[PATCH v2 2/2] arm64: dts: rockchip: Add WWAN overlay for Radxa ROCK 3B

[Adam Wermuth <adam@wermuth.pl>]

The M.2 B-key slot on the ROCK 3B is intended for 4G/5G modules and
is not always populated. Add a device tree overlay which enables the
slot when a module is fitted:

 - The USB 2.0 data lines of the slot are routed to USB2_HOST3, served
   by usb_host1_ehci/ohci through the host port of usb2phy1. The slot
   has no VBUS, so no supply is attached to the PHY port.
 - GPIO0_C6 (4G_PWREN_H) enables the 3.3V supply of the slot, which is
   generated from vcc5v0_sys by a dedicated buck converter.
 - GPIO0_D6 (4G_RESET) drives RESET# and GPIO1_B0 (4G_DISABLE) drives
   W_DISABLE1# of the slot. Both are hogged in their inactive state.

Tested with a SIMCom SIM7600G-H module.

Signed-off-by: Adam Wermuth <adam@wermuth.pl>
---
 arch/arm64/boot/dts/rockchip/Makefile         |  5 ++
 .../dts/rockchip/rk3568-rock-3b-wwan.dtso     | 65 +++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 arch/arm64/boot/dts/rockchip/rk3568-rock-3b-wwan.dtso

diff --git a/arch/arm64/boot/dts/rockchip/Makefile b/arch/arm64/boot/dts/rockchip/Makefile
index b677914cd3f1..8a1f24ccaa32 100644
--- a/arch/arm64/boot/dts/rockchip/Makefile
+++ b/arch/arm64/boot/dts/rockchip/Makefile
@@ -165,6 +165,7 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-radxa-e25.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-roc-pc.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-rock-3a.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-rock-3b.dtb
+dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-rock-3b-wwan.dtbo
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-wolfvision-pf5.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-wolfvision-pf5-display-vz.dtbo
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-wolfvision-pf5-io-expander.dtbo
@@ -300,6 +301,10 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-qnap-ts433-pcb-12-10.dtb
 rk3568-qnap-ts433-pcb-12-10-dtbs := rk3568-qnap-ts433.dtb \
 	rk3568-qnap-ts433-pcb-12-10.dtbo
 
+dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-rock-3b-wwan.dtb
+rk3568-rock-3b-wwan-dtbs := rk3568-rock-3b.dtb \
+	rk3568-rock-3b-wwan.dtbo
+
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-wolfvision-pf5-vz-2-uhd.dtb
 rk3568-wolfvision-pf5-vz-2-uhd-dtbs := rk3568-wolfvision-pf5.dtb \
 	rk3568-wolfvision-pf5-display-vz.dtbo \
diff --git a/arch/arm64/boot/dts/rockchip/rk3568-rock-3b-wwan.dtso b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b-wwan.dtso
new file mode 100644
index 000000000000..73a19408d61c
--- /dev/null
+++ b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b-wwan.dtso
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Device tree overlay for a WWAN module in the M.2 B-key slot
+ * of the Radxa ROCK 3B.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/pinctrl/rockchip.h>
+
+&{/} {
+	vcc3v3_wwan: regulator-3v3-vcc-wwan {
+		compatible = "regulator-fixed";
+		enable-active-high;
+		gpios = <&gpio0 RK_PC6 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&wwan_pwren_h>;
+		regulator-name = "vcc3v3_wwan";
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		vin-supply = <&vcc5v0_sys>;
+	};
+};
+
+&gpio0 {
+	wwan-reset-hog {
+		gpio-hog;
+		gpios = <RK_PD6 GPIO_ACTIVE_LOW>;
+		output-low;
+		line-name = "wwan-reset";
+	};
+};
+
+&gpio1 {
+	wwan-disable-hog {
+		gpio-hog;
+		gpios = <RK_PB0 GPIO_ACTIVE_LOW>;
+		output-low;
+		line-name = "wwan-w-disable";
+	};
+};
+
+&pinctrl {
+	wwan {
+		wwan_pwren_h: wwan-pwren-h {
+			rockchip,pins = <0 RK_PC6 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
+};
+
+&usb_host1_ehci {
+	status = "okay";
+};
+
+&usb_host1_ohci {
+	status = "okay";
+};
+
+&usb2phy1_host {
+	status = "okay";
+};
-- 
2.43.0