b344de4d0d
In order to support various types of data stored in device tree properties or ACPI _DSD packages, create a new enum so the caller can specify the expected type of a property they want to read, according to the binding. The bus logic will use that information to process the underlying data. For example in DT all integer properties are stored in BE format. In order to get constant results across different platforms we need to convert its endianness to match the host. Another example are ACPI_TYPE_INTEGER properties stored as uint64_t. Before this patch the ACPI logic would refuse to read them if the provided buffer was smaller than 8 bytes. Now this can be handled by using DEVICE_PROP_UINT32 type. Modify the existing consumers of this API to reflect the changes and update the man pages accordingly. Reviewed by: mw Obtained from: Semihalf MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D33457
77 lines
2.4 KiB
Groff
77 lines
2.4 KiB
Groff
.\" -
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.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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.\"
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.\" Copyright (c) 2021 Semihalf
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd February 18, 2022
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.Dt BUS_GET_PROPERTY 9
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.Os
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.Sh NAME
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.Nm BUS_GET_PROPERTY
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.Nd get child's specific property
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.Sh SYNOPSIS
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.In sys/param.h
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.In sys/bus.h
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.Ft ssize_t
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.Fn BUS_GET_PROPERTY "device_t dev" "device_t child" "const char *propname" \
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"void *propvalue" "size_t size" "device_property_type_t type"
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.Sh DESCRIPTION
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The
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.Fn BUS_GET_PROPERTY
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method
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is called from driver code which wants to access a child's specific data stored
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on the bus.
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A property has a name and an associated value.
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Implementation shall copy to
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.Fa propvalue
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at most
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.Fa size
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bytes.
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.Pp
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.Fn BUS_GET_PROPERTY
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supports different property types specified via the
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.Fa type
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argument.
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The
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.Fa size
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is guaranteed to be a multiple of the underlying property type.
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If a type is not supported,
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.Fn BUS_GET_PROPERTY
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shall return -1.
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.Sh NOTES
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If
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.Fa propvalue
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is NULL or
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.Fa size
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is zero, the implementation shall return only the size of the property.
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.Sh RETURN VALUES
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The property size if successful, otherwise -1.
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.Sh SEE ALSO
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.Xr device 9 ,
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.Xr device_get_property 9
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.Sh AUTHORS
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This manual page was written by
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.An Bartlomiej Grzesik .
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