/*      $NetBSD: amdpm.c,v 1.43 2022/03/19 11:37:06 riastradh Exp $     */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Enami Tsugutomo.
 *
 * 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: amdpm.c,v 1.43 2022/03/19 11:37:06 riastradh Exp $");

#include "opt_amdpm.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/callout.h>
#include <sys/rndsource.h>
#include <sys/mutex.h>

#include <sys/bus.h>
#include <dev/ic/acpipmtimer.h>

#include <dev/i2c/i2cvar.h>

#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcidevs.h>

#include <dev/pci/amdpmreg.h>
#include <dev/pci/amdpmvar.h>
#include <dev/pci/amdpm_smbusreg.h>

static void     amdpm_rnd_callout(void *);
static void     amdpm_rnd_callout_locked(void *);

#ifdef AMDPM_RND_COUNTERS
#define AMDPM_RNDCNT_INCR(ev)   (ev)->ev_count++
#endif

static int
amdpm_match(device_t parent, cfdata_t match, void *aux)
{
        struct pci_attach_args *pa = aux;

        if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_AMD) {
                switch (PCI_PRODUCT(pa->pa_id)) {
                case PCI_PRODUCT_AMD_PBC768_PMC:
                case PCI_PRODUCT_AMD_PBC8111_ACPI:
                        return (1);
                }
        }
        if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_NVIDIA) {
                switch (PCI_PRODUCT(pa->pa_id)) {
                case PCI_PRODUCT_NVIDIA_XBOX_SMBUS:
                        return (1);
                }
        }

        return (0);
}

static void
amdpm_rnd_get(size_t bytes, void *priv)
{
        struct amdpm_softc *sc = priv;

        mutex_enter(&sc->sc_mutex);
        sc->sc_rnd_need = bytes;
        amdpm_rnd_callout_locked(sc);
        mutex_exit(&sc->sc_mutex);
}

static void
amdpm_attach(device_t parent, device_t self, void *aux)
{
        struct amdpm_softc *sc = device_private(self);
        struct pci_attach_args *pa = aux;
        pcireg_t confreg, pmptrreg;
        u_int32_t pmreg;
        int i;

        pci_aprint_devinfo(pa, NULL);

        sc->sc_dev = self;

        if (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_NVIDIA_XBOX_SMBUS)
                sc->sc_nforce = 1;
        else
                sc->sc_nforce = 0;

        sc->sc_pc = pa->pa_pc;
        sc->sc_tag = pa->pa_tag;
        sc->sc_iot = pa->pa_iot;
        sc->sc_pa = pa;

        confreg = pci_conf_read(pa->pa_pc, pa->pa_tag, AMDPM_CONFREG);
        /* enable pm i/o space for AMD-8111 and nForce */
        if (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_PBC8111_ACPI ||
            sc->sc_nforce)
                confreg |= AMDPM_PMIOEN;

        /* Enable random number generation for everyone */
        pci_conf_write(pa->pa_pc, pa->pa_tag, AMDPM_CONFREG,
            confreg | AMDPM_RNGEN);
        confreg = pci_conf_read(pa->pa_pc, pa->pa_tag, AMDPM_CONFREG);

        if ((confreg & AMDPM_PMIOEN) == 0) {
                aprint_error_dev(self, "PMxx space isn't enabled\n");
                return;
        }

        if (sc->sc_nforce) {
                pmptrreg = pci_conf_read(pa->pa_pc, pa->pa_tag, NFORCE_PMPTR);
                aprint_normal_dev(self, "power management at 0x%04x\n",
                    NFORCE_PMBASE(pmptrreg));
                if (bus_space_map(sc->sc_iot, NFORCE_PMBASE(pmptrreg),
                    AMDPM_PMSIZE, 0, &sc->sc_ioh)) {
                        aprint_error_dev(self, "failed to map PMxx space\n");
                        return;
                }
        } else {
                pmptrreg = pci_conf_read(pa->pa_pc, pa->pa_tag, AMDPM_PMPTR);
                if (bus_space_map(sc->sc_iot, AMDPM_PMBASE(pmptrreg),
                    AMDPM_PMSIZE, 0, &sc->sc_ioh)) {
                        aprint_error_dev(self, "failed to map PMxx space\n");
                        return;
                }
        }

