nymea-gpio/libnymea-gpio/gpio.cpp

356 lines
10 KiB
C++

#include "gpio.h"
Q_LOGGING_CATEGORY(dcGpio, "Gpio")
/*! Constructs a \l{Gpio} object to represent a GPIO with the given \a gpio number and \a parent. */
Gpio::Gpio(int gpio, QObject *parent) :
QObject(parent),
m_gpio(gpio),
m_direction(Gpio::DirectionInvalid),
m_gpioDirectory(QDir(QString("/sys/class/gpio/gpio%1").arg(QString::number(gpio))))
{
}
/*! Destroys and unexports the \l{Gpio}. */
Gpio::~Gpio()
{
unexportGpio();
}
/*! Returns true if the directories \tt {/sys/class/gpio} and \tt {/sys/class/gpio/export} do exist. */
bool Gpio::isAvailable()
{
return QFile("/sys/class/gpio/export").exists();
}
/*! Returns the directory \tt {/sys/class/gpio/gpio<number>} of this Gpio. */
QString Gpio::gpioDirectory() const
{
return m_gpioDirectory.canonicalPath();
}
/*! Returns the number of this \l{Gpio}. \note The Gpio number is mostly not equivalent with the pin number. */
int Gpio::gpioNumber() const
{
return m_gpio;
}
/*! Returns true if this \l{Gpio} could be exported in the system file \tt {/sys/class/gpio/export}. If this Gpio is already exported, this function will return true. */
bool Gpio::exportGpio()
{
qCDebug(dcGpio()) << "Export GPIO" << m_gpio;
// Check if already exported
if (m_gpioDirectory.exists()) {
qCDebug(dcGpio()) << "GPIO" << m_gpio << "already exported.";
return true;
}
QFile exportFile("/sys/class/gpio/export");
if (!exportFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO export file:" << exportFile.errorString();
return false;
}
QTextStream out(&exportFile);
out << m_gpio;
exportFile.close();
return true;
}
/*! Returns true if this \l{Gpio} could be unexported in the system file \tt {/sys/class/gpio/unexport}. */
bool Gpio::unexportGpio()
{
qCDebug(dcGpio()) << "Unexport GPIO" << m_gpio;
QFile unexportFile("/sys/class/gpio/unexport");
if (!unexportFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO unexport file:" << unexportFile.errorString();
return false;
}
QTextStream out(&unexportFile);
out << m_gpio;
unexportFile.close();
return true;
}
/*! Returns true if the \a direction of this GPIO could be set. \sa Gpio::Direction, */
bool Gpio::setDirection(Gpio::Direction direction)
{
qCDebug(dcGpio()) << "Set GPIO" << m_gpio << "direction" << direction;
if (direction == Gpio::DirectionInvalid) {
qCWarning(dcGpio()) << "Setting an invalid direction is forbidden.";
return false;
}
QFile directionFile(m_gpioDirectory.path() + QDir::separator() + "direction");
if (!directionFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "direction file:" << directionFile.errorString();
return false;
}
m_direction = direction;
QTextStream out(&directionFile);
switch (m_direction) {
case DirectionInput:
out << "in";
break;
case DirectionOutput:
out << "out";
break;
default:
break;
}
directionFile.close();
return true;
}
/*! Returns the direction of this \l{Gpio}. */
Gpio::Direction Gpio::direction()
{
QFile directionFile(m_gpioDirectory.path() + QDir::separator() + "direction");
if (!directionFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "direction file:" << directionFile.fileName() << directionFile.errorString();
return Gpio::DirectionInvalid;
}
QString direction;
QTextStream in(&directionFile);
in >> direction;
directionFile.close();
if (direction == "in") {
m_direction = DirectionInput;
return Gpio::DirectionInput;
} else if (direction == "out") {
m_direction = DirectionOutput;
return Gpio::DirectionOutput;
}
return Gpio::DirectionInvalid;
}
/*! Returns true if the digital \a value of this \l{Gpio} could be set correctly. */
bool Gpio::setValue(Gpio::Value value)
{
qCDebug(dcGpio()) << "Set GPIO" << m_gpio << "value" << value;
// Check given value
if (value == Gpio::ValueInvalid) {
qCWarning(dcGpio()) << "Setting an invalid value is forbidden.";
return false;
}
// Check current direction
if (m_direction == Gpio::DirectionInput) {
qCWarning(dcGpio()) << "Setting the value of an input GPIO is forbidden.";
return false;
}
if (m_direction == Gpio::DirectionInvalid) {
qCWarning(dcGpio()) << "The direction of GPIO" << m_gpio << "is invalid.";
return false;
}
QFile valueFile(m_gpioDirectory.path() + QDir::separator() + "value");
if (!valueFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "value file:" << valueFile.errorString();
