summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-01-18 02:52:56 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-01-18 02:52:56 +0100
commitf31c376025b5b295908d4b8ec74811be7d7e15f8 (patch)
tree766845cd39d7adfc192ce0b16d75d8a8e4f8be02 /Documentation
parentbee344cb70e9bf5ad929e0a493c0f7aa3a587bfb (diff)
parentf06970f4b03dffeb9831a8ad605db3c85a55aca1 (diff)
Merge branch 'pm-cpufreq'
* pm-cpufreq: (36 commits) cpufreq: scpi: remove arm_big_little dependency drivers: psci: remove cluster terminology and dependency on physical_package_id cpufreq: powernv: Dont assume distinct pstate values for nominal and pmin cpufreq: intel_pstate: Add Skylake servers support cpufreq: intel_pstate: Replace bxt_funcs with core_funcs cpufreq: imx6q: add 696MHz operating point for i.mx6ul ARM: dts: imx6ul: add 696MHz operating point cpufreq: stats: Change return type of cpufreq_stats_update() as void powernv-cpufreq: Treat pstates as opaque 8-bit values powernv-cpufreq: Fix pstate_to_idx() to handle non-continguous pstates powernv-cpufreq: Add helper to extract pstate from PMSR cpu_cooling: Remove static-power related documentation cpufreq: imx6q: switch to Use clk_bulk_get() to refine clk operations PM / OPP: Make local function ti_opp_supply_set_opp() static PM / OPP: Add ti-opp-supply driver dt-bindings: opp: Introduce ti-opp-supply bindings cpufreq: ti-cpufreq: Add support for multiple regulators cpufreq: ti-cpufreq: Convert to module_platform_driver cpufreq: Add DVFS support for Armada 37xx MAINTAINERS: add new entries for Armada 37xx cpufreq driver ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/arm/marvell/armada-37xx.txt19
-rw-r--r--Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt63
-rw-r--r--Documentation/thermal/cpu-cooling-api.txt115
3 files changed, 87 insertions, 110 deletions
diff --git a/Documentation/devicetree/bindings/arm/marvell/armada-37xx.txt b/Documentation/devicetree/bindings/arm/marvell/armada-37xx.txt
index 51336e5fc761..35c3c3460d17 100644
--- a/Documentation/devicetree/bindings/arm/marvell/armada-37xx.txt
+++ b/Documentation/devicetree/bindings/arm/marvell/armada-37xx.txt
@@ -14,3 +14,22 @@ following property before the previous one:
Example:
compatible = "marvell,armada-3720-db", "marvell,armada3720", "marvell,armada3710";
+
+
+Power management
+----------------
+
+For power management (particularly DVFS and AVS), the North Bridge
+Power Management component is needed:
+
+Required properties:
+- compatible : should contain "marvell,armada-3700-nb-pm", "syscon";
+- reg : the register start and length for the North Bridge
+ Power Management
+
+Example:
+
+nb_pm: syscon@14000 {
+ compatible = "marvell,armada-3700-nb-pm", "syscon";
+ reg = <0x14000 0x60>;
+}
diff --git a/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt b/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
new file mode 100644
index 000000000000..832346e489a3
--- /dev/null
+++ b/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
@@ -0,0 +1,63 @@
+Texas Instruments OMAP compatible OPP supply description
+
+OMAP5, DRA7, and AM57 family of SoCs have Class0 AVS eFuse registers which
+contain data that can be used to adjust voltages programmed for some of their
+supplies for more efficient operation. This binding provides the information
+needed to read these values and use them to program the main regulator during
+an OPP transitions.
+
+Also, some supplies may have an associated vbb-supply which is an Adaptive Body
+Bias regulator which much be transitioned in a specific sequence with regards
+to the vdd-supply and clk when making an OPP transition. By supplying two
+regulators to the device that will undergo OPP transitions we can make use
+of the multi regulator binding that is part of the OPP core described here [1]
+to describe both regulators needed by the platform.
