/*      $NetBSD: zs.c,v 1.92 2024/12/20 23:52:00 tsutsui 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 1.92 2024/12/20 23:52:00 tsutsui Exp $");

#include "opt_kgdb.h"

#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/intr.h>

#include <uvm/uvm_extern.h>

#include <machine/autoconf.h>
#include <machine/mon.h>
#include <machine/z8530var.h>

#include <sun3/sun3/machdep.h>
#ifdef  _SUN3X_
#include <sun3/sun3x/obio.h>
#else
#include <sun3/sun3/obio.h>
#endif
#include <sun3/dev/zs_cons.h>

#include <dev/cons.h>
#include <dev/ic/z8530reg.h>

#include "ioconf.h"
#include "kbd.h"        /* NKBD */
#include "zsc.h"        /* NZSC */
#define NZS NZSC

/* Make life easier for the initialized arrays here. */
#if NZS < 2
#undef  NZS
#define NZS 2
#endif

/*
 * 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);

/*
 * The Sun3 provides a 4.9152 MHz clock to the ZS chips.
 */
#define PCLK    (9600 * 512)    /* PCLK pin input clock rate */

/*
 * Define interrupt levels.
 */
#define ZSHARD_PRI      6       /* Wired on the CPU board... */
#define ZSSOFT_PRI      _IPL_SOFT_LEVEL3 /* Want tty pri (4) but this is OK. */

#define ZS_DELAY()                      delay(2)

/* The layout of this is hardware-dependent (padding, order). */
struct zschan {
        volatile uint8_t zc_csr;        /* ctrl,status, and indirect access */
        uint8_t         zc_xxx0;
        volatile uint8_t zc_data;       /* data */
        uint8_t         zc_xxx1;
};
struct zsdevice {
        /* Yes, they are backwards. */
        struct  zschan zs_chan_b;
        struct  zschan zs_chan_a;
};


/* Default OBIO addresses. */
static int zs_physaddr[NZS] = {
        OBIO_ZS_KBD_MS,
        OBIO_ZS_TTY_AB };

/* Saved PROM mappings */
static struct zsdevice *zsaddr[NZS];

/* Flags from cninit() */
static int zs_hwflags[NZS][2];

/* Default speed for each channel */
static int zs_defspeed[NZS][2] = {
        { 1200,         /* keyboard */
          1200 },       /* mouse */
        { 9600,         /* ttya */
          9600 },       /* ttyb */
};

static uint8_t zs_init_reg[16] = {
        0,      /* 0: CMD (reset, etc.) */
        0,      /* 1: No interrupts yet. */
        0x18 + ZSHARD_PRI,      /* 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,
        0,      /*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,
};


/* Find PROM mappings (for console support). */
void
zs_init(void)
{
        vaddr_t va;
        int i;

        for (i = 0; i < NZS; i++) {
                if (find_prom_map(zs_physaddr[i], PMAP_OBIO,
                    sizeof(struct zschan), &va) == 0)
                        zsaddr[i] = (void *)va;
        }
}

struct zschan *
zs_get_chan_addr(int zs_unit, int channel)
{
        struct zsdevice *addr;
        struct zschan *zc;

        if (zs_unit >= NZS)
                return NULL;
        addr = zsaddr[zs_unit];
        if (addr == NULL)
                return NULL;
        if (channel == 0) {
                zc = &addr->zs_chan_a;
        } else {
                zc = &addr->zs_chan_b;
        }
        return (zc);
}


/****************************************************************
 * 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 *);

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 confargs *ca = aux;
        int unit;
        void *va;

        /*
         * This driver only supports its wired-in mappings,
         * because the console support depends on those.
         */
        if (ca->ca_paddr == zs_physaddr[0]) {
                unit = 0;
        } else if (ca->ca_paddr == zs_physaddr[1]) {
                unit = 1;
        } else {
                return (0);
        }

        /* Make sure zs_init() found mappings. */
        va = zsaddr[unit];
        if (va == NULL)
                return (0);

        /* This returns -1 on a fault (bus error). */
        if (peek_byte(va) == -1)
                return (0);

