/* $NetBSD: argpio.c,v 1.10 2021/08/07 16:18:58 thorpej Exp $ */

/*-
 * Copyright (c) 2006 Garrett D'Amore
 * All rights reserved.
 *
 * Written by Garrett D'Amore.
 *
 * 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.
 * 3. The name of the author may not be used to endorse
 *    or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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: argpio.c,v 1.10 2021/08/07 16:18:58 thorpej Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/gpio.h>
#include <sys/intr.h>
#include <sys/kernel.h>
#include <sys/types.h>

#include <mips/atheros/include/arbusvar.h>

#include <dev/gpio/gpiovar.h>
#include <dev/sysmon/sysmonvar.h>
#include <dev/sysmon/sysmon_taskq.h>

#include <mips/atheros/dev/argpioreg.h>

/*
 * General Plan:
 *
 * Register GPIOs for all pins that are _not_ associated with the reset
 * pin.  (Possibly also not the system LED.)
 */

struct argpio_softc {
        device_t                sc_dev;
        struct gpio_chipset_tag sc_gc;
        gpio_pin_t              sc_pins[ARGPIO_NPINS];
        int                     sc_npins;
        bus_space_tag_t         sc_st;
        bus_space_handle_t      sc_sh;
        bus_size_t              sc_size;
        int                     sc_caps;
        struct sysmon_pswitch   sc_resetbtn;
        void                    *sc_ih;
        int                     sc_rstpin;
        int                     sc_ledpin;
};

static int argpio_match(device_t, cfdata_t, void *);
static void argpio_attach(device_t, device_t, void *);
static int argpio_intr(void *);
static void argpio_reset_pressed(void *);
static void argpio_ctl(void *, int, int);
static void argpio_write(void *, int, int);
static int argpio_read(void *, int);

CFATTACH_DECL_NEW(argpio, sizeof (struct argpio_softc), argpio_match,
    argpio_attach, NULL, NULL);

#define INPUT(pin)      (1 << (pin))            /* input bit */
#define INTR(pin)       (1 << ((pin) + 8))      /* interrupt bit */
#define SERIAL(pin)     (1 << ((pin) + 16))     /* serial mux bit */

#define GETREG(sc, o)           bus_space_read_4(sc->sc_st, sc->sc_sh, o)
#define PUTREG(sc, o, v)        bus_space_write_4(sc->sc_st, sc->sc_sh, o, v)
#define FLUSH(sc)               bus_space_barrier(sc->sc_st, sc->sc_sh, \
                                0, 12, BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE)

int
argpio_match(device_t parent, cfdata_t match, void *aux)
{
        struct arbus_attach_args *aa = aux;

        return ((strcmp(aa->aa_name, "argpio") == 0) ? 1 : 0);
}

void
argpio_attach(device_t parent, device_t self, void *aux)
{
        struct argpio_softc *sc = device_private(self);
        struct arbus_attach_args *aa = aux;
        struct gpiobus_attach_args gba;
        prop_number_t   pn;
        int i;
        uint32_t reg;

        sc->sc_dev = self;
        sc->sc_st = aa->aa_bst;
        sc->sc_npins = ARGPIO_NPINS;
        sc->sc_size = aa->aa_size;
        sc->sc_ledpin = -1;
        sc->sc_rstpin = -1;

        if (bus_space_map(sc->sc_st, aa->aa_addr, sc->sc_size, 0,
                &sc->sc_sh) != 0) {
                printf(": unable to map registers!\n");
                return;
        }

        sc->sc_gc.gp_cookie = sc;
        sc->sc_gc.gp_pin_read = argpio_read;
        sc->sc_gc.gp_pin_write = argpio_write;
        sc->sc_gc.gp_pin_ctl = argpio_ctl;

        aprint_normal(": Atheros AR531X GPIO");
        pn = prop_dictionary_get(device_properties(sc->sc_dev), "reset-pin");
        if (pn != NULL) {
                KASSERT(prop_object_type(pn) == PROP_TYPE_NUMBER);
                sc->sc_rstpin = (int)prop_number_integer_value(pn);
                aprint_normal(", reset button pin %d", sc->sc_rstpin);
        }
        pn = prop_dictionary_get(device_properties(sc->sc_dev), "sysled-pin");
        if (pn != NULL) {
                KASSERT(prop_object_type(pn) == PROP_TYPE_NUMBER);
                sc->sc_ledpin = (int)prop_number_integer_value(pn);
                aprint_normal(", system led pin %d", sc->sc_ledpin);
        }

