Driver for the OpenTitan's I2C block. More...

#include <platform-i2c.hh>

Inheritance diagram for OpenTitanI2c:

Collaboration diagram for OpenTitanI2c:

Public Types
enum class	Interrupt { FormatThreshold , ReceiveThreshold , AcquiredThreshold , ReceiveOverflow , ControllerHalt , SclInterference , SdaInterference , StretchTimeout , SdaUnstable , CommandComplete , TransmitStretch , TransmitThreshold , AcquiredFull , UnexpectedStop , HostTimeout }
	The interrupts of the OpenTitan's I2C block. More...
enum	: uint32_t { ControlEnableHost = 1 << 0 , ControlEnableTarget = 1 << 1 , ControlLineLoopback = 1 << 2 , ControlNackAddressAfterTimeout = 1 << 3 , ControlAckControlEnable = 1 << 4 , ControlMultiControllerMonitorEnable = 1 << 5 , ControlTransmitStretchEnable = 1 << 6 }
	Control Register Fields. More...
enum	: uint32_t { StatusFormatFull = 1 << 0 , StatusReceiveFull = 1 << 1 , StatusFormatEmpty = 1 << 2 , StatusHostIdle = 1 << 3 , StatusTargetIdle = 1 << 4 , SmatusReceiveEmpty = 1 << 5 , StatusTransmitFull = 1 << 6 , StatusAcquiredFull = 1 << 7 , StatusTransmitEmpty = 1 << 8 , StatusAcquiredEmpty = 1 << 9 , StatusAckControlStretch = 1 << 10 }
	Status Register Fields. More...
enum	: uint32_t { FormatDataStart = 1 << 8 , FormatDataStop = 1 << 9 , FormatDataReadBytes = 1 << 10 , FormatDataReadCount = 1 << 11 , FormatDataNakOk = 1 << 12 }
	FormatData Register Fields. More...
enum	: uint32_t { FifoControlReceiveReset = 1 << 0 , FifoControlFormatReset = 1 << 1 , FifoControlAcquiredReset = 1 << 7 , FifoControlTransmitReset = 1 << 8 }
	FifoControl Register Fields. More...
enum	: uint32_t { ControllerEventsNack = 1 << 0 , ControllerEventsUnhandledNackTimeout = 1 << 1 , ControllerEventsBusTimeout = 1 << 2 , ControllerEventsArbitrationLost = 1 << 3 }
	ControllerEvents Register Fields. More...
enum	: uint32_t { ControlEnableHost = 1 << 0 , ControlEnableTarget = 1 << 1 , ControlLineLoopback = 1 << 2 }
	Control Register Fields. More...
enum	: uint32_t { StatusFormatFull = 1 << 0 , StatusReceiveFull = 1 << 1 , StatusFormatEmpty = 1 << 2 , StatusHostIdle = 1 << 3 , StatusTargetIdle = 1 << 4 , SmatusReceiveEmpty = 1 << 5 , StatusTransmitFull = 1 << 6 , StatusAcquiredFull = 1 << 7 , StatusTransmitEmpty = 1 << 8 , StatusAcquiredEmpty = 1 << 9 , StatusHostDisabledNackTimeout = 1 << 10 }
	Status Register Fields. More...
enum	: uint32_t { FormatDataStart = 1 << 8 , FormatDataStop = 1 << 9 , FormatDataReadBytes = 1 << 10 , FormatDataReadCount = 1 << 11 , FormatDataNakOk = 1 << 12 }
	FormatData Register Fields. More...
enum	: uint32_t { FifoControlReceiveReset = 1 << 0 , FifoControlFormatReset = 1 << 1 , FifoControlAcquiredReset = 1 << 7 , FifoControlTransmitReset = 1 << 8 }
	FifoControl Register Fields. More...
using	Debug = ConditionalDebug<DebugOpenTitanI2c, "OpenTitan I2C">
	Helper for conditional debug logs and assertions.
using	Debug = ConditionalDebug<DebugOpenTitanI2c, "OpenTitan I2C">
	Helper for conditional debug logs and assertions.

