An earlier commit populated the OPP tables from the "required-opps"
property, this commit populates the individual OPPs. This is repeated
for each OPP in the OPP table and these populated OPPs will be used by
later commits.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The current implementation works only for the case where a single
phandle is present in the "required-opps" property, while DT allows
multiple phandles to be present there.

This patch adds new infrastructure to parse all the phandles present in
"required-opps" property and save pointers of the required OPP's OPP
tables. These will be used by later commits.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

We need to handle genpd OPP tables differently, this is already the case
at one location and will be extended going forward. Add another field to
the OPP table to check if the table belongs to a genpd or not.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

When two or more devices are sharing their clock and voltage rails, they
share the same OPP table. But there are some corner cases where the OPP
core incorrectly creates separate OPP tables for them.

For example, CPU 0 and 1 share clock/voltage rails. The platform
specific code calls dev_pm_opp_set_regulators() for CPU0 and the OPP
core creates an OPP table for it (the individual OPPs aren't initialized
as of now). The same is repeated for CPU1 then. Because
_opp_get_opp_table() doesn't compare DT node pointers currently, it
fails to find the link between CPU0 and CPU1 and so creates a new OPP
table.

Fix this by calling _managed_opp() from _opp_get_opp_table().
_managed_opp() gain an additional argument (index) to get the right node
pointer. This resulted in simplifying code in _of_add_opp_table_v2() as
well.
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

Currently there are two separate ways to free the OPP table based on how
it is created in the first place.

We call _dev_pm_opp_remove_table() to free the static and/or dynamic
OPP, OPP list devices, etc. This is done for the case where the OPP
table is added while initializing the OPPs, like via the path
dev_pm_opp_of_add_table().

We also call dev_pm_opp_put_opp_table() in some cases which eventually
frees the OPP table structure once the reference count reaches 0. This
is used by the first case as well as other cases like
dev_pm_opp_set_regulators() where the OPPs aren't necessarily
initialized at this point.

This whole thing is a bit unclear and messy and obstruct any further
cleanup/fixup of OPP core.

This patch tries to streamline this by keeping a single path for OPP
table destruction, i.e. dev_pm_opp_put_opp_table().

All the cleanup happens in _opp_table_kref_release() now after the
reference count reaches 0. _dev_pm_opp_remove_table() is removed as it
isn't required anymore.

We don't drop the reference to the OPP table after creating it from
_of_add_opp_table_v{1|2}() anymore and the same is dropped only when we
try to remove them.
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

Only one platform was depending on this feature and it is already
updated now. Stop removing dynamic OPPs from _dev_pm_opp_remove_table().
This simplifies lot of paths and removes unnecessary parameters.
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The static OPPs don't always get freed with the OPP table, it can happen
before that as well. For example, if the OPP table is first created
using helpers like dev_pm_opp_set_supported_hw() and the OPPs are
created at a later point. Now when the OPPs are removed, the OPP table
stays until the time dev_pm_opp_put_supported_hw() is called.

Later patches will streamline the freeing of OPP table and that requires
the static OPPs to get freed with help of a separate kernel reference.
This patch prepares for that by creating a separate kref for static OPPs
list.
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

Parse the DT properties present in the OPP table from
_of_init_opp_table(), which is a dedicated routine for DT parsing.

Minor relocation of helpers is required for this.

It is possible now for _managed_opp() to return a partially initialized
OPP table if the OPP table is created via the helpers like
dev_pm_opp_set_supported_hw() and we need another flag to indicate if
the static OPP are already parsed or not to make sure we don't
incorrectly skip initializing the static OPPs.
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

This is a preparatory patch required for the next commit which will
start using OPP table's node pointer in _of_init_opp_table(), which
requires the index in order to read the OPP table's phandle.

This commit adds the index argument in the call chains in order to get
it delivered to _of_init_opp_table().
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The dev_list needs to be protected with a lock, else we may have
simultaneous access (addition/removal) to it and that would be racy.
Extend scope of the opp_table lock to protect dev_list as well.
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

dev_pm_opp_of_cpumask_add_table() creates the OPP table for all CPUs
present in the cpumask and on errors it should revert all changes it has
done.

It actually is doing a bit more than that. On errors, it tries to free
all the OPP tables, even the one it hasn't created yet. This may also
end up freeing the OPP tables which were created from separate path,
like dev_pm_opp_set_supported_hw().
Reported-and-tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

These helpers aren't used anymore, remove them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

A device's DT node or its OPP nodes can contain a phandle to other
device's OPP node, in the "required-opps" property.

