网站建设中首页模板下载,备案网站系统,网站图片如何做缓存,网站开发合同范本下载编写LED灯的驱动#xff0c;使用GPIO子系统#xff0c;里面添加按键的中断处理
1.应用程序发送指令控制LED亮灭
2.按键1 按下#xff0c;led1电位反转 按键2按下#xff0c;led2电位反转 按键3 按下#xff0c;led3电位反转 驱动程序
#include linux/init.h
#i…编写LED灯的驱动使用GPIO子系统里面添加按键的中断处理
1.应用程序发送指令控制LED亮灭
2.按键1 按下led1电位反转 按键2按下led2电位反转 按键3 按下led3电位反转 驱动程序
#include linux/init.h
#include linux/module.h
#include linux/of.h
#include linux/of_irq.h
#include linux/interrupt.h
#include linux/of_gpio.h
#include linux/gpio.h
#include linux/fs.h
#include linux/io.h
#include linux/device.h
#include head.h
struct device_node *dev_key;
unsigned int irqno_key1;
unsigned int irqno_key2;
unsigned int irqno_key3;struct device_node *dev_led;
struct gpio_desc *gpiono_led1;
struct gpio_desc *gpiono_led2;
struct gpio_desc *gpiono_led3;int major;
struct class *cls;
struct device *dev;
// 中断处理函数
irqreturn_t myirq_handler_key1(int irq, void *dev)
{gpiod_set_value(gpiono_led1,!gpiod_get_value(gpiono_led1));return IRQ_HANDLED;
}
irqreturn_t myirq_handler_key2(int irq, void *dev)
{gpiod_set_value(gpiono_led2,!gpiod_get_value(gpiono_led2));return IRQ_HANDLED;
}
irqreturn_t myirq_handler_key3(int irq, void *dev)
{gpiod_set_value(gpiono_led3,!gpiod_get_value(gpiono_led3));return IRQ_HANDLED;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{switch (cmd){case LED_ON:switch (arg){case 1: // LED1gpiod_set_value(gpiono_led1,1);; // LED1开灯break;case 2: // LED2gpiod_set_value(gpiono_led2,1); // LED2开灯break;case 3: // LED3gpiod_set_value(gpiono_led3,1); // LED3开灯break;}break;case LED_OFF:switch (arg){case 1:gpiod_set_value(gpiono_led1,0);break;case 2:gpiod_set_value(gpiono_led2,0);break;case 3:gpiod_set_value(gpiono_led3,0);break;}break;}return 0;
}
struct file_operations fops {.unlocked_ioctl mycdev_ioctl,};
static int __init mycdev_init(void)
{int i;// 字符设备驱动注册major register_chrdev(0, mychrdev, fops);if (major 0){printk(字符设备驱动注册失败\n);return major;}printk(字符设备驱动注册成功:major%d\n, major);// 向上提交目录cls class_create(THIS_MODULE, myled);if (IS_ERR(cls)){printk(向上提交目录失败\n);return -PTR_ERR(cls);}printk(向上提交目录信息成功\n);// 向上提交设备节点信息for (i 0; i 3; i){dev device_create(cls, NULL, MKDEV(major, i), NULL, myled%d, i);if (IS_ERR(dev)){printk(向上提交设备节点信息失败\n);return -PTR_ERR(dev);}}printk(向上提交设备节点成功\n);int ret;// 解析按键的设备树节点dev_key of_find_node_by_path(/myirq);if (dev_key NULL){printk(解析设备树节点失败\n);return -EFAULT;}printk(解析设备树节点成功\n);// 根据设备树节点解析出软中断号irqno_key1 irq_of_parse_and_map(dev_key, 0); // 按键1索引号为0if (!irqno_key1){printk(解析软中断号失败\n);return -ENXIO;}printk(key1解析软中断号成功 irqno%d\n, irqno_key1);irqno_key2 irq_of_parse_and_map(dev_key, 1); // 按键1索引号为0if (!irqno_key2){printk(解析软中断号失败\n);return -ENXIO;}printk(key2解析软中断号成功 irqno%d\n, irqno_key2);irqno_key3 irq_of_parse_and_map(dev_key, 2); // 