Enable T096 DC/DC initialization before battery checks

.github/workflows/run-unit-tests.yml

@@ -317,6 +317,7 @@ jobs:
           python3 -B test/test_sensor_tracker_gps.py -v
           python3 -B test/test_sensor_tracker_sleep.py -v
           python3 -B test/test_power_saving_deadlines.py -v
+          python3 -B test/test_t096_regulator.py -v
           python3 -B test/test_power_saving_diagnostics.py -v
           python3 -B test/test_power_saving_role_diagnostics.py -v
           python3 -B test/test_companion_power_diagnostics.py -v

test/test_t096_regulator.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+"""Execute T096 startup and the real DC/DC initializer with counted SDK I/O."""
+from pathlib import Path
+import os
+import subprocess
+import tempfile
+import unittest
+
+from cpp_source import body
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+class T096RegulatorTests(unittest.TestCase):
+    def test_startup_selects_dcdc_before_voltage_check_with_or_without_softdevice(self):
+        methods = body((ROOT / 'src/helpers/NRF52Board.cpp').read_text(),
+                       'void NRF52BoardDCDC::begin()')
+        methods += body((ROOT / 'variants/heltec_t096/T096Board.cpp').read_text(),
+                        'void T096Board::begin()')
+        source = r'''
+#include <cassert>
+#include <cstdint>
+#define NRF52_POWER_MANAGEMENT 1
+#define PIN_BOARD_SDA 1
+#define PIN_BOARD_SCL 2
+constexpr int OUTPUT = 1, LOW = 0, P_LORA_TX_LED = 28;
+constexpr int NRF_POWER_DCDC_ENABLE = 1;
+static unsigned base_calls, sdk_calls, voltage_checks;
+static uint8_t softdevice;
+struct Power { unsigned DCDCEN; } power;
+#define NRF_POWER (&power)
+namespace mesh_nrf52 {
+void softdeviceIsEnabled(uint8_t& enabled) { enabled = softdevice; }
+}
+void sd_power_dcdc_mode_set(int mode) {
+  assert(softdevice && mode == NRF_POWER_DCDC_ENABLE);
+  ++sdk_calls;
+}
+void pinMode(int, int) {}
+void digitalWrite(int, int) {}
+void delay(unsigned) {}
+struct Bus { void setPins(int, int) {} void begin() {} } Wire;
+struct Peripheral { void begin() {} void init() {} };
+struct Config {} power_config;
+struct NRF52Board { void begin() { ++base_calls; } };
+struct NRF52BoardDCDC : NRF52Board { void begin(); };
+struct T096Board : NRF52BoardDCDC {
+  Peripheral periph_power, loRaFEMControl;
+  void begin();
+  void checkBootVoltage(const Config*) {
+    ++voltage_checks;
+    assert(softdevice ? sdk_calls == 1 : power.DCDCEN == 1);
+  }
+};
+@METHODS@
+int main() {
+  for (softdevice = 0; softdevice < 2; ++softdevice) {
+    power.DCDCEN = base_calls = sdk_calls = voltage_checks = 0;
+    T096Board board;
+    board.begin();
+    assert(base_calls == 1 && voltage_checks == 1);
+    assert(sdk_calls == softdevice);
+    assert(power.DCDCEN == (softdevice ? 0U : 1U));
+  }
+}
+'''
+        with tempfile.TemporaryDirectory(prefix='meshcore-t096-regulator-') as tmp:
+            cpp, binary = Path(tmp) / 'test.cpp', Path(tmp) / 'test'
+            cpp.write_text(source.replace('@METHODS@', methods), encoding='ascii')
+            subprocess.run([os.environ.get('CXX', 'c++'), '-std=c++17',
+                            '-Wall', '-Wextra', '-Werror', str(cpp), '-o', str(binary)],
+                           check=True, capture_output=True, text=True, timeout=60)
+            result = subprocess.run([str(binary)], capture_output=True, text=True, timeout=10)
+            self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
+
+
+if __name__ == '__main__':
+    unittest.main()

variants/heltec_t096/T096Board.cpp

@@ -33,7 +33,9 @@ void T096Board::initiateShutdown(uint8_t reason) {
 #endif // NRF52_POWER_MANAGEMENT
 
 void T096Board::begin() {
-  NRF52Board::begin();
+  // T096 populates the nRF52840 DC/DC network. Do not bypass the regulator
+  // initializer and leave application efficiency dependent on bootloader state.
+  NRF52BoardDCDC::begin();
 
 #ifdef NRF52_POWER_MANAGEMENT
   // Boot voltage protection check (may not return if voltage too low)