基于tiny210v2的linux-3.9.6内核驱动移植1:led驱动

来源：互联网发布：透明显示屏软件下载编辑：程序博客网时间：2024/05/21 17:06

    tiny210v2上有4个led，可以通过gpio直接控制，今天尝试最简单的led驱动移植，主要通过对比友善给的linux-3.0.8来进行移植。
    参考：http://blog.csdn.net/it_114/article/details/6203681
第一步：
           查得对应GPIO为GPJ_0---GPJ_3;
           在drivers/char/ 下新建smdkv210_led.c

#include <linux/kernel.h>#include <linux/module.h>#include <linux/miscdevice.h>#include <linux/fs.h>#include <linux/types.h>#include <linux/moduleparam.h>#include <linux/slab.h>#include <linux/ioctl.h>#include <linux/cdev.h>#include <linux/delay.h>#include <mach/gpio.h>#include <mach/regs-gpio.h>#include <plat/gpio-cfg.h>#define DEVICE_NAME "leds"static int led_gpios[] = {   S5PV210_GPJ2(0),   S5PV210_GPJ2(1),   S5PV210_GPJ2(2),   S5PV210_GPJ2(3),};#defineLED_NUM      ARRAY_SIZE(led_gpios)static long smdkv210_leds_ioctl(struct file *filp, unsigned intcmd,       unsignedlong arg){    switch(cmd){       case0:       case1:          if (arg> LED_NUM) {             return-EINVAL;          }         gpio_set_value(led_gpios[arg], !cmd);         //printk(DEVICE_NAME": %d %d\n", arg, cmd);          break;      default:          return-EINVAL;    }    return0;}static struct file_operations smdkv210_led_dev_fops = {   .owner          =THIS_MODULE,   .unlocked_ioctl   = smdkv210_leds_ioctl,};static struct miscdevice smdkv210_led_dev = {   .minor          =MISC_DYNAMIC_MINOR,   .name          =DEVICE_NAME,   .fops          =&smdkv210_led_dev_fops,};static int __init smdkv210_led_dev_init(void) {    intret;    int i;    for (i = 0;i < LED_NUM; i++) {       ret =gpio_request(led_gpios[i], "LED");       if (ret){          printk("%s:request GPIO %d for LED failed, ret = %d\n", DEVICE_NAME,               led_gpios[i], ret);          returnret;       }      s3c_gpio_cfgpin(led_gpios[i], S3C_GPIO_OUTPUT);      gpio_set_value(led_gpios[i], 1);    }    ret =misc_register(&smdkv210_led_dev);   printk(DEVICE_NAME"\tinitialized\n");    returnret;}static void __exit smdkv210_led_dev_exit(void) {    int i;    for (i = 0;i < LED_NUM; i++) {      gpio_free(led_gpios[i]);    }   misc_deregister(&smdkv210_led_dev);}module_init(smdkv210_led_dev_init);module_exit(smdkv210_led_dev_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("FriendlyARM Inc.");

修改该目录下的Kconfig文件
添加：
config SMDKV210_LEDS
    tristate"LED Support for FriendlyARM Mini210 GPIO LEDs"
    depends onMACH_SMDKV210
    defaulty
    help
     This option enables support for LEDs connectedto GPIO lines
     on tiny210v2 boards.
修改该目录下的Makefile文件
添加：
obj-$(CONFIG_SMDKV210_LEDS)   += smdkv210_leds.o
修改arch/arm/mach-s5pv210/include/mach/gpio.h
   添加：
      #definegpio_get_value   __gpio_get_value
     #definegpio_set_value   __gpio_set_value
     #definegpio_cansleep   __gpio_cansleep
     #definegpio_to_irq   __gpio_to_irq
    #include <asm-generic/gpio.h>

    #include <plat/gpio-cfg.h>
保存make,led驱动就编译到内核了。
友善的测试程序：

 #include<stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/ioctl.h>int main(int argc, char **argv){int on;int led_no;int fd;if (argc != 3 || sscanf(argv[1], "%d", &led_no) !=1 || sscanf(argv[2],"%d", &on) != 1 ||on < 0 || on > 1 || led_no< 0 || led_no > 3) {fprintf(stderr, "Usage: leds led_no 0|1\n");exit(1);}fd = open("/dev/leds0", 0);if (fd < 0) {fd = open("/dev/leds", 0);}if (fd < 0) {perror("open device leds");exit(1);}ioctl(fd, on, led_no);close(fd);return 0;}