linux-dev/Documentation/power, branch linus/master

Documentation: EM: Add artificial EM registration description

2022-04-13T14:26:18Z

Add description about new artificial EM registration and use cases. Update also the documentation with the new .get_cost() callback description and usage. Signed-off-by: Lukasz Luba Reviewed-by: Ionela Voinescu Signed-off-by: Rafael J. Wysocki

PM: EM: Change the order of arguments in the .active_power() callback

2022-04-13T14:26:17Z

The .active_power() callback passes the device pointer when it's called. Aligned with a convetion present in other subsystems and pass the 'dev' as a first argument. It looks more cleaner. Adjust all affected drivers which implement that API callback. Suggested-by: Ionela Voinescu Signed-off-by: Lukasz Luba Reviewed-by: Ionela Voinescu Signed-off-by: Rafael J. Wysocki

Documentation: EM: Describe new registration method using DT

2022-03-03T04:05:04Z

The new registration method allows to get power values from the DT OPP definition. The new OPP entry property "opp-microwatt" contains total power expressed in micro-Watts. Align the EM documentation with this new possible registration method of EM. Signed-off-by: Lukasz Luba Signed-off-by: Viresh Kumar

Merge branches 'pm-opp', 'pm-devfreq' and 'powercap'

2022-01-10T17:00:31Z

Merge an operating performance points (OPP) update, devfreq updates and power capping updates for 5.17-rc1: - Update outdated OPP documentation (Tang Yizhou). - Reduce log severity for informative message regarding frequency transition failures in devfreq (Tzung-Bi Shih). - Add DRAM frequency controller devfreq driver for Allwinner sunXi SoCs (Samuel Holland). - Add missing COMMON_CLK dependency to the sun8i devfreq driver (Arnd Bergmann). - Add support for new layout of Psys PowerLimit Register on SPR to the Intel RAPL power capping driver (Zhang Rui). - Fix typo in a comment in idle_inject.c (Jason Wang). - Remove unused function definition from the DTPM (Dynamit Thermal Power Management) power capping framework (Daniel Lezcano). - Reduce DTPM trace verbosity (Daniel Lezcano). * pm-opp: Documentation: power: Update outdated contents in opp.rst * pm-devfreq: PM / devfreq: Reduce log severity for informative message PM / devfreq: sun8i: addd COMMON_CLK dependency PM / devfreq: Add a driver for the sun8i/sun50i MBUS * powercap: powercap/drivers/dtpm: Reduce trace verbosity powercap/drivers/dtpm: Remove unused function definition powercap: fix typo in a comment in idle_inject.c powercap: intel_rapl: support new layout of Psys PowerLimit Register on SPR

Merge branch 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm

2021-12-30T14:53:41Z

Pull OPP (operating performance points) updates for 5.17-rc1 from Viresh Kumar: "This updates the documentation to match the latest code." * 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm: Documentation: power: Update outdated contents in opp.rst

Documentation: power: Update outdated contents in opp.rst

2021-12-27T04:17:52Z

Three problems have been revised: 1. CONFIG_PM_OPP no longer depends on CONFIG_PM. 2. opp_find_freq_{ceil, floor} is renamed as dev_pm_opp_find_freq_{ceil, floor}. 3. Make it clear that the 'opp' struct is actually dev_pm_opp. Signed-off-by: Tang Yizhou Signed-off-by: Viresh Kumar

PM: runtime: Capture device status before disabling runtime PM

2021-12-17T15:16:40Z

In some cases (for example, during system-wide suspend and resume of devices) it is useful to know whether or not runtime PM has ever been enabled for a given device and, if so, what the runtime PM status of it had been right before runtime PM was disabled for it last time. For this reason, introduce a new struct dev_pm_info field called last_status that will be used for capturing the runtime PM status of the device when its power.disable_depth counter changes from 0 to 1. The new field will be set to RPM_INVALID to start with and whenever power.disable_depth changes from 1 to 0, so it will be valid only when runtime PM of the device is currently disabled, but it has been enabled at least once. Immediately use power.last_status in rpm_resume() to make it handle the case when PM runtime is disabled for the device, but its runtime PM status is RPM_ACTIVE more consistently. Namely, make it return 1 if power.last_status is also equal to RPM_ACTIVE in that case (the idea being that if the status was RPM_ACTIVE last time when power.disable_depth was changing from 0 to 1 and it is still RPM_ACTIVE, it can be assumed to reflect what happened to the device last time when it was using runtime PM) and -EACCES otherwise. Update the documentation to provide a description of last_status and change the description of pm_runtime_resume() in it to reflect the new behavior of rpm_active(). While at it, rearrange the code in pm_runtime_enable() to be more straightforward and replace the WARN() macro in it with a pr_warn() invocation which is less disruptive. Link: https://lore.kernel.org/linux-pm/20211026222626.39222-1-ulf.hansson@linaro.org/t/#u Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

Documentation: power: Describe 'advanced' and 'simple' EM models

2021-11-10T20:26:34Z

The Energy Model (EM) can be registered in two ways: 1) Using a helper function, which under the hood relies on OPP framework and DT entry in CPU node: 'dynamic-power-coefficient'. This is a 'simple' EM because it's tied to the math formula: Power = dynamic-power-coefficient * V^2 * f 2) Using em_dev_register_perf_domain() API function with a driver custom callback which provides power for each performance state. This is 'advanced' EM, since it can better reflect real power measurements for each performance state. It's not limited to any math formula and can better reflect real physics of the device. Add description of these two methods to the documentation, so developers could choose the suitable registration method (option). Signed-off-by: Lukasz Luba [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

Documentation: power: Add description about new callback for EM registration

2021-11-10T20:26:34Z

The Energy Model (EM) registration for CPUs should now be done using a dedicated callback added recently into CPUFreq framework and drivers. Commit c17495b01b72 ("cpufreq: Add callback to register with energy model") The callback guaranties that the EM registration is called at the right time during driver setup. To avoid mistakes update the documentation to align with the existing code implementation. Signed-off-by: Lukasz Luba Signed-off-by: Rafael J. Wysocki

Documentation: power: include kernel-doc in Energy Model doc

2021-09-07T19:17:28Z

Improve the existing documentation of the Energy Model and add kernel-doc comments. This extends an API description and helps better understanding the usage. Signed-off-by: Lukasz Luba Signed-off-by: Rafael J. Wysocki