        /* Default interrupt priority (always splbio==2) */
        if (ca->ca_intpri == -1)
                ca->ca_intpri = ZSHARD_PRI;

        return (1);
}

/*
 * Attach a found zs.
 *
 * Match slave number to zs unit number, so that misconfiguration will
 * not set up the keyboard as ttya, etc.
 */
static void
zs_attach(device_t parent, device_t self, void *aux)
{
        struct zsc_softc *zsc = device_private(self);
        struct confargs *ca = aux;
        struct zsc_attach_args zsc_args;
        volatile struct zschan *zc;
        struct zs_chanstate *cs;
        int zs_unit, channel;

        zsc->zsc_dev = self;
        zs_unit = device_unit(self);

        aprint_normal(": (softpri %d)\n", ZSSOFT_PRI);

        /* Use the mapping setup by the Sun PROM. */
        if (zsaddr[zs_unit] == NULL)
                panic("zs_attach: zs%d not mapped", zs_unit);

        /*
         * Initialize software state for each channel.
         */
        for (channel = 0; channel < 2; channel++) {
                zsc_args.channel = channel;
                zsc_args.hwflags = zs_hwflags[zs_unit][channel];
                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;

                zc = zs_get_chan_addr(zs_unit, channel);
                cs->cs_reg_csr  = &zc->zc_csr;
                cs->cs_reg_data = &zc->zc_data;

                memcpy(cs->cs_creg, zs_init_reg, 16);
                memcpy(cs->cs_preg, zs_init_reg, 16);

                /* XXX: Get these from the EEPROM instead? */
                /* XXX: See the mvme167 code.  Better. */
                if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE)
                        cs->cs_defspeed = zs_get_speed(cs);
                else
                        cs->cs_defspeed = zs_defspeed[zs_unit][channel];
                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) {
                        zs_write_reg(cs, 9, 0);
                }

                /*
                 * Look for a child driver for this channel.
                 * The child attach will setup the hardware.
                 */
                if (!config_found(self, (void *)&zsc_args, zs_print,
                    CFARGS_NONE)) {
                        /* No sub-driver.  Just reset it. */
                        uint8_t reset = (channel == 0) ?
                                ZSWR9_A_RESET : ZSWR9_B_RESET;
                        zs_lock_chan(cs);
                        zs_write_reg(cs,  9, reset);
                        zs_unlock_chan(cs);
                }
        }

        /*
         * Now safe to install interrupt handlers.
         */
        isr_add_autovect(zshard, zsc, ca->ca_intpri);
        zsc->zs_si = 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];
        zs_lock_chan(cs);
        /* interrupt vector */
        zs_write_reg(cs, 2, zs_init_reg[2]);
        /* master interrupt control (enable) */
        zs_write_reg(cs, 9, zs_init_reg[9]);
        zs_unlock_chan(cs);

        /*
         * XXX: L1A hack - We would like to be able to break into
         * the debugger during the rest of autoconfiguration, so
         * lower interrupts just enough to let zs interrupts in.
         * This is done after both zs devices are attached.
         */
        if (zs_unit == 1) {
                (void)spl5(); /* splzs - 1 */
        }
}

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;
}

/*
 * Our ZS chips all share a common, autovectored interrupt,
 * but we establish zshard handler per each ZS chip
 * to avoid holding unnecessary locks in interrupt context.
 */
static 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->zs_si);

        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)
{
        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 /* bits per second */)
{

        /*
         * 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.
         */
        zs_lock_chan(cs);
        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;
        }
        zs_unlock_chan(cs);

        /* 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 (Sun3 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
 ****************************************************************/

void *zs_conschan;

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

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

        /* This is always available on the Sun3. */
        Debugger();
}

/*
 * Polled input char.
 */
int
zs_getc(void *arg)
{
        volatile struct zschan *zc = arg;
        int s, c, rr0;

        s = splhigh();
        /* Wait for a character to arrive. */
        do {
                rr0 = zc->zc_csr;
                ZS_DELAY();
        } while ((rr0 & ZSRR0_RX_READY) == 0);

        c = zc->zc_data;
        ZS_DELAY();
        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.
 */
void
zs_putc(void *arg, int c)
{
        volatile struct zschan *zc = arg;
        int s, rr0;

        s = splhigh();
        /* Wait for transmitter to become ready. */
        do {
                rr0 = zc->zc_csr;
                ZS_DELAY();
        } while ((rr0 & ZSRR0_TX_READY) == 0);

        zc->zc_data = c;
        ZS_DELAY();
        splx(s);
}

/*****************************************************************/

static void zscninit(struct consdev *);
static int  zscngetc(dev_t);
static void zscnputc(dev_t, int);

