/* $NetBSD: acpi_power.c,v 1.38 2025/08/25 21:27:11 christos Exp $ */

/*-
 * Copyright (c) 2009, 2010, 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jukka Ruohonen.
 *
 * 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.
 */

/*-
 * Copyright (c) 2001 Michael Smith
 * 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 AUTHOR 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 AUTHOR 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: acpi_power.c,v 1.38 2025/08/25 21:27:11 christos Exp $");

#include "pci.h"

#include <sys/param.h>
#include <sys/kmem.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>

#include <dev/acpi/acpireg.h>
#include <dev/acpi/acpivar.h>
#include <dev/acpi/acpi_pci.h>
#include <dev/acpi/acpi_power.h>

#define _COMPONENT                      ACPI_BUS_COMPONENT
ACPI_MODULE_NAME                        ("acpi_power")

#define ACPI_STA_POW_OFF                0x00
#define ACPI_STA_POW_ON                 0x01

struct acpi_power_res {
        ACPI_HANDLE                     res_handle;
        ACPI_INTEGER                    res_level;
        ACPI_INTEGER                    res_order;
        ACPI_HANDLE                     res_ref[5];
        char                            res_name[5];
        kmutex_t                        res_mutex;

        TAILQ_ENTRY(acpi_power_res)     res_list;
};

static TAILQ_HEAD(, acpi_power_res) res_head =
        TAILQ_HEAD_INITIALIZER(res_head);

static int32_t acpi_power_acpinode = CTL_EOL;
static int32_t acpi_power_powernode = CTL_EOL;

static struct acpi_power_res    *acpi_power_res_init(ACPI_HANDLE);
static struct acpi_power_res    *acpi_power_res_get(ACPI_HANDLE);

static ACPI_STATUS       acpi_power_get_direct(struct acpi_devnode *);
static ACPI_STATUS       acpi_power_get_indirect(struct acpi_devnode *);
static ACPI_STATUS       acpi_power_switch(struct acpi_devnode *,
                                                   int, bool);
static ACPI_STATUS       acpi_power_res_ref(struct acpi_power_res *,
                                            ACPI_HANDLE);
static ACPI_STATUS       acpi_power_res_deref(struct acpi_power_res *,
                                              ACPI_HANDLE);
static ACPI_STATUS       acpi_power_res_sta(ACPI_OBJECT *, void *);

static ACPI_OBJECT      *acpi_power_pkg_get(ACPI_HANDLE, int);
static int               acpi_power_sysctl(SYSCTLFN_PROTO);
static const char       *acpi_xname(ACPI_HANDLE);

static struct acpi_power_res *
acpi_power_res_init(ACPI_HANDLE hdl)
{
        struct acpi_power_res *tmp = NULL;
        struct acpi_power_res *res = NULL;
        ACPI_OBJECT *obj;
        ACPI_BUFFER buf;
        ACPI_STATUS rv;
        size_t i;

        rv = acpi_eval_struct(hdl, NULL, &buf);

        if (ACPI_FAILURE(rv))
                goto out;

        obj = buf.Pointer;

        if (obj->Type != ACPI_TYPE_POWER) {
                rv = AE_TYPE;
                goto out;
        }

        res = kmem_zalloc(sizeof(*res), KM_SLEEP);
        res->res_handle = hdl;
        res->res_level = obj->PowerResource.SystemLevel;
        res->res_order = obj->PowerResource.ResourceOrder;

        (void)strlcpy(res->res_name,
            acpi_xname(hdl), sizeof(res->res_name));

        for (i = 0; i < __arraycount(res->res_ref); i++)
                res->res_ref[i] = NULL;

        mutex_init(&res->res_mutex, MUTEX_DEFAULT, IPL_NONE);

        /*
         * Power resources should be ordered.
         *
         * These *should* be enabled from low values to high
         * values and disabled from high values to low values.
         */
        TAILQ_FOREACH(tmp, &res_head, res_list) {

                if (res->res_order < tmp->res_order) {
                        TAILQ_INSERT_BEFORE(tmp, res, res_list);
                        break;
                }
        }

        if (tmp == NULL)
                TAILQ_INSERT_TAIL(&res_head, res, res_list);

