[CPUFREQ] Documentation: ABI: /sys/devices/system/cpu/cpu#/cpufreq/

This is a complex interface and is already described in
Documentation/cpu-freq/, especially in the user-guide.txt file.

No need to copy/paste all that information. Let's just alert the reader
to the presence of the user-guide.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index a703b9e9aeb9..974e29f5da86 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -136,6 +136,24 @@ Description:	Discover cpuidle policy and mechanism
                 See files in Documentation/cpuidle/ for more information.
 
 
+What:           /sys/devices/system/cpu/cpu#/cpufreq/*
+Date:           pre-git history
+Contact:        cpufreq@vger.kernel.org
+Description:    Discover and change clock speed of CPUs
+
+                Clock scaling allows you to change the clock speed of the
+                CPUs on the fly. This is a nice method to save battery
+                power, because the lower the clock speed, the less power
+                the CPU consumes.
+
+                There are many knobs to tweak in this directory.
+
+                See files in Documentation/cpu-freq/ for more information.
+
+                In particular, read Documentation/cpu-freq/user-guide.txt
+                to learn how to control the knobs.
+
+
 What:      /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X
 Date:      August 2008
 KernelVersion:  2.6.27