/* $NetBSD: auvitek_i2c.c,v 1.9 2025/09/15 13:23:03 thorpej Exp $ */

/*-
 * Copyright (c) 2010 Jared D. McNeill <jmcneill@invisible.ca>
 * 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.
 *
 * 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.
 */

/*
 * Auvitek AU0828 USB controller - I2C access ops
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: auvitek_i2c.c,v 1.9 2025/09/15 13:23:03 thorpej Exp $");

#ifdef _KERNEL_OPT
#include "opt_usb.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/module.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <dev/usb/usbdevs.h>

#include <dev/i2c/i2cvar.h>

#include <dev/usb/auvitekreg.h>
#include <dev/usb/auvitekvar.h>

/* #define AUVITEK_I2C_DEBUG */

static int      auvitek_i2c_exec(void *, i2c_op_t, i2c_addr_t,
                                 const void *, size_t, void *, size_t, int);

static int      auvitek_i2c_read(struct auvitek_softc *, i2c_addr_t,
                                 uint8_t *, size_t);
static int      auvitek_i2c_write(struct auvitek_softc *, i2c_addr_t,
                                  const uint8_t *, size_t);
static bool     auvitek_i2c_wait(struct auvitek_softc *);
static bool     auvitek_i2c_wait_rdack(struct auvitek_softc *);
static bool     auvitek_i2c_wait_rddone(struct auvitek_softc *);
static bool     auvitek_i2c_wait_wrdone(struct auvitek_softc *);

int
auvitek_i2c_attach(struct auvitek_softc *sc)
{

        iic_tag_init(&sc->sc_i2c);
        sc->sc_i2c.ic_cookie = sc;
        sc->sc_i2c.ic_exec = auvitek_i2c_exec;

        auvitek_i2c_rescan(sc, NULL, NULL);

        sc->sc_i2c_attached = true;

        return 0;
}

int
auvitek_i2c_detach(struct auvitek_softc *sc, int flags)
{

        if (!sc->sc_i2c_attached)
                return 0;

        iic_tag_fini(&sc->sc_i2c);

        return 0;
}

void
auvitek_i2c_rescan(struct auvitek_softc *sc, const char *ifattr,
    const int *locs)
{
#ifdef AUVITEK_I2C_DEBUG
        if (ifattr_match(ifattr, "i2cbus") && sc->sc_i2cdev == NULL) {
                sc->sc_i2cdev = iicbus_attach(sc->sc_dev, &sc->sc_i2c);
        }
#endif
}

void
auvitek_i2c_childdet(struct auvitek_softc *sc, device_t child)
{
        if (sc->sc_i2cdev == child)
                sc->sc_i2cdev = NULL;
}

static int
auvitek_i2c_exec(void *opaque, i2c_op_t op, i2c_addr_t addr,
    const void *cmd, size_t cmdlen, void *vbuf, size_t buflen, int flags)
{
        struct auvitek_softc *sc = opaque;

        if (I2C_OP_READ_P(op))
                return auvitek_i2c_read(sc, addr, vbuf, buflen);
        else
                return auvitek_i2c_write(sc, addr, cmd, cmdlen);
}

static int
auvitek_i2c_read(struct auvitek_softc *sc, i2c_addr_t addr,
    uint8_t *buf, size_t buflen)
{
        uint8_t v;
        unsigned int i;

        auvitek_write_1(sc, AU0828_REG_I2C_MBMODE, 1);
        auvitek_write_1(sc, AU0828_REG_I2C_CLKDIV, sc->sc_i2c_clkdiv);
        auvitek_write_1(sc, AU0828_REG_I2C_DSTADDR, addr << 1);

        if (buflen == 0) {
                auvitek_write_1(sc, AU0828_REG_I2C_TRIGGER,
                    AU0828_I2C_TRIGGER_RD);
                if (auvitek_i2c_wait_rdack(sc) == false)
                        return EBUSY;
                return 0;
        }

