HAL_Linux: added RCInput_Multi

this allows for multiple RCInput methods on one board. On Disco it
combines RCInput_115200 with RCInput_SBUS

libraries/AP_HAL_Linux/HAL_Linux_Class.cpp

@@ -28,6 +28,8 @@
 #include "RCInput_SBUS.h"
 #include "RCInput_UART.h"
 #include "RCInput_UDP.h"
+#include "RCInput_115200.h"
+#include "RCInput_Multi.h"
 #include "RCOutput_AeroIO.h"
 #include "RCOutput_AioPRU.h"
 #include "RCOutput_Bebop.h"
@@ -146,8 +148,9 @@ static RCInput_UDP  rcinDriver;
 static RCInput_UART rcinDriver("/dev/ttyS2");
 #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_QFLIGHT
 static RCInput_DSM rcinDriver;
-#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_DISCO || \
-      CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_AERO
+#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_DISCO
+static RCInput_Multi rcinDriver{2, new RCInput_SBUS, new RCInput_115200("/dev/uart-sumd")};
+#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_AERO
 static RCInput_SBUS rcinDriver;
 #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_NAVIO2
 static RCInput_Navio2 rcinDriver;

libraries/AP_HAL_Linux/RCInput_Multi.cpp

@@ -0,0 +1,68 @@
+/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
+/*
+   This program is free software: you can redistribute it and/or modify
+   it 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.
+
+   This program is distributed in the hope that it 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 program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/*
+  this is a driver for multiple RCInput methods on one board
+ */
+
+#include <AP_HAL/AP_HAL.h>
+
+#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_DISCO
+#include "RCInput_Multi.h"
+
+extern const AP_HAL::HAL& hal;
+
+using namespace Linux;
+
+// constructor
+RCInput_Multi::RCInput_Multi(uint8_t _num_inputs, ...) :
+    num_inputs(_num_inputs)
+{
+    va_list ap;
+    inputs = new RCInput*[num_inputs];
+    if (inputs == nullptr) {
+        AP_HAL::panic("failed to allocated RCInput array");
+    }
+    va_start(ap, _num_inputs);
+    for (uint8_t i=0; i<num_inputs; i++) {
+        inputs[i] = va_arg(ap, RCInput *);
+        if (inputs[i] == nullptr) {
+            AP_HAL::panic("Bad RCInput object");
+        }
+    }
+    va_end(ap);
+}
+
+void RCInput_Multi::init()
+{
+    for (uint8_t i=0; i<num_inputs; i++) {
+        inputs[i]->init();
+    }
+}
+
+void RCInput_Multi::_timer_tick(void)
+{
+    for (uint8_t i=0; i<num_inputs; i++) {
+        inputs[i]->_timer_tick();
+        if (inputs[i]->new_input()) {
+            inputs[i]->read(_pwm_values, inputs[i]->num_channels());
+            _num_channels = inputs[i]->num_channels();
+            new_rc_input = true;
+        }        
+    }
+}
+
+#endif // CONFIG_HAL_BOARD_SUBTYPE
+

libraries/AP_HAL_Linux/RCInput_Multi.h

@@ -0,0 +1,39 @@
+/*
+   This program is free software: you can redistribute it and/or modify
+   it 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.
+
+   This program is distributed in the hope that it 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 program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <AP_HAL/AP_HAL.h>
+#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_DISCO
+
+#include "RCInput.h"
+#include <stdarg.h>
+
+namespace Linux {
+
+class RCInput_Multi : public RCInput
+{
+public:
+    RCInput_Multi(uint8_t num_inputs, ...);
+    void init() override;
+    void _timer_tick(void) override;
+
+private:
+    uint8_t num_inputs;
+    RCInput **inputs;
+};
+};
+
+#endif // CONFIG_HAL_BOARD_SUBTYPE