From deb6852dc5e9da365a33c744f2dc107ae11b407a Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Thu, 16 Aug 2012 08:01:21 +0200 Subject: [PATCH v2] pwm: Improve Kconfig help text The Kconfig help text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework. Signed-off-by: Thierry Reding --- drivers/pwm/Kconfig | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 8fc3808..cd602e7 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. + + The new 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 + new framework yet. The new 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 -- 1.7.11.5