Requirements:
Code writing:
Header file
#ifndef __MYCDEV_H__
#define __MYCDEV_H__
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/device.h>
#define CNAME "myled"
//GPIOx group controller structure
typedef struct {
volatile unsigned int MODER; // 0x00
volatile unsigned int OTYPER; // 0x04
volatile unsigned int OSPEEDR; // 0x08
volatile unsigned int PUPDR; // 0x0C
volatile unsigned int IDR; // 0x10
volatile unsigned int ODR; // 0x14
volatile unsigned int BSRR; // 0x18
volatile unsigned int LCKR; // 0x1C
volatile unsigned int AFRL; // 0x20
volatile unsigned int AFRH; // 0x24
volatile unsigned int BRR; // 0x28
volatile unsigned int res;
volatile unsigned int SECCFGR; // 0x30
}gpio_t;
char kbuf[128] = {0};
//Initialize rcc, GPIOE, GPIOF, GPIOZ group controllers
unsigned int* AHB4_virt_rcc;
unsigned int* AHB5_virt_rcc;
gpio_t* virt_gpioe;
gpio_t* virt_gpiof;
gpio_t* virt_gpioz;
struct class* c;
struct device* d;
//Specify the GPIOE group base address
#define PHY_GPIOE_ADDR 0x50006000
//Specify the GPIOF group base address
#define PHY_GPIOF_ADDR 0x50007000
//Specify the GPIOZ group base address
#define PHY_GPIOZ_ADDR 0x54004000
//AHB4_RCC base address: 0x50000A28
#define PHY_RCC_AHB4 0x50000A28
//AHB5_RCC base address: 0x50000A28
#define PHY_RCC_AHB5 0x54000210
//LED lighting command code
#define LED_ON _IOW('a',1,int)
// LED off command code
#define LED_OFF _IOW('a',0,int)
//LED flip command code
#define LED_TOGGLE _IOW('a',2,int)
//LED1~6 flip
#define LED1_TOGGLE (virt_gpioe->ODR ^= (0x1 << 10))
#define LED2_TOGGLE (virt_gpiof->ODR ^= (0x1 << 10))
#define LED3_TOGGLE (virt_gpioe->ODR ^= (0x1 << 8))
#define LED4_TOGGLE (virt_gpioz->ODR ^= (0x1 << 5))
#define LED5_TOGGLE (virt_gpioz->ODR ^= (0x1 << 6))
#define LED6_TOGGLE (virt_gpioz->ODR ^= (0x1 << 7))
//LED1 is on
#define LED1_ON (virt_gpioe->ODR |= (0x1 << 10))
//LED1 off
#define LED1_OFF (virt_gpioe->ODR &= (~(0x1 << 10)))
//LED2 is on
#define LED2_ON (virt_gpiof->ODR |= (0x1 << 10))
//LED2 off
#define LED2_OFF (virt_gpiof->ODR & amp;= (~(0x1 << 10)))
//LED3 is on
#define LED3_ON (virt_gpioe->ODR |= (0x1 << 8))
//LED3 off
#define LED3_OFF (virt_gpioe->ODR & amp;= (~(0x1 << 8)))
//LED4 is on
#define LED4_ON (virt_gpioz->ODR |= (0x1 << 5))
//LED4 off
#define LED4_OFF (virt_gpioz->ODR & amp;= (~(0x1 << 5)))
//LED5 is on
#define LED5_ON (virt_gpioz->ODR |= (0x1 << 6))
//LED5 off
#define LED5_OFF (virt_gpioz->ODR & amp;= (~(0x1 << 6)))
//LED6 is on
#define LED6_ON (virt_gpioz->ODR |= (0x1 << 7))
//LED6 off
#define LED6_OFF (virt_gpioz->ODR & amp;= (~(0x1 << 7)))
enum {
LED1,
LED2,
LED3,
LED4,
LED5,
LED6,
};
#endif
source file
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include "mycdev.h"
struct cdev* cdev;
dev_t devno;
#if 0
unsigned int major = 0;
#else
unsigned int major = 500;
#endif
unsigned int minor = 0;
struct class* cls;
struct device* dev;
int mycdev_open(struct inode* inode, struct file* file)
{
printk("%s:%s:%d\\
",__FILE__,__func__,__LINE__);
return 0;
}
