1Intel INT3496 ACPI device extcon driver documentation 2----------------------------------------------------- 3 4The Intel INT3496 ACPI device extcon driver is a driver for ACPI 5devices with an acpi-id of INT3496, such as found for example on 6Intel Baytrail and Cherrytrail tablets. 7 8This ACPI device describes how the OS can read the id-pin of the devices' 9USB-otg port, as well as how it optionally can enable Vbus output on the 10otg port and how it can optionally control the muxing of the data pins 11between an USB host and an USB peripheral controller. 12 13The ACPI devices exposes this functionality by returning an array with up 14to 3 gpio descriptors from its ACPI _CRS (Current Resource Settings) call: 15 16Index 0: The input gpio for the id-pin, this is always present and valid 17Index 1: The output gpio for enabling Vbus output from the device to the otg 18 port, write 1 to enable the Vbus output (this gpio descriptor may 19 be absent or invalid) 20Index 2: The output gpio for muxing of the data pins between the USB host and 21 the USB peripheral controller, write 1 to mux to the peripheral 22 controller 23 24There is a mapping between indices and GPIO connection IDs as follows 25 id index 0 26 vbus index 1 27 mux index 2 28