Hi Maxime, Am Montag, den 11.08.2014, 19:33 +0200 schrieb Maxime Ripard: > > Mostly because Maxime and I seem to have a completely different opinion > > and nobody else argued one way or the other. > > Yep, mostly because I don't see how a generic approach can work. > > The existing reset-gpios property only provide the gpio to use, but > some informations are encoded in the driver, such as the reset > duration, or a reset sequence if any. The driver should provide the duration. I'd really like to see an example where sequencing is necessary. I agree that as soon as things get significantly more complicated than pulsing a single GPIO, the reset-gpios binding is too limited. Still, I'm not happy to mandate a separate gpio reset device for each reset line if most devices are simple enough for it to work without. What about using reset-gpios for the majority of simple cases and have a separate gpio-reset-sequencer driver when multiple GPIO resets have to be timed? > How do you plan on giving that information to your generic driver? > > The only solution I can think of would be to add an extra property > that your code would parse. But then, you break the existing DT > bindings. > > And if we're going to break those bindings, at least do it in a way > consistent with reset bindings. For the backwards compatibility case, the driver already has to provide the duration. I don't want to break the existing bindings at all. > Plus, your approach doesn't cover the weird corner cases such as: > - reset-gpio > - wlf,reset-gpios > - phy-reset-gpios > - snps,reset-gpio > - the drivers that need several gpio and expect the reset one as a > positional argument. > - etc. Those are just an issue of the implementation I posted earlier because gpiod_get doesn't support custom names other than %s-gpios. This could be extended and handled just as well if deemed necessary. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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