Data Structures
struct	pi_i2c_conf_t
	I2C master configuration structure. More...

Enumerations
enum	pi_i2c_xfer_flags_e
	Properties for I2C transfers. More...

enum	pi_i2c_ioctl_e
	Commands for pi_i2c_control. More...

Functions
void	pi_i2c_conf_init (pi_i2c_conf_t *conf)
	Initialize an I2C configuration with default values. More...

void	pi_i2c_conf_set_slave_addr (struct pi_i2c_conf *conf, uint16_t slave_addr, int8_t is_10_bits)
	set slave addr in conf. More...

void	pi_i2c_conf_set_wait_cycles (struct pi_i2c_conf *conf, uint16_t wait_cycles)
	set wait_cycles in conf. More...

int	pi_i2c_open (struct pi_device *device)
	Open an I2C device. More...

void	pi_i2c_close (struct pi_device *device)
	Close an opened I2C device. More...

void	pi_i2c_ioctl (struct pi_device device, uint32_t cmd, void arg)
	Dynamically change the device configuration. More...

int	pi_i2c_read (struct pi_device device, uint8_t rx_buff, int length, pi_i2c_xfer_flags_e flags)
	Enqueue a burst read copy from the I2C (from I2C device to chip). More...

int	pi_i2c_write (struct pi_device device, uint8_t tx_data, int length, pi_i2c_xfer_flags_e flags)
	Enqueue a burst write copy to the I2C (from chip to I2C device). More...

void	pi_i2c_write_read (struct pi_device device, void tx_buffer, void *rx_buffer, uint32_t tx_size, uint32_t rx_size)

void	pi_i2c_write_dual (struct pi_device device, void tx_buffer0, void *tx_buffer1, uint32_t tx_size0, uint32_t tx_size1)

void	pi_i2c_read_async (struct pi_device device, uint8_t rx_buff, int length, pi_i2c_xfer_flags_e flags, pi_task_t *task)
	Enqueue an asynchronous burst read copy from the I2C (from I2C device to chip). More...

void	pi_i2c_write_async (struct pi_device device, uint8_t tx_data, int length, pi_i2c_xfer_flags_e flags, pi_task_t *task)
	Enqueue a burst write copy to the I2C (from chip to I2C device). More...

void	pi_i2c_write_read_async (struct pi_device device, void tx_buffer, void rx_buffer, uint32_t tx_size, uint32_t rx_size, pi_task_t callback)

void	pi_i2c_write_dual_async (struct pi_device device, void tx_buffer0, void tx_buffer1, uint32_t tx_size0, uint32_t tx_size1, pi_task_t callback)

int	pi_i2c_read_timeout (struct pi_device device, uint8_t rx_buff, int length, pi_i2c_xfer_flags_e flags, uint32_t timeout_us)
	Enqueue an asynchronous burst read copy from the I2C (from I2C device to chip), with timeout. More...

int	pi_i2c_write_timeout (struct pi_device device, uint8_t tx_data, int length, pi_i2c_xfer_flags_e flags, uint32_t timeout_us)
	Enqueue a burst write copy to the I2C (from chip to I2C device), with timeout. More...

int	pi_i2c_get_request_status (pi_task_t *task)
	get the request status from a task More...

int	pi_i2c_detect (struct pi_device device, struct pi_i2c_conf conf, uint8_t *rx_data)
	Scan i2c bus to detect a dev. More...

Description

The I2C driver provides support for transferring data between an external I2C device and the chip running this driver.

Enumeration Type Documentation

enum pi_i2c_ioctl_e

This is used to tell which command to execute through pi_i2c_control.

Enumerator

PI_I2C_CTRL_SET_MAX_BAUDRATE

Change maximum baudrate.

Parameters

baudrate Max baudrate.

PI_I2C_IOCTL_ABORT_RX

Abort RX transfer.

Abort current RX transfert.

PI_I2C_IOCTL_ABORT_TX

Abort TX transfer.

Abort current TX transfert.

PI_I2C_IOCTL_ATTACH_TIMEOUT_RX

Attach UDMA timer.

This command attaches a UDMA timer channel to UDMA reception channel.

Parameters

timeout_id UDMA timeout channel ID.

PI_I2C_IOCTL_DETACH_TIMEOUT_RX

Detach UDMA timer.

This command removes a UDMA timer channel attached to UDMA reception channel.

Parameters

timeout_id UDMA timeout channel ID.

PI_I2C_IOCTL_ATTACH_TIMEOUT_TX

Attach UDMA timer.

This command attaches a UDMA timer channel to UDMA transmission channel.

Parameters

timeout_id UDMA timeout channel ID.

PI_I2C_IOCTL_DETACH_TIMEOUT_TX

Detach UDMA timer.

This command removes a UDMA timer channel attached to UDMA transmission channel.

Parameters

timeout_id UDMA timeout channel ID.

enum pi_i2c_xfer_flags_e

This is used to specify additional behaviors when transfering data through I2C.

