Introduction

This module contains structures that define the PRU-ICSS firmware interface for Tamagawa encoder communication. These structures are mapped to PRU DRAM and provide the communication interface between ARM and PRU cores.

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

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

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

struct	tamagawa_rx_frames
	Tamagawa received frame data. More...

struct	tamagawa_interface
	Tamagawa main interface structure. More...

struct	tamagawa_channel_config
	Tamagawa channel configuration structure. More...

struct	tamagawa_periodic_trigger_cfg
	Tamagawa periodic trigger configuration structure. More...

struct	tamagawa_eeprom_interface
	Tamagawa EEPROM interface structure. More...

struct	tamagawa_xchg
	Structure defining complete Tamagawa PRU-ICSS exchange interface. More...

struct	tamagawa_clk_cfg
	Tamagawa clock configuration structure. More...

struct	tamagawa_attrs
	Tamagawa attributes structure. More...

struct	tamagawa_priv
	Tamagawa private runtime state structure. More...

struct	tamagawa_config
	Tamagawa configuration structure (handle) More...

struct	tamagawa_params
	Tamagawa initialization parameters structure. More...

Functions
void	tamagawa_params_init (tamagawa_params *params)
	Initialize Tamagawa parameters structure with default values. More...

tamagawa_handle	tamagawa_init (uint32_t index, const tamagawa_params *params)
	Initialize a Tamagawa instance. More...

void	tamagawa_deinit (tamagawa_handle handle)
	Deinitialize Tamagawa interface and release resources. More...

int32_t	tamagawa_command_process (tamagawa_handle handle, int32_t cmd)
	Process a Tamagawa command (build, send, and wait for completion) More...

int32_t	tamagawa_command_build (tamagawa_handle handle, int32_t cmd)
	Build a Tamagawa command in the PRU interface. More...

int32_t	tamagawa_command_send (tamagawa_handle handle)
	Trigger sending the Tamagawa command in PRU. More...

int32_t	tamagawa_command_wait (tamagawa_handle handle)
	Wait until PRU finishes Tamagawa transaction. More...

int32_t	tamagawa_config_global_rx_arm_cnt (tamagawa_handle handle, uint16_t rx_en_cnt)
	Configure global RX auto arm counter for Tamagawa interface. More...

int32_t	tamagawa_config_clock (tamagawa_handle handle, tamagawa_clk_cfg *clk_cfg)
	Configure Tamagawa clock dividers and source selection. More...

int32_t	tamagawa_config_host_trigger (tamagawa_handle handle)
	Configure Tamagawa interface for host trigger mode. More...

int32_t	tamagawa_config_periodic_trigger_cmp_mode (tamagawa_handle handle)
	Configure Tamagawa interface for periodic trigger using IEP compare mode. More...

int32_t	tamagawa_config_channel (tamagawa_handle handle, uint8_t mask)
	Configure channel mask for Tamagawa interface. More...

int32_t	tamagawa_multi_channel_set_cur (tamagawa_handle handle, uint8_t ch)
	Set current channel for receive processing in multi-channel mode. More...

int32_t	tamagawa_update_data_id (tamagawa_handle handle, int32_t cmd)
	Update the current requested command ID in Tamagawa interface. More...

int32_t	tamagawa_update_adf (tamagawa_handle handle, uint32_t val, uint8_t ch)
	Update the ADF (EEPROM address) field for EEPROM command. More...

int32_t	tamagawa_update_edf (tamagawa_handle handle, uint32_t val, uint8_t ch)
	Update the EDF (EEPROM data) field for EEPROM Write command. More...

int32_t	tamagawa_parse (tamagawa_handle handle, int32_t cmd)
	Parse the data in Tamagawa interface received from the encoder. More...

int32_t	tamagawa_crc_verify (tamagawa_handle handle)
	Verify the CRC computed by PRU firmware against encoder CRC. More...

int32_t	tamagawa_update_crc (tamagawa_handle handle, int32_t cmd, uint8_t ch)
	Update CRC field for EEPROM command. More...

int32_t	tamagawa_set_baudrate (tamagawa_handle handle, double baud_rate)
	Set Tamagawa communication baud rate. More...

const tamagawa_attrs *	tamagawa_get_attrs (tamagawa_handle handle)
	Get pointer to Tamagawa attributes structure. More...

tamagawa_priv *	tamagawa_get_priv (tamagawa_handle handle)
	Get pointer to Tamagawa private structure. More...

int32_t	tamagawa_config_iep_cmp_event (tamagawa_handle handle, uint8_t channel, uint8_t event_num)
	Configure IEP CMP event for periodic trigger (DMEM configuration only) More...

int32_t	tamagawa_config_iep_cap_event (tamagawa_handle handle, uint8_t channel, uint8_t event_num)
	Configure IEP CAP event for periodic trigger (DMEM configuration only) More...

int32_t	tamagawa_config_periodic_trigger_cap_mode (tamagawa_handle handle)
	Configure Tamagawa interface for periodic trigger using IEP capture mode. More...

