476 	ZS_DELAY();
    477 	splx(s);
    478 
    479 	return (c);
    480 }
    481 
    482 /*
    483  * Polled output char.
    484  */
    485 void
    486 zs_putc(arg, c)
    487 	void *arg;
    488 	int c;
    489 {
    490 	register struct zs_chanstate *cs = arg;
    491 	register int s, rr0;
    492 
    493 	s = splhigh();
    494 	/* Wait for transmitter to become ready. */
    495 	do {
    496 		rr0 = *cs->cs_reg_csr;
    497 		ZS_DELAY();
    498 	} while ((rr0 & ZSRR0_TX_READY) == 0);
    499 
    500 	*cs->cs_reg_data = c;
    501 	ZS_DELAY();
    502 	splx(s);
    503 }
    504 
    505 /*
    506  * Common parts of console init.
    507  */
    508 void
    509 zs_cnconfig(zsc_unit, channel, zc)
    510 	int zsc_unit, channel;
    511 	struct zschan *zc;
    512 {
    513 	struct zs_chanstate *cs;
    514 
    515 	/*
    516 	 * Pointer to channel state.  Later, the console channel
    517 	 * state is copied into the softc, and the console channel
    518 	 * pointer adjusted to point to the new copy.
    519 	 */
    520 	zs_conschan = cs = &zs_conschan_store;
    521 	zs_hwflags[zsc_unit][channel] = ZS_HWFLAG_CONSOLE;
    522 
    523 	/* Setup temporary chanstate. */
    524 	cs->cs_reg_csr  = &zc->zc_csr;
    525 	cs->cs_reg_data = &zc->zc_data;
    526 
    527 	/* Initialize the pending registers. */
    528 	bcopy(zs_init_reg, cs->cs_preg, 16);
    529 	cs->cs_preg[5] |= (ZSWR5_DTR | ZSWR5_RTS);
    530 
    531 	/* XXX: Preserve BAUD rate from boot loader. */
    532 	/* XXX: Also, why reset the chip here? -gwr */
    533 	/* cs->cs_defspeed = zs_get_speed(cs); */
    534 	cs->cs_defspeed = 9600;	/* XXX */
    535 
    536 	/* Clear the master interrupt enable. */
    537 	zs_write_reg(cs, 9, 0);
    538 
    539 	/* Reset the whole SCC chip. */
    540 	zs_write_reg(cs, 9, ZSWR9_HARD_RESET);
    541 
    542 	/* Copy "pending" to "current" and H/W. */
    543 	zs_loadchannelregs(cs);
    544 }
    545 
    546 /*
    547  * Polled console input putchar.
    548  */
    549 int
    550 zscngetc(dev)
    551 	dev_t dev;
    552 {
    553 	register struct zs_chanstate *cs = zs_conschan;
    554 	register int c;
    555 
    556 	c = zs_getc(cs);
    557 	return (c);
    558 }
    559 
    560 /*
    561  * Polled console output putchar.
    562  */
    563 void
    564 zscnputc(dev, c)
    565 	dev_t dev;
    566 	int c;
    567 {
    568 	register struct zs_chanstate *cs = zs_conschan;
    569 
    570 	zs_putc(cs, c);
    571 }
    572 
    573 /*
    574  * Handle user request to enter kernel debugger.
    575  */
    576 void
    577 zs_abort(cs)
    578 	struct zs_chanstate *cs;
    579 {
    580 	int rr0;
    581 
    582 	/* Wait for end of break to avoid PROM abort. */
    583 	/* XXX - Limit the wait? */
    584 	do {
    585 		rr0 = *cs->cs_reg_csr;
    586 		ZS_DELAY();
    587 	} while (rr0 & ZSRR0_BREAK);
    588 
    589 	mvme68k_abort("SERIAL LINE ABORT");
    590 }
    591