/*      $OpenBSD: bcm2835_gpio.c,v 1.6 2025/07/31 11:03:37 jsg Exp $    */
/*
 * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
 *
 * 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 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.
 */

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

#include <machine/bus.h>
#include <machine/fdt.h>

#include <dev/gpio/gpiovar.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_gpio.h>
#include <dev/ofw/ofw_pinctrl.h>
#include <dev/ofw/fdt.h>

#include "gpio.h"

/* Registers */
#define GPFSEL(n)               (0x00 + ((n) * 4))
#define  GPFSEL_MASK            0x7
#define  GPFSEL_GPIO_IN         0x0
#define  GPFSEL_GPIO_OUT        0x1
#define  GPFSEL_ALT0            0x4
#define  GPFSEL_ALT1            0x5
#define  GPFSEL_ALT2            0x6
#define  GPFSEL_ALT3            0x7
#define  GPFSEL_ALT4            0x3
#define  GPFSEL_ALT5            0x2
#define GPSET(n)                (0x1c + ((n) * 4))
#define GPCLR(n)                (0x28 + ((n) * 4))
#define GPLEV(n)                (0x34 + ((n) * 4))
#define GPPUD                   0x94
#define  GPPUD_PUD              0x3
#define  GPPUD_PUD_OFF          0x0
#define  GPPUD_PUD_DOWN         0x1
#define  GPPUD_PUD_UP           0x2
#define GPPUDCLK(n)             (0x98 + ((n) * 4))
#define GPPULL(n)               (0xe4 + ((n) * 4))
#define  GPPULL_MASK            0x3

#define BCMGPIO_MAX_PINS        58

#define HREAD4(sc, reg)                                                 \
        (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
#define HWRITE4(sc, reg, val)                                           \
        bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))

struct bcmgpio_softc {
        struct device           sc_dev;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;

        void    (*sc_config_pull)(struct bcmgpio_softc *, int, int);
        int                     sc_num_pins;

        struct gpio_controller  sc_gc;

        struct gpio_chipset_tag sc_gpio_tag;
        gpio_pin_t              sc_gpio_pins[BCMGPIO_MAX_PINS];
        int                     sc_gpio_claimed[BCMGPIO_MAX_PINS];
};

int     bcmgpio_match(struct device *, void *, void *);
void    bcmgpio_attach(struct device *, struct device *, void *);

const struct cfattach bcmgpio_ca = {
        sizeof (struct bcmgpio_softc), bcmgpio_match, bcmgpio_attach
};

struct cfdriver bcmgpio_cd = {
        NULL, "bcmgpio", DV_DULL
};

void    bcm2711_config_pull(struct bcmgpio_softc *, int, int);
void    bcm2835_config_pull(struct bcmgpio_softc *, int, int);
int     bcmgpio_pinctrl(uint32_t, void *);
void    bcmgpio_config_pin(void *, uint32_t *, int);
int     bcmgpio_get_pin(void *, uint32_t *);
void    bcmgpio_set_pin(void *, uint32_t *, int);
void    bcmgpio_attach_gpio(struct device *);

int
bcmgpio_match(struct device *parent, void *match, void *aux)
{
        struct fdt_attach_args *faa = aux;

        return (OF_is_compatible(faa->fa_node, "brcm,bcm2711-gpio") ||
            OF_is_compatible(faa->fa_node, "brcm,bcm2835-gpio"));
}

void
bcmgpio_attach(struct device *parent, struct device *self, void *aux)
{
        struct bcmgpio_softc *sc = (struct bcmgpio_softc *)self;
        struct fdt_attach_args *faa = aux;

        if (faa->fa_nreg < 1) {
                printf(": no registers\n");
                return;
        }

        sc->sc_iot = faa->fa_iot;
        if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
            faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
                printf(": can't map registers\n");
                return;
        }

        printf("\n");

        if (OF_is_compatible(faa->fa_node, "brcm,bcm2711-gpio")) {
            sc->sc_config_pull = bcm2711_config_pull;
            sc->sc_num_pins = 58;
        } else {
            sc->sc_config_pull = bcm2835_config_pull;
            sc->sc_num_pins = 54;
        }

        pinctrl_register(faa->fa_node, bcmgpio_pinctrl, sc);

        sc->sc_gc.gc_node = faa->fa_node;
        sc->sc_gc.gc_cookie = sc;
        sc->sc_gc.gc_config_pin = bcmgpio_config_pin;
        sc->sc_gc.gc_get_pin = bcmgpio_get_pin;
        sc->sc_gc.gc_set_pin = bcmgpio_set_pin;
        gpio_controller_register(&sc->sc_gc);

