root/sys/dev/fdt/gpioleds.c
/*      $OpenBSD: gpioleds.c,v 1.4 2022/04/06 18:59:28 naddy Exp $      */
/*
 * Copyright (c) 2021 Klemens Nanni <kn@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/systm.h>
#include <sys/device.h>
#include <sys/gpio.h>
#include <sys/malloc.h>

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

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

struct gpioleds_softc {
        struct device    sc_dev;
        int              sc_node;
};

int     gpioleds_match(struct device *, void *, void *);
void    gpioleds_attach(struct device *, struct device *, void *);

const struct cfattach gpioleds_ca = {
        sizeof (struct gpioleds_softc), gpioleds_match, gpioleds_attach
};

struct cfdriver gpioleds_cd = {
        NULL, "gpioleds", DV_DULL
};

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

        return OF_is_compatible(faa->fa_node, "gpio-leds");
}

void
gpioleds_attach(struct device *parent, struct device *self, void *aux)
{
        struct fdt_attach_args  *faa = aux;
        uint32_t                *led_pin;
        char                    *function, *default_state;
        char                    *function_prop = "function";
        int                      function_len, default_state_len, gpios_len;
        int                      node, leds = 0;

        pinctrl_byname(faa->fa_node, "default");

        for (node = OF_child(faa->fa_node); node; node = OF_peer(node)) {
                function_len = OF_getproplen(node, function_prop);
                if (function_len <= 0) {
                        function_prop = "label";
                        function_len = OF_getproplen(node, function_prop);
                        if (function_len <= 0)
                                continue;
                }
                default_state_len = OF_getproplen(node, "default-state");
                if (default_state_len <= 0)
                        continue;
                gpios_len = OF_getproplen(node, "gpios");
                if (gpios_len <= 0)
                        continue;

                function = malloc(function_len, M_TEMP, M_WAITOK);
                OF_getprop(node, function_prop, function, function_len);
                default_state = malloc(default_state_len, M_TEMP, M_WAITOK);
                OF_getprop(node, "default-state", default_state, default_state_len);
                led_pin = malloc(gpios_len, M_TEMP, M_WAITOK);
                OF_getpropintarray(node, "gpios", led_pin, gpios_len);
                gpio_controller_config_pin(led_pin, GPIO_CONFIG_OUTPUT);
                if (strcmp(default_state, "on") == 0)
                        gpio_controller_set_pin(led_pin, 1);
                else if (strcmp(default_state, "off") == 0)
                        gpio_controller_set_pin(led_pin, 0);

                printf("%s \"%s\"", leds++ ? "," : ":", function);
                free(function, M_TEMP, function_len);
                free(default_state, M_TEMP, default_state_len);
                free(led_pin, M_TEMP, gpios_len);
        }

        if (leds == 0)
                printf(": no LEDs");
        printf("\n");
}