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authorNishanth Menon <nm@ti.com>2013-09-19 16:03:50 -0500
committerRafael J. Wysocki <rjw@rjwysocki.net>2013-10-25 22:33:23 +0200
commit5d4879cda67b09f086807821cf594ee079d6dfbe (patch)
tree58532256e9bff42902510175e7cb7c727a89280b /Documentation/power
parent31d141e3a666269a3b6fcccddb0351caf7454240 (diff)
downloadlinux-linaro-stable-5d4879cda67b09f086807821cf594ee079d6dfbe.tar.gz
PM / OPP: rename functions to dev_pm_opp*
Since Operating Performance Points (OPP) functions are specific to device specific power management, be specific and rename opp_* accessors in OPP library with dev_pm_opp_* equivalent. Affected functions are: opp_get_voltage opp_get_freq opp_get_opp_count opp_find_freq_exact opp_find_freq_floor opp_find_freq_ceil opp_add opp_enable opp_disable opp_get_notifier opp_init_cpufreq_table opp_free_cpufreq_table Reported-by: Randy Dunlap <rdunlap@infradead.org> 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>
Diffstat (limited to 'Documentation/power')
-rw-r--r--Documentation/power/opp.txt102
1 files changed, 51 insertions, 51 deletions
diff --git a/Documentation/power/opp.txt b/Documentation/power/opp.txt
index 425c51d56aef..185367b1848f 100644
--- a/Documentation/power/opp.txt
+++ b/Documentation/power/opp.txt
@@ -71,14 +71,14 @@ 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}, opp_get_voltage, opp_get_freq, opp_get_opp_count
-and opp_init_cpufreq_table
+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
-opp_find_freq_exact is meant to be used to find the opp pointer which can then
-be used for opp_enable/disable functions to make an opp available as required.
+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.
WARNING: Users of OPP library should refresh their availability count using
-get_opp_count if opp_enable/disable functions are invoked for a device, the
+get_opp_count if dev_pm_opp_enable/disable functions are invoked for a device, the
exact mechanism to trigger these or the notification mechanism to other
dependent subsystems such as cpufreq are left to the discretion of the SoC
specific framework which uses the OPP library. Similar care needs to be taken
@@ -96,24 +96,24 @@ 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. opp_init_cpufreq_table acts as an updater and uses
+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.
2. Initial OPP List Registration
================================
-The SoC implementation calls opp_add function iteratively to add OPPs per
+The SoC implementation calls dev_pm_opp_add function iteratively to add OPPs per
device. It is expected that the SoC framework will register the OPP entries
optimally- typical numbers range to be less than 5. The list generated by
registering the OPPs is maintained by OPP library throughout the device
operation. The SoC framework can subsequently control the availability of the
-OPPs dynamically using the opp_enable / disable functions.
+OPPs dynamically using the dev_pm_opp_enable / disable functions.
-opp_add - Add a new OPP for a specific domain represented by the device pointer.
+dev_pm_opp_add - Add a new OPP for a specific domain represented by the device pointer.
The OPP is defined using the frequency and voltage. Once added, the OPP
is assumed to be available and control of it's availability can be done
- with the opp_enable/disable functions. OPP library internally stores
+ with the dev_pm_opp_enable/disable functions. OPP library internally stores
and manages this information in the opp struct. This function may be
used by SoC framework to define a optimal list as per the demands of
SoC usage environment.
@@ -124,7 +124,7 @@ opp_add - Add a new OPP for a specific domain represented by the device pointer.
soc_pm_init()
{
/* Do things */
- r = opp_add(mpu_dev, 1000000, 900000);
+ r = dev_pm_opp_add(mpu_dev, 1000000, 900000);
if (!r) {
pr_err("%s: unable to register mpu opp(%d)\n", r);
goto no_cpufreq;
@@ -143,44 +143,44 @@ functions return the matching pointer representing the opp if a match is
found, else returns error. These errors are expected to be handled by standard
error checks such as IS_ERR() and appropriate actions taken by the caller.
-opp_find_freq_exact - Search for an OPP based on an *exact* frequency and
+dev_pm_opp_find_freq_exact - Search for an OPP based on an *exact* frequency and
availability. This function is especially useful to enable an OPP which
is not available by default.
Example: In a case when SoC framework detects a situation where a
higher frequency could be made available, it can use this function to
- find the OPP prior to call the opp_enable to actually make it available.
+ find the OPP prior to call the dev_pm_opp_enable to actually make it available.
rcu_read_lock();
- opp = opp_find_freq_exact(dev, 1000000000, false);
+ opp = dev_pm_opp_find_freq_exact(dev, 1000000000, false);
rcu_read_unlock();
/* dont operate on the pointer.. just do a sanity check.. */
if (IS_ERR(opp)) {
pr_err("frequency not disabled!\n");
/* trigger appropriate actions.. */
} else {
- opp_enable(dev,1000000000);
+ dev_pm_opp_enable(dev,1000000000);
}
NOTE: This is the only search function that operates on OPPs which are
not available.
