A GPIO implementation using the Linux kernel's userspace interface in syfs. More...

#include <SysFsPort.hpp>

Inheritance diagram for duds::hardware::interface::linux::SysFsPort:

Collaboration diagram for duds::hardware::interface::linux::SysFsPort:

Classes
class	FsPin

Public Member Functions
	SysFsPort (const std::vector< unsigned int > &ids, unsigned int firstid)
	Make a SysFsPort object with the given pins. More...

virtual	~SysFsPort ()

virtual bool	simultaneousOperations () const
	The sysfs interface does not support simultaneous operations; returns false. More...

Public Member Functions inherited from duds::hardware::interface::DigitalPortIndependentPins
virtual bool	independentConfig () const
	Always true. More...

virtual bool	independentConfig (unsigned int, const DigitalPinConfig &, const DigitalPinConfig &) const
	Always true. More...

Public Member Functions inherited from duds::hardware::interface::DigitalPort
virtual	~DigitalPort ()
	Derived classes should call shutdown() early in their destructors. More...

void	access (const unsigned int pins, const unsigned int len, std::unique_ptr< DigitalPinAccess > acc)
	Obtain access objects to use a set of pins. More...

template<std::size_t Len>
void	access (const unsigned int pins[Len], std::unique_ptr< DigitalPinAccess > acc[Len])

std::unique_ptr< DigitalPinAccess >	access (const unsigned int pin)

void	access (const unsigned int pins, const unsigned int len, DigitalPinAccess acc)
	Obtain access objects to use a set of pins. More...

void	access (const std::vector< unsigned int > &pins, DigitalPinAccess *acc)

template<std::size_t alen, std::size_t plen>
void	access (const unsigned int pins[plen], DigitalPinAccess acc[alen])
	This is a nice idea that may fail at compile time. More...

void	access (const unsigned int *pins, const unsigned int len, DigitalPinSetAccess &acc)
	Obtain access objects to use a set of pins. More...

void	access (const unsigned int begin, const unsigned int end, DigitalPinSetAccess &acc)

void	access (const std::vector< unsigned int > &pins, DigitalPinSetAccess &acc)

std::unique_ptr< DigitalPinSetAccess >	access (const std::vector< unsigned int > &pins)

template<class InputIter >
void	access (const InputIter &begin, const InputIter &end, DigitalPinSetAccess &acc)

DigitalPinCap	capabilities (unsigned int globalPinId) const
	Returns the capabilities of a pin. More...

std::vector< DigitalPinCap >	capabilities () const
	Returns the capabilities of all pins in the port. More...

std::vector< DigitalPinCap >	capabilities (const std::vector< unsigned int > &pvec) const
	Returns the capabilities of all the pins requested by global ID. More...

std::vector< DigitalPinCap >	capabilitiesLocalIds (const std::vector< unsigned int > &pvec) const
	Returns the capabilities of all the pins requested by local ID. More...

DigitalPinConfig	configuration (unsigned int globalPinId) const
	Returns the current configuration of a pin. More...

std::vector< DigitalPinConfig >	configuration () const
	Returns the configuration of all pins in the port. More...

std::vector< DigitalPinConfig >	configuration (const std::vector< unsigned int > &pvec) const
	Returns the configuration of all the pins requested by global ID. More...

std::vector< DigitalPinConfig >	configurationLocalIds (const std::vector< unsigned int > &pvec) const
	Returns the configuration of all the pins requested by local ID. More...

bool	exists (unsigned int gid) const
	Returns true if the pin exists in this port. More...

unsigned int	globalId (unsigned int localId) const
	Returns the global ID for a pin given the local ID. More...

std::vector< unsigned int >	globalIds (const std::vector< unsigned int > &localIds) const
	Converts the provided local pin IDs to global pin IDs. More...

unsigned int	localId (unsigned int globalId) const
	Returns the local ID for a pin given the global ID. More...

std::vector< unsigned int >	localIds (const std::vector< unsigned int > &globalIds) const
	Converts the provided global pin IDs to local pin IDs. More...

unsigned int	offset () const
	Returns the offset for the port's pins. More...

void	poll ()

void	pollInput ()

void	pollSignal ()

DigitalPinRejectedConfiguration::Reason	proposeConfig (unsigned int gid, DigitalPinConfig &pconf, DigitalPinConfig &iconf) const
	Proposes a configuration change for a single pin. More...

