Write pwmX_enable for fans that have a fanX_target

For fans that have a fanX_target hwmon sysfs attribute,
write the pwmX_enable on startup to put that fan into
RPM mode, which is safe to do because this application
requires that the target is written in RPMs.  The write
will only occur if the  pwm_enable file exists.

In the future, if fans with a target need to run in pwm
mode, this code will need to be updated to convert between
RPM and pwm anyway and the pwm_enable value can then
be different based on that.

Resolves openbmc/openbmc#1584

Change-Id: I4f6f3ac8d6651314367aaf5c51ac176220f1fba6
Signed-off-by: Matt Spinler <spinler@us.ibm.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/mainloop.cpp b/mainloop.cpp
index 34970b1..9714d0f 100644
--- a/mainloop.cpp
+++ b/mainloop.cpp
@@ -242,7 +242,13 @@ void MainLoop::run()
         addThreshold<CriticalObject>(i.first, sensorValue, info);
         //TODO openbmc/openbmc#1347
         //     Handle application restarts to set/refresh fan speed values
-        addTarget<hwmon::FanSpeed>(i.first, _hwmonRoot, _instance, info);
+        auto target = addTarget<hwmon::FanSpeed>(
+                i.first, _hwmonRoot, _instance, info);
+
+        if (target)
+        {
+            target->enable();
+        }
 
         // All the interfaces have been created.  Go ahead
         // and emit InterfacesAdded.