        for (i = 0; i < buflen; i++) {
                v = AU0828_I2C_TRIGGER_RD;
                if (i < (buflen - 1))
                        v |= AU0828_I2C_TRIGGER_HOLD;
                auvitek_write_1(sc, AU0828_REG_I2C_TRIGGER, v);

                if (auvitek_i2c_wait_rddone(sc) == false)
                        return EBUSY;

                buf[i] = auvitek_read_1(sc, AU0828_REG_I2C_FIFORD);
        }

        if (auvitek_i2c_wait(sc) == false)
                return EBUSY;

        return 0;
}

static int
auvitek_i2c_write(struct auvitek_softc *sc, i2c_addr_t addr,
    const uint8_t *buf, size_t buflen)
{
        uint8_t v;
        unsigned int i, fifolen;

        auvitek_write_1(sc, AU0828_REG_I2C_MBMODE, 1);
        auvitek_write_1(sc, AU0828_REG_I2C_CLKDIV, sc->sc_i2c_clkdiv);
        auvitek_write_1(sc, AU0828_REG_I2C_DSTADDR, addr << 1);

        if (buflen == 0) {
                auvitek_write_1(sc, AU0828_REG_I2C_TRIGGER,
                    AU0828_I2C_TRIGGER_RD);
                if (auvitek_i2c_wait(sc) == false)
                        return EBUSY;
                if (auvitek_i2c_wait_rdack(sc) == false)
                        return EBUSY;
                return 0;
        }

        fifolen = 0;
        for (i = 0; i < buflen; i++) {
                v = AU0828_I2C_TRIGGER_WR;
                if (i < (buflen - 1))
                        v |= AU0828_I2C_TRIGGER_HOLD;

                auvitek_write_1(sc, AU0828_REG_I2C_FIFOWR, buf[i]);
                ++fifolen;

                if (fifolen == 4 || i == (buflen - 1)) {
                        auvitek_write_1(sc, AU0828_REG_I2C_TRIGGER, v);
                        fifolen = 0;

                        if (auvitek_i2c_wait_wrdone(sc) == false)
                                return EBUSY;
                }
        }

        if (auvitek_i2c_wait(sc) == false)
                return EBUSY;

        return 0;
}

static bool
auvitek_i2c_wait(struct auvitek_softc *sc)
{
        uint8_t status;
        int retry = 1000;

        while (--retry > 0) {
                status = auvitek_read_1(sc, AU0828_REG_I2C_STATUS);
                if (!(status & AU0828_I2C_STATUS_BUSY))
                        break;
                delay(10);
        }
        if (retry == 0)
                return false;

        return true;
}

static bool
auvitek_i2c_wait_rdack(struct auvitek_softc *sc)
{
        uint8_t status;
        int retry = 1000;

        while (--retry > 0) {
                status = auvitek_read_1(sc, AU0828_REG_I2C_STATUS);
                if (!(status & AU0828_I2C_STATUS_NO_RD_ACK))
                        break;
                delay(10);
        }
        if (retry == 0)
                return false;

        return true;
}

static bool
auvitek_i2c_wait_rddone(struct auvitek_softc *sc)
{
        uint8_t status;
        int retry = 1000;

        while (--retry > 0) {
                status = auvitek_read_1(sc, AU0828_REG_I2C_STATUS);
                if (status & AU0828_I2C_STATUS_RD_DONE)
                        break;
                delay(10);
        }
        if (retry == 0)
                return false;

        return true;
}

static bool
auvitek_i2c_wait_wrdone(struct auvitek_softc *sc)
{
        uint8_t status;
        int retry = 1000;

        while (--retry > 0) {
                status = auvitek_read_1(sc, AU0828_REG_I2C_STATUS);
                if (status & AU0828_I2C_STATUS_WR_DONE)
                        break;
                delay(10);
        }
        if (retry == 0)
                return false;

        return true;
}