kc1: Power off when the power on reason is not a valid one

Some power on reasons are not desirable (e.g. too short press on the power
button), battery plug. Thus, power off the device when one of those occurs.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
diff --git a/board/amazon/kc1/kc1.c b/board/amazon/kc1/kc1.c
index 9367b50..54e3fa3 100644
--- a/board/amazon/kc1/kc1.c
+++ b/board/amazon/kc1/kc1.c
@@ -86,6 +86,7 @@
 int misc_init_r(void)
 {
 	char reboot_mode[2] = { 0 };
+	u32 data = 0;
 	u32 value;
 
 	/* Reboot mode */
@@ -101,10 +102,25 @@
 		reboot_mode[0] = 'b';
 
 	if (reboot_mode[0] > 0 && isascii(reboot_mode[0])) {
+		if (reboot_mode[0] == 'o')
+			twl6030_power_off();
+
 		if (!getenv("reboot-mode"))
 			setenv("reboot-mode", (char *)reboot_mode);
 
 		omap_reboot_mode_clear();
+	} else {
+		/*
+		 * When not rebooting, valid power on reasons are either the
+		 * power button, charger plug or USB plug.
+		 */
+
+		data |= twl6030_input_power_button();
+		data |= twl6030_input_charger();
+		data |= twl6030_input_usb();
+
+		if (!data)
+			twl6030_power_off();
 	}
 
 	/* Serial number */