Orange PI GPIO控制 详细教程
一、sysfs方式
通过sysfs方式控制GPIO,先访问/sys/class/gpio目录,向export文件写入GPIO编号,使得该GPIO的操作接口从内核空间暴露到用户空间,GPIO的操作接口包括direction和value等,direction控制GPIO方向,而value可控制GPIO输出或获得GPIO输入。文件IO方式操作GPIO,使用到了4个函数open、close、read、write。
首先,看看系统中有没有”/sys/class/gpio”这个文件夹。如果没有请在编译内核的时候加入 Device Drivers-> GPIO Support ->/sys/class/gpio/… (sysfs interface)。
/sys/class/gpio 的使用说明:
gpio_operation 通过/sys/文件接口操作IO端口 GPIO到文件系统的映射
◇ 控制GPIO的目录位于/sys/class/gpio
◇ /sys/class/gpio/export文件用于通知系统需要导出控制的GPIO引脚编号
◇ /sys/class/gpio/unexport 用于通知系统取消导出
◇ /sys/class/gpio/gpiochipX目录保存系统中GPIO寄存器的信息,包括每个寄存器控制引脚的起始编号base,寄存器名称,引脚总数 导出一个引脚的操作步骤
◇ 首先计算此引脚编号,引脚编号 = 控制引脚的寄存器基数 + 控制引脚寄存器位数
◇ 向/sys/class/gpio/export写入此编号,比如12号引脚,在shell中可以通过以下命令实现,命令成功后生成/sys/class/gpio/gpio12目录,如果没有出现相应的目录,说明此引脚不可导出
◇ direction文件,定义输入输入方向,可以通过下面命令定义为输出。direction接受的参数:in, out, high, low。high/low同时设置方向为输出,并将value设置为相应的1/0
◇ value文件是端口的数值,为1或0
几个例子:
1. 导出
/sys/class/gpio# echo 44 > export
2. 设置方向
/sys/class/gpio/gpio44# echo out > direction
3. 查看方向
/sys/class/gpio/gpio44# cat direction
4. 设置输出
/sys/class/gpio/gpio44# echo 1 > value
5. 查看输出值
/sys/class/gpio/gpio44# cat value
6. 取消导出
/sys/class/gpio# echo 44 > unexport
二、文件读写例程
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<span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> stdlib.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> stdio.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> string.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> unistd.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> fcntl.h <span style="color: green;">/* define O_WRONLY and O_RDONLY */ </span></span></span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;">/* </span><span style="font-family: 等线; background-color: white;">芯片复位引脚</span><span style="font-family: Consolas; background-color: white;">: P1_16 */ </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> SYSFS_GPIO_EXPORT <span style="color: #a31515;">"/sys/class/gpio/export" </span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> SYSFS_GPIO_RST_PIN_VAL <span style="color: #a31515;">"48" </span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> SYSFS_GPIO_RST_DIR <span style="color: #a31515;">"/sys/class/gpio/gpio48/direction" </span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> SYSFS_GPIO_RST_DIR_VAL <span style="color: #a31515;">"OUT" </span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> SYSFS_GPIO_RST_VAL <span style="color: #a31515;">"/sys/class/gpio/gpio48/value" </span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> SYSFS_GPIO_RST_VAL_H <span style="color: #a31515;">"1" </span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> SYSFS_GPIO_RST_VAL_L <span style="color: #a31515;">"0" </span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">int<span style="color: black;"> main() </span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> fd; </span></span></span><span style="color: black; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;"> <span style="color: green;">/* </span></span><span style="font-family: 等线; background-color: white;">打开端口</span><span style="color: green; font-family: Consolas; background-color: white;">/sys/class/gpio# echo 48 > export */ </span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( SYSFS_GPIO_EXPORT, O_WRONLY ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd == -1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> printf( <span style="color: #a31515;">"ERR: Radio hard reset pin open error.\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(EXIT_FAILURE); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> write( fd, SYSFS_GPIO_RST_PIN_VAL, <span style="color: blue;">sizeof<span style="color: black;">(SYSFS_GPIO_RST_PIN_VAL) ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;"> <span style="color: green;">/* </span></span><span style="font-family: 等线; background-color: white;">设置端口方向</span><span style="color: green; font-family: Consolas; background-color: white;">/sys/class/gpio/gpio48# echo out > direction */ </span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( SYSFS_GPIO_RST_DIR, O_WRONLY ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd == -1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> printf( <span style="color: #a31515;">"ERR: Radio hard reset pin direction open error.\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(EXIT_FAILURE); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> write( fd, SYSFS_GPIO_RST_DIR_VAL, <span style="color: blue;">sizeof<span style="color: black;">(SYSFS_GPIO_RST_DIR_VAL) ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;"> <span style="color: green;">/* </span></span><span style="font-family: 等线; background-color: white;">输出复位信号</span><span style="color: green;"><span style="font-family: Consolas; background-color: white;">: </span><span style="font-family: 等线; background-color: white;">拉高</span><span style="font-family: Consolas; background-color: white;">>100ns */ </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( SYSFS_GPIO_RST_VAL, O_RDWR ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd == -1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> printf( <span style="color: #a31515;">"ERR: Radio hard reset pin value open error.\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(EXIT_FAILURE); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">while<span style="color: black;"> ( 1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> write( fd, SYSFS_GPIO_RST_VAL_H, <span style="color: blue;">sizeof<span style="color: black;">(SYSFS_GPIO_RST_VAL_H) ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> usleep( 1000000 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> write( fd, SYSFS_GPIO_RST_VAL_L, <span style="color: blue;">sizeof<span style="color: black;">(SYSFS_GPIO_RST_VAL_L) ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> usleep( 1000000 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> printf( <span style="color: #a31515;">"INFO: Radio hard reset pin value open error.\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(0); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span> |
三、中断检测
