蚂蚁S9矿板PS并发和竞争驱动 ---信号量 参考蚂蚁S9矿板引脚定义.csdn蚂蚁S9矿板PS并发和竞争驱动 —目录.csdn蚂蚁S9矿板PS并发和竞争驱动 —原子操作.csdn蚂蚁S9矿板PS并发和竞争驱动 —自旋锁.csdn蚂蚁S9矿板PS并发和竞争驱动 —信号量.csdn蚂蚁S9矿板PS并发和竞争驱动 —互斥体.csdn驱动 semaphore.kosemaphore.c#includelinux/types.h#includelinux/kernel.h#includelinux/delay.h#includelinux/ide.h#includelinux/init.h#includelinux/module.h#includelinux/errno.h#includelinux/gpio.h#includeasm/mach/map.h#includeasm/uaccess.h#includeasm/io.h#includelinux/cdev.h#includelinux/of.h#includelinux/of_address.h#includelinux/of_gpio.h#includelinux/semaphore.h#defineGPIOLED_CNT1/* 设备号个数 */#defineGPIOLED_NAMEgpioled/* 名字 *//* dtsled设备结构体 */structgpioled_dev{dev_tdevid;/* 设备号 */structcdevcdev;/* cdev */structclass*class;/* 类 */structdevice*device;/* 设备 */intmajor;/* 主设备号 */intminor;/* 次设备号 */structdevice_node*nd;/* 设备节点 */intled_gpio;/* LED所使用的GPIO编号 */structsemaphoresem;/* 信号量 */};staticstructgpioled_devgpioled;/* led设备 *//* * description : 打开设备 * param – inode : 传递给驱动的inode * param - filp : 设备文件file结构体有个叫做private_data的成员变量 * 一般在open的时候将private_data指向设备结构体。 * return : 0 成功;其他 失败 */staticintled_open(structinode*inode,structfile*filp){/* 获取信号量,如果获取不到则会进入休眠状态 */if(down_interruptible(gpioled.sem))return-ERESTARTSYS;#if0down(gpioled.sem);#endifreturn0;}/* * description : 从设备读取数据 * param - filp : 要打开的设备文件(文件描述符) * param - buf : 返回给用户空间的数据缓冲区 * param - cnt : 要读取的数据长度 * param - offt : 相对于文件首地址的偏移 * return : 读取的字节数如果为负值表示读取失败 */staticssize_tled_read(structfile*filp,char__user*buf,size_tcnt,loff_t*offt){return0;}/* * description : 向设备写数据 * param - filp : 设备文件表示打开的文件描述符 * param - buf : 要写给设备写入的数据 * param - cnt : 要写入的数据长度 * param - offt : 相对于文件首地址的偏移 * return : 写入的字节数如果为负值表示写入失败 */staticssize_tled_write(structfile*filp,constchar__user*buf,size_tcnt,loff_t*offt){intret;charkern_buf[1];retcopy_from_user(kern_buf,buf,cnt);// 得到应用层传递过来的数据if(0ret){printk(KERN_ERRkernel write failed!\r\n);return-EFAULT;}if(0kern_buf[0])gpio_set_value(gpioled.led_gpio,0);// 如果传递过来的数据是0则关闭ledelseif(1kern_buf[0])gpio_set_value(gpioled.led_gpio,1);// 如果传递过来的数据是1则点亮ledreturn0;}/* * description : 关闭/释放设备 * param – filp : 要关闭的设备文件(文件描述符) * return : 0 成功;其他 失败 */staticintled_release(structinode*inode,structfile*filp){/* 释放信号量信号量值加1 */up(gpioled.sem);return0;}/* 设备操作函数 */staticstructfile_operationsgpioled_fops{.ownerTHIS_MODULE,.openled_open,.readled_read,.writeled_write,.releaseled_release,};staticint__initled_init(void){constchar*str;intret;/* 1.获取led设备节点 */gpioled.ndof_find_node_by_path(/led);if(NULLgpioled.nd){printk(KERN_ERRgpioled: Failed to get /led node\n);return-EINVAL;}/* 2.读取status属性 */retof_property_read_string(gpioled.nd,status,str);if(!ret){if(strcmp(str,okay))return-EINVAL;}/* 2、获取compatible属性值并进行匹配 */retof_property_read_string(gpioled.nd,compatible,str);if(0ret){printk(KERN_ERRgpioled: Failed to get compatible property\n);returnret;}if(strcmp(str,ming,led)){printk(KERN_ERRgpioled: Compatible match failed\n);return-EINVAL;}printk(KERN_INFOgpioled: device matching successful!\r\n);/* 4.获取设备树中的led-gpio属性得到LED所使用的GPIO编号 */gpioled.led_gpioof_get_named_gpio(gpioled.nd,led-gpio,0);if(!gpio_is_valid(gpioled.led_gpio)){printk(KERN_ERRgpioled: Failed to get led-gpio\n);return-EINVAL;}printk(KERN_INFOgpioled: led-gpio num %d\r\n,gpioled.led_gpio);/* 5.