Enumerator
PI_I2C_XFER_STOP	Generate a STOP bit at the end of the transfer.
PI_I2C_XFER_NO_STOP	Don't generate a STOP bit at the end of the transfer.
PI_I2C_XFER_START	Generate a START bit at the beginning of the transfer.
PI_I2C_XFER_NO_START	Don't generate a START bit at the beginning of the transfer.
PI_I2C_XFER_RESTART	Generate a RESTART bit at the beginning of the transfer.
PI_I2C_XFER_NO_RESTART	Don't generate a RESTART bit at the beginning of the transfer.

Function Documentation

void pi_i2c_close ( struct pi_device * device )

This function can be called to close an opened I2C device once it is not needed anymore, in order to free all allocated resources. Once this function is called, the device is not accessible anymore and must be opened again before being used.

Parameters

device The device structure of the device to close.

void pi_i2c_conf_init ( pi_i2c_conf_t * conf )

This function can be called to get default values for all parameters before setting some of them. The structure containing the configuration must be kept alive until the I2C device is opened.

Parameters

conf	A pointer to the I2C configuration.

void pi_i2c_conf_set_slave_addr	(	struct pi_i2c_conf *	conf,
		uint16_t	slave_addr,
		int8_t	is_10_bits
	)

Parameters

conf	A pointer to the I2C configuration.
slave_addr	Address of the slave device.
is_10_bits	Indicate if slave address is 7 bits or 10 bits.

void pi_i2c_conf_set_wait_cycles	(	struct pi_i2c_conf *	conf,
		uint16_t	wait_cycles
	)

Parameters

conf	A pointer to the I2C configuration.
wait_cycles	Number of wait cycles applied at the end of transfer

int pi_i2c_detect	(	struct pi_device *	device,
		struct pi_i2c_conf *	conf,
		uint8_t *	rx_data
	)

This function can be used to detect if a device is connected to the i2c bus. The pi_i2c_conf_t structure is used to pass the address of the device to look for, with different baudrate if needed.

Parameters

device	Pointer to device structure.
conf	Conf struct holding address and baudrate.
rx_data	Pointer to 1 Byte buffer to store data.

Return values

0x00	If a device has been detected at given address.
0xFF	Otherwise.

int pi_i2c_get_request_status ( pi_task_t * task )

This function can be used to retrieve the request status from a task.

Parameters

task	the task to retrieve the status from

Warning: in order to be able to retrieve the request status you need to pass a pointer to the task as the first callback argument. You can use next arguments as you please.

Returns: PI_OK if the request was successful PI_ERR_I2C_NACK if a NACK was received during the request

void pi_i2c_ioctl	(	struct pi_device *	device,
		uint32_t	cmd,
		void *	arg
	)

This function can be called to change part of the device configuration after it has been opened.

Parameters

device	A pointer to the structure describing the device.
cmd	The command which specifies which parameters of the driver to modify and for some of them also their values. The command must be one of those defined in pi_i2c_ioctl_e.
arg	An additional value which is required for some parameters when they are set.

int pi_i2c_open ( struct pi_device * device )

This function must be called before the Hyperbus device can be used. It will do all the needed configuration to make it usable and initialize the handle used to refer to this opened device when calling other functions.

Parameters

device A pointer to the device structure of the device to open. This structure is allocated by the called and must be kept alive until the device is closed.

Returns: 0 if the operation is successfull, -1 if there was an error.

int pi_i2c_read	(	struct pi_device *	device,
		uint8_t *	rx_buff,
		int	length,
		pi_i2c_xfer_flags_e	flags
	)

This function can be used to read at least 1 byte of data from the I2C device. The copy will make a synchronous transfer between the I2C and one of the chip memory. The caller is blocked until the transfer is finished. Depending on the chip, there may be some restrictions on the memory which can be used. Check the chip-specific documentation for more details.

Parameters

device	A pointer to the structure describing the device.
rx_buff	The address in the chip where the received data must be written.
length	The size in bytes of the copy.
flags	Specify additional transfer behaviors like start and stop bits management.

Returns: PI_OK if request is successful PI_ERR_I2C_NACK if a NACK was received during the request

void pi_i2c_read_async	(	struct pi_device *	device,
		uint8_t *	rx_buff,
		int	length,
		pi_i2c_xfer_flags_e	flags,
		pi_task_t *	task
	)

This function can be used to read at least 1 byte of data from the I2C device. The copy will make an asynchronous transfer between the I2C and one of the chip memory. A task must be specified in order to specify how the caller should be notified when the transfer is finished. The task will contain the request status (success or error). It should be retrieved using the pi_i2c_get_request_status function. Depending on the chip, there may be some restrictions on the memory which can be used. Check the chip-specific documentation for more details.

