/*      $NetBSD: ki2c.c,v 1.45 2026/03/24 07:30:19 macallan Exp $       */
/*      Id: ki2c.c,v 1.7 2002/10/05 09:56:05 tsubai Exp */

/*-
 * Copyright (c) 2001 Tsubai Masanari.  All rights reserved.
 *
 * 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#include <sys/param.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/mutex.h>

#include <dev/ofw/openfirm.h>
#include <machine/autoconf.h>
#include <powerpc/pic/picvar.h>

#include "opt_ki2c.h"
#include <macppc/dev/ki2cvar.h>

#ifdef KI2C_DEBUG
#define DPRINTF printf
#else
#define DPRINTF while (0) printf
#endif

#define KI2C_EXEC_MAX_CMDLEN    32
#define KI2C_EXEC_MAX_BUFLEN    32

int ki2c_match(device_t, cfdata_t, void *);
void ki2c_attach(device_t, device_t, void *);
inline uint8_t ki2c_readreg(struct ki2c_softc *, int);
inline void ki2c_writereg(struct ki2c_softc *, int, uint8_t);
u_int ki2c_getmode(struct ki2c_softc *);
void ki2c_setmode(struct ki2c_softc *, u_int);
u_int ki2c_getspeed(struct ki2c_softc *);
void ki2c_setspeed(struct ki2c_softc *, u_int);
int ki2c_intr(void *);
int ki2c_poll(struct ki2c_softc *, int);
int ki2c_start(struct ki2c_softc *, int, int, void *, int);
int ki2c_read(struct ki2c_softc *, int, int, void *, int);
int ki2c_write(struct ki2c_softc *, int, int, void *, int);

/* I2C glue */
static int ki2c_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *, size_t,
                    void *, size_t, int);

static void
ki2c_select_channel(struct ki2c_softc *sc, int channel)
{
        uint8_t val = channel ? 0x10 : 0x00;

        /* We handle the subaddress stuff ourselves. */
        ki2c_setmode(sc, val | I2C_STDMODE);    
}

static int
ki2c_acquire_bus(void *v, int flags)
{
        struct ki2c_channel *ch = v;
        struct ki2c_softc *sc = ch->ch_sc;

        int error = iic_acquire_bus_lock(&sc->sc_mux_lock, flags);
        if (error) {
                return error;
        }

        ki2c_select_channel(sc, ch->ch_channel);
        return 0;
}

static void
ki2c_release_bus(void *v, int flags)
{
        struct ki2c_channel *ch = v;
        struct ki2c_softc *sc = ch->ch_sc;

        iic_release_bus_lock(&sc->sc_mux_lock);
}

static void
ki2c_init_channel(struct ki2c_softc *sc, int channel, int node)
{
        struct ki2c_channel *ch = &sc->sc_channels[channel];

        /*
         * XXX PowerMac G5 11,2 has two channel-0 nodes for ki2c1.
         *
         * The first one has 2 audio codecs, the second one has
         * only 1 (which is a duplicate of the pcm3052 under the
         * first node).  This //appears// to be an error in the
         * OpenFirmware device tree.
         *
         * See port-macppc/59673.
         */
        if (ch->ch_sc != NULL) {
                aprint_debug_dev(sc->sc_dev,
                    "skipping duplicate channel %d (device tree error?)\n",
                    channel);
                return;
        }

        iic_tag_init(&ch->ch_i2c);
        ch->ch_i2c.ic_channel = channel;
        ch->ch_i2c.ic_cookie = ch;
        ch->ch_i2c.ic_exec = ki2c_i2c_exec;
        ch->ch_i2c.ic_acquire_bus = ki2c_acquire_bus;
        ch->ch_i2c.ic_release_bus = ki2c_release_bus;

        ch->ch_sc = sc;
        ch->ch_node = node;
        ch->ch_channel = channel;
}

CFATTACH_DECL_NEW(ki2c, sizeof(struct ki2c_softc), ki2c_match, ki2c_attach,
        NULL, NULL);

int
ki2c_match(device_t parent, cfdata_t match, void *aux)
{
        struct confargs *ca = aux;

        if (strcmp(ca->ca_name, "i2c") == 0)
                return 1;

