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zs.c revision 1.3.44.1
      1 /*	$NetBSD: zs.c,v 1.3.44.1 2017/12/03 11:36:00 jdolecek 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 1.3.44.1 2017/12/03 11:36:00 jdolecek Exp $");
     41 
     42 #include "opt_ddb.h"
     43 
     44 #include <sys/param.h>
     45 #include <sys/conf.h>
     46 #include <sys/cpu.h>
     47 #include <sys/device.h>
     48 #include <sys/intr.h>
     49 #include <sys/tty.h>
     50 #include <sys/systm.h>
     51 
     52 #include <dev/cons.h>
     53 #include <dev/ic/z8530reg.h>
     54 
     55 #include <mips/cpuregs.h>
     56 
     57 #include <machine/autoconf.h>
     58 #include <machine/z8530var.h>
     59 
     60 #include <cobalt/cobalt/console.h>
     61 
     62 #include "ioconf.h"
     63 
     64 /*
     65  * Some warts needed by z8530tty.c -
     66  * The default parity REALLY needs to be the same as the PROM uses,
     67  * or you can not see messages done with printf during boot-up...
     68  */
     69 int zs_def_cflag = (CREAD | CS8 | HUPCL);
     70 
     71 #define ZS_DEFSPEED	115200
     72 #define PCLK		(115200 * 96)	/*  11.0592MHz */
     73 
     74 #define ZS_DELAY()	delay(2)
     75 
     76 /* The layout of this is hardware-dependent (padding, order). */
     77 /* A/~B (Channel A/Channel B) pin is connected to DAdr0 */
     78 #define ZS_CHAN_A	0x01
     79 #define ZS_CHAN_B	0x00
     80 
     81 /* D/~C (Data/Control) pin is connected to DAdr1 */
     82 #define ZS_CSR		0x00		/* ctrl, status, and indirect access */
     83 #define ZS_DATA		0x02		/* data */
     84 
     85 
     86 /* Definition of the driver for autoconfig. */
     87 static int  zs_match(device_t, cfdata_t, void *);
     88 static void zs_attach(device_t, device_t, void *);
     89 static int  zs_print(void *, const char *name);
     90 
     91 CFATTACH_DECL_NEW(zsc, sizeof(struct zsc_softc),
     92     zs_match, zs_attach, NULL, NULL);
     93 
     94 static int zshard(void *);
     95 #if 0
     96 static int zs_get_speed(struct zs_chanstate *);
     97 #endif
     98 static int  zs_getc(void *);
     99 static void zs_putc(void *, int);
    100 
    101 /* console status from cninit */
    102 static struct zs_chanstate zs_conschan_store;
    103 static struct zs_chanstate *zs_conschan;
    104 static uint8_t *zs_cons;
    105 
    106 /* default speed for all channels */
    107 static int zs_defspeed = ZS_DEFSPEED;
    108 
    109 static uint8_t zs_init_reg[16] = {
    110 	0,					/* 0: CMD (reset, etc.) */
    111 	0,					/* 1: No interrupts yet. */
    112 	0,					/* 2: no IVECT */
    113 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,		/* 3: RX params and ctrl */
    114 	ZSWR4_CLK_X16 | ZSWR4_ONESB,		/* 4: TX/RX misc params */
    115 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,		/* 5: TX params and ctrl */
    116 	0,					/* 6: TXSYNC/SYNCLO */
    117 	0,					/* 7: RXSYNC/SYNCHI */
    118 	0,					/* 8: alias for data port */
    119 	ZSWR9_MASTER_IE,			/* 9: Master interrupt ctrl */
    120 	0,					/*10: Misc TX/RX ctrl */
    121 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,	/*11: Clock Mode ctrl */
    122 	BPS_TO_TCONST((PCLK/16), ZS_DEFSPEED),	/*12: BAUDLO */
    123 	0,					/*13: BAUDHI */
    124 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK, /*14: Misc ctrl */
    125 	ZSWR15_BREAK_IE,			/*15: Ext/Status intr ctrl */
    126 };
    127 
    128 /* register address offset for each channel */
    129 static const int chanoff[] = { ZS_CHAN_A, ZS_CHAN_B };
    130 
    131 
    132 static int
    133 zs_match(device_t parent, cfdata_t cf, void *aux)
    134 {
    135 	static int matched;
    136 
    137 	/* only one zs */
    138 	if (matched)
    139 		return 0;
    140 
    141 	/* only Qube 2700 could have Z85C30 serial */
    142 	if (cobalt_id != COBALT_ID_QUBE2700)
    143 		return 0;
    144 
    145 	if (!console_present)
    146 		return 0;
    147 
    148 	matched = 1;
    149 	return 1;
    150 }
    151 
    152 /*
    153  * Attach a found zs.
