Merge tag 'v3.12-rc2' into patchwork

[cascardo/linux.git] / Documentation / devicetree / bindings / pinctrl / pinctrl-bindings.txt

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
index c95ea82..1958ca9 100644 (file)
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
@@ -126,3 +126,62 @@ device; they may be grandchildren, for example. Whether this is legal, and
 whether there is any interaction between the child and intermediate parent
 nodes, is again defined entirely by the binding for the individual pin
 controller device.
+
+== Generic pin configuration node content ==
+
+Many data items that are represented in a pin configuration node are common
+and generic. Pin control bindings should use the properties defined below
+where they are applicable; not all of these properties are relevant or useful
+for all hardware or binding structures. Each individual binding document
+should state which of these generic properties, if any, are used, and the
+structure of the DT nodes that contain these properties.
+
+Supported generic properties are:
+
+pins                   - the list of pins that properties in the node
+                         apply to
+function               - the mux function to select
+bias-disable           - disable any pin bias
+bias-high-impedance    - high impedance mode ("third-state", "floating")
+bias-bus-hold          - latch weakly
+bias-pull-up           - pull up the pin
+bias-pull-down         - pull down the pin
+bias-pull-pin-default  - use pin-default pull state
+drive-push-pull                - drive actively high and low
+drive-open-drain       - drive with open drain
+drive-open-source      - drive with open source
+drive-strength         - sink or source at most X mA
+input-schmitt-enable   - enable schmitt-trigger mode
+input-schmitt-disable  - disable schmitt-trigger mode
+input-debounce         - debounce mode with debound time X
+low-power-enable       - enable low power mode
+low-power-disable      - disable low power mode
+output-low             - set the pin to output mode with low level
+output-high            - set the pin to output mode with high level
+
+Some of the generic properties take arguments. For those that do, the
+arguments are described below.
+
+- pins takes a list of pin names or IDs as a required argument. The specific
+  binding for the hardware defines:
+  - Whether the entries are integers or strings, and their meaning.
+
+- function takes a list of function names/IDs as a required argument. The
+  specific binding for the hardware defines:
+  - Whether the entries are integers or strings, and their meaning.
+  - Whether only a single entry is allowed (which is applied to all entries
+    in the pins property), or whether there may alternatively be one entry per
+    entry in the pins property, in which case the list lengths must match, and
+    for each list index i, the function at list index i is applied to the pin
+    at list index i.
+
+- bias-pull-up, -down and -pin-default take as optional argument on hardware
+  supporting it the pull strength in Ohm. bias-disable will disable the pull.
+
+- drive-strength takes as argument the target strength in mA.
+
+- input-debounce takes the debounce time in usec as argument
+  or 0 to disable debouncing
+
+More in-depth documentation on these parameters can be found in
+<include/linux/pinctrl/pinconfig-generic.h>