diff options
author | Sascha Hauer <s.hauer@pengutronix.de> | 2014-04-25 11:22:32 +0200 |
---|---|---|
committer | Sascha Hauer <s.hauer@pengutronix.de> | 2014-04-28 09:08:46 +0200 |
commit | 00ce25c6dcdae5582ae4be37147ab33678adc995 (patch) | |
tree | 41c93102ae304a61738c31353e3cb5336ef0b297 /dts/Bindings/iio/iio-bindings.txt | |
parent | 0af79fbb6779921d3f1962773adb7fb57d3c89d4 (diff) | |
download | barebox-00ce25c6dcdae5582ae4be37147ab33678adc995.tar.gz barebox-00ce25c6dcdae5582ae4be37147ab33678adc995.tar.xz |
Add devicetree source files as of Linux-3.15-rc2
This adds the Linux dts files to barebox. The dts files are
generated from Ian Campbells device-tree-rebasing.git:
git://xenbits.xen.org/people/ianc/device-tree-rebasing.git
The dts are found in dts/ in the barebox repository and
will be updated from upstream regularly, probably for each upstream
-rc.
To keep the synchronization with upstream easy no changes to
the original files are allowed under dts/. Instead changes to
upstream dts files will be done using overlays in arch/$ARCH/dts/.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'dts/Bindings/iio/iio-bindings.txt')
-rw-r--r-- | dts/Bindings/iio/iio-bindings.txt | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/dts/Bindings/iio/iio-bindings.txt b/dts/Bindings/iio/iio-bindings.txt new file mode 100644 index 0000000000..0b447d9ad1 --- /dev/null +++ b/dts/Bindings/iio/iio-bindings.txt @@ -0,0 +1,97 @@ +This binding is derived from clock bindings, and based on suggestions +from Lars-Peter Clausen [1]. + +Sources of IIO channels can be represented by any node in the device +tree. Those nodes are designated as IIO providers. IIO consumer +nodes use a phandle and IIO specifier pair to connect IIO provider +outputs to IIO inputs. Similar to the gpio specifiers, an IIO +specifier is an array of one or more cells identifying the IIO +output on a device. The length of an IIO specifier is defined by the +value of a #io-channel-cells property in the IIO provider node. + +[1] http://marc.info/?l=linux-iio&m=135902119507483&w=2 + +==IIO providers== + +Required properties: +#io-channel-cells: Number of cells in an IIO specifier; Typically 0 for nodes + with a single IIO output and 1 for nodes with multiple + IIO outputs. + +Example for a simple configuration with no trigger: + + adc: voltage-sensor@35 { + compatible = "maxim,max1139"; + reg = <0x35>; + #io-channel-cells = <1>; + }; + +Example for a configuration with trigger: + + adc@35 { + compatible = "some-vendor,some-adc"; + reg = <0x35>; + + adc1: iio-device@0 { + #io-channel-cells = <1>; + /* other properties */ + }; + adc2: iio-device@1 { + #io-channel-cells = <1>; + /* other properties */ + }; + }; + +==IIO consumers== + +Required properties: +io-channels: List of phandle and IIO specifier pairs, one pair + for each IIO input to the device. Note: if the + IIO provider specifies '0' for #io-channel-cells, + then only the phandle portion of the pair will appear. + +Optional properties: +io-channel-names: + List of IIO input name strings sorted in the same + order as the io-channels property. Consumers drivers + will use io-channel-names to match IIO input names + with IIO specifiers. +io-channel-ranges: + Empty property indicating that child nodes can inherit named + IIO channels from this node. Useful for bus nodes to provide + and IIO channel to their children. + +For example: + + device { + io-channels = <&adc 1>, <&ref 0>; + io-channel-names = "vcc", "vdd"; + }; + +This represents a device with two IIO inputs, named "vcc" and "vdd". +The vcc channel is connected to output 1 of the &adc device, and the +vdd channel is connected to output 0 of the &ref device. + +==Example== + + adc: max1139@35 { + compatible = "maxim,max1139"; + reg = <0x35>; + #io-channel-cells = <1>; + }; + + ... + + iio_hwmon { + compatible = "iio-hwmon"; + io-channels = <&adc 0>, <&adc 1>, <&adc 2>, + <&adc 3>, <&adc 4>, <&adc 5>, + <&adc 6>, <&adc 7>, <&adc 8>, + <&adc 9>; + }; + + some_consumer { + compatible = "some-consumer"; + io-channels = <&adc 10>, <&adc 11>; + io-channel-names = "adc1", "adc2"; + }; |