[U-Boot] [PATCH] rockchip: rk3288: dts: remove 'vmmc' from emmc node

Heiko Stuebner
2018-12-04T14:49:26Z

Am Dienstag, 4. Dezember 2018, 10:35:48 CET schrieb Philipp Tomsich:
> Kever,
>
> > On 04.12.2018, at 08:06, Kever Yang <kever.yang@rock-chips.com> wrote:
> >
> > Hi Fabio,
> >
> >
> > On 12/03/2018 07:27 PM, Fabio Estevam wrote:
> >> Hi Kever,
> >>
> >> On Mon, Dec 3, 2018 at 2:00 AM Kever Yang <kever.yang@rock-chips.com> wrote:
> >>> The U-Boot eMMC does not need to care about the power for Rockchip
> >>> SoC, because if the board is using eMMC, the power will default on
> >>> (for bootrom), and we do not do power management for it like kernel,
> >>> so the 'vmmc', 'vqmmc' is only useful for SD in U-Boot.
> >> Devicetree should represent the hardware and should not rely on
> >> details of BootROM / kernel / U-Boot.
> >>
> >> If these supplies are present in the hardware, they should be
> >> represented in the devicetree.
> >>
> >> What is the exact issue you are trying to solve?
> >
> > The U-Boot will fail to boot if eMMC driver try to enable the regulator
> > with error return.
> > These two nodes makes the eMMC driver need depends on pmic/regulator driver
> > works good.
> > My case is I have two similar boards, but have different pmic or pmic
> > config,
> > then only the one with correct config can boot successful.
> > I know you would ask me to commit a new dts with correct pmic config,
> > but please
> > note that there are much much more boards then what the upstream already
> > have.
> > We are not possible to add every board, and I don't think we have to.
>
> These boards should have their own DTS, as that’s the main function of
> the DTS (i.e. to describe the actual hardware).
>
> Why is it not possible to add these boards?

I'd also like to have each board represented correctly.

I think the main issue for Kever is, that each marketed device (hundreds?)
is largely following a reference design for the soc with smallish per-
board changes for their relevant features. So I guess the hope is that
it will save effort if there is common devicetree/board.

While these largely similar dts are somewhat of a concern, on the kernel-
side I try to only allow shared files for boards of the same vendor ... aka
when it really is safe to assume that everybody knows what really is shared
like the Vamrs Ficus+Rock960 or of course the Google-Gru series of devices.

Heiko