Introduction

Here is the list of APIs used for Tamagawa encoder communication protocol

Data Structures
struct	tamagawa_ch_info
	Structure defining tamagawa per channel interface. More...

struct	tamagawa_cmd
	Structure defining Tamagawa command interface. More...

struct	tamagawa_config
	Structure defining Tamagawa configuration interface. More...

struct	rx_frames_received
	Tamagawa Interface Received data. More...

struct	tamagawa_interface
	Tamagawa Interface. More...

struct	config

struct	tamagawa_eeprom_interface
	Tamagawa EEPROM Interface. More...

struct	tamagawa_xchg
	Structure defining Tamagawa interface. More...

struct	tamagawa_clk_cfg
	Used to configure the Tamagawa Clock. More...

struct	register_offsets
	Used to store the register offsets depending on different PRU slices. More...

struct	tamagawa_priv
	Used to structures defining the Tamagawa interface, PRU slice and register offsets. More...

Functions
int32_t	tamagawa_command_process (struct tamagawa_priv *priv, int32_t cmd, uint8_t gTamagawa_multi_ch_mask)
	send the tamagawa command and wait till firmware acknowledges More...

int32_t	tamagawa_command_build (struct tamagawa_priv *priv, int32_t cmd, uint8_t gTamagawa_multi_ch_mask)
	setup the tamagawa command in the PRU interface buffer More...

void	tamagawa_command_send (struct tamagawa_priv *priv)
	trigger sending the tamagawa command in PRU More...

void	tamagawa_command_wait (struct tamagawa_priv *priv)
	wait till PRU finishes tamagawa transaction More...

void	tamagawa_config_clock (struct tamagawa_priv priv, struct tamagawa_clk_cfg clk_cfg)
	configure tamagawa clock More...

void	tamagawa_config_host_trigger (struct tamagawa_priv *priv)
	configure tamagawa master for host trigger mode More...

void	tamagawa_config_periodic_trigger (struct tamagawa_priv *priv)
	configure tamagawa master in periodic trigger mode More...

void	tamagawa_config_channel (struct tamagawa_priv *priv, uint32_t ch)
	select channel to be used by tamagawa master More...

void	tamagawa_config_multi_channel_mask (struct tamagawa_priv *priv, uint8_t mask)
	select mask of channels to be used in multi channel configuration by tamagawa master More...

uint8_t	tamagawa_multi_channel_detected (struct tamagawa_priv *priv)
	select channels detected in multi channel configuration by tamagawa master. required to be invoked only if firmware indicates initialization failure to know the channels that has been detected. Initialization success implies that all channels indicated has been detected. More...

void	tamagawa_multi_channel_set_cur (struct tamagawa_priv *priv, uint32_t ch)
	In multi channel configuration, select channel before receive processing in multi channel configuration. After receive is complete, select each channel and invoke rx API's to parse data recieved in each channel. More...

struct tamagawa_priv *	tamagawa_init (struct tamagawa_xchg tamagawa_xchg, void pruss_cfg, void *pruss_iep, uint32_t slice_value)
	Initialize tamagawa firmware interface address and get the pointer to struct tamagawa_priv instance. More...

void	tamagawa_update_data_id (struct tamagawa_priv *priv, int32_t cmd)
	update the current requested command id in tamagawa interface. More...

void	tamagawa_update_adf (struct tamagawa_priv *priv, uint32_t val, uint32_t ch)
	update the adf(address of EEPROM) field entered by user for EEPROM command in tamagawa interface. More...

void	tamagawa_update_edf (struct tamagawa_priv *priv, uint32_t val, uint32_t ch)
	update the edf(data for EEPROM) field entered by user for EEPROM command in tamagawa interface. More...

int32_t	tamagawa_parse (int32_t cmd, struct tamagawa_priv *priv)
	Parse the data in tamagawa interface. More...

int32_t	tamagawa_crc_verify (struct tamagawa_priv *priv)
	verify the CRC computed with the encoder crc. More...

void	tamagawa_update_crc (struct tamagawa_priv *priv, int32_t cmd, uint32_t ch)
	Pass the values of CF(Control Field), ADF(address of EEPROM) and EDF(data for EEPROM) to the CRC calculator fucntion and update the CRC field. More...

void	tamagawa_set_baudrate (struct tamagawa_priv *priv, double baudrate)
	Update the values for oversample rate and division factor for Tx and Rx. More...

