// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <ddk/device.h>
#include <ddk/driver.h>
#include <ddk/binding.h>
#include <ddk/protocol/pci.h>
#include <zircon/assert.h>
#include <fbl/auto_call.h>
#include <fbl/auto_lock.h>
#include <stdio.h>
#include <string.h>
#include <threads.h>

#include <dispatcher-pool/dispatcher-thread-pool.h>
#include <intel-hda/utils/intel-hda-registers.h>
#include <intel-hda/utils/intel-hda-proto.h>

#include "debug-logging.h"
#include "intel-hda-codec.h"
#include "intel-hda-controller.h"
#include "utils.h"

namespace audio {
namespace intel_hda {

// static member variable declaration
constexpr uint        IntelHDAController::RIRB_RESERVED_RESPONSE_SLOTS;
fbl::atomic_uint32_t IntelHDAController::device_id_gen_(0u);

// Device interface thunks
#define DEV(_ctx)  static_cast<IntelHDAController*>(_ctx)
zx_protocol_device_t IntelHDAController::CONTROLLER_DEVICE_THUNKS = {
    .version      = DEVICE_OPS_VERSION,
    .get_protocol = nullptr,
    .open         = nullptr,
    .open_at      = nullptr,
    .close        = nullptr,
    .unbind       = [](void* ctx) { DEV(ctx)->DeviceShutdown(); },
    .release      = [](void* ctx) { DEV(ctx)->DeviceRelease(); },
    .read         = nullptr,
    .write        = nullptr,
    .get_size     = nullptr,
    .ioctl        = [](void*        ctx,
                       uint32_t     op,
                       const void*  in_buf,
                       size_t       in_len,
                       void*        out_buf,
                       size_t       out_len,
                       size_t*      out_actual) -> zx_status_t {
                        return DEV(ctx)->DeviceIoctl(op, out_buf, out_len, out_actual);
                   },
    .suspend      = nullptr,
    .resume       = nullptr,
    .rxrpc        = nullptr,
    .message      = nullptr,
};
#undef DEV

IntelHDAController::IntelHDAController()
    : state_(static_cast<StateStorage>(State::STARTING)),
      id_(device_id_gen_.fetch_add(1u)) {
    snprintf(log_prefix_, sizeof(log_prefix_), "IHDA Controller (unknown BDF)");
}

IntelHDAController::~IntelHDAController() {
    ZX_DEBUG_ASSERT((GetState() == State::STARTING) || (GetState() == State::SHUT_DOWN));
    // TODO(johngro) : place the device into reset.

    // Release our register window.
    mapped_regs_.Unmap();

    // Release our IRQ.
    irq_.reset();

    // Disable IRQs at the PCI level.
    if (pci_.ops != nullptr) {
        ZX_DEBUG_ASSERT(pci_.ctx != nullptr);
        pci_.ops->set_irq_mode(pci_.ctx, ZX_PCIE_IRQ_MODE_DISABLED, 0);
    }

    // Let go of our stream state.
    free_input_streams_.clear();
    free_output_streams_.clear();
    free_bidir_streams_.clear();

    // Unmap, unpin and release the memory we use for the command/response ring buffers.
    cmd_buf_cpu_mem_.Unmap();
    cmd_buf_hda_mem_.Unpin();

    if (pci_.ops != nullptr) {
        // TODO(johngro) : unclaim the PCI device.  Right now, there is no way
        // to do this aside from closing the device handle (which would
        // seriously mess up the DevMgr's brain)
        pci_.ops = nullptr;
        pci_.ctx = nullptr;
    }
}

fbl::RefPtr<IntelHDAStream> IntelHDAController::AllocateStream(IntelHDAStream::Type type) {
    fbl::AutoLock lock(&stream_pool_lock_);
    IntelHDAStream::Tree* src;

    switch (type) {
    case IntelHDAStream::Type::INPUT:  src = &free_input_streams_;  break;
    case IntelHDAStream::Type::OUTPUT: src = &free_output_streams_; break;

    // Users are not allowed to directly request bidirectional stream contexts.
    // It's just what they end up with if there are no other choices.
    default:
        ZX_DEBUG_ASSERT(false);
        return nullptr;
    }

    if (src->is_empty()) {
        src = &free_bidir_streams_;
        if (src->is_empty())
            return nullptr;
    }

    // Allocation fails if we cannot assign a unique tag to this stream.
    uint8_t stream_tag = AllocateStreamTagLocked(type == IntelHDAStream::Type::INPUT);
    if (!stream_tag)
        return nullptr;

    auto ret = src->pop_front();
    ret->Configure(type, stream_tag);

    return ret;
}

void IntelHDAController::ReturnStream(fbl::RefPtr<IntelHDAStream>&& ptr) {
    fbl::AutoLock lock(&stream_pool_lock_);
    ReturnStreamLocked(fbl::move(ptr));
}

void IntelHDAController::ReturnStreamLocked(fbl::RefPtr<IntelHDAStream>&& ptr) {
    IntelHDAStream::Tree* dst;

