PM / devfreq: Add support for QCOM devfreq firmware

The firmware present in some QCOM chipsets offloads the steps necessary for
changing the frequency of some devices (Eg: L3). This driver implements the
devfreq interface for this firmware so that various governors could be used
to scale the frequency of these devices.

Each client (say cluster 0 and cluster 1) that wants to vote for a
particular device's frequency (say, L3 frequency) is represented as a
separate voter device (qcom,devfreq-fw-voter) that's a child of the
firmware device (qcom,devfreq-fw).

Change-Id: Ibf09a800a6b16ac4196a26d29d5da701c28ac459
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
4 files changed