gcc warns quite a bit about values returned from allocate_resources()
in cpufreq-dt.c:

cpufreq-dt.c: In function 'cpufreq_init':
cpufreq-dt.c:327:6: error: 'cpu_dev' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:197:17: note: 'cpu_dev' was declared here
cpufreq-dt.c:376:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:199:14: note: 'cpu_clk' was declared here
cpufreq-dt.c: In function 'dt_cpufreq_probe':
cpufreq-dt.c:461:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:447:14: note: 'cpu_clk' was declared here

The problem is that it's slightly hard for gcc to follow return
codes across PTR_ERR() calls.

This patch uses explicit assignments to the "ret" variable to make
it easier for gcc to verify that the code is actually correct,
without the need to add a bogus initialization.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The function can return negative values so it should be assigned
to signed type.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci.

Link: http://permalink.gmane.org/gmane.linux.kernel/2038576Signed-off-by: NAndrzej Hajda <a.hajda@samsung.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Support registering cooling devices with dynamic power coefficient
where provided by the device tree. This allows OF registered cooling
devices driver to be used with the power_allocator thermal governor.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NJavi Merino <javi.merino@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

That's the naming convention followed in most of opp core, but few
routines didn't follow this, fix them.
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NShawn Guo <shawnguo@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

free-table routines are opposite of init-table ones, and must be named
to make that clear. Opposite of 'init' is 'exit', but those doesn't suit
really well.

Replace 'init' with 'add' and 'free' with 'remove'.
Reported-by: NPavel Machek <pavel@ucw.cz>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NShawn Guo <shawnguo@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add suspend frequency support and if needed set it to
the frequency obtained from the suspend opp (can be defined
using opp-v2 bindings and is optional).
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Tolerance applies on both sides of the target voltage, i.e. both min and
max sides. But while checking if a voltage is supported by the regulator
or not, we haven't taken care of tolerance on the lower side. Fix that.

Cc: Lucas Stach <l.stach@pengutronix.de>
Fixes: 045ee45c ("cpufreq: cpufreq-dt: disable unsupported OPPs")
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We need to explicitly mark OPPs as shared, when they are not defined
with OPP-v2 bindings. This operation can potentially fail, and in that
case we should at least print an error message.

Fixes: 2e02d872 ("cpufreq: dt: Add support for operating-points-v2 bindings")
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We need to explicitly mark OPPs as shared, when they are not defined
with OPP-v2 bindings. But this isn't required to be done if we failed to
initialize OPP table.

Reorder code to verify OPP count before marking them shared.

Fixes: 2e02d872 ("cpufreq: dt: Add support for operating-points-v2 bindings")
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make scaling_boost_freqs sysfs attribute is available when
cpufreq-dt driver is used and boost support is enabled.
Suggested-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With opp-v2 DT bindings, few OPPs can be used only for the boost mode.
But using such OPPs require the boost mode to be supported by cpufreq
driver.

We will parse DT bindings only during ->init() and so can enable boost
support only after registering cpufreq driver.

This enables boost support as soon as any policy has boost/turbo OPPs
for its CPUs.

We don't need to disable boost support as that is done by the core, when
the driver is unregistered.
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>

Support for parsing operating-points-v2 bindings is in place now, lets
modify cpufreq-dt driver to use them.

For backward compatibility we will continue to support earlier bindings.
Special handling for that is required, to make sure OPPs are initialized
for all the CPUs.
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
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>

by adding the missing MODULE_ALIAS(), cpufreq-dt
can be autoloaded by udev/systemd.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Acked-by: NNishanth Menon <nm@ti.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The cpufreq_cooling_unregister() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
[ rjw: Subject ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq-dt driver supports mode when OPP table is provided by platform
code and not device tree. However on certain platforms code that fills
OPP table may run after cpufreq driver tries to initialize, so let's
report -EPROBE_DEFER if we do not find any entires in OPP table for the
CPU.
Signed-off-by: NDmitry Torokhov <dtor@chromium.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP layer now supports freeing of OPPs and we should free them once they aren't
useful anymore.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently we are calling of_cpufreq_cooling_register() from ->init() callback.
At this point of time cpufreq driver's policy isn't completely ready to be used
as few of its fields/structure/pointers aren't yet initialized.

Because of_cpufreq_cooling_register() tries to access policy with help of
cpufreq_cpu_get() and then tries to get freq-table as well, these calls fail.

To fix this, register the cooling device after the policy is ready to be used.
And the right callback for it is the newly added ->ready() one.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NEduardo Valentin <edubezval@gmail.com>
Tested-by: NEduardo Valentin <edubezval@gmail.com>
Reviewed-by: NLukasz Majewski <l.majewski@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The second parameter of of_cpufreq_cooling_register() should be the CPUs to
which the frequency constraint will apply. As the cpufreq-dt driver now supports
platforms with multiple 'struct cpufreq_policy' instances (i.e. > 1 clock
domains for CPUs), passing 'cpu_present_mask' isn't correct anymore. As every
policy will have a set of CPUs and that may not be equal to 'cpu_present_mask'
always.

