/*-
 * Copyright (c) 2020 Alstom Group.
 * Copyright (c) 2020 Semihalf.
 * Copyright (c) 2015 Justin Hibbits
 * 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <sys/gpio.h>
#include <sys/stdarg.h>

#include <machine/bus.h>
#include <machine/resource.h>

#include <dev/gpio/gpiobusvar.h>
#include <dev/gpio/qoriq_gpio.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include "gpio_if.h"

static device_t
qoriq_gpio_get_bus(device_t dev)
{
        struct qoriq_gpio_softc *sc;

        sc = device_get_softc(dev);

        return (sc->busdev);
}

static int
qoriq_gpio_pin_max(device_t dev, int *maxpin)
{

        *maxpin = MAXPIN;
        return (0);
}

/* Get a specific pin's capabilities. */
static int
qoriq_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
        struct qoriq_gpio_softc *sc;

        sc = device_get_softc(dev);

        if (!VALID_PIN(pin))
                return (EINVAL);

        GPIO_LOCK(sc);
        *caps = sc->sc_pins[pin].gp_caps;
        GPIO_UNLOCK(sc);

        return (0);
}

/* Get a specific pin's name. */
static int
qoriq_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
{

        if (!VALID_PIN(pin))
                return (EINVAL);

        snprintf(name, GPIOMAXNAME, "qoriq_gpio%d.%d",
            device_get_unit(dev), pin);
        name[GPIOMAXNAME-1] = '\0';

        return (0);
}

static int
qoriq_gpio_pin_configure(device_t dev, uint32_t pin, uint32_t flags)
{
        struct qoriq_gpio_softc *sc;
        uint32_t reg;

        sc = device_get_softc(dev);

        if ((flags & sc->sc_pins[pin].gp_caps) != flags) {
                return (EINVAL);
        }

        if (flags & GPIO_PIN_INPUT) {
                reg = bus_read_4(sc->sc_mem, GPIO_GPDIR);
                reg &= ~(1 << (31 - pin));
                bus_write_4(sc->sc_mem, GPIO_GPDIR, reg);
        }
        else if (flags & GPIO_PIN_OUTPUT) {
                reg = bus_read_4(sc->sc_mem, GPIO_GPDIR);
                reg |= (1 << (31 - pin));
                bus_write_4(sc->sc_mem, GPIO_GPDIR, reg);
                reg = bus_read_4(sc->sc_mem, GPIO_GPODR);
                if (flags & GPIO_PIN_OPENDRAIN)
                        reg |= (1 << (31 - pin));
                else
                        reg &= ~(1 << (31 - pin));
                bus_write_4(sc->sc_mem, GPIO_GPODR, reg);
        }
        sc->sc_pins[pin].gp_flags = flags;

        return (0);
}

/* Set flags for the pin. */
static int
qoriq_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
        struct qoriq_gpio_softc *sc = device_get_softc(dev);
        uint32_t ret;

        if (!VALID_PIN(pin))
                return (EINVAL);

        if ((flags & (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT)) ==
            (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT))
                return (EINVAL);

        GPIO_LOCK(sc);
        ret = qoriq_gpio_pin_configure(dev, pin, flags);
        GPIO_UNLOCK(sc);
        return (ret);
}

static int
qoriq_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *pflags)
{
        struct qoriq_gpio_softc *sc;

        if (!VALID_PIN(pin))
                return (EINVAL);

        sc = device_get_softc(dev);

        GPIO_LOCK(sc);
        *pflags = sc->sc_pins[pin].gp_flags;
        GPIO_UNLOCK(sc);

        return (0);
}

/* Set a specific output pin's value. */
static int
qoriq_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
{
        struct qoriq_gpio_softc *sc = device_get_softc(dev);
        uint32_t outvals;
        uint8_t pinbit;

        if (!VALID_PIN(pin) || value > 1)
                return (EINVAL);

        GPIO_LOCK(sc);
        pinbit = 31 - pin;

        outvals = bus_read_4(sc->sc_mem, GPIO_GPDAT);
        outvals &= ~(1 << pinbit);
        outvals |= (value << pinbit);
        bus_write_4(sc->sc_mem, GPIO_GPDAT, outvals);

        GPIO_UNLOCK(sc);

        return (0);
}

/* Get a specific pin's input value. */
static int
qoriq_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *value)
{
        struct qoriq_gpio_softc *sc = device_get_softc(dev);

        if (!VALID_PIN(pin))
                return (EINVAL);

        *value = (bus_read_4(sc->sc_mem, GPIO_GPDAT) >> (31 - pin)) & 1;

        return (0);
}

/* Toggle a pin's output value. */
static int
qoriq_gpio_pin_toggle(device_t dev, uint32_t pin)
{
        struct qoriq_gpio_softc *sc = device_get_softc(dev);
        uint32_t val;

        if (!VALID_PIN(pin))
                return (EINVAL);

        GPIO_LOCK(sc);

        val = bus_read_4(sc->sc_mem, GPIO_GPDAT);
        val ^= (1 << (31 - pin));
        bus_write_4(sc->sc_mem, GPIO_GPDAT, val);

        GPIO_UNLOCK(sc);

        return (0);
}

static struct ofw_compat_data gpio_matches[] = {
    {"fsl,pq3-gpio", 1},
    {"fsl,mpc8572-gpio", 1},
    {"fsl,qoriq-gpio", 1},
    {0, 0}
};

static int
qoriq_gpio_probe(device_t dev)
{

        if (ofw_bus_search_compatible(dev, gpio_matches)->ocd_data == 0)
                return (ENXIO);

        device_set_desc(dev, "Freescale QorIQ GPIO driver");

        return (0);
}

static int
qoriq_gpio_pin_access_32(device_t dev, uint32_t first_pin, uint32_t clear_pins,
    uint32_t change_pins, uint32_t *orig_pins)
{
        struct qoriq_gpio_softc *sc;
        uint32_t hwstate;

        sc = device_get_softc(dev);

        if (first_pin != 0)
                return (EINVAL);

        GPIO_LOCK(sc);
        hwstate = bus_read_4(sc->sc_mem, GPIO_GPDAT);
        bus_write_4(sc->sc_mem, GPIO_GPDAT,
            (hwstate & ~clear_pins) ^ change_pins);
        GPIO_UNLOCK(sc);

        if (orig_pins != NULL)
                *orig_pins = hwstate;

        return (0);
}

static int
qoriq_gpio_pin_config_32(device_t dev, uint32_t first_pin, uint32_t num_pins,
    uint32_t *pin_flags)
{
        uint32_t dir, odr, mask, reg;
        struct qoriq_gpio_softc *sc;
        uint32_t newflags[32];
        int i;

        if (first_pin != 0 || !VALID_PIN(num_pins))
                return (EINVAL);

        sc = device_get_softc(dev);

        dir = odr = mask = 0;

        for (i = 0; i < num_pins; i++) {
                newflags[i] = 0;
                mask |= (1 << i);

                if (pin_flags[i] & GPIO_PIN_INPUT) {
                        newflags[i] = GPIO_PIN_INPUT;
                        dir &= ~(1 << i);
                } else {
                        newflags[i] = GPIO_PIN_OUTPUT;
                        dir |= (1 << i);

                        if (pin_flags[i] & GPIO_PIN_OPENDRAIN) {
                                newflags[i] |= GPIO_PIN_OPENDRAIN;
                                odr |= (1 << i);
                        } else {
                                newflags[i] |= GPIO_PIN_PUSHPULL;
                                odr &= ~(1 << i);
                        }
                }
        }

        GPIO_LOCK(sc);

        reg = (bus_read_4(sc->sc_mem, GPIO_GPDIR) & ~mask) | dir;
        bus_write_4(sc->sc_mem, GPIO_GPDIR, reg);

        reg = (bus_read_4(sc->sc_mem, GPIO_GPODR) & ~mask) | odr;
        bus_write_4(sc->sc_mem, GPIO_GPODR, reg);

        for (i = 0; i < num_pins; i++)
                sc->sc_pins[i].gp_flags = newflags[i];

        GPIO_UNLOCK(sc);

        return (0);
}

static int
qoriq_gpio_map_gpios(device_t bus, phandle_t dev, phandle_t gparent, int gcells,
    pcell_t *gpios, uint32_t *pin, uint32_t *flags)
{
        struct qoriq_gpio_softc *sc;
        int err;

        if (!VALID_PIN(gpios[0]))
                return (EINVAL);

        sc = device_get_softc(bus);
        GPIO_LOCK(sc);
        err = qoriq_gpio_pin_configure(bus, gpios[0], gpios[1]);
        GPIO_UNLOCK(sc);

        if (err == 0) {
                *pin = gpios[0];
                *flags = gpios[1];
        }

        return (err);
}

int
qoriq_gpio_attach(device_t dev)
{
        struct qoriq_gpio_softc *sc = device_get_softc(dev);
        int i, rid;

        sc->dev = dev;

        GPIO_LOCK_INIT(sc);

        /* Allocate memory. */
        rid = 0;
        sc->sc_mem = bus_alloc_resource_any(dev,
                     SYS_RES_MEMORY, &rid, RF_ACTIVE);
        if (sc->sc_mem == NULL) {
                device_printf(dev, "Can't allocate memory for device output port");
                qoriq_gpio_detach(dev);
                return (ENOMEM);
        }

        for (i = 0; i <= MAXPIN; i++)
                sc->sc_pins[i].gp_caps = DEFAULT_CAPS;

        /*
         * Enable the GPIO Input Buffer for all GPIOs.
         * This is safe on devices without a GPIBE register, because those
         * devices ignore writes and read 0's in undefined portions of the map.
         */
        if (ofw_bus_is_compatible(dev, "fsl,qoriq-gpio"))
                bus_write_4(sc->sc_mem, GPIO_GPIBE, 0xffffffff);

        OF_device_register_xref(OF_xref_from_node(ofw_bus_get_node(dev)), dev);

        sc->busdev = gpiobus_add_bus(dev);
        if (sc->busdev == NULL) {
                qoriq_gpio_detach(dev);
                return (ENOMEM);
        }

        bus_attach_children(dev);
        return (0);
}

int
qoriq_gpio_detach(device_t dev)
{
        struct qoriq_gpio_softc *sc = device_get_softc(dev);

        gpiobus_detach_bus(dev);

        if (sc->sc_mem != NULL) {
                /* Release output port resource. */
                bus_release_resource(dev, SYS_RES_MEMORY,
                                     rman_get_rid(sc->sc_mem), sc->sc_mem);
        }

        GPIO_LOCK_DESTROY(sc);

        return (0);
}

static device_method_t qoriq_gpio_methods[] = {
        /* device_if */
        DEVMETHOD(device_probe,         qoriq_gpio_probe),
        DEVMETHOD(device_attach,        qoriq_gpio_attach),
        DEVMETHOD(device_detach,        qoriq_gpio_detach),

        /* GPIO protocol */
        DEVMETHOD(gpio_get_bus,         qoriq_gpio_get_bus),
        DEVMETHOD(gpio_pin_max,         qoriq_gpio_pin_max),
        DEVMETHOD(gpio_pin_getname,     qoriq_gpio_pin_getname),
        DEVMETHOD(gpio_pin_getcaps,     qoriq_gpio_pin_getcaps),
        DEVMETHOD(gpio_pin_get,         qoriq_gpio_pin_get),
        DEVMETHOD(gpio_pin_set,         qoriq_gpio_pin_set),
        DEVMETHOD(gpio_pin_getflags,    qoriq_gpio_pin_getflags),
        DEVMETHOD(gpio_pin_setflags,    qoriq_gpio_pin_setflags),
        DEVMETHOD(gpio_pin_toggle,      qoriq_gpio_pin_toggle),

        DEVMETHOD(gpio_map_gpios,       qoriq_gpio_map_gpios),
        DEVMETHOD(gpio_pin_access_32,   qoriq_gpio_pin_access_32),
        DEVMETHOD(gpio_pin_config_32,   qoriq_gpio_pin_config_32),

        DEVMETHOD_END
};

DEFINE_CLASS_0(gpio, qoriq_gpio_driver, qoriq_gpio_methods,
    sizeof(struct qoriq_gpio_softc));

EARLY_DRIVER_MODULE(qoriq_gpio, simplebus, qoriq_gpio_driver, NULL, NULL,
    BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);