Implemented power management (#67)

- Implemented HAL for for power management
- Implemented the Power app (accessible via Settings app)
- Implemented status bar icon for battery status

tactility-headless/src/assets.h

@@ -7,6 +7,7 @@
 #define TT_ASSETS_APP_ICON_FALLBACK TT_ASSET("app_icon_fallback.png")
 #define TT_ASSETS_APP_ICON_FILES TT_ASSET("app_icon_files.png")
 #define TT_ASSETS_APP_ICON_DISPLAY_SETTINGS TT_ASSET("app_icon_display_settings.png")
+#define TT_ASSETS_APP_ICON_POWER_SETTINGS TT_ASSET("app_icon_power_settings.png")
 #define TT_ASSETS_APP_ICON_SETTINGS TT_ASSET("app_icon_settings.png")
 #define TT_ASSETS_APP_ICON_SYSTEM_INFO TT_ASSET("app_icon_system_info.png")
 
@@ -29,3 +30,10 @@
 #define TT_ASSETS_ICON_WIFI_SIGNAL_3_LOCKED TT_ASSET("wifi_signal_3_locked.png")
 #define TT_ASSETS_ICON_WIFI_SIGNAL_4 TT_ASSET("wifi_signal_4.png")
 #define TT_ASSETS_ICON_WIFI_SIGNAL_4_LOCKED TT_ASSET("wifi_signal_4_locked.png")
+
+// Power status
+#define TT_ASSETS_ICON_POWER_020 TT_ASSET("power_020.png")
+#define TT_ASSETS_ICON_POWER_040 TT_ASSET("power_040.png")
+#define TT_ASSETS_ICON_POWER_060 TT_ASSET("power_060.png")
+#define TT_ASSETS_ICON_POWER_080 TT_ASSET("power_080.png")
+#define TT_ASSETS_ICON_POWER_100 TT_ASSET("power_100.png")

tactility-headless/src/hardware_config.h

@@ -2,6 +2,7 @@
 
 #include "tactility_core.h"
 #include "sdcard.h"
+#include "power.h"
 
 typedef bool (*Bootstrap)();
 typedef bool (*InitGraphics)();
@@ -35,4 +36,9 @@ typedef struct {
      * An optional SD card interface.
      */
     const SdCard* _Nullable sdcard;
+
+    /**
+     * An optional power interface for battery or other power delivery.
+     */
+    const Power* _Nullable power;
 } HardwareConfig;

tactility-headless/src/power.c

@@ -0,0 +1 @@
+#include "power.h"

tactility-headless/src/power.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+#include <stdint.h>
+
+typedef bool (*PowerIsCharging)();
+typedef void (*PowerSetChargingEnabled)(bool enabled);
+typedef uint8_t (*PowerGetBatteryCharge)(); // Power value [0, 255] which maps to 0-100% charge
+typedef int32_t (*PowerGetCurrent)(); // Consumption or charge current in mAh
+
+typedef struct {
+    PowerIsCharging is_charging;
+    PowerSetChargingEnabled set_charging_enabled;
+    PowerGetBatteryCharge get_charge_level;
+    PowerGetCurrent get_current;
+} Power;
+
+#ifdef __cplusplus
+}
+#endif