/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2023 Vladimir Kondratyev <wulf@FreeBSD.org>
 *
 * 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/param.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/sbuf.h>
#include <sys/systm.h>

#include <machine/resource.h>

#include <contrib/dev/acpica/include/acpi.h>
#include <contrib/dev/acpica/include/accommon.h>
#include <contrib/dev/acpica/include/amlcode.h>
#include <dev/acpica/acpivar.h>

#include <dev/spibus/spibusvar.h>

/*
 * Make a copy of ACPI_RESOURCE_SPI_SERIALBUS type and replace "pointer to ACPI
 * object name string" field with pointer to ACPI object itself.
 * This saves us extra strdup()/free() pair on acpi_spibus_get_acpi_res call.
 */
typedef ACPI_RESOURCE_SPI_SERIALBUS     ACPI_SPIBUS_RESOURCE_SPI_SERIALBUS;
#define ResourceSource_Handle   ResourceSource.StringPtr

/* Hooks for the ACPI CA debugging infrastructure. */
#define _COMPONENT      ACPI_BUS
ACPI_MODULE_NAME("SPI")

#if defined (__amd64__) || defined (__i386__)
static bool is_apple;
#endif

struct acpi_spibus_ivar {
        struct spibus_ivar      super_ivar;
        ACPI_HANDLE             handle;
};

static inline bool
acpi_resource_is_spi_serialbus(ACPI_RESOURCE *res)
{
        return (res->Type == ACPI_RESOURCE_TYPE_SERIAL_BUS &&
            res->Data.CommonSerialBus.Type == ACPI_RESOURCE_SERIAL_TYPE_SPI);
}

static ACPI_STATUS
acpi_spibus_get_acpi_res_cb(ACPI_RESOURCE *res, void *context)
{
        ACPI_SPIBUS_RESOURCE_SPI_SERIALBUS *sb = context;
        ACPI_STATUS status;
        ACPI_HANDLE handle;

        if (acpi_resource_is_spi_serialbus(res)) {
                status = AcpiGetHandle(ACPI_ROOT_OBJECT,
                    res->Data.SpiSerialBus.ResourceSource.StringPtr, &handle);
                if (ACPI_FAILURE(status))
                        return (status);
                memcpy(sb, &res->Data.SpiSerialBus,
                    sizeof(ACPI_SPIBUS_RESOURCE_SPI_SERIALBUS));
                /*
                 * replace "pointer to ACPI object name string" field
                 * with pointer to ACPI object itself.
                 */
                sb->ResourceSource_Handle = handle;
                return (AE_CTRL_TERMINATE);
        } else if (res->Type == ACPI_RESOURCE_TYPE_END_TAG)
                return (AE_NOT_FOUND);

        return (AE_OK);
}

static void
acpi_spibus_dump_res(device_t dev, ACPI_SPIBUS_RESOURCE_SPI_SERIALBUS *sb)
{
        device_printf(dev, "found ACPI child\n");
        printf("  DeviceSelection:   0x%04hx\n", sb->DeviceSelection);
        printf("  ConnectionSpeed:   %uHz\n", sb->ConnectionSpeed);
        printf("  WireMode:          %s\n",
            sb->WireMode == ACPI_SPI_4WIRE_MODE ?
            "FourWireMode" : "ThreeWireMode");
        printf("  DevicePolarity:    %s\n",
             sb->DevicePolarity == ACPI_SPI_ACTIVE_LOW ?
            "PolarityLow" : "PolarityHigh");
        printf("  DataBitLength:     %uBit\n", sb->DataBitLength);
        printf("  ClockPhase:        %s\n",
            sb->ClockPhase == ACPI_SPI_FIRST_PHASE ?
            "ClockPhaseFirst" : "ClockPhaseSecond");
        printf("  ClockPolarity:     %s\n",
            sb->ClockPolarity == ACPI_SPI_START_LOW ?
            "ClockPolarityLow" : "ClockPolarityHigh");
        printf("  SlaveMode:         %s\n",
            sb->SlaveMode == ACPI_CONTROLLER_INITIATED ?
            "ControllerInitiated" : "DeviceInitiated");
        printf("  ConnectionSharing: %s\n", sb->ConnectionSharing == 0 ?
            "Exclusive" : "Shared");
}

static int
acpi_spibus_get_acpi_res(device_t spibus, ACPI_HANDLE dev,
    struct spibus_ivar *res)
{
        ACPI_SPIBUS_RESOURCE_SPI_SERIALBUS sb;

