From 2f556bdb9f2e3794722c0d9186db9799b35071c4 Mon Sep 17 00:00:00 2001 From: David Cohen Date: Wed, 21 Dec 2016 12:20:25 +0100 Subject: extcon: int3496: Add Intel INT3496 ACPI device extcon driver Add an extcon driver for USB OTG ports controlled by an Intel INT3496 ACPI device (e.g. Baytrail, Cherrytrail devices). Signed-off-by: David Cohen [hdgoede@redhat.com: Port to current kernel, cleanup, submit upstream] [hdgoede@redhat.com: Add Documentation/extcon/intel-int3496.txt] Signed-off-by: Hans de Goede Signed-off-by: Chanwoo Choi --- Documentation/extcon/intel-int3496.txt | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 Documentation/extcon/intel-int3496.txt (limited to 'Documentation/extcon') diff --git a/Documentation/extcon/intel-int3496.txt b/Documentation/extcon/intel-int3496.txt new file mode 100644 index 000000000000..af0b366c25b7 --- /dev/null +++ b/Documentation/extcon/intel-int3496.txt @@ -0,0 +1,22 @@ +Intel INT3496 ACPI device extcon driver documentation +----------------------------------------------------- + +The Intel INT3496 ACPI device extcon driver is a driver for ACPI +devices with an acpi-id of INT3496, such as found for example on +Intel Baytrail and Cherrytrail tablets. + +This ACPI device describes how the OS can read the id-pin of the devices' +USB-otg port, as well as how it optionally can enable Vbus output on the +otg port and how it can optionally control the muxing of the data pins +between an USB host and an USB peripheral controller. + +The ACPI devices exposes this functionality by returning an array with up +to 3 gpio descriptors from its ACPI _CRS (Current Resource Settings) call: + +Index 0: The input gpio for the id-pin, this is always present and valid +Index 1: The output gpio for enabling Vbus output from the device to the otg + port, write 1 to enable the Vbus output (this gpio descriptor may + be absent or invalid) +Index 2: The output gpio for muxing of the data pins between the USB host and + the USB peripheral controller, write 1 to mux to the peripheral + controller -- cgit