Typedefs
typedef tamagawa_config *	tamagawa_handle
	Tamagawa handle type. More...

Enumerations
enum	tamagawa_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_CMP_CMD, PERIODIC_TRIGGER_CAP_CMD, DATA_ID_NUM }
	Tamagawa Data ID codes. More...

Macros
#define	TAMAGAWA_MAX_CHANNELS_PER_SLICE (3)
	Maximum number of channels supported per PRU slice. More...

#define	TAMAGAWA_MODE_SINGLE_CHANNEL_SINGLE_PRU (0U)
	Single PRU - Single channel configuration mode. More...

#define	TAMAGAWA_MODE_MULTI_CHANNEL_SINGLE_PRU (1U)
	Single PRU - Multichannel configuration mode. More...

#define	TAMAGAWA_MODE_MULTI_CHANNEL_MULTI_PRU (2U)
	Multi PRU - Load share configuration mode. More...

#define	TAMAGAWA_OPMODE_PERIODIC_CMP (0x0U)
	Tamagawa operation mode: Periodic trigger mode using iep compare event. More...

#define	TAMAGAWA_OPMODE_HOST_TRIGGER (0x1U)
	Tamagawa operation mode: Host trigger. More...

#define	TAMAGAWA_OPMODE_PERIODIC_CAP (0x2U)
	Tamagawa operation mode: Periodic trigger mode using iep capture event. More...

#define	TAMAGAWA_ENABLE_CYCLE_TRIGGER (0x1)
	Enable cycle trigger for firmware. More...

#define	TAMAGAWA_DISABLE_CYCLE_TRIGGER (0x0)
	Disable cycle trigger for firmware. More...

#define	TAMAGAWA_FREQ_2_5_MHZ (2500000U)
	Allowed Tamagawa communication frequency: 2.5 MHz. More...

#define	TAMAGAWA_FREQ_5_MHZ (5000000U)
	Allowed Tamagawa communication frequency: 5 MHz. More...

#define	TAMAGAWA_IEP_MAX_CAP_EVENT (0x8U)
	Maximum IEP CAP event number (0-7) More...

#define	TAMAGAWA_IEP_MAX_CMP_EVENT (0x10U)
	Maximum IEP CMP event number (0-15) More...

#define	TAMAGAWA_MAX_EEPROM_ADDRESS (127)
	Maximum EEPROM address that can be used for EEPROM Read/Write. More...

#define	TAMAGAWA_MAX_EEPROM_WRITE_DATA (255)
	Maximum value that can be written to EEPROM. More...

#define	TAMAGAWA_RX_OVERSAMPLING_RATE (7)
	RX oversampling rate. Set 7 for 8x oversampling. More...

#define	TAMAGAWA_DELAY_COUNTER_INCREMENT (5)
	Delay counter increment value. 5 ns based on 200 MHz clock, as Three Channel Peripheral interface needs this value in 200 MHz clock units. More...

#define	TAMAGAWA_EEPROM_WRITE_CRC_BYTES (3)
	Number of bytes in CRC calculation for EEPROM Write (CF + ADF + EDF) More...

#define	TAMAGAWA_EEPROM_READ_CRC_BYTES (2)
	Number of bytes in CRC calculation for EEPROM Read (CF + ADF) More...

#define	TAMAGAWA_BITS_PER_BYTE (8)
	Number of bits in a byte. More...

#define	TAMAGAWA_CRC_DATA_ARRAY_SIZE (12)
	CRC calculation array size for storing frame data. More...

#define	TAMAGAWA_DEFAULT_CMD_WAIT_DELAY_US (100)
	Default command process delay in microseconds. More...

#define	TAMAGAWA_DEFAULT_MAX_WAIT_LOOP_COUNT (50U)
	Default maximum wait loop count. More...

#define	TAMAGAWA_CF_EEPROM_WRITE (0x32U)
	Tamagawa EEPROM Control Field value for Write operation. More...

#define	TAMAGAWA_CF_EEPROM_READ (0xEAU)
	Tamagawa EEPROM Control Field value for Read operation. More...

#define	TAMAGAWA_CFG_REG_SIZE (4U)
	IEP CAP0 register offset - cslr common file does not have defined cap registers FIXME: Remove these definitions once they are available in cslr_common.h. More...

#define	TAMAGAWA_CSL_ICSS_PR1_IEP0_SLV_CAP0_REG0 (CSL_ICSS_PR1_IEP0_SLV_CAP_CFG_REG + 2U*TAMAGAWA_CFG_REG_SIZE)

#define	TAMAGAWA_8_BYTE_REG_OFFSET (8U)
	8-byte register offset for IEP registers More...

Macro Definition Documentation

◆ TAMAGAWA_MAX_CHANNELS_PER_SLICE

#define TAMAGAWA_MAX_CHANNELS_PER_SLICE (3)

Maximum number of channels supported per PRU slice.

