Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-10-04 Thread Rob Herring 
On Wed, Oct 4, 2017 at 3:12 AM, Richard Leitner
 wrote:
>
> On 09/21/2017 07:10 PM, Serge Semin wrote:
>> On Thu, Sep 21, 2017 at 11:26:04AM -0500, Rob Herring  
>> wrote:
>>> On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  
>>> wrote:
>
> ...
>
 These are different parameters of the device. They got different 
 configuration
 registers and descriptions:
 max_power* - ... This value also includes the power consumption of a
 permanently attached peripheral if the hub is configured as a compound
 device, and the embedded peripheral reports 0mA in its descriptors.
 max_current* - ... This value does NOT include the power consumption of a
 permanently attached peripheral if the hub is configured as a compound
 device.
>>>
>>> Then the names here should somehow reflect the above. Perhaps
>>> "composite-current" and "hub-current" or something like that.
>>>
>>
>> I left the naming in accordance with the device datasheet. I thought it 
>> would be
>> better since the driver user would still need to consult with the device
>> documentation to properly set them. I don't really get how the difference is 
>> reflected
>> with the naming declared there though. So what naming would you prefer then? 
>> Might be
>> something like:
>> {sp,bp}-max-total-current - for so named {sp,bp}-max-power, since it 
>> includes all the
>> permanently attached peripherals.
>> {sp,bp}-max-removable-current - for so named {sp,bp}-max-current, since it 
>> doesn't
>> include the permanently attached peripherals.
>>
>> Or is it better to leave it in compliance with the documentation naming?
>
> I'd prefer the naming to be in accordance with the device datasheet too.
> Changing it will IMHO generate avoidable misunderstandings...

Okay, then add a vendor prefix.

> But if we should go with Robs proposal please make sure the name from
> the device datasheet is mentioned somewhere in the description of the
> binding.
>
>>

 Additionally as you can see, they both are measured in "mA", so it isn't
 a real physical power.
>>>
>>> Well, I can't because there's no units.
>>>
>>
>> What this line means then?
>> - sp-max-{power,current} : ... The value is given in mA in a 0 - 100 range 
>> (default is 1mA).
>> - bp-max-{power,current} : ... The value is given in mA in a 0 - 510 range 
>> (default is 100mA).
>>
>> Maybe I don't know something and the description line should state the units 
>> somehow
>> clearer?

The reason we have units in the name is so we don't have to go lookup
the documentation to find the units and so people don't use the same
property name with different units.

> Append the unit to the binding name, just like in "power-on-time-ms". As
> there's no "Standard Unit Suffix" for mA stated in the documentation
> (Documentation/devicetree/bindings/property-units.txt) I think it should
> be "-milliamp"?

The reason being is we align around microamps and try to avoid
everyone picking their own units (celliamps anyone?). So unless
microamps is not enough range for you, I would stick with that.

If you have both units and vendor prefix, then I care less about the
poorly written datasheet naming used.

Rob

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-10-04 Thread Rob Herring 
On Wed, Oct 4, 2017 at 3:12 AM, Richard Leitner
 wrote:
>
> On 09/21/2017 07:10 PM, Serge Semin wrote:
>> On Thu, Sep 21, 2017 at 11:26:04AM -0500, Rob Herring  
>> wrote:
>>> On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  
>>> wrote:
>
> ...
>
 These are different parameters of the device. They got different 
 configuration
 registers and descriptions:
 max_power* - ... This value also includes the power consumption of a
 permanently attached peripheral if the hub is configured as a compound
 device, and the embedded peripheral reports 0mA in its descriptors.
 max_current* - ... This value does NOT include the power consumption of a
 permanently attached peripheral if the hub is configured as a compound
 device.
>>>
>>> Then the names here should somehow reflect the above. Perhaps
>>> "composite-current" and "hub-current" or something like that.
>>>
>>
>> I left the naming in accordance with the device datasheet. I thought it 
>> would be
>> better since the driver user would still need to consult with the device
>> documentation to properly set them. I don't really get how the difference is 
>> reflected
>> with the naming declared there though. So what naming would you prefer then? 
>> Might be
>> something like:
>> {sp,bp}-max-total-current - for so named {sp,bp}-max-power, since it 
>> includes all the
>> permanently attached peripherals.
>> {sp,bp}-max-removable-current - for so named {sp,bp}-max-current, since it 
>> doesn't
>> include the permanently attached peripherals.
>>
>> Or is it better to leave it in compliance with the documentation naming?
>
> I'd prefer the naming to be in accordance with the device datasheet too.
> Changing it will IMHO generate avoidable misunderstandings...

