STM32MP157Linux系统移植开发篇18：Linux内核蓝⽛驱动
移植
FS-MP1A开发板蓝⽛采⽤AP6236，WIFI蓝⽛⼆合⼀芯⽚。蓝⽛部分通过usart3与SoC进⾏数据交互。
蓝⽛部分移需要配置usart3的设备树与AP_CK32KO管脚，可参考stm32mp157c-dk2.dts中的相关配置。 查看原理图得出AP6236数据管脚与STM32MP157A的管脚对应关系如下：
原理图⽹络编号对应管脚管脚功能管脚功能码
BT_UART_TX PD8USART3_TX AF7
BT_UART_RX PD9USART3_RX AF7
BT_UART_CTS PD11USART3_CTS AF7
BT_UART_RTS PD12USART3_RTS AF7
BT_WIFI_RST PD13IO ANALOG
BT_WIFI_RST PD13IO ANALOG AP_CK32KO PI8RTC_OUT2ANALOG 1. 蓝⽛设备树节点 参考⽂档：
Documentation/devicetree/bindings/
Documentation/devicetree/bindings/serial/
内核中ST对STM32MP15x系列芯⽚的设备树资源了做了定义，可参见：
arch/arm/boot/dts/stm32mp151.dtsi
stm32mp151中usart3定义如下：
usart3: serial@4000f000 {
compatible = "st,stm32h7-uart";
reg = <0x4000f000 0x400>;
interrupts-extended = <&exti 28 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&rcc USART3_K>;
resets = <&rcc USART3_R>;
wakeup-source;
power-domains = <&pd_core>;
dmas = <&dmamux1 45 0x400 0x5>,
<&dmamux1 46 0x400 0x1>;
dma-names = "rx", "tx";
status = "disabled";
};
上述代码只对usart3做了基本的初始化，并没有针对不同的硬件设计做适配，所以需结合硬件补全设备树节点信息。参考⽂档或stm32mp157c-dk2.dts对于usart2设备节点的描述，增加usart3内容如下：
&usart3 {
pinctrl-names = "default", "sleep", "idle";
pinctrl-0 = <&usart3_pins_bt>;
pinctrl-1 = <&usart3_idle_pins_bt>;
pinctrl-2 = <&usart3_sleep_pins_bt>;
uart-has-rtscts;
status = "okay";
bluetooth {竖井滑模生产厂家
shutdown-gpios = <&gpiod 13 GPIO_ACTIVE_HIGH>;
compatible = "brcm,bcm43438-bt";
max-speed = <3000000>;
vbat-supply = <&v3v3>;
vddio-supply = <&v3v3>;
};
};
同时stm32mp15-pinctrl.dtsi对于usart3的描述与FS-MP1A所使⽤管脚不⼀致，所以⽆法直接使⽤，需参考其增加如下内容：usart3_pins_bt: usart3-bt-0 {
pins1 {
pinmux = <STM32_PINMUX('D', 8, AF7)>, /* USART3_TX */
<STM32_PINMUX('D', 12, AF7)>; /* USART3_RTS */
bias-disable;
drive-push-pull;
slew-rate = <0>;
};
pins2 {
pinmux = <STM32_PINMUX('D', 9, AF7)>, /* USART3_RX */
<STM32_PINMUX('D', 11, AF7)>; /* USART3_CTS_NSS */
bias-disable;
};
};
usart3_idle_pins_bt: usart3-idle-bt-0 {
pins1 {
pinmux = <STM32_PINMUX('D', 8, ANALOG)>, /* USART3_TX */
<STM32_PINMUX('D', 12, ANALOG)>, /* USART3_RTS */
<STM32_PINMUX('D', 11, ANALOG)>; /* USART3_CTS_NSS */
};
pins2 {
pinmux = <STM32_PINMUX('D', 9, AF7)>; /* USART3_RX */
bias-disable;
};
};
谷氨酰胺合成酶usart3_sleep_pins_bt: usart3-sleep-bt-0 {
pins {
pinmux = <STM32_PINMUX('D', 8, ANALOG)>, /* USART3_TX */
<STM32_PINMUX('D', 12, ANALOG)>, /* USART3_RTS */
<STM32_PINMUX('D', 11, ANALOG)>, /* USART3_CTS_NSS */
<STM32_PINMUX('D', 9, ANALOG)>; /* USART3_RX */
};
};
2）RTC节点
AP6236需要使⽤⼀个外部输⼊的32.768KHz的时钟源，因此我们需要使能RTC的外部32.768KHz功能
参考⽂档：
Documentation/devicetree/bindings/rtc/
内核中ST对STM32MP15x系列芯⽚的设备树资源了做了定义，可参见：
arch/arm/boot/dts/stm32mp151.dtsi
物流企业财务管理stm32mp151中rtc定义如下：
rtc: rtc@5c004000 {
compatible = "st,stm32mp1-rtc";
reg = <0x5c004000 0x400>;
clocks = <&scmi0_clk CK_SCMI0_RTCAPB>,
<&scmi0_clk CK_SCMI0_RTC>;
clock-names = "pclk", "rtc_ck";
interrupts-extended = <&exti 19 IRQ_TYPE_LEVEL_HIGH>;
status = "disabled";
};
上述代码只对rtc做了基本的初始化，并没有针对不同的硬件设计做适配，所以需结合硬件补全设备树节点信息。参考stm32mp157f-dk2.dts对于rtc设备节点的描述，需增加内容如下：
rtc {
st,lsco = <RTC_OUT2_RMP>;
狗字成语pinctrl-0 = <&rtc_out2_rmp_pins_a>;
pinctrl-names = "default";
status = "okay";
};
2.实验⽬的
熟悉基于Linux操作系统下的蓝⽛设备驱动移植配置过程。
3.实验平台
华清远见开发环境，FS-MP1A平台；
4.实验步骤
1. 导⼊交叉编译⼯具链
linux@ubuntu:$ source /opt/st/stm32mp1/3.1-openstlinux-5.4-dunfell-mp1-20-06-24/environment-setup-cortexa7t2hf-neon-vfpv4-ostl-linux-gnueabi
1. 开启3
2.768KHz时钟
修改arch/arm/boot/dts/stm32mp15xx-fsmp1x.dtsi⽂件中的rtc节点添加如下内容：
rtc {
离退休干部清违规住房st,lsco = <RTC_OUT2_RMP>;
pinctrl-0 = <&rtc_out2_rmp_pins_a>;
短路容量
pinctrl-names = "default";
status = "okay";
};
其中红⾊字体部分为要添加的内容。
添加rtc相关头⽂件。
#include <dt-bindings/rtc/rtc-stm32.h>
1. 添加usart3配置
修改arch/arm/boot/dts/stm32mp15xx-fsmp1x.dtsi⽂件，在⽂件末尾添加如下内容：
&usart3 {
pinctrl-names = "default", "sleep", "idle";
pinctrl-0 = <&usart3_pins_bt>;
pinctrl-1 = <&usart3_idle_pins_bt>;
pinctrl-2 = <&usart3_sleep_pins_bt>;
uart-has-rtscts;
status = "okay";
bluetooth {
shutdown-gpios = <&gpiod 13 GPIO_ACTIVE_HIGH>;
compatible = "brcm,bcm43438-bt";
max-speed = <3000000>;
vbat-supply = <&v3v3>;
vddio-supply = <&v3v3>;
};
};
1. 添加功能管脚配置
