Learn the Linux drive automatically creating device nodes in one step

<span style= "FONT-SIZE:12PX;" >extern struct device *device_create (struct class *cls, struct device *parent,    dev_t devt, void *drvdata,    cons T char *fmt, ...)    __ATTRIBUTE__ (Format (printf, 5, 6));</span>

function Function:The function device_create () is used to dynamically establish a logical device, and initializes the new logical device class, associating it with the logical class represented by the first parameter of the function, and then adding the logical device to the device driver model of the Linux kernel system. function to automatically create a new logical device directory under the/sys/devices/virtual directory, and create a device file corresponding to the logical class in the/dev directoryparameter Description:struct class CLS: A logical class related to the amount of logical devices that are about to be created. dev_t Dev: device numbera pointer of type void *drvdata:void that represents the input parameter of the callback functionconst char *FMT: The device name of the logical device, which is the directory name of the logical device directory created in directory/sys/devices/virtual.

#include <linux/module.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/init.h > #include <linux/delay.h> #include <linux/irq.h> #include <asm/uaccess.h> #include <asm/irq.h > #include <asm/io.h> #include <linux/poll.h> #include <linux/device.h>static struct class *   Myleddrv_class; Auto-register drive main device static struct device *myleddrv_dev;volatile unsigned long *gpbcon = NULL; Control register volatile unsigned long *gpbdat = NULL; data register static int myleddrv_open (void) {PRINTK ("Hello Linux world!\n"); return 0;} static int myleddrv_write (void) {return 0;}    static struct File_operations Myleddrv_fops = {. Owner = This_module,/* This is a macro that is automatically created when you push the module to compile the __this_module variable */ . open = Myleddrv_open,. Write=myleddrv_write,};static int major; global variable static int myleddrv_init (void) {major = Register_chrdev (0, "Myleddrv", &myleddrv_fops);//register, tell the kernel myleddrv_ class = Class_create (This_module, "myleddrv"); Myleddrv_dev = Device_create (MYleddrv_class, NULL, MKDEV (major, 0), NULL, "Myleddrv"); /*/dev/myleddrv */return 0;} static void Myleddrv_exit (void) {Unregister_chrdev (Major, "myleddrv");//Unload PRINTK ("Myleddrv has been unregistered!\n") ;d Evice_unregister (Myleddrv_dev);d Evice_destroy (myleddrv_class,major);} Module_init (Myleddrv_init); Module_exit (Myleddrv_exit); Module_license ("GPL");

Learn the Linux drive automatically creating device nodes in one step