From 9c4a4d0ff0f218551023cbb04f5462f9f20336c1 Mon Sep 17 00:00:00 2001
From: Jon Trulson <jtrulson@ics.com>
Date: Thu, 10 Sep 2015 16:26:36 -0600
Subject: [PATCH] ak8975: throw exception(s) on fatal errors

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
---
 src/mpu9150/ak8975.cxx | 39 +++++++++++++++++++++++----------------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/src/mpu9150/ak8975.cxx b/src/mpu9150/ak8975.cxx
index cd4b5b31..7330eb37 100644
--- a/src/mpu9150/ak8975.cxx
+++ b/src/mpu9150/ak8975.cxx
@@ -25,6 +25,7 @@
 #include <unistd.h>
 #include <iostream>
 #include <string>
+#include <stdexcept>
 
 #include "ak8975.h"
 
@@ -43,8 +44,8 @@ AK8975::AK8975(int bus, uint8_t address):
   mraa::Result rv;
   if ( (rv = m_i2c.address(m_addr)) != mraa::SUCCESS)
     {
-      cerr << __FUNCTION__ << ": Could not initialize i2c address. " << endl;
-      printError(rv);
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": I2c.address() failed");
       return;
     }
 }
@@ -62,13 +63,15 @@ bool AK8975::init()
 
   if (!setMode(CNTL_PWRDWN))
     {
-      cerr << __FUNCTION__ << ": Unable to set PWRDWN mode" << endl;
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": Unable to set PWRDWN mode");
       return false;
     }
 
   if (!setMode(CNTL_FUSE_ACCESS))
     {
-      cerr << __FUNCTION__ << ": Unable to set FUSE mode" << endl;
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": Unable to set FUSE mode");
       return false;
     }
 
@@ -80,7 +83,8 @@ bool AK8975::init()
   // now, place back in power down mode
   if (!setMode(CNTL_PWRDWN))
     {
-      cerr << __FUNCTION__ << ": Unable to reset PWRDWN mode" << endl;
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": Unable to set reset PWRDWN mode");
       return false;
     }
 
@@ -92,8 +96,8 @@ bool AK8975::setMode(CNTL_MODES_T mode)
   mraa::Result rv;
   if ((rv = m_i2c.writeReg(REG_CNTL, mode)) != mraa::SUCCESS)
     {
-      cerr << __FUNCTION__ << ": failed:" << endl;
-      printError(rv);
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": I2c.writeReg() failed");
       return false;
     } 
 
@@ -128,8 +132,8 @@ bool AK8975::waitforDeviceReady()
       retries++;
     }
   
-  cerr << __FUNCTION__ << ": timeout waiting for device to become ready"
-       << endl;
+  throw std::runtime_error(std::string(__FUNCTION__) +
+                           ": timeout waiting for device to become ready");
 
   return false;
 }
@@ -145,7 +149,8 @@ bool AK8975::update(bool selfTest)
       // First set measurement mode (take a measurement)
       if (!setMode(CNTL_MEASURE))
         {
-          cerr << __FUNCTION__ << ": Unable to set MEASURE mode" << endl;
+          throw std::runtime_error(std::string(__FUNCTION__) +
+                                   ": Unable to set MEASURE mode");
           return false;
         }
     }
@@ -176,22 +181,24 @@ bool AK8975::selfTest()
   // set power down first
   if (!setMode(CNTL_PWRDWN))
     {
-      cerr << __FUNCTION__ << ": Unable to set PWRDWN mode" << endl;
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": Unable to set PWRDWN mode");
       return false;
     }
 
   // enable self test bit
   if ((rv = m_i2c.writeReg(REG_ASTC, ASTC_SELF)) != mraa::SUCCESS)
     {
-      cerr << __FUNCTION__ << ": failed to enable self test:" << endl;
-      printError(rv);
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": failed to enable self test");
       return false;
     } 
   
   // now set self test mode
   if (!setMode(CNTL_SELFTEST))
     {
-      cerr << __FUNCTION__ << ": Unable to set SELFTEST mode" << endl;
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": Unable to set SELFTEST mode");
       return false;
     }
   
@@ -203,8 +210,8 @@ bool AK8975::selfTest()
   reg &= ~ASTC_SELF;
   if ((rv = m_i2c.writeReg(REG_ASTC, reg)) != mraa::SUCCESS)
     {
-      cerr << __FUNCTION__ << ": failed to disable self test:" << endl;
-      printError(rv);
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": failed to disable self test");
       return false;
     }