        aprint_normal("\n");

        if (sc->sc_ledpin) {
                sc->sc_ih = arbus_intr_establish(aa->aa_cirq, aa->aa_mirq,
                    argpio_intr, sc);
                if (sc->sc_ih == NULL) {
                        aprint_error_dev(sc->sc_dev,
                            "couldn't establish interrupt\n");
                }
        }

        if (sc->sc_ih) {
                sysmon_task_queue_init();

                sc->sc_resetbtn.smpsw_name = device_xname(sc->sc_dev);
                sc->sc_resetbtn.smpsw_type = PSWITCH_TYPE_RESET;
                if (sysmon_pswitch_register(&sc->sc_resetbtn) != 0) {
                        aprint_normal_dev(sc->sc_dev,
                            "unable to register reset button\n");
                }
        }

        reg = GETREG(sc, GPIO_CR);

        for (i = 0; i < sc->sc_npins; i++) {
                gpio_pin_t      *pp;

                pp = &sc->sc_pins[i];

                if (i == sc->sc_rstpin) {
                        /* configure as interrupt for reset */
                        pp->pin_caps = GPIO_PIN_INPUT;
                        reg &= ~SERIAL(i);
                        reg |= INPUT(i);
                        /* only if we were able to set up the handler, tho' */
                        if (sc->sc_ih != NULL)
                                reg |= INTR(i);

                } else if (i == sc->sc_ledpin) {
                        /* configure as output for LED */
                        pp->pin_caps = GPIO_PIN_OUTPUT;
                        reg &= ~SERIAL(i);
                        reg &= ~INPUT(i);
                        reg &= ~INTR(i);

                } else {
                        if (reg & SERIAL(i)) {
                                /* pin multiplexed with serial bit */
                                pp->pin_caps = 0;
                        } else {
                                pp->pin_caps = GPIO_PIN_INPUT |
                                    GPIO_PIN_OUTPUT;
                        }
                }
        }

        PUTREG(sc, GPIO_CR, reg);
        FLUSH(sc);

        gba.gba_gc = &sc->sc_gc;
        gba.gba_pins = sc->sc_pins;
        gba.gba_npins = sc->sc_npins;
        config_found(sc->sc_dev, &gba, gpiobus_print, CFARGS_NONE);
}

void
argpio_ctl(void *arg, int pin, int flags)
{
        struct argpio_softc     *sc = arg;
        uint32_t                reg;

        reg = GETREG(sc, GPIO_CR);
        if (reg & (SERIAL(pin) | INTR(pin))) {
                printf("pin %d cannot be changed!\n", pin);
                /* don't allow changes to these bits */
                return;
        }
        if (flags & GPIO_PIN_INPUT) {
                reg |= INPUT(pin);
        } else {
                reg &= ~INPUT(pin);
        }
        
        PUTREG(sc, GPIO_CR, reg);
        FLUSH(sc);
}

void
argpio_write(void *arg, int pin, int value)
{
        struct argpio_softc     *sc = arg;
        uint32_t                reg;

        reg = GETREG(sc, GPIO_DO);
        if (value)
                reg &= ~(1 << pin);
        else
                reg |= (1 << pin);
        PUTREG(sc, GPIO_DO, reg);
        FLUSH(sc);
}

int
argpio_read(void *arg, int pin)
{
        struct argpio_softc     *sc = arg;

        return ((GETREG(sc, GPIO_DI) & (1 << pin)) ?
            GPIO_PIN_HIGH : GPIO_PIN_LOW);
}

void
argpio_reset_pressed(void *arg)
{
        struct argpio_softc     *sc = arg;
        int                     x;

        sysmon_pswitch_event(&sc->sc_resetbtn, PSWITCH_EVENT_PRESSED);

        /* reenable the interrupt */
        x = splhigh();
        PUTREG(sc, GPIO_CR,
            GETREG(sc, GPIO_CR) | INTR(sc->sc_rstpin));
        splx(x);
}

int
argpio_intr(void  *arg)
{
        struct argpio_softc     *sc = arg;

        if (sc->sc_rstpin < 0)
                return 0;
        
        /* this is an edge triggered interrupt, so disable it for now */
        PUTREG(sc, GPIO_CR, GETREG(sc, GPIO_CR) & ~INTR(sc->sc_rstpin));

        /* no other interrupt on this, so we have to claim it */
        sysmon_task_queue_sched(0, argpio_reset_pressed, sc);

        return 1;
}