//*****************************************************************************
//
// timers.c - Timers example.
//
// Copyright (c) 2012-2014 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
// 
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// 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. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
// 
// This is part of revision 2.1.0.12573 of the EK-TM4C123GXL Firmware Package.
//
//*****************************************************************************

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.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/timer.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"

//*****************************************************************************
//
//! \addtogroup example_list
//! <h1>Timer (timers)</h1>
//!
//! This example application demonstrates the use of the timers to generate
//! periodic interrupts.  One timer is set up to interrupt once per second and
//! the other to interrupt twice per second; each interrupt handler will toggle
//! its own indicator on the display.
//!
//! UART0, connected to the Virtual Serial Port and running at 115,200, 8-N-1,
//! is used to display messages from this application.
//
//*****************************************************************************

//*****************************************************************************
//
// Flags that contain the current value of the interrupt indicator as displayed
// on the UART.
//
//*****************************************************************************
uint32_t g_ui32Flags;

//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

//*****************************************************************************
//
// The interrupt handler for the first timer interrupt.
//
//*****************************************************************************
void
Timer0IntHandler(void)
{
    char cOne, cTwo;

    //
    // Clear the timer interrupt.
    //
    ROM_TimerIntClear(TIMER0_BASE, TIMER_TIMA_TIMEOUT);

    //
    // Toggle the flag for the first timer.
    //
    HWREGBITW(&g_ui32Flags, 0) ^= 1;

    //
    // Use the flags to Toggle the LED for this timer
    //
    GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1, g_ui32Flags << 1);

    //
    // Update the interrupt status on the display.
    //
    ROM_IntMasterDisable();
    cOne = HWREGBITW(&g_ui32Flags, 0) ? '1' : '0';
    cTwo = HWREGBITW(&g_ui32Flags, 1) ? '1' : '0';
    UARTprintf("\rT1: %c  T2: %c", cOne, cTwo);
    ROM_IntMasterEnable();
}

//*****************************************************************************
//
// The interrupt handler for the second timer interrupt.
//
//*****************************************************************************
void
Timer1IntHandler(void)
{
    char cOne, cTwo;

    //
    // Clear the timer interrupt.
    //
    ROM_TimerIntClear(TIMER1_BASE, TIMER_TIMA_TIMEOUT);

    //
    // Toggle the flag for the second timer.
    //
    HWREGBITW(&g_ui32Flags, 1) ^= 1;

    //
    // Use the flags to Toggle the LED for this timer
    //
    GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, g_ui32Flags << 1);

    //
    // Update the interrupt status on the display.
    //
    ROM_IntMasterDisable();
    cOne = HWREGBITW(&g_ui32Flags, 0) ? '1' : '0';
    cTwo = HWREGBITW(&g_ui32Flags, 1) ? '1' : '0';
    UARTprintf("\rT1: %c  T2: %c", cOne, cTwo);
    ROM_IntMasterEnable();
}

//*****************************************************************************
//
// Configure the UART and its pins.  This must be called before UARTprintf().
//
//*****************************************************************************
void
ConfigureUART(void)
{
    //
    // Enable the GPIO Peripheral used by the UART.
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Enable UART0
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

    //
    // Configure GPIO Pins for UART mode.
    //
    ROM_GPIOPinConfigure(GPIO_PA0_U0RX);
    ROM_GPIOPinConfigure(GPIO_PA1_U0TX);
    ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    //
    // Use the internal 16MHz oscillator as the UART clock source.
    //
    UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);

    //
    // Initialize the UART for console I/O.
    //
    UARTStdioConfig(0, 115200, 16000000);
}

//*****************************************************************************
//
// This example application demonstrates the use of the timers to generate
// periodic interrupts.
//
//*****************************************************************************
int
main(void)
{
    //
    // Enable lazy stacking for interrupt handlers.  This allows floating-point
    // instructions to be used within interrupt handlers, but at the expense of
    // extra stack usage.
    //
    ROM_FPULazyStackingEnable();

    //
    // Set the clocking to run directly from the crystal.
    //
    ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
                       SYSCTL_XTAL_16MHZ);

    //
    // Initialize the UART and write status.
    //
    ConfigureUART();

    UARTprintf("\033[2JTimers example\n");
    UARTprintf("T1: 0  T2: 0");

    //
    // Enable the GPIO port that is used for the on-board LED.
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);

    //
    // Enable the GPIO pins for the LED (PF1 & PF2).
    //
    ROM_GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_2 | GPIO_PIN_1);


    //
    // Enable the peripherals used by this example.
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER1);

    //
    // Enable processor interrupts.
    //
    ROM_IntMasterEnable();

    //
    // Configure the two 32-bit periodic timers.
    //
    ROM_TimerConfigure(TIMER0_BASE, TIMER_CFG_PERIODIC);
    ROM_TimerConfigure(TIMER1_BASE, TIMER_CFG_PERIODIC);
    ROM_TimerLoadSet(TIMER0_BASE, TIMER_A, ROM_SysCtlClockGet());
    ROM_TimerLoadSet(TIMER1_BASE, TIMER_A, ROM_SysCtlClockGet() / 2);

    //
    // Setup the interrupts for the timer timeouts.
    //
    ROM_IntEnable(INT_TIMER0A);
    ROM_IntEnable(INT_TIMER1A);
    ROM_TimerIntEnable(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
    ROM_TimerIntEnable(TIMER1_BASE, TIMER_TIMA_TIMEOUT);

    //
    // Enable the timers.
    //
    ROM_TimerEnable(TIMER0_BASE, TIMER_A);
    ROM_TimerEnable(TIMER1_BASE, TIMER_A);

    //
    // Loop forever while the timers run.
    //
    while(1)
    {
    }
}