cpufreq: Documentation: Updates based on current code

The cpufreq core has gone though lots of updates in recent times, but on
many occasions the documentation wasn't updated along with the code.
This patch tries to catchup the documentation with the code.

Also add Rafael and Viresh as the contributors to the documentation.

Based on a patch from Claudio Scordino.

Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 32 insertions, 28 deletions

diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt
index 109e97bbab77..107f6fdd7d14 100644
--- a/Documentation/cpu-freq/user-guide.txt
+++ b/Documentation/cpu-freq/user-guide.txt
@@ -18,7 +18,7 @@
 Contents:
 ---------
 1. Supported Architectures and Processors
-1.1 ARM
+1.1 ARM and ARM64
 1.2 x86
 1.3 sparc64
 1.4 ppc
@@ -37,16 +37,10 @@ Contents:
 1. Supported Architectures and Processors
 =========================================
 
-1.1 ARM
--------
-
-The following ARM processors are supported by cpufreq:
-
-ARM Integrator
-ARM-SA1100
-ARM-SA1110
-Intel PXA
+1.1 ARM and ARM64
+-----------------
 
+Almost all ARM and ARM64 platforms support CPU frequency scaling.
 
 1.2 x86
 -------
@@ -69,6 +63,7 @@ Transmeta Crusoe
 Transmeta Efficeon
 VIA Cyrix 3 / C3
 various processors on some ACPI 2.0-compatible systems [*]
+And many more
 
 [*] Only if "ACPI Processor Performance States" are available
 to the ACPI<->BIOS interface.
@@ -147,10 +142,19 @@ mounted it at /sys, the cpufreq interface is located in a subdirectory
 "cpufreq" within the cpu-device directory
 (e.g. /sys/devices/system/cpu/cpu0/cpufreq/ for the first CPU).
 
+affected_cpus :			List of Online CPUs that require software
+				coordination of frequency.
+
+cpuinfo_cur_freq :		Current frequency of the CPU as obtained from
+				the hardware, in KHz. This is the frequency
+				the CPU actually runs at.
+
 cpuinfo_min_freq :		this file shows the minimum operating
 				frequency the processor can run at(in kHz) 
+
 cpuinfo_max_freq :		this file shows the maximum operating
 				frequency the processor can run at(in kHz) 
+
 cpuinfo_transition_latency	The time it takes on this CPU to
 				switch between two frequencies in nano
 				seconds. If unknown or known to be
@@ -163,25 +167,30 @@ cpuinfo_transition_latency	The time it takes on this CPU to
 				userspace daemon. Make sure to not
 				switch the frequency too often
 				resulting in performance loss.
-scaling_driver :		this file shows what cpufreq driver is
-				used to set the frequency on this CPU
+
+related_cpus :			List of Online + Offline CPUs that need software
+				coordination of frequency.
+
+scaling_available_frequencies : List of available frequencies, in KHz.
 
 scaling_available_governors :	this file shows the CPUfreq governors
 				available in this kernel. You can see the
 				currently activated governor in
 
+scaling_cur_freq :		Current frequency of the CPU as determined by
+				the governor and cpufreq core, in KHz. This is
+				the frequency the kernel thinks the CPU runs
+				at.
+
+scaling_driver :		this file shows what cpufreq driver is
+				used to set the frequency on this CPU
+
 scaling_governor,		and by "echoing" the name of another
 				governor you can change it. Please note
 				that some governors won't load - they only
 				work on some specific architectures or
 				processors.
 
-cpuinfo_cur_freq :		Current frequency of the CPU as obtained from
-				the hardware, in KHz. This is the frequency
-				the CPU actually runs at.
-
-scaling_available_frequencies : List of available frequencies, in KHz.
-
 scaling_min_freq and
 scaling_max_freq		show the current "policy limits" (in
 				kHz). By echoing new values into these
@@ -190,16 +199,11 @@ scaling_max_freq		show the current "policy limits" (in
 				first set scaling_max_freq, then
 				scaling_min_freq.
 
-affected_cpus :			List of Online CPUs that require software
-				coordination of frequency.
-
-related_cpus :			List of Online + Offline CPUs that need software
-				coordination of frequency.
-
-scaling_cur_freq :		Current frequency of the CPU as determined by
-				the governor and cpufreq core, in KHz. This is
-				the frequency the kernel thinks the CPU runs
-				at.
+scaling_setspeed		This can be read to get the currently programmed
+				value by the governor. This can be written to
+				change the current frequency for a group of
+				CPUs, represented by a policy. This is supported
+				currently only by the userspace governor.
 
 bios_limit :			If the BIOS tells the OS to limit a CPU to
 				lower frequencies, the user can read out the