apps: Add ability to do a clean reboot

Allow a clean shutdown to end in either power off or reboot. Add a
new event SYS_REBOOT to signal it and sys_reboot() to trigger the
event. SYS_REBOOT signals a reboot request and should be listened
for alongside SYS_POWEROFF events.

Change-Id: I99ba7fb5feed2bb5a0a40a274e8466ad74fe3a43

firmware/backlight.c

@@ -668,6 +668,7 @@ void backlight_thread(void)
 #endif /* HAVE_BUTTONLIGHT_BRIGHTNESS */
 #endif /* HAVE_BUTTON_LIGHT */
 
+            case SYS_REBOOT:
             case SYS_POWEROFF:  /* Lock backlight on poweroff so it doesn't */
                 locked = true;      /* go off before power is actually cut. */
 #if !defined(BOOTLOADER)

firmware/export/powermgmt.h

@@ -70,6 +70,12 @@ extern unsigned int power_thread_inputs;
 
 #endif /* CONFIG_CHARGING */
 
+enum shutdown_type
+{
+    SHUTDOWN_POWER_OFF,
+    SHUTDOWN_REBOOT,
+};
+
 #if CONFIG_CHARGING == CHARGING_TARGET
 /* Include target-specific definitions */
 #include "powermgmt-target.h"
@@ -164,8 +170,9 @@ void handle_auto_poweroff(void);
 void set_car_adapter_mode(bool setting);
 void reset_poweroff_timer(void);
 void cancel_shutdown(void);
-void shutdown_hw(void);
+void shutdown_hw(enum shutdown_type sd_type);
 void sys_poweroff(void);
+void sys_reboot(void);
 /* Returns true if the system should force shutdown for some reason -
  * eg. low battery */
 bool query_force_shutdown(void);

firmware/kernel/include/queue.h

@@ -58,6 +58,7 @@
 #define SYS_CHARGER_CONNECTED     MAKE_SYS_EVENT(SYS_EVENT_CLS_POWER, 1)
 #define SYS_CHARGER_DISCONNECTED  MAKE_SYS_EVENT(SYS_EVENT_CLS_POWER, 2)
 #define SYS_BATTERY_UPDATE        MAKE_SYS_EVENT(SYS_EVENT_CLS_POWER, 3)
+#define SYS_REBOOT                MAKE_SYS_EVENT(SYS_EVENT_CLS_POWER, 4)
 #define SYS_FS_CHANGED            MAKE_SYS_EVENT(SYS_EVENT_CLS_FILESYS, 0)
 #define SYS_HOTSWAP_INSERTED      MAKE_SYS_EVENT(SYS_EVENT_CLS_PLUG, 0)
 #define SYS_HOTSWAP_EXTRACTED     MAKE_SYS_EVENT(SYS_EVENT_CLS_PLUG, 1)

firmware/powermgmt.c

@@ -823,7 +823,7 @@ void powermgmt_init(void)
 }
 
 /* Various hardware housekeeping tasks relating to shutting down the player */
-void shutdown_hw(void)
+void shutdown_hw(enum shutdown_type sd_type)
 {
     charging_algorithm_close();
     audio_stop();
@@ -863,7 +863,17 @@ void shutdown_hw(void)
        eeprom chips are quite slow and might be still writing the last
        byte. */
     sleep(HZ/4);
-    power_off();
+
+    switch (sd_type) {
+    case SHUTDOWN_POWER_OFF:
+    default:
+        power_off();
+        break;
+
+    case SHUTDOWN_REBOOT:
+        system_reboot();
+        break;
+    }
 }
 
 void set_poweroff_timeout(int timeout)
@@ -878,10 +888,9 @@ void reset_poweroff_timer(void)
         set_sleep_timer(sleeptimer_duration);
 }
 
-void sys_poweroff(void)
-{
 #ifndef BOOTLOADER
-    logf("sys_poweroff()");
+static void sys_shutdown_common(void)
+{
     /* If the main thread fails to shut down the system, we will force a
        power off after an 20 second timeout - 28 seconds if recording */
     if (shutdown_timeout == 0) {
@@ -899,9 +908,26 @@ void sys_poweroff(void)
         shutdown_timeout += HZ*20;
 #endif
     }
-
-    queue_broadcast(SYS_POWEROFF, 0);
+}
 #endif /* BOOTLOADER */
+
+void sys_poweroff(void)
+{
+#ifndef BOOTLOADER
+    logf("sys_poweroff()");
+    sys_shutdown_common();
+    queue_broadcast(SYS_POWEROFF, 0);
+#endif
+}
+
+/* not to be confused with system_reboot... :( */
+void sys_reboot(void)
+{
+#ifndef BOOTLOADER
+    logf("sys_reboot()");
+    sys_shutdown_common();
+    queue_broadcast(SYS_REBOOT, 0);
+#endif
 }
 
 void cancel_shutdown(void)