Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / devicetree / bindings / spi / spi-samsung.txt

diff --git a/kernel/Documentation/devicetree/bindings/spi/spi-samsung.txt b/kernel/Documentation/devicetree/bindings/spi/spi-samsung.txt
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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,exynos7-spi: for exynos7 platforms
+
+- 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.
+
+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)
+
+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>;
+                       };
+               };
+       };