So, pass only mask of CPUs which are controlled by current policy.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NEduardo Valentin <edubezval@gmail.com>
Tested-by: NEduardo Valentin <edubezval@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently the error message is needlessly splitted across two lines.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

In error cases regulator_get_voltage() returns a negative value.
So take care of it.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

During test of new DT OPPs it's very helpful to print the matching
OPP in case of frequency change. So it will be easier to find frequency
rounding issues in the dts file.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix the swapped arguments in the clock failure dev_err.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 34e5a527 ("cpufreq: cpufreq-dt: extend with
platform_data") changed cpufreq_init() to only call
cpumask_setall(policy->cpus) if the platform data indicates that all
CPUs share the same clock. Before, cpufreq_generic_init() did this
unconditionally.

This causes a crash on r8a7791/koelsch when resuming from s2ram:

    Enabling non-boot CPUs ...
    CPU1: Booted secondary processor
    Unable to handle kernel NULL pointer dereference at virtual address 0000003c
    pgd = ee71f980
    [0000003c] *pgd=6eeb6003, *pmd=6e0e9003, *pte=00000000
    Internal error: Oops: a07 [#1] SMP ARM
    Modules linked in:
    CPU: 0 PID: 1397 Comm: s2ram Tainted: G        W      3.18.0-rc2-koelsch-00762-g7eed2a4e61d2d978 #581
    task: ee6b76c0 ti: ee7f0000 task.ti: ee7f0000
    PC is at __cpufreq_add_dev.isra.24+0x24c/0x77c
    LR is at __cpufreq_add_dev.isra.24+0x244/0x77c
    pc : [<c029e084>]    lr : [<c029e07c>]    psr: 60000153
    sp : ee7f1d48  ip : ee7f1d48  fp : ee7f1d84
    r10: c04e8448  r9 : 00000000  r8 : 00000001
    r7 : c054a8c4  r6 : 00000001  r5 : 00000001  r4 : 00000000
    r3 : 00000000  r2 : 00000000  r1 : 20000153  r0 : c054a950
    Flags: nZCv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment user
    Control: 30c5307d  Table: 6e71f980  DAC: fffffffd
    Process s2ram (pid: 1397, stack limit = 0xee7f0240)

    ...

    Backtrace:
    [<c029de38>] (__cpufreq_add_dev.isra.24) from [<c029e620>] (cpufreq_cpu_callback+0x6c/0x74)
     r10:eec75240 r9:c04e8448 r8:c04ef3a0 r7:00000001 r6:00000012 r5:00000000
     r4:00000012
    [<c029e5b4>] (cpufreq_cpu_callback) from [<c003f20c>] (notifier_call_chain+0x48/0x70)
     r4:ffffffdd r3:c029e5b4
    [<c003f1c4>] (notifier_call_chain) from [<c003f2cc>] (__raw_notifier_call_chain+0x1c/0x24)
     r8:00000001 r7:00000010 r6:00000000 r5:00000000 r4:00000012 r3:ffffffff
    [<c003f2b0>] (__raw_notifier_call_chain) from [<c0026a00>] (__cpu_notify+0x34/0x50)
    [<c00269cc>] (__cpu_notify) from [<c0026a34>] (cpu_notify+0x18/0x1c)
     r4:00000001
    [<c0026a1c>] (cpu_notify) from [<c0026c44>] (_cpu_up+0x108/0x144)
    [<c0026b3c>] (_cpu_up) from [<c0381c68>] (enable_nonboot_cpus+0x68/0xb8)
     r10:00000000 r9:c04e8ee6 r8:00000000 r7:00000003 r6:c04e8528 r5:c0506248
     r4:00000001
    [<c0381c00>] (enable_nonboot_cpus) from [<c0059038>] (suspend_devices_and_enter+0x29c/0x3e8)
     r6:c0506e70 r5:00000000 r4:00000000 r3:60000153

Restore the old default of calling cpumask_setall(policy->cpus) if no
platform data is available to fix this.

Fixes: 34e5a527 (cpufreq: cpufreq-dt: extend with platform_data)
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If the regulator connected to the CPU voltage plane doesn't
support an OPP specified voltage with the acceptable tolerance
it's better to just disable the OPP instead of constantly
failing the voltage scaling later on.