void	tamagawa_eeprom_crc_reinit (struct tamagawa_priv *priv)
	Reset the values of the variables used in CRC calculation to 0. More...

uint32_t	tamagawa_reverse_bits (int8_t data)
	Reverse the bits of a number. More...

uint64_t	tamagawa_prepare_eeprom_tx_data (uint64_t eeprom_tx_data, volatile uint32_t data)
	Add the start and the stop bit to the reversed data. More...

void	tamagawa_prepare_eeprom_command (struct tamagawa_priv *priv, int32_t cmd, uint32_t ch)
	Prepare the required EEPROM command from the CF(Control Field), ADF(address of EEPROM) and EDF(data for EEPROM). More...

Enumerations
enum	data_id { DATA_ID_0, DATA_ID_1, DATA_ID_2, DATA_ID_3, DATA_ID_6, DATA_ID_7, DATA_ID_8, DATA_ID_C, DATA_ID_D, PERIODIC_TRIGGER_CMD, DATA_ID_NUM }
	Data ID codes. More...

Macros
#define	TAMAGAWA_MULTI_CH0 (1 << 0)
	Used to set the value of Tamagawa multi-channel mask based on the whether the Channel 0 is selected or not. More...

#define	TAMAGAWA_MULTI_CH1 (1 << 1)
	Used to set the value of Tamagawa multi-channel mask based on the whether the Channel 1 is selected or not. More...

#define	TAMAGAWA_MULTI_CH2 (1 << 2)
	Used to set the value of Tamagawa multi-channel mask based on the whether the Channel 2 is selected or not. More...

#define	MAX_CHANNELS (3)
	Used to set the maximum channels supported. More...

#define	MAX_EEPROM_ADDRESS (127)
	Used to set the maximum address that can be used for EEPROM Read/Write. More...

#define	MAX_EEPROM_WRITE_DATA (255)
	Used to set the maximum value that can be written in EEPROM. More...

Macro Definition Documentation

◆ TAMAGAWA_MULTI_CH0

#define TAMAGAWA_MULTI_CH0 (1 << 0)

Used to set the value of Tamagawa multi-channel mask based on the whether the Channel 0 is selected or not.

◆ TAMAGAWA_MULTI_CH1

#define TAMAGAWA_MULTI_CH1 (1 << 1)

Used to set the value of Tamagawa multi-channel mask based on the whether the Channel 1 is selected or not.

◆ TAMAGAWA_MULTI_CH2

#define TAMAGAWA_MULTI_CH2 (1 << 2)

Used to set the value of Tamagawa multi-channel mask based on the whether the Channel 2 is selected or not.

◆ MAX_CHANNELS

#define MAX_CHANNELS (3)

Used to set the maximum channels supported.

◆ MAX_EEPROM_ADDRESS

#define MAX_EEPROM_ADDRESS (127)

Used to set the maximum address that can be used for EEPROM Read/Write.

◆ MAX_EEPROM_WRITE_DATA

#define MAX_EEPROM_WRITE_DATA (255)

Used to set the maximum value that can be written in EEPROM.

Enumeration Type Documentation

◆ data_id

enum data_id

Data ID codes.

Enumerator
DATA_ID_0	Data readout data in one revolution
DATA_ID_1	Data readout multi-turn data
DATA_ID_2	Data readout encoder ID
DATA_ID_3	Data readout data in one revolution, encoder ID, multi-turn, encoder error
DATA_ID_6	EEPROM write
DATA_ID_7	Reset
DATA_ID_8	Reset
DATA_ID_C	Reset
DATA_ID_D	EEPROM read
PERIODIC_TRIGGER_CMD	periodic trigger command
DATA_ID_NUM	Number of Data ID codes

Function Documentation

◆ tamagawa_command_process()

int32_t tamagawa_command_process	(	struct tamagawa_priv *	priv,
		int32_t	cmd,
		uint8_t	gTamagawa_multi_ch_mask
	)

send the tamagawa command and wait till firmware acknowledges

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	cmd	tamagawa command number
[in]	gTamagawa_multi_ch_mask	Multi-channel mask to keep track of which channels are selected