-opp_find_freq_floor - Search for an available OPP which is *at most* the
+dev_pm_opp_find_freq_floor - Search for an available OPP which is *at most* the
provided frequency. This function is useful while searching for a lesser
match OR operating on OPP information in the order of decreasing
frequency.
Example: To find the highest opp for a device:
freq = ULONG_MAX;
rcu_read_lock();
- opp_find_freq_floor(dev, &freq);
+ dev_pm_opp_find_freq_floor(dev, &freq);
rcu_read_unlock();
-opp_find_freq_ceil - Search for an available OPP which is *at least* the
+dev_pm_opp_find_freq_ceil - Search for an available OPP which is *at least* the
provided frequency. This function is useful while searching for a
higher match OR operating on OPP information in the order of increasing
frequency.
Example 1: To find the lowest opp for a device:
freq = 0;
rcu_read_lock();
- opp_find_freq_ceil(dev, &freq);
+ dev_pm_opp_find_freq_ceil(dev, &freq);
rcu_read_unlock();
Example 2: A simplified implementation of a SoC cpufreq_driver->target:
soc_cpufreq_target(..)
@@ -188,7 +188,7 @@ opp_find_freq_ceil - Search for an available OPP which is *at least* the
/* Do stuff like policy checks etc. */
/* Find the best frequency match for the req */
rcu_read_lock();
- opp = opp_find_freq_ceil(dev, &freq);
+ opp = dev_pm_opp_find_freq_ceil(dev, &freq);
rcu_read_unlock();
if (!IS_ERR(opp))
soc_switch_to_freq_voltage(freq);
@@ -208,34 +208,34 @@ as thermal considerations (e.g. don't use OPPx until the temperature drops).
WARNING: Do not use these functions in interrupt context.
-opp_enable - Make a OPP available for operation.
+dev_pm_opp_enable - Make a OPP available for operation.
Example: Lets say that 1GHz OPP is to be made available only if the
SoC temperature is lower than a certain threshold. The SoC framework
implementation might choose to do something as follows:
if (cur_temp < temp_low_thresh) {
/* Enable 1GHz if it was disabled */
rcu_read_lock();
- opp = opp_find_freq_exact(dev, 1000000000, false);
+ opp = dev_pm_opp_find_freq_exact(dev, 1000000000, false);
rcu_read_unlock();
/* just error check */
if (!IS_ERR(opp))
- ret = opp_enable(dev, 1000000000);
+ ret = dev_pm_opp_enable(dev, 1000000000);
else
goto try_something_else;
}
-opp_disable - Make an OPP to be not available for operation
+dev_pm_opp_disable - Make an OPP to be not available for operation
Example: Lets say that 1GHz OPP is to be disabled if the temperature
exceeds a threshold value. The SoC framework implementation might
choose to do something as follows:
if (cur_temp > temp_high_thresh) {
/* Disable 1GHz if it was enabled */
rcu_read_lock();
- opp = opp_find_freq_exact(dev, 1000000000, true);
+ opp = dev_pm_opp_find_freq_exact(dev, 1000000000, true);
rcu_read_unlock();
/* just error check */
if (!IS_ERR(opp))
- ret = opp_disable(dev, 1000000000);
+ ret = dev_pm_opp_disable(dev, 1000000000);
else
goto try_something_else;
}
@@ -247,7 +247,7 @@ information from the OPP structure is necessary. Once an OPP pointer is
retrieved using the search functions, the following functions can be used by SoC
framework to retrieve the information represented inside the OPP layer.
-opp_get_voltage - Retrieve the voltage represented by the opp pointer.
+dev_pm_opp_get_voltage - Retrieve the voltage represented by the opp pointer.
Example: At a cpufreq transition to a different frequency, SoC
framework requires to set the voltage represented by the OPP using
the regulator framework to the Power Management chip providing the
@@ -256,15 +256,15 @@ opp_get_voltage - Retrieve the voltage represented by the opp pointer.
{
/* do things */
rcu_read_lock();
- opp = opp_find_freq_ceil(dev, &freq);
- v = opp_get_voltage(opp);
+ opp = dev_pm_opp_find_freq_ceil(dev, &freq);
+ v = dev_pm_opp_get_voltage(opp);
rcu_read_unlock();
if (v)
regulator_set_voltage(.., v);
/* do other things */
}
-opp_get_freq - Retrieve the freq represented by the opp pointer.
+dev_pm_opp_get_freq - Retrieve the freq represented by the opp pointer.
Example: Lets say the SoC framework uses a couple of helper functions
we could pass opp pointers instead of doing additional parameters to
handle quiet a bit of data parameters.
@@ -273,8 +273,8 @@ opp_get_freq - Retrieve the freq represented by the opp pointer.
