/* $NetBSD: plgpio_acpi.c,v 1.7 2021/01/29 15:49:55 thorpej Exp $ */

/*-
 * Copyright (c) 2018 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jared McNeill <jmcneill@invisible.ca>.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__KERNEL_RCSID(0, "$NetBSD: plgpio_acpi.c,v 1.7 2021/01/29 15:49:55 thorpej Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/gpio.h>

#include <dev/acpi/acpireg.h>
#include <dev/acpi/acpivar.h>
#include <dev/acpi/acpi_intr.h>
#include <dev/acpi/acpi_event.h>

#include <dev/gpio/gpiovar.h>
#include <dev/ic/pl061var.h>
#include <dev/ic/pl061reg.h>

struct plgpio_acpi_softc;

struct plgpio_acpi_softc {
        struct plgpio_softc     sc_base;

        ACPI_HANDLE             sc_handle;

        struct acpi_event *     sc_event[8];
};

static int      plgpio_acpi_match(device_t, cfdata_t, void *);
static void     plgpio_acpi_attach(device_t, device_t, void *);

static void     plgpio_acpi_register_event(void *, struct acpi_event *, ACPI_RESOURCE_GPIO *);
static int      plgpio_acpi_intr(void *);

CFATTACH_DECL_NEW(plgpio_acpi, sizeof(struct plgpio_acpi_softc), plgpio_acpi_match, plgpio_acpi_attach, NULL, NULL);

static const struct device_compatible_entry compat_data[] = {
        { .compat = "ARMH0061" },
        DEVICE_COMPAT_EOL
};

static int
plgpio_acpi_match(device_t parent, cfdata_t cf, void *aux)
{
        struct acpi_attach_args *aa = aux;

        return acpi_compatible_match(aa, compat_data);
}

static void
plgpio_acpi_attach(device_t parent, device_t self, void *aux)
{
        struct plgpio_acpi_softc * const asc = device_private(self);
        struct plgpio_softc * const sc = &asc->sc_base;
        struct acpi_attach_args *aa = aux;
        struct acpi_resources res;
        struct acpi_mem *mem;
        struct acpi_irq *irq;
        ACPI_STATUS rv;
        int error;
        void *ih;

        sc->sc_dev = self;
        asc->sc_handle = aa->aa_node->ad_handle;

        rv = acpi_resource_parse(sc->sc_dev, aa->aa_node->ad_handle, "_CRS",
            &res, &acpi_resource_parse_ops_default);
        if (ACPI_FAILURE(rv))
                return;

        mem = acpi_res_mem(&res, 0);
        if (mem == NULL) {
                aprint_error_dev(self, "couldn't find mem resource\n");
                goto done;
        }

        irq = acpi_res_irq(&res, 0);
        if (irq == NULL) {
                aprint_error_dev(self, "couldn't find irq resource\n");
                goto done;
        }

        sc->sc_dev = self;
        sc->sc_bst = aa->aa_memt;
        error = bus_space_map(sc->sc_bst, mem->ar_base, mem->ar_length, 0, &sc->sc_bsh);
        if (error) {
                aprint_error_dev(self, "couldn't map registers\n");
                return;
        }

        plgpio_attach(sc);

        rv = acpi_event_create_gpio(self, asc->sc_handle, plgpio_acpi_register_event, asc);
        if (ACPI_FAILURE(rv)) {
                if (rv != AE_NOT_FOUND)
                        aprint_error_dev(self, "failed to create events: %s\n", AcpiFormatException(rv));
                goto done;
        }

        ih = acpi_intr_establish(self,
            (uint64_t)(uintptr_t)asc->sc_handle,
            IPL_VM, false, plgpio_acpi_intr, asc, device_xname(self));
        if (ih == NULL)
                aprint_error_dev(self, "couldn't establish interrupt\n");

done:
        acpi_resource_cleanup(&res);
}

static void
plgpio_acpi_register_event(void *priv, struct acpi_event *ev, ACPI_RESOURCE_GPIO *gpio)
{
        struct plgpio_acpi_softc * const asc = priv;
        struct plgpio_softc * const sc = &asc->sc_base;
        uint32_t ibe, iev, is, ie;

        const int pin = gpio->PinTable[0];

        if (pin >= __arraycount(asc->sc_event)) {
                aprint_error_dev(asc->sc_base.sc_dev,
                    "ignoring event for pin %u (out of range)\n", pin);
                return;
        }
        if (asc->sc_event[pin] != NULL) {
                aprint_error_dev(asc->sc_base.sc_dev,
                    "ignoring duplicate pin %u\n", pin);
                return;
        }

        asc->sc_event[pin] = ev;
        asc->sc_base.sc_reserved_mask |= __BIT(pin);

        /*
         * Configure and enable interrupts for this pin.
         */

        ibe = PLGPIO_READ(sc, PL061_GPIOIBE_REG);
        iev = PLGPIO_READ(sc, PL061_GPIOIEV_REG);
        switch (gpio->Polarity) {
        case ACPI_ACTIVE_HIGH:
                ibe &= ~__BIT(pin);
                iev |= __BIT(pin);
                break;
        case ACPI_ACTIVE_LOW:
                ibe &= ~__BIT(pin);
                iev &= ~__BIT(pin);
                break;
        case ACPI_ACTIVE_BOTH:
                ibe |= __BIT(pin);
                break;
        }
        PLGPIO_WRITE(sc, PL061_GPIOIBE_REG, ibe);
        PLGPIO_WRITE(sc, PL061_GPIOIEV_REG, iev);

        is = PLGPIO_READ(sc, PL061_GPIOIS_REG);
        switch (gpio->Triggering) {
        case ACPI_LEVEL_SENSITIVE:
                is |= __BIT(pin);
                break;
        case ACPI_EDGE_SENSITIVE:
                is &= ~__BIT(pin);
                break;
        }
        PLGPIO_WRITE(sc, PL061_GPIOIS_REG, is);

        delay(20);

        PLGPIO_WRITE(sc, PL061_GPIOIC_REG, __BIT(pin));

        ie = PLGPIO_READ(sc, PL061_GPIOIE_REG);
        ie |= __BIT(pin);
        PLGPIO_WRITE(sc, PL061_GPIOIE_REG, ie);
}

static int
plgpio_acpi_intr(void *priv)
{
        struct plgpio_acpi_softc * const asc = priv;
        struct plgpio_softc * const sc = &asc->sc_base;
        uint32_t mis;
        int bit;

        mis = PLGPIO_READ(sc, PL061_GPIOMIS_REG);
        PLGPIO_WRITE(sc, PL061_GPIOIC_REG, mis);

        while ((bit = __builtin_ffs(mis)) != 0) {
                const int pin = bit - 1;
                struct acpi_event * const ev = asc->sc_event[pin];
                KASSERT(ev != NULL);

                acpi_event_notify(ev);

                mis &= ~__BIT(pin);
        }

        return 1;
}