/*-
 * Copyright (c) 1998, 2001 Nicolas Souchu
 * 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 AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD: src/sys/dev/iicbus/iicbus.c,v 1.29 2009/02/10 22:50:23 imp Exp $
 */

/*
 * Autoconfiguration and support routines for the Philips serial I2C bus
 */

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

#include <bus/iicbus/iiconf.h>
#include <bus/iicbus/iicbus.h>

#include "iicbus_if.h"

#define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev))

devclass_t iicbus_devclass;

/* See comments below for why auto-scanning is a bad idea. */
#define SCAN_IICBUS 0

/*
 * Device methods
 */
static int iicbus_probe(device_t);
static int iicbus_attach(device_t);
static int iicbus_detach(device_t);
static int iicbus_add_child(device_t dev, int order, const char *name, int unit);

static device_method_t iicbus_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         iicbus_probe),
        DEVMETHOD(device_attach,        iicbus_attach),
        DEVMETHOD(device_detach,        iicbus_detach),

        /* bus interface */
        DEVMETHOD(bus_add_child,        iicbus_add_child),
        DEVMETHOD(bus_driver_added,     bus_generic_driver_added),
        DEVMETHOD(bus_print_child,      bus_generic_print_child),

        DEVMETHOD(iicbus_transfer,      iicbus_transfer_gen),

        DEVMETHOD_END
};

driver_t iicbus_driver = {
        "iicbus",
        iicbus_methods,
        sizeof(struct iicbus_softc),
};

static int
iicbus_probe(device_t dev)
{

        device_set_desc(dev, "Philips I2C bus");

        /* Allow other subclasses to override this driver. */
        return (BUS_PROBE_GENERIC);
}

#if SCAN_IICBUS
static int
iic_probe_device(device_t dev, u_char addr)
{
        int count;
        char byte;

        if ((addr & 1) == 0) {
                /* is device writable? */
                if (!iicbus_start(dev, addr, 0)) {
                        iicbus_stop(dev);
                        return (1);
                }
        } else {
                /* is device readable? */
                if (!iicbus_block_read(dev, addr, &byte, 1, &count))
                        return (1);
        }

        return (0);
}
#endif

/*
 * We add all the devices which we know about.
 * The generic attach routine will attach them if they are alive.
 */
static int
iicbus_attach(device_t dev)
{
#if SCAN_IICBUS
        unsigned char addr;
#endif

        iicbus_reset(dev, IIC_FASTEST, 0, NULL);

        /* device probing is meaningless since the bus is supposed to be
         * hot-plug. Moreover, some I2C chips do not appreciate random
         * accesses like stop after start to fast, reads for less than
         * x bytes...
         */
#if SCAN_IICBUS
        kprintf("Probing for devices on iicbus%d:", device_get_unit(dev));

        /* probe any devices */
        for (addr = 16; addr < 240; addr++) {
                if (iic_probe_device(dev, (u_char)addr)) {
                        kprintf(" <%x>", addr);
                }
        }
        kprintf("\n");
#endif

        device_add_child(dev, "ic", -1);
        device_add_child(dev, "iic", -1);
        device_add_child(dev, "iicsmb", -1);
#if 0
        /* attach any known device */
        device_add_child(dev, "iic", -1);
#endif
        bus_generic_attach(dev);
         
        return (0);
}

static int
iicbus_detach(device_t dev)
{
        iicbus_reset(dev, IIC_FASTEST, 0, NULL);
        bus_generic_detach(dev);
        return (0);
}

static int
iicbus_add_child(device_t dev, int order, const char *name, int unit)
{

        device_add_child_ordered(dev, order, name, unit);
        bus_generic_attach(dev);
        return (0);
}

int
iicbus_generic_intr(device_t dev, int event, char *buf)
{

        return (0);
}

int
iicbus_null_callback(device_t dev, int index, caddr_t data)
{

        return (0);
}

int
iicbus_null_repeated_start(device_t dev, u_char addr)
{

        return (IIC_ENOTSUPP);
}

DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, NULL, NULL);
MODULE_VERSION(iicbus, IICBUS_MODVER);