Re: [PATCH 02/23] arm64: zynqmp: Fix usb node drive strength and slew rate

Laurent Pinchart
2023-05-10T06:54:35Z

Hi Michal,

Thank you for the patch.

On Tue, May 02, 2023 at 03:35:30PM +0200, Michal Simek wrote:
> From: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
>
> As per design, all input/rx pins should have fast slew rate and 12mA
> drive strength.

Why does the slow rate and drive strength matter for input pins ?

> Rest all pins should be slow slew rate and 4mA drive
> strength. Fix usb nodes as per this and remove setting of slow slew rate
> for all the usb group pins.
>
> Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
> Signed-off-by: Michal Simek <michal.simek@amd.com>
> ---
>
> .../arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revA.dtso | 8 ++++++--
> .../arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revB.dtso | 8 ++++++--
> .../boot/dts/xilinx/zynqmp-zc1751-xm015-dc1.dts | 8 ++++++--
> .../boot/dts/xilinx/zynqmp-zc1751-xm016-dc2.dts | 8 ++++++--
> arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts | 13 ++++++++++---
> arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts | 5 ++++-
> arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revA.dts | 6 ++++--
> arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revC.dts | 6 ++++--
> arch/arm64/boot/dts/xilinx/zynqmp-zcu106-revA.dts | 5 ++++-
> arch/arm64/boot/dts/xilinx/zynqmp-zcu111-revA.dts | 5 ++++-
> 10 files changed, 54 insertions(+), 18 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revA.dtso b/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revA.dtso
> index b610e65e0cdf..2f7a17ec58b4 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revA.dtso
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revA.dtso
> @@ -2,7 +2,8 @@
> /*
> * dts file for KV260 revA Carrier Card
> *
> - * (C) Copyright 2020 - 2021, Xilinx, Inc.
> + * (C) Copyright 2020 - 2022, Xilinx, Inc.
> + * (C) Copyright 2022 - 2023, Advanced Micro Devices, Inc.
> *
> * SD level shifter:
> * "A" – A01 board un-modified (NXP)
> @@ -259,19 +260,22 @@ mux {
> pinctrl_usb0_default: usb0-default {
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
>
> mux {
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revB.dtso b/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revB.dtso
> index a52dafbfd59e..4695e0e3714f 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revB.dtso
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revB.dtso
> @@ -2,7 +2,8 @@
> /*
> * dts file for KV260 revA Carrier Card
> *
> - * (C) Copyright 2020 - 2021, Xilinx, Inc.
> + * (C) Copyright 2020 - 2022, Xilinx, Inc.
> + * (C) Copyright 2022 - 2023, Advanced Micro Devices, Inc.
> *
> * Michal Simek <michal.simek@xilinx.com>
> */
> @@ -242,19 +243,22 @@ mux {
> pinctrl_usb0_default: usb0-default {
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
>
> mux {
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm015-dc1.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm015-dc1.dts
> index f89ef2afcd9e..5fa9604f05d1 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm015-dc1.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm015-dc1.dts
> @@ -2,7 +2,8 @@
> /*
> * dts file for Xilinx ZynqMP zc1751-xm015-dc1
> *
> - * (C) Copyright 2015 - 2021, Xilinx, Inc.
> + * (C) Copyright 2015 - 2022, Xilinx, Inc.
> + * (C) Copyright 2022 - 2023, Advanced Micro Devices, Inc.
> *
> * Michal Simek <michal.simek@xilinx.com>
> */
> @@ -187,19 +188,22 @@ mux {
>
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
>
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm016-dc2.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm016-dc2.dts
> index 938b76bd0527..a2031187d9b3 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm016-dc2.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zc1751-xm016-dc2.dts
> @@ -2,7 +2,8 @@
> /*
> * dts file for Xilinx ZynqMP zc1751-xm016-dc2
> *
> - * (C) Copyright 2015 - 2021, Xilinx, Inc.
> + * (C) Copyright 2015 - 2022, Xilinx, Inc.
> + * (C) Copyright 2022 - 2023, Advanced Micro Devices, Inc.
> *
> * Michal Simek <michal.simek@xilinx.com>
> */
> @@ -281,19 +282,22 @@ mux {
>
> conf {
> groups = "usb1_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO64", "MIO65", "MIO67";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO66", "MIO68", "MIO69", "MIO70", "MIO71",
> "MIO72", "MIO73", "MIO74", "MIO75";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
>
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts
> index c74bc3ff703b..2dd552cf51fb 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts
> @@ -2,7 +2,8 @@
> /*
> * dts file for Xilinx ZynqMP ZCU100 revC
> *
> - * (C) Copyright 2016 - 2021, Xilinx, Inc.
> + * (C) Copyright 2016 - 2022, Xilinx, Inc.
> + * (C) Copyright 2022 - 2023, Advanced Micro Devices, Inc.
> *
> * Michal Simek <michal.simek@xilinx.com>
> * Nathalie Chan King Choy
> @@ -423,19 +424,22 @@ mux {
>
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
>
> @@ -447,19 +451,22 @@ mux {
>
> conf {
> groups = "usb1_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO64", "MIO65", "MIO67";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO66", "MIO68", "MIO69", "MIO70", "MIO71",
> "MIO72", "MIO73", "MIO74", "MIO75";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
> };
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts
> index c193579400cf..78043d9de7cc 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts
> @@ -783,19 +783,22 @@ mux {
>
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
>
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revA.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revA.dts
> index 11c1eaef9f53..c1779c88ec34 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revA.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revA.dts
> @@ -410,20 +410,22 @@ mux {
>
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> - drive-strength = <12>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
> };
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revC.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revC.dts
> index c06c138fa3e5..b857c1950496 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revC.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu104-revC.dts
> @@ -422,20 +422,22 @@ mux {
>
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> - drive-strength = <12>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
> };
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu106-revA.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu106-revA.dts
> index 52cdec33f190..e4e09afbdc1a 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu106-revA.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu106-revA.dts
> @@ -794,19 +794,22 @@ mux {
>
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
>
> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu111-revA.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu111-revA.dts
> index 699cc9ce7898..791b2ac9fbdb 100644
> --- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu111-revA.dts
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu111-revA.dts
> @@ -660,19 +660,22 @@ mux {
>
> conf {
> groups = "usb0_0_grp";
> - slew-rate = <SLEW_RATE_SLOW>;
> power-source = <IO_STANDARD_LVCMOS18>;
> };
>
> conf-rx {
> pins = "MIO52", "MIO53", "MIO55";
> bias-high-impedance;
> + drive-strength = <12>;
> + slew-rate = <SLEW_RATE_FAST>;
> };
>
> conf-tx {
> pins = "MIO54", "MIO56", "MIO57", "MIO58", "MIO59",
> "MIO60", "MIO61", "MIO62", "MIO63";
> bias-disable;
> + drive-strength = <4>;
> + slew-rate = <SLEW_RATE_SLOW>;
> };
> };
>

--
Regards,

Laurent Pinchart