kc1: Proper reboot mode and boot reason validation

With the previous implementation, rebooting without registering a recognized
reboot mode would end up with U-Boot checking for a valid power-on reason, which
might result in the device turning off (e.g. with no USB cable attached and no
buttons pressed).

Since this approach is not viable (breaks reboot in most cases), the validity of
the reboot reason is checked (in turn, by checking that a warm reset happened,
as there is no magic) to detect a reboot and the 'o' char is recognized to
indicate that power-off is required. Still, that might be overridden by the
detection of usual power-on reasons, on purpose.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>

diff --git a/board/amazon/kc1/kc1.c b/board/amazon/kc1/kc1.c
index ca63af8be472981beb6698a8a2c4f80ca3e771fb..469a83eeef38a2346f9363f49f2696d6e846e0b9 100644 (file)
--- a/board/amazon/kc1/kc1.c
+++ b/board/amazon/kc1/kc1.c
@@ -88,10 +88,11 @@ int misc_init_r(void)
        char reboot_mode[2] = { 0 };
        u32 data = 0;
        u32 value;
+       int rc;
 
        /* Reboot mode */
 
-       omap_reboot_mode(reboot_mode, sizeof(reboot_mode));
+       rc = omap_reboot_mode(reboot_mode, sizeof(reboot_mode));
 
        /* USB ID pin pull-up indicates factory (fastboot) cable detection. */
        gpio_request(KC1_GPIO_USB_ID, "USB_ID");
@@ -101,18 +102,7 @@ int misc_init_r(void)
        if (value)
                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 {
-               /* Reboot mode garbage may still be valid, so clear it. */
-               omap_reboot_mode_clear();
-
+       if (rc < 0 || reboot_mode[0] == 'o') {
                /*
                 * When not rebooting, valid power on reasons are either the
                 * power button, charger plug or USB plug.
@@ -126,6 +116,13 @@ int misc_init_r(void)
                        twl6030_power_off();
        }
 
+       if (reboot_mode[0] > 0 && isascii(reboot_mode[0])) {
+               if (!getenv("reboot-mode"))
+                       setenv("reboot-mode", (char *)reboot_mode);
+       }
+
+       omap_reboot_mode_clear();
+
        /* Serial number */
 
        omap_die_id_serial();