Public Member Functions
uint32_t	reset_controller_events () volatile
	Reset the controller Events so that the ControllerHalt interrupt will be released, allowing the I2C driver to continue after the controller FSM has halted due to e.g.
void	reset_fifos () volatile
	Reset all of the fifos.
void	host_mode_set () volatile
	Configure the I2C block to be in host mode.
void	speed_set (const uint32_t SpeedKhz) volatile
	Set the I2C timing parameters appropriately for the given bit rate.
void	blocking_write_byte (const uint32_t Fmt) volatile
bool	format_is_empty () volatile
	Returns true when the format fifo is empty.
bool	blocking_write (const uint8_t Addr7, const uint8_t data[], const uint32_t NumBytes, const bool SkipStop) volatile
bool	blocking_read (const uint8_t Addr7, uint8_t buf[], const uint32_t NumBytes) volatile
bool	interrupt_is_asserted (Interrupt interrupt) volatile
	Returns true if the given interrupt is asserted.
void	interrupt_clear (Interrupt interrupt) volatile
	Clears the given interrupt.
void	interrupt_enable (Interrupt interrupt) volatile
	Enables the given interrupt.
void	interrupt_disable (Interrupt interrupt) volatile
	Disables the given interrupt.
void	host_thresholds_set (uint16_t formatThreshold, uint16_t receiveThreshold) volatile
	Sets the thresholds for the format and receive fifos.
void	reset_fifos () volatile
	Reset all of the fifos.
void	host_mode_set () volatile
	Configure the I2C block to be in host mode.
void	speed_set (const uint32_t SpeedKhz) volatile
	Set the I2C timing parameters appropriately for the given bit rate.
void	blocking_write_byte (const uint32_t Fmt) volatile
bool	format_is_empty () volatile
	Returns true when the format fifo is empty.
void	blocking_write (const uint8_t Addr7, const uint8_t data[], const uint32_t NumBytes, const bool SkipStop) volatile
bool	blocking_read (const uint8_t Addr7, uint8_t buf[], const uint32_t NumBytes) volatile
bool	interrupt_is_asserted (OpenTitanI2cInterrupt interrupt) volatile
	Returns true if the given interrupt is asserted.
void	interrupt_clear (OpenTitanI2cInterrupt interrupt) volatile
	Clears the given interrupt.
void	interrupt_enable (OpenTitanI2cInterrupt interrupt) volatile
	Enables the given interrupt.
void	interrupt_disable (OpenTitanI2cInterrupt interrupt) volatile
	Disables the given interrupt.
void	host_thresholds_set (uint16_t formatThreshold, uint16_t receiveThreshold) volatile
	Sets the thresholds for the format and receive fifos.

Static Public Member Functions
static constexpr uint32_t	interrupt_bit (const InterruptInterrupt InterruptInterrupt)
static uint16_t	round_up_divide (uint32_t a, uint32_t b)
	Performs a 32-bit integer unsigned division, rounding up.
static uint16_t	round_up_divide (uint32_t a, uint32_t b)
	Performs a 32-bit integer unsigned division, rounding up.

Public Attributes
uint32_t	interruptState
	Interrupt State Register.
uint32_t	interruptEnable
	Interrupt Enable Register.
uint32_t	interruptTest
	Interrupt Test Register.
uint32_t	alertTest
	Alert Test Register (Unused in Sonata).
uint32_t	control
	I2C Control Register.
uint32_t	status
	I2C Live Status Register for Host and Target modes.
uint32_t	readData
	I2C Read Data.
uint32_t	formatData
	I2C Host Format Data.
uint32_t	fifoCtrl
	I2C FIFO control register.
uint32_t	hostFifoConfiguration
	Host mode FIFO configuration.
uint32_t	targetFifoConfiguration
	Target mode FIFO configuration.
uint32_t	hostFifoStatus
	Host mode FIFO status register.
uint32_t	targetFifoStatus
	Target mode FIFO status register.
uint32_t	override
	I2C Override Control Register.
uint32_t	values
	Oversampled Receive values.
uint32_t	timing [5]
	Detailed I2C Timings (directly corresponding to table 10 in the I2C Specification).
uint32_t	timeoutControl
	I2C clock stretching timeout control.
uint32_t	targetId
	I2C target address and mask pairs.
uint32_t	acquiredData
	I2C target acquired data.
uint32_t	transmitData
	I2C target transmit data.
uint32_t	hostTimeoutControl
	I2C host clock generation timeout value (in units of input clock frequency).
uint32_t	targetTimeoutControl
	I2C target internal stretching timeout control.
uint32_t	targetNackCount
	Number of times the I2C target has NACK'ed a new transaction since the last read of this register.
uint32_t	targetAckControl
	Controls for mid-transfer (N)ACK phase handling.
uint32_t	acquireFifoNextData
	The data byte pending to be written to the Acquire (ACQ) FIFO.
uint32_t	hostNackHandlerTimeout
	Timeout in Host-Mode for an unhandled NACK before hardware automatically ends the transaction.
uint32_t	controllerEvents
	Latched events that explain why the controller halted.
uint32_t	targetEvents
	Latched events that can cause the target module to stretch the clock at the beginning of a read transfer.

