diff mbox

[1/3] Documentation: dt: dwc3: Add snps, configure-fladj property

Message ID 1437646161-1764-1-git-send-email-nikhil.badola@freescale.com
State Needs Review / ACK, archived
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Commit Message

Nikhil Badola July 23, 2015, 10:09 a.m. UTC
Add property snps,configure-fladj for enabling post silicon
frame length adjustment

Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
---
 Documentation/devicetree/bindings/usb/dwc3.txt | 1 +
 1 file changed, 1 insertion(+)

Comments

Mark Rutland July 23, 2015, 9:56 a.m. UTC | #1
On Thu, Jul 23, 2015 at 11:09:21AM +0100, Nikhil Badola wrote:
> Add property snps,configure-fladj for enabling post silicon
> frame length adjustment
> 
> Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
> ---
>  Documentation/devicetree/bindings/usb/dwc3.txt | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> index 0815eac..90c3972 100644
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> @@ -40,6 +40,7 @@ Optional properties:
>   - snps,hird-threshold: HIRD threshold
>   - snps,hsphy_interface: High-Speed PHY interface selection between "utmi" for
>     UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has value 3.
> + - snps,configure-fladj: enables post-silicon frame length adjustment

Could you elaborate on what this means and why you think it's necessary?

Mark.

>  
>  This is usually a subnode to DWC3 glue to which it is connected.
>  
> -- 
> 2.1.0
> 
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Nikhil Badola July 23, 2015, 10:52 a.m. UTC | #2
> -----Original Message-----
> From: Mark Rutland [mailto:mark.rutland@arm.com]
> Sent: Thursday, July 23, 2015 3:27 PM
> To: Badola Nikhil-B46172
> Cc: linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; balbi@ti.com
> Subject: Re: [PATCH 1/3] Documentation: dt: dwc3: Add snps,configure-fladj
> property
> 
> On Thu, Jul 23, 2015 at 11:09:21AM +0100, Nikhil Badola wrote:
> > Add property snps,configure-fladj for enabling post silicon frame
> > length adjustment
> >
> > Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
> > ---
> >  Documentation/devicetree/bindings/usb/dwc3.txt | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
> > b/Documentation/devicetree/bindings/usb/dwc3.txt
> > index 0815eac..90c3972 100644
> > --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> > @@ -40,6 +40,7 @@ Optional properties:
> >   - snps,hird-threshold: HIRD threshold
> >   - snps,hsphy_interface: High-Speed PHY interface selection between
> "utmi" for
> >     UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has
> value 3.
> > + - snps,configure-fladj: enables post-silicon frame length adjustment
> 
> Could you elaborate on what this means and why you think it's necessary?

This property enables the use of GFLADJ_30MHZ field value of gfladj register for frame length 
adjustment instead of considering from the sideband input signal fladj_30mhz_reg from SOC. 
This is required when signal fladj_30mhz_reg is connected to a wrong value or is not valid as 
in our case, hence post-silicon.

However this field can be used to adjust any offset ranging from 00h to 3Fh, from the
clock source generating SOF(start of frame) packets. Thus, this property can be added to device 
tree with appropriate adjustment value.

> 
> >
> >  This is usually a subnode to DWC3 glue to which it is connected.
> >
> > --
> > 2.1.0
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe devicetree"
> > in the body of a message to majordomo@vger.kernel.org More
> majordomo
> > info at  http://vger.kernel.org/majordomo-info.html
> >
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Mark Rutland July 23, 2015, 10:57 a.m. UTC | #3
On Thu, Jul 23, 2015 at 11:52:19AM +0100, Badola Nikhil wrote:
> > -----Original Message-----
> > From: Mark Rutland [mailto:mark.rutland@arm.com]
> > Sent: Thursday, July 23, 2015 3:27 PM
> > To: Badola Nikhil-B46172
> > Cc: linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; balbi@ti.com
> > Subject: Re: [PATCH 1/3] Documentation: dt: dwc3: Add snps,configure-fladj
> > property
> > 
> > On Thu, Jul 23, 2015 at 11:09:21AM +0100, Nikhil Badola wrote:
> > > Add property snps,configure-fladj for enabling post silicon frame
> > > length adjustment
> > >
> > > Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
> > > ---
> > >  Documentation/devicetree/bindings/usb/dwc3.txt | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > index 0815eac..90c3972 100644
> > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > @@ -40,6 +40,7 @@ Optional properties:
> > >   - snps,hird-threshold: HIRD threshold
> > >   - snps,hsphy_interface: High-Speed PHY interface selection between
> > "utmi" for
> > >     UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has
> > value 3.
> > > + - snps,configure-fladj: enables post-silicon frame length adjustment
> > 
> > Could you elaborate on what this means and why you think it's necessary?
> 
> This property enables the use of GFLADJ_30MHZ field value of gfladj register for frame length 
> adjustment instead of considering from the sideband input signal fladj_30mhz_reg from SOC. 
> This is required when signal fladj_30mhz_reg is connected to a wrong value or is not valid as 
> in our case, hence post-silicon.

