Man page 9 : i2c_smbus_read_block_data

i2c_smbus_read_block_data - SMBus « block read » protocol

s32 i2c_smbus_read_block_data(const struct i2c_client *  client , u8  command , u8 *  values );

client
    Handle to slave device

command
    Byte interpreted by slave

values
    Byte array into which data will be read; big enough to hold the data returned by the slave. SMBus allows at most 32 bytes.

This executes the SMBus « block read » protocol, returning negative errno else the number of data bytes in the slaveAqs response.

Note that using this function requires that the clientAqs adapter support the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers support this; its emulation through I2C messaging relies on a specific mechanism (I2C_M_RECV_LEN) which may not be implemented.