Hi John,
On Mon, Mar 21, 2005 at 07:50:31AM +1030, John Steele Scott wrote:
> It doesn't show up in Linux, but if you boot into OpenFirmware you might find
> it. In OpenFirmware, try "dev /cpus/PowerPC,G4@0" to change to the CPU node,
> and then "words" to show you what commands are available there. If you have
> set-dfs-high, you can use "see set-dfs-high" to get some idea of how it
> works.
This is cool! My forth is a little bit rusty but I was able to read the
output nevertheless and it looks quite similar to the stuff in the Linnux driver.
I will investigate.
> > Would I expect the return value 5 or 1 for high voltage or does
> > reading not work like this. I always get 0, even after I did
> >
> > pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 5)
>
> I can't remember if this is supposed to work, it's possible that that GPIO is
> write-only.
In OpenFirmware I can read back the value using the following forth
command
1 GPIO@ .
The number 1 seems to be the "GPIO channel" whatever this is (if I do
not set it I get an error message telling me that the "GPIO channel"
must be in the range 0, ..., 63).
I will investigate further.
All the best,
Jochen
--
http://seehuhn.de/
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