/*
 * Copyright (c) 2026 Abdelkader Boudih <freebsd@seuros.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Apple T2 Buffer Copy Engine (BCE) PCI driver.
 * Provides the transport layer for T2 coprocessor communication:
 * mailbox handshake, DMA queue setup, and firmware keepalive.
 */

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/sema.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/rman.h>
#include <sys/time.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/atomic.h>

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

#include "apple_bce.h"
#include "apple_bce_mailbox.h"
#include "apple_bce_queue.h"
#include "apple_bce_vhci.h"

static int      apple_bce_probe(device_t dev);
static int      apple_bce_attach(device_t dev);
static int      apple_bce_detach(device_t dev);
static int      apple_bce_suspend(device_t dev);
static int      apple_bce_resume(device_t dev);
static void     apple_bce_timestamp_cb(void *arg);
static void     apple_bce_timestamp_init(struct apple_bce_softc *sc);
static void     apple_bce_timestamp_start(struct apple_bce_softc *sc,
                    int is_initial);
static void     apple_bce_timestamp_stop(struct apple_bce_softc *sc);

/*
 * Timestamp protocol -- T2 firmware expects periodic boottime updates.
 *
 * Register layout at BAR4 + 0xC000:
 *   regb + 0 (0xC000): high 32 bits / control
 *   regb + 8 (0xC008): low 32 bits / data
 *
 * Control opcodes (written to regb+8 with 0xFFFFFFFF to regb+0):
 *   -4 (0xFFFFFFFC): initial start
 *   -3 (0xFFFFFFFD): restart
 *   -2 (0xFFFFFFFE): stop
 */
static void
apple_bce_timestamp_init(struct apple_bce_softc *sc)
{
        /* Read control register and barrier to sync with firmware */
        bus_read_4(sc->sc_bar4, BCE_REG_TIMESTAMP);
        mb();
}

static void
apple_bce_timestamp_start(struct apple_bce_softc *sc, int is_initial)
{
        /* Send start opcode: -4 for initial, -3 for restart */
        bus_write_4(sc->sc_bar4, BCE_REG_TIMESTAMP + 8,
            is_initial ? 0xFFFFFFFC : 0xFFFFFFFD);
        bus_write_4(sc->sc_bar4, BCE_REG_TIMESTAMP, 0xFFFFFFFF);

        mtx_lock_spin(&sc->sc_timestamp_lock);
        sc->sc_timestamp_stopped = 0;
        mtx_unlock_spin(&sc->sc_timestamp_lock);

        callout_reset(&sc->sc_timestamp_co, hz * BCE_TIMESTAMP_MS / 1000,
            apple_bce_timestamp_cb, sc);
}

static void
apple_bce_timestamp_stop(struct apple_bce_softc *sc)
{
        mtx_lock_spin(&sc->sc_timestamp_lock);
        sc->sc_timestamp_stopped = 1;
        mtx_unlock_spin(&sc->sc_timestamp_lock);

        callout_drain(&sc->sc_timestamp_co);

        /* Send stop opcode */
        bus_write_4(sc->sc_bar4, BCE_REG_TIMESTAMP + 8, 0xFFFFFFFE);
        bus_write_4(sc->sc_bar4, BCE_REG_TIMESTAMP, 0xFFFFFFFF);
}

static void
apple_bce_timestamp_cb(void *arg)
{
        struct apple_bce_softc *sc = arg;
        struct bintime bt;
        uint64_t ns;

        /* Read to sync, then barrier */
        bus_read_4(sc->sc_bar4, BCE_REG_TIMESTAMP + 8);
        mb();

        /* Get boot time in nanoseconds */
        binuptime(&bt);
        ns = (uint64_t)bt.sec * 1000000000ULL +
            (((uint64_t)(bt.frac >> 32) * 1000000000ULL) >> 32);

        /* Write: low 32 bits to regb+8, high 32 bits to regb+0 */
        bus_write_4(sc->sc_bar4, BCE_REG_TIMESTAMP + 8, (uint32_t)ns);
        bus_write_4(sc->sc_bar4, BCE_REG_TIMESTAMP, (uint32_t)(ns >> 32));

        mtx_lock_spin(&sc->sc_timestamp_lock);
        if (!sc->sc_timestamp_stopped)
                callout_schedule(&sc->sc_timestamp_co,
                    hz * BCE_TIMESTAMP_MS / 1000);
        mtx_unlock_spin(&sc->sc_timestamp_lock);
}

