Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/kernel/drivers/staging/iio/Documentation/trigger.txt b/kernel/drivers/staging/iio/Documentation/trigger.txt
new file mode 100644
index 000000000..7c0e505e4
--- /dev/null
+++ b/kernel/drivers/staging/iio/Documentation/trigger.txt
@@ -0,0 +1,35 @@
+IIO trigger drivers.
+
+Many triggers are provided by hardware that will also be registered as
+an IIO device.  Whilst this can create device specific complexities
+such triggers are registered with the core in the same way as
+stand-alone triggers.
+
+struct iio_trig *trig = iio_trigger_alloc("<trigger format string>", ...);
+
+allocates a trigger structure.  The key elements to then fill in within
+a driver are:
+
+trig->owner
+	Typically set to THIS_MODULE. Used to ensure correct
+	ownership of core allocated resources.
+
+trig->set_trigger_state:
+	Function that enables / disables the underlying source of the trigger.
+
+There is also a
+trig->alloc_list which is useful for drivers that allocate multiple
+triggers to keep track of what they have created.
+
+When these have been set call:
+
+iio_trigger_register(trig);
+
+to register the trigger with the core, making it available to trigger
+consumers.
+
+Trigger Consumers
+
+Currently triggers are only used for the filling of software
+buffers and as such any device supporting INDIO_BUFFER_TRIGGERED has the
+consumer interface automatically created.