Thread (6 messages) 6 messages, 2 authors, 2026-01-12

Re: [PATCH v5 2/2] arm64: dts: ti: Add TQ-Systems TQMa62xx SoM and MBa62xx carrier board Device Trees

From: Nishanth Menon <nm@ti.com>
Date: 2026-01-09 19:59:17
Also in: linux-devicetree, linux-hardening, lkml

On 09:14-20260107, Matthias Schiffer wrote:
The TQMa62xx is a SoM family with a pluggable board connector based on the
TI AM62x SoCs. Add DTS(I) for the AM625 (2x Cortex-A53) variant and its
combination with our MBa62xx carrier board.

Signed-off-by: Matthias Schiffer <redacted>
Few clarifications below..

[...]
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/boot/dts/ti/k3-am625-tqma62xx-mba62xx.dts b/arch/arm64/boot/dts/ti/k3-am625-tqma62xx-mba62xx.dts
new file mode 100644
index 0000000000000..cca8d0018504d
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am625-tqma62xx-mba62xx.dts
@@ -0,0 +1,930 @@
[...]
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pinctrl-names = "default";
+		pinctrl-0 = <&backlight_pins>;
+		enable-gpios = <&main_gpio0 38 GPIO_ACTIVE_HIGH>;
+		status = "disabled";
Document why disabled?

[...]
+
+	panel: panel {
+		pinctrl-names = "default";
Missing compatible? thinking again.. Should'nt these be part of some
panel dtsi?
+		pinctrl-0 = <&lvds_panel_pins>;
+		enable-gpios = <&main_gpio0 36 GPIO_ACTIVE_HIGH>;
+		power-supply = <&reg_lvds_pwr>;
+	};
+
+	fan0: pwm-fan {
+		compatible = "pwm-fan";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pwm_fan_pins>;
+		fan-supply = <&reg_pwm_fan>;
+		#cooling-cells = <2>;
+		/* typical 25 kHz -> 40.000 nsec */
+		pwms = <&epwm0 1 40000 PWM_POLARITY_INVERTED>;
+		cooling-levels = <0 32 64 128 196 240>;
+		pulses-per-revolution = <2>;
+		interrupt-parent = <&main_gpio1>;
+		interrupts = <30 IRQ_TYPE_EDGE_FALLING>;
+		status = "disabled";
please document why disabled?

[...]
+
+	reg_pwm_fan: regulator-pwm-fan {
+		compatible = "regulator-fixed";
+		pinctrl-names = "default";
+		pinctrl-0 = <&reg_pwm_fan_pins>;
+		regulator-name = "FAN_PWR";
+		regulator-min-microvolt = <12000000>;
+		regulator-max-microvolt = <12000000>;
Just checking.. Did you intent a 12v supply for fan?
+		gpio = <&main_gpio0 62 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+	};
+
[...]
+
+	lvds_panel_pins: lvds-panel-pins {
+		pinctrl-single,pins = <
+			/* (N20) GPMC0_BE1n.GPIO0_36 - LVDS0_RESET# */
+			AM62X_IOPAD(0x0094, PIN_OUTPUT, 7)
Could you follow the comment convention you have elsewhere? please follow the
same in gpio below etc..
AM62X_IOPAD(....) /* (N20) ... */

btw, panel node uses it as:
enable-gpios = <&main_gpio0 36 GPIO_ACTIVE_HIGH>;

isn't RESET# meant to be active low?
+		>;
+	};
+
[...]

quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/boot/dts/ti/k3-am625-tqma62xx.dtsi b/arch/arm64/boot/dts/ti/k3-am625-tqma62xx.dtsi
new file mode 100644
index 0000000000000..1b7d58cb7b936
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am625-tqma62xx.dtsi
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Copyright (C) 2021-2022 Texas Instruments Incorporated - https://www.ti.com/
+ * Copyright (c) 2023-2025 TQ-Systems GmbH <linux@ew.tq-group.com>, D-82229 Seefeld, Germany.
+ * Author: Matthias Schiffer
+ */
[...]
+		regulators {
+			reg_buck1: buck1 {
+				regulator-name = "V_VDD_CORE";
+				regulator-min-microvolt = <750000>;
+				regulator-max-microvolt = <750000>;
+				regulator-boot-on;
+				regulator-always-on;
+			};
+
[...]
+
+&a53_opp_table {
+	opp-1400000000 {
+		opp-hz = /bits/ 64 <1400000000>;
+		opp-supported-hw = <0x01 0x0004>;
+		opp-suspend;
+		clock-latency-ns = <6000000>;
+		/* Enabled by bootloader if supported */
+		status = "disabled";
This (bootloader enabling just this node) wont work unless vdd_core
voltage is configured to 0.8v as well, no?
+	};
+};
+
-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D
https://ti.com/opensource
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