Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/Documentation/extcon/intel-int3496.txt b/Documentation/extcon/intel-int3496.txt
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+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
+
+There is a mapping between indices and GPIO connection IDs as follows
+	id	index 0
+	vbus	index 1
+	mux	index 2