027b25b264
On systems booting with a device tree, every struct device is associated with a struct device_node, that provides its DT firmware representation. The device node can be used in generic kernel contexts (eg IRQ translation, IOMMU streamid mapping), to retrieve the properties associated with the device and carry out kernel operations accordingly. Owing to the 1:1 relationship between the device and its device_node, the device_node can also be used as a look-up token for the device (eg looking up a device through its device_node), to retrieve the device in kernel paths where the device_node is available. On systems booting with ACPI, the same abstraction provided by the device_node is required to provide look-up functionality. The struct acpi_device, that represents firmware objects in the ACPI namespace already includes a struct fwnode_handle of type FWNODE_ACPI as their member; the same abstraction is missing though for devices that are instantiated out of static ACPI tables entries (eg ARM SMMU devices). Add a new fwnode_handle type to associate devices created out of static ACPI table entries to the respective firmware components and create a simple ACPI core layer interface to dynamically allocate and free the corresponding firmware nodes so that kernel subsystems can use it to instantiate the nodes and associate them with the respective devices. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Tomasz Nowicki <tn@semihalf.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Tomasz Nowicki <tn@semihalf.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
31 lines
650 B
C
31 lines
650 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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FWNODE_ACPI_DATA,
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FWNODE_ACPI_STATIC,
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FWNODE_PDATA,
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FWNODE_IRQCHIP
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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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