/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
 * Copyright (c) 2012-2015 Luiz Otavio O Souza <loos@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, 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/cdefs.h>
#include "opt_platform.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/sx.h>
#include <sys/proc.h>

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

#include <arm/broadcom/bcm2835/bcm2835_firmware.h>

#include "gpio_if.h"

#define RPI_FW_GPIO_PINS                8
#define RPI_FW_GPIO_BASE                128
#define RPI_FW_GPIO_DEFAULT_CAPS        (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT)

struct rpi_fw_gpio_softc {
        device_t                sc_busdev;
        device_t                sc_firmware;
        struct sx               sc_sx;
        struct gpio_pin         sc_gpio_pins[RPI_FW_GPIO_PINS];
        uint8_t                 sc_gpio_state;
};

#define RPI_FW_GPIO_LOCK(_sc)   sx_xlock(&(_sc)->sc_sx)
#define RPI_FW_GPIO_UNLOCK(_sc) sx_xunlock(&(_sc)->sc_sx)

static struct ofw_compat_data compat_data[] = {
        {"raspberrypi,firmware-gpio",   1},
        {NULL,                          0}
};

static int
rpi_fw_gpio_pin_configure(struct rpi_fw_gpio_softc *sc, struct gpio_pin *pin,
    unsigned int flags)
{
        union msg_get_gpio_config old_cfg;
        union msg_set_gpio_config new_cfg;
        int rv;

        bzero(&old_cfg, sizeof(old_cfg));
        bzero(&new_cfg, sizeof(new_cfg));
        old_cfg.req.gpio = RPI_FW_GPIO_BASE + pin->gp_pin;

        RPI_FW_GPIO_LOCK(sc);
        rv = bcm2835_firmware_property(sc->sc_firmware,
            BCM2835_FIRMWARE_TAG_GET_GPIO_CONFIG, &old_cfg, sizeof(old_cfg));
        if (rv == 0 && old_cfg.resp.gpio != 0)
                rv = EIO;
        if (rv != 0)
                goto fail;

        new_cfg.req.gpio = RPI_FW_GPIO_BASE + pin->gp_pin;
        if (flags & GPIO_PIN_INPUT) {
                new_cfg.req.dir = BCM2835_FIRMWARE_GPIO_IN;
                new_cfg.req.state = 0;
                pin->gp_flags = GPIO_PIN_INPUT;
        } else if (flags & GPIO_PIN_OUTPUT) {
                new_cfg.req.dir = BCM2835_FIRMWARE_GPIO_OUT;
                if (flags & (GPIO_PIN_PRESET_HIGH | GPIO_PIN_PRESET_LOW)) {
                        if (flags & GPIO_PIN_PRESET_HIGH) {
                                new_cfg.req.state = 1;
                                sc->sc_gpio_state |= (1 << pin->gp_pin);
                        } else {
                                new_cfg.req.state = 0;
                                sc->sc_gpio_state &= ~(1 << pin->gp_pin);
                        }
                } else {
                        if ((sc->sc_gpio_state & (1 << pin->gp_pin)) != 0) {
                                new_cfg.req.state = 1;
                        } else {
                                new_cfg.req.state = 0;
                        }
                }
                pin->gp_flags = GPIO_PIN_OUTPUT;
        } else {
                new_cfg.req.dir = old_cfg.resp.dir;
                /* Use the old state to decide high/low */
                if ((sc->sc_gpio_state & (1 << pin->gp_pin)) != 0)
                        new_cfg.req.state = 1;
                else
                        new_cfg.req.state = 0;
        }
        new_cfg.req.pol = old_cfg.resp.pol;
        new_cfg.req.term_en = 0;
        new_cfg.req.term_pull_up = 0;

        rv = bcm2835_firmware_property(sc->sc_firmware,
            BCM2835_FIRMWARE_TAG_SET_GPIO_CONFIG, &new_cfg, sizeof(new_cfg));

fail:
        RPI_FW_GPIO_UNLOCK(sc);

        return (rv);
}

static device_t
rpi_fw_gpio_get_bus(device_t dev)
{
        struct rpi_fw_gpio_softc *sc;

        sc = device_get_softc(dev);

        return (sc->sc_busdev);
}

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

        *maxpin = RPI_FW_GPIO_PINS - 1;
        return (0);
}

static int
rpi_fw_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
        struct rpi_fw_gpio_softc *sc;
        int i;

        sc = device_get_softc(dev);
        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                if (sc->sc_gpio_pins[i].gp_pin == pin)
                        break;
        }

        if (i >= RPI_FW_GPIO_PINS)
                return (EINVAL);

