pinctrl: add DT binding doc for pincontrol of PMIC max77620/max20024

Maxim Semiconductor's PMIC MAX77620/MAX20024 has 8 GPIO pins
which act as GPIO as well as special function mode.

Add DT binding document to configure pins in function mode as
well as pin configuration parameters.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-max77620.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-max77620.txt
new file mode 100644 (file)
index 0000000..ad4fce3
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+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-max77620.txt
@@ -0,0 +1,127 @@
+Pincontrol driver for MAX77620 Power management IC from Maxim Semiconductor.
+
+Device has 8 GPIO pins which can be configured as GPIO as well as the
+special IO functions.
+
+Please refer file <devicetree/bindings/pinctrl/pinctrl-bindings.txt>
+for details of the common pinctrl bindings used by client devices,
+including the meaning of the phrase "pin configuration node".
+
+Optional Pinmux properties:
+--------------------------
+Following properties are required if default setting of pins are required
+at boot.
+- pinctrl-names: A pinctrl state named per <pinctrl-binding.txt>.
+- pinctrl[0...n]: Properties to contain the phandle for pinctrl states per
+               <pinctrl-binding.txt>.
+
+The pin configurations are defined as child of the pinctrl states node. Each
+sub-node have following properties:
+
+Required properties:
+------------------
+- pins: List of pins. Valid values of pins properties are:
+                     gpio0, gpio1, gpio2, gpio3, gpio4, gpio5, gpio6, gpio7.
+
+Optional properties:
+-------------------
+Following are optional properties defined as pinmux DT binding document
+<pinctrl-bindings.txt>. Absence of properties will leave the configuration
+on default.
+       function,
+       drive-push-pull,
+       drive-open-drain,
+       bias-pull-up,
+       bias-pull-down.
+
+Valid values for function properties are:
+       gpio, lpm-control-in, fps-out, 32k-out, sd0-dvs-in, sd1-dvs-in,
+       reference-out
+
+Theres is also customised properties for the GPIO1, GPIO2 and GPIO3. These
+customised properties are required to configure FPS configuration parameters
+of these GPIOs. Please refer <devicetree/bindings/mfd/max77620.txt> for more
+detail of Flexible Power Sequence (FPS).
+
+- maxim,active-fps-source:             FPS source for the GPIOs to get
+                                       enabled/disabled when system is in
+                                       active state.  Valid values are:
+                                       - MAX77620_FPS_SRC_0,
+                                               FPS source is FPS0.
+                                       - MAX77620_FPS_SRC_1,
+                                               FPS source is FPS1
+                                       - MAX77620_FPS_SRC_2 and
+                                               FPS source is FPS2
+                                       - MAX77620_FPS_SRC_NONE.
+                                               GPIO is not controlled
+                                               by FPS events and it gets
+                                               enabled/disabled by register
+                                               access.
+                                       Absence of this property will leave
+                                       the FPS configuration register for that
+                                       GPIO to default configuration.
+
+- maxim,active-fps-power-up-slot:      Sequencing event slot number on which
+                                       the GPIO get enabled when
+                                       master FPS input event set to HIGH.
+                                       Valid values are 0 to 7.
+                                       This is applicable if FPS source is
+                                       selected as FPS0, FPS1 or FPS2.
+
+- maxim,active-fps-power-down-slot:    Sequencing event slot number on which
+                                       the GPIO get disabled when master
+                                       FPS input event set to LOW.
+                                       Valid values are 0 to 7.
+                                       This is applicable if FPS source is
+                                       selected as FPS0, FPS1 or FPS2.
+
+- maxim,suspend-fps-source:            This is same as property
+                                       "maxim,active-fps-source" but value
+                                       get configured when system enters in
+                                       to suspend state.
+
+- maxim,suspend-fps-power-up-slot:     This is same as property
+                                       "maxim,active-fps-power-up-slot" but
+                                       this value get configured into FPS
+                                       configuration register when system
+                                       enters into suspend.
+                                       This is applicable if suspend state
+                                       FPS source is selected as FPS0, FPS1 or
+
+- maxim,suspend-fps-power-down-slot:   This is same as property
+                                       "maxim,active-fps-power-down-slot" but
+                                       this value get configured into FPS
+                                       configuration register when system
+                                       enters into suspend.
+                                       This is applicable if suspend state
+                                       FPS source is selected as FPS0, FPS1 or
+                                       FPS2.
+
+Example:
+--------
+#include <dt-bindings/mfd/max77620.h>
+...
+max77620@3c {
+
+       pinctrl-names = "default";
+       pinctrl-0 = <&spmic_default>;
+
+       spmic_default: pinmux@0 {
+               pin_gpio0 {
+                       pins = "gpio0";
+                       function = "gpio";
+               };
+
+               pin_gpio1 {
+                       pins = "gpio1";
+                       function = "fps-out";
+                       maxim,active-fps-source = <MAX77620_FPS_SRC_0>;
+               };
+
+               pin_gpio2 {
+                       pins = "gpio2";
+                       function = "fps-out";
+                       maxim,active-fps-source = <MAX77620_FPS_SRC_1>;
+               };
+       };
+};