Add license headers

src/battery.c

@@ -1,3 +1,9 @@
+/*
+ * Copyright (c) 2021 Tobias Schramm <t.schramm@t-sys.eu>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <device.h>
 #include <drivers/adc.h>
 

src/display_pinetime.c

@@ -1,6 +1,11 @@
+/*
+ * Copyright (c) 2021 Tobias Schramm <t.schramm@t-sys.eu>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #ifdef PLATFORM_PINETIME
 
-#include <zephyr.h>
 #include <device.h>
 #include <display/cfb.h>
 #include <drivers/gpio.h>

zephyr/dts/bindings/power/simple-battery.yaml

@@ -1,4 +1,4 @@
-# Copyright (c) 2020, Tobias Schramm <t.schramm@t-sys.eu>
+# Copyright (c) 2021, Tobias Schramm <t.schramm@t-sys.eu>
 # SPDX-License-Identifier: Apache-2.0
 
 description: |
@@ -15,3 +15,5 @@ properties:
       description: |
         Array containing pairs of state-of-charge and associated
         open circuit battery voltage in millivolts
+        Entries must be strictly monotonically decreasing in both
+        battery voltage and state-of-charge