/*      $OpenBSD: pwmfan.c,v 1.3 2025/09/16 08:46:33 kettenis Exp $     */
/*
 * Copyright (c) 2019 Krystian Lewandowski
 * Copyright (c) 2019 Mark Kettenis <kettenis@openbsd.org>
 * Copyright (c) 2019 Patrick Wildt <patrick@blueri.se>
 *
 * 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/malloc.h>

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

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_gpio.h>
#include <dev/ofw/ofw_misc.h>
#include <dev/ofw/ofw_thermal.h>

struct pwmfan_softc {
        struct device           sc_dev;
        uint32_t                *sc_pwm;
        int                     sc_pwm_len;
        uint32_t                *sc_levels;
        int                     sc_nlevels;
        int                     sc_curlevel;

        struct cooling_device   sc_cd;
};

int     pwmfan_match(struct device *, void *, void *);
void    pwmfan_attach(struct device *, struct device *, void *);

const struct cfattach pwmfan_ca = {
        sizeof(struct pwmfan_softc), pwmfan_match, pwmfan_attach
};

struct cfdriver pwmfan_cd = {
        NULL, "pwmfan", DV_DULL
};

uint32_t pwmfan_get_cooling_level(void *, uint32_t *);
void    pwmfan_set_cooling_level(void *, uint32_t *, uint32_t);

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

        return OF_is_compatible(faa->fa_node, "pwm-fan");
}

void
pwmfan_attach(struct device *parent, struct device *self, void *aux)
{
        struct pwmfan_softc *sc = (struct pwmfan_softc *)self;
        struct fdt_attach_args *faa = aux;
        int len;

        len = OF_getproplen(faa->fa_node, "pwms");
        if (len < 0) {
                printf(": no pwm\n");
                return;
        }

        sc->sc_pwm = malloc(len, M_DEVBUF, M_WAITOK);
        OF_getpropintarray(faa->fa_node, "pwms", sc->sc_pwm, len);
        sc->sc_pwm_len = len;

        len = OF_getproplen(faa->fa_node, "cooling-levels");
        if (len < 0) {
                free(sc->sc_pwm, M_DEVBUF, sc->sc_pwm_len);
                printf(": no cooling levels\n");
                return;
        }

        sc->sc_levels = malloc(len, M_DEVBUF, M_WAITOK);
        OF_getpropintarray(faa->fa_node, "cooling-levels",
            sc->sc_levels, len);
        sc->sc_nlevels = len / sizeof(uint32_t);

        printf("\n");

        /* Start fan at maximum speed. */
        pwmfan_set_cooling_level(sc, NULL, sc->sc_nlevels - 1);

        sc->sc_cd.cd_node = faa->fa_node;
        sc->sc_cd.cd_cookie = sc;
        sc->sc_cd.cd_get_level = pwmfan_get_cooling_level;
        sc->sc_cd.cd_set_level = pwmfan_set_cooling_level;
        cooling_device_register(&sc->sc_cd);
}

uint32_t
pwmfan_get_cooling_level(void *cookie, uint32_t *cells)
{
        struct pwmfan_softc *sc = cookie;

        return sc->sc_curlevel;
}

void
pwmfan_set_cooling_level(void *cookie, uint32_t *cells, uint32_t level)
{
        struct pwmfan_softc *sc = cookie;
        struct pwm_state ps;

        if (level == sc->sc_curlevel || level > sc->sc_nlevels ||
            sc->sc_levels[level] > 255)
                return;

        if (pwm_init_state(sc->sc_pwm, &ps))
                return;

        sc->sc_curlevel = level;
        level = sc->sc_levels[level];

        ps.ps_enabled = level ? 1 : 0;
        ps.ps_pulse_width = (ps.ps_period * level) / 255;
        pwm_set_state(sc->sc_pwm, &ps);
}