Includes a fix to move initialization of opp_freq outside
the loop to avoid an endless loop from Geert Uytterhoeven.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The cpufreq-dt driver tries to get a regulator for each CPU. This
regulator is optional, but when not present, a scary message "failed
to get cpuX regulator" is displayed. To solve this, we reduce the
severity of the message from dev_warn() to dev_dbg() and we reword the
message to not be as scary.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This commit extends the cpufreq-dt driver to take a platform_data
structure. This structure is for now used to tell the cpufreq-dt
driver the layout of the clocks on the platform, i.e whether all CPUs
share the same clock or whether each CPU has a separate clock.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If cpufreq_generic_init() fails we jump into the resource
cleanup path which contains a of_node_put() call. Another
instance of this has already been called at that time
resulting a double decrement of the refcount.

Fix this by calling of_node_put() only after we are sure
that nothing has gone wrong.

Fixes: d2f31f1d "cpufreq: cpu0: Move per-cluster initialization code to ->init()"
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The naming convention of this driver was always under the scanner, people
complained that it should have a more generic name than cpu0, as it manages all
CPUs that are sharing clock lines.

Also, in future it will be modified to support any number of clusters with
separate clock/voltage lines.

Lets rename it to 'cpufreq_dt' from 'cpufreq_cpu0'.
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently allocate_resources() supports only CPU0 and it would need to allocate
resources for any CPU going forward.

Add another argument to it, i.e. cpu, and update code accordingly.
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, we expect regulator name to be "cpu0", but as we are going to support
multiple cpu-blocks (all CPUs in a block share clock/voltage) later, we need to
pass some generic string instead of that.

For backwards compatibility try for "cpu0" first and if it fails, then try for
"cpu".
Suggested-by: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently this driver only support platforms on which all CPUs share clock &
voltage lines and there is requirement to support platforms which have separate
clock & voltage lines for CPUs, like Qualcomm's Krait and ARM's big LITTLE.

Each group of CPUs sharing clock/voltage lines are represented by 'struct
cpufreq_policy' in cpufreq framework. And core calls ->init() once for each
policy.

Currently we do all initialization/allocation from probe() which wouldn't work
for above scenario. To make it work for these platforms, the first step is to
move all initialization/allocation to ->init() and add ->exit() to do the
reverse of it.

Also, remove all global variables and allocate space for them at runtime.

This patch creates 'struct private_data' for keeping all such information and
a pointer to that would be stored in policy->driver_data.

The changed probe() routine now tries to see if regulator/clocks are available
or we need to defer probe. In case they are available, it registers cpufreq
driver. Otherwise, returns with -EPROBE_DEFER.

We still *don't* support platforms with separate clock/voltage lines for CPUs.
This would be done in a separate patch later.
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We already have cpu_dev and is used at multiple places for printing errors using
dev_*(). But some prints are still using pr_*(). Lets make it consistent and
replace those pr_*() macros with dev_*() macros.
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, we defer probe if regulator_get() returned -EPROBE_DEFER, i.e.
regulator isn't registered yet. We do a dev_err() in this case. Sending a
message to the log on probe defer just duplicates what the driver core is
already doing. Convert it to dev_dbg() instead.

We should defer in case of clk_get() as well.

Current code already does it, but it wasn't intentional probably. Its just that
we are returning the right error with wrong print message.

Fix print message to convey right error.
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

CPU clk is not optional for this driver and probe would fail if it couldn't find
a suitable clock.

And so, while calling clk_put() we don't need to validate clocks.
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Two people are maintaining it now, Viresh and Shawn. Add Viresh's details in
MODULE_AUTHOR() and copyright section.
Suggested-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

-EPROBE_DEFER is no real error. We are just waiting unti the necessary
components are ready. The driver core infrastructure will also print an
appropriate info message.

This patch changes the error message to a debug message.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPPs can be populated statically, via DT, or added at run time with
dev_pm_opp_add().

While this driver handles the first case correctly, it would fail to populate
OPPs added at runtime. Because call to of_init_opp_table() would fail as there
are no OPPs in DT and probe will return early.

To fix this, remove error checking and call dev_pm_opp_init_cpufreq_table()
unconditionally.

Update bindings as well.
Suggested-by: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Sometimes boot loaders set CPU frequency to a value outside of frequency table
present with cpufreq core. In such cases CPU might be unstable if it has to run
on that frequency for long duration of time and so its better to set it to a
frequency which is specified in frequency table.

Sachin recently found this problem with cpufreq-cpu0 driver when he was testing
it for Exynos.

Set this flag for cpufreq-cpu0 driver.
Reported-and-tested-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This driver is using devres managed calls incorrectly, giving the cpu0
device as first parameter instead of the cpufreq platform device.
This results in resources not being freed if the cpufreq platform device
is unbound, for example if probing has to be deferred for a missing
regulator.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: 3.9+ <stable@vger.kernel.org> # 3.9+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>