// 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.

#pragma once

#include <ddk/device.h>
#include <ddktl/device.h>
#include <ddktl/protocol/clk.h>
#include <ddktl/protocol/gpioimpl.h>
#include <ddktl/protocol/i2cimpl.h>
#include <ddktl/protocol/iommu.h>
#include <ddktl/protocol/platform/bus.h>
#include <fbl/array.h>
#include <fbl/intrusive_wavl_tree.h>
#include <fbl/mutex.h>
#include <fbl/unique_ptr.h>
#include <fbl/vector.h>
#include <lib/sync/completion.h>
#include <lib/zx/iommu.h>
#include <lib/zx/resource.h>
#include <lib/zx/vmo.h>
#include <stdint.h>
#include <threads.h>
#include <zircon/types.h>

#include <optional>

#include "platform-device.h"
#include "platform-protocol-device.h"
#include "platform-i2c.h"
#include "proxy-protocol.h"

namespace platform_bus {

class PlatformBus;
using PlatformBusType = ddk::Device<PlatformBus, ddk::GetProtocolable>;

// This is the main class for the platform bus driver.
class PlatformBus : public PlatformBusType,
                    public ddk::PBusProtocol<PlatformBus, ddk::base_protocol>,
                    public ddk::IommuProtocol<PlatformBus> {
public:
    static zx_status_t Create(zx_device_t* parent, const char* name, zx::vmo zbi);

    zx_status_t Proxy(
         const void* req_buffer, size_t req_size, const zx_handle_t* req_handle_list,
         size_t req_handle_count, void* out_resp_buffer, size_t resp_size, size_t* out_resp_actual,
         zx_handle_t* out_resp_handle_list, size_t resp_handle_count,
         size_t* out_resp_handle_actual);

    // Device protocol implementation.
    zx_status_t DdkGetProtocol(uint32_t proto_id, void* out);
    void DdkRelease();

    // Platform bus protocol implementation.
    zx_status_t PBusDeviceAdd(const pbus_dev_t* dev);
    zx_status_t PBusProtocolDeviceAdd(uint32_t proto_id, const pbus_dev_t* dev);
    zx_status_t PBusRegisterProtocol(uint32_t proto_id, const void* protocol, size_t protocol_size,
                                     const platform_proxy_cb_t* proxy_cb);
    zx_status_t PBusGetBoardInfo(pdev_board_info_t* out_info);
    zx_status_t PBusSetBoardInfo(const pbus_board_info_t* info);

    // IOMMU protocol implementation.
    zx_status_t IommuGetBti(uint32_t iommu_index, uint32_t bti_id, zx::bti* out_bti);

    // Returns the resource handle to be used for creating MMIO regions, IRQs, and SMC ranges.
    // Currently this just returns the root resource, but we may change this to a more
    // limited resource in the future.
    zx::unowned_resource GetResource() const { return zx::unowned_resource(get_root_resource()); }

    // Used by PlatformDevice to queue I2C transactions on an I2C bus.
    zx_status_t I2cTransact(uint32_t txid, rpc_i2c_req_t* req, const pbus_i2c_channel_t* channel,
                            zx_handle_t channel_handle);

    zx_status_t GetZbiMetadata(uint32_t type, uint32_t extra, const void** out_metadata,
                               uint32_t* out_size);

    // Protocol accessors for PlatformDevice.
    inline ddk::ClkProtocolClient* clk() { return &*clk_; }
    inline ddk::GpioImplProtocolClient* gpio() { return &*gpio_; }
    inline ddk::I2cImplProtocolClient* i2c() { return &*i2c_; }

private:
    // This class is a wrapper for a platform_proxy_cb_t added via pbus_register_protocol().
    // It also is the element type for the proto_proxys_ WAVL tree.
    class ProtoProxy : public fbl::WAVLTreeContainable<fbl::unique_ptr<ProtoProxy>> {
    public:
        ProtoProxy(uint32_t proto_id, const ddk::AnyProtocol* protocol,
                   const platform_proxy_cb_t& proxy_cb)
            : proto_id_(proto_id), protocol_(*protocol), proxy_cb_(proxy_cb) {}

        inline uint32_t GetKey() const { return proto_id_; }
        inline void GetProtocol(void* out) const { memcpy(out, &protocol_, sizeof(protocol_)); }

        inline void Proxy(const void* req_buffer, size_t req_size,
                          const zx_handle_t* req_handle_list, size_t req_handle_count,
                          void* out_resp_buffer, size_t resp_size, size_t* out_resp_actual,
                          zx_handle_t* out_resp_handle_list, size_t resp_handle_count,
                          size_t* out_resp_handle_actual) {
            proxy_cb_.callback(proxy_cb_.ctx, req_buffer, req_size,
                               req_handle_list, req_handle_count,
                               out_resp_buffer, resp_size, out_resp_actual,
                               out_resp_handle_list, resp_handle_count,
                               out_resp_handle_actual);
        }

    private:
        const uint32_t proto_id_;
        const ddk::AnyProtocol protocol_;
        platform_proxy_cb_t proxy_cb_;
    };


    explicit PlatformBus(zx_device_t* parent);

    DISALLOW_COPY_ASSIGN_AND_MOVE(PlatformBus);

    zx_status_t Init(zx::vmo zbi);

    // Reads the platform ID and driver metadata records from the boot image.
    zx_status_t ReadZbi(zx::vmo zbi);

    zx_status_t I2cInit(const i2c_impl_protocol_t* i2c);

    pdev_board_info_t board_info_;

    // Protocols that are optionally provided by the board driver.
    std::optional<ddk::ClkProtocolClient> clk_;
    std::optional<ddk::GpioImplProtocolClient> gpio_;
    std::optional<ddk::IommuProtocolClient> iommu_;
    std::optional<ddk::I2cImplProtocolClient> i2c_;

    // Completion used by WaitProtocol().
    sync_completion_t proto_completion_ __TA_GUARDED(proto_completion_mutex_);
    // Protects proto_completion_.
    fbl::Mutex proto_completion_mutex_;

    // Metadata extracted from ZBI.
    fbl::Array<uint8_t> metadata_;

    // List of I2C buses.
    fbl::Vector<fbl::unique_ptr<PlatformI2cBus>> i2c_buses_;

    // Dummy IOMMU.
    zx::iommu iommu_handle_;

    fbl::WAVLTree<uint32_t, fbl::unique_ptr<ProtoProxy>> proto_proxys_
                                                __TA_GUARDED(proto_proxys_mutex_);
    // Protects proto_proxys_.
    fbl::Mutex proto_proxys_mutex_;
};

} // namespace platform_bus

__BEGIN_CDECLS
zx_status_t platform_bus_create(void* ctx, zx_device_t* parent, const char* name,
                                const char* args, zx_handle_t rpc_channel);
__END_CDECLS