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* [PATCH] i2c: add binding to mark a bus as SMBus
@ 2020-07-01 21:48 Wolfram Sang
  2020-07-15 20:38 ` Rob Herring
  0 siblings, 1 reply; 5+ messages in thread
From: Wolfram Sang @ 2020-07-01 21:48 UTC (permalink / raw)
  To: linux-i2c
  Cc: linux-renesas-soc, devicetree, Alain Volmat, Rob Herring, Wolfram Sang

SMBus is largely compatible with I2C but there are some specifics. In
case we need them on a bus, we can now use this new binding.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 Documentation/devicetree/bindings/i2c/i2c.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
index 438ae123107e..d1f8cf3bd236 100644
--- a/Documentation/devicetree/bindings/i2c/i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c.txt
@@ -77,6 +77,11 @@ wants to support one of the below features, it should adapt these bindings.
 	this information to detect a stalled bus more reliably, for example.
 	Can not be combined with 'multi-master'.
 
+- smbus
+	states that additional SMBus restrictions and features apply to this bus.
+	Examples of features are SMBusHostNotify and SMBusAlert. Examples of
+	restrictions are more reserved addresses and timeout definitions.
+
 Required properties (per child device)
 --------------------------------------
 
-- 
2.27.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] i2c: add binding to mark a bus as SMBus
  2020-07-01 21:48 [PATCH] i2c: add binding to mark a bus as SMBus Wolfram Sang
@ 2020-07-15 20:38 ` Rob Herring
  2020-07-24 19:36   ` Wolfram Sang
  0 siblings, 1 reply; 5+ messages in thread
From: Rob Herring @ 2020-07-15 20:38 UTC (permalink / raw)
  To: Wolfram Sang; +Cc: linux-i2c, linux-renesas-soc, devicetree, Alain Volmat

On Wed, Jul 01, 2020 at 11:48:30PM +0200, Wolfram Sang wrote:
> SMBus is largely compatible with I2C but there are some specifics. In
> case we need them on a bus, we can now use this new binding.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>  Documentation/devicetree/bindings/i2c/i2c.txt | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> index 438ae123107e..d1f8cf3bd236 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> @@ -77,6 +77,11 @@ wants to support one of the below features, it should adapt these bindings.
>  	this information to detect a stalled bus more reliably, for example.
>  	Can not be combined with 'multi-master'.
>  
> +- smbus

This is a boolean?

> +	states that additional SMBus restrictions and features apply to this bus.
> +	Examples of features are SMBusHostNotify and SMBusAlert. Examples of

Do features need to be enumerated separately?

> +	restrictions are more reserved addresses and timeout definitions.
> +
>  Required properties (per child device)
>  --------------------------------------
>  
> -- 
> 2.27.0
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] i2c: add binding to mark a bus as SMBus
  2020-07-15 20:38 ` Rob Herring
@ 2020-07-24 19:36   ` Wolfram Sang
  2020-07-25 12:07     ` Wolfram Sang
  0 siblings, 1 reply; 5+ messages in thread
From: Wolfram Sang @ 2020-07-24 19:36 UTC (permalink / raw)
  To: Rob Herring; +Cc: linux-i2c, linux-renesas-soc, devicetree, Alain Volmat


[-- Attachment #1: Type: text/plain, Size: 1391 bytes --]

Hi Rob,

> > SMBus is largely compatible with I2C but there are some specifics. In
> > case we need them on a bus, we can now use this new binding.
> > 
> > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> > ---
> >  Documentation/devicetree/bindings/i2c/i2c.txt | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> > index 438ae123107e..d1f8cf3bd236 100644
> > --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> > +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> > @@ -77,6 +77,11 @@ wants to support one of the below features, it should adapt these bindings.
> >  	this information to detect a stalled bus more reliably, for example.
> >  	Can not be combined with 'multi-master'.
> >  
> > +- smbus
> 
> This is a boolean?

Yes.

> 
> > +	states that additional SMBus restrictions and features apply to this bus.
> > +	Examples of features are SMBusHostNotify and SMBusAlert. Examples of
> 
> Do features need to be enumerated separately?

They could be, do you think this is of advantage? For now, we would then
need "host-notify" and "smbus-alert". Maybe later things like "timeout"
could show up.

