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/*
* Copyright 2014-present Facebook. All Rights Reserved.
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
//#define DEBUG
//#define VERBOSE
#include "gpio.h"
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <openbmc/log.h>
void gpio_init_default(gpio_st *g) {
g->gs_gpio = -1;
g->gs_fd = -1;
}
int gpio_open(gpio_st *g, int gpio)
{
char buf[128];
int rc;
snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%u/value", gpio);
rc = open(buf, O_RDWR);
if (rc == -1) {
rc = errno;
LOG_ERR(rc, "Failed to open %s", buf);
return -rc;
}
g->gs_fd = rc;
g->gs_gpio = gpio;
return 0;
}
void gpio_close(gpio_st *g)
{
if (g && g->gs_fd != -1) {
close(g->gs_fd);
}
gpio_init_default(g);
}
gpio_value_en gpio_read(gpio_st *g)
{
char buf[32] = {0};
gpio_value_en v;
lseek(g->gs_fd, 0, SEEK_SET);
read(g->gs_fd, buf, sizeof(buf));
v = atoi(buf) ? GPIO_VALUE_HIGH : GPIO_VALUE_LOW;
LOG_VER("read gpio=%d value=%d %d", g->gs_gpio, atoi(buf), v);
return v;
}
void gpio_write(gpio_st *g, gpio_value_en v)
{
lseek(g->gs_fd, 0, SEEK_SET);
write(g->gs_fd, (v == GPIO_VALUE_HIGH) ? "1" : "0", 1);
LOG_VER("write gpio=%d value=%d", g->gs_gpio, v);
}
int gpio_change_direction(gpio_st *g, gpio_direction_en dir)
{
char buf[128];
char *val;
int fd = -1;
int rc = 0;
snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%u/direction", g->gs_gpio);
fd = open(buf, O_WRONLY);
if (fd == -1) {
rc = errno;
LOG_ERR(rc, "Failed to open %s", buf);
return -rc;
}
val = (dir == GPIO_DIRECTION_IN) ? "in" : "out";
write(fd, val, strlen(val));
LOG_VER("change gpio=%d direction=%s", g->gs_gpio, val);
out:
if (fd != -1) {
close(fd);
}
return -rc;
}
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