openwrt通过字符驱动的方式控制LED灯光（四-- 二）

墨蓝 2022-12-22 09:39 181阅读 0赞

### openwrt通过字符驱动的方式控制LED灯光 ###

*  1、概述
 *  2、在源码目录的 ./package/kernel下创建gpio\_control\_driver文件夹
 *  3、在gpio\_control\_driver文件夹下创建Makefile和src文件夹
 *  4、编写Makefile
 *  5、进入src目录下创建gpio\_control\_driver.c 、 Makefile
 *  6、编写gpio\_control\_driver.c 、Makefile
 *  7、配置menuconfig
 *  8、编译
 *  9、把生成的ipk包发送到板子上去
 *  10、安装ipk包
 *  11、加载驱动
 *  12、驱动测试
 *   *  12.1、同样的方式把测试文件也打包成ipk包发送到板子上运行

# 1、概述 #

通过在openwrt源码目录下（或者SDK包的openwrt的目录下）编写gpio的字符驱动生成ipk包，发送到开发板上insmod加载驱动，然后通过编写APP来进行测试。

# 2、在源码目录的 ./package/kernel下创建gpio\_control\_driver文件夹 #

mkdir gpio_control_driver

![在这里插入图片描述][20201119143949801.png_pic_center]

# 3、在gpio\_control\_driver文件夹下创建Makefile和src文件夹 #

mkdir src
    touch Makefile

# 4、编写Makefile #

include $(TOPDIR)/rules.mk
    include $(INCLUDE_DIR)/kernel.mk
     
    PKG_NAME:=gpio_control_driver
    PKG_RELEASE:=1
    
    include $(INCLUDE_DIR)/package.mk
     
    define KernelPackage/$(PKG_NAME)
      SUBMENU:=Other modules
      DEPENDS:=@GPIO_SUPPORT
      TITLE:=Driver for FA156 gpios control
      FILES:=$(PKG_BUILD_DIR)/gpio_control_driver.ko
      AUTOLOAD:=$(call AutoLoad,30,gpio_control_driver)
    endef
     
    define KernelPackage/$(PKG_NAME)/description
     Kernel module to control gpios for  FA156
    endef
     
     
    define Build/Prepare
    	mkdir -p $(PKG_BUILD_DIR)
    	cp -rf  ./src/* $(PKG_BUILD_DIR)/
    endef
     
    define Build/Compile
    	$(MAKE) -C "$(LINUX_DIR)" \
    		CROSS_COMPILE="$(TARGET_CROSS)" \
    		ARCH="$(LINUX_KARCH)" \
    		SUBDIRS="$(PKG_BUILD_DIR)" \
    		EXTRA_CFLAGS="$(BUILDFLAGS)" \
    		$(EXTRA_KCONFIG) \
    		modules
    endef
    
    $(eval $(call KernelPackage,$(PKG_NAME)))

makefile注释在[https://editor.csdn.net/md/?articleId=109803571][https_editor.csdn.net_md_articleId_109803571]这篇文章里，我详细注释了。

# 5、进入src目录下创建gpio\_control\_driver.c 、 Makefile #

touch gpio_control_driver.c 
    touch Makefile

![在这里插入图片描述][20201119144438139.png_pic_center]

# 6、编写gpio\_control\_driver.c 、Makefile #

**Makefile：**

obj-m := gpio_control_driver.o

**gpio\_control\_driver.c:**

#include <linux/types.h>
    #include <linux/kernel.h>
    #include <linux/delay.h>
    #include <linux/ide.h>
    #include <linux/init.h>
    #include <linux/module.h>
    #include <linux/errno.h>
    #include <linux/gpio.h>
    #include <linux/cdev.h>
    #include <linux/device.h>
    #include <asm/uaccess.h>
    #include <asm/io.h>
    
    #define NEWCHRLED_CNT 1 
    #define NEWCHRLED_NAME "gpio_control" 
    #define GPIO_CONTROL_SET_OUT 0x01
    #define GPIO_CONTROL_SET_IN 0x02
    //#define GPIO_CONTROL_GET_DIRECTION 0x03
    #define GPIO_CONTROL_SET_VALUE 0x04
    #define GPIO_CONTROL_GET_VALUE 0x05
    #define GPIO_CONTROL_REQUEST_GPIO 0x06
    #define GPIO_CONTROL_FREE_GPIO 0x07
    #define GET_GPIO_NUM(arg1) (unsigned char)((arg1 >> 24) & 0xff)
    #define GET_GPIO_VALUE(arg1) (unsigned char)((arg1 >> 16) & 0xff)
    
