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zs.c revision 1.2.6.1
      1 /*	$NetBSD: zs.c,v 1.2.6.1 2008/05/16 02:22:09 yamt 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  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Zilog Z8530 Dual UART driver (machine-dependent part)
     34  *
     35  * Runs two serial lines per chip using slave drivers.
     36  * Plain tty/async lines use the zs_async slave.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.2.6.1 2008/05/16 02:22:09 yamt Exp $");
     41 
     42 #include "opt_ddb.h"
     43 
     44 #include <sys/param.h>
     45 #include <sys/systm.h>
     46 #include <sys/conf.h>
     47 #include <sys/device.h>
     48 #include <sys/tty.h>
     49 #include <sys/intr.h>
     50 
     51 #include <dev/cons.h>
     52 #include <dev/ic/z8530reg.h>
     53 
     54 #include <machine/autoconf.h>
     55 #include <machine/z8530var.h>
     56 
     57 #include <cobalt/cobalt/console.h>
     58 
     59 #include "ioconf.h"
     60 
     61 /*
     62  * Some warts needed by z8530tty.c -
     63  * The default parity REALLY needs to be the same as the PROM uses,
     64  * or you can not see messages done with printf during boot-up...
     65  */
     66 int zs_def_cflag = (CREAD | CS8 | HUPCL);
     67 
     68 #define ZS_DEFSPEED	115200
     69 #define PCLK		(115200 * 96)	/*  11.0592MHz */
     70 
     71 #define ZS_DELAY()	delay(2)
     72 
     73 /* The layout of this is hardware-dependent (padding, order). */
     74 /* A/~B (Channel A/Channel B) pin is connected to DAdr0 */
     75 #define ZS_CHAN_A	0x01
     76 #define ZS_CHAN_B	0x00
     77 
     78 /* D/~C (Data/Control) pin is connected to DAdr1 */
     79 #define ZS_CSR		0x00		/* ctrl, status, and indirect access */
     80 #define ZS_DATA		0x02		/* data */
     81 
     82 
     83 /* Definition of the driver for autoconfig. */
     84 static int  zs_match(device_t, cfdata_t, void *);
     85 static void zs_attach(device_t, device_t, void *);
     86 static int  zs_print(void *, const char *name);
     87 
     88 CFATTACH_DECL_NEW(zsc, sizeof(struct zsc_softc),
     89     zs_match, zs_attach, NULL, NULL);
     90 
     91 static int zshard(void *);
     92 #if 0
     93 static int zs_get_speed(struct zs_chanstate *);
     94 #endif
     95 static int  zs_getc(void *);
     96 static void zs_putc(void *, int);
     97 
     98 /* console status from cninit */
     99 static struct zs_chanstate zs_conschan_store;
    100 static struct zs_chanstate *zs_conschan;
    101 static uint8_t *zs_cons;
    102 
    103 /* default speed for all channels */
    104 static int zs_defspeed = ZS_DEFSPEED;
    105 
    106 static uint8_t zs_init_reg[16] = {
    107 	0,					/* 0: CMD (reset, etc.) */
    108 	0,					/* 1: No interrupts yet. */
    109 	0,					/* 2: no IVECT */
    110 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,		/* 3: RX params and ctrl */
    111 	ZSWR4_CLK_X16 | ZSWR4_ONESB,		/* 4: TX/RX misc params */
    112 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,		/* 5: TX params and ctrl */
    113 	0,					/* 6: TXSYNC/SYNCLO */
    114 	0,					/* 7: RXSYNC/SYNCHI */
    115 	0,					/* 8: alias for data port */
    116 	ZSWR9_MASTER_IE,			/* 9: Master interrupt ctrl */
    117 	0,					/*10: Misc TX/RX ctrl */
    118 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,	/*11: Clock Mode ctrl */
    119 	BPS_TO_TCONST((PCLK/16), ZS_DEFSPEED),	/*12: BAUDLO */
    120 	0,					/*13: BAUDHI */
    121 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK, /*14: Misc ctrl */
    122 	ZSWR15_BREAK_IE,			/*15: Ext/Status intr ctrl */
    123 };
    124 
    125 /* register address offset for each channel */
    126 static const int chanoff[] = { ZS_CHAN_A, ZS_CHAN_B };
    127 
    128 
    129 static int
    130 zs_match(device_t parent, cfdata_t cf, void *aux)
    131 {
    132 	static int matched;
    133 
    134 	/* only one zs */
    135 	if (matched)
    136 		return 0;
    137 
    138 	/* only Qube 2700 could have Z85C30 serial */
    139 	if (cobalt_id != COBALT_ID_QUBE2700)
    140 		return 0;
    141 
    142 	if (!console_present)
    143 		return 0;
    144 
    145 	matched = 1;
    146 	return 1;
    147 }
    148 
    149 /*
    150  * Attach a found zs.