    ZX_DEBUG_ASSERT(ptr);

    switch (ptr->type()) {
    case IntelHDAStream::Type::INPUT:  dst = &free_input_streams_;  break;
    case IntelHDAStream::Type::OUTPUT: dst = &free_output_streams_; break;
    case IntelHDAStream::Type::BIDIR:  dst = &free_bidir_streams_;  break;
    default: ZX_DEBUG_ASSERT(false); return;
    }

    ptr->Configure(IntelHDAStream::Type::INVALID, 0);
    dst->insert(fbl::move(ptr));
}

uint8_t IntelHDAController::AllocateStreamTagLocked(bool input) {
    uint16_t& tag_pool = input ? free_input_tags_ : free_output_tags_;

    for (uint8_t ret = 1; ret < (sizeof(tag_pool) << 3); ++ret) {
        if (tag_pool & (1u << ret)) {
            tag_pool = static_cast<uint16_t>(tag_pool & ~(1u << ret));
            return ret;
        }
    }

    return 0;
}

void IntelHDAController::ReleaseStreamTagLocked(bool input, uint8_t tag) {
    uint16_t& tag_pool = input ? free_input_tags_ : free_output_tags_;

    ZX_DEBUG_ASSERT((tag > 0) && (tag <= 15));
    ZX_DEBUG_ASSERT((tag_pool & (1u << tag)) == 0);

    tag_pool = static_cast<uint16_t>((tag_pool | (1u << tag)));
}

void IntelHDAController::ShutdownIRQThread() {
    if (irq_thread_started_) {
        SetState(State::SHUTTING_DOWN);
        WakeupIRQThread();
        thrd_join(irq_thread_, NULL);
        ZX_DEBUG_ASSERT(GetState() == State::SHUT_DOWN);
        irq_thread_started_ = false;
    }
}

void IntelHDAController::DeviceShutdown() {
    // Make sure we have closed all of the event sources (eg. channels clients
    // are using to talk to us) and that we have synchronized with any dispatch
    // callbacks in flight.
    default_domain_->Deactivate();

    // If the IRQ thread is running, make sure we shut it down too.
    ShutdownIRQThread();
}

void IntelHDAController::DeviceRelease() {
    // Take our unmanaged reference back from our published device node.
    auto thiz = fbl::internal::MakeRefPtrNoAdopt(this);

    // ASSERT that we have been properly shut down, then release the DDK's
    // reference to our state as we allow thiz to go out of scope.
    ZX_DEBUG_ASSERT(GetState() == State::SHUT_DOWN);
    thiz.reset();
}

zx_status_t IntelHDAController::DeviceIoctl(uint32_t op,
                                            void*    out_buf,
                                            size_t   out_len,
                                            size_t*  out_actual) {
    dispatcher::Channel::ProcessHandler phandler(
    [controller = fbl::WrapRefPtr(this)](dispatcher::Channel* channel) -> zx_status_t {
        OBTAIN_EXECUTION_DOMAIN_TOKEN(t, controller->default_domain_);
        return controller->ProcessClientRequest(channel);
    });

    return HandleDeviceIoctl(op, out_buf, out_len, out_actual,
                             default_domain_,
                             fbl::move(phandler),
                             nullptr);
}

void IntelHDAController::RootDeviceRelease() {
    // Take our unmanaged reference back from our published device node.
    auto thiz = fbl::internal::MakeRefPtrNoAdopt(this);
    // Now let go of it.
    thiz.reset();
}

zx_status_t IntelHDAController::ProcessClientRequest(dispatcher::Channel* channel) {
    zx_status_t res;
    uint32_t req_size;
    union RequestBuffer {
        ihda_cmd_hdr_t                      hdr;
        ihda_get_ids_req_t                  get_ids;
        ihda_controller_snapshot_regs_req_t snapshot_regs;
    } req;

    // TODO(johngro) : How large is too large?
    static_assert(sizeof(req) <= 256, "Request buffer is too large to hold on the stack!");

    // Read the client request.
    ZX_DEBUG_ASSERT(channel != nullptr);
    res = channel->Read(&req, sizeof(req), &req_size);
    if (res != ZX_OK) {
        LOG(TRACE, "Failed to read client request (res %d)\n", res);
        return res;
    }

    // Sanity checks
    if (req_size < sizeof(req.hdr)) {
        LOG(TRACE, "Client request too small to contain header (%u < %zu)\n",
                req_size, sizeof(req.hdr));
        return ZX_ERR_INVALID_ARGS;
    }

