Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove PCI_SET_POWERSTATE method from acpi.c and eradicate all PCI-specific
knowledges from the file. All PCI devices enumerated in ACPI tree must use
correct one from acpi_pci.c any way. Reduce duplicate codes as we did for
pci.c in r213905. Do not return ESRCH from PCIB_POWER_FOR_SLEEP method.
When the method is not found, just return zero without modifying the given
default value as it is completely optional. As a side effect, the return
state must not be NULL. Note there is actually no functional change by
removing ESRCH because acpi_pcib_power_for_sleep() always returns zero.
Adjust debugging messages and add new ones under bootverbose to help
debugging device power state related issues.

Reviewed by: jhb, imp (earlier versions)

Merge ACPICA 20100121.

Import ACPICA 20090521.

Canonize the include of acpi.h.

Rewrite the acpi_battery interface to allow for other battery types
(i.e., smart battery) and fix various bugs found during the cleanup.

API changes:
* kernel access:
Access to individual batteries is now via devclass_find("battery").
Introduce new methods ACPI_BATT_GET_STATUS (for _BST-formatted data) and
ACPI_BATT_GET_INFO (for _BIF-formatted data). The helper function
acpi_battery_get_battinfo() now takes a device_t instead of a unit #
argument. If dev is NULL, this signifies all batteries.

* ioctl access:
The ACPIIO_BATT_GET_TYPE and ACPIIO_BATT_GET_BATTDESC ioctls have been
removed. Since there is now no need for a mapping between "virtual" unit
and physical unit, usermode programs can just specify the unit directly and
skip the old translation steps. In fact, acpiconf(8) was actually already
doing this and virtual unit was the same as physical unit in all cases
since there was previously only one battery type (acpi_cmbat). Additionally,
we now map the ACPIIO_BATT_GET_BIF and ACPIIO_BATT_GET_BST ioctls for all
batteries, if they provide the associated methods.

* apm compatibility device/ioctls: no change
* sysctl: no change

Since most third-party applications use the apm(4) compat interface, there
should be very few affected applications (if any).

Reviewed by: bruno
MFC after: 5 days

Add the acpi_get_features() method. This method is called on child drivers
to see what features they may support before calling identify/probe/attach.
This is necessary because the ACPI 3.0 spec requires driver support be
advertised before running any methods. For now, the flags are as specified
in for the _PDC and _OSC methods but we can support private flags as needed.

Add an implementation of this for acpi_cpu. It checks all its children
(notably cpufreq drivers) and calls the _PDC method to report the results.

Add the acpi_ec_read and write methods. This allows an external driver
(like an EC/SMbus controller) to access the EC address space. Access
is synchronized by the EcLock/Unlock routines in EcSpaceHandler().

Tested by: Hans Petter Selasky

Start each of the license/copyright comments with /*-, minor shuffle of lines

Add the ACPI_PWR_FOR_SLEEP method. It takes a device and outputs the
appropriate power (Dx) state, if the BIOS suggests one.

MFC after: 3 weeks

Update the interface for child drivers. Add acpi_scan_children, which
allows a bus to re-enumerate its child handles and optionally replace
them with new children, arranged to the bus's liking. (The current device
space is flat with all devices immediately under acpi0). Add comments
for each interface.

Add acpi methods for HID/CID probing, evaluating objects, and walking the
namespace. This is to allow decoupling of attachments from ACPI where they
need some functionality when ACPI is present but do not want to require ACPI
to always be loaded.