/*
 * IRQ handlers.
 */
static void
apple_bce_mbox_intr(void *arg)
{
        struct apple_bce_softc *sc = arg;

        bce_mailbox_handle_interrupt(&sc->sc_mbox);
}

static void
apple_bce_dma_intr(void *arg)
{
        struct apple_bce_softc *sc = arg;
        int i;

        /*
         * Only process registered CQs. sc_cq_list[] contains only CQ
         * pointers -- separate from sc_queues[] which mixes CQ and SQ.
         */
        mtx_lock(&sc->sc_queues_lock);
        for (i = 0; i < BCE_MAX_CQ_COUNT; i++) {
                if (sc->sc_cq_list[i] != NULL)
                        bce_handle_cq_completions(sc, sc->sc_cq_list[i]);
        }
        mtx_unlock(&sc->sc_queues_lock);
}

/*
 * Enable bus master on PCI function 0 (NVMe).
 * T2 requires function 0 to be bus master for DMA on function 1.
 */
static int
apple_bce_enable_pci0_busmaster(device_t dev)
{
        device_t pci0;
        device_t bus;

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

        /*
         * Find function 0 on the same bus/slot.
         * Our device is function 1; function 0 is NVMe.
         */
        pci0 = pci_find_dbsf(pci_get_domain(dev), pci_get_bus(dev),
            pci_get_slot(dev), 0);
        if (pci0 == NULL) {
                device_printf(dev, "cannot find PCI function 0\n");
                return (ENXIO);
        }

        pci_enable_busmaster(pci0);
        device_printf(dev, "enabled bus master on function 0 (%s)\n",
            device_get_nameunit(pci0));
        return (0);
}

/*
 * Firmware handshake via mailbox.
 */
static int
apple_bce_fw_handshake(struct apple_bce_softc *sc)
{
        uint64_t reply;
        int error;

        error = bce_mailbox_send(&sc->sc_mbox,
            BCE_MB_MSG(BCE_MB_SET_FW_PROTOCOL_VER, BCE_FW_PROTOCOL_VER),
            &reply, BCE_MBOX_TIMEOUT_MS);
        if (error != 0) {
                device_printf(sc->sc_dev, "firmware handshake timeout\n");
                return (error);
        }

        if (BCE_MB_TYPE(reply) != BCE_MB_SET_FW_PROTOCOL_VER ||
            BCE_MB_VALUE(reply) != BCE_FW_PROTOCOL_VER) {
                device_printf(sc->sc_dev,
                    "firmware version mismatch: got type=%u val=0x%llx\n",
                    BCE_MB_TYPE(reply),
                    (unsigned long long)BCE_MB_VALUE(reply));
                return (ENODEV);
        }

        device_printf(sc->sc_dev, "firmware handshake OK (protocol 0x%x)\n",
            BCE_FW_PROTOCOL_VER);
        return (0);
}

/*
 * DMA callback for command queue registration.
 */
static void
bce_reg_dma_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
        struct { bus_addr_t addr; int error; } *cb = arg;

        cb->error = error;
        if (error == 0)
                cb->addr = segs[0].ds_addr;
}

/*
 * Register a command queue (CQ or SQ) with firmware via mailbox.
 * The memcfg struct is DMA-mapped and its physical address sent
 * in the mailbox message -- firmware reads the config from DMA.
 */
static int
apple_bce_register_cmd_queue(struct apple_bce_softc *sc,
    struct bce_queue_memcfg *cfg, int is_sq)
{
        bus_dma_tag_t tag;
        bus_dmamap_t map;
        bus_addr_t paddr;
        struct bce_queue_memcfg *dma_cfg;
        struct {
                bus_addr_t addr;
                int error;
        } cb;
        uint64_t reply;
        int error, cmd_type;

        /* Allocate DMA-coherent buffer for memcfg (8-byte aligned) */
        error = bus_dma_tag_create(sc->sc_dma_tag,
            8, 0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
            NULL, NULL, sizeof(*cfg), 1, sizeof(*cfg),
            BUS_DMA_WAITOK, NULL, NULL, &tag);
        if (error != 0)
                return (error);

        error = bus_dmamem_alloc(tag, (void **)&dma_cfg,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT, &map);
        if (error != 0) {
                bus_dma_tag_destroy(tag);
                return (error);
        }

