cpufreq: omap: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: Make cpufreq_unregister_driver() return void

All but a few drivers ignore the return value of
cpufreq_unregister_driver(). Those few that don't only call it after
cpufreq_register_driver() succeeded, in which case the call doesn't
fail.

Make the function return no value and add a WARN_ON for the case that
the function is called in an invalid situation (i.e. without a previous
successful call to cpufreq_register_driver()).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com> # brcmstb-avs-cpufreq.c
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: omap: Use .register_em() to register with energy model

Set the newly added .register_em() callback with
cpufreq_register_em_with_opp() to register with the EM core.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: Remove CPUFREQ_STICKY flag

During cpufreq driver's registration, if the ->init() callback for all
the CPUs fail then there is not much point in keeping the driver around
as it will only account for more of unnecessary noise, for example
cpufreq core will try to suspend/resume the driver which never got
registered properly.

The removal of such a driver is avoided if the driver carries the
CPUFREQ_STICKY flag. This was added way back [1] in 2004 and perhaps no
one should ever need it now. A lot of drivers do set this flag, probably
because they just copied it from other drivers.

This was added earlier for some platforms [2] because their cpufreq
drivers were getting registered before the CPUs were registered with
subsys framework. And hence they used to fail.

The same isn't true anymore though. The current code flow in the kernel
is:

start_kernel()
-> kernel_init()
-> kernel_init_freeable()
-> do_basic_setup()
-> driver_init()
-> cpu_dev_init()
-> subsys_system_register() //For CPUs

-> do_initcalls()
-> cpufreq_register_driver()

Clearly, the CPUs will always get registered with subsys framework
before any cpufreq driver can get probed. Remove the flag and update the
relevant drivers.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/include/linux/cpufreq.h?id=7cc9f0d9a1ab04cedc60d64fd8dcf7df224a3b4d # [1]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/arch/arm/mach-sa1100/cpu-sa1100.c?id=f59d3bbe35f6268d729f51be82af8325d62f20f5 # [2]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP: refactor dev_pm_opp_of_register_em() and update related drivers

The Energy Model framework supports not only CPU devices. Drop the CPU
specific interface with cpumask and add struct device. Add also a return
value, user might use it. This new interface provides easy way to create
a simple Energy Model, which then might be used by e.g. thermal subsystem.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: Make cpufreq_generic_init() return void

It always returns 0 (success) and its return type should really be void.

Over that, many drivers have added error handling code based on its
return value, which is not required at all.

Change its return type to void and update all the callers.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

cpufreq: OMAP: Register an Energy Model

Try and register an Energy Model from omap-cpufreq.c to allow
interested subsystems like the task scheduler to use the provided
information.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

PM / OPP: Update OPP users to put reference

This patch updates dev_pm_opp_find_freq_*() routines to get a reference
to the OPPs returned by them.

Also updates the users of dev_pm_opp_find_freq_*() routines to call
dev_pm_opp_put() after they are done using the OPPs.

As it is guaranteed the that OPPs wouldn't get freed while being used,
the RCU read side locking present with the users isn't required anymore.
Drop it as well.

This patch also updates all users of devfreq_recommended_opp() which was
returning an OPP received from the OPP core.

Note that some of the OPP core routines have gained
rcu_read_{lock|unlock}() calls, as those still use RCU specific APIs
within them.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> [Devfreq]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

remove lots of IS_ERR_VALUE abuses

Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

#define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro - Linus ]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cpufreq: Use consistent prefixing via pr_fmt

Use the more common kernel style adding a define for pr_fmt.

Miscellanea:

o Remove now unused PFX defines

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: Convert printk(KERN_<LEVEL> to pr_<level>

Use the more common logging style.

Miscellanea:

o Coalesce formats
o Realign arguments
o Add a missing space between a coalesced format

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

cpufreq: add 'freq_table' in struct cpufreq_policy

freq table is not per CPU but per policy, so it makes more sense to
keep it within struct cpufreq_policy instead of a per-cpu variable.

This patch does it. Over that, there is no need to set policy->freq_table
to NULL in ->exit(), as policy structure is going to be freed soon.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: introduce cpufreq_generic_get() routine

CPUFreq drivers that use clock frameworks interface,i.e. clk_get_rate(),
to get CPUs clk rate, have similar sort of code used in most of them.

