Date: Sun, 20 Dec 2015 19:56:06 +0100 From: Toby <misc.lists@fsck.ch> To: freebsd-arm@freebsd.org Subject: Re: Set GPIO at boot on Raspberry Pi Message-ID: <5676F9C6.9050904@fsck.ch> In-Reply-To: <1450633367.25138.145.camel@freebsd.org> References: <5676DF0F.1060602@fsck.ch> <5676E368.7080800@denninger.net> <1450633367.25138.145.camel@freebsd.org>
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On 20/12/15 18:42, Ian Lepore wrote: > But I don't think pin state when changing config is quite what Toby was > asking; he needs a way to configure driven pins very early in boot. Yes, that was my question. > Right now we have no way of preconfiguring gpio pins to be driven a > certain way early in boot. By manipulating the device-tree data you > can configure a pin as input or output, and usually you can configure > pull up/down values for inputs, but there's no standard device-tree > syntax to configure the drive value when configuring a pin to be > driven. Can you be a bit more specific on how I would do that? > Maybe we could add some dev.gpioc tunables so that pins could be > configured via loader.conf. That's what linux has, setting max_usb_current=1 in their /boot/config.txt sets GPIO38 to high. I don't know if they have a generic way of configuring pins though. Thanks, Toby
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