sensors/zones: place in namespace and cleanup

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I527dbc8477a232945f696227a7b0b2adbee45175
diff --git a/sysfs/sysfsread.cpp b/sysfs/sysfsread.cpp
index a070af2..eee1c8a 100644
--- a/sysfs/sysfsread.cpp
+++ b/sysfs/sysfsread.cpp
@@ -20,6 +20,9 @@
 #include <fstream>
 #include <iostream>
 
+namespace pid_control
+{
+
 ReadReturn SysFsRead::read(void)
 {
     int64_t value;
@@ -34,3 +37,5 @@
 
     return r;
 }
+
+} // namespace pid_control
diff --git a/sysfs/sysfsread.hpp b/sysfs/sysfsread.hpp
index 4c1baec..32ce18e 100644
--- a/sysfs/sysfsread.hpp
+++ b/sysfs/sysfsread.hpp
@@ -5,6 +5,9 @@
 
 #include <string>
 
+namespace pid_control
+{
+
 /*
  * A ReadInterface that is expecting a path that's sysfs, but really could be
  * any filesystem path.
@@ -21,3 +24,5 @@
   private:
     const std::string _path;
 };
+
+} // namespace pid_control
diff --git a/sysfs/sysfswrite.cpp b/sysfs/sysfswrite.cpp
index 93a64dc..db903cb 100644
--- a/sysfs/sysfswrite.cpp
+++ b/sysfs/sysfswrite.cpp
@@ -19,6 +19,9 @@
 #include <fstream>
 #include <iostream>
 
+namespace pid_control
+{
+
 void SysFsWritePercent::write(double value)
 {
     double minimum = getMin();
@@ -45,3 +48,5 @@
 
     return;
 }
+
+} // namespace pid_control
diff --git a/sysfs/sysfswrite.hpp b/sysfs/sysfswrite.hpp
index 276d936..615cb37 100644
--- a/sysfs/sysfswrite.hpp
+++ b/sysfs/sysfswrite.hpp
@@ -5,6 +5,9 @@
 
 #include <string>
 
+namespace pid_control
+{
+
 /*
  * A WriteInterface that is expecting a path that's sysfs, but really could be
  * any filesystem path.
@@ -34,3 +37,5 @@
   private:
     std::string _writePath;
 };
+
+} // namespace pid_control
diff --git a/sysfs/util.cpp b/sysfs/util.cpp
index da678ce..b7cc6f3 100644
--- a/sysfs/util.cpp
+++ b/sysfs/util.cpp
@@ -20,6 +20,9 @@
 #include <iostream>
 #include <string>
 
+namespace pid_control
+{
+
 /*
  * There are two basic paths I want to support:
  * 1. /sys/class/hwmon/hwmon0/pwm1
@@ -68,3 +71,5 @@
         return original;
     }
 }
+
+} // namespace pid_control