◆ TAMAGAWA_MODE_SINGLE_CHANNEL_SINGLE_PRU

#define TAMAGAWA_MODE_SINGLE_CHANNEL_SINGLE_PRU (0U)

Single PRU - Single channel configuration mode.

Only one channel (ch0, ch1, or ch2) is used with a single PRU core. This is the simplest configuration for single encoder applications.

◆ TAMAGAWA_MODE_MULTI_CHANNEL_SINGLE_PRU

#define TAMAGAWA_MODE_MULTI_CHANNEL_SINGLE_PRU (1U)

Single PRU - Multichannel configuration mode.

Multiple channels (up to 3: ch0, ch1, ch2) are managed by a single PRU core. All channels share the same PRU core resources without load sharing.

◆ TAMAGAWA_MODE_MULTI_CHANNEL_MULTI_PRU

#define TAMAGAWA_MODE_MULTI_CHANNEL_MULTI_PRU (2U)

Multi PRU - Load share configuration mode.

Multiple channels are distributed across multiple PRU cores with load sharing. Each PRU core handles different channels with synchronized global reinit operations.

◆ TAMAGAWA_OPMODE_PERIODIC_CMP

#define TAMAGAWA_OPMODE_PERIODIC_CMP (0x0U)

Tamagawa operation mode: Periodic trigger mode using iep compare event.

In periodic mode, the PRU firmware automatically triggers position readout based on IEP compare events.

◆ TAMAGAWA_OPMODE_HOST_TRIGGER

#define TAMAGAWA_OPMODE_HOST_TRIGGER (0x1U)

Tamagawa operation mode: Host trigger.

In host trigger mode, the R5F host processor explicitly triggers each position readout by setting the trigger bit.

◆ TAMAGAWA_OPMODE_PERIODIC_CAP

#define TAMAGAWA_OPMODE_PERIODIC_CAP (0x2U)

Tamagawa operation mode: Periodic trigger mode using iep capture event.

In periodic mode, the PRU firmware automatically triggers position readout based on IEP capture events.

◆ TAMAGAWA_ENABLE_CYCLE_TRIGGER

#define TAMAGAWA_ENABLE_CYCLE_TRIGGER (0x1)

Enable cycle trigger for firmware.

◆ TAMAGAWA_DISABLE_CYCLE_TRIGGER

#define TAMAGAWA_DISABLE_CYCLE_TRIGGER (0x0)

Disable cycle trigger for firmware.

◆ TAMAGAWA_FREQ_2_5_MHZ

#define TAMAGAWA_FREQ_2_5_MHZ (2500000U)

Allowed Tamagawa communication frequency: 2.5 MHz.

◆ TAMAGAWA_FREQ_5_MHZ

#define TAMAGAWA_FREQ_5_MHZ (5000000U)

Allowed Tamagawa communication frequency: 5 MHz.

◆ TAMAGAWA_IEP_MAX_CAP_EVENT

#define TAMAGAWA_IEP_MAX_CAP_EVENT (0x8U)

Maximum IEP CAP event number (0-7)

IEP supports 8 capture events (CAP0-CAP7)

◆ TAMAGAWA_IEP_MAX_CMP_EVENT

#define TAMAGAWA_IEP_MAX_CMP_EVENT (0x10U)

Maximum IEP CMP event number (0-15)

IEP supports 16 compare events (CMP0-CMP15)

◆ TAMAGAWA_MAX_EEPROM_ADDRESS

#define TAMAGAWA_MAX_EEPROM_ADDRESS (127)

Maximum EEPROM address that can be used for EEPROM Read/Write.

◆ TAMAGAWA_MAX_EEPROM_WRITE_DATA

#define TAMAGAWA_MAX_EEPROM_WRITE_DATA (255)

Maximum value that can be written to EEPROM.

◆ TAMAGAWA_RX_OVERSAMPLING_RATE

#define TAMAGAWA_RX_OVERSAMPLING_RATE (7)

RX oversampling rate. Set 7 for 8x oversampling.

◆ TAMAGAWA_DELAY_COUNTER_INCREMENT

#define TAMAGAWA_DELAY_COUNTER_INCREMENT (5)

Delay counter increment value. 5 ns based on 200 MHz clock, as Three Channel Peripheral interface needs this value in 200 MHz clock units.

◆ TAMAGAWA_EEPROM_WRITE_CRC_BYTES

#define TAMAGAWA_EEPROM_WRITE_CRC_BYTES (3)

Number of bytes in CRC calculation for EEPROM Write (CF + ADF + EDF)

◆ TAMAGAWA_EEPROM_READ_CRC_BYTES

#define TAMAGAWA_EEPROM_READ_CRC_BYTES (2)

Number of bytes in CRC calculation for EEPROM Read (CF + ADF)

◆ TAMAGAWA_BITS_PER_BYTE

#define TAMAGAWA_BITS_PER_BYTE (8)

Number of bits in a byte.

◆ TAMAGAWA_CRC_DATA_ARRAY_SIZE

#define TAMAGAWA_CRC_DATA_ARRAY_SIZE (12)

CRC calculation array size for storing frame data.

