On 1/5/2010 10:38 PM, Bill Gatliff wrote:
Ayman El-Khashab wrote:
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.
Isn't that the "flags" parameter, e.g.:
gpios = <phandle gpioid flags>
?
If you are passing a 0 for the flags, try a 1. I know of at least one
driver that interprets that to mean a polarity inversion. Maybe you'll
get lucky. :)
Possibly, I saw that in the documentation directory, but didn't quite
follow the explanation that
was given. Below is what I was using as a reference, but is it as
simple as that? Do the flags encode
just the state or also, the open drain, hi-z and everything else? In my
case, I want the GPIO 3 actively
driven high.
Example of the node using GPIOs:
20
21 node {
22 gpios = <&qe_pio_e 18 0>;
23 };
24
25 In this example gpio-specifier is "18 0" and encodes GPIO pin number,
26 and empty GPIO flags as accepted by the "qe_pio_e" gpio-controller.
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