regulator: core: Add REGULATOR_EVENT_PRE_VOLTAGE_CHANGE (and ABORT)

In some cases we need to know when a regulator is about to be changed.
Add a way for clients to be notified.  Note that for set_voltage() we
don't necessarily know what voltage we'll end up with, so we tell the
client what the range will be so they can prepare.

Signed-off-by: Heiko Stübner <heiko@sntech.de>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie+linaro@kernel.org>
Documentation: arm: define DT idle states bindings

ARM based platforms implement a variety of power management schemes that
allow processors to enter idle states at run-time.
The parameters defining these idle states vary on a per-platform basis forcing
the OS to hardcode the state parameters in platform specific static tables
whose size grows as the number of platforms supported in the kernel increases
and hampers device drivers standardization.

Therefore, this patch aims at standardizing idle state device tree bindings
for ARM platforms. Bindings define idle state parameters inclusive of entry
methods and state latencies, to allow operating systems to retrieve the
configuration entries from the device tree and initialize the related power
management drivers, paving the way for common code in the kernel to deal with
idle states and removing the need for static data in current and previous
kernel versions.

ARM64 platforms require the DT to define an entry-method property
for idle states.

On system implementing PSCI as an enable-method to enter low-power
states the PSCI CPU suspend method requires the power_state parameter to
be passed to the PSCI CPU suspend function.

This parameter is specific to a power state and platform specific,
therefore must be provided by firmware to the OS in order to enable
proper call sequence.

Thus, this patch also adds a property in the PSCI bindings that
describes how the PSCI CPU suspend power_state parameter should be
defined in DT in all device nodes that rely on PSCI CPU suspend method usage.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Sebastian Capella <sebcape@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: kernel: refactor the CPU suspend API for retention states

CPU suspend is the standard kernel interface to be used to enter
low-power states on ARM64 systems. Current cpu_suspend implementation
by default assumes that all low power states are losing the CPU context,
so the CPU registers must be saved and cleaned to DRAM upon state
entry. Furthermore, the current cpu_suspend() implementation assumes
that if the CPU suspend back-end method returns when called, this has
to be considered an error regardless of the return code (which can be
successful) since the CPU was not expected to return from a code path that
is different from cpu_resume code path - eg returning from the reset vector.

All in all this means that the current API does not cope well with low-power
states that preserve the CPU context when entered (ie retention states),
since first of all the context is saved for nothing on state entry for
those states and a successful state entry can return as a normal function
return, which is considered an error by the current CPU suspend
implementation.

This patch refactors the cpu_suspend() API so that it can be split in
two separate functionalities. The arm64 cpu_suspend API just provides
a wrapper around CPU suspend operation hook. A new function is
introduced (for architecture code use only) for states that require
context saving upon entry:

__cpu_suspend(unsigned long arg, int (*fn)(unsigned long))

__cpu_suspend() saves the context on function entry and calls the
so called suspend finisher (ie fn) to complete the suspend operation.
The finisher is not expected to return, unless it fails in which case
the error is propagated back to the __cpu_suspend caller.

The API refactoring results in the following pseudo code call sequence for a
suspending CPU, when triggered from a kernel subsystem:

/*
 * int cpu_suspend(unsigned long idx)
 * @idx: idle state index
 */
{
-> cpu_suspend(idx)
	|---> CPU operations suspend hook called, if present
		|--> if (retention_state)
			|--> direct suspend back-end call (eg PSCI suspend)
		     else
			|--> __cpu_suspend(idx, &back_end_finisher);
}

By refactoring the cpu_suspend API this way, the CPU operations back-end
has a chance to detect whether idle states require state saving or not
and can call the required suspend operations accordingly either through
simple function call or indirectly through __cpu_suspend() which carries out
state saving and suspend finisher dispatching to complete idle state entry.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: kernel: introduce cpu_init_idle CPU operation

The CPUidle subsystem on ARM64 machines requires the idle states
implementation back-end to initialize idle states parameter upon
boot. This patch adds a hook in the CPU operations structure that
should be initialized by the CPU operations back-end in order to
provide a function that initializes cpu idle states.

This patch also adds the infrastructure to arm64 kernel required
to export the CPU operations based initialization interface, so
that drivers (ie CPUidle) can use it when they are initialized
at probe time.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: add PSCI CPU_SUSPEND based cpu_suspend support

This patch implements the cpu_suspend cpu operations method through
the PSCI CPU SUSPEND API. The PSCI implementation translates the idle state
index passed by the cpu_suspend core call into a valid PSCI state according to
the PSCI states initialized at boot through the cpu_init_idle() CPU
operations hook.

The PSCI CPU suspend operation hook checks if the PSCI state is a
standby state. If it is, it calls the PSCI suspend implementation
straight away, without saving any context. If the state is a power
down state the kernel calls the __cpu_suspend API (that saves the CPU
context) and passed the PSCI suspend finisher as a parameter so that PSCI
can be called by the __cpu_suspend implementation after saving and flushing
the context as last function before power down.

For power down states, entry point is set to cpu_resume physical address,
that represents the default kernel execution address following a CPU reset.

Reviewed-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
ACPI / LPSS: not using UART RTS override with Auto Flow Control

Adding a check for UART Auto Flow Control feature and only
enabling the RTS override when it's not supported. RTS
override is not needed when Auto Flow Control is used and
they shouldn't be used together.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / video: force vendor backlight on Lenovo Ideapad Z570

Lenovo Ideapad 570 is a pre-win8 laptop where not using vendor
backlight causes the backlight controls not to work.

