Tasmota/lib/RF24/utility/SPIDEV/gpio.cpp

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2020-01-01 18:09:20 +00:00
/*
* https://github.com/mrshu/GPIOlib
* Copyright (c) 2011, Copyright (c) 2011 mr.Shu
* All rights reserved.
*
* Modified on 24 June 2012, 11:06 AM
* File: gpio.cpp
* Author: purinda (purinda@gmail.com)
*
* Patched for filedescriptor catching and error control by L Diaz 2018
*/
#include "gpio.h"
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
std::map<int,GPIOfdCache_t> GPIO::cache;
GPIO::GPIO() {
}
GPIO::~GPIO() {
}
void GPIO::open(int port, int DDR)
{
FILE *f;
f = fopen("/sys/class/gpio/export", "w");
if(f==NULL) throw GPIOException("can't export GPIO pin .check access rights");
fprintf(f, "%d\n", port);
fclose(f);
int counter = 0;
char file[128];
sprintf(file, "/sys/class/gpio/gpio%d/direction", port);
while( ( f = fopen(file,"w")) == NULL ){ //Wait 10 seconds for the file to be accessible if not open on first attempt
sleep(1);
counter++;
if(counter > 10){
throw GPIOException("can't access /sys/class/gpio/gpio%d/direction GPIO pin. check access rights");
/*perror("Could not open /sys/class/gpio/gpio%d/direction");
exit(0); */
}
}
int l=(DDR==0) ? fprintf(f, "in\n") : fprintf(f, "out\n");
if(!(l==3 || l==4)) {
fclose(f);
throw GPIOException("can't set direction on GPIO pin. check access rights");
}
/*
if (DDR == 0)
fprintf(f, "in\n");
else printf(f, "out\n");
*/
fclose(f);
// Caches the GPIO descriptor;
sprintf(file, "/sys/class/gpio/gpio%d/value", port);
int flags= (DDR==0) ? O_RDONLY : O_WRONLY;
int fd=::open(file,flags);
if(fd<0) {
throw GPIOException("Can't open the GPIO");
} else {
cache[port]=fd; // cache the fd;
lseek(fd,SEEK_SET,0);
}
}
void GPIO::close(int port)
{
std::map<int,GPIOfdCache_t>::iterator i;
i=cache.find(port);
if(i!=cache.end()){
close(i->second); // close the cached fd
cache.erase(i); // Delete cache entry
}
// Do unexport
FILE *f;
f = fopen("/sys/class/gpio/unexport", "w");
if(f!=NULL) {
fprintf(f, "%d\n", port);
fclose(f);
}
}
int GPIO::read(int port)
{
std::map<int,GPIOfdCache_t>::iterator i;
int fd;
i=cache.find(port);
if(i==cache.end()){ // Fallback to open the gpio
GPIO::open(port,GPIO::DIRECTION_IN);
i=cache.find(port);
if(i==cache.end()) throw GPIOException("can't access to GPIO");
else fd=i->second;
} else fd=i->second;
char c;
if(lseek(fd,0,SEEK_SET)==0 && ::read(fd,&c,1)==1){
return (c=='0') ? 0 : 1;
} else throw GPIOException("can't access to GPIO");
/*FILE *f;
char file[128];
sprintf(file, "/sys/class/gpio/gpio%d/value", port);
f = fopen(file, "r");
int i;
fscanf(f, "%d", &i);
fclose(f);
return i;
*/
}
void GPIO::write(int port, int value){
std::map<int,GPIOfdCache_t>::iterator i;
int fd;
i=cache.find(port);
if(i==cache.end()){ // Fallback to open the gpio
GPIO::open(port,GPIO::DIRECTION_OUT);
i=cache.find(port);
if(i==cache.end()) throw GPIOException("can't access to GPIO");
else fd=i->second;
} else fd=i->second;
if(lseek(fd,0,SEEK_SET)!=0) throw GPIOException("can't access to GPIO");
int l=(value==0) ? ::write(fd,"0\n",2) : ::write(fd,"1\n",2);
if(l!=2) throw GPIOException("can't access to GPIO");
/*FILE *f;
char file[128];
sprintf(file, "/sys/class/gpio/gpio%d/value", port);
f = fopen(file, "w");
if (value == 0) fprintf(f, "0\n");
else fprintf(f, "1\n");
fclose(f);*/
}