Merge branch 'acpi-cleanup'

Currently the kernel is not able to automatically determine from which ACPI

device it should make the corresponding platform device so we need to add

the ACPI device explicitly to acpi_platform_device_ids list defined in

drivers/acpi/scan.c. This limitation is only for the platform devices, SPI

and I2C devices are created automatically as described below.

drivers/acpi/acpi_platform.c. This limitation is only for the platform

devices, SPI and I2C devices are created automatically as described below.

SPI serial bus support

~~~~~~~~~~~~~~~~~~~~~~

ACPI Scan Handlers

Copyright (C) 2012, Intel Corporation

Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

During system initialization and ACPI-based device hot-add, the ACPI namespace

is scanned in search of device objects that generally represent various pieces

of hardware.  This causes a struct acpi_device object to be created and

registered with the driver core for every device object in the ACPI namespace

and the hierarchy of those struct acpi_device objects reflects the namespace

layout (i.e. parent device objects in the namespace are represented by parent

struct acpi_device objects and analogously for their children).  Those struct

acpi_device objects are referred to as "device nodes" in what follows, but they

should not be confused with struct device_node objects used by the Device Trees

parsing code (although their role is analogous to the role of those objects).

During ACPI-based device hot-remove device nodes representing pieces of hardware

being removed are unregistered and deleted.

The core ACPI namespace scanning code in drivers/acpi/scan.c carries out basic

initialization of device nodes, such as retrieving common configuration

information from the device objects represented by them and populating them with

appropriate data, but some of them require additional handling after they have

been registered.  For example, if the given device node represents a PCI host

bridge, its registration should cause the PCI bus under that bridge to be

enumerated and PCI devices on that bus to be registered with the driver core.

Similarly, if the device node represents a PCI interrupt link, it is necessary

to configure that link so that the kernel can use it.

Those additional configuration tasks usually depend on the type of the hardware

component represented by the given device node which can be determined on the

basis of the device node's hardware ID (HID).  They are performed by objects

called ACPI scan handlers represented by the following structure:

struct acpi_scan_handler {

	const struct acpi_device_id *ids;

	struct list_head list_node;

	int (*attach)(struct acpi_device *dev, const struct acpi_device_id *id);

	void (*detach)(struct acpi_device *dev);

};

where ids is the list of IDs of device nodes the given handler is supposed to

take care of, list_node is the hook to the global list of ACPI scan handlers

maintained by the ACPI core and the .attach() and .detach() callbacks are

executed, respectively, after registration of new device nodes and before

unregistration of device nodes the handler attached to previously.

The namespace scanning function, acpi_bus_scan(), first registers all of the

device nodes in the given namespace scope with the driver core.  Then, it tries

to match a scan handler against each of them using the ids arrays of the

available scan handlers.  If a matching scan handler is found, its .attach()

callback is executed for the given device node.  If that callback returns 1,

that means that the handler has claimed the device node and is now responsible

for carrying out any additional configuration tasks related to it.  It also will

be responsible for preparing the device node for unregistration in that case.

The device node's handler field is then populated with the address of the scan

handler that has claimed it.

If the .attach() callback returns 0, it means that the device node is not

interesting to the given scan handler and may be matched against the next scan

handler in the list.  If it returns a (negative) error code, that means that

the namespace scan should be terminated due to a serious error.  The error code

returned should then reflect the type of the error.

The namespace trimming function, acpi_bus_trim(), first executes .detach()

callbacks from the scan handlers of all device nodes in the given namespace

scope (if they have scan handlers).  Next, it unregisters all of the device

nodes in that scope.

ACPI scan handlers can be added to the list maintained by the ACPI core with the

help of the acpi_scan_add_handler() function taking a pointer to the new scan

handler as an argument.  The order in which scan handlers are added to the list

is the order in which they are matched against device nodes during namespace

scans.

All scan handles must be added to the list before acpi_bus_scan() is run for the

first time and they cannot be removed from it.

	return aml_nfw_add_global_handler();

}

static int aml_nfw_remove(struct acpi_device *device, int type)

static int aml_nfw_remove(struct acpi_device *device)

{

	return aml_nfw_remove_global_handler();

}

	return r;

}

static int xo15_sci_remove(struct acpi_device *device, int type)

static int xo15_sci_remove(struct acpi_device *device)

{

	acpi_disable_gpe(NULL, xo15_sci_gpe);

	acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);

	  systems require this timer. 

config ACPI_CONTAINER

	tristate "Container and Module Devices (EXPERIMENTAL)"

	bool "Container and Module Devices (EXPERIMENTAL)"

	depends on EXPERIMENTAL

	default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU || ACPI_HOTPLUG_IO)

	help