◆ TAMAGAWA_DEFAULT_CMD_WAIT_DELAY_US

#define TAMAGAWA_DEFAULT_CMD_WAIT_DELAY_US (100)

Default command process delay in microseconds.

This delay is used in command wait loops to prevent busy-waiting and allow timeout detection. Can be overridden via tamagawa_params.

◆ TAMAGAWA_DEFAULT_MAX_WAIT_LOOP_COUNT

#define TAMAGAWA_DEFAULT_MAX_WAIT_LOOP_COUNT (50U)

Default maximum wait loop count.

Maximum number of wait loop iterations in tamagawa_command_wait to detect communication failures. The actual timeout is: max_wait_loop_count × cmd_wait_delay_us. With defaults (50 × 100 us = 5000 us). Can be overridden via tamagawa_params.

◆ TAMAGAWA_CF_EEPROM_WRITE

#define TAMAGAWA_CF_EEPROM_WRITE (0x32U)

Tamagawa EEPROM Control Field value for Write operation.

◆ TAMAGAWA_CF_EEPROM_READ

#define TAMAGAWA_CF_EEPROM_READ (0xEAU)

Tamagawa EEPROM Control Field value for Read operation.

◆ TAMAGAWA_CFG_REG_SIZE

#define TAMAGAWA_CFG_REG_SIZE (4U)

IEP CAP0 register offset - cslr common file does not have defined cap registers FIXME: Remove these definitions once they are available in cslr_common.h.

◆ TAMAGAWA_CSL_ICSS_PR1_IEP0_SLV_CAP0_REG0

#define TAMAGAWA_CSL_ICSS_PR1_IEP0_SLV_CAP0_REG0 (CSL_ICSS_PR1_IEP0_SLV_CAP_CFG_REG + 2U*TAMAGAWA_CFG_REG_SIZE)

◆ TAMAGAWA_8_BYTE_REG_OFFSET

#define TAMAGAWA_8_BYTE_REG_OFFSET (8U)

8-byte register offset for IEP registers

Typedef Documentation

◆ tamagawa_handle

typedef tamagawa_config* tamagawa_handle

Tamagawa handle type.

Opaque pointer to a Tamagawa configuration structure. Returned by tamagawa_init and used in all Tamagawa APIs.

Enumeration Type Documentation

◆ tamagawa_data_id

enum tamagawa_data_id

Tamagawa 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_CMP_CMD	Periodic trigger command using IEP compare event
PERIODIC_TRIGGER_CAP_CMD	Periodic trigger command using IEP capture event
DATA_ID_NUM	Number of Data ID codes

Function Documentation

◆ tamagawa_params_init()

void tamagawa_params_init ( tamagawa_params * params )

Initialize Tamagawa parameters structure with default values.

This function initializes a tamagawa_params structure with default values. Call this function before setting custom parameters and passing to tamagawa_init.

Parameters

[out] params Pointer to tamagawa_params structure to initialize

◆ tamagawa_init()

tamagawa_handle tamagawa_init	(	uint32_t	index,
		const tamagawa_params *	params
	)

Initialize a Tamagawa instance.

This function initializes a Tamagawa instance by setting up the firmware interface and configuring hardware based on tamagawa_attrs and tamagawa_params. The function validates all input parameters and initializes the PRU-ICSS interface.

This function performs the following operations:

Validates index against the number of configured instances (gTamagawaConfigNum)
Validates PRUICSS handle is not NULL
Validates PRU slice value (0 or 1)
Validates IEP compare event (0-15) and capture event (0-7) for enabled channels
Validates clock frequencies (must be positive)
Validates IEP instance (0 or 1)
Validates clock source selection (0 or 1)
Validates baud rate (must be TAMAGAWA_FREQ_2_5_MHZ or TAMAGAWA_FREQ_5_MHZ)
Sets up PRU DRAM base address for firmware interface
Marks handle as open

Internal API calls (in order):

tamagawa_config_clr_cfg0() - Clears PRU Three Channel Peripheral Interface CFG0 registers
tamagawa_config_channel() - Configures channel mask for both single and multi-channel modes
PRUICSS_setGpMuxSelect() - Sets GP mux selection for Three Channel Peripheral Interface
tamagawa_config_iep_base_address() - Writes IEP base address offset to PRU DRAM
tamagawa_config_iep_cmp_event() - Configures IEP CMP event number in PRU DRAM for enabled channels
tamagawa_config_iep_cap_event() - Configures IEP CAP event number and capture register in PRU DRAM for enabled channels
tamagawa_config_load_share() - Configures primary core mask and enables load-share hardware (for TAMAGAWA_MODE_MULTI_CHANNEL_MULTI_PRU mode only)
tamagawa_set_baudrate() - Configures communication baud rate from attrs configuration
tamagawa_config_host_trigger() - Sets default trigger mode to host trigger

Parameters

[in]	index	Index of Tamagawa handle to use in the gTamagawaHandle handle array
[in]	params	Pointer to structure containing Tamagawa parameters. Use tamagawa_params_init to initialize with defaults before setting custom values. Must not be NULL.

