ramips: add support for HiWiFi HC5661A

HC5661A is almost the same as HC5661 but MT7628AN is used instead of MT7620A.

- MT7628AN
- 128 MiB DDR2 RAM (W971GG6KB-25)
- 16 MiB SPI NOR flash (W25Q128)
- SD slot (not work yet)
- 1+4 x 100M Ethernet
- 802.11 b/g/n Wi-Fi
- 3 x LED
- 1 x button
- UART pad on PCB (JP1: TX, RX, GND, 3.3V)

The factory flash layout seems different from HC5661.
"hwf_config" is renamed to "oem" and its size changes to 0x20000.
It is modified accordingly in the dts file.

0x000000000000-0x000000030000 : "u-boot"
0x000000030000-0x000000040000 : "hw_panic"
0x000000040000-0x000000050000 : "Factory"
0x000000050000-0x000000160000 : "kernel"
0x000000160000-0x000000fc0000 : "rootfs"
0x000000bb0000-0x000000fc0000 : "rootfs_data"
0x000000fc0000-0x000000fe0000 : "oem"
0x000000fe0000-0x000000ff0000 : "bdinfo"
0x000000ff0000-0x000001000000 : "backup"
0x000000050000-0x000000fc0000 : "firmware"

To install LEDE, enabled the "developer mode",
which will *void your warranty* and open the SSH server at port 1022.

sysupgrade -n -F lede-ramips-mt7628-hc5661a-squashfs-sysupgrade.bin

SD slot:
- Tried to add modules kmod-sdhci kmod-sdhci-mt7620, and corresponding dts block.
- It will block WAN + 3xLAN ports, only one LAN works.
- I'm not sure why, everything else works fine.

Signed-off-by: Wang JiaWei <buaawjw@gmail.com>

target/linux/ramips/base-files/etc/board.d/01_leds

@@ -181,7 +181,8 @@ gl-mt300n|\
 gl-mt750)
 	set_wifi_led "$board:wlan"
 	;;
-hc5661)
+hc5661|\
+hc5661a)
 	ucidef_set_led_default "system" "system" "$board:blue:system" "1"
 	ucidef_set_led_netdev "internet" "internet" "$board:blue:internet" "eth0.2"
 	set_wifi_led "$board:blue:wlan2g"

target/linux/ramips/base-files/etc/board.d/02_network

@@ -79,6 +79,7 @@ ramips_setup_interfaces()
 	dir-610-a1|\
 	dir-615-h1|\
 	firewrt|\
+	hc5661a|\
 	hlk-rm04|\
 	mac1200rv2|\
 	miwifi-mini|\
@@ -343,7 +344,8 @@ ramips_setup_macs()
 	e1700)
 		wan_mac=$(mtd_get_mac_ascii config WAN_MAC_ADDR)
 		;;
-	hc5*61)
+	hc5*61|\
+	hc5661a)
 		lan_mac=`mtd_get_mac_ascii bdinfo "Vfac_mac "`
 		[ -n "$lan_mac" ] || lan_mac=$(cat /sys/class/net/eth0/address)
 		wan_mac=$(macaddr_add "$lan_mac" 1)

target/linux/ramips/base-files/etc/diag.sh

@@ -140,6 +140,7 @@ get_status_led() {
 		status_led="$board:orange:status"
 		;;
 	hc5*61|\
+	hc5661a|\
 	jhr-n805r|\
 	jhr-n926r|\
 	mlw221|\