/*-
 * Copyright (c) 2009, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
 * 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 unmodified, 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 ``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/bus.h>
#include <sys/kernel.h>
#include <sys/libkern.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>

#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/openfirm.h>

#include "iicbus_if.h"
#include "ofw_iicbus_if.h"

/* Methods */
static device_probe_t ofw_iicbus_probe;
static device_attach_t ofw_iicbus_attach;
static device_t ofw_iicbus_add_child(device_t dev, u_int order,
    const char *name, int unit);
static const struct ofw_bus_devinfo *ofw_iicbus_get_devinfo(device_t bus,
    device_t dev);
static int ofw_iicbus_set_devinfo(device_t bus, device_t dev,
    phandle_t ofw_node, char *ofw_name, char *ofw_compat, uint32_t i2c_addr);

static device_method_t ofw_iicbus_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ofw_iicbus_probe),
        DEVMETHOD(device_attach,        ofw_iicbus_attach),

        /* Bus interface */
        DEVMETHOD(bus_child_pnpinfo,    ofw_bus_gen_child_pnpinfo),
        DEVMETHOD(bus_add_child,        ofw_iicbus_add_child),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_get_devinfo,  ofw_iicbus_get_devinfo),
        DEVMETHOD(ofw_bus_get_compat,   ofw_bus_gen_get_compat),
        DEVMETHOD(ofw_bus_get_model,    ofw_bus_gen_get_model),
        DEVMETHOD(ofw_bus_get_name,     ofw_bus_gen_get_name),
        DEVMETHOD(ofw_bus_get_node,     ofw_bus_gen_get_node),
        DEVMETHOD(ofw_bus_get_type,     ofw_bus_gen_get_type),

        /* ofw_iicbus interface */
        DEVMETHOD(ofw_iicbus_set_devinfo, ofw_iicbus_set_devinfo),

        DEVMETHOD_END
};

struct ofw_iicbus_devinfo {
        struct iicbus_ivar      opd_dinfo;      /* Must be the first. */
        struct ofw_bus_devinfo  opd_obdinfo;
};

DEFINE_CLASS_1(iicbus, ofw_iicbus_driver, ofw_iicbus_methods,
    sizeof(struct iicbus_softc), iicbus_driver);
EARLY_DRIVER_MODULE(ofw_iicbus, iicbb, ofw_iicbus_driver, 0, 0, BUS_PASS_BUS);
EARLY_DRIVER_MODULE(ofw_iicbus, iichb, ofw_iicbus_driver, 0, 0, BUS_PASS_BUS);
EARLY_DRIVER_MODULE(ofw_iicbus, twsi, ofw_iicbus_driver, 0, 0, BUS_PASS_BUS);
MODULE_VERSION(ofw_iicbus, 1);
MODULE_DEPEND(ofw_iicbus, iicbus, 1, 1, 1);

static int
ofw_iicbus_probe(device_t dev)
{

        if (ofw_bus_get_node(dev) == -1)
                return (ENXIO);
        device_set_desc(dev, "OFW I2C bus");

        return (0);
}

static int
ofw_iicbus_attach(device_t dev)
{
        struct iicbus_softc *sc = IICBUS_SOFTC(dev);
        struct ofw_iicbus_devinfo *dinfo;
        phandle_t child, node, root;
        pcell_t freq, paddr;
        device_t childdev;
        ssize_t compatlen;
        char compat[255];
        char *curstr;
        u_int iic_addr_8bit = 0;

        sc->dev = dev;
        mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF);

        /*
         * If there is a clock-frequency property for the device node, use it as
         * the starting value for the bus frequency.  Then call the common
         * routine that handles the tunable/sysctl which allows the FDT value to
         * be overridden by the user.
         */
        node = ofw_bus_get_node(dev);
        freq = 0;
        OF_getencprop(node, "clock-frequency", &freq, sizeof(freq));
        iicbus_init_frequency(dev, freq);
        
        iicbus_reset(dev, IIC_FASTEST, 0, NULL);

        bus_identify_children(dev);
        bus_enumerate_hinted_children(dev);

