/******************************************************************************
 * @file     SWO.c
 * @brief    CMSIS-DAP SWO I/O
 * @version  V1.00
 * @date     20. May 2015
 *
 * @note
 * Copyright (C) 2015 ARM Limited. All rights reserved.
 *
 * @par
 * ARM Limited (ARM) is supplying this software for use with Cortex-M
 * processor based microcontrollers.
 *
 * @par
 * THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
 * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
 * ARM SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
 * CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
 *
 ******************************************************************************/

#include "DAP_config.h"
#include "DAP.h"
#if (SWO_UART != 0)
#include "Driver_USART.h"
#endif


#if (SWO_UART != 0)

#ifndef  USART_PORT
#define  USART_PORT 0           /* USART Port Number */
#endif

// USART Driver
#define _USART_Driver_(n)  Driver_USART##n
#define  USART_Driver_(n) _USART_Driver_(n)
extern ARM_DRIVER_USART    USART_Driver_(USART_PORT);
#define pUSART           (&USART_Driver_(USART_PORT))

static uint8_t  USART_Ready;

#endif  /* (SWO_UART != 0) */


#if ((SWO_UART != 0) || (SWO_MANCHESTER != 0))


// Trace State
static uint8_t  TraceTransport =  0U;       /* Trace Transport */
static uint8_t  TraceMode      =  0U;       /* Trace Mode */
static uint8_t  TraceStatus    =  0U;       /* Trace Status without Errors */
static uint8_t  TraceError[2]  = {0U, 0U};  /* Trace Error flags (banked) */
static uint8_t  TraceError_n   =  0U;       /* Active Trace Error bank */

// Trace Buffer
static uint8_t  TraceBuf[SWO_BUFFER_SIZE];  /* Trace Buffer (must be 2^n) */
static volatile uint32_t TraceIn      = 0U; /* Incoming Trace Index */
static volatile uint32_t TraceOut     = 0U; /* Outgoing Trace Index */
static volatile uint32_t TracePending = 0U; /* Pending Trace Count */

// Trace Helper functions
static void     ClearTrace(void);
static uint32_t GetTraceSpace(void);
static uint32_t GetTraceCount(void);
static uint8_t  GetTraceStatus(void);
static void     SetTraceError(uint8_t flag);


#if (SWO_UART != 0)

// USART Driver Callback function
//   event: event mask
static void USART_Callback(uint32_t event)
{
    uint32_t count;

    if(event &  ARM_USART_EVENT_RECEIVE_COMPLETE)
    {
        TracePending = 0U;
        TraceIn += pUSART->GetRxCount();
        count = GetTraceSpace();
        if(count != 0U)
        {
            pUSART->Receive(&TraceBuf[TraceIn & (SWO_BUFFER_SIZE - 1U)], count);
        }
        else
        {
            TraceStatus = DAP_SWO_CAPTURE_ACTIVE | DAP_SWO_CAPTURE_PAUSED;
        }
    }
    if(event &  ARM_USART_EVENT_RX_OVERFLOW)
    {
        SetTraceError(DAP_SWO_BUFFER_OVERRUN);
    }
    if(event & (ARM_USART_EVENT_RX_BREAK         |
                ARM_USART_EVENT_RX_FRAMING_ERROR |
                ARM_USART_EVENT_RX_PARITY_ERROR))
    {
        SetTraceError(DAP_SWO_STREAM_ERROR);
    }
}

// Enable or disable UART SWO Mode
//   enable: enable flag
//   return: 1 - Success, 0 - Error
__weak uint32_t UART_SWO_Mode(uint32_t enable)
{
    int32_t status;

    USART_Ready = 0U;

    if(enable)
    {
        status = pUSART->Initialize(USART_Callback);
        if(status != ARM_DRIVER_OK)
        {
            return (0U);
        }
        status = pUSART->PowerControl(ARM_POWER_FULL);
        if(status != ARM_DRIVER_OK)
        {
            pUSART->Uninitialize();
            return (0U);
        }
    }
    else
    {
        pUSART->Control(ARM_USART_ABORT_RECEIVE, 0U);
        pUSART->PowerControl(ARM_POWER_OFF);
        pUSART->Uninitialize();
    }
    return (1U);
}

