I found the part that control RF output and can reduce the the transmission power.
radio-driver.c
uint8_t paLevelValue=0x25; /* for example, this value will give 23dBm about */
S2LPSpiWriteRegisters(PA_POWER8_ADDR, 1, &paLevelValue);
There is 8 power level can set in S2LP mcu address from 0x5A~0x61.
Anyone can explain how the settings can be done?
