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Diffstat (limited to 'src/usr/i2c/i2c.H')
| -rwxr-xr-x | src/usr/i2c/i2c.H | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/src/usr/i2c/i2c.H b/src/usr/i2c/i2c.H index baf95df32..5b69b302e 100755 --- a/src/usr/i2c/i2c.H +++ b/src/usr/i2c/i2c.H @@ -63,6 +63,15 @@ enum PAGE_ONE_ADDR = 0x6E, }; +/** + * @brief Value of the rightmost (7th) bit of an I2C address, which on the + * wire indicates whether the operation is a read or a write + */ +enum I2C_OP_DIRECTION : uint8_t +{ + WRITE = 0x00, ///< Write operation + READ = 0x01, ///< Read operation +}; /** * @brief FIFO size (width) in bytes. This dictates how many bytes @@ -959,6 +968,259 @@ void setLogicalFsiEnginePort(size_t &io_logical_engine, void addHwCalloutsI2c(errlHndl_t i_err, TARGETING::Target * i_target, const misc_args_t & i_args); + +namespace SMBUS +{ + +/** + * @brief Calculates a packet error code (PEC) over the specified number of + * bytes at the specified address. + * + * @par Detailed Description: + * Calculates a packet error code (PEC) over the specified number of bytes + * at the specified address. Specifically, it applies a CRC-8 algorithm, a + * very common/simple CRC detailed @ + * https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks + * + * @param[in] i_pData Pointer to the start of the data; must not be nullptr + * @param[in] i_size Number of bytes to consider when computing the PEC + * + * return uint8_t Computed PEC byte + */ +uint8_t calculatePec( + const uint8_t* const i_pData, + const size_t i_size); + +/** + * @brief Structure which tracks the Send Byte + * transaction to assist in calculating the PEC byte at the end (if + * applicable) + */ +struct SendByte +{ + // The following fields are known prior to the transaction: + + // The remote device's address which starts the transaction; + // RW bit will be 0 + uint8_t writeAddr; + + // Data byte to send + uint8_t dataByte; + + // PEC byte + uint8_t pec; + + // Size of message to send, excluding address byte, including PEC byte if + // applicable + size_t messageSize; + + /** + * @brief Constructor + * + * @param[in] i_address Address of the remote device + * @param[in] i_pDataByte Pointer to byte to send. Must not be nullptr. + * @param[in] i_usePec Whether to suffix transaction with PEC byte or not + */ + SendByte( uint8_t i_address, + const void* i_pDataByte, + bool i_usePec); +} PACKED; + +/** + * @brief Structure which tracks the Write Byte or Write Word + * transaction to assist in calculating the PEC byte at the end (if + * applicable) + */ +struct WriteByteOrWord +{ + // The following fields are known prior to the transaction: + + // The remote device's address which starts the transaction; + // RW bit will be 0 + uint8_t writeAddr; + + // The PMBUS command code to send as part of the write + uint8_t commandCode; + + // Data bytes the originator intends to send. + // 1 for Write byte + // 2 for Write word + // One more byte is added in case there is a PEC byte. + uint8_t dataBytes[sizeof(uint16_t)+sizeof(uint8_t)]; + + // How many data bytes (excluding PEC) the originator intends to send + uint8_t byteCount; + + // Size of message to send, excluding address byte, including PEC byte if + // applicable + size_t messageSize; + + /** + * @brief Constructor + * + * @param[in] i_address Address of the remote device + * @param[in] i_commandCode PMBUS command code to execute + * @param[in] i_byteCount Number of data bytes to send (1 or 2) + * @param[in] i_pDataBytes Pointer to byte stream to send. Must not be + * nullptr + * @param[in] i_usePec Whether to suffix transaction with PEC byte or not + */ + WriteByteOrWord( uint8_t i_address, + uint8_t i_commandCode, + uint8_t i_byteCount, + const void* i_pDataBytes, + bool i_usePec); +} PACKED; + +/** + * @brief Structure which tracks the block write transaction to assist in + * calculating the PEC byte at the end + */ +struct