This patch implements a routine to find that required OPP from the node
that contains the "required-opps" property.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

"opp-hz" property is optional for power domains now and we shouldn't
error out if it is missing for power domains.

This patch creates two new routines, _get_opp_count() and
_opp_is_duplicate(), by separating existing code from their parent
functions. Also skip duplicate OPP check for power domain OPPs as they
may not have any the "opp-hz" field, but a platform specific performance
state binding to uniquely identify OPP nodes.

By default the debugfs OPP nodes are named using the "rate" value, but
that isn't possible for the power domain OPP nodes and hence they use
the index of the OPP node in the OPP node list instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

This adds the dev_pm_opp_{un}register_get_pstate_helper() helper
routines which will be used to set the get_pstate() callback for a
device. This callback will be later called internally by the OPP core to
get performance state corresponding to an OPP.

This is required temporarily until the time we have proper DT bindings
to include the performance state information.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The genpd framework now provides an API to request device's power
domain to update its performance state.  Use that interface from the
OPP core for devices whose power domains support performance states.

Note that this commit doesn't add any mechanism by which performance
states are made available to the OPP core. That would be done by a
later commit.

Note that the current implementation is restricted to the case where
the device doesn't have separate regulators for itself. We shouldn't
over engineer the code before we have real use case for them. We can
always come back and add more code to support such cases later on.
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The drivers/base/power/ directory is special and contains code related
to power management core like system suspend/resume, hibernation, etc.
It was fine to keep the OPP code inside it when we had just one file for
it, but it is growing now and already has a directory for itself.

Lets move it directly under drivers/ directory, just like cpufreq and
cpuidle.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The RCU locking isn't well suited for the OPP core. The RCU locking fits
better for reader heavy stuff, while the OPP core have at max one or two
readers only at a time.

Over that, it was getting very confusing the way RCU locking was used
with the OPP core. The individual OPPs are mostly well handled, i.e. for
an update a new structure was created and then that replaced the older
one. But the OPP tables were updated directly all the time from various
parts of the core. Though they were mostly used from within RCU locked
region, they didn't had much to do with RCU and were governed by the
mutex instead.

And that mixed with the 'opp_table_lock' has made the core even more
confusing.

Now that we are already managing the OPPs and the OPP tables with kernel
reference infrastructure, we can get rid of RCU locking completely and
simplify the code a lot.

Remove all RCU references from code and comments.

Acquire opp_table->lock while parsing the list of OPPs though.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add kref to struct dev_pm_opp for easier accounting of the OPPs.

Note that the OPPs are freed under the opp_table->lock mutex only.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Migrate all users of _add_opp_table() to use dev_pm_opp_get_opp_table()
to guarantee that the OPP table doesn't get freed while being used.

Also update _managed_opp() to get the reference to the OPP table.

Now that the OPP table wouldn't get freed while these routines are
executing after dev_pm_opp_get_opp_table() is called, there is no need
to take opp_table_lock. Drop them as well.

Now that _add_opp_table(), _remove_opp_table() and the unlocked release
routines aren't used anymore, remove them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add kref to struct opp_table for easier accounting of the OPP table.

Note that the new routine dev_pm_opp_get_opp_table() takes the reference
from under the opp_table_lock, which guarantees that the OPP table
doesn't get freed unless dev_pm_opp_put_opp_table() is called for the
OPP table.

Two separate release mechanisms are added: locked and unlocked. In
unlocked version the routines aren't required to take/drop
opp_table_lock as the callers have already done that. This is required
to avoid breaking git bisect, otherwise we may get lockdeps between
commits. Once all the users of OPP table are updated the unlocked
version shall be removed.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add per OPP table lock to protect opp_table->opp_list.

Note that at few places opp_list is used under the rcu_read_lock() and
so a mutex can't be added there for now. This will be fixed by a later
patch.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no point in trying to find/allocate the table for every OPP
that is added for a device. It would be far more efficient to allocate
the table only once and pass its pointer to the routines that add the
OPP entry.

Locking is removed from _opp_add_static_v2() and _opp_add_v1() now as
the callers call them with that lock already held.

Call to _remove_opp_table() routine is also removed from _opp_free()
now, as opp_table isn't allocated from within _opp_allocate(). This is
handled by the routines which created the OPP table in the first place.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Later patches would want to remove OPP table (and its OPPs) using the
opp_table pointer instead of 'dev'.

In order to prepare for that, rename _dev_pm_opp_remove_table() as
_dev_pm_opp_find_and_remove_table() split out part of it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The OPPs which are never successfully added using _opp_add() are not
required to be freed with the _opp_remove() routine, as a simple kfree()
is enough for them.

Introduce a new light weight routine _opp_free(), which will do that.

