[PATCH 1/2] dt-bindings: usb: usb251xb: add documentation for data lane swapping

[PATCH 1/2] dt-bindings: usb: usb251xb: add documentation for data lane swapping

[Marco Felsch]

Add optional binding to allow USB differential-pair (D+/D-) data lane
swapping. The swapping can be specified for each port separately,
default is no swapping.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 Documentation/devicetree/bindings/usb/usb251xb.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt b/Documentation/devicetree/bindings/usb/usb251xb.txt
index 168ff819e827..aec93a92870d 100644
--- a/Documentation/devicetree/bindings/usb/usb251xb.txt
+++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
@@ -64,6 +64,8 @@ Optional properties :
  - 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).
+ - sw-dx-lanes-ports : Specifies the ports which will swap the differential-pair
+	(D+/D-), default is not-swapped.
 
 Examples:
 	usb2512b@2c {
@@ -81,4 +83,6 @@ Examples:
 		manufacturer = "Foo";
 		product = "Foo-Bar";
 		serial = "1234567890A";
+		/* correct misplaced usb connectors on port 1,2 */
+		sw-dx-lanes-ports = <1 2>;
 	};
-- 
2.19.1

[PATCH 2/2] usb: usb251xb: add usb data lane port swap feature

[Marco Felsch]

The HW can swap the USB differential-pair (D+/D-) for each port
separately. So the USB signals can be re-aligned with a misplaced
USB connector on the PCB.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/usb/misc/usb251xb.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/misc/usb251xb.c b/drivers/usb/misc/usb251xb.c
index a6efb9a72939..cd89618e11f1 100644
--- a/drivers/usb/misc/usb251xb.c
+++ b/drivers/usb/misc/usb251xb.c
@@ -337,10 +337,12 @@ static int usb251xb_get_ofdata(struct usb251xb *hub,
 	struct device *dev = hub->dev;
 	struct device_node *np = dev->of_node;
 	int len, err, i;
-	u32 property_u32 = 0;
+	u32 port, property_u32 = 0;
 	const u32 *cproperty_u32;
 	const char *cproperty_char;
 	char str[USB251XB_STRING_BUFSIZE / 2];
+	struct property *prop;
+	const __be32 *p;
 
 	if (!np) {
 		dev_err(dev, "failed to get ofdata\n");
@@ -539,6 +541,12 @@ static int usb251xb_get_ofdata(struct usb251xb *hub,
 			      (wchar_t *)hub->serial,
 			      USB251XB_STRING_BUFSIZE);
 
+	hub->port_swap = USB251XB_DEF_PORT_SWAP;
+	of_property_for_each_u32(np, "sw-dx-lanes-ports", prop, p, port) {
+		if ((port >= 0) && (port <= data->port_cnt))
+			hub->port_swap |= BIT(port);
+	}
+
 	/* The following parameters are currently not exposed to devicetree, but
 	 * may be as soon as needed.
 	 */
@@ -546,7 +554,6 @@ static int usb251xb_get_ofdata(struct usb251xb *hub,
 	hub->boost_up = USB251XB_DEF_BOOST_UP;
 	hub->boost_57 = USB251XB_DEF_BOOST_57;
 	hub->boost_14 = USB251XB_DEF_BOOST_14;
-	hub->port_swap = USB251XB_DEF_PORT_SWAP;
 	hub->port_map12 = USB251XB_DEF_PORT_MAP_12;
 	hub->port_map34 = USB251XB_DEF_PORT_MAP_34;
 	hub->port_map56 = USB251XB_DEF_PORT_MAP_56;
-- 
2.19.1

Re: [PATCH 1/2] dt-bindings: usb: usb251xb: add documentation for data lane swapping

[Rob Herring]

On Wed, Dec 19, 2018 at 03:59:40PM +0100, Marco Felsch wrote:
> Add optional binding to allow USB differential-pair (D+/D-) data lane
> swapping. The swapping can be specified for each port separately,
> default is no swapping.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  Documentation/devicetree/bindings/usb/usb251xb.txt | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt b/Documentation/devicetree/bindings/usb/usb251xb.txt
> index 168ff819e827..aec93a92870d 100644
> --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> @@ -64,6 +64,8 @@ Optional properties :
>   - 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).
> + - sw-dx-lanes-ports : Specifies the ports which will swap the differential-pair
> +	(D+/D-), default is not-swapped.

Perhaps 'swap-dx-ports' would be a more obvious name.

