pwm: Improve Kconfig help text

[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / pwm / Kconfig

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 8fc3808..90c5c73 100644 (file)
--- 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