    151  */
    152 static void
    153 zs_attach(device_t parent, device_t self, void *aux)
    154 {
    155 	struct zsc_softc *zsc = device_private(self);
    156 	struct mainbus_attach_args *maa = aux;
    157 	struct zsc_attach_args zsc_args;
    158 	uint8_t *zs_base;
    159 	struct zs_chanstate *cs;
    160 	int s, channel;
    161 
    162 	zsc->zsc_dev = self;
    163 
    164 	/* XXX: MI z8530 doesn't use bus_space(9) yet */
    165 	zs_base = (void *)MIPS_PHYS_TO_KSEG1(maa->ma_addr);
    166 
    167 	aprint_normal(": optional Z85C30 serial port\n");
    168 
    169 	/*
    170 	 * Initialize software state for each channel.
    171 	 */
    172 	for (channel = 0; channel < 2; channel++) {
    173 		zsc_args.channel = channel;
    174 		cs = &zsc->zsc_cs_store[channel];
    175 
    176 		zsc->zsc_cs[channel] = cs;
    177 
    178 		zs_init_reg[2] = 0;
    179 
    180 		if ((zs_base + chanoff[channel]) == zs_cons) {
    181 			memcpy(cs, zs_conschan, sizeof(struct zs_chanstate));
    182 			zs_conschan = cs;
    183 			zsc_args.hwflags = ZS_HWFLAG_CONSOLE;
    184 		} else {
    185 			cs->cs_reg_csr  = zs_base + chanoff[channel] + ZS_CSR;
    186 			cs->cs_reg_data = zs_base + chanoff[channel] + ZS_DATA;
    187 			memcpy(cs->cs_creg, zs_init_reg, 16);
    188 			memcpy(cs->cs_preg, zs_init_reg, 16);
    189 			cs->cs_defspeed = zs_defspeed;
    190 			zsc_args.hwflags = 0;
    191 		}
    192 
    193 		zs_lock_init(cs);
    194 		cs->cs_defcflag = zs_def_cflag;
    195 
    196 		cs->cs_channel = channel;
    197 		cs->cs_private = NULL;
    198 		cs->cs_ops = &zsops_null;
    199 		cs->cs_brg_clk = PCLK / 16;
    200 
    201 		/* Make these correspond to cs_defcflag (-crtscts) */
    202 		cs->cs_rr0_dcd = ZSRR0_DCD;
    203 		cs->cs_rr0_cts = 0;
    204 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    205 		cs->cs_wr5_rts = 0;
    206 
    207 		/*
    208 		 * Clear the master interrupt enable.
    209 		 * The INTENA is common to both channels,
    210 		 * so just do it on the A channel.
    211 		 */
    212 		if (channel == 0) {
    213 			s = splhigh();
    214 			zs_write_reg(cs, 9, 0);
    215 			splx(s);
    216 		}
    217 
    218 		/*
    219 		 * Look for a child driver for this channel.
    220 		 * The child attach will setup the hardware.
    221 		 */
    222 		if (!config_found(self, (void *)&zsc_args, zs_print)) {
    223 			/* No sub-driver.  Just reset it. */
    224 			uint8_t reset = (channel == 0) ?
    225 			    ZSWR9_A_RESET : ZSWR9_B_RESET;
    226 			s = splhigh();
    227 			zs_write_reg(cs,  9, reset);
    228 			splx(s);
    229 		}
    230 	}
    231 
    232 	/*
    233 	 * Now safe to install interrupt handlers.
    234 	 */
    235 	icu_intr_establish(maa->ma_irq, IST_EDGE, IPL_SERIAL, zshard, zsc);
    236 	zsc->zsc_softintr_cookie = softint_establish(SOFTINT_SERIAL,
    237 	    (void (*)(void *))zsc_intr_soft, zsc);
    238 
    239 	/*
    240 	 * Set the master interrupt enable and interrupt vector.