Return values

0	success
-EINVAL	failure

◆ tamagawa_command_build()

int32_t tamagawa_command_build	(	struct tamagawa_priv *	priv,
		int32_t	cmd,
		uint8_t	gTamagawa_multi_ch_mask
	)

setup the tamagawa command in the PRU interface buffer

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	cmd	tamagawa command number
[in]	gTamagawa_multi_ch_mask	Multi-channel mask to keep track of which channels are selected

Return values

0	success
-EINVAL	failure

◆ tamagawa_command_send()

void tamagawa_command_send ( struct tamagawa_priv * priv )

trigger sending the tamagawa command in PRU

Parameters

[in] priv cookie returned by tamagawa_init

◆ tamagawa_command_wait()

void tamagawa_command_wait ( struct tamagawa_priv * priv )

wait till PRU finishes tamagawa transaction

Parameters

[in] priv cookie returned by tamagawa_init

◆ tamagawa_config_clock()

void tamagawa_config_clock	(	struct tamagawa_priv *	priv,
		struct tamagawa_clk_cfg *	clk_cfg
	)

configure tamagawa clock

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	clk_cfg	pointer to structure containing clock configuration data

◆ tamagawa_config_host_trigger()

void tamagawa_config_host_trigger ( struct tamagawa_priv * priv )

configure tamagawa master for host trigger mode

Parameters

[in] priv cookie returned by tamagawa_init

◆ tamagawa_config_periodic_trigger()

void tamagawa_config_periodic_trigger ( struct tamagawa_priv * priv )

configure tamagawa master in periodic trigger mode

Parameters

[in] priv cookie returned by tamagawa_init

◆ tamagawa_config_channel()

void tamagawa_config_channel	(	struct tamagawa_priv *	priv,
		uint32_t	ch
	)

select channel to be used by tamagawa master

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	ch	channel to be selected

◆ tamagawa_config_multi_channel_mask()

void tamagawa_config_multi_channel_mask	(	struct tamagawa_priv *	priv,
		uint8_t	mask
	)

select mask of channels to be used in multi channel configuration by tamagawa master

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	mask	channel mask

◆ tamagawa_multi_channel_detected()

uint8_t tamagawa_multi_channel_detected ( struct tamagawa_priv * priv )

select channels detected in multi channel configuration by tamagawa master.
required to be invoked only if firmware indicates initialization failure
to know the channels that has been detected. Initialization success implies
that all channels indicated has been detected.

Parameters

[in] priv cookie returned by tamagawa_init

Return values

mask	mask of the detected channels

◆ tamagawa_multi_channel_set_cur()

void tamagawa_multi_channel_set_cur	(	struct tamagawa_priv *	priv,
		uint32_t	ch
	)

In multi channel configuration, select channel before receive processing in
multi channel configuration. After receive is complete, select each channel
and invoke rx API's to parse data recieved in each channel.

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	ch	channel number to be selected

◆ tamagawa_init()

struct tamagawa_priv* tamagawa_init	(	struct tamagawa_xchg *	tamagawa_xchg,
		void *	pruss_cfg,
		void *	pruss_iep,
		uint32_t	slice_value
	)

Initialize tamagawa firmware interface address and get the pointer to struct tamagawa_priv instance.

Parameters

[in]	tamagawa_xchg	tamagawa firmware interface address
[in]	pruss_cfg	ICSS PRU config base address
[in]	pruss_iep	ICSS PRU IEP base address
[in]	slice_value	PRUx slice value : 0 for PRU0 and 1 for PRU1

Return values

priv	pointer to struct tamagawa_priv instance

◆ tamagawa_update_data_id()

void tamagawa_update_data_id	(	struct tamagawa_priv *	priv,
		int32_t	cmd
	)

update the current requested command id in tamagawa interface.

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	cmd	tamagawa command number

◆ tamagawa_update_adf()

void tamagawa_update_adf	(	struct tamagawa_priv *	priv,
		uint32_t	val,
		uint32_t	ch
	)

update the adf(address of EEPROM) field entered by user for EEPROM command in tamagawa interface.

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	val	ADF value to be updated
[in]	ch	channel number that is currently selected

◆ tamagawa_update_edf()

void tamagawa_update_edf	(	struct tamagawa_priv *	priv,
		uint32_t	val,
		uint32_t	ch
	)

update the edf(data for EEPROM) field entered by user for EEPROM command in tamagawa interface.