Okay, then add a vendor prefix.

> But if we should go with Robs proposal please make sure the name from
> the device datasheet is mentioned somewhere in the description of the
> binding.
>
>>

 Additionally as you can see, they both are measured in "mA", so it isn't
 a real physical power.
>>>
>>> Well, I can't because there's no units.
>>>
>>
>> What this line means then?
>> - sp-max-{power,current} : ... The value is given in mA in a 0 - 100 range 
>> (default is 1mA).
>> - bp-max-{power,current} : ... The value is given in mA in a 0 - 510 range 
>> (default is 100mA).
>>
>> Maybe I don't know something and the description line should state the units 
>> somehow
>> clearer?

The reason we have units in the name is so we don't have to go lookup
the documentation to find the units and so people don't use the same
property name with different units.

> Append the unit to the binding name, just like in "power-on-time-ms". As
> there's no "Standard Unit Suffix" for mA stated in the documentation
> (Documentation/devicetree/bindings/property-units.txt) I think it should
> be "-milliamp"?

The reason being is we align around microamps and try to avoid
everyone picking their own units (celliamps anyone?). So unless
microamps is not enough range for you, I would stick with that.

If you have both units and vendor prefix, then I care less about the
poorly written datasheet naming used.

Rob

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-10-04 Thread Richard Leitner 

On 09/21/2017 07:10 PM, Serge Semin wrote:
> On Thu, Sep 21, 2017 at 11:26:04AM -0500, Rob Herring  wrote:
>> On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  wrote:

...

>>> These are different parameters of the device. They got different 
>>> configuration
>>> registers and descriptions:
>>> max_power* - ... This value also includes the power consumption of a
>>> permanently attached peripheral if the hub is configured as a compound
>>> device, and the embedded peripheral reports 0mA in its descriptors.
>>> max_current* - ... This value does NOT include the power consumption of a
>>> permanently attached peripheral if the hub is configured as a compound
>>> device.
>>
>> Then the names here should somehow reflect the above. Perhaps
>> "composite-current" and "hub-current" or something like that.
>>
> 
> I left the naming in accordance with the device datasheet. I thought it would 
> be
> better since the driver user would still need to consult with the device
> documentation to properly set them. I don't really get how the difference is 
> reflected
> with the naming declared there though. So what naming would you prefer then? 
> Might be
> something like:
> {sp,bp}-max-total-current - for so named {sp,bp}-max-power, since it includes 
> all the
> permanently attached peripherals.
> {sp,bp}-max-removable-current - for so named {sp,bp}-max-current, since it 
> doesn't
> include the permanently attached peripherals.
> 
> Or is it better to leave it in compliance with the documentation naming?

I'd prefer the naming to be in accordance with the device datasheet too.
Changing it will IMHO generate avoidable misunderstandings...

But if we should go with Robs proposal please make sure the name from
the device datasheet is mentioned somewhere in the description of the
binding.

> 
>>>
>>> Additionally as you can see, they both are measured in "mA", so it isn't
>>> a real physical power.
>>
>> Well, I can't because there's no units.
>>
> 
> What this line means then?
> - sp-max-{power,current} : ... The value is given in mA in a 0 - 100 range 
> (default is 1mA).
> - bp-max-{power,current} : ... The value is given in mA in a 0 - 510 range 
> (default is 100mA).
> 
> Maybe I don't know something and the description line should state the units 
> somehow
> clearer?

Append the unit to the binding name, just like in "power-on-time-ms". As
there's no "Standard Unit Suffix" for mA stated in the documentation
(Documentation/devicetree/bindings/property-units.txt) I think it should
be "-milliamp"?

regards,
Richard.L

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-10-04 Thread Richard Leitner 

On 09/21/2017 07:10 PM, Serge Semin wrote:
> On Thu, Sep 21, 2017 at 11:26:04AM -0500, Rob Herring  wrote:
>> On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  wrote:

...

