Inheritance diagram for TivaSPI:

Public Member Functions
	TivaSPI (const char name, unsigned long base, uint32_t interrupt, ChipSelectMethod cs_assert, ChipSelectMethod cs_deassert, OSMutex bus_lock=nullptr, size_t dma_threshold=DEFAULT_DMA_THRESHOLD_BYTES, uint32_t dma_channel_index_tx=UDMA_CH11_SSI0TX, uint32_t dma_channel_index_rx=UDMA_CH10_SSI0RX)
	Constructor.

	~TivaSPI ()
	Destructor.

void	interrupt_handler ()
	Call this from the SPI device's interrupt handler.

OSMutex *	get_lock ()
	This method provides a reference to the Mutex used by this device driver.

Public Member Functions inherited from SPI
int	transfer_with_cs_assert (struct spi_ioc_transfer *msg)
	Method to transmit/receive the data.

int	transfer_with_cs_assert_polled (struct spi_ioc_transfer *msgs, int num=1)
	Method to transmit/receive the data.

int	transfer_messages (struct spi_ioc_transfer *msgs, int num)
	Conduct multiple message transfers with one stop at the end.

Public Member Functions inherited from Device
	Device (const char *name)
	Constructor.

virtual	~Device ()
	Destructor.

Private Member Functions
void	enable () override
	Function to enable device.

void	disable () override
	Function to disable device.

int	update_configuration () override
	Update the configuration of the bus.

int	transfer (struct spi_ioc_transfer *msg) override
	Method to transmit/receive the data.

template<typename T >
int	transfer_polled (struct spi_ioc_transfer *msg)
	Method to transmit/receive the data.

int	transfer_polled (struct spi_ioc_transfer *msg) override
	Method to transmit/receive the data.

void	config_dma (struct spi_ioc_transfer *msg)
	Configure a DMA transaction.

long	data_get_non_blocking (uint16_t *data)
	Receives a word from the specified port.

long	data_put_non_blocking (uint16_t data)
	Transmits a word on the specified port.

void	data_put (uint16_t data)
	Waits until the word is transmitted on the specified port.

void	set_configuration ()
	Set the instance local configuration.

	DISALLOW_COPY_AND_ASSIGN (TivaSPI)

Private Attributes
OSSem *	sem_
	reference to the semaphore belonging to this bus

unsigned long	base_
	base address of this device

unsigned long	interrupt_
	interrupt of this device

size_t	dmaThreshold_
	threshold in bytes to start using DMA

uint32_t	dmaChannelIndexTx_
	TX DMA channel index.

uint32_t	dmaChannelIndexRx_
	RX DMA channel index.

uint16_t	spiCr0_
	Configuration register 0 local copy.

uint16_t	spiCr1_
	Configuration register 1 local copy.

uint16_t	spiPrescaler_
	Prescale register local copy.

Static Private Attributes
static constexpr size_t	DEFAULT_DMA_THRESHOLD_BYTES = 0
	Transfers longer than this will be with dma by default.

static constexpr size_t	MAX_DMA_TRANSFER_AMOUNT = 1024
	Maximum number of bytes transferred in a single DMA transaction.

static constexpr uint32_t	dmaRxConfig_ []
	This lookup table is used to configure the DMA channels for the appropriate (8bit or 16bit) transfer sizes.

static constexpr uint32_t	dmaTxConfig_ []
	This lookup table is used to configure the DMA channels for the appropriate (8bit or 16bit) transfer sizes.

static constexpr uint32_t	dmaNullConfig_ []
	This lookup table is used to configure the DMA channels for the appropriate (8bit or 16bit) transfer sizes when either txBuf or rxBuf are NULL.

Additional Inherited Members
Public Types inherited from SPI
typedef void(*	ChipSelectMethod) ()
	Function point for the chip select assert and deassert methods.

Static Public Member Functions inherited from Device
static int	open (struct _reent reent, const char path, int flags, int mode)
	Open a file or device.

static int	close (struct _reent *reent, int fd)
	Close a file or device.

static int	stat (struct _reent reent, const char path, struct stat *stat)
	Get the status information of a file or device.

static int	select (int nfds, fd_set readfds, fd_set writefds, fd_set *exceptfds, long long timeout)
	POSIX select().

static void	select_clear ()
	Clears the current thread's select bits.

