Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1451938 > unrolled thread

Re: [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for Allwinner sun8i-emac

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for  Allwinner sun8i-emac LABBE Corentin <clabbe.montjoie@gmail.com> - 2016-07-28 15:50 +0200
    Re: [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for  Allwinner sun8i-emac Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-07-28 20:50 +0200
      Re: [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for  Allwinner sun8i-emac LABBE Corentin <clabbe.montjoie@gmail.com> - 2016-07-29 10:20 +0200
        Re: [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for  Allwinner sun8i-emac Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-07-29 20:20 +0200

#1451938 — Re: [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for Allwinner sun8i-emac

On Thu, Jul 21, 2016 at 09:55:19AM +0200, Maxime Ripard wrote:
> Hi,
> 
> On Wed, Jul 20, 2016 at 10:03:18AM +0200, LABBE Corentin wrote:
> > This patch adds documentation for Device-Tree bindings for the
> > Allwinner sun8i-emac driver.
> > 
> > Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
> > ---
> >  .../bindings/net/allwinner,sun8i-emac.txt          | 65 ++++++++++++++++++++++
> >  1 file changed, 65 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > new file mode 100644
> > index 0000000..4bf4e53
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > @@ -0,0 +1,65 @@
> > +* Allwinner sun8i EMAC ethernet controller
> > +
> > +Required properties:
> > +- compatible: "allwinner,sun8i-a83t-emac", "allwinner,sun8i-h3-emac",
> > +		or "allwinner,sun50i-a64-emac"
> > +- reg: address and length of the register sets for the device.
> > +- reg-names: should be "emac" and "syscon", matching the register sets
> 
> Blindly mapping a register of some other device on the SoC doesn't
> look very reasonable.
> 

As we discuss after this mail on IRC, this register is dedicated to EMAC.

> > +- interrupts: interrupt for the device
> > +- clocks: A phandle to the reference clock for this device
> > +- clock-names: should be "ahb"
> > +- resets: A phandle to the reset control for this device
> > +- reset-names: should be "ahb"
> > +- phy-mode: See ethernet.txt
> > +- phy or phy-handle: See ethernet.txt
> > +- #address-cells: shall be 1
> > +- #size-cells: shall be 0
> > +
> > +"allwinner,sun8i-h3-emac" also requires:
> > +- clocks: an extra phandle to the reference clock for the EPHY
> > +- clock-names: an extra "ephy" entry matching the clocks property
> > +- resets: an extra phandle to the reset control for the EPHY
> > +- resets-names: an extra "ephy" entry matching the resets property
> 
> Shouldn't that be attached to the phy itself?
> 

Ok I will move them.

> > +See ethernet.txt in the same directory for generic bindings for ethernet
> > +controllers.
> > +
> > +The device node referenced by "phy" or "phy-handle" should be a child node
> > +of this node. See phy.txt for the generic PHY bindings.
> > +
> > +Optional properties:
> > +- phy-supply: phandle to a regulator if the PHY needs one
> > +- phy-io-supply: phandle to a regulator if the PHY needs a another one for I/O.
> > +		 This is sometimes found with RGMII PHYs, which use a second
> > +		 regulator for the lower I/O voltage.
> > +- allwinner,tx-delay: The setting of the TX clock delay chain
> > +- allwinner,rx-delay: The setting of the RX clock delay chain
> 
> In which unit? What is the default value?
> 

The unit is unknown to me, but I have added a comment for the default and acceptable range value.

> > +
> > +The TX/RX clock delay chain settings are board specific.
> > +
> > +Optional properties for "allwinner,sun8i-h3-emac":
> > +- allwinner,use-internal-phy: Use the H3 SoC's internal E(thernet) PHY
> 
> Can't that be derived from the presence of the phy property?
> 

Yes, I have reworked the "variant" of the driver for easily handling this.

> > +- allwinner,leds-active-low: EPHY LEDs are active low
> 
> That also seems PHY related. Overall, I feel like we really need a phy
> node for the internal phy.
> 

Moved also in the phy node.

> Maxime
> 
> -- 
> Maxime Ripard, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com

Best regards

Thanks

LABBE Corentin

[toc] | [next] | [standalone]

#1452048

[Multipart message — attachments visible in raw view] — view raw

On Thu, Jul 28, 2016 at 03:40:31PM +0200, LABBE Corentin wrote:
> On Thu, Jul 21, 2016 at 09:55:19AM +0200, Maxime Ripard wrote:
> > Hi,
> > 
> > On Wed, Jul 20, 2016 at 10:03:18AM +0200, LABBE Corentin wrote:
> > > This patch adds documentation for Device-Tree bindings for the
> > > Allwinner sun8i-emac driver.
> > > 
> > > Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
> > > ---
> > >  .../bindings/net/allwinner,sun8i-emac.txt          | 65 ++++++++++++++++++++++
> > >  1 file changed, 65 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > 
> > > diff --git a/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > new file mode 100644
> > > index 0000000..4bf4e53
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > @@ -0,0 +1,65 @@
> > > +* Allwinner sun8i EMAC ethernet controller
> > > +
> > > +Required properties:
> > > +- compatible: "allwinner,sun8i-a83t-emac", "allwinner,sun8i-h3-emac",
> > > +		or "allwinner,sun50i-a64-emac"
> > > +- reg: address and length of the register sets for the device.
> > > +- reg-names: should be "emac" and "syscon", matching the register sets
> > 
> > Blindly mapping a register of some other device on the SoC doesn't
> > look very reasonable.
> 
> As we discuss after this mail on IRC, this register is dedicated to EMAC.

I don't think we did. It's still right in the middle of some other
hardware block register space. You actually have a syscon driver to do
just that, why not use it?

