Revert "ADC: added an enable_channel() API"

This reverts commit dafeac01d8f14162600cf821404ba4072dcae14d.

ADC will be disabled on APM2

libraries/AP_ADC/AP_ADC.h

@@ -37,14 +37,9 @@ class AP_ADC
 
 	   The function returns the amount of time (in microseconds)
 	   since the last call to Ch6().
-
-	   NOTE: You must enable the channels using enable_channel()
-	   before use
 	*/
 	virtual uint32_t Ch6(const uint8_t *channel_numbers, uint16_t *result) = 0;
 
-	virtual void enable_channel(const uint8_t ch) = 0;
-
   private:
 };
 

libraries/AP_ADC/AP_ADC_ADS7844.cpp

@@ -100,7 +100,6 @@ void AP_ADC_ADS7844::read(void)
 		return;
 	}
 
-	// build a sequence of commands to use to fetch the channels
 	for (ch = 0; ch < 8; ch++) {
 		if (enable_mask & (1<<ch)) {
 			enable_cmd[num_enabled++] = adc_cmd[ch];
@@ -188,13 +187,6 @@ void AP_ADC_ADS7844::Init( AP_PeriodicProcess * scheduler )
 
 }
 
-
-// enable a channel
-void AP_ADC_ADS7844::enable_channel(uint8_t ch)
-{
-	enable_mask |= (1<<ch);
-}
-
 // Read one channel value
 float AP_ADC_ADS7844::Ch(uint8_t ch_num)
 {
@@ -228,6 +220,10 @@ uint32_t AP_ADC_ADS7844::Ch6(const uint8_t *channel_numbers, uint16_t *result)
 	uint32_t sum[6];
 	uint8_t i;
 
+	for (i=0; i<6; i++) {
+		enable_mask |= (1<<channel_numbers[i]);
+	}
+
 	// ensure we have at least one value
 	for (i=0; i<6; i++) {
 		while (_count[channel_numbers[i]] == 0) /* noop */;

libraries/AP_ADC/AP_ADC_ADS7844.h

@@ -29,7 +29,6 @@ class AP_ADC_ADS7844 : public AP_ADC
 
 	// Read 6 sensors at once
 	uint32_t Ch6(const uint8_t *channel_numbers, uint16_t *result);
-	void enable_channel(uint8_t ch);
 	bool	filter_result;
 
 	private:

libraries/AP_ADC/examples/AP_ADC_test/AP_ADC_test.pde

@@ -1,4 +1,4 @@
-/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
+
 /*
   Example of APM_ADC library.
   Code by Jordi Muñoz and Jose Julio. DIYDrones.com
@@ -18,8 +18,6 @@ AP_PeriodicProcess  adc_scheduler;
 unsigned long timer;
 AP_ADC_ADS7844 adc;
 
-static const uint8_t channel_map[6] = { 1, 2, 0, 4, 5, 6};
-
 void setup()
 {
 	Serial.begin(115200, 128, 128);
@@ -32,12 +30,9 @@ void setup()
 	adc.Init(&adc_scheduler);   // APM ADC initialization
 	delay(1000);
 	timer = millis();
-
-	for (uint8_t ch=0; ch<6; ch++) {
-		adc.enable_channel(channel_map[ch]);
-	}
 }
 
+static const uint8_t channel_map[6] = { 1, 2, 0, 4, 5, 6};
 float v;
 uint32_t last_usec = 0;
 

libraries/AP_InertialSensor/AP_InertialSensor_Oilpan.cpp

@@ -50,11 +50,6 @@ AP_InertialSensor_Oilpan::AP_InertialSensor_Oilpan( AP_ADC * adc ) :
 void AP_InertialSensor_Oilpan::init( AP_PeriodicProcess * scheduler)
 {
   _adc->Init(scheduler);
-
-  // tell the ADC driver that we will be needed some channels
-  for (uint8_t ch=0; ch<6; ch++) {
-	  _adc->enable_channel(_sensors[ch]);
-  }
 }
 
 bool AP_InertialSensor_Oilpan::update()