On Thu, 20 May 2021 at 01:41, Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > > On Tue, May 11, 2021 at 10:48 AM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > > > I think this boils down to that to allow the mmc core to detect and > > initialize the SDIO card, it needs to manage potential reset pins as > > well. > > > > In cases when the SDIO func driver may need to execute a reset, the > > mmc core provides two APIs, mmc_hw|sw_reset(). > > > > Does this make sense to you? > > I think so, in this case (Samsung Janice on Ux500) the boot loader > desserts reset so we are fine, but I think it should be utilized properly > somehow, the vendor went to lots of trouble to put this reset line > there physically. > > What is my next step? :D Have a look at the mmc-pwrseq simple DT bindings. Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.yaml If things are as simple as I hope/think, all you should need to do is to add a mmc-pwrseq node where you specify the GPIO reset line. Then from the mmc controller node, just add a phandle to the mmc-pwrseq node and things should just work. :-) git grep mmc-pwrseq should give you a bunch of references of existing users. Kind regards Uffe
