Merge tag 'iio-for-4.3b-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of new device support, features and cleanup for the 4.3 cycle.
Take 2 also includes a fix set that was too late for the 4.2 cycle.

As we had a lot of tools and docs work in this set, I have broken those
out into their own categories in this description.

Fixes from the pull request '4th set of IIO fixes for the 4.2 cycle'.
* Poll functions for both event chardev and the buffer one were returning
  negative error codes (via a positive value).
* A recent change to lsiio adding some error handling that was wrong and
  stopped the tool working.
* bmg160 was missing some dependencies in Kconfig
* berlin2-adc had a misshandled register (wrote a value rather than a bitmap)

New device support
* TI opt3001 light sensor
* TXC PA12 ALS and proximity sensor.
* mcp3301 ADC support (in mcp320x driver)
* ST lsm303agr accelerometer and magnetometer drivers (plus some st-sensors
  common support to allow different WHOAMI register addresses, devices with
  fixed scale and allow interrupt equiped magnetometers).
* ADIS16305, ADIS16367, ADIS16445IMUs (in the adis16400 driver)
* ADIS16266 gyro (in the adis16260 driver)
* ADIS16137 gyro (in the adis16136 driver)

New functionality
* mmc35240 DT bindings.
* Inverse unit conversion macros to aid handing of values written to sysfs
  attributes.

Core cleanup
* Forward declaration of struct iio_trigger to avoid a compile warning.

Driver cleanup / fixes
* mxs-lradc
  - Clarify which parts are supported.
  - Fix spelling erorrs.
  - Missing/extra includes
  - reorder includes
  - add datasheet name listings for all usable channels (to allow them
    to be bound by name from consumer drivers)
* acpi-als - add some function prefixes as per general iio style.
* bmc150_magn - replace a magic value with the existing define.
* vf610 - determine possible sample frequencies taking into account the
  electrical characteristics (defining a minimum sample time)
* dht11
  - whitespace
  - additional docs
  - avoid mulitple assignments in one line
  - Use the new funciton ktime_get_resolution_ns to cleanup a nasty trick
    previously used for timing.
* Fix all drivers that consider 0 a valid IRQ for historical reasons.
* Export I2C module alias info where previously missing (to allow autoprobing)
* Export OF module alias info where previously missing.
* mmc35240 - switch some variables into arrays to improve readability.
* mlx90614 - define some magic numbers for readability.
* bmc150_magn
  - expand area locked by a mutex to cover all the use of the
    data->buffer.
  - use descriptive naming for a mask instead of a magic value.
* berin2-adc
  - pass up an error code rather that a generic error
  - constify the iio_chan_spec
  - some other little tidy ups.
* stk8312
  - fix a dependency on triggered buffers in kconfig
  - add a check for invalid attribute values
  - improve error handling by returning error codes where possible and
    return immediately where relevant
  - rework macro defs to use GENMASK etc
  - change some variable types to reduce unnecessary casting
  - clean up code style
  - drop a local buffer copy for bulk reads and use the one in data->buffer
     instead.
* adis16400 - the adis16448 gyroscope scale was wrong.
* adis16480 - some more wrong scales for various parts.
* adis16300 - has an undocumented product id and serial number registers so
  use them.
* iio_simple_dummy - fix some wrong code indentation.
* bmc150-accel - use the chip ID to detect the chip present rather than
  verifying the expected part was there.  This was in response to a wrong
  ACPI entry on the WinBook TW100.
* mma8452
  - fix _get_hp_filter_index
  - drop a double include
  - pass up an error code rather than rewriting it
  - range check input values to attribute writes
  - register defs tidy up using GENMASK and reordering them to be easier to
    follow.
  - various coding style cleanups
  - put the Kconfig entry in the write place (alphabetically).

Tools related
* Tools cleanup - drop an explicity NULL comparison, some unnecessary braces,
  use the ARRAY_SIZE macro, send error messages to stderr instead of dropping
  them in the middle of normal output.
* Fix tools to allow that scale and offset attributes are optional.
* More tools fixes including allowing true 32bit data (previously an overflow
  prevented more than 31bits)
* Drop a stray header guard that ended up in a c file.
* Make calc_digits static as it isn't exported or in the header.
* Set ci_array pointer to NULL after free as a protection against non safe
  usage of the tools core code.  Also convert a double pointer to a single
  one as the extra level of indirection was unnecessary.

Docs
* DocBook introduction by Daniel Baluta.  Glad we are beginning to
  draw together some more introductory docs to suplement the various
  tools / examples.
* Drop bytes_per_datum sysfs attribute docs as it no longer exists.
* A whole load of missing / fixing of kernel-doc for the core of IIO.
* Document the trigger name sysfs attribute in the ABI docs.
* Minor typos in the ABI docs related to power down modes.

