Messages in this thread | | | From | Ulf Hansson <> | Date | Fri, 27 Jan 2017 16:36:36 +0100 | Subject | Re: [PATCH v5 05/12] dt: bindings: Add bindings for Marvell Xenon SD Host Controller |
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> > OK, but maybe we could keep the part about the mmcard for the eMMC to > emphasize that we need to setup this option for the controller.
Right!
> >>> + >>> +- no-1-8-v: >>> + Select this property when 1.8V signaling voltage supply is unavailable. >>> + When this property is enabled, both mmc-ddr-1_8v and mmc-hs400-1_8v should be >>> + cleared. >> >> Please don't use this sdhci property, unless really needed. > > Actually this is a mmc property, at least it is described in this the > mmc binding: > Documentation/devicetree/bindings/mmc/mmc.txt
Yes, the documentation is wrong. It should we be moved into the docs for sdhci.
I will send a patch updating it. Apologize for the misleading information.
> > The description of this optional property is: > "no-1-8-v: when present, denotes that 1.8v card voltage is not supported on > this system, even if the controller claims it is." > > So as it is also part of the mmc binding we can remove it from our > bindings as we are going to do it for the other mmc property.
Nope.
> > But I am curious to know why do you think we could use it without any > need. Are you aware of some abuse of this property?
Yes.
> >> >> Perhaps you can elaborate exactly why it makes sense for your case. Or >> perhaps we already discussed this, in either case, please re-fresh my >> mind. > > For instance we need it now on the 7040DB board which does not have the > 1.8V signal voltage available.
It it's better to describe what the controller/board support, instead of what it doesn't.
I think you should be able to use other existing mmc DT bindings (perhaps also you need the brand new "mmc-ddr-3_3v"), instead of the "no-1-8-v".
Kind regards Uffe
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