        /* Copy config and load DMA address */
        memcpy(dma_cfg, cfg, sizeof(*cfg));

        cb.error = 0;
        error = bus_dmamap_load(tag, map, dma_cfg, sizeof(*cfg),
            bce_reg_dma_cb, &cb, BUS_DMA_WAITOK);
        if (error != 0 || cb.error != 0) {
                bus_dmamem_free(tag, dma_cfg, map);
                bus_dma_tag_destroy(tag);
                return (error != 0 ? error : cb.error);
        }
        paddr = cb.addr;

        /* Sync DMA buffer before device access */
        bus_dmamap_sync(tag, map, BUS_DMASYNC_PREWRITE);

        /* Send DMA address of memcfg to firmware */
        cmd_type = is_sq ? BCE_MB_REGISTER_CMD_SQ : BCE_MB_REGISTER_CMD_CQ;
        error = bce_mailbox_send(&sc->sc_mbox,
            BCE_MB_MSG(cmd_type, paddr), &reply, BCE_MBOX_TIMEOUT_MS);

        bus_dmamap_sync(tag, map, BUS_DMASYNC_POSTWRITE);
        bus_dmamap_unload(tag, map);
        bus_dmamem_free(tag, dma_cfg, map);
        bus_dma_tag_destroy(tag);

        if (error != 0)
                return (error);

        if (BCE_MB_TYPE(reply) != BCE_MB_REGISTER_QUEUE_REPLY) {
                device_printf(sc->sc_dev,
                    "unexpected queue registration reply: type=%u\n",
                    BCE_MB_TYPE(reply));
                return (EINVAL);
        }

        return (0);
}

/*
 * Setup command queues (CQ qid=0, SQ qid=1).
 */
static int
apple_bce_setup_cmd_queues(struct apple_bce_softc *sc)
{
        struct bce_queue_memcfg cfg;
        struct bce_queue_sq *sq;
        int error;

        /* Allocate command CQ (qid 0, 32 entries) */
        sc->sc_cmd_cq = bce_alloc_cq(sc, 0, 32);
        if (sc->sc_cmd_cq == NULL) {
                device_printf(sc->sc_dev, "failed to allocate command CQ\n");
                return (ENOMEM);
        }

        /* Register CQ with firmware via DMA-mapped memcfg */
        bce_get_cq_memcfg(sc->sc_cmd_cq, &cfg);
        error = apple_bce_register_cmd_queue(sc, &cfg, 0);
        if (error != 0) {
                device_printf(sc->sc_dev, "failed to register command CQ\n");
                goto fail_cq;
        }

        /* Store CQ in queue registries */
        mtx_lock(&sc->sc_queues_lock);
        sc->sc_queues[0] = sc->sc_cmd_cq;
        sc->sc_cq_list[0] = sc->sc_cmd_cq;
        mtx_unlock(&sc->sc_queues_lock);

        /* Allocate command SQ (qid 1, 64-byte elements, 32 entries) */
        sq = bce_alloc_sq(sc, 1, BCE_CMD_SIZE, 32, NULL, NULL);
        if (sq == NULL) {
                device_printf(sc->sc_dev, "failed to allocate command SQ\n");
                goto fail_cq;
        }

        /* Wrap SQ in command queue (sets completion callback internally) */
        sc->sc_cmd_cmdq = bce_alloc_cmdq(sc, sq);
        if (sc->sc_cmd_cmdq == NULL) {
                bce_free_sq(sc, sq);
                goto fail_cq;
        }

        /* Register SQ with firmware via DMA-mapped memcfg */
        bce_get_sq_memcfg(sq, sc->sc_cmd_cq, &cfg);
        error = apple_bce_register_cmd_queue(sc, &cfg, 1);
        if (error != 0) {
                device_printf(sc->sc_dev, "failed to register command SQ\n");
                goto fail_sq;
        }

        /* Store SQ in queue registry */
        mtx_lock(&sc->sc_queues_lock);
        sc->sc_queues[1] = sq;
        sc->sc_int_sq_list[0] = sq;
        mtx_unlock(&sc->sc_queues_lock);

        device_printf(sc->sc_dev, "command queues created (CQ=0, SQ=1)\n");
        return (0);

fail_sq:
        bce_free_cmdq(sc->sc_cmd_cmdq);
        sc->sc_cmd_cmdq = NULL;
        bce_free_sq(sc, sq);
fail_cq:
        /* Clear CQ from registries before freeing */
        mtx_lock(&sc->sc_queues_lock);
        sc->sc_queues[0] = NULL;
        sc->sc_cq_list[0] = NULL;
        mtx_unlock(&sc->sc_queues_lock);
        bce_free_cq(sc, sc->sc_cmd_cq);
        sc->sc_cmd_cq = NULL;
        return (error != 0 ? error : ENOMEM);
}