ssize_t mycdev_read(struct file* file, char* ubuf, size_t size, loff_t *off)
{
printk("%s:%s:%d\\
",__FILE__,__func__,__LINE__);
return 0;
}
ssize_t mycdev_write(struct file* file, const char* ubuf, size_t size, loff_t *off)
{
printk("%s:%s:%d\\
",__FILE__,__func__,__LINE__);
return 0;
}
int mycdev_close(struct inode* inode, struct file* file)
{
printk("%s:%s:%d\\
",__FILE__,__func__,__LINE__);
return 0;
}
long mycdev_ioctl(struct file* file, unsigned int cmd, unsigned long args)
{
//1. Judgment cmd switch(cmd)
//2. Determine which light to operate and flip copy_from_user
int whitch;
int ret;
switch(cmd)
{
//LED lights up
case LED_ON:
ret = copy_from_user( & amp;whitch,(void*)args,sizeof(int));
if(ret)
{
printk("copy_from_user failed\\
");
return -EIO;
}
switch (whitch)
{
case LED1:
LED1_ON;
break;
case LED2:
LED2_ON;
break;
case LED3:
LED3_ON;
break;
case LED4:
LED4_ON;
break;
case LED5:
LED5_ON;
break;
case LED6:
LED6_ON;
break;
}
break;
// LED off
case LED_OFF:
ret = copy_from_user( & amp;whitch,(void*)args,sizeof(int));
if(ret)
{
printk("copy from user is error\\
");
return -EIO;
}
switch (whitch)
{
case LED1:
LED1_OFF;
break;
case LED2:
LED2_OFF;
break;
case LED3:
LED3_OFF;
break;
case LED4:
LED4_OFF;
break;
case LED5:
LED5_OFF;
break;
case LED6:
LED6_OFF;
break;
}
break;
//LED flip
case LED_TOGGLE:
ret = copy_from_user( & amp;whitch,(void*)args,sizeof(int));
if(ret)
{
printk("copy from user is error\\
");
return -EIO;
}
switch (whitch)
{
case LED1:
LED1_TOGGLE;
break;
case LED2:
LED2_TOGGLE;
break;
case LED3:
LED3_TOGGLE;
break;
case LED4:
LED4_TOGGLE;
break;
case LED5:
LED5_TOGGLE;
break;
case LED6:
LED6_TOGGLE;
break;
}
}
return 0;
}
const struct file_operations fops = {
.unlocked_ioctl = mycdev_ioctl,
.open = mycdev_open,
.read = mycdev_read,
.write = mycdev_write,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
int ret, i;
//Map physical address to virtual address
AHB4_virt_rcc = ioremap(PHY_RCC_AHB4,4);
if(NULL == AHB4_virt_rcc)
{
printk("rcc ioremap is failed\\
");
return -ENOMEM;
}
AHB5_virt_rcc = ioremap(PHY_RCC_AHB5,4);
if(NULL == AHB5_virt_rcc)
{
printk("rcc ioremap is failed\\
");
return -ENOMEM;
}
virt_gpioe = ioremap(PHY_GPIOE_ADDR, sizeof(gpio_t));
{
if(NULL == virt_gpioe)
{
printk("gpioe ioremap is failed\\
");
return -ENOMEM;
}
}
virt_gpiof = ioremap(PHY_GPIOF_ADDR, sizeof(gpio_t));
{
if(NULL == virt_gpiof)
{
printk("gpioe ioremap is failed\\
");
return -ENOMEM;
}
}
virt_gpioz = ioremap(PHY_GPIOZ_ADDR, sizeof(gpio_t));
{
if(NULL == virt_gpioz)
{
printk("gpioz ioremap is failed\\
");
return -ENOMEM;
}
}
//RCC enable GPIO E F Z
*AHB4_virt_rcc |= (0x3 << 4);
*AHB5_virt_rcc |= (0x1);
//LED1 PE10
virt_gpioe->MODER &= (~(0x3 << 20));
virt_gpioe->MODER |= (0x1 << 20);
virt_gpioe->ODR &= (~(0x1 << 10));
//LED2 PF10
virt_gpiof->MODER & amp;= (~(0x3 << 20));
virt_gpiof->MODER |= (0x1 << 20);
virt_gpiof->ODR &= (~(0x1 << 10));
//LED3 PE8
virt_gpioe->MODER &= (~(0x3 << 16));
virt_gpioe->MODER |= (0x1 << 16);
virt_gpioe->ODR & amp;= (~(0x1 << 8));
// //LED4 PZ5