Static Public Attributes
static constexpr uint32_t	ReceiveFifoDepth = 8
static constexpr bool	DebugOpenTitanI2c = false
	Flag set when we're debugging this driver.

Detailed Description

Driver for the OpenTitan's I2C block.

Documentation source can be found at: https://github.com/lowRISC/opentitan/tree/4fe1b8dd1a09af9dbc242434481ae031955dfd85/hw/ip/i2c

Documentation source can be found at: https://github.com/lowRISC/opentitan/tree/9ddf276c64e2974ed8e528e8b2feb00b977861de/hw/ip/i2c

Definition at line 13 of file platform-i2c.hh.

Member Typedef Documentation

◆ Debug [1/2]

using OpenTitanI2c::Debug = ConditionalDebug<DebugOpenTitanI2c, "OpenTitan I2C">

Helper for conditional debug logs and assertions.

Definition at line 302 of file platform-i2c.hh.

◆ Debug [2/2]

using OpenTitanI2c::Debug = ConditionalDebug<DebugOpenTitanI2c, "OpenTitan I2C">

Helper for conditional debug logs and assertions.

Definition at line 240 of file platform-i2c.hh.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum : uint32_t

ControllerEvents Register Fields.

Enumerator
ControllerEventsNack	Controller FSM is halted due to receiving an unexpected NACK.
ControllerEventsUnhandledNackTimeout	Controller FSM is halted due to a Host-Mode active transaction being ended by the hostNackHandlerTimeout mechanism.
ControllerEventsBusTimeout	Controller FSM is halted due to a Host-Mode active transaction being terminated because of a bus timeout activated by timeoutControl.
ControllerEventsArbitrationLost	Controller FSM is halted due to a Host-Mode active transaction being terminated because of lost arbitration.

Definition at line 274 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

FifoControl Register Fields.

Enumerator
FifoControlReceiveReset	Receive fifo reset. Receive fifo reset. Write 1 to the register resets it. Read returns 0. Write 1 to the register resets it. Read returns 0
FifoControlFormatReset	Format fifo reset. Write 1 to the register resets it. Read returns 0.
FifoControlAcquiredReset	Acquired FIFO reset. Aquired FIFO reset. Write 1 to the register resets it. Read returns 0. Write 1 to the register resets it. Read returns 0
FifoControlTransmitReset	Transmit FIFO reset. Transmit FIFO reset. Write 1 to the register resets it. Read returns 0. Write 1 to the register resets it. Read returns 0

Definition at line 258 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

FifoControl Register Fields.

Enumerator
FifoControlReceiveReset	Receive fifo reset. Receive fifo reset. Write 1 to the register resets it. Read returns 0. Write 1 to the register resets it. Read returns 0
FifoControlFormatReset	Format fifo reset. Write 1 to the register resets it. Read returns 0.
FifoControlAcquiredReset	Acquired FIFO reset. Aquired FIFO reset. Write 1 to the register resets it. Read returns 0. Write 1 to the register resets it. Read returns 0
FifoControlTransmitReset	Transmit FIFO reset. Transmit FIFO reset. Write 1 to the register resets it. Read returns 0. Write 1 to the register resets it. Read returns 0

Definition at line 225 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

Status Register Fields.

Enumerator
StatusFormatFull	Host mode Format FIFO is full.
StatusReceiveFull	Host mode Receive FIFO is full.
StatusFormatEmpty	Host mode Format FIFO is empty.
StatusHostIdle	Host functionality is idle. No Host transaction is in progress.
StatusTargetIdle	Target functionality is idle. No Target transaction is in progress.
SmatusReceiveEmpty	Host mode Receive FIFO is empty.
StatusTransmitFull	Target mode Transmit FIFO is full.
StatusAcquiredFull	Target mode Acquired FIFO is full. Target mode Receive FIFO is full.
StatusTransmitEmpty	Target mode Transmit FIFO is empty.
StatusAcquiredEmpty	Target mode Acquired FIFO is empty. Target mode Aquired FIFO is empty.
StatusHostDisabledNackTimeout	A Host-Mode active transaction has been ended by the HostNackHandlerTimeout mechanism. This bit is cleared when Control.EnableHost is set by software to start a new transaction.

