Add MSP override mode

The MSP override mode allows for use of MSP togehter with
another RX feature like SBUS. When enabling the MSP override
mode all channels from the `msp_override_channels` bitmask
will be overwritten by data comming from MSP instead of the
main RX.

make/source.mk

@@ -124,6 +124,7 @@ COMMON_SRC = \
             rx/sumh.c \
             rx/xbus.c \
             rx/fport.c \
+            rx/msp_override.c \
             sensors/acceleration.c \
             sensors/boardalignment.c \
             sensors/compass.c \

src/main/cli/settings.c

@@ -757,6 +757,9 @@ const clivalue_t valueTable[] = {
     { "rx_min_usec",                VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { PWM_PULSE_MIN, PWM_PULSE_MAX }, PG_RX_CONFIG, offsetof(rxConfig_t, rx_min_usec) },
     { "rx_max_usec",                VAR_UINT16 | MASTER_VALUE, .config.minmaxUnsigned = { PWM_PULSE_MIN, PWM_PULSE_MAX }, PG_RX_CONFIG, offsetof(rxConfig_t, rx_max_usec) },
     { "serialrx_halfduplex",        VAR_UINT8  | MASTER_VALUE | MODE_LOOKUP, .config.lookup = { TABLE_OFF_ON }, PG_RX_CONFIG, offsetof(rxConfig_t, halfDuplex) },
+#if defined(USE_RX_MSP_OVERRIDE)
+    { "msp_override_channels_mask",      VAR_UINT32 | MASTER_VALUE, .config.u32Max = (1 << MAX_SUPPORTED_RC_CHANNEL_COUNT) - 1, PG_RX_CONFIG, offsetof(rxConfig_t, msp_override_channels_mask)},
+#endif
 #ifdef USE_RX_SPI
     { "rx_spi_protocol",            VAR_UINT8  | HARDWARE_VALUE | MODE_LOOKUP, .config.lookup = { TABLE_RX_SPI }, PG_RX_SPI_CONFIG, offsetof(rxSpiConfig_t, rx_spi_protocol) },
     { "rx_spi_bus",                 VAR_UINT8   | HARDWARE_VALUE, .config.minmaxUnsigned = { 0, SPIDEV_COUNT }, PG_RX_SPI_CONFIG, offsetof(rxSpiConfig_t, spibus) },

src/main/config/config.c

@@ -596,6 +596,14 @@ static void validateAndFixConfig(void)
             }
         }
     }
+#if defined(USE_RX_MSP_OVERRIDE)
+    for (int i = 0; i < MAX_MODE_ACTIVATION_CONDITION_COUNT; i++) {
+        const modeActivationCondition_t *mac = modeActivationConditions(i);
+        if (mac->modeId == BOXMSPOVERRIDE && ((1 << (mac->auxChannelIndex) & (rxConfig()->msp_override_channels_mask)))) {
+            rxConfigMutable()->msp_override_channels_mask &= ~(1 << (mac->auxChannelIndex + NON_AUX_CHANNEL_COUNT));
+        }
+    }
+#endif
 }
 
 void validateAndFixGyroConfig(void)

src/main/fc/rc_modes.h

@@ -74,6 +74,7 @@ typedef enum {
     BOXACROTRAINER,
     BOXVTXCONTROLDISABLE,
     BOXLAUNCHCONTROL,
+    BOXMSPOVERRIDE,
     CHECKBOX_ITEM_COUNT
 } boxId_e;
 

src/main/msp/msp_box.c

@@ -97,6 +97,7 @@ static const box_t boxes[CHECKBOX_ITEM_COUNT] = {
     { BOXACROTRAINER, "ACRO TRAINER", 47 },
     { BOXVTXCONTROLDISABLE, "DISABLE VTX CONTROL", 48},
     { BOXLAUNCHCONTROL, "LAUNCH CONTROL", 49 },
+    { BOXMSPOVERRIDE, "MSP OVERRIDE", 50},
 };
 
 // mask of enabled IDs, calculated on startup based on enabled features. boxId_e is used as bit index

src/main/pg/rx.c

@@ -73,6 +73,7 @@ void pgResetFn_rxConfig(rxConfig_t *rxConfig)
         .srxl2_baud_fast = true,
         .sbus_baud_fast = false,
         .crsf_use_rx_snr = false,
+        .msp_override_channels_mask = 0,
     );
 
 #ifdef RX_CHANNELS_TAER

src/main/pg/rx.h

@@ -66,6 +66,8 @@ typedef struct rxConfig_s {
     uint8_t srxl2_baud_fast; // Select Spektrum SRXL2 fast baud rate
     uint8_t sbus_baud_fast; // Select SBus fast baud rate
     uint8_t crsf_use_rx_snr; // Use RX SNR (in dB) instead of RSSI dBm for CRSF
+
+    uint32_t msp_override_channels_mask; // Channels to override when the MSP override mode is enabled
 } rxConfig_t;
 
