From f7cba024c1eb4ff93dd9b59e434ad63004af26dc Mon Sep 17 00:00:00 2001
From: Iampete1 <iampete@hotmail.co.uk>
Date: Wed, 22 Sep 2021 20:47:38 +0100
Subject: [PATCH] AP_HAL_ChibiOS: AnalogSource: check for valid pin

---
 libraries/AP_HAL_ChibiOS/AnalogIn.cpp | 20 ++++++++++++++++++--
 libraries/AP_HAL_ChibiOS/AnalogIn.h   |  2 +-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/libraries/AP_HAL_ChibiOS/AnalogIn.cpp b/libraries/AP_HAL_ChibiOS/AnalogIn.cpp
index 73fe8c6ddb..2bd608a367 100644
--- a/libraries/AP_HAL_ChibiOS/AnalogIn.cpp
+++ b/libraries/AP_HAL_ChibiOS/AnalogIn.cpp
@@ -140,11 +140,26 @@ float AnalogSource::voltage_latest()
     return _pin_scaler() * read_latest();
 }
 
-void AnalogSource::set_pin(uint8_t pin)
+bool AnalogSource::set_pin(uint8_t pin)
 {
     if (_pin == pin) {
-        return;
+        return true;
     }
+    bool found_pin = false;
+    if (_pin == ANALOG_SERVO_VRSSI_PIN) {
+        found_pin = true;
+    } else {
+        for (uint8_t i=0; i<ADC_GRP1_NUM_CHANNELS; i++) {
+            if (AnalogIn::pin_config[i].channel == pin) {
+                found_pin = true;
+                break;
+            }
+        }
+    }
+    if (!found_pin) {
+        return false;
+    }
+
     WITH_SEMAPHORE(_semaphore);
     _pin = pin;
     _sum_value = 0;
@@ -153,6 +168,7 @@ void AnalogSource::set_pin(uint8_t pin)
     _latest_value = 0;
     _value = 0;
     _value_ratiometric = 0;
+    return true;
 }
 
 /*
diff --git a/libraries/AP_HAL_ChibiOS/AnalogIn.h b/libraries/AP_HAL_ChibiOS/AnalogIn.h
index cedfbf32f7..753f487d72 100644
--- a/libraries/AP_HAL_ChibiOS/AnalogIn.h
+++ b/libraries/AP_HAL_ChibiOS/AnalogIn.h
@@ -32,7 +32,7 @@ public:
     AnalogSource(int16_t pin);
     float read_average() override;
     float read_latest() override;
-    void set_pin(uint8_t p) override;
+    bool set_pin(uint8_t p) override WARN_IF_UNUSED;
     float voltage_average() override;
     float voltage_latest() override;
     float voltage_average_ratiometric() override;