regulator: gpio: Reword the binding document

Reword the binding document to make it clear how the propeties work
and which properties affect which other properties.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Harald Geyer <harald@ccbib.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: linux-renesas-soc@vger.kernel.org
To: devicetree@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/Documentation/devicetree/bindings/regulator/gpio-regulator.txt b/Documentation/devicetree/bindings/regulator/gpio-regulator.txt
index 1f496159e2bb9ec3638dc6c977388c66cdb65a80..dd25e73b5d7939c9ebef0ae8641538ff26d056a6 100644 (file)
--- a/Documentation/devicetree/bindings/regulator/gpio-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/gpio-regulator.txt
@@ -4,16 +4,30 @@ Required properties:
 - compatible           : Must be "regulator-gpio".
 - regulator-name       : Defined in regulator.txt as optional, but required
                          here.
-- states               : Selection of available voltages and GPIO configs.
-                          if there are no states, then use a fixed regulator
+- gpios                        : Array of one or more GPIO pins used to select the
+                         regulator voltage/current listed in "states".
+- states               : Selection of available voltages/currents provided by
+                         this regulator and matching GPIO configurations to
+                         achieve them. If there are no states in the "states"
+                         array, use a fixed regulator instead.
 
 Optional properties:
-- enable-gpio          : GPIO to use to enable/disable the regulator.
-- gpios                        : GPIO group used to control voltage.
-- gpios-states         : gpios pin's initial states array. 0: LOW, 1: HIGH.
-                         defualt is LOW if nothing is specified.
+- enable-gpios         : GPIO used to enable/disable the regulator.
+                         Warning, the GPIO phandle flags are ignored and the
+                         GPIO polarity is controlled solely by the presence
+                         of "enable-active-high" DT property. This is due to
+                         compatibility with old DTs.
+- enable-active-high   : Polarity of "enable-gpio" GPIO is active HIGH.
+                         Default is active LOW.
+- gpios-states         : On operating systems, that don't support reading back
+                         gpio values in output mode (most notably linux), this
+                         array provides the state of GPIO pins set when
+                         requesting them from the gpio controller. Systems,
+                         that are capable of preserving state when requesting
+                         the lines, are free to ignore this property.
+                         0: LOW, 1: HIGH. Default is LOW if nothing else
+                         is specified.
 - startup-delay-us     : Startup time in microseconds.
-- enable-active-high   : Polarity of GPIO is active high (default is low).
 - regulator-type       : Specifies what is being regulated, must be either
                          "voltage" or "current", defaults to voltage.
 
@@ -30,7 +44,7 @@ Example:
                regulator-max-microvolt = <2600000>;
                regulator-boot-on;
 
-               enable-gpio = <&gpio0 23 0x4>;
+               enable-gpios = <&gpio0 23 0x4>;
                gpios = <&gpio0 24 0x4
                         &gpio0 25 0x4>;
                states = <1800000 0x3