Hi Javier, ? 2016?01?12? 00:02, Javier Martinez Canillas ??: > Hello Heiko, > > On 01/08/2016 11:42 PM, Heiko Stuebner wrote: >> Am Freitag, 8. Januar 2016, 09:22:31 schrieb Javier Martinez Canillas: >>>> For example: >>>> we need enable wifi module power to via the WL_REG_ON >>>> pin, we need enable it as the regulator if this pin is connected to >>>> the gpio of cpu. >>> This part confuses me, so does your chip have an actual regulator that >>> needs to be enabled or is just a fake regulator whose gpio property is >>> used not to enable the regulator but to toggle the WL_REG_ON pin of >>> the WiFi chip? >> another option would be to use the reset-gpio-handles. rk3288-veyron and I >> think some Exynos as well use it that way. >> > Yes I know, my point was that the reset-gpios property should be used > instead of a fake regulator if what's needed is to toggle a chip pin. > >>>> Maybe, someone will say that can pull up/down from dts. >>>> Unfortunately some SoCs can't support pinctrl pull up/down in >>>> internal. >>> Can you please elaborate on this? AFAIU this limitation is the reason >>> why you went with the regulator approach so I think it deserve a more >>> deep explanation. >> On the rk3036 each pin has an individual unchangable pull direction. So it's >> either no bias or pulling in the predefined direction (the pin_default bias >> option). >> > I think each change has to be justified on its own so I would say that > having a regulator enabled as a part of a SDIO chip's power sequencing > is something needed for many platforms, and that this provider should > be extended to support that (something like commit msg in patch 05/12). > > And then in the kylin DTS change (patch 08/12), I would explain why a > chained regulators approach is used/needed instead of the reset-gpios > due any platform limitations. Okay, I 'm agreed with your points in here. The reset-gpios/pwrsq can meet the demand of some wlan chips trigger condition. No matter whatever is the BT_EN or WL_EN triggers pin. >> Heiko >> > Best regards, -- Thanks, Caesar
