v851s uart3 设置成普通串口收发

chhjnavy LV 5

由于UART0 被设定为系统dubug 输出（简单来说就是将ttyS0 设定为console），所以使用UART3 作为普通的串口，进行与别的设备通信。

1. 查看硬件电路图SCH_Schematic1_2022-11-23，查看uart3 的TX RX pin 脚
电路图pdf路径：Yuzukilizard/Hardware/Schematic/SCH_Schematic1_2022-11-23.pdf

从图中可以看出TX = PE12 RX = PE13 。

PE12 PE13 可以通过排插用杜邦线接出，排插电路图如下：

2. 由于pin脚复用原因，我们需要查看pin 脚复用情况

pin 脚复用手册V851SE_PINOUT_V0.1.xlsx路径：
Yuzukilizard/Hardware/Datasheets/V851SE_PINOUT_V0.1.xlsx

记住PE12 PE13 用作UART3-TX UART3-RX 是function7 ，这个很重要，一会我们在board.dts 文件中需要用到。

3. 配置设备树文件 board.dts
设备树文件通过of 文件解析出属性，进一步被应用（原理此处不再介绍）。

board.dts 路径：tina-v853-docker/device/config/chips/v851s/configs/lizard/board.dts

在设备树中搜索UART 找到UART3 相关配置

&uart0 {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&uart0_pins_active>;
	pinctrl-1 = <&uart0_pins_sleep>;
	status = "okay";
};

&uart1 {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&uart1_pins_active>;
	pinctrl-1 = <&uart1_pins_sleep>;
	status = "disabled";
};

&uart2 {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&uart2_pins_active>;
	pinctrl-1 = <&uart2_pins_sleep>;
	status = "disabled";
};

&uart3 {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&uart3_pins_active>;
	pinctrl-1 = <&uart3_pins_sleep>;
	status = "okay";
};

&pio {
	uart0_pins_active: uart0@0 {
		allwinner,pins = "PH9", "PH10";
		allwinner,function = "uart0";
		allwinner,muxsel = <5>;
		allwinner,drive = <1>;
		allwinner,pull = <1>;
	};

	uart0_pins_sleep: uart0@1 {
		allwinner,pins = "PH9", "PH10";
		allwinner,function = "gpio_in";
		allwinner,muxsel = <0>;
	};

	uart1_pins_active: uart1@0 {
		allwinner,pins = "PG6", "PG7";
		allwinner,function = "uart1";
		allwinner,muxsel = <4>;
		allwinner,drive = <1>;
		allwinner,pull = <1>;
	};

	uart1_pins_sleep: uart1@1 {
		allwinner,pins = "PG6", "PG7";
		allwinner,function = "gpio_in";
		allwinner,muxsel = <0>;
	};

	uart2_pins_active: uart2@0 {
		allwinner,pins = "PA8", "PA9";
		allwinner,function = "uart2";
		allwinner,muxsel = <6>;
		allwinner,drive = <1>;
		allwinner,pull = <1>;
	};

	uart2_pins_sleep: uart2@1 {
		allwinner,pins = "PA8", "PA9";
		allwinner,function = "gpio_in";
		allwinner,muxsel = <0>;
	};

	uart3_pins_active: uart3@0 {
		allwinner,pins = "PE12", "PE13";
		allwinner,function = "uart3";
		allwinner,muxsel = <7>;
		allwinner,drive = <1>;
		allwinner,pull = <1>;
	};

	uart3_pins_sleep: uart3@1 {
		allwinner,pins = "PE12", "PE13";
		allwinner,function = "gpio_in";
		allwinner,muxsel = <0>;
	};

1）将uart3 设定为 status = "okay";
2）将uart3 pin 脚设为 allwinner,pins = "PE12", "PE13";
3）将uart3 pin复用为function7 ：allwinner,muxsel = <7>;

修改完成后，重新编译img

make -j1 V=s
pack

使用烧录软件：PhoenixSuit ，具体烧录方法参考：https://dongshanpi.com/YuzukiHD-Lizard/03-1_FlashSystem/#usb

烧录后,通过adb shell 进入终端，就可以查看到设备节点：/dev/ttyS3 ,通过open 设备终端，就可以进行read write 操作。

4. 通过设备节点 /dev/ttyS3 进行收发操作

1）写应用程序

#include <stdio.h>     /*标准输入输出定义*/
#include <stdlib.h>    /*标准函数库定义*/
#include <unistd.h>    /*Unix标准函数定义*/
#include <sys/types.h> 
#include <sys/stat.h>  /*六文件控制定义*/
#include <fcntl.h>      /*PX终端控制定义*/
#include <termios.h>    
#include <errno.h>
#include <string.h> 

enum parameter_type {
    PT_PROGRAM_NAME = 0,
    PT_DEV_NAME,
    PT_CYCLE,
    PT_NUM
};

#define DBG(string, args...) \
    do { \
            printf("%s, %s()%u---",__FILE__,__FUNCTION__,__LINE__); \
            printf(string, ##args); \
            printf("\n"); \
    } while (0)


void usage(void) {
    printf("You should input as: \n");
    printf("\t select_test [/dev/name] [Cyclee Cnt]\n");
}

int OpenDev(char *name) {
    int fd = open(name, O_RDWR ); 
    if (-1 == fd)
        DBG("Can not OPen(%s)!", name);
    return fd;
}

/*
 * @brief  设置串口通信速率
 * @param fd 类型 int打开串口的文件句柄长 
 * @param speed 类型 int 串口速度
 * @return void
*/

void set_speed(int fd, int speed) {

    int	i;
    int	status;
    struct termios Opt = {0};
    int speed_arr[] = {B230400, B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B300, B38400, B19200, B9600, B4800, B2400, B1200, B300, };
    int name_arr[] = {230400,115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 300, 38400, 19200, 9600, 4800, 2400, 1200, 300, };

    tcgetattr(fd, &Opt);

    for ( i= 0; i < sizeof(speed_arr) / sizeof(int); i++) {
        if (speed == name_arr[i])
            break;
    }

    tcflush(fd, TCIOFLUSH);
    cfsetispeed(&Opt, speed_arr[i]);
    cfsetospeed(&Opt, speed_arr[i]);

    Opt.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); /*Input*/
    Opt.c_oflag &= ~OPOST;	/*Output*/

    status = tcsetattr(fd, TCSANOW, &Opt);
    if (status != 0) {
        DBG("tcsetattr fd");
        return;
	}
	tcflush(fd, TCIOFLUSH);
 }

/**
*@brief	设置串口数据位，停止位和效验位
*@param fd	类型    int 打开的串口文件句柄
*@param  databits 类 型  int 数 据位	取值  为  7 或者8
*@param  stopbits 类 型  int 停 止位	取值为  1 或者2
*@param parity 类型 int 效验类型 取值为N,E,O,,S
 */

int set_Parity(int fd,int databits,int stopbits,int parity) {
	struct termios options;

    if ( tcgetattr( fd,&options) != 0) {
        perror("SetupSerial 1");
        return -1;
    }
    options.c_cflag &= ~CSIZE;
    switch (databits) /*设置数据位数*/
    {
        case 7:
        options.c_cflag |= CS7;
        break;
        case 8:
        options.c_cflag |= CS8;
        break;
        default:
        fprintf(stderr,"Unsupported data size\n");
        return -1;
    }
    switch (parity)	
    {	
        case 'n':	
        case 'N':	
            options.c_cflag &= ~PARENB;	/* Clear parity enable */
            options.c_iflag &= ~INPCK;	/* Enable parity checking */
            break;	
        case 'o':
        case 'O':
            options.c_cflag |= (PARODD | PARENB); /* 设置为奇效验*/
            options.c_iflag |= INPCK;	/* Disnable parity checking */
            break;
        case 'e':
        case 'E':
            options.c_cflag |= PARENB;	/* Enable parity */
            options.c_cflag &= ~PARODD;	/*	*/
            options.c_iflag |= INPCK;	/* Disnable parity checking */
            break;
        case 'S':
        case 's': /*as no parity*/
            options.c_cflag &= ~PARENB;
            options.c_cflag &= ~CSTOPB;break;
        default:
            fprintf(stderr,"Unsupported parity\n");
            return -1;
    }
    /* 设置停止位*/
    switch (stopbits)
    {
        case 1:
            options.c_cflag &= ~CSTOPB;
            break;
        case 2:
            options.c_cflag |= CSTOPB;
            break;
        default:
            fprintf(stderr,"Unsupported stop bits\n");
            return -1;
    }
    /* Set input parity option */
    if (parity != 'n')
        options.c_iflag |= INPCK;
    tcflush(fd,TCIFLUSH);
    options.c_cc[VTIME] = 150; /*	15 seconds*/
    options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
    if (tcsetattr(fd,TCSANOW,&options) != 0) {
        perror("SetupSerial 3");
        return -1;
    }
    return 0;
}

void str_print(char *buf, int len) {
    int i;
    for (i=0; i<len; i++) {
	    if (i%10 == 0)
	    printf("\n");
	    printf("0x%02x ", buf[i]);
	}
	printf("\n");
}	
	
int	main(int argc, char **argv)
{	
	int i = 0;
	int fd = 0;
	int cnt = 0;
	char buf[256];
	char buf_s[4];

	int ret;
	fd_set rd_fdset;
	struct timeval dly_tm;	// delay time in select()
	
	if (argc != PT_NUM) {
        usage();
        return -1;
	}
	
	sscanf(argv[PT_CYCLE], "%d", &cnt);
	if (cnt == 0)
	    cnt = 0xFFFF;
	
	fd = OpenDev(argv[PT_DEV_NAME]);
	if (fd < 0)
	    return -1;
	
	set_speed(fd,19200);
	if (set_Parity(fd,8,1,'N') == -1) {
        printf("Set Parity Error\n");
        exit (0);
	}
	
	printf("Select(%s), Cnt %d. \n", argv[PT_DEV_NAME], cnt);
	while (i<cnt) {
        FD_ZERO(&rd_fdset);
        FD_SET(fd, &rd_fdset);
        
        dly_tm.tv_sec = 5;
        dly_tm.tv_usec = 0;
        memset(buf, 0, 256);
        ret = select(fd+1, &rd_fdset, NULL, NULL, &dly_tm);
        DBG("select() return %d, fd = %d", ret, fd);
        if (ret == 0)
            continue;

        if (ret < 0) {
            printf("select(%s) return %d. [%d]: %s \n", argv[PT_DEV_NAME], ret, errno,
            strerror(errno));
            continue;
        }

        i++;
        ret = read(fd, buf, 256);
        printf("Cnt%d: read(%s) return %d.\n", i, argv[PT_DEV_NAME], ret); 
        str_print(buf, ret);
        buf_s[0] = 0x55;
        buf_s[1] = 0xAA;
        buf_s[2] = 0x55;
        buf_s[3] = 0xAA;
        write(fd, buf_s, 256);
        DBG("send over %d\n");
    }
    close(fd);
    return 0;
}

2）编写makefile


#CROSS_COMPILE = arm-linux-
#CROSS_COMPILE = arm-linux-gnueabihf-

CROSS_COMPILE=/home/xxx/v851s/Yuzukilizard/toolchain/gcc-linaro-5.3.1-2016.05-x86_64_arm-linux-gnueabi/bin/arm-linux-gnueabi-

# CPU = cortex-a7
# FPU = fpv4-sp-d16

AS                = $(CROSS_COMPILE)as
LD                = $(CROSS_COMPILE)ld
CC                = $(CROSS_COMPILE)gcc
CXX               = $(CROSS_COMPILE)g++
CPP               = $(CC) -E
AR                = $(CROSS_COMPILE)ar
NM                = $(CROSS_COMPILE)nm
STRIP             = $(CROSS_COMPILE)strip
OBJCOPY           = $(CROSS_COMPILE)objcopy
OBJDUMP           = $(CROSS_COMPILE)objdump
RANLIB            = $(CROSS_COMPILE)ranlib
SIZE              = $(CROSS_COMPILE)size

TOP_DIR           = $(shell pwd)

CFLAGS_inc_path   += -I$(TOP_DIR)

EXE	= UARTTest

# CFLAGS_inc_path   += -I$(TOP_DIR)external/jpeg-9a

# for H.264 hardware codec
#CFLAGS_inc_path   += -I$(TOP_DIR)/../../prebuilt/include/cedar

# CFLAGS += -std=gnu99 -mthumb -mabi=aapcs-linux -mlittle-endian
# CFLAGS += -fdata-sections -ffunction-sections
# CFLAGS += -mcpu=$(CPU) -mtune=$(CPU) -mfpu=$(FPU) -mfloat-abi=hard

SRC_HAL += ./ 

LIB_SRC := $(foreach spath, $(SRC_HAL), $(wildcard $(spath)*.c))
OBJECT += $(patsubst %.c,%.o,$(LIB_SRC))

LOCAL_INCLUDE += -I./

#CFLAGS            += -O2 -ggdb3 -DNDEBUG
CFLAGS            += $(LOCAL_INCLUDE) -static

# LDFLAGS = -L../../library/arm-linux-gnueabihf
# LIBS += -lawh264 -lvdecoder -lcdc_base -lMemAdapter -lVE -lvencoder -lvideoengine

all:$(EXE)
$(EXE):$(OBJECT)
	@$(CC)  $(OBJECT) -o $(EXE) $(CFLAGS)
#	@echo -- gcc  $(SRCS) --
	@echo "Compile target done."
	@echo "use src files"

$(OBJECT):
.PHONY:clean
clean:
	@rm -rf *.o $(OBJECT) $(EXE)
	@echo "Clean done."

需注意，将makefile 中的编译工具路径修改为自己的工具路径。

3） make 后，产生可执行文件，adb push 到开发板中进行执行，执行命令：

./UARTTest /dev/ttyS3 4

4）用杜邦线将PE12 PE13 GND 三根线接到电脑串口（需要串口转换小板子），波特率目前设定19200 ，使用串口工具，向板子随便发送数据，板子接受到数据，就会发送数据到电脑。

yelong98 LV 7

@chhjnavy 感谢谢谢帖子，对于入门非常有用，万丈高楼平地起

aaabbb222 LV 4

请问，nanopi neo的板子，如何修改串口设置？我在公司提供的内核代码中没有找到board.dts文件，只有sun8i-h3-nanopi-neo.dtsi文件，但该文件内容非常少。

danny LV 3

感谢楼主知识分享