#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/hw_uart.h"
#include "driverlib/fpu.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/sysctl.h"
#include "driverlib/systick.h"
#include "driverlib/uart.h"
#include "driverlib/udma.h"
#include "utils/cpu_usage.h"
#include "utils/uartstdio.h"
#include "utils/ustdlib.h"

//*****************************************************************************

//*****************************************************************************
#if defined(ewarm)
#pragma data_alignment=1024
uint8_t ui8ControlTable[1024];
#elif defined(ccs)
#pragma DATA_ALIGN(ui8ControlTable, 1024)
uint8_t ui8ControlTable[1024];
#else
uint8_t ui8ControlTable[1024] __attribute__ ((aligned(1024)));
#endif

#define UART_TXBUF_SIZE         16
#define UART_RXBUF_SIZE         16
static uint8_t g_pui8TxBuf[UART_TXBUF_SIZE];
static uint8_t g_pui8RxPing[UART_RXBUF_SIZE];
static uint8_t g_pui8RxPong[UART_RXBUF_SIZE];

// Error counter
static uint32_t g_ui32DMAErrCount = 0;

// Transfer counters
static uint32_t g_ui32RxPingCount = 0;
static uint32_t g_ui32RxPongCount = 0;
volatile int UARTIntHitsCounter = 0;

// uDMA control table aligned to 1024-byte boundary
#pragma DATA_ALIGN(ucControlTable, 64)
uint8_t ucControlTable[64];

void
uDMAErrorHandler(void)
{
    uint32_t ui32Status;

    ui32Status = ROM_uDMAErrorStatusGet();

    if(ui32Status)
    {
        ROM_uDMAErrorStatusClear();
        g_ui32DMAErrCount++;
    }
}

// UART interrupt handler. Called on completion of uDMA transfer
void
UART0IntHandler(void)
{
    uint32_t ui32Status;
    uint32_t ui32Mode;

    ui32Status = ROM_UARTIntStatus(UART0_BASE, 1);

    ROM_UARTIntClear(UART0_BASE, ui32Status);
    UARTIntHitsCounter++;

    ui32Mode = ROM_uDMAChannelModeGet(UDMA_CHANNEL_UART0RX | UDMA_PRI_SELECT);

    if(ui32Mode == UDMA_MODE_STOP)
    {
        g_ui32RxPingCount++;

        ROM_uDMAChannelTransferSet(UDMA_CHANNEL_UART0RX | UDMA_PRI_SELECT,
                                   UDMA_MODE_PINGPONG,
                                   (void *)(UART0_BASE + UART_O_DR),
                                   g_pui8RxPing, sizeof(g_pui8RxPing));
    }

    ui32Mode = ROM_uDMAChannelModeGet(UDMA_CHANNEL_UART0RX | UDMA_ALT_SELECT);

    if(ui32Mode == UDMA_MODE_STOP)
    {
        g_ui32RxPongCount++;

        ROM_uDMAChannelTransferSet(UDMA_CHANNEL_UART0RX | UDMA_ALT_SELECT,
                                   UDMA_MODE_PINGPONG,
                                   (void *)(UART0_BASE + UART_O_DR),
                                   g_pui8RxPong, sizeof(g_pui8RxPong));
    }

    if(!ROM_uDMAChannelIsEnabled(UDMA_CHANNEL_UART0TX))
    {

        ROM_uDMAChannelTransferSet(UDMA_CHANNEL_UART0TX | UDMA_PRI_SELECT,
                                   UDMA_MODE_BASIC, g_pui8TxBuf,
                                   (void *)(UART0_BASE + UART_O_DR),
                                   sizeof(g_pui8TxBuf));

        ROM_uDMAChannelEnable(UDMA_CHANNEL_UART0TX);
    }

}

// Initialize UART uDMA transfer
void
InitUART1Enable(void)
{
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    // Enable UART1 and make sure it can run while the CPU sleeps
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
    ROM_SysCtlPeripheralSleepEnable(SYSCTL_PERIPH_UART0);

    ROM_GPIOPinConfigure(GPIO_PA0_U0RX);
    ROM_GPIOPinConfigure(GPIO_PA1_U0TX);
    // Configure and enable the UART with DMA
    ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    ROM_UARTConfigSetExpClk(UART0_BASE, ROM_SysCtlClockGet(), 115200,
                            UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
                            UART_CONFIG_PAR_NONE);

    ROM_UARTFIFOLevelSet(UART0_BASE, UART_FIFO_TX4_8, UART_FIFO_RX4_8);

    ROM_UARTEnable(UART0_BASE);
    ROM_UARTDMAEnable(UART0_BASE, UART_DMA_RX);

    ROM_IntEnable(INT_UART0);

    // Receive channel setup for ping and pong
    ROM_uDMAChannelAttributeDisable(UDMA_CHANNEL_UART0RX,
                                    UDMA_ATTR_ALTSELECT | UDMA_ATTR_USEBURST |
                                    UDMA_ATTR_HIGH_PRIORITY |
                                    UDMA_ATTR_REQMASK);

    ROM_uDMAChannelAttributeEnable(UDMA_CHANNEL_UART0RX,
                                    UDMA_ATTR_ALTSELECT | UDMA_ATTR_USEBURST |
                                    UDMA_ATTR_HIGH_PRIORITY |
                                    UDMA_ATTR_REQMASK);

    ROM_uDMAChannelControlSet(UDMA_CHANNEL_UART0RX | UDMA_PRI_SELECT,
                              UDMA_SIZE_8 | UDMA_SRC_INC_NONE | UDMA_DST_INC_8 |
                              UDMA_ARB_4);

    ROM_uDMAChannelControlSet(UDMA_CHANNEL_UART0RX | UDMA_ALT_SELECT,
                              UDMA_SIZE_8 | UDMA_SRC_INC_NONE | UDMA_DST_INC_8 |
                              UDMA_ARB_4);

    ROM_uDMAChannelTransferSet(UDMA_CHANNEL_UART0RX | UDMA_PRI_SELECT,
                               UDMA_MODE_PINGPONG,
                               (void *)(UART0_BASE + UART_O_DR),
                               g_pui8RxPing, sizeof(g_pui8RxPing));

    ROM_uDMAChannelTransferSet(UDMA_CHANNEL_UART0RX | UDMA_ALT_SELECT,
                               UDMA_MODE_PINGPONG,
                               (void *)(UART0_BASE + UART_O_DR),
                               g_pui8RxPong, sizeof(g_pui8RxPong));
    // Enable both channels
    ROM_uDMAChannelEnable(UDMA_CHANNEL_UART0RX);
}

int
main(void)
{
    volatile uint32_t ui32Loop;

    ROM_FPULazyStackingEnable();

    ROM_SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |
                       SYSCTL_XTAL_16MHZ);

    ROM_SysCtlPeripheralClockGating(true);

    // GPIO setup for LEDs
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
    ROM_GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_2);
    
    // Enable uDMA
    ROM_SysCtlPeripheralReset(SYSCTL_PERIPH_UDMA);
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UDMA);
    ROM_SysCtlPeripheralSleepEnable(SYSCTL_PERIPH_UDMA);
    //ROM_IntEnable(INT_UDMAERR);
    ROM_uDMAEnable();
    ROM_uDMAControlBaseSet(ucControlTable);

    // Initialize the uDMA/UART
    InitUART1Enable();

    while(1)
    {
        if(UARTIntHitsCounter > 0)
        {
            GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, GPIO_PIN_2);

            SysCtlDelay(SysCtlClockGet() / 20 / 3);

            GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 0);

            SysCtlDelay(SysCtlClockGet() / 20 / 3);
        }
    }
}