AP_HAL_Linux: AnalogIIO: Remove unused code, add scaling for BBBMINI, rework

libraries/AP_HAL_Linux/AnalogIn_IIO.cpp

@@ -6,8 +6,7 @@
 
 extern const AP_HAL::HAL& hal;
 
-const char* AnalogSource_IIO::analog_sources[IIO_ANALOG_IN_COUNT] = {
-#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
+const char* AnalogSource_IIO::analog_sources[] = {
     "in_voltage0_raw",
     "in_voltage1_raw",
     "in_voltage2_raw",
@@ -16,14 +15,12 @@ const char* AnalogSource_IIO::analog_sources[IIO_ANALOG_IN_COUNT] = {
     "in_voltage5_raw",
     "in_voltage6_raw",
     "in_voltage7_raw",
-#else
-    "in_voltage0_raw",
-#endif
 };
 
-AnalogSource_IIO::AnalogSource_IIO(int16_t pin, float initial_value) :
+AnalogSource_IIO::AnalogSource_IIO(int16_t pin, float initial_value, float voltage_scaling) :
     _pin(pin),
     _value(initial_value),
+    _voltage_scaling(voltage_scaling),
     _sum_value(0),
     _sum_count(0),
     _pin_fd(-1)
@@ -35,15 +32,12 @@ AnalogSource_IIO::AnalogSource_IIO(int16_t pin, float initial_value) :
 void AnalogSource_IIO::init_pins(void)
 {
     char buf[100];
-    for (int i=0; i < IIO_ANALOG_IN_COUNT; i++) {
+    for (unsigned int i = 0; i < ARRAY_SIZE(AnalogSource_IIO::analog_sources); i++) {
         // Construct the path by appending strings
         strncpy(buf, IIO_ANALOG_IN_DIR, sizeof(buf));
-        strncat(buf, AnalogSource_IIO::analog_sources[i], sizeof(buf) - strlen(buf) -1);
+        strncat(buf, AnalogSource_IIO::analog_sources[i], sizeof(buf) - strlen(buf) - 1);
 
         fd_analog_sources[i] = open(buf, O_RDONLY | O_NONBLOCK);
-        if (fd_analog_sources[i] == -1) {
-            ::printf("Failed to open analog pin %s\n", buf);
-        }
     }
 }
 
@@ -55,39 +49,6 @@ void AnalogSource_IIO::select_pin(void)
     _pin_fd = fd_analog_sources[_pin];
 }
 
-/*
-  reopens an analog source (by closing and opening it again) and selects it
- */
-void AnalogSource_IIO::reopen_pin(void)
-{
-    char buf[100];
-
-    if (fd_analog_sources[_pin] != -1) {
-        close(fd_analog_sources[_pin]);
-        fd_analog_sources[_pin] = -1;
-        _pin_fd = -1;
-    }
-
-    if (_pin < 0) {
-        return;
-    }
-
-    if (_pin > IIO_ANALOG_IN_COUNT) {
-        // invalid pin
-        return;
-    }
-
-    // Construct the path by appending strings
-    strncpy(buf, IIO_ANALOG_IN_DIR, sizeof(buf));
-    strncat(buf, AnalogSource_IIO::analog_sources[_pin], sizeof(buf) - strlen(buf) - 1);
-
-    fd_analog_sources[_pin] = open(buf, O_RDONLY | O_NONBLOCK);
-    if (fd_analog_sources[_pin] == -1) {
-        ::printf("Failed to open analog pin %s\n", buf);
-    }
-    _pin_fd = fd_analog_sources[_pin];
-}
-
 float AnalogSource_IIO::read_average()
 {
     read_latest();
@@ -96,9 +57,7 @@ float AnalogSource_IIO::read_average()
     }
     hal.scheduler->suspend_timer_procs();
     _value = _sum_value / _sum_count;
-    // _value_ratiometric = _sum_ratiometric / _sum_count;
     _sum_value = 0;
-    // _sum_ratiometric = 0;
     _sum_count = 0;
     hal.scheduler->resume_timer_procs();
     return _value;
@@ -114,12 +73,8 @@ float AnalogSource_IIO::read_latest()
     }
 
     memset(sbuf, 0, sizeof(sbuf));
-    pread(_pin_fd, sbuf, sizeof(sbuf)-1, 0);
-#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
-    _latest = atoi(sbuf) * BBB_VOLTAGE_SCALING;
-#else
-    _latest = atoi(sbuf);
-#endif
+    pread(_pin_fd, sbuf, sizeof(sbuf) - 1, 0);
+    _latest = atoi(sbuf) * _voltage_scaling;
     _sum_value += _latest;
     _sum_count++;
 
@@ -147,12 +102,10 @@ void AnalogSource_IIO::set_pin(uint8_t pin)
     hal.scheduler->suspend_timer_procs();
     _pin = pin;
     _sum_value = 0;
-    // _sum_ratiometric = 0;
     _sum_count = 0;
     _latest = 0;
     _value = 0;
     select_pin();
-    // _value_ratiometric = 0;
     hal.scheduler->resume_timer_procs();
 }
 
@@ -170,7 +123,7 @@ void AnalogIn_IIO::init()
 
 
 AP_HAL::AnalogSource* AnalogIn_IIO::channel(int16_t pin) {
-    return new AnalogSource_IIO(pin, 0);
+    return new AnalogSource_IIO(pin, 0.0f, IIO_VOLTAGE_SCALING);
 }
 
 #endif // CONFIG_HAL_BOARD

libraries/AP_HAL_Linux/AnalogIn_IIO.h

@@ -1,29 +1,27 @@
+/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 #pragma once
 
 #include "AP_HAL_Linux.h"
 #include <AP_ADC/AP_ADC.h>
 
-#include <stdio.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <stdlib.h>
 
-#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
 #define IIO_ANALOG_IN_COUNT 8
-// Note that echo BB-ADC cape should be loaded
 #define IIO_ANALOG_IN_DIR "/sys/bus/iio/devices/iio:device0/"
-#define BBB_VOLTAGE_SCALING 0.00142602816
+#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
+// Note that echo BB-ADC cape should be loaded
+#define IIO_VOLTAGE_SCALING 0.00142602816
+#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI
+#define IIO_VOLTAGE_SCALING 10.0/30.0*1.8/4096.0
 #else
-#define IIO_ANALOG_IN_COUNT 8
-#define IIO_ANALOG_IN_DIR "/sys/bus/iio/devices/iio:device0/"
+#define IIO_VOLTAGE_SCALING 1.0
 #endif
 
 class AnalogSource_IIO : public AP_HAL::AnalogSource {
 public:
     friend class AnalogIn_IIO;
-    AnalogSource_IIO(int16_t pin, float v);
+    AnalogSource_IIO(int16_t pin, float initial_value, float voltage_scaling);
     float read_average();
     float read_latest();
     void set_pin(uint8_t p);
@@ -36,17 +34,16 @@ private:
     float       _value;
     float       _latest;
     float       _sum_value;
-    // float       _value_ratiometric;
+    float       _voltage_scaling;
     uint8_t     _sum_count;
     int16_t     _pin;
     int         _pin_fd;
     int         fd_analog_sources[IIO_ANALOG_IN_COUNT];
 
-    void reopen_pin(void);
     void init_pins(void);
     void select_pin(void);
 
-    static const char *analog_sources[IIO_ANALOG_IN_COUNT];
+    static const char *analog_sources[];
 };
 
 class AnalogIn_IIO : public AP_HAL::AnalogIn {