>  
>  Examples:
>  	usb2512b@2c {
> @@ -81,4 +83,6 @@ Examples:
>  		manufacturer = "Foo";
>  		product = "Foo-Bar";
>  		serial = "1234567890A";
> +		/* correct misplaced usb connectors on port 1,2 */
> +		sw-dx-lanes-ports = <1 2>;
>  	};
> -- 
> 2.19.1
> 

Re: [PATCH 1/2] dt-bindings: usb: usb251xb: add documentation for data lane swapping

[Marco Felsch]

Hi,

On 18-12-28 17:45, Rob Herring wrote:
> On Wed, Dec 19, 2018 at 03:59:40PM +0100, Marco Felsch wrote:
> > Add optional binding to allow USB differential-pair (D+/D-) data lane
> > swapping. The swapping can be specified for each port separately,
> > default is no swapping.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> >  Documentation/devicetree/bindings/usb/usb251xb.txt | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > index 168ff819e827..aec93a92870d 100644
> > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > @@ -64,6 +64,8 @@ Optional properties :
> >   - 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).
> > + - sw-dx-lanes-ports : Specifies the ports which will swap the differential-pair
> > +	(D+/D-), default is not-swapped.
> 
> Perhaps 'swap-dx-ports' would be a more obvious name.

What you think about 'swap-dx-lanes' since it has nothing to do with
port swapping, it's rather swapping port properties internally.

Regards,
Marco

> 
> >  
> >  Examples:
> >  	usb2512b@2c {
> > @@ -81,4 +83,6 @@ Examples:
> >  		manufacturer = "Foo";
> >  		product = "Foo-Bar";
> >  		serial = "1234567890A";
> > +		/* correct misplaced usb connectors on port 1,2 */
> > +		sw-dx-lanes-ports = <1 2>;
> >  	};
> > -- 
> > 2.19.1
> > 
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH 1/2] dt-bindings: usb: usb251xb: add documentation for data lane swapping

[Richard Leitner]

Hi,

On 31/12/2018 12:05, Marco Felsch wrote:
> Hi,
> 
> On 18-12-28 17:45, Rob Herring wrote:
>> On Wed, Dec 19, 2018 at 03:59:40PM +0100, Marco Felsch wrote:
>>> Add optional binding to allow USB differential-pair (D+/D-) data lane
>>> swapping. The swapping can be specified for each port separately,
>>> default is no swapping.
>>>
>>> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
>>> ---
>>>   Documentation/devicetree/bindings/usb/usb251xb.txt | 4 ++++
>>>   1 file changed, 4 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt b/Documentation/devicetree/bindings/usb/usb251xb.txt
>>> index 168ff819e827..aec93a92870d 100644
>>> --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
>>> +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
>>> @@ -64,6 +64,8 @@ Optional properties :
>>>    - 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).
>>> + - sw-dx-lanes-ports : Specifies the ports which will swap the differential-pair
>>> +	(D+/D-), default is not-swapped.
>>
>> Perhaps 'swap-dx-ports' would be a more obvious name.
> 
> What you think about 'swap-dx-lanes' since it has nothing to do with
> port swapping, it's rather swapping port properties internally.

I'd also prefer 'swap-dx-lanes'. For me it's short and clear.

The only downside is that the feature is called "PORT SWAP" in the
datasheet. Therefore you should maybe mention it in a comment somewhere
in the code so people know what to look for in the datasheet?

regards;Richard.L

Re: [PATCH 1/2] dt-bindings: usb: usb251xb: add documentation for data lane swapping

[Marco Felsch]

Hi,

On 19-01-02 06:44, Richard Leitner wrote:
> Hi,
> 
> On 31/12/2018 12:05, Marco Felsch wrote:
> > Hi,
> > 
> > On 18-12-28 17:45, Rob Herring wrote:
> > > On Wed, Dec 19, 2018 at 03:59:40PM +0100, Marco Felsch wrote:
> > > > Add optional binding to allow USB differential-pair (D+/D-) data lane
> > > > swapping. The swapping can be specified for each port separately,
> > > > default is no swapping.
> > > > 
> > > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > > > ---
> > > >   Documentation/devicetree/bindings/usb/usb251xb.txt | 4 ++++
> > > >   1 file changed, 4 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > > > index 168ff819e827..aec93a92870d 100644
> > > > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt
> > > > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt
> > > > @@ -64,6 +64,8 @@ Optional properties :
> > > >    - 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).
> > > > + - sw-dx-lanes-ports : Specifies the ports which will swap the differential-pair
> > > > +	(D+/D-), default is not-swapped.
> > > 
> > > Perhaps 'swap-dx-ports' would be a more obvious name.
> > 
> > What you think about 'swap-dx-lanes' since it has nothing to do with
> > port swapping, it's rather swapping port properties internally.
> 
> I'd also prefer 'swap-dx-lanes'. For me it's short and clear.
> 
> The only downside is that the feature is called "PORT SWAP" in the
> datasheet. Therefore you should maybe mention it in a comment somewhere
> in the code so people know what to look for in the datasheet?

Okay, I can do this. Should I place the comment into the driver code or
into the bindings description? Both places seems to be correct for me.

Regards,
Marco

> 
> regards;Richard.L
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |