/*      $NetBSD: gpiic_opb.c,v 1.12 2021/08/07 16:19:03 thorpej Exp $   */

/*
* Copyright 2002, 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Steve C. Woodford for Wasabi Systems, Inc.
*
* 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. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed for the NetBSD Project by
*      Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
*    or promote products derived from this software without specific prior
*    written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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 "locators.h"

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

#include <dev/i2c/i2cvar.h>
#include <dev/i2c/i2c_bitbang.h>

#include <powerpc/ibm4xx/cpu.h>
#include <powerpc/ibm4xx/dev/opbvar.h>
#include <powerpc/ibm4xx/dev/gpiicreg.h>

struct gpiic_softc {
       device_t sc_dev;
       bus_space_tag_t sc_bust;
       bus_space_handle_t sc_bush;
       uint8_t sc_txen;
       uint8_t sc_tx;
       struct i2c_controller sc_i2c;
       struct i2c_bitbang_ops sc_bops;
};

static int      gpiic_match(device_t, cfdata_t, void *);
static void     gpiic_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(gpiic, sizeof(struct gpiic_softc),
   gpiic_match, gpiic_attach, NULL, NULL);

static int      gpiic_send_start(void *, int);
static int      gpiic_send_stop(void *, int);
static int      gpiic_initiate_xfer(void *, i2c_addr_t, int);
static int      gpiic_read_byte(void *, uint8_t *, int);
static int      gpiic_write_byte(void *, uint8_t, int);
static void     gpiic_set_dir(void *, uint32_t);
static void     gpiic_set_bits(void *, uint32_t);
static uint32_t gpiic_read_bits(void *);

static int
gpiic_match(device_t parent, cfdata_t cf, void *args)
{
       struct opb_attach_args * const oaa = args;

       if (strcmp(oaa->opb_name, cf->cf_name) != 0)
               return 0;

       return (1);
}

static void
gpiic_attach(device_t parent, device_t self, void *args)
{
       struct gpiic_softc * const sc = device_private(self);
       struct opb_attach_args * const oaa = args;
       struct i2cbus_attach_args iba;

       aprint_naive(": IIC controller\n");
       aprint_normal(": On-Chip IIC controller\n");

       sc->sc_dev = self;
       sc->sc_bust = oaa->opb_bt;

       bus_space_map(sc->sc_bust, oaa->opb_addr, IIC_NREG, 0, &sc->sc_bush);

       sc->sc_txen = 0;
       sc->sc_tx = IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC;
       iic_tag_init(&sc->sc_i2c);
       sc->sc_i2c.ic_cookie = sc;
       sc->sc_i2c.ic_send_start = gpiic_send_start;
       sc->sc_i2c.ic_send_stop = gpiic_send_stop;
       sc->sc_i2c.ic_initiate_xfer = gpiic_initiate_xfer;
       sc->sc_i2c.ic_read_byte = gpiic_read_byte;
       sc->sc_i2c.ic_write_byte = gpiic_write_byte;

       sc->sc_bops.ibo_set_dir = gpiic_set_dir;
       sc->sc_bops.ibo_set_bits = gpiic_set_bits;
       sc->sc_bops.ibo_read_bits = gpiic_read_bits;
       sc->sc_bops.ibo_bits[I2C_BIT_SDA] = IIC_DIRECTCNTL_SDAC;
       sc->sc_bops.ibo_bits[I2C_BIT_SCL] = IIC_DIRECTCNTL_SCC;
       sc->sc_bops.ibo_bits[I2C_BIT_OUTPUT] = 1;
       sc->sc_bops.ibo_bits[I2C_BIT_INPUT] = 0;

       /*
        * Put the controller into Soft Reset. This allows us to
        * manually bit-bang the I2C clock/data lines.
        */
       bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_XTCNTLSS,
           IIC_XTCNTLSS_SRST);
       delay(10);
       bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL,
           IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);

       memset(&iba, 0, sizeof(iba));
       iba.iba_tag = &sc->sc_i2c;
       config_found(self, &iba, iicbus_print, CFARGS_NONE);
}

static int
gpiic_send_start(void *arg, int flags)
{
       struct gpiic_softc * const sc = arg;

       return (i2c_bitbang_send_start(sc, flags, &sc->sc_bops));
}

static int
gpiic_send_stop(void *arg, int flags)
{
       struct gpiic_softc * const sc = arg;

       return (i2c_bitbang_send_stop(sc, flags, &sc->sc_bops));
}

static int
gpiic_initiate_xfer(void *arg, i2c_addr_t addr, int flags)
{
       struct gpiic_softc * const sc = arg;

       return (i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_bops));
}

static int
gpiic_read_byte(void *arg, uint8_t *vp, int flags)
{
       struct gpiic_softc * const sc = arg;

       return (i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_bops));
}

static int
gpiic_write_byte(void *arg, uint8_t v, int flags)
{
       struct gpiic_softc * const sc = arg;

       return (i2c_bitbang_write_byte(sc, v, flags, &sc->sc_bops));
}

static void
gpiic_set_dir(void *arg, uint32_t bits)
{
       struct gpiic_softc * const sc = arg;
       uint8_t tx, txen;

       txen = (uint8_t)bits;
       if (sc->sc_txen == txen)
               return;

       sc->sc_txen = txen;

       tx = sc->sc_tx;
       if (sc->sc_txen == 0)
               tx |= IIC_DIRECTCNTL_SDAC;
       bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL, tx);
}

static void
gpiic_set_bits(void *arg, uint32_t bits)
{
       struct gpiic_softc * const sc = arg;

       sc->sc_tx = (uint8_t)bits;
       if (sc->sc_txen == 0)
               bits |= IIC_DIRECTCNTL_SDAC;

       bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL, bits);
}

static uint32_t
gpiic_read_bits(void *arg)
{
       struct gpiic_softc * const sc = arg;
       uint8_t rv;

       rv = bus_space_read_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL) << 2;
       rv &= (IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);

       return ((uint32_t)rv);
}

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