    
    
    struct  gpio_control_dev{ 
    	dev_t devid;			
    	struct cdev cdev;		
    	struct class *class;		
    	struct device *device;	
    	int major;				
    	int minor;				
    };
    struct  gpio_control_dev  gpio_control;
    
    static int gpio_control_open(struct inode *pinode, struct file *pfile)
    { 
            printk("***%s***\n",__func__);
    
            return 0;
    }
    
    static int gpio_control_release(struct inode *pinode, struct file *pfile)
    { 
            printk("***%s***\n",__func__);
    
            return 0;
    }
    static long gpio_control_ioctl(struct file *pfile, unsigned int cmd, unsigned long arg)
    { 
    	int ret;
    	unsigned char gpio_number;
    	unsigned char gpio_value;
     
     
    	gpio_number = GET_GPIO_NUM(arg);
    	gpio_value  = GET_GPIO_VALUE(arg);
     
    	switch (cmd){ 
    	case GPIO_CONTROL_SET_OUT:
    		ret = gpio_direction_output(gpio_number, gpio_value);
    		if (ret < 0){ 
    			return -1;
    		}
    		break;
     
    	case GPIO_CONTROL_SET_IN:
    		ret = gpio_direction_input(gpio_number);
    		if (ret < 0){ 
    			return -1;
    		}
    		break;
    	case GPIO_CONTROL_SET_VALUE:
    		gpio_set_value(gpio_number, gpio_value);
    		break;
     
    	case GPIO_CONTROL_GET_VALUE:
    		ret = gpio_get_value(gpio_number);
    		if (ret < 0){ 
    			return -1;
    		}
    		break;
     
    	case GPIO_CONTROL_REQUEST_GPIO:
    		if (0 > gpio_request(gpio_number, "gpio_ctrl")){ 
    			return -1;
    		}
    		break;
     
    	case GPIO_CONTROL_FREE_GPIO:
    		gpio_free(gpio_number);
    		break;
     
    	default:
    		printk("***Unknown command:0x%02X\n***\n", cmd);
    		break;
     
    	}
     
    	return 0;
    }
    
    static const struct file_operations gpio_control_ops = { 
                    .owner                  = THIS_MODULE,
                    .open                   = gpio_control_open,
                    .release                = gpio_control_release,
                    .unlocked_ioctl         = gpio_control_ioctl,
    };
    
    static int __init led_init(void)
    { 
        unsigned int ret = 0;
    
        /*1. register chrdev*/
        if (gpio_control.major) { 		
    		gpio_control.devid = MKDEV(gpio_control.major, 0);
    		ret =register_chrdev_region(gpio_control.devid, NEWCHRLED_CNT, NEWCHRLED_NAME);
    	} else { 						
    		ret = alloc_chrdev_region(&gpio_control.devid, 0, NEWCHRLED_CNT, NEWCHRLED_NAME);	
    	}
        if(ret < 0 )
        { 
            goto faial_alloc_chrdeev;
        }
    
        /* 2. init chrdev*/
        gpio_control.cdev.owner = THIS_MODULE;
    	cdev_init(&gpio_control.cdev, &gpio_control_ops);
        
        /* 3. add chrdev */
        ret = cdev_add(&gpio_control.cdev, gpio_control.devid, NEWCHRLED_CNT);
        if (ret < 0)
        { 
            goto faial_add_chrdeev;
        }
        /* 4. create class */
        gpio_control.class = class_create(THIS_MODULE, NEWCHRLED_NAME);
    	if (IS_ERR(gpio_control.class)) { 
            goto  faial_create_class;
    	}
        
        /* 5. create device */
        gpio_control.device = device_create(gpio_control.class, NULL, gpio_control.devid, NULL, NEWCHRLED_NAME);
    	if (IS_ERR(gpio_control.device)) { 
    		goto faial_create_device;
    	}
    
        return 0;
    
    faial_create_device:
        device_destroy(gpio_control.class, gpio_control.devid);
    faial_create_class:
        class_destroy(gpio_control.class);
    faial_add_chrdeev:
        cdev_del(&gpio_control.cdev);
    faial_alloc_chrdeev:
        unregister_chrdev_region(gpio_control.devid, NEWCHRLED_CNT);
    
