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From: Ayman El-Khashab <ayman@elkhashab.com>
To: linuxppc-dev@ozlabs.org
Subject: How to set GPIO state in the dts or in platform
Date: Tue, 05 Jan 2010 22:17:32 -0600	[thread overview]
Message-ID: <4B440EDC.3060805@elkhashab.com> (raw)

I've got a custom board akin to the walnut.  I've successfully got u-boot,
the kernel, and a working filesystem.  The only thing I lack is a clear idea
of how to set a GPIO. 

I have the PHY reset connected to GPIO 3.  I've got it setup in u-boot
correctly, but by the time linux boots, it has touched the GPIOs and now the
PHY is held in reset.  I tried to follow how to adjust my device tree, 
but I
haven't been able to get it to work yet.  My kernel (circa mid 2008) 
doesn't
have the "keep" property of the GPIO node, so I can't use that. 

Based on what I've read it seems that I might need to add a node to the dts
and then a custom piece of code in the platform directory for my board.  I
am just not sure how to proceed there.

thanks
ayman

             reply	other threads:[~2010-01-06  4:34 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-06  4:17 Ayman El-Khashab [this message]
2010-01-06  4:38 ` How to set GPIO state in the dts or in platform Bill Gatliff
2010-01-06  5:08   ` Ayman El-Khashab
2010-01-06 15:16     ` Bill Gatliff

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