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-rw-r--r--Documentation/DocBook/device-drivers.tmpl27
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl
index faf09d4a0ea8..172bff8cda79 100644
--- a/Documentation/DocBook/device-drivers.tmpl
+++ b/Documentation/DocBook/device-drivers.tmpl
@@ -455,4 +455,31 @@ 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>