Benq S6 ACPI EC (Embedded Controller)

The Benq S6 MID uses an ACPI compliant Embedded Controller to control several functions of its hardware:

• Enable/disable wireless lan, bluetooth and hsdpa modem (also gps, but at least on my model is not present)
  
• Control leds
  
• Control brightness
  
• Keylock

EC protocol

The EC allows to write/read 8 bit data in 256 registers.
The Benq S6 MID use a protocol with only two registers for all the functions.
The protocol to read the hardware status is:

• Read the register 0x60, must read 0x0
  
• Write in the register 0x60 the opcode for the hardware to query
  
• Read the register 0x60, must read 0x0
  
• Read the register 0x61, the value in this register is the result of the query

The protocol to change the hardware status is:

• Read the register 0x60, must read 0x0
  
• Write in the register 0x61 the data to change the hardware status
  
• Write in the register 0x60 the opcode for the hardware to change
  
• Read the register 0x60, must read 0x0

There are two special registers for the status of the power button: 0x46 and 0x47.

opcodes

Query opcodes:

• 0x15 : get_brightness
  
• 0x17 : get_keylock
  
• 0x19 : get_sd_cd
  
• 0x28 : get_hsdpa
  
• 0x2a : get_wireless
  
• 0x2c : get_gps

Write opcodes (for most of them 0 is off, 1 is on):

• 0x16 : set_keylock
  
• 0x18 : set_sd_cd (the meaning of this opcode is not yet fully understood)
  
• 0x22 : set_brightness (accepts data from 0 to 7)
  
• 0x27 : set_hsdpa
  
• 0x29 : set_wireless (enable both wlan and bluetooth)
  
• 0x2b : set_gps
  
• 0x40 : set_wirelesslanled
  
• 0x41 : set_wwanled
  
• 0x42 : set_sysled (0 off, 1 on still, 2 on flashing)
  
• 0x43 : set_chargingled