Ok, so this is basically an override for the GFLADJ_30MHZ field of the
gfladj register when there was a problem at integration time.

> However this field can be used to adjust any offset ranging from 00h to 3Fh, from the
> clock source generating SOF(start of frame) packets. Thus, this property can be added to device 
> tree with appropriate adjustment value.

It takes a value? The description above makes it sound like a boolean
property.

I'd expect a description more like:

- snps,fladj-override: Value for GFLADJ_30MHZ when the fladj_30mhz_reg
  signal is invalid or incorrect.

Which makes it clear what the value is and when it should be set.

Thanks,
Mark.
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Nikhil Badola July 23, 2015, 11:07 a.m. UTC | #4
> -----Original Message-----
> From: Mark Rutland [mailto:mark.rutland@arm.com]
> Sent: Thursday, July 23, 2015 4:27 PM
> To: Badola Nikhil-B46172
> Cc: linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; balbi@ti.com
> Subject: Re: [PATCH 1/3] Documentation: dt: dwc3: Add snps,configure-fladj
> property
> 
> On Thu, Jul 23, 2015 at 11:52:19AM +0100, Badola Nikhil wrote:
> > > -----Original Message-----
> > > From: Mark Rutland [mailto:mark.rutland@arm.com]
> > > Sent: Thursday, July 23, 2015 3:27 PM
> > > To: Badola Nikhil-B46172
> > > Cc: linux-kernel@vger.kernel.org; devicetree@vger.kernel.org;
> > > balbi@ti.com
> > > Subject: Re: [PATCH 1/3] Documentation: dt: dwc3: Add
> > > snps,configure-fladj property
> > >
> > > On Thu, Jul 23, 2015 at 11:09:21AM +0100, Nikhil Badola wrote:
> > > > Add property snps,configure-fladj for enabling post silicon frame
> > > > length adjustment
> > > >
> > > > Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
> > > > ---
> > > >  Documentation/devicetree/bindings/usb/dwc3.txt | 1 +
> > > >  1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > index 0815eac..90c3972 100644
> > > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > @@ -40,6 +40,7 @@ Optional properties:
> > > >   - snps,hird-threshold: HIRD threshold
> > > >   - snps,hsphy_interface: High-Speed PHY interface selection
> > > > between
> > > "utmi" for
> > > >     UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE
> > > > has
> > > value 3.
> > > > + - snps,configure-fladj: enables post-silicon frame length
> > > > + adjustment
> > >
> > > Could you elaborate on what this means and why you think it's
> necessary?
> >
> > This property enables the use of GFLADJ_30MHZ field value of gfladj
> > register for frame length adjustment instead of considering from the
> sideband input signal fladj_30mhz_reg from SOC.
> > This is required when signal fladj_30mhz_reg is connected to a wrong
> > value or is not valid as in our case, hence post-silicon.
> 
> Ok, so this is basically an override for the GFLADJ_30MHZ field of the gfladj
> register when there was a problem at integration time.
>

That's right. 
 
