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Diffstat (limited to 'Documentation/devicetree/bindings/spi/spi-samsung.txt')
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diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt new file mode 100644 index 000000000..49028a4f5 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt @@ -0,0 +1,122 @@ +* Samsung SPI Controller + +The Samsung SPI controller is used to interface with various devices such as flash +and display controllers using the SPI communication interface. + +Required SoC Specific Properties: + +- compatible: should be one of the following. + - samsung,s3c2443-spi: for s3c2443, s3c2416 and s3c2450 platforms + - samsung,s3c6410-spi: for s3c6410 platforms + - samsung,s5pv210-spi: for s5pv210 and s5pc110 platforms + - samsung,exynos5433-spi: for exynos5433 compatible controllers + - samsung,exynos7-spi: for exynos7 platforms <DEPRECATED> + +- reg: physical base address of the controller and length of memory mapped + region. + +- interrupts: The interrupt number to the cpu. The interrupt specifier format + depends on the interrupt controller. + +- dmas : Two or more DMA channel specifiers following the convention outlined + in bindings/dma/dma.txt + +- dma-names: Names for the dma channels. There must be at least one channel + named "tx" for transmit and named "rx" for receive. + +- clocks: specifies the clock IDs provided to the SPI controller; they are + required for interacting with the controller itself, for synchronizing the bus + and as I/O clock (the latter is required by exynos5433 and exynos7). + +- clock-names: string names of the clocks in the 'clocks' property; for all the + the devices the names must be "spi", "spi_busclkN" (where N is determined by + "samsung,spi-src-clk"), while Exynos5433 should specify a third clock + "spi_ioclk" for the I/O clock. + +Required Board Specific Properties: + +- #address-cells: should be 1. +- #size-cells: should be 0. + +Optional Board Specific Properties: + +- samsung,spi-src-clk: If the spi controller includes a internal clock mux to + select the clock source for the spi bus clock, this property can be used to + indicate the clock to be used for driving the spi bus clock. If not specified, + the clock number 0 is used as default. + +- num-cs: Specifies the number of chip select lines supported. If + not specified, the default number of chip select lines is set to 1. + +- cs-gpios: should specify GPIOs used for chipselects (see spi-bus.txt) + +- no-cs-readback: the CS line is disconnected, therefore the device should not + operate based on CS signalling. + +SPI Controller specific data in SPI slave nodes: + +- The spi slave nodes should provide the following information which is required + by the spi controller. + + - samsung,spi-feedback-delay: The sampling phase shift to be applied on the + miso line (to account for any lag in the miso line). The following are the + valid values. + + - 0: No phase shift. + - 1: 90 degree phase shift sampling. + - 2: 180 degree phase shift sampling. + - 3: 270 degree phase shift sampling. + +Aliases: + +- All the SPI controller nodes should be represented in the aliases node using + the following format 'spi{n}' where n is a unique number for the alias. + + +Example: + +- SoC Specific Portion: + + spi_0: spi@12d20000 { + compatible = "samsung,exynos4210-spi"; + reg = <0x12d20000 0x100>; + interrupts = <0 66 0>; + dmas = <&pdma0 5 + &pdma0 4>; + dma-names = "tx", "rx"; + #address-cells = <1>; + #size-cells = <0>; + }; + +- Board Specific Portion: + + spi_0: spi@12d20000 { + #address-cells = <1>; + #size-cells = <0>; + pinctrl-names = "default"; + pinctrl-0 = <&spi0_bus>; + cs-gpios = <&gpa2 5 0>; + + w25q80bw@0 { + #address-cells = <1>; + #size-cells = <1>; + compatible = "w25x80"; + reg = <0>; + spi-max-frequency = <10000>; + + controller-data { + samsung,spi-feedback-delay = <0>; + }; + + partition@0 { + label = "U-Boot"; + reg = <0x0 0x40000>; + read-only; + }; + + partition@40000 { + label = "Kernel"; + reg = <0x40000 0xc0000>; + }; + }; + }; |