[PATCH v2 0/7] usb: add support for Intel dual role port mux

[Lu Baolu <baolu.lu@linux.intel.com>]

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: mux: add common code for Intel dual role port mux
  usb: mux: add driver for Intel gpio controlled port mux
  usb: mux: 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

 Documentation/ABI/testing/sysfs-bus-platform |  15 +++
 MAINTAINERS                                  |  10 ++
 drivers/extcon/extcon-usb-gpio.c             |  10 +-
 drivers/mfd/Kconfig                          |   8 ++
 drivers/mfd/Makefile                         |   1 +
 drivers/mfd/intel-vuport.c                   |  78 +++++++++++++
 drivers/usb/Kconfig                          |   2 +
 drivers/usb/Makefile                         |   1 +
 drivers/usb/host/pci-quirks.c                |  47 +++++++-
 drivers/usb/host/xhci-ext-caps.h             |   2 +
 drivers/usb/mux/Kconfig                      |  25 ++++
 drivers/usb/mux/Makefile                     |   6 +
 drivers/usb/mux/intel-mux-drcfg.c            | 161 ++++++++++++++++++++++++++
 drivers/usb/mux/intel-mux-gpio.c             | 125 ++++++++++++++++++++
 drivers/usb/mux/intel-mux.c                  | 166 +++++++++++++++++++++++++++
 include/linux/usb/intel-mux.h                |  47 ++++++++
 16 files changed, 701 insertions(+), 3 deletions(-)
 create mode 100644 drivers/mfd/intel-vuport.c
 create mode 100644 drivers/usb/mux/Kconfig
 create mode 100644 drivers/usb/mux/Makefile
 create mode 100644 drivers/usb/mux/intel-mux-drcfg.c
 create mode 100644 drivers/usb/mux/intel-mux-gpio.c
 create mode 100644 drivers/usb/mux/intel-mux.c
 create mode 100644 include/linux/usb/intel-mux.h

Change log:

v1->v2:
 - move mux driver from drivers/usb/misc to drivers/usb/mux;
 - replace debugfs with sysfs for user level mux control;
 - remove unnecessary register restore if mux registeration failed;
 - Add "Acked-by: Chanwoo Choi <cw00.choi@samsung.com>" to extcon changes;
 - Make the file names and exported function names more specific;
 - Remove the usb_mux_get_dev() interface;
 - Move "struct intel_usb_mux" from .h to .c file;
 - Fix various kbuild robot warnings.

-- 
2.1.4