On 02/26/2013 10:44 AM, Lee Jones wrote:
On Tue, 05 Feb 2013, Mark Brown wrote:
On Mon, Feb 04, 2013 at 10:21:36PM +0100, Linus Walleij wrote:
What is needed is some way to model that
electronic relationship into both the regulator
and clock subsystems (Ulf Hansson is working on
the ABx500 clocks as we speak.)
Maybe the actual place to have it would be
somewhere like drivers/mfd/ab8500-core.c.
Have you seen similar stuff in other PMICs?
Yes, it's fairly common to at least have hardware enable signals. If
what was going on was actually understood by the driver in some way it
might be better but right now... Especially in a series like this it's
really bad to just see loads of patches which boil down to "change the
semi-documented magic value" - this just makes the series depressing to
read.
Okay, I've just re-read this thread and it appears you're both talking
about different things.
Linus is talking about a discussion with Bengt regarding how these
strange sysclkreq thingies work. When I first read the code they
appear to be equivalent to GPIO regulators, but in actual fact the
hardware logic is different on enable/disable. So they probably don't
belong in regulator code at all.
Where as, Mark is complaining about how the regulators are initialised
by lots of magic register writes during init. Although, comments are
inserted for each of the values, they're by no means exhaustive and
aren't really even helpful if you don't have the uber-s3cr3t design
specification. What he would like to see is that most of this stuff
being handled by the framework. Some of this stuff is clearly only
setting voltages and power-states and the like.
I'd certainly be up for taking this on, but I think an in-depth
knowledge of the AB8500 regulator subsystem would be required.
We got a comment about this some years before and then I thought that it
was best to just initialise the registers because (1) there are many
settings that could not be handled by the regulator framework and (2)
many settings are mixed up in same registers which would lead to many
more write operations. The risk is also that everything gets more
complicated if we mix regulator framework initialisation with our own
initialisation.
I still doubt that letting the framework initialise the regulator
registers is the way to go but of course we should have a look at it. I
agree that the current code is depressing, it does not provide much
understanding. I can go through the register initialisation and propose
what to do with each bit.
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