// Configure UART SWO Baudrate
//   baudrate: requested baudrate
//   return:   actual baudrate or 0 when not configured
__weak uint32_t UART_SWO_Baudrate(uint32_t baudrate)
{
    int32_t  status;
    uint32_t count;

    if(baudrate > SWO_UART_MAX_BAUDRATE)
    {
        baudrate = SWO_UART_MAX_BAUDRATE;
    }

    if(TraceStatus & DAP_SWO_CAPTURE_ACTIVE)
    {
        pUSART->Control(ARM_USART_CONTROL_RX, 0U);
        if(pUSART->GetStatus().rx_busy)
        {
            TracePending = 0U;
            TraceIn += pUSART->GetRxCount();
            pUSART->Control(ARM_USART_ABORT_RECEIVE, 0U);
        }
    }

    status = pUSART->Control(ARM_USART_MODE_ASYNCHRONOUS |
                             ARM_USART_DATA_BITS_8       |
                             ARM_USART_PARITY_NONE       |
                             ARM_USART_STOP_BITS_1,
                             baudrate);

    if(status == ARM_DRIVER_OK)
    {
        USART_Ready = 1U;
    }
    else
    {
        USART_Ready = 0U;
        baudrate = 0U;
    }

    if((TraceStatus & DAP_SWO_CAPTURE_ACTIVE) && USART_Ready)
    {
        pUSART->Control(ARM_USART_CONTROL_RX, 1U);
        count = GetTraceSpace();
        if(count != 0U)
        {
            pUSART->Receive(&TraceBuf[TraceIn & (SWO_BUFFER_SIZE - 1U)], count);
        }
        else
        {
            TraceStatus = DAP_SWO_CAPTURE_ACTIVE | DAP_SWO_CAPTURE_PAUSED;
        }
    }

    return (baudrate);
}

// Control UART SWO Capture
//   active: active flag
//   return: 1 - Success, 0 - Error
__weak uint32_t UART_SWO_Control(uint32_t active)
{
    int32_t status;

    if(active)
    {
        if(!USART_Ready)
        {
            return (0U);
        }
        status = pUSART->Control(ARM_USART_CONTROL_RX, 1U);
        if(status != ARM_DRIVER_OK)
        {
            return (0U);
        }
        status = pUSART->Receive(TraceBuf, SWO_BUFFER_SIZE);
        if(status != ARM_DRIVER_OK)
        {
            return (0U);
        }
    }
    else
    {
        pUSART->Control(ARM_USART_CONTROL_RX, 0U);
        if(pUSART->GetStatus().rx_busy)
        {
            TracePending = 0U;
            TraceIn += pUSART->GetRxCount();
            pUSART->Control(ARM_USART_ABORT_RECEIVE, 0U);
        }
    }
    return (1U);
}

// Start UART SWO Capture
//   buf:   pointer to buffer for capturing
//   count: number of bytes to capture
__weak void UART_SWO_Capture(uint8_t *buf, uint32_t count)
{
    pUSART->Receive(buf, count);
}

// Update UART SWO Trace Info
__weak void UART_SWO_Update(void)
{
    TracePending = pUSART->GetRxCount();
}

#endif  /* (SWO_UART != 0) */


#if (SWO_MANCHESTER != 0)

// Enable or disable Manchester SWO Mode
//   enable: enable flag
//   return: 1 - Success, 0 - Error
__weak uint32_t Manchester_SWO_Mode(uint32_t enable)
{
    return (0U);
}

// Configure Manchester SWO Baudrate
//   baudrate: requested baudrate
//   return:   actual baudrate or 0 when not configured
__weak uint32_t Manchester_SWO_Baudrate(uint32_t baudrate)
{
    return (0U);
}

// Control Manchester SWO Capture
//   active: active flag
//   return: 1 - Success, 0 - Error
__weak uint32_t Manchester_SWO_Control(uint32_t active)
{
    return (0U);
}

// Start Manchester SWO Capture
//   buf:   pointer to buffer for capturing
//   count: number of bytes to capture
__weak void Manchester_SWO_Capture(uint8_t *buf, uint32_t count)
{
}

// Update Manchester SWO Trace Info
__weak void Manchester_SWO_Update(void)
{
}

#endif  /* (SWO_MANCHESTER != 0) */


// Clear Trace Errors and Data
static void ClearTrace(void)
{
    TraceError[0] = 0U;
    TraceError[1] = 0U;
    TraceError_n  = 0U;
    TraceIn       = 0U;
    TraceOut      = 0U;
    TracePending  = 0U;
}

