Merge branches 'pm-core', 'pm-qos', 'pm-domains' and 'pm-opp'

[linux.git] / Documentation / cpu-freq / user-guide.txt

diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt
index 109e97bbab7717e8b9dd721b47a992ba5773ea31..107f6fdd7d14b126016dd9a8179452900d0d5b97 100644 (file)
--- 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