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zs.c revision 1.10
      1 /*	$NetBSD: zs.c,v 1.10 2006/03/28 17:38:24 thorpej 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 
     46 #include <sys/cdefs.h>
     47 __KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.10 2006/03/28 17:38:24 thorpej Exp $");
     48 
     49 #include "opt_ddb.h"
     50 
     51 #include <sys/param.h>
     52 #include <sys/systm.h>
     53 #include <sys/conf.h>
     54 #include <sys/device.h>
     55 #include <sys/file.h>
     56 #include <sys/ioctl.h>
     57 #include <sys/kernel.h>
     58 #include <sys/malloc.h>
     59 #include <sys/proc.h>
     60 #include <sys/tty.h>
     61 #include <sys/time.h>
     62 #include <sys/syslog.h>
     63 
     64 #include <dev/cons.h>
     65 #include <dev/ic/z8530reg.h>
     66 
     67 #include <machine/cpu.h>
     68 
     69 #include <machine/z8530var.h>
     70 #include <cesfic/dev/zsvar.h>
     71 
     72 int zs_getc __P((void*));
     73 void zs_putc __P((void*, int));
     74 
     75 static struct zs_chanstate zs_conschan_store;
     76 static int zs_hwflags[2][2];
     77 int zssoftpending;
     78 
     79 extern struct cfdriver zsc_cd;
     80 
     81 u_char zs_init_reg[16] = {
     82 	0,	/* 0: CMD (reset, etc.) */
     83 	0,	/* 1: No interrupts yet. */
     84 	0x18 + ZSHARD_PRI,	/* IVECT */
     85 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
     86 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
     87 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
     88 	0,	/* 6: TXSYNC/SYNCLO */
     89 	0,	/* 7: RXSYNC/SYNCHI */
     90 	0,	/* 8: alias for data port */
     91 	ZSWR9_MASTER_IE,
     92 	0,	/*10: Misc. TX/RX control bits */
     93 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
     94 	11,	/*12: BAUDLO (default=9600) */
     95 	0,	/*13: BAUDHI (default=9600) */
     96 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
     97 	ZSWR15_BREAK_IE | ZSWR15_DCD_IE,
     98 };
     99 
    100 static int zsc_print __P((void *, const char *));
    101 int zscngetc __P((dev_t));
    102 void zscnputc __P((dev_t, int));
    103 
    104 static struct consdev zscons = {
    105 	NULL, NULL,
    106 	zscngetc, zscnputc, nullcnpollc, NULL, NULL, NULL,
    107 	NODEV, 1
    108 };
    109 
    110 void
    111 zs_config(zsc, base)
    112 	struct zsc_softc *zsc;
    113         char *base;
    114 {
    115 	struct zsc_attach_args zsc_args;
    116 	struct zs_chanstate *cs;
    117 	int zsc_unit, channel, s;
    118 
    119 	zsc_unit = device_unit(&zsc->zsc_dev);
    120 	printf(": Zilog 8530 SCC\n");
    121 
    122 	/*
    123 	 * Initialize software state for each channel.
    124 	 */
    125 	for (channel = 0; channel < 2; channel++) {
    126 		zsc_args.channel = channel;
    127 		zsc_args.hwflags = zs_hwflags[zsc_unit][channel];
    128 
    129 		/*
    130 		 * If we're the console, copy the channel state, and
    131 		 * adjust the console channel pointer.
    132 		 */
    133 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE) {
    134 			cs = &zs_conschan_store;
    135 		} else {
    136 			cs = malloc(sizeof(struct zs_chanstate),
    137 				    M_DEVBUF, M_NOWAIT | M_ZERO);
    138 			if(channel==0){
    139 				cs->cs_reg_csr  = base+7;
    140 				cs->cs_reg_data = base+15;
    141 			} else {
    142 				cs->cs_reg_csr  = base+3;
    143 				cs->cs_reg_data = base+11;
    144 			}
    145 			bcopy(zs_init_reg, cs->cs_creg, 16);
    146 			bcopy(zs_init_reg, cs->cs_preg, 16);
    147 			cs->cs_defspeed = 9600;
    148 		}
    149 		zsc->zsc_cs[channel] = cs;
    150 		simple_lock_init(&cs->cs_lock);
    151 
    152 		cs->cs_defcflag = CREAD | CS8 | HUPCL;
    153 
    154 		/* Make these correspond to cs_defcflag (-crtscts) */
    155 		cs->cs_rr0_dcd = ZSRR0_DCD;
    156 		cs->cs_rr0_cts = 0;
    157 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    158 		cs->cs_wr5_rts = 0;
    159 
    160 		cs->cs_channel = channel;
    161 		cs->cs_private = NULL;
    162 		cs->cs_ops = &zsops_null;
    163 		cs->cs_brg_clk = 4000000 / 16;
    164 
    165 		/*
    166 		 * Clear the master interrupt enable.
