On Thu, Aug 09, 2018 at 05:06:04PM +0300, Aapo Vienamo wrote: > On Thu, 9 Aug 2018 15:46:48 +0200 > Thierry Reding <thierry.reding@xxxxxxxxx> wrote: > > > On Thu, Aug 09, 2018 at 02:45:15PM +0300, Aapo Vienamo wrote: > > > On Thu, 9 Aug 2018 13:36:09 +0200 > > > Thierry Reding <thierry.reding@xxxxxxxxx> wrote: > > > > > > > On Tue, Aug 07, 2018 at 04:59:57PM +0300, Aapo Vienamo wrote: > > > > > Document HS400 DQS trim value device tree property. > > > > > > > > > > Signed-off-by: Aapo Vienamo <avienamo@xxxxxxxxxx> > > > > > --- > > > > > Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt | 3 +++ > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt > > > > > index 3c7960a..7d294f3 100644 > > > > > --- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt > > > > > +++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt > > > > > @@ -72,6 +72,7 @@ Optional properties for Tegra210 and Tegra186: > > > > > trimmer value for non-tunable modes. > > > > > - nvidia,default-trim : Specify the default outbound clock trimmer > > > > > value. > > > > > +- nvidia,dqs-trim : Specify DQS trim value for HS400 timing > > > > > > > > > > Notes on the pad calibration pull up and pulldown offset values: > > > > > - The property values are drive codes which are programmed into the > > > > > @@ -88,6 +89,8 @@ Optional properties for Tegra210 and Tegra186: > > > > > - The values are programmed to the Vendor Clock Control Register. > > > > > Please refer to the reference manual of the SoC for correct > > > > > values. > > > > > + - The DQS trim values are only used on controllers which support > > > > > + HS400 timing. > > > > > > > > One of these additions says "DQS trim values", the other says "DQS trim > > > > value". It is unclear from the above how many values there are. I think > > > > this should be more explicit. Also, I don't see why the note about which > > > > controllers the DQS trim value(s) applies to is in a separate paragraph. > > > > Couldn't it be moved to the property description? > > > > > > It's a single value. The plural form is a mistake. > > > > > > > Also, I think the bindings should specify which generations of Tegra do > > > > support HS400. Where else are people supposed to find that information? > > > > > > This property is under the "Optional properties for Tegra210 and > > > Tegra186" section and it only applies for the said generations. > > > > What's the point of specifying that they are only used on controllers > > which support HS400? Are you saying that only a subset of the SDHCI > > controllers on Tegra210 and Tegra186 support HS400? > > Yes, on Tegra210 and Tegra186 only SDMMC4 supports HS400. Good. I think that'd be good to have as part of the DT bindings documentation. Thierry
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