[PATCH 2/4 v6] pinmux: add a driver for the U300 pinmux
Stephen Warren
swarren at nvidia.com
Fri Sep 2 12:04:42 EDT 2011
Linus Walleij wrote at Friday, September 02, 2011 2:12 AM:
> On Thu, Sep 1, 2011 at 11:33 PM, Stephen Warren <swarren at nvidia.com> wrote:
>
> >> +static const struct u300_pmx_func u300_pmx_functions[] = {
> >> + {
> >> + .name = "power",
> >> + .groups = { POWERGRP_INDEX },
> >> + /* Mask is N/A */
> >> + },
> >
> > Hmmm. That's a lot of _INDEX defines that'd need to be set up, at least
> > to fully represent a chip like Tegra. Can the pinmux core be modified
> > such that the group list is an array of names (char*) rather than the
> > actual numeric IDs of the groups? Still, perhaps we could use the enum
> > we already have for this, so perhaps it isn't a big deal...
>
> Well I could think about a lot of ways to do this, but it's basically up
> to the driver, the U300 is just some simple example of what you can
> do, it's just trying to satisfy the API.
>
> Maybe as part of writing the nVidia driver you find a clever
> mechanism for doing this, if it's looking generally useful at that
> point then let's move it to the core I'd say.
The reason I asked about the pinmux core handling this is because the
driver op get_function_groups:
+ int (*get_function_groups) (struct pinctrl_dev *pctldev,
+ unsigned selector,
+ unsigned ** const groups,
+ unsigned * const num_groups);
returns an array of integer indexes. I think the only way to get rid of
the index definitions in the drivers is to allow get_function_groups to
return an array of strings instead.
Well, I suppose the implementation of get_function_groups could convert
from an internal array of strings to the returned array of integers at
run-time, but that doesn't seem like a great idea.
--
nvpublic
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