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	val	EDF value to be updated
[in]	ch	channel number that is currently selected

◆ tamagawa_parse()

int32_t tamagawa_parse	(	int32_t	cmd,
		struct tamagawa_priv *	priv
	)

Parse the data in tamagawa interface.

Parameters

[in]	cmd	tamagawa command number
[in]	priv	cookie returned by tamagawa_init

◆ tamagawa_crc_verify()

int32_t tamagawa_crc_verify ( struct tamagawa_priv * priv )

verify the CRC computed with the encoder crc.

Parameters

[in] priv cookie returned by tamagawa_init

Return values

1/0	if verify correctly, return 1 else return 0.

◆ tamagawa_update_crc()

void tamagawa_update_crc	(	struct tamagawa_priv *	priv,
		int32_t	cmd,
		uint32_t	ch
	)

Pass the values of CF(Control Field), ADF(address of EEPROM) and EDF(data for EEPROM) to the CRC calculator fucntion and update the CRC field.

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	cmd	tamagawa command number
[in]	ch	channel number that is currently selected

◆ tamagawa_set_baudrate()

void tamagawa_set_baudrate	(	struct tamagawa_priv *	priv,
		double	baudrate
	)

Update the values for oversample rate and division factor for Tx and Rx.

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	baudrate	baud rate of the tamagawa encoder

◆ tamagawa_eeprom_crc_reinit()

void tamagawa_eeprom_crc_reinit ( struct tamagawa_priv * priv )

Reset the values of the variables used in CRC calculation to 0.

Parameters

[in] priv cookie returned by tamagawa_init

◆ tamagawa_reverse_bits()

uint32_t tamagawa_reverse_bits ( int8_t data )

Reverse the bits of a number.

Parameters

[in] data 8 bit value for any of CF(Control Field), ADF(address of EEPROM) or EDF(data for EEPROM)

Return values

reversed_num number obtained after reversing the bits of data provided

◆ tamagawa_prepare_eeprom_tx_data()

uint64_t tamagawa_prepare_eeprom_tx_data	(	uint64_t	eeprom_tx_data,
		volatile uint32_t	data
	)

Add the start and the stop bit to the reversed data.

Parameters

[in]	eeprom_tx_data	holds the value of the Tx data to be sent
[in]	data	holds the value of CF(Control Field), ADF(address of EEPROM) or EDF(data for EEPROM)

Return values

eeprom_tx_data 64 bit integer that holds the value of the Tx data to be sent

◆ tamagawa_prepare_eeprom_command()

void tamagawa_prepare_eeprom_command	(	struct tamagawa_priv *	priv,
		int32_t	cmd,
		uint32_t	ch
	)

Prepare the required EEPROM command from the CF(Control Field), ADF(address of EEPROM) and EDF(data for EEPROM).

Parameters

[in]	priv	cookie returned by tamagawa_init
[in]	cmd	tamagawa command number
[in]	ch	channel number that is currently selected

Introduction

Data Structures

Functions

Enumerations

Macros

Macro Definition Documentation

◆ TAMAGAWA_MULTI_CH0

◆ TAMAGAWA_MULTI_CH1

◆ TAMAGAWA_MULTI_CH2

◆ MAX_CHANNELS

◆ MAX_EEPROM_ADDRESS

◆ MAX_EEPROM_WRITE_DATA

Enumeration Type Documentation

◆ data_id

Function Documentation

◆ tamagawa_command_process()

◆ tamagawa_command_build()

◆ tamagawa_command_send()

◆ tamagawa_command_wait()

◆ tamagawa_config_clock()

◆ tamagawa_config_host_trigger()

◆ tamagawa_config_periodic_trigger()

◆ tamagawa_config_channel()

◆ tamagawa_config_multi_channel_mask()

◆ tamagawa_multi_channel_detected()

◆ tamagawa_multi_channel_set_cur()

◆ tamagawa_init()

◆ tamagawa_update_data_id()

◆ tamagawa_update_adf()

◆ tamagawa_update_edf()

◆ tamagawa_parse()

◆ tamagawa_crc_verify()

◆ tamagawa_update_crc()

◆ tamagawa_set_baudrate()

◆ tamagawa_eeprom_crc_reinit()

◆ tamagawa_reverse_bits()

◆ tamagawa_prepare_eeprom_tx_data()

◆ tamagawa_prepare_eeprom_command()