> > > +See ethernet.txt in the same directory for generic bindings for ethernet
> > > +controllers.
> > > +
> > > +The device node referenced by "phy" or "phy-handle" should be a child node
> > > +of this node. See phy.txt for the generic PHY bindings.
> > > +
> > > +Optional properties:
> > > +- phy-supply: phandle to a regulator if the PHY needs one
> > > +- phy-io-supply: phandle to a regulator if the PHY needs a another one for I/O.
> > > +		 This is sometimes found with RGMII PHYs, which use a second
> > > +		 regulator for the lower I/O voltage.
> > > +- allwinner,tx-delay: The setting of the TX clock delay chain
> > > +- allwinner,rx-delay: The setting of the RX clock delay chain
> > 
> > In which unit? What is the default value?
> 
> The unit is unknown to me, but I have added a comment for the
> default and acceptable range value.

That's unfortunate. We'll see how the DT maintainers feel about that.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[toc] | [prev] | [next] | [standalone]

#1452309

On Thu, Jul 28, 2016 at 08:49:16PM +0200, Maxime Ripard wrote:
> On Thu, Jul 28, 2016 at 03:40:31PM +0200, LABBE Corentin wrote:
> > On Thu, Jul 21, 2016 at 09:55:19AM +0200, Maxime Ripard wrote:
> > > Hi,
> > > 
> > > On Wed, Jul 20, 2016 at 10:03:18AM +0200, LABBE Corentin wrote:
> > > > This patch adds documentation for Device-Tree bindings for the
> > > > Allwinner sun8i-emac driver.
> > > > 
> > > > Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
> > > > ---
> > > >  .../bindings/net/allwinner,sun8i-emac.txt          | 65 ++++++++++++++++++++++
> > > >  1 file changed, 65 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > > new file mode 100644
> > > > index 0000000..4bf4e53
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > > @@ -0,0 +1,65 @@
> > > > +* Allwinner sun8i EMAC ethernet controller
> > > > +
> > > > +Required properties:
> > > > +- compatible: "allwinner,sun8i-a83t-emac", "allwinner,sun8i-h3-emac",
> > > > +		or "allwinner,sun50i-a64-emac"
> > > > +- reg: address and length of the register sets for the device.
> > > > +- reg-names: should be "emac" and "syscon", matching the register sets
> > > 
> > > Blindly mapping a register of some other device on the SoC doesn't
> > > look very reasonable.
> > 
> > As we discuss after this mail on IRC, this register is dedicated to EMAC.
> 
> I don't think we did. It's still right in the middle of some other
> hardware block register space. You actually have a syscon driver to do
> just that, why not use it?
> 

I will try with syscon driver

> > > > +See ethernet.txt in the same directory for generic bindings for ethernet
> > > > +controllers.
> > > > +
> > > > +The device node referenced by "phy" or "phy-handle" should be a child node
> > > > +of this node. See phy.txt for the generic PHY bindings.
> > > > +
> > > > +Optional properties:
> > > > +- phy-supply: phandle to a regulator if the PHY needs one
> > > > +- phy-io-supply: phandle to a regulator if the PHY needs a another one for I/O.
> > > > +		 This is sometimes found with RGMII PHYs, which use a second
> > > > +		 regulator for the lower I/O voltage.
> > > > +- allwinner,tx-delay: The setting of the TX clock delay chain
> > > > +- allwinner,rx-delay: The setting of the RX clock delay chain
> > > 
> > > In which unit? What is the default value?
> > 
> > The unit is unknown to me, but I have added a comment for the
> > default and acceptable range value.
> 
> That's unfortunate. We'll see how the DT maintainers feel about that.
> 

I have searched for txdelay in Documentation, and found a few driver that give the units (us/ps).
But in that case, the value in ps/us must be found in a table indexed by the Xxdelay value.
So the settings seems always a raw number, and for sun8i-emac nothing in user manual could help to find what each value is/related to.

So the good value is either found by "try and test" or "copy the value found in fex file".

Regards

LABBE Corentin

[toc] | [prev] | [next] | [standalone]

#1452508

[Multipart message — attachments visible in raw view] — view raw

On Fri, Jul 29, 2016 at 10:15:19AM +0200, LABBE Corentin wrote:
> > > > > +See ethernet.txt in the same directory for generic bindings for ethernet
> > > > > +controllers.
> > > > > +
> > > > > +The device node referenced by "phy" or "phy-handle" should be a child node
> > > > > +of this node. See phy.txt for the generic PHY bindings.
> > > > > +
> > > > > +Optional properties:
> > > > > +- phy-supply: phandle to a regulator if the PHY needs one
> > > > > +- phy-io-supply: phandle to a regulator if the PHY needs a another one for I/O.
> > > > > +		 This is sometimes found with RGMII PHYs, which use a second
> > > > > +		 regulator for the lower I/O voltage.
> > > > > +- allwinner,tx-delay: The setting of the TX clock delay chain
> > > > > +- allwinner,rx-delay: The setting of the RX clock delay chain
> > > > 
> > > > In which unit? What is the default value?
> > > 
> > > The unit is unknown to me, but I have added a comment for the
> > > default and acceptable range value.
> > 
> > That's unfortunate. We'll see how the DT maintainers feel about that.
> > 
> 
> I have searched for txdelay in Documentation, and found a few driver
> that give the units (us/ps).
>
> But in that case, the value in ps/us must be found in a table
> indexed by the Xxdelay value.
>
> So the settings seems always a raw number, and for sun8i-emac
> nothing in user manual could help to find what each value is/related
> to.
> 
> So the good value is either found by "try and test" or "copy the
> value found in fex file".

What I meant was that, just like you found out already, most of the
time the properties should be in absolute units, so that it doesn't
depend on some clock rate most likely in that case.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web