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.

On some systems we can't really say what frequency we're running at the moment
and so for these we shouldn't check if we are running at a frequency present in
frequency table. And so we really can't force this for all the cpufreq drivers.

Hence we are created another flag here: CPUFREQ_NEED_INITIAL_FREQ_CHECK that
will be marked by platforms which want to go for this check at boot time.

Initially this is done for all ARM platforms but others may follow if required.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With a recent change "d4019f0a cpufreq: move freq change notifications to cpufreq
core" few variables (r & ret) are removed by mistake and hence these warnings:

drivers/cpufreq/omap-cpufreq.c: In function omap_target:
drivers/cpufreq/omap-cpufreq.c:64:2: error: ret undeclared (first use in this function)
drivers/cpufreq/omap-cpufreq.c:64:2: note: each undeclared identifier is reported only once for each function it appears in
drivers/cpufreq/omap-cpufreq.c:94:3: error: r undeclared (first use in this function)
drivers/cpufreq/omap-cpufreq.c:116:1: warning: control reaches end of non-void function [-Wreturn-type]

Lets fix them by declaring those variables again.

Fixes: d4019f0a (cpufreq: move freq change notifications to cpufreq core)
Reported-by: NSebastian Capella <sebastian.capella@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Most of the drivers do following in their ->target_index() routines:

	struct cpufreq_freqs freqs;
	freqs.old = old freq...
	freqs.new = new freq...

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	/* Change rate here */

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

This is replicated over all cpufreq drivers today and there doesn't exists a
good enough reason why this shouldn't be moved to cpufreq core instead.

There are few special cases though, like exynos5440, which doesn't do everything
on the call to ->target_index() routine and call some kind of bottom halves for
doing this work, work/tasklet/etc..

They may continue doing notification from their own code as flag:
CPUFREQ_ASYNC_NOTIFICATION is already set for them.

All drivers are also modified in this patch to avoid breaking 'git bisect', as
double notification would happen otherwise.
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NRussell King <linux@arm.linux.org.uk>
Acked-by: NStephen Warren <swarren@nvidia.com>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, the prototype of cpufreq_drivers target routines is:

int target(struct cpufreq_policy *policy, unsigned int target_freq,
		unsigned int relation);

And most of the drivers call cpufreq_frequency_table_target() to get a valid
index of their frequency table which is closest to the target_freq. And they
don't use target_freq and relation after that.

So, it makes sense to just do this work in cpufreq core before calling
cpufreq_frequency_table_target() and simply pass index instead. But this can be
done only with drivers which expose their frequency table with cpufreq core. For
others we need to stick with the old prototype of target() until those drivers
are converted to expose frequency tables.

This patch implements the new light weight prototype for target_index() routine.
It looks like this:

int target_index(struct cpufreq_policy *policy, unsigned int index);

CPUFreq core will call cpufreq_frequency_table_target() before calling this
routine and pass index to it. Because CPUFreq core now requires to call routines
present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time.

This also marks target() interface as deprecated. So, that new drivers avoid
using it. And Documentation is updated accordingly.

It also converts existing .target() to newly defined light weight
.target_index() routine for many driver.
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NRussell King <linux@arm.linux.org.uk>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@rjwysocki.net>

Since Operating Performance Points (OPP) functions are specific
to device specific power management, be specific and rename opp.h
to pm_opp.h
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since Operating Performance Points (OPP) data structures are specific
to device specific power management, be specific and rename opp_* data
structures in OPP library with dev_pm_opp_* equivalent.

Affected structures are:
 struct opp
 enum opp_event

Minor checkpatch warning resulting of this change was fixed as well.
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since Operating Performance Points (OPP) functions are specific to
device specific power management, be specific and rename opp_*
accessors in OPP library with dev_pm_opp_* equivalent.

Affected functions are:
 opp_get_voltage
 opp_get_freq
 opp_get_opp_count
 opp_find_freq_exact
 opp_find_freq_floor
 opp_find_freq_ceil
 opp_add
 opp_enable
 opp_disable
 opp_get_notifier
 opp_init_cpufreq_table
 opp_free_cpufreq_table
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-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>

Use generic cpufreq_generic_init() routine instead of replicating the same code
here.

This also rearranges the code a bit to make it more sensible. Also removes some
unnecessary checks.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Many common initializations of struct policy are moved to core now and hence
this driver doesn't need to do it. This patch removes such code.

Most recent of those changes is to call ->get() in the core after calling
->init().

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Most of the CPUFreq drivers do similar things in .exit() and .verify() routines
and .attr. So its better if we have generic routines for them which can be used
by cpufreq drivers then.

This patch uses these generic routines in the OMAP driver.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Drivers which have an exit path must call cpufreq_frequency_table_put_attr() if
they have called cpufreq_frequency_table_get_attr() in their init path.

This driver was missing this part and is fixed with this patch.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Lets use cpufreq_table_validate_and_show() instead of calling
cpufreq_frequency_table_cpuinfo() and cpufreq_frequency_table_get_attr().
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the drivers/cpufreq uses of the __cpuinit macros
from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

[v2: leave 2nd lines of args misaligned as requested by Viresh]
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Acked-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

PRECHANGE and POSTCHANGE notifiers must be called in groups, i.e either both
should be called or both shouldn't be.

