[PATCH] Add Apple Carplay driver

[Chunfeng Yun]

>From bf48dcd9cb254576cfea373c9a5d2ab996408895 Mon Sep 17 00:00:00 2001
From: Chunfeng Yun <chunfeng.yun at mediatek.com>
Date: Tue, 13 Mar 2018 11:47:38 +0800
Subject: [PATCH] Add Apple Carplay driver

Some Apple devices which support Carplay can enter USB Host Mode from USB
Device Mode after receiving a specific USB Vendor Request. There is a
requirement apply to accesssories that support the USB dual role switch
feature, and must have a USB-A receptacle that is capable of functioning
in both USB Host and USB Device roles.
It means that the driver should supports manual Dual-Role switch, due to
no IDDIG pin is avaliable.

There is no suitable place to add this spicific USB Vendor Request, so
here I extract a single driver which allow user force to send it by a debug
interface when need it, and keep it independent on USB Dual-Role Controller
Drivers.
But to implement carplay feature, there are some requirments for USB Dual-Role
Driver:
1. supports manual dual-role switch, such as, by a debug interface;
2. keep vbus alive even when switch host into device mode;

More information please refer to "Chapter 46. USB Role Switch" in
MFI Accessroy Interface Specification.pdf

Chunfeng Yun (1):
  usb: misc: supports Apple Carplay driver

 drivers/usb/misc/Kconfig   |    9 +++
 drivers/usb/misc/Makefile  |    1 +
 drivers/usb/misc/carplay.c |  193 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 203 insertions(+)
 create mode 100644 drivers/usb/misc/carplay.c

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