AP_RCProtocol: move handling of AP_Radio RC input down into AP_RCProtocol

libraries/AP_RCProtocol/AP_RCProtocol.cpp

@@ -38,6 +38,7 @@
 #include "AP_RCProtocol_Joystick_SFML.h"
 #include "AP_RCProtocol_UDP.h"
 #include "AP_RCProtocol_FDM.h"
+#include "AP_RCProtocol_Radio.h"
 #include <AP_Math/AP_Math.h>
 #include <RC_Channel/RC_Channel.h>
 
@@ -110,7 +111,9 @@ void AP_RCProtocol::init()
     UDP_backend->set_fdm_backend(FDM_backend);
 #endif  // AP_RCPROTOCOL_UDP_ENABLED
 #endif  // AP_RCPROTOCOL_FDM_ENABLED
-
+#if AP_RCPROTOCOL_RADIO_ENABLED
+    backend[AP_RCProtocol::RADIO] = new AP_RCProtocol_Radio(*this);
+#endif
 }
 
 AP_RCProtocol::~AP_RCProtocol()
@@ -472,6 +475,9 @@ bool AP_RCProtocol::new_input()
 #endif
 #if AP_RCPROTOCOL_FDM_ENABLED
         AP_RCProtocol::FDM,
+#endif
+#if AP_RCPROTOCOL_RADIO_ENABLED
+        AP_RCProtocol::RADIO,
 #endif
     };
     for (const auto protocol : pollable) {
@@ -620,6 +626,10 @@ const char *AP_RCProtocol::protocol_name_from_protocol(rcprotocol_t protocol)
 #if AP_RCPROTOCOL_FDM_ENABLED
     case FDM:
         return "FDM";
+#endif
+#if AP_RCPROTOCOL_RADIO_ENABLED
+    case RADIO:
+        return "Radio";
 #endif
     case NONE:
         break;

libraries/AP_RCProtocol/AP_RCProtocol.h

@@ -89,6 +89,9 @@ public:
 #endif
 #if AP_RCPROTOCOL_FDM_ENABLED
         FDM = 18,
+#endif
+#if AP_RCPROTOCOL_RADIO_ENABLED
+        RADIO = 19,
 #endif
         NONE    //last enum always is None
     };
@@ -125,6 +128,12 @@ public:
         _disabled_for_pulses |= (1U<<(uint8_t)protocol);
     }
 
+// in the case we've disabled most backends then the "return true" in
+// the following method can never be reached, and the compiler gets
+// annoyed at that.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wswitch-unreachable"
+
     // for protocols without strong CRCs we require 3 good frames to lock on
     bool requires_3_frames(enum rcprotocol_t p) {
         switch (p) {
@@ -185,12 +194,16 @@ public:
 #endif
 #if AP_RCPROTOCOL_FDM_ENABLED
         case FDM:
+#endif
+#if AP_RCPROTOCOL_RADIO_ENABLED
+        case RADIO:
 #endif
         case NONE:
             return false;
         }
         return false;
     }
+#pragma GCC diagnostic pop
 
     uint8_t num_channels();
     uint16_t read(uint8_t chan);

libraries/AP_RCProtocol/AP_RCProtocol_Radio.cpp

@@ -0,0 +1,53 @@
+#include "AP_RCProtocol_config.h"
+
+#if AP_RCPROTOCOL_RADIO_ENABLED
+
+#include "AP_RCProtocol_Radio.h"
+#include <AP_Radio/AP_Radio.h>
+
+void AP_RCProtocol_Radio::update()
+{
+    auto *radio = AP_Radio::get_singleton();
+    if (radio == nullptr) {
+        return;
+    }
+    if (!init_done) {
+        radio->init();
+        init_done = true;
+    }
+
+    // allow the radio to handle mavlink on the main thread:
+    radio->update();
+
+    const uint32_t last_recv_us = radio->last_recv_us();
+    if (last_recv_us == last_input_us) {
+        // no new data
+        return;
+    }
+    last_input_us = last_recv_us;
+
+    const auto num_channels = radio->num_channels();
+    uint16_t rcin_values[MAX_RCIN_CHANNELS];
+    for (uint8_t i=0; i<num_channels; i++) {
+        rcin_values[i] = radio->read(i);
+    }
+
+    add_input(
+        num_channels,
+        rcin_values,
+        false,  // failsafe
+        0, // check me
+        0  // link quality
+        );
+}
+
+void AP_RCProtocol_Radio::start_bind()
+{
+    auto *radio = AP_Radio::get_singleton();
+    if (radio == nullptr) {
+        return;
+    }
+    radio->start_recv_bind();
+}
+
+#endif // AP_RCPROTOCOL_RADIO_ENABLED

libraries/AP_RCProtocol/AP_RCProtocol_Radio.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "AP_RCProtocol_config.h"
+
+#if AP_RCPROTOCOL_RADIO_ENABLED
+
+/*
+ * Reads fixed-length packets containing either 8 or 16 2-byte values,
+ * and interprets them as RC input.
+ */
+
+#include "AP_RCProtocol_Backend.h"
+
+class AP_RCProtocol_Radio : public AP_RCProtocol_Backend {
+public:
+
+    using AP_RCProtocol_Backend::AP_RCProtocol_Backend;
+
+    void update() override;
+
+    void start_bind(void) override;
+
+private:
+
+    bool init();
+    bool init_done;
+
+    uint32_t last_input_us;
+};
+
+
+#endif  // AP_RCPROTOCOL_RADIO_ENABLED

libraries/AP_RCProtocol/AP_RCProtocol_config.h

@@ -3,6 +3,7 @@
 #include <AP_HAL/AP_HAL_Boards.h>
 #include <AP_Frsky_Telem/AP_Frsky_config.h>
 #include <GCS_MAVLink/GCS_config.h>
+#include <AP_Radio/AP_Radio_config.h>
 
 #ifndef AP_RCPROTOCOL_ENABLED
 #define AP_RCPROTOCOL_ENABLED 1
@@ -43,6 +44,10 @@
 #define AP_RCPROTOCOL_PPMSUM_ENABLED AP_RCPROTOCOL_BACKEND_DEFAULT_ENABLED
 #endif
 
+#ifndef AP_RCPROTOCOL_RADIO_ENABLED
+#define AP_RCPROTOCOL_RADIO_ENABLED AP_RCPROTOCOL_BACKEND_DEFAULT_ENABLED && AP_RADIO_ENABLED
+#endif
+
 #ifndef AP_RCPROTOCOL_SBUS_ENABLED
 #define AP_RCPROTOCOL_SBUS_ENABLED AP_RCPROTOCOL_BACKEND_DEFAULT_ENABLED
 #endif