Definition at line 178 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

FormatData Register Fields.

Enumerator
FormatDataStart	Issue a START condition before transmitting BYTE.
FormatDataStop	Issue a STOP condition after this operation.
FormatDataReadBytes	Read BYTE bytes from I2C. (256 if BYTE==0).
FormatDataReadCount	Do not NACK the last byte read, let the read operation continue.
FormatDataNakOk	Do not signal an exception if the current byte is not ACK’d.

Definition at line 240 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

FormatData Register Fields.

Enumerator
FormatDataStart	Issue a START condition before transmitting BYTE.
FormatDataStop	Issue a STOP condition after this operation.
FormatDataReadBytes	Read BYTE bytes from I2C. (256 if BYTE==0).
FormatDataReadCount	Do not NACK the last byte read, let the read operation continue.
FormatDataNakOk	Do not signal an exception if the current byte is not ACK’d.

Definition at line 208 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

Control Register Fields.

Enumerator
ControlEnableHost	Enable Host I2C functionality.
ControlEnableTarget	Enable Target I2C functionality.
ControlLineLoopback	Enable I2C line loopback test If line loopback is enabled, the internal design sees ACQ and RX data as "1".
ControlNackAddressAfterTimeout	Enable NACKing the address on a stretch timeout. This is a target mode feature. If enabled, a stretch timeout will cause the device to NACK the address byte. If disabled, it will ACK instead.
ControlAckControlEnable	Enable ACK Control Mode, which works with the targetAckControl register to allow software to control upper-layer (N)ACKing.
ControlMultiControllerMonitorEnable	Enable the bus monitor in multi-controller mode.
ControlTransmitStretchEnable	If set, causes a read transfer addressed to the this target to set the corresponding bit in the targetEvents register. While the transmitPending field is 1, subsequent read transactions will stretch the clock, even if there is data in the Transmit FIFO.

Definition at line 186 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

Status Register Fields.

Enumerator
StatusFormatFull	Host mode Format FIFO is full.
StatusReceiveFull	Host mode Receive FIFO is full.
StatusFormatEmpty	Host mode Format FIFO is empty.
StatusHostIdle	Host functionality is idle. No Host transaction is in progress.
StatusTargetIdle	Target functionality is idle. No Target transaction is in progress.
SmatusReceiveEmpty	Host mode Receive FIFO is empty.
StatusTransmitFull	Target mode Transmit FIFO is full.
StatusAcquiredFull	Target mode Acquired FIFO is full. Target mode Receive FIFO is full.
StatusTransmitEmpty	Target mode Transmit FIFO is empty.
StatusAcquiredEmpty	Target mode Acquired FIFO is empty. Target mode Aquired FIFO is empty.
StatusAckControlStretch	Target mode stretching at (N)ACK phase due to zero count in the targetAckControl register.

Definition at line 212 of file platform-i2c.hh.

◆ anonymous enum

anonymous enum : uint32_t

Control Register Fields.

Enumerator
ControlEnableHost	Enable Host I2C functionality.
ControlEnableTarget	Enable Target I2C functionality.
ControlLineLoopback	Enable I2C line loopback test If line loopback is enabled, the internal design sees ACQ and RX data as "1".

Definition at line 167 of file platform-i2c.hh.

◆ Interrupt

enum class OpenTitanI2c::Interrupt

strong

The interrupts of the OpenTitan's I2C block.

Documentation source can be found at: https://github.com/lowRISC/opentitan/blob/4fe1b8dd1a09af9dbc242434481ae031955dfd85/hw/ip/i2c/doc/interfaces.md

