gpio.c

/*
 *  Squeezelite - lightweight headless squeezebox emulator
 *
 *  (c) Adrian Smith 2012-2015, triode1@btinternet.com
 *      Ralph Irving 2015-2023, ralph_irving@hotmail.com
 *
 * This program 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
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * gpio.c (c) Paul Hermann, 2015-2023 under the same license terms
 *   -Control of Raspberry pi GPIO for amplifier power
 *   -Launch script on power status change from LMS
 */

#if GPIO

#include "squeezelite.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

static int gpio_state = -1;
static int initialized = -1;
static int power_state = -1;

void relay( int state) {
#ifdef RPI
    gpio_state = state;

  // Set up gpio  using BCM Pin #'s
	if (initialized == -1){
		if ( gpioInitialise() == 0 ){
			initialized = 1;
		}
	}
	if ( initialized == 1){
		gpioSetMode (gpio_pin, PI_OUTPUT);
	}

	if(gpio_state == 1)
		gpioWrite(gpio_pin, PI_HIGH^gpio_active_low);
	else if(gpio_state == 0)
		gpioWrite(gpio_pin, PI_LOW^gpio_active_low);
  // Done!
#endif
}

char *cmdline;
int argloc;

void relay_script( int state) {
	gpio_state = state;
	int err;

  // Call script with init parameter
	if (initialized == -1){
		int strsize = strlen(power_script);
		cmdline = (char*) malloc(strsize+3);
		argloc = strsize + 1;

		strcpy(cmdline, power_script);
		strcat(cmdline, " 2");
		if ((err = system(cmdline)) != 0){ 
			fprintf (stderr, "%s exit status = %d\n", cmdline, err);
		}
		else{
			initialized = 1;
		}
  	}

  // Call Script to turn on or off  on = 1, off = 0
  // Checks current status to avoid calling script excessivly on track changes where alsa re-inits.

	if( (gpio_state == 1) && (power_state != 1)){
		cmdline[argloc] = '1';
		if ((err = system(cmdline)) != 0){ 
			fprintf (stderr, "%s exit status = %d\n", cmdline, err);
		}
		else {
			power_state = 1;
		}
	}
	else if( (gpio_state == 0) && (power_state != 0)){
		cmdline[argloc] = '0';
		if ((err = system(cmdline)) != 0){ 
			fprintf (stderr, "%s exit status = %d\n", cmdline, err);
		}
		else {
			power_state = 0;
		}
	}
// Done!
}

#endif // GPIO