    }
    
    static void __exit led_exit(void)
    { 
        cdev_del(&gpio_control.cdev);
        unregister_chrdev_region(gpio_control.devid, NEWCHRLED_CNT);
        
        device_destroy(gpio_control.class, gpio_control.devid);
        class_destroy(gpio_control.class);
    }
    
    module_init(led_init);
    module_exit(led_exit);
    
    MODULE_LICENSE("GPL");
    MODULE_AUTHOR("qingmu");

# 7、配置menuconfig #

make  menuconfig

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTMwOTkxNg_size_16_color_FFFFFF_t_70_pic_center]  
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# 8、编译 #

回到openwrt的根目录下

make ./package/kernel/gpio_control_driver/compile V=s

# 9、把生成的ipk包发送到板子上去 #

找到生成的ipk包  
![在这里插入图片描述][20201119165656654.png_pic_center]  
发送到板子上去

scp ./bin/ipq/packages/base/kmod-gpio_control_driver_4.4.60-1_ipq.ipk root@192.168.1.1:/root

# 10、安装ipk包 #

opkg install kmod-gpio_control_driver_4.4.60-1_ipq.ipk

# 11、加载驱动 #

在/lib/modules/4.19.57/下可以找到gpio\_control\_driver.ko,执行

insmod gpio_control_driver.ko

这样驱动就加载完成了，如果想卸载，可以执行

rmmod gpio_control_driver.ko

# 12、驱动测试 #

## 12.1、同样的方式把测试文件也打包成ipk包发送到板子上运行 ##

*  1、在openwrt的源码目录下（SDK包的openwrt的目录下）的./package目录下创建gpio\_test目录，

mkdir gpio_test

![在这里插入图片描述][20201119170544995.png_pic_center]

*  2、在gpio\_test的目录下创建Makefile和src目录

touch Makefile
    mkdir src

![在这里插入图片描述][20201119170714131.png_pic_center]

*  3、编写Makefile  
    makefile:

obj-m := gpio_control_driver.o

*  4、在src的目录下创建gpiotest.c、gpio\_test.h、Makefile

touch gpiotest.c
    touch gpiotest.h
    touch Makefile

![在这里插入图片描述][20201119170958699.png_pic_center]  
gpio\_test.c :

#include <stdio.h>
    #include <fcntl.h>
    #include <unistd.h>
    #include <sys/ioctl.h>
    #include <signal.h>
    #include <stdlib.h>
    #include <sys/time.h>
    #include <sys/types.h>
    #include "gpio_test.h"
     
    static unsigned char gpio_pin;//define GPIOs to be use
    static int gpio_dev_fd;
     
    void demo1_release(int signal_no)
    { 
    	ioctl(gpio_dev_fd, GPIO_CONTROL_SET_IN, GPIO_IOCTL_PRAM(gpio_pin, 0));
    	ioctl(gpio_dev_fd, GPIO_CONTROL_FREE_GPIO, GPIO_IOCTL_PRAM(gpio_pin, 0));
    	exit(0);
    }
     
     
    //指定管脚拉高, 拉低
    int set_gpio(unsigned char pin, int state)
    {    
     
        if(state == 1)
        { 
            ioctl(gpio_dev_fd, GPIO_CONTROL_SET_VALUE, GPIO_IOCTL_PRAM(pin, 1));
        }
        else if(state == 0)
        { 
            ioctl(gpio_dev_fd, GPIO_CONTROL_SET_VALUE, GPIO_IOCTL_PRAM(pin, 0));
        }
        else
        { 
            printf("No such set\n");
            goto ERROR;
        }
     
        return 0;
     
