* Copyright (c) 1998 Minoura Makoto

/* $NetBSD: zs.c,v 1.48 2022/05/26 14:30:11 tsutsui Exp $ */

/*-
* Copyright (c) 1998 Minoura Makoto
* Copyright (c) 1996 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Gordon W. Ross.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/*
* Zilog Z8530 Dual UART driver (machine-dependent part)
*
* X68k uses one Z8530 built-in. Channel A is for RS-232C serial port;
* while channel B is dedicated to the mouse.
* Extra Z8530's can be installed for serial ports. This driver
* supports up to 5 chips including the built-in one.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.48 2022/05/26 14:30:11 tsutsui Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/time.h>
#include <sys/syslog.h>
#include <sys/cpu.h>
#include <sys/bus.h>
#include <sys/intr.h>

#include <arch/x68k/dev/intiovar.h>
#include <machine/z8530var.h>

#include <dev/ic/z8530reg.h>

#include "ioconf.h"
#include "zsc.h" /* NZSC */
#include "opt_zsc.h"
#ifndef ZSCN_SPEED
#define ZSCN_SPEED 9600
#endif
#include "zstty.h"

extern void Debugger(void);

/*
* Some warts needed by z8530tty.c -
* The default parity REALLY needs to be the same as the PROM uses,
* or you can not see messages done with printf during boot-up...
*/
int zs_def_cflag = (CREAD | CS8 | HUPCL);
int zscn_def_cflag = (CREAD | CS8 | HUPCL);

/*
* X68k provides a 5.0 MHz clock to the ZS chips.
*/
#define PCLK (5 * 1000 * 1000) /* PCLK pin input clock rate */

/* Default physical addresses. */
#define ZS_MAXDEV 5
static const bus_addr_t zs_physaddr[ZS_MAXDEV] = {
0x00e98000,
0x00eafc00,
0x00eafc10,
0x00eafc20,
0x00eafc30
};

static uint8_t zs_init_reg[16] = {
0, /* 0: CMD (reset, etc.) */
0, /* 1: No interrupts yet. */
0x70, /* 2: XXX: IVECT */
ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
0, /* 6: TXSYNC/SYNCLO */
0, /* 7: RXSYNC/SYNCHI */
0, /* 8: alias for data port */
ZSWR9_MASTER_IE,
ZSWR10_NRZ, /*10: Misc. TX/RX control bits */
ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
((PCLK/32)/9600)-2, /*12: BAUDLO (default=9600) */
0, /*13: BAUDHI (default=9600) */
ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
ZSWR15_BREAK_IE,
};

static volatile struct zschan *conschan = 0;

/****************************************************************
* Autoconfig
****************************************************************/

/* Definition of the driver for autoconfig. */
static int zs_match(device_t, cfdata_t, void *);
static void zs_attach(device_t, device_t, void *);
static int zs_print(void *, const char *name);

CFATTACH_DECL_NEW(zsc, sizeof(struct zsc_softc),
zs_match, zs_attach, NULL, NULL);

static int zshard(void *);
static int zs_get_speed(struct zs_chanstate *);

/*
* Is the zs chip present?
*/
static int
zs_match(device_t parent, cfdata_t cf, void *aux)
{
struct intio_attach_args *ia = aux;
struct zsdevice *zsaddr = (void *)ia->ia_addr;
int i;

if (strcmp(ia->ia_name, "zsc") != 0)
return 0;

for (i = 0; i < ZS_MAXDEV; i++)
if (zsaddr == (void *)zs_physaddr[i]) /* XXX */
break;
if (i == ZS_MAXDEV) {
/* not a recognized address */
return 0;
}

ia->ia_size = 8;
if (intio_map_allocate_region(parent, ia, INTIO_MAP_TESTONLY))
return 0;

if (badaddr((void *)IIOV(zsaddr)))
return 0;

return (1);
}

/*
* Attach a found zs.
*/
static void
zs_attach(device_t parent, device_t self, void *aux)
{
struct zsc_softc *zsc = device_private(self);
struct intio_attach_args *ia = aux;
struct zsc_attach_args zsc_args;
volatile struct zschan *zc;
struct zs_chanstate *cs;
int r __diagused;
int s, channel;

zsc->zsc_dev = self;
aprint_normal("\n");

zsc->zsc_addr = (void *)ia->ia_addr;

ia->ia_size = 8;
r = intio_map_allocate_region(parent, ia, INTIO_MAP_ALLOCATE);
#ifdef DIAGNOSTIC
if (r)
panic("zs: intio IO map corruption");
#endif

