lib_two_wire.h File Reference

(git 08d871f1, 2023-10-06)

#include "edtinc.h"

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Data Structures
struct	edt_two_wire
struct	EdtRegisterDescriptor

Macros
#define	TWO_WIRE_SFP   0x03
#define	TWO_WIRE_XFP   0x06
#define	TWO_WIRE_SERIAL_ID_DEVICE   0x50

Typedefs
typedef struct edt_two_wire	EdtTwoWire

Enumerations
enum	EdtTwoWireOptions { TWO_WIRE_OPT_CLK_STRETCH = (1 << 0) }
	Two-Wire interface options, for use in EdtTwoWire config struct. More...

Functions
int	edt_two_wire_reset (EdtDev edt_p, const EdtTwoWire *tw_ptr)
	Reset two wire interface in FPGA. More...
uint16_t	edt_two_wire_read (EdtDev edt_p, const EdtTwoWire *tw_ptr, uint8_t chip_id, uint32_t address, uint16_t len_data, uint8_t *data)
	Block read transaction. More...
int	edt_two_wire_write_byte (EdtDev edt_p, const EdtTwoWire *tw_ptr, uint8_t chip_id, uint32_t address, uint8_t data)
	Write a single byte. More...
void	edt_serial_dev_reg_write (EdtDev edt_p, uint32_t base_desc, uint8_t device_id, uint8_t address, uint8_t value)
	Write to a two-wire I2C or SPI device. More...
uint8_t	edt_serial_dev_reg_read (EdtDev edt_p, uint32_t base_desc, uint8_t device_id, uint8_t address)
	Read from a two-wire I2C or SPI device. More...
uint16_t	edt_serial_dev_reg_read_block (EdtDev edt_p, uint32_t base_desc, uint8_t device_id, uint8_t address, uint16_t length, uint8_t *block)
	Block read from a two-wire I2C or SPI device. More...
uint16_t	edt_serial_dev_reg_write_block (EdtDev edt_p, uint32_t base_desc, uint8_t device_id, uint8_t address, uint16_t length, uint8_t *block)
	Block write to a two-wire I2C or SPI device. More...
uint8_t	edt_serial_dev_set_bits (EdtDev edt_p, uint32_t base_desc, uint8_t device_id, uint8_t address, uint8_t value, uint8_t offset, uint8_t mask)
	Read/modify/write bits in a data byte on target device. More...
uint32_t	edt_get_two_wire_value (EdtDev edt_p, const EdtRegisterDescriptor *map, uint32_t base_desc, uint8_t device)
	Read arbitrary value up to 32-bits wide from an 8-bit interface. More...
int	edt_set_two_wire_value (EdtDev edt_p, const EdtRegisterDescriptor *map, uint32_t base_desc, uint32_t device, uint32_t value)
	Write arbitrary value up to 32-bits wide. More...
int	edt_two_wire_reg_dump_raw (EdtDev edt_p, const EdtRegisterDescriptor *map, uint32_t base_desc, uint32_t device)
	Read all registers included in a given register map and print to STDOUT. More...
int	edt_two_wire_reg_dump (EdtDev edt_p, const EdtRegisterDescriptor *map, uint32_t base_desc, uint32_t device)
	Read register fields from a register map and print to STDOUT. More...

Detailed Description

Copyright

Copyright (C) 2011 Engineering Design Team, Inc.

Library to read a 2 wire protocol device such as a serial EEPROM or a diagnostic port on a serial transceiver.

The port must be implemented as a register address like the PCISS/GS OCM

• bit 1 is the two wire clock, it is always an output
• bit 2 is the two wire serial data out, it is enable onto the serial data when
• bit 3 enables bit 2 onto the serial data bus when low
• bit 4 reads back the stat of the serial data wire, it should follow bit 2 when bit 3 is on

The OCM has three 2-wire device addresses:

1. channel 0 SFP transceiver at 0x23
2. channel 1 SFP transceiver at 0x33
3. serial EEPROM calibration - [!] currently unimplemented

Some two wire devices have 1 byte address others 2 etc. The EdtTwoWire::address_length field designates number of bytes.

The page write size varies from device to device. Setting to 1 will work on anything but writes will be slow.

