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>

Currently the _of_add_opp_table_v2 call loops through the OPP nodes in
the operating-points-v2 table in the device tree and calls
_opp_add_static_v2 for each to add them to the table. It counts each
iteration through this loop as an added OPP, however there are cases
where _opp_add_static_v2() returns 0 but no new OPP is added to the
list.

This can happen while adding duplicate OPP or if the OPP isn't supported
by hardware.

Because of this the count variable will contain the number of OPP nodes
in the table in device tree but not necessarily the ones that are
actually added.

As this count value is what is checked to determine if there are any
valid OPPs, if a platform has an operating-points-v2 table with all OPP
nodes containing opp-supported-hw values that are not currently
supported, then _of_add_opp_table_v2 will fail to abort as it should due
to an empty table.

Additionally, since commit 3ba98324 ("PM / OPP: Get
performance state using genpd helper"), the same count variable is
compared against the number of OPPs containing performance states and
requires that either all or none have pstates set, however in the case
of any opp table that has any entries that do not get added by
_opp_add_static_v2 due to incompatible opp-supported-hw fields, these
numbers will not match and _of_add_opp_table_v2 will incorrectly fail.

We need to clearly identify all the three cases (success, failure,
unsupported/duplicate OPPs) and then increment count only on success
case. Change return type of _opp_add_static_v2() to return the pointer
to the newly added OPP instead of an integer. This routine now returns a
valid pointer if the OPP is really added, NULL for unsupported or
duplicate OPPs, and error value cased as a pointer on errors.

Ideally the fixes tag in this commit should point back to the commit
that introduced OPP v2 initially, as that's where we started incorrectly
accounting for duplicate OPPs:

commit 27465902 ("PM / OPP: Add support to parse "operating-points-v2" bindings")

But it wasn't a real problem until recently as the count was only used
to check if any OPPs are added or not. And so this commit points to a
rather recent commit where we added more code that depends on the value
of "count".

Fixes: 3ba98324 ("PM / OPP: Get performance state using genpd helper")
Reported-by: NDave Gerlach <d-gerlach@ti.com>
Reported-by: NNiklas Cassel <niklas.cassel@linaro.org>
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NDave Gerlach <d-gerlach@ti.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The error handling wasn't appropriate in
dev_pm_opp_of_cpumask_add_table(). For example it returns 0 on success
and also for the case where cpumask is empty or cpu_device wasn't found
for any of the CPUs.

It should really return error on such cases, so that the callers can be
aware of the outcome.

Fix it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

Both _of_add_opp_table_v1() and _of_add_opp_table_v2() contain similar
code to get the OPP table and their parent routine also parses the DT to
find the OPP table's node pointer. This can be simplified by getting the
OPP table in advance and then passing it as argument to these routines.
Tested-by: NNiklas Cassel <niklas.cassel@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>

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>

The OPP table was freed, but not the individual OPPs which is done from
_dev_pm_opp_remove_table(). Fix it by calling _dev_pm_opp_remove_table()
as well.

Cc: 4.18 <stable@vger.kernel.org> # v4.18
Fixes: 3ba98324 ("PM / OPP: Get performance state using genpd helper")
Tested-by: NNiklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The OPP binding says:

	Property: operating-points-v2

	...

	This can contain more than one phandle for power domain
	providers that provide multiple power domains. That is, one
	phandle for each power domain. If only one phandle is available,
	then the same OPP table will be used for all power domains
	provided by the power domain provider.

But the OPP core isn't allowing the same OPP table to be used for
multiple domains. Update dev_pm_opp_of_add_table_indexed() to allow
that.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>

Smatch complains that it's possible we print "rate" in the debug output
when it hasn't been initialized.  It should be zero on that path.

Fixes: a1e8c136 ("PM / OPP: "opp-hz" is optional for power domains")
[ Viresh: Added the Fixes tag ]
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The genpd core provides an API now to retrieve the performance state
from DT, use that instead of the ->get_pstate() callback.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

This adds a new helper to let the power domain drivers to access
opp->np, so that they can read platform specific properties from the
node.
Signed-off-by: NJordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: NRajendra Nayak <rnayak@codeaurora.org>
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>

The "operating-points-v2" property can contain a list of phandles now,
specifically for the power domain providers that provide multiple
domains.

