[RFC 1/3] pinctrl: add a driver for NVIDIA Tegra
tony at atomide.com
Fri Dec 9 12:07:22 EST 2011
* Linus Walleij <linus.walleij at linaro.org> [111209 05:29]:
> On Thu, Dec 8, 2011 at 11:13 PM, Stephen Warren <swarren at nvidia.com> wrote:
> > This adds a driver for the Tegra pinmux, and required parameterization
> > data for Tegra20 and Tegra30.
> > Signed-off-by: Stephen Warren <swarren at nvidia.com>
> This is looking good from a framework point of view (obviously,
> since you've designed the framework with me you sure know what
> you're doing).
> What we could worry about is the amount of hard-coded chip data
> which sort of correlates with the discussion with Tony on how to
> provide DT info for pin control drivers.
> If say this same controller appear in Tegra 4 with no changes but
> different pin names, it makes sense to try to push this into the
> DT as soon as possible, so as to avoid the situation Tony is
> having with the OMAP muxes. If Tegra 4 will be all-new and not even
> related, it doesn't.
> So, just think a bit about it.
> It will fit way better here than any place under
> arch/arm/* in any case, so it's a great achievement!
Sorry I still need some more time with pinmux-simple.c, will have
to get pending omap patches merged first. Just want to recap the
findings so far:
- We can have automatically generated device to pinmux driver
mapping from DT, so that's nice
- Describing pins for each driver in DT is still open.. And
using mixed-property arrays in DT won't nicely as the data
gets unaligned easily with string properties..
- We currently have hard time supporting pin groups with pins
coming from multiple pinmux driver instances
- Mixing pinmux data from various sources is still open; Some
pinmux data may need to be static, some come from DT, some
come from loadable modules or even /lib/firmware if the data
gets insanely big. Basically we may not always have a phandle
in DT data for the pinmux function, and should somehow allow
also using names there
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