/* do things.. */
max_freq = ULONG_MAX;
rcu_read_lock();
- max_opp = opp_find_freq_floor(dev,&max_freq);
- requested_opp = opp_find_freq_ceil(dev,&freq);
+ max_opp = dev_pm_opp_find_freq_floor(dev,&max_freq);
+ requested_opp = dev_pm_opp_find_freq_ceil(dev,&freq);
if (!IS_ERR(max_opp) && !IS_ERR(requested_opp))
r = soc_test_validity(max_opp, requested_opp);
rcu_read_unlock();
@@ -282,25 +282,25 @@ opp_get_freq - Retrieve the freq represented by the opp pointer.
}
soc_test_validity(..)
{
- if(opp_get_voltage(max_opp) < opp_get_voltage(requested_opp))
+ if(dev_pm_opp_get_voltage(max_opp) < dev_pm_opp_get_voltage(requested_opp))
return -EINVAL;
- if(opp_get_freq(max_opp) < opp_get_freq(requested_opp))
+ if(dev_pm_opp_get_freq(max_opp) < dev_pm_opp_get_freq(requested_opp))
return -EINVAL;
/* do things.. */
}
-opp_get_opp_count - Retrieve the number of available opps for a device
+dev_pm_opp_get_opp_count - Retrieve the number of available opps for a device
Example: Lets say a co-processor in the SoC needs to know the available
frequencies in a table, the main processor can notify as following:
soc_notify_coproc_available_frequencies()
{
/* Do things */
rcu_read_lock();
- num_available = opp_get_opp_count(dev);
+ num_available = dev_pm_opp_get_opp_count(dev);
speeds = kzalloc(sizeof(u32) * num_available, GFP_KERNEL);
/* populate the table in increasing order */
freq = 0;
- while (!IS_ERR(opp = opp_find_freq_ceil(dev, &freq))) {
+ while (!IS_ERR(opp = dev_pm_opp_find_freq_ceil(dev, &freq))) {
speeds[i] = freq;
freq++;
i++;
@@ -313,7 +313,7 @@ opp_get_opp_count - Retrieve the number of available opps for a device
6. Cpufreq Table Generation
===========================
-opp_init_cpufreq_table - cpufreq framework typically is initialized with
+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
@@ -326,7 +326,7 @@ opp_init_cpufreq_table - cpufreq framework typically is initialized with
soc_pm_init()
{
/* Do things */
- r = opp_init_cpufreq_table(dev, &freq_table);
+ r = dev_pm_opp_init_cpufreq_table(dev, &freq_table);
if (!r)
cpufreq_frequency_table_cpuinfo(policy, freq_table);
/* Do other things */
@@ -336,7 +336,7 @@ opp_init_cpufreq_table - cpufreq framework typically is initialized with
addition to CONFIG_PM as power management feature is required to
dynamically scale voltage and frequency in a system.
-opp_free_cpufreq_table - Free up the table allocated by opp_init_cpufreq_table
+dev_pm_opp_free_cpufreq_table - Free up the table allocated by dev_pm_opp_init_cpufreq_table
7. Data Structures
==================
@@ -366,8 +366,8 @@ struct opp - The internal data structure of OPP library which is used to
identifier for OPP in the interactions with OPP layer.
WARNING: The struct opp pointer should not be parsed or modified by the
- users. The defaults of for an instance is populated by opp_add, but the
- availability of the OPP can be modified by opp_enable/disable functions.
+ users. The defaults of for an instance is populated by dev_pm_opp_add, but the
+ availability of the OPP can be modified by dev_pm_opp_enable/disable functions.
struct device - This is used to identify a domain to the OPP layer. The
nature of the device and it's implementation is left to the user of
@@ -377,19 +377,19 @@ Overall, in a simplistic view, the data structure operations is represented as
following:
Initialization / modification:
- +-----+ /- opp_enable
-opp_add --> | opp | <-------
- | +-----+ \- opp_disable
+ +-----+ /- dev_pm_opp_enable
+dev_pm_opp_add --> | opp | <-------
+ | +-----+ \- dev_pm_opp_disable
\-------> domain_info(device)
Search functions:
- /-- opp_find_freq_ceil ---\ +-----+
-domain_info<---- opp_find_freq_exact -----> | opp |
- \-- opp_find_freq_floor ---/ +-----+
+ /-- dev_pm_opp_find_freq_ceil ---\ +-----+
+domain_info<---- dev_pm_opp_find_freq_exact -----> | opp |
+ \-- dev_pm_opp_find_freq_floor ---/ +-----+
Retrieval functions:
-+-----+ /- opp_get_voltage
++-----+ /- dev_pm_opp_get_voltage
| opp | <---
-+-----+ \- opp_get_freq
++-----+ \- dev_pm_opp_get_freq
-domain_info <- opp_get_opp_count
+domain_info <- dev_pm_opp_get_opp_count