virt_gpioz->MODER &= (~(0x3 << 10));
virt_gpioz->MODER |= (0x1 << 10);
virt_gpioz->ODR &= (~(0x1 << 5));
//LED5 PZ6
virt_gpioz->MODER &= (~(0x3 << 12));
virt_gpioz->MODER |= (0x1 << 12);
virt_gpioz->ODR &= (~(0x1 << 6));
//LED6 PZ7
virt_gpioz->MODER &= (~(0x3 << 14));
virt_gpioz->MODER |= (0x1 << 14);
virt_gpioz->ODR &= (~(0x1 << 7));
/*
1. Assign object
2. Object initialization
3. Application for equipment resources (equipment number)
4. Register
5. Submit directory up
6. Submit the device node information upward
*/
//1. Assign object
cdev = cdev_alloc();
if(NULL == cdev)
{
printk("Failed to allocate object space\\
");
ret=-ENOMEM;
goto ERR1;
}
printk("Successful allocation of object space\\
");
//2. Initialize the driver object
cdev_init(cdev, &fops);
//3. Application for device resources (device number)
if(0 == major)
{
ret = alloc_chrdev_region( & devno,minor,3,"mycdev");
if(ret)
{
printk("Dynamic application for device number failed\\
");
goto ERR2;
}
major = MAJOR(devno);
minor = MINOR(devno);
}
else if(major > 0)
{
ret = register_chrdev_region(MKDEV(major,minor),3,"mycdev");
if(ret)
{
printk("Static application device number failed\\
");
goto ERR2;
}
}
//4. Register object
ret = cdev_add(cdev,MKDEV(major,minor),3);
if(ret)
{
printk("Failed to register the driver object into the kernel\\
");
goto ERR3;
}
printk("The driver object is successfully registered into the kernel\\
");
//5. Submit directory up
cls = class_create(THIS_MODULE,"mycdev");
if(IS_ERR(cls))
{
printk("Failed to submit directory up\\
");
goto ERR4;
}
printk("submit directory successfully\\
");
//6. Submit device node information upward
for(i=0;i<3;i ++ )
{
dev = device_create(cls,NULL,MKDEV(major,i),NULL,"mycdev%d",i);
if(IS_ERR(dev))
{
printk("Upward submission of node information failed\\
");
goto ERR5;
}
printk("Upward submission of node information successfully\\
");
}
printk("Submit the device node up successfully\\
");
printk("major = %d\\
",major);
return 0;
//Release resources according to ERR level
ERR5:
for(--i;i>=0;i--)
{
device_destroy(cls,MKDEV(major,i));
}
class_destroy(cls);
ERR4:
cdev_del(cdev);
ERR3:
unregister_chrdev_region(MKDEV(major,minor),3);
ERR2:
kfree(cdev);
ERR1:
return ret;
}
static void __exit mycdev_exit(void)
{
/*
1. Destroy the device node
2. Destroy the directory
3. Unregister the drive object
4. Release device resources (device number)
5. Release object space
6. Unmap
*/
//1. Destroy the device node
int i;
for(i=0;i<3;i ++ )
{
device_destroy(cls,MKDEV(major,i));
}
//2. Destroy the directory
class_destroy(cls);
//3. Unregister the driver object
cdev_del(cdev);
//4. Release device resources (device number)
unregister_chrdev_region(MKDEV(major,minor),3);
//5. Release object space
kfree(cdev);
//6. Unmap
iounmap(AHB4_virt_rcc);
iounmap(AHB5_virt_rcc);
iounmap(virt_gpioe);
iounmap(virt_gpiof);
iounmap(virt_gpioz);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
Test file
#include <sys/ioctl.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#define LED_ON _IOW('a',1,int)
