Hi, On 09-03-16 11:50, Maxime Ripard wrote:
Hi, The axp209 PMIC used in combination to some Allwinner SoCs has a bunch of GPIOs accessible. Some boards use these to control their backlight or a few LEDs.
Thanks for working on this, but IMHO this cannot go upstream like this, the gpio pins on the axp pmics need a pinctrl driver, not a gpio driver. I.E. on the axp209 gpio0 and gpio1 can also be used to output an additional low-noise ldo (so as a regulator), or as an adc input. I've been working on gsl1680 touchscreen support lately and on at least a few a23 tablets, the low-noise ldo is used as AVCC for the touchscreen controller. Now these use an axp223 pmic, but nothing is stopping someone from doing something similar with an axp209 and I think it would be best to support this from day one, rather then hope we can retro-fit this later without breaking dts.
There's supposed to be 4 of them, but the fourth one has a different configuration register scheme, and I couldn't find any board that was using this GPIO. It will be probably be supported eventually, but until then, we support only the first 3 GPIOs.
He he, this matches what I've done in u-boot, the 4th gpio indeed is somewhat funky (and the docs are not quite clear on how it works exactly IIRC), leaving it out for now indeed seems for the best. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
