/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2013-2014 Ruslan Bukin <br@bsdpad.com>
 * 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.
 */

/*
 * Vybrid Family Input/Output Multiplexer Controller (IOMUXC)
 * Chapter 5, Vybrid Reference Manual, Rev. 5, 07/2013
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>

#include <dev/fdt/fdt_common.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>

#include <arm/freescale/vybrid/vf_iomuxc.h>
#include <arm/freescale/vybrid/vf_common.h>

#define MUX_MODE_MASK           7
#define MUX_MODE_SHIFT          20
#define MUX_MODE_GPIO           0
#define MUX_MODE_VBUS_EN_OTG    2

#define IBE             (1 << 0)        /* Input Buffer Enable Field */
#define OBE             (1 << 1)        /* Output Buffer Enable Field. */
#define PUE             (1 << 2)        /* Pull / Keep Select Field. */
#define PKE             (1 << 3)        /* Pull / Keep Enable Field. */
#define HYS             (1 << 9)        /* Hysteresis Enable Field */
#define ODE             (1 << 10)       /* Open Drain Enable Field. */
#define SRE             (1 << 11)       /* Slew Rate Field. */

#define SPEED_SHIFT             12
#define SPEED_MASK              0x3
#define SPEED_LOW               0       /* 50 MHz */
#define SPEED_MEDIUM            0x1     /* 100 MHz */
#define SPEED_HIGH              0x3     /* 200 MHz */

#define PUS_SHIFT               4       /* Pull Up / Down Config Field Shift */
#define PUS_MASK                0x3
#define PUS_100_KOHM_PULL_DOWN  0
#define PUS_47_KOHM_PULL_UP     0x1
#define PUS_100_KOHM_PULL_UP    0x2
#define PUS_22_KOHM_PULL_UP     0x3

#define DSE_SHIFT               6       /* Drive Strength Field Shift */
#define DSE_MASK                0x7
#define DSE_DISABLED            0       /* Output driver disabled */
#define DSE_150_OHM             0x1
#define DSE_75_OHM              0x2
#define DSE_50_OHM              0x3
#define DSE_37_OHM              0x4
#define DSE_30_OHM              0x5
#define DSE_25_OHM              0x6
#define DSE_20_OHM              0x7

#define MAX_MUX_LEN             1024

struct iomuxc_softc {
        struct resource         *tmr_res[1];
        bus_space_tag_t         bst;
        bus_space_handle_t      bsh;
        device_t                dev;
};

static struct resource_spec iomuxc_spec[] = {
        { SYS_RES_MEMORY,       0,      RF_ACTIVE },
        { -1, 0 }
};

static int
iomuxc_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (!ofw_bus_is_compatible(dev, "fsl,mvf600-iomuxc"))
                return (ENXIO);

        device_set_desc(dev, "Vybrid Family IOMUXC Unit");
        return (BUS_PROBE_DEFAULT);
}

static int
pinmux_set(struct iomuxc_softc *sc)
{
        phandle_t child, parent, root;
        pcell_t iomux_config[MAX_MUX_LEN];
        int len;
        int values;
        int pin;
        int pin_cfg;
        int i;

        root = OF_finddevice("/");
        len = 0;
        parent = root;

        /* Find 'iomux_config' prop in the nodes */
        for (child = OF_child(parent); child != 0; child = OF_peer(child)) {
                /* Find a 'leaf'. Start the search from this node. */
                while (OF_child(child)) {
                        parent = child;
                        child = OF_child(child);
                }

                if (!ofw_bus_node_status_okay(child))
                        continue;

                if ((len = OF_getproplen(child, "iomux_config")) > 0) {
                        OF_getencprop(child, "iomux_config", iomux_config, len);

                        values = len / (sizeof(uint32_t));
                        for (i = 0; i < values; i += 2) {
                                pin = iomux_config[i];
                                pin_cfg = iomux_config[i+1];
#if 0
                                device_printf(sc->dev, "Set pin %d to 0x%08x\n",
                                    pin, pin_cfg);
#endif
                                WRITE4(sc, IOMUXC(pin), pin_cfg);
                        }
                }

                if (OF_peer(child) == 0) {
                        /* No more siblings. */
                        child = parent;
                        parent = OF_parent(child);
                }
        }

        return (0);
}

static int
iomuxc_attach(device_t dev)
{
        struct iomuxc_softc *sc;

        sc = device_get_softc(dev);
        sc->dev = dev;

        if (bus_alloc_resources(dev, iomuxc_spec, sc->tmr_res)) {
                device_printf(dev, "could not allocate resources\n");
                return (ENXIO);
        }

        /* Memory interface */
        sc->bst = rman_get_bustag(sc->tmr_res[0]);
        sc->bsh = rman_get_bushandle(sc->tmr_res[0]);

        pinmux_set(sc);

        return (0);
}

static device_method_t iomuxc_methods[] = {
        DEVMETHOD(device_probe,         iomuxc_probe),
        DEVMETHOD(device_attach,        iomuxc_attach),
        { 0, 0 }
};

static driver_t iomuxc_driver = {
        "iomuxc",
        iomuxc_methods,
        sizeof(struct iomuxc_softc),
};

DRIVER_MODULE(iomuxc, simplebus, iomuxc_driver, 0, 0);