/*      $OpenBSD: skgpio.c,v 1.5 2022/04/06 18:59:29 naddy Exp $ */

/*
 * Copyright (c) 2014 Matt Dainty <matt@bodgit-n-scarper.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * Soekris net6501 GPIO and LEDs as implemented by the onboard Xilinx FPGA 
 */

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

#include <machine/bus.h>

#include <dev/isa/isavar.h>

#include <dev/gpio/gpiovar.h>

#define SKGPIO_BASE             0x680   /* Base address of FPGA I/O */
#define SKGPIO_IOSIZE           32      /* I/O region size */

#define SKGPIO_NPINS            16      /* Number of Pins */
#define SKGPIO_GPIO_INPUT       0x000   /* Current state of pins */
#define SKGPIO_GPIO_OUTPUT      0x004   /* Set state of output pins */
#define SKGPIO_GPIO_RESET       0x008   /* Reset output pins */
#define SKGPIO_GPIO_SET         0x00c   /* Set output pins */
#define SKGPIO_GPIO_DIR         0x010   /* Direction, set for output */

#define SKGPIO_NLEDS            2       /* Number of LEDs */
#define SKGPIO_LED_ERROR        0x01c   /* Offset to error LED */
#define SKGPIO_LED_READY        0x01d   /* Offset to ready LED */

const u_int skgpio_led_offset[SKGPIO_NLEDS] = {
        SKGPIO_LED_ERROR, SKGPIO_LED_READY
};

struct skgpio_softc {
        struct device            sc_dev;

        bus_space_tag_t          sc_iot;
        bus_space_handle_t       sc_ioh;

        struct gpio_chipset_tag  sc_gpio_gc;
        gpio_pin_t               sc_gpio_pins[SKGPIO_NPINS];

        /* Fake GPIO device for the LEDs */
        struct gpio_chipset_tag  sc_led_gc;
        gpio_pin_t               sc_led_pins[SKGPIO_NLEDS];
};

int      skgpio_match(struct device *, void *, void *);
void     skgpio_attach(struct device *, struct device *, void *);
int      skgpio_gpio_read(void *, int);
void     skgpio_gpio_write(void *, int, int);
void     skgpio_gpio_ctl(void *, int, int);
int      skgpio_led_read(void *, int);
void     skgpio_led_write(void *, int, int);
void     skgpio_led_ctl(void *, int, int);

const struct cfattach skgpio_ca = {
        sizeof(struct skgpio_softc), skgpio_match, skgpio_attach
};

struct cfdriver skgpio_cd = {
        NULL, "skgpio", DV_DULL
};

int
skgpio_match(struct device *parent, void *match, void *aux)
{
        struct isa_attach_args *ia = aux;
        bus_space_handle_t ioh;

        if (hw_vendor == NULL || hw_prod == NULL ||
            strcmp(hw_vendor, "Soekris Engineering") != 0 ||
            strcmp(hw_prod, "net6501") != 0)
                return (0);

        if (ia->ia_iobase != SKGPIO_BASE || bus_space_map(ia->ia_iot,
            ia->ia_iobase, SKGPIO_IOSIZE, 0, &ioh) != 0)
                return (0);

        bus_space_unmap(ia->ia_iot, ioh, SKGPIO_IOSIZE);
        ia->ia_iosize = SKGPIO_IOSIZE;
        ia->ipa_nio = 1;
        ia->ipa_nmem = 0;
        ia->ipa_nirq = 0;
        ia->ipa_ndrq = 0;

        return (1);
}

void
skgpio_attach(struct device *parent, struct device *self, void *aux)
{
        struct skgpio_softc *sc = (void *)self;
        struct isa_attach_args *ia = aux;
        struct gpiobus_attach_args gba1, gba2;
        u_int data;
        int i;

        if (bus_space_map(ia->ia_iot, ia->ia_iobase, ia->ia_iosize, 0,
            &sc->sc_ioh) != 0) {
                printf(": can't map i/o space\n");
                return;
        }

        printf("\n");

        sc->sc_iot = ia->ia_iot;

        data = bus_space_read_2(sc->sc_iot, sc->sc_ioh, SKGPIO_GPIO_DIR);