In case we have started PRECHANGE notifier and found an error, we must call
POSTCHANGE notifier with freqs.new = freqs.old to guarantee that sequence of
calling notifiers is complete.

Omap driver was taking care of it well, but wasn't restoring freqs.new to
freqs.old in some cases. I wasn't required to add code for it as moving
PRECHANGE notifier down was a better option, so that we call it just before
starting frequency transition.
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

As multi-platform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully.  For example, when
CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init()
will be called on all the platforms to initialize omap-cpufreq driver.

Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device
tree entries.  To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist
for OMAP in a single image, we need to ensure the following:
 1. With device tree boot, we use cpufreq-cpu0
 2. With non device tree boot, we use omap-cpufreq

In the case of (1), we will have cpu OPPs and regulator registered
as part of the device tree nodes, to ensure that omap-cpufreq
and cpufreq-cpu0 don't conflict in managing the frequency of the
same CPU, we should not permit omap-cpufreq to be probed.

In the case of (2), we will not have the cpufreq-cpu0 device, hence
only omap-cpufreq will be active.

To eliminate this undesired these effects, we change omap-cpufreq
driver to have it instantiated as a platform_driver and register
"omap-cpufreq" device only when booted without device tree nodes on
OMAP platforms.

This allows the following:
 a) Will only run on platforms that create the platform_device
    "omap-cpufreq".
 b) Since the platform_device is registered only when device tree nodes
    are *not* populated, omap-cpufreq driver does not conflict with
    the usage of cpufreq-cpu0 driver which is used on OMAP platforms when
    device tree nodes are present.

Inspired by commit 5553f9e2
(cpufreq: instantiate cpufreq-cpu0 as a platform_driver)

[robherring2@gmail.com: reported conflict of omap-cpufreq vs other
driver in an non-device tree supported boot]
Reported-by: NRob Herring <robherring2@gmail.com>
Signed-off-by: NNishanth Menon <nm@ti.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some assignments of policy-> min/max/cur/cpuinfo.min_freq/cpuinfo.max_freq
aren't required as part of it is done by cpufreq driver or cpufreq core.

Remove them.

At some places we merge multiple lines together too.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->cpus contains all online cpus that have single shared clock line. And
their frequencies are always updated together.

Many SMP system's cpufreq drivers take care of this in individual drivers but
the best place for this code is in cpufreq core.

This patch modifies cpufreq_notify_transition() to notify frequency change for
all cpus in policy->cpus and hence updates all users of this API.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NStephen Warren <swarren@nvidia.com>
Tested-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->shared_type field was added only for SoCs with ACPI support:

commit 3b2d9942
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Wed Dec 14 15:05:00 2005 -0500

    P-state software coordination for ACPI core

    http://bugzilla.kernel.org/show_bug.cgi?id=5737

Many non-ACPI systems are filling this field by mistake, which makes its usage
confusing. Lets clean it.
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>

OPP pointer is RCU protected, hence after finding it, de-reference
also should be protected with the same RCU context else the OPP
pointer may become invalid.
Reported-by: NAlexander Holler <holler@ahsoftware.de>
Tested-by: NAlexander Holler <holler@ahsoftware.de>
Acked-by: NAlexander Holler <holler@ahsoftware.de>
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OMAP PM core code has moved to using the existing, generic CPU devices
for attaching OPPs, so the CPUfreq driver can now use the generic
get_cpu_device() API instead of the OMAP-specific omap_device API.

This allows us to remove the last <plat/*> include from this driver.

Cc: Paul Walmsley <paul@pwsan.com>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NKevin Hilman <khilman@ti.com>

OMAP core code now has SoC-independent clock alias for the scalable
CPU clock.  Using it means driver is SoC independent and will work for
AM3xxx SoCs as well as OMAP1/3/4.

While here, remove some unnecessary plat/ includes that are
interfering with multi-subarch ARM kernels.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
[tony@atomide.com: updated already changed clock aliases]
Signed-off-by: NTony Lindgren <tony@atomide.com>
[khilman@ti.com: minor shortlog/changelog updates]
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NKevin Hilman <khilman@ti.com>

The <plat/*.h> headers are going away, and this one is not used.  remove it.
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Ensure the clock rate that will be used is a valid one before
attempting to scale the voltage.  Currently the driver assumes it has
a valid frequency from the OPP table, but boards using different
system oscillators might not have exact matches with the OPP table,
and result in a failing call to clk_set_rate().

This is particularily bad because the voltage may be scaled even
though the frequency is not.  This will obviously lead to some
unpredictable behavior, especially if the frequency is high and
the voltage is dropped.

