#include <bus.hh>

Inheritance diagram for gem5::I2CBus:

Public Member Functions
	I2CBus (const I2CBusParams &p)
	4KB - see e.g.

Tick	read (PacketPtr pkt) override
	Reads will always be to SB_CONTROLS.

Tick	write (PacketPtr pkt) override
	The default i2c bus driver used by the realview pbx board writes to this device one bit at a time.

void	serialize (CheckpointOut &cp) const override
	Serialize an object.

void	unserialize (CheckpointIn &cp) override
	Unserialize an object.

Public Member Functions inherited from gem5::BasicPioDevice
	PARAMS (BasicPioDevice)

	BasicPioDevice (const Params &p, Addr size)

AddrRangeList	getAddrRanges () const override
	Determine the address ranges that this device responds to.

Public Member Functions inherited from gem5::PioDevice
	PioDevice (const Params &p)

virtual	~PioDevice ()

void	init () override
	init() is called after all C++ SimObjects have been created and all ports are connected.

Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID) override
	Get a port with a given name and index.

Public Member Functions inherited from gem5::ClockedObject
	ClockedObject (const ClockedObjectParams &p)

Public Member Functions inherited from gem5::SimObject
const Params &	params () const

	SimObject (const Params &p)

virtual	~SimObject ()

virtual void	loadState (CheckpointIn &cp)
	loadState() is called on each SimObject when restoring from a checkpoint.

virtual void	initState ()
	initState() is called on each SimObject when not restoring from a checkpoint.

virtual void	regProbePoints ()
	Register probe points for this object.

virtual void	regProbeListeners ()
	Register probe listeners for this object.

ProbeManager *	getProbeManager ()
	Get the probe manager for this object.

virtual void	startup ()
	startup() is the final initialization call before simulation.

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining.

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes.

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers.

void	serialize (CheckpointOut &cp) const override
	Serialize an object.

void	unserialize (CheckpointIn &cp) override
	Unserialize an object.

Public Member Functions inherited from gem5::EventManager
EventQueue *	eventQueue () const

void	schedule (Event &event, Tick when)

void	deschedule (Event &event)

void	reschedule (Event &event, Tick when, bool always=false)

void	schedule (Event *event, Tick when)

void	deschedule (Event *event)

void	reschedule (Event *event, Tick when, bool always=false)

void	wakeupEventQueue (Tick when=(Tick) -1)
	This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers.

void	setCurTick (Tick newVal)

	EventManager (EventManager &em)
	Event manger manages events in the event queue.

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

Public Member Functions inherited from gem5::Serializable
	Serializable ()

virtual	~Serializable ()

void	serializeSection (CheckpointOut &cp, const char *name) const
	Serialize an object into a new section.

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object.

void	unserializeSection (CheckpointIn &cp, const std::string &name)

Public Member Functions inherited from gem5::Drainable
DrainState	drainState () const
	Return the current drain state of an object.

virtual void	notifyFork ()
	Notify a child process of a fork.

Public Member Functions inherited from gem5::statistics::Group
	Group (Group parent, const char name=nullptr)
	Construct a new statistics group.

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters.

virtual void	resetStats ()
	Callback to reset stats.

virtual void	preDumpStats ()
	Callback before stats are dumped.

void	addStat (statistics::Info *info)
	Register a stat with this group.

const std::map< std::string, Group * > &	getStatGroups () const
	Get all child groups associated with this object.

const std::vector< Info * > &	getStats () const
	Get all stats associated with this object.

void	addStatGroup (const char name, Group block)
	Add a stat block as a child of this block.

const Info *	resolveStat (std::string name) const
	Resolve a stat by its name within this group.

void	mergeStatGroup (Group *block)
	Merge the contents (stats & children) of a block to this block.

	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

Public Member Functions inherited from gem5::Named
	Named (const std::string &name_)

virtual	~Named ()=default

virtual std::string	name () const

Public Member Functions inherited from gem5::Clocked
void	updateClockPeriod ()
	Update the tick to the current tick.

