MacBookPro12,X and older:

• ALS and Keyboard Backlight is controlled by SMC
• ALS keys: AL, ALI0, ALI1, ALRV, ALV0, ALV1
• Keyboard Backlight keys: LKSB, LKSS, MSLD
• See AsusSMC

Newer MacBook:

• On Macbook without Touchbar, ALS sensor is called ALS0. IOService is AppleLMUController.
• On Macbook with Touchbar, ALS sensor is connected via USB. IOService is AppleUSBALSService (com.apple.driver.AppleHIDALSService)
• Keyboard Backlight seems to be controlled by the keyboard itself. IOService is AppleHIDKeyboardEventDriverV2. It has a property named KeyboardBacklightBrightness
• There's a boolean property KeyboardBacklight in IOResources.
• AppleHIDKeyboardEventDriverV2 location: /S/L/E/AppleTopCase.kext/Contents/PlugIns/AppleTopCaseDriverV2.kext
• AppleUSBALSService location: /S/L/E/AppleHIDALSService.kext