34 lines · plain
1=====================================================2Intel INT3496 ACPI device extcon driver documentation3=====================================================4 5The Intel INT3496 ACPI device extcon driver is a driver for ACPI6devices with an acpi-id of INT3496, such as found for example on7Intel Baytrail and Cherrytrail tablets.8 9This ACPI device describes how the OS can read the id-pin of the devices'10USB-otg port, as well as how it optionally can enable Vbus output on the11otg port and how it can optionally control the muxing of the data pins12between an USB host and an USB peripheral controller.13 14The ACPI devices exposes this functionality by returning an array with up15to 3 gpio descriptors from its ACPI _CRS (Current Resource Settings) call:16 17======= =====================================================================18Index 0 The input gpio for the id-pin, this is always present and valid19Index 1 The output gpio for enabling Vbus output from the device to the otg20 port, write 1 to enable the Vbus output (this gpio descriptor may21 be absent or invalid)22Index 2 The output gpio for muxing of the data pins between the USB host and23 the USB peripheral controller, write 1 to mux to the peripheral24 controller25======= =====================================================================26 27There is a mapping between indices and GPIO connection IDs as follows28 29 ======= =======30 id index 031 vbus index 132 mux index 233 ======= =======34