全志v851s uart3 设置成普通串口收发

本文转载自：https://bbs.aw-ol.com/topic/3281/

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-d16AS                = $(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)sizeTOP_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=hardSRC_HAL += ./ LIB_SRC := $(foreach spath, $(SRC_HAL), $(wildcard $(spath)*.c))
OBJECT += $(patsubst %.c,%.o,$(LIB_SRC))LOCAL_INCLUDE += -I./#CFLAGS            += -O2 -ggdb3 -DNDEBUG
CFLAGS            += $(LOCAL_INCLUDE) -static# LDFLAGS = -L../../library/arm-linux-gnueabihf
# LIBS += -lawh264 -lvdecoder -lcdc_base -lMemAdapter -lVE -lvencoder -lvideoengineall:$(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。