[PATCH v3 2/2] dt: brcm, bcm2835-aux-spi: add binding documentation for new spi-bcm2835aux

[kernel at martin.sperl.org]

From: Martin Sperl <kernel at martin.sperl.org>

Document the necessary device-tree bindings of the spi-bcm2835aux driver.

Signed-off-by: Martin Sperl <kernel at martin.sperl.org>

---

 .../bindings/spi/brcm,bcm2835-aux-spi.txt          |   46 ++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/brcm,bcm2835-aux-spi.txt

Changelog:
    V1->V2:     fixed typo
                added cs-gpios
    V2->V3:     added reference to spi-bus in cs-gpios
                added required additional config for syscon

diff --git a/Documentation/devicetree/bindings/spi/brcm,bcm2835-aux-spi.txt b/Documentation/devicetree/bindings/spi/brcm,bcm2835-aux-spi.txt
new file mode 100644
index 0000000..ce5f3be
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/brcm,bcm2835-aux-spi.txt
@@ -0,0 +1,46 @@
+Broadcom BCM2835 auxiliar SPI1/2 controller
+
+The BCM2835 contains two forms of SPI master controller, one known simply as
+SPI0, and the other known as the "Universal SPI Master"; part of the
+auxiliary block. This binding applies to the SPI1/2 controller.
+
+Required properties:
+- compatible: Should be "brcm,bcm2835-aux-spi".
+- reg: Should contain register location and length for the spi block
+       as well as for the common aux block control
+- interrupts: Should contain shared interrupt of the aux block
+- clocks: The clock feeding the SPI controller.
+- cs-gpios: the cs-gpios (native cs is NOT supported)
+            see also spi-bus.txt
+- syscon: the syscon config entry to handle the shared
+          register access by multiple drivers
+
+Example:
+
+spi1 at 7e215080 {
+	compatible = "brcm,bcm2835-aux-spi";
+	reg = <0x7e215080 0x40>;
+	interrupts = <1 29>;
+	clocks = <&clk_spi>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	cs-gpios = <&gpio 18>, <&gpio 17>, <&gpio 16>;
+	syscon = <&aux_syscon>;
+};
+
+spi2 at 7e2150c0 {
+	compatible = "brcm,bcm2835-aux-spi";
+	reg = <0x7e2150c0 0x40>;
+	interrupts = <1 29>;
+	clocks = <&clk_spi>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	cs-gpios = <&gpio 43>, <&gpio 44>, <&gpio 45>;
+	syscon = <&aux_syscon>;
+};
+
+/* the necessary syscon config referenced above */
+aux_syscon: aux_syscon at 0x7e215000 {
+	compatible = "syscon";
+	reg = <0x7e215000 0x08>;
+};
--
1.7.10.4