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mraa/src/gpio/gpio.c
Thomas Ingleby e64ffcf77d gpio: gpio in/out both work
* Python example included.

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>
2014-04-11 15:55:01 +01:00

126 lines
3.0 KiB
C

/*
* Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
*
* Copyright © 2014 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <stdlib.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include "gpio.h"
#ifdef __cplusplus
extern "C" {
#endif
int
gpio_get_valfp(gpio_t *gpio);
void
gpio_init(gpio_t *gpio, int pin) {
FILE *export_f;
if((export_f = fopen("/sys/class/gpio/export", "w")) == NULL) {
fprintf(stderr, "Failed to open export for writing!\n");
} else {
fprintf(export_f, "%d", pin);
fclose(export_f);
}
gpio->pin = pin;
}
int
gpio_set(int pin) {
//Stuff
return 0;
}
void
gpio_mode(gpio_t *gpio, gpio_mode_t mode) {
//gpio->pin
}
void
gpio_dir(gpio_t *gpio, gpio_dir_t dir) {
fclose(gpio->value_fp);
gpio->value_fp = NULL;
char filepath[64];
snprintf(filepath, 64, "/sys/class/gpio/gpio%d/direction", gpio->pin);
int fd;
fd = open(filepath, O_WRONLY);
if(fd == -1) {
fprintf(stderr, "Failed to open direction for writing!\n");
} else if(write(fd, dir, 5) == -1) {
fprintf(stderr, "Failed to set direction\n");
} else {
close(fd);
}
}
int
gpio_read(gpio_t *gpio) {
if(gpio->value_fp == NULL) {
gpio_get_valfp(gpio);
}
fseek(gpio->value_fp, SEEK_SET, 0);
char buffer[2];
fread(buffer, 2, 1, gpio->value_fp);
fseek(gpio->value_fp, SEEK_SET, 0);
return atoi(buffer);
}
void
gpio_write(gpio_t *gpio, int value) {
if(gpio->value_fp == NULL) {
gpio_get_valfp(gpio);
}
fseek(gpio->value_fp, SEEK_SET, 0);
fprintf(gpio->value_fp, "%d", value);
fseek(gpio->value_fp, SEEK_SET, 0);
}
void
gpio_close(gpio_t *gpio) {
}
int
gpio_get_valfp(gpio_t *gpio) {
char bu[64];
sprintf(bu, "/sys/class/gpio/gpio%d/value", gpio->pin);
if((gpio->value_fp = fopen(bu, "r+b")) == NULL) {
return 1;
} else {
return 0;
}
return 1;
}
#ifdef __cplusplus
}
#endif