1* Samsung SPI Controller 2 3The Samsung SPI controller is used to interface with various devices such as flash 4and display controllers using the SPI communication interface. 5 6Required SoC Specific Properties: 7 8- compatible: should be one of the following. 9 - samsung,s3c2443-spi: for s3c2443, s3c2416 and s3c2450 platforms 10 - samsung,s3c6410-spi: for s3c6410 platforms 11 - samsung,s5pv210-spi: for s5pv210 and s5pc110 platforms 12 - samsung,exynos7-spi: for exynos7 platforms 13 14- reg: physical base address of the controller and length of memory mapped 15 region. 16 17- interrupts: The interrupt number to the cpu. The interrupt specifier format 18 depends on the interrupt controller. 19 20- dmas : Two or more DMA channel specifiers following the convention outlined 21 in bindings/dma/dma.txt 22 23- dma-names: Names for the dma channels. There must be at least one channel 24 named "tx" for transmit and named "rx" for receive. 25 26Required Board Specific Properties: 27 28- #address-cells: should be 1. 29- #size-cells: should be 0. 30 31Optional Board Specific Properties: 32 33- samsung,spi-src-clk: If the spi controller includes a internal clock mux to 34 select the clock source for the spi bus clock, this property can be used to 35 indicate the clock to be used for driving the spi bus clock. If not specified, 36 the clock number 0 is used as default. 37 38- num-cs: Specifies the number of chip select lines supported. If 39 not specified, the default number of chip select lines is set to 1. 40 41- cs-gpios: should specify GPIOs used for chipselects (see spi-bus.txt) 42 43SPI Controller specific data in SPI slave nodes: 44 45- The spi slave nodes should provide the following information which is required 46 by the spi controller. 47 48 - samsung,spi-feedback-delay: The sampling phase shift to be applied on the 49 miso line (to account for any lag in the miso line). The following are the 50 valid values. 51 52 - 0: No phase shift. 53 - 1: 90 degree phase shift sampling. 54 - 2: 180 degree phase shift sampling. 55 - 3: 270 degree phase shift sampling. 56 57Aliases: 58 59- All the SPI controller nodes should be represented in the aliases node using 60 the following format 'spi{n}' where n is a unique number for the alias. 61 62 63Example: 64 65- SoC Specific Portion: 66 67 spi_0: spi@12d20000 { 68 compatible = "samsung,exynos4210-spi"; 69 reg = <0x12d20000 0x100>; 70 interrupts = <0 66 0>; 71 dmas = <&pdma0 5 72 &pdma0 4>; 73 dma-names = "tx", "rx"; 74 #address-cells = <1>; 75 #size-cells = <0>; 76 }; 77 78- Board Specific Portion: 79 80 spi_0: spi@12d20000 { 81 #address-cells = <1>; 82 #size-cells = <0>; 83 pinctrl-names = "default"; 84 pinctrl-0 = <&spi0_bus>; 85 cs-gpios = <&gpa2 5 0>; 86 87 w25q80bw@0 { 88 #address-cells = <1>; 89 #size-cells = <1>; 90 compatible = "w25x80"; 91 reg = <0>; 92 spi-max-frequency = <10000>; 93 94 controller-data { 95 samsung,spi-feedback-delay = <0>; 96 }; 97 98 partition@0 { 99 label = "U-Boot"; 100 reg = <0x0 0x40000>; 101 read-only; 102 }; 103 104 partition@40000 { 105 label = "Kernel"; 106 reg = <0x40000 0xc0000>; 107 }; 108 }; 109 }; 110