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Diffstat (limited to 'Documentation/power/opp.rst')
| -rw-r--r-- | Documentation/power/opp.rst | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/Documentation/power/opp.rst b/Documentation/power/opp.rst index 209c7613f5a4..e3cc4f349ea8 100644 --- a/Documentation/power/opp.rst +++ b/Documentation/power/opp.rst @@ -73,19 +73,21 @@ factors. Example usage: Thermal management or other exceptional situations where SoC framework might choose to disable a higher frequency OPP to safely continue operations until that OPP could be re-enabled if possible. -OPP library facilitates this concept in it's implementation. The following +OPP library facilitates this concept in its 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 +opp_find_freq_{ceil, floor}, dev_pm_opp_get_voltage, dev_pm_opp_get_freq, +dev_pm_opp_get_opp_count -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. +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 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 -care to refresh the cpufreq table in cases of these operations. +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 care to refresh the cpufreq table in cases of these operations. 2. Initial OPP List Registration ================================ @@ -99,11 +101,11 @@ OPPs dynamically using the dev_pm_opp_enable / disable functions. 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 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. + is assumed to be available and control of its availability can be done + 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. WARNING: Do not use this function in interrupt context. @@ -354,7 +356,7 @@ struct dev_pm_opp 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 + nature of the device and its implementation is left to the user of OPP library such as the SoC framework. Overall, in a simplistic view, the data structure operations is represented as |