>>> These are different parameters of the device. They got different 
>>> configuration
>>> registers and descriptions:
>>> max_power* - ... This value also includes the power consumption of a
>>> permanently attached peripheral if the hub is configured as a compound
>>> device, and the embedded peripheral reports 0mA in its descriptors.
>>> max_current* - ... This value does NOT include the power consumption of a
>>> permanently attached peripheral if the hub is configured as a compound
>>> device.
>>
>> Then the names here should somehow reflect the above. Perhaps
>> "composite-current" and "hub-current" or something like that.
>>
> 
> I left the naming in accordance with the device datasheet. I thought it would 
> be
> better since the driver user would still need to consult with the device
> documentation to properly set them. I don't really get how the difference is 
> reflected
> with the naming declared there though. So what naming would you prefer then? 
> Might be
> something like:
> {sp,bp}-max-total-current - for so named {sp,bp}-max-power, since it includes 
> all the
> permanently attached peripherals.
> {sp,bp}-max-removable-current - for so named {sp,bp}-max-current, since it 
> doesn't
> include the permanently attached peripherals.
> 
> Or is it better to leave it in compliance with the documentation naming?

I'd prefer the naming to be in accordance with the device datasheet too.
Changing it will IMHO generate avoidable misunderstandings...

But if we should go with Robs proposal please make sure the name from
the device datasheet is mentioned somewhere in the description of the
binding.

> 
>>>
>>> Additionally as you can see, they both are measured in "mA", so it isn't
>>> a real physical power.
>>
>> Well, I can't because there's no units.
>>
> 
> What this line means then?
> - sp-max-{power,current} : ... The value is given in mA in a 0 - 100 range 
> (default is 1mA).
> - bp-max-{power,current} : ... The value is given in mA in a 0 - 510 range 
> (default is 100mA).
> 
> Maybe I don't know something and the description line should state the units 
> somehow
> clearer?

Append the unit to the binding name, just like in "power-on-time-ms". As
there's no "Standard Unit Suffix" for mA stated in the documentation
(Documentation/devicetree/bindings/property-units.txt) I think it should
be "-milliamp"?

regards,
Richard.L

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-21 Thread Serge Semin 
On Thu, Sep 21, 2017 at 11:26:04AM -0500, Rob Herring  wrote:
> On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  wrote:
> > On Wed, Sep 20, 2017 at 03:52:55PM -0500, Rob Herring  
> > wrote:
> >> On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
> >> > This parameters may be varied in accordance with hardware specifics.
> >> > So lets add the corresponding settings to the usb251x driver dts
> >> > specification.
> >> >
> >> > Signed-off-by: Serge Semin 
> >> > ---
> >> >  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
> >> >  drivers/usb/misc/usb251xb.c  | 20 
> >> > 
> >> >  2 files changed, 22 insertions(+), 4 deletions(-)
> >> >
> >> > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
> >> > b/Documentation/devicetree/bindings/usb/usb251xb.txt
> >> > index 3d84626d3..dd59a32e7 100644
> >> > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> >> > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> >> > @@ -44,6 +44,12 @@ Optional properties :
> >> > device connected.
> >> >   - sp-disabled-ports : Specifies the ports which will be self-power 
> >> > disabled
> >> >   - bp-disabled-ports : Specifies the ports which will be bus-power 
> >> > disabled
> >> > + - sp-max-{power,current} : Indicates the power/current consumed by hub 
> >> > from
> >> > +   an upstream port (VBUS) when operation as a self-powered hub. The 
> >> > value
> >> > +   is given in mA in a 0 - 100 range (default is 1mA).
> >> > + - bp-max-{power,current} : Indicates the power/current consumed by hub 
> >> > from
> >> > +   an upstream port (VBUS) when operation as a bus-powered hub. The 
> >> > value
> >> > +   is given in mA in a 0 - 510 range (default is 100mA).
> >>
> >> These need units as defined in property-units.txt.
> >>
> >
> > Ok.
> >
> >> Why do you need power and current? Can't you calculate power?
> >>
> >
> > These are different parameters of the device. They got different 
> > configuration
> > registers and descriptions:
> > max_power* - ... This value also includes the power consumption of a
> > permanently attached peripheral if the hub is configured as a compound
> > device, and the embedded peripheral reports 0mA in its descriptors.
> > max_current* - ... This value does NOT include the power consumption of a
> > permanently attached peripheral if the hub is configured as a compound
> > device.
> 
> Then the names here should somehow reflect the above. Perhaps
> "composite-current" and "hub-current" or something like that.
> 

