marvell/services/mgui/gpio.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/tcp.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <pthread.h>
#include <netdb.h>
#include <sys/epoll.h>
#include <termios.h>
#include <string.h>
#include <poll.h>

#include "gpio.h"

#define SYSFS_GPIO_DIR "/sys/class/gpio"
#define MAX_BUF 64

int gpio_export(unsigned int gpio)
{
    int fd, len;
    char buf[MAX_BUF]={0};

    snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR  "/gpio%d", gpio);
    if (access(buf, F_OK) == 0)
        /* already exist */
        return 0;

    fd = open(SYSFS_GPIO_DIR "/export", O_WRONLY);
    if (fd < 0) {
        printf("gpio/export: %d\n", gpio);
        return fd;
    }

    len = snprintf(buf, sizeof(buf), "%d", gpio);
    write(fd, buf, len);
    close(fd);

    return 0;
}

int gpio_unexport(unsigned int gpio)
{
    int fd, len;
    char buf[MAX_BUF]={0};

    fd = open(SYSFS_GPIO_DIR "/unexport", O_WRONLY);
    if (fd < 0) {
        printf("gpio: %d\n", gpio);
        return fd;
    }

    len = snprintf(buf, sizeof(buf), "%d", gpio);
    write(fd, buf, len);
    close(fd);
    return 0;    
}

int gpio_set_dir(unsigned int gpio, unsigned int out_flag)
{
    int fd, len;
    char buf[MAX_BUF]={0};

    len = snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR  "/gpio%d/direction", gpio);
    (void)len;

    fd = open(buf, O_WRONLY);
    if (fd < 0) {
		printf("gpio: %d, dir: %d\n", gpio, out_flag);
        return fd;
    }

    if (out_flag == GPIO_DIR_OUT)
        write(fd, "out", 4);
    else
        write(fd, "in", 3);

    close(fd);
    return 0;
}

int gpio_set_value(unsigned int gpio, unsigned int value)
{
    int fd, len;
    char buf[MAX_BUF]={0};

    len = snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
    (void)len;

    fd = open(buf, O_WRONLY);
    if (fd < 0) {
        printf("gpio: %d, val: %d\n", gpio, value);
        return fd;
    }

    if (value)
        write(fd, "1", 2);
    else
        write(fd, "0", 2);

    close(fd);
    return 0;
}

int gpio_get_value(unsigned int gpio, unsigned int *value)
{
    int fd, len;
    char buf[MAX_BUF]={0};
    char ch;

    len = snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
    (void)len;

    fd = open(buf, O_RDONLY);
    if (fd < 0) {
        printf("gpio: %d\n", gpio);
        return fd;
    }

    read(fd, &ch, 1);

    if (ch != '0') {
        *value = 1;
    } else {
        *value = 0;
    }

    close(fd);
    return 0;
}

int gpio_set_edge(unsigned int gpio, const unsigned char *edge)
{
    int fd, len;
    char buf[MAX_BUF]={0};

    len = snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/edge", gpio);
    (void)len;

    fd = open(buf, O_WRONLY);
    if (fd < 0) {
        printf("gpio: %d\n", gpio);
        return fd;
    }

    write(fd, edge, strlen((char *)edge));
    close(fd);
    return 0;
}

int gpio_value_open(unsigned int gpio)
{
    int fd, len;
    char buf[MAX_BUF]={0};

    len = snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
    (void)len;

    fd = open(buf, O_RDONLY | O_NONBLOCK);
    if (fd < 0)
        printf("gpio: %d\n", gpio);
    return fd;
}

int gpio_value_close(int fd)
{
    return close(fd);
}