Enumerator
FormatThreshold	A host mode interrupt. This is asserted whilst the Format FIFO level is below the low threshold. This is a level status interrupt.
ReceiveThreshold	A host mode interrupt. This is asserted whilst the Receive FIFO level is above the high threshold. This is a level status interrupt.
AcquiredThreshold	A target mode interrupt. This is asserted whilst the Aquired FIFO level is above the high threshold. This is a level status interrupt.
ReceiveOverflow	A host mode interrupt. This is raised if the Receive FIFO has overflowed.
ControllerHalt	A host mode interrupt. This is raised if the controller FSM is halted, such as on an unexpected NACK or lost arbitration. Check the controllerEvents register for the reason. The interrupt will only be released when the bits in controllerEvents are cleared.
SclInterference	A host mode interrupt. This is raised if the SCL line drops early (not supported without clock synchronization).
SdaInterference	A host mode interrupt. This is raised if the SDA line goes low when host is trying to assert high.
StretchTimeout	A host mode interrupt. This is raised if target stretches the clock beyond the allowed timeout period.
SdaUnstable	A host mode interrupt. This is raised if the target does not assert a constant value of SDA during transmission.
CommandComplete	A host and target mode interrupt. In host mode, raised if the host issues a repeated START or terminates the transaction by issuing STOP. In target mode, raised if the external host issues a STOP or repeated START.
TransmitStretch	A target mode interrupt. This is raised if the target is stretching clocks for a read command. This is a level status interrupt.
TransmitThreshold	A target mode interrupt. This is asserted whilst the Transmit FIFO level is below the low threshold. This is a level status interrupt.
AcquiredFull	A target mode interrupt. This is raised if the target is stretching clocks due to full Aquired FIFO or zero count in targetAckControl.NBYTES (if enabled). This is a level status interrupt.
UnexpectedStop	A target mode interrupt. This is raised if STOP is received without a preceding NACK during an external host read.
HostTimeout	A target mode interrupt. This is raised if the host stops sending the clock during an ongoing transaction.

Definition at line 95 of file platform-i2c.hh.

Member Function Documentation

◆ blocking_read() [1/2]

bool OpenTitanI2c::blocking_read	(	const uint8_t	Addr7,
		uint8_t	buf[],
		const uint32_t	NumBytes ) volatile

inlinenodiscard

Definition at line 450 of file platform-i2c.hh.

◆ blocking_read() [2/2]

bool OpenTitanI2c::blocking_read	(	const uint8_t	Addr7,
		uint8_t	buf[],
		const uint32_t	NumBytes ) volatile

inlinenodiscard

Definition at line 357 of file platform-i2c.hh.

◆ blocking_write() [1/2]

bool OpenTitanI2c::blocking_write	(	const uint8_t	Addr7,
		const uint8_t	data[],
		const uint32_t	NumBytes,
		const bool	SkipStop ) volatile

inlinenodiscard

Definition at line 423 of file platform-i2c.hh.

◆ blocking_write() [2/2]

void OpenTitanI2c::blocking_write	(	const uint8_t	Addr7,
		const uint8_t	data[],
		const uint32_t	NumBytes,
		const bool	SkipStop ) volatile

inline

Definition at line 339 of file platform-i2c.hh.

◆ blocking_write_byte() [1/2]

void OpenTitanI2c::blocking_write_byte ( const uint32_t Fmt ) volatile

inline

Definition at line 409 of file platform-i2c.hh.

◆ blocking_write_byte() [2/2]

void OpenTitanI2c::blocking_write_byte ( const uint32_t Fmt ) volatile

inline

Definition at line 327 of file platform-i2c.hh.

◆ format_is_empty() [1/2]

bool OpenTitanI2c::format_is_empty ( ) volatile

inlinenodiscard

Returns true when the format fifo is empty.

Definition at line 418 of file platform-i2c.hh.

References status, and StatusFormatEmpty.

◆ format_is_empty() [2/2]

bool OpenTitanI2c::format_is_empty ( ) volatile

inlinenodiscard

Returns true when the format fifo is empty.

Definition at line 334 of file platform-i2c.hh.

References status, and StatusFormatEmpty.

◆ host_mode_set() [1/2]

void OpenTitanI2c::host_mode_set ( ) volatile

inline

Configure the I2C block to be in host mode.

Definition at line 350 of file platform-i2c.hh.

References control, and ControlEnableHost.

◆ host_mode_set() [2/2]

void OpenTitanI2c::host_mode_set ( ) volatile

inline

Configure the I2C block to be in host mode.

Definition at line 268 of file platform-i2c.hh.

References control, and ControlEnableHost.

◆ host_thresholds_set() [1/2]

void OpenTitanI2c::host_thresholds_set	(	uint16_t	formatThreshold,
		uint16_t	receiveThreshold ) volatile

inline

Sets the thresholds for the format and receive fifos.

Definition at line 511 of file platform-i2c.hh.

References hostFifoConfiguration.

◆ host_thresholds_set() [2/2]

void OpenTitanI2c::host_thresholds_set	(	uint16_t	formatThreshold,
		uint16_t	receiveThreshold ) volatile

inline

Sets the thresholds for the format and receive fifos.

Definition at line 415 of file platform-i2c.hh.

References hostFifoConfiguration.