I left the naming in accordance with the device datasheet. I thought it would be
better since the driver user would still need to consult with the device
documentation to properly set them. I don't really get how the difference is 
reflected
with the naming declared there though. So what naming would you prefer then? 
Might be
something like:
{sp,bp}-max-total-current - for so named {sp,bp}-max-power, since it includes 
all the
permanently attached peripherals.
{sp,bp}-max-removable-current - for so named {sp,bp}-max-current, since it 
doesn't
include the permanently attached peripherals.

Or is it better to leave it in compliance with the documentation naming?

> >
> > Additionally as you can see, they both are measured in "mA", so it isn't
> > a real physical power.
> 
> Well, I can't because there's no units.
> 

What this line means then?
- sp-max-{power,current} : ... The value is given in mA in a 0 - 100 range 
(default is 1mA).
- bp-max-{power,current} : ... The value is given in mA in a 0 - 510 range 
(default is 100mA).

Maybe I don't know something and the description line should state the units 
somehow
clearer?

> Rob

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-21 Thread Serge Semin 
On Thu, Sep 21, 2017 at 11:26:04AM -0500, Rob Herring  wrote:
> On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  wrote:
> > On Wed, Sep 20, 2017 at 03:52:55PM -0500, Rob Herring  
> > wrote:
> >> On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
> >> > This parameters may be varied in accordance with hardware specifics.
> >> > So lets add the corresponding settings to the usb251x driver dts
> >> > specification.
> >> >
> >> > Signed-off-by: Serge Semin 
> >> > ---
> >> >  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
> >> >  drivers/usb/misc/usb251xb.c  | 20 
> >> > 
> >> >  2 files changed, 22 insertions(+), 4 deletions(-)
> >> >
> >> > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
> >> > b/Documentation/devicetree/bindings/usb/usb251xb.txt
> >> > index 3d84626d3..dd59a32e7 100644
> >> > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> >> > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> >> > @@ -44,6 +44,12 @@ Optional properties :
> >> > device connected.
> >> >   - sp-disabled-ports : Specifies the ports which will be self-power 
> >> > disabled
> >> >   - bp-disabled-ports : Specifies the ports which will be bus-power 
> >> > disabled
> >> > + - sp-max-{power,current} : Indicates the power/current consumed by hub 
> >> > from
> >> > +   an upstream port (VBUS) when operation as a self-powered hub. The 
> >> > value
> >> > +   is given in mA in a 0 - 100 range (default is 1mA).
> >> > + - bp-max-{power,current} : Indicates the power/current consumed by hub 
> >> > from
> >> > +   an upstream port (VBUS) when operation as a bus-powered hub. The 
> >> > value
> >> > +   is given in mA in a 0 - 510 range (default is 100mA).
> >>
> >> These need units as defined in property-units.txt.
> >>
> >
> > Ok.
> >
> >> Why do you need power and current? Can't you calculate power?
> >>
> >
> > These are different parameters of the device. They got different 
> > configuration
> > registers and descriptions:
> > max_power* - ... This value also includes the power consumption of a
> > permanently attached peripheral if the hub is configured as a compound
> > device, and the embedded peripheral reports 0mA in its descriptors.
> > max_current* - ... This value does NOT include the power consumption of a
> > permanently attached peripheral if the hub is configured as a compound
> > device.
> 
> Then the names here should somehow reflect the above. Perhaps
> "composite-current" and "hub-current" or something like that.
> 

I left the naming in accordance with the device datasheet. I thought it would be
better since the driver user would still need to consult with the device
documentation to properly set them. I don't really get how the difference is 
reflected
with the naming declared there though. So what naming would you prefer then? 
Might be
something like:
{sp,bp}-max-total-current - for so named {sp,bp}-max-power, since it includes 
all the
permanently attached peripherals.
{sp,bp}-max-removable-current - for so named {sp,bp}-max-current, since it 
doesn't
include the permanently attached peripherals.