Return values

handle	Pointer to initialized tamagawa_handle instance
NULL	On validation failure (invalid index, NULL params, invalid configuration, or internal API call failure)

Note: Channel configuration, trigger mode, and baud rate are automatically set during initialization based on SysConfig parameters. Applications do not need to call configuration functions separately.

◆ tamagawa_deinit()

void tamagawa_deinit ( tamagawa_handle handle )

Deinitialize Tamagawa interface and release resources.

This function deinitializes a Tamagawa instance by marking it as closed. It does not free memory as the handle is statically allocated via SysConfig. After calling this function, the handle should not be used until reinitialized with tamagawa_init.

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Note: NULL check: If handle is NULL, function returns without performing any operation.

◆ tamagawa_command_process()

int32_t tamagawa_command_process	(	tamagawa_handle	handle,
		int32_t	cmd
	)

Process a Tamagawa command (build, send, and wait for completion)

This function combines command setup, triggering, and waiting for completion in a single call. It internally calls:

tamagawa_command_build : Setup command in PRU interface buffer
tamagawa_command_send : Trigger PRU to send command
tamagawa_command_wait : Wait for PRU to complete transaction

For EEPROM commands (DATA_ID_6, DATA_ID_D), the function also resets the command ID for all channels after completion. The multi-channel mask for EEPROM operations is determined automatically from the enabled channels configured in the attrs structure.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	cmd	Tamagawa command number (see tamagawa_data_id)

Return values

SystemP_SUCCESS	Command processed successfully
SystemP_TIMEOUT	On timeout waiting for firmware acknowledgment (propagated from tamagawa_command_wait)
SystemP_FAILURE	Command processing failed (invalid handle or invalid command)

◆ tamagawa_command_build()

int32_t tamagawa_command_build	(	tamagawa_handle	handle,
		int32_t	cmd
	)

Build a Tamagawa command in the PRU interface.

This function sets up the Tamagawa command parameters in the PRU interface based on the command type. The command is not sent until tamagawa_command_send is called. For EEPROM commands (DATA_ID_6, DATA_ID_D), this function prepares the TX data with CF, ADF, EDF, and CRC fields. The multi-channel mask for EEPROM operations is determined automatically from the enabled channels configured in the attrs structure.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	cmd	Tamagawa command number (see tamagawa_data_id)

Return values

SystemP_SUCCESS	Command built successfully
SystemP_FAILURE	Command build failed (invalid handle, unsupported command)

◆ tamagawa_command_send()

int32_t tamagawa_command_send ( tamagawa_handle handle )

Trigger sending the Tamagawa command in PRU.

This function triggers the PRU firmware to send the command that was previously set up using tamagawa_command_build. It sets the trigger bit in the PRU interface, which signals the firmware to start the transaction.

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

SystemP_SUCCESS	Command trigger successful
SystemP_FAILURE	NULL handle provided

◆ tamagawa_command_wait()

int32_t tamagawa_command_wait ( tamagawa_handle handle )

Wait until PRU finishes Tamagawa transaction.

This function waits in a polling loop until the PRU firmware clears the trigger bit, indicating that the command has been completed. This is a blocking call with timeout protection.

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

SystemP_SUCCESS	Command completed successfully
SystemP_FAILURE	NULL handle provided
SystemP_TIMEOUT	Timeout occurred (configured via tamagawa_params.max_wait_loop_count before calling tamagawa_init, default: 5000 us = 50 loops × 100 us/loop)

◆ tamagawa_config_global_rx_arm_cnt()

int32_t tamagawa_config_global_rx_arm_cnt	(	tamagawa_handle	handle,
		uint16_t	rx_en_cnt
	)

Configure global RX auto arm counter for Tamagawa interface.

This function configures the global RX auto arm counter register for all three channels. The counter value determines the timing for RX enable.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	rx_en_cnt	Value to be set in global RX auto arm counter register

Return values

SystemP_SUCCESS	Configuration successful
SystemP_FAILURE	NULL handle provided

◆ tamagawa_config_clock()

int32_t tamagawa_config_clock	(	tamagawa_handle	handle,
		tamagawa_clk_cfg *	clk_cfg
	)

Configure Tamagawa clock dividers and source selection.

This function configures the PRU Three Channel Peripheral Interface's RX and TX clock dividers and clock source selection. It writes to PRUx_ED_RXCFG and PRUx_ED_TXCFG registers.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	clk_cfg	Pointer to structure containing clock configuration data

Return values

SystemP_SUCCESS	Configuration successful
SystemP_FAILURE	NULL handle or NULL clk_cfg provided

◆ tamagawa_config_host_trigger()

int32_t tamagawa_config_host_trigger ( tamagawa_handle handle )

Configure Tamagawa interface for host trigger mode.

In this mode, commands are sent when explicitly triggered by the host using tamagawa_command_send.