Macro Definition Documentation

TWO_WIRE_SFP

#define TWO_WIRE_SFP   0x03

ID of SFP-type transceivers. Section 4.2 in [1]

TWO_WIRE_XFP

#define TWO_WIRE_XFP   0x06

ID of XFP-type transceivers. Section 4.2 in [1]

TWO_WIRE_SERIAL_ID_DEVICE

#define TWO_WIRE_SERIAL_ID_DEVICE   0x50

I2C Chip ID of SFF transceiver devices.

Typedef Documentation

EdtTwoWire

typedef struct edt_two_wire EdtTwoWire

Two-wire interface configuration.

Enumeration Type Documentation

EdtTwoWireOptions

enum EdtTwoWireOptions

Two-Wire interface options, for use in EdtTwoWire config struct.

Enumerator
TWO_WIRE_OPT_CLK_STRETCH	Enable support for I2C targets which may hold the SCL line until data is ready ("clock stretching"). This will cause the software to tristate the FPGA I2C SCL line during a transaction and wait until the line actually goes high.

Function Documentation

edt_two_wire_reset()

int edt_two_wire_reset	(	EdtDev	edt_p,
		const EdtTwoWire *	tw_ptr
	)

Reset two wire interface in FPGA.

Send up to 9 SCLKs while reading SDA until SDA is high. Then enable SDA and bring it low to make an I2C start condition.

Parameters

edt_p	The open EDT device handle.
tw_ptr	Two-wire configuration.

Returns

Zero if successful.

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edt_two_wire_read()

uint16_t edt_two_wire_read	(	EdtDev	edt_p,
		const EdtTwoWire *	tw_ptr,
		uint8_t	chip_id,
		uint32_t	address,
		uint16_t	len_data,
		uint8_t *	data
	)

Block read transaction.

Parameters

	edt_p	The open EDT device handle.
	tw_ptr	Two-wire configuration.
	chip_id	I2C chip ID of the target device.
	address	Address/command to send to target. Number of bits in address configured by EdtTwoWire::address_length.
	len_data	Number of bytes to read from target device.
[out]	data	Data read from target device. Must be at least len_data bytes.

Returns

Number of bytes actually read from target.

edt_two_wire_write_byte()

int edt_two_wire_write_byte	(	EdtDev	edt_p,
		const EdtTwoWire *	tw_ptr,
		uint8_t	chip_id,
		uint32_t	address,
		uint8_t	data
	)

Write a single byte.

Parameters

edt_p	The open EDT device handle.
tw_ptr	Two-wire configuration.
chip_id	I2C chip ID of the target device.
address	Address/command to send to target. Number of bits in address configured by EdtTwoWire::address_length.
data	Byte to send to target.

Returns

Zero if successful.

edt_serial_dev_reg_write()

void edt_serial_dev_reg_write	(	EdtDev	edt_p,
		uint32_t	base_desc,
		uint8_t	device_id,
		uint8_t	address,
		uint8_t	value
	)

Write to a two-wire I2C or SPI device.

Parameters

edt_p	The open EDT device handle.
base_desc	The base address of the FPGA two-wire interface.
device_id	7-bit I2C chip id, or address extension for SPI.
address	Target address/command.
value	Data to write to the target.

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edt_serial_dev_reg_read()

uint8_t edt_serial_dev_reg_read	(	EdtDev	edt_p,
		uint32_t	base_desc,
		uint8_t	device_id,
		uint8_t	address
	)

Read from a two-wire I2C or SPI device.

Parameters

edt_p	The open EDT device handle.
base_desc	The base address of the FPGA two-wire interface.
device_id	7-bit I2C chip id, or address extension for SPI.
address	Target address/command.

Returns

Data read from target.

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edt_serial_dev_reg_read_block()

uint16_t edt_serial_dev_reg_read_block	(	EdtDev	edt_p,
		uint32_t	base_desc,
		uint8_t	device_id,
		uint8_t	address,
		uint16_t	length,
		uint8_t *	block
	)

Block read from a two-wire I2C or SPI device.

Parameters

	edt_p	The open EDT device handle.
	base_desc	The base address of the FPGA two-wire interface.
	device_id	7-bit I2C chip id, or address extension for SPI.
	address	Target address/command.
	length	Number of bytes to read from target device.
[out]	block	Array of data read from target. Must be at least length bytes.