Tick	clockEdge (Cycles cycles=Cycles(0)) const
	Determine the tick when a cycle begins, by default the current one, but the argument also enables the caller to determine a future cycle.

Cycles	curCycle () const
	Determine the current cycle, corresponding to a tick aligned to a clock edge.

Tick	nextCycle () const
	Based on the clock of the object, determine the start tick of the first cycle that is at least one cycle in the future.

uint64_t	frequency () const

Tick	clockPeriod () const

double	voltage () const

Cycles	ticksToCycles (Tick t) const

Tick	cyclesToTicks (Cycles c) const

Protected Types
enum	I2CState { IDLE , RECEIVING_ADDR , RECEIVING_DATA , SENDING_DATA }

Protected Member Functions
void	updateSignals (PacketPtr pkt)
	Update data (sda) and clock (scl) to match any transitions specified by pkt.

bool	isClockSet (PacketPtr pkt) const
	Clock set check.

bool	isStart (PacketPtr pkt) const
	i2c start signal check

bool	isEnd (PacketPtr pkt) const
	i2c end signal check

Protected Member Functions inherited from gem5::Drainable
	Drainable ()

virtual	~Drainable ()

virtual void	drainResume ()
	Resume execution after a successful drain.

void	signalDrainDone () const
	Signal that an object is drained.

Protected Member Functions inherited from gem5::Clocked
	Clocked (ClockDomain &clk_domain)
	Create a clocked object and set the clock domain based on the parameters.

	Clocked (Clocked &)=delete

Clocked &	operator= (Clocked &)=delete

virtual	~Clocked ()
	Virtual destructor due to inheritance.

void	resetClock () const
	Reset the object's clock using the current global tick value.

virtual void	clockPeriodUpdated ()
	A hook subclasses can implement so they can do any extra work that's needed when the clock rate is changed.

Protected Attributes
uint8_t	scl
	I2C clock wire (0, 1).

uint8_t	sda
	I2C data wire (0, 1)

enum I2CState	state
	State used by I2CBus::write to determine what stage of an i2c transmission it is currently in.

int	currBit
	Order of the bit of the current message that is being sent or received (0 - 7).

uint8_t	i2cAddr
	Key used to access a device in the slave devices map.

uint8_t	message
	8-bit buffer used to send and receive messages bit by bit.

std::map< uint8_t, I2CDevice * >	devices
	All the slave i2c devices that are connected to this bus.

Protected Attributes inherited from gem5::BasicPioDevice
Addr	pioAddr
	Address that the device listens to.

Addr	pioSize
	Size that the device's address range.

Tick	pioDelay
	Delay that the device experinces on an access.

Protected Attributes inherited from gem5::PioDevice
System *	sys

PioPort< PioDevice >	pioPort
	The pioPort that handles the requests for us and provides us requests that it sees.

Protected Attributes inherited from gem5::SimObject
const SimObjectParams &	_params
	Cached copy of the object parameters.

Protected Attributes inherited from gem5::EventManager
EventQueue *	eventq
	A pointer to this object's event queue.

Static Protected Attributes
static const int	SB_CONTROLS = 0x0
	Read [and Set] serial control bits: Bit [0] is SCL Bit [1] is SDA.

static const int	SB_CONTROLC = 0x4
	Clear control bits.

Additional Inherited Members
Public Types inherited from gem5::PioDevice
using	Params = PioDeviceParams

Public Types inherited from gem5::ClockedObject
using	Params = ClockedObjectParams
	Parameters of ClockedObject.

Public Types inherited from gem5::SimObject
typedef SimObjectParams	Params

Static Public Member Functions inherited from gem5::SimObject
static void	serializeAll (const std::string &cpt_dir)
	Create a checkpoint by serializing all SimObjects in the system.

static SimObject *	find (const char *name)
	Find the SimObject with the given name and return a pointer to it.

static void	setSimObjectResolver (SimObjectResolver *resolver)
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

static SimObjectResolver *	getSimObjectResolver ()
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

Static Public Member Functions inherited from gem5::Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section.

static void	generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
	Generate a checkpoint file so that the serialization can be routed to it.

