#define LED_ON _IOW('l',1,int *)
#define LED_OFF _IOW('l',0,int *)
text.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include "head.h"
int main(int argc,const char * argv[])
{
int a;
int b;
while(1)
{
int fd;
//Get the function we want to implement from the interrupt
printf("Please select the lights to be controlled: 1-LED1, 2-LED2, 3-LED3\\
");
scanf("%d", & amp;a);
switch(a)
{
case 1:
fd = open("/dev/mycdev0",O_RDWR);
break;
case 2:
fd = open("/dev/mycdev1",O_RDWR);
break;
case 3:
fd = open("/dev/mycdev2",O_RDWR);
break;
}
if(fd<0)
{
printf("Failed to open device file\\
");
return -1;
}
printf("Open device file successfully\\
");
printf("Please enter the function you want to implement");
printf("0(lights off)1(lights on)\\
");
printf("Please enter:");
scanf("%d", & amp;b);
switch (b)
{
case 1:
ioctl(fd,LED_ON, & amp;b);
break;
case 0:
ioctl(fd,LED_OFF, & amp;b);
break;
}
close(fd);
}
return 0;
}
pdrv.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/gpio.h>
#include "head.h"
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
struct cdev* cdev;
unsigned int major=0;
unsigned int minor=0;
dev_t devno;
struct class* cls;
struct device *dev;
struct resource *res;
struct gpio_desc *gpiono[3];
//Build device tree matching table
struct of_device_id oftable[]={
{.compatible="Yuki,myplatform",},
{.compatible="Yuki,myplatform1",},
{},//Prevent crossing the boundary
};
struct platform_device_id idtable[]=
{
{"aaaaa",0},
{"bbbbb",1},
{"ccccc",2},
{"dddd",3},
{},
};
/************************************************/
int mycdev_open(struct inode * inode,struct file* file)
{
unsigned int min=MINOR(inode->i_rdev);//Get the minor device number of the opened file
file->private_data=(void *)min;
printk("%s:%s:%d\\
",__FILE__,__func__,__LINE__);
return 0;
}
int mycdev_close(struct inode * indode,struct file* file)
{
printk("%s:%s:%d\\
",__FILE__,__func__,__LINE__);
return 0;
}
long mycdev_ioctl(struct file *file,unsigned int cmd,unsigned long arg)
{
int min=(int)file->private_data;//Get the minor device number of the file
switch(min)
{
case 0://LED1
switch(cmd)
{
case LED_ON://turn on the light
gpiod_set_value(gpiono[0],1);
break;
case LED_OFF://turn off the light
gpiod_set_value(gpiono[0],0);
break;
}
break;
case 1://LED2
switch(cmd)
{
case LED_ON://turn on the light
gpiod_set_value(gpiono[1],1);
break;
case LED_OFF://turn off the light
gpiod_set_value(gpiono[1],0);
break;
}
break;
case 2://LED3
switch(cmd)
{
case LED_ON://turn on the light
gpiod_set_value(gpiono[2],1);
break;
case LED_OFF://turn off the light
gpiod_set_value(gpiono[2],0);
break;
}
break;
}
printk("%s:%s:%d\\
",__FILE__,__func__,__LINE__);
return 0;
}
struct file_operations fops = {
.open=mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release=mycdev_close,
};
//Executed when the driver and device are successfully matched
int pdrv_probe(struct platform_device *pdev)
{
int i;
/******************************************/
//1. Apply for an object space cdev_alloc
int ret;
cdev=cdev_alloc();
if(cdev==NULL)
{
printk("Failed to apply for character device driver object space\\
");
ret =-EFAULT;
goto out1;
}
printk("Application for character device driver object space successful\\
");
//2.Initialize object cdev_init
cdev_init(cdev, & amp;fops);
//3. Apply for device number register_chrdev_region()/alloc_chrdev_region()
if(major==0)//Dynamic application
{
ret=alloc_chrdev_region( & amp;devno,minor,3,"mychrdev");
if(ret)
{
printk("Dynamic application for device number failed\\
");
goto out2;
}
major=MAJOR(devno);//Get the major device number based on the device number
minor=MINOR(devno);//Get the minor device number based on the device number
}
else//static application
{
ret=register_chrdev_region(MKDEV(major,minor),3,"mychrdev");
if(ret)
{
printk("Static application for device number failed\\
");
goto out2;
}
}
printk("Device number application successful\\
");
//4. Register driver object cdev_add
ret=cdev_add(cdev,MKDEV(major,minor),3);
if(ret)
{
printk("Failed to register character device driver object\\
");
goto out3;
}
printk("Registration of character device driver object successful\\
");
//5. Submit the directory upward class_create
cls=class_create(THIS_MODULE,"mychrdev");
if(IS_ERR(cls))
{
printk("Failed to access the submission directory\\
");
goto out4;
}
printk("I want to upload the submission directory successfully\\
");
//6. Submit device node information upward device_create
for(i=0;i<3;i + + )
{
dev=device_create(cls,NULL,MKDEV(major,i),NULL,"mycdev%d",i);
if(IS_ERR(dev))
{
printk("Failed to submit device node\\
");
goto out5;
}
}
printk("I want to submit the device node successfully\\
");
/************************************************/
//Get gpio information
for(i=0;i<3;i + + )
{
gpiono[i]=gpiod_get_from_of_node(pdev->dev.of_node,"led-gpios",i,GPIOD_OUT_HIGH,NULL);
if(IS_ERR(gpiono[i]))
{
printk("Failed to parse gpio information\\
");
return -PTR_ERR(gpiono[i]);
}
printk("Parsing gpio information successfully\\
");
//Initialize to 0
gpiod_set_value(gpiono[i],0);
}
return 0;
/****************************************************** ***/
out5:
//When submitting the device node fails, the successfully submitted node will be released.