BlockWrite +{ + // The following fields are known prior to the transaction: + + // The remote device's address which starts the transaction; + // RW bit will be 0 + uint8_t writeAddr; + + // The PMBUS command code to send as part of the write + uint8_t commandCode; + + // How many data bytes (excluding PEC) the originator intends to send + uint8_t byteCount; + + // Data bytes the originator intends to send. Max 255. One more byte is + // added in case there is a PEC byte + uint8_t dataBytes[UINT8_MAX+sizeof(uint8_t)]; + + // Size of message to send, excluding address byte, including PEC byte if + // applicable + size_t messageSize; + + /** + * @brief Constructor + * + * @param[in] i_address Address of the remote device + * @param[in] i_commandCode PMBUS command code to execute + * @param[in] i_byteCount Number of data bytes to send + * @param[in] i_pDataBytes Pointer to byte stream to send. Must not be + * nullptr + * @param[in] i_usePec Whether to suffix transaction with PEC byte or not + */ + BlockWrite( uint8_t i_address, + uint8_t i_commandCode, + uint8_t i_byteCount, + const void* i_pDataBytes, + bool i_usePec); + +} PACKED; + +/** + * @brief Structure which tracks the read byte|word transaction to assist in + * calculating the PEC byte at the end + */ +struct ReadByteOrWord +{ + // The following fields are known prior to the transaction: + + // The remote device's address which starts the transaction; + // RW bit will be 0 + uint8_t writeAddr; + + // The PMBUS command code to send as part of the write + uint8_t commandCode; + + // The remote device's address (sent after repeated start); + // RW bit will be 1 + uint8_t readAddr; + + // The following fields are filled in during the transaction: + + // Data bytes (1 if read byte, 2 if read word) returned by the remote device + uint8_t dataBytes[sizeof(uint16_t)]; + + // PEC byte returned by the remote device (if supported) + uint8_t pec; + + // # data byte requested (1 or 2) + uint8_t byteCount; + + /** + * @brief Constructor + * + * @param[in] i_address Address of the remote device + * @param[in] i_commandCode PMBUS command code to execute + * @param[in] i_byteCount Number of bytes to read (1 or 2) + */ + ReadByteOrWord(uint8_t i_address, + uint8_t i_commandCode, + uint8_t i_byteCount) + : writeAddr(i_address), + commandCode(i_commandCode), + readAddr(i_address | I2C_OP_DIRECTION::READ), + pec(0), + byteCount(i_byteCount) + { + assert(((byteCount==1) || (byteCount==2)), + "Invalid byte count %d for read byte or read word", byteCount); + memset(dataBytes,0x00,sizeof(dataBytes)); + } + +} PACKED; + +/** + * @brief Structure which tracks the block read transaction to assist in + * calculating the PEC byte at the end + */ +struct BlockRead +{ + // The following fields are known prior to the transaction: + + // The remote device's address which starts the transaction; + // RW bit will be 0 + uint8_t writeAddr; + + // The PMBUS command code to send as part of the write + uint8_t commandCode; + + // The remote device's address (sent after repeated start); + // RW bit will be 1 + uint8_t readAddr; + + // The following fields are filled in during the transaction: + + // How many data bytes (excluding PEC) the remote device intends + // to return. + uint8_t blockCount; + + // Data bytes (blockCount of them) returned by the remote device + uint8_t dataBytes[UINT8_MAX]; + + // PEC byte returned by the remote device (if supported) + uint8_t pec; + + /** + * @brief Constructor + * + * @param[in] i_address Address of the remote device + * @param[in] i_commandCode PMBUS command code to execute + */ + BlockRead(const uint8_t i_address, + const uint8_t i_commandCode) + : writeAddr(i_address), + commandCode(i_commandCode), + readAddr(i_address | I2C_OP_DIRECTION::READ), + blockCount(0), + pec(0) + { + memset(dataBytes,0x00,sizeof(dataBytes)); + } + +} PACKED; + +} // End SMBUS namespace + }; // end I2C namespace #endif // __I2C_H |
