[1/2] dt-bindings: rockchip-dw-mshc: add optional rockchip, default-num-phases

By default, dw_mmc-rockchip will execute tuning for each degree.
So we won't miss every point of the good sample windows. However,
probably the phases are linear inside the good sample window.
Actually we don't need to do tuning for each degree so that we could
save some time, for instance, probe the driver or resume from S3.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

 Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt | 4 ++++
 1 file changed, 4 insertions(+)

On Wed, Apr 19, 2017 at 05:00:33PM +0800, Shawn Lin wrote:
> By default, dw_mmc-rockchip will execute tuning for each degree.
> So we won't miss every point of the good sample windows. However,
> probably the phases are linear inside the good sample window.
> Actually we don't need to do tuning for each degree so that we could
> save some time, for instance, probe the driver or resume from S3.
> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> ---
> 
>  Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
> index 520d61d..ea47ec0 100644
> --- a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
> +++ b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
> @@ -31,6 +31,10 @@ Optional Properties:
>    probing, low speeds or in case where all phases work at tuning time.
>    If not specified 0 deg will be used.
>  
> +* rockchip,default-num-phases: The default number of times that the host
> +  execute tuning when needed. If not specified, the host will do tuning
> +  for 360 times, namely tuning for each degree.

How is it default when you specify it? I would think default here is 
360.

Should this be common?

Rob
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On Tue, May 02, 2017 at 03:03:03PM +0800, Shawn Lin wrote:
> Hi Rob,
> 
> 在 2017/4/28 21:34, Rob Herring 写道:
> > On Wed, Apr 19, 2017 at 05:00:33PM +0800, Shawn Lin wrote:
> > > By default, dw_mmc-rockchip will execute tuning for each degree.
> > > So we won't miss every point of the good sample windows. However,
> > > probably the phases are linear inside the good sample window.
> > > Actually we don't need to do tuning for each degree so that we could
> > > save some time, for instance, probe the driver or resume from S3.
> > > 
> > > Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> > > ---
> > > 
> > >  Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
> > > index 520d61d..ea47ec0 100644
> > > --- a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
> > > +++ b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
> > > @@ -31,6 +31,10 @@ Optional Properties:
> > >    probing, low speeds or in case where all phases work at tuning time.
> > >    If not specified 0 deg will be used.
> > > 
> > > +* rockchip,default-num-phases: The default number of times that the host
> > > +  execute tuning when needed. If not specified, the host will do tuning
> > > +  for 360 times, namely tuning for each degree.
> > 
> > How is it default when you specify it? I would think default here is
> > 360.
> > 
> 
> I don't get your point here. Do you mean the name, default-num-phases,
> isn't correct, so I need another one?

Right, as we usually say "if not present, the default value is X."

Rob
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