Lines Matching refs:the
13 to the caller. The binding of the cooling devices to the trip point is left for
14 the user. The registration APIs returns the cooling device pointer.
22 This interface function registers the cpufreq cooling device with the name
26 clip_cpus: cpumask of cpus where the frequency constraints will happen.
31 This interface function registers the cpufreq cooling device with
32 the name "thermal-cpufreq-%x" linking it with a device tree node, in
33 order to bind it via the thermal DT code. This api can support multiple
36 np: pointer to the cooling device device tree node
37 clip_cpus: cpumask of cpus where the frequency constraints will happen.
44 cooling device. Using this function, the cooling device will
45 implement the power extensions by using a simple cpu power model. The
46 cpus must have registered their OPPs using the OPP library.
48 The additional parameters are needed for the power model (See 2. Power
49 models). "capacitance" is the dynamic power coefficient (See 2.1
50 Dynamic power). "plat_static_func" is a function to calculate the
58 cpufreq cooling device with power extensions using the device tree
59 information supplied by the np parameter.
63 This interface function unregisters the "thermal-cpufreq-%x" cooling device.
71 static power. This power model requires that the operating-points of
72 the CPUs are registered using the kernel's opp library and the
73 `cpufreq_frequency_table` is assigned to the `struct device` of the
74 cpu. If you are using CONFIG_CPUFREQ_DT then the
75 `cpufreq_frequency_table` should already be assigned to the cpu
85 For a given processor implementation the primary factors are:
87 - The time the processor spends running, consuming dynamic power, as
88 compared to the time in idle states where dynamic consumption is
92 - In running time the 'execution' behaviour (instruction types, memory
95 but typically it is of a much lesser impact than the factors above.
101 f(run) here represents the described execution behaviour and its
110 consistent with the relative contribution to overall power variation.
119 from 100 to 500. For reference, the approximate values for the SoC in
120 ARM's Juno Development Platform are 530 for the Cortex-A57 cluster and
121 140 for the Cortex-A53 cluster.
127 given circuit implementation the primary factors are:
129 - Time the circuit spends in each 'power state'
134 The time the circuit spends in each 'power state' for a given
139 Note: The visibility of state entries to the OS can vary, according to
140 platform specifics, and this can then impact the accuracy of a model
145 of the circuit are all significant factors in static leakage power
148 Circuit implementation specific factors include the chosen silicon
149 process as well as the type, number and size of transistors in both
150 the logic gates and any RAM elements included.
152 The static power consumption modelling must take into account the
153 power managed regions that are implemented. Taking the example of an
154 ARM processor cluster, the modelling would take into account whether
156 region is implemented for the complete cluster.
162 are then scaled for all of the following: the time in each state, the
163 process grade, the current temperature and the operating voltage.
165 dominate the estimate, the appropriate interface to the model from the
167 the static power in this platform. When registering the cpu cooling
168 device pass a function pointer that follows the `get_static_t`
174 `cpumask` is the cpumask of the cpus involved in the calculation.
175 `voltage` is the voltage at which they are operating. The function
176 should calculate the average static power for the last `interval`
178 succeeds, it should store the static power in `power`. Reading the
179 temperature of the cpus described by `cpumask` is left for
180 plat_get_static() to do as the platform knows best which thermal
181 sensor is closest to the cpu.
187 and/or equations to permute the estimated value. Process grade
188 information is not passed to the model since access to such data, from
192 Note: the significance of static power for CPUs in comparison to
193 dynamic power is highly dependent on implementation. Given the
194 potential complexity in implementation, the importance and accuracy of