May I know what's response of you have been received when you said the firmware is stuck in I2C_I2C_MSTAT_WR_CMPLT. It should be good to check this status, and you could get many example code in CCGx host SDK, for example, CCG5 notebook design, the NCP81239 is controlled by I2C master of CCG5.
A: If you could like to use EZI2C, the operation will became easier to use, since the write and read of EZI2C is FIFO/Buffer write and read.
B: If you are using uint32 SCB_I2CMasterWriteBuf(uint32 slaveAddress, uint8 * wrData, uint32 cnt, uint32 mode), the mode you can fill with I2C_MODE_COMPLETE_XFER.
CCGx support multi salve mode.
i solve the issue from slave side define buffer for slave before I2S_Start() need define after
I2CS_I2CSlaveInitReadBuf (i2cReadBuffer, BUFFER_SIZE);
thank i will download the EZ-PD™ Host Software Development Kit and lookup the example