/*      $NetBSD: gpio_ebus.c,v 1.5 2021/08/07 16:18:48 thorpej Exp $    */

/*-
 * Copyright (c) 2010 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code was written by Alessandro Forin and Neil Pittman
 * at Microsoft Research and contributed to The NetBSD Foundation
 * by Microsoft Corporation.
 *
 * 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>                  /* RCS ID & Copyright macro defns */
__KERNEL_RCSID(0, "$NetBSD: gpio_ebus.c,v 1.5 2021/08/07 16:18:48 thorpej Exp $");

#include <sys/param.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/gpio.h>
#include <dev/gpio/gpiovar.h>

#include <emips/ebus/ebusvar.h>
#include <emips/emips/machdep.h>
#include <machine/emipsreg.h>

/*
 * Device softc
 */
#define GPIO_NPINS 32

struct epio_softc {
        device_t sc_dev;
        struct _Pio *sc_dp;
        struct gpio_chipset_tag sc_gpio_gc;
        gpio_pin_t sc_gpio_pins[GPIO_NPINS];
};

static int      epio_ebus_match(device_t, cfdata_t, void *);
static void     epio_ebus_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(epio, sizeof (struct epio_softc),
    epio_ebus_match, epio_ebus_attach, NULL, NULL);

static int      epio_pin_read(void *, int);
static void     epio_pin_write(void *, int, int);
static void     epio_pin_ctl(void *, int, int);

static int
epio_ebus_match(device_t parent, cfdata_t cf, void *aux)
{
        struct ebus_attach_args *ia = aux;
        struct _Pio *f = (struct _Pio *)ia->ia_vaddr;

        if (strcmp("gpio", ia->ia_name) != 0)
                return 0;
        if ((f == NULL) ||
                (f->Tag != PMTTAG_GPIO))
                return 0;

        return 1;
}

static void
epio_ebus_attach(device_t parent, device_t self, void *aux)
{
        struct epio_softc *sc = device_private(self);
        struct ebus_attach_args *ia =aux;
        struct gpiobus_attach_args gba;
        int i;
        uint32_t data;

        sc->sc_dev = self;
        sc->sc_dp = (struct _Pio *)ia->ia_vaddr;
        data = sc->sc_dp->PinData;

#if DEBUG
        printf(" virt=%p data=%zx", (void*)sc->sc_dp, data);
#endif
        printf(": GPIO controller\n");

        /* BUGBUG Initialize pins properly */
        for (i = 0 ; i < GPIO_NPINS ; i++) {
                sc->sc_gpio_pins[i].pin_num = i;
                sc->sc_gpio_pins[i].pin_caps =
                    GPIO_PIN_INOUT |
                    GPIO_PIN_OPENDRAIN |
                    GPIO_PIN_TRISTATE;

                /* current defaults */
                sc->sc_gpio_pins[i].pin_flags = GPIO_PIN_INOUT;
                sc->sc_gpio_pins[i].pin_state =
                    (data & (1 << i)) ? GPIO_PIN_HIGH : GPIO_PIN_LOW;
                sc->sc_gpio_pins[i].pin_mapped = 0;
        }

        /* Create controller tag */
        sc->sc_gpio_gc.gp_cookie = sc;
        sc->sc_gpio_gc.gp_pin_read = epio_pin_read;
        sc->sc_gpio_gc.gp_pin_write = epio_pin_write;
        sc->sc_gpio_gc.gp_pin_ctl = epio_pin_ctl;

        gba.gba_gc = &sc->sc_gpio_gc;
        gba.gba_pins = sc->sc_gpio_pins;
        gba.gba_npins = GPIO_NPINS;

        /* Attach GPIO framework */
        (void)config_found(self, &gba, gpiobus_print, CFARGS_NONE);
}

static int
epio_pin_read(void *arg, int pin)
{
        struct epio_softc *sc = arg;
        uint32_t data = sc->sc_dp->PinData;
        int p;

        p = pin % GPIO_NPINS;
        return (data >> p) & 0x01;
}

static void
epio_pin_write(void *arg, int pin, int value)
{
        struct epio_softc *sc = arg;
        uint32_t data;
        int p;

        p = pin % GPIO_NPINS;
        data = 1 << p;
        if (value)
                sc->sc_dp->PinData = data;
        else
                sc->sc_dp->ClearData = data;
}

static void
epio_pin_ctl(void *arg, int pin, int flags)
{
        struct epio_softc *sc = arg;
        uint32_t data;
        int p;

        p = pin % GPIO_NPINS;
        data = (1 << p);

        if (flags & GPIO_PIN_INOUT) {
                sc->sc_dp->Direction = data;
        }

        if (flags & GPIO_PIN_TRISTATE) {
                sc->sc_dp->OutDisable = data;
        }

        if (flags & GPIO_PIN_OPENDRAIN) {
                sc->sc_dp->Enable = data;
        }
}