On Sun, Jun 24, 2012 at 03:27:42PM +0200, Marc Dietrich wrote:

On Sunday 24 June 2012 13:31:51 Mark Brown wrote:

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On Sun, Jun 24, 2012 at 02:01:58PM +0200, Marc Dietrich wrote:

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On Sunday 24 June 2012 12:03:06 Mark Brown wrote:

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+                                 	regulator-name = "+3.3vs_ldo0";
+					regulator-max-microvolt = <3300000>;

This is one example, it looks like the rail needs to be fixed to 3.3V.

I think nowhere in the code a regulator (beside sm*) is programmed to some
different value that the maximum given here (this is not the maximum the
regulator can provide). I never understood why the kernel code always sets
the regulator to the maximum value if no other value was specified. IMHO,
there should be some initial value, e.g. regulator-default-microvolt, as
the original driver (from 2.6.32 ages) did. This way the maximum value
can be set

That's *never* been in mainline, and nobody even bothered trying to
submit it.

which was the best thing to do ;-)

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to the hw limits, but maybe this is a bit dangerous.

One of two things should be happening.  Either a single voltage is
specified (in which case that voltage will be configured in the

I'm not an expert on this, but it seems to me that only sm0 and sm1 should be 
changeable (and some rail called vdd_aon, which seems to be ldo2 in case of 
paz00 connected to the rtc). So, all others can be constant voltage. Maybe 
Stephen can comment on the actual requirements (also for the other boards 
which may have similar layout).

I can confirm that at least for ldo0 the value needs to be fixed. I did
in fact post a patch back in February that was needed to fix PCIe on
Harmony. I also sat down with one of our hardware engineers and worked
through the list and wrote down the requirements for Harmony. I need to
check where our notes have gone, though.

Thierry
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