FROMLIST: PM / OPP: Support adjusting OPP voltages at runtime
On some SoCs the Adaptive Voltage Scaling (AVS) technique is
employed to optimize the operating voltage of a device. At a
given frequency, the hardware monitors dynamic factors and either
makes a suggestion for how much to adjust a voltage for the
current frequency, or it automatically adjusts the voltage
without software intervention. Add an API to the OPP library for
the former case, so that AVS type devices can update the voltages
for an OPP when the hardware determines the voltage should
change. The assumption is that drivers like CPUfreq or devfreq
will register for the OPP notifiers and adjust the voltage
according to suggestions that AVS makes.
This patch is devired from [1] submitted by Stephen.
[1] https://lore.kernel.org/patchwork/patch/599279/
(am from https://patchwork.kernel.org/patch/10946069/)
BUG=b:129039370
TEST=boot to shell
Change-Id: I1bc83a75bb0577a084c40411829fca19af8b0b58
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Roger Lu <roger.lu@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Reviewed-on: https://chromium-review.googlesource.com/1628412
Commit-Ready: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
2 files changed