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s added to the "
                "power resource queue\n", res->res_name));

out:
        if (buf.Pointer != NULL)
                ACPI_FREE(buf.Pointer);

        return res;
}

static struct acpi_power_res *
acpi_power_res_get(ACPI_HANDLE hdl)
{
        struct acpi_power_res *res;

        TAILQ_FOREACH(res, &res_head, res_list) {

                if (res->res_handle == hdl)
                        return res;
        }

        return acpi_power_res_init(hdl);
}

bool
acpi_power_register(ACPI_HANDLE hdl)
{
        return true;
}

void
acpi_power_deregister(ACPI_HANDLE hdl)
{
        struct acpi_devnode *ad = acpi_match_node(hdl);
        struct acpi_power_res *res;

        if (ad == NULL)
                return;

        /*
         * Remove all references in each resource.
         */
        TAILQ_FOREACH(res, &res_head, res_list)
            (void)acpi_power_res_deref(res, ad->ad_handle);
}

/*
 * Get the D-state of an ACPI device node.
 */
bool
acpi_power_get(ACPI_HANDLE hdl, int *state)
{
        struct acpi_devnode *ad = acpi_match_node(hdl);
        ACPI_STATUS rv;

        if (ad == NULL)
                return false;

        /*
         * As _PSC may be broken, first try to
         * retrieve the power state indirectly
         * via power resources.
         */
        rv = acpi_power_get_indirect(ad);

        if (ACPI_FAILURE(rv))
                rv = acpi_power_get_direct(ad);

        if (ACPI_FAILURE(rv))
                goto fail;

        KASSERT(ad->ad_state != ACPI_STATE_ERROR);

        if (ad->ad_state < ACPI_STATE_D0 || ad->ad_state > ACPI_STATE_D3) {
                rv = AE_BAD_VALUE;
                goto fail;
        }

        if (state != NULL)
                *state = ad->ad_state;

        return true;

fail:
        ad->ad_state = ACPI_STATE_ERROR;

        if (state != NULL)
                *state = ad->ad_state;

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "failed to get power state "
                "for %s: %s\n", ad->ad_name, AcpiFormatException(rv)));

        return false;
}

static ACPI_STATUS
acpi_power_get_direct(struct acpi_devnode *ad)
{
        ACPI_INTEGER val = 0;
        ACPI_STATUS rv;

        rv = acpi_eval_integer(ad->ad_handle, "_PSC", &val);

        KDASSERT((uint64_t)val < INT_MAX);

        ad->ad_state = (int)val;

        return rv;
}

static ACPI_STATUS
acpi_power_get_indirect(struct acpi_devnode *ad)
{
        ACPI_OBJECT *pkg;
        ACPI_STATUS rv;
        int i;

        CTASSERT(ACPI_STATE_D0 == 0 && ACPI_STATE_D1 == 1);
        CTASSERT(ACPI_STATE_D2 == 2 && ACPI_STATE_D3_HOT == 3);
        CTASSERT(ACPI_STATE_D3_COLD == 4 &&
            ACPI_STATE_D3_COLD == ACPI_STATE_D3);

        /*
         * The device is in a given D-state if all resources are on.
         * To derive this, evaluate all elements in each _PRx package
         * (x = 0 ... 4) and break if the noted condition becomes true.
         */
        for (ad->ad_state = ACPI_STATE_D3, i = 0; i < ACPI_STATE_D3; i++) {

                pkg = acpi_power_pkg_get(ad->ad_handle, i);

                if (pkg == NULL)
                        continue;

                /*
                 * For each element in the _PRx package, evaluate _STA
                 * and return AE_OK only if all power resources are on.
                 */
                rv = acpi_foreach_package_object(pkg, acpi_power_res_sta, ad);

                if (ACPI_FAILURE(rv) && rv != AE_CTRL_FALSE)
                        goto out;

                if (ACPI_SUCCESS(rv)) {
                        ad->ad_state = i;
                        goto out;
                }