This patch adds a generic ->get() which will do the same thing for them.
All those drivers are required to now is to set .get to cpufreq_generic_get()
and set their clk pointer in policy->clk during ->init().

Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: Mark ARM drivers with CPUFREQ_NEED_INITIAL_FREQ_CHECK flag

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: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: OMAP: Fix compilation error 'r & ret undeclared'

With a recent change "d4019f0 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: d4019f0a92ab (cpufreq: move freq change notifications to cpufreq core)
Reported-by: Sebastian Capella <sebastian.capella@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: move freq change notifications to cpufreq core

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: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: Implement light weight ->target_index() routine

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: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>

PM / OPP: rename header to linux/pm_opp.h

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: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / OPP: rename data structures to dev_pm equivalents

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: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / OPP: rename functions to dev_pm_opp*

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: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: omap: use cpufreq_generic_init()

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: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: omap: don't initialize part of policy set by core

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: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: omap: Use generic cpufreq routines

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: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: omap: call cpufreq_frequency_table_put_attr()

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: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: omap: use cpufreq_table_validate_and_show()

Lets use cpufreq_table_validate_and_show() instead of calling
cpufreq_frequency_table_cpuinfo() and cpufreq_frequency_table_get_attr().

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

cpufreq: delete __cpuinit usage from all cpufreq files

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 5e427ec2d0 ("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: Dirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

cpufreq: omap: call CPUFREQ_POSTCHANGE notfier in error cases

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: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver

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 5553f9e26f6f49a93ba732fd222eac6973a4cf35
(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: Rob Herring <robherring2@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: drivers: Remove unnecessary assignments of policy-> members

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: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: Notify all policy->cpus in cpufreq_notify_transition()

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: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: Remove unnecessary use of policy->shared_type

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

commit 3b2d99429e3386b6e2ac949fc72486509c8bbe36
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: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: OMAP: use RCU locks around usage of OPP

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: Alexander Holler <holler@ahsoftware.de>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Acked-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq: OMAP: use get_cpu_device() instead of omap_device API

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: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: fix clock usage to be SoC independent, remove plat/ includes

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: Paul Walmsley <paul@pwsan.com>
[tony@atomide.com: updated already changed clock aliases]
Signed-off-by: Tony Lindgren <tony@atomide.com>
[khilman@ti.com: minor shortlog/changelog updates]
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: remove unused <plat/omap-pm.h>

The <plat/*.h> headers are going away, and this one is not used. remove it.

Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: ensure valid clock rate before scaling

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: Joni Lapilainen <joni.lapilainen@gmail.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: Check IS_ERR() instead of NULL for omap_device_get_by_hwmod_name

omap_device_get_by_hwmod_name() returns ERR_PTR on error.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

cpufreq: OMAP: remove loops_per_jiffy recalculate for smp

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: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

cpufreq: OMAP: Handle missing frequency table on SMP systems

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: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: <linux-pm@vger.kernel.org>
Signed-off-by: Kevin Hilman <khilman@ti.com>

Remove all #inclusions of asm/system.h

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: David Howells <dhowells@redhat.com>

cpufreq: OMAP: specify range for voltage scaling

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: Afzal Mohammed <afzal@ti.com>

cpufreq: OMAP: scale voltage along with frequency

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: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: fixup for omap_device changes, include <linux/module.h>

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: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: fix freq_table leak

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: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: put clk if cpu_init failed

Release the mpu_clk in fail paths.

Reported-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: only supports OPP library

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: Nishanth Menon <nm@ti.com>
[khilman@ti.com: changelog edits, and graceful failure mode changes]
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: dont support !freq_table

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: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: deny initialization if no mpudev

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: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: move clk name decision to init

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: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: notify even with bad boot frequency

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: Nishanth Menon <nm@ti.com>
Signed-off-by: Colin Cross <ccross@google.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: Enable all CPUs in shared policy mask

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: Todd Poynor <toddpoynor@google.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

cpufreq: OMAP: Add SMP support for OMAP4+

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

cpufreq: OMAP: cleanup for multi-SoC support, move into drivers/cpufreq

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: Santosh Shilimkar <santosh.shilimkar@ti.com>
[khilman@ti.com: move to drivers]
Signed-off-by: Kevin Hilman <khilman@ti.com>