On 10/31/2012 05:59 PM, Simon Glass wrote: > Hi, > > On Fri, Oct 26, 2012 at 12:17 AM, Lucas Stach <d...@lynxeye.de> wrote: >> Am Donnerstag, den 25.10.2012, 19:31 -0700 schrieb Simon Glass: >>> From: Sean Paul <seanp...@chromium.org> >>> >>> Add get and set gpio functions to fdtdec that take into account the >>> polarity field in fdtdec_gpio_state.flags. >>> >> In another thread Stephen Warren and I came to the conclusion that we >> most likely should remove this polarity flag from the GPIO bindings. >> >> Currently it is only for the USB VBUS GPIO which should move over to >> regulators once they land in U-Boot. Do you have any other applications >> for this flag, so we might reconsider removing it? >> > > Well, any time you have a flag which is inverted in meaning, it can be > useful. We have several switches on the board which can be active high > or low, and polarity is used for that. > > In fact, it would be nice IMO to be able to specify input/output as > well. I know the exynos bindings do this. There is a noddy function > called fdtdec_setup_gpio() in U-Boot which really needs to be sorted > out. I discussed with Stephen some time ago how GPIOs should be > SOC-specific and it should be possible to set up a GPIO with a single > call, as Linux does. The more information there is in the binding, the > more it can do automatically. > > Does the Tegra Linux GPIO binding still have a polarity?
Yes it does, although in practice it can't be used (and hence should really be removed), since not all GPIO bindings have such a flag, so there is always a need for a separate property to indicate the polarity (c.f. fixed-regulator with GPIO control bindings for example). _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