                ACPI_FREE(pkg); pkg = NULL;
        }

        KASSERT(ad->ad_state == ACPI_STATE_D3);

        return AE_OK;

out:
        ACPI_FREE(pkg);

        return rv;
}

/*
 * Set the D-state of an ACPI device node.
 */
bool
acpi_power_set(ACPI_HANDLE hdl, int state)
{
        struct acpi_devnode *ad = acpi_match_node(hdl);
        ACPI_STATUS rv;
        char path[5];
        int old;

        if (ad == NULL)
                return false;

        if (state < ACPI_STATE_D0 || state > ACPI_STATE_D3) {
                rv = AE_BAD_PARAMETER;
                goto fail;
        }

        if (acpi_power_get(ad->ad_handle, &old) != true) {
                rv = AE_NOT_FOUND;
                goto fail;
        }

        KASSERT(ad->ad_state == old);
        KASSERT(ad->ad_state != ACPI_STATE_ERROR);

        if (ad->ad_state == state) {
                rv = AE_ALREADY_EXISTS;
                goto fail;
        }

        /*
         * It is only possible to go to D0 ("on") from D3 ("off").
         */
        if (ad->ad_state == ACPI_STATE_D3 && state != ACPI_STATE_D0) {
                rv = AE_BAD_PARAMETER;
                goto fail;
        }

        /*
         * As noted in ACPI 4.0 (appendix A.2.1), the bus power state
         * should never be lower than the highest state of one of its
         * devices. Consequently, we cannot set the state to a lower
         * (i.e. higher power) state than the parent device's state.
         */
        if ((ad->ad_parent != NULL) &&
            (ad->ad_parent->ad_flags & ACPI_DEVICE_POWER) != 0) {

                if (ad->ad_parent->ad_state > state) {
                        rv = AE_ABORT_METHOD;
                        goto fail;
                }
        }

        /*
         * We first sweep through the resources required for the target
         * state, turning things on and building references. After this
         * we dereference the resources required for the current state,
         * turning the resources off as we go.
         */
        rv = acpi_power_switch(ad, state, true);

        if (ACPI_FAILURE(rv) && rv != AE_CTRL_CONTINUE)
                goto fail;

        rv = acpi_power_switch(ad, ad->ad_state, false);

        if (ACPI_FAILURE(rv) && rv != AE_CTRL_CONTINUE)
                goto fail;

        /*
         * Last but not least, invoke the power state switch method,
         * if available. Because some systems use only _PSx for the
         * power state transitions, we do this even if there is no _PRx.
         */
        (void)snprintf(path, sizeof(path), "_PS%d", state);
        (void)AcpiEvaluateObject(ad->ad_handle, path, NULL, NULL);

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s turned from "
                "D%d to D%d\n", ad->ad_name, old, state));

        ad->ad_state = state;

        return true;

fail:
        ad->ad_state = ACPI_STATE_ERROR;

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "failed to set power state to D%d "
                "for %s: %s\n", state, ad->ad_name, AcpiFormatException(rv)));

        return false;
}

static ACPI_STATUS
acpi_power_switch(struct acpi_devnode *ad, int state, bool on)
{
        ACPI_OBJECT *elm, *pkg;
        ACPI_STATUS rv = AE_OK;
        ACPI_HANDLE hdl;
        uint32_t i, n;

        /*
         * For each element in the _PRx package, fetch
         * the reference handle, search for this handle
         * from the power resource queue, and turn the
         * resource behind the handle on or off.
         */
        pkg = acpi_power_pkg_get(ad->ad_handle, state);

        if (pkg == NULL)
                return AE_CTRL_CONTINUE;

        n = pkg->Package.Count;

        for (i = 0; i < n; i++) {

                elm = &pkg->Package.Elements[i];
                rv = acpi_eval_reference_handle(elm, &hdl);

                if (ACPI_FAILURE(rv))
                        continue;

