97badf873a
Add a secondary pointer to struct fwnode_handle so as to make it
possible for a device to have two firmware nodes associated with
it at the same time, for example, an ACPI node and a node with
a set of properties provided by platform initialization code.
In the future that will allow device property lookup to fall back
from the primary firmware node to the secondary one if the given
property is not present there to make it easier to provide defaults
for device properties used by device drivers.
Introduce two helper routines, set_primary_fwnode() and
set_secondary_fwnode() allowing callers to add a primary/secondary
firmware node to the given device in such a way that
(1) If there's only one firmware node for that device, it will be
pointed to by the device's firmware node pointer.
(2) If both the primary and secondary firmware nodes are present,
the primary one will be pointed to by the device's firmware
node pointer, while the secondary one will be pointed to by the
primary node's secondary pointer.
(3) If one of these nodes is removed (by calling one of the new
nelpers with NULL as the second argument), the other one will
be preserved.
Make ACPI use set_primary_fwnode() for attaching its firmware nodes
to devices.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
27 lines
579 B
C
27 lines
579 B
C
/*
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* fwnode.h - Firmware device node object handle type definition.
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*
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* Copyright (C) 2015, Intel Corporation
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* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef _LINUX_FWNODE_H_
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#define _LINUX_FWNODE_H_
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enum fwnode_type {
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FWNODE_INVALID = 0,
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FWNODE_OF,
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FWNODE_ACPI,
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};
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struct fwnode_handle {
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enum fwnode_type type;
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struct fwnode_handle *secondary;
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};
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#endif
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