        /*
         * Read "SPI Serial Bus Connection Resource Descriptor"
         * described in p.19.6.126 of ACPI specification.
         */
        bzero(&sb, sizeof(ACPI_SPIBUS_RESOURCE_SPI_SERIALBUS));
        if (ACPI_FAILURE(AcpiWalkResources(dev, "_CRS",
            acpi_spibus_get_acpi_res_cb, &sb)))
                return (ENXIO);
        if (sb.ResourceSource_Handle !=
            acpi_get_handle(device_get_parent(spibus)))
                return (ENXIO);
        if (bootverbose)
                acpi_spibus_dump_res(spibus, &sb);
        /*
         * The Windows Baytrail and Braswell SPI host controller
         * drivers uses 1 as the first (and only) value for ACPI
         * DeviceSelection.
         */
        if (sb.DeviceSelection != 0 &&
            (acpi_MatchHid(sb.ResourceSource_Handle, "80860F0E") ||
             acpi_MatchHid(sb.ResourceSource_Handle, "8086228E")))
                res->cs = sb.DeviceSelection - 1;
        else
                res->cs = sb.DeviceSelection;
        res->mode =
            (sb.ClockPhase != ACPI_SPI_FIRST_PHASE ? SPIBUS_MODE_CPHA : 0) |
            (sb.ClockPolarity != ACPI_SPI_START_LOW ? SPIBUS_MODE_CPOL : 0);
        res->clock =  sb.ConnectionSpeed;

        return (0);
}

#if defined (__amd64__) || defined (__i386__)
static int
acpi_spibus_get_apple_res(device_t spibus, ACPI_HANDLE dev,
    struct spibus_ivar *ivar)
{
        /* a0b5b7c6-1318-441c-b0c9-fe695eaf949b */
        static const uint8_t apple_guid[ACPI_UUID_LENGTH] = {
            0xC6, 0xB7, 0xB5, 0xA0, 0x18, 0x13, 0x1C, 0x44,
            0xB0, 0xC9, 0xFE, 0x69, 0x5E, 0xAF, 0x94, 0x9B,
        };
        ACPI_BUFFER buf;
        ACPI_OBJECT *pkg, *comp;
        ACPI_HANDLE parent;
        char *k;
        uint64_t val;

        /* Apple does not use _CRS but nested devices for SPI slaves */
        if (ACPI_FAILURE(AcpiGetParent(dev, &parent)))
                return (ENXIO);
        if (parent != acpi_get_handle(device_get_parent(spibus)))
                return (ENXIO);
        if (ACPI_FAILURE(acpi_EvaluateDSMTyped(dev, apple_guid,
                         1, 1, NULL, &buf, ACPI_TYPE_PACKAGE)))
                return (ENXIO);

        pkg = ((ACPI_OBJECT *)buf.Pointer);
        if (pkg->Package.Count % 2 != 0) {
                device_printf(spibus, "_DSM length %d not even\n",
                    pkg->Package.Count);
                AcpiOsFree(pkg);
                return (ENXIO);
        }

        if (bootverbose)
                device_printf(spibus, "found ACPI child\n");

        for (comp = pkg->Package.Elements;
             comp < pkg->Package.Elements + pkg->Package.Count;
             comp += 2) {

                if (comp[0].Type != ACPI_TYPE_STRING ||
                    comp[1].Type != ACPI_TYPE_BUFFER) {
                        device_printf(spibus, "expected string+buffer, "
                            "got %d+%d\n", comp[0].Type, comp[1].Type);
                        continue;
                }
                k = comp[0].String.Pointer;
                val = comp[1].Buffer.Length >= 8 ?
                    *(uint64_t *)comp[1].Buffer.Pointer : 0;

