i2c/pcf8574: No arbitrary initialization
Do not initialize the PCF8574 with an arbitrary value. Users will have
to write the initial value to sysfs themselves.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
diff --git a/Documentation/i2c/chips/pcf8574 b/Documentation/i2c/chips/pcf8574
index 2752c8c..5c1ad13 100644
--- a/Documentation/i2c/chips/pcf8574
+++ b/Documentation/i2c/chips/pcf8574
@@ -62,8 +62,6 @@
value, that is to say 0.
The write file is read/write. Writing a value outputs it on the I/O
-port. Reading returns the last written value.
-
-On module initialization the chip is configured as eight inputs (all
-outputs to 1), so you can connect any circuit to the PCF8574(A) without
-being afraid of short-circuit.
+port. Reading returns the last written value. As it is not possible
+to read this value from the chip, you need to write at least once to
+this file before you can read back from it.