spi: Move cadence-quadspi.txt to Documentation/devicetree/bindings/spi

Move the Documentation/devicetree/bindings/mtd/cadence-quadspi.txt to
Documentation/devicetree/bindings/spi/

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201124041840.31066-5-vadivel.muruganx.ramuthevar@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/spi/cadence-quadspi.txt b/Documentation/devicetree/bindings/spi/cadence-quadspi.txt
new file mode 100644
index 000000000000..945be7d5b236
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/cadence-quadspi.txt
@@ -0,0 +1,67 @@
+* Cadence Quad SPI controller
+
+Required properties:
+- compatible : should be one of the following:
+	Generic default - "cdns,qspi-nor".
+	For TI 66AK2G SoC - "ti,k2g-qspi", "cdns,qspi-nor".
+	For TI AM654 SoC  - "ti,am654-ospi", "cdns,qspi-nor".
+- reg : Contains two entries, each of which is a tuple consisting of a
+	physical address and length. The first entry is the address and
+	length of the controller register set. The second entry is the
+	address and length of the QSPI Controller data area.
+- interrupts : Unit interrupt specifier for the controller interrupt.
+- clocks : phandle to the Quad SPI clock.
+- cdns,fifo-depth : Size of the data FIFO in words.
+- cdns,fifo-width : Bus width of the data FIFO in bytes.
+- cdns,trigger-address : 32-bit indirect AHB trigger address.
+
+Optional properties:
+- cdns,is-decoded-cs : Flag to indicate whether decoder is used or not.
+- cdns,rclk-en : Flag to indicate that QSPI return clock is used to latch
+  the read data rather than the QSPI clock. Make sure that QSPI return
+  clock is populated on the board before using this property.
+
+Optional subnodes:
+Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional
+custom properties:
+- cdns,read-delay : Delay for read capture logic, in clock cycles
+- cdns,tshsl-ns : Delay in nanoseconds for the length that the master
+                  mode chip select outputs are de-asserted between
+		  transactions.
+- cdns,tsd2d-ns : Delay in nanoseconds between one chip select being
+                  de-activated and the activation of another.
+- cdns,tchsh-ns : Delay in nanoseconds between last bit of current
+                  transaction and deasserting the device chip select
+		  (qspi_n_ss_out).
+- cdns,tslch-ns : Delay in nanoseconds between setting qspi_n_ss_out low
+                  and first bit transfer.
+- resets	: Must contain an entry for each entry in reset-names.
+		  See ../reset/reset.txt for details.
+- reset-names	: Must include either "qspi" and/or "qspi-ocp".
+
+Example:
+
+	qspi: spi@ff705000 {
+		compatible = "cdns,qspi-nor";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0xff705000 0x1000>,
+		      <0xffa00000 0x1000>;
+		interrupts = <0 151 4>;
+		clocks = <&qspi_clk>;
+		cdns,is-decoded-cs;
+		cdns,fifo-depth = <128>;
+		cdns,fifo-width = <4>;
+		cdns,trigger-address = <0x00000000>;
+		resets = <&rst QSPI_RESET>, <&rst QSPI_OCP_RESET>;
+		reset-names = "qspi", "qspi-ocp";
+
+		flash0: n25q00@0 {
+			...
+			cdns,read-delay = <4>;
+			cdns,tshsl-ns = <50>;
+			cdns,tsd2d-ns = <50>;
+			cdns,tchsh-ns = <4>;
+			cdns,tslch-ns = <4>;
+		};
+	};