Static Public Member Functions inherited from FileIO
static ssize_t	read (struct _reent reent, int fd, void buf, size_t count)
	Read from a file or device.

static ssize_t	write (struct _reent reent, int fd, const void buf, size_t count)
	Write to a file or device.

static _off_t	lseek (struct _reent *reent, int fd, _off_t offset, int whence)
	Change the offset index of a file or device.

static int	fstat (struct _reent reent, int fd, struct stat stat)
	Get the status information of a file or device.

static int	ioctl (int fd, unsigned long int key, unsigned long data)
	Request and ioctl transaction.

static int	fcntl (int fd, int cmd, unsigned long data)
	Manipulate a file descriptor.

static bool	is_device (int fd)
	Test if the file descriptor belongs to a device.

Protected Member Functions inherited from SPI
	SPI (const char name, ChipSelectMethod cs_assert, ChipSelectMethod cs_deassert, OSMutex bus_lock=nullptr)
	Constructor.

	~SPI ()
	Destructor.

void	bus_lock ()
	Lock the bus shared by many chip selects.

void	bus_unlock ()
	Unlock the bus shared by many chip selects.

int	ioctl (File *file, unsigned long int key, unsigned long data) override
	Request an ioctl transaction.

Protected Member Functions inherited from Node
	Node (const char *name)
	Constructor.

virtual	~Node ()
	Destructor.

int	open (File , const char , int, int) OVERRIDE
	Open method.

int	close (File *) OVERRIDE
	Close method.

virtual int	fstat (File file, struct stat stat) override
	Get the status information of a file or device.

Protected Member Functions inherited from FileIO
	FileIO (const char *name)
	Constructor.

virtual	~FileIO ()
	Destructor.

virtual off_t	lseek (File *f, off_t offset, int whence)
	Seek method.

virtual int	fcntl (File *file, int cmd, unsigned long data)
	Manipulate a file descriptor.

virtual bool	select (File *file, int mode)
	Device select method.

Static Protected Member Functions inherited from Device
static void	select_insert (SelectInfo *info)
	Add client to list of clients needing woken.

static void	select_wakeup (SelectInfo *info)
	Wakeup the list of clients needing woken.

static void	select_wakeup_from_isr (SelectInfo info, int woken)
	Wakeup the list of clients needing woken.

Static Protected Member Functions inherited from FileIO
static int	fd_alloc (void)
	Allocate a free file descriptor.

static void	fd_free (int fd)
	Free up a file descriptor.

static File *	file_lookup (int fd)
	Looks up a reference to a File corresponding to a given file descriptor.

static int	fd_lookup (File *file)
	Looks up a file descriptor corresponding to a given File reference.

Protected Attributes inherited from SPI
ChipSelectMethod	csAssert
	function pointer to a method that asserts chip select.

ChipSelectMethod	csDeassert
	function pointer to a method that deasserts chip select.

uint32_t	speedHz
	Max default speed in Hz.

uint8_t	bitsPerWord
	number of bits per word transaction

uint8_t	mode
	one of four SPI modes

bool	lsbFirst
	transmit LSB first if true

Protected Attributes inherited from Node
OSMutex	lock_
	protects internal structures.

mode_t	mode_
	File open mode, such as O_NONBLOCK.

unsigned int	references_
	number of open references

Protected Attributes inherited from FileIO
const char *	name
	device name

Static Protected Attributes inherited from FileIO
static const unsigned int	numOpenFiles = 20

static File	files []
	File descriptor pool.

static OSMutex	mutex
	mutual exclusion for fileio

Detailed Description

Definition at line 44 of file TivaSPI.hxx.

Constructor & Destructor Documentation

◆ TivaSPI()

TivaSPI::TivaSPI	(	const char *	name,
		unsigned long	base,
		uint32_t	interrupt,
		ChipSelectMethod	cs_assert,
		ChipSelectMethod	cs_deassert,
		OSMutex *	bus_lock = `nullptr`,
		size_t	dma_threshold = `DEFAULT_DMA_THRESHOLD_BYTES`,
		uint32_t	dma_channel_index_tx = `UDMA_CH11_SSI0TX`,
		uint32_t	dma_channel_index_rx = `UDMA_CH10_SSI0RX`
	)

Constructor.

Parameters

name	name of this device instance in the file system
base	base address of this device
interrupt	interrupt number of this device
cs_assert	function pointer to a method that asserts chip select
cs_deassert	function pointer to a method that deasserts chip select
bus_lock	the user must provide a shared mutex if the device instance represents more than one chip select on the same bus interface.
dma_threshold	the threshold in bytes to use a DMA transaction, 0 = DMA always disabled
dma_channel_index_tx	UDMA_CHn_SSInTX
dma_channel_index_rx	UDMA_CHn_SSInRX

Definition at line 45 of file TivaSPI.cxx.