/*
 * PCI probe.
 */
static int
apple_bce_probe(device_t dev)
{
        if (pci_get_vendor(dev) != BCE_PCI_VENDOR_APPLE ||
            pci_get_device(dev) != BCE_PCI_DEVICE_T2)
                return (ENXIO);

        /* Only attach to function 1 (BCE), not function 0 (NVMe) */
        if (pci_get_function(dev) != 1)
                return (ENXIO);

        device_set_desc(dev, "Apple T2 Buffer Copy Engine");
        return (BUS_PROBE_DEFAULT);
}

/*
 * PCI attach.
 */
static int
apple_bce_attach(device_t dev)
{
        struct apple_bce_softc *sc = device_get_softc(dev);
        int error;

        sc->sc_dev = dev;
        pci_enable_busmaster(dev);
        mtx_init(&sc->sc_queues_lock, "bce_queues", NULL, MTX_DEF);
        mtx_init(&sc->sc_timestamp_lock, "bce_ts", NULL, MTX_SPIN);
        callout_init(&sc->sc_timestamp_co, 1);

        /* Map BAR2 (DMA) and BAR4 (mailbox) */
        sc->sc_bar2_rid = PCIR_BAR(2);
        sc->sc_bar2 = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
            &sc->sc_bar2_rid, RF_ACTIVE);
        if (sc->sc_bar2 == NULL) {
                device_printf(dev, "cannot map BAR2 (DMA)\n");
                error = ENXIO;
                goto fail;
        }

        sc->sc_bar4_rid = PCIR_BAR(4);
        sc->sc_bar4 = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
            &sc->sc_bar4_rid, RF_ACTIVE);
        if (sc->sc_bar4 == NULL) {
                device_printf(dev, "cannot map BAR4 (mailbox)\n");
                error = ENXIO;
                goto fail;
        }

        /* Allocate MSI vectors (need at least 5: mbox=0, dma=4) */
        sc->sc_msi_count = 8;   /* Must be power of 2 for FreeBSD */
        error = pci_alloc_msi(dev, &sc->sc_msi_count);
        if (error != 0 || sc->sc_msi_count < 8) {
                device_printf(dev, "cannot allocate MSI vectors: "
                    "error=%d got=%d\n", error, sc->sc_msi_count);
                if (error == 0 && sc->sc_msi_count > 0)
                        pci_release_msi(dev);
                sc->sc_msi_count = 0;
                error = ENXIO;
                goto fail;
        }

        /* Initialize mailbox before installing handlers */
        bce_mailbox_init(&sc->sc_mbox, sc->sc_bar4);

        /* Setup IRQ: vector 0 = mailbox, vector 4 = DMA */
        sc->sc_irq_rid_mbox = 1;        /* MSI vectors start at rid 1 */
        sc->sc_irq_mbox = bus_alloc_resource_any(dev, SYS_RES_IRQ,
            &sc->sc_irq_rid_mbox, RF_ACTIVE);
        if (sc->sc_irq_mbox == NULL) {
                device_printf(dev, "cannot allocate mailbox IRQ\n");
                error = ENXIO;
                goto fail;
        }

        error = bus_setup_intr(dev, sc->sc_irq_mbox,
            INTR_TYPE_MISC | INTR_MPSAFE,
            NULL, apple_bce_mbox_intr, sc, &sc->sc_irq_mbox_cookie);
        if (error != 0) {
                device_printf(dev, "cannot setup mailbox IRQ\n");
                goto fail;
        }

        sc->sc_irq_rid_dma = 5; /* Vector 4 = rid 5 */
        sc->sc_irq_dma = bus_alloc_resource_any(dev, SYS_RES_IRQ,
            &sc->sc_irq_rid_dma, RF_ACTIVE);
        if (sc->sc_irq_dma == NULL) {
                device_printf(dev, "cannot allocate DMA IRQ\n");
                error = ENXIO;
                goto fail;
        }

        error = bus_setup_intr(dev, sc->sc_irq_dma,
            INTR_TYPE_MISC | INTR_MPSAFE,
            NULL, apple_bce_dma_intr, sc, &sc->sc_irq_dma_cookie);
        if (error != 0) {
                device_printf(dev, "cannot setup DMA IRQ\n");
                goto fail;
        }