        for (i = 0; i < SKGPIO_NPINS; i++) {
                sc->sc_gpio_pins[i].pin_num = i;
                sc->sc_gpio_pins[i].pin_caps = GPIO_PIN_INPUT |
                    GPIO_PIN_OUTPUT;
                sc->sc_gpio_pins[i].pin_flags = (data & (1 << i)) ?
                    GPIO_PIN_OUTPUT : GPIO_PIN_INPUT;
                sc->sc_gpio_pins[i].pin_state = skgpio_gpio_read(sc, i);
        }

        sc->sc_gpio_gc.gp_cookie = sc;
        sc->sc_gpio_gc.gp_pin_read = skgpio_gpio_read;
        sc->sc_gpio_gc.gp_pin_write = skgpio_gpio_write;
        sc->sc_gpio_gc.gp_pin_ctl = skgpio_gpio_ctl;

        gba1.gba_name = "gpio";
        gba1.gba_gc = &sc->sc_gpio_gc;
        gba1.gba_pins = sc->sc_gpio_pins;
        gba1.gba_npins = SKGPIO_NPINS;

        (void)config_found(&sc->sc_dev, &gba1, gpiobus_print);

        for (i = 0; i < SKGPIO_NLEDS; i++) {
                sc->sc_led_pins[i].pin_num = i;
                sc->sc_led_pins[i].pin_caps = GPIO_PIN_OUTPUT;
                sc->sc_led_pins[i].pin_flags = GPIO_PIN_OUTPUT;
                sc->sc_led_pins[i].pin_state = skgpio_led_read(sc, i);
        }

        sc->sc_led_gc.gp_cookie = sc;
        sc->sc_led_gc.gp_pin_read = skgpio_led_read;
        sc->sc_led_gc.gp_pin_write = skgpio_led_write;
        sc->sc_led_gc.gp_pin_ctl = skgpio_led_ctl;

        gba2.gba_name = "gpio";
        gba2.gba_gc = &sc->sc_led_gc;
        gba2.gba_pins = sc->sc_led_pins;
        gba2.gba_npins = SKGPIO_NLEDS;

        (void)config_found(&sc->sc_dev, &gba2, gpiobus_print);
}

int
skgpio_gpio_read(void *arg, int pin)
{
        struct skgpio_softc *sc = arg;
        u_int16_t data;

        data = bus_space_read_2(sc->sc_iot, sc->sc_ioh, SKGPIO_GPIO_INPUT);

        return (data & (1 << pin)) ? GPIO_PIN_HIGH : GPIO_PIN_LOW;
}

void
skgpio_gpio_write(void *arg, int pin, int value)
{
        struct skgpio_softc *sc = arg;
        u_int16_t data;

        data = bus_space_read_2(sc->sc_iot, sc->sc_ioh, SKGPIO_GPIO_INPUT);

        if (value == GPIO_PIN_LOW)
                data &= ~(1 << pin);
        else if (value == GPIO_PIN_HIGH)
                data |= (1 << pin);

        bus_space_write_2(sc->sc_iot, sc->sc_ioh, SKGPIO_GPIO_OUTPUT, data);
}

void
skgpio_gpio_ctl(void *arg, int pin, int flags)
{
        struct skgpio_softc *sc = arg;
        u_int16_t data;

        data = bus_space_read_2(sc->sc_iot, sc->sc_ioh, SKGPIO_GPIO_DIR);

        if (flags & GPIO_PIN_INPUT)
                data &= ~(1 << pin);
        if (flags & GPIO_PIN_OUTPUT)
                data |= (1 << pin);

        bus_space_write_2(sc->sc_iot, sc->sc_ioh, SKGPIO_GPIO_DIR, data);
}

int
skgpio_led_read(void *arg, int pin)
{
        struct skgpio_softc *sc = arg;
        u_int8_t value;

        value = bus_space_read_1(sc->sc_iot, sc->sc_ioh,
            skgpio_led_offset[pin]);

        return (value & 0x1) ? GPIO_PIN_HIGH : GPIO_PIN_LOW;
}

void
skgpio_led_write(void *arg, int pin, int value)
{
        struct skgpio_softc *sc = arg;

        bus_space_write_1(sc->sc_iot, sc->sc_ioh, skgpio_led_offset[pin],
            value);
}

void
skgpio_led_ctl(void *arg, int pin, int flags)
{
}