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
next 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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