◆ interrupt_bit()

constexpr uint32_t OpenTitanI2c::interrupt_bit ( const Interrupt Interrupt )

inlinestaticconstexpr

Definition at line 180 of file platform-i2c.hh.

◆ interrupt_clear() [1/2]

void OpenTitanI2c::interrupt_clear ( Interrupt interrupt ) volatile

inline

Clears the given interrupt.

Definition at line 491 of file platform-i2c.hh.

References interruptState.

◆ interrupt_clear() [2/2]

void OpenTitanI2c::interrupt_clear ( OpenTitanI2cInterrupt interrupt ) volatile

inline

Clears the given interrupt.

Definition at line 395 of file platform-i2c.hh.

References interruptState.

◆ interrupt_disable() [1/2]

void OpenTitanI2c::interrupt_disable ( Interrupt interrupt ) volatile

inline

Disables the given interrupt.

Definition at line 503 of file platform-i2c.hh.

References interruptEnable.

◆ interrupt_disable() [2/2]

void OpenTitanI2c::interrupt_disable ( OpenTitanI2cInterrupt interrupt ) volatile

inline

Disables the given interrupt.

Definition at line 407 of file platform-i2c.hh.

References interruptEnable.

◆ interrupt_enable() [1/2]

void OpenTitanI2c::interrupt_enable ( Interrupt interrupt ) volatile

inline

Enables the given interrupt.

Definition at line 497 of file platform-i2c.hh.

References interruptEnable.

◆ interrupt_enable() [2/2]

void OpenTitanI2c::interrupt_enable ( OpenTitanI2cInterrupt interrupt ) volatile

inline

Enables the given interrupt.

Definition at line 401 of file platform-i2c.hh.

References interruptEnable.

◆ interrupt_is_asserted() [1/2]

bool OpenTitanI2c::interrupt_is_asserted ( Interrupt interrupt ) volatile

inlinenodiscard

Returns true if the given interrupt is asserted.

Definition at line 485 of file platform-i2c.hh.

References interruptState.

◆ interrupt_is_asserted() [2/2]

bool OpenTitanI2c::interrupt_is_asserted ( OpenTitanI2cInterrupt interrupt ) volatile

inlinenodiscard

Returns true if the given interrupt is asserted.

Definition at line 389 of file platform-i2c.hh.

References interruptState.

◆ reset_controller_events()

uint32_t OpenTitanI2c::reset_controller_events ( ) volatile

inline

Reset the controller Events so that the ControllerHalt interrupt will be released, allowing the I2C driver to continue after the controller FSM has halted due to e.g.

a NACK, configured timeout, or loss of arbitration.

Returns the (masked) result of reading the register before clearing the controller events, so that you can use the controllerEvent register fields to determine why the Controller FSM was halted.

Definition at line 332 of file platform-i2c.hh.

References controllerEvents, ControllerEventsArbitrationLost, ControllerEventsBusTimeout, ControllerEventsNack, and ControllerEventsUnhandledNackTimeout.

◆ reset_fifos() [1/2]

void OpenTitanI2c::reset_fifos ( ) volatile

inline

Reset all of the fifos.

Definition at line 343 of file platform-i2c.hh.

References FifoControlAcquiredReset, FifoControlFormatReset, FifoControlReceiveReset, FifoControlTransmitReset, and fifoCtrl.

◆ reset_fifos() [2/2]

void OpenTitanI2c::reset_fifos ( ) volatile

inline

Reset all of the fifos.

Definition at line 261 of file platform-i2c.hh.

References FifoControlAcquiredReset, FifoControlFormatReset, FifoControlReceiveReset, FifoControlTransmitReset, and fifoCtrl.

◆ round_up_divide() [1/2]

uint16_t OpenTitanI2c::round_up_divide	(	uint32_t	a,
		uint32_t	b )

inlinestatic

Performs a 32-bit integer unsigned division, rounding up.

The bottom 16 bits of the result are then returned.

As usual, a divisor of 0 is still Undefined Behavior.

Definition at line 310 of file platform-i2c.hh.

Referenced by speed_set().

◆ round_up_divide() [2/2]

uint16_t OpenTitanI2c::round_up_divide	(	uint32_t	a,
		uint32_t	b )

inlinestatic

Performs a 32-bit integer unsigned division, rounding up.

The bottom 16 bits of the result are then returned.

As usual, a divisor of 0 is still Undefined Behavior.

Definition at line 248 of file platform-i2c.hh.