Thanks to Joni Lapilainen for reporting crashes seen on 3430/n900.
Reported-by: NJoni Lapilainen <joni.lapilainen@gmail.com>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NKevin Hilman <khilman@ti.com>

omap_device_get_by_hwmod_name() returns ERR_PTR on error.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

With ARM smp common code recalculating loops_per_jiffy in a cpufreq
transiton notifier call, the loops_per_jiffy recalculate in omap-cpufreq
driver becomes redundant.  Remove it.
Signed-off-by: NRichard Zhao <richard.zhao@freescale.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

On OMAP4, if the first CPU fails to get a valid frequency table (this
could happen if the platform does not register any OPP table), the
subsequent CPU instances end up dealing with a NULL freq_table and
crash.

Check for an already existing freq_table, before trying to create one,
and increment the freq_table_users only if the table is sucessfully
created.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Cc: <linux-pm@vger.kernel.org>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Specify voltage in ranges for regulator. Range
used is tolerance specified for OPP.

This helps to achieve DVFS with a wider range of
regulators.

Cc: Kevin Hilman <khilman@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: NAfzal Mohammed <afzal@ti.com>

Use the regulator framework to get the voltage regulator associated
with the MPU voltage domain and use it to scale voltage along with
frequency.

While here, CONFIG_CPU_FREQ_DEBUG doesn't exist anymore, so move
debug prints to use dev_dbg().

Special thanks to Afzal Mohammed for suggestions on more robust error
checking.

Cc: Afzal Mohammed  <afzal@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Minor fixups to work starting with v3.2:
- use the new omap_device API for getting a device by name.
- need to include <linux/module.h>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We use a single frequency table for multiple CPUs. But, with
OMAP4, since we have multiple CPUs, the cpu_init call for CPU1
causes freq_table previously allocated for CPU0 to be overwritten.
In addition, we dont free the table on exit path.

We solve this by maintaining an atomic type counter to ensure
just a single table exists at a given time.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Release the mpu_clk in fail paths.
Reported-by: NTodd Poynor <toddpoynor@google.com>
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

OMAP2 is the only family using clk_[init|exit]_cpufreq_table, however,
the cpufreq code does not currently use clk_init_cpufreq_table. As a
result, it is unusuable for OMAP2 and only usable only on platforms
using OPP library.

Remove the unbalanced clk_exit_cpufreq_table().  Any platforms where
OPPs are not availble will fail on init because a freq table will not
be properly initialized.
Signed-off-by: NNishanth Menon <nm@ti.com>
[khilman@ti.com: changelog edits, and graceful failure mode changes]
Signed-off-by: NKevin Hilman <khilman@ti.com>

OMAP2+ all have frequency tables, hence the hacks we had for older
silicon do not need to be carried forward. As part of this change,
use cpufreq_frequency_table_target to find the best match for
frequency requested.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

if we do not have mpu_dev we normally fail in cpu_init. It is better
to fail driver registration if the devices are not available.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Clk name does'nt need to dynamically detected during clk init.
move them off to driver initialization, if we dont have a clk name,
there is no point in registering the driver anyways. The actual clk
get and put is left at cpu_init and exit functions.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Sometimes, bootloaders starts up with a frequency which is not
in the OPP table. At cpu_init, policy->cur contains the frequency
we pick at boot.  It is possible that system might have fixed
it's boot frequency later on as part of power initialization.
After this condition, the first call to omap_target results in the
following:

omap_getspeed(actual device frequency) != policy->cur(frequency that
cpufreq thinks that the system is at), and it is possible that
freqs.old == freqs.new (because the governor requested a scale down).

We exit without triggering the notifiers in the current code, which
does'nt let code which depends on cpufreq_notify_transition to have
accurate information as to what the system frequency is.

Instead, we do a normal transition if policy->cur is wrong, then,
freqs.old will be the actual cpu frequency, freqs.new will be the
actual new cpu frequency and all required notifiers have the accurate
information.
Acked-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NColin Cross <ccross@google.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Enable all CPUs in the shared policy in the CPU init callback.
Otherwise, the governor CPUFREQ_GOV_START event is invoked with
a policy that only includes the first CPU, leaving other CPUs
uninitialized by the governor.
Signed-off-by: NTodd Poynor <toddpoynor@google.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

On OMAP SMP configuartion, both processors share the voltage
and clock. So both CPUs needs to be scaled together and hence
needs software co-ordination.

Also, update lpj with reference value to avoid progressive error.

Adjust _both_ the per-cpu loops_per_jiffy and global lpj. Calibrate
them with with reference to the initial values to avoid a
progressively bigger and bigger error in the value over time.

While at this, re-use the notifiers for UP/SMP since on UP machine or
UP_ON_SMP policy->cpus mask would contain only the boot CPU.

Based on initial SMP support by Santosh Shilimkar.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
[khilman@ti.com: due to overlap/rework, combined original Santosh patch
                 and Russell's rework]
Signed-off-by: NKevin Hilman <khilman@ti.com>

Move OMAP cpufreq driver from arch/arm/mach-omap2 into
drivers/cpufreq, along with a few cleanups:

- generalize support for better handling of different SoCs in the OMAP
- use OPP layer instead of OMAP clock internals for frequency table init
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
[khilman@ti.com: move to drivers]
Signed-off-by: NKevin Hilman <khilman@ti.com>