◆ ~TivaSPI()

TivaSPI::~TivaSPI ( )

Destructor.

Definition at line 85 of file TivaSPI.cxx.

Member Function Documentation

◆ config_dma()

void TivaSPI::config_dma ( struct spi_ioc_transfer * msg )

private

Configure a DMA transaction.

Parameters

msg	message to transact.

Definition at line 157 of file TivaSPI.cxx.

◆ data_get_non_blocking()

long TivaSPI::data_get_non_blocking ( uint16_t * data )

inlineprivate

Receives a word from the specified port.

This function gets a SPI word from the receive FIFO for the specified port.

Parameters

data	is pointer to receive data variable.

Returns: Returns the number of elements read from the receive FIFO.

Definition at line 254 of file TivaSPI.hxx.

◆ data_put()

void TivaSPI::data_put ( uint16_t data )

inlineprivate

Waits until the word is transmitted on the specified port.

This function transmits a SPI word on the transmit FIFO for the specified port. This function waits until the space is available on transmit FIFO.

Parameters

data	is data to be transmitted.

Definition at line 287 of file TivaSPI.hxx.

◆ data_put_non_blocking()

long TivaSPI::data_put_non_blocking ( uint16_t data )

inlineprivate

Transmits a word on the specified port.

This function transmits a SPI word on the transmit FIFO for the specified port.

Parameters

data	is data to be transmitted.

Returns: Returns the number of elements written to the transmit FIFO.

Definition at line 271 of file TivaSPI.hxx.

◆ disable()

void TivaSPI::disable ( )

overrideprivatevirtual

Function to disable device.

Implements Node.

Definition at line 93 of file TivaSPI.cxx.

◆ enable()

void TivaSPI::enable ( )

overrideprivatevirtual

Function to enable device.

Implements Node.

Definition at line 89 of file TivaSPI.cxx.

◆ get_lock()

OSMutex * TivaSPI::get_lock ( )

inline

This method provides a reference to the Mutex used by this device driver.

It can be passed into another SPI driver instance as a bus wide lock such that a SPI bus can be shared between this driver and another use case with another chip select.

Returns: a reference to this device driver instance lock

Definition at line 81 of file TivaSPI.hxx.

◆ interrupt_handler()

void TivaSPI::interrupt_handler ( )

Call this from the SPI device's interrupt handler.

Definition at line 163 of file TivaSPI.cxx.

◆ set_configuration()

void TivaSPI::set_configuration ( )

inlineprivate

Set the instance local configuration.

Definition at line 295 of file TivaSPI.hxx.

◆ transfer()

int TivaSPI::transfer ( struct spi_ioc_transfer * msg )

inlineoverrideprivatevirtual

Method to transmit/receive the data.

Parameters

msg	message to transact.

Implements SPI.

Definition at line 144 of file TivaSPI.hxx.

◆ transfer_polled() [1/2]

template<typename T >

int TivaSPI::transfer_polled ( struct spi_ioc_transfer * msg )

inlineprivatevirtual

Method to transmit/receive the data.

This is a template in order to preserve execution speed on type specific pointer math.

Parameters

msg	message to transact.

Implements SPI.

Definition at line 169 of file TivaSPI.hxx.

◆ transfer_polled() [2/2]

int TivaSPI::transfer_polled ( struct spi_ioc_transfer * msg )

inlineoverrideprivatevirtual

Method to transmit/receive the data.

Parameters

msg	message to transact.

Implements SPI.

Definition at line 226 of file TivaSPI.hxx.

◆ update_configuration()

int TivaSPI::update_configuration ( )

overrideprivatevirtual

Update the configuration of the bus.

Returns: >= 0 upon success, -errno upon failure

Implements SPI.

Definition at line 100 of file TivaSPI.cxx.

Member Data Documentation

◆ base_

unsigned long TivaSPI::base_

private

base address of this device

Definition at line 306 of file TivaSPI.hxx.

◆ DEFAULT_DMA_THRESHOLD_BYTES

constexpr size_t TivaSPI::DEFAULT_DMA_THRESHOLD_BYTES = 0

staticconstexprprivate

Transfers longer than this will be with dma by default.

Todo:: this should be 64 bytes

Definition at line 89 of file TivaSPI.hxx.

