Kernel-4.18.0-80.el8_fsl-imx-cspi

published: updated: Kernel_4.18.0-80.el8_内核文档
  • Freescale (Enhanced) Configurable Serial Peripheral Interface
    (CSPI/eCSPI) for i.MX

Required properties:

  • compatible :
    • “fsl,imx1-cspi” for SPI compatible with the one integrated on i.MX1
    • “fsl,imx21-cspi” for SPI compatible with the one integrated on i.MX21
    • “fsl,imx27-cspi” for SPI compatible with the one integrated on i.MX27
    • “fsl,imx31-cspi” for SPI compatible with the one integrated on i.MX31
    • “fsl,imx35-cspi” for SPI compatible with the one integrated on i.MX35
    • “fsl,imx51-ecspi” for SPI compatible with the one integrated on i.MX51
    • “fsl,imx53-ecspi” for SPI compatible with the one integrated on i.MX53 and later Soc
  • reg : Offset and length of the register set for the device
  • interrupts : Should contain CSPI/eCSPI interrupt
  • clocks : Clock specifiers for both ipg and per clocks.
  • clock-names : Clock names should include both “ipg” and “per”
    See the clock consumer binding,
    Documentation/devicetree/bindings/clock/clock-bindings.txt

Recommended properties:

  • cs-gpios : GPIOs to use as chip selects, see spi-bus.txt. While the native chip
    select lines can be used, they appear to always generate a pulse between each
    word of a transfer. Most use cases will require GPIO based chip selects to
    generate a valid transaction.

Optional properties:

  • num-cs : Number of total chip selects, see spi-bus.txt.
  • dmas: DMA specifiers for tx and rx dma. See the DMA client binding,
    Documentation/devicetree/bindings/dma/dma.txt.
  • dma-names: DMA request names, if present, should include “tx” and “rx”.
  • fsl,spi-rdy-drctl: Integer, representing the value of DRCTL, the register
    controlling the SPI_READY handling. Note that to enable the DRCTL consideration,
    the SPI_READY mode-flag needs to be set too.
    Valid values are: 0 (disabled), 1 (edge-triggered burst) and 2 (level-triggered burst).

Obsolete properties:

  • fsl,spi-num-chipselects : Contains the number of the chipselect

Example:

ecspi@70010000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = “fsl,imx51-ecspi”;
reg = <0x70010000 0x4000>;
interrupts = <36>;
cs-gpios = <&gpio3 24 0>, /* GPIO3_24 /
<&gpio3 25 0>; / GPIO3_25 */
dmas = <&sdma 3 7 1>, <&sdma 4 7 2>;
dma-names = “rx”, “tx”;
fsl,spi-rdy-drctl = <1>;
};

oosTech by Sam Lee