[PATCH v2 1/2] dt-bindings: Document the STM32 QSPI bindings

[Ludovic Barre <ludovic.Barre@st.com>]

From: Ludovic Barre <ludovic.barre@st.com>

This patch adds documentation of device tree bindings for the STM32
QSPI controller.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 .../devicetree/bindings/mtd/stm32-quadspi.txt      | 45 ++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/stm32-quadspi.txt

diff --git a/Documentation/devicetree/bindings/mtd/stm32-quadspi.txt b/Documentation/devicetree/bindings/mtd/stm32-quadspi.txt
new file mode 100644
index 0000000..95a8ebd
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/stm32-quadspi.txt
@@ -0,0 +1,45 @@
+* STMicroelectronics Quad Serial Peripheral Interface(QuadSPI)
+
+Required properties:
+- compatible: should be "st,stm32f469-qspi"
+- reg: contains the register location and length.
+  (optional) the memory mapping address and length
+- reg-names: list of the names corresponding to the previous register
+  Should contain "qspi" to register location
+  (optional) "qspi_mm" if read in memory map mode (improve read throughput)
+- interrupts: should contain the interrupt for the device
+- clocks: the phandle of the clock needed by the QSPI controller
+- A pinctrl must be defined to set pins in mode of operation for QSPI transfer
+
+Optional properties:
+- resets: must contain the phandle to the reset controller.
+
+A spi flash must be a child of the nor_flash node and could have some
+properties. Also see jedec,spi-nor.txt.
+
+Required properties:
+- reg: chip-Select number (QSPI controller may connect 2 nor flashes)
+- spi-max-frequency: max frequency of spi bus
+
+Optional property:
+- spi-rx-bus-width: the bus width (number of data wires)
+
+Example:
+
+qspi: qspi@a0001000 {
+	compatible = "st,stm32f469-qspi";
+	reg = <0xa0001000 0x1000>, <0x90000000 0x10000000>;
+	reg-names = "qspi", "qspi_mm";
+	interrupts = <91>;
+	resets = <&rcc STM32F4_AHB3_RESET(QSPI)>;
+	clocks = <&rcc 0 STM32F4_AHB3_CLOCK(QSPI)>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_qspi0>;
+
+	flash@0 {
+		reg = <0>;
+		spi-rx-bus-width = <4>;
+		spi-max-frequency = <108000000>;
+		...
+	};
+};
-- 
2.7.4