// Get Trace Space
//   return: number of contiguous free bytes in trace buffer
static uint32_t GetTraceSpace(void)
{
    uint32_t index;
    uint32_t limit;
    uint32_t count;

    index = TraceIn & (SWO_BUFFER_SIZE - 1U);
    limit = SWO_BUFFER_SIZE - index;
    count = SWO_BUFFER_SIZE - (TraceIn - TraceOut);
    if(count > limit)
    {
        count = limit;
    }

    return (count);
}

// Get Trace Count
//   return: number of available data bytes in trace buffer
static uint32_t GetTraceCount(void)
{
    uint32_t count;

    if(TraceStatus == DAP_SWO_CAPTURE_ACTIVE)
    {
        count = (TraceIn - TraceOut) + TracePending;
        if(TracePending == 0U)
        {
            count = TraceIn - TraceOut;
        }
    }
    else
    {
        count = TraceIn - TraceOut;
    }

    return (count);
}

// Get Trace Status (clear Error flags)
//   return: Trace Status (Active flag and Error flags)
static uint8_t GetTraceStatus(void)
{
    uint8_t  status;
    uint32_t n;

    n = TraceError_n;
    TraceError_n ^= 1U;
    status = TraceStatus | TraceError[n];
    TraceError[n] = 0U;

    return (status);
}

// Set Trace Error flag(s)
//   flag:  error flag(s) to set
static void SetTraceError(uint8_t flag)
{
    TraceError[TraceError_n] |= flag;
}


// Process SWO Transport command and prepare response
//   request:  pointer to request data
//   response: pointer to response data
//   return:   number of bytes in response (lower 16 bits)
//             number of bytes in request (upper 16 bits)
uint32_t SWO_Transport(const uint8_t *request, uint8_t *response)
{
    uint8_t  transport;
    uint32_t result;

    if(!(TraceStatus & DAP_SWO_CAPTURE_ACTIVE))
    {
        transport = *request;
        switch(transport)
        {
            case 0:
            case 1:
                TraceTransport = transport;
                result = 1U;
                break;
            default:
                result = 0U;
                break;
        }
    }
    else
    {
        result = 0U;
    }

    if(result != 0U)
    {
        *response = DAP_OK;
    }
    else
    {
        *response = DAP_ERROR;
    }

    return ((1U << 16) | 1U);
}


// Process SWO Mode command and prepare response
//   request:  pointer to request data
//   response: pointer to response data
//   return:   number of bytes in response (lower 16 bits)
//             number of bytes in request (upper 16 bits)
uint32_t SWO_Mode(const uint8_t *request, uint8_t *response)
{
    uint8_t  mode;
    uint32_t result;

    mode = *request;

    switch(TraceMode)
    {
#if (SWO_UART != 0)
        case DAP_SWO_UART:
            UART_SWO_Mode(0U);
            break;
#endif
#if (SWO_MANCHESTER != 0)
        case DAP_SWO_MANCHESTER:
            Manchester_SWO_Mode(0U);
            break;
#endif
        default:
            break;
    }
    switch(mode)
    {
        case DAP_SWO_OFF:
            result = 1U;
            break;
#if (SWO_UART != 0)
        case DAP_SWO_UART:
            result = UART_SWO_Mode(1U);
            break;
#endif
#if (SWO_MANCHESTER != 0)
        case DAP_SWO_MANCHESTER:
            result = Manchester_SWO_Mode(1U);
            break;
#endif
        default:
            result = 0U;
            break;
    }
    if(result != 0U)
    {
        TraceMode = mode;
    }
    else
    {
        TraceMode = DAP_SWO_OFF;
    }
    TraceStatus = 0U;
    ClearTrace();

    if(result != 0U)
    {
        *response = DAP_OK;
    }
    else
    {
        *response = DAP_ERROR;
    }

    return ((1U << 16) | 1U);
}


// Process SWO Baudrate command and prepare response
//   request:  pointer to request data
//   response: pointer to response data
//   return:   number of bytes in response (lower 16 bits)
//             number of bytes in request (upper 16 bits)
uint32_t SWO_Baudrate(const uint8_t *request, uint8_t *response)
{
    uint32_t baudrate;

    baudrate = (*(request + 0) <<  0) |
               (*(request + 1) <<  8) |
               (*(request + 2) << 16) |
               (*(request + 3) << 24);

    switch(TraceMode)
    {
#if (SWO_UART != 0)
        case DAP_SWO_UART:
            baudrate = UART_SWO_Baudrate(baudrate);
            break;
#endif
#if (SWO_MANCHESTER != 0)
        case DAP_SWO_MANCHESTER:
            baudrate = Manchester_SWO_Baudrate(baudrate);
            break;
#endif
        default:
            baudrate = 0U;
            break;
    }

    if(baudrate == 0U)
    {
        TraceStatus = 0U;
    }

    *response++ = (uint8_t)(baudrate >>  0);
    *response++ = (uint8_t)(baudrate >>  8);
    *response++ = (uint8_t)(baudrate >> 16);
    *response   = (uint8_t)(baudrate >> 24);