/*
* Initialize software state for each channel.
*/
for (channel = 0; channel < 2; channel++) {
device_t child;

zsc_args.channel = channel;
zsc_args.hwflags = 0;
cs = &zsc->zsc_cs_store[channel];
zsc->zsc_cs[channel] = cs;

zs_lock_init(cs);
cs->cs_channel = channel;
cs->cs_private = NULL;
cs->cs_ops = &zsops_null;
cs->cs_brg_clk = PCLK / 16;

if (channel == 0)
zc = (volatile void *)IIOV(&zsc->zsc_addr->zs_chan_a);
else
zc = (volatile void *)IIOV(&zsc->zsc_addr->zs_chan_b);
cs->cs_reg_csr = &zc->zc_csr;
cs->cs_reg_data = &zc->zc_data;

zs_init_reg[2] = ia->ia_intr;
memcpy(cs->cs_creg, zs_init_reg, 16);
memcpy(cs->cs_preg, zs_init_reg, 16);

if (zc == conschan) {
zsc_args.hwflags |= ZS_HWFLAG_CONSOLE;
cs->cs_defspeed = zs_get_speed(cs);
cs->cs_defcflag = zscn_def_cflag;
} else {
cs->cs_defspeed = 9600;
cs->cs_defcflag = zs_def_cflag;
}

/* Make these correspond to cs_defcflag (-crtscts) */
cs->cs_rr0_dcd = ZSRR0_DCD;
cs->cs_rr0_cts = 0;
cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
cs->cs_wr5_rts = 0;

/*
* Clear the master interrupt enable.
* The INTENA is common to both channels,
* so just do it on the A channel.
*/
if (channel == 0) {
s = splzs();
zs_write_reg(cs, 9, 0);
splx(s);
}

/*
* Look for a child driver for this channel.
* The child attach will setup the hardware.
*/
child = config_found(self, (void *)&zsc_args, zs_print,
CFARGS_NONE);
#if ZSTTY > 0
if (zc == conschan &&
((child && strcmp(device_xname(child), "zstty0")) ||
child == NULL)) /* XXX */
panic("%s: console device mismatch", __func__);
#endif
if (child == NULL) {
/* No sub-driver. Just reset it. */
uint8_t reset = (channel == 0) ?
ZSWR9_A_RESET : ZSWR9_B_RESET;
s = splzs();
zs_write_reg(cs, 9, reset);
splx(s);
}
}

/*
* Now safe to install interrupt handlers.
*/
if (intio_intr_establish(ia->ia_intr, "zs", zshard, zsc))
panic("%s: interrupt vector busy", __func__);
zsc->zsc_softintr_cookie = softint_establish(SOFTINT_SERIAL,
(void (*)(void *))zsc_intr_soft, zsc);
/* XXX; evcnt_attach() ? */

/*
* Set the master interrupt enable and interrupt vector.
* (common to both channels, do it on A)
*/
cs = zsc->zsc_cs[0];
s = splzs();
/* interrupt vector */
zs_write_reg(cs, 2, ia->ia_intr);
/* master interrupt control (enable) */
zs_write_reg(cs, 9, zs_init_reg[9]);
splx(s);
}

static int
zs_print(void *aux, const char *name)
{
struct zsc_attach_args *args = aux;

if (name != NULL)
aprint_normal("%s: ", name);

if (args->channel != -1)
aprint_normal(" channel %d", args->channel);

return UNCONF;
}

/*
* For x68k-port, we don't use autovectored interrupt.
* We do not need to look at all of the zs chips.
*/
static int
zshard(void *arg)
{
struct zsc_softc *zsc = arg;
int rval;
int s;