    241 	 * (common to both channels, do it on A)
    242 	 */
    243 	cs = zsc->zsc_cs[0];
    244 	s = splhigh();
    245 	/* interrupt vector */
    246 	zs_write_reg(cs, 2, 0);
    247 	/* master interrupt control (enable) */
    248 	zs_write_reg(cs, 9, zs_init_reg[9]);
    249 	splx(s);
    250 }
    251 
    252 static int
    253 zs_print(void *aux, const char *name)
    254 {
    255 	struct zsc_attach_args *args = aux;
    256 
    257 	if (name != NULL)
    258 		aprint_normal("%s: ", name);
    259 
    260 	if (args->channel != -1)
    261 		aprint_normal(" channel %d", args->channel);
    262 
    263 	return UNCONF;
    264 }
    265 
    266 static int
    267 zshard(void *arg)
    268 {
    269 	struct zsc_softc *zsc = arg;
    270 	int rval;
    271 
    272 	rval = zsc_intr_hard(zsc);
    273 
    274 #if 1
    275 	/* XXX: there is some race condition? */
    276 	if (rval)
    277 		while (zsc_intr_hard(zsc))
    278 			;
    279 #endif
    280 
    281 	/* We are at splzs here, so no need to lock. */
    282 	if (zsc->zsc_cs[0]->cs_softreq || zsc->zsc_cs[1]->cs_softreq)
    283 		softint_schedule(zsc->zsc_softintr_cookie);
    284 
    285 	return rval;
    286 }
    287 
    288 /*
    289  * Compute the current baud rate given a ZS channel.
    290  */
    291 #if 0
    292 static int
    293 zs_get_speed(struct zs_chanstate *cs)
    294 {
    295 	int tconst;
    296 
    297 	tconst =  zs_read_reg(cs, 12);
    298 	tconst |= zs_read_reg(cs, 13) << 8;
    299 	return TCONST_TO_BPS(cs->cs_brg_clk, tconst);
    300 }
    301 #endif
    302 
    303 /*
    304  * MD functions for setting the baud rate and control modes.
    305  */
    306 int
    307 zs_set_speed(struct zs_chanstate *cs, int bps)
    308 {
    309 	int tconst, real_bps;
    310 
    311 	if (bps == 0)
    312 		return 0;
    313 
    314 #ifdef	DIAGNOSTIC
    315 	if (cs->cs_brg_clk == 0)
    316 		panic("zs_set_speed");
    317 #endif
    318 
    319 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
    320 	if (tconst < 0)
    321 		return EINVAL;
    322 
    323 	/* Convert back to make sure we can do it. */
    324 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
    325 
    326 	/* Allow ~4% tolerance here */
    327 	if (abs(real_bps - bps) >= bps * 4 / 100)
    328 		return EINVAL;
    329 
    330 	cs->cs_preg[12] = tconst;
    331 	cs->cs_preg[13] = tconst >> 8;
    332 
    333 	/* Caller will stuff the pending registers. */
    334 	return 0;
    335 }
    336 
    337 int
    338 zs_set_modes(struct zs_chanstate *cs, int cflag)
    339 {
    340 	int s;
    341 
    342 	/*
    343 	 * Output hardware flow control on the chip is horrendous:
    344 	 * if carrier detect drops, the receiver is disabled, and if
    345 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
    346 	 * Therefore, NEVER set the HFC bit, and instead use the
    347 	 * status interrupt to detect CTS changes.
    348 	 */
    349 	s = splzs();
    350 	cs->cs_rr0_pps = 0;
    351 	if ((cflag & (CLOCAL | MDMBUF)) != 0) {
    352 		cs->cs_rr0_dcd = 0;
    353 		if ((cflag & MDMBUF) == 0)
    354 			cs->cs_rr0_pps = ZSRR0_DCD;
    355 	} else
    356 		cs->cs_rr0_dcd = ZSRR0_DCD;
    357 	if ((cflag & CRTSCTS) != 0) {
    358 		cs->cs_wr5_dtr = ZSWR5_DTR;
    359 		cs->cs_wr5_rts = ZSWR5_RTS;
    360 		cs->cs_rr0_cts = ZSRR0_CTS;
    361 	} else if ((cflag & MDMBUF) != 0) {
    362 		cs->cs_wr5_dtr = 0;
    363 		cs->cs_wr5_rts = ZSWR5_DTR;
    364 		cs->cs_rr0_cts = ZSRR0_DCD;
    365 	} else {
    366 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    367 		cs->cs_wr5_rts = 0;
    368 		cs->cs_rr0_cts = 0;
    369 	}
    370 	splx(s);
    371 
    372 	/* Caller will stuff the pending registers. */
    373 	return 0;
    374 }
    375 
    376 
    377 /*
    378  * Read or write the chip with suitable delays.
