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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /Documentation/devicetree/bindings/spi/spi-samsung.txt
parentInitial commit. (diff)
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Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+* 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>;
+ };
+ };
+ };