+
+[1] Documentation/devicetree/bindings/opp/opp.txt
+
+Required Properties for Device Node:
+- vdd-supply: phandle to regulator controlling VDD supply
+- vbb-supply: phandle to regulator controlling Body Bias supply
+ (Usually Adaptive Body Bias regulator)
+
+Required Properties for opp-supply node:
+- compatible: Should be one of:
+ "ti,omap-opp-supply" - basic OPP supply controlling VDD and VBB
+ "ti,omap5-opp-supply" - OMAP5+ optimized voltages in efuse(class0)VDD
+ along with VBB
+ "ti,omap5-core-opp-supply" - OMAP5+ optimized voltages in efuse(class0) VDD
+ but no VBB.
+- reg: Address and length of the efuse register set for the device (mandatory
+ only for "ti,omap5-opp-supply")
+- ti,efuse-settings: An array of u32 tuple items providing information about
+ optimized efuse configuration. Each item consists of the following:
+ volt: voltage in uV - reference voltage (OPP voltage)
+ efuse_offseet: efuse offset from reg where the optimized voltage is stored.
+- ti,absolute-max-voltage-uv: absolute maximum voltage for the OPP supply.
+
+Example:
+
+/* Device Node (CPU) */
+cpus {
+ cpu0: cpu@0 {
+ device_type = "cpu";
+
+ ...
+
+ vdd-supply = <&vcc>;
+ vbb-supply = <&abb_mpu>;
+ };
+};
+
+/* OMAP OPP Supply with Class0 registers */
+opp_supply_mpu: opp_supply@4a003b20 {
+ compatible = "ti,omap5-opp-supply";
+ reg = <0x4a003b20 0x8>;
+ ti,efuse-settings = <
+ /* uV offset */
+ 1060000 0x0
+ 1160000 0x4
+ 1210000 0x8
+ >;
+ ti,absolute-max-voltage-uv = <1500000>;
+};
diff --git a/Documentation/thermal/cpu-cooling-api.txt b/Documentation/thermal/cpu-cooling-api.txt
index 71653584cd03..7df567eaea1a 100644
--- a/Documentation/thermal/cpu-cooling-api.txt
+++ b/Documentation/thermal/cpu-cooling-api.txt
@@ -26,39 +26,16 @@ the user. The registration APIs returns the cooling device pointer.
clip_cpus: cpumask of cpus where the frequency constraints will happen.
1.1.2 struct thermal_cooling_device *of_cpufreq_cooling_register(
- struct device_node *np, const struct cpumask *clip_cpus)
+ struct cpufreq_policy *policy)
This interface function registers the cpufreq cooling device with
the name "thermal-cpufreq-%x" linking it with a device tree node, in
order to bind it via the thermal DT code. This api can support multiple
instances of cpufreq cooling devices.
- np: pointer to the cooling device device tree node
- clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ policy: CPUFreq policy.
-1.1.3 struct thermal_cooling_device *cpufreq_power_cooling_register(
- const struct cpumask *clip_cpus, u32 capacitance,
- get_static_t plat_static_func)
-
-Similar to cpufreq_cooling_register, this function registers a cpufreq
-cooling device. Using this function, the cooling device will
-implement the power extensions by using a simple cpu power model. The
-cpus must have registered their OPPs using the OPP library.
-
-The additional parameters are needed for the power model (See 2. Power
-models). "capacitance" is the dynamic power coefficient (See 2.1
-Dynamic power). "plat_static_func" is a function to calculate the
-static power consumed by these cpus (See 2.2 Static power).
-
-1.1.4 struct thermal_cooling_device *of_cpufreq_power_cooling_register(
- struct device_node *np, const struct cpumask *clip_cpus, u32 capacitance,
- get_static_t plat_static_func)
-
-Similar to cpufreq_power_cooling_register, this function register a
-cpufreq cooling device with power extensions using the device tree
-information supplied by the np parameter.
-
-1.1.5 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
+1.1.3 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
This interface function unregisters the "thermal-cpufreq-%x" cooling device.
@@ -67,20 +44,14 @@ information supplied by the np parameter.
