Documentation: ACPI: move scan_handlers.txt to driver-api/acpi and convert to reST

This converts the plain text documentation to reStructuredText format
and adds it to Sphinx TOC tree.

No essential content change.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 0 insertions, 77 deletions

diff --git a/Documentation/acpi/scan_handlers.txt b/Documentation/acpi/scan_handlers.txt
deleted file mode 100644
index 3246ccf15992..000000000000
--- a/Documentation/acpi/scan_handlers.txt
+++ /dev/null
@@ -1,77 +0,0 @@
-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.