>> "Crap origin" here is that in vast majority of cases, polarity is >> per-chip, not per-chip-use, knowledge. And proper location for per-chip >> knowledge is chip's driver. Moving this knowledge to per-chip-use >> location in device trees only provides a source for errors, with little >> gain. >> >> Vladimir Barinov mentions possibility that signal can be inverted by >> board between gpio provider and chip's pin ... but do we have at least >> one practical case of this? And if we even do, it's quite uncommon, and >> something special should be required in device tree for these special >> cases and not for "normal" cases. > > I disagree. Not for hi8435, but I have seen quite some board designs > invert GPIOs before getting them into board level components. That's > why we should define those xxx-gpios properties on board level DTS, > where polarity can be chosen per board design. Even if such, still board specific knowledge is "is gpio as-is or inverted", but knowledge if chip expects signal to be active low or active high, remains chip-specific. I'm thinking of proposing new flags in gpio binding, say GPIO_NATIVE_POLARITY / GPIO_INVERTED_POLARITY, that could be used instead of GPIO_ACTIVE_HIGH / GPIO_ACTIVE_LOW, and leave knowledge about signal polarity to chip's driver, while still allow to describe inversion of needed. Nikita -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
