* Copyright (c) 1996 The NetBSD Foundation, Inc.

/* $NetBSD: zs.c,v 1.28 2021/09/11 20:28:04 andvar Exp $ */

/*-
* 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)
*
* Runs two serial lines per chip using slave drivers.
* Plain tty/async lines use the zs_async slave.
* Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.28 2021/09/11 20:28:04 andvar Exp $");

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/device.h>
#include <sys/tty.h>
#include <sys/systm.h>
#include <sys/cpu.h>
#include <sys/intr.h>

#include <machine/adrsmap.h>
#include <machine/z8530var.h>

#include <dev/ic/z8530reg.h>

#include "ioconf.h"

void (*zs_delay)(void);

#define ZS_DELAY() (*zs_delay)()

/*
* 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
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;
}

/*
* Our ZS chips all share a common interrupt level,
* but we establish zshard handler per each ZS chips
* to avoid holding unnecessary locks in interrupt context.
*/
int
zshard(void *arg)
{
struct zsc_softc *zsc = arg;
int rval;

rval = zsc_intr_hard(zsc);
if (zsc->zsc_cs[0]->cs_softreq || zsc->zsc_cs[1]->cs_softreq)
softint_schedule(zsc->zsc_si);

return rval;
}

/*
* Compute the current baud rate given a ZS channel.
*/
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)
{
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);

/* XXX - Allow some tolerance here? */
if (real_bps != bps)
return EINVAL;

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)
{
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 = splserial();
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();
}

void
zs_abort(struct zs_chanstate *cs)
{

#ifdef DDB
Debugger();
#endif
}