    167 		 * The INTENA is common to both channels,
    168 		 * so just do it on the A channel.
    169 		 */
    170 		if (channel == 0) {
    171 			zs_write_reg(cs, 9, 0);
    172 		}
    173 
    174 		/*
    175 		 * Look for a child driver for this channel.
    176 		 * The child attach will setup the hardware.
    177 		 */
    178 		if (!config_found(&zsc->zsc_dev, (void *)&zsc_args, zsc_print)) {
    179 			/* No sub-driver.  Just reset it. */
    180 			u_char reset = (channel == 0) ?
    181 				ZSWR9_A_RESET : ZSWR9_B_RESET;
    182 			s = splzs();
    183 			zs_write_reg(cs,  9, reset);
    184 			splx(s);
    185 		}
    186 	}
    187 }
    188 
    189 static int
    190 zsc_print(aux, name)
    191 	void *aux;
    192 	const char *name;
    193 {
    194 	struct zsc_attach_args *args = aux;
    195 
    196 	if (name != NULL)
    197 		aprint_normal("%s: ", name);
    198 
    199 	if (args->channel != -1)
    200 		aprint_normal(" channel %d", args->channel);
    201 
    202 	return UNCONF;
    203 }
    204 
    205 int
    206 zshard(arg)
    207 	void *arg;
    208 {
    209 	register struct zsc_softc *zsc;
    210 	register int unit, rval;
    211 
    212 	rval = 0;
    213 	for (unit = 0; unit < zsc_cd.cd_ndevs; unit++) {
    214 		zsc = zsc_cd.cd_devs[unit];
    215 		if (zsc == NULL)
    216 			continue;
    217 		rval |= zsc_intr_hard(zsc);
    218 		if ((zsc->zsc_cs[0]->cs_softreq) ||
    219 			(zsc->zsc_cs[1]->cs_softreq))
    220 		{
    221 			/* zsc_req_softint(zsc); */
    222 			/* We are at splzs here, so no need to lock. */
    223 			if (zssoftpending == 0) {
    224 				zssoftpending = 1;
    225 				setsoftzs();
    226 			}
    227 		}
    228 	}
    229 	return (rval);
    230 }
    231 
    232 void
    233 softzs()
    234 {
    235 	register struct zsc_softc *zsc;
    236 	register int unit;
    237 
    238 	/* This is not the only ISR on this IPL. */
    239 	if (zssoftpending == 0)
    240 		return;
    241 
    242 	/*
    243 	 * The soft intr. bit will be set by zshard only if
    244 	 * the variable zssoftpending is zero.
    245 	 */
    246 	zssoftpending = 0;
    247 
    248 	for (unit = 0; unit < zsc_cd.cd_ndevs; ++unit) {
    249 		zsc = zsc_cd.cd_devs[unit];
    250 		if (zsc == NULL)
    251 			continue;
    252 		(void) zsc_intr_soft(zsc);
    253 	}
    254 	return;
    255 }
    256 
    257 u_char
    258 zs_read_reg(cs, reg)
    259 	struct zs_chanstate *cs;
    260 	u_char reg;
    261 {
    262 	u_char val;
    263 
    264 	*cs->cs_reg_csr = reg;
    265 	ZS_DELAY();
    266 	val = *cs->cs_reg_csr;
    267 	ZS_DELAY();
    268 	return val;
    269 }
    270 
    271 void
    272 zs_write_reg(cs, reg, val)
    273 	struct zs_chanstate *cs;
    274 	u_char reg, val;
    275 {
    276 	*cs->cs_reg_csr = reg;
    277 	ZS_DELAY();
    278 	*cs->cs_reg_csr = val;
    279 	ZS_DELAY();
    280 }
    281 
    282 u_char zs_read_csr(cs)
    283 	struct zs_chanstate *cs;
    284 {
    285 	register u_char val;
    286 
    287 	val = *cs->cs_reg_csr;
    288 	ZS_DELAY();
    289 	return val;
    290 }
    291 
    292 void  zs_write_csr(cs, val)
    293 	struct zs_chanstate *cs;
    294 	u_char val;
    295 {
    296 	*cs->cs_reg_csr = val;
    297 	ZS_DELAY();
    298 }
    299 
    300 u_char zs_read_data(cs)
    301 	struct zs_chanstate *cs;
    302 {
    303 	register u_char val;
    304 
    305 	val = *cs->cs_reg_data;
    306 	ZS_DELAY();
    307 	return val;
    308 }
    309 
    310 void  zs_write_data(cs, val)
    311 	struct zs_chanstate *cs;
    312 	u_char val;
    313 {
    314 	*cs->cs_reg_data = val;
    315 	ZS_DELAY();
    316 }
    317 
    318 int
    319 zs_set_speed(cs, bps)
    320 	struct zs_chanstate *cs;
    321 	int bps;	/* bits per second */
    322 {
    323 	int tconst, real_bps;
    324 
    325 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
    326 
    327 	if (tconst < 0)
    328 		return (EINVAL);
    329 
    330 	/* Convert back to make sure we can do it. */
    331 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
    332 #if 0
    333 	/* XXX - Allow some tolerance here? */
    334 	if (real_bps != bps)
    335 		return (EINVAL);
    336 #endif
    337 	cs->cs_preg[12] = tconst;
    338 	cs->cs_preg[13] = tconst >> 8;
    339 
    340 	return (0);
    341 }
    342 
    343 int
    344 zs_set_modes(cs, cflag)
    345 	struct zs_chanstate *cs;
    346 	int cflag;	/* bits per second */
    347 {
    348 	int s;
    349 
    350 	/*
    351 	 * Output hardware flow control on the chip is horrendous:
    352 	 * if carrier detect drops, the receiver is disabled, and if
    353 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
    354 	 * Therefore, NEVER set the HFC bit, and instead use the
    355 	 * status interrupt to detect CTS changes.
    356 	 */
    357 	s = splzs();
    358 #if 0	/* XXX - See below. */
    359 	if (cflag & CLOCAL) {
    360 		cs->cs_rr0_dcd = 0;
    361 		cs->cs_preg[15] &= ~ZSWR15_DCD_IE;
    362 	} else {
    363 		/* XXX - Need to notice DCD change here... */
    364 		cs->cs_rr0_dcd = ZSRR0_DCD;
    365 		cs->cs_preg[15] |= ZSWR15_DCD_IE;
    366 	}
    367 #endif	/* XXX */
    368 	if (cflag & CRTSCTS) {
    369 		cs->cs_wr5_dtr = ZSWR5_DTR;
    370 		cs->cs_wr5_rts = ZSWR5_RTS;
    371 		cs->cs_rr0_cts = ZSRR0_CTS;
    372 		cs->cs_preg[15] |= ZSWR15_CTS_IE;
    373 	} else {
    374 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    375 		cs->cs_wr5_rts = 0;
    376 		cs->cs_rr0_cts = 0;
    377 		cs->cs_preg[15] &= ~ZSWR15_CTS_IE;
    378 	}
    379 	splx(s);
    380 
    381 	/* Caller will stuff the pending registers. */
    382 	return (0);
    383 }
    384 
    385 /*
    386  * Handle user request to enter kernel debugger.
    387  */
    388 void
    389 zs_abort(cs)
    390 	struct zs_chanstate *cs;
    391 {
    392 	int rr0;
    393 
    394 	/* Wait for end of break to avoid PROM abort. */
    395 	/* XXX - Limit the wait? */
    396 	do {
    397 		rr0 = *cs->cs_reg_csr;
    398 		ZS_DELAY();
    399 	} while (rr0 & ZSRR0_BREAK);
    400 #ifdef DDB
    401 	console_debugger();
    402 #endif
    403 }
    404 
    405 /*
    406  * Polled input char.
    407  */
    408 int
    409 zs_getc(arg)
    410 	void *arg;
    411 {
    412 	register struct zs_chanstate *cs = arg;
    413 	register int s, c, rr0, stat;
    414 
    415 	s = splhigh();
    416 top:
    417 	/* Wait for a character to arrive. */
    418 	do {
    419 		rr0 = *cs->cs_reg_csr;
    420 		ZS_DELAY();
    421 	} while ((rr0 & ZSRR0_RX_READY) == 0);
    422 
    423 	/* Read error register. */
    424 	stat = zs_read_reg(cs, 1) & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE);
    425 	if (stat) {
    426 		zs_write_csr(cs, ZSM_RESET_ERR);
    427 		goto top;
    428 	}
    429 
    430 	/* Read character. */
    431 	c = *cs->cs_reg_data;
    432 	ZS_DELAY();
    433 	splx(s);
    434 
    435 	return (c);
    436 }
    437 
    438 /*
    439  * Polled output char.
    440  */
    441 void
    442 zs_putc(arg, c)
    443 	void *arg;
    444 	int c;
    445 {
    446 	register struct zs_chanstate *cs = arg;
    447 	register int s, rr0;
    448 
    449 	s = splhigh();
    450 	/* Wait for transmitter to become ready. */
    451 	do {
    452 		rr0 = *cs->cs_reg_csr;
    453 		ZS_DELAY();
    454 	} while ((rr0 & ZSRR0_TX_READY) == 0);
    455 
    456 	*cs->cs_reg_data = c;
    457 	ZS_DELAY();
    458 	splx(s);
    459 }
    460 
    461 int zscngetc(dev)
    462 dev_t dev;
    463 {
    464 	register struct zs_chanstate *cs = &zs_conschan_store;
    465 	register int c;
    466 
    467 	c = zs_getc(cs);
    468 	return (c);
    469 }
    470 
    471 void zscnputc(dev, c)
    472 dev_t dev;
    473 int c;
    474 {
    475 	register struct zs_chanstate *cs = &zs_conschan_store;
    476 
    477 	zs_putc(cs, c);
    478 }
    479 
    480 /*
    481  * Common parts of console init.
    482  */
    483 void
    484 zs_cninit(base)
    485 	void *base;
    486 {
    487 	struct zs_chanstate *cs;
    488 	/*
    489 	 * Pointer to channel state.  Later, the console channel
    490 	 * state is copied into the softc, and the console channel
    491 	 * pointer adjusted to point to the new copy.
    492 	 */
    493 	cs = &zs_conschan_store;
    494 	zs_hwflags[0][0] = ZS_HWFLAG_CONSOLE;
    495 
    496 	/* Setup temporary chanstate. */
    497 	cs->cs_reg_csr  = (char *)base + 7;
    498 	cs->cs_reg_data = (char *)base + 15;
    499 
    500 	/* Initialize the pending registers. */
    501 	bcopy(zs_init_reg, cs->cs_preg, 16);
    502 	cs->cs_preg[5] |= (ZSWR5_DTR | ZSWR5_RTS);
    503 
    504 	/* XXX: Preserve BAUD rate from boot loader. */
    505 	/* XXX: Also, why reset the chip here? -gwr */
    506 	/* cs->cs_defspeed = zs_get_speed(cs); */
    507 	cs->cs_defspeed = 9600;	/* XXX */
    508 
    509 	/* Clear the master interrupt enable. */
    510 	zs_write_reg(cs, 9, 0);
    511 
    512 	/* Reset the whole SCC chip. */
    513 	zs_write_reg(cs, 9, ZSWR9_HARD_RESET);
    514 
    515 	/* Copy "pending" to "current" and H/W. */
    516 	zs_loadchannelregs(cs);
    517 
    518 	/* Point the console at the SCC. */
    519 	cn_tab = &zscons;
    520 }
    521