/*
 * Console table shared by ttya, ttyb
 */
struct consdev consdev_tty = {
        nullcnprobe,
        zscninit,
        zscngetc,
        zscnputc,
        nullcnpollc,
        NULL,
};

static void
zscninit(struct consdev *cn)
{
}

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

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

/*****************************************************************/

static void prom_cninit(struct consdev *);
static int  prom_cngetc(dev_t);
static void prom_cnputc(dev_t, int);

/*
 * The console is set to this one initially,
 * which lets us use the PROM until consinit()
 * is called to select a real console.
 */
struct consdev consdev_prom = {
        nullcnprobe,
        prom_cninit,
        prom_cngetc,
        prom_cnputc,
        nullcnpollc,
};

void
nullcnprobe(struct consdev *cn)
{
}

static void
prom_cninit(struct consdev *cn)
{
}

/*
 * PROM console input putchar.
 * (dummy - this is output only)
 */
static int
prom_cngetc(dev_t dev)
{
        return (0);
}

/*
 * PROM console output putchar.
 */
static void
prom_cnputc(dev_t dev, int c)
{
        (*romVectorPtr->putChar)(c & 0x7f);
}

/*****************************************************************/

extern struct consdev consdev_kd;

static const struct {
        int zs_unit, channel;
} zstty_conf[NZS*2] = {
        /* XXX: knowledge from the config file here... */
        { 1, 0 },       /* ttya */
        { 1, 1 },       /* ttyb */
        { 0, 0 },       /* ttyc */
        { 0, 1 },       /* ttyd */
};

static const char * const prom_inSrc_name[] = {
        "keyboard/display",
        "ttya", "ttyb",
        "ttyc", "ttyd" };

/*
 * This function replaces sys/dev/cninit.c
 * Determine which device is the console using
 * the PROM "input source" and "output sink".
 */
void
cninit(void)
{
        struct sunromvec *v;
        struct zschan *zc;
        struct consdev *cn;
        int channel, zs_unit, zstty_unit;
        uint8_t inSource, outSink;
        extern const struct cdevsw zstty_cdevsw;

        /* Get the zs driver ready for console duty. */
        zs_init();

        v = romVectorPtr;
        inSource = *v->inSource;
        outSink  = *v->outSink;
        if (inSource != outSink) {
                mon_printf("cninit: mismatched PROM output selector\n");
        }

        switch (inSource) {
        default:
                mon_printf("cninit: invalid inSource=%d\n", inSource);
                sunmon_abort();
                inSource = 0;
                /* fall through */

        case 0: /* keyboard/display */
#if NKBD > 0
                zs_unit = 0;
                channel = 0;
                cn = &consdev_kd;
                /* Set cn_dev, cn_pri in kd.c */
                break;
#else   /* NKBD */
                mon_printf("cninit: kdb/display not configured\n");
                sunmon_abort();
                inSource = 1;
                /* fall through */
#endif  /* NKBD */

        case 1: /* ttya */
        case 2: /* ttyb */
        case 3: /* ttyc (rewired keyboard connector) */
        case 4: /* ttyd (rewired mouse connector)   */
                zstty_unit = inSource - 1;
                zs_unit = zstty_conf[zstty_unit].zs_unit;
                channel = zstty_conf[zstty_unit].channel;
                cn = &consdev_tty;
                cn->cn_dev = makedev(cdevsw_lookup_major(&zstty_cdevsw),
                                     zstty_unit);
                cn->cn_pri = CN_REMOTE;
                break;

        }
        /* Now that inSource has been validated, print it. */
        mon_printf("console is %s\n", prom_inSrc_name[inSource]);

        zc = zs_get_chan_addr(zs_unit, channel);
        if (zc == NULL) {
                mon_printf("cninit: zs not mapped.\n");
                return;
        }
        zs_conschan = zc;
        zs_hwflags[zs_unit][channel] = ZS_HWFLAG_CONSOLE;
        cn_tab = cn;
        (*cn->cn_init)(cn);
#ifdef  KGDB
        zs_kgdb_init();
#endif
}