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<span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> stdlib.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> stdio.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> string.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> unistd.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> fcntl.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#include<span style="color: black;"> poll.h </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">#define<span style="color: black;"> MSG( args ... ) printf( args ) </span></span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;">/* </span><span style="font-family: 等线; background-color: white;">函数声明</span><span style="font-family: Consolas; background-color: white;"> */ </span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static <span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_export( <span style="color: blue;">int<span style="color: black;"> pin ); </span></span></span></span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_unexport( <span style="color: blue;">int<span style="color: black;"> pin ); </span></span></span></span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_direction( <span style="color: blue;">int<span style="color: black;"> pin, <span style="color: blue;">int<span style="color: black;"> dir ); </span></span></span></span></span></span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_write( <span style="color: blue;">int<span style="color: black;"> pin, <span style="color: blue;">int<span style="color: black;"> value ); </span></span></span></span></span></span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_read( <span style="color: blue;">int<span style="color: black;"> pin ); </span></span></span></span></span></span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_export( <span style="color: blue;">int<span style="color: black;"> pin ) </span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> buffer[64]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> len; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> fd; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( <span style="color: #a31515;">"/sys/class/gpio/export"<span style="color: black;">, O_WRONLY ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to open export for writing!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> len = snprintf( buffer, <span style="color: blue;">sizeof<span style="color: black;">(buffer), <span style="color: #a31515;">"%d"<span style="color: black;">, pin ); </span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( write( fd, buffer, len ) < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to export gpio!"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(0); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_unexport( <span style="color: blue;">int<span style="color: black;"> pin ) </span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> buffer[64]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> len; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> fd; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( <span style="color: #a31515;">"/sys/class/gpio/unexport"<span style="color: black;">, O_WRONLY ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to open unexport for writing!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> len = snprintf( buffer, <span style="color: blue;">sizeof<span style="color: black;">(buffer), <span style="color: #a31515;">"%d"<span style="color: black;">, pin ); </span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( write( fd, buffer, len ) < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to unexport gpio!"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(0); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span><span style="color: green; font-family: Consolas; font-size: 9pt; background-color: white;">/* dir: 0-->IN, 1-->OUT */ </span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_direction( <span style="color: blue;">int<span style="color: black;"> pin, <span style="color: blue;">int<span style="color: black;"> dir ) </span></span></span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">static<span style="color: black;"> <span style="color: blue;">const<span style="color: black;"> <span style="color: blue;">char<span style="color: black;"> dir_str[] = <span style="color: #a31515;">"in\0out"<span style="color: black;">; </span></span></span></span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> path[64]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> fd; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> snprintf( path, <span style="color: blue;">sizeof<span style="color: black;">(path), <span style="color: #a31515;">"/sys/class/gpio/gpio%d/direction"<span style="color: black;">, pin ); </span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( path, O_WRONLY ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to open gpio direction for writing!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( write( fd, &dir_str[dir == 0 ? 0 : 3], dir == 0 ? 2 : 3 ) < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to set direction!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(0); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span><span style="color: green; font-family: Consolas; font-size: 9pt; background-color: white;">/* value: 0-->LOW, 1-->HIGH */ </span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_write( <span style="color: blue;">int<span style="color: black;"> pin, <span style="color: blue;">int<span style="color: black;"> value ) </span></span></span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">static<span style="color: black;"> <span style="color: blue;">const<span style="color: black;"> <span style="color: blue;">char<span style="color: black;"> values_str[] = <span style="color: #a31515;">"01"<span style="color: black;">; </span></span></span></span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> path[64]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> fd; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> snprintf( path, <span style="color: blue;">sizeof<span style="color: black;">(path), <span style="color: #a31515;">"/sys/class/gpio/gpio%d/value"<span style="color: black;">, pin ); </span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( path, O_WRONLY ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to open gpio value for writing!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( write( fd, &values_str[value == 0 ? 0 : 1], 1 ) < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to write value!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(0); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_read( <span style="color: blue;">int<span style="color: black;"> pin ) </span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> path[64]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> value_str[3]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> fd; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> snprintf( path, <span style="color: blue;">sizeof<span style="color: black;">(path), <span style="color: #a31515;">"/sys/class/gpio/gpio%d/value"<span style="color: black;">, pin ); </span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( path, O_RDONLY ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to open gpio value for reading!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( read( fd, value_str, 3 ) < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to read value!