[PATCH v2 0/3] Add support for Tegra Activity Monitor

Tomeu Vizoso tomeu.vizoso at collabora.com
Mon Nov 24 04:28:15 PST 2014


in this v2 I have made the driver use devfreq. It works just as fine as the
previous revision, but it's almost 200 lines more of code for not that much

Though I don't see much point in using devfreq, I think it's probably better
than an ad-hoc driver because in the future I hope that devfreq will gain
functionality that will be of use (PM_QOS_MEMORY_BANDWIDTH support, for

These patches implement support for setting the rate of the EMC clock based on
stats collected from the ACTMON, a piece of hw in the Tegra124 that counts
memory accesses (among others).

It depends on the following in-flight patches:

* EMC driver: http://thread.gmane.org/gmane.linux.drivers.devicetree/99304
* CPUFreq driver: http://thread.gmane.org/gmane.linux.kernel/1812962

I have pushed a branch here for testing:




Tomeu Vizoso (3):
  of: Add binding for NVIDIA Tegra ACTMON node
  PM / devfreq: tegra: add devfreq driver for Tegra Activity Monitor
  ARM: tegra: Add Tegra124 ACTMON support

 .../devicetree/bindings/arm/tegra/actmon.txt       |  38 ++
 arch/arm/boot/dts/tegra124.dtsi                    |  23 +
 drivers/devfreq/Kconfig                            |  10 +
 drivers/devfreq/Makefile                           |   1 +
 drivers/devfreq/tegra-devfreq.c                    | 718 +++++++++++++++++++++
 5 files changed, 790 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/tegra/actmon.txt
 create mode 100644 drivers/devfreq/tegra-devfreq.c


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