Parameters

device	A pointer to the structure describing the device.
rx_buff	The address in the chip where the received data must be written.
length	The size in bytes of the copy.
flags	Specify additional transfer behaviors like start and stop bits management.
task	The task used to notify the end of transfer. See the documentation of pi_task_t for more details.

int pi_i2c_read_timeout	(	struct pi_device *	device,
		uint8_t *	rx_buff,
		int	length,
		pi_i2c_xfer_flags_e	flags,
		uint32_t	timeout_us
	)

This function has the same behaviour as pi_i2c_read(), with timeout. This timeout value is used to abort/cancel a transfer when timeout is reached.

Parameters

device	Pointer to the structure describing the device.
rx_buff	Address in the chip where the received data must be written.
length	Size in bytes of the copy.
flags	Specify additional transfer behaviors like start and stop bits management.
timeout_us	Timeout value in us.

Note

To use this feature, a UDMA timeout channel must be allocated before a call to this functions :

pi_udma_timeout_alloc()
pi_i2c_ioctl() //PI_I2C_IOCTL_ATTACH_TIMEOUT_RX

To use this feature asynchronously, proceed as follows :

pi_udma_timeout_alloc()
pi_i2c_ioctl() //PI_I2C_IOCTL_ATTACH_TIMEOUT_RX
pi_task_timeout_set()
pi_i2c_write_async()

int pi_i2c_write	(	struct pi_device *	device,
		uint8_t *	tx_data,
		int	length,
		pi_i2c_xfer_flags_e	flags
	)

This function can be used to write at least 1 byte of data to the I2C device. The copy will make a synchronous transfer between the I2C and one of the chip memory. The caller is blocked until the transfer is finished. Depending on the chip, there may be some restrictions on the memory which can be used. Check the chip-specific documentation for more details.

Parameters

device	A pointer to the structure describing the device.
tx_data	The address in the chip where the data to be sent is read.
length	The size in bytes of the copy.
flags	Specify additional transfer behaviors like start and stop bits management.

Returns: PI_OK if request is successful PI_ERR_I2C_NACK if a NACK was received during the request

void pi_i2c_write_async	(	struct pi_device *	device,
		uint8_t *	tx_data,
		int	length,
		pi_i2c_xfer_flags_e	flags,
		pi_task_t *	task
	)

This function can be used to write at least 1 byte of data to the I2C device. The copy will make an asynchronous transfer between the I2C and one of the chip memory. A task must be specified in order to specify how the caller should be notified when the transfer is finished. The task will contain the request status (success or error). It should be retrieved using the pi_i2c_get_request_status function. Depending on the chip, there may be some restrictions on the memory which can be used. Check the chip-specific documentation for more details.

Parameters

device	A pointer to the structure describing the device.
tx_data	The address in the chip where the data to be sent is read.
length	The size in bytes of the copy
flags	Specify additional transfer behaviors like start and stop bits management.
task	The task used to notify the end of transfer. See the documentation of pi_task_t for more details.

void pi_i2c_write_dual	(	struct pi_device *	device,
		void *	tx_buffer0,
		void *	tx_buffer1,
		uint32_t	tx_size0,
		uint32_t	tx_size1
	)

void pi_i2c_write_dual_async	(	struct pi_device *	device,
		void *	tx_buffer0,
		void *	tx_buffer1,
		uint32_t	tx_size0,
		uint32_t	tx_size1,
		pi_task_t *	callback
	)

void pi_i2c_write_read	(	struct pi_device *	device,
		void *	tx_buffer,
		void *	rx_buffer,
		uint32_t	tx_size,
		uint32_t	rx_size
	)

void pi_i2c_write_read_async	(	struct pi_device *	device,
		void *	tx_buffer,
		void *	rx_buffer,
		uint32_t	tx_size,
		uint32_t	rx_size,
		pi_task_t *	callback
	)

int pi_i2c_write_timeout	(	struct pi_device *	device,
		uint8_t *	tx_data,
		int	length,
		pi_i2c_xfer_flags_e	flags,
		uint32_t	timeout_us
	)

This function has the same behaviour as pi_i2c_write(), with timeout. This timeout value is used to abort/cancel a transfer when timeout is reached.

Parameters

device	Pointer to the structure describing the device.
tx_data	Address in the chip where the data to be sent is read.
length	Size in bytes of the copy
flags	Specify additional transfer behaviors like start and stop bits management.
timeout_us	Timeout value in us.

Note

To use this feature, a UDMA timeout channel must be allocated before a call to this functions :

pi_udma_timeout_alloc()
pi_i2c_ioctl() //PI_I2C_IOCTL_ATTACH_TIMEOUT_TX

To use this feature asynchronously, proceed as follows :

pi_udma_timeout_alloc()
pi_i2c_ioctl() //PI_I2C_IOCTL_ATTACH_TIMEOUT_TX
pi_task_timeout_set()
pi_i2c_write_async()

Data Structures

Enumerations

Functions

Description

Enumeration Type Documentation

Function Documentation