[snip] >> >> We don't typically actually bind multiple compatibles for a single >> device. We've got a bunch of options we can choose from but we >> generally pick the one that matches best and ignore the others. >> >>> Where as what you're suggesting is to always pick driver foo, unless >>> driver bar is available and has a special flag saying to not use foo, this >>> is a whole new way to use compatibles really, and not one which I think >>> we want to introduce. >> >> I'm not sure I'm buying the idea that we have a powerup driver that's >> meaningfully not part of the main device driver. I am having a bit hard to follow the terminology here. :-) What is a "powerup driver" and what is a "main device driver" in this context? I had a slide which I used at a mmc subsystem crash course recently, please have a look - hopefully this will help us to sort out this. https://drive.google.com/file/d/0B2ePGK-iqMupbDQ2S0o5b3Bhek0/edit?usp=sharing > > Well, if we merge some variant of Olof's code, we will have a powerup driver > that is part of the mmc core, and thus not of the sdio function driver. > >>>> Well, if things aren't going to work either way for these devices >>>> without extra stuff it seems it doesn't much matter but it helps the >>>> simple case to have things default to working. >> >>> The simple case still needs a child node describing the needed resources, >>> adding a compatible = "simple-sdio-powerup" to that at the same as creating >>> the child node in the first place really is no extra effort at all. >> >> From where I'm sitting it's more effort since instead of just putting >> the device in there (and possibly also some other devices that are >> software compatible) we have to put in another compatible string which >> is really just a boolean flag to be used in conjunction with the others. >> That's harder to think about and we clearly don't want to go through the >> compatible list, decide that we don't know how to handle the device >> except power it up so go and do that. >> >> If it were done as something like "set boolean property X or >> powerup-method = Y in the card description" or whatever it'd seem a bit >> annoying but not a big deal, I think it's the fact that it's getting put >> into the compatible list that's really concerning me. > > Ok, so lets switch it over to a boolean, options for the name I see are: > > linux,mmc-host-powerup (opt in to powerup being dealt with by the mmc core, implementation specific) > simple-powerup (platform neutral opt in to say just enable all resources and be done with it) > custom-powerup (platform neutral opt out version of simple-powerup) > linux,custom-powerup (same, but consider this something linux specific) This seems reasonable to me. Well, I don't like the "simple-powerup", because I think a simple powerup sequence is to me already supported by the mmc core, through the regular host interface (->set_ios()). If I understand correctly, this binding is supposed to be configured per host device and thus also per host device slots? Kind regards Ulf Hansson -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
