regulators: Create README in application directory

Create a README file in the phosphor-regulators directory.  The file
summarizes the features of the application.  It also contains a link to
the config file documentation.

Also made minor updates to the config file README.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: Idf04501234237d84e6a0350fd93de3f9d3a7c431
diff --git a/phosphor-regulators/README.md b/phosphor-regulators/README.md
new file mode 100644
index 0000000..2ef7779
--- /dev/null
+++ b/phosphor-regulators/README.md
@@ -0,0 +1,59 @@
+## Overview
+
+The `phosphor-regulators` application configures and monitors voltage
+regulators.  The application is controlled by a JSON configuration file.
+
+The application does not control how voltage regulators are enabled or how to
+monitor their Power Good (pgood) status.  Those operations are typically
+performed by power sequencer hardware and related firmware.
+
+
+## Configuring Voltage Regulators
+
+The configuration of voltage regulators can be modified.  Configuration changes
+usually override hardware default settings.
+
+The most common configuration change is setting the output voltage for a
+regulator rail.  Other examples include modifying pgood thresholds and
+overcurrent settings.
+
+The configuration changes are applied early in the boot process before
+regulators are enabled.
+
+
+## Monitoring Voltage Regulators
+
+Two types of regulator monitoring are supported:
+* Sensor monitoring
+* Phase fault monitoring
+
+### Sensor Monitoring
+
+The sensor values for a voltage rail are read, such as voltage output, current
+output, and temperature.  Sensor values are measured, actual values rather than
+target values.
+
+Sensors are read once per second.  The sensor values are stored on D-Bus on the
+BMC, making them available to external interfaces like Redfish.
+
+### Phase Fault Monitoring
+
+Some voltage regulators contain redundant phases.  If a redundant phase fails,
+the regulator can continue functioning normally.  However redundancy has been
+lost, and the regulator may fail if another phase fails.
+
+Voltage regulators can be monitored for redundant phase faults.  If a fault is
+detected, an error is logged on the BMC.
+
+
+## JSON Configuration File
+
+The JSON configuration file defines the following:
+* Voltage regulators in the system.
+* Operations to perform on those regulators, such as configuration or sensor
+  monitoring.
+
+Configuration files are stored in the `config_files` directory.
+
+See the [configuration file documentation](docs/config_file/README.md) for
+information on the file format, validation tool, and installation directories.
diff --git a/phosphor-regulators/docs/config_file/README.md b/phosphor-regulators/docs/config_file/README.md
index 3ef8eb7..6a62dc1 100644
--- a/phosphor-regulators/docs/config_file/README.md
+++ b/phosphor-regulators/docs/config_file/README.md
@@ -136,7 +136,7 @@
 
 `/usr/share/phosphor-regulators`
 
-The standard version of the config file should be installed in this read-only
+The standard version of the config file is installed in this read-only
 directory as part of the firmware image install.  This is the config file that
 will normally be used.
 
@@ -150,9 +150,10 @@
 
 ### Search Order
 
-The `phosphor-regulators` application will search first in the test directory
-for a config file.  If no config file is found or the file contains errors, the
-application will next search in the standard directory.
+The `phosphor-regulators` application will search the installation directories
+in the following order to find a config file:
+1. test directory
+2. standard directory
 
 
 ## Loading and Reloading
@@ -162,7 +163,11 @@
 To force the application to reload the config file, use the following command
 on the BMC:
 
-``kill -SIGHUP `pidof phosphor-regulators` ``
+``systemctl kill -s HUP phosphor-regulators.service``
+
+To confirm which config file was loaded, use the following command on the BMC:
+
+``journalctl -u phosphor-regulators.service | grep Loading``
 
 
 ## Testing