blob: 0ec3051eb47eb7ec6624245beaee60df4401f2ff [file] [log] [blame]
#include "bbb/gpios.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "aos/common/logging/logging.h"
namespace bbb {
GpioPin::GpioPin(int bank, int pin, bool input, bool initial_value)
: bank_(bank), pin_(pin), kernel_pin_(bank * 32 + pin) {
// Export the pin.
FILE *export_handle = fopen("/sys/class/gpio/export", "w");
if (export_handle == NULL) {
PLOG(WARNING, "Could not open file to export pin (%d,%d)", bank_, pin_);
} else {
if (fprintf(export_handle, "%d", kernel_pin_) < 0) {
PLOG(WARNING, "Could not write to file %p to export pin (%d,%d)",
export_handle, bank_, pin_);
}
if (fclose(export_handle) == -1) {
PLOG(WARNING, "fclose(%p) failed", export_handle);
}
}
char direction_path[64];
snprintf(direction_path, sizeof(direction_path),
"/sys/class/gpio/gpio%d/direction", kernel_pin_);
FILE *direction_handle = fopen(direction_path, "w");
if (direction_handle == NULL) {
PLOG(FATAL, "fopen(%s, \"w\") failed", direction_path);
}
if (fputs(input ? "in" : (initial_value ? "high" : "low"),
direction_handle) < 0) {
PLOG(FATAL, "setting direction for pin (%d,%d) failed", bank_, pin_);
}
if (fclose(direction_handle) == -1) {
PLOG(WARNING, "fclose(%p) failed", direction_handle);
}
char value_path[64];
snprintf(value_path, sizeof(value_path),
"/sys/class/gpio/gpio%d/value", kernel_pin_);
value_handle_ = fopen(value_path, "w+");
if (value_handle_ == NULL) {
PLOG(FATAL, "fopen(%s, \"w+\") failed", value_path);
}
}
GpioPin::~GpioPin() {
// Unexport the pin.
FILE *unexport_handle = fopen("/sys/class/gpio/unexport", "a");
if (unexport_handle == NULL) {
PLOG(WARNING, "Could not open file to unexport pin (%d,%d)", bank_, pin_);
} else {
if (fprintf(unexport_handle, "%d", kernel_pin_) < 0) {
PLOG(WARNING, "Could not write to file %p to unexport pin (%d,%d)",
unexport_handle, bank_, pin_);
}
if (fclose(unexport_handle) == -1) {
PLOG(WARNING, "fclose(%p) failed", unexport_handle);
}
}
}
} // namespace bbb