    154  */
    155 static void
    156 zs_attach(device_t parent, device_t self, void *aux)
    157 {
    158 	struct zsc_softc *zsc = device_private(self);
    159 	struct mainbus_attach_args *maa = aux;
    160 	struct zsc_attach_args zsc_args;
    161 	uint8_t *zs_base;
    162 	struct zs_chanstate *cs;
    163 	int s, channel;
    164 
    165 	zsc->zsc_dev = self;
    166 
    167 	/* XXX: MI z8530 doesn't use bus_space(9) yet */
    168 	zs_base = (void *)MIPS_PHYS_TO_KSEG1(maa->ma_addr);
    169 
    170 	aprint_normal(": optional Z85C30 serial port\n");
    171 
    172 	/*
    173 	 * Initialize software state for each channel.
    174 	 */
    175 	for (channel = 0; channel < 2; channel++) {
    176 		zsc_args.channel = channel;
    177 		cs = &zsc->zsc_cs_store[channel];
    178 
    179 		zsc->zsc_cs[channel] = cs;
    180 
    181 		zs_init_reg[2] = 0;
    182 
    183 		if ((zs_base + chanoff[channel]) == zs_cons) {
    184 			memcpy(cs, zs_conschan, sizeof(struct zs_chanstate));
    185 			zs_conschan = cs;
    186 			zsc_args.hwflags = ZS_HWFLAG_CONSOLE;
    187 		} else {
    188 			cs->cs_reg_csr  = zs_base + chanoff[channel] + ZS_CSR;
    189 			cs->cs_reg_data = zs_base + chanoff[channel] + ZS_DATA;
    190 			memcpy(cs->cs_creg, zs_init_reg, 16);
    191 			memcpy(cs->cs_preg, zs_init_reg, 16);
    192 			cs->cs_defspeed = zs_defspeed;
    193 			zsc_args.hwflags = 0;
    194 		}
    195 
    196 		zs_lock_init(cs);
    197 		cs->cs_defcflag = zs_def_cflag;
    198 
    199 		cs->cs_channel = channel;
    200 		cs->cs_private = NULL;
    201 		cs->cs_ops = &zsops_null;
    202 		cs->cs_brg_clk = PCLK / 16;
    203 
    204 		/* Make these correspond to cs_defcflag (-crtscts) */
    205 		cs->cs_rr0_dcd = ZSRR0_DCD;
    206 		cs->cs_rr0_cts = 0;
    207 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    208 		cs->cs_wr5_rts = 0;
    209 
    210 		/*
    211 		 * Clear the master interrupt enable.
    212 		 * The INTENA is common to both channels,
    213 		 * so just do it on the A channel.
    214 		 */
    215 		if (channel == 0) {
    216 			s = splhigh();
    217 			zs_write_reg(cs, 9, 0);
    218 			splx(s);
    219 		}
    220 
    221 		/*
    222 		 * Look for a child driver for this channel.
    223 		 * The child attach will setup the hardware.
    224 		 */
    225 		if (!config_found(self, (void *)&zsc_args, zs_print)) {
    226 			/* No sub-driver.  Just reset it. */
    227 			uint8_t reset = (channel == 0) ?
    228 			    ZSWR9_A_RESET : ZSWR9_B_RESET;
    229 			s = splhigh();
    230 			zs_write_reg(cs,  9, reset);
    231 			splx(s);
    232 		}
    233 	}
    234 
    235 	/*
    236 	 * Now safe to install interrupt handlers.
    237 	 */
    238 	icu_intr_establish(maa->ma_irq, IST_EDGE, IPL_SERIAL, zshard, zsc);
    239 	zsc->zsc_softintr_cookie = softint_establish(SOFTINT_SERIAL,
    240 	    (void (*)(void *))zsc_intr_soft, zsc);
    241 
    242 	/*
    243 	 * Set the master interrupt enable and interrupt vector.