Or is it better to leave it in compliance with the documentation naming?

> >
> > Additionally as you can see, they both are measured in "mA", so it isn't
> > a real physical power.
> 
> Well, I can't because there's no units.
> 

What this line means then?
- sp-max-{power,current} : ... The value is given in mA in a 0 - 100 range 
(default is 1mA).
- bp-max-{power,current} : ... The value is given in mA in a 0 - 510 range 
(default is 100mA).

Maybe I don't know something and the description line should state the units 
somehow
clearer?

> Rob

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-21 Thread Rob Herring 
On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  wrote:
> On Wed, Sep 20, 2017 at 03:52:55PM -0500, Rob Herring  wrote:
>> On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
>> > This parameters may be varied in accordance with hardware specifics.
>> > So lets add the corresponding settings to the usb251x driver dts
>> > specification.
>> >
>> > Signed-off-by: Serge Semin 
>> > ---
>> >  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
>> >  drivers/usb/misc/usb251xb.c  | 20 
>> > 
>> >  2 files changed, 22 insertions(+), 4 deletions(-)
>> >
>> > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
>> > b/Documentation/devicetree/bindings/usb/usb251xb.txt
>> > index 3d84626d3..dd59a32e7 100644
>> > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
>> > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
>> > @@ -44,6 +44,12 @@ Optional properties :
>> > device connected.
>> >   - sp-disabled-ports : Specifies the ports which will be self-power 
>> > disabled
>> >   - bp-disabled-ports : Specifies the ports which will be bus-power 
>> > disabled
>> > + - sp-max-{power,current} : Indicates the power/current consumed by hub 
>> > from
>> > +   an upstream port (VBUS) when operation as a self-powered hub. The value
>> > +   is given in mA in a 0 - 100 range (default is 1mA).
>> > + - bp-max-{power,current} : Indicates the power/current consumed by hub 
>> > from
>> > +   an upstream port (VBUS) when operation as a bus-powered hub. The value
>> > +   is given in mA in a 0 - 510 range (default is 100mA).
>>
>> These need units as defined in property-units.txt.
>>
>
> Ok.
>
>> Why do you need power and current? Can't you calculate power?
>>
>
> These are different parameters of the device. They got different configuration
> registers and descriptions:
> max_power* - ... This value also includes the power consumption of a
> permanently attached peripheral if the hub is configured as a compound
> device, and the embedded peripheral reports 0mA in its descriptors.
> max_current* - ... This value does NOT include the power consumption of a
> permanently attached peripheral if the hub is configured as a compound
> device.

Then the names here should somehow reflect the above. Perhaps
"composite-current" and "hub-current" or something like that.

>
> Additionally as you can see, they both are measured in "mA", so it isn't
> a real physical power.

Well, I can't because there's no units.

Rob

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-21 Thread Rob Herring 
On Wed, Sep 20, 2017 at 4:27 PM, Serge Semin  wrote:
> On Wed, Sep 20, 2017 at 03:52:55PM -0500, Rob Herring  wrote:
>> On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
>> > This parameters may be varied in accordance with hardware specifics.
>> > So lets add the corresponding settings to the usb251x driver dts
>> > specification.
>> >
>> > Signed-off-by: Serge Semin 
>> > ---
>> >  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
>> >  drivers/usb/misc/usb251xb.c  | 20 
>> > 
>> >  2 files changed, 22 insertions(+), 4 deletions(-)
>> >
>> > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
>> > b/Documentation/devicetree/bindings/usb/usb251xb.txt
>> > index 3d84626d3..dd59a32e7 100644
>> > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
>> > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
>> > @@ -44,6 +44,12 @@ Optional properties :
>> > device connected.
>> >   - sp-disabled-ports : Specifies the ports which will be self-power 
>> > disabled
>> >   - bp-disabled-ports : Specifies the ports which will be bus-power 
>> > disabled
>> > + - sp-max-{power,current} : Indicates the power/current consumed by hub 
>> > from
>> > +   an upstream port (VBUS) when operation as a self-powered hub. The value
>> > +   is given in mA in a 0 - 100 range (default is 1mA).
>> > + - bp-max-{power,current} : Indicates the power/current consumed by hub 
>> > from
>> > +   an upstream port (VBUS) when operation as a bus-powered hub. The value
>> > +   is given in mA in a 0 - 510 range (default is 100mA).
>>
>> These need units as defined in property-units.txt.
>>
>
> Ok.
>
>> Why do you need power and current? Can't you calculate power?
>>
>
> These are different parameters of the device. They got different configuration
> registers and descriptions:
> max_power* - ... This value also includes the power consumption of a
> permanently attached peripheral if the hub is configured as a compound
> device, and the embedded peripheral reports 0mA in its descriptors.
> max_current* - ... This value does NOT include the power consumption of a
> permanently attached peripheral if the hub is configured as a compound
> device.