67 files changed, 3148 insertions, 574 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index b8753f74af67..42d360fe66a5 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -493,7 +493,7 @@ Contact:	linux-iio@vger.kernel.org
 Description:
 		Specifies the output powerdown mode.
 		DAC output stage is disconnected from the amplifier and
-		1kohm_to_gnd: connected	to ground via an 1kOhm resistor,
+		1kohm_to_gnd: connected to ground via an 1kOhm resistor,
 		6kohm_to_gnd: connected to ground via a 6kOhm resistor,
 		20kohm_to_gnd: connected to ground via a 20kOhm resistor,
 		100kohm_to_gnd: connected to ground via an 100kOhm resistor,
@@ -503,9 +503,9 @@ Description:
 		outX_powerdown_mode_available. If Y is not present the
 		mode is shared across all outputs.
 
-What:		/sys/.../iio:deviceX/out_votlageY_powerdown_mode_available
+What:		/sys/.../iio:deviceX/out_voltageY_powerdown_mode_available
 What:		/sys/.../iio:deviceX/out_voltage_powerdown_mode_available
-What:		/sys/.../iio:deviceX/out_altvotlageY_powerdown_mode_available
+What:		/sys/.../iio:deviceX/out_altvoltageY_powerdown_mode_available
 What:		/sys/.../iio:deviceX/out_altvoltage_powerdown_mode_available
 KernelVersion:	2.6.38
 Contact:	linux-iio@vger.kernel.org
@@ -1040,13 +1040,6 @@ Contact:	linux-iio@vger.kernel.org
 Description:
 		Number of scans contained by the buffer.
 
-What:		/sys/bus/iio/devices/iio:deviceX/buffer/bytes_per_datum
-KernelVersion:	2.6.37
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Bytes per scan.  Due to alignment fun, the scan may be larger
-		than implied directly by the scan_element parameters.
-
 What:		/sys/bus/iio/devices/iio:deviceX/buffer/enable
 KernelVersion:	2.6.35
 Contact:	linux-iio@vger.kernel.org
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs b/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs
index 5235e6c749ab..bbb039237a25 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs
+++ b/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs
@@ -9,3 +9,12 @@ Description:
 		automated testing or in situations, where other trigger methods
 		are not applicable. For example no RTC or spare GPIOs.
 		X is the IIO index of the trigger.
+
+What:		/sys/bus/iio/devices/triggerX/name
+KernelVersion:	2.6.39
+Contact:	linux-iio@vger.kernel.org
+Description:
+		The name attribute holds a description string for the current
+		trigger. In order to associate the trigger with an IIO device
+		one should write this name string to
+		/sys/bus/iio/devices/iio:deviceY/trigger/current_trigger.
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index b6a6a2e0dd3b..9e086067b4ae 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -15,7 +15,7 @@ DOCBOOKS := z8530book.xml device-drivers.xml \
 	    80211.xml debugobjects.xml sh.xml regulator.xml \
 	    alsa-driver-api.xml writing-an-alsa-driver.xml \
 	    tracepoint.xml drm.xml media_api.xml w1.xml \
-	    writing_musb_glue_layer.xml crypto-API.xml
+	    writing_musb_glue_layer.xml crypto-API.xml iio.xml
 