DigitalPinRejectedConfiguration::Reason	proposeConfig (unsigned int gid, DigitalPinConfig &pconf) const
	Proposes a configuration change for a single pin from the port's current configuration. More...

bool	proposeConfig (const std::vector< unsigned int > &globalPinIds, std::vector< DigitalPinConfig > &propConf, std::vector< DigitalPinConfig > &initConf, std::function< void(DigitalPinRejectedConfiguration::Reason)> insertReason=std::function< void(DigitalPinRejectedConfiguration::Reason)>()) const

bool	proposeConfig (const std::vector< unsigned int > &pins, std::vector< DigitalPinConfig > &propConf, std::function< void(DigitalPinRejectedConfiguration::Reason)> insertReason=std::function< void(DigitalPinRejectedConfiguration::Reason)>()) const

bool	proposeConfigLocalIds (const std::vector< unsigned int > &localPinIds, std::vector< DigitalPinConfig > &propConf, std::vector< DigitalPinConfig > &initConf, std::function< void(DigitalPinRejectedConfiguration::Reason)> insertReason=std::function< void(DigitalPinRejectedConfiguration::Reason)>()) const

bool	proposeConfigLocalIds (const std::vector< unsigned int > &pins, std::vector< DigitalPinConfig > &propConf, std::function< void(DigitalPinRejectedConfiguration::Reason)> insertReason=std::function< void(DigitalPinRejectedConfiguration::Reason)>()) const

bool	proposeFullConfig (std::vector< DigitalPinConfig > &propConf, std::vector< DigitalPinConfig > &initConf, std::function< void(DigitalPinRejectedConfiguration::Reason)> insertReason=std::function< void(DigitalPinRejectedConfiguration::Reason)>()) const

unsigned int	size () const
	The maximum number of pins on the port. More...

Static Public Member Functions
static std::shared_ptr< SysFsPort >	makeConfiguredPort (PinConfiguration &pc, const std::string &name="default")
	Make a SysFsPort object according to the given configuration, and attach to the configuration. More...

Protected Member Functions
virtual void	configurePort (unsigned int localPinId, const DigitalPinConfig &cfg, DigitalPinAccessBase::PortData *)
	Changes the hardware configuration for a single pin. More...

virtual bool	inputImpl (unsigned int gid, DigitalPinAccessBase::PortData *)
	Reads input from the given pin. More...

virtual void	outputImpl (unsigned int lid, bool state, DigitalPinAccessBase::PortData *)
	Changes the output state of the given pin. More...

Protected Member Functions inherited from duds::hardware::interface::DigitalPortIndependentPins
	DigitalPortIndependentPins (unsigned int numpins, unsigned int firstid)

virtual void	configurePort (const std::vector< DigitalPinConfig > &cfgs, DigitalPinAccessBase::PortData *pdata)
	Changes the hardware configuration for the whole port by calling configurePort(const DigitalPinConfig &, unsigned int, DigitalPinAccessBase::PortData *) for each pin. More...

virtual DigitalPinRejectedConfiguration::Reason	proposeConfigImpl (unsigned int gid, DigitalPinConfig &pconf, DigitalPinConfig &iconf) const
	Considers the proposed configuration for one pin. More...

virtual bool	proposeConfigImpl (const std::vector< unsigned int > &localPinIds, std::vector< DigitalPinConfig > &propConf, std::vector< DigitalPinConfig > &initConf, std::function< void(DigitalPinRejectedConfiguration::Reason)> insertReason=std::function< void(DigitalPinRejectedConfiguration::Reason)>()) const
	Considers the proposed configuration one pin at a time in the order specified in pins. More...

virtual bool	proposeFullConfigImpl (std::vector< DigitalPinConfig > &propConf, std::vector< DigitalPinConfig > &initConf, std::function< void(DigitalPinRejectedConfiguration::Reason)> insertReason=std::function< void(DigitalPinRejectedConfiguration::Reason)>()) const
	Considers the proposed configuration one pin at a time for all pins in the port. More...

Protected Member Functions inherited from duds::hardware::interface::DigitalPort
	DigitalPort (unsigned int numpins, unsigned int firstid)
	Initializes internal data. More...

std::vector< DigitalPinCap >	capabilities (const std::vector< unsigned int > &pvec, bool global) const

const DigitalPinConfig &	configRef (unsigned int localPinId) const
	Returns a reference to a pin's configuration on behalf of an access object. More...

std::vector< DigitalPinConfig >	configuration (const std::vector< unsigned int > &pvec, bool global) const

std::vector< DigitalPinConfig >	configurationImpl () const
	Returns the configuration of all pins in the port. More...

bool	input (unsigned int gid, DigitalPinAccessBase::PortData *pdata)
	Does error checking in advance of calling inputImpl(unsigned int) to read the input of the given pin. More...

