Zynq-7000、FMQL45T900的GPIO控制（三）---linux管脚编号计算

news2024/10/6 17:20:29

本文主要对在Linux下使用zynq-7000或者FMQL45T900控制MIO/EMIO

首先内核配置项

如下，这个不用太多关注，一般都是默认打开的

CONFIG_GPIO_SYSFS=y
CONFIG_SYSVIPC=y
CONFIG_GPIO_ZYNQ=y

两者的控制都是流程都是一样的，在细节上又区别

首先都在/sys/class/gpio/查看对应节点

FMQL45T900

Zynq-7000平台

这里两者的明显的区别在于FMQL45T900节点个数比较多有四个，这里简单分析一下原因

两者的GPIO的驱动设计不一样

Zynq驱动设计从设备树zynq-7000.dtsi可以看出确实只有一个节点

		gpio0: gpio@e000a000 {
			compatible = "xlnx,zynq-gpio-1.0";
			#gpio-cells = <2>;
			clocks = <&clkc 42>;
			gpio-controller;
			interrupt-controller;
			#interrupt-cells = <2>;
			interrupt-parent = <&intc>;
			interrupts = <0 20 4>;
			reg = <0xe000a000 0x1000>;
		};

FMQL45T900中设备文件fmsh-psoc.dtsi可以看出有四个节点

gpio0: gpio@e0003000 {
			compatible = "snps,dw-apb-gpio";
			reg = <0xe0003000 0x100>;
			#address-cells = <1>;
			#size-cells = <0>;
			clocks = <&clkc NCLK_APB_GPIO>;
			status = "disabled";

			porta: gpio-controller@0 {
				compatible = "snps,dw-apb-gpio-port";
				bank-name = "porta";
				gpio-controller;
				#gpio-cells = <2>;
				snps,nr-gpios = <32>;
				reg = <0>;
				interrupt-controller;
				#interrupt-cells = <2>;
				interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>;
			};
		};

		gpio1: gpio@e0003100 {
			compatible = "snps,dw-apb-gpio";
			reg = <0xe0003100 0x100>;
			#address-cells = <1>;
			#size-cells = <0>;
			clocks = <&clkc NCLK_APB_GPIO>;
			status = "disabled";

			portb: gpio-controller@0 {
				compatible = "snps,dw-apb-gpio-port";
				bank-name = "portb";
				gpio-controller;
				#gpio-cells = <2>;
				snps,nr-gpios = <22>;
				reg = <0>;
				interrupt-controller;
				#interrupt-cells = <2>;
				interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
			};
		};

		gpio2: gpio@e0003200 {
			compatible = "snps,dw-apb-gpio";
			reg = <0xe0003200 0x100>;
			#address-cells = <1>;
			#size-cells = <0>;
			clocks = <&clkc NCLK_APB_GPIO>;
			status = "disabled";

			portc: gpio-controller@0 {
				compatible = "snps,dw-apb-gpio-port";
				bank-name = "portc";
				gpio-controller;
				#gpio-cells = <2>;
				snps,nr-gpios = <32>;
				reg = <0>;
				interrupt-controller;
				#interrupt-cells = <2>;
				interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
			};
		};

		gpio3: gpio@e0003400 {
			compatible = "snps,dw-apb-gpio";
			reg = <0xe0003400 0x100>;
			#address-cells = <1>;
			#size-cells = <0>;
			clocks = <&clkc NCLK_APB_GPIO>;
			status = "disabled";

			portd: gpio-controller@0 {
				compatible = "snps,dw-apb-gpio-port";
				bank-name = "portd";
				gpio-controller;
				#gpio-cells = <2>;
				snps,nr-gpios = <32>;
				reg = <0>;
				interrupt-controller;
				#interrupt-cells = <2>;
				interrupts = <GIC_SPI 38 IRQ_TYPE_LEVEL_HIGH>;
			};
		};

怎么计算我们需要操作的原理图上的IO管脚

Zynq-7000假如要操作MIO10

从上图可以看到设备中第一个IO编号为906，这个编号属于MIO的编号。即第一个GPIO为gpio906。你需要操作某个GPIO直接找出对应的GPIO编号，比如：我要使用MIO10对应第11个GPIO对应的编号为：gpio916。注意第一个为906对应MIO0。

FMQL45T900的计算稍微复杂一点，提供了四个根节点，分别对应每个bank

其他MIO/EMIO可以根据下表格计算出来，这里列举几个实际使用的IO

Linux节点	对应bank	对应IO	最大偏移量
gpiochip394	BANK3起始节点	EMIO32	32
gpiochip426	BANK2起始节点	EMIO0	32
gpiochip458	BANK1起始节点	MIO32	54-32
gpiochip480	BANK0起始节点	MIO0	32