    379  */
    380 
    381 uint8_t
    382 zs_read_reg(struct zs_chanstate *cs, uint8_t reg)
    383 {
    384 	uint8_t val;
    385 
    386 	*cs->cs_reg_csr = reg;
    387 	ZS_DELAY();
    388 	val = *cs->cs_reg_csr;
    389 	ZS_DELAY();
    390 	return val;
    391 }
    392 
    393 void
    394 zs_write_reg(struct zs_chanstate *cs, uint8_t reg, uint8_t val)
    395 {
    396 
    397 	*cs->cs_reg_csr = reg;
    398 	ZS_DELAY();
    399 	*cs->cs_reg_csr = val;
    400 	ZS_DELAY();
    401 }
    402 
    403 uint8_t
    404 zs_read_csr(struct zs_chanstate *cs)
    405 {
    406 	uint8_t val;
    407 
    408 	val = *cs->cs_reg_csr;
    409 	ZS_DELAY();
    410 	return val;
    411 }
    412 
    413 void
    414 zs_write_csr(struct zs_chanstate *cs, uint8_t val)
    415 {
    416 
    417 	*cs->cs_reg_csr = val;
    418 	ZS_DELAY();
    419 }
    420 
    421 uint8_t
    422 zs_read_data(struct zs_chanstate *cs)
    423 {
    424 	uint8_t val;
    425 
    426 	val = *cs->cs_reg_data;
    427 	ZS_DELAY();
    428 	return val;
    429 }
    430 
    431 void
    432 zs_write_data(struct zs_chanstate *cs, uint8_t val)
    433 {
    434 
    435 	*cs->cs_reg_data = val;
    436 	ZS_DELAY();
    437 }
    438 
    439 void
    440 zs_abort(struct zs_chanstate *cs)
    441 {
    442 
    443 #ifdef DDB
    444 	Debugger();
    445 #endif
    446 }
    447 
    448 /*
    449  * Polled input char.
    450  */
    451 int
    452 zs_getc(void *arg)
    453 {
    454 	struct zs_chanstate *cs = arg;
    455 	int s, c;
    456 	uint8_t rr0;
    457 
    458 	s = splhigh();
    459 	/* Wait for a character to arrive. */
    460 	do {
    461 		rr0 = *cs->cs_reg_csr;
    462 		ZS_DELAY();
    463 	} while ((rr0 & ZSRR0_RX_READY) == 0);
    464 
    465 	c = *cs->cs_reg_data;
    466 	ZS_DELAY();
    467 	splx(s);
    468 
    469 	return c;
    470 }
    471 
    472 /*
    473  * Polled output char.
    474  */
    475 void
    476 zs_putc(void *arg, int c)
    477 {
    478 	struct zs_chanstate *cs = arg;
    479 	int s;
    480 	uint8_t rr0;
    481 
    482 	s = splhigh();
    483 	/* Wait for transmitter to become ready. */
    484 	do {
    485 		rr0 = *cs->cs_reg_csr;
    486 		ZS_DELAY();
    487 	} while ((rr0 & ZSRR0_TX_READY) == 0);
    488 
    489 	*cs->cs_reg_data = c;
    490 	ZS_DELAY();
    491 	splx(s);
    492 }
    493 
    494 void
    495 zscnprobe(struct consdev *cn)
    496 {
    497 
    498 	cn->cn_pri = (console_present != 0 && cobalt_id == COBALT_ID_QUBE2700)
    499 	    ? CN_NORMAL : CN_DEAD;
    500 }
    501 
    502 void
    503 zscninit(struct consdev *cn)
    504 {
    505 	struct zs_chanstate *cs;
    506 
    507 	extern const struct cdevsw zstty_cdevsw;
    508 
    509 	cn->cn_dev = makedev(cdevsw_lookup_major(&zstty_cdevsw), 0);
    510 
    511 	zs_cons = (uint8_t *)MIPS_PHYS_TO_KSEG1(ZS_BASE) + ZS_CHAN_A; /* XXX */
    512 
    513 	zs_conschan = cs = &zs_conschan_store;
    514 
    515 	/* Setup temporary chanstate. */
    516 	cs->cs_reg_csr  = zs_cons + ZS_CSR;
    517 	cs->cs_reg_data = zs_cons + ZS_DATA;
    518 
    519 	/* Initialize the pending registers. */
    520 	memcpy(cs->cs_preg, zs_init_reg, 16);
    521 	cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
    522 
    523 	cs->cs_preg[12] = BPS_TO_TCONST(PCLK / 16, ZS_DEFSPEED);
    524 	cs->cs_preg[13] = 0;
    525 	cs->cs_defspeed = ZS_DEFSPEED;
    526 
    527 	/* Clear the master interrupt enable. */
    528 	zs_write_reg(cs, 9, 0);
    529 
    530 	/* Reset the whole SCC chip. */
    531 	zs_write_reg(cs, 9, ZSWR9_HARD_RESET);
    532 
    533 	/* Copy "pending" to "current" and H/W */
    534 	zs_loadchannelregs(cs);
    535 }
    536 
    537 int
    538 zscngetc(dev_t dev)
    539 {
    540 
    541 	return zs_getc((void *)zs_conschan);
    542 }
    543 
    544 void
    545 zscnputc(dev_t dev, int c)
    546 {
    547 
    548 	zs_putc((void *)zs_conschan, c);
    549 }
    550