 include Documentation/DocBook/media/Makefile
 
diff --git a/Documentation/DocBook/iio.tmpl b/Documentation/DocBook/iio.tmpl
new file mode 100644
index 000000000000..06bb53de5a47
--- /dev/null
+++ b/Documentation/DocBook/iio.tmpl
@@ -0,0 +1,697 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
+	"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
+
+<book id="iioid">
+  <bookinfo>
+    <title>Industrial I/O driver developer's guide </title>
+
+    <authorgroup>
+      <author>
+        <firstname>Daniel</firstname>
+        <surname>Baluta</surname>
+        <affiliation>
+          <address>
+            <email>daniel.baluta@intel.com</email>
+          </address>
+        </affiliation>
+      </author>
+    </authorgroup>
+
+    <copyright>
+      <year>2015</year>
+      <holder>Intel Corporation</holder>
+    </copyright>
+
+    <legalnotice>
+      <para>
+        This documentation is free software; you can redistribute
+        it and/or modify it under the terms of the GNU General Public
+        License version 2.
+      </para>
+    </legalnotice>
+  </bookinfo>
+
+  <toc></toc>
+
+  <chapter id="intro">
+    <title>Introduction</title>
+    <para>
+      The main purpose of the Industrial I/O subsystem (IIO) is to provide
+      support for devices that in some sense perform either analog-to-digital
+      conversion (ADC) or digital-to-analog conversion (DAC) or both. The aim
+      is to fill the gap between the somewhat similar hwmon and input
+      subsystems.
+      Hwmon is directed at low sample rate sensors used to monitor and
+      control the system itself, like fan speed control or temperature
+      measurement. Input is, as its name suggests, focused on human interaction
+      input devices (keyboard, mouse, touchscreen). In some cases there is
+      considerable overlap between these and IIO.
+  </para>
+  <para>
+    Devices that fall into this category include:
+    <itemizedlist>
+      <listitem>
+        analog to digital converters (ADCs)
+      </listitem>
+      <listitem>
+        accelerometers
+      </listitem>
+      <listitem>
+        capacitance to digital converters (CDCs)
+      </listitem>
+      <listitem>
+        digital to analog converters (DACs)
+      </listitem>
+      <listitem>
+        gyroscopes
+      </listitem>
+      <listitem>
+        inertial measurement units (IMUs)
+      </listitem>
+      <listitem>
+        color and light sensors
+      </listitem>
+      <listitem>
+        magnetometers
+      </listitem>
+      <listitem>
+        pressure sensors
+      </listitem>
+      <listitem>
+        proximity sensors
+      </listitem>
+      <listitem>
+        temperature sensors
+      </listitem>
+    </itemizedlist>
+    Usually these sensors are connected via SPI or I2C. A common use case of the
+    sensors devices is to have combined functionality (e.g. light plus proximity
+    sensor).
+  </para>
+  </chapter>
+  <chapter id='iiosubsys'>
+    <title>Industrial I/O core</title>
+    <para>
+      The Industrial I/O core offers:
+      <itemizedlist>
+        <listitem>
+         a unified framework for writing drivers for many different types of
+         embedded sensors.
+        </listitem>
+        <listitem>
+         a standard interface to user space applications manipulating sensors.
+        </listitem>
+      </itemizedlist>
+      The implementation can be found under <filename>
+      drivers/iio/industrialio-*</filename>
+  </para>
+  <sect1 id="iiodevice">
+    <title> Industrial I/O devices </title>
+
+!Finclude/linux/iio/iio.h iio_dev
+!Fdrivers/iio/industrialio-core.c iio_device_alloc
+!Fdrivers/iio/industrialio-core.c iio_device_free
+!Fdrivers/iio/industrialio-core.c iio_device_register
+!Fdrivers/iio/industrialio-core.c iio_device_unregister
+
+    <para>
+      An IIO device usually corresponds to a single hardware sensor and it
+      provides all the information needed by a driver handling a device.
+      Let's first have a look at the functionality embedded in an IIO
+      device then we will show how a device driver makes use of an IIO
+      device.
+    </para>
+    <para>
+        There are two ways for a user space application to interact
+        with an IIO driver.
+      <itemizedlist>
+        <listitem>
+          <filename>/sys/bus/iio/iio:deviceX/</filename>, this
+          represents a hardware sensor and groups together the data
+          channels of the same chip.
+        </listitem>
+        <listitem>
+          <filename>/dev/iio:deviceX</filename>, character device node
+          interface used for buffered data transfer and for events information
+          retrieval.
+        </listitem>
+      </itemizedlist>
+    </para>
+    A typical IIO driver will register itself as an I2C or SPI driver and will
+    create two routines, <function> probe </function> and <function> remove
+    </function>. At <function>probe</function>:
+    <itemizedlist>
+    <listitem>call <function>iio_device_alloc</function>, which allocates memory
+      for an IIO device.
+    </listitem>
+    <listitem> initialize IIO device fields with driver specific information
+              (e.g. device name, device channels).
+    </listitem>
+    <listitem>call <function> iio_device_register</function>, this registers the
+      device with the IIO core. After this call the device is ready to accept
+      requests from user space applications.
+    </listitem>
+    </itemizedlist>
+      At <function>remove</function>, we free the resources allocated in
+      <function>probe</function> in reverse order:
+    <itemizedlist>
+    <listitem><function>iio_device_unregister</function>, unregister the device