    244 	 * (common to both channels, do it on A)
    245 	 */
    246 	cs = zsc->zsc_cs[0];
    247 	s = splhigh();
    248 	/* interrupt vector */
    249 	zs_write_reg(cs, 2, 0);
    250 	/* master interrupt control (enable) */
    251 	zs_write_reg(cs, 9, zs_init_reg[9]);
    252 	splx(s);
    253 }
    254 
    255 static int
    256 zs_print(void *aux, const char *name)
    257 {
    258 	struct zsc_attach_args *args = aux;
    259 
    260 	if (name != NULL)
    261 		aprint_normal("%s: ", name);
    262 
    263 	if (args->channel != -1)
    264 		aprint_normal(" channel %d", args->channel);
    265 
    266 	return UNCONF;
    267 }
    268 
    269 static int
    270 zshard(void *arg)
    271 {
    272 	struct zsc_softc *zsc = arg;
    273 	int rval;
    274 
    275 	rval = zsc_intr_hard(zsc);
    276 
    277 #if 1
    278 	/* XXX: there is some race condition? */
    279 	if (rval)
    280 		while (zsc_intr_hard(zsc))
    281 			;
    282 #endif
    283 
    284 	/* We are at splzs here, so no need to lock. */
    285 	if (zsc->zsc_cs[0]->cs_softreq || zsc->zsc_cs[1]->cs_softreq)
    286 		softint_schedule(zsc->zsc_softintr_cookie);
    287 
    288 	return rval;
    289 }
    290 
    291 /*
    292  * Compute the current baud rate given a ZS channel.
    293  */
    294 #if 0
    295 static int
    296 zs_get_speed(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 #endif
    305 
    306 /*
    307  * MD functions for setting the baud rate and control modes.
    308  */
    309 int
    310 zs_set_speed(struct zs_chanstate *cs, int bps)
    311 {
    312 	int tconst, real_bps;
    313 
    314 	if (bps == 0)
    315 		return 0;
    316 
    317 #ifdef	DIAGNOSTIC
    318 	if (cs->cs_brg_clk == 0)
    319 		panic("zs_set_speed");
    320 #endif
    321 
    322 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
    323 	if (tconst < 0)
    324 		return EINVAL;
    325 
    326 	/* Convert back to make sure we can do it. */
    327 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
    328 
    329 	/* Allow ~4% tolerance here */
    330 	if (abs(real_bps - bps) >= bps * 4 / 100)
    331 		return EINVAL;
    332 
    333 	cs->cs_preg[12] = tconst;
    334 	cs->cs_preg[13] = tconst >> 8;
    335 
    336 	/* Caller will stuff the pending registers. */
    337 	return 0;
    338 }
    339 
    340 int
    341 zs_set_modes(struct zs_chanstate *cs, int cflag)
    342 {
    343 	int s;
    344 
    345 	/*
    346 	 * Output hardware flow control on the chip is horrendous:
    347 	 * if carrier detect drops, the receiver is disabled, and if
    348 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
    349 	 * Therefore, NEVER set the HFC bit, and instead use the
    350 	 * status interrupt to detect CTS changes.
    351 	 */
    352 	s = splzs();
    353 	cs->cs_rr0_pps = 0;
    354 	if ((cflag & (CLOCAL | MDMBUF)) != 0) {
    355 		cs->cs_rr0_dcd = 0;
    356 		if ((cflag & MDMBUF) == 0)
    357 			cs->cs_rr0_pps = ZSRR0_DCD;
    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 uint8_t
    385 zs_read_reg(struct zs_chanstate *cs, uint8_t reg)
    386 {
    387 	uint8_t val;
    388 
    389 	*cs->cs_reg_csr = reg;
    390 	ZS_DELAY();
    391 	val = *cs->cs_reg_csr;
    392 	ZS_DELAY();
    393 	return val;
    394 }
    395 
    396 void
    397 zs_write_reg(struct zs_chanstate *cs, uint8_t reg, uint8_t val)
    398 {
    399 
    400 	*cs->cs_reg_csr = reg;
    401 	ZS_DELAY();
    402 	*cs->cs_reg_csr = val;
    403 	ZS_DELAY();
    404 }
    405 
    406 uint8_t
    407 zs_read_csr(struct zs_chanstate *cs)
    408 {
    409 	uint8_t val;
    410 
    411 	val = *cs->cs_reg_csr;
    412 	ZS_DELAY();
    413 	return val;
    414 }
    415 
    416 void
    417 zs_write_csr(struct zs_chanstate *cs, uint8_t val)
    418 {
    419 
    420 	*cs->cs_reg_csr = val;
    421 	ZS_DELAY();
    422 }
    423 
    424 uint8_t
    425 zs_read_data(struct zs_chanstate *cs)
    426 {
    427 	uint8_t val;
    428 
    429 	val = *cs->cs_reg_data;
    430 	ZS_DELAY();
    431 	return val;
    432 }
    433 
    434 void
    435 zs_write_data(struct zs_chanstate *cs, uint8_t val)
    436 {
    437 
    438 	*cs->cs_reg_data = val;
    439 	ZS_DELAY();
    440 }
    441 
    442 void
    443 zs_abort(struct zs_chanstate *cs)
    444 {
    445 
    446 #ifdef DDB
    447 	Debugger();
    448 #endif
    449 }
    450 
    451 /*
    452  * Polled input char.