        /*
         * Check if we're running on a PowerMac, needed for the I2C
         * address below.
         */
        root = OF_peer(0);
        compatlen = OF_getprop(root, "compatible", compat,
                                sizeof(compat));
        if (compatlen != -1) {
            for (curstr = compat; curstr < compat + compatlen;
                curstr += strlen(curstr) + 1) {
                if (strncmp(curstr, "MacRISC", 7) == 0)
                    iic_addr_8bit = 1;
            }
        }

        /*
         * Attach those children represented in the device tree.
         */
        for (child = OF_child(node); child != 0; child = OF_peer(child)) {
                /*
                 * Try to get the I2C address first from the i2c-address
                 * property, then try the reg property.  It moves around
                 * on different systems.
                 */
                if (OF_getencprop(child, "i2c-address", &paddr,
                    sizeof(paddr)) == -1)
                        if (OF_getencprop(child, "reg", &paddr,
                            sizeof(paddr)) == -1)
                                continue;

                /*
                 * Now set up the I2C and OFW bus layer devinfo and add it
                 * to the bus.
                 */
                dinfo = malloc(sizeof(struct ofw_iicbus_devinfo), M_DEVBUF,
                    M_NOWAIT | M_ZERO);
                if (dinfo == NULL)
                        continue;
                /*
                 * FreeBSD drivers expect I2C addresses to be expressed as
                 * 8-bit values.  Apple OFW data contains 8-bit values, but
                 * Linux FDT data contains 7-bit values, so shift them up to
                 * 8-bit format.
                 */
                if (iic_addr_8bit)
                    dinfo->opd_dinfo.addr = paddr;
                else
                    dinfo->opd_dinfo.addr = paddr << 1;

                if (ofw_bus_gen_setup_devinfo(&dinfo->opd_obdinfo, child) !=
                    0) {
                        free(dinfo, M_DEVBUF);
                        continue;
                }

                childdev = device_add_child(dev, NULL, DEVICE_UNIT_ANY);
                resource_list_init(&dinfo->opd_dinfo.rl);
                ofw_bus_intr_to_rl(childdev, child,
                                        &dinfo->opd_dinfo.rl, NULL);
                device_set_ivars(childdev, dinfo);
        }

        /* Register bus */
        OF_device_register_xref(OF_xref_from_node(node), dev);
        bus_attach_children(dev);
        return (0);
}

static device_t
ofw_iicbus_add_child(device_t dev, u_int order, const char *name, int unit)
{
        device_t child;
        struct ofw_iicbus_devinfo *devi;

        child = device_add_child_ordered(dev, order, name, unit);
        if (child == NULL)
                return (child);
        devi = malloc(sizeof(struct ofw_iicbus_devinfo), M_DEVBUF,
            M_NOWAIT | M_ZERO);
        if (devi == NULL) {
                device_delete_child(dev, child);
                return (0);
        }

        /*
         * NULL all the OFW-related parts of the ivars for non-OFW
         * children.
         */
        devi->opd_obdinfo.obd_node = -1;
        devi->opd_obdinfo.obd_name = NULL;
        devi->opd_obdinfo.obd_compat = NULL;
        devi->opd_obdinfo.obd_type = NULL;
        devi->opd_obdinfo.obd_model = NULL;

        device_set_ivars(child, devi);

        return (child);
}

static const struct ofw_bus_devinfo *
ofw_iicbus_get_devinfo(device_t bus, device_t dev)
{
        struct ofw_iicbus_devinfo *dinfo;

        dinfo = device_get_ivars(dev);
        return (&dinfo->opd_obdinfo);
}

static int
ofw_iicbus_set_devinfo(device_t bus, device_t dev, phandle_t ofw_node,
    char *ofw_name, char *ofw_compat, uint32_t i2c_addr)
{
        struct ofw_iicbus_devinfo *devi;

        /*
         * Setup OFW-related parts of the ivars for manually
         * created ofw_iicbus childern.
         */
        devi = device_get_ivars(dev);
        if (devi == NULL)
                return (ENXIO);

        devi->opd_obdinfo.obd_node = ofw_node;
        if (ofw_name != NULL)
                devi->opd_obdinfo.obd_name = strdup(ofw_name, M_OFWPROP);
        if (ofw_compat != NULL)
                devi->opd_obdinfo.obd_compat = strdup(ofw_compat, M_OFWPROP);
        devi->opd_dinfo.addr = i2c_addr;
        return (0);
}