Messages in this thread | | | Date | Tue, 14 Apr 2020 19:39:21 +0100 | From | Mark Brown <> | Subject | Re: [PATCH v2 10/16] gpio: add a reusable generic gpio_chip using regmap |
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On Tue, Apr 14, 2020 at 08:36:23PM +0200, Michael Walle wrote: > Am 2020-04-14 19:21, schrieb Mark Brown:
> > You could define REGMAP_INVALID_ADDR to be (unsigned int)(-1) or some > > other suitably implausible address and use that as a value. It's > > possible that there might be a collision with a real address on some > > device but it should be sufficiently unlikely to be useful, especially > > if it's not something regmap in general goes and evaluates. For extra > > safety we could have an API for allowing users to query the register > > validity information regmap has (or can be given) and gpiolib could then > > use that to figure out if the value was actually a dummy value but > > that's probably overdoing it.
> If possible, I'd like to have the opposite logic. That is, if it is not > set it should be invalid. If we have a magic macro like > REGMAP_INVALID_ADDR, we must assign it to all the unused addresses. Thus > every driver would have to assign all addresses and if in the future > there will be some added, we'd have to touch all the drivers which use > gpio_regmap.
Sure, for that you'd need a separate flag since zero is such a commonly valid address. [unhandled content-type:application/pgp-signature] | |