/*
 *  Copyright (c) 2019, The OpenThread Authors.
 *  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.
 *  3. Neither the name of the copyright holder nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file
 *   This file includes definitions for the SPI interface to radio (RCP).
 */

#ifndef OT_POSIX_PLATFORM_SPI_INTERFACE_HPP_
#define OT_POSIX_PLATFORM_SPI_INTERFACE_HPP_

#include "openthread-posix-config.h"

#include "logger.hpp"
#include "platform-posix.h"
#include "lib/hdlc/hdlc.hpp"
#include "lib/spinel/multi_frame_buffer.hpp"
#include "lib/spinel/spi_frame.hpp"
#include "lib/spinel/spinel_interface.hpp"

#include <openthread/openthread-system.h>

namespace ot {
namespace Posix {

/**
 * Defines an SPI interface to the Radio Co-processor (RCP).
 *
 */
class SpiInterface : public ot::Spinel::SpinelInterface, public Logger<SpiInterface>
{
public:
    static const char kLogModuleName[]; ///< Module name used for logging.

    /**
     * Initializes the object.
     *
     * @param[in] aRadioUrl  RadioUrl parsed from radio url.
     *
     */
    SpiInterface(const Url::Url &aRadioUrl);

    /**
     * This destructor deinitializes the object.
     *
     */
    ~SpiInterface(void);

    /**
     * Initializes the interface to the Radio Co-processor (RCP).
     *
     * @note This method should be called before reading and sending spinel frames to the interface.
     *
     * @param[in] aCallback         Callback on frame received
     * @param[in] aCallbackContext  Callback context
     * @param[in] aFrameBuffer      A reference to a `RxFrameBuffer` object.
     *
     * @retval OT_ERROR_NONE       The interface is initialized successfully
     * @retval OT_ERROR_ALREADY    The interface is already initialized.
     * @retval OT_ERROR_FAILED     Failed to initialize the interface.
     *
     */
    otError Init(ReceiveFrameCallback aCallback, void *aCallbackContext, RxFrameBuffer &aFrameBuffer);

    /**
     * Deinitializes the interface to the RCP.
     *
     */
    void Deinit(void);

    /**
     * Encodes and sends a spinel frame to Radio Co-processor (RCP) over the socket.
     *
     * @param[in] aFrame     A pointer to buffer containing the spinel frame to send.
     * @param[in] aLength    The length (number of bytes) in the frame.
     *
     * @retval OT_ERROR_NONE     Successfully encoded and sent the spinel frame.
     * @retval OT_ERROR_BUSY     Failed due to another operation is on going.
     * @retval OT_ERROR_NO_BUFS  Insufficient buffer space available to encode the frame.
     * @retval OT_ERROR_FAILED   Failed to call the SPI driver to send the frame.
     *
     */
    otError SendFrame(const uint8_t *aFrame, uint16_t aLength);

    /**
     * Waits for receiving part or all of spinel frame within specified interval.
     *
     * @param[in]  aTimeout  The timeout value in microseconds.
     *
     * @retval OT_ERROR_NONE             Part or all of spinel frame is received.
     * @retval OT_ERROR_RESPONSE_TIMEOUT No spinel frame is received within @p aTimeout.
     *
     */
    otError WaitForFrame(uint64_t aTimeoutUs);

    /**
     * Updates the file descriptor sets with file descriptors used by the radio driver.
     *
     * @param[in,out]   aMainloopContext  A pointer to the mainloop context containing fd_sets.
     *
     */
    void UpdateFdSet(void *aMainloopContext);

    /**
     * Performs radio driver processing.
     *
     * @param[in]   aMainloopContext  A pointer to the mainloop context containing fd_sets.
     *
     */
    void Process(const void *aMainloopContext);

    /**
     * Returns the bus speed between the host and the radio.
     *
     * @returns   Bus speed in bits/second.
     *
     */
    uint32_t GetBusSpeed(void) const { return ((mSpiDevFd >= 0) ? mSpiSpeedHz : 0); }

    /**
     * Hardware resets the RCP.
     *
     * @retval OT_ERROR_NONE            Successfully reset the RCP.
     * @retval OT_ERROR_NOT_IMPLEMENT   The hardware reset is not implemented.
     *
     */
    otError HardwareReset(void);

    /**
     * Returns the RCP interface metrics.
     *
     * @returns The RCP interface metrics.
     *
     */
    const otRcpInterfaceMetrics *GetRcpInterfaceMetrics(void) const { return &mInterfaceMetrics; }

