致远电子IMX283A之点亮扩展板led

来源：互联网发布：奥运会标志知乎编辑：程序博客网时间：2024/06/18 02:12

编译环境：ubuntu Kylin 14.04 LTS
编译工具：gcc-4.4.4-glibc-2.11.1-multilib-1.0_EasyARM-iMX283.tar.bz2
测试硬件：EasyARM-iMX283A AP-283Demo扩展板

1、通过AP-283Demo数据手册查询到要点亮的四个LED所对应的GPIO并短接扩展板的J8A与J8C管脚
这里写图片描述

2、编写LED的驱动，驱动这里时参照资料包里led驱动编写，目前只了解大概意思，说不出个所以然来，所以直接贴代码：
代码只是例程代码复制了四份修改了下函数名

//#define LED_GPIO  MXS_PIN_TO_GPIO(PINID_LCD_D23)      //for 283 287A/B#define LED1_GPIO   MXS_PIN_TO_GPIO(PINID_SAIF1_SDATA0)     //for 283 287A/B#define LED2_GPIO   MXS_PIN_TO_GPIO(PINID_SAIF0_BITCLK)     //for 283 287A/B#define LED3_GPIO   MXS_PIN_TO_GPIO(PINID_SAIF0_MCLK)       //for 283 287A/B#define LED4_GPIO   MXS_PIN_TO_GPIO(PINID_SSP0_DATA7)       //for 283 287A/Bstatic int gpio_open(struct inode *inode, struct file *filp);static int  gpio_release(struct inode *inode, struct file *filp);ssize_t gpio_write(struct file *filp, const char __user *buf, size_t count,                loff_t *f_pos);static int gpio_ioctl(struct inode *inode,struct file *flip,unsigned int command,unsigned long arg);static int gpio_init(void);static void gpio_exit(void);/*--------------------------------------------------------------------------------------------------------*/// led1 funcstatic int gpio_open(struct inode *inode, struct file *filp){    gpio_request(LED1_GPIO, "imx283_led");    return 0;}static int  gpio_release(struct inode *inode, struct file *filp){    gpio_free(LED1_GPIO);    return 0;}ssize_t gpio_write(struct file *filp, const char __user *buf, size_t count,loff_t *f_pos){    char data[2];    copy_from_user(data, buf, count);    gpio_direction_output(LED1_GPIO, data[0]);    return count;}static int gpio_ioctl(struct inode *inode,struct file *flip,unsigned int command,unsigned long arg){    int data;    switch (command) {    case 0:         gpio_direction_output(LED1_GPIO, 0);        break;    case 1:        gpio_direction_output(LED1_GPIO, 1);        break;    }    return 0;}static struct file_operations gpio_fops1={    .owner      = THIS_MODULE,    .open       = gpio_open,    .write      = gpio_write,    .release    = gpio_release,    .ioctl      = gpio_ioctl,};// led2 funcstatic int gpio_open2(struct inode *inode, struct file *filp){    gpio_request(LED2_GPIO, "imx283_led");    return 0;}static int  gpio_release2(struct inode *inode, struct file *filp){    gpio_free(LED2_GPIO);    return 0;}ssize_t gpio_write2(struct file *filp, const char __user *buf, size_t count,loff_t *f_pos){    char data[2];    copy_from_user(data, buf, count);    gpio_direction_output(LED2_GPIO, data[0]);    return count;}static int gpio_ioctl2(struct inode *inode,struct file *flip,unsigned int command,unsigned long arg){    int data;    switch (command) {    case 0:         gpio_direction_output(LED2_GPIO, 0);        break;    case 1:        gpio_direction_output(LED2_GPIO, 1);        break;    }    return 0;}static struct file_operations gpio_fops2={    .owner      = THIS_MODULE,    .open       = gpio_open2,    .write      = gpio_write2,    .release    = gpio_release2,    .ioctl      = gpio_ioctl2,};// led3 funcstatic int gpio_open3(struct inode *inode, struct file *filp){    gpio_request(LED3_GPIO, "imx283_led");    return 0;}static int  gpio_release3(struct inode *inode, struct file *filp){    gpio_free(LED3_GPIO);    return 0;}ssize_t gpio_write3(struct file *filp, const char __user *buf, size_t count,loff_t *f_pos){    char data[2];    copy_from_user(data, buf, count);    gpio_direction_output(LED3_GPIO, data[0]);    return count;}static int gpio_ioctl3(struct inode *inode,struct file *flip,unsigned int command,unsigned long arg){    int data;    switch (command) {    case 0:         gpio_direction_output(LED3_GPIO, 0);        break;    case 1:        gpio_direction_output(LED3_GPIO, 1);        break;    }    return 0;}static struct file_operations gpio_fops3={    .owner      = THIS_MODULE,    .open       = gpio_open3,    .write      = gpio_write3,    .release    = gpio_release3,    .ioctl      = gpio_ioctl3,};// led4 funcstatic int gpio_open4(struct inode *inode, struct file *filp){    gpio_request(LED4_GPIO, "imx283_led");    return 0;}static int  gpio_release4(struct inode *inode, struct file *filp){    gpio_free(LED4_GPIO);    return 0;}ssize_t gpio_write4(struct file *filp, const char __user *buf, size_t count,loff_t *f_pos){    char data[2];    copy_from_user(data, buf, count);    gpio_direction_output(LED4_GPIO, data[0]);    return count;}static int gpio_ioctl4(struct inode *inode,struct file *flip,unsigned int command,unsigned long arg){    int data;    switch (command) {    case 0:         gpio_direction_output(LED4_GPIO, 0);        break;    case 1:        gpio_direction_output(LED4_GPIO, 1);        break;    }    return 0;}static struct file_operations gpio_fops4={    .owner      = THIS_MODULE,    .open       = gpio_open4,    .write      = gpio_write4,    .release    = gpio_release4,    .ioctl      = gpio_ioctl4,};static struct miscdevice gpio_miscdev1 = {    .minor  = MISC_DYNAMIC_MINOR,    .name   = DEVICE_NAME1,    .fops   = &gpio_fops1,};  static struct miscdevice gpio_miscdev2 = {    .minor  = MISC_DYNAMIC_MINOR,    .name   = DEVICE_NAME2,    .fops   = &gpio_fops2,};static struct miscdevice gpio_miscdev3 = {    .minor  = MISC_DYNAMIC_MINOR,    .name   = DEVICE_NAME3,    .fops   = &gpio_fops3,};static struct miscdevice gpio_miscdev4 = {    .minor  = MISC_DYNAMIC_MINOR,    .name   = DEVICE_NAME4,    .fops   = &gpio_fops4,};static int __init gpio_init(void){    misc_register(&gpio_miscdev1);    misc_register(&gpio_miscdev2);    misc_register(&gpio_miscdev3);    misc_register(&gpio_miscdev4);    return 0;}static void __exit gpio_exit(void){    misc_deregister(&gpio_miscdev1);    misc_deregister(&gpio_miscdev2);    misc_deregister(&gpio_miscdev3);    misc_deregister(&gpio_miscdev4);}module_init(gpio_init);module_exit(gpio_exit);MODULE_LICENSE("Dual BSD/GPL");MODULE_AUTHOR("zhuguojun, ZhiYuan Electronics Co, Ltd.");MODULE_DESCRIPTION("GPIO DRIVER FOR EasyARM-i.MX28xx");