    return ((4U << 16) | 4U);
}


// Process SWO Control command and prepare response
//   request:  pointer to request data
//   response: pointer to response data
//   return:   number of bytes in response (lower 16 bits)
//             number of bytes in request (upper 16 bits)
uint32_t SWO_Control(const uint8_t *request, uint8_t *response)
{
    uint8_t  active;
    uint32_t result;

    active = *request & DAP_SWO_CAPTURE_ACTIVE;

    if(active != (TraceStatus & DAP_SWO_CAPTURE_ACTIVE))
    {
        if(active)
        {
            ClearTrace();
        }
        switch(TraceMode)
        {
#if (SWO_UART != 0)
            case DAP_SWO_UART:
                result = UART_SWO_Control(active);
                break;
#endif
#if (SWO_MANCHESTER != 0)
            case DAP_SWO_MANCHESTER:
                result = Manchester_SWO_Control(active);
                break;
#endif
            default:
                result = 0U;
                break;
        }
        if(result != 0U)
        {
            TraceStatus = active;
        }
    }
    else
    {
        result = 1U;
    }

    if(result != 0U)
    {
        *response = DAP_OK;
    }
    else
    {
        *response = DAP_ERROR;
    }

    return ((1U << 16) | 1U);
}


// Process SWO Status command and prepare response
//   response: pointer to response data
//   return:   number of bytes in response
uint32_t SWO_Status(uint8_t *response)
{
    uint8_t  status;
    uint32_t count;

    if(TraceStatus == DAP_SWO_CAPTURE_ACTIVE)
    {
        switch(TraceMode)
        {
#if (SWO_UART != 0)
            case DAP_SWO_UART:
                UART_SWO_Update();
                break;
#endif
#if (SWO_MANCHESTER != 0)
            case DAP_SWO_MANCHESTER:
                Manchester_SWO_Update();
                break;
#endif
            default:
                break;
        }
    }

    status = GetTraceStatus();
    count  = GetTraceCount();

    *response++ = status;
    *response++ = (uint8_t)(count >>  0);
    *response++ = (uint8_t)(count >>  8);
    *response++ = (uint8_t)(count >> 16);
    *response   = (uint8_t)(count >> 24);

    return (5U);
}


// Process SWO Data command and prepare response
//   request:  pointer to request data
//   response: pointer to response data
//   return:   number of bytes in response (lower 16 bits)
//             number of bytes in request (upper 16 bits)
uint32_t SWO_Data(const uint8_t *request, uint8_t *response)
{
    uint8_t  status;
    uint32_t count;
    uint32_t n;

    if(TraceStatus == DAP_SWO_CAPTURE_ACTIVE)
    {
        switch(TraceMode)
        {
#if (SWO_UART != 0)
            case DAP_SWO_UART:
                UART_SWO_Update();
                break;
#endif
#if (SWO_MANCHESTER != 0)
            case DAP_SWO_MANCHESTER:
                Manchester_SWO_Update();
                break;
#endif
            default:
                break;
        }
    }

    status = GetTraceStatus();
    count  = GetTraceCount();

    if(TraceTransport == 1U)
    {
        n = (*(request + 0) << 0) |
            (*(request + 1) << 8);
    }
    else
    {
        n = 0U;
    }
    if(count > n)
    {
        count = n;
    }

    *response++ = status;
    *response++ = (uint8_t)(count >> 0);
    *response++ = (uint8_t)(count >> 8);

    for(n = count; n; n--)
    {
        *response++ = TraceBuf[TraceOut++ & (SWO_BUFFER_SIZE - 1U)];
    }

    if(TraceStatus == (DAP_SWO_CAPTURE_ACTIVE | DAP_SWO_CAPTURE_PAUSED))
    {
        n = GetTraceSpace();
        if(n != 0U)
        {
            switch(TraceMode)
            {
#if (SWO_UART != 0)
                case DAP_SWO_UART:
                    UART_SWO_Capture(&TraceBuf[TraceIn & (SWO_BUFFER_SIZE - 1U)], n);
                    TraceStatus = DAP_SWO_CAPTURE_ACTIVE;
                    break;
#endif
#if (SWO_MANCHESTER != 0)
                case DAP_SWO_MANCHESTER:
                    Manchester_SWO_Capture(&TraceBuf[TraceIn & (SWO_BUFFER_SIZE - 1U)], n);
                    TraceStatus = DAP_SWO_CAPTURE_ACTIVE;
                    break;
#endif
                default:
                    break;
            }
        }
    }

    return ((2U << 16) | (3U + count));
}


#endif  /* ((SWO_UART != 0) || (SWO_MANCHESTER != 0)) */