/*
* Actually, zs hardware ipl is 5.
* Here we disable all interrupts to shorten the zshard
* handling time. Otherwise, too many characters are
* dropped.
*/
s = splhigh();
rval = zsc_intr_hard(zsc);

/* We are at splzs here, so no need to lock. */
if (zsc->zsc_cs[0]->cs_softreq || zsc->zsc_cs[1]->cs_softreq)
softint_schedule(zsc->zsc_softintr_cookie);
splx(s);

return (rval);
}

/*
* Compute the current baud rate given a ZS channel.
*/
static int
zs_get_speed(struct zs_chanstate *cs)
{
int tconst;

tconst = zs_read_reg(cs, 12);
tconst |= zs_read_reg(cs, 13) << 8;
return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
}

/*
* MD functions for setting the baud rate and control modes.
*/
int
zs_set_speed(struct zs_chanstate *cs, int bps /* bits per second */)
{
int tconst, real_bps;

if (bps == 0)
return (0);

#ifdef DIAGNOSTIC
if (cs->cs_brg_clk == 0)
panic("zs_set_speed");
#endif

tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
if (tconst < 0)
return (EINVAL);

/* Convert back to make sure we can do it. */
real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);

#if 0 /* XXX */
/* XXX - Allow some tolerance here? */
if (real_bps != bps)
return (EINVAL);
#else
/*
* Since our PCLK has somewhat strange value,
* we have to allow tolerance here.
*/
if (BPS_TO_TCONST(cs->cs_brg_clk, real_bps) != tconst)
return (EINVAL);
#endif

cs->cs_preg[12] = tconst;
cs->cs_preg[13] = tconst >> 8;

/* Caller will stuff the pending registers. */
return (0);
}

int
zs_set_modes(struct zs_chanstate *cs, int cflag /* bits per second */)
{
int s;

/*
* Output hardware flow control on the chip is horrendous:
* if carrier detect drops, the receiver is disabled, and if
* CTS drops, the transmitter is stopped IN MID CHARACTER!
* Therefore, NEVER set the HFC bit, and instead use the
* status interrupt to detect CTS changes.
*/
s = splzs();
cs->cs_rr0_pps = 0;
if ((cflag & (CLOCAL | MDMBUF)) != 0) {
cs->cs_rr0_dcd = 0;
if ((cflag & MDMBUF) == 0)
cs->cs_rr0_pps = ZSRR0_DCD;
} else
cs->cs_rr0_dcd = ZSRR0_DCD;
if ((cflag & CRTSCTS) != 0) {
cs->cs_wr5_dtr = ZSWR5_DTR;
cs->cs_wr5_rts = ZSWR5_RTS;
cs->cs_rr0_cts = ZSRR0_CTS;
} else if ((cflag & MDMBUF) != 0) {
cs->cs_wr5_dtr = 0;
cs->cs_wr5_rts = ZSWR5_DTR;
cs->cs_rr0_cts = ZSRR0_DCD;
} else {
cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
cs->cs_wr5_rts = 0;
cs->cs_rr0_cts = 0;
}
splx(s);

/* Caller will stuff the pending registers. */
return (0);
}

/*
* Read or write the chip with suitable delays.
*/

uint8_t
zs_read_reg(struct zs_chanstate *cs, uint8_t reg)
{
uint8_t val;

*cs->cs_reg_csr = reg;
ZS_DELAY();
val = *cs->cs_reg_csr;
ZS_DELAY();
return val;
}

void
zs_write_reg(struct zs_chanstate *cs, uint8_t reg, uint8_t val)
{
*cs->cs_reg_csr = reg;
ZS_DELAY();
*cs->cs_reg_csr = val;
ZS_DELAY();
}

uint8_t
zs_read_csr(struct zs_chanstate *cs)
{
uint8_t val;

val = *cs->cs_reg_csr;
ZS_DELAY();
return val;
}

void
zs_write_csr(struct zs_chanstate *cs, uint8_t val)
{
*cs->cs_reg_csr = val;
ZS_DELAY();
}

uint8_t
zs_read_data(struct zs_chanstate *cs)
{
uint8_t val;

val = *cs->cs_reg_data;
ZS_DELAY();
return val;
}

void
zs_write_data(struct zs_chanstate *cs, uint8_t val)
{
*cs->cs_reg_data = val;
ZS_DELAY();
}