        *caps = RPI_FW_GPIO_DEFAULT_CAPS;
        return (0);
}

static int
rpi_fw_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
{
        struct rpi_fw_gpio_softc *sc = device_get_softc(dev);
        int i;

        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                if (sc->sc_gpio_pins[i].gp_pin == pin)
                        break;
        }

        if (i >= RPI_FW_GPIO_PINS)
                return (EINVAL);

        RPI_FW_GPIO_LOCK(sc);
        *flags = sc->sc_gpio_pins[i].gp_flags;
        RPI_FW_GPIO_UNLOCK(sc);

        return (0);
}

static int
rpi_fw_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
{
        struct rpi_fw_gpio_softc *sc;
        int i;

        sc = device_get_softc(dev);
        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                if (sc->sc_gpio_pins[i].gp_pin == pin)
                        break;
        }

        if (i >= RPI_FW_GPIO_PINS)
                return (EINVAL);

        RPI_FW_GPIO_LOCK(sc);
        memcpy(name, sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME);
        RPI_FW_GPIO_UNLOCK(sc);

        return (0);
}

static int
rpi_fw_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
        struct rpi_fw_gpio_softc *sc;
        int i;

        sc = device_get_softc(dev);
        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                if (sc->sc_gpio_pins[i].gp_pin == pin)
                        break;
        }

        if (i >= RPI_FW_GPIO_PINS)
                return (EINVAL);

        return (rpi_fw_gpio_pin_configure(sc, &sc->sc_gpio_pins[i], flags));
}

static int
rpi_fw_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
{
        struct rpi_fw_gpio_softc *sc;
        union msg_set_gpio_state state;
        int i, rv;

        sc = device_get_softc(dev);
        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                if (sc->sc_gpio_pins[i].gp_pin == pin)
                        break;
        }
        if (i >= RPI_FW_GPIO_PINS)
                return (EINVAL);

        state.req.gpio = RPI_FW_GPIO_BASE + pin;
        state.req.state = value;

        RPI_FW_GPIO_LOCK(sc);
        rv = bcm2835_firmware_property(sc->sc_firmware,
            BCM2835_FIRMWARE_TAG_SET_GPIO_STATE, &state, sizeof(state));
        /* The firmware sets gpio to 0 on success */
        if (rv == 0 && state.resp.gpio != 0)
                rv = EINVAL;
        if (rv == 0) {
                sc->sc_gpio_pins[i].gp_flags &= ~(GPIO_PIN_PRESET_HIGH |
                    GPIO_PIN_PRESET_LOW);
                if (value)
                        sc->sc_gpio_state |= (1 << i);
                else
                        sc->sc_gpio_state &= ~(1 << i);
        }
        RPI_FW_GPIO_UNLOCK(sc);

        return (rv);
}

static int
rpi_fw_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
{
        struct rpi_fw_gpio_softc *sc;
        union msg_get_gpio_state state;
        int i, rv;

        sc = device_get_softc(dev);
        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                if (sc->sc_gpio_pins[i].gp_pin == pin)
                        break;
        }
        if (i >= RPI_FW_GPIO_PINS)
                return (EINVAL);

        bzero(&state, sizeof(state));
        state.req.gpio = RPI_FW_GPIO_BASE + pin;

        RPI_FW_GPIO_LOCK(sc);
        rv = bcm2835_firmware_property(sc->sc_firmware,
            BCM2835_FIRMWARE_TAG_GET_GPIO_STATE, &state, sizeof(state));
        RPI_FW_GPIO_UNLOCK(sc);

        /* The firmware sets gpio to 0 on success */
        if (rv == 0 && state.resp.gpio != 0)
                rv = EINVAL;
        if (rv == 0)
                *val = !state.resp.state;

        return (rv);
}

static int
rpi_fw_gpio_pin_toggle(device_t dev, uint32_t pin)
{
        struct rpi_fw_gpio_softc *sc;
        union msg_get_gpio_state old_state;
        union msg_set_gpio_state new_state;
        int i, rv;

        sc = device_get_softc(dev);
        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                if (sc->sc_gpio_pins[i].gp_pin == pin)
                        break;
        }
        if (i >= RPI_FW_GPIO_PINS)
                return (EINVAL);

        bzero(&old_state, sizeof(old_state));
        bzero(&new_state, sizeof(new_state));

        old_state.req.gpio = RPI_FW_GPIO_BASE + pin;
        new_state.req.gpio = RPI_FW_GPIO_BASE + pin;

