2513563edc
Some MeeGoPad top-set boxes have an ANX7428 Type-C Switch for USB3.1 Gen 1 and DisplayPort over Type-C alternate mode support. The ANX7428 has a microcontroller which takes care of the PD negotiation and automatically sets the builtin Crosspoint Switch to send the right signal to the 4 highspeed pairs of the Type-C connector. It also takes care of HPD and AUX channel routing for DP alternate mode. IOW the ANX7428 operates fully autonomous and to the x5-Z8350 SoC things look like there simple is a USB-3 Type-A connector and a separate DisplayPort connector. Except that the BIOS does not power on the ANX7428 at boot (meh). Add a driver to power on the ANX7428. This driver is added under drivers/platform/x86 rather than under drivers/usb/typec for 2 reasons: 1. This driver is specifically written to work with how the ANX7428 is described in the ACPI tables of the MeeGoPad x86 (Cherry Trail) devices. 2. This driver only powers on the ANX7428 and does not do anything wrt its Type-C functionality. It should be possible to tell the controller which data- and/or power-role to negotiate and to swap the role(s) after negotiation but the MeeGoPad top-set boxes always draw their power from a separate power-connector and they only support USB host-mode. So this functionality is unnecessary and due to lack of documentation this is tricky to support. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20240514180343.70795-1-hdegoede@redhat.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.