按键1索引号为0if (!irqno_key3){printk(解析软中断号失败\n);return -ENXIO;}printk(key3解析软中断号成功 irqno%d\n, irqno_key3);// 注册中断ret request_irq(irqno_key1, myirq_handler_key1, IRQF_TRIGGER_FALLING, key1, NULL);if (ret){printk(注册中断失败\n);return ret;}printk(key1注册中断成功\n);ret request_irq(irqno_key2, myirq_handler_key2, IRQF_TRIGGER_FALLING, key2, NULL);if (ret){printk(注册中断失败\n);return ret;}printk(key2注册中断成功\n);ret request_irq(irqno_key3, myirq_handler_key3, IRQF_TRIGGER_FALLING, key3, NULL);if (ret){printk(注册中断失败\n);return ret;}printk(key3注册中断成功\n);// 根据设备树节点的路径解析设备树信息dev_led of_find_node_by_path(/leds);if (dev_led NULL){printk(解析设备树节点失败\n);return -EFAULT;}printk(解析设备树节点成功\n);// 申请gpio_desc对象并设置输出为低电平gpiono_led1 gpiod_get_from_of_node(dev_led, led1-gpios, 0, GPIOD_OUT_LOW, NULL);if (IS_ERR(gpiono_led1)){printk(申请gpio对象失败\n);return -PTR_ERR(gpiono_led1);}printk(申请gpio_led1对象成功\n);gpiono_led2 gpiod_get_from_of_node(dev_led, led2-gpios, 0, GPIOD_OUT_LOW, NULL);if (IS_ERR(gpiono_led2)){printk(申请gpio对象失败\n);return -PTR_ERR(gpiono_led2);}printk(申请gpio_led1对象成功\n);gpiono_led3 gpiod_get_from_of_node(dev_led, led3-gpios, 0, GPIOD_OUT_LOW, NULL);if (IS_ERR(gpiono_led3)){printk(申请gpio对象失败\n);return -PTR_ERR(gpiono_led3);}printk(申请gpio_led1对象成功\n);return 0;
}
static void __exit mycdev_exit(void)
{// 注销中断free_irq(irqno_key1, NULL);free_irq(irqno_key2, NULL);free_irq(irqno_key3, NULL);// 灭灯gpiod_set_value(gpiono_led1, 0);// 释放gpio编号gpiod_put(gpiono_led1);// 灭灯gpiod_set_value(gpiono_led2, 0);// 释放gpio编号gpiod_put(gpiono_led2);// 灭灯gpiod_set_value(gpiono_led3, 0);// 释放gpio编号gpiod_put(gpiono_led3);int i;for (i 0; i 3; i){device_destroy(cls, MKDEV(major, i));}// 销毁目录信息class_destroy(cls);// 注销字符设备驱动unregister_chrdev(major, mychrdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE(GPL);
应用程序
#include stdlib.h
#include stdio.h
#include sys/types.h
#include sys/stat.h
#include fcntl.h
#include unistd.h
#include string.h
#include sys/ioctl.h
#include head.hint main(int argc, char const *argv[])
{int a, b;char buf[128] {0};int fd0 open(/dev/mycdev0, O_RDWR);if (fd0 0){printf(打开设备文件失败\n);exit(-1);}int fd1 open(/dev/mycdev1, O_RDWR);if (fd1 0){printf(打开设备文件失败\n);exit(-1);}int fd2 open(/dev/mycdev2, O_RDWR);if (fd2 0){printf(打开设备文件失败\n);exit(-1);}while (1){// 从终端读取printf(请输入指令\n);printf(0(关灯) 1(开灯)\n);printf(请输入);scanf(%d, a);printf(请输入要控制的灯 1(LED1) 2(LED2) 3(LED3));scanf(%d, b);switch (b){case 1:switch (a){case 1:ioctl(fd0, LED_ON); // 开灯break;case 0:ioctl(fd0, LED_OFF);break;}break;case 2:switch (a){case 1:ioctl(fd1, LED_ON); // 开灯break;case 0:ioctl(fd1, LED_OFF);break;}break;case 3:switch (a){case 1:ioctl(fd2, LED_ON); // 开灯break;case 0:ioctl(fd2, LED_OFF);break;}break;}}close(fd0);close(fd1);close(fd2);return 0;
}