◆ speed_set() [1/2]

void OpenTitanI2c::speed_set ( const uint32_t SpeedKhz ) volatile

inline

Set the I2C timing parameters appropriately for the given bit rate.

Distilled from: https://github.com/lowRISC/opentitan/blob/9ddf276c64e2974ed8e528e8b2feb00b977861de/hw/ip/i2c/doc/programmers_guide.md

Definition at line 360 of file platform-i2c.hh.

References round_up_divide(), and timing.

◆ speed_set() [2/2]

void OpenTitanI2c::speed_set ( const uint32_t SpeedKhz ) volatile

inline

Set the I2C timing parameters appropriately for the given bit rate.

Distilled from: https://github.com/lowRISC/opentitan/blob/9ddf276c64e2974ed8e528e8b2feb00b977861de/hw/ip/i2c/doc/programmers_guide.md

Definition at line 278 of file platform-i2c.hh.

References round_up_divide(), and timing.

Member Data Documentation

◆ acquiredData

uint32_t OpenTitanI2c::acquiredData

I2C target acquired data.

Definition at line 55 of file platform-i2c.hh.

◆ acquireFifoNextData

uint32_t OpenTitanI2c::acquireFifoNextData

The data byte pending to be written to the Acquire (ACQ) FIFO.

Definition at line 75 of file platform-i2c.hh.

◆ alertTest

uint32_t OpenTitanI2c::alertTest

Alert Test Register (Unused in Sonata).

Definition at line 22 of file platform-i2c.hh.

◆ control

uint32_t OpenTitanI2c::control

I2C Control Register.

Definition at line 24 of file platform-i2c.hh.

Referenced by host_mode_set().

◆ controllerEvents

uint32_t OpenTitanI2c::controllerEvents

Latched events that explain why the controller halted.

Definition at line 82 of file platform-i2c.hh.

Referenced by reset_controller_events().

◆ DebugOpenTitanI2c

constexpr bool OpenTitanI2c::DebugOpenTitanI2c = false

staticconstexpr

Flag set when we're debugging this driver.

Definition at line 299 of file platform-i2c.hh.

◆ fifoCtrl

uint32_t OpenTitanI2c::fifoCtrl

I2C FIFO control register.

Definition at line 32 of file platform-i2c.hh.

Referenced by reset_fifos().

◆ formatData

uint32_t OpenTitanI2c::formatData

I2C Host Format Data.

Definition at line 30 of file platform-i2c.hh.

◆ hostFifoConfiguration

uint32_t OpenTitanI2c::hostFifoConfiguration

Host mode FIFO configuration.

Definition at line 34 of file platform-i2c.hh.

Referenced by host_thresholds_set().

◆ hostFifoStatus

uint32_t OpenTitanI2c::hostFifoStatus

Host mode FIFO status register.

Definition at line 38 of file platform-i2c.hh.

◆ hostNackHandlerTimeout

uint32_t OpenTitanI2c::hostNackHandlerTimeout

Timeout in Host-Mode for an unhandled NACK before hardware automatically ends the transaction.

Definition at line 80 of file platform-i2c.hh.

◆ hostTimeoutControl

uint32_t OpenTitanI2c::hostTimeoutControl

I2C host clock generation timeout value (in units of input clock frequency).

Definition at line 62 of file platform-i2c.hh.

◆ interruptEnable

uint32_t OpenTitanI2c::interruptEnable

Interrupt Enable Register.

Definition at line 18 of file platform-i2c.hh.

Referenced by interrupt_disable(), interrupt_disable(), interrupt_enable(), and interrupt_enable().

◆ interruptState

uint32_t OpenTitanI2c::interruptState

Interrupt State Register.

Definition at line 16 of file platform-i2c.hh.

Referenced by interrupt_clear(), interrupt_clear(), interrupt_is_asserted(), and interrupt_is_asserted().

◆ interruptTest

uint32_t OpenTitanI2c::interruptTest

Interrupt Test Register.

Definition at line 20 of file platform-i2c.hh.

◆ override

uint32_t OpenTitanI2c::override

I2C Override Control Register.

Definition at line 42 of file platform-i2c.hh.

◆ readData

uint32_t OpenTitanI2c::readData

I2C Read Data.

Definition at line 28 of file platform-i2c.hh.

◆ ReceiveFifoDepth

uint32_t OpenTitanI2c::ReceiveFifoDepth = 8

staticconstexpr

Definition at line 296 of file platform-i2c.hh.

