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 5553f9e26f
(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>
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>
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>
policy->shared_type field was added only for SoCs with ACPI support:
commit 3b2d99429e
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>
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>
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>
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>
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>
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>
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>
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>
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>
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system
Pull "Disintegrate and delete asm/system.h" from David Howells:
"Here are a bunch of patches to disintegrate asm/system.h into a set of
separate bits to relieve the problem of circular inclusion
dependencies.
I've built all the working defconfigs from all the arches that I can
and made sure that they don't break.
The reason for these patches is that I recently encountered a circular
dependency problem that came about when I produced some patches to
optimise get_order() by rewriting it to use ilog2().
This uses bitops - and on the SH arch asm/bitops.h drags in
asm-generic/get_order.h by a circuituous route involving asm/system.h.
The main difficulty seems to be asm/system.h. It holds a number of
low level bits with no/few dependencies that are commonly used (eg.
memory barriers) and a number of bits with more dependencies that
aren't used in many places (eg. switch_to()).
These patches break asm/system.h up into the following core pieces:
(1) asm/barrier.h
Move memory barriers here. This already done for MIPS and Alpha.
(2) asm/switch_to.h
Move switch_to() and related stuff here.
(3) asm/exec.h
Move arch_align_stack() here. Other process execution related bits
could perhaps go here from asm/processor.h.
(4) asm/cmpxchg.h
Move xchg() and cmpxchg() here as they're full word atomic ops and
frequently used by atomic_xchg() and atomic_cmpxchg().
(5) asm/bug.h
Move die() and related bits.
(6) asm/auxvec.h
Move AT_VECTOR_SIZE_ARCH here.
Other arch headers are created as needed on a per-arch basis."
Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that. We'll find out anything that got broken and fix it..
* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
Delete all instances of asm/system.h
Remove all #inclusions of asm/system.h
Add #includes needed to permit the removal of asm/system.h
Move all declarations of free_initmem() to linux/mm.h
Disintegrate asm/system.h for OpenRISC
Split arch_align_stack() out from asm-generic/system.h
Split the switch_to() wrapper out of asm-generic/system.h
Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
Create asm-generic/barrier.h
Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
Disintegrate asm/system.h for Xtensa
Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
Disintegrate asm/system.h for Tile
Disintegrate asm/system.h for Sparc
Disintegrate asm/system.h for SH
Disintegrate asm/system.h for Score
Disintegrate asm/system.h for S390
Disintegrate asm/system.h for PowerPC
Disintegrate asm/system.h for PA-RISC
Disintegrate asm/system.h for MN10300
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Nishanth Menon