首先在exynos4412-x4412.dts文件中添加HelloWorld节点,如下:
HelloWorld {
compatible = "x4412, hello_world";
status = "okay";
};
然后新建一个 hello_world.c 源文件,具体源码如下:
/*
* Hello World Driver for X4412
*
* Copyright (c) 2018
* Author: YYH
* This is a simple module driver example for x4412 base on dts
*
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/of.h>
static int hello_world_probe(struct platform_device *pdev)
{
pr_notice("Driver probe : %s\n", __func__);
return 0;
}
static int hello_world_remove(struct platform_device *pdev)
{
pr_notice("Driver remove : %s\n", __func__);
return 0;
}
static void hello_world_shutdown(struct platform_device *pdev)
{
pr_notice("Driver shutdown : %s\n", __func__);
return ;
}
static int hello_world_suspend(struct platform_device *pdev, pm_message_t state)
{
pr_notice("Driver suspend : %s\n", __func__);
return 0;
}
static int hello_world_resume(struct platform_device *pdev)
{
pr_notice("Driver resume : %s\n", __func__);
return 0;
}
static const struct of_device_id tiny4412_hello_world_dt_match[] = {
{
.compatible = "x4412,hello_world" },
{},
};
static struct platform_driver x4412_hello_world_driver = {
.probe = hello_world_probe,
.remove = hello_world_remove,
.shutdown = hello_world_shutdown,
.suspend = hello_world_suspend,
.resume = hello_world_resume,
.driver = {
.name = "hello world",
.of_match_table = tiny4412_hello_world_dt_match,
},
};
module_platform_driver(x4412_hello_world_driver);
MODULE_AUTHOR("YYH");
MODULE_LICENSE("GPL v2");
最后新建一个Makefile文件用来编译生成hello_world.ko文件。具体内容如下
obj-m := hello_world.o
PWD := $(shell pwd)
KDIR := /home/yyh/Desktop/farsight/linux-4.9.123
all:
make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=/home/yyh/Desktop/farsight/gcc4.6/gcc-4.6.4/bin/arm-none-linux-gnueabi-
clean:
rm -rf .*.cmd *.o *.mod.c *.ko .tmp_versions