◆ status

uint32_t OpenTitanI2c::status

I2C Live Status Register for Host and Target modes.

Definition at line 26 of file platform-i2c.hh.

Referenced by format_is_empty().

◆ targetAckControl

uint32_t OpenTitanI2c::targetAckControl

Controls for mid-transfer (N)ACK phase handling.

Timeout in Host-Mode for an unhandled NACK before hardware automatically ends the transaction.

Definition at line 73 of file platform-i2c.hh.

◆ targetEvents

uint32_t OpenTitanI2c::targetEvents

Latched events that can cause the target module to stretch the clock at the beginning of a read transfer.

Definition at line 87 of file platform-i2c.hh.

◆ targetFifoConfiguration

uint32_t OpenTitanI2c::targetFifoConfiguration

Target mode FIFO configuration.

Definition at line 36 of file platform-i2c.hh.

◆ targetFifoStatus

uint32_t OpenTitanI2c::targetFifoStatus

Target mode FIFO status register.

Definition at line 40 of file platform-i2c.hh.

◆ targetId

uint32_t OpenTitanI2c::targetId

I2C target address and mask pairs.

Definition at line 53 of file platform-i2c.hh.

◆ targetNackCount

uint32_t OpenTitanI2c::targetNackCount

Number of times the I2C target has NACK'ed a new transaction since the last read of this register.

Definition at line 69 of file platform-i2c.hh.

◆ targetTimeoutControl

uint32_t OpenTitanI2c::targetTimeoutControl

I2C target internal stretching timeout control.

Definition at line 64 of file platform-i2c.hh.

◆ timeoutControl

uint32_t OpenTitanI2c::timeoutControl

I2C clock stretching timeout control.

Definition at line 51 of file platform-i2c.hh.

◆ timing

uint32_t OpenTitanI2c::timing

Detailed I2C Timings (directly corresponding to table 10 in the I2C Specification).

Definition at line 49 of file platform-i2c.hh.

Referenced by speed_set().

◆ transmitData

uint32_t OpenTitanI2c::transmitData

I2C target transmit data.

Definition at line 57 of file platform-i2c.hh.

◆ values

uint32_t OpenTitanI2c::values

Oversampled Receive values.

Definition at line 44 of file platform-i2c.hh.

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

sdk/include/platform/sunburst/platform-i2c.hh
sdk/include/platform/sunburst/v0.2/platform-i2c.hh

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Detailed Description

Member Typedef Documentation

◆ Debug [1/2]

◆ Debug [2/2]

Member Enumeration Documentation

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ Interrupt

Member Function Documentation

◆ blocking_read() [1/2]

◆ blocking_read() [2/2]

◆ blocking_write() [1/2]

◆ blocking_write() [2/2]

◆ blocking_write_byte() [1/2]

◆ blocking_write_byte() [2/2]

◆ format_is_empty() [1/2]

◆ format_is_empty() [2/2]

◆ host_mode_set() [1/2]

◆ host_mode_set() [2/2]

◆ host_thresholds_set() [1/2]

◆ host_thresholds_set() [2/2]

◆ interrupt_bit()

◆ interrupt_clear() [1/2]

◆ interrupt_clear() [2/2]

◆ interrupt_disable() [1/2]

◆ interrupt_disable() [2/2]

◆ interrupt_enable() [1/2]

◆ interrupt_enable() [2/2]

◆ interrupt_is_asserted() [1/2]

◆ interrupt_is_asserted() [2/2]

◆ reset_controller_events()

◆ reset_fifos() [1/2]

◆ reset_fifos() [2/2]

◆ round_up_divide() [1/2]

◆ round_up_divide() [2/2]

◆ speed_set() [1/2]

◆ speed_set() [2/2]

Member Data Documentation

◆ acquiredData

◆ acquireFifoNextData

◆ alertTest

◆ control

◆ controllerEvents

◆ DebugOpenTitanI2c

◆ fifoCtrl

◆ formatData

◆ hostFifoConfiguration

◆ hostFifoStatus

◆ hostNackHandlerTimeout

◆ hostTimeoutControl

◆ interruptEnable

◆ interruptState

◆ interruptTest

◆ override

◆ readData

◆ ReceiveFifoDepth

◆ status

◆ targetAckControl

◆ targetEvents

◆ targetFifoConfiguration

◆ targetFifoStatus

◆ targetId

◆ targetNackCount

◆ targetTimeoutControl

◆ timeoutControl

◆ timing

◆ transmitData

◆ values