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

SystemP_SUCCESS	Configuration successful
SystemP_FAILURE	NULL handle provided

◆ tamagawa_config_periodic_trigger_cmp_mode()

int32_t tamagawa_config_periodic_trigger_cmp_mode ( tamagawa_handle handle )

Configure Tamagawa interface for periodic trigger using IEP compare mode.

Configures the Tamagawa firmware to use IEP CMP (compare) events for periodic triggering. Position data is sampled automatically when the IEP compare event occurs.

Configuration requirements:

IEP hardware CMP registers must be configured separately
Use tamagawa_config_iep_cmp_event to set event number in firmware. This function is called inside tamagawa_init by default.
CMP event range: 0-15

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

SystemP_SUCCESS	Configuration successful
SystemP_FAILURE	NULL handle provided

◆ tamagawa_config_channel()

int32_t tamagawa_config_channel	(	tamagawa_handle	handle,
		uint8_t	mask
	)

Configure channel mask for Tamagawa interface.

This function configures the channel mask for both single-channel and multi-channel modes. In single-channel mode, it also stores the specific channel index in priv->channel based on the channel enable flags (channel0_enabled, channel1_enabled, channel2_enabled).

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	mask	Channel mask (valid range 1-7 for up to 3 channels) Bit 0: Channel 0 Bit 1: Channel 1 Bit 2: Channel 2

Return values

SystemP_SUCCESS	Configuration successful
SystemP_FAILURE	NULL handle or invalid mask (mask == 0 or mask > 0x07)

Note: NULL check: Strict check on handle. Mask bounds checked (1-7).

◆ tamagawa_multi_channel_set_cur()

int32_t tamagawa_multi_channel_set_cur	(	tamagawa_handle	handle,
		uint8_t	ch
	)

Set current channel for receive processing in multi-channel mode.

In multi-channel configuration, after the receive transaction is complete, call this function to select each channel before invoking RX parsing APIs to process the data received on that channel.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	ch	Channel number to be selected (0-2, see TAMAGAWA_MAX_CHANNELS_PER_SLICE)

Return values

SystemP_SUCCESS	Configuration successful
SystemP_FAILURE	NULL handle or invalid channel (ch >= TAMAGAWA_MAX_CHANNELS_PER_SLICE)

Note: NULL check: Strict check on handle. Channel bounds checked (0-2).

◆ tamagawa_update_data_id()

int32_t tamagawa_update_data_id	(	tamagawa_handle	handle,
		int32_t	cmd
	)

Update the current requested command ID in Tamagawa interface.

This function updates the data_id field in the Tamagawa interface structure. For EEPROM commands (DATA_ID_6, DATA_ID_D), it also sets the command ID for all three channels in the EEPROM interface.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	cmd	Tamagawa command number (see tamagawa_data_id)

Return values

SystemP_SUCCESS	Update successful
SystemP_FAILURE	NULL handle provided

◆ tamagawa_update_adf()

int32_t tamagawa_update_adf	(	tamagawa_handle	handle,
		uint32_t	val,
		uint8_t	ch
	)

Update the ADF (EEPROM address) field for EEPROM command.

This function updates the ADF (Address Field) in the Tamagawa EEPROM interface for the specified channel. This is used for both EEPROM Read (DATA_ID_D) and EEPROM Write (DATA_ID_6) commands.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	val	ADF value to be updated (valid range 0-127, see TAMAGAWA_MAX_EEPROM_ADDRESS)
[in]	ch	Channel number that is currently selected (0-2, see TAMAGAWA_MAX_CHANNELS_PER_SLICE)

Return values

SystemP_SUCCESS	Update successful
SystemP_FAILURE	NULL handle, invalid channel (ch >= TAMAGAWA_MAX_CHANNELS_PER_SLICE), or invalid ADF value (val > TAMAGAWA_MAX_EEPROM_ADDRESS)

Note: NULL check: Strict check on handle. Channel and ADF value bounds checked.

◆ tamagawa_update_edf()

int32_t tamagawa_update_edf	(	tamagawa_handle	handle,
		uint32_t	val,
		uint8_t	ch
	)

Update the EDF (EEPROM data) field for EEPROM Write command.

This function updates the EDF (Encoder Data Field) in the Tamagawa EEPROM interface for the specified channel. This is used only for EEPROM Write (DATA_ID_6) commands.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	val	EDF value to be updated (valid range 0-255, see TAMAGAWA_MAX_EEPROM_WRITE_DATA)
[in]	ch	Channel number that is currently selected (0-2, see TAMAGAWA_MAX_CHANNELS_PER_SLICE)

Return values

SystemP_SUCCESS	Update successful
SystemP_FAILURE	NULL handle, invalid channel (ch >= TAMAGAWA_MAX_CHANNELS_PER_SLICE), or invalid EDF value (val > TAMAGAWA_MAX_EEPROM_WRITE_DATA)

Note: NULL check: Strict check on handle. Channel and EDF value bounds checked.

◆ tamagawa_parse()

int32_t tamagawa_parse	(	tamagawa_handle	handle,
		int32_t	cmd
	)

Parse the data in Tamagawa interface received from the encoder.