        config_mountroot(self, bcmgpio_attach_gpio);
}

void
bcmgpio_config_func(struct bcmgpio_softc *sc, int pin, int func)
{
        int reg = (pin / 10);
        int shift = (pin % 10) * 3;
        uint32_t val;

        val = HREAD4(sc, GPFSEL(reg));
        val &= ~(GPFSEL_MASK << shift);
        HWRITE4(sc, GPFSEL(reg), val);
        val |= ((func & GPFSEL_MASK) << shift);
        HWRITE4(sc, GPFSEL(reg), val);
}

void
bcm2711_config_pull(struct bcmgpio_softc *sc, int pin, int pull)
{
        int reg = (pin / 16);
        int shift = (pin % 16) * 2;
        uint32_t val;

        val = HREAD4(sc, GPPULL(reg));
        val &= ~(GPPULL_MASK << shift);
        pull = ((pull & 1) << 1) | ((pull & 2) >> 1);
        val |= (pull << shift);
        HWRITE4(sc, GPPULL(reg), val);
}

void
bcm2835_config_pull(struct bcmgpio_softc *sc, int pin, int pull)
{
        int reg = (pin / 32);
        int shift = (pin % 32);

        HWRITE4(sc, GPPUD, pull & GPPUD_PUD);
        delay(1);
        HWRITE4(sc, GPPUDCLK(reg), 1 << shift);
        delay(1);
        HWRITE4(sc, GPPUDCLK(reg), 0);
}

int
bcmgpio_pinctrl(uint32_t phandle, void *cookie)
{
        struct bcmgpio_softc *sc = cookie;
        uint32_t *pins, *pull = NULL;
        int len, plen = 0;
        int node, i;
        int func;

        node = OF_getnodebyphandle(phandle);
        if (node == 0)
                return -1;

        len = OF_getproplen(node, "brcm,pins");
        if (len <= 0)
                return -1;

        pins = malloc(len, M_TEMP, M_WAITOK);
        if (OF_getpropintarray(node, "brcm,pins", pins, len) != len)
                goto fail;
        func = OF_getpropint(node, "brcm,function", -1);

        plen = OF_getproplen(node, "brcm,pull");
        if (plen > 0) {
                pull = malloc(plen, M_TEMP, M_WAITOK);
                if (OF_getpropintarray(node, "brcm,pull", pull, plen) != plen)
                        goto fail;
        }

        for (i = 0; i < len / sizeof(uint32_t); i++) {
                bcmgpio_config_func(sc, pins[i], func);
                if (plen > 0 && i < plen / sizeof(uint32_t))
                        sc->sc_config_pull(sc, pins[i], pull[i]);
                sc->sc_gpio_claimed[pins[i]] = 1;
        }

        free(pull, M_TEMP, plen);
        free(pins, M_TEMP, len);
        return 0;

fail:
        free(pull, M_TEMP, plen);
        free(pins, M_TEMP, len);
        return -1;
}

void
bcmgpio_config_pin(void *cookie, uint32_t *cells, int config)
{
        struct bcmgpio_softc *sc = cookie;
        uint32_t pin = cells[0];

        if (pin >= sc->sc_num_pins)
                return;

        if (config & GPIO_CONFIG_OUTPUT)
                bcmgpio_config_func(sc, pin, GPFSEL_GPIO_OUT);
        else
                bcmgpio_config_func(sc, pin, GPFSEL_GPIO_IN);
        if (config & GPIO_CONFIG_PULL_UP)
                sc->sc_config_pull(sc, pin, GPPUD_PUD_UP);
        else if (config & GPIO_CONFIG_PULL_DOWN)
                sc->sc_config_pull(sc, pin, GPPUD_PUD_DOWN);
        else
                sc->sc_config_pull(sc, pin, GPPUD_PUD_OFF);
}

int
bcmgpio_get_pin(void *cookie, uint32_t *cells)
{
        struct bcmgpio_softc *sc = cookie;
        uint32_t pin = cells[0];
        uint32_t flags = cells[1];
        uint32_t reg;
        int val;

        if (pin >= sc->sc_num_pins)
                return 0;

        reg = HREAD4(sc, GPLEV(pin / 32));
        val = (reg >> (pin % 32)) & 1;
        if (flags & GPIO_ACTIVE_LOW)
                val = !val;
        return val;
}

void
bcmgpio_set_pin(void *cookie, uint32_t *cells, int val)
{
        struct bcmgpio_softc *sc = cookie;
        uint32_t pin = cells[0];
        uint32_t flags = cells[1];

        if (pin >= sc->sc_num_pins)
                return;

        if (flags & GPIO_ACTIVE_LOW)
                val = !val;
        if (val)
                HWRITE4(sc, GPSET(pin / 32), (1 << (pin % 32)));
        else
                HWRITE4(sc, GPCLR(pin / 32), (1 << (pin % 32)));
}

