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, 484 insertions, 0 deletions

diff --git a/kernel/Documentation/DocBook/media/v4l/dev-subdev.xml b/kernel/Documentation/DocBook/media/v4l/dev-subdev.xml
new file mode 100644
index 000000000..4f0ba58c9
--- /dev/null
+++ b/kernel/Documentation/DocBook/media/v4l/dev-subdev.xml
@@ -0,0 +1,484 @@
+  <title>Sub-device Interface</title>
+
+  <note>
+    <title>Experimental</title>
+    <para>This is an <link linkend="experimental">experimental</link>
+    interface and may change in the future.</para>
+  </note>
+
+  <para>The complex nature of V4L2 devices, where hardware is often made of
+  several integrated circuits that need to interact with each other in a
+  controlled way, leads to complex V4L2 drivers. The drivers usually reflect
+  the hardware model in software, and model the different hardware components
+  as software blocks called sub-devices.</para>
+
+  <para>V4L2 sub-devices are usually kernel-only objects. If the V4L2 driver
+  implements the media device API, they will automatically inherit from media
+  entities. Applications will be able to enumerate the sub-devices and discover
+  the hardware topology using the media entities, pads and links enumeration
+  API.</para>
+
+  <para>In addition to make sub-devices discoverable, drivers can also choose
+  to make them directly configurable by applications. When both the sub-device
+  driver and the V4L2 device driver support this, sub-devices will feature a
+  character device node on which ioctls can be called to
+  <itemizedlist>
+    <listitem><para>query, read and write sub-devices controls</para></listitem>
+    <listitem><para>subscribe and unsubscribe to events and retrieve them</para></listitem>
+    <listitem><para>negotiate image formats on individual pads</para></listitem>
+  </itemizedlist>
+  </para>
+
+  <para>Sub-device character device nodes, conventionally named
+  <filename>/dev/v4l-subdev*</filename>, use major number 81.</para>
+
+  <section>
+    <title>Controls</title>
+    <para>Most V4L2 controls are implemented by sub-device hardware. Drivers
+    usually merge all controls and expose them through video device nodes.
+    Applications can control all sub-devices through a single interface.</para>
+
+    <para>Complex devices sometimes implement the same control in different
+    pieces of hardware. This situation is common in embedded platforms, where
+    both sensors and image processing hardware implement identical functions,
+    such as contrast adjustment, white balance or faulty pixels correction. As
+    the V4L2 controls API doesn't support several identical controls in a single
+    device, all but one of the identical controls are hidden.</para>
+
+    <para>Applications can access those hidden controls through the sub-device
+    node with the V4L2 control API described in <xref linkend="control" />. The
+    ioctls behave identically as when issued on V4L2 device nodes, with the
+    exception that they deal only with controls implemented in the sub-device.
+    </para>
+
+    <para>Depending on the driver, those controls might also be exposed through
+    one (or several) V4L2 device nodes.</para>
+  </section>
+
+  <section>
+    <title>Events</title>
+    <para>V4L2 sub-devices can notify applications of events as described in
+    <xref linkend="event" />. The API behaves identically as when used on V4L2
+    device nodes, with the exception that it only deals with events generated by
+    the sub-device. Depending on the driver, those events might also be reported
+    on one (or several) V4L2 device nodes.</para>
+  </section>
+
+  <section id="pad-level-formats">
+    <title>Pad-level Formats</title>
+
+    <warning><para>Pad-level formats are only applicable to very complex device that
+    need to expose low-level format configuration to user space. Generic V4L2
+    applications do <emphasis>not</emphasis> need to use the API described in
+    this section.</para></warning>
+
+    <note><para>For the purpose of this section, the term
+    <wordasword>format</wordasword> means the combination of media bus data
+    format, frame width and frame height.</para></note>
+
+    <para>Image formats are typically negotiated on video capture and
+    output devices using the format and <link
+    linkend="vidioc-subdev-g-selection">selection</link> ioctls. The
+    driver is responsible for configuring every block in the video
+    pipeline according to the requested format at the pipeline input
+    and/or output.</para>
+
+    <para>For complex devices, such as often found in embedded systems,
+    identical image sizes at the output of a pipeline can be achieved using
+    different hardware configurations. One such example is shown on
+    <xref linkend="pipeline-scaling" />, where
+    image scaling can be performed on both the video sensor and the host image
+    processing hardware.</para>
+
+    <figure id="pipeline-scaling">
+      <title>Image Format Negotiation on Pipelines</title>
+      <mediaobject>
+	<imageobject>
+	  <imagedata fileref="pipeline.pdf" format="PS" />
+	</imageobject>
+	<imageobject>
+	  <imagedata fileref="pipeline.png" format="PNG" />
+	</imageobject>
+	<textobject>
+	  <phrase>High quality and high speed pipeline configuration</phrase>
+	</textobject>
+      </mediaobject>
+    </figure>
+
+    <para>The sensor scaler is usually of less quality than the host scaler, but
+    scaling on the sensor is required to achieve higher frame rates. Depending
+    on the use case (quality vs. speed), the pipeline must be configured
+    differently. Applications need to configure the formats at every point in
+    the pipeline explicitly.</para>
+
+    <para>Drivers that implement the <link linkend="media-controller-intro">media
+    API</link> can expose pad-level image format configuration to applications.
