Re: [PATCH] i2c: document the SDA hold time binding

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Sorry I didn't keep the addition of Jarkko to the CC list.

On Wed, Feb 13, 2019 at 11:24:37AM +0100, Ludovic Desroches wrote:
> Hi Wolfram,
> 
> On Mon, Feb 11, 2019 at 02:25:15PM +0100, Wolfram Sang wrote:
> > The documentation was forgotten when the feature was added.
> > 
> > Fixes: 4717be73c284 ("i2c: core: Parse SDA hold time from firmware")
> > Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> > ---
> > 
> > To everyone on CC: I want to confirm here that you use the value really for
> > t(hd:sta) and not t(hd:dat). I'd be a little confused otherwise...
> 
> 
> No in our case, it's t(hd:dat):
> TWD is kept unchanged after TWCK falling edge for a
> period of (HOLD + 3) × t peripheral clock
> 
> 
> Ludovic
> 
> > 
> >  Documentation/devicetree/bindings/i2c/i2c.txt | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> > index 44efafdfd7f5..b7bc4c4cc2e6 100644
> > --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> > +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> > @@ -55,6 +55,10 @@ wants to support one of the below features, it should adapt the bindings below.
> >  	Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C
> >  	specification.
> >  
> > +- i2c-sda-hold-time-ns
> > +	Number of nanoseconds the SDA signal needs to be held; t(hd:sta) in
> > +	the I2C specification.
> > +
> >  - interrupts
> >  	interrupts used by the device.
> >  
> > -- 
> > 2.11.0
> > 



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