Why is this a kernel-level driver, rather than a userspace application that uses libusb to send the single vendor-specific command required? Since this command would be applicable to many CarPlay devices, with many different VID/PIDs, it would seem to make more sense as a userspace app that took a reference to a USB device or VID/PID. Matt On Tue, Mar 13, 2018 at 11:02 PM, Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> wrote: > From bf48dcd9cb254576cfea373c9a5d2ab996408895 Mon Sep 17 00:00:00 2001 > From: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> > 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 > > -- > 1.7.9.5 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Matthew Dharm Former Maintainer, USB Mass Storage driver for Linux -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