+    When they do, applications can use the &VIDIOC-SUBDEV-G-FMT; and
+    &VIDIOC-SUBDEV-S-FMT; ioctls. to negotiate formats on a per-pad basis.</para>
+
+    <para>Applications are responsible for configuring coherent parameters on
+    the whole pipeline and making sure that connected pads have compatible
+    formats. The pipeline is checked for formats mismatch at &VIDIOC-STREAMON;
+    time, and an &EPIPE; is then returned if the configuration is
+    invalid.</para>
+
+    <para>Pad-level image format configuration support can be tested by calling
+    the &VIDIOC-SUBDEV-G-FMT; ioctl on pad 0. If the driver returns an &EINVAL;
+    pad-level format configuration is not supported by the sub-device.</para>
+
+    <section>
+      <title>Format Negotiation</title>
+
+      <para>Acceptable formats on pads can (and usually do) depend on a number
+      of external parameters, such as formats on other pads, active links, or
+      even controls. Finding a combination of formats on all pads in a video
+      pipeline, acceptable to both application and driver, can't rely on formats
+      enumeration only. A format negotiation mechanism is required.</para>
+
+      <para>Central to the format negotiation mechanism are the get/set format
+      operations. When called with the <structfield>which</structfield> argument
+      set to <constant>V4L2_SUBDEV_FORMAT_TRY</constant>, the
+      &VIDIOC-SUBDEV-G-FMT; and &VIDIOC-SUBDEV-S-FMT; ioctls operate on a set of
+      formats parameters that are not connected to the hardware configuration.
+      Modifying those 'try' formats leaves the device state untouched (this
+      applies to both the software state stored in the driver and the hardware
+      state stored in the device itself).</para>
+
+      <para>While not kept as part of the device state, try formats are stored
+      in the sub-device file handles. A &VIDIOC-SUBDEV-G-FMT; call will return
+      the last try format set <emphasis>on the same sub-device file
+      handle</emphasis>. Several applications querying the same sub-device at
+      the same time will thus not interact with each other.</para>
+
+      <para>To find out whether a particular format is supported by the device,
+      applications use the &VIDIOC-SUBDEV-S-FMT; ioctl. Drivers verify and, if
+      needed, change the requested <structfield>format</structfield> based on
+      device requirements and return the possibly modified value. Applications
+      can then choose to try a different format or accept the returned value and
+      continue.</para>
+
+      <para>Formats returned by the driver during a negotiation iteration are
+      guaranteed to be supported by the device. In particular, drivers guarantee
+      that a returned format will not be further changed if passed to an
+      &VIDIOC-SUBDEV-S-FMT; call as-is (as long as external parameters, such as
+      formats on other pads or links' configuration are not changed).</para>
+
+      <para>Drivers automatically propagate formats inside sub-devices. When a
+      try or active format is set on a pad, corresponding formats on other pads
+      of the same sub-device can be modified by the driver. Drivers are free to
+      modify formats as required by the device. However, they should comply with
+      the following rules when possible:
+      <itemizedlist>
+        <listitem><para>Formats should be propagated from sink pads to source pads.
