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Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller

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On Thursday, November 24, 2016 10:05:45 AM CET Ulf Hansson wrote:
> > You also mentioned other bindings using child nodes, but for this one
> > we have one controller with only one set of register with multiple slots
> > (Atmel is an example). Here each slot have it own set of register.
> >
> > Actually giving the fact that each slot is controlled by a different set
> > of register I wonder why the hardware can't also deduce the slot number
> > from the address register. For me it looks like an hardware bug but we
> > have to deal with it.
> >
> > Do you still think we needchild node here?
> 
> Using child-nodes for slots like what's done in the atmel case, is
> currently broken. I would recommend to avoid using child-nodes for
> slots, if possible.
> 
> To give you some more background, currently the mmc core treats child
> nodes as embedded non-removable cards or SDIO funcs. However, we can
> change to make child-nodes also allowed to describe slots, but it
> requires a specific compatible for "slots" and of course then we also
> need to update the DT parsing of the child-nodes in the mmc core.
> 
> Documentation/devicetree/bindings/mmc/mmc.txt
> Documentation/devicetree/bindings/mmc/mmc-card.txt

I don't see anything wrong with having child nodes for the slots
even with the current binding, under one condition:

The mmc.txt binding above must refer only to the child node, while
the parent node conceptually becomes a plain bus or MFD that
happens to encapsulate multiple MMC host controllers, and possibly
provides some shared registers to them.

	Arnd

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Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller Gregory CLEMENT <gregory.clement@free-electrons.com> - 2016-11-22 18:40 +0100
  Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller Ulf Hansson <ulf.hansson@linaro.org> - 2016-11-24 10:10 +0100
    Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller Arnd Bergmann <arnd@arndb.de> - 2016-11-24 10:20 +0100
      Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller Gregory CLEMENT <gregory.clement@free-electrons.com> - 2016-11-24 10:30 +0100
        Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller Arnd Bergmann <arnd@arndb.de> - 2016-11-24 10:40 +0100
          Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD  Host Controller Thomas Petazzoni <thomas.petazzoni@free-electrons.com> - 2016-11-24 10:50 +0100
            Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller Arnd Bergmann <arnd@arndb.de> - 2016-11-24 11:10 +0100
          Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host Controller Marcin Wojtas <mw@semihalf.com> - 2016-11-24 10:50 +0100
            Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD  Host Controller Thomas Petazzoni <thomas.petazzoni@free-electrons.com> - 2016-11-24 11:20 +0100
              Re: [PATCH 5/10] dt: bindings: Add bindings for Marvell Xenon SD Host  Controller Ziji Hu <huziji@marvell.com> - 2016-11-24 11:40 +0100

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