Re: MMC: Make the configuration memory resource optional

From: Ian Molton
Date: Wed Jul 29 2009 - 08:37:45 EST


Mark Brown wrote:

Hi Mark,

Looking at the original patch I'm not sure exactly why it runs into
clock API issues so I'm not sure if this is a relevant concern or not
here

The problem for tmio-mmc is that its an MFD driver. The idea behind the MFD framework was to allow drivers that work on similar hardware to work both independantly and as part of a MFD, which often have extra core logic.

Using the clock API is problematic, then, because for MFD based users of tmio-mmc, the clock API isnt useable, but for non-MFD users, it is.

tmio-mmc has (currently) some code in it that uses a second IO range to control both clocks and power on the toshiba family of MFDs. This ideally would be replaced by the clock API and a bunch of power control callbacks that would abstract it out completely from the tmio-mmc driver and into either platform or MFD core code depending on what the user of the driver is.

IOW, using the clock API will fix it for everyone.

> bI'd kind of expect an impact on the
SoCs from addressing it due to the way the clock API functions are
currently provided.

Quite.

-Ian
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