ath79: add support for MikroTik RB951G-2HnD

MikroTik RB951G-2HnD is a wireless SOHO router that was previously
supported by the ar71xx target, see commit 7a709573d7 ("ar71xx: add
kernel support for the Mikrotik RB951G board").

Specifications
--------------

  - SoC: Atheros AR9344 (600 MHz)
  - RAM: 128 MB (2x 64 MB)
  - Storage: 128 MB NAND flash (various manufacturers)
  - Ethernet: Atheros AR8327 switch, 5x 10/100/1000 Mbit/s
      - 1x PoE in (port 1, 8-30 V input)
  - Wireless: Atheros AR9340 (802.11b/g/n)
  - USB: 2.0 (1A)
  - 8x LED:
      - 1x power (green, not configurable)
      - 1x user (green, not configurable)
      - 5x GE ports (green, not configurable)
      - 1x wireless (green, not configurable)
  - 1x button (restart)

Unlike on the RB951Ui-2HnD, none of the LEDs on this device seem to be
GPIO-controllable, which was also the case for older OpenWRT versions
that supported this board via a mach file.  The Ethernet port LEDs are
controlled by the switch chip.

See https://mikrotik.com/product/RB951G-2HnD for more details.

Flashing
--------

TFTP boot initramfs image and then perform sysupgrade.  Follow
common MikroTik procedures at https://openwrt.org/toh/mikrotik/common.

Signed-off-by: Michał Kępień <openwrt@kempniu.pl>
(cherry picked from commit db02cecd6ad2e5962e6e9d8307da34855a083ad6)

1 files changed, 58 insertions, 0 deletions

diff --git a/target/linux/ath79/dts/ar9344_mikrotik_routerboard-951g-2hnd.dts b/target/linux/ath79/dts/ar9344_mikrotik_routerboard-951g-2hnd.dts
new file mode 100644
index 0000000000..16da7a3c95
--- /dev/null
+++ b/target/linux/ath79/dts/ar9344_mikrotik_routerboard-951g-2hnd.dts
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "ar9344_mikrotik_routerboard-951x-2hnd.dtsi"
+
+/ {
+	compatible = "mikrotik,routerboard-951g-2hnd", "qca,ar9344";
+	model = "Mikrotik RouterBOARD 951G-2HnD";
+
+	/delete-node/ aliases;
+	/delete-node/ leds;
+
+	gpio-export {
+		compatible = "gpio-export";
+
+		gpio_usb_power {
+			gpio-export,name = "rb951g-2hnd:power:usb";
+			gpio-export,output = <1>;
+			gpios = <&gpio 20 GPIO_ACTIVE_HIGH>;
+		};
+	};
+};
+
+&ref {
+	clock-frequency = <25000000>;
+};
+
+&mdio0 {
+	status = "okay";
+
+	phy0: ethernet-phy@0 {
+		reg = <0>;
+
+                qca,ar8327-initvals = <
+			0x04 0x07600000 /* PAD0_MODE */
+			0x7c 0x0000007e /* PORT0_STATUS */
+		>;
+	};
+};
+
+&eth0 {
+	status = "okay";
+
+	pll-data = <0x6f000000 0x00000101 0x00001616>;
+
+	phy-mode = "rgmii";
+	phy-handle = <&phy0>;
+
+	gmac-config {
+		device = <&gmac>;
+		rgmii-gmac0 = <1>;
+		rxd-delay = <1>;
+		switch-only-mode = <1>;
+	};
+};
+
+&eth1 {
+	status = "disabled";
+};