std::vector< bool >	input (const std::vector< unsigned int > &pvec, DigitalPinAccessBase::PortData *pdata)
	Does error checking in advance of calling inputImpl(const std::vector<unsigned int> &) to read the input of a set of pins. More...

virtual std::vector< bool >	inputImpl (const std::vector< unsigned int > &pvec, DigitalPinAccessBase::PortData *pdata)
	Reads input from the requested pins. More...

virtual void	madeAccess (DigitalPinAccess &acc)
	Called after a new access object is made to allow a port implementation to take further action. More...

virtual void	madeAccess (DigitalPinSetAccess &acc)
	Called after a new access object is made to allow a port implementation to take further action. More...

DigitalPinConfig	modifyConfig (unsigned int globalPinId, const DigitalPinConfig &cfg, DigitalPinAccessBase::PortData *pdata)
	Modifies the configuration of a single pin with an independent configuration. More...

void	modifyConfig (std::vector< DigitalPinConfig > &cfgs, DigitalPinAccessBase::PortData *pdata)
	Modifies the configuration of multiple pins. More...

void	modifyConfig (const std::vector< unsigned int > &pvec, std::vector< DigitalPinConfig > &cfgs, DigitalPinAccessBase::PortData *pdata)

void	modifyFullConfig (std::vector< DigitalPinConfig > &propConf, std::vector< DigitalPinConfig > &initConf, DigitalPinAccessBase::PortData *pdata)
	Does the work of the modifyConfig() functions in the case that the whole port configuration must be considered for possible changes. More...

void	output (unsigned int gid, bool state, DigitalPinAccessBase::PortData *pdata)
	Does error checking in advance of calling outputImpl(unsigned int, bool) to change the output of the given pin. More...

void	output (const std::vector< unsigned int > &pvec, const std::vector< bool > &state, DigitalPinAccessBase::PortData *pdata)
	Does error checking in advance of calling outputImpl(const std::vector<unsigned int> &,const std::vector<bool> &) to change the output of a set of pins. More...

virtual void	outputImpl (const std::vector< unsigned int > &pvec, const std::vector< bool > &state, DigitalPinAccessBase::PortData *pdata)
	Changes the outputs of several pins. More...

virtual void	retiredAccess (const DigitalPinAccess &acc) noexcept
	Called just before an access object is retired to allow a port implementation to take further action. More...

virtual void	retiredAccess (const DigitalPinSetAccess &acc) noexcept
	Called just before an access object is retired to allow a port implementation to take further action. More...

void	shutdown ()
	Waits for access to all pins so that any user of access objects may finish with their operation, then destroys all pin data and awakens threads waiting on access, but they will not receive access. More...

Private Types
typedef std::vector< FsPin >	FsPinVector

Private Attributes
FsPinVector	fspins
	Internal pin objects for each pin that will be made available through this port object. More...

Additional Inherited Members
Protected Types inherited from duds::hardware::interface::DigitalPort
typedef std::vector< PinEntry >	PinVector

Static Protected Member Functions inherited from duds::hardware::interface::DigitalPort
static DigitalPinAccessBase::PortData &	portData (const DigitalPinAccessBase &acc)
	Returns a reference to the port specific data in the given DigitalPinAccessBase object. More...

template<typename T >
static void	portDataPtr (const DigitalPinAccessBase &acc, T **ptr)
	Provides a pointer to type T stored in the port specific data of the given DigitalPinAccessBase object. More...

Protected Attributes inherited from duds::hardware::interface::DigitalPort
PinVector	pins
	Data on each pin handled by the port. More...

Detailed Description

A GPIO implementation using the Linux kernel's userspace interface in syfs.

This implementation expects that the pins to use have already been exported and the process has adequate access rights to use the pins.

Support is provided for read-only value and direction files. A read-only value forces the pin to be input only. A read-only direction forces the pin to remain in the direction indicated by the file. If both files are read-only and the direction reads back as "out", open() will throw a PinUnsupportedOperation exception to indicate a useless state.

It is assumed that the process using this object for a given pin will be the only process on the host using the pin. This should be a fairly safe assumption since it should only be violated by bad behavior. A host can be configured using specific user accounts or groups to limit access to the pins to particular processes to help enforce good behavior. This can also be used to force a particlar I/O direction and make this class report it in the pin's capabilities.

Author: Jeff Jackowski

Definition at line 45 of file SysFsPort.hpp.

