pinctrl: gpio: vt8500: Add pincontrol driver for arch-vt8500

This patch adds support for the GPIO/pinmux controller found on the VIA
VT8500 and Wondermedia WM8xxx-series SoCs.

Each pin within the controller is capable of operating as a GPIO or as
an alternate function. The pins are numbered according to their control
bank/bit so that if new pins are added, the existing numbering is maintained.

All currently supported SoCs are included: VT8500, WM8505, WM8650, WM8750 and
WM8850.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-vt8500.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-vt8500.txt
new file mode 100644
index 000000000000..b3aa90f0ce44
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-vt8500.txt
@@ -0,0 +1,57 @@
+VIA VT8500 and Wondermedia WM8xxx-series pinmux/gpio controller
+
+These SoCs contain a combined Pinmux/GPIO module. Each pin may operate as
+either a GPIO in, GPIO out or as an alternate function (I2C, SPI etc).
+
+Required properties:
+- compatible: "via,vt8500-pinctrl", "wm,wm8505-pinctrl", "wm,wm8650-pinctrl",
+        "wm8750-pinctrl" or "wm,wm8850-pinctrl"
+- reg: Should contain the physical address of the module's registers.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells: Should be two.
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells : Should be two. The first cell is the pin number and the
+  second cell is used to specify optional parameters.
+        bit 0 - active low
+
+Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
+
+Please refer to pinctrl-bindings.txt in this directory for details of the
+common pinctrl bindings used by client devices, including the meaning of the
+phrase "pin configuration node".
+
+Each pin configuration node lists the pin(s) to which it applies, and one or
+more of the mux functions to select on those pin(s), and pull-up/down
+configuration. Each subnode only affects those parameters that are explicitly
+listed. In other words, a subnode that lists only a mux function implies no
+information about any pull configuration. Similarly, a subnode that lists only
+a pull parameter implies no information about the mux function.
+
+Required subnode-properties:
+- wm,pins: An array of cells. Each cell contains the ID of a pin.
+
+Optional subnode-properties:
+- wm,function: Integer, containing the function to mux to the pin(s):
+  0: GPIO in
+  1: GPIO out
+  2: alternate
+
+- wm,pull: Integer, representing the pull-down/up to apply to the pin(s):
+  0: none
+  1: down
+  2: up
+
+Each of wm,function and wm,pull may contain either a single value which
+will be applied to all pins in wm,pins, or one value for each entry in
+wm,pins.
+
+Example:
+
+        pinctrl: pinctrl {
+                compatible = "wm,wm8505-pinctrl";
+                reg = <0xD8110000 0x10000>;
+                interrupt-controller;
+                #interrupt-cells = <2>;
+                gpio-controller;
+                #gpio-cells = <2>;
+        };