Merge tag 'usb-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB 3.5-rc1 changes from Greg Kroah-Hartman:
 "Here is the big USB 3.5-rc1 pull request for the 3.5-rc1 merge window.

  It's touches a lot of different parts of the kernel, all USB drivers,
  due to some API cleanups (getting rid of the ancient err() macro) and
  some changes that are needed for USB 3.0 power management updates.

  There are also lots of new drivers, pimarily gadget, but others as
  well.  We deleted a staging driver, which was nice, and finally
  dropped the obsolete usbfs code, which will make Al happy to never
  have to touch that again.

  There were some build errors in the tree that linux-next found a few
  days ago, but those were fixed by the most recent changes (all were
  due to us not building with CONFIG_PM disabled.)

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'usb-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (477 commits)
  xhci: Fix DIV_ROUND_UP compile error.
  xhci: Fix compile with CONFIG_USB_SUSPEND=n
  USB: Fix core compile with CONFIG_USB_SUSPEND=n
  brcm80211: Fix compile error for .disable_hub_initiated_lpm.
  Revert "USB: EHCI: work around bug in the Philips ISP1562 controller"
  MAINTAINERS: Add myself as maintainer to the USB PHY Layer
  USB: EHCI: fix command register configuration lost problem
  USB: Remove races in devio.c
  USB: ehci-platform: remove update_device
  USB: Disable hub-initiated LPM for comms devices.
  xhci: Add Intel U1/U2 timeout policy.
  xhci: Add infrastructure for host-specific LPM policies.
  USB: Add macros for interrupt endpoint types.
  xhci: Reserve one command for USB3 LPM disable.
  xhci: Some Evaluate Context commands must succeed.
  USB: Disable USB 3.0 LPM in critical sections.
  USB: Add support to enable/disable USB3 link states.
  USB: Allow drivers to disable hub-initiated LPM.
  USB: Calculate USB 3.0 exit latencies for LPM.
  USB: Refactor code to set LPM support flag.
  ...

Conflicts:
	arch/arm/mach-exynos/mach-nuri.c
	arch/arm/mach-exynos/mach-universal_c210.c
	drivers/net/wireless/ath/ath6kl/usb.c

1 files changed, 67 insertions, 0 deletions

diff --git a/Documentation/usb/functionfs.txt b/Documentation/usb/functionfs.txt
new file mode 100644
index 00000000000..eaaaea019fc
--- /dev/null
+++ b/Documentation/usb/functionfs.txt
@@ -0,0 +1,67 @@
+*How FunctionFS works*
+
+From kernel point of view it is just a composite function with some
+unique behaviour.  It may be added to an USB configuration only after
+the user space driver has registered by writing descriptors and
+strings (the user space program has to provide the same information
+that kernel level composite functions provide when they are added to
+the configuration).
+
+This in particular means that the composite initialisation functions
+may not be in init section (ie. may not use the __init tag).
+
+From user space point of view it is a file system which when
+mounted provides an "ep0" file.  User space driver need to
+write descriptors and strings to that file.  It does not need
+to worry about endpoints, interfaces or strings numbers but
+simply provide descriptors such as if the function was the
+only one (endpoints and strings numbers starting from one and
+interface numbers starting from zero).  The FunctionFS changes
+them as needed also handling situation when numbers differ in
+different configurations.
+
+When descriptors and strings are written "ep#" files appear
+(one for each declared endpoint) which handle communication on
+a single endpoint.  Again, FunctionFS takes care of the real
+numbers and changing of the configuration (which means that
+"ep1" file may be really mapped to (say) endpoint 3 (and when
+configuration changes to (say) endpoint 2)).  "ep0" is used
+for receiving events and handling setup requests.
+
+When all files are closed the function disables itself.
+
+What I also want to mention is that the FunctionFS is designed in such
+a way that it is possible to mount it several times so in the end
+a gadget could use several FunctionFS functions. The idea is that
+each FunctionFS instance is identified by the device name used
+when mounting.
+
+One can imagine a gadget that has an Ethernet, MTP and HID interfaces
+where the last two are implemented via FunctionFS.  On user space
+level it would look like this:
+
+$ insmod g_ffs.ko idVendor=<ID> iSerialNumber=<string> functions=mtp,hid
+$ mkdir /dev/ffs-mtp && mount -t functionfs mtp /dev/ffs-mtp
+$ ( cd /dev/ffs-mtp && mtp-daemon ) &
+$ mkdir /dev/ffs-hid && mount -t functionfs hid /dev/ffs-hid
+$ ( cd /dev/ffs-hid && hid-daemon ) &
+
+On kernel level the gadget checks ffs_data->dev_name to identify
+whether it's FunctionFS designed for MTP ("mtp") or HID ("hid").
+
+If no "functions" module parameters is supplied, the driver accepts
+just one function with any name.
+
+When "functions" module parameter is supplied, only functions
+with listed names are accepted. In particular, if the "functions"
+parameter's value is just a one-element list, then the behaviour
+is similar to when there is no "functions" at all; however,
+only a function with the specified name is accepted.
+
+The gadget is registered only after all the declared function
+filesystems have been mounted and USB descriptors of all functions
+have been written to their ep0's.
+
+Conversely, the gadget is unregistered after the first USB function
+closes its endpoints.
+