[PATCH 0/5] MMC: mmci: Provide bindings for Device Tree

[Linus Walleij]

On Thu, Mar 15, 2012 at 9:58 PM, Arnd Bergmann <arnd at arndb.de> wrote:
> [Per]
>> The stedma40 filter function is not really specific for ux500. ux500
>> use stedma40 but it should be possible to replace this DMA.IP with
>> some other DMA-controller. This is board specific configuration. You
>> should not need to change the mmci-driver just because the dma-driver
>> has changed, right?
>> Or will the board-configuration now be placed in mmci-ux500?
>
> Right, the DMA configuration does not really belong in there, but
> the voltage setup might (unless we convert that to the regulator
> setup).

The voltage to power the card is already using the regulator
framework with the MMC-specific helpers in the MMCI driver.

But I guess you're after modelling the levelshifter as a regulator?

Basically the level shifter is a separate device has two voltage
inputs A and B (from other regulators) that is controlled by a
simple GPIO to select voltage A or B to drive the signals to
the card.

That could probably be modelled as a regulator with two
volategs for sure, but then we should maybe create a more
generic "struct level_shifter_regulator" (or whatever) for the
concept as a whole.

Let's page Mark about what to do with levelshifters and whether
they are regulators of sorts in his book.

Yours,
Linus Walleij