Then the names here should somehow reflect the above. Perhaps
"composite-current" and "hub-current" or something like that.

>
> Additionally as you can see, they both are measured in "mA", so it isn't
> a real physical power.

Well, I can't because there's no units.

Rob

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-20 Thread Serge Semin 
On Wed, Sep 20, 2017 at 03:52:55PM -0500, Rob Herring  wrote:
> On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
> > This parameters may be varied in accordance with hardware specifics.
> > So lets add the corresponding settings to the usb251x driver dts
> > specification.
> > 
> > Signed-off-by: Serge Semin 
> > ---
> >  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
> >  drivers/usb/misc/usb251xb.c  | 20 
> > 
> >  2 files changed, 22 insertions(+), 4 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
> > b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > index 3d84626d3..dd59a32e7 100644
> > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > @@ -44,6 +44,12 @@ Optional properties :
> > device connected.
> >   - sp-disabled-ports : Specifies the ports which will be self-power 
> > disabled
> >   - bp-disabled-ports : Specifies the ports which will be bus-power disabled
> > + - sp-max-{power,current} : Indicates the power/current consumed by hub 
> > from
> > +   an upstream port (VBUS) when operation as a self-powered hub. The value
> > +   is given in mA in a 0 - 100 range (default is 1mA).
> > + - bp-max-{power,current} : Indicates the power/current consumed by hub 
> > from
> > +   an upstream port (VBUS) when operation as a bus-powered hub. The value
> > +   is given in mA in a 0 - 510 range (default is 100mA).
> 
> These need units as defined in property-units.txt.
> 

Ok.

> Why do you need power and current? Can't you calculate power?
> 

These are different parameters of the device. They got different configuration
registers and descriptions:
max_power* - ... This value also includes the power consumption of a
permanently attached peripheral if the hub is configured as a compound
device, and the embedded peripheral reports 0mA in its descriptors.
max_current* - ... This value does NOT include the power consumption of a
permanently attached peripheral if the hub is configured as a compound
device.

Additionally as you can see, they both are measured in "mA", so it isn't
a real physical power.

> >   - power-on-time-ms : Specifies the time it takes from the time the host
> > initiates the power-on sequence to a port until the port has adequate
> > power. The value is given in ms in a 0 - 510 range (default is 100ms).

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-20 Thread Serge Semin 
On Wed, Sep 20, 2017 at 03:52:55PM -0500, Rob Herring  wrote:
> On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
> > This parameters may be varied in accordance with hardware specifics.
> > So lets add the corresponding settings to the usb251x driver dts
> > specification.
> > 
> > Signed-off-by: Serge Semin 
> > ---
> >  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
> >  drivers/usb/misc/usb251xb.c  | 20 
> > 
> >  2 files changed, 22 insertions(+), 4 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
> > b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > index 3d84626d3..dd59a32e7 100644
> > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > @@ -44,6 +44,12 @@ Optional properties :
> > device connected.
> >   - sp-disabled-ports : Specifies the ports which will be self-power 
> > disabled
> >   - bp-disabled-ports : Specifies the ports which will be bus-power disabled
> > + - sp-max-{power,current} : Indicates the power/current consumed by hub 
> > from
> > +   an upstream port (VBUS) when operation as a self-powered hub. The value
> > +   is given in mA in a 0 - 100 range (default is 1mA).
> > + - bp-max-{power,current} : Indicates the power/current consumed by hub 
> > from
> > +   an upstream port (VBUS) when operation as a bus-powered hub. The value
> > +   is given in mA in a 0 - 510 range (default is 100mA).
> 
> These need units as defined in property-units.txt.
> 

Ok.