> 
> > +	restrictions are more reserved addresses and timeout definitions.
> > +

All the best,

   Wolfram


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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] i2c: add binding to mark a bus as SMBus
  2020-07-24 19:36   ` Wolfram Sang
@ 2020-07-25 12:07     ` Wolfram Sang
  2020-07-29 10:53       ` Wolfram Sang
  0 siblings, 1 reply; 5+ messages in thread
From: Wolfram Sang @ 2020-07-25 12:07 UTC (permalink / raw)
  To: Rob Herring; +Cc: linux-i2c, linux-renesas-soc, devicetree, Alain Volmat


[-- Attachment #1: Type: text/plain, Size: 1739 bytes --]

On Fri, Jul 24, 2020 at 09:36:35PM +0200, Wolfram Sang wrote:
> Hi Rob,
> 
> > > SMBus is largely compatible with I2C but there are some specifics. In
> > > case we need them on a bus, we can now use this new binding.
> > > 
> > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> > > ---
> > >  Documentation/devicetree/bindings/i2c/i2c.txt | 5 +++++
> > >  1 file changed, 5 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> > > index 438ae123107e..d1f8cf3bd236 100644
> > > --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> > > +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> > > @@ -77,6 +77,11 @@ wants to support one of the below features, it should adapt these bindings.
> > >  	this information to detect a stalled bus more reliably, for example.
> > >  	Can not be combined with 'multi-master'.
> > >  
> > > +- smbus
> > 
> > This is a boolean?
> 
> Yes.
> 
> > 
> > > +	states that additional SMBus restrictions and features apply to this bus.
> > > +	Examples of features are SMBusHostNotify and SMBusAlert. Examples of
> > 
> > Do features need to be enumerated separately?
> 
> They could be, do you think this is of advantage? For now, we would then
> need "host-notify" and "smbus-alert". Maybe later things like "timeout"
> could show up.

I also recall now that I thought that "smbus" fits better the
"describing hardware" aspect, i.e. "this bus is an SMBus and not I2C".
Enumerating features felt more like configuration to me.

> 
> > 
> > > +	restrictions are more reserved addresses and timeout definitions.
> > > +
> 
> All the best,
> 
>    Wolfram
> 



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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] i2c: add binding to mark a bus as SMBus
  2020-07-25 12:07     ` Wolfram Sang
@ 2020-07-29 10:53       ` Wolfram Sang
  0 siblings, 0 replies; 5+ messages in thread
From: Wolfram Sang @ 2020-07-29 10:53 UTC (permalink / raw)
  To: Rob Herring; +Cc: linux-i2c, linux-renesas-soc, devicetree, Alain Volmat


[-- Attachment #1: Type: text/plain, Size: 1727 bytes --]


> > > > SMBus is largely compatible with I2C but there are some specifics. In
> > > > case we need them on a bus, we can now use this new binding.
> > > > 
> > > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> > > > ---
> > > >  Documentation/devicetree/bindings/i2c/i2c.txt | 5 +++++
> > > >  1 file changed, 5 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> > > > index 438ae123107e..d1f8cf3bd236 100644
> > > > --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> > > > +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> > > > @@ -77,6 +77,11 @@ wants to support one of the below features, it should adapt these bindings.
> > > >  	this information to detect a stalled bus more reliably, for example.
> > > >  	Can not be combined with 'multi-master'.
> > > >  
> > > > +- smbus
> > > 
> > > This is a boolean?
> > 
> > Yes.
> > 
> > > 
> > > > +	states that additional SMBus restrictions and features apply to this bus.
> > > > +	Examples of features are SMBusHostNotify and SMBusAlert. Examples of
> > > 
> > > Do features need to be enumerated separately?
> > 
> > They could be, do you think this is of advantage? For now, we would then
> > need "host-notify" and "smbus-alert". Maybe later things like "timeout"
> > could show up.
> 
> I also recall now that I thought that "smbus" fits better the
> "describing hardware" aspect, i.e. "this bus is an SMBus and not I2C".
> Enumerating features felt more like configuration to me.

Rob, if you have a minute to comment on it, I would much appreciate it.
I'd love to get this into 5.9.

Thanks and all the best!


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^ permalink raw reply	[flat|nested] 5+ messages in thread

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Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2020-07-01 21:48 [PATCH] i2c: add binding to mark a bus as SMBus Wolfram Sang
2020-07-15 20:38 ` Rob Herring
2020-07-24 19:36   ` Wolfram Sang
2020-07-25 12:07     ` Wolfram Sang
2020-07-29 10:53       ` Wolfram Sang

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