2. Power models
The power API registration functions provide a simple power model for
-CPUs. The current power is calculated as dynamic + (optionally)
-static power. This power model requires that the operating-points of
+CPUs. The current power is calculated as dynamic power (static power isn't
+supported currently). This power model requires that the operating-points of
the CPUs are registered using the kernel's opp library and the
`cpufreq_frequency_table` is assigned to the `struct device` of the
cpu. If you are using CONFIG_CPUFREQ_DT then the
`cpufreq_frequency_table` should already be assigned to the cpu
device.
-The `plat_static_func` parameter of `cpufreq_power_cooling_register()`
-and `of_cpufreq_power_cooling_register()` is optional. If you don't
-provide it, only dynamic power will be considered.
-
-2.1 Dynamic power
-
The dynamic power consumption of a processor depends on many factors.
For a given processor implementation the primary factors are:
@@ -119,79 +90,3 @@ mW/MHz/uVolt^2. Typical values for mobile CPUs might lie in range
from 100 to 500. For reference, the approximate values for the SoC in
ARM's Juno Development Platform are 530 for the Cortex-A57 cluster and
140 for the Cortex-A53 cluster.
-
-
-2.2 Static power
-
-Static leakage power consumption depends on a number of factors. For a
-given circuit implementation the primary factors are:
-
-- Time the circuit spends in each 'power state'
-- Temperature
-- Operating voltage
-- Process grade
-
-The time the circuit spends in each 'power state' for a given
-evaluation period at first order means OFF or ON. However,
-'retention' states can also be supported that reduce power during
-inactive periods without loss of context.
-
-Note: The visibility of state entries to the OS can vary, according to
-platform specifics, and this can then impact the accuracy of a model
-based on OS state information alone. It might be possible in some
-cases to extract more accurate information from system resources.
-
-The temperature, operating voltage and process 'grade' (slow to fast)
-of the circuit are all significant factors in static leakage power
-consumption. All of these have complex relationships to static power.
-
-Circuit implementation specific factors include the chosen silicon
-process as well as the type, number and size of transistors in both
-the logic gates and any RAM elements included.
-
-The static power consumption modelling must take into account the
-power managed regions that are implemented. Taking the example of an
-ARM processor cluster, the modelling would take into account whether
-each CPU can be powered OFF separately or if only a single power
-region is implemented for the complete cluster.
-
-In one view, there are others, a static power consumption model can
-then start from a set of reference values for each power managed
-region (e.g. CPU, Cluster/L2) in each state (e.g. ON, OFF) at an
-arbitrary process grade, voltage and temperature point. These values
-are then scaled for all of the following: the time in each state, the
-process grade, the current temperature and the operating voltage.
-However, since both implementation specific and complex relationships
-dominate the estimate, the appropriate interface to the model from the
-cpu cooling device is to provide a function callback that calculates
-the static power in this platform. When registering the cpu cooling
-device pass a function pointer that follows the `get_static_t`
-prototype:
-
- int plat_get_static(cpumask_t *cpumask, int interval,
- unsigned long voltage, u32 &power);
-
-`cpumask` is the cpumask of the cpus involved in the calculation.
-`voltage` is the voltage at which they are operating. The function
-should calculate the average static power for the last `interval`
-milliseconds. It returns 0 on success, -E* on error. If it
-succeeds, it should store the static power in `power`. Reading the
-temperature of the cpus described by `cpumask` is left for
-plat_get_static() to do as the platform knows best which thermal
-sensor is closest to the cpu.
-
-If `plat_static_func` is NULL, static power is considered to be
-negligible for this platform and only dynamic power is considered.
-
-The platform specific callback can then use any combination of tables
-and/or equations to permute the estimated value. Process grade
-information is not passed to the model since access to such data, from
-on-chip measurement capability or manufacture time data, is platform
-specific.
-
-Note: the significance of static power for CPUs in comparison to
-dynamic power is highly dependent on implementation. Given the
-potential complexity in implementation, the importance and accuracy of
-its inclusion when using cpu cooling devices should be assessed on a
-case by case basis.
-