PM / OPP: Move cpufreq specific OPP functions out of generic OPP library

CPUFreq specific helper functions for OPP (Operating Performance Points)
now use generic OPP functions that allow CPUFreq to be be moved back
into CPUFreq framework. This allows for independent modifications
or future enhancements as needed isolated to just CPUFreq framework
alone.

Here, we just move relevant code and documentation to make this part of
CPUFreq infrastructure.

Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/Documentation/cpu-freq/core.txt b/Documentation/cpu-freq/core.txt
index 0060d76b445f..70933eadc308 100644
--- a/Documentation/cpu-freq/core.txt
+++ b/Documentation/cpu-freq/core.txt
@@ -20,6 +20,7 @@ Contents:
 ---------
 1.  CPUFreq core and interfaces
 2.  CPUFreq notifiers
+3.  CPUFreq Table Generation with Operating Performance Point (OPP)
 
 1. General Information
 =======================
@@ -92,3 +93,31 @@ values:
 cpu     - number of the affected CPU
 old     - old frequency
 new     - new frequency
+
+3. CPUFreq Table Generation with Operating Performance Point (OPP)
+==================================================================
+For details about OPP, see Documentation/power/opp.txt
+
+dev_pm_opp_init_cpufreq_table - cpufreq framework typically is initialized with
+        cpufreq_frequency_table_cpuinfo which is provided with the list of
+        frequencies that are available for operation. This function provides
+        a ready to use conversion routine to translate the OPP layer's internal
+        information about the available frequencies into a format readily
+        providable to cpufreq.
+
+        WARNING: Do not use this function in interrupt context.
+
+        Example:
+         soc_pm_init()
+         {
+                /* Do things */
+                r = dev_pm_opp_init_cpufreq_table(dev, &freq_table);
+                if (!r)
+                        cpufreq_frequency_table_cpuinfo(policy, freq_table);
+                /* Do other things */
+         }
+
+        NOTE: This function is available only if CONFIG_CPU_FREQ is enabled in
+        addition to CONFIG_PM_OPP.
+
+dev_pm_opp_free_cpufreq_table - Free up the table allocated by dev_pm_opp_init_cpufreq_table