                (void)acpi_power_res(hdl, ad->ad_handle, on);
        }

        ACPI_FREE(pkg);

        return rv;
}

ACPI_STATUS
acpi_power_res(ACPI_HANDLE hdl, ACPI_HANDLE ref, bool on)
{
        struct acpi_power_res *res;
        const char *str;
        ACPI_STATUS rv;

        /*
         * Search for the resource.
         */
        res = acpi_power_res_get(hdl);

        if (res == NULL)
                return AE_NOT_FOUND;

        if (ref == NULL)
                return AE_BAD_PARAMETER;

        /*
         * Adjust the reference counting. This is
         * necessary since a single power resource
         * can be shared by multiple devices.
         */
        if (on) {
                rv = acpi_power_res_ref(res, ref);
                str = "_ON";
        } else {
                rv = acpi_power_res_deref(res, ref);
                str = "_OFF";
        }

        if (ACPI_FAILURE(rv))
                return rv;

        /*
         * Turn the resource on or off.
         */
        return AcpiEvaluateObject(res->res_handle, str, NULL, NULL);
}

static ACPI_STATUS
acpi_power_res_ref(struct acpi_power_res *res, ACPI_HANDLE ref)
{
        size_t i, j = SIZE_MAX;

        mutex_enter(&res->res_mutex);

        for (i = 0; i < __arraycount(res->res_ref); i++) {

                /*
                 * Do not error out if the handle
                 * has already been referenced.
                 */
                if (res->res_ref[i] == ref) {
                        mutex_exit(&res->res_mutex);
                        return AE_OK;
                }

                if (j == SIZE_MAX && res->res_ref[i] == NULL)
                        j = i;
        }

        if (j == SIZE_MAX) {
                mutex_exit(&res->res_mutex);
                return AE_LIMIT;
        }

        res->res_ref[j] = ref;
        mutex_exit(&res->res_mutex);

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s referenced "
                "by %s\n", res->res_name, acpi_xname(ref)));

        return AE_OK;
}

static ACPI_STATUS
acpi_power_res_deref(struct acpi_power_res *res, ACPI_HANDLE ref)
{
        size_t i;

        mutex_enter(&res->res_mutex);

        for (i = 0; i < __arraycount(res->res_ref); i++) {

                if (res->res_ref[i] != ref)
                        continue;

                res->res_ref[i] = NULL;
                mutex_exit(&res->res_mutex);

                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s dereferenced "
                        "by %s\n", res->res_name, acpi_xname(ref)));

                return AE_OK;
        }

        /*
         * If the array remains to be non-empty,
         * something else is using the resource
         * and hence it can not be turned off.
         */
        mutex_exit(&res->res_mutex);

        return AE_ABORT_METHOD;
}

static ACPI_STATUS
acpi_power_res_sta(ACPI_OBJECT *elm, void *arg)
{
        ACPI_INTEGER val;
        ACPI_HANDLE hdl;
        ACPI_STATUS rv;

        rv = acpi_eval_reference_handle(elm, &hdl);

        if (ACPI_FAILURE(rv))
                goto fail;

        rv = acpi_eval_integer(hdl, "_STA", &val);

        if (ACPI_FAILURE(rv))
                goto fail;

        KDASSERT((uint64_t)val < INT_MAX);

        if ((int)val != ACPI_STA_POW_ON && (int)val != ACPI_STA_POW_OFF)
                return AE_BAD_VALUE;

        if ((int)val != ACPI_STA_POW_ON)
                return AE_CTRL_FALSE;           /* XXX: Not an error. */

        return AE_OK;

fail:
        if (rv == AE_CTRL_FALSE)
                rv = AE_ERROR;

        ACPI_DEBUG_PRINT((ACPI_DB_DEBUG_OBJECT, "failed to evaluate _STA "
                "for %s: %s\n", acpi_xname(hdl), AcpiFormatException(rv)));

        return rv;
}

static ACPI_OBJECT *
acpi_power_pkg_get(ACPI_HANDLE hdl, int state)
{
        char path[5] = "_PR?";
        ACPI_OBJECT *obj;
        ACPI_BUFFER buf;
        ACPI_STATUS rv;

        path[3] = '0' + state;

        rv = acpi_eval_struct(hdl, path, &buf);

        if (ACPI_FAILURE(rv))
                goto fail;

        if (buf.Length == 0) {
                rv = AE_LIMIT;
                goto fail;
        }

        obj = buf.Pointer;

        if (obj->Type != ACPI_TYPE_PACKAGE) {
                rv = AE_TYPE;
                goto fail;
        }

        if (obj->Package.Count == 0) {
                rv = AE_LIMIT;
                goto fail;
        }

        return obj;

fail:
        if (buf.Pointer != NULL)
                ACPI_FREE(buf.Pointer);

