Use slightly flatter directory structure since some developers did not

like too many folders.
Extracted code from some files into separate files to fit with the new
layout.

src/telemetry_common.c

@@ -0,0 +1,136 @@
+#include "board.h"
+#include "mw.h"
+
+#include "telemetry_frsky.h"
+#include "telemetry_hott.h"
+
+static bool isTelemetryConfigurationValid = false; // flag used to avoid repeated configuration checks
+
+bool isTelemetryProviderFrSky(void)
+{
+    return mcfg.telemetry_provider == TELEMETRY_PROVIDER_FRSKY;
+}
+
+bool isTelemetryProviderHoTT(void)
+{
+    return mcfg.telemetry_provider == TELEMETRY_PROVIDER_HOTT;
+}
+
+bool canUseTelemetryWithCurrentConfiguration(void)
+{
+
+    if (!feature(FEATURE_TELEMETRY)) {
+        return false;
+    }
+
+    if (!feature(FEATURE_SOFTSERIAL)) {
+        if (mcfg.telemetry_port == TELEMETRY_PORT_SOFTSERIAL_1 || mcfg.telemetry_port == TELEMETRY_PORT_SOFTSERIAL_2) {
+            // softserial feature must be enabled to use telemetry on softserial ports
+            return false;
+        }
+    }
+
+    if (isTelemetryProviderHoTT()) {
+        if (mcfg.telemetry_port == TELEMETRY_PORT_UART) {
+            // HoTT requires a serial port that supports RX/TX mode swapping
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void initTelemetry(void)
+{
+    // Force telemetry to uart when softserial disabled
+    if (!feature(FEATURE_SOFTSERIAL))
+        mcfg.telemetry_port = TELEMETRY_PORT_UART;
+
+    isTelemetryConfigurationValid = canUseTelemetryWithCurrentConfiguration();
+
+    if (mcfg.telemetry_port == TELEMETRY_PORT_SOFTSERIAL_1)
+        core.telemport = &(softSerialPorts[0].port);
+    else if (mcfg.telemetry_port == TELEMETRY_PORT_SOFTSERIAL_2)
+        core.telemport = &(softSerialPorts[1].port);
+    else
+        core.telemport = core.mainport;
+
+    checkTelemetryState();
+}
+
+static bool telemetryEnabled = false;
+
+bool determineNewTelemetryEnabledState(void)
+{
+    bool enabled = true;
+
+    if (mcfg.telemetry_port == TELEMETRY_PORT_UART) {
+        if (!mcfg.telemetry_switch)
+            enabled = f.ARMED;
+        else
+            enabled = rcOptions[BOXTELEMETRY];
+    }
+
+    return enabled;
+}
+
+bool shouldChangeTelemetryStateNow(bool newState)
+{
+    return newState != telemetryEnabled;
+}
+
+static void configureTelemetryPort(void)
+{
+    if (isTelemetryProviderFrSky()) {
+        configureFrSkyTelemetryPort();
+    }
+
+    if (isTelemetryProviderHoTT()) {
+        configureHoTTTelemetryPort();
+    }
+}
+
+void freeTelemetryPort(void)
+{
+    if (isTelemetryProviderFrSky()) {
+        freeFrSkyTelemetryPort();
+    }
+
+    if (isTelemetryProviderHoTT()) {
+        freeHoTTTelemetryPort();
+    }
+}
+
+void checkTelemetryState(void)
+{
+    if (!isTelemetryConfigurationValid) {
+        return;
+    }
+
+    bool newEnabledState = determineNewTelemetryEnabledState();
+
+    if (!shouldChangeTelemetryStateNow(newEnabledState)) {
+        return;
+    }
+
+    if (newEnabledState)
+        configureTelemetryPort();
+    else
+        freeTelemetryPort();
+
+    telemetryEnabled = newEnabledState;
+}
+
+void handleTelemetry(void)
+{
+    if (!isTelemetryConfigurationValid || !determineNewTelemetryEnabledState())
+        return;
+
+    if (isTelemetryProviderFrSky()) {
+        handleFrSkyTelemetry();
+    }
+
+    if (isTelemetryProviderHoTT()) {
+        handleHoTTTelemetry();
+    }
+}