                if (bootverbose)
                        printf("  %s: %ju\n", k, (intmax_t)val);

                if (strcmp(k, "spiSclkPeriod") == 0) {
                        if (val != 0)
                                ivar->clock = 1000000000 / val;
                } else if (strcmp(k, "spiSPO") == 0) {
                        if (val != 0)
                                ivar->mode |= SPIBUS_MODE_CPOL;
                } else if (strcmp(k, "spiSPH") == 0) {
                        if (val != 0)
                                ivar->mode |= SPIBUS_MODE_CPHA;
                } else if (strcmp(k, "spiCSDelay") == 0) {
                        ivar->cs_delay = val;
                }
        }

        AcpiOsFree(pkg);

        return (0);
}
#endif

static int
acpi_spibus_delete_acpi_child(ACPI_HANDLE handle)
{
        device_t acpi_child, acpi0;

        /* Delete existing child of acpi bus */
        acpi_child = acpi_get_device(handle);
        if (acpi_child != NULL) {
                acpi0 = devclass_get_device(devclass_find("acpi"), 0);
                if (device_get_parent(acpi_child) != acpi0)
                        return (ENXIO);

                if (device_is_attached(acpi_child))
                        return (ENXIO);

                if (device_delete_child(acpi0, acpi_child) != 0)
                        return (ENXIO);
        }

        return (0);
}

static device_t
acpi_spibus_add_child(device_t dev, u_int order, const char *name, int unit)
{
        return (spibus_add_child_common(
            dev, order, name, unit, sizeof(struct acpi_spibus_ivar)));
}

static ACPI_STATUS
acpi_spibus_enumerate_child(ACPI_HANDLE handle, UINT32 level,
    void *context, void **result)
{
        device_t spibus, child;
        struct spibus_ivar res;
        ACPI_STATUS status;
        UINT32 sta;
        bool found = false;

        spibus = context;

        /*
         * If no _STA method or if it failed, then assume that
         * the device is present.
         */
        if (!ACPI_FAILURE(acpi_GetInteger(handle, "_STA", &sta)) &&
            !ACPI_DEVICE_PRESENT(sta))
                return (AE_OK);

        if (!acpi_has_hid(handle))
                return (AE_OK);

        bzero(&res, sizeof(res));
        if (acpi_spibus_get_acpi_res(spibus, handle, &res) == 0)
                found = true;
#if defined (__amd64__) || defined (__i386__)
        if (!found && is_apple &&
            acpi_spibus_get_apple_res(spibus, handle, &res) == 0)
                found = true;
#endif
        if (!found || res.clock == 0)
                return (AE_OK);

        /* Delete existing child of acpi bus */
        if (acpi_spibus_delete_acpi_child(handle) != 0)
                return (AE_OK);

        child = BUS_ADD_CHILD(spibus, 0, NULL, DEVICE_UNIT_ANY);
        if (child == NULL) {
                device_printf(spibus, "add child failed\n");
                return (AE_OK);
        }

        spibus_set_cs(child, res.cs);
        spibus_set_mode(child, res.mode);
        spibus_set_clock(child, res.clock);
        spibus_set_cs_delay(child, res.cs_delay);
        acpi_set_handle(child, handle);
        acpi_parse_resources(child, handle, &acpi_res_parse_set, NULL);