Signed-off-by: Stepan Bujnak <stepanbujnak@fastmail.fm>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / processor: use container_of instead of casting first structure member

Use container_of instead of casting first structure member to resolve
acpi_madt_local_apic/sapic/x2apic from acpi_subtable_header.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
[ rjw: Subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / blacklist: add Win8 OSI quirks for some Dell laptop models

The wireless hotkey of those machines does not work with Win8 OSI.
Due to insufficient documentation for the driver implementation,
blacklist those machines as a workaround.

"audo wake on after shutdown" bug on Dell Inspiron 7737 is fixed by BIOS.
But this machine still suffers the hotkey issue. So keep the quirk for the
wireless hotkey issue.

Link: http://www.dell.com/support/home/us/en/19/Drivers/DriversDetails?driverId=MJWNX
Signed-off-by: Edward Lin <yidi.lin@canonical.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / utils: Update acpi_check_dsm() comments

Update function comments.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / battery: Replace strnicmp with strncasecmp

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics
and a slightly buggy strncasecmp. The latter is the POSIX name, so
strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper
for the new strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in
the future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / SBS: Don't assume the existence of an SBS charger

Apple hardware continues to expose an ACPI AC charger even when using
SBS to report battery state. The charger status byte returns all 0s in
this case.  Since the spec requires that bit 4 be 1 at all times, assume
that there's not really a charger if it's set to zero.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / SBS: Disable smart battery manager on Apple

Touching the smart battery manager at all on Apple hardware appears to
make it unhappy - unplugging the AC adapter triggers accesses that hang
the controller for several minutes. Quirk it out via DMI in order to
avoid this.  Compensate by changing battery presence if we fail to
communicate with the battery.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: Support _OSI("Darwin") correctly

Apple hardware queries _OSI("Darwin") in order to determine whether the
system is running OS X, and changes firmware behaviour based on the
answer.  The most obvious difference in behaviour is that Thunderbolt
hardware is forcibly powered down unless the system is running OS X. The
obvious solution would be to simply add Darwin to the list of supported
_OSI strings, but this causes problems.

Recent Apple hardware includes two separate methods for checking _OSI
strings. The first will check whether Darwin is supported, and if so
will exit. The second will check whether Darwin is supported, but will
then continue to check for further operating systems. If a further
operating system is found then later firmware code will assume that the
OS is not OS X.  This results in the unfortunate situation where the
Thunderbolt controller is available at boot time but remains powered
down after suspend.

The easiest way to handle this is to special-case it in the
Linux-specific OSI handling code. If we see Darwin, we should answer
true and then disable all other _OSI vendor strings.

The next problem is that the Apple PCI _OSC method has the following
code:

if (LEqual (0x01, OSDW ()))
  if (LAnd (LEqual (Arg0, GUID), NEXP)
    (do stuff)
  else
    (fail)
NEXP is a value in high memory and is presumably under the control of
the firmware. No methods sets it. The methods that are called in the "do
stuff" path are dummies. Unless there's some additional firmware call in
early boot, there's no way for this call to succeed - and even if it
does, it doesn't do anything.

The easiest way to handle this is simply to ignore it. We know which
flags would be set, so just set them by hand if the platform is running
in Darwin mode.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
[andreas.noever@gmail.com: merged two patches, do not touch ACPICA]
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / devfreq: Remove ARCH_HAS_OPP completely

The Kconfig symbol ARCH_HAS_OPP became redundant in v3.16: commit
049d595a4db3 ("PM / OPP: Make OPP invisible to users in Kconfig")
removed the only dependency that used it. Setting it had no effect
anymore.

So commit 78c5e0bb145d ("PM / OPP: Remove ARCH_HAS_OPP") removed it. For
some reason that commit did not remove all select statements for that
symbol. These statements are now useless. Remove one from devfreq too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec

This patch ensures the cpus to kexec/reboot at nominal frequency.
Nominal frequency is the highest cpu frequency on PowerPC at
which the cores can run without getting throttled.

If the host kernel had set the cpus to a low pstate and then it
kexecs/reboots to a cpufreq disabled kernel it would cause the target
kernel to perform poorly. It will also increase the boot up time of
the target kernel. So set the cpus to high pstate, in this case to
nominal frequency before rebooting to avoid such scenarios.

The reboot notifier will set the cpus to nominal frequncy.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Replace strnicmp with strncasecmp

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics
and a slightly buggy strncasecmp. The latter is the POSIX name, so
strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper
for the new strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in
the future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: Replace strnicmp with strncasecmp

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics
and a slightly buggy strncasecmp. The latter is the POSIX name, so
strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper
for the new strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in
the future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'for-next/cpuidle' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into cpuidle/3.18

These are the specific changes for ARM64 to make it possible to integrate the
DT based generic cpuidle driver in this tree.

It contains:
  * The documentation for the DT definitions for ARM
  * The refactoring of the cpu_suspend function for ARM64
  * Introduce the cpu_idle_init function for ARM64
  * Add the PSCI CPU SUSPEND based on the previous changes on cpu_suspend

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
cpuidle: big.LITTLE: add Exynos5800 compatible string

Exynos 5800 is big.LITTLE SoC compatible with the 5420.  Add the
compatible string so this driver works on the 5800.

Tested on exynos5800-peach-pi (aka Samsung Chromebook2)

Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>