/*
 * GPIO support code
 */

int     bcmgpio_pin_read(void *, int);
void    bcmgpio_pin_write(void *, int, int);
void    bcmgpio_pin_ctl(void *, int, int);

static const struct gpio_chipset_tag bcmgpio_gpio_tag = {
        .gp_pin_read = bcmgpio_pin_read,
        .gp_pin_write = bcmgpio_pin_write,
        .gp_pin_ctl = bcmgpio_pin_ctl
};

int
bcmgpio_pin_read(void *cookie, int pin)
{
        struct bcmgpio_softc *sc = cookie;
        uint32_t cells[2];

        cells[0] = pin;
        cells[1] = 0;

        return bcmgpio_get_pin(sc, cells) ? GPIO_PIN_HIGH : GPIO_PIN_LOW;
}

void
bcmgpio_pin_write(void *cookie, int pin, int val)
{
        struct bcmgpio_softc *sc = cookie;
        uint32_t cells[2];

        cells[0] = pin;
        cells[1] = 0;

        bcmgpio_set_pin(sc, cells, val);
}

void
bcmgpio_pin_ctl(void *cookie, int pin, int flags)
{
        struct bcmgpio_softc *sc = cookie;
        uint32_t cells[2];
        uint32_t config;

        cells[0] = pin;
        cells[1] = 0;

        config = 0;
        if (ISSET(flags, GPIO_PIN_OUTPUT))
                config |= GPIO_CONFIG_OUTPUT;
        if (ISSET(flags, GPIO_PIN_PULLUP))
                config |= GPIO_CONFIG_PULL_UP;
        if (ISSET(flags, GPIO_PIN_PULLDOWN))
                config |= GPIO_CONFIG_PULL_DOWN;

        bcmgpio_config_pin(sc, cells, config);
}

void
bcmgpio_attach_gpio(struct device *parent)
{
        struct bcmgpio_softc *sc = (struct bcmgpio_softc *)parent;
        struct gpiobus_attach_args gba;
        uint32_t reg;
        int func, state, flags;
        int pin;

        for (pin = 0; pin < sc->sc_num_pins; pin++) {
                /* Skip pins claimed by other devices. */
                if (sc->sc_gpio_claimed[pin])
                        continue;

                /* Get pin configuration. */
                reg = HREAD4(sc, GPFSEL(pin / 10));
                func = (reg >> ((pin % 10) * 3)) & GPFSEL_MASK;

                switch (func) {
                case GPFSEL_GPIO_IN:
                        flags = GPIO_PIN_SET | GPIO_PIN_INPUT;
                        break;
                case GPFSEL_GPIO_OUT:
                        flags = GPIO_PIN_SET | GPIO_PIN_OUTPUT;
                        break;
                default:
                        /* Ignore pins with an assigned function. */
                        continue;
                }

                /* Get pin state. */
                reg = HREAD4(sc, GPLEV(pin / 32));
                state = (reg >> (pin % 32)) & 1;

                sc->sc_gpio_pins[pin].pin_caps =
                    GPIO_PIN_INPUT | GPIO_PIN_OUTPUT |
                    GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN;
                sc->sc_gpio_pins[pin].pin_flags = flags;
                sc->sc_gpio_pins[pin].pin_state = state;
                sc->sc_gpio_pins[pin].pin_num = pin;
        }

        memcpy(&sc->sc_gpio_tag, &bcmgpio_gpio_tag, sizeof(bcmgpio_gpio_tag));
        sc->sc_gpio_tag.gp_cookie = sc;

        gba.gba_name = "gpio";
        gba.gba_gc = &sc->sc_gpio_tag;
        gba.gba_pins = &sc->sc_gpio_pins[0];
        gba.gba_npins = sc->sc_num_pins;

#if NGPIO > 0
        config_found(&sc->sc_dev, &gba, gpiobus_print);
#endif
}