Add support to parse that.
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>

Commit 76279291 (PM / OPP: Fix get sharing CPUs when hotplug
is used) moved away from using cpu_dev->of_node because of some
limitations.

However, commit 7467c9d9 (of: return of_get_cpu_node from
of_cpu_device_node_get if CPUs are not registered) added support to
fall back to of_get_cpu_node() if called if CPUs are not registered
yet.

Add the missing of_node_put() for the CPU device nodes. Also go back
to using of_cpu_device_node_get() in dev_pm_opp_of_get_sharing_cpus()
to avoid scanning the device tree again.
Acked-by: NViresh Kumar <vireshk@kernel.org>
Fixes: 76279291 (PM / OPP: Fix get sharing CPUs when hotplug is used)
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The for_each_available_child_of_node() loop in _of_add_opp_table_v2()
doesn't drop the reference to "np" on errors. Fix that.

Fixes: 27465902 (PM / OPP: Add support to parse "operating-points-v2" bindings)
Cc: 4.3+ <stable@vger.kernel.org> # 4.3+
Signed-off-by: NTobias Jordan <Tobias.Jordan@elektrobit.com>
[ VK: Improved commit log. ]
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 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>

We fail dev_pm_opp_of_get_sharing_cpus() when possible CPU device does
not exist. This can happen on platforms where not all possible CPUs
are available at start up ie. hotplugged out.  The CPU device is not
registered in the system so we are not able to check struct device to
set the sharing CPUs bitmask properly.

Example (real use case):
2 physical MIPS cores, 4 VPE, cpu0/2 run Linux and cpu1/3 are not
available for Linux at boot up. cpufreq-dt driver + OPP v2 fail to
register opp_table due to the fact there is no struct device for
cpu1 (remains offline at
bootup).

To solve the bug, stop using device struct to check device_node.
Instead get CPU device_node directly from device tree with
of_get_cpu_node().
Signed-off-by: NWaldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com>
Acked-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>

Some platforms add the OPPs dynamically from platform specific drivers
instead of getting them statically from DT. The cpufreq-dt driver
already ignores the return value of dev_pm_opp_of_cpumask_add_table() to
not error out for such cases, but we still end up printing error message
from that routine. That's not nice.

Convert the print message to use pr_debug() instead.
Reported-by: NMason <slash.tmp@free.fr>
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>

If dev_pm_opp_set_regulators() is called for a device and its regulators
are set in the OPP core, the OPP nodes for the device must contain the
"opp-microvolt" property, otherwise there is something wrong and we
better error out.
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>

Rename _of_get_opp_desc_node to dev_pm_opp_of_get_opp_desc_node and add it
to include/linux/pm_opp.h to allow other drivers, such as platform OPP
and cpufreq drivers, to make use of it.
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NDave Gerlach <d-gerlach@ti.com>
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>

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>

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>

The code adding static OPPs for V2 bindings already does so. Make the V1
bindings specific code behave the same.
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>

This TODO doesn't make sense anymore as we have all the information in a
single OPP table. Remove 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>

There are two types of duplicate OPPs that get different behavior from
the core:
A) An earlier OPP is marked 'available' and has same freq/voltages as
   the new one.
B) An earlier OPP with same frequency, but is marked 'unavailable' OR
   doesn't have same voltages as the new one.

The OPP core returns 0 for the first one, but -EEXIST for the second.

While the OPP core returns 0 for the first case, its callers don't free
the newly allocated OPP structure which isn't used anymore. Fix that by
returning -EBUSY instead of 0, but make the callers return 0 eventually.

As this isn't a critical fix, its not getting marked for stable kernel.
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 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>

These log messages are wrong because _of_get_opp_desc_node() returns
an operating-points-v2 node.

Commit a6eed752 ("PM / OPP: passing NULL to PTR_ERR()") fixed
static checker warnings, and reworded the messages at the same time
(but the latter was not mentioned in the git-log).

Restore the correct messages.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-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>