/*
 *  spreadspace avr utils
 *
 *
 *  Copyright (C) 2012 Christian Pointner <equinox@spreadspace.org>
 *
 *  This file is part of spreadspace avr utils.
 *
 *  spreadspace avr utils is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  spreadspace avr utils is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
 */


/* this is based on the LUFA example Project USBtoSerial
   this is their LICENSE Header */

/*
             LUFA Library
     Copyright (C) Dean Camera, 2012.

  dean [at] fourwalledcubicle [dot] com
           www.lufa-lib.org
*/

/*
  Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com)

  Permission to use, copy, modify, distribute, and sell this
  software and its documentation for any purpose is hereby granted
  without fee, provided that the above copyright notice appear in
  all copies and that both that the copyright notice and this
  permission notice and warranty disclaimer appear in supporting
  documentation, and that the name of the author not be used in
  advertising or publicity pertaining to distribution of the
  software without specific, written prior permission.

  The author disclaim all warranties with regard to this
  software, including all implied warranties of merchantability
  and fitness.  In no event shall the author be liable for any
  special, indirect or consequential damages or any damages
  whatsoever resulting from loss of use, data or profits, whether
  in an action of contract, negligence or other tortious action,
  arising out of or in connection with the use or performance of
  this software.
*/

/** \file
 *
 *  Main source file for the USBtoSerial project. This file contains the main tasks of
 *  the project and is responsible for the initial application hardware configuration.
 */


#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/interrupt.h>
#include <avr/power.h>

#include "lufa-descriptor-usbserial.h"

#include "util.h"
#include "led.h"

#include <LUFA/Version.h>
#include <LUFA/Drivers/Misc/RingBuffer.h>
#include <LUFA/Drivers/USB/USB.h>

    /* Hardware Defines: */
#define SPI_DDR DDRB
#define SPI_PORT PORTB
#define SPI_PINB_REG  PINB
#define CS   0
#define SCK  1
#define MOSI 2
#define MISO 3

    /* Function Prototypes: */
void SetupHardware(void);
void SPI_TransferBuffer(void);

void EVENT_USB_Device_Connect(void);
void EVENT_USB_Device_Disconnect(void);
void EVENT_USB_Device_ConfigurationChanged(void);
void EVENT_USB_Device_ControlRequest(void);

static RingBuffer_t USBtoSPI_Buffer;
static uint8_t      USBtoSPI_Buffer_Data[128];
static RingBuffer_t SPItoUSB_Buffer;
static uint8_t      SPItoUSB_Buffer_Data[128];

/** LUFA CDC Class driver interface configuration and state information. This structure is
 *  passed to all CDC Class driver functions, so that multiple instances of the same class
 *  within a device can be differentiated from one another.
 */
USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
  {
    .Config =
      {
        .ControlInterfaceNumber         = 0,

        .DataINEndpointNumber           = CDC_TX_EPNUM,
        .DataINEndpointSize             = CDC_TXRX_EPSIZE,
        .DataINEndpointDoubleBank       = false,

        .DataOUTEndpointNumber          = CDC_RX_EPNUM,
        .DataOUTEndpointSize            = CDC_TXRX_EPSIZE,
        .DataOUTEndpointDoubleBank      = false,

        .NotificationEndpointNumber     = CDC_NOTIFICATION_EPNUM,
        .NotificationEndpointSize       = CDC_NOTIFICATION_EPSIZE,
        .NotificationEndpointDoubleBank = false,
      },
  };


int main(void)
{
  SetupHardware();

  RingBuffer_InitBuffer(&USBtoSPI_Buffer, USBtoSPI_Buffer_Data, sizeof(USBtoSPI_Buffer_Data));
  RingBuffer_InitBuffer(&SPItoUSB_Buffer, SPItoUSB_Buffer_Data, sizeof(SPItoUSB_Buffer_Data));

  sei();

  for (;;) {
    int16_t BytesReceived = CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface);
    while(BytesReceived > 0) {
      if(!(RingBuffer_IsFull(&USBtoSPI_Buffer))) {
        int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
        if (!(ReceivedByte < 0))
          RingBuffer_Insert(&USBtoSPI_Buffer, ReceivedByte);

        BytesReceived--;
      }
    }

    uint16_t BufferCount = RingBuffer_GetCount(&SPItoUSB_Buffer);
    if ((TIFR0 & (1 << TOV0)) || (BufferCount > (uint8_t)(sizeof(SPItoUSB_Buffer_Data) * .75))) {
      TIFR0 |= (1 << TOV0);
      while (BufferCount--) {
        if (CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
                                RingBuffer_Peek(&SPItoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
          break;

        RingBuffer_Remove(&SPItoUSB_Buffer);
      }
    }

    if (!(RingBuffer_IsEmpty(&USBtoSPI_Buffer)))
      SPI_TransferBuffer();

    CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
    USB_USBTask();
  }
}

void SetupHardware(void)
{
  MCUSR &= ~(1 << WDRF);
  wdt_disable();

  cpu_init();
  led_init();
  USB_Init();

  TCCR0B = (1 << CS02);

  SPI_DDR = (1<<MOSI)|(1<<SCK)|(1<<CS);
  SPI_PORT = (1<<CS);
  SPCR = (1<<SPE)|(1<<MSTR);
}

void SPI_TransferBuffer()
{
  SPI_PORT &= ~(1<<CS);

  while(!(RingBuffer_IsEmpty(&USBtoSPI_Buffer))) {
    SPDR = RingBuffer_Remove(&USBtoSPI_Buffer);
    while(!(SPSR & (1<<SPIF)));

    uint8_t ReceivedByte = SPDR;
    if (USB_DeviceState == DEVICE_STATE_Configured) {
      RingBuffer_Insert(&SPItoUSB_Buffer, ReceivedByte);
      if(RingBuffer_IsFull(&USBtoSPI_Buffer))
        break;
    }
  }

  SPI_PORT |= (1<<CS);
}

void EVENT_USB_Device_Connect(void)
{
  led_on();
}

void EVENT_USB_Device_Disconnect(void)
{
  led_off();
}

void EVENT_USB_Device_ConfigurationChanged(void)
{
  bool ConfigSuccess = true;

  ConfigSuccess &= CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);

  led_toggle();
  _delay_ms(10);
  led_toggle();
}

void EVENT_USB_Device_ControlRequest(void)
{
  CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
}