 PG_DECLARE(rxConfig_t, rxConfig);

src/main/rx/msp.c

@@ -36,7 +36,7 @@
 static uint16_t mspFrame[MAX_SUPPORTED_RC_CHANNEL_COUNT];
 static bool rxMspFrameDone = false;
 
-static uint16_t rxMspReadRawRC(const rxRuntimeState_t *rxRuntimeState, uint8_t chan)
+uint16_t rxMspReadRawRC(const rxRuntimeState_t *rxRuntimeState, uint8_t chan)
 {
     UNUSED(rxRuntimeState);
     return mspFrame[chan];

src/main/rx/msp.h

@@ -22,5 +22,6 @@
 
 struct rxConfig_s;
 struct rxRuntimeState_s;
+uint16_t rxMspReadRawRC(const rxRuntimeState_t *rxRuntimeState, uint8_t chan);
 void rxMspInit(const struct rxConfig_s *rxConfig, struct rxRuntimeState_s *rxRuntimeState);
 void rxMspFrameReceive(uint16_t *frame, int channelCount);

src/main/rx/msp_override.c

@@ -0,0 +1,44 @@
+/*
+ * This file is part of Cleanflight and Betaflight.
+ *
+ * Cleanflight and Betaflight are free software. You can redistribute
+ * this software and/or modify this software under the terms of the
+ * GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * Cleanflight and Betaflight are distributed in the hope that they
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "platform.h"
+
+#if defined(USE_RX_MSP_OVERRIDE)
+
+#include "rx/msp_override.h"
+#include "rx/msp.h"
+#include "fc/rc_modes.h"
+#include "common/maths.h"
+
+
+uint16_t rxMspOverrideReadRawRc(const rxRuntimeState_t *rxRuntimeState, const rxConfig_t *rxConfig, uint8_t chan)
+{
+    uint16_t rxSample = (rxRuntimeState->rcReadRawFn)(rxRuntimeState, chan);
+
+    uint16_t overrideSample = rxMspReadRawRC(rxRuntimeState, chan);
+    bool override = (1 << chan) & rxConfig->msp_override_channels_mask;
+
+    if (IS_RC_MODE_ACTIVE(BOXMSPOVERRIDE) && override) {
+        return overrideSample;
+    } else {
+        return rxSample;
+    }
+}
+#endif

src/main/rx/msp_override.h

@@ -0,0 +1,27 @@
+/*
+ * This file is part of Cleanflight and Betaflight.
+ *
+ * Cleanflight and Betaflight are free software. You can redistribute
+ * this software and/or modify this software under the terms of the
+ * GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * Cleanflight and Betaflight are distributed in the hope that they
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "rx/rx.h"
+#include "pg/rx.h"
+
+uint16_t rxMspOverrideReadRawRc(const rxRuntimeState_t *rxRuntimeState, const rxConfig_t *rxConfig, uint8_t chan);
+

src/main/rx/rx.c

@@ -67,6 +67,7 @@
 #include "rx/crsf.h"
 #include "rx/rx_spi.h"
 #include "rx/targetcustomserial.h"
+#include "rx/msp_override.h"
 
 
 const char rcChannelLetters[] = "AERT12345678abcdefgh";
@@ -591,7 +592,15 @@ static void readRxChannelsApplyRanges(void)
         const uint8_t rawChannel = channel < RX_MAPPABLE_CHANNEL_COUNT ? rxConfig()->rcmap[channel] : channel;
 
         // sample the channel
-        uint16_t sample = rxRuntimeState.rcReadRawFn(&rxRuntimeState, rawChannel);
+        uint16_t sample;
+#if defined(USE_RX_MSP_OVERRIDE)
+        if (rxConfig()->msp_override_channels_mask) {
+            sample = rxMspOverrideReadRawRc(&rxRuntimeState, rxConfig(), rawChannel);
+        } else
+#endif
+        {
+            sample = rxRuntimeState.rcReadRawFn(&rxRuntimeState, rawChannel);
+        }
 
         // apply the rx calibration
         if (channel < NON_AUX_CHANNEL_COUNT) {

src/main/target/common_pre.h

@@ -368,4 +368,5 @@
 #define USE_INTERPOLATED_SP
 #define USE_CUSTOM_BOX_NAMES
 #define USE_BATTERY_VOLTAGE_SAG_COMPENSATION
+#define USE_RX_MSP_OVERRIDE
 #endif