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+Davinci SPI controller device bindings
+
+Links on DM:
+Keystone 2 - https://www.ti.com/lit/ug/sprugp2a/sprugp2a.pdf
+dm644x - https://www.ti.com/lit/ug/sprue32a/sprue32a.pdf
+OMAP-L138/da830 - http://www.ti.com/lit/ug/spruh77a/spruh77a.pdf
+
+Required properties:
+- #address-cells: number of cells required to define a chip select
+ address on the SPI bus. Should be set to 1.
+- #size-cells: should be zero.
+- compatible:
+ - "ti,dm6441-spi" for SPI used similar to that on DM644x SoC family
+ - "ti,da830-spi" for SPI used similar to that on DA8xx SoC family
+ - "ti,keystone-spi" for SPI used similar to that on Keystone2 SoC
+ family
+- reg: Offset and length of SPI controller register space
+- num-cs: Number of chip selects. This includes internal as well as
+ GPIO chip selects.
+- ti,davinci-spi-intr-line: interrupt line used to connect the SPI
+ IP to the interrupt controller within the SoC. Possible values
+ are 0 and 1. Manual says one of the two possible interrupt
+ lines can be tied to the interrupt controller. Set this
+ based on a specific SoC configuration.
+- interrupts: interrupt number mapped to CPU.
+- clocks: spi clk phandle
+ For 66AK2G this property should be set per binding,
+ Documentation/devicetree/bindings/clock/ti,sci-clk.yaml
+
+SoC-specific Required Properties:
+
+The following are mandatory properties for Keystone 2 66AK2G SoCs only:
+
+- power-domains: Should contain a phandle to a PM domain provider node
+ and an args specifier containing the SPI device id
+ value. This property is as per the binding,
+
+Optional:
+- cs-gpios: gpio chip selects
+ For example to have 3 internal CS and 2 GPIO CS, user could define
+ cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>;
+ where first three are internal CS and last two are GPIO CS.
+
+Optional properties for slave devices:
+SPI slave nodes can contain the following properties.
+Not all SPI Peripherals from Texas Instruments support this.
+Please check SPI peripheral documentation for a device before using these.
+
+- ti,spi-wdelay : delay between transmission of words
+ (SPIFMTn.WDELAY, SPIDAT1.WDEL) must be specified in number of SPI module
+ clock periods.
+
+ delay = WDELAY * SPI_module_clock_period + 2 * SPI_module_clock_period
+
+Below is timing diagram which shows functional meaning of
+"ti,spi-wdelay" parameter.
+
+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+
+SPI_CLK | | | | | | | | | | | | | | | |
+ +----------+ +-+ +-+ +-+ +-+ +---------------------------+ +-+ +-+ +-
+
+SPI_SOMI/SIMO+-----------------+ +-----------
+ +----------+ word1 +---------------------------+word2
+ +-----------------+ +-----------
+ WDELAY
+ <-------------------------->
+
+Example of a NOR flash slave device (n25q032) connected to DaVinci
+SPI controller device over the SPI bus.
+
+spi0:spi@20bf0000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "ti,dm6446-spi";
+ reg = <0x20BF0000 0x1000>;
+ num-cs = <4>;
+ ti,davinci-spi-intr-line = <0>;
+ interrupts = <338>;
+ clocks = <&clkspi>;
+
+ flash: flash@0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "st,m25p32";
+ spi-max-frequency = <25000000>;
+ reg = <0>;
+ ti,spi-wdelay = <8>;
+
+ partition@0 {
+ label = "u-boot-spl";
+ reg = <0x0 0x80000>;
+ read-only;
+ };
+
+ partition@1 {
+ label = "test";
+ reg = <0x80000 0x380000>;
+ };
+ };
+};