QUADSPI device tree configuration

Article purpose

本文介绍如何在将 QUADSPI internal peripheral 分配给 Linux^®操作系统时对其进行配置。 在这种情况下，它由MTD framework控制.

使用device tree 机制执行配置，该机制提供由STM32 QUADSPI Linux驱动程序和MTD框架使用的QUADSPI外围设备的硬件描述。

如果外围设备已分配给另一个执行上下文，请参阅[[[How to assign an internal peripheral to a runtime context]] 文章，了解有关外围设备分配和配置的指南。

DT bindings documentation

QUADSPI设备树绑定由以下组成：

• generic SPI-NOR / SPI-NAND Flash memory bindings .

• QUADSPI driver bindings .

在接下来的章节中，SPI-NAND绑定只与ecosystem release ≥ v1.1.0{{#set:Ecosystem release=revision of a previous flow 1.1.0}} 兼容。

DT configuration

该硬件描述是“STM32微处理器”设备树文件（扩展名为.dtsi）和“板子”设备树文件（扩展名为.dts）的组合。 有关设备树文件分割的说明，请参见Device tree. STM32CubeMX可用于生成板设备树。 有关详细信息，请参阅How to configure the DT using STM32CubeMX 。

DT configuration (STM32 level)

QUADSPI外设节点位于``stm32mp157c.dtsi 文件。

   qspi: spi@58003000 {                                      Comments
       compatible = "st,stm32f469-qspi";
       reg = <0x58003000 0x1000>,                            --> Register location
             <0x70000000 0x10000000>;                        --> Memory mapping address
       reg-names = "qspi", "qspi_mm";
       interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_HIGH>;        --> The interrupt number used
       dmas = <&mdma1 22 0x10 0x100002 0x0 0x0 0x0>,         --> DMA specifiers 
              <&mdma1 22 0x10 0x100008 0x0 0x0 0x0>;
       dma-names = "tx", "rx";
       clocks = <&rcc QSPI_K>;
       resets = <&rcc QSPI_R>;   
       status = "disabled";
   };

与STM32相关的该设备树部分应保持原样，客户不应对其进行修改。

DT configuration (board level)

QUADSPI外设最多可连接2个SPI-NOR闪存。

SPI-NOR闪存节点 必须是QUADSPI外设节点的子级。

   &qspi {                                                   Comments
       pinctrl-names = "default", "sleep";                   --> For pinctrl configuration, please refer to Pinctrl device tree configuration
       pinctrl-0 = <&qspi_clk_pins_a &qspi_bk1_pins_a &qspi_bk2_pins_a>;
       pinctrl-1 = <&qspi_clk_sleep_pins_a &qspi_bk1_sleep_pins_a &qspi_bk2_sleep_pins_a>;
       reg = <0x58003000 0x1000>,
             <0x70000000 0x4000000>;                         --> Overwrite the memory map to the Flash device size, avoid the waste of virtual memory that will not be used
       #address-cells = <1>;
       #size-cells = <0>;
       status = "okay";                                      --> Enable the node

       flash0: mx66l51235l@0 {     
           compatible = "jdec,spi-nor";                                  
           reg = <0>;                                        --> Chip select number
           spi-rx-bus-width = <4>;                           --> The bus width (number of data wires used)
           spi-max-frequency = <108000000>;                  --> Maximum SPI clocking speed of device in Hz
           #address-cells = <1>;
           #size-cells = <1>;
       };
   };

DT configuration example

以下示例显示了在连接1个SPI-NAND闪存和1个SPI-NOR闪存时如何配置QUADSPI外设。

   &qspi {                                                    
       pinctrl-names = "default", "sleep";                    
       pinctrl-0 = <&qspi_clk_pins_a &qspi_bk1_pins_a &qspi_bk2_pins_a>;
       pinctrl-1 = <&qspi_clk_sleep_pins_a &qspi_bk1_sleep_pins_a &qspi_bk2_sleep_pins_a>;
       reg = <0x58003000 0x1000>,
             <0x70000000 0x4000000>;                          
       #address-cells = <1>;
       #size-cells = <0>;
       status = "okay";

       flash0: mx66l51235l@0 {                                 
           compatible = "jdec,spi-nor";
           reg = <0>;
           spi-rx-bus-width = <4>;
           spi-max-frequency = <108000000>;
           #address-cells = <1>;
           #size-cells = <1>;
       };

       flash1: mt29f2g01abagd@1 {                             
           compatible = "spi-nand";
           reg = <1>;
           spi-rx-bus-width = <4>;
           spi-tx-bus-width = <4>;
           spi-max-frequency = <133000000>;
           #address-cells = <1>;
           #size-cells = <1>;
       };
   };

How to configure the DT using STM32CubeMX

STM32CubeMX 工具可用于配置STM32MPU设备并获取相应的platform configuration device tree文件。
STM32CubeMX可能不支持上述DT bindings documentation p段落中描述的所有属性。 如果是这样的话，该工具会在生成的设备树中插入“”User Sections“”。 然后可以编辑这些部分以添加某些属性，并将它们代代相传。 有关详细信息，请参阅STM32CubeMX 用户手册。

References

请参考以下链接以获得完整描述: