Hello Caesar, On 01/07/2016 05:25 AM, Caesar Wang wrote: > This patch enables support for power-on sequencing of SDIO > peripherals through DT. > I think the subject line and this first paragraph are misleading since the simple power sequence provider already supports power-on sequencing. This patch does not add or enable support but extends the current support to also enable a regulator as a part of the SDIO chip power on sequencing. > In general, it's quite common that wifi modules and other similar > peripherals have several signals in addition to the SDIO interface that > needs wiggling before the module will power on. > > 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? > 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. > Anyway, we can add this patch to supprt the power-on sequencing for s/supprt/support > sdio. > > Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx> > Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
