dt-bindings: mfd: Add A33 GPADC binding

This patch adds documentation for the A33 GPADC binding.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/Documentation/devicetree/bindings/mfd/sun4i-gpadc.txt b/Documentation/devicetree/bindings/mfd/sun4i-gpadc.txt
new file mode 100644 (file)
index 0000000..badff36
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/sun4i-gpadc.txt
@@ -0,0 +1,59 @@
+Allwinner SoCs' GPADC Device Tree bindings
+------------------------------------------
+The Allwinner SoCs all have an ADC that can also act as a thermal sensor
+and sometimes as a touchscreen controller.
+
+Required properties:
+  - compatible: "allwinner,sun8i-a33-ths",
+  - reg: mmio address range of the chip,
+  - #thermal-sensor-cells: shall be 0,
+  - #io-channel-cells: shall be 0,
+
+Example:
+       ths: ths@01c25000 {
+               compatible = "allwinner,sun8i-a33-ths";
+               reg = <0x01c25000 0x100>;
+               #thermal-sensor-cells = <0>;
+               #io-channel-cells = <0>;
+       };
+
+sun4i, sun5i and sun6i SoCs are also supported via the older binding:
+
+sun4i resistive touchscreen controller
+--------------------------------------
+
+Required properties:
+ - compatible: "allwinner,sun4i-a10-ts", "allwinner,sun5i-a13-ts" or
+   "allwinner,sun6i-a31-ts"
+ - reg: mmio address range of the chip
+ - interrupts: interrupt to which the chip is connected
+ - #thermal-sensor-cells: shall be 0
+
+Optional properties:
+ - allwinner,ts-attached        : boolean indicating that an actual touchscreen
+                                  is attached to the controller
+ - allwinner,tp-sensitive-adjust : integer (4 bits)
+                                  adjust sensitivity of pen down detection
+                                  between 0 (least sensitive) and 15
+                                  (defaults to 15)
+ - allwinner,filter-type        : integer (2 bits)
+                                  select median and averaging filter
+                                  samples used for median / averaging filter
+                                  0: 4/2
+                                  1: 5/3
+                                  2: 8/4
+                                  3: 16/8
+                                  (defaults to 1)
+
+Example:
+
+       rtp: rtp@01c25000 {
+               compatible = "allwinner,sun4i-a10-ts";
+               reg = <0x01c25000 0x100>;
+               interrupts = <29>;
+               allwinner,ts-attached;
+               #thermal-sensor-cells = <0>;
+               /* sensitive/noisy touch panel */
+               allwinner,tp-sensitive-adjust = <0>;
+               allwinner,filter-type = <3>;
+       };