[PATCH v4] ath79: add support for Ubiquiti PowerBeam M (XW)

[Russell Senior]

This patch adds support for the Ubiquiti PowerBeam M (XW), e.g. PBE-M5-400,
a 802.11n wireless with a feed+dish form factor. This device was previously
supported by the ar71xx loco-m-xw firmware.

Specifications:
 - Atheros AR9342 SoC
 - 64 MB RAM
 - 8 MB SPI flash
 - 1x 10/100 Mbps Ethernet port, 24 Vdc PoE-in
 - Power and LAN green LEDs
 - 4x RSSI LEDs (red, orange, green, green)
 - UART (115200 8N1)

Flashing via stock GUI:
 - Downgrade to AirOS v5.5.x (latest available is 5.5.10-u2) first (see
   https://openwrt.org/toh/ubiquiti/powerbeam installation instructions)
 - Upload the factory image via AirOS web GUI.

Flashing via TFTP:
 - Use a pointy tool (e.g., unbent paperclip) to keep the
   reset button pressed.
 - Power on the device (keep reset button pressed).
 - Keep pressing until LEDs flash alternatively LED1+LED3 =>
   LED2+LED4 => LED1+LED3, etc.
 - Release reset button.
 - The device starts a TFTP server at 192.168.1.20.
 - Set a static IP on the computer (e.g., 192.168.1.21/24).
 - Upload via tftp the factory image:
    $ tftp 192.168.1.20
    tftp> bin
    tftp> trace
    tftp> put openwrt-ath79-generic-xxxxx-ubnt_powerbeam-m-xw-squashfs-factory.bin

WARNING: so far, no non-destructive method has been discovered for
opening the enclosure to reach the serial console. Internal photos
are available here: https://fcc.io/SWX-NBM5HP

since v1:
 * renamed from ubnt,powerbeam-m to ubnt,powerbeam-m-xw
since v2:
 * removed redundant mtd-mac-address from dts
since v3:
 * based on testimony of Joe Ayers <joe at ayerscasa.com>:
  * the bricking problem was resolved by 076d58d3440f (2016-02)
  * the tftp flashing problem was resolved by 6009b3fd586a (2018-11)
   so, removed the associated warnings.

Signed-off-by: Russell Senior <russell at personaltelco.net>
---
 .../ath79/dts/ar9342_ubnt_powerbeam-m-xw.dts  | 34 +++++++++++++++++++
 .../generic/base-files/etc/board.d/01_leds    |  1 +
 .../generic/base-files/etc/board.d/02_network |  1 +
 target/linux/ath79/image/generic-ubnt.mk      |  8 +++++
 4 files changed, 44 insertions(+)
 create mode 100644 target/linux/ath79/dts/ar9342_ubnt_powerbeam-m-xw.dts

diff --git a/target/linux/ath79/dts/ar9342_ubnt_powerbeam-m-xw.dts b/target/linux/ath79/dts/ar9342_ubnt_powerbeam-m-xw.dts
new file mode 100644
index 0000000000..6db058f887
--- /dev/null
+++ b/target/linux/ath79/dts/ar9342_ubnt_powerbeam-m-xw.dts
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "ar9342_ubnt_xw.dtsi"
+
+/ {
+	compatible = "ubnt,powerbeam-m-xw", "ubnt,xw", "qca,ar9342";
+	model = "Ubiquiti PowerBeam M (XW)";
+};
+
+&mdio0 {
+	status = "okay";
+
+	phy-mask = <4>;
+
+	phy4: ethernet-phy at 4 {
+		reg = <4>;
+	};
+};
+
+&eth0 {
+	status = "okay";
+
+	/* default for ar934x, except for 1000M and 10M */
+	pll-data = <0x02000000 0x00000101 0x00001313>;
+
+	phy-mode = "rgmii-id";
+	phy-handle = <&phy4>;
+
+	gmac-config {
+		device = <&gmac>;
+		rxd-delay = <3>;
+		rxdv-delay = <3>;
+	};
+};
diff --git a/target/linux/ath79/generic/base-files/etc/board.d/01_leds b/target/linux/ath79/generic/base-files/etc/board.d/01_leds
index 1990353394..35ce90aeb4 100644
--- a/target/linux/ath79/generic/base-files/etc/board.d/01_leds
+++ b/target/linux/ath79/generic/base-files/etc/board.d/01_leds
@@ -383,6 +383,7 @@ ubnt,nanostation-loco-m-xw|\
 ubnt,nanostation-m|\
 ubnt,nanostation-m-xw|\
 ubnt,picostation-m|\
+ubnt,powerbeam-m-xw|\
 ubnt,powerbridge-m|\
 ubnt,rocket-m)
 	ucidef_set_rssimon "wlan0" "200000" "1"
diff --git a/target/linux/ath79/generic/base-files/etc/board.d/02_network b/target/linux/ath79/generic/base-files/etc/board.d/02_network
index 4133b9d7d3..6e31cdac69 100644
--- a/target/linux/ath79/generic/base-files/etc/board.d/02_network
+++ b/target/linux/ath79/generic/base-files/etc/board.d/02_network
@@ -85,6 +85,7 @@ ath79_setup_interfaces()
 	ubnt,picostation-m|\
 	ubnt,powerbeam-5ac-500|\
 	ubnt,powerbeam-5ac-gen2|\
+	ubnt,powerbeam-m-xw|\
 	ubnt,powerbridge-m|\
 	ubnt,rocket-m|\
 	ubnt,unifiac-lite|\
diff --git a/target/linux/ath79/image/generic-ubnt.mk b/target/linux/ath79/image/generic-ubnt.mk
index 733d803d7a..5948e059e8 100644
--- a/target/linux/ath79/image/generic-ubnt.mk
+++ b/target/linux/ath79/image/generic-ubnt.mk
@@ -328,6 +328,14 @@ define Device/ubnt_powerbeam-5ac-gen2
 endef
 TARGET_DEVICES += ubnt_powerbeam-5ac-gen2
 
+define Device/ubnt_powerbeam-m-xw
+  $(Device/ubnt-xw)
+  DEVICE_MODEL := PowerBeam M
+  DEVICE_PACKAGES += rssileds
+  SUPPORTED_DEVICES += loco-m-xw
+endef
+TARGET_DEVICES += ubnt_powerbeam-m-xw
+
 define Device/ubnt_powerbridge-m
   $(Device/ubnt-xm)
   SOC := ar7241
-- 
2.31.1