/****************************************************************
* Console support functions (x68k specific!)
* Note: this code is allowed to know about the layout of
* the chip registers, and uses that to keep things simple.
* XXX - I think I like the mvme167 code better. -gwr
****************************************************************/

/*
* Handle user request to enter kernel debugger.
*/
void
zs_abort(struct zs_chanstate *cs)
{
int rr0;

/* Wait for end of break to avoid PROM abort. */
/* XXX - Limit the wait? */
do {
rr0 = *cs->cs_reg_csr;
ZS_DELAY();
} while (rr0 & ZSRR0_BREAK);

#ifdef DDB
Debugger();
#else
printf("BREAK!!\n");
#endif
}

#if NZSTTY > 0

#include <dev/cons.h>
cons_decl(zs);

static int zs_getc(void);
static void zs_putc(int);

static struct zs_chanstate zscn_cs;

/*
* Polled input char.
*/
static int
zs_getc(void)
{
int s, c, rr0;

s = splzs();
/* Wait for a character to arrive. */
do {
rr0 = zs_read_csr(&zscn_cs);
} while ((rr0 & ZSRR0_RX_READY) == 0);

c = zs_read_data(&zscn_cs);
splx(s);

/*
* This is used by the kd driver to read scan codes,
* so don't translate '\r' ==> '\n' here...
*/
return (c);
}

/*
* Polled output char.
*/
static void
zs_putc(int c)
{
int s, rr0;

s = splzs();
/* Wait for transmitter to become ready. */
do {
rr0 = zs_read_csr(&zscn_cs);
} while ((rr0 & ZSRR0_TX_READY) == 0);

zs_write_data(&zscn_cs, c);
splx(s);
}

void
zscninit(struct consdev *cn)
{
volatile struct zschan *cnchan = (volatile void *)IIOV(ZSCN_PHYSADDR);
int s;

memset(&zscn_cs, 0, sizeof(struct zs_chanstate));
zscn_cs.cs_reg_csr = &cnchan->zc_csr;
zscn_cs.cs_reg_data = &cnchan->zc_data;
zscn_cs.cs_channel = 0;
zscn_cs.cs_brg_clk = PCLK / 16;
memcpy(zscn_cs.cs_preg, zs_init_reg, 16);
zscn_cs.cs_preg[4] = ZSWR4_CLK_X16 | ZSWR4_ONESB; /* XXX */
zscn_cs.cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
zs_set_speed(&zscn_cs, ZSCN_SPEED);
s = splzs();
zs_write_reg(&zscn_cs, 9, 0);
zs_write_reg(&zscn_cs, 9, ZSWR9_HARD_RESET);
zs_loadchannelregs(&zscn_cs);
splx(s);
conschan = cnchan;
}

/*
* Polled console input putchar.
*/
int
zscngetc(dev_t dev)
{
return (zs_getc());
}

/*
* Polled console output putchar.
*/
void
zscnputc(dev_t dev, int c)
{
zs_putc(c);
}

void
zscnprobe(struct consdev *cd)
{
int maj;
extern const struct cdevsw zstty_cdevsw;

/* locate the major number */
maj = cdevsw_lookup_major(&zstty_cdevsw);
/* XXX: minor number is 0 */

if (maj == -1)
cd->cn_pri = CN_DEAD;
else {
#ifdef ZSCONSOLE
cd->cn_pri = CN_REMOTE; /* higher than ITE (CN_INTERNAL) */
#else
cd->cn_pri = CN_NORMAL;
#endif
cd->cn_dev = makedev(maj, 0);
}
}

void
zscnpollc(dev_t dev, int on)
{
}

#endif