> Why do you need power and current? Can't you calculate power?
> 

These are different parameters of the device. They got different configuration
registers and descriptions:
max_power* - ... This value also includes the power consumption of a
permanently attached peripheral if the hub is configured as a compound
device, and the embedded peripheral reports 0mA in its descriptors.
max_current* - ... This value does NOT include the power consumption of a
permanently attached peripheral if the hub is configured as a compound
device.

Additionally as you can see, they both are measured in "mA", so it isn't
a real physical power.

> >   - power-on-time-ms : Specifies the time it takes from the time the host
> > initiates the power-on sequence to a port until the port has adequate
> > power. The value is given in ms in a 0 - 510 range (default is 100ms).

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-20 Thread Rob Herring 
On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
> This parameters may be varied in accordance with hardware specifics.
> So lets add the corresponding settings to the usb251x driver dts
> specification.
> 
> Signed-off-by: Serge Semin 
> ---
>  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
>  drivers/usb/misc/usb251xb.c  | 20 
> 
>  2 files changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
> b/Documentation/devicetree/bindings/usb/usb251xb.txt
> index 3d84626d3..dd59a32e7 100644
> --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> @@ -44,6 +44,12 @@ Optional properties :
>   device connected.
>   - sp-disabled-ports : Specifies the ports which will be self-power disabled
>   - bp-disabled-ports : Specifies the ports which will be bus-power disabled
> + - sp-max-{power,current} : Indicates the power/current consumed by hub from
> + an upstream port (VBUS) when operation as a self-powered hub. The value
> + is given in mA in a 0 - 100 range (default is 1mA).
> + - bp-max-{power,current} : Indicates the power/current consumed by hub from
> + an upstream port (VBUS) when operation as a bus-powered hub. The value
> + is given in mA in a 0 - 510 range (default is 100mA).

These need units as defined in property-units.txt.

Why do you need power and current? Can't you calculate power?

>   - power-on-time-ms : Specifies the time it takes from the time the host
>   initiates the power-on sequence to a port until the port has adequate
>   power. The value is given in ms in a 0 - 510 range (default is 100ms).

Re: [PATCH 8/9 v2] usb: usb251xb: Add max power/current dts property support

2017-09-20 Thread Rob Herring 
On Sat, Sep 16, 2017 at 01:42:19PM +0300, Serge Semin wrote:
> This parameters may be varied in accordance with hardware specifics.
> So lets add the corresponding settings to the usb251x driver dts
> specification.
> 
> Signed-off-by: Serge Semin 
> ---
>  Documentation/devicetree/bindings/usb/usb251xb.txt   |  6 ++
>  drivers/usb/misc/usb251xb.c  | 20 
> 
>  2 files changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt 
> b/Documentation/devicetree/bindings/usb/usb251xb.txt
> index 3d84626d3..dd59a32e7 100644
> --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> @@ -44,6 +44,12 @@ Optional properties :
>   device connected.
>   - sp-disabled-ports : Specifies the ports which will be self-power disabled
>   - bp-disabled-ports : Specifies the ports which will be bus-power disabled
> + - sp-max-{power,current} : Indicates the power/current consumed by hub from
> + an upstream port (VBUS) when operation as a self-powered hub. The value
> + is given in mA in a 0 - 100 range (default is 1mA).
> + - bp-max-{power,current} : Indicates the power/current consumed by hub from
> + an upstream port (VBUS) when operation as a bus-powered hub. The value
> + is given in mA in a 0 - 510 range (default is 100mA).

These need units as defined in property-units.txt.

Why do you need power and current? Can't you calculate power?

>   - power-on-time-ms : Specifies the time it takes from the time the host
>   initiates the power-on sequence to a port until the port has adequate
>   power. The value is given in ms in a 0 - 510 range (default is 100ms).