CPR (Core Power Reduction) is a technology that reduces core power on a
CPU or other device. It reads voltage settings in efuse from product
test process as initial settings.
Each OPP corresponds to a "corner" that has a range of valid voltages
for a particular frequency. While the device is running at a particular
frequency, CPR monitors dynamic factors such as temperature, etc. and
adjusts the voltage for that frequency accordingly to save power
and meet silicon characteristic requirements.
This driver is based on an RFC by Stephen Boyd[1], which in turn is
based on work by others on codeaurora.org[2].
[1] https://lkml.org/lkml/2015/9/18/833
[2] https://source.codeaurora.org/quic/la/kernel/msm-4.14/tree/drivers/regulator/cpr-regulator.c?h=msm-4.14
Co-developed-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IO domain voltages on some Rockchip SoCs are variable but need to be
kept in sync between the regulators and the SoC using a special
register.
A specific example using rk3288:
- If the regulator hooked up to a pin like SDMMC0_VDD is 3.3V then
bit 7 of GRF_IO_VSEL needs to be 0. If the regulator hooked up to
that same pin is 1.8V then bit 7 of GRF_IO_VSEL needs to be 1.
Said another way, this driver simply handles keeping bits in the SoC's
general register file (GRF) in sync with the actual value of a voltage
hooked up to the pins.
Note that this driver specifically doesn't include:
- any logic for deciding what voltage we should set regulators to
- any logic for deciding whether regulators (or internal SoC blocks)
should have power or not have power
If there were some other software that had the smarts of making
decisions about regulators, it would work in conjunction with this
driver. When that other software adjusted a regulator's voltage then
this driver would handle telling the SoC about it. A good example is
vqmmc for SD. In that case the dw_mmc driver simply is told about a
regulator. It changes the regulator between 3.3V and 1.8V at the
right time. This driver notices the change and makes sure that the
SoC is on the same page.
Signed-off-by: Heiko Stübner <heiko@sntech.de>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
[khilman: fix compiler warnings]
Signed-off-by: Kevin Hilman <khilman@linaro.org>
After a clean-up of the interfaces the OMAP Smartreflex IP driver is now a
generic driver. Move it to drivers/power/avs/.
The build is controlled by the following Kconfig options:
. CONFIG_POWER_AVS: general knob for Adaptive Voltage Scaling support,
. CONFIG_POWER_AVS_OMAP: AVS(Adaptive Voltage Scaling)
support on OMAP containing the version 1 or version 2 of the SmartReflex IP,
. CONFIG_POWER_AVS_OMAP_CLASS3: Class 3 implementation of Smartreflex.
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: J Keerthy <j-keerthy@ti.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Niklas Cassel