        return 0;
}

void
ki2c_attach(device_t parent, device_t self, void *aux)
{
        struct ki2c_softc *sc = device_private(self);
        struct confargs *ca = aux;
        int node = ca->ca_node;
        uint32_t addr, channel;
        int rate, child, irq, type;
        char name[32], intr_xname[32];

        sc->sc_dev = self;
        sc->sc_tag = ca->ca_tag;
        ca->ca_reg[0] += ca->ca_baseaddr;

        if (OF_getprop(node, "AAPL,i2c-rate", &rate, 4) != 4) {
                aprint_error(": cannot get i2c-rate\n");
                return;
        }
        if (OF_getprop(node, "AAPL,address", &addr, 4) != 4) {
                aprint_error(": unable to find i2c address\n");
                return;
        }
        if (bus_space_map(sc->sc_tag, addr, PAGE_SIZE, 0, &sc->sc_bh) != 0) {
                aprint_error_dev(sc->sc_dev, "failed to map registers\n");
                return;
        }

        if (OF_getprop(node, "AAPL,address-step", &sc->sc_regstep, 4) != 4) {
                aprint_error(": unable to find i2c address step\n");
                return;
        }

        irq = OF_get_intr(node, intr_xname, 32, &type);
        sc->sc_poll = (irq == -1);

        if (sc->sc_poll) {
                aprint_normal(" polling");
        } else aprint_normal(" %s", intr_xname);

        printf("\n");

        ki2c_writereg(sc, STATUS, 0);
        ki2c_writereg(sc, ISR, 0);
        ki2c_writereg(sc, IER, 0);

        ki2c_setmode(sc, I2C_STDSUBMODE);
        ki2c_setspeed(sc, I2C_100kHz);          /* XXX rate */

        ki2c_writereg(sc, IER,I2C_INT_DATA|I2C_INT_ADDR|I2C_INT_STOP);

        /*
         * Newer OpenFirmware will have "i2c-bus" nodes below the controller
         * node.  If we don't find any, then the devices are direct children
         * of the controller node, and the channel number is encoded in
         * bit 8 of the i2c address cell (see ofw_i2c_machdep.c).
         */
        bool found_busnode = false;
        for (child = OF_child(node); child != 0; child = OF_peer(child)) {
                OF_getprop(child, "name", name, sizeof(name));
                if (strcmp(name, "i2c-bus") == 0) {
                        OF_getprop(child, "reg", &channel, sizeof(channel));
                        DPRINTF("found channel %x\n", channel);
                        if (channel >= KI2C_MAX_CHANNELS) {
                                aprint_error_dev(self,
                                    "ignoring invalid I2C channel %u\n",
                                    channel);
                                continue;
                        }
                        ki2c_init_channel(sc, channel, child);
                        found_busnode = true;
                }
        }
        if (!found_busnode) {
                for (channel = 0; channel < KI2C_MAX_CHANNELS; channel++) {
                        ki2c_init_channel(sc, channel, node);
                }
        }

        /*
         * The Keywest I2C controller has a built-in I2C mux, but it's not
         * really a distinct device in the device tree, so we handle it here.
         *
         * The locking order is:
         *
         *      iic bus mutex -> mux_lock
         *
         * mux_lock is taken in ki2c_acquire_bus().
         */
        mutex_init(&sc->sc_mux_lock, MUTEX_DEFAULT, IPL_NONE);

        cv_init(&sc->sc_todev, device_xname(self));
        mutex_init(&sc->sc_todevmtx, MUTEX_DEFAULT, IPL_NONE);

        if(sc->sc_poll == 0) {
                snprintf(intr_xname, sizeof(intr_xname), "%s intr", device_xname(self));
                intr_establish_xname(irq, type, IPL_BIO, ki2c_intr, sc,
                    intr_xname);

                ki2c_writereg(sc, IER, I2C_INT_DATA | I2C_INT_ADDR| I2C_INT_STOP);
        }

        for (channel = 0; channel < KI2C_MAX_CHANNELS; channel++) {
                if (sc->sc_channels[channel].ch_node == 0) {
                        continue;
                }
                iicbus_attach_with_devhandle(sc->sc_dev,
                    &sc->sc_channels[channel].ch_i2c,
                    devhandle_from_of(device_handle(sc->sc_dev),
                                      sc->sc_channels[channel].ch_node));
        }
}

