Re: [PATCH 01/23] arm64: zynqmp: Describe TI phy as ethernet-phy-id

From: Michal Simek
Date: Wed May 10 2023 - 03:12:59 EST


Hi Laurent,

On 5/10/23 08:52, Laurent Pinchart wrote:
Hi Michal,

Thank you for the patch.

On Tue, May 02, 2023 at 03:35:29PM +0200, Michal Simek wrote:
TI DP83867 is using strapping based on MIO pins. Tristate setup can influce

And typo here.

PHY address. That's why switch description with ethernet-phy-id compatible
string which enable calling reset. PHY itself setups phy address after
power up or reset.

I'm sorry but I don't understand this :-(

What exactly is not clear? Phy has some pins which is using for strapping for phy address after phy reset or power on. Pretty much it is resistor array which based on datasheet is decoded to certain phy address.
And because some phy pins are also used as data pin for RGMII they are connected via MIO pins on a silicon. That's why IO block output setting really matter here because it changes resistor array and it moves phy address.
That's why there is a need to do proper IO pin setup and after it call phy reset to get it to address which was decided by PCB designer.


Phy reset is done via gpio.

Signed-off-by: Michal Simek <michal.simek@xxxxxxx>
---

Checkpatch is reporting issue
warning: DT compatible string "ethernet-phy-id2000.a231" appears un-documented
but it should be fully aligned with
Documentation/devicetree/bindings/net/ethernet-phy.yaml
---
.../boot/dts/xilinx/zynqmp-zcu102-revA.dts | 23 +++++++++++------
.../boot/dts/xilinx/zynqmp-zcu102-revB.dts | 25 +++++++++++--------
.../boot/dts/xilinx/zynqmp-zcu104-revA.dts | 22 ++++++++++------
.../boot/dts/xilinx/zynqmp-zcu104-revC.dts | 22 ++++++++++------
.../boot/dts/xilinx/zynqmp-zcu106-revA.dts | 22 ++++++++++------
.../boot/dts/xilinx/zynqmp-zcu111-revA.dts | 22 ++++++++++------
6 files changed, 90 insertions(+), 46 deletions(-)

diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts
index 13c43324f1d2..c193579400cf 100644
--- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts
+++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts
@@ -2,7 +2,8 @@
/*
* dts file for Xilinx ZynqMP ZCU102 RevA
*
- * (C) Copyright 2015 - 2021, Xilinx, Inc.
+ * (C) Copyright 2015 - 2022, Xilinx, Inc.
+ * (C) Copyright 2022 - 2023, Advanced Micro Devices, Inc.
*
* Michal Simek <michal.simek@xxxxxxxxxx>
*/
@@ -200,13 +201,19 @@ &gem3 {
phy-mode = "rgmii-id";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_gem3_default>;
- phy0: ethernet-phy@21 {
- reg = <21>;
- ti,rx-internal-delay = <0x8>;
- ti,tx-internal-delay = <0xa>;
- ti,fifo-depth = <0x1>;
- ti,dp83867-rxctrl-strap-quirk;
- /* reset-gpios = <&tca6416_u97 6 GPIO_ACTIVE_LOW>; */
+ mdio: mdio {

The "mdio" label isn't needed. Same below.

I am doing it by purpose to be able to reference all nodes and add/remove property in an easy way. There shouldn't be any conflict with dt spec to have labels even they are not used in current DT.

Thanks,
Michal