a9f41deff6
Attaching syscon_generic earlier than BUS_PASS_DEFAULT makes it more difficult for specific syscon drivers to attach to the syscon node and to get ordering right. Further discussion yielded the following set of decisions: - Move syscon_generic to BUS_PASS_DEFAULT - If a platform needs a syscon with different attach order or probe behavior, it should subclass syscon_generic and match on the SoC specific compat string - When we come across a need for a syscon that attaches earlier but only specifies compatible = "syscon", we should create a syscon_exclusive driver that provides generic access but probes earlier and only matches if "syscon" is the only compatible. Such fdt nodes do exist in the wild right now, but we don't really use them at the moment. Additionally: - Any syscon provider that has needs any more complex than a spinlock solely for syscon access and a single memory resource should subclass syscon directly rather than attempting to subclass syscon_generic or add complexity to it. syscon_generic's attach/detach methods may be made public should the need arise to subclass it with additional attach/detach behavior. We introduce aw_syscon(4) that just subclasses syscon_generic but probes earlier to meet our requirements for if_awg and implements #2 above for this specific situation. It currently only matches a64/a83t/h3 since these are the only platforms that really need it at the time being. Discussed with: ian Reviewed by: manu, andrew, bcr (manpages, content unchanged since review) Differential Revision: https://reviews.freebsd.org/D13793
61 lines
2.1 KiB
Groff
61 lines
2.1 KiB
Groff
.\"-
|
|
.\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 7, 2018
|
|
.Dt AW_SYSCON 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm aw_syscon
|
|
.Nd driver for the system controller in Allwinner SoC
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
device driver provides support for the Allwinner system controller.
|
|
This controller provides registers for tying together related functionality in a
|
|
common space.
|
|
.Nm
|
|
is required for ethernet functionality on supported devices.
|
|
.Sh HARDWARE
|
|
The
|
|
.Nm
|
|
driver supports the system controller with one of the following compatible
|
|
strings:
|
|
.Pp
|
|
.Bl -bullet -compact
|
|
.It
|
|
allwinner,sun50i-a64-system-controller
|
|
.It
|
|
allwinner,sun8i-a83t-system-controller
|
|
.It
|
|
allwinner,sun8i-h3-system-controller
|
|
.El
|
|
.Sh AUTHORS
|
|
The
|
|
.Nm
|
|
device driver was written by
|
|
.An Kyle Evans Aq Mt kevans@FreeBSD.org .
|