◆ dmaChannelIndexRx_

uint32_t TivaSPI::dmaChannelIndexRx_

private

RX DMA channel index.

Definition at line 310 of file TivaSPI.hxx.

◆ dmaChannelIndexTx_

uint32_t TivaSPI::dmaChannelIndexTx_

private

TX DMA channel index.

Definition at line 309 of file TivaSPI.hxx.

◆ dmaNullConfig_

constexpr uint32_t TivaSPI::dmaNullConfig_[]

staticconstexprprivate

Initial value:

=
    {
        UDMA_SIZE_8  | UDMA_SRC_INC_NONE | UDMA_DST_INC_NONE | UDMA_ARB_1,
        UDMA_SIZE_16 | UDMA_SRC_INC_NONE | UDMA_DST_INC_NONE | UDMA_ARB_1,
    }

This lookup table is used to configure the DMA channels for the appropriate (8bit or 16bit) transfer sizes when either txBuf or rxBuf are NULL.

Definition at line 121 of file TivaSPI.hxx.

◆ dmaRxConfig_

constexpr uint32_t TivaSPI::dmaRxConfig_[]

staticconstexprprivate

Initial value:

=
    {
        UDMA_SIZE_8  | UDMA_SRC_INC_NONE | UDMA_DST_INC_8  | UDMA_ARB_1,
        UDMA_SIZE_16 | UDMA_SRC_INC_NONE | UDMA_DST_INC_16 | UDMA_ARB_1,
    }

This lookup table is used to configure the DMA channels for the appropriate (8bit or 16bit) transfer sizes.

Table for an SPI DMA RX channel.

Definition at line 99 of file TivaSPI.hxx.

◆ dmaThreshold_

size_t TivaSPI::dmaThreshold_

private

threshold in bytes to start using DMA

Definition at line 308 of file TivaSPI.hxx.

◆ dmaTxConfig_

constexpr uint32_t TivaSPI::dmaTxConfig_[]

staticconstexprprivate

Initial value:

=
    {
        UDMA_SIZE_8  | UDMA_SRC_INC_8  | UDMA_DST_INC_NONE | UDMA_ARB_1,
        UDMA_SIZE_16 | UDMA_SRC_INC_16 | UDMA_DST_INC_NONE | UDMA_ARB_1,
    }

This lookup table is used to configure the DMA channels for the appropriate (8bit or 16bit) transfer sizes.

Table for an SPI DMA TX channel

Definition at line 110 of file TivaSPI.hxx.

◆ interrupt_

unsigned long TivaSPI::interrupt_

private

interrupt of this device

Definition at line 307 of file TivaSPI.hxx.

◆ MAX_DMA_TRANSFER_AMOUNT

constexpr size_t TivaSPI::MAX_DMA_TRANSFER_AMOUNT = 1024

staticconstexprprivate

Maximum number of bytes transferred in a single DMA transaction.

Definition at line 92 of file TivaSPI.hxx.

◆ sem_

OSSem* TivaSPI::sem_

private

reference to the semaphore belonging to this bus

Definition at line 305 of file TivaSPI.hxx.

◆ spiCr0_

uint16_t TivaSPI::spiCr0_

private

Configuration register 0 local copy.

Definition at line 312 of file TivaSPI.hxx.

◆ spiCr1_

uint16_t TivaSPI::spiCr1_

private

Configuration register 1 local copy.

Definition at line 313 of file TivaSPI.hxx.

◆ spiPrescaler_

uint16_t TivaSPI::spiPrescaler_

private

Prescale register local copy.

Definition at line 314 of file TivaSPI.hxx.

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

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TivaSPI()

◆ ~TivaSPI()

Member Function Documentation

◆ config_dma()

◆ data_get_non_blocking()

◆ data_put()

◆ data_put_non_blocking()

◆ disable()

◆ enable()

◆ get_lock()

◆ interrupt_handler()

◆ set_configuration()

◆ transfer()

◆ transfer_polled() [1/2]

◆ transfer_polled() [2/2]

◆ update_configuration()

Member Data Documentation

◆ base_

◆ DEFAULT_DMA_THRESHOLD_BYTES

◆ dmaChannelIndexRx_

◆ dmaChannelIndexTx_

◆ dmaNullConfig_

◆ dmaRxConfig_

◆ dmaThreshold_

◆ dmaTxConfig_

◆ interrupt_

◆ MAX_DMA_TRANSFER_AMOUNT

◆ sem_

◆ spiCr0_

◆ spiCr1_

◆ spiPrescaler_