I2C Control

Provide an interface to access I2C devices. Please refer to the Hardware User Manual to check how many i2c interfaces which supported on your products

Note: Only available with Tiva BMC and can’t be supported on Renesas BMC.

How to use in Linux

After adl-bmc-i2c driver loaded, please use i2cdetect command to look for ADLINK BMC I2C driver. Then, you can use i2c-tools commands to access your devices.

install4

Note: please refer to here to guide you how to use i2c-tools command

command	Description
i2cdetect	detect I2C chips
i2cdump	examine I2C registers
i2cget	read from I2C/SMBus chip registers
i2cset	set I2C registers

SEMA EAPI (Only for Windows)

uint32_t EApiI2CGetBusCap(uint32_t Id, uint32_t *pMaxBlkLen)

Description

Returns the capabilities of the selected I2C bus.

Parameters:

uint32_t Id:

Select i2c Bus ID as the first parameter

ID	Description
EAPI_ID_I2C_EXTERNAL	Baseboard I2C Interface
EAPI_ID_I2C_LVDS_1	LVDS/EDP 1 Interface

uint32_t *pMaxBlkLen:

Size in bytes, pointer to a buffer that receives the maximum transfer block length for the given interface. Note that care must be taken if used in combination withEapiI2CWriteTransfer as the maximum data payload length will be pMaxBlkLen (write overhead). For example, a 7-bit addressed device with extended command has a write overhead of 2 bytes which are command.

Note: Max length of data byte to write is 29 Bytes; Max length of data byte to read is 32 Bytes

uint32_t EApiI2CProbeDevice(uint32_t Id, uint32_t Addr)

Description

Probes I2C address to test I2C Device present

Parameters:

uint32_t Id:

Select i2c Bus ID as the first parameter

ID	Description
EAPI_ID_I2C_EXTERNAL	Baseboard I2C Interface
EAPI_ID_I2C_LVDS_1	LVDS/EDP 1 Interface

uint32_t Addr:

Encoded 7 bit I2C device address

uint32_t EApiI2CGetBusSts(uint32_t Id, uint8_t *sts)

Description

Gets current status of the I2C bus.

Parameters:
- uint32_t Id:
  
  Select i2c Bus ID as the first parameter

ID	Description
EAPI_ID_I2C_EXTERNAL	Baseboard I2C Interface
EAPI_ID_I2C_LVDS_1	LVDS/EDP 1 Interface

uint8_t *sts:

This describes the definition of I2C bus status:

Bit	Description
Bit 7	I2C_MASTER_ERR_CLK_TOUT No Error = 0 Clock Timeout Error = 1
Bit 6	reserved
Bit 5	I2C Transaction timeout - No error = 0 - Transaction timeout error = 1
Bit 4	I2C_MASTER_ERR_ARB_LOST - No error = 0 - Arbitration error = 1
Bit 3	I2C_MASTER_ERR_DATA_ACK - No error = 0 - Data acknowledge error = 1
Bit 2	I2C_MASTER_ERR_ADDR_ACK - No error = 0 - Address acknowledge error = 1
Bit 1	I2C Transaction result - Transaction ok = 0 - No data send/received = 1
Bit 0	I2C Bus status - I2C transaction ongoing = 0 - I2C bus is free = 1

uint32_t EApiI2CReadTransfer(
        uint32_t Id,
        uint32_t Addr,
        uint32_t Cmd,
        void *pBuffer,
        uint32_t BufLen,
        uint32_t ByteCnt
)

Description

Reads from a specific register in the selected I2C device. Reads from I2C device at the I2C address Addr the amount of ByteCnt bytes to the buffer pBuffer while using the device specific command Cmd. Depending on the addressed I2C device Cmd can be a specific command or a byte offset.

Parameters:

uint32_t Id:

Select i2c Bus ID as the first parameter

ID	Description
EAPI_ID_I2C_EXTERNAL	Baseboard I2C Interface
EAPI_ID_I2C_LVDS_1	LVDS/EDP 1 Interface

uint32_t Addr:

Encoded 7 Bit I2C Device Address.
uint32_t Cmd:

Encoded I2C Device Command / Index.
void *pBuffer:

Pointer to a buffer that receives the read data. This parameter can be NULL if the data is not required
uint32_t BufLen:

Size, in bytes, of the buffer pointed to by the pBuffer parameter. If the buffer specified by pBuffer parameter is not large enough to hold the data, the function returns the value EAPI_STATUS_MORE_DATA
uint32_t ByteCnt:

Size in bytes of data to be read

uint32_t EApiI2CWriteTransfer(
        uint32_t Id,
        uint32_t Addr,
        uint32_t Cmd,
        void *pBuffer,
        uint32_t ByteCnt
)

Description

Write to a specific register in the selected I2C device. Writes to an I2C device at the I2C address Addr the amount of ByteCnt bytes from the buffer *pBuffer while using the device specific command Cmd. Depending on the addressed I2C device Cmd can be a specific command or a byte offset.

Parameters:

uint32_t Id:

Select i2c Bus ID as the first parameter

ID	Description
EAPI_ID_I2C_EXTERNAL	Baseboard I2C Interface
EAPI_ID_I2C_LVDS_1	LVDS/EDP 1 Interface

uint32_t Addr:

Encoded 7 Bit I2C Device Address.
uint32_t Cmd:

Encoded I2C Device Command / Index.
void *pBuffer:

Pointer to a buffer that receives the read data. This parameter can be NULL if the data is not required
uint32_t ByteCnt:

Size, in bytes, of the information pointed to by the pBuffer parameter

uint32_t EApiI2CWriteReadRaw(
        uint32_t Id,
        uint8_t Addr,
        void *pWBuffer,
        uint32_t WriteBCnt,
        void *pRBuffer,
        uint32_t RBufLen,
        uint32_t ReadBCnt
)

Description

Universal function for read and write operations to the I2C bus. Refer to PICMG EAPI 1.0

Parameters:

uint32_t Id:

Select i2c Bus ID as the first parameter

ID	Description
EAPI_ID_I2C_EXTERNAL	Baseboard I2C Interface
EAPI_ID_I2C_LVDS_1	LVDS/EDP 1 Interface

uint32_t Addr:

Encoded 7 Bit I2C Device Address.
void *pWBuffer:

Pointer to a buffer containing the data to be transferred. This parameter can be NULL if the data is not required
uint32_t WriteBCnt:

Size, in bytes, of the information pointed to by the pWBuffer parameter plus 1 If pWBuffer is NULL this must be zero or one.
void *pRBuffer:

Pointer to a buffer that receives the read data. This parameter can be NULL if the data is not required.
uint32_t RBufLen:

Size, in bytes, of the buffer pointed to by the pRBuffer parameter. If the buffer specified by pRBuffer parameter is not large enough to hold the data, the function returns the value EAPI_STATUS_MORE_DATA If pRBuffer is NULL this must be zero.
uint32_t ReadBCnt:

Size, in bytes, to be read to pRBuffer plus 1. If pRBuffer is NULL, this must be zero or one.