        /* Create parent DMA tag with 37-bit addressing limit */
        error = bus_dma_tag_create(bus_get_dma_tag(dev),
            1, 0,                       /* alignment, boundary */
            (1ULL << 37) - 1,           /* lowaddr: 37-bit limit */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter */
            BUS_SPACE_MAXSIZE,          /* maxsize */
            BUS_SPACE_UNRESTRICTED,     /* nsegments */
            BUS_SPACE_MAXSIZE,          /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc */
            &sc->sc_dma_tag);
        if (error != 0) {
                device_printf(dev, "cannot create DMA tag\n");
                goto fail;
        }

        /*
         * Enable bus master on function 0 (NVMe) -- T2 quirk.
         * Must be done before firmware handshake; T2 rejects DMA
         * on function 1 unless function 0 is bus master.
         */
        apple_bce_enable_pci0_busmaster(dev);

        /* Initialize and start timestamp keepalive */
        apple_bce_timestamp_init(sc);
        apple_bce_timestamp_start(sc, 1);

        /* Firmware handshake */
        error = apple_bce_fw_handshake(sc);
        if (error != 0)
                goto fail;

        /* Setup command queues */
        error = apple_bce_setup_cmd_queues(sc);
        if (error != 0)
                goto fail;

        device_printf(dev, "Apple T2 BCE initialized\n");

        /* Create VHCI child for virtual USB */
        error = bce_vhci_attach(sc);
        if (error != 0)
                goto fail;

        return (0);

fail:
        apple_bce_detach(dev);
        return (error);
}

/*
 * PCI detach.
 */
static int
apple_bce_detach(device_t dev)
{
        struct apple_bce_softc *sc = device_get_softc(dev);

        /* 0. Detach VHCI child first (before destroying parent resources) */
        bce_vhci_detach(sc);

        /* 1. Stop timestamp */
        if (sc->sc_bar4 != NULL && mtx_initialized(&sc->sc_timestamp_lock))
                apple_bce_timestamp_stop(sc);
        else
                callout_drain(&sc->sc_timestamp_co);

        /* 2. Tear down IRQs first -- no more interrupts after this */
        if (sc->sc_irq_dma_cookie != NULL) {
                bus_teardown_intr(dev, sc->sc_irq_dma, sc->sc_irq_dma_cookie);
                sc->sc_irq_dma_cookie = NULL;
        }
        if (sc->sc_irq_mbox_cookie != NULL) {
                bus_teardown_intr(dev, sc->sc_irq_mbox,
                    sc->sc_irq_mbox_cookie);
                sc->sc_irq_mbox_cookie = NULL;
        }

        /* 3. Free command queues (safe now -- no IRQs can fire) */
        if (sc->sc_cmd_cmdq != NULL) {
                struct bce_queue_sq *cmd_sq;

                cmd_sq = sc->sc_cmd_cmdq->sq;
                bce_free_cmdq(sc->sc_cmd_cmdq);
                sc->sc_cmd_cmdq = NULL;
                bce_free_sq(sc, cmd_sq);
        }
        if (sc->sc_cmd_cq != NULL) {
                bce_free_cq(sc, sc->sc_cmd_cq);
                sc->sc_cmd_cq = NULL;
        }

        /* 4. Clear queue registries */
        if (mtx_initialized(&sc->sc_queues_lock)) {
                mtx_lock(&sc->sc_queues_lock);
                memset(sc->sc_queues, 0, sizeof(sc->sc_queues));
                memset(sc->sc_cq_list, 0, sizeof(sc->sc_cq_list));
                memset(sc->sc_int_sq_list, 0, sizeof(sc->sc_int_sq_list));
                mtx_unlock(&sc->sc_queues_lock);
        }

        /* 5. Destroy mailbox */
        bce_mailbox_destroy(&sc->sc_mbox);

        /* 6. Release DMA tag */
        if (sc->sc_dma_tag != NULL) {
                bus_dma_tag_destroy(sc->sc_dma_tag);
                sc->sc_dma_tag = NULL;
        }

