[RFC,5/7] dt-bindings: regulator: bd9576 add FET ON-resistance for OCW

BD9576MUF provides over-current protection and detection. Current is
measured as voltage loss over external FET. Allow specifying FET's on
resistance so current monitoring limits can be converted to voltages.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
 .../devicetree/bindings/regulator/rohm,bd9576-regulator.yaml | 5 +++++
 1 file changed, 5 insertions(+)

On Thu, Feb 11, 2021 at 02:35:41PM +0200, Matti Vaittinen wrote:
> BD9576MUF provides over-current protection and detection. Current is
> measured as voltage loss over external FET. Allow specifying FET's on
> resistance so current monitoring limits can be converted to voltages.
> 
> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
> ---
>  .../devicetree/bindings/regulator/rohm,bd9576-regulator.yaml | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/regulator/rohm,bd9576-regulator.yaml b/Documentation/devicetree/bindings/regulator/rohm,bd9576-regulator.yaml
> index b6515a0cee62..ad3f57e9cd9b 100644
> --- a/Documentation/devicetree/bindings/regulator/rohm,bd9576-regulator.yaml
> +++ b/Documentation/devicetree/bindings/regulator/rohm,bd9576-regulator.yaml
> @@ -27,6 +27,11 @@ patternProperties:
>        Properties for single regulator.
>      $ref: "regulator.yaml#"
>  
> +    properties:
> +      rohm,ocw-fet-ron-milliohms:

We have '-ohms' and '-micro-ohms' already. Neither range works for you?

> +      description: External FET's ON-resistance. Required if VoutS1 OCP/OCW is
> +        to be set.
> +
>      required:
>        - regulator-name
>  
> -- 
> 2.25.4
> 
> 
> -- 
> Matti Vaittinen, Linux device drivers
> ROHM Semiconductors, Finland SWDC
> Kiviharjunlenkki 1E
> 90220 OULU
> FINLAND
> 
> ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
> Simon says - in Latin please.
> ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
> Thanks to Simon Glass for the translation =]

Morning Rob,

On Wed, 2021-02-17 at 15:34 -0600, Rob Herring wrote:
> On Thu, Feb 11, 2021 at 02:35:41PM +0200, Matti Vaittinen wrote:

> > BD9576MUF provides over-current protection and detection. Current

> > is

> > measured as voltage loss over external FET. Allow specifying FET's

> > on

> > resistance so current monitoring limits can be converted to

> > voltages.

> > 

> > Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>

> > ---

> >  .../devicetree/bindings/regulator/rohm,bd9576-regulator.yaml | 5

> > +++++

> >  1 file changed, 5 insertions(+)

> > 

> > diff --git

> > a/Documentation/devicetree/bindings/regulator/rohm,bd9576-

> > regulator.yaml

> > b/Documentation/devicetree/bindings/regulator/rohm,bd9576-

> > regulator.yaml

> > index b6515a0cee62..ad3f57e9cd9b 100644

> > --- a/Documentation/devicetree/bindings/regulator/rohm,bd9576-

> > regulator.yaml

> > +++ b/Documentation/devicetree/bindings/regulator/rohm,bd9576-

> > regulator.yaml

> > @@ -27,6 +27,11 @@ patternProperties:

> >        Properties for single regulator.

> >      $ref: "regulator.yaml#"

> >  

> > +    properties:

> > +      rohm,ocw-fet-ron-milliohms:

> 

> We have '-ohms' and '-micro-ohms' already. Neither range works for

> you?


Thanks for taking a look at this :)

I expect values to be magnitude of few hundred milliohms - which means
micro-ohms should be usable. I'll try to still check this as I am far
from being HW-expert. I probably can convert this to micro-ohms for v2.

Best Regards
	Matti Vaittinen

--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland
SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~

Simon says - in Latin please.
"non cogito me" dixit Rene Descarte, deinde evanescavit

(Thanks for the translation Simon)