Intel SOC chips are featured with USB dual role. The host role is
provided by Intel xHCI IP, and the gadget role is provided by IP
from designware. Tablet platform designs always share a single
port for both host and gadget controllers. There is a mux to
switch the port to the right controller according to the cable
type. OS needs to provide the callback to control the mux when
a plug-in event raises. The method to control the mux is platform
dependent. At least three types of implementation can be found
across current devices. 1) GPIO pins; 2) a unit which can be
controlled by memory mapped registers; 3) ACPI ASL code.
This patch series adds supports for Intel dual role port mux.
It includes:
(1) A helper layer on top of extcon for individual mux driver.
It listens to the USB-HOST extcon cable and call the switch
call-back when the cable state changes.
(2) Drivers for GPIO controlled port mux which could be found on
Baytrail devices. A mfd driver is used to split the GPIOs into
USB gpio extcon device and a USB mux device. Driver for USB
gpio extcon device is already in upstream Linux. This patch
series includes a driver for GPIO USB mux.
(3) Drivers for USB port mux controlled through memory mapped
registers and the logic to create the mux device. This type
of dual role port mux could be found in Cherry Trail and
Broxton devices.
Lu Baolu (7):
extcon: usb-gpio: add device binding for platform device
extcon: usb-gpio: add support for ACPI gpio interface
usb: misc: add common code for Intel dual role port mux
usb: misc: add driver for Intel gpio controlled port mux
usb: misc: add driver for Intel drcfg controlled port mux
usb: pci-quirks: add Intel USB drcfg mux device
mfd: intel_vuport: Add Intel virtual USB port MFD Driver
MAINTAINERS | 10 +++
drivers/extcon/extcon-usb-gpio.c | 10 ++-
drivers/mfd/Kconfig | 7 ++
drivers/mfd/Makefile | 1 +
drivers/mfd/intel-vuport.c | 79 +++++++++++++++++
drivers/usb/host/pci-quirks.c | 47 +++++++++-
drivers/usb/host/xhci-ext-caps.h | 2 +
drivers/usb/misc/Kconfig | 20 +++++
drivers/usb/misc/Makefile | 4 +
drivers/usb/misc/intel-mux-drcfg.c | 174 +++++++++++++++++++++++++++++++++++++
drivers/usb/misc/intel-mux-gpio.c | 126 +++++++++++++++++++++++++++
drivers/usb/misc/mux.c | 172 ++++++++++++++++++++++++++++++++++++
include/linux/usb/mux.h | 71 +++++++++++++++
13 files changed, 720 insertions(+), 3 deletions(-)
create mode 100644 drivers/mfd/intel-vuport.c
create mode 100644 drivers/usb/misc/intel-mux-drcfg.c
create mode 100644 drivers/usb/misc/intel-mux-gpio.c
create mode 100644 drivers/usb/misc/mux.c
create mode 100644 include/linux/usb/mux.h
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2.1.4
