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authorThierry Reding <thierry.reding@avionic-design.de>2012-08-16 02:01:21 -0400
committerThierry Reding <thierry.reding@avionic-design.de>2012-08-20 05:58:43 -0400
commitb817bf5c72774556345a9043c6b0c497cdcb7295 (patch)
treea30d2a8b0f3fd59d958c5303313569e73223f826 /drivers
parente50d3523ff45646a48666ebbd3d8aeb0c75084ed (diff)
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 <thierry.reding@avionic-design.de> Acked-by: Borislav Petkov <bp@alien8.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pwm/Kconfig31
1 files changed, 25 insertions, 6 deletions
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 8fc3808d7a3e..90c5c7357a50 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -1,12 +1,31 @@
1menuconfig PWM 1menuconfig PWM
2 bool "PWM Support" 2 bool "Pulse-Width Modulation (PWM) Support"
3 depends on !MACH_JZ4740 && !PUV3_PWM 3 depends on !MACH_JZ4740 && !PUV3_PWM
4 help 4 help
5 This enables PWM support through the generic PWM framework. 5 Generic Pulse-Width Modulation (PWM) support.
6 You only need to enable this, if you also want to enable 6
7 one or more of the PWM drivers below. 7 In Pulse-Width Modulation, a variation of the width of pulses
8 8 in a rectangular pulse signal is used as a means to alter the
9 If unsure, say N. 9 average power of the signal. Applications include efficient
10 power delivery and voltage regulation. In computer systems,
11 PWMs are commonly used to control fans or the brightness of
12 display backlights.
13
14 This framework provides a generic interface to PWM devices
15 within the Linux kernel. On the driver side it provides an API
16 to register and unregister a PWM chip, an abstraction of a PWM
17 controller, that supports one or more PWM devices. Client
18 drivers can request PWM devices and use the generic framework
19 to configure as well as enable and disable them.
20
21 This generic framework replaces the legacy PWM framework which
22 allows only a single driver implementing the required API. Not
23 all legacy implementations have been ported to the framework
24 yet. The framework provides an API that is backward compatible
25 with the legacy framework so that existing client drivers
26 continue to work as expected.
27
28 If unsure, say no.
10 29
11if PWM 30if PWM
12 31