+      from the IIO core.
+    </listitem>
+    <listitem><function>iio_device_free</function>, free the memory allocated
+      for the IIO device.
+    </listitem>
+    </itemizedlist>
+
+    <sect2 id="iioattr"> <title> IIO device sysfs interface </title>
+      <para>
+        Attributes are sysfs files used to expose chip info and also allowing
+        applications to set various configuration parameters. For device
+        with index X, attributes can be found under
+        <filename>/sys/bus/iio/iio:deviceX/ </filename> directory.
+        Common attributes are:
+        <itemizedlist>
+          <listitem><filename>name</filename>, description of the physical
+            chip.
+          </listitem>
+          <listitem><filename>dev</filename>, shows the major:minor pair
+            associated with <filename>/dev/iio:deviceX</filename> node.
+          </listitem>
+          <listitem><filename>sampling_frequency_available</filename>,
+            available discrete set of sampling frequency values for
+            device.
+          </listitem>
+      </itemizedlist>
+      Available standard attributes for IIO devices are described in the
+      <filename>Documentation/ABI/testing/sysfs-bus-iio </filename> file
+      in the Linux kernel sources.
+      </para>
+    </sect2>
+    <sect2 id="iiochannel"> <title> IIO device channels </title>
+!Finclude/linux/iio/iio.h iio_chan_spec structure.
+      <para>
+        An IIO device channel is a representation of a data channel. An
+        IIO device can have one or multiple channels. For example:
+        <itemizedlist>
+          <listitem>
+          a thermometer sensor has one channel representing the
+          temperature measurement.
+          </listitem>
+          <listitem>
+          a light sensor with two channels indicating the measurements in
+          the visible and infrared spectrum.
+          </listitem>
+          <listitem>
+          an accelerometer can have up to 3 channels representing
+          acceleration on X, Y and Z axes.
+          </listitem>
+        </itemizedlist>
+      An IIO channel is described by the <type> struct iio_chan_spec
+      </type>. A thermometer driver for the temperature sensor in the
+      example above would have to describe its channel as follows:
+      <programlisting>
+      static const struct iio_chan_spec temp_channel[] = {
+          {
+              .type = IIO_TEMP,
+              .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+          },
+      };
+
+      </programlisting>
+      Channel sysfs attributes exposed to userspace are specified in
+      the form of <emphasis>bitmasks</emphasis>. Depending on their
+      shared info, attributes can be set in one of the following masks:
+      <itemizedlist>
+      <listitem><emphasis>info_mask_separate</emphasis>, attributes will
+        be specific to this channel</listitem>
+      <listitem><emphasis>info_mask_shared_by_type</emphasis>,
+        attributes are shared by all channels of the same type</listitem>
+      <listitem><emphasis>info_mask_shared_by_dir</emphasis>, attributes
+        are shared by all channels of the same direction </listitem>
+      <listitem><emphasis>info_mask_shared_by_all</emphasis>,
+        attributes are shared by all channels</listitem>
+      </itemizedlist>
+      When there are multiple data channels per channel type we have two
+      ways to distinguish between them:
+      <itemizedlist>
+      <listitem> set <emphasis> .modified</emphasis> field of <type>
+        iio_chan_spec</type> to 1. Modifiers are specified using
+        <emphasis>.channel2</emphasis> field of the same
+        <type>iio_chan_spec</type> structure and are used to indicate a
+        physically unique characteristic of the channel such as its direction
+        or spectral response. For example, a light sensor can have two channels,
+        one for infrared light and one for both infrared and visible light.
+      </listitem>
+      <listitem> set <emphasis>.indexed </emphasis> field of
+        <type>iio_chan_spec</type> to 1. In this case the channel is
+        simply another instance with an index specified by the
+        <emphasis>.channel</emphasis> field.
+      </listitem>
+      </itemizedlist>
+      Here is how we can make use of the channel's modifiers:
+      <programlisting>
+      static const struct iio_chan_spec light_channels[] = {
+          {
+              .type = IIO_INTENSITY,
+              .modified = 1,
+              .channel2 = IIO_MOD_LIGHT_IR,
+              .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+              .info_mask_shared = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+          },
+          {
+              .type = IIO_INTENSITY,
+              .modified = 1,
+              .channel2 = IIO_MOD_LIGHT_BOTH,
+              .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+              .info_mask_shared = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+          },
+          {
+              .type = IIO_LIGHT,
+              .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+              .info_mask_shared = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+          },
+
+      }
+      </programlisting>
+      This channel's definition will generate two separate sysfs files
+      for raw data retrieval:
+      <itemizedlist>
+      <listitem>
+      <filename>/sys/bus/iio/iio:deviceX/in_intensity_ir_raw</filename>
+      </listitem>
+      <listitem>
+      <filename>/sys/bus/iio/iio:deviceX/in_intensity_both_raw</filename>
+      </listitem>
+      </itemizedlist>
+      one file for processed data:
+      <it