From 04d7b5ffe4d8e5f05d6bbdb3ccb793b1bd7e8a07 Mon Sep 17 00:00:00 2001
From: Pat Hickey <pat@galois.com>
Date: Tue, 4 Dec 2012 14:51:17 -0800
Subject: [PATCH] AP_HAL_AVR: implement changes to AnalogIn

---
 libraries/AP_HAL_AVR/AnalogIn.h          |  8 +++++---
 libraries/AP_HAL_AVR/AnalogIn_ADC.cpp    | 10 +++++++++-
 libraries/AP_HAL_AVR/AnalogIn_Common.cpp | 16 ++++++++++------
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/libraries/AP_HAL_AVR/AnalogIn.h b/libraries/AP_HAL_AVR/AnalogIn.h
index 3b065cbda9..ae6cb563a9 100644
--- a/libraries/AP_HAL_AVR/AnalogIn.h
+++ b/libraries/AP_HAL_AVR/AnalogIn.h
@@ -16,6 +16,7 @@ public:
 
     /* implement AnalogSource virtual api: */
     float read();
+    void set_pin(uint8_t p);
 
     /* implementation specific interface: */
 
@@ -37,7 +38,7 @@ private:
     volatile uint16_t _sum;
 
     /* _pin designates the ADC input mux for the sample */
-    const uint8_t _pin;
+    uint8_t _pin;
     /* prescale scales the raw measurments for read()*/
     const float _prescale;
 };
@@ -49,10 +50,11 @@ public:
     AVRAnalogIn();
     void init(void* ap_hal_scheduler);
     AP_HAL::AnalogSource* channel(int n);
+    AP_HAL::AnalogSource* channel(int n, float prescale);
 
 protected: 
-    static ADCSource* _find_or_create_channel(int num);
-    static ADCSource* _create_channel(int num);
+    static ADCSource* _find_or_create_channel(int num, float scale);
+    static ADCSource* _create_channel(int num, float scale);
     static void _register_channel(ADCSource*);
     static void _timer_event(uint32_t);
     static ADCSource* _channels[AVR_INPUT_MAX_CHANNELS];
diff --git a/libraries/AP_HAL_AVR/AnalogIn_ADC.cpp b/libraries/AP_HAL_AVR/AnalogIn_ADC.cpp
index 16aecba90c..ed3a9155ec 100644
--- a/libraries/AP_HAL_AVR/AnalogIn_ADC.cpp
+++ b/libraries/AP_HAL_AVR/AnalogIn_ADC.cpp
@@ -16,6 +16,10 @@ float ADCSource::read() {
     return _prescale * read_average();
 }
 
+void ADCSource::set_pin(uint8_t pin) {
+    _pin = pin;
+}
+
 /* read_average is called from the normal thread (not an interrupt). */
 float ADCSource::read_average() {
     uint16_t sum;
@@ -28,12 +32,16 @@ float ADCSource::read_average() {
     while( _sum_count == 0 );
 
     /* Read and clear in a critical section */
+    uint8_t sreg = SREG;
     cli();
+
     sum = _sum;
     sum_count = _sum_count;
     _sum = 0;
     _sum_count = 0;
-    sei();
+
+    SREG = sreg;
+
     float avg = sum / (float) sum_count;
     return avg;
 
diff --git a/libraries/AP_HAL_AVR/AnalogIn_Common.cpp b/libraries/AP_HAL_AVR/AnalogIn_Common.cpp
index 1d7cc0e892..f073dcdb70 100644
--- a/libraries/AP_HAL_AVR/AnalogIn_Common.cpp
+++ b/libraries/AP_HAL_AVR/AnalogIn_Common.cpp
@@ -29,17 +29,17 @@ void AVRAnalogIn::init(void* machtnichts) {
     _register_channel(&_vcc);
 }
 
-ADCSource* AVRAnalogIn::_find_or_create_channel(int pin) {
+ADCSource* AVRAnalogIn::_find_or_create_channel(int pin, float scale) {
     for(int i = 0; i < _num_channels; i++) {
         if (_channels[i]->_pin == pin) {
             return _channels[i];
         }
     }
-    return _create_channel(pin);
+    return _create_channel(pin, scale);
 }
 
-ADCSource* AVRAnalogIn::_create_channel(int chnum) {
-    ADCSource *ch = new ADCSource(chnum);
+ADCSource* AVRAnalogIn::_create_channel(int chnum, float scale) {
+    ADCSource *ch = new ADCSource(chnum, scale);
     _register_channel(ch);
     return ch;
 }
@@ -55,9 +55,10 @@ void AVRAnalogIn::_register_channel(ADCSource* ch) {
     _channels[_num_channels] = ch;
     /* Need to lock to increment _num_channels as it is used
      * by the interrupt to access _channels */
+    uint8_t sreg = SREG;
     cli();
     _num_channels++;
-    sei();
+    SREG = sreg;
 
     if (_num_channels == 1) {
         /* After registering the first channel, we can enable the ADC */
@@ -111,10 +112,13 @@ next_channel:
 
 
 AP_HAL::AnalogSource* AVRAnalogIn::channel(int ch) {
+    return this->channel(ch, 1.0);
+}
+AP_HAL::AnalogSource* AVRAnalogIn::channel(int ch, float scale) {
     if (ch == ANALOG_INPUT_BOARD_VCC) {
             return &_vcc;
     } else {
-        return _find_or_create_channel(ch);
+        return _find_or_create_channel(ch, scale);
     }
 }