On 26 Jun 2010, at 18:37, Linus Walleij wrote: > 2010/6/25 Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>: >> >> So, the feedback from folks at the time this was originally written was >> that the MMC code was unable to cope with sharing regulators since it >> really needs to be able to set specific voltages. This needn't be a >> showstopper since people can force a single voltage in the constraints >> but it does need to be considered here. > Well hm, that's not strictly true. If you only provide one standard > voltage ONLY in your OCR mask, i.e. MMC_VDD_* then you can use > the same regulator for two or more MMC cards. This is what I'm saying about forcing a voltage in the constraints - the existing code should i believe implement the above automatically. > Further that's a perfectly reasonable thing to do if you have e.g. > two embedded eMMC cards and you know which voltage they like > to operate on ... so share the same regulator, why not. The above > assumption comes from a slot-based world. Right, but this code supports all MMC cards. To repeat what I said above this does need to be considered here. I don't think it's a particular problem, probably just turning it into a consumer capable of sharing the regulator would be enough. > Another argument is that a function named > mmc_regulator_set_ocr() shouldn't be enabling/disabling regulators > anyway because it's hopeless to read the code, and the other > functions in mmc/core.c only deals with voltages, not on/off:ing. > (Maybe it's just me who have a hard time reading code like that.) This seems rather surprising - are you saying that no other MMC drivers are able to manage power to the slot? There was a strong insistence when this code was originally written that it was essential to be able to power up and down the regulators for MMC applications. -- 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