        /*
         * Update ACPI-CA to use the IIC enumerated device_t for this handle.
         */
        status = AcpiAttachData(handle, acpi_fake_objhandler, child);
        if (ACPI_FAILURE(status))
                printf("WARNING: Unable to attach object data to %s - %s\n",
                    acpi_name(handle), AcpiFormatException(status));

        return (AE_OK);
}

static ACPI_STATUS
acpi_spibus_enumerate_children(device_t dev)
{
        return (AcpiWalkNamespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
            ACPI_UINT32_MAX, acpi_spibus_enumerate_child, NULL, dev, NULL));
}

static void
acpi_spibus_set_power_children(device_t dev, int state, bool all_children)
{
        device_t *devlist;
        int i, numdevs;

        if (device_get_children(dev, &devlist, &numdevs) != 0)
                return;

        for (i = 0; i < numdevs; i++)
                if (all_children || device_is_attached(devlist[i]) != 0)
                        acpi_set_powerstate(devlist[i], state);

        free(devlist, M_TEMP);
}

static int
acpi_spibus_probe(device_t dev)
{
        ACPI_HANDLE handle;
        device_t controller;

        if (acpi_disabled("spibus"))
                return (ENXIO);

        controller = device_get_parent(dev);
        if (controller == NULL)
                return (ENXIO);

        handle = acpi_get_handle(controller);
        if (handle == NULL)
                return (ENXIO);

        device_set_desc(dev, "SPI bus (ACPI-hinted)");
        return (BUS_PROBE_DEFAULT + 1);
}

static int
acpi_spibus_attach(device_t dev)
{

#if defined (__amd64__) || defined (__i386__)
        char *vendor = kern_getenv("smbios.bios.vendor");
        if (vendor != NULL &&
            (strcmp(vendor, "Apple Inc.") == 0 ||
             strcmp(vendor, "Apple Computer, Inc.") == 0))
                is_apple = true;
#endif

        if (ACPI_FAILURE(acpi_spibus_enumerate_children(dev)))
                device_printf(dev, "children enumeration failed\n");

        acpi_spibus_set_power_children(dev, ACPI_STATE_D0, true);
        return (spibus_attach(dev));
}

static int
acpi_spibus_detach(device_t dev)
{
        acpi_spibus_set_power_children(dev, ACPI_STATE_D3, false);

        return (bus_generic_detach(dev));
}

static int
acpi_spibus_suspend(device_t dev)
{
        acpi_spibus_set_power_children(dev, ACPI_STATE_D3, false);

        return (bus_generic_suspend(dev));
}

static int
acpi_spibus_resume(device_t dev)
{
        acpi_spibus_set_power_children(dev, ACPI_STATE_D0, false);

        return (bus_generic_resume(dev));
}

#ifndef INTRNG
/* Mostly copy of acpi_alloc_resource() */
static struct resource *
acpi_spibus_alloc_resource(device_t dev, device_t child, int type, int rid,
    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
        ACPI_RESOURCE ares;
        struct resource_list *rl;
        struct resource *res;

        if (device_get_parent(child) != dev)
                return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
                    type, rid, start, end, count, flags));

        rl = BUS_GET_RESOURCE_LIST(dev, child);
        if (rl == NULL)
                return (NULL);

        res = resource_list_alloc(rl, dev, child, type, rid,
            start, end, count, flags);
        if (res != NULL && type == SYS_RES_IRQ &&
            ACPI_SUCCESS(acpi_lookup_irq_resource(child, rid, res, &ares)))
                acpi_config_intr(child, &ares);

        return (res);
}
#endif

/*
 * If this device is an ACPI child but no one claimed it, attempt
 * to power it off.  We'll power it back up when a driver is added.
 */
static void
acpi_spibus_probe_nomatch(device_t bus, device_t child)
{
        spibus_probe_nomatch(bus, child);
        acpi_set_powerstate(child, ACPI_STATE_D3);
}

/*
 * If a new driver has a chance to probe a child, first power it up.
 */
static void
acpi_spibus_driver_added(device_t dev, driver_t *driver)
{
        device_t child, *devlist;
        int i, numdevs;

