On Sun, Jun 24, 2012 at 03:27:42PM +0200, Marc Dietrich wrote: > On Sunday 24 June 2012 13:31:51 Mark Brown wrote: > > On Sun, Jun 24, 2012 at 02:01:58PM +0200, Marc Dietrich wrote: > > > On Sunday 24 June 2012 12:03:06 Mark Brown wrote: > > > > > > + 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 ;-) > > > > 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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