return false;
}
QTextStream out(&valueFile);
switch (value) {
case ValueLow:
out << "0";
break;
case ValueHigh:
out << "1";
break;
default:
valueFile.close();
return false;
}
valueFile.close();
return true;
}
/*! Returns the current digital value of this \l{Gpio}. */
Gpio::Value Gpio::value()
{
QFile valueFile(m_gpioDirectory.path() + QDir::separator() + "value");
if (!valueFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "value file:" << valueFile.errorString();
return Gpio::ValueInvalid;
}
QString value;
QTextStream in(&valueFile);
in >> value;
valueFile.close();
if (value == "0") {
return Gpio::ValueLow;
} else if (value == "1") {
return Gpio::ValueHigh;
}
return Gpio::ValueInvalid;
}
/*! This method allows to invert the logic of this \l{Gpio}. Returns true, if the GPIO could be set \a activeLow. */
bool Gpio::setActiveLow(bool activeLow)
{
qCDebug(dcGpio()) << "Set GPIO" << m_gpio << "active low" << activeLow;
QFile activeLowFile(m_gpioDirectory.path() + QDir::separator() + "active_low");
if (!activeLowFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "active_low file:" << activeLowFile.errorString();
return false;
}
QTextStream out(&activeLowFile);
if (activeLow) {
out << "0";
} else {
out << "1";
}
activeLowFile.close();
return true;
}
/*! Returns true if the logic of this \l{Gpio} is inverted (1 = low, 0 = high). */
bool Gpio::activeLow()
{
QFile activeLowFile(m_gpioDirectory.path() + QDir::separator() + "active_low");
if (!activeLowFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "active_low file:" << activeLowFile.errorString();
return false;
}
QString value;
QTextStream in(&activeLowFile);
in >> value;
activeLowFile.close();
if (value == "0")
return true;
return false;
}
/*! Returns true if the \a edge of this GPIO could be set correctly. The \a edge parameter specifies,
* when an interrupt occurs. */
bool Gpio::setEdgeInterrupt(Gpio::Edge edge)
{
if (m_direction == Gpio::DirectionOutput) {
qCWarning(dcGpio()) << "Could not set edge interrupt, GPIO is configured as an output.";
return false;
}
qCDebug(dcGpio()) << "Set GPIO" << m_gpio << "edge interrupt" << edge;
QFile edgeFile(m_gpioDirectory.path() + QDir::separator() + "edge");
if (!edgeFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "edge file:" << edgeFile.errorString();
return false;
}
QTextStream out(&edgeFile);
switch (edge) {
case EdgeFalling:
out << "falling";
break;
case EdgeRising:
out << "rising";
break;
case EdgeBoth:
out << "both";
break;
case EdgeNone:
out << "none";
break;
}
edgeFile.close();
return true;
}
/*! Returns the edge interrupt of this \l{Gpio}. */
Gpio::Edge Gpio::edgeInterrupt()
{
QFile edgeFile(m_gpioDirectory.path() + QDir::separator() + "edge");
if (!edgeFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
qCWarning(dcGpio()) << "Could not open GPIO" << m_gpio << "edge file:" << edgeFile.errorString();
return Gpio::EdgeNone;
}
QString edge;
QTextStream in(&edgeFile);
in >> edge;
edgeFile.close();
if (edge.contains("falling")) {
return Gpio::EdgeFalling;
} else if (edge.contains("rising")) {
return Gpio::EdgeRising;
} else if (edge.contains("both")) {
return Gpio::EdgeBoth;
} else if (edge.contains("none")) {
return Gpio::EdgeNone;
}
return Gpio::EdgeNone;
}
QDebug operator<<(QDebug debug, Gpio *gpio)
{
debug.nospace() << "Gpio(" << gpio->gpioNumber() << ", ";
if (gpio->direction() == Gpio::DirectionInput) {
debug.nospace() << "input, ";
switch (gpio->edgeInterrupt()) {
case Gpio::EdgeFalling:
debug.nospace() << "edge: falling, ";
break;
case Gpio::EdgeRising:
debug.nospace() << "edge: rising, ";
break;
case Gpio::EdgeBoth:
debug.nospace() << "edge: both, ";
break;
case Gpio::EdgeNone:
debug.nospace() << "edge: none, ";
break;
}
} else if (gpio->direction() == Gpio::DirectionOutput) {
debug.nospace() << "output, ";
} else {
debug.nospace() << "invalid, ";
}
if (gpio->activeLow()) {
debug.nospace() << "active low: 1, ";
} else {
debug.nospace() << "active low: 0, ";
}
if (gpio->value() == Gpio::ValueHigh) {
debug.nospace() << "value: 1";
} else if (gpio->value() == Gpio::ValueLow) {
debug.nospace() << "value: 0";
} else {
debug.nospace() << "value: invalid";
}
debug.nospace() << ")";
return debug.space();
}