From 17de4f2523a976741f941ffd8a60419d53b8b64f Mon Sep 17 00:00:00 2001
From: Tobias Schramm <t.schramm@t-sys.eu>
Date: Tue, 9 Feb 2021 14:34:35 +0100
Subject: [PATCH] Use battery only if specified in devicetree

---
 src/battery.c | 12 +++++++++---
 src/battery.h | 12 +++++++++++-
 src/main.c    |  4 ++++
 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/battery.c b/src/battery.c
index f2a1638..10ba7f8 100644
--- a/src/battery.c
+++ b/src/battery.c
@@ -4,11 +4,13 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#include "battery.h"
+
+#ifdef BATTERY_SUPPORTED
+
 #include <device.h>
 #include <drivers/adc.h>
 
-#include "battery.h"
-
 #define VBATT DT_PATH(vbatt)
 #define BATTERY_ADC_GAIN ADC_GAIN_1_6
 #define BATTERY DT_PATH(battery)
@@ -74,6 +76,9 @@ uint16_t battery_get_voltage_mv() {
     return battery_adc_config.value_mv;
 }
 
+#endif
+
+#ifdef BATTERY_SOC_SUPPORTED
 const uint32_t battery_soc_voltage_mv_pairs[] = DT_PROP(BATTERY, soc_voltage_mv);
 
 #if DT_PROP_LEN(BATTERY, soc_voltage_mv) % 2 != 0
@@ -113,4 +118,5 @@ uint32_t battery_voltage_mv_to_soc(uint16_t batt_mv) {
     }
 
     return last_soc;
-}
\ No newline at end of file
+}
+#endif
\ No newline at end of file
diff --git a/src/battery.h b/src/battery.h
index be66fc6..78bbbe9 100644
--- a/src/battery.h
+++ b/src/battery.h
@@ -1,8 +1,18 @@
 #pragma once
 
+#include <devicetree.h>
 #include <stdint.h>
 
+// Generic voltage divider based battery support
+#if DT_NODE_HAS_STATUS(DT_PATH(vbatt), okay)
+#define BATTERY_SUPPORTED
 int battery_init();
 int battery_update();
 uint16_t battery_get_voltage_mv();
-uint32_t battery_voltage_mv_to_soc(uint16_t batt_mv);
\ No newline at end of file
+#endif
+
+// SOC estimation support
+#if DT_NODE_HAS_STATUS(DT_PATH(battery), okay)
+#define BATTERY_SOC_SUPPORTED
+uint32_t battery_voltage_mv_to_soc(uint16_t batt_mv);
+#endif
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 81f7a28..d15dcfc 100644
--- a/src/main.c
+++ b/src/main.c
@@ -36,6 +36,7 @@ void main(void)
 	platform_display_draw_string(0, 0, "Hello World!");
 	platform_display_draw_string(0, DISPLAY_LINE_LAST_CONTACTS_START, "Seen identifiers:");
 
+#ifdef BATTERY_SUPPORTED
 	err = battery_init();
 	if (err) {
 		printk("Failed to initialize battery gauging: %d\n", err);
@@ -50,6 +51,7 @@ void main(void)
 
 	platform_display_draw_string(0, DISPLAY_LINE_BATTERY_VOLTAGE, "Battery voltage:");
 	platform_display_draw_string(0, DISPLAY_LINE_BATTERY_VOLTAGE + 2, "Battery SOC:");
+#endif
 
     // first init everything
 	// Use custom randomization as the mbdet_tls context initialization messes with the Zeyhr BLE stack.
@@ -98,8 +100,10 @@ void main(void)
 			snprintf(tmpstr, sizeof(tmpstr), "%04u mV", battery_get_voltage_mv());
 			platform_display_draw_string(0, DISPLAY_LINE_BATTERY_VOLTAGE + 1, tmpstr);
 
+#ifdef BATTERY_SOC_SUPPORTED
 			snprintf(tmpstr, sizeof(tmpstr), "% 3u%%", battery_voltage_mv_to_soc(battery_get_voltage_mv()));
 			platform_display_draw_string(0, DISPLAY_LINE_BATTERY_VOLTAGE + 3, tmpstr);
+#endif
 		}
 		do_covid();
 		do_gatt();