        /* 7. Release IRQ resources */
        if (sc->sc_irq_dma != NULL) {
                bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irq_rid_dma,
                    sc->sc_irq_dma);
                sc->sc_irq_dma = NULL;
        }
        if (sc->sc_irq_mbox != NULL) {
                bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irq_rid_mbox,
                    sc->sc_irq_mbox);
                sc->sc_irq_mbox = NULL;
        }
        if (sc->sc_msi_count > 0) {
                pci_release_msi(dev);
                sc->sc_msi_count = 0;
        }

        /* 8. Release BARs */
        if (sc->sc_bar4 != NULL) {
                bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_bar4_rid,
                    sc->sc_bar4);
                sc->sc_bar4 = NULL;
        }
        if (sc->sc_bar2 != NULL) {
                bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_bar2_rid,
                    sc->sc_bar2);
                sc->sc_bar2 = NULL;
        }

        if (mtx_initialized(&sc->sc_timestamp_lock))
                mtx_destroy(&sc->sc_timestamp_lock);
        if (mtx_initialized(&sc->sc_queues_lock))
                mtx_destroy(&sc->sc_queues_lock);

        return (0);
}

static int
apple_bce_suspend(device_t dev)
{
        struct apple_bce_softc *sc = device_get_softc(dev);
        int error, restore_error;

        apple_bce_timestamp_stop(sc);

        error = bce_vhci_detach(sc);
        if (error != 0) {
                device_printf(dev, "failed to detach VHCI for suspend: %d\n",
                    error);
                apple_bce_timestamp_start(sc, 0);
                return (error);
        }

        error = bce_mailbox_send(&sc->sc_mbox,
            BCE_MB_MSG(BCE_MB_SLEEP_NO_STATE, 0), NULL,
            BCE_MBOX_TIMEOUT_MS);
        if (error != 0) {
                device_printf(dev,
                    "failed to send SLEEP_NO_STATE mailbox command: %d\n",
                    error);
                restore_error = bce_vhci_attach(sc);
                if (restore_error != 0) {
                        device_printf(dev,
                            "failed to reattach VHCI after suspend error: %d\n",
                            restore_error);
                }
                apple_bce_timestamp_start(sc, 0);
                return (error);
        }

        return (0);
}

static int
apple_bce_resume(device_t dev)
{
        struct apple_bce_softc *sc = device_get_softc(dev);
        uint64_t reply;
        int error;

        error = bce_mailbox_send(&sc->sc_mbox,
            BCE_MB_MSG(BCE_MB_RESTORE_NO_STATE, 0), &reply,
            BCE_MBOX_TIMEOUT_MS);
        if (error != 0) {
                device_printf(dev,
                    "failed to send RESTORE_NO_STATE mailbox command: %d\n",
                    error);
                return (error);
        }

        if (BCE_MB_TYPE(reply) != BCE_MB_RESTORE_NO_STATE) {
                device_printf(dev,
                    "unexpected RESTORE_NO_STATE reply: type=%u val=0x%llx\n",
                    BCE_MB_TYPE(reply),
                    (unsigned long long)BCE_MB_VALUE(reply));
                return (EINVAL);
        }

        error = bce_vhci_attach(sc);
        if (error != 0) {
                device_printf(dev, "failed to reattach VHCI after resume: %d\n",
                    error);
                apple_bce_timestamp_start(sc, 0);
                return (error);
        }

        apple_bce_timestamp_start(sc, 0);
        return (0);
}

static device_method_t apple_bce_methods[] = {
        DEVMETHOD(device_probe,         apple_bce_probe),
        DEVMETHOD(device_attach,        apple_bce_attach),
        DEVMETHOD(device_detach,        apple_bce_detach),
        DEVMETHOD(device_suspend,       apple_bce_suspend),
        DEVMETHOD(device_resume,        apple_bce_resume),
        DEVMETHOD_END
};

static driver_t apple_bce_driver = {
        "apple_bce",
        apple_bce_methods,
        sizeof(struct apple_bce_softc)
};

DRIVER_MODULE(apple_bce, pci, apple_bce_driver, NULL, NULL);
MODULE_DEPEND(apple_bce, pci, 1, 1, 1);
static const struct {
        uint16_t        vendor;
        uint16_t        device;
} apple_bce_pnp[] = {
        { BCE_PCI_VENDOR_APPLE, BCE_PCI_DEVICE_T2 },
};

MODULE_PNP_INFO("U16:vendor;U16:device", pci, apple_bce, apple_bce_pnp,
    nitems(apple_bce_pnp));