This function extracts and parses the received frame data based on the command type. It populates the rx_frames_received structure in the Tamagawa interface with the parsed data (CF, SF, ABS, ABM, ENID, ALMC, ADF, EDF, CRC).

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	cmd	Tamagawa command number (see tamagawa_data_id)

Return values

SystemP_SUCCESS	Data parsed successfully
SystemP_FAILURE	Parsing failed (invalid handle or unsupported command)

◆ tamagawa_crc_verify()

int32_t tamagawa_crc_verify ( tamagawa_handle handle )

Verify the CRC computed by PRU firmware against encoder CRC.

This function checks the CRC verification result computed by the PRU firmware. The firmware calculates CRC and stores the result in cal_crc field. A value of 1 indicates successful CRC verification.

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

SystemP_SUCCESS	CRC verification passed
SystemP_FAILURE	CRC verification failed or NULL handle

◆ tamagawa_update_crc()

int32_t tamagawa_update_crc	(	tamagawa_handle	handle,
		int32_t	cmd,
		uint8_t	ch
	)

Update CRC field for EEPROM command.

This function calculates and updates the CRC field for EEPROM commands based on CF, ADF, and EDF values. It internally calls the CRC calculation function. For EEPROM Write (DATA_ID_6), CRC is calculated over 3 bytes (CF + ADF + EDF). For EEPROM Read (DATA_ID_D), CRC is calculated over 2 bytes (CF + ADF).

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	cmd	Tamagawa command number (DATA_ID_6 or DATA_ID_D)
[in]	ch	Channel number that is currently selected (0-2, see TAMAGAWA_MAX_CHANNELS_PER_SLICE)

Return values

SystemP_SUCCESS	CRC update successful
SystemP_FAILURE	NULL handle or invalid channel (ch >= TAMAGAWA_MAX_CHANNELS_PER_SLICE)

Note: NULL check: Strict check on handle. Channel bounds checked (0-2).

◆ tamagawa_set_baudrate()

int32_t tamagawa_set_baudrate	(	tamagawa_handle	handle,
		double	baud_rate
	)

Set Tamagawa communication baud rate.

This function calculates and configures the RX/TX division factors and oversampling rate based on the specified baud rate. It internally calls:

tamagawa_config_clock : Configure clock dividers
tamagawa_config_global_rx_arm_cnt : Configure RX auto arm counter

The function also updates the firmware interface with the calculated division factors and oversampling rate.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	baud_rate	Baud rate of the Tamagawa encoder in Hz (2.5 MHz or 5 MHz)

Return values

SystemP_SUCCESS	Configuration successful
SystemP_FAILURE	NULL handle provided

Note: The RX auto arm counter is configured for 1us delay. This may need adjustment based on specific encoder requirements.

◆ tamagawa_get_attrs()

const tamagawa_attrs* tamagawa_get_attrs ( tamagawa_handle handle )

Get pointer to Tamagawa attributes structure.

This function returns a const pointer to the attributes structure containing compile-time configuration parameters from SysConfig. The attrs structure is read-only and should not be modified.

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

attrs	Pointer to const tamagawa_attrs structure
NULL	If handle is NULL

Note: NULL check: Strict check on handle. Returns NULL on NULL handle.

◆ tamagawa_get_priv()

tamagawa_priv* tamagawa_get_priv ( tamagawa_handle handle )

Get pointer to Tamagawa private structure.

This function returns a pointer to the private structure containing runtime state information. This is typically used for advanced operations or debugging.

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

priv	Pointer to tamagawa_priv structure
NULL	If handle is NULL

Note: NULL check: Strict check on handle. Returns NULL on NULL handle.

Warning: Modifying priv structure fields directly can lead to undefined behavior. Use provided APIs for configuration changes.

◆ tamagawa_config_iep_cmp_event()

int32_t tamagawa_config_iep_cmp_event	(	tamagawa_handle	handle,
		uint8_t	channel,
		uint8_t	event_num
	)

Configure IEP CMP event for periodic trigger (DMEM configuration only)

This function configures the IEP compare event information in PRU shared memory (DMEM) for firmware access. It writes the event number to trigger_params structure. This function does NOT configure IEP hardware registers.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	channel	Tamagawa channel number (0-2). Used in load share mode, ignored in single PRU mode (always uses index 0).
[in]	event_num	CMP event number (0-15)

Return values

SystemP_SUCCESS	CMP event configured successfully
SystemP_FAILURE	On NULL handle or invalid event_num/channel

Note: This function only configures firmware DMEM, not IEP hardware. Application must separately configure IEP CMP hardware registers.

◆ tamagawa_config_iep_cap_event()

int32_t tamagawa_config_iep_cap_event	(	tamagawa_handle	handle,
		uint8_t	channel,
		uint8_t	event_num
	)

Configure IEP CAP event for periodic trigger (DMEM configuration only)

This function configures the IEP capture event information in PRU shared memory (DMEM) for firmware access. It writes the capture register address and event number to trigger_params structure. This function does NOT configure IEP hardware registers.