+	Modifying a format on a source pad should not modify the format on any
+	sink pad.</para></listitem>
+        <listitem><para>Sub-devices that scale frames using variable scaling factors
+	should reset the scale factors to default values when sink pads formats
+	are modified. If the 1:1 scaling ratio is supported, this means that
+	source pads formats should be reset to the sink pads formats.</para></listitem>
+      </itemizedlist>
+      </para>
+
+      <para>Formats are not propagated across links, as that would involve
+      propagating them from one sub-device file handle to another. Applications
+      must then take care to configure both ends of every link explicitly with
+      compatible formats. Identical formats on the two ends of a link are
+      guaranteed to be compatible. Drivers are free to accept different formats
+      matching device requirements as being compatible.</para>
+
+      <para><xref linkend="sample-pipeline-config" />
+      shows a sample configuration sequence for the pipeline described in
+      <xref linkend="pipeline-scaling" /> (table
+      columns list entity names and pad numbers).</para>
+
+      <table pgwide="0" frame="none" id="sample-pipeline-config">
+	<title>Sample Pipeline Configuration</title>
+	<tgroup cols="3">
+	  <colspec colname="what"/>
+	  <colspec colname="sensor-0 format" />
+	  <colspec colname="frontend-0 format" />
+	  <colspec colname="frontend-1 format" />
+	  <colspec colname="scaler-0 format" />
+	  <colspec colname="scaler-0 compose" />
+	  <colspec colname="scaler-1 format" />
+	  <thead>
+	    <row>
+	      <entry></entry>
+	      <entry>Sensor/0 format</entry>
+	      <entry>Frontend/0 format</entry>
+	      <entry>Frontend/1 format</entry>
+	      <entry>Scaler/0 format</entry>
+	      <entry>Scaler/0 compose selection rectangle</entry>
+	      <entry>Scaler/1 format</entry>
+	    </row>
+	  </thead>
+	  <tbody valign="top">
+	    <row>
+	      <entry>Initial state</entry>
+	      <entry>2048x1536/SGRBG8_1X8</entry>
+	      <entry>(default)</entry>
+	      <entry>(default)</entry>
+	      <entry>(default)</entry>
+	      <entry>(default)</entry>
+	      <entry>(default)</entry>
+	    </row>
+	    <row>
+	      <entry>Configure frontend sink format</entry>
+	      <entry>2048x1536/SGRBG8_1X8</entry>
+	      <entry><emphasis>2048x1536/SGRBG8_1X8</emphasis></entry>
+	      <entry><emphasis>2046x1534/SGRBG8_1X8</emphasis></entry>
+	      <entry>(default)</entry>
+	      <entry>(default)</entry>
+	      <entry>(default)</entry>
+	    </row>
+	    <row>
+	      <entry>Configure scaler sink format</entry>
+	      <entry>2048x1536/SGRBG8_1X8</entry>
+	      <entry>2048x1536/SGRBG8_1X8</entry>
+	      <entry>2046x1534/SGRBG8_1X8</entry>
+	      <entry><emphasis>2046x1534/SGRBG8_1X8</emphasis></entry>
+	      <entry><emphasis>0,0/2046x1534</emphasis></entry>
+	      <entry><emphasis>2046x1534/SGRBG8_1X8</emphasis></entry>
+	    </row>
+	    <row>
+	      <entry>Configure scaler sink compose selection</entry>
+	      <entry>2048x1536/SGRBG8_1X8</entry>
+	      <entry>2048x1536/SGRBG8_1X8</entry>
+	      <entry>2046x1534/SGRBG8_1X8</entry>
+	      <entry>2046x1534/SGRBG8_1X8</entry>
+	      <entry><emphasis>0,0/1280x960</emphasis></entry>
+	      <entry><emphasis>1280x960/SGRBG8_1X8</emphasis></entry>
+	    </row>
+	  </tbody>
+	</tgroup>
+      </table>
+
+      <para>
+      <orderedlist>
+	<listitem><para>Initial state. The sensor source pad format is
+	set to its native 3MP size and V4L2_MBUS_FMT_SGRBG8_1X8
+	media bus code. Formats on the host frontend and scaler sink
+	and source pads have the default values, as well as the
+	compose rectangle on the scaler's sink pad.</para></listitem>
+
+	<listitem><para>The application configures the frontend sink
+	pad format's size to 2048x1536 and its media bus code to
+	V4L2_MBUS_FMT_SGRBG_1X8. The driver propagates the format to
+	the frontend source pad.</para></listitem>
+
+	<listitem><para>The application configures the scaler sink pad
+	format's size to 2046x1534 and the media bus code to
+	V4L2_MBUS_FMT_SGRBG_1X8 to match the frontend source size and
+	media bus code. The media bus code on the sink pad is set to
+	V4L2_MBUS_FMT_SGRBG_1X8. The driver propagates the size to the
+	compose selection rectangle on the scaler's sink pad, and the
+	format to the scaler source pad.</para></listitem>
+
+	<listitem><para>The application configures the size of the compose
+	selection rectangle of the scaler's sink pad 1280x960. The driver
+	propagates the size to the scaler's source pad
+	format.</para></listitem>
+
+      </orderedlist>
+      </para>
+
+      <para>When satisfied with the try results, applications can set the active
+      formats by setting the <structfield>which</structfield> argument to
+      <constant>V4L2_SUBDEV_FORMAT_ACTIVE</constant>. Active formats are changed
+      exactly as try formats by drivers. To avoid modifying the hardware state
+      during format negotiation, applications should negotiate try formats first
+      and then modify the active settings using the try formats returned during
+      the last negotiation iteration. This guarantees that the active format
+      will be applied as-is by the driver without being modified.
