cpufreq: powernv: Register for OCC related opal_message notification

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OCC is an On-Chip-Controller which takes care of power and thermal
safety of the chip. During runtime due to power failure or
overtemperature the OCC may throttle the frequencies of the CPUs to
remain within the power budget.

We want the cpufreq driver to be aware of such situations to be able
to report the reason to the user. We register to opal_message_notifier
to receive OCC messages from opal.

powernv_cpufreq_throttle_check() reports any frequency throttling and
this patch will report the reason or event that caused throttling. We
can be throttled if OCC is reset or OCC limits Pmax due to power or
thermal reasons. We are also notified of unthrottling after an OCC
reset or if OCC restores Pmax on the chip.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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Shilpasri G Bhat 2015-07-16 13:34:20 +05:30 • committed by Rafael J. Wysocki

parent 196ba2d514

commit cb166fa937

1 changed files with 73 additions and 1 deletions

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drivers/cpufreq/powernv-cpufreq.c

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