        /* don't attach a timecounter on nforce boards */
        if ((confreg & AMDPM_TMRRST) == 0 && (confreg & AMDPM_STOPTMR) == 0 &&
            !sc->sc_nforce) {
                acpipmtimer_attach(self, sc->sc_iot, sc->sc_ioh,
                  AMDPM_TMR, ((confreg & AMDPM_TMR32) ? ACPIPMT_32BIT : 0));
        }

        mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_SOFTSERIAL);

        /* try to attach devices on the smbus */
        if (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_PBC8111_ACPI ||
            PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_PBC768_PMC ||
            sc->sc_nforce) {
                amdpm_smbus_attach(sc);
        }

        if (confreg & AMDPM_RNGEN) {
                /* Check to see if we can read data from the RNG. */
                (void) bus_space_read_4(sc->sc_iot, sc->sc_ioh,
                    AMDPM_RNGDATA);
                for (i = 0; i < 1000; i++) {
                        pmreg = bus_space_read_4(sc->sc_iot,
                            sc->sc_ioh, AMDPM_RNGSTAT);
                        if (pmreg & AMDPM_RNGDONE)
                                break;
                        delay(1);
                }
                if ((pmreg & AMDPM_RNGDONE) != 0) {
                        aprint_normal_dev(self, ""
                            "random number generator enabled (apprx. %dms)\n",
                            i);
                        callout_init(&sc->sc_rnd_ch, CALLOUT_MPSAFE);
#ifdef AMDPM_RND_COUNTERS
                        evcnt_attach_dynamic(&sc->sc_rnd_hits, EVCNT_TYPE_MISC,
                            NULL, device_xname(self), "rnd hits");
                        evcnt_attach_dynamic(&sc->sc_rnd_miss, EVCNT_TYPE_MISC,
                            NULL, device_xname(self), "rnd miss");
                        for (i = 0; i < 256; i++) {
                                evcnt_attach_dynamic(&sc->sc_rnd_data[i],
                                    EVCNT_TYPE_MISC, NULL, device_xname(self),
                                    "rnd data");
                        }
#endif
                        rndsource_setcb(&sc->sc_rnd_source,
                                        amdpm_rnd_get, sc);
                        rnd_attach_source(&sc->sc_rnd_source,
                            device_xname(self), RND_TYPE_RNG,
                            RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
                }
        }
}

CFATTACH_DECL_NEW(amdpm, sizeof(struct amdpm_softc),
    amdpm_match, amdpm_attach, NULL, NULL);

static void
amdpm_rnd_callout_locked(void *v)
{
        struct amdpm_softc *sc = v;
        u_int32_t rngreg;
#ifdef AMDPM_RND_COUNTERS
        int i;
#endif

        if (sc->sc_rnd_need < 1) {
                callout_stop(&sc->sc_rnd_ch);
                return;
        }

        if ((bus_space_read_4(sc->sc_iot, sc->sc_ioh, AMDPM_RNGSTAT) &
            AMDPM_RNGDONE) != 0) {
                rngreg = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
                    AMDPM_RNGDATA);
                rnd_add_data(&sc->sc_rnd_source, &rngreg,
                    sizeof(rngreg), sizeof(rngreg) * NBBY);
                sc->sc_rnd_need -= sizeof(rngreg);
#ifdef AMDPM_RND_COUNTERS
                AMDPM_RNDCNT_INCR(&sc->sc_rnd_hits);
                for (i = 0; i < sizeof(rngreg); i++, rngreg >>= NBBY)
                        AMDPM_RNDCNT_INCR(&sc->sc_rnd_data[rngreg & 0xff]);
#endif
        }
#ifdef AMDPM_RND_COUNTERS
        else
                AMDPM_RNDCNT_INCR(&sc->sc_rnd_miss);
#endif
        if (sc->sc_rnd_need > 0) {
                callout_reset(&sc->sc_rnd_ch, 1, amdpm_rnd_callout, sc);
        }
}

static void
amdpm_rnd_callout(void *v)
{
        struct amdpm_softc *sc = v;

        mutex_enter(&sc->sc_mutex);
        amdpm_rnd_callout_locked(v);
        mutex_exit(&sc->sc_mutex);
}