ARM: dts: zte: Add D-Link DWR-932M support

This adds base DT definition for zx297520v3 and one board that consumes it.

The stock kernel does not use the armv7 timer, but it seems to work
fine. The board has other board-specific timers that would need a driver
and I see no reason to bother with them since the arm standard timer
works.

The caveat is the non-standard GIC setup needed to handle the timer's
level-low PPI. This is the responsibility of the boot loader and
documented in Documentation/arch/arm/zte/zx297520v3.rst.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Stefan Dösinger <stefandoesinger@gmail.com>
---

Changes in
v8: Remove redundant label, use "arm,pl011" for uart0 and 2 too.
v6: Squash board + timer + uart patches into one
v5: Prepend the SoC name in the device specific DTS filename.
v4:
  Declare all uarts
  Remove the UART aliases for now. I can revisit this when I get my
  hands on a board that exposes two UARTs.

diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index efe38eb25301648f231ced32c0e5dc02c68daa90..28fba538d552051983b1a34606bdc2d8873cf171 100644 (file)
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -39,3 +39,4 @@ subdir-y += unisoc
 subdir-y += vt8500
 subdir-y += xen
 subdir-y += xilinx
+subdir-y += zte

diff --git a/arch/arm/boot/dts/zte/Makefile b/arch/arm/boot/dts/zte/Makefile
new file mode 100644 (file)
index 0000000..f052cfb
--- /dev/null
+++ b/arch/arm/boot/dts/zte/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+dtb-$(CONFIG_SOC_ZX297520V3) += \
+       zx297520v3-dlink-dwr932m.dtb

diff --git a/arch/arm/boot/dts/zte/zx297520v3-dlink-dwr932m.dts b/arch/arm/boot/dts/zte/zx297520v3-dlink-dwr932m.dts
new file mode 100644 (file)
index 0000000..1700f46
--- /dev/null
+++ b/arch/arm/boot/dts/zte/zx297520v3-dlink-dwr932m.dts
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2026 Stefan Dösinger <stefandoesinger@gmail.com>
+ */
+
+/dts-v1/;
+
+#include "zx297520v3.dtsi"
+
+/ {
+       model = "D-Link DWR-932M";
+       compatible = "dlink,dwr932m", "zte,zx297520v3";
+
+       memory@20000000 {
+               device_type = "memory";
+               reg = <0x20000000 0x04000000>;
+       };
+};
+
+&uart1 {
+       status = "okay";
+};

diff --git a/arch/arm/boot/dts/zte/zx297520v3.dtsi b/arch/arm/boot/dts/zte/zx297520v3.dtsi
new file mode 100644 (file)
index 0000000..a16c30a
--- /dev/null
+++ b/arch/arm/boot/dts/zte/zx297520v3.dtsi
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2026 Stefan Dösinger <stefandoesinger@gmail.com>
+ */
+
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+/ {
+       #address-cells = <1>;
+       #size-cells = <1>;
+
+       cpus {
+               #address-cells = <1>;
+               #size-cells = <0>;
+
+               cpu@0 {
+                       device_type = "cpu";
+                       compatible = "arm,cortex-a53";
+                       reg = <0>;
+               };
+       };
+
+       /* Base bus clock and default for the UART. It will be replaced once a clock driver has
+        * been added.
+        */
+       uartclk: uartclk-26000000 {
+               #clock-cells = <0>;
+               compatible = "fixed-clock";
+               clock-frequency = <26000000>;
+       };
+
+       timer {
+               compatible = "arm,armv7-timer";
+               interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>,
+                            <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>,
+                            <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>,
+                            <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>;
+               clock-frequency = <26000000>;
+               interrupt-parent = <&gic>;
+               /* I don't think uboot sets CNTVOFF and the stock kernel doesn't use the
+                * arm timer at all. Since this is a single CPU system I don't think it
+                * really matters that the offset is random though.
+                */
+               arm,cpu-registers-not-fw-configured;
+       };
+
+       soc {
+               #address-cells = <1>;
+               #size-cells = <1>;
+               compatible = "simple-bus";
+               interrupt-parent = <&gic>;
+               ranges;
+
+               /* The GIC has a non-standard way of configuring ints between level-low/level
+                * high or rising edge/falling edge at 0xf2202070 and onwards. See AP_INT_MODE_BASE
+                * and AP_PPI_MODE_REG in the ZTE kernel, although the offsets in the kernel source
+                * seem wrong.
+                *
+                * Everything defaults to active-high/rising edge, but the timer is active-low. We
+                * currently rely on the boot loader to change timer IRQs to active-low for us for
+                * now.
+                */
+               gic: interrupt-controller@f2000000 {
+                       compatible = "arm,gic-v3";
+                       interrupt-controller;
+                       #interrupt-cells = <3>;
+                       #address-cells = <1>;
+                       #size-cells = <1>;
+                       reg = <0xf2000000 0x10000>,
+                             <0xf2040000 0x20000>;
+               };
+
+               uart0: serial@131000 {
+                       compatible = "arm,pl011", "arm,primecell";
+                       arm,primecell-periphid = <0x0018c011>;
+                       reg = <0x00131000 0x1000>;
+                       interrupts = <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&uartclk>, <&uartclk>;
+                       clock-names = "uartclk", "apb_pclk";
+                       status = "disabled";
+               };
+
+               uart1: serial@1408000 {
+                       compatible = "arm,pl011", "arm,primecell";
+                       arm,primecell-periphid = <0x0018c011>;
+                       reg = <0x01408000 0x1000>;
+                       interrupts = <GIC_SPI 1 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&uartclk>, <&uartclk>;
+                       clock-names = "uartclk", "apb_pclk";
+                       status = "disabled";
+               };
+
+               uart2: serial@140d000 {
+                       compatible = "arm,pl011", "arm,primecell";
+                       arm,primecell-periphid = <0x0018c011>;
+                       reg = <0x0140d000 0x1000>;
+                       interrupts = <GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&uartclk>, <&uartclk>;
+                       clock-names = "uartclk", "apb_pclk";
+                       status = "disabled";
+               };
+       };
+};