linux-stable.git/drivers/opp/core.c, branch v5.8

opp: Remove bandwidth votes when target_freq is zero

2020-05-29T04:45:12+00:00

We already drop several votes when target_freq is set to zero, drop
bandwidth votes as well.

Reported-by: Sibi Sankar 
Reviewed-by: Georgi Djakov 
Tested-by: Georgi Djakov 
Reviewed-by: Sibi Sankar 
Tested-by: Sibi Sankar 
Signed-off-by: Viresh Kumar

opp: core: add regulators enable and disable

2020-05-29T04:45:12+00:00

Add enable regulators to dev_pm_opp_set_regulators() and disable
regulators to dev_pm_opp_put_regulators(). Even if bootloader
leaves regulators enabled, they should be enabled in kernel in
order to increase the reference count.

Tested-by: Marek Szyprowski 
Acked-by: Clément Péron 
Tested-by: Clément Péron 
Signed-off-by: Kamil Konieczny 
[ Viresh: Enable the regulator only after it is programmed and add a
	  flag to track its status. ]
Signed-off-by: Viresh Kumar

opp: Reorder the code for !target_freq case

2020-05-29T04:45:12+00:00

Reorder the code a bit to make it more readable. Add additional comment
as well.

Tested-by: Marek Szyprowski 
Acked-by: Clément Péron 
Tested-by: Clément Péron 
Signed-off-by: Viresh Kumar

opp: Update the bandwidth on OPP frequency changes

2020-05-29T04:45:10+00:00

If the OPP bandwidth values are populated, we want to switch also the
interconnect bandwidth in addition to frequency and voltage.

Signed-off-by: Georgi Djakov 
Reviewed-by: Matthias Kaehlcke 
Reviewed-by: Sibi Sankar 
Signed-off-by: Viresh Kumar

opp: Add support for parsing interconnect bandwidth

2020-05-29T04:45:08+00:00

The OPP bindings now support bandwidth values, so add support to parse it
from device tree and store it into the new dev_pm_opp_icc_bw struct, which
is part of the dev_pm_opp.

Signed-off-by: Georgi Djakov 
Reviewed-by: Matthias Kaehlcke 
[ Viresh: Create _read_bw() and use it, renamed _of_find_icc_paths() to
	  dev_pm_opp_of_find_icc_paths(), exported it and made opp_table
	  argument optional. Also drop the depends on from Kconfig. ]
Signed-off-by: Viresh Kumar

OPP: Add helpers for reading the binding properties

2020-05-13T06:18:13+00:00

The opp-hz DT property is not mandatory and we may use another property
as a key in the OPP table. Add helper functions to simplify the reading
and comparing the keys.

Signed-off-by: Saravana Kannan 
Signed-off-by: Georgi Djakov 
Reviewed-by: Matthias Kaehlcke 
Reviewed-by: Sibi Sankar 
[ Viresh: Removed an unnecessary comment ]
Signed-off-by: Viresh Kumar

opp: Manage empty OPP tables with clk handle

2020-04-13T10:44:55+00:00

With OPP core now supporting DVFS for IO devices, we have instances of
IO devices (same IP block) which require an OPP on some platforms/SoCs
while just needing to scale the clock on some others.

In order to avoid conditional code in every driver which supports such
devices (to check for availability of OPPs and then deciding to do
either dev_pm_opp_set_rate() or clk_set_rate()) add support to manage
empty OPP tables with a clk handle.

This makes dev_pm_opp_set_rate() equivalent of a clk_set_rate() for
devices with just a clk and no OPPs specified, and makes
dev_pm_opp_set_rate(0) bail out without throwing an error.

Signed-off-by: Rajendra Nayak 
Signed-off-by: Viresh Kumar

opp: Replace list_kref with a local counter

2019-12-10T10:27:00+00:00

A kref or refcount isn't the right tool to be used here for counting
number of devices that are sharing the static OPPs created for the OPP
table. For example, we are reinitializing the kref again, after it
reaches a value of 0 and frees the resources, if the static OPPs get
added for the same OPP table structure (as the OPP table structure was
never freed). That is messy and very unclear.

This patch makes parsed_static_opps an unsigned integer and uses it to
count the number of users of the static OPPs. The increment and
decrement to parsed_static_opps is done under opp_table->lock now to
make sure no races are possible if the OPP table is getting added and
removed in parallel (which doesn't happen in practice, but can in
theory).

Signed-off-by: Viresh Kumar

PM / OPP: Support adjusting OPP voltages at runtime

2019-11-11T04:57:15+00:00

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 derived from [1] submitted by Stephen.
[1] https://lore.kernel.org/patchwork/patch/599279/

Signed-off-by: Stephen Boyd 
[Roger Lu: Changed to rcu less implementation]
Signed-off-by: Roger Lu 
[s.nawrocki@samsung.com: added handling of OPP min/max voltage]
Signed-off-by: Sylwester Nawrocki 
Signed-off-by: Viresh Kumar

opp: core: Revert "add regulators enable and disable"

2019-10-21T02:28:12+00:00

All the drivers, which use the OPP framework control regulators, which
are already enabled. Typically those regulators are also system critical,
due to providing power to CPU core or system buses. It turned out that
there are cases, where calling regulator_enable() on such boot-enabled
regulator has side-effects and might change its initial voltage due to
performing initial voltage balancing without all restrictions from the
consumers. Until this issue becomes finally solved in regulator core,
avoid calling regulator_enable()/disable() from the OPP framework.

This reverts commit 7f93ff73f7c8c8bfa6be33bcc16470b0b44682aa.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Mark Brown 
Signed-off-by: Viresh Kumar