3、编译生成驱动并加载驱动，led驱动依赖gpio驱动，所以先加载gpio_driver.ko驱动，再加载编译生成的led.ko
这里写图片描述

查看生成的设备
这里写图片描述

4、至此可以在程序中对led对应的IO进行open、write 操作

    int fd1,fd2,fd3,fd4;    char buf[1] = {0};    fd1 = open("/dev/imx283_led1", O_RDWR);    fd2 = open("/dev/imx283_led2", O_RDWR);    fd3 = open("/dev/imx283_led3", O_RDWR);    fd4 = open("/dev/imx283_led4", O_RDWR);    printf("fd = %d-%d-%d-%d\n",fd1,fd2,fd3,fd4);    if (!(fd1 && fd2 && fd3 && fd4 )) {        perror("open /dev/imx283_led*");    }    printf("test write....\n");    if(fd1 && fd2 && fd3 && fd4){        buf[0] = 0;        write(fd1, buf, 1);         write(fd2, buf, 1);         write(fd3, buf, 1);         write(fd4, buf, 1);         while(1){            buf[0] = 1;     //true on led1            write(fd1, buf, 1);            sleep(1);               buf[0] = 0;     //true off led1            write(fd1, buf, 1);            buf[0] = 1;     //rue on led2            write(fd2, buf, 1);                     sleep(1);                   buf[0] = 0;     //true off led2            write(fd2, buf, 1);            buf[0] = 1;     //rue on led3            write(fd3, buf, 1);                     sleep(1);                   buf[0] = 0;     //true off led3            write(fd3, buf, 1);            buf[0] = 1;     //rue on led4            write(fd4, buf, 1);                     sleep(1);               buf[0] = 0;     //rue off led4            write(fd4, buf, 1);                 }    }    printf("test ioctl..... \n");    ioctl(fd1, 0);    sleep(2);    ioctl(fd1, 1);}5、运行程序，依次循环点亮

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