mfd: Add documentation for atmel-hlcdc DT bindings

The HLCDC IP available on some Atmel SoCs (i.e. at91sam9n12, at91sam9x5
family or sama5d3 family) exposes 2 subdevices:
- a display controller (controlled by a DRM driver)
- a PWM chip

This patch adds documentation for atmel-hlcdc DT bindings.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Anthony Harivel <anthony.harivel@emtrion.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt b/Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt
new file mode 100644 (file)
index 0000000..f64de95
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt
@@ -0,0 +1,51 @@
+Device-Tree bindings for Atmel's HLCDC (High LCD Controller) MFD driver
+
+Required properties:
+ - compatible: value should be one of the following:
+   "atmel,sama5d3-hlcdc"
+ - reg: base address and size of the HLCDC device registers.
+ - clock-names: the name of the 3 clocks requested by the HLCDC device.
+   Should contain "periph_clk", "sys_clk" and "slow_clk".
+ - clocks: should contain the 3 clocks requested by the HLCDC device.
+ - interrupts: should contain the description of the HLCDC interrupt line
+
+The HLCDC IP exposes two subdevices:
+ - a PWM chip: see ../pwm/atmel-hlcdc-pwm.txt
+ - a Display Controller: see ../drm/atmel-hlcdc-dc.txt
+
+Example:
+
+       hlcdc: hlcdc@f0030000 {
+               compatible = "atmel,sama5d3-hlcdc";
+               reg = <0xf0030000 0x2000>;
+               clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
+               clock-names = "periph_clk","sys_clk", "slow_clk";
+               interrupts = <36 IRQ_TYPE_LEVEL_HIGH 0>;
+               status = "disabled";
+
+               hlcdc-display-controller {
+                       compatible = "atmel,hlcdc-display-controller";
+                       pinctrl-names = "default";
+                       pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb888>;
+                       #address-cells = <1>;
+                       #size-cells = <0>;
+
+                       port@0 {
+                               #address-cells = <1>;
+                               #size-cells = <0>;
+                               reg = <0>;
+
+                               hlcdc_panel_output: endpoint@0 {
+                                       reg = <0>;
+                                       remote-endpoint = <&panel_input>;
+                               };
+                       };
+               };
+
+               hlcdc_pwm: hlcdc-pwm {
+                       compatible = "atmel,hlcdc-pwm";
+                       pinctrl-names = "default";
+                       pinctrl-0 = <&pinctrl_lcd_pwm>;
+                       #pwm-cells = <3>;
+               };
+       };