Public Attributes inherited from gem5::ClockedObject
PowerState *	powerState

Detailed Description

Definition at line 56 of file bus.hh.

Member Enumeration Documentation

◆ I2CState

enum gem5::I2CBus::I2CState

protected

Enumerator
IDLE
RECEIVING_ADDR
RECEIVING_DATA
SENDING_DATA

Definition at line 60 of file bus.hh.

Constructor & Destructor Documentation

◆ I2CBus()

gem5::I2CBus::I2CBus ( const I2CBusParams & p )

4KB - see e.g.

http://infocenter.arm.com/help/topic/com.arm.doc.dui0440b/Bbajihec.html

Definition at line 58 of file bus.cc.

References gem5::ArmISA::d, devices, and gem5::MipsISA::p.

Member Function Documentation

◆ isClockSet()

bool gem5::I2CBus::isClockSet ( PacketPtr pkt ) const

protected

Clock set check.

Parameters

pkt	memory request packet

Returns: true if pkt indicates that scl transition from 0 to 1

Definition at line 196 of file bus.cc.

References gem5::Packet::getAddr(), gem5::Packet::getRaw(), gem5::BasicPioDevice::pioAddr, and SB_CONTROLS.

Referenced by write().

◆ isEnd()

bool gem5::I2CBus::isEnd ( PacketPtr pkt ) const

protected

i2c end signal check

Parameters

pkt	memory request packet

Returns: true if pkt indicates stopping the current transmission

Definition at line 212 of file bus.cc.

References gem5::Packet::getAddr(), gem5::Packet::getRaw(), gem5::BasicPioDevice::pioAddr, SB_CONTROLS, and scl.

Referenced by write().

◆ isStart()

bool gem5::I2CBus::isStart ( PacketPtr pkt ) const

protected

i2c start signal check

Parameters

pkt	memory request packet

Returns: true if pkt indicates a new transmission

Definition at line 204 of file bus.cc.

References gem5::Packet::getAddr(), gem5::Packet::getRaw(), gem5::BasicPioDevice::pioAddr, SB_CONTROLC, and scl.

Referenced by write().

◆ read()

Tick gem5::I2CBus::read ( PacketPtr pkt )

overridevirtual

Reads will always be to SB_CONTROLS.

The kernel wants to know the state of sda and scl.

Implements gem5::PioDevice.

Definition at line 74 of file bus.cc.

References gem5::Packet::getAddr(), gem5::Packet::makeAtomicResponse(), gem5::BasicPioDevice::pioAddr, gem5::BasicPioDevice::pioDelay, SB_CONTROLS, scl, sda, and gem5::Packet::setRaw().

◆ serialize()

void gem5::I2CBus::serialize ( CheckpointOut & cp ) const

overridevirtual

Serialize an object.

Output an object's state into the current checkpoint section.

Parameters

cp	Checkpoint state

Reimplemented from gem5::ClockedObject.

Definition at line 219 of file bus.cc.

References currBit, DPRINTF, i2cAddr, message, scl, sda, SERIALIZE_ENUM, SERIALIZE_SCALAR, and state.

◆ unserialize()

void gem5::I2CBus::unserialize ( CheckpointIn & cp )

overridevirtual

Unserialize an object.

Read an object's state from the current checkpoint section.

Parameters

cp	Checkpoint state

Reimplemented from gem5::ClockedObject.

Definition at line 231 of file bus.cc.

References currBit, DPRINTF, i2cAddr, message, scl, sda, state, UNSERIALIZE_ENUM, and UNSERIALIZE_SCALAR.

◆ updateSignals()

void gem5::I2CBus::updateSignals ( PacketPtr pkt )

protected

Update data (sda) and clock (scl) to match any transitions specified by pkt.

Parameters

pkt	memory request packet

Definition at line 176 of file bus.cc.

References gem5::Packet::getAddr(), gem5::Packet::getRaw(), gem5::BasicPioDevice::pioAddr, SB_CONTROLC, SB_CONTROLS, scl, and sda.

