Re: [PATCH v6 2/3] arm64: dts: ti: Add support for Variscite VAR-SOM-AM62P

[Stefano Radaelli <stefano.radaelli21@gmail.com>]

Hi Judith,

On Mon, Sep 08, 2025 at 01:06:45PM -0500, Judith Mendez wrote:
> Hi Stefano,
> 
> On 9/4/25 8:22 AM, Stefano Radaelli wrote:
> > Add device tree support for the Variscite VAR-SOM-AM62P system on module.
> > This SOM is designed to be used with various carrier boards.
> > 
> > The module includes:
> > - AM62P Sitara MPU processor
> > - Up to 8GB of DDR4-3733 memory
> > - eMMC storage memory
> > - PS6522430 chip as a Power Management Integrated circuit (PMIC)
> > - Integrated 10/100/1000 Mbps Ethernet Transceiver Analog Devices ADIN1300
> > - Resistive touch panel interface controller TI TSC2046
> > - I2C interfaces
> > 
> > Only SOM-specific peripherals are enabled by default. Carrier board
> > specific interfaces are left disabled to be enabled in the respective
> > carrier board device trees.
> > 
> > Link: https://www.variscite.it/product/system-on-module-som/cortex-a53-krait/var-som-am62p-ti-sitara-am62px/
> > 
> > Signed-off-by: Stefano Radaelli <stefano.radaelli21@gmail.com>
> > ---
> > v6:
> >   - Removed unnecessary sdhci properties
> > v5:
> >   - Update to match up with coding guidelines for device tree
> > v4:
> >   - Moved every MCUs-related node into the SOM dtsi
> >   - Removed unused audio node
> > v3:
> >   - Change compatible string to match existing mainline format
> >   - Lower case hex digits
> >   - Generic node names
> > v2:
> >   - Fixed warnings and cleanup
> > 
> >   arch/arm64/boot/dts/ti/k3-am62p5-var-som.dtsi | 385 ++++++++++++++++++
> >   1 file changed, 385 insertions(+)
> >   create mode 100644 arch/arm64/boot/dts/ti/k3-am62p5-var-som.dtsi
> > 
> > diff --git a/arch/arm64/boot/dts/ti/k3-am62p5-var-som.dtsi b/arch/arm64/boot/dts/ti/k3-am62p5-var-som.dtsi
> > new file mode 100644
> > index 000000000000..da037993574f
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/ti/k3-am62p5-var-som.dtsi
> > @@ -0,0 +1,385 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Common dtsi for Variscite VAR-SOM-AM62P
> > + *
> > + * Link: https://www.variscite.com/product/system-on-module-som/cortex-a53-krait/var-som-am62p-ti-sitara-am62px/
> > + *
> > + * Copyright (C) 2025 Variscite Ltd. - https://www.variscite.com/
> > + *
> > + */
> > +
> > +/dts-v1/;
> > +
> > +#include <dt-bindings/gpio/gpio.h>
> > +#include <dt-bindings/input/input.h>
> > +#include <dt-bindings/interrupt-controller/arm-gic.h>
> > +#include <dt-bindings/leds/common.h>
> > +#include <dt-bindings/pwm/pwm.h>
> > +#include "k3-am62p5.dtsi"
> > +
> > +/ {
> > +	compatible = "variscite,var-som-am62p", "ti,am62p5";
> > +
> > +	wifi_pwrseq: wifi-pwrseq {
> > +		compatible = "mmc-pwrseq-simple";
> > +		post-power-on-delay-ms = <100>;
> > +		power-off-delay-us = <10000>;
