Messages in this thread | | | Date | Thu, 24 Apr 2014 15:26:20 +0200 | From | Thomas Petazzoni <> | Subject | Re: [PATCH v2 0/7] ARM: berlin: add pinctrl support |
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Dear Linus Walleij,
On Thu, 24 Apr 2014 14:52:20 +0200, Linus Walleij wrote:
> > Tested on the Berlin BG2Q. > > So now I need some advice from the mvebu pinctrl maintainers > (Thomas, Sebastian etc): > > - Is this a totally different pin controller so that drivers/pinctrl/mvebu > can not be used?
It is. The CPU families are completely different, made from completely separate divisions of Marvell. Just think that they come from different companies :-)
On the mvebu side, each pin can be independently configured to a different function: there is a 4-bits field for each pin to configure the function.
On the berlin side, pins are only configured in groups. You can't independently set the functions of each pin: you can set a function to a pre-defined set of pins.
> - Really?
Yes.
> - OK can you help me review this thing?
Sure. I believe Sebastian already had a very detailed look so he can provide his review.
> - Should the base folder really be named "berlin" or is this going to > be part of a bigger family of pin controllers so a more neutral name > should be sought?
berlin is the name of the mach-<foo> directory in arch/arm, and that's really the code name for this SoC family.
> - Why do hardware engineers seek to reinvent wheels like pin > controllers, GPIO and DMA engines all the time :-/
I guess Russell already gave you a good answer to this question :-)
Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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