        ACPI_DEBUG_PRINT((ACPI_DB_DEBUG_OBJECT, "failed to evaluate %s for "
                "%s: %s\n", path, acpi_xname(hdl), AcpiFormatException(rv)));

        return NULL;
}

SYSCTL_SETUP(sysctl_acpi_power_setup, "sysctl hw.acpi.power subtree setup")
{
        const struct sysctlnode *anode;
        int err;

        err = sysctl_createv(NULL, 0, NULL, &anode,
            CTLFLAG_PERMANENT, CTLTYPE_NODE, "acpi",
            NULL, NULL, 0, NULL, 0,
            CTL_HW, CTL_CREATE, CTL_EOL);

        if (err != 0)
                return;

        acpi_power_acpinode = anode->sysctl_num;

        err = sysctl_createv(NULL, 0, &anode, &anode,
            CTLFLAG_PERMANENT, CTLTYPE_NODE,
            "power", SYSCTL_DESCR("ACPI device power states"),
            NULL, 0, NULL, 0,
            CTL_CREATE, CTL_EOL);

        if (err != 0)
                return;

        acpi_power_powernode = anode->sysctl_num;
}

void
acpi_power_add(struct acpi_devnode *ad)
{
        const char *str = NULL;
        int err;

        KASSERT(ad != NULL && ad->ad_root != NULL);
        KASSERT((ad->ad_flags & ACPI_DEVICE_POWER) != 0);

        if (acpi_power_acpinode == CTL_EOL ||
            acpi_power_powernode == CTL_EOL)
                return;

        if (ad->ad_device != NULL)
                str = device_xname(ad->ad_device);
#if NPCI > 0
        else {
                device_t dev = acpi_pcidev_find_dev(ad);

                if (dev != NULL)
                        str = device_xname(dev);
        }
#endif

        if (str == NULL)
                return;

        err = sysctl_createv(NULL, 0, NULL, NULL,
            CTLFLAG_READONLY, CTLTYPE_STRING, str,
            NULL, acpi_power_sysctl, 0, (void *)ad, 0, CTL_HW,
            acpi_power_acpinode, acpi_power_powernode,
            CTL_CREATE, CTL_EOL);

        if (err != 0)
                aprint_error_dev(ad->ad_root, "sysctl_createv"
                    "(hw.acpi.power.%s) failed (err %d)\n", str, err);
}

static int
acpi_power_sysctl(SYSCTLFN_ARGS)
{
        struct acpi_devnode *ad;
        struct sysctlnode node;
        int err, state;
        char t[3];

        node = *rnode;
        ad = rnode->sysctl_data;

        if (acpi_power_get(ad->ad_handle, &state) != true)
                state = 0;

        (void)memset(t, '\0', sizeof(t));
        (void)snprintf(t, sizeof(t), "D%d", state);

        node.sysctl_data = &t;

        err = sysctl_lookup(SYSCTLFN_CALL(&node));

        if (err || newp == NULL)
                return err;

        return 0;
}

/*
 * XXX: Move this to acpi_util.c by refactoring
 *      acpi_name() to optionally return a single name.
 */
static const char *
acpi_xname(ACPI_HANDLE hdl)
{
        static char str[5];
        ACPI_BUFFER buf;
        ACPI_STATUS rv;

        buf.Pointer = str;
        buf.Length = sizeof(str);

        rv = AcpiGetName(hdl, ACPI_SINGLE_NAME, &buf);

        if (ACPI_FAILURE(rv))
                return "????";

        return str;
}