    /**
     * Indicates whether or not the given interface matches this interface name.
     *
     * @param[in] aInterfaceName A pointer to the interface name.
     *
     * @retval TRUE   The given interface name matches this interface name.
     * @retval FALSE  The given interface name doesn't match this interface name.
     */
    static bool IsInterfaceNameMatch(const char *aInterfaceName)
    {
        static const char kInterfaceName[] = "spinel+spi";
        return (strncmp(aInterfaceName, kInterfaceName, strlen(kInterfaceName)) == 0);
    }

private:
    void    ResetStates(void);
    int     SetupGpioHandle(int aFd, uint8_t aLine, uint32_t aHandleFlags, const char *aLabel);
    int     SetupGpioEvent(int aFd, uint8_t aLine, uint32_t aHandleFlags, uint32_t aEventFlags, const char *aLabel);
    void    SetGpioValue(int aFd, uint8_t aValue);
    uint8_t GetGpioValue(int aFd);

    void InitResetPin(const char *aCharDev, uint8_t aLine);
    void InitIntPin(const char *aCharDev, uint8_t aLine);
    void InitSpiDev(const char *aPath, uint8_t aMode, uint32_t aSpeed);
    void TriggerReset(void);

    uint8_t *GetRealRxFrameStart(uint8_t *aSpiRxFrameBuffer, uint8_t aAlignAllowance, uint16_t &aSkipLength);
    otError  DoSpiTransfer(uint8_t *aSpiRxFrameBuffer, uint32_t aTransferLength);
    otError  PushPullSpi(void);

    bool CheckInterrupt(void);
    void LogStats(void);
    void LogError(const char *aString);
    void LogBuffer(const char *aDesc, const uint8_t *aBuffer, uint16_t aLength, bool aForce);

    enum
    {
        kSpiModeMax           = 3,
        kSpiAlignAllowanceMax = 16,
        kSpiFrameHeaderSize   = 5,
        kSpiBitsPerWord       = 8,
        kSpiTxRefuseWarnCount = 30,
        kSpiTxRefuseExitCount = 100,
        kImmediateRetryCount  = 5,
        kFastRetryCount       = 15,
        kDebugBytesPerLine    = 16,
        kGpioIntAssertState   = 0,
        kGpioResetAssertState = 0,
    };

    enum
    {
        kMsecPerSec              = 1000,
        kUsecPerMsec             = 1000,
        kSpiPollPeriodUs         = kMsecPerSec * kUsecPerMsec / 30,
        kSecPerDay               = 60 * 60 * 24,
        kResetHoldOnUsec         = 10 * kUsecPerMsec,
        kImmediateRetryTimeoutUs = 1 * kUsecPerMsec,
        kFastRetryTimeoutUs      = 10 * kUsecPerMsec,
        kSlowRetryTimeoutUs      = 33 * kUsecPerMsec,
    };

    ReceiveFrameCallback mReceiveFrameCallback;
    void                *mReceiveFrameContext;
    RxFrameBuffer       *mRxFrameBuffer;
    const Url::Url      &mRadioUrl;

    int mSpiDevFd;
    int mResetGpioValueFd;
    int mIntGpioValueFd;

    uint8_t  mSpiMode;
    uint8_t  mSpiAlignAllowance;
    uint32_t mSpiResetDelay;
    uint16_t mSpiCsDelayUs;
    uint16_t mSpiSmallPacketSize;
    uint32_t mSpiSpeedHz;

    uint64_t mSlaveResetCount;
    uint64_t mSpiDuplexFrameCount;
    uint64_t mSpiUnresponsiveFrameCount;

    bool     mSpiTxIsReady;
    uint16_t mSpiTxRefusedCount;
    uint16_t mSpiTxPayloadSize;
    uint8_t  mSpiTxFrameBuffer[kMaxFrameSize + kSpiAlignAllowanceMax];

    bool     mDidPrintRateLimitLog;
    uint16_t mSpiSlaveDataLen;

    bool mDidRxFrame;

    otRcpInterfaceMetrics mInterfaceMetrics;

    // Non-copyable, intentionally not implemented.
    SpiInterface(const SpiInterface &);
    SpiInterface &operator=(const SpiInterface &);
};

} // namespace Posix
} // namespace ot

#endif // OT_POSIX_PLATFORM_SPI_INTERFACE_HPP_