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Diffstat (limited to 'Documentation/devicetree/bindings/spi/spi-davinci.txt')
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diff --git a/Documentation/devicetree/bindings/spi/spi-davinci.txt b/Documentation/devicetree/bindings/spi/spi-davinci.txt new file mode 100644 index 000000000..f01288865 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt @@ -0,0 +1,100 @@ +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>; + }; + }; +}; |