2021-03-13 08:18:53

by Qii Wang (王琪)

Subject: [PATCH] dt-bindings: i2c: Add device clock-stretch time via dts

From: Qii Wang <[email protected]>

tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device
clock-stretching or circuit loss, we could get device
clock-stretch time from dts to adjust these parameters
to meet the spec via EXT_CONF register.

Signed-off-by: Qii Wang <[email protected]>
---
Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 1 +
1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
index 7f0194f..97f66f0 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
@@ -32,6 +32,7 @@ Optional properties:
- mediatek,have-pmic: platform can control i2c form special pmic side.
Only mt6589 and mt8135 support this feature.
- mediatek,use-push-pull: IO config use push-pull mode.
+ - clock-stretch-ns: Slave device clock-stretch time.

Example:

--
1.9.1

2021-03-25 03:19:23

by Rob Herring

Subject: Re: [PATCH] dt-bindings: i2c: Add device clock-stretch time via dts

On Sat, Mar 13, 2021 at 04:07:09PM +0800, [email protected] wrote:
> From: Qii Wang <[email protected]>
>
> tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device
> clock-stretching or circuit loss, we could get device
> clock-stretch time from dts to adjust these parameters
> to meet the spec via EXT_CONF register.
>
> Signed-off-by: Qii Wang <[email protected]>
> ---
> Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> index 7f0194f..97f66f0 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> @@ -32,6 +32,7 @@ Optional properties:
> - mediatek,have-pmic: platform can control i2c form special pmic side.
> Only mt6589 and mt8135 support this feature.
> - mediatek,use-push-pull: IO config use push-pull mode.
> + - clock-stretch-ns: Slave device clock-stretch time.

Should be a common I2C property?

>
> Example:
>
> --
> 1.9.1
>

2021-03-26 01:33:09

by Qii Wang (王琪)

Subject: Re: [PATCH] dt-bindings: i2c: Add device clock-stretch time via dts

On Wed, 2021-03-24 at 11:12 -0600, Rob Herring wrote:
> On Sat, Mar 13, 2021 at 04:07:09PM +0800, [email protected] wrote:
> > From: Qii Wang <[email protected]>
> >
> > tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device
> > clock-stretching or circuit loss, we could get device
> > clock-stretch time from dts to adjust these parameters
> > to meet the spec via EXT_CONF register.
> >
> > Signed-off-by: Qii Wang <[email protected]>
> > ---
> > Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> > index 7f0194f..97f66f0 100644
> > --- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> > +++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> > @@ -32,6 +32,7 @@ Optional properties:
> > - mediatek,have-pmic: platform can control i2c form special pmic side.
> > Only mt6589 and mt8135 support this feature.
> > - mediatek,use-push-pull: IO config use push-pull mode.
> > + - clock-stretch-ns: Slave device clock-stretch time.
>
> Should be a common I2C property?
>

Wolfram Sang will look at this next and think about it. I hope it would
be a common I2C property.

> >
> > Example:
> >
> > --
> > 1.9.1
> >