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authorOlof Johansson <olof@lixom.net>2012-09-05 15:35:48 -0700
committerOlof Johansson <olof@lixom.net>2012-09-05 15:35:48 -0700
commit1875962377574b4edb7b164001e3e341c25290d5 (patch)
tree374a5299403ec21e2d9a66a6548ce876a388b589 /drivers/pwm/Kconfig
parent5cbee140a28c2746449ae31e85738043ae4da927 (diff)
parentc88a79a7789b2909ad1cf69ea2c9142030bbd6f4 (diff)
downloadop-kernel-dev-1875962377574b4edb7b164001e3e341c25290d5.zip
op-kernel-dev-1875962377574b4edb7b164001e3e341c25290d5.tar.gz
Merge branch 'soc-core' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into next/dt
* 'soc-core' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas: ARM: mach-shmobile: Add compilation support for dtbs using 'make dtbs' + sync to 3.6-rc3
Diffstat (limited to 'drivers/pwm/Kconfig')
-rw-r--r--drivers/pwm/Kconfig31
1 files changed, 25 insertions, 6 deletions
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 8fc3808..90c5c73 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -1,12 +1,31 @@
menuconfig PWM
- bool "PWM Support"
+ bool "Pulse-Width Modulation (PWM) Support"
depends on !MACH_JZ4740 && !PUV3_PWM
help
- This enables PWM support through the generic PWM framework.
- You only need to enable this, if you also want to enable
- one or more of the PWM drivers below.
-
- If unsure, say N.
+ Generic Pulse-Width Modulation (PWM) support.
+
+ In Pulse-Width Modulation, a variation of the width of pulses
+ in a rectangular pulse signal is used as a means to alter the
+ average power of the signal. Applications include efficient
+ power delivery and voltage regulation. In computer systems,
+ PWMs are commonly used to control fans or the brightness of
+ display backlights.
+
+ This framework provides a generic interface to PWM devices
+ within the Linux kernel. On the driver side it provides an API
+ to register and unregister a PWM chip, an abstraction of a PWM
+ controller, that supports one or more PWM devices. Client
+ drivers can request PWM devices and use the generic framework
+ to configure as well as enable and disable them.
+
+ This generic framework replaces the legacy PWM framework which
+ allows only a single driver implementing the required API. Not
+ all legacy implementations have been ported to the framework
+ yet. The framework provides an API that is backward compatible
+ with the legacy framework so that existing client drivers
+ continue to work as expected.
+
+ If unsure, say no.
if PWM
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