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(atoi( value_str ) ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span><span style="color: green; font-family: Consolas; font-size: 9pt; background-color: white;">/* </span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;"> * none</span><span style="font-family: 等线; background-color: white;">表示引脚为输入,不是中断引脚</span> </span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;"> * rising</span><span style="font-family: 等线; background-color: white;">表示引脚为中断输入,上升沿触发</span> </span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;"> * falling</span><span style="font-family: 等线; background-color: white;">表示引脚为中断输入,下降沿触发</span> </span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;"> * both</span><span style="font-family: 等线; background-color: white;">表示引脚为中断输入,边沿触发</span> </span><span style="color: green; font-family: Consolas; font-size: 9pt; background-color: white;"> * 0-->none, 1-->rising, 2-->falling, 3-->both </span><span style="color: green; font-family: Consolas; font-size: 9pt; background-color: white;">*/ </span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">static<span style="color: black;"> <span style="color: blue;">int<span style="color: black;"> gpio_edge( <span style="color: blue;">int<span style="color: black;"> pin, <span style="color: blue;">int<span style="color: black;"> edge ) </span></span></span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">const<span style="color: black;"> <span style="color: blue;">char<span style="color: black;"> dir_str[] = <span style="color: #a31515;">"none\0rising\0falling\0both"<span style="color: black;">; </span></span></span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> ptr; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> path[64]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> fd; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">switch<span style="color: black;"> ( edge ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">case<span style="color: black;"> 0: </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ptr = 0; </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">break<span style="color: black;">; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">case<span style="color: black;"> 1: </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ptr = 5; </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">break<span style="color: black;">; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">case<span style="color: black;"> 2: </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ptr = 12; </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">break<span style="color: black;">; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">case<span style="color: black;"> 3: </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ptr = 20; </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">break<span style="color: black;">; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">default<span style="color: black;">: </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ptr = 0; </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> snprintf( path, <span style="color: blue;">sizeof<span style="color: black;">(path), <span style="color: #a31515;">"/sys/class/gpio/gpio%d/edge"<span style="color: black;">, pin ); </span></span></span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fd = open( path, O_WRONLY ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fd < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to open gpio edge for writing!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( write( fd, &dir_str[ptr], strlen( &dir_str[ptr] ) ) < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to set edge!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> close( fd ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(0); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span><span style="color: green; font-family: Consolas; font-size: 9pt; background-color: white;">/* GPIO1_17 */ </span><span style="color: blue; font-family: Consolas; font-size: 9pt; background-color: white;">int<span style="color: black;"> main() </span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">{ </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">int<span style="color: black;"> gpio_fd, ret; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">struct<span style="color: black;"> pollfd fds[1]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">char<span style="color: black;"> buff[10]; </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">unsigned<span style="color: black;"> <span style="color: blue;">char<span style="color: black;"> cnt = 0; </span></span></span></span></span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;">/* LED</span><span style="font-family: 等线; background-color: white;">引脚初始化</span><span style="font-family: Consolas; background-color: white;"> */ </span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_export( 115 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_direction( 115, 1 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_write( 115, 0 ); </span><span style="color: green; font-size: 9pt;"><span style="font-family: Consolas; background-color: white;">/*</span><span style="font-family: 等线; background-color: white;">按键引脚初始化</span><span style="font-family: Consolas; background-color: white;"> */ </span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_export( 49 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_direction( 49, 0 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_edge( 49, 1 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_fd = open( <span style="color: #a31515;">"/sys/class/gpio/gpio49/value"<span style="color: black;">, O_RDONLY ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( gpio_fd < 0 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"Failed to open value!\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(-1); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fds[0].fd = gpio_fd; </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> fds[0].events = POLLPRI; </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ret = read( gpio_fd, buff, 10 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( ret == -1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"read\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">while<span style="color: black;"> ( 1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ret = poll( fds, 1, 0 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( ret == -1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"poll\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( fds[0].revents & POLLPRI ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> { </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ret = lseek( gpio_fd, 0, SEEK_SET ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( ret == -1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"lseek\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> ret = read( gpio_fd, buff, 10 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">if<span style="color: black;"> ( ret == -1 ) </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> MSG( <span style="color: #a31515;">"read\n"<span style="color: black;"> ); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> gpio_write( 115, cnt++ % 2 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> usleep( 100000 ); </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> } </span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;"> <span style="color: blue;">return<span style="color: black;">(0); </span></span></span><span style="color: black; font-family: Consolas; font-size: 9pt; background-color: white;">} </span> |
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