> > However this field can be used to adjust any offset ranging from 00h
> > to 3Fh, from the clock source generating SOF(start of frame) packets.
> > Thus, this property can be added to device tree with appropriate
> adjustment value.
> 
> It takes a value? The description above makes it sound like a boolean
> property.
> 
> I'd expect a description more like:
> 
> - snps,fladj-override: Value for GFLADJ_30MHZ when the fladj_30mhz_reg
>   signal is invalid or incorrect.
> 
> Which makes it clear what the value is and when it should be set.

Agreed. Will change and send a new version of the patch-set.

> 
> Thanks,
> Mark.
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Felipe Balbi July 23, 2015, 2:34 p.m. UTC | #5
On Thu, Jul 23, 2015 at 11:07:09AM +0000, Badola Nikhil wrote:
> > -----Original Message-----
> > From: Mark Rutland [mailto:mark.rutland@arm.com]
> > Sent: Thursday, July 23, 2015 4:27 PM
> > To: Badola Nikhil-B46172
> > Cc: linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; balbi@ti.com
> > Subject: Re: [PATCH 1/3] Documentation: dt: dwc3: Add snps,configure-fladj
> > property
> > 
> > On Thu, Jul 23, 2015 at 11:52:19AM +0100, Badola Nikhil wrote:
> > > > -----Original Message-----
> > > > From: Mark Rutland [mailto:mark.rutland@arm.com]
> > > > Sent: Thursday, July 23, 2015 3:27 PM
> > > > To: Badola Nikhil-B46172
> > > > Cc: linux-kernel@vger.kernel.org; devicetree@vger.kernel.org;
> > > > balbi@ti.com
> > > > Subject: Re: [PATCH 1/3] Documentation: dt: dwc3: Add
> > > > snps,configure-fladj property
> > > >
> > > > On Thu, Jul 23, 2015 at 11:09:21AM +0100, Nikhil Badola wrote:
> > > > > Add property snps,configure-fladj for enabling post silicon frame
> > > > > length adjustment
> > > > >
> > > > > Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
> > > > > ---
> > > > >  Documentation/devicetree/bindings/usb/dwc3.txt | 1 +
> > > > >  1 file changed, 1 insertion(+)
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > > b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > > index 0815eac..90c3972 100644
> > > > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > > > @@ -40,6 +40,7 @@ Optional properties:
> > > > >   - snps,hird-threshold: HIRD threshold
> > > > >   - snps,hsphy_interface: High-Speed PHY interface selection
> > > > > between
> > > > "utmi" for
> > > > >     UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE
> > > > > has
> > > > value 3.
> > > > > + - snps,configure-fladj: enables post-silicon frame length
> > > > > + adjustment
> > > >
> > > > Could you elaborate on what this means and why you think it's
> > necessary?
> > >
> > > This property enables the use of GFLADJ_30MHZ field value of gfladj
> > > register for frame length adjustment instead of considering from the
> > sideband input signal fladj_30mhz_reg from SOC.
> > > This is required when signal fladj_30mhz_reg is connected to a wrong
> > > value or is not valid as in our case, hence post-silicon.
> > 
> > Ok, so this is basically an override for the GFLADJ_30MHZ field of the gfladj
> > register when there was a problem at integration time.
> >
> 
> That's right. 
>  
> > > However this field can be used to adjust any offset ranging from 00h
> > > to 3Fh, from the clock source generating SOF(start of frame) packets.
> > > Thus, this property can be added to device tree with appropriate
> > adjustment value.
> > 
> > It takes a value? The description above makes it sound like a boolean
> > property.
> > 
> > I'd expect a description more like:
> > 
> > - snps,fladj-override: Value for GFLADJ_30MHZ when the fladj_30mhz_reg
> >   signal is invalid or incorrect.
> > 
> > Which makes it clear what the value is and when it should be set.
> 
> Agreed. Will change and send a new version of the patch-set.

BTW, I'm not going to accept this without a glue layer making use of it.
Also, this patch needs to go to linux-usb as well, please resend.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index 0815eac..90c3972 100644
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -40,6 +40,7 @@  Optional properties:
  - snps,hird-threshold: HIRD threshold
  - snps,hsphy_interface: High-Speed PHY interface selection between "utmi" for
    UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has value 3.
+ - snps,configure-fladj: enables post-silicon frame length adjustment
 
 This is usually a subnode to DWC3 glue to which it is connected.