android mtk 建一个设备misc

最新推荐文章于 2025-08-21 09:00:00 发布

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本文介绍了一个基于MTK平台的内核驱动示例，包括Makefile配置、设备节点注册、GPIO操作及设备文件接口实现等内容。示例展示了如何通过ioctl进行设备控制，如开启和关闭闪光灯。

alps\mediatek\kernel\drivers\Makefile 加一行

obj-y += emd_ctl/

obj-y += scandriver/

obj-y += hello/

alps\mediatek\kernel\drivers\scandriver\Makefile 加一行

obj-y += demo1.o

alps\mediatek\kernel\drivers\scandriver\test.h

#ifndef TEST_H
#define TEST_H


#define test1_MAGIC 'w'      //定义幻数为 w
#define test1_POWER_ON           _IOWR(test1_MAGIC, 0, int)
#define test1_POWER_OFF          _IOWR(test1_MAGIC, 1, int)
#define test1_TRIG_LOW           _IOWR(test1_MAGIC, 3, int)
#define test1_TRIG_HIGH          _IOWR(test1_MAGIC, 4, int)


#define test1_MAXNR 5




#define TEST1_CMD1    _IO(test1_MAGIC,0x1a)
#define TEST1_CMD2    _IO(test1_MAGIC,0x1b)


#endif

alps\mediatek\kernel\drivers\scandriver\test.c

#include <linux/init.h>
#include <linux/slab.h>
#include <asm/errno.h>
#include <asm/delay.h>
#include <linux/mm.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/cdev.h>
#include <linux/wait.h>
#include <linux/timer.h>
//#include <mach/gpio.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include "test.h"

#include <mach/mt_gpio.h>
#include <mach/mt_sleep.h>
#include <mach/mt_pm_ldo.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>


#define FLASH_LIGHT_GPIO    GPIO126


//#define GPIO_ModeSetup(pin, mode)      mt_set_gpio_mode(pin, mode)
//#define GPIO_InitIO(dir, pin)                mt_set_gpio_dir(pin, dir)
//#define GPIO_WriteIO(out, pin)            mt_set_gpio_out(pin, out)
//#define GPIO_ReadIO(pin)                  mt_get_gpio_in(pin)


void flash_light_set_low(void)
{
	mt_set_gpio_mode(FLASH_LIGHT_GPIO, 0);
	mt_set_gpio_dir(FLASH_LIGHT_GPIO, 1);
	mt_set_gpio_out(FLASH_LIGHT_GPIO, 0);
}

void flash_light_set_high(void)
{
	mt_set_gpio_mode(FLASH_LIGHT_GPIO, 0);
	mt_set_gpio_dir(FLASH_LIGHT_GPIO, 1);
	mt_set_gpio_out(FLASH_LIGHT_GPIO, 1);
}

void flash_light_poweron(void)
{
	flash_light_set_high();

//    hwPowerDown(MT6323_POWER_LDO_VGP2, "TP");
//    hwPowerOn(MT6323_POWER_LDO_VGP2, VOL_1800, "TP");
	
//    hwPowerDown(MT6323_POWER_LDO_VGP1, "TP");
//    hwPowerOn(MT6323_POWER_LDO_VGP1, VOL_3300, "TP");
}

void flash_light_poweroff(void)
{
	flash_light_set_low();
}


#define test1_MAJOR 184
#define test1_MINOR 0
#define INVALID_NO -1

static unsigned char DEV_NAME[10] = "test_flash_light_gpio";
static struct cdev test1Dev;

static int test1_open(struct inode* inode, struct file* filp)
{	
	flash_light_poweron();
	return 0;

}

//static int test1_ioctl(struct inode *i, struct file *f, unsigned int cmd, unsigned long arg)
static long test1_ioctl(struct file *f, unsigned int cmd,
                               unsigned long arg)
{
	int err = 0;
	int retval = 0;

	if(_IOC_TYPE(cmd) != test1_MAGIC){               //如果幻数不相同则返回错误
		printk("cmd is not equal test1_MAGIC\n");   
		return -ENOTTY;
	}
//	if(_IOC_NR(cmd) > FLASH_LIGHT_POWER_ON){                 //如果序数大于最大值，则返回错误
//		printk("the number of cmd max FLASH_LIGHT_POWER_ON\n");
//		return -ENOTTY;
//	}
	//检查指向的用户空间是否合法
       //if(_IOC_DIR(cmd) & _IOC_READ)
 		//err = !access_ok(VERIFY_WRITE, (void *)arg, _IOC_SIZE(cmd));     //_IOC_SIZE(cmd) 是字节数
       //else if(_IOC_DIR(cmd) & _IOC_WRITE)
		//err = !access_ok(VERIFY_READ, (void *)arg, _IOC_SIZE(cmd));     //读取用户空间的内存区是否合法
	                                                                       ////*arg是用户空间的地址
       //if(err) 
		//return -EFAULT;
	switch(cmd)
	{ 
                case test1_POWER_ON:
				flash_light_poweron();
				printk("FLASH_LIGHT_POWER_ON!\n");	
                break;

                case test1_POWER_OFF:
			    flash_light_poweroff();
                         printk("FLASH_LIGHT_POWER_OFF!\n");
                break;

		default:
		break;
	}
	return 0;	
}

static int test1_release(struct inode* i,struct file* f)
{
	
	return 0;

}

struct file_operations test1_fops = 
{
	.owner=       THIS_MODULE,
	.open=        test1_open,
	.unlocked_ioctl=       test1_ioctl,
	.release=     test1_release,
};

static struct miscdevice test1 = {
	
	.minor = MISC_DYNAMIC_MINOR,
	.name  = "test_flash_light_gpio",
	.fops  =  &test1_fops
};

static int __init test1_reg(void)
{	
	misc_register(&test1);
	
	printk("test1 driver initilization Success\n");
	
	return 0;
}

static void __exit test1_exit(void)
{

	cdev_del(&test1Dev);
	unregister_chrdev_region(MKDEV(test1_MAJOR, 0), 1);
	return;
}

module_init(test1_reg)
module_exit(test1_exit)