Merge tag 'pwm/for-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This set of changes introduces the beginnings of a new API that's
  based around the concept of states that can be atomically applied.
  Drivers go to various lengths to implement something similar, which
  indicates that the core should really be providing the necessary
  framework.

  On top of that, there is a bit of cleanup as well as improved
  kerneldoc and integration into the device-drivers DocBook.

  Regarding drivers there is a new one for the NXP LPC18xx family of
  SoCs and a couple of fixes for existing drivers (pca9685, Broadcom
  Kona and Atmel HLCDC)"

* tag 'pwm/for-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  ARM: at91: pwm: atmel-hlcdc: Add at91sam9n12 errata
  pwm: Add NXP LPC18xx PWM/SCT DT binding documentation
  pwm: NXP LPC18xx PWM/SCT driver
  pwm-pca9685: Support changing the output frequency
  pwm-pca9685: Fix several driver bugs
  pwm: kona: Modify settings application sequence
  pwm: pca9685: Drop owner assignment
  pwm: Add to device-drivers documentation
  pwm: Clean up kerneldoc
  pwm: Remove useless whitespace
  pwm: sysfs: Remove unnecessary padding
  pwm: sysfs: Properly convert from enum to string
  pwm: Make use of pwm_get_xxx() helpers where appropriate
  pwm: Add pwm_get_polarity() helper function
  pwm: Constify PWM device where possible
  pwm: Add the pwm_is_enabled() helper

1 files changed, 27 insertions, 0 deletions

diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl
index abba93f9d64a..1d6008d51b55 100644
--- a/Documentation/DocBook/device-drivers.tmpl
+++ b/Documentation/DocBook/device-drivers.tmpl
@@ -490,4 +490,31 @@ X!Ilib/fonts/fonts.c
 !Edrivers/hsi/hsi.c
   </chapter>
 
+  <chapter id="pwm">
+    <title>Pulse-Width Modulation (PWM)</title>
+    <para>
+      Pulse-width modulation is a modulation technique primarily used to
+      control power supplied to electrical devices.
+    </para>
+    <para>
+      The PWM framework provides an abstraction for providers and consumers
+      of PWM signals. A controller that provides one or more PWM signals is
+      registered as <structname>struct pwm_chip</structname>. Providers are
+      expected to embed this structure in a driver-specific structure. This
+      structure contains fields that describe a particular chip.
+    </para>
+    <para>
+      A chip exposes one or more PWM signal sources, each of which exposed
+      as a <structname>struct pwm_device</structname>. Operations can be
+      performed on PWM devices to control the period, duty cycle, polarity
+      and active state of the signal.
+    </para>
+    <para>
+      Note that PWM devices are exclusive resources: they can always only be
+      used by one consumer at a time.
+    </para>
+!Iinclude/linux/pwm.h
+!Edrivers/pwm/core.c
+  </chapter>
+
 </book>