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e-Paper/RaspberryPi_JetsonNano/c/lib/Config/sysfs_gpio.c

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+/*****************************************************************************
+* | File        :   SYSFS_GPIO.c
+* | Author      :   Waveshare team
+* | Function    :   Drive SYSFS_ GPIO
+* | Info        :   Read and write /sys/class/gpio
+*----------------
+* |	This version:   V1.0
+* | Date        :   2019-06-04
+* | Info        :   Basic version
+*
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documnetation 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
+# furished 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 OR 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 "sysfs_gpio.h"
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+int SYSFS_GPIO_Export(int Pin)
+{
+    char buffer[NUM_MAXBUF];
+    int len;
+    int fd;
+
+    fd = open("/sys/class/gpio/export", O_WRONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Export Failed: Pin%d\n", Pin);
+        return -1;
+    }
+
+    len = snprintf(buffer, NUM_MAXBUF, "%d", Pin);
+    write(fd, buffer, len);
+    
+    SYSFS_GPIO_Debug( "Export: Pin%d\r\n", Pin);
+
+    close(fd);
+    return 0;
+}
+
+int SYSFS_GPIO_Unexport(int Pin)
+{
+    char buffer[NUM_MAXBUF];
+    int len;
+    int fd;
+
+    fd = open("/sys/class/gpio/unexport", O_WRONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "unexport Failed: Pin%d\n", Pin);
+        return -1;
+    }
+
+    len = snprintf(buffer, NUM_MAXBUF, "%d", Pin);
+    write(fd, buffer, len);
+    
+    SYSFS_GPIO_Debug( "Unexport: Pin%d\r\n", Pin);
+    
+    close(fd);
+    return 0;
+}
+
+int SYSFS_GPIO_Direction(int Pin, int Dir)
+{
+    const char dir_str[]  = "in\0out";
+    char path[DIR_MAXSIZ];
+    int fd;
+    
+    snprintf(path, DIR_MAXSIZ, "/sys/class/gpio/gpio%d/direction", Pin);
+    fd = open(path, O_WRONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Set Direction failed: Pin%d\n", Pin);
+        return -1;
+    }
+
+    if (write(fd, &dir_str[Dir == IN ? 0 : 3], Dir == IN ? 2 : 3) < 0) {
+        SYSFS_GPIO_Debug("failed to set direction!\r\n");
+        return -1;
+    }
+
+    if(Dir == IN){
+        SYSFS_GPIO_Debug("Pin%d:intput\r\n", Pin);
+    }else{
+        SYSFS_GPIO_Debug("Pin%d:Output\r\n", Pin);
+    }
+    
+    close(fd);
+    return 0;
+}
+
+int SYSFS_GPIO_Read(int Pin)
+{
+    char path[DIR_MAXSIZ];
+    char value_str[3];
+    int fd;
+    
+    snprintf(path, DIR_MAXSIZ, "/sys/class/gpio/gpio%d/value", Pin);
+    fd = open(path, O_RDONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Read failed Pin%d\n", Pin);
+        return -1;
+    }
+
+    if (read(fd, value_str, 3) < 0) {
+        SYSFS_GPIO_Debug( "failed to read value!\n");
+        return -1;
+    }
+
+    close(fd);
+    return(atoi(value_str));
+}
+
+int SYSFS_GPIO_Write(int Pin, int value)
+{
+    const char s_values_str[] = "01";
+    char path[DIR_MAXSIZ];
+    int fd;
+    
+    snprintf(path, DIR_MAXSIZ, "/sys/class/gpio/gpio%d/value", Pin);
+    fd = open(path, O_WRONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Write failed : Pin%d,value = %d\n", Pin, value);
+        return -1;
+    }
+
+    if (write(fd, &s_values_str[value == LOW ? 0 : 1], 1) < 0) {
+        SYSFS_GPIO_Debug( "failed to write value!\n");
+        return -1;
+    }
+    
+    close(fd);
+    return 0;
+}