From 82a29bf9952acd1be7e76783604686abeb4e5b1d Mon Sep 17 00:00:00 2001 From: Amelie Delaunay Date: Wed, 21 Jun 2017 16:32:05 +0200 Subject: spi: Document the STM32 SPI bindings This patch adds the documentation of device tree bindings for the STM32 SPI controller. Signed-off-by: Amelie Delaunay Signed-off-by: Mark Brown --- .../devicetree/bindings/spi/spi-stm32.txt | 60 ++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 Documentation/devicetree/bindings/spi/spi-stm32.txt (limited to 'Documentation/devicetree/bindings/spi/spi-stm32.txt') diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt new file mode 100644 index 000000000000..3958bf6e8b37 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt @@ -0,0 +1,60 @@ +STMicroelectronics STM32 SPI Controller + +The STM32 SPI controller is used to communicate with external devices using +the Serial Peripheral Interface. It supports full-duplex, half-duplex and +simplex synchronous serial communication with external devices. It supports +from 4 to 32-bit data size. Although it can be configured as master or slave, +only master is supported by the driver. + +Required properties: +- compatible: Must be "st,stm32-spi". +- reg: Offset and length of the device's register set. +- interrupts: Must contain the interrupt id. +- clocks: Must contain an entry for spiclk (which feeds the internal clock + generator). +- #address-cells: Number of cells required to define a chip select address. +- #size-cells: Should be zero. + +Optional properties: +- resets: Must contain the phandle to the reset controller. +- A pinctrl state named "default" may be defined to set pins in mode of + operation for SPI transfer. +- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the + STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt. +- dma-names: DMA request names should include "tx" and "rx" if present. +- cs-gpios: list of GPIO chip selects. See the SPI bus bindings, + Documentation/devicetree/bindings/spi/spi-bus.txt + + +Child nodes represent devices on the SPI bus + See ../spi/spi-bus.txt + +Optional properties: +- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in + nanoseconds inserted between two consecutive data frames. + + +Example: + spi2: spi@40003800 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "st,stm32-spi"; + reg = <0x40003800 0x400>; + interrupts = <36>; + clocks = <&rcc SPI2_CK>; + resets = <&rcc 1166>; + dmas = <&dmamux1 0 39 0x400 0x01>, + <&dmamux1 1 40 0x400 0x01>; + dma-names = "rx", "tx"; + pinctrl-0 = <&spi2_pins_b>; + pinctrl-names = "default"; + status = "okay"; + cs-gpios = <&gpioa 11 0>; + + spidev@0 { + compatible = "spidev"; + reg = <0>; + spi-max-frequency = <4000000>; + st,spi-midi = <4000>; + }; + }; -- cgit