Depending on hardware version, Tegra SoC may require a higher voltages
during resume from system suspend, otherwise hardware will crash. Set
SoC voltages to a nominal levels during suspend.
Link: https://lore.kernel.org/all/a8280b5b-7347-8995-c97b-10b798cdf057@gmail.com/
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The core voltage shall not drop until state of core domain is synced,
i.e. all device drivers that use core domain are loaded and ready.
Support core domain state syncing. The core domain driver invokes the
core-regulator voltage syncing once the state of domain is synced, at
this point the core voltage is allowed to go lower than the level left
after bootloader.
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Paul Fertser <fercerpav@gmail.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Ensure that SoC voltages are at a level suitable for a system reboot.
This is important for some devices that use CPU reset method for the
rebooting. SoC CPU and core voltages now are be restored to a level
that is suitable for rebooting. This patch fixes hang on reboot on
Asus Transformer TF101, it was also reported as fixing some of reboot
issues on Toshiba AC100.
Reported-by: Nikola Milosavljević <mnidza@outlook.com>
Tested-by: Nikola Milosavljević <mnidza@outlook.com> # TF101
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
There is no need to re-apply the same voltage. This change is just a minor
cleanup.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Add regulators coupler for Tegra20 SoCs that performs voltage balancing
of a coupled regulators and thus provides voltage scaling functionality.
There are 3 coupled regulators on all Tegra20 SoCs: CORE, RTC and CPU.
The CORE and RTC voltages shall be in range of 170mV from each other and
they both shall be higher than the CPU voltage by at least 120mV. This
sounds like it could be handle by a generic voltage balancer, but the CORE
voltage scaling isn't implemented in any of the upstream drivers yet.
It will take quite some time and effort to hook up voltage scaling for
all of the drivers, hence we will use a custom coupler that will manage
the CPU voltage scaling for the starter.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Dmitry Osipenko