Returns

Number of bytes read from target.

edt_serial_dev_reg_write_block()

uint16_t edt_serial_dev_reg_write_block	(	EdtDev	edt_p,
		uint32_t	base_desc,
		uint8_t	device_id,
		uint8_t	address,
		uint16_t	length,
		uint8_t *	block
	)

Block write to a two-wire I2C or SPI device.

Address in address will be incremented and sent before each data byte.

Parameters

edt_p	The open EDT device handle.
base_desc	The base address of the FPGA two-wire interface.
device_id	7-bit I2C chip id, or address extension for SPI.
address	Target address/command.
length	Number of bytes to write to target device.
block	Data to send. Must be at least length bytes.

Returns

Number of bytes sent to target.

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edt_serial_dev_set_bits()

uint8_t edt_serial_dev_set_bits	(	EdtDev	edt_p,
		uint32_t	base_desc,
		uint8_t	device_id,
		uint8_t	address,
		uint8_t	value,
		uint8_t	offset,
		uint8_t	mask
	)

Read/modify/write bits in a data byte on target device.

Useful to set specific bits in a bitfield of a target device register. For example, to set a value of 3 to a 2-bit field with an offset of 4 bits, pass 3 to value, 4 to offset, and 0x3 to mask.

Parameters

edt_p	The open EDT device handle.
base_desc	The base address of the FPGA two-wire interface.
device_id	7-bit I2C chip id, or address extension for SPI.
address	Target address/command.
value	Data value to write in the bitfield.
offset	Bit offset in the target register. value will be left-shifted by this amount.
mask	Bit mask to clear in byte read from target. Typically indicates the width of the bitfield. The mask will be shifted by offset.

Returns

Copy of the value written to the target.

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edt_get_two_wire_value()

uint32_t edt_get_two_wire_value	(	EdtDev	edt_p,
		const EdtRegisterDescriptor *	map,
		uint32_t	base_desc,
		uint8_t	device
	)

Read arbitrary value up to 32-bits wide from an 8-bit interface.

Parameters

edt_p	The open EDT device handle.
map	Descriptor of register to read from.
base_desc	The base address of the FPGA two-wire interface.
device	7-bit I2C chip id, or address extension for SPI.

Returns

Data value read from target device.

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edt_set_two_wire_value()

int edt_set_two_wire_value	(	EdtDev	edt_p,
		const EdtRegisterDescriptor *	map,
		uint32_t	base_desc,
		uint32_t	device,
		uint32_t	value
	)

Write arbitrary value up to 32-bits wide.

Parameters

edt_p	The open EDT device handle.
map	Descriptor of register to read from.
base_desc	The base address of the FPGA two-wire interface.
device	7-bit I2C chip id, or address extension for SPI.
value	Data value to write to target.

Returns

Zero if successful.

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edt_two_wire_reg_dump_raw()

int edt_two_wire_reg_dump_raw	(	EdtDev	edt_p,
		const EdtRegisterDescriptor *	map,
		uint32_t	base_desc,
		uint32_t	device
	)

Read all registers included in a given register map and print to STDOUT.

The entire 8-bit data value read from the target registers is shown. The field offsets and shifts specified in the register map are ignored.

Parameters

edt_p	The open EDT device handle.
map	Array of register descriptors to read from. Last element in the map MUST be all zeros to indicate the end of the array.
base_desc	The base address of the FPGA two-wire interface.
device	7-bit I2C chip id, or address extension for SPI.

Returns

Zero if successful.

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edt_two_wire_reg_dump()

int edt_two_wire_reg_dump	(	EdtDev	edt_p,
		const EdtRegisterDescriptor *	map,
		uint32_t	base_desc,
		uint32_t	device
	)

Read register fields from a register map and print to STDOUT.

Only shows the values of the register fields defined in the provided register map.

Parameters

edt_p	The open EDT device handle.
map	Array of register descriptors to read from. Last element in the map MUST be all zeros to indicate the end of the array.
base_desc	The base address of the FPGA two-wire interface.
device	7-bit I2C chip id, or address extension for SPI.

Returns

Zero if successful.

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