    // Dispatch
    LOG(SPEW, "Client Request 0x%04x len %u\n", req.hdr.cmd, req_size);
    switch (req.hdr.cmd) {
    case IHDA_CMD_GET_IDS: {
        if (req_size != sizeof(req.get_ids)) {
            LOG(TRACE, "Bad GET_IDS request length (%u != %zu)\n",
                    req_size, sizeof(req.get_ids));
            return ZX_ERR_INVALID_ARGS;
        }

        ZX_DEBUG_ASSERT(pci_dev_ != nullptr);
        ZX_DEBUG_ASSERT(regs() != nullptr);

        ihda_get_ids_resp_t resp;
        resp.hdr       = req.hdr;
        resp.vid       = pci_dev_info_.vendor_id;
        resp.did       = pci_dev_info_.device_id;
        resp.ihda_vmaj = REG_RD(&regs()->vmaj);
        resp.ihda_vmin = REG_RD(&regs()->vmin);
        resp.rev_id    = 0;
        resp.step_id   = 0;

        return channel->Write(&resp, sizeof(resp));
    }

    case IHDA_CONTROLLER_CMD_SNAPSHOT_REGS:
        if (req_size != sizeof(req.snapshot_regs)) {
            LOG(TRACE, "Bad SNAPSHOT_REGS request length (%u != %zu)\n",
                    req_size, sizeof(req.snapshot_regs));
            return ZX_ERR_INVALID_ARGS;
        }

        return SnapshotRegs(channel, req.snapshot_regs);

    default:
        return ZX_ERR_INVALID_ARGS;
    }
}

#define DEV(_ctx)  static_cast<IntelHDAController*>(_ctx)
zx_protocol_device_t IntelHDAController::ROOT_DEVICE_THUNKS = {
    .version      = DEVICE_OPS_VERSION,
    .get_protocol = nullptr,
    .open         = nullptr,
    .open_at      = nullptr,
    .close        = nullptr,
    .unbind       = nullptr,
    .release      = [](void* ctx) { DEV(ctx)->RootDeviceRelease(); },
    .read         = nullptr,
    .write        = nullptr,
    .get_size     = nullptr,
    .ioctl        = nullptr,
    .suspend      = nullptr,
    .resume       = nullptr,
    .rxrpc        = nullptr,
    .message      = nullptr,
};
#undef DEV

zx_status_t IntelHDAController::DriverInit(void** out_ctx) {
    // Note: It is assumed that calls to Init/Release are serialized by the
    // pci_dev manager.  If this assumption ever needs to be relaxed, explicit
    // serialization will need to be added here.

    return ZX_OK;
}

zx_status_t IntelHDAController::DriverBind(void* ctx,
                                           zx_device_t* device) {
    fbl::AllocChecker ac;
    fbl::RefPtr<IntelHDAController> controller(fbl::AdoptRef(new (&ac) IntelHDAController()));

    if (!ac.check()) {
        return ZX_ERR_NO_MEMORY;
    }

    zx_status_t ret = controller->Init(device);
    if (ret != ZX_OK) {
        return ret;
    }

    // Initialize our device and fill out the protocol hooks
    device_add_args_t args = { };
    args.version = DEVICE_ADD_ARGS_VERSION;
    args.name = "intel-hda-controller";
    {
        // use a different refptr to avoid problems in error path
        auto ddk_ref = controller;
        args.ctx = ddk_ref.leak_ref();
    }
    args.ops =  &ROOT_DEVICE_THUNKS;
    args.flags = DEVICE_ADD_NON_BINDABLE;

    // Publish the device.
    ret = device_add(device, &args, nullptr);
    if (ret != ZX_OK) {
        controller.reset();
    }
    return ret;
}

void IntelHDAController::DriverRelease(void* ctx) {
    // If we are the last one out the door, turn off the lights in the thread pool.
    dispatcher::ThreadPool::ShutdownAll();
}

}  // namespace intel_hda
}  // namespace audio

extern "C" {
zx_status_t ihda_init_hook(void** out_ctx) {
    zx_status_t res = ::audio::intel_hda::DriverVmars::Initialize();

    if (res == ZX_OK) {
        res = ::audio::intel_hda::IntelHDAController::DriverInit(out_ctx);
    }

    if (res != ZX_OK) {
        ::audio::intel_hda::DriverVmars::Shutdown();
    }

    return res;
}

zx_status_t ihda_bind_hook(void* ctx, zx_device_t* pci_dev) {
    return ::audio::intel_hda::IntelHDAController::DriverBind(ctx, pci_dev);
}

void ihda_release_hook(void* ctx) {
    ::audio::intel_hda::IntelHDAController::DriverRelease(ctx);
    ::audio::intel_hda::DriverVmars::Shutdown();
}
}  // extern "C"