Member Typedef Documentation

◆ FsPinVector

typedef std::vector<FsPin> duds::hardware::interface::linux::SysFsPort::FsPinVector

private

Definition at line 138 of file SysFsPort.hpp.

Constructor & Destructor Documentation

◆ SysFsPort()

duds::hardware::interface::linux::SysFsPort::SysFsPort	(	const std::vector< unsigned int > &	ids,
		unsigned int	firstid
	)

Make a SysFsPort object with the given pins.

Parameters

ids	The pin numbers from the filesystem. The index of each inside ids will be the local pin ID used by this port. A value of -1 will create an unavailable pin and may be used multiple times. Other values must only be used once.
firstid	The gloabl ID that will be assigned to the first pin (local ID zero) of this port.

Exceptions

PinIoError	A required file could not be opened.
PinUnsupportedOperation	A pin has read-only value and direction files with the direction set to output.

Definition at line 19 of file SysFsPort.cpp.

◆ ~SysFsPort()

duds::hardware::interface::linux::SysFsPort::~SysFsPort ( )

virtual

Definition at line 68 of file SysFsPort.cpp.

Member Function Documentation

◆ configurePort()

void duds::hardware::interface::linux::SysFsPort::configurePort	(	unsigned int	localPinId,
		const DigitalPinConfig &	cfg,
		DigitalPinAccessBase::PortData *	pdata
	)

protectedvirtual

Changes the hardware configuration for a single pin.

If this function does not throw, its caller will record the configuration change inside pins. It is only called after error checking is performed on its parameters.

Parameters

cfg	The new configuration.
localPinId	The local ID for the pin to modify.
pdata	A pointer to the port specific data stored in the corresponding access object for the pin.

Bug:: Is this the right place for such a check? Should it be done by the caller?

Implements duds::hardware::interface::DigitalPortIndependentPins.

Definition at line 77 of file SysFsPort.cpp.

◆ inputImpl()

bool duds::hardware::interface::linux::SysFsPort::inputImpl	(	unsigned int	gid,
		DigitalPinAccessBase::PortData *	pdata
	)

protectedvirtual

Reads input from the given pin.

Precondition: The pin is configured as an input.

Parameters

gid	The global ID of the pin to read.
pdata	A pointer to the port specific data stored in the corresponding access object for the pin.

Implements duds::hardware::interface::DigitalPort.

Definition at line 97 of file SysFsPort.cpp.

◆ makeConfiguredPort()

std::shared_ptr< SysFsPort > duds::hardware::interface::linux::SysFsPort::makeConfiguredPort	(	PinConfiguration &	pc,
		const std::string &	name = `"default"`
	)

static

Make a SysFsPort object according to the given configuration, and attach to the configuration.

Parameters

pc	The object with the port configuration data.
name	The name of the port in the configuration.

Exceptions

PortDoesNotExistError There is no port called name in the given configuration.

Examples:: clockLCD.cpp, and st7920.cpp.

Definition at line 40 of file SysFsPort.cpp.

◆ outputImpl()

void duds::hardware::interface::linux::SysFsPort::outputImpl	(	unsigned int	lid,
		bool	state,
		DigitalPinAccessBase::PortData *	pdata
	)

protectedvirtual

Changes the output state of the given pin.

If the pin is not configured as an output, its configuration will not change. However, this new state will be the output state once the configuration is changed to output.

Precondition: The pin is capable of output.

Parameters

lid	The local ID of the pin to change.
state	The new output state.
pdata	A pointer to the port specific data stored in the corresponding access object for the pin.

Implements duds::hardware::interface::DigitalPort.

Definition at line 105 of file SysFsPort.cpp.

◆ simultaneousOperations()

bool duds::hardware::interface::linux::SysFsPort::simultaneousOperations ( ) const

virtual

The sysfs interface does not support simultaneous operations; returns false.

Implements duds::hardware::interface::DigitalPort.

Definition at line 73 of file SysFsPort.cpp.

Member Data Documentation

◆ fspins

FsPinVector duds::hardware::interface::linux::SysFsPort::fspins

private

Internal pin objects for each pin that will be made available through this port object.

Definition at line 143 of file SysFsPort.hpp.

Referenced by configurePort(), inputImpl(), outputImpl(), and SysFsPort().

The documentation for this class was generated from the following files:

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Private Types

Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ FsPinVector

Constructor & Destructor Documentation

◆ SysFsPort()

◆ ~SysFsPort()

Member Function Documentation

◆ configurePort()

◆ inputImpl()

◆ makeConfiguredPort()

◆ outputImpl()

◆ simultaneousOperations()

Member Data Documentation

◆ fspins