向gpio子系统申请使用GPIO */retgpio_request(gpioled.led_gpio,LED-GPIO);if(ret){printk(KERN_ERRgpioled: Failed to request led-gpio\n);returnret;}/* 6.将led gpio管脚设置为输出模式 */gpio_direction_output(gpioled.led_gpio,0);/* 7.初始化LED的默认状态 */retof_property_read_string(gpioled.nd,default-state,str);if(!ret){if(!strcmp(str,on))gpio_set_value(gpioled.led_gpio,1);elsegpio_set_value(gpioled.led_gpio,0);}elsegpio_set_value(gpioled.led_gpio,0);/* 8.注册字符设备驱动 *//* 创建设备号 */if(gpioled.major){gpioled.devidMKDEV(gpioled.major,0);retregister_chrdev_region(gpioled.devid,GPIOLED_CNT,GPIOLED_NAME);if(ret)gotoout1;}else{retalloc_chrdev_region(gpioled.devid,0,GPIOLED_CNT,GPIOLED_NAME);if(ret)gotoout1;gpioled.majorMAJOR(gpioled.devid);gpioled.minorMINOR(gpioled.devid);}printk(gpioled: major%d,minor%d\r\n,gpioled.major,gpioled.minor);/* 初始化cdev */gpioled.cdev.ownerTHIS_MODULE;cdev_init(gpioled.cdev,gpioled_fops);/* 添加一个cdev */retcdev_add(gpioled.cdev,gpioled.devid,GPIOLED_CNT);if(ret)gotoout2;/* 创建类 */gpioled.classclass_create(THIS_MODULE,GPIOLED_NAME);if(IS_ERR(gpioled.class)){retPTR_ERR(gpioled.class);gotoout3;}/* 创建设备 */gpioled.devicedevice_create(gpioled.class,NULL,gpioled.devid,NULL,GPIOLED_NAME);if(IS_ERR(gpioled.device)){retPTR_ERR(gpioled.device);gotoout4;}/* 初始化信号量 */sema_init(gpioled.sem,1);return0;out4:class_destroy(gpioled.class);out3:cdev_del(gpioled.cdev);out2:unregister_chrdev_region(gpioled.devid,GPIOLED_CNT);out1:gpio_free(gpioled.led_gpio);returnret;}staticvoid__exitled_exit(void){/* 注销设备 */device_destroy(gpioled.class,gpioled.devid);/* 注销类 */class_destroy(gpioled.class);/* 删除cdev */cdev_del(gpioled.cdev);/* 注销设备号 */unregister_chrdev_region(gpioled.devid,GPIOLED_CNT);/* 释放GPIO */gpio_free(gpioled.led_gpio);}/* 驱动模块入口和出口函数注册 */module_init(led_init);module_exit(led_exit);MODULE_AUTHOR(DengTao 773904075qq.com);MODULE_DESCRIPTION(ming ZYNQ GPIO LED Driver);MODULE_LICENSE(GPL);spinlockApp.c#includestdio.h#includeunistd.h#includesys/types.h#includesys/stat.h#includefcntl.h#includestdlib.h#includestring.h/* * description : main主程序 * param - argc : argv数组元素个数 * param - argv : 具体参数 * return : 0 成功;其他 失败 */intmain(intargc,char*argv[]){intfd,ret;intcnt0;unsignedcharbuf[1];if(3!argc){printf(Usage:\n\t./semaphoreApp /dev/gpioled 1 close led\n\t./semaphoreApp /dev/gpioled 0 open led\n);return-1;}/* 打开设备 */fdopen(argv[1],O_RDWR);if(0fd){printf(ERROR: file %s open failed!\r\n,argv[1]);return-1;}/* 将字符串转换为int型数据 */buf[0]atoi(argv[2]);/* 向驱动写入数据 */retwrite(fd,buf,sizeof(buf));if(0ret){printf(ERROR: LED Control Failed!\r\n);close(fd);return-1;}/* 模拟占用25秒LED设备 */for(;;){sleep(5);cnt;printf(App running times:%d\r\n,cnt);if(cnt5)break;}printf(App running finished!\n);/* 关闭设备 */close(fd);return0;}编译驱动和app$CC-o semaphoreApp semaphoreApp.c测试rootant:~# insmod semaphore.kogpioled: device matching successful!gpioled: led-gpio num943gpioled:major244,minor0rootant:~# chmod 777 semaphoreApprootant:~# ./semaphoreApp /dev/gpioled 0^C rootant:~# ./semaphoreApp /dev/gpioled 1^C rootant:~# ./semaphoreApp /dev/gpioled 1 [1]520# ./semaphoreApp /dev/gpioled 1 执行1会自动关闭rootant:~# ./semaphoreApp /dev/gpioled 0App running times:1 App running times:2 App running times:3 App running times:4 App running times:5 App running finished!