That also helps us removing the 'notify' parameter to _opp_remove(),
which isn't required anymore.

Note that _opp_free() contains a call to _remove_opp_table() as the OPP
table might have been added for this very OPP only. The
_remove_opp_table() routine returns quickly if there are more OPPs in
the table. This will be simplified in later patches though.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the naming consistent with how other routines are named.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The generic set_opp() handler isn't sufficient for platforms with
complex DVFS.  For example, some TI platforms have multiple regulators
for a CPU device. The order in which various supplies need to be
programmed is only known to the platform code and its best to leave it
to it.

This patch implements APIs to register platform specific set_opp()
callback.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NDave Gerlach <d-gerlach@ti.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Later patches would add support for custom set_opp() callbacks. This
patch separates out the code for _generic_set_opp() handler in order to
prepare for that.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NDave Gerlach <d-gerlach@ti.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch adds infrastructure to manage multiple regulators and updates
the only user (cpufreq-dt) of dev_pm_opp_set{put}_regulator().

This is preparatory work for adding full support for devices with
multiple regulators.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NDave Gerlach <d-gerlach@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This is a preparatory step for multiple regulator per device support.
Move the voltage/current variables to a new structure.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NDave Gerlach <d-gerlach@ti.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since commit f47b72a1 ("PM / OPP: Move CONFIG_OF dependent code
in a separate file"), this function is defined and called only in
drivers/base/power/opp/of.c .
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

dev_pm_opp_get_sharing_cpus() returns 0 even in the case when the OPP
core doesn't know whether or not the table is shared. It works on the
majority of platforms, where the OPP table is never created before
invoking the function and then -ENODEV is returned by it.

But in the case of one platform (Jetson TK1) at least, the situation
is a bit different. The OPP table has been created (somehow) before
dev_pm_opp_get_sharing_cpus() is called and it returns 0. Its caller
treats that as 'the CPUs don't share OPPs' and that leads to degraded
performance.

Fix this by converting 'shared_opp' in struct opp_table to an enum
and making dev_pm_opp_get_sharing_cpus() return -EINVAL in case when
the value of that field is "access unknown", so that the caller can
handle it accordingly (cpufreq-dt considers that as 'all CPUs share
the table', for example).

Fixes: 6f707daa "PM / OPP: Add dev_pm_opp_get_sharing_cpus()"
Reported-and-tested-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
[ rjw : Subject & changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Recently, a few issues were noticed in the code where CONFIG_OF wasn't
consistently used for many routines. The core file is big enough now and
ifdef hackery makes it less readable.

Move OF-specific code to another file and compile that only if CONFIG_OF
is enabled.

Compile-tested:
- For ARM (exynos) with CONFIG_OF enabled
- For X86 with CONFIG_OF disabled (have to enable CONFIG_PM_OPP separately)

No functional changes.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Stephen pointed out recently, that few structures always confuse him as
they aren't named properly. And this patch tries to address that:

Names are updated as:
- device_opp or dev_opp -> opp_table
- dev_opp_list -> opp_tables
- dev_opp_list_lock -> opp_table_lock
- device_list_opp -> opp_device (it was never a list, but a structure)
- list_dev -> opp_dev
- And similar changes in comments and function names as well.

This also fixes checkpatch warnings that were generated with this patch.

No functional changes.
Suggested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP core has got almost everything now to manage device's OPP
transitions, the only thing left is device's clk. Get that as well.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

V2 bindings have better support for clock-latency and voltage-tolerance
and doesn't need special care. To use callbacks, like
dev_pm_opp_get_max_{transition|volt}_latency(), irrespective of the
bindings, the core needs to know clock-latency/voltage-tolerance for the
earlier bindings.

This patch reads clock-latency/voltage-tolerance from the device node,
irrespective of the bindings (to keep it simple) and use them only for
V1 bindings.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This allows the OPP core to request/free the regulator resource,
attached to a device OPP. The regulator device is fetched using the name
provided by the driver, while calling: dev_pm_opp_set_regulator().

This will work for both OPP-v1 and v2 bindings.

This is a preliminary step for moving the OPP switching logic into the
OPP core.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP bindings (for few properties) allow a platform to choose a
value/range among a set of available options. The options are present as
opp-<prop>-<name>, where the platform needs to supply the <name> string.

The OPP properties which allow such an option are: opp-microvolt and
opp-microamp.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_prop_name() APIs.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP bindings allow a platform to enable OPPs based on the version of the
hardware they are used for.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_supported_hw() APIs.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Few doc-style comments were missing, add them. Rearrange another one to
match the sequence within the structure.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>