mfd: Add DT binding documentation for imx25 ADC/TSC

This documentation describes the devicetree bindings for the
ADC/Touchscreen unit of the i.MX25 SoC.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt b/Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
new file mode 100644 (file)
index 0000000..b035052
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
@@ -0,0 +1,47 @@
+Freescale MX25 ADC/TSC MultiFunction Device (MFD)
+
+This device combines two general purpose conversion queues one used for general
+ADC and the other used for touchscreens.
+
+Required properties:
+ - compatible:                 Should be "fsl,imx25-tsadc".
+ - reg:                                Start address and size of the memory area of
+                                       the device
+ - interrupts:                 Interrupt for this device
+                                       (See: ../interrupt-controller/interrupts.txt)
+ - clocks:                     An 'ipg' clock (See: ../clock/clock-bindings.txt)
+ - interrupt-controller:       This device is an interrupt controller. It
+                                       controls the interrupts of both
+                                       conversion queues.
+ - #interrupt-cells:           Should be '<1>'.
+ - #address-cells:             Should be '<1>'.
+ - #size-cells:                        Should be '<1>'.
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+       tscadc: tscadc@50030000 {
+               compatible = "fsl,imx25-tsadc";
+               reg = <0x50030000 0xc>;
+               interrupts = <46>;
+               clocks = <&clks 119>;
+               clock-names = "ipg";
+               interrupt-controller;
+               #interrupt-cells = <1>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               ranges;
+
+               tsc: tcq@50030400 {
+                       compatible = "fsl,imx25-tcq";
+                       reg = <0x50030400 0x60>;
+                       ...
+               };
+
+               adc: gcq@50030800 {
+                       compatible = "fsl,imx25-gcq";
+                       reg = <0x50030800 0x60>;
+                       ...
+               };
+       };