[PATCH v4 0/5] Register an Energy Model for Arm reference platforms

[Quentin Perret <quentin.perret@arm.com>]

The Energy Model (EM) framework feeds interested subsystems (the
scheduler/EAS as of now) with power costs provided by drivers. Yet, no
driver is actually doing that upstream yet. This series updates a set of
CPUFreq drivers in order to register power costs in the EM framework for
some of the Arm reference platforms for EAS: Hikey960, Juno and TC2.

The series is split as follows:
 - Patch 01 introduces in PM_OPP a helper function which estimates the
   CPU power using the P=CV²f equation also used by IPA. It should be
   noted that this introduces duplicate code with IPA, which will
   eventually be fixed by migrating IPA to using PM_EM. The ideal plan
   would be to do so later, in a separate patch series. I would indeed
   prefer to keep the thermal and CPUFreq discussion separate at this
   stage, if deemed acceptable.
 - Patches 02-04 make use of that PM_OPP helper function from the
   following CPUFreq drivers: cpufreq-dt, scpi-cpufreq and
   arm_big_little.
 - Patch 05 modifies the SCMI cpufreq driver to pass the power costs
   obtained from firmware to PM_EM. This patch is independent from the
   rest of the series.


Changes since v3 (20190201093101.31869-1-quentin.perret@arm.com)
 - Moved the OPP count inside dev_pm_opp_of_register_em() (Matthias,
   Sudeep)

Changes since v2 (20190130170506.20450-1-quentin.perret@arm.com)
 - Added comment to explain why we check only the dynamic-power-coeff
   property and not voltages in dev_pm_opp_of_register_em() (Viresh)
 - Fixed comments/docstrings of new functions in opp/of.c (Matthias)
 - Added Matthias' Tested-by to patch 01

Changes since v1 (20190128165522.31749-1-quentin.perret@arm.com):
 - Dropped the DT patches that have been queued by Sudeep
 - Introduced dev_pm_opp_of_register_em() helper to check the presence
   of the DT coeff before calling PM_EM (Viresh, Matthias)
 - Coding-style improvements (Viresh, Matthias)

Thanks,
Quentin

Dietmar Eggemann (1):
  cpufreq: arm_big_little: Register an Energy Model

Quentin Perret (4):
  PM / OPP: Introduce a power estimation helper
  cpufreq: dt: Register an Energy Model
  cpufreq: scpi: Register an Energy Model
  cpufreq: scmi: Register an Energy Model

 drivers/cpufreq/arm_big_little.c |  2 +
 drivers/cpufreq/cpufreq-dt.c     |  2 +
 drivers/cpufreq/scmi-cpufreq.c   | 39 ++++++++++++-
 drivers/cpufreq/scpi-cpufreq.c   |  3 +
 drivers/opp/of.c                 | 99 ++++++++++++++++++++++++++++++++
 include/linux/pm_opp.h           |  6 ++
 6 files changed, 148 insertions(+), 3 deletions(-)

-- 
2.20.1