+      </para>
+    </section>
+
+    <section id="v4l2-subdev-selections">
+      <title>Selections: cropping, scaling and composition</title>
+
+      <para>Many sub-devices support cropping frames on their input or output
+      pads (or possible even on both). Cropping is used to select the area of
+      interest in an image, typically on an image sensor or a video decoder. It can
+      also be used as part of digital zoom implementations to select the area of
+      the image that will be scaled up.</para>
+
+      <para>Crop settings are defined by a crop rectangle and represented in a
+      &v4l2-rect; by the coordinates of the top left corner and the rectangle
+      size. Both the coordinates and sizes are expressed in pixels.</para>
+
+      <para>As for pad formats, drivers store try and active
+      rectangles for the selection targets <xref
+      linkend="v4l2-selections-common" />.</para>
+
+      <para>On sink pads, cropping is applied relative to the
+      current pad format. The pad format represents the image size as
+      received by the sub-device from the previous block in the
+      pipeline, and the crop rectangle represents the sub-image that
+      will be transmitted further inside the sub-device for
+      processing.</para>
+
+      <para>The scaling operation changes the size of the image by
+      scaling it to new dimensions. The scaling ratio isn't specified
+      explicitly, but is implied from the original and scaled image
+      sizes. Both sizes are represented by &v4l2-rect;.</para>
+
+      <para>Scaling support is optional. When supported by a subdev,
+      the crop rectangle on the subdev's sink pad is scaled to the
+      size configured using the &VIDIOC-SUBDEV-S-SELECTION; IOCTL
+      using <constant>V4L2_SEL_TGT_COMPOSE</constant>
+      selection target on the same pad. If the subdev supports scaling
+      but not composing, the top and left values are not used and must
+      always be set to zero.</para>
+
+      <para>On source pads, cropping is similar to sink pads, with the
+      exception that the source size from which the cropping is
+      performed, is the COMPOSE rectangle on the sink pad. In both
+      sink and source pads, the crop rectangle must be entirely
+      contained inside the source image size for the crop
+      operation.</para>
+
+      <para>The drivers should always use the closest possible
+      rectangle the user requests on all selection targets, unless
+      specifically told otherwise.
