| 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 |