Parameters

[in]	handle	Tamagawa handle returned by tamagawa_init
[in]	channel	Tamagawa channel number (0-2). Used in load share mode, ignored in single PRU mode (always uses index 0).
[in]	event_num	CAP event number (0-7)

Return values

SystemP_SUCCESS	CAP event configured successfully
SystemP_FAILURE	On NULL handle, invalid event_num/channel, or NULL IEP base address

Note: This function only configures firmware DMEM, not IEP hardware. Application must separately configure IEP CAP hardware registers.

◆ tamagawa_config_periodic_trigger_cap_mode()

int32_t tamagawa_config_periodic_trigger_cap_mode ( tamagawa_handle handle )

Configure Tamagawa interface for periodic trigger using IEP capture mode.

Configures the Tamagawa firmware to use IEP CAP (capture) events for periodic triggering. Position data is sampled automatically when an external signal triggers the IEP capture event.

Configuration requirements:

IEP hardware CAP registers must be configured separately
External signal to IEP capture input should be configured
Use tamagawa_config_iep_cap_event to set event number in firmware. This function is called inside tamagawa_init by default.
CAP event range: 0-7

Parameters

[in] handle Tamagawa handle returned by tamagawa_init

Return values

SystemP_SUCCESS	CAP mode configured successfully
SystemP_FAILURE	On NULL handle

Note: This function only configures firmware DMEM, not IEP hardware. Application must separately configure IEP CAP hardware registers.

Introduction

Data Structures

Functions

Typedefs

Enumerations

Macros

Macro Definition Documentation

◆ TAMAGAWA_MAX_CHANNELS_PER_SLICE

◆ TAMAGAWA_MODE_SINGLE_CHANNEL_SINGLE_PRU

◆ TAMAGAWA_MODE_MULTI_CHANNEL_SINGLE_PRU

◆ TAMAGAWA_MODE_MULTI_CHANNEL_MULTI_PRU

◆ TAMAGAWA_OPMODE_PERIODIC_CMP

◆ TAMAGAWA_OPMODE_HOST_TRIGGER

◆ TAMAGAWA_OPMODE_PERIODIC_CAP

◆ TAMAGAWA_ENABLE_CYCLE_TRIGGER

◆ TAMAGAWA_DISABLE_CYCLE_TRIGGER

◆ TAMAGAWA_FREQ_2_5_MHZ

◆ TAMAGAWA_FREQ_5_MHZ

◆ TAMAGAWA_IEP_MAX_CAP_EVENT

◆ TAMAGAWA_IEP_MAX_CMP_EVENT

◆ TAMAGAWA_MAX_EEPROM_ADDRESS

◆ TAMAGAWA_MAX_EEPROM_WRITE_DATA

◆ TAMAGAWA_RX_OVERSAMPLING_RATE

◆ TAMAGAWA_DELAY_COUNTER_INCREMENT

◆ TAMAGAWA_EEPROM_WRITE_CRC_BYTES

◆ TAMAGAWA_EEPROM_READ_CRC_BYTES

◆ TAMAGAWA_BITS_PER_BYTE

◆ TAMAGAWA_CRC_DATA_ARRAY_SIZE

◆ TAMAGAWA_DEFAULT_CMD_WAIT_DELAY_US

◆ TAMAGAWA_DEFAULT_MAX_WAIT_LOOP_COUNT

◆ TAMAGAWA_CF_EEPROM_WRITE

◆ TAMAGAWA_CF_EEPROM_READ

◆ TAMAGAWA_CFG_REG_SIZE

◆ TAMAGAWA_CSL_ICSS_PR1_IEP0_SLV_CAP0_REG0

◆ TAMAGAWA_8_BYTE_REG_OFFSET

Typedef Documentation

◆ tamagawa_handle

Enumeration Type Documentation

◆ tamagawa_data_id

Function Documentation

◆ tamagawa_params_init()

◆ tamagawa_init()

◆ tamagawa_deinit()

◆ tamagawa_command_process()

◆ tamagawa_command_build()

◆ tamagawa_command_send()

◆ tamagawa_command_wait()

◆ tamagawa_config_global_rx_arm_cnt()

◆ tamagawa_config_clock()

◆ tamagawa_config_host_trigger()

◆ tamagawa_config_periodic_trigger_cmp_mode()

◆ tamagawa_config_channel()

◆ tamagawa_multi_channel_set_cur()

◆ tamagawa_update_data_id()

◆ tamagawa_update_adf()

◆ tamagawa_update_edf()

◆ tamagawa_parse()

◆ tamagawa_crc_verify()

◆ tamagawa_update_crc()

◆ tamagawa_set_baudrate()

◆ tamagawa_get_attrs()

◆ tamagawa_get_priv()

◆ tamagawa_config_iep_cmp_event()

◆ tamagawa_config_iep_cap_event()

◆ tamagawa_config_periodic_trigger_cap_mode()