for(i--;i>=0;i--)
{
device_destroy(cls,MKDEV(major,i));
}
//Destroy directory
class_destroy(cls);
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),3);
out2:
kfree(cdev);
out1:
return ret;
}
int pdrv_remove(struct platform_device *pdev)
{
int i;
//1. Destroy device node information
for(i=0;i<3;i + + )
{
device_destroy(cls,MKDEV(major,i));
}
//2. Destroy the directory
class_destroy(cls);
//3. Unregister the character device driver object
cdev_del(cdev);
//4. Release the device number
unregister_chrdev_region(MKDEV(major,minor),3);
//5. Release the applied character device driver object space
kfree(cdev);
//Release gpio information
for(i=0;i<3;i + + )
{
gpiod_set_value(gpiono[i],0);
gpiod_put(gpiono[i]);
}
return 0;
}
//1. Allocate driver information object
struct platform_driver pdrv={
.probe=pdrv_probe,
.remove=pdrv_remove,
.driver={
.name="aaaaa",//Driver name, corresponding to the device
.of_match_table=oftable,
},
.id_table=idtable,
};
//Register macro with one click
module_platform_driver(pdrv);
MODULE_LICENSE("GPL");
Platform-based button external interrupt control LED
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
struct resource *res;
unsigned int irqno[3];
bool a=0,b=0,c=0;
struct gpio_desc *gpiono[3];
//Build device tree matching table
struct of_device_id oftable[]={
{.compatible="Yuki,myplatform",},
{.compatible="Yuki,myplatform1",},
{},//Prevent crossing the boundary
};
struct platform_device_id idtable[]=
{
{"aaaaa",0},
{"bbbbb",1},
{"ccccc",2},
{"dddd",3},
{},
};
irqreturn_t key_handler(int irq,void *dev)
{
switch ((unsigned int)dev)
{
case 0:
gpiod_set_value(gpiono[0],!a);
a=!a;
break;
case 1:
gpiod_set_value(gpiono[1],!b);
b=!b;
break;
case 2:
gpiod_set_value(gpiono[2],!c);
c=!c;
break;
}
return IRQ_HANDLED;
}
//Executed when the driver and device are successfully matched
int pdrv_probe(struct platform_device *pdev)
{
int i;
int ret;
//Get gpio information
for(i=0;i<3;i + + )
{
//Get interrupt type resources
irqno[i]=platform_get_irq(pdev,i);
if(irqno[i]<0)
{
printk("Failed to obtain interrupt type resource\\
");
}
//Registration interrupted
ret=request_irq(irqno[i],key_handler,IRQF_TRIGGER_FALLING,"keyi",(void *)i);
if(ret<0)
{
printk("Registration interruption failed\\
");
}
printk("Registration interrupt %d successful\\
",i);
gpiono[i]=gpiod_get_from_of_node(pdev->dev.of_node,"led-gpios",i,GPIOD_OUT_HIGH,NULL);
if(IS_ERR(gpiono[i]))
{
printk("Failed to parse gpio information\\
");
return -PTR_ERR(gpiono[i]);
}
printk("Parsing gpio information successfully\\
");
//Initialize to 0
gpiod_set_value(gpiono[i],0);
}
return 0;
}
int pdrv_remove(struct platform_device *pdev)
{
int i;
for(i=0;i<3;i + + )
{
gpiod_set_value(gpiono[i],0);
gpiod_put(gpiono[i]);
}
return 0;
}
//1. Allocate driver information object
struct platform_driver pdrv={
.probe=pdrv_probe,
.remove=pdrv_remove,
.driver={
.name="aaaaa",//Driver name, corresponding to the device
.of_match_table=oftable,
},
.id_table=idtable,
};
//Register macro with one click
module_platform_driver(pdrv);
MODULE_LICENSE("GPL");
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