From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Oleksij Rempel <linux@rempel-privat.de>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Rob Herring <robh+dt@kernel.org>, Andrew Lunn <andrew@lunn.ch>,
Philippe Schenker <philippe.schenker@toradex.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Heiner Kallweit <hkallweit1@gmail.com>,
Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
netdev <netdev@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH/RFC 1/5] dt-bindings: net: renesas,ravb: Document internal clock delay properties
Date: Sun, 21 Jun 2020 10:23:00 +0200 [thread overview]
Message-ID: <CAMuHMdWFA9YoeMgHGbhvW7Mqv6tBgcpqyYvWdNc1Vdn23KebLg@mail.gmail.com> (raw)
In-Reply-To: <e6d0bfc5-9d75-2dc9-2bfa-671c32cb0b7c@rempel-privat.de>
Hi Oleksij,
On Sat, Jun 20, 2020 at 7:47 AM Oleksij Rempel <linux@rempel-privat.de> wrote:
> Am 19.06.20 um 21:15 schrieb Geert Uytterhoeven:
> > Some EtherAVB variants support internal clock delay configuration, which
> > can add larger delays than the delays that are typically supported by
> > the PHY (using an "rgmii-*id" PHY mode, and/or "[rt]xc-skew-ps"
> > properties).
> >
> > Add properties for configuring the internal MAC delays.
> > These properties are mandatory, even when specified as zero, to
> > distinguish between old and new DTBs.
> >
> > Update the example accordingly.
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > --- a/Documentation/devicetree/bindings/net/renesas,ravb.txt
> > +++ b/Documentation/devicetree/bindings/net/renesas,ravb.txt
> > + This property is mandatory and valid only on R-Car Gen3
> > + and RZ/G2 SoCs.
> > + Valid values are 0 and 1800.
> > + A non-zero value is allowed only if phy-mode = "rgmii".
> > + Zero is not supported on R-Car D3.
> > +- renesas,txc-delay-ps: Internal TX clock delay.
> > + This property is mandatory and valid only on R-Car H3,
> > + M3-W, M3-W+, M3-N, V3M, and V3H, and RZ/G2M and RZ/G2N.
> > + Valid values are 0 and 2000.
>
> In the driver i didn't found sanity check for valid values.
As EtherAVB supports only zero and a single non-zero value, I didn't
bother validating the actual non-zero value in the driver.
However, I did implement full validation in the json-schema version of
the DT bindings, cfr. "[PATCH/RFC] dt-bindings: net: renesas,etheravb:
Convert to json-schema"
(https://lore.kernel.org/r/20200621081710.10245-1-geert+renesas@glider.be)
(In hindsight, I should not have postponed posting that patch)
> > @@ -105,8 +117,10 @@ Example:
> > "ch24";
> > clocks = <&cpg CPG_MOD 812>;
> > power-domains = <&cpg>;
> > - phy-mode = "rgmii-id";
> > + phy-mode = "rgmii";
> > phy-handle = <&phy0>;
> > + renesas,rxc-delay-ps = <0>;
> > + renesas,txc-delay-ps = <2000>;
> >
> > pinctrl-0 = <ðer_pins>;
> > pinctrl-names = "default";
> > @@ -115,18 +129,7 @@ Example:
> > #size-cells = <0>;
> >
> > phy0: ethernet-phy@0 {
> > - rxc-skew-ps = <900>;
> > - rxdv-skew-ps = <0>;
> > - rxd0-skew-ps = <0>;
> > - rxd1-skew-ps = <0>;
> > - rxd2-skew-ps = <0>;
> > - rxd3-skew-ps = <0>;
> > - txc-skew-ps = <900>;
> > - txen-skew-ps = <0>;
> > - txd0-skew-ps = <0>;
> > - txd1-skew-ps = <0>;
> > - txd2-skew-ps = <0>;
> > - txd3-skew-ps = <0>;
> > + rxc-skew-ps = <1500>;
>
>
> I'm curios, how this numbers ware taken?
> Old configurations was:
> TX delay:
> (txd*-skew-ps = 0) == -420ns
> (txc-skew-ps = 900) == 0ns
> resulting delays 0.420ns
Please ignore the actual contents of the old example. It was based on a
very old DTS, which has received several fixes in the mean time.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2020-06-21 8:27 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-19 19:15 [PATCH/RFC 0/5] ravb: Add support for explicit internal clock delay configuration Geert Uytterhoeven
2020-06-19 19:15 ` [PATCH/RFC 1/5] dt-bindings: net: renesas,ravb: Document internal clock delay properties Geert Uytterhoeven
2020-06-20 5:47 ` Oleksij Rempel
2020-06-20 14:43 ` Andrew Lunn
2020-06-21 8:23 ` Geert Uytterhoeven [this message]
2020-06-20 18:15 ` Sergei Shtylyov
2020-06-21 8:26 ` Geert Uytterhoeven
2020-06-19 19:15 ` [PATCH/RFC 2/5] ravb: Split delay handling in parsing and applying Geert Uytterhoeven
2020-06-20 18:34 ` Sergei Shtylyov
2020-06-19 19:15 ` [PATCH/RFC 3/5] ravb: Add support for explicit internal clock delay configuration Geert Uytterhoeven
2020-06-20 19:03 ` Sergei Shtylyov
2020-06-19 19:15 ` [PATCH/RFC 4/5] arm64: dts: renesas: rcar-gen3: Convert EtherAVB to explicit delay handling Geert Uytterhoeven
2020-06-19 19:15 ` [PATCH/RFC 5/5] arm64: dts: renesas: rzg2: " Geert Uytterhoeven
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