WhyCan Forum(哇酷开发者社区)

root@lzq:/test# cat /proc/devices
Character devices:
  1 mem
  2 pty
  3 ttyp
  4 /dev/vc/0
  4 tty
  4 ttyS
  5 /dev/tty
  5 /dev/console
  5 /dev/ptmx
  7 vcs
 10 misc
 13 input
 14 sound
 29 fb
 81 video4linux
 89 i2c
 90 mtd
116 alsa
128 ptm
136 pts
180 usb
189 usb_device
212 DVB
226 drm
248 rpmb
249 ttyGS
250 bsg
251 watchdog
252 media
253 rtc
254 gpiochip

Block devices:
  8 sd
 65 sd
 66 sd
 67 sd
 68 sd
 69 sd
 70 sd
 71 sd
128 sd
129 sd
130 sd
131 sd
132 sd
133 sd
134 sd
135 sd
179 mmc
259 blkext
root@lzq:/test# 

root@lzq:/test# insmod led.ko 
root@lzq:/test# cat /proc/devices
Character devices:
  1 mem
  2 pty
  3 ttyp
  4 /dev/vc/0
  4 tty
  4 ttyS
  5 /dev/tty
  5 /dev/console
  5 /dev/ptmx
  7 vcs
 10 misc
 13 input
 14 sound
 29 fb
 81 video4linux
 89 i2c
 90 mtd
116 alsa
128 ptm
136 pts
180 usb
189 usb_device
200 myled
212 DVB
226 drm
248 rpmb
249 ttyGS
250 bsg
251 watchdog
252 media
253 rtc
254 gpiochip

root@lzq:/test# mknod /dev/myled c 200 0
root@lzq:/test# ls /dev/myled 
/dev/myled
root@lzq:/test# 

root@lzq:/test# ./led_test /dev/myled on
root@lzq:/test# ./led_test /dev/myled off
root@lzq:/test# 

vim run.sh
chmod +x run.sh
./run.sh

#!/bin/bash
while(true)
do
./led_test /dev/myled on
sleep 0.3
./led_test /dev/myled off
sleep 0.3
done

rmmod myled
rm /dev/myled

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <mach/gpio.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/device.h> // 内核源码里创建/移除设备，产生热插拔事件的函数class
 
 
#define MYMA  200
#define MYMI  3333
#define COUNT    1
 
#define LED_IO   GPIOB(5)//注意修改! 对应开发板上的led灯引脚
 
dev_t devid; //用于存放设备号
struct cdev mycdev; 
static struct class *mycls;
 
 
 
//打开设备文件时开启中断
static int myopen(struct inode *ind,struct file *fl)
{
    int ret;
    ret = gpio_request(LED_IO, "led_0"); //请求gpio口,tldev则是为其取一个名字。
    if(ret<0)
        goto err0;
    gpio_direction_output(LED_IO, 0); //配置gpio口为输出，先输出低电平
    return 0;
 
err0:
    return ret;
}
 
static ssize_t mywrite(struct file *fl,const char *__user buf,size_t len,loff_t *off)
{
    char stat;
 
    copy_from_user(&stat,buf,sizeof(char));
    if(stat)
        gpio_set_value(LED_IO,1);
    else
        gpio_set_value(LED_IO,0);
 
    return 0;
}
 
//关闭设备文件时释放中断
static int myclose(struct inode *inode,struct file *fl)
{
    gpio_set_value(LED_IO,0);
    gpio_free(LED_IO);
 
    return 0;
}
 
static struct file_operations fops= {
    .owner = THIS_MODULE,
    .open  = myopen,
    .write = mywrite,
    .release= myclose,
};
 
 
 
static int __init test_init(void)
{
    int ret;
 
    devid = MKDEV(MYMA, MYMI); //生成一个设备号
    ret = register_chrdev_region(devid, COUNT, DEVNAME); //name设备名(用于查看用, 长度不能超过64字节   )
    if (ret < 0)
        goto err0;
 
    cdev_init(&mycdev, &fops);
    mycdev.owner = THIS_MODULE;
    ret = cdev_add(&mycdev, devid, COUNT);
    if (ret < 0)
        goto err1;  
  
    mycls= class_create(THIS_MODULE,"mykeycls");
    if(mycls== NULL)
        goto err2;
    device_create(mycls,NULL,devid,NULL,DEVNAME);
 
 
    return 0;
 
err2:
    cdev_del(&mycdev);
err1:
    unregister_chrdev_region(devid, COUNT);
err0:
    return ret;
}
 
static void __exit test_exit(void)
{
    device_destroy(mycls,devid);
    class_destroy(mycls);
    unregister_chrdev_region(devid, COUNT);
    cdev_del(&mycdev);
    gpio_free(LED_IO); //释放gpio
}
 
module_init(test_init);
module_exit(test_exit);
 
MODULE_LICENSE("GPL");
MODULE_AUTHOR("xxx");
MODULE_DESCRIPTION("led");
MODULE_VERSION("v0.0");

/*
 * arch/arm/mach-sunxi/include/mach/gpio.h
 *
 * Copyright(c) 2013-2015 Allwinnertech Co., Ltd. 
 *         http://www.allwinnertech.com
 *
 * Author: sunny <sunny@allwinnertech.com>
 *
 * allwinner sunxi gpio defines.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */


#include <linux/slab.h>


#ifndef __SUNXI_MACH_GPIO_H
#define __SUNXI_MACH_GPIO_H


/* pin group base number name space,
 * the max pin number : 26*32=832.
 */
#define SUNXI_PINCTRL 	"sunxi-pinctrl"
#define SUNXI_BANK_SIZE 32
#define SUNXI_PA_BASE	0
#define SUNXI_PB_BASE	32
#define SUNXI_PC_BASE	64
#define SUNXI_PD_BASE	96
#define SUNXI_PE_BASE	128
#define SUNXI_PF_BASE	160
#define SUNXI_PG_BASE	192
#define SUNXI_PH_BASE	224
#define SUNXI_PI_BASE	256
#define SUNXI_PJ_BASE	288
#define SUNXI_PK_BASE	320
#define SUNXI_PL_BASE	352
#define SUNXI_PM_BASE	384
#define SUNXI_PN_BASE	416
#define SUNXI_PO_BASE	448
#define AXP_PIN_BASE	1024

#define SUNXI_PIN_NAME_MAX_LEN	8

/* sunxi gpio name space */
#define GPIOA(n)	(SUNXI_PA_BASE + (n))
#define GPIOB(n)	(SUNXI_PB_BASE + (n))
#define GPIOC(n)	(SUNXI_PC_BASE + (n))
#define GPIOD(n)	(SUNXI_PD_BASE + (n))
#define GPIOE(n)	(SUNXI_PE_BASE + (n))
#define GPIOF(n)	(SUNXI_PF_BASE + (n))
#define GPIOG(n)	(SUNXI_PG_BASE + (n))
#define GPIOH(n)	(SUNXI_PH_BASE + (n))
#define GPIOI(n)	(SUNXI_PI_BASE + (n))
#define GPIOJ(n)	(SUNXI_PJ_BASE + (n))
#define GPIOK(n)	(SUNXI_PK_BASE + (n))
#define GPIOL(n)	(SUNXI_PL_BASE + (n))
#define GPIOM(n)	(SUNXI_PM_BASE + (n))
#define GPION(n)	(SUNXI_PN_BASE + (n))
#define GPIOO(n)	(SUNXI_PO_BASE + (n))
#define GPIO_AXP(n)	(AXP_PIN_BASE  + (n))

/* sunxi specific input/output/eint functions */
#define SUNXI_PIN_INPUT_FUNC	(0)
#define SUNXI_PIN_OUTPUT_FUNC	(1)
#define SUNXI_PIN_EINT_FUNC     (6)
#define SUNXI_PIN_IO_DISABLE	(7)

/* axp group base number name space,
 * axp pinctrl number space coherent to sunxi-pinctrl.
 */
#define AXP_PINCTRL 	        "axp-pinctrl"
#define AXP_CFG_GRP 		(0xFFFF)
#define AXP_PIN_INPUT_FUNC	(0)
#define AXP_PIN_OUTPUT_FUNC	(1)
#define IS_AXP_PIN(pin)         (pin >= AXP_PIN_BASE)


/* sunxi specific pull up/down */
enum sunxi_pull_up_down {
	SUNXI_PULL_DISABLE = 0,
	SUNXI_PULL_UP,
	SUNXI_PULL_DOWN,
};

/* sunxi specific data types */
enum sunxi_data_type {
	SUNXI_DATA_LOW = 0,
	SUNXI_DATA_HIGH = 0,
};

/* sunxi specific pull status */
enum sunxi_pin_pull {
	SUNXI_PIN_PULL_DISABLE 	= 0x00,
	SUNXI_PIN_PULL_UP	= 0x01,
	SUNXI_PIN_PULL_DOWN	= 0x02,
	SUNXI_PIN_PULL_RESERVED	= 0x03,
};

/* sunxi specific driver levels */
enum sunxi_pin_drv_level {
	SUNXI_DRV_LEVEL0 = 10,
	SUNXI_DRV_LEVEL1 = 20,
	SUNXI_DRV_LEVEL2 = 30,
	SUNXI_DRV_LEVEL3 = 40,
};

/* sunxi specific data bit status */
enum sunxi_pin_data_status {
    SUNXI_PIN_DATA_LOW  = 0x00,
    SUNXI_PIN_DATA_HIGH = 0x01,
};

/* sunxi pin interrupt trigger mode */
enum sunxi_pin_int_trigger_mode {
    SUNXI_PIN_EINT_POSITIVE_EDGE   =   0x0,
    SUNXI_PIN_EINT_NEGATIVE_EDGE   =   0x1,
    SUNXI_PIN_EINT_HIGN_LEVEL      =   0x2,
    SUNXI_PIN_EINT_LOW_LEVEL       =   0x3,
    SUNXI_PIN_EINT_DOUBLE_EDGE     =   0x4
};

/* the source clock of pin int */
enum sunxi_pin_int_source_clk {
    SUNXI_PIN_INT_SRC_CLK_32K = 0x0,
    SUNXI_PIN_INT_SRC_CLK_24M = 0x1
};

static inline int sunxi_gpio_to_name(int gpio, char *name)
{
	int bank, index;
	if (!name) {
		return -EINVAL;
	}
	if (IS_AXP_PIN(gpio)) {
		/* axp gpio name like this : GPIO0/GPIO1/.. */
		index = gpio - AXP_PIN_BASE;
		sprintf(name, "GPIO%d", index);
	} else {
		/* sunxi gpio name like this : PA0/PA1/PB0 */
		bank = gpio / SUNXI_BANK_SIZE;
		index = gpio % SUNXI_BANK_SIZE;
		sprintf(name, "P%c%d", ('A' + bank), index);	
	}
	return 0;
}

#endif /* __SUNXI_MACH_GPIO_H */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
 
 
int main(int argc, char** argv)
{
    int fd;
    char LED_ON=1,LED_OFF=0,flag=0;
 
    fd = open("/dev/tldev", O_RDWR);
    if (fd < 0)
    {
        perror("open");
  
    }
   
    while (1)
    {
        write(fd,&LED_ON,1); //led灯亮
        sleep(1);
        write(fd,&LED_OFF,1); //led灯灭
        sleep(1);
 
    }
 
    return 0;
}