        RPI_FW_GPIO_LOCK(sc);
        rv = bcm2835_firmware_property(sc->sc_firmware,
            BCM2835_FIRMWARE_TAG_GET_GPIO_STATE, &old_state, sizeof(old_state));
        /* The firmware sets gpio to 0 on success */
        if (rv == 0 && old_state.resp.gpio == 0) {
                /* Set the new state to invert the GPIO */
                new_state.req.state = !old_state.resp.state;
                rv = bcm2835_firmware_property(sc->sc_firmware,
                    BCM2835_FIRMWARE_TAG_SET_GPIO_STATE, &new_state,
                    sizeof(new_state));
        }
        if (rv == 0 && (old_state.resp.gpio != 0 || new_state.resp.gpio != 0))
                rv = EINVAL;
        RPI_FW_GPIO_UNLOCK(sc);

        return (rv);
}

static int
rpi_fw_gpio_probe(device_t dev)
{

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

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

        device_set_desc(dev, "Raspberry Pi Firmware GPIO controller");
        return (BUS_PROBE_DEFAULT);
}

static int
rpi_fw_gpio_attach(device_t dev)
{
        union msg_get_gpio_config cfg;
        struct rpi_fw_gpio_softc *sc;
        char *names;
        phandle_t gpio;
        int i, nelems, elm_pos, rv;

        sc = device_get_softc(dev);
        sc->sc_firmware = device_get_parent(dev);
        sx_init(&sc->sc_sx, "Raspberry Pi firmware gpio");
        /* Find our node. */
        gpio = ofw_bus_get_node(dev);
        if (!OF_hasprop(gpio, "gpio-controller"))
                /* This is not a GPIO controller. */
                goto fail;

        nelems = OF_getprop_alloc(gpio, "gpio-line-names", (void **)&names);
        if (nelems <= 0)
                names = NULL;
        elm_pos = 0;
        for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
                /* Set the current pin name */
                if (names != NULL && elm_pos < nelems &&
                    names[elm_pos] != '\0') {
                        snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
                            "%s", names + elm_pos);
                        /* Find the next pin name */
                        elm_pos += strlen(names + elm_pos) + 1;
                } else {
                        snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
                            "pin %d", i);
                }

                sc->sc_gpio_pins[i].gp_pin = i;
                sc->sc_gpio_pins[i].gp_caps = RPI_FW_GPIO_DEFAULT_CAPS;

                bzero(&cfg, sizeof(cfg));
                cfg.req.gpio = RPI_FW_GPIO_BASE + i;
                rv = bcm2835_firmware_property(sc->sc_firmware,
                    BCM2835_FIRMWARE_TAG_GET_GPIO_CONFIG, &cfg, sizeof(cfg));
                if (rv == 0 && cfg.resp.gpio == 0) {
                        if (cfg.resp.dir == BCM2835_FIRMWARE_GPIO_IN)
                                sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_INPUT;
                        else
                                sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_OUTPUT;
                } else {
                        sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_INPUT;
                }
        }
        free(names, M_OFWPROP);
        sc->sc_busdev = gpiobus_add_bus(dev);
        if (sc->sc_busdev == NULL)
                goto fail;

        bus_attach_children(dev);
        return (0);

fail:
        sx_destroy(&sc->sc_sx);

        return (ENXIO);
}

static int
rpi_fw_gpio_detach(device_t dev)
{

        return (EBUSY);
}

static device_method_t rpi_fw_gpio_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         rpi_fw_gpio_probe),
        DEVMETHOD(device_attach,        rpi_fw_gpio_attach),
        DEVMETHOD(device_detach,        rpi_fw_gpio_detach),

        /* GPIO protocol */
        DEVMETHOD(gpio_get_bus,         rpi_fw_gpio_get_bus),
        DEVMETHOD(gpio_pin_max,         rpi_fw_gpio_pin_max),
        DEVMETHOD(gpio_pin_getname,     rpi_fw_gpio_pin_getname),
        DEVMETHOD(gpio_pin_getflags,    rpi_fw_gpio_pin_getflags),
        DEVMETHOD(gpio_pin_getcaps,     rpi_fw_gpio_pin_getcaps),
        DEVMETHOD(gpio_pin_setflags,    rpi_fw_gpio_pin_setflags),
        DEVMETHOD(gpio_pin_get,         rpi_fw_gpio_pin_get),
        DEVMETHOD(gpio_pin_set,         rpi_fw_gpio_pin_set),
        DEVMETHOD(gpio_pin_toggle,      rpi_fw_gpio_pin_toggle),

        DEVMETHOD_END
};

static driver_t rpi_fw_gpio_driver = {
        "gpio",
        rpi_fw_gpio_methods,
        sizeof(struct rpi_fw_gpio_softc),
};

EARLY_DRIVER_MODULE(rpi_fw_gpio, bcm2835_firmware, rpi_fw_gpio_driver, 0, 0,
    BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LATE);