+      <constant>V4L2_SEL_FLAG_GE</constant> and
+      <constant>V4L2_SEL_FLAG_LE</constant> flags may be
+      used to round the image size either up or down. <xref
+      linkend="v4l2-selection-flags" /></para>
+    </section>
+
+    <section>
+      <title>Types of selection targets</title>
+
+      <section>
+	<title>Actual targets</title>
+
+	<para>Actual targets (without a postfix) reflect the actual
+	hardware configuration at any point of time. There is a BOUNDS
+	target corresponding to every actual target.</para>
+      </section>
+
+      <section>
+	<title>BOUNDS targets</title>
+
+	<para>BOUNDS targets is the smallest rectangle that contains all
+	valid actual rectangles. It may not be possible to set the actual
+	rectangle as large as the BOUNDS rectangle, however. This may be
+	because e.g. a sensor's pixel array is not rectangular but
+	cross-shaped or round. The maximum size may also be smaller than the
+	BOUNDS rectangle.</para>
+      </section>
+
+    </section>
+
+    <section>
+      <title>Order of configuration and format propagation</title>
+
+      <para>Inside subdevs, the order of image processing steps will
+      always be from the sink pad towards the source pad. This is also
+      reflected in the order in which the configuration must be
+      performed by the user: the changes made will be propagated to
+      any subsequent stages. If this behaviour is not desired, the
+      user must set
+      <constant>V4L2_SEL_FLAG_KEEP_CONFIG</constant> flag. This
+      flag causes no propagation of the changes are allowed in any
+      circumstances. This may also cause the accessed rectangle to be
+      adjusted by the driver, depending on the properties of the
+      underlying hardware.</para>
+
+      <para>The coordinates to a step always refer to the actual size
+      of the previous step. The exception to this rule is the source
+      compose rectangle, which refers to the sink compose bounds
+      rectangle --- if it is supported by the hardware.</para>
+
+      <orderedlist>
+	<listitem><para>Sink pad format. The user configures the sink pad
+	format. This format defines the parameters of the image the
+	entity receives through the pad for further processing.</para></listitem>
+
+	<listitem><para>Sink pad actual crop selection. The sink pad crop
+	defines the crop performed to the sink pad format.</para></listitem>
+
+	<listitem><para>Sink pad actual compose selection. The size of the
+	sink pad compose rectangle defines the scaling ratio compared
+	to the size of the sink pad crop rectangle. The location of
+	the compose rectangle specifies the location of the actual
+	sink compose rectangle in the sink compose bounds
+	rectangle.</para></listitem>
+
+	<listitem><para>Source pad actual crop selection. Crop on the source
+	pad defines crop performed to the image in the sink compose
+	bounds rectangle.</para></listitem>
+
+	<listitem><para>Source pad format. The source pad format defines the
+	output pixel format of the subdev, as well as the other
+	parameters with the exception of the image width and height.
+	Width and height are defined by the size of the source pad
+	actual crop selection.</para></listitem>
+      </orderedlist>
+
+      <para>Accessing any of the above rectangles not supported by the
+      subdev will return <constant>EINVAL</constant>. Any rectangle
+      referring to a previous unsupported rectangle coordinates will
+      instead refer to the previous supported rectangle. For example,
+      if sink crop is not supported, the compose selection will refer
+      to the sink pad format dimensions instead.</para>
+
+      <figure id="subdev-image-processing-crop">
+	<title>Image processing in subdevs: simple crop example</title>
+	<mediaobject>
+	  <imageobject>
+	    <imagedata fileref="subdev-image-processing-crop.svg"
+	    format="SVG" scale="200" />
+	  </imageobject>
+	</mediaobject>
+      </figure>
+
+      <para>In the above example, the subdev supports cropping on its
+      sink pad. To configure it, the user sets the media bus format on
+      the subdev's sink pad. Now the actual crop rectangle can be set
+      on the sink pad --- the location and size of this rectangle
+      reflect the location and size of a rectangle to be cropped from
+      the sink format. The size of the sink crop rectangle will also
+      be the size of the format of the subdev's source pad.</para>
+
+      <figure id="subdev-image-processing-scaling-multi-source">
+	<title>Image processing in subdevs: scaling with multiple sources</title>
+	<mediaobject>
+	  <imageobject>
+	    <imagedata fileref="subdev-image-processing-scaling-multi-source.svg"
+	    format="SVG" scale="200" />
+	  </imageobject>
+	</mediaobject>
+      </figure>
+
+      <para>In this example, the subdev is capable of first cropping,
+      then scaling and finally cropping for two source pads
+      individually from the resulting scaled image. The location of
+      the scaled image in the cropped image is ignored in sink compose
+      target. Both of the locations of the source crop rectangles
+      refer to the sink scaling rectangle, independently cropping an
+      area at location specified by the source crop rectangle from
+      it.</para>
+
+      <figure id="subdev-image-processing-full">
+	<title>Image processing in subdevs: scaling and composition
+	with multiple sinks and sources</title>
+	<mediaobject>
+	  <imageobject>
+	    <imagedata fileref="subdev-image-processing-full.svg"
+	    format="SVG" scale="200" />
+	  </imageobject>
+	</mediaobject>
+      </figure>
+
+      <para>The subdev driver supports two sink pads and two source
+      pads. The images from both of the sink pads are individually
+      cropped, then scaled and further composed on the composition
+      bounds rectangle. From that, two independent streams are cropped
+      and sent out of the subdev from the source pads.</para>
+
+    </section>
+
+  </section>
+
+  &sub-subdev-formats;