This is a introduction for flashlight chip LM3643

[Scope]
- Two channel for two LEDs


[Hardware Interface]
- I2C
	* For general control
	* Slave address 0x63

- GPIO
	* For enable/disable chip


[Limit]
- Channel couple:
	* Torch/Strobe

- Channel decouple:
	* Enable/Disable
	* Brightness level

- Torch Mode
	* Step current: 1.4 mA
	* Min currnet: 0.977 mA
	* Max current: 179 mA

- Strobe Mode
	* Step current: 11.725 mA
	* Min currnet: 10.9 mA
	* Max current: 1500 mA
	* Max current for two channel: 1500 mA
	* Min protected timeout: 10 ms
	* Max protected timeout: 400 ms