The Zynq/Zedboard GPIO driver attempts to tri-state all GPIO pins on
boot up but the order in which I reset the hardware can cause the pins
to be briefly held low before being tri-stated. This is a problem on
boards that use GPIO pins to reset devices.
In particular, the Zybo and ZC-706 boards use a GPIO pin as a USB PHY
reset. If U-boot enables the USB port before booting the kernel, the
GPIO driver attach causes a glitch on the USB PHY reset and the USB
port loses power. My fix is to have the GPIO driver leave the pins in
whatever configuration U-boot placed them.
PR: 225713
Submitted by: Thomas Skibo <thoma555-bsd@yahoo.com>
MFC after: 1 week
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
string.
With this change it is not necessary redeclare the driver relations with
gpiobus and gpioc.
This also prevents redundant declarations when gpiobusvar.h is included
(which is going to happen soon).
unit 0.
It seems that this 'simplification' was copied to all GPIO drivers in tree.
This fix a bug where a GPIO controller could fail to attach its children
(gpioc and gpiobus) if another GPIO driver attach first.
to check the status property in their probe routines.
Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.
Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
Communication on src-commiters, Sat, 27 Apr 2013 22:09:06 -0700,
Subject was: "Re: svn commit: r249997"
As I'm here, fix the style main block comments in files' headers.
