linux-toradex.git/include/linux/pm_opp.h, branch v5.0-rc3

cpufreq: scpi/scmi: Fix freeing of dynamic OPPs

2019-01-04T11:19:40+00:00

Since the commit 2a4eb7358aba "OPP: Don't remove dynamic OPPs from
_dev_pm_opp_remove_table()", dynamically created OPP aren't
automatically removed anymore by dev_pm_opp_cpumask_remove_table(). This
affects the scpi and scmi cpufreq drivers which no longer free OPPs on
failures or on invocations of the policy->exit() callback.

Create a generic OPP helper dev_pm_opp_remove_all_dynamic() which can be
called from these drivers instead of dev_pm_opp_cpumask_remove_table().

In dev_pm_opp_remove_all_dynamic(), we need to make sure that the
opp_list isn't getting accessed simultaneously from other parts of the
OPP core while the helper is freeing dynamic OPPs, i.e. we can't drop
the opp_table->lock while traversing through the OPP list. And to
accomplish that, this patch also creates _opp_kref_release_unlocked()
which can be called from this new helper with the opp_table lock already
held.

Cc: 4.20  # v4.20
Reported-by: Valentin Schneider 
Fixes: 2a4eb7358aba "OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()"
Signed-off-by: Viresh Kumar 
Tested-by: Valentin Schneider 
Reviewed-by: Sudeep Holla 
Signed-off-by: Rafael J. Wysocki

OPP: Don't return 0 on error from of_get_required_opp_performance_state()

2018-12-14T10:58:12+00:00

of_get_required_opp_performance_state() returns 0 on errors currently
and a positive performance state otherwise. Since 0 is a valid
performance state (representing off), it would be better if this routine
returns negative values on error.

That will also make it behave similar to
dev_pm_opp_xlate_performance_state(), which also returns performance
states and returns negative values on error. Change the return type of
the function to "int" in order to return negative values.

This doesn't have any users for now and so no other part of the kernel
will be impacted with this change.

Reviewed-by: Ulf Hansson 
Signed-off-by: Viresh Kumar

OPP: Add dev_pm_opp_xlate_performance_state() helper

2018-12-14T10:58:09+00:00

dev_pm_genpd_set_performance_state() needs to handle performance state
propagation going forward. Currently this routine only gets the required
performance state of the device's genpd as an argument, but it doesn't
know how to translate that to master genpd(s) of the device's genpd.

Introduce a new helper dev_pm_opp_xlate_performance_state() which will
be used to translate from performance state of a device (or genpd
sub-domain) to another device (or master genpd).

Normally the src_table (of genpd sub-domain) will have the
"required_opps" property set to point to one of the OPPs in the
dst_table (of master genpd), but in some cases the genpd and its master
have one to one mapping of performance states and so none of them have
the "required-opps" property set. Return the performance state of the
src_table as it is in such cases.

Tested-by: Rajendra Nayak 
Reviewed-by: Ulf Hansson 
Signed-off-by: Viresh Kumar

OPP: Remove of_dev_pm_opp_find_required_opp()

2018-11-05T02:10:43+00:00

This isn't used anymore, remove it.

Reviewed-by: Ulf Hansson 
Signed-off-by: Viresh Kumar

OPP: Rename and relocate of_genpd_opp_to_performance_state()

2018-11-05T02:10:43+00:00

The OPP core already has the performance state values for each of the
genpd's OPPs and there is no need to call the genpd callback again to
get the performance state for the case where the end device doesn't have
an OPP table and has the "required-opps" property directly in its node.

This commit renames of_genpd_opp_to_performance_state() as
of_get_required_opp_performance_state() and moves it to the OPP core, as
it is all about OPP stuff now.

Reviewed-by: Ulf Hansson 
Signed-off-by: Viresh Kumar

OPP: Add dev_pm_opp_{set|put}_genpd_virt_dev() helper

2018-11-05T02:10:43+00:00

Multiple generic power domains for a consumer device are supported with
the help of virtual devices, which are created for each consumer device
- genpd pair. These are the device structures which are attached to the
power domain and are required by the OPP core to set the performance
state of the genpd.

The helpers added by this commit are required to be called once for each
of these virtual devices. These are required only if multiple domains
are available for a device, otherwise the actual device structure will
be used instead by the OPP core.

The new helpers also support the complex cases where the consumer device
wouldn't always require all the domains. For example, a camera may
require only one power domain during normal operations but two during
high resolution operations. The consumer driver can call
dev_pm_opp_put_genpd_virt_dev(high_resolution_genpd_virt_dev) if it is
currently operating in the normal mode and doesn't have any performance
requirements from the genpd which manages high resolution power
requirements. The consumer driver can later call
dev_pm_opp_set_genpd_virt_dev(high_resolution_genpd_virt_dev) once it
switches back to the high resolution mode.

The new helpers differ from other OPP set/put helpers as the new ones
can be called with OPPs initialized for the table as we may need to call
them on the fly because of the complex case explained above. For this
reason it is possible that the genpd virt_dev structure may be used in
parallel while the new helpers are running and a new mutex is added to
protect against that. We didn't use the existing opp_table->lock mutex
as that is widely used in the OPP core and we will need this lock in the
dev_pm_opp_set_rate() helper while changing OPP and we need to make sure
there is not much contention while doing that as that's the hotpath.

Reviewed-by: Ulf Hansson 
Signed-off-by: Viresh Kumar

OPP: Pass index to _of_init_opp_table()

2018-09-19T21:56:41+00:00

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: Niklas Cassel 
Signed-off-by: Viresh Kumar

PM / OPP: Remove dev_pm_opp_{un}register_get_pstate_helper()

2018-05-09T04:45:21+00:00

These helpers aren't used anymore, remove them.

Signed-off-by: Viresh Kumar 
Reviewed-by: Ulf Hansson

PM / OPP: Implement dev_pm_opp_get_of_node()

2018-05-09T04:45:19+00:00

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: Jordan Crouse 
Signed-off-by: Rajendra Nayak 
Signed-off-by: Viresh Kumar 
Reviewed-by: Ulf Hansson

PM / OPP: Implement of_dev_pm_opp_find_required_opp()

2018-05-09T04:45:19+00:00

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: Viresh Kumar 
Reviewed-by: Ulf Hansson