        DEVICE_IDENTIFY(driver, dev);
        if (device_get_children(dev, &devlist, &numdevs) != 0)
                return;

        for (i = 0; i < numdevs; i++) {
                child = devlist[i];
                if (device_get_state(child) == DS_NOTPRESENT) {
                        acpi_set_powerstate(child, ACPI_STATE_D0);
                        if (device_probe_and_attach(child) != 0)
                                acpi_set_powerstate(child, ACPI_STATE_D3);
                }
        }
        free(devlist, M_TEMP);
}

static void
acpi_spibus_child_deleted(device_t bus, device_t child)
{
        struct acpi_spibus_ivar *devi = device_get_ivars(child);

        if (acpi_get_device(devi->handle) == child)
                AcpiDetachData(devi->handle, acpi_fake_objhandler);
}

static int
acpi_spibus_read_ivar(device_t bus, device_t child, int which, uintptr_t *res)
{
        struct acpi_spibus_ivar *devi = device_get_ivars(child);

        switch (which) {
        case ACPI_IVAR_HANDLE:
                *res = (uintptr_t)devi->handle;
                break;
        default:
                return (spibus_read_ivar(bus, child, which, res));
        }

        return (0);
}

static int
acpi_spibus_write_ivar(device_t bus, device_t child, int which, uintptr_t val)
{
        struct acpi_spibus_ivar *devi = device_get_ivars(child);

        switch (which) {
        case ACPI_IVAR_HANDLE:
                if (devi->handle != NULL)
                        return (EINVAL);
                devi->handle = (ACPI_HANDLE)val;
                break;
        default:
                return (spibus_write_ivar(bus, child, which, val));
        }

        return (0);
}

/* Location hint for devctl(8). Concatenate IIC and ACPI hints. */
static int
acpi_spibus_child_location(device_t bus, device_t child, struct sbuf *sb)
{
        struct acpi_spibus_ivar *devi = device_get_ivars(child);
        int error;

        /* read SPI location hint string into the buffer. */
        error = spibus_child_location(bus, child, sb);
        if (error != 0)
                return (error);

        /* Place ACPI string right after IIC one's terminating NUL. */
        if (devi->handle != NULL)
                sbuf_printf(sb, " handle=%s", acpi_name(devi->handle));

        return (0);
}

/* PnP information for devctl(8). */
static int
acpi_spibus_child_pnpinfo(device_t bus, device_t child, struct sbuf *sb)
{
        struct acpi_spibus_ivar *devi = device_get_ivars(child);

        return (
            devi->handle == NULL ? ENOTSUP : acpi_pnpinfo(devi->handle, sb));
}

static device_method_t acpi_spibus_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         acpi_spibus_probe),
        DEVMETHOD(device_attach,        acpi_spibus_attach),
        DEVMETHOD(device_detach,        acpi_spibus_detach),
        DEVMETHOD(device_suspend,       acpi_spibus_suspend),
        DEVMETHOD(device_resume,        acpi_spibus_resume),

        /* Bus interface */
#ifndef INTRNG
        DEVMETHOD(bus_alloc_resource,   acpi_spibus_alloc_resource),
#endif
        DEVMETHOD(bus_add_child,        acpi_spibus_add_child),
        DEVMETHOD(bus_child_deleted,    spibus_child_deleted),
        DEVMETHOD(bus_probe_nomatch,    acpi_spibus_probe_nomatch),
        DEVMETHOD(bus_driver_added,     acpi_spibus_driver_added),
        DEVMETHOD(bus_child_deleted,    acpi_spibus_child_deleted),
        DEVMETHOD(bus_read_ivar,        acpi_spibus_read_ivar),
        DEVMETHOD(bus_write_ivar,       acpi_spibus_write_ivar),
        DEVMETHOD(bus_child_location,   acpi_spibus_child_location),
        DEVMETHOD(bus_child_pnpinfo,    acpi_spibus_child_pnpinfo),
        DEVMETHOD(bus_get_device_path,  acpi_get_acpi_device_path),

        DEVMETHOD_END,
};

DEFINE_CLASS_1(spibus, acpi_spibus_driver, acpi_spibus_methods,
    sizeof(struct spibus_softc), spibus_driver);
DRIVER_MODULE(acpi_spibus, spi, acpi_spibus_driver, NULL, NULL);
MODULE_VERSION(acpi_spibus, 1);
MODULE_DEPEND(acpi_spibus, acpi, 1, 1, 1);