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: "Rafael J. Wysocki"
Cc: Viresh Kumar
Cc: Kevin Hilman
Cc: cpuf...@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-o...@vger.kernel.org
Cc: linux-arm-ker...@lists.infradead.org
Cc: linux...@vger.kernel.org
Cc: linux-ker...@vger.kernel.org
Signed-off-by: Nishanth Menon
---
List of files impacted by this change detected by:
# check if pm_opp.h header is needed anymore:
git grep dev_pm_opp_init_cpufreq_table .|cut -d ':' -f1|sort|uniq|xargs
grep dev_pm_opp |grep -v cpufreq
# check if any file is missing cpufreq.h header is needed anymore:
git grep dev_pm_opp_init_cpufreq_table .|cut -d ':' -f1|sort|uniq|xargs
grep "cpufreq.h"
Documentation/cpu-freq/core.txt | 29 +++
Documentation/power/opp.txt | 40 ++
drivers/base/power/opp.c| 92
drivers/cpufreq/Makefile|2 +
drivers/cpufreq/cpufreq_opp.c | 110 +++
include/linux/cpufreq.h | 21
include/linux/pm_opp.h | 20 ---
7 files changed, 167 insertions(+), 147 deletions(-)
create mode 100644 drivers/cpufreq/cpufreq_opp.c
diff --git a/Documentation/cpu-freq/core.txt b/Documentation/cpu-freq/core.txt
index 0060d76..70933ea 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
diff --git a/Documentation/power/opp.txt b/Documentation/power/opp.txt
index b8a907d..a9adad8 100644
--- a/Documentation/power/opp.txt
+++ b/Documentation/power/opp.txt
@@ -10,8 +10,7 @@ Contents
3. OPP Search Functions
4. OPP Availability Control Functions
5. OPP Data Retrieval Functions
-6. Cpufreq Table Generation
-7. Data Structures
+6. Data Structures
1. Introduction
===
@@ -72,7 +71,6 @@ operations until that OPP could be re-enabled if possible.
OPP library facilitates this concept in it's implementation. The following
operational functions operate only on available opps:
opp_find_freq_{ceil, floor}, dev_pm_opp_get_voltage, dev_pm_opp_get_freq,
dev_pm_opp_get_opp_count
-and dev_pm_opp_init_cpufreq_table
dev_pm_opp_find_freq_exact is meant to be used to find the opp pointer which
can then
be used for dev_pm_opp_enable/disable functions to make an opp available as
required.
@@ -96,10 +94,9 @@ using RCU read locks. The opp_find_freq_{exact,ceil,floor},
opp_get_{voltage, freq, opp_count} fall into this category.
opp_{add,enable,disable} are updaters which use mutex and implement it's own
-RCU locking mechanisms. dev_pm_opp_init_cpufreq_table acts as an updater and
uses
-mutex to implment RCU updater strategy. These functions should *NOT* be called
-under RCU locks and other contexts that prevent blocking functions in RCU or
-mutex operations from working.
+RCU locking mechanisms. These functions should *NOT* be called under RCU locks
+and other contexts that prevent blocking functions in RCU or mutex operations
+from working.
2. Initial OPP List Registration
@@ -311,34 +308,7 @@ dev_pm_opp_get_opp_count - Retrieve the number of
available
