linux.git/drivers/base/power/opp/core.c, branch v4.10

PM / OPP: Don't WARN on multiple calls to dev_pm_opp_set_regulators()

2016-12-06T01:28:00+00:00

If a platform specific OPP driver has called this routine first and set
the regulators, then the second call from cpufreq-dt driver will hit the
WARN_ON(). Remove the WARN_ON(), but continue to return error in such
cases.

Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Tested-by: Dave Gerlach 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Allow platform specific custom set_opp() callbacks

2016-12-06T01:27:59+00:00

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: Viresh Kumar 
Tested-by: Dave Gerlach 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Separate out _generic_set_opp()

2016-12-06T01:27:59+00:00

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: Viresh Kumar 
Tested-by: Dave Gerlach 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Add infrastructure to manage multiple regulators

2016-12-06T01:27:59+00:00

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: Viresh Kumar 
Tested-by: Dave Gerlach 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Pass struct dev_pm_opp_supply to _set_opp_voltage()

2016-12-06T01:27:59+00:00

Pass the entire supply structure instead of all of its fields.

Signed-off-by: Viresh Kumar 
Tested-by: Dave Gerlach 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Manage supply's voltage/current in a separate structure

2016-12-06T01:27:59+00:00

This is a preparatory step for multiple regulator per device support.
Move the voltage/current variables to a new structure.

Signed-off-by: Viresh Kumar 
Tested-by: Dave Gerlach 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Don't use OPP structure outside of rcu protected section

2016-12-06T01:27:58+00:00

The OPP structure must not be used out of the rcu protected section.
Cache the values to be used in separate variables instead.

Cc: 4.6+  # 4.6+
Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Tested-by: Dave Gerlach 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Pass opp_table to dev_pm_opp_put_regulator()

2016-11-30T21:41:28+00:00

Joonyoung Shim reported an interesting problem on his ARM octa-core
Odoroid-XU3 platform. During system suspend, dev_pm_opp_put_regulator()
was failing for a struct device for which dev_pm_opp_set_regulator() is
called earlier.

This happened because an earlier call to
dev_pm_opp_of_cpumask_remove_table() function (from cpufreq-dt.c file)
removed all the entries from opp_table->dev_list apart from the last CPU
device in the cpumask of CPUs sharing the OPP.

But both dev_pm_opp_set_regulator() and dev_pm_opp_put_regulator()
routines get CPU device for the first CPU in the cpumask. And so the OPP
core failed to find the OPP table for the struct device.

This patch attempts to fix this problem by returning a pointer to the
opp_table from dev_pm_opp_set_regulator() and using that as the
parameter to dev_pm_opp_put_regulator(). This ensures that the
dev_pm_opp_put_regulator() doesn't fail to find the opp table.

Note that similar design problem also exists with other
dev_pm_opp_put_*() APIs, but those aren't used currently by anyone and
so we don't need to update them for now.

Cc: 4.4+  # 4.4+
Reported-by: Joonyoung Shim 
Signed-off-by: Stephen Boyd 
Signed-off-by: Viresh Kumar 
[ Viresh: Wrote commit log and tested on exynos 5250 ]
Signed-off-by: Rafael J. Wysocki

PM / OPP: avoid maybe-uninitialized warning

2016-09-16T22:58:00+00:00

When CONFIG_OPTIMIZE_INLINING is set and we are building with -Wmaybe-uninitialized
enabled, we can get a warning for the opp core driver:

drivers/base/power/opp/core.c: In function 'dev_pm_opp_set_rate':
drivers/base/power/opp/core.c:560:8: warning: 'ou_volt_min' may be used uninitialized in this function [-Wmaybe-uninitialized]

This has only now appeared as a result of commit 797da5598f3a ("PM / devfreq:
Add COMPILE_TEST for build coverage"), which makes the driver visible in
some configurations that didn't have it before.

The warning is a false positive that I got with gcc-6.1.1, but there is
a simple workaround in removing the local variables that we get warnings
for (all three are affected depending on the configuration). This also
makes the code easier to read.

Signed-off-by: Arnd Bergmann 
Reviewed-by: Stephen Boyd 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

PM / OPP: optimize dev_pm_opp_set_rate() performance a bit

2016-07-28T21:54:16+00:00

In dev_pm_opp_set_rate(), _find_opp_table() is called 4 times: once by
_get_opp_clk(), once by dev_pm_opp_set_rate() itself, and twice by
dev_pm_opp_find_freq_ceil(). If there are several opp_tables in the
system, three times of opp table finding is a big waste. This patch
reduced the call of _find_opp_table() to twice.

Signed-off-by: Jisheng Zhang 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki