Docs: Add IIO device limitation information
Add an IIO devices README to ward off the typical questions
about IIO.
Change-Id: If126daf1ddf550d9d7bf475b4d68ae2566f72c74
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/README.iio.md b/README.iio.md
new file mode 100644
index 0000000..c1b3f7b
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+++ b/README.iio.md
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+Phosphor OpenBMC and IIO devices
+
+Phosphor OpenBMC currently does not provide an IIO device to DBUS bridge in the
+same way that hwmon devices are bridged by the phosphor-hwmon-readd application.
+
+Until a daemon can be written, the hwmon-iio bridge driver can be used with
+the phosphor-hwmon-readd application, with the limitation that only a single
+iio channel can be configured per iio-hwmon platform instance. Typically
+device trees are setup with all the iio-channels under a single iio-hwmon
+platform device - doing this will result in undefined behavior from
+phosphor-hwmon-readd.
+
+If a true IIO bridging daemon becomes available in the future, phosphor-hwmon-readd
+will not support hwmon-iio bridge devices in any capacity.