uint8_t
ki2c_readreg(struct ki2c_softc *sc, int reg)
{

        return bus_space_read_1(sc->sc_tag, sc->sc_bh, sc->sc_regstep * reg);
}

void
ki2c_writereg(struct ki2c_softc *sc, int reg, uint8_t val)
{

        bus_space_write_1(sc->sc_tag, sc->sc_bh, reg * sc->sc_regstep, val);
        delay(10);
}

u_int
ki2c_getmode(struct ki2c_softc *sc)
{
        return ki2c_readreg(sc, MODE) & I2C_MODE;
}

void
ki2c_setmode(struct ki2c_softc *sc, u_int mode)
{
        ki2c_writereg(sc, MODE, mode);
}

u_int
ki2c_getspeed(struct ki2c_softc *sc)
{
        return ki2c_readreg(sc, MODE) & I2C_SPEED;
}

void
ki2c_setspeed(struct ki2c_softc *sc, u_int speed)
{
        u_int x;

        KASSERT((speed & ~I2C_SPEED) == 0);
        x = ki2c_readreg(sc, MODE);
        x &= ~I2C_SPEED;
        x |= speed;
        ki2c_writereg(sc, MODE, x);
}

int
ki2c_intr(void *cookie)
{
        struct ki2c_softc *sc = cookie;
        u_int isr, x;
        isr = ki2c_readreg(sc, ISR);
        if (isr & I2C_INT_ADDR) {
#if 0
                if ((ki2c_readreg(sc, STATUS) & I2C_ST_LASTAAK) == 0) {
                        /* No slave responded. */
                        sc->sc_flags |= I2C_ERROR;
                        goto out;
                }
#endif

                if (sc->sc_flags & I2C_READING) {
                        if (sc->sc_resid > 1) {
                                x = ki2c_readreg(sc, CONTROL);
                                x |= I2C_CT_AAK;
                                ki2c_writereg(sc, CONTROL, x);
                        }
                } else {
                        ki2c_writereg(sc, DATA, *sc->sc_data++);
                        sc->sc_resid--;
                }
        }

        if (isr & I2C_INT_DATA) {
                if (sc->sc_flags & I2C_READING) {
                        *sc->sc_data++ = ki2c_readreg(sc, DATA);
                        sc->sc_resid--;

                        if (sc->sc_resid == 0) {        /* Completed */
                                ki2c_writereg(sc, CONTROL, 0);
                                goto out;
                        }
                } else {
#if 0
                        if ((ki2c_readreg(sc, STATUS) & I2C_ST_LASTAAK) == 0) {
                                /* No slave responded. */
                                sc->sc_flags |= I2C_ERROR;
                                goto out;
                        }
#endif

                        if (sc->sc_resid == 0) {
                                x = ki2c_readreg(sc, CONTROL) | I2C_CT_STOP;
                                ki2c_writereg(sc, CONTROL, x);
                        } else {
                                ki2c_writereg(sc, DATA, *sc->sc_data++);
                                sc->sc_resid--;
                        }
                }
        }

out:
        if (isr & I2C_INT_STOP) {
                ki2c_writereg(sc, CONTROL, 0);
                sc->sc_flags &= ~I2C_BUSY;
                cv_signal(&sc->sc_todev);
        }

        ki2c_writereg(sc, ISR, isr);

        return 1;
}

int
ki2c_poll(struct ki2c_softc *sc, int timo)
{
        int bail = 0;
        while (sc->sc_flags & I2C_BUSY) {
                if ((cold) || (bail > 10) || (sc->sc_poll)) {
                        if (ki2c_readreg(sc, ISR))
                                ki2c_intr(sc);
                        timo -= 10;
                        if (timo < 0) {
                                DPRINTF("i2c_poll: timeout\n");
                                return -1;
                        }
                        delay(10);
                } else {
                        mutex_enter(&sc->sc_todevmtx);
                        cv_timedwait_sig(&sc->sc_todev, &sc->sc_todevmtx, hz/10);
                        mutex_exit(&sc->sc_todevmtx);
                        bail++;
                }
        }
        return 0;
}

int
ki2c_start(struct ki2c_softc *sc, int addr, int subaddr, void *data, int len)
{
        int rw = (sc->sc_flags & I2C_READING) ? 1 : 0;
        int timo, x;

