1, create a node in the dts file, in /kernel-3.18/arch/arm64/boot/dts/mt6735.dtsi
Mygpio create a device node name, the matching name "mykgpio".
2, do not write the drive frame
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <generated/autoconf.h>
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include "mt-plat/mtgpio.h"
#include <linux/types.h>
#include <mt-plat/mt_gpio.h>
#include <mt-plat/mt_gpio_core.h>
#include <mach/gpio_const.h>
/* 生命函数定义 */
static int mygpio_probe(struct platform_device *pdev);
static int mygpio_remove(struct platform_device *pdev);
static const struct of_device_id mygpio_of_match[] = {
{ .compatible = "mykgpio", },
{},
};
static struct platform_driver mygpio_driver = {
.remove = mygpio_remove,
.probe = mygpio_probe,
.driver = {
.name = "myGPIO",
.owner = THIS_MODULE,
.of_match_table = mygpio_of_match,
},
};
static int mygpio_misc_open(struct inode *inode, struct file *file)
{
printk("MyGPIO OPen. \r\n");
return 0;
}
static int mygpio_misc_release(struct inode *inode, struct file *file)
{
printk("MyGPIO Release. \r\n");
return 0;
}
static long mygpio_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
printk("MyGPIO Ioctl. \r\n");
printk("MyGPIO cmd=%d \r\n", cmd);
return 0;
}
static const struct file_operations mygpio_fops = {
/* .owner = THIS_MODULE, */
.open = mygpio_misc_open,
.release = mygpio_misc_release,
.unlocked_ioctl = mygpio_unlocked_ioctl,
};
static struct miscdevice mygpio_misc_device = {
.minor = MISC_DYNAMIC_MINOR, //动态设备号
.name = "myGPIO",
.fops = &mygpio_fops,
};
/* My GPIO probe */
static int mygpio_probe(struct platform_device *pdev)
{
int ret = 0;
printk("MyGPIO Probe. \r\n");
ret = misc_register(&mygpio_misc_device);
if (ret != 0 )
printk("myGPIO: mygpio_device register failed\n");
return ret;
}
static int mygpio_remove(struct platform_device *pdev)
{
int err;
printk("MyGPIO remove. \r\n");
err = misc_deregister(&mygpio_misc_device);
if (err)
printk("deregister gpio\n");
return err;
}
static int __init my_gpio_init(void)
{
int ret = 0;
printk("Register MyGPIO platform_driver. \r\n");
ret = platform_driver_register(&mygpio_driver);
if(ret != 0 )
printk("unable to register MyGPIO driver.\n");
return ret;
}
/*---------------------------------------------------------------------------*/
static void __exit my_gpio_exit(void)
{
platform_driver_unregister(&mygpio_driver);
}
subsys_initcall(my_gpio_init);
/*module_init(my_gpio_init);*/
module_exit(my_gpio_exit);
MODULE_AUTHOR ( "Zue,");
MODULE_DESCRIPTION ( "MY General Purpose Driver (the GPIO)");
MODULE_LICENSE ( "the GPL v2");
this process is very simple, first register a device driver, when DTS matched to the name "mykgpio" of when the device is called probe function in the probe function, register a "myGPIO" miscellaneous device driver is named.
The driver files into the kernel, compile and write less compile the mirror.
After the development board to start, you can see the devices registered in the / dev directory. Such a framework would drive OK, here you can write the substance of the GPIO driver.