#define LED_OFF _IOW('a',0,int)
#define LED_TOGGLE _IOW('a',2,int)
enum {
LED1,
LED2,
LED3,
LED4,
LED5,
LED6,
};
void menu_set();
void menu_toggle();
void ioctl_cmd_set(int,int);
void ioctl_cmd_toggle(int,int);
int main(int argc, const char * argv[])
{
char buf[128] = {0};
int cmd;
int fd = -1;
fd = open("/dev/mycdev0",O_RDWR);
if(fd == -1)
{
perror("open is error\\
");
return -1;
}
int whitch;
while (1)
{
//menu_set();
menu_toggle(); //Print command list
fgets(buf, sizeof(buf), stdin);
cmd = atoi(buf);
printf("cmd = %d\\
",cmd);
//ioctl_cmd_set(fd,cmd);
ioctl_cmd_toggle(fd,cmd); //Send toggle command
system("clear");
}
close(fd);
return 0;
}
void menu_set()
{
printf("Command 1: **********LED1 is on*********\\
");
printf("Command 2: **********LED1 off**********\\
");
printf("Command 3: **********LED2 is on**********\\
");
printf("Command 4: **********LED2 off********\\
");
printf("Command 5: **********LED3 is on**********\\
");
printf("Command 6: **********LED3 off**********\\
");
printf("Command 7: **********LED4 lights up**********\\
");
printf("Command 8: **********LED4 off********\\
");
printf("Command 9: **********LED5 is on********\\
");
printf("Command 10: **********LED5 off**********\\
");
printf("Command 11: **********LED6 lights up**********\\
");
printf("Command 12: **********LED6 off**********\\
");
printf("Please enter the command >>>>>>>");
}
void menu_toggle()
{
printf("Command 1: **********LED1 Flip********\\
");
printf("Command 2: **********LED2 Flip********\\
");
printf("Command 3: **********LED3 rollover********\\
");
printf("Command 4:********LED4 Flip********\\
");
printf("Command 5:********LED5 Flip********\\
");
printf("Command 6: **********LED6 Flip********\\
");
printf("Please enter the command >>>>>>>");
}
void ioctl_cmd_toggle(int fd, int cmd)
{
int whitch;
switch (cmd)
{
case 1:
whitch = LED1;
ioctl(fd, LED_TOGGLE, &whitch);
break;
case 2:
whitch = LED2;
ioctl(fd, LED_TOGGLE, &whitch);
break;
case 3:
whitch = LED3;
ioctl(fd, LED_TOGGLE, &whitch);
break;
case 4:
whitch = LED4;
ioctl(fd, LED_TOGGLE, &whitch);
break;
case 5:
whitch = LED5;
ioctl(fd, LED_TOGGLE, &whitch);
break;
case 6:
whitch = LED6;
ioctl(fd, LED_TOGGLE, &whitch);
break;
}
}
void ioctl_cmd_set(int fd, int cmd)
{
int whitch;
switch(cmd)
{
case 1:
whitch = LED1;
ioctl(fd, LED_ON, &whitch);
break;
case 3:
whitch = LED2;
ioctl(fd, LED_ON, &whitch);
break;
case 5:
whitch = LED3;
ioctl(fd, LED_ON, &whitch);
break;
case 7:
whitch = LED4;
ioctl(fd, LED_ON, &whitch);
break;
case 9:
whitch = LED5;
ioctl(fd, LED_ON, &whitch);
break;
case 11:
whitch = LED6;
ioctl(fd, LED_ON, &whitch);
break;
case 2:
whitch = LED1;
ioctl(fd, LED_OFF, &whitch);
break;
case 4:
whitch = LED2;
ioctl(fd, LED_OFF, &whitch);
break;
case 6:
whitch = LED3;
ioctl(fd, LED_OFF, &whitch);
break;
case 8:
whitch = LED4;
ioctl(fd, LED_OFF, &whitch);
break;
case 10:
whitch = LED5;
ioctl(fd, LED_OFF, &whitch);
break;
case 12:
whitch = LED6;
ioctl(fd, LED_OFF, &whitch);
break;
}
}
Code implementation:
