/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>
 *
 * 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 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/bus.h>

#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/gpio.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <dev/gpio/gpiobusvar.h>

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

#include <dev/fdt/fdt_pinctrl.h>

#include "qcom_tlmm_var.h"
#include "qcom_tlmm_pin.h"

#include "qcom_tlmm_ipq4018_reg.h"
#include "qcom_tlmm_ipq4018_hw.h"

#include "gpio_if.h"

static struct gpio_pin *
qcom_tlmm_pin_lookup(struct qcom_tlmm_softc *sc, int pin)
{
        if (pin >= sc->gpio_npins)
                return (NULL);

        return &sc->gpio_pins[pin];
}

static void
qcom_tlmm_pin_configure(struct qcom_tlmm_softc *sc,
    struct gpio_pin *pin, unsigned int flags)
{

        GPIO_LOCK_ASSERT(sc);

        /*
         * Manage input/output
         */
        if (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
                pin->gp_flags &= ~(GPIO_PIN_INPUT|GPIO_PIN_OUTPUT);
                if (flags & GPIO_PIN_OUTPUT) {
                        /*
                         * XXX TODO: read GPIO_PIN_PRESET_LOW /
                         * GPIO_PIN_PRESET_HIGH and if we're a GPIO
                         * function pin here, set the output
                         * pin value before we flip on oe_output.
                         */
                        pin->gp_flags |= GPIO_PIN_OUTPUT;
                        qcom_tlmm_ipq4018_hw_pin_set_oe_output(sc,
                            pin->gp_pin);
                } else {
                        pin->gp_flags |= GPIO_PIN_INPUT;
                        qcom_tlmm_ipq4018_hw_pin_set_oe_input(sc,
                            pin->gp_pin);
                }
        }

        /*
         * Set pull-up / pull-down configuration
         */
        if (flags & GPIO_PIN_PULLUP) {
                pin->gp_flags |= GPIO_PIN_PULLUP;
                qcom_tlmm_ipq4018_hw_pin_set_pupd_config(sc, pin->gp_pin,
                    QCOM_TLMM_PIN_PUPD_CONFIG_PULL_UP);
        } else if (flags & GPIO_PIN_PULLDOWN) {
                pin->gp_flags |= GPIO_PIN_PULLDOWN;
                qcom_tlmm_ipq4018_hw_pin_set_pupd_config(sc, pin->gp_pin,
                    QCOM_TLMM_PIN_PUPD_CONFIG_PULL_DOWN);
        } else if ((flags & (GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN)) ==
            (GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN)) {
                pin->gp_flags |= GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN;
                qcom_tlmm_ipq4018_hw_pin_set_pupd_config(sc, pin->gp_pin,
                    QCOM_TLMM_PIN_PUPD_CONFIG_BUS_HOLD);
        } else {
                pin->gp_flags &= ~(GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN);
                qcom_tlmm_ipq4018_hw_pin_set_pupd_config(sc, pin->gp_pin,
                    QCOM_TLMM_PIN_PUPD_CONFIG_DISABLE);
        }
}

device_t
qcom_tlmm_get_bus(device_t dev)
{
        struct qcom_tlmm_softc *sc;

        sc = device_get_softc(dev);

        return (sc->busdev);
}

int
qcom_tlmm_pin_max(device_t dev, int *maxpin)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);

        *maxpin = sc->gpio_npins - 1;
        return (0);
}

int
qcom_tlmm_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);
        struct gpio_pin *p;

        p = qcom_tlmm_pin_lookup(sc, pin);
        if (p == NULL)
                return (EINVAL);

        GPIO_LOCK(sc);
        *caps = p->gp_caps;
        GPIO_UNLOCK(sc);

        return (0);
}

int
qcom_tlmm_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);
        uint32_t ret = 0, val;
        bool is_output;
        qcom_tlmm_pin_pupd_config_t pupd_config;

        if (pin >= sc->gpio_npins)
                return (EINVAL);

        *flags = 0;

        GPIO_LOCK(sc);

        /* Lookup function - see what it is, whether we're a GPIO line */
        ret = qcom_tlmm_ipq4018_hw_pin_get_function(sc, pin, &val);
        if (ret != 0)
                goto done;

        /* Lookup input/output state */
        ret = qcom_tlmm_ipq4018_hw_pin_get_oe_state(sc, pin, &is_output);
        if (ret != 0)
                goto done;
        if (is_output)
                *flags |= GPIO_PIN_OUTPUT;
        else
                *flags |= GPIO_PIN_INPUT;

        /* Lookup pull-up / pull-down state */
        ret = qcom_tlmm_ipq4018_hw_pin_get_pupd_config(sc, pin,
            &pupd_config);
        if (ret != 0)
                goto done;

        switch (pupd_config) {
        case QCOM_TLMM_PIN_PUPD_CONFIG_DISABLE:
                break;
        case QCOM_TLMM_PIN_PUPD_CONFIG_PULL_DOWN:
                *flags |= GPIO_PIN_PULLDOWN;
                break;
        case QCOM_TLMM_PIN_PUPD_CONFIG_PULL_UP:
                *flags |= GPIO_PIN_PULLUP;
                break;
        case QCOM_TLMM_PIN_PUPD_CONFIG_BUS_HOLD:
                *flags |= (GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN);
                break;
        }

done:
        GPIO_UNLOCK(sc);
        return (ret);
}

int
qcom_tlmm_pin_getname(device_t dev, uint32_t pin, char *name)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);
        struct gpio_pin *p;

        p = qcom_tlmm_pin_lookup(sc, pin);
        if (p == NULL)
                return (EINVAL);

        GPIO_LOCK(sc);
        memcpy(name, p->gp_name, GPIOMAXNAME);
        GPIO_UNLOCK(sc);

        return (0);
}

int
qcom_tlmm_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);
        struct gpio_pin *p;

        p = qcom_tlmm_pin_lookup(sc, pin);
        if (p == NULL)
                return (EINVAL);

        GPIO_LOCK(sc);
        qcom_tlmm_pin_configure(sc, p, flags);
        GPIO_UNLOCK(sc);

        return (0);
}

int
qcom_tlmm_pin_set(device_t dev, uint32_t pin, unsigned int value)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);
        int ret;

        if (pin >= sc->gpio_npins)
                return (EINVAL);

        GPIO_LOCK(sc);
        ret = qcom_tlmm_ipq4018_hw_pin_set_output_value(sc, pin, value);
        GPIO_UNLOCK(sc);

        return (ret);
}

int
qcom_tlmm_pin_get(device_t dev, uint32_t pin, unsigned int *val)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);
        int ret;

        if (pin >= sc->gpio_npins)
                return (EINVAL);

        GPIO_LOCK(sc);
        ret = qcom_tlmm_ipq4018_hw_pin_get_input_value(sc, pin, val);
        GPIO_UNLOCK(sc);

        return (ret);
}

int
qcom_tlmm_pin_toggle(device_t dev, uint32_t pin)
{
        struct qcom_tlmm_softc *sc = device_get_softc(dev);
        int ret;

        if (pin >= sc->gpio_npins)
                return (EINVAL);

        GPIO_LOCK(sc);
        ret = qcom_tlmm_ipq4018_hw_pin_toggle_output_value(sc, pin);
        GPIO_UNLOCK(sc);

        return (ret);
}

int
qcom_tlmm_filter(void *arg)
{

        /* TODO: something useful */
        return (FILTER_STRAY);
}

void
qcom_tlmm_intr(void *arg)
{
        struct qcom_tlmm_softc *sc = arg;
        GPIO_LOCK(sc);
        /* TODO: something useful */
        GPIO_UNLOCK(sc);
}

/*
 * ofw bus interface
 */
phandle_t
qcom_tlmm_pin_get_node(device_t dev, device_t bus)
{

        /* We only have one child, the GPIO bus, which needs our own node. */
        return (ofw_bus_get_node(dev));
}