// SSR.c
// Runs on LM3S811
// Provide functions that initialize a GPIO pin and turn it on and off.
// Use bit-banded I/O.
// Daniel Valvano
// July 11, 2011

/* This example accompanies the book
   "Embedded Systems: Real Time Interfacing to the Arm Cortex M3",
   ISBN: 978-1463590154, Jonathan Valvano, copyright (c) 2011
   Example 2.1, Program 2.7, Figure 2.25

 Copyright 2011 by Jonathan W. Valvano, valvano@mail.utexas.edu
    You may use, edit, run or distribute this file
    as long as the above copyright notice remains
 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.
 VALVANO SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL,
 OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
 For more information about my classes, my research, and my books, see
 http://users.ece.utexas.edu/~valvano/
 */

// solid state relay connected to PD5

#define GPIO_PORTD_DATA_R       (*((volatile unsigned long *)0x400073FC))
#define GPIO_PORTD_DIR_R        (*((volatile unsigned long *)0x40007400))
#define GPIO_PORTD_AFSEL_R      (*((volatile unsigned long *)0x40007420))
#define GPIO_PORTD_DEN_R        (*((volatile unsigned long *)0x4000751C))
#define PD5                     (*((volatile unsigned long *)0x40007080))
#define SYSCTL_RCGC2_R          (*((volatile unsigned long *)0x400FE108))
#define SYSCTL_RCGC2_GPIOD      0x00000008  // port D Clock Gating Control

// Make PD5 an output and enable digital I/O
SSR_Init(void){ volatile unsigned long delay;
  SYSCTL_RCGC2_R |= 0x00000008;  // 1) activate clock for Port D
  delay = SYSCTL_RCGC2_R;        // allow time for clock to start
  GPIO_PORTD_DIR_R |= 0x20;      // 2) set direction register
  GPIO_PORTD_AFSEL_R &= ~0x20;   // 3) regular port function
  GPIO_PORTD_DEN_R |= 0x20;      // 4) enable digital port
}
// Make PD5 high
void SSR_On(void){
  PD5 = 0x20;
//  GPIO_PORTD_DATA_R |= 0x20;
}
// Make PD5 low
void SSR_Off(void){
  PD5 = 0x00;
//  GPIO_PORTD_DATA_R &= ~0x20;
}

//debug code
#define GPIO_PORTC_DATA_R       (*((volatile unsigned long *)0x400063FC))
#define GPIO_PORTC_DIR_R        (*((volatile unsigned long *)0x40006400))
#define GPIO_PORTC_DEN_R        (*((volatile unsigned long *)0x4000651C))
#define SYSCTL_RCGC2_GPIOC      0x00000004  // port C Clock Gating Control
int main(void){
  SYSCTL_RCGC2_R |= SYSCTL_RCGC2_GPIOC;// activate port C
  SSR_Init();               // initialize PD5 and make it output
  GPIO_PORTC_DIR_R &= ~0x10;// make PC4 in (PC4 built-in button)
  GPIO_PORTC_DEN_R |= 0x10; // enable digital I/O on PC4
  while(1){
    SSR_On();
    while(GPIO_PORTC_DATA_R&0x10); // wait for button press
    SSR_Off();
    while(GPIO_PORTC_DATA_R&0x10); // wait for button press
  }
}