Add unbind/bind around fan speed i2csets

When the max31785 device driver becomes available,
we'll need to unbind it before using i2sets to talk
to the chip.

Change-Id: I25967d753ca81b899880a160f3ea4a022be48e77
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-phosphor/fans/fan-default-speed/set_fan_speeds.sh b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-phosphor/fans/fan-default-speed/set_fan_speeds.sh
index 073c031..82e931a 100755
--- a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-phosphor/fans/fan-default-speed/set_fan_speeds.sh
+++ b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-phosphor/fans/fan-default-speed/set_fan_speeds.sh
@@ -7,6 +7,12 @@
   RPM=$1
 fi
 
+path="/sys/bus/i2c/drivers/max31785"
+if [ -e $path ]
+then
+    echo 3-0052 > $path/unbind
+fi
+
 for fan in `seq 0 3`; do
     i2cset -y 3 0x52 0x00 $fan b
     i2cset -y 3 0x52 0x3A 0xD0 b
@@ -17,3 +23,8 @@
     i2cset -y 3 0x52 0xF6 0x00 0x00 i
     i2cset -y 3 0x52 0x3B $RPM w
 done
+if [ -e $path ]
+
+then
+    echo 3-0052 > $path/bind
+fi