    453  */
    454 int
    455 zs_getc(void *arg)
    456 {
    457 	struct zs_chanstate *cs = arg;
    458 	int s, c;
    459 	uint8_t rr0;
    460 
    461 	s = splhigh();
    462 	/* Wait for a character to arrive. */
    463 	do {
    464 		rr0 = *cs->cs_reg_csr;
    465 		ZS_DELAY();
    466 	} while ((rr0 & ZSRR0_RX_READY) == 0);
    467 
    468 	c = *cs->cs_reg_data;
    469 	ZS_DELAY();
    470 	splx(s);
    471 
    472 	return c;
    473 }
    474 
    475 /*
    476  * Polled output char.
    477  */
    478 void
    479 zs_putc(void *arg, int c)
    480 {
    481 	struct zs_chanstate *cs = arg;
    482 	int s;
    483 	uint8_t rr0;
    484 
    485 	s = splhigh();
    486 	/* Wait for transmitter to become ready. */
    487 	do {
    488 		rr0 = *cs->cs_reg_csr;
    489 		ZS_DELAY();
    490 	} while ((rr0 & ZSRR0_TX_READY) == 0);
    491 
    492 	*cs->cs_reg_data = c;
    493 	ZS_DELAY();
    494 	splx(s);
    495 }
    496 
    497 void
    498 zscnprobe(struct consdev *cn)
    499 {
    500 
    501 	cn->cn_pri = (console_present != 0 && cobalt_id == COBALT_ID_QUBE2700)
    502 	    ? CN_NORMAL : CN_DEAD;
    503 }
    504 
    505 void
    506 zscninit(struct consdev *cn)
    507 {
    508 	struct zs_chanstate *cs;
    509 
    510 	extern const struct cdevsw zstty_cdevsw;
    511 
    512 	cn->cn_dev = makedev(cdevsw_lookup_major(&zstty_cdevsw), 0);
    513 
    514 	zs_cons = (uint8_t *)MIPS_PHYS_TO_KSEG1(ZS_BASE) + ZS_CHAN_A; /* XXX */
    515 
    516 	zs_conschan = cs = &zs_conschan_store;
    517 
    518 	/* Setup temporary chanstate. */
    519 	cs->cs_reg_csr  = zs_cons + ZS_CSR;
    520 	cs->cs_reg_data = zs_cons + ZS_DATA;
    521 
    522 	/* Initialize the pending registers. */
    523 	memcpy(cs->cs_preg, zs_init_reg, 16);
    524 	cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
    525 
    526 	cs->cs_preg[12] = BPS_TO_TCONST(PCLK / 16, ZS_DEFSPEED);
    527 	cs->cs_preg[13] = 0;
    528 	cs->cs_defspeed = ZS_DEFSPEED;
    529 
    530 	/* Clear the master interrupt enable. */
    531 	zs_write_reg(cs, 9, 0);
    532 
    533 	/* Reset the whole SCC chip. */
    534 	zs_write_reg(cs, 9, ZSWR9_HARD_RESET);
    535 
    536 	/* Copy "pending" to "current" and H/W */
    537 	zs_loadchannelregs(cs);
    538 }
    539 
    540 int
    541 zscngetc(dev_t dev)
    542 {
    543 
    544 	return zs_getc((void *)zs_conschan);
    545 }
    546 
    547 void
    548 zscnputc(dev_t dev, int c)
    549 {
    550 
    551 	zs_putc((void *)zs_conschan, c);
    552 }
    553