        ERROR:
            return -1; 
    }
     
    int gpio_init(int pin)
    { 
        int ret;
     
        gpio_pin = pin;
     
        gpio_dev_fd = open(GPIO_CONTROL_DEVICE_PATH, O_RDWR);//open gpio device
        if (gpio_dev_fd < 0){ 
            printf("###open %s ERROR###\n", GPIO_CONTROL_DEVICE_PATH);
            goto ERROR;
        }else{ 
            printf("***open %s success***\n", GPIO_CONTROL_DEVICE_PATH);
        }
        
        ret = ioctl(gpio_dev_fd, GPIO_CONTROL_REQUEST_GPIO, GPIO_IOCTL_PRAM(pin, 0));
    	if (ret < 0){ 
    		printf("###request GPIO %d error###", pin);
    		goto ERROR;
    	}
    	ret = ioctl(gpio_dev_fd, GPIO_CONTROL_SET_OUT, GPIO_IOCTL_PRAM(pin, 0));
    	if (ret < 0){ 
    		printf("###set GPIO %d output error###", pin);
    		goto ERROR;
    	}
     
    	signal(SIGINT, demo1_release);//register terminal signal
     
        return 0;
     
        ERROR:
            return -1; 
    }
     
     
    int main()
    { 
        gpio_init(30);
        gpio_init(29);
       
        while(1)
        { 
            set_gpio(30, 0);
            usleep(200000);
            set_gpio(30, 1);
            usleep(200000);
            set_gpio(29, 0);
            usleep(200000);
            set_gpio(29, 1);
            usleep(200000);
        }
    	return 0;
    }

注意：我这里的LED的灯的gpio口是GPIO30和GPIO29，大家个根据自己的GPIO口进行更改

gpio\_test.h :

#ifndef GPIO_CONTROL_TEST_H_
    #define GPIO_CONTROL_TEST_H_
     
    #define GPIO_CONTROL_DEVICE_PATH "/dev/gpio_control"
     
    #define GPIO_IOCTL_PRAM(gpio_num, arg1) (((unsigned long)gpio_num << 24) + ((unsigned long)arg1 << 16))
    #define GET_GPIO_NUM(arg1) (unsigned char)((arg1 >> 24) & 0xff)
    #define GET_GPIO_VALUE(arg1) (unsigned char)((arg1 >> 16) & 0xff)
     
    //IOCTRL CMDs
    #define GPIO_CONTROL_SET_OUT 0x01
    #define GPIO_CONTROL_SET_IN 0x02
    //#define GPIO_CONTROL_GET_DIRECTION 0x03
    #define GPIO_CONTROL_SET_VALUE 0x04
    #define GPIO_CONTROL_GET_VALUE 0x05
    #define GPIO_CONTROL_REQUEST_GPIO 0x06
    #define GPIO_CONTROL_FREE_GPIO 0x07
     
    int set_gpio(unsigned char pin, int state);
    int gpio_init(int pin);
    void delay_ms(int ms);
     
     
     
    #endif

*  5、回到openwrt根目录下编译

make ./package/gpio_test/compile V=s

*  6、找到对应的ipk包并发送到板子上

find ./ -name gpio_te*.ipk

![在这里插入图片描述][20201119171547969.png_pic_center]  
发送到对应的开发板，这里大家根据自己的实际情况来：

scp ./bin/ipq/packages/base/gpio_test_1-1.0_ipq.ipk root@192.168.1.1:/root

*  6、安装goio\_test的ipk包

opkg install gpio_test_1-1.0_ipq.ipk

*  7、运行gpio\_test应用程序

gpio_test

此时LED灯开始闪烁，大功告成

[20201119143949801.png_pic_center]: /images/20221120/0b4c9bd4838f4030942fb57b89c19b9e.png
[https_editor.csdn.net_md_articleId_109803571]: https://editor.csdn.net/md/?articleId=109803571
[20201119144438139.png_pic_center]: https://img-blog.csdnimg.cn/20201119144438139.png#pic_center
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTMwOTkxNg_size_16_color_FFFFFF_t_70_pic_center]: https://img-blog.csdnimg.cn/20201119165256738.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTMwOTkxNg==,size_16,color_FFFFFF,t_70#pic_center
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[20201119165656654.png_pic_center]: https://img-blog.csdnimg.cn/20201119165656654.png#pic_center
[20201119170544995.png_pic_center]: https://img-blog.csdnimg.cn/20201119170544995.png#pic_center
[20201119170714131.png_pic_center]: https://img-blog.csdnimg.cn/20201119170714131.png#pic_center
[20201119170958699.png_pic_center]: https://img-blog.csdnimg.cn/20201119170958699.png#pic_center
[20201119171547969.png_pic_center]: https://img-blog.csdnimg.cn/20201119171547969.png#pic_center