Re: [RFC PATCH 4/5] arm64: dts: ti: Enable multiple MCAN for AM62x in MCU MCAN overlay

[Krzysztof Kozlowski]

On 14/04/2023 00:30, Judith Mendez wrote:
> Enable two MCAN in MCU domain. AM62x does not have on-board CAN
> transcievers, so instead of changing the DTB permanently, add
> MCU MCAN nodes and transceiver nodes to a MCU MCAN overlay.
> 
> If there are no hardware interrupts rounted to the GIC interrupt
> controller for MCAN IP, A53 Linux will not receive hardware
> interrupts. If an hrtimer is used to generate software interrupts,
> the two required interrupt attributes in the MCAN node do not have
> to be included.
> 
> Signed-off-by: Judith Mendez <jm@xxxxxx>
> ---
>  arch/arm64/boot/dts/ti/Makefile               |  2 +-
>  .../boot/dts/ti/k3-am625-sk-mcan-mcu.dtso     | 75 +++++++++++++++++++
>  2 files changed, 76 insertions(+), 1 deletion(-)
>  create mode 100644 arch/arm64/boot/dts/ti/k3-am625-sk-mcan-mcu.dtso
> 
> diff --git a/arch/arm64/boot/dts/ti/Makefile b/arch/arm64/boot/dts/ti/Makefile
> index abe15e76b614..c76be3888e4d 100644
> --- a/arch/arm64/boot/dts/ti/Makefile
> +++ b/arch/arm64/boot/dts/ti/Makefile
> @@ -9,7 +9,7 @@
>  # alphabetically.
>  
>  # Boards with AM62x SoC
> -k3-am625-sk-mcan-dtbs := k3-am625-sk.dtb k3-am625-sk-mcan-main.dtbo
> +k3-am625-sk-mcan-dtbs := k3-am625-sk.dtb k3-am625-sk-mcan-main.dtbo k3-am625-sk-mcan-mcu.dtbo
>  dtb-$(CONFIG_ARCH_K3) += k3-am625-beagleplay.dtb
>  dtb-$(CONFIG_ARCH_K3) += k3-am625-sk.dtb
>  dtb-$(CONFIG_ARCH_K3) += k3-am625-sk-mcan.dtb
> diff --git a/arch/arm64/boot/dts/ti/k3-am625-sk-mcan-mcu.dtso b/arch/arm64/boot/dts/ti/k3-am625-sk-mcan-mcu.dtso
> new file mode 100644
> index 000000000000..777705aea546
> --- /dev/null
> +++ b/arch/arm64/boot/dts/ti/k3-am625-sk-mcan-mcu.dtso
> @@ -0,0 +1,75 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * DT overlay for MCAN in MCU domain on AM625 SK
> + *
> + * Copyright (C) 2022 Texas Instruments Incorporated - https://www.ti.com/
> + */
> +
> +/dts-v1/;
> +/plugin/;
> +
> +#include <dt-bindings/pinctrl/k3.h>
> +#include <dt-bindings/soc/ti,sci_pm_domain.h>
> +
> +
> +&{/} {
> +	transceiver2: can-phy1 {
> +		compatible = "ti,tcan1042";
> +		#phy-cells = <0>;
> +		max-bitrate = <5000000>;
> +	};
> +
> +	transceiver3: can-phy2 {
> +		compatible = "ti,tcan1042";
> +		#phy-cells = <0>;
> +		max-bitrate = <5000000>;
> +	};
> +};
> +
> +&mcu_pmx0 {
> +	mcu_mcan1_pins_default: mcu-mcan1-pins-default {
> +		pinctrl-single,pins = <
> +			AM62X_IOPAD(0x038, PIN_INPUT, 0) /* (B3) MCU_MCAN0_RX */
> +			AM62X_IOPAD(0x034, PIN_OUTPUT, 0) /* (D6) MCU_MCAN0_TX */
> +		>;
> +	};
> +
> +	mcu_mcan2_pins_default: mcu-mcan2-pins-default {
> +		pinctrl-single,pins = <
> +			AM62X_IOPAD(0x040, PIN_INPUT, 0) /* (D4) MCU_MCAN1_RX */
> +			AM62X_IOPAD(0x03C, PIN_OUTPUT, 0) /* (E5) MCU_MCAN1_TX */
> +		>;
> +	};
> +};
> +
> +&cbass_mcu {
> +	mcu_mcan1: can@4e00000 {
> +		compatible = "bosch,m_can";
> +		reg = <0x00 0x4e00000 0x00 0x8000>,
> +			  <0x00 0x4e08000 0x00 0x200>;
> +		reg-names = "message_ram", "m_can";
> +		power-domains = <&k3_pds 188 TI_SCI_PD_EXCLUSIVE>;
> +		clocks = <&k3_clks 188 6>, <&k3_clks 188 1>;
> +		clock-names = "hclk", "cclk";
> +		bosch,mram-cfg = <0x0 128 64 64 64 64 32 32>;
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&mcu_mcan1_pins_default>;
> +		phys = <&transceiver2>;
> +		status = "okay";

okay is by default. Why do you need it?



Best regards,
Krzysztof