/*      $NetBSD: obiofan.c,v 1.3 2025/07/01 06:36:35 macallan Exp $     */

/*-
 * Copyright (c) 2021 Michael Lorenz
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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/param.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/mutex.h>
#include <sys/callout.h>
#include <sys/time.h>

#include <dev/ofw/openfirm.h>
#include <dev/sysmon/sysmonvar.h>
#include <machine/autoconf.h>
#include <macppc/dev/obiovar.h>

#include "opt_obiofan.h"

#ifdef OBIOFAN_DEBUG
#define DPRINTF printf
#else
#define DPRINTF if (0) printf
#endif

struct obiofan_softc {
        device_t sc_dev;
        struct sysmon_envsys    *sc_sme;
        envsys_data_t           sc_sensors[4];
        callout_t               sc_callout;
        time_t                  sc_stamp;
        int                     sc_node;
        int                     sc_reg[4], sc_shift[4];
        int                     sc_count[4], sc_rpm[4];
        int                     sc_fans;
};

int obiofan_match(device_t, cfdata_t, void *);
void obiofan_attach(device_t, device_t, void *);
static void obiofan_refresh(struct sysmon_envsys *, envsys_data_t *);
static void obiofan_update(void *);

CFATTACH_DECL_NEW(obiofan, sizeof(struct obiofan_softc), obiofan_match,
        obiofan_attach, NULL, NULL);

int
obiofan_match(device_t parent, cfdata_t match, void *aux)
{
        struct confargs *ca = aux;

        if (strcmp(ca->ca_name, "fans") == 0)
                return 1;

        return 0;
}

void
obiofan_attach(device_t parent, device_t self, void *aux)
{
        struct obiofan_softc *sc = device_private(self);
        struct confargs *ca = aux;
        char descr[32] = "fan";
        int node = ca->ca_node, tc_node, f, cnt;
        uint32_t regs[8], tc_regs[32];

        printf("\n");

        if (OF_getprop(node, "reg", regs, sizeof(regs)) <= 0)
                return;

        sc->sc_node = node;

#ifdef OBIOFAN_DEBUG
        int i;
        for (i = 0; i < 7; i += 2)
                printf("%02x: %08x\n", regs[i], obio_read_4(regs[i]));
#endif

        tc_node = OF_parent(node);

        if (OF_getprop(tc_node, "platform-do-getTACHCount", tc_regs, 128) <= 0) {
                aprint_error("no platform-do-getTACHCount\n");
                return;
        }

        /*
         * XXX this is guesswork based on poking around & observation
         *
         * the parameter format seems to be:
         * reg[0] - node number for the fan, or pointer into OF space
         * reg[1] - 0x08000000
         * reg[2] - 0x0000001a - varies with different platform-do-*
         * reg[3] - register number in obio space
         * reg[4] - bitmask in the register
         * reg[5] - unknown
         * reg[6] - unknown
         */

        sc->sc_sme = sysmon_envsys_create();
        sc->sc_sme->sme_name = device_xname(self);
        sc->sc_sme->sme_cookie = sc;
        sc->sc_sme->sme_refresh = obiofan_refresh;

        /* now look for which fan register(s) we can use */
        f = OF_child(node);
        cnt = 0;
        while (f != 0) {
                int num = -1;
                OF_getprop(f, "reg", &num, 4);
                if (OF_getprop(f, "hwctrl-location", descr, 32) <= 0)
                        goto skip;
                sc->sc_reg[cnt] = tc_regs[num * 7 + 3];
                sc->sc_shift[cnt] = ffs(tc_regs[num * 7 + 4]) - 1;

                DPRINTF("%s: %d %02x %d\n", descr, num, sc->sc_reg[cnt], sc->sc_shift[cnt]);

                sc->sc_stamp = time_second;
                sc->sc_count[cnt] = 
                    obio_read_4(sc->sc_reg[cnt]) >> sc->sc_shift[cnt];
                sc->sc_rpm[cnt] = -1;
        
                sc->sc_sensors[cnt].units = ENVSYS_SFANRPM;
                sc->sc_sensors[cnt].state = ENVSYS_SINVALID;
                sc->sc_sensors[cnt].private = cnt;
                strcpy(sc->sc_sensors[cnt].desc, descr);
                sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensors[cnt]);
                cnt++;
skip:
                f = OF_peer(f);
        }
        sc->sc_fans = cnt;
        sysmon_envsys_register(sc->sc_sme);

        callout_init(&sc->sc_callout, 0);
        callout_setfunc(&sc->sc_callout, obiofan_update, sc);
        callout_schedule(&sc->sc_callout, mstohz(5000));
}

static void
obiofan_update(void *cookie)
{
        struct obiofan_softc *sc = cookie;
        time_t now = time_second, diff;
        int spin, spins, i;
        for (i = 0; i < sc->sc_fans; i++) {
                diff = now - sc->sc_stamp;
                if (diff < 5) return;
                spin = obio_read_4(sc->sc_reg[i]) >> sc->sc_shift[i];
                spins = (spin - sc->sc_count[i]) & 0xffff;
                sc->sc_rpm[i] = spins * 60 / diff;
                sc->sc_count[i] = spin;
                DPRINTF("%s %lld %d\n", __func__, diff, spins);
        }
        sc->sc_stamp = now;
        callout_schedule(&sc->sc_callout, mstohz(5000));
}

static void
obiofan_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
        struct obiofan_softc *sc = sme->sme_cookie;
        int i = edata->private;

        if (sc->sc_rpm[i] >= 0) {
                edata->state = ENVSYS_SVALID;
                edata->value_cur = sc->sc_rpm[i];
        }
}