        KASSERT((addr & 1) == 0);

        sc->sc_data = data;
        sc->sc_resid = len;
        sc->sc_flags |= I2C_BUSY;

        timo = 1000 + len * 200;

        /* XXX TAS3001 sometimes takes 50ms to finish writing registers. */
        /* if (addr == 0x68) */
                timo += 100000;

        ki2c_writereg(sc, ADDR, addr | rw);
        ki2c_writereg(sc, SUBADDR, subaddr);

        x = ki2c_readreg(sc, CONTROL) | I2C_CT_ADDR;
        ki2c_writereg(sc, CONTROL, x);

        if (ki2c_poll(sc, timo))
                return -1;
        if (sc->sc_flags & I2C_ERROR) {
                DPRINTF("I2C_ERROR\n");
                return -1;
        }
        return 0;
}

int
ki2c_read(struct ki2c_softc *sc, int addr, int subaddr, void *data, int len)
{
        sc->sc_flags = I2C_READING;
        DPRINTF("ki2c_read: %02x %d\n", addr, len);
        return ki2c_start(sc, addr, subaddr, data, len);
}

int
ki2c_write(struct ki2c_softc *sc, int addr, int subaddr, void *data, int len)
{
        sc->sc_flags = 0;
        DPRINTF("ki2c_write: %02x %d\n",addr,len);
        return ki2c_start(sc, addr, subaddr, data, len);
}

int
ki2c_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr, const void *vcmd,
    size_t cmdlen, void *vbuf, size_t buflen, int flags)
{
        struct ki2c_channel *ch = cookie;
        struct ki2c_softc *sc = ch->ch_sc;
        int i;
        size_t w_len;
        uint8_t *wp;
        uint8_t wrbuf[KI2C_EXEC_MAX_CMDLEN + KI2C_EXEC_MAX_CMDLEN];

        /*
         * We don't have any idea if the ki2c controller can execute
         * i2c quick_{read,write} operations, so if someone tries one,
         * return an error.
         */
        if (cmdlen == 0 && buflen == 0)
                return -1;

        /*
         * Transaction could be much larger now. Bail if it exceeds our
         * small combining buffer, we don't expect such devices.
         */
        if (cmdlen + buflen > sizeof(wrbuf))
                return -1;

        addr &= 0x7f;   /* KASSERT((addr & ~0x7f) == 0); ??? */

        ki2c_setspeed(sc, I2C_50kHz);

        /* Write-buffer defaults to vcmd */
        wp = (uint8_t *)(__UNCONST(vcmd));
        w_len = cmdlen;

        /*
         * Concatenate vcmd and vbuf for write operations
         *
         * Drivers written specifically for ki2c might already do this,
         * but "generic" i2c drivers still provide separate arguments
         * for the cmd and buf parts of iic_smbus_write_{byte,word}.
         */
        if (I2C_OP_WRITE_P(op) && buflen != 0) {
                if (cmdlen == 0) {
                        wp = (uint8_t *)vbuf;
                        w_len = buflen;
                } else {
                        KASSERT((cmdlen + buflen) <= sizeof(wrbuf));
                        wp = (uint8_t *)(__UNCONST(vcmd));
                        w_len = 0;
                        for (i = 0; i < cmdlen; i++)
                                wrbuf[w_len++] = *wp++;
                        wp = (uint8_t *)vbuf;
                        for (i = 0; i < buflen; i++)
                                wrbuf[w_len++] = *wp++;
                        wp = wrbuf;
                }
        }

        if (w_len > 0)
                if (ki2c_write(sc, addr << 1, 0, wp, w_len) !=0 )
                        return -1;

        if (I2C_OP_READ_P(op)) {
                if (ki2c_read(sc, addr << 1, 0, vbuf, buflen) !=0 )
                        return -1;
        }
        return 0;
}