Update pcf8591 default configuration, make it compliant with 2.6

driver.


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2399 7894878c-1315-0410-8ee3-d5d059ff63e0

etc/sensors.conf.eg

@@ -1630,12 +1630,28 @@ chip "pcf8591-*"
 # Analog inputs
 
    ignore ain_conf
-   set    ain_conf    0
+# Since Linux 2.6, input configuration is set as module parameter,
+# so the line below is for older kernels only.
+#  set    ain_conf    0
+
+# You may discard ch2 and ch3 if you don't use them (depends on the input
+# configuration)
+#  ignore ch2
+#  ignore ch3
+
    label  ch0         "Chan. 0"
    label  ch1         "Chan. 1"
    label  ch2         "Chan. 2"
    label  ch3         "Chan. 3"
 
+# The driver assumes Vref = 2.56V and Agnd = 0V. If it doesn't match
+# your hardware, you have to use compute lines. The example below is
+# correct for Vref = 5.0V and Agnd = 0V.
+#  compute ch0 (@ * 500 / 256), (@ * 256 / 500)
+#  compute ch1 (@ * 500 / 256), (@ * 256 / 500)
+#  compute ch2 (@ * 500 / 256), (@ * 256 / 500)
+#  compute ch3 (@ * 500 / 256), (@ * 256 / 500)
+
 # Analog output
 
    ignore aout_enable