> > +		reset-gpios = <&main_gpio0 54 GPIO_ACTIVE_LOW>,	/* WIFI_PWR_EN */
> > +			      <&main_gpio0 59 GPIO_ACTIVE_LOW>;	/* WIFI_EN */
> > +	};
> > +
> > +	mmc_pwrseq: mmc-pwrseq {
> > +		compatible = "mmc-pwrseq-emmc";
> > +		pinctrl-names = "default";
> > +		pinctrl-0 = <&pinctrl_mmc_pwrseq>;
> > +		reset-gpios = <&main_gpio0 49 GPIO_ACTIVE_LOW>;
> > +	};
> > +
> > +	memory@80000000 {
> > +		/* 8G RAM */
> > +		reg = <0x00000000 0x80000000 0x00000000 0x80000000>,
> > +		      <0x00000008 0x80000000 0x00000001 0x80000000>;
> > +		device_type = "memory";
> > +		bootph-pre-ram;
> > +	};
> > +
> > +	opp-table {
> > +		/* Add 1.4GHz OPP for am62p5-sk board. Requires VDD_CORE at 0v85 */
> > +		opp-1400000000 {
> > +			opp-hz = /bits/ 64 <1400000000>;
> > +			opp-supported-hw = <0x01 0x0004>;
> > +			clock-latency-ns = <6000000>;
> > +		};
> > +	};
> > +
> > +	reserved_memory: reserved-memory {
> > +		#address-cells = <2>;
> > +		#size-cells = <2>;
> > +		ranges;
> > +
> > +		rtos_ipc_memory_region: rtos-ipc-memory@9b500000 {
> > +			compatible = "shared-dma-pool";
> > +			reg = <0x00 0x9b500000 0x00 0x00300000>;
> > +			no-map;
> > +		};
> > +
> > +		mcu_r5fss0_core0_dma_memory_region: mcu-r5fss-dma-memory-region@9b800000 {
> > +			compatible = "shared-dma-pool";
> > +			reg = <0x00 0x9b800000 0x00 0x00100000>;
> > +			no-map;
> > +		};
> > +
> > +		mcu_r5fss0_core0_memory_region: mcu-r5fss-memory-region@9b900000 {
> > +			compatible = "shared-dma-pool";
> > +			reg = <0x00 0x9b900000 0x00 0x00f00000>;
> > +			no-map;
> > +		};
> 
> Perhaps it will be a good idea to do the same refactoring as this:
> 
> https://lore.kernel.org/linux-arm-kernel/20250905051846.1189612-30-b-padhi@ti.com/
> 
> Meaning we drop the memory carve-outs for MCU R5SS here.
> 
> 
> > +
> > +		wkup_r5fss0_core0_dma_memory_region: r5f-dma-memory@9c800000 {
> > +			compatible = "shared-dma-pool";
> > +			reg = <0x00 0x9c800000 0x00 0x00100000>;
> > +			no-map;
> > +		};
> > +
> > +		wkup_r5fss0_core0_memory_region: r5f-memory@9c900000 {
> > +			compatible = "shared-dma-pool";
> > +			reg = <0x00 0x9c900000 0x00 0x01e00000>;
> > +			no-map;
> > +		};
> > +
> > +		secure_tfa_ddr: tfa@9e780000 {
> > +			reg = <0x00 0x9e780000 0x00 0x80000>;
> > +			no-map;
> > +		};
> > +
> > +		secure_ddr: optee@9e800000 {
> > +			reg = <0x00 0x9e800000 0x00 0x01800000>; /* for OP-TEE */
> > +			no-map;
> > +		};
> > +	};
> > +
> > +	reg_3v3: regulator-3v3 {
> > +		compatible = "regulator-fixed";
> > +		regulator-name = "On-module +V3.3";
> > +		regulator-min-microvolt = <3300000>;
> > +		regulator-max-microvolt = <3300000>;
> > +		regulator-always-on;
> > +		regulator-boot-on;
> > +	};
> > +
> > +	reg_1v8: regulator-1v8 {
> > +		compatible = "regulator-fixed";
> > +		regulator-name = "On-module +V1.8";
> > +		regulator-min-microvolt = <1800000>;
> > +		regulator-max-microvolt = <1800000>;
> > +		vin-supply = <&reg_3v3>;
> > +		regulator-always-on;
> > +		regulator-boot-on;
> > +	};
> > +
> > +	reg_3v3_phy: regulator-3v3-phy {
> > +		compatible = "regulator-fixed";
> > +		regulator-name = "On-module +V3.3_PHY";
> > +		gpios = <&main_gpio0 45 GPIO_ACTIVE_HIGH>;
> > +		enable-active-high;
> > +		regulator-always-on;
> > +	};
> > +};
> > +
> > +&cpsw3g {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_rgmii1>;
> > +};
> > +
> > +&cpsw3g_mdio {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_mdio1>;
> > +	status = "okay";
> > +
> > +	cpsw3g_phy0: ethernet-phy@4 {
> > +		compatible = "ethernet-phy-id0283.bc30";
> > +		reg = <4>;
> > +		reset-gpios = <&main_gpio0 46 GPIO_ACTIVE_LOW>;
> > +		reset-assert-us = <10000>;
> > +		reset-deassert-us = <100000>;
> > +	};
> > +};
> > +
> > +&cpsw_port1 {
> > +	/*
> > +	 * The required RGMII TX and RX 2ns delays are implemented directly
> > +	 * in hardware via passive delay elements on the SOM PCB.
> > +	 * No delay configuration is needed in software via PHY driver.
> > +	 */
> > +	phy-mode = "rgmii";
> > +	phy-handle = <&cpsw3g_phy0>;
> > +	status = "okay";
> > +};
> > +
> > +&main_i2c2 {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_i2c2>;
> > +	clock-frequency = <400000>;
> > +	status = "okay";
> > +};
> > +
> > +&main_i2c3 {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_i2c3>;
> > +	clock-frequency = <400000>;
> > +	status = "okay";
> > +};
> > +
> > +&main_pmx0 {
> > +	pinctrl_mmc_pwrseq: main-emmc-pwrseq-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x00c8, PIN_OUTPUT, 7) /* (AB23) VOUT0_DATA4.GPIO0_49 */
> > +		>;
> > +	};
> > +
> > +	pinctrl_i2c2: main-i2c2-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x00b0, PIN_INPUT_PULLUP, 1) /* (T22) GPMC0_CSn2.I2C2_SCL */
> > +			AM62PX_IOPAD(0x00b4, PIN_INPUT_PULLUP, 1) /* (U25) GPMC0_CSn3.I2C2_SDA */
> > +		>;
> > +	};
> > +
> > +	pinctrl_i2c3: main-i2c3-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x01d0, PIN_INPUT_PULLUP, 2) /* (A23) UART0_CTSn.I2C3_SCL */
> > +			AM62PX_IOPAD(0x01d4, PIN_INPUT_PULLUP, 2) /* (C22) UART0_RTSn.I2C3_SDA */
> > +		>;
> > +	};
> > +
> > +	pinctrl_mdio1: main-mdio1-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x0160, PIN_OUTPUT, 0) /* (F17) MDIO0_MDC */
> > +			AM62PX_IOPAD(0x015c, PIN_INPUT, 0) /* (F16) MDIO0_MDIO */
> > +		>;
> > +	};
> > +
> > +	pinctrl_mmc2: main-mmc2-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x0120, PIN_INPUT_PULLUP, 0) /* (K24) MMC2_CMD */
> > +			AM62PX_IOPAD(0x0118, PIN_INPUT_PULLDOWN, 0) /* (K21) MMC2_CLK */
> > +			AM62PX_IOPAD(0x011c, PIN_INPUT_PULLUP, 0) /* () MMC2_CLKLB */
> > +			AM62PX_IOPAD(0x0114, PIN_INPUT_PULLUP, 0) /* (K23) MMC2_DAT0 */
> > +			AM62PX_IOPAD(0x0110, PIN_INPUT_PULLUP, 0) /* (K22) MMC2_DAT1 */
> > +			AM62PX_IOPAD(0x010c, PIN_INPUT_PULLUP, 0) /* (L20) MMC2_DAT2 */
> > +			AM62PX_IOPAD(0x0108, PIN_INPUT_PULLUP, 0) /* (L21) MMC2_DAT3 */
> > +		>;
> > +	};
> > +
> > +	pinctrl_rgmii1: main-rgmii1-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x014c, PIN_INPUT, 0) /* (B15) RGMII1_RD0 */
> > +			AM62PX_IOPAD(0x0150, PIN_INPUT, 0) /* (B16) RGMII1_RD1 */
> > +			AM62PX_IOPAD(0x0154, PIN_INPUT, 0) /* (A14) RGMII1_RD2 */
> > +			AM62PX_IOPAD(0x0158, PIN_INPUT, 0) /* (B14) RGMII1_RD3 */
> > +			AM62PX_IOPAD(0x0148, PIN_INPUT, 0) /* (A16) RGMII1_RXC */
> > +			AM62PX_IOPAD(0x0144, PIN_INPUT, 0) /* (A15) RGMII1_RX_CTL */
> > +			AM62PX_IOPAD(0x0134, PIN_INPUT, 0) /* (A18) RGMII1_TD0 */
> > +			AM62PX_IOPAD(0x0138, PIN_INPUT, 0) /* (C17) RGMII1_TD1 */
> > +			AM62PX_IOPAD(0x013c, PIN_INPUT, 0) /* (A17) RGMII1_TD2 */
> > +			AM62PX_IOPAD(0x0140, PIN_INPUT, 0) /* (C16) RGMII1_TD3 */
> > +			AM62PX_IOPAD(0x0130, PIN_INPUT, 0) /* (B17) RGMII1_TXC */
> > +			AM62PX_IOPAD(0x012c, PIN_INPUT, 0) /* (B18) RGMII1_TX_CTL */
> > +		>;
> > +		bootph-all;
> > +	};
> > +
> > +	pinctrl_spi0: main-spi0-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x01bc, PIN_OUTPUT, 0) /* (B21) SPI0_CLK */
> > +			AM62PX_IOPAD(0x01b4, PIN_OUTPUT, 0) /* (D20) SPI0_CS0 */
> > +			AM62PX_IOPAD(0x01c0, PIN_OUTPUT, 0) /* (B20) SPI0_D0 */
> > +			AM62PX_IOPAD(0x01c4, PIN_INPUT, 0) /* (C21) SPI0_D1 */
> > +		>;
> > +	};
> > +
> > +	pinctrl_uart5: main-uart5-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x00ec, PIN_INPUT, 4) /* (AC21) VOUT0_DATA13.UART5_CTSn */
> > +			AM62PX_IOPAD(0x00e8, PIN_OUTPUT, 4) /* (AD21) VOUT0_DATA12.UART5_RTSn */
> > +			AM62PX_IOPAD(0x00d0, PIN_INPUT, 4) /* (AC23) VOUT0_DATA6.UART5_RXD */
> > +			AM62PX_IOPAD(0x00d4, PIN_OUTPUT, 4) /* (AE23) VOUT0_DATA7.UART5_TXD */
> > +		>;
> > +	};
> > +
> > +	pinctrl_bt: main-btgrp-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x00f4, PIN_OUTPUT, 7) /* (Y20) VOUT0_DATA15.GPIO0_60 (BT_EN) */
> > +		>;
> > +	};
> > +
> > +	pinctrl_restouch: main-restouch-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x00c4, PIN_INPUT_PULLUP, 7) /* (Y23) VOUT0_DATA3.GPIO0_48 */
> > +		>;
> > +	};
> > +
> > +	pinctrl_wifi: main-wifi-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_IOPAD(0x00dc, PIN_OUTPUT, 7) /* (AC22) VOUT0_DATA9.GPIO0_54 - WIFI_PWR_EN - */
> > +			AM62PX_IOPAD(0x00f0, PIN_OUTPUT, 7) /* (AA20) VOUT0_DATA14.GPIO0_59 - WIFI_EN - */
> > +		>;
> > +	};
> > +};
> > +
> > +&mcu_pmx0 {
> > +	pinctrl_wkup_clkout0: wkup-clkout0-default-pins {
> > +		pinctrl-single,pins = <
> > +			AM62PX_MCU_IOPAD(0x0084, PIN_OUTPUT, 0) /* (F13) WKUP_CLKOUT0 */
> > +		>;
> > +	};
> > +};
> > +
> > +&main_spi0 {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_spi0>;
> > +	ti,pindir-d0-out-d1-in;
> > +	status = "okay";
> > +};
> > +
> > +&main_uart5 {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_uart5>, <&pinctrl_bt>;
> > +	uart-has-rtscts;
> > +	status = "okay";
> > +
> > +	bluetooth {
> > +		compatible = "nxp,88w8987-bt";
> > +	};
> > +};
> > +
> > +&sdhci0 {
> > +	ti,driver-strength-ohm = <50>;
> > +	mmc-pwrseq = <&mmc_pwrseq>;
> > +	bootph-all;
> > +	status = "okay";
> > +};
> > +
> > +&sdhci2 {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_mmc2>, <&pinctrl_wifi>;
> > +	bus-width = <4>;
> > +	non-removable;
> > +	keep-power-in-suspend;
> > +	mmc-pwrseq = <&wifi_pwrseq>;
> > +	ti,fails-without-test-cd;
> > +	status = "okay";
> > +};
> > +
> > +&usbss0 {
> > +	ti,vbus-divider;
> > +};
> > +
> > +&usbss1 {
> > +	ti,vbus-divider;
> > +};
> > +
> > +&mailbox0_cluster0 {
> > +	status = "okay";
> > +
> > +	mbox_r5_0: mbox-r5-0 {
> > +		ti,mbox-rx = <0 0 0>;
> > +		ti,mbox-tx = <1 0 0>;
> > +	};
> > +};
> > +
> > +&mailbox0_cluster1 {
> > +	status = "okay";
> > +
> > +	mbox_mcu_r5_0: mbox-mcu-r5-0 {
> > +		ti,mbox-rx = <0 0 0>;
> > +		ti,mbox-tx = <1 0 0>;
> > +	};
> > +};
> > +
> > +&mcu_r5fss0 {
> > +	status = "okay";
> > +};
> > +
> > +&mcu_r5fss0_core0 {
> > +	mboxes = <&mailbox0_cluster1 &mbox_mcu_r5_0>;
> > +	memory-region = <&mcu_r5fss0_core0_dma_memory_region>,
> > +			<&mcu_r5fss0_core0_memory_region>;
> > +};
> > +
> > +&wkup_r5fss0 {
> > +	status = "okay";
> > +};
> > +
> > +&wkup_r5fss0_core0 {
> > +	mboxes = <&mailbox0_cluster0 &mbox_r5_0>;
> > +	memory-region = <&wkup_r5fss0_core0_dma_memory_region>,
> > +			<&wkup_r5fss0_core0_memory_region>;
> > +};
> > +
> > +/* mcu_gpio0 and mcu_gpio_intr are reserved for mcu firmware usage */
> > +&mcu_gpio0 {
> > +	status = "reserved";
> > +};
> 
> And also drop the IPC stuff above.
> 
> 
> > +
> > +&mcu_gpio_intr {
> > +	status = "reserved";
> > +};
> > +
> > +&wkup_rtc0 {
> > +	status = "disabled";
> > +};
> > +
> > +&wkup_rti0 {
> > +	/* WKUP RTI0 is used by DM firmware */
> > +	status = "reserved";
> > +};
> > +
> > +&wkup_uart0 {
> > +	/* WKUP UART0 is used by DM firmware */
> > +	status = "reserved";
> > +};
> > +
> > +&main_uart1 {
> > +	/* Main UART1 is used by TIFS firmware */
> > +	status = "reserved";
> > +};
> 
> And include:
> 
> +#include "k3-am62p-ti-ipc-firmware.dtsi"
> 
> 
> so that this SOM can be left in a refactored state like all other DT.
> Of course, this means this series would have a dependency on beleswar's
> series:
> https://lore.kernel.org/linux-arm-kernel/20250905051846.1189612-1-b-padhi@ti.com/
> 
> Just a suggestion here. (:
> 
> ~ Judith

thank you very much for the review! That does make sense, you are right.

Would you think it makes sense to leave this refactoring for a follow‑up,
so that this series can go in without depending on Beleswar’s?
That way the patch could be merged right away, and later we include:

#include "k3-am62p-ti-ipc-firmware.dtsi"

to bring the DT in line with the others.

Just checking if that sounds reasonable to you. (:

Thanks again,
Stefano

> 
>