Referenced by write().

◆ write()

Tick gem5::I2CBus::write ( PacketPtr pkt )

overridevirtual

The default i2c bus driver used by the realview pbx board writes to this device one bit at a time.

To facilitate making new i2c devices, i2cBus::write takes care of the low-level details of the i2c protocol. See the I2C Specification [1] for a detailed description of the protocol.

[1] - http://www.nxp.com/documents/user_manual/UM10204.pdf

Implements gem5::PioDevice.

Definition at line 93 of file bus.cc.

References currBit, gem5::ArmISA::d, devices, gem5::Packet::getAddr(), i2cAddr, IDLE, isClockSet(), isEnd(), isStart(), message, panic, gem5::BasicPioDevice::pioAddr, gem5::BasicPioDevice::pioDelay, RECEIVING_ADDR, RECEIVING_DATA, SB_CONTROLC, SB_CONTROLS, sda, SENDING_DATA, state, and updateSignals().

Member Data Documentation

◆ currBit

int gem5::I2CBus::currBit

protected

Order of the bit of the current message that is being sent or received (0 - 7).

Definition at line 94 of file bus.hh.

Referenced by serialize(), unserialize(), and write().

◆ devices

std::map<uint8_t, I2CDevice*> gem5::I2CBus::devices

protected

All the slave i2c devices that are connected to this bus.

Each device has an address that points to the actual device.

Definition at line 111 of file bus.hh.

Referenced by I2CBus(), and write().

◆ i2cAddr

uint8_t gem5::I2CBus::i2cAddr

protected

Key used to access a device in the slave devices map.

This is the same address that is specified in kernel board initialization code (e.g., arch/arm/mach-realview/core.c).

Definition at line 101 of file bus.hh.

Referenced by serialize(), unserialize(), and write().

◆ message

uint8_t gem5::I2CBus::message

protected

8-bit buffer used to send and receive messages bit by bit.

Definition at line 104 of file bus.hh.

Referenced by serialize(), unserialize(), and write().

◆ SB_CONTROLC

const int gem5::I2CBus::SB_CONTROLC = 0x4

staticprotected

Clear control bits.

Analogous to SB_CONTROLS

Definition at line 77 of file bus.hh.

Referenced by isStart(), updateSignals(), and write().

◆ SB_CONTROLS

const int gem5::I2CBus::SB_CONTROLS = 0x0

staticprotected

Read [and Set] serial control bits: Bit [0] is SCL Bit [1] is SDA.

http://infocenter.arm.com/help/topic/com.arm.doc.dui0440b/Bbajdjeg.html

Definition at line 75 of file bus.hh.

Referenced by isClockSet(), isEnd(), read(), updateSignals(), and write().

◆ scl

uint8_t gem5::I2CBus::scl

protected

I2C clock wire (0, 1).

Definition at line 80 of file bus.hh.

Referenced by isEnd(), isStart(), read(), serialize(), unserialize(), and updateSignals().

◆ sda

uint8_t gem5::I2CBus::sda

protected

I2C data wire (0, 1)

Definition at line 82 of file bus.hh.

Referenced by read(), serialize(), unserialize(), updateSignals(), and write().

◆ state

enum I2CState gem5::I2CBus::state

protected

State used by I2CBus::write to determine what stage of an i2c transmission it is currently in.

Definition at line 88 of file bus.hh.

Referenced by serialize(), unserialize(), and write().

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

dev/i2c/bus.hh
dev/i2c/bus.cc

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Static Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ I2CState

Constructor & Destructor Documentation

◆ I2CBus()

Member Function Documentation

◆ isClockSet()

◆ isEnd()

◆ isStart()

◆ read()

◆ serialize()

◆ unserialize()

◆ updateSignals()

◆ write()

Member Data Documentation

◆ currBit

◆ devices

◆ i2cAddr

◆ message

◆ SB_CONTROLC

◆ SB_CONTROLS

◆ scl

◆ sda

◆ state