Can't access mmc #0 on mt7623 when booted from external SD

[David Woodhouse]

On Thu, 2020-06-18 at 21:34 +0200, Michael Nazzareno Trimarchi wrote:
> > Looks like the pinctrl driver. This *ought* to work (with the caveat
> > that I really ought to make two pinctrl setups and change between them
> > according to the voltage, like the Linux DT and mtk-sd driver do).
> > 
> > --- a/arch/arm/dts/mt7623n-bananapi-bpi-r2.dts
> > +++ b/arch/arm/dts/mt7623n-bananapi-bpi-r2.dts
> > @@ -133,12 +133,14 @@
> >                                 "MSDC0_DAT2", "MSDC0_DAT3", "MSDC0_DAT4",
> >                                 "MSDC0_DAT5", "MSDC0_DAT6", "MSDC0_DAT7";
> >                          input-enable;
> > -                       bias-pull-up;
> > +                       drive-strength = <2>;
> > +                       bias-pull-up = <3>;
> >                  };
> > 
> >                  conf-clk {
> >                          pins = "MSDC0_CLK";
> > -                       bias-pull-down;
> > +                       drive-strength = <2>;
> > +                       bias-pull-down = <3>;
> >                  };
> > 
> >                  conf-rst {
> > 
> > 
> > But it doesn't work. Partly because the U-Boot mtk pinctrl driver
> > doesn't support the R0 R1 bits encoded in that <3>, and partly because
> > it doesn't *even* get pullup/pulldown right at all; it sets the bit in
> > the GPIO_PULLSEL registers but *not* the PUPD bit in the correct
> > register for MSDC and other pins.
> 
> So change them manually, make it work, You have the board. I don't
> have any MediaTek board at the moment. Can you implement the missed part?

I think I'd rather let the MediaTek folks handle it, as it affects
other SoCs too.

It turns out Linux has a pinctrl-mt7623.c driver which looks a lot like
the U-Boot one, but *isn't* actually the one being used, because in
Linux it only matches "mediatek,mt7623-moore-pinctrl" which isn't in
this board's DT.

Linux also has a pinctrl-mt2701.c driver that matches the
"mediatek,mt7623-pinctrl" that *is* on this board, and which *does*
work correctly.

So I don't know if we just have the wrong driver in U-Boot. Or if the
mediatek,mt7623-moore-pinctrl compatible string is a temporary name for
the *same* hardware, to invoke the new driver that isn't complete yet
so it isn't being used in Linux... but is in U-Boot?

Sean?

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 5174 bytes
Desc: not available
URL: <https://lists.denx.de/pipermail/u-boot/attachments/20200618/04c310d1/attachment.bin>