[openwrt/openwrt] ath79: ZTE MF286[A, R]: add "Power button blocker" GPIO switch

[LEDE Commits]

chunkeey pushed a commit to openwrt/openwrt.git, branch openwrt-22.03:
https://git.openwrt.org/9ef931f96b50e7d5ce3e1e598483d0b71e9ab62a

commit 9ef931f96b50e7d5ce3e1e598483d0b71e9ab62a
Author: Lech Perczak <lech.perczak at gmail.com>
AuthorDate: Sat May 14 14:50:02 2022 +0200

    ath79: ZTE MF286[A,R]: add "Power button blocker" GPIO switch
    
    ZTE MF286A and MF286R feature a "power switch override" GPIO in stock
    firmware as means to prevent power interruption during firmware update,
    especially when used with internal battery.
    To ensure that this GPIO is
    properly driven as in stock firmware, configure it with userspace GPIO
    switch.
    
    It was observed that on some units, the modem would not be
    restarted together with the board itself on reboot, this should help
    with that as well.
    
    Signed-off-by: Lech Perczak <lech.perczak at gmail.com>
    (cherry picked from commit 1fabeeb799abca1d4fb5ba541410ba847cdc20d9)
---
 .../nand/base-files/etc/board.d/03_gpio_switches     | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/target/linux/ath79/nand/base-files/etc/board.d/03_gpio_switches b/target/linux/ath79/nand/base-files/etc/board.d/03_gpio_switches
new file mode 100644
index 0000000000..775778a2be
--- /dev/null
+++ b/target/linux/ath79/nand/base-files/etc/board.d/03_gpio_switches
@@ -0,0 +1,20 @@
+#
+# Copyright (C) 2022 OpenWrt.org
+#
+
+. /lib/functions/uci-defaults.sh
+
+board_config_update
+
+board=$(board_name)
+
+case "$board" in
+zte,mf286a|\
+zte,mf286r)
+	ucidef_add_gpio_switch "power_btn_block" "Power button blocker" "20" "0"
+	;;
+esac
+
+board_config_flush
+
+exit 0