字符驱动移植--bus(平台总线), device, driver

bus

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>

char bus_version[128] = "bus version v1";

// 如果匹配成功，返回1， 失败返回0
int mybus_match(struct device *dev, struct device_driver *drv)
{

//  匹配的基本规则就是匹配名字(注意：dev是父类的名字 )
if(!strncmp(drv->name, dev->kobj.name, strlen(drv->name))){
printk("match ok\n");
return 1;

}else{
printk("match failed\n");
return 0;

}

}

struct bus_type  mybus = {
.name = "my_bus",
.match = mybus_match,

};

//当用cat 调用此函数
ssize_t bus_version_show(struct bus_type *bus, char *buf)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);

return snprintf(buf,128, "%s", bus_version);
}
//当用ech xxxx > ultoa, 会调用此函数
ssize_t bus_version_store(struct bus_type *bus, const char *buf, size_t count)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);

return snprintf(bus_version,count,"%s", buf);
}

//定义一个新文件--属性文件 struct bus_attribute,用 一个宏来初始化

//  变量名＝＝ bus_attr_bus_version
//BUS_ATTR(bus_version,0666,bus_version_show, bus_version_store);

//  BUS_ATTR==>等同于下面
struct bus_attribute   bus_file_attr = {
.attr = {
.name = "bus_version",  //   /sys/bus/my_bus/bus_version
.mode = 0666,
},
.show = bus_version_show,
.store = bus_version_store,
};

EXPORT_SYMBOL(mybus);  //导出，否则mydev中拿不到该变量

static int __init mybus_init(void)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
int ret;
//注册一个总线
ret = bus_register(&mybus);
if(ret != 0)
{
printk("bus_register");
return ret;
}

//  /sys/bus/my_bus/bus_version
//变量名＝＝ bus_attr_bus_version
//bus_create_file(&mybus, &bus_attr_bus_version);

bus_create_file(&mybus, &bus_file_attr);

return 0;

}

static void __exit mybus_exit(void)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
//变量名＝＝ bus_attr_bus_version
//bus_remove_file(&mybus, &bus_attr_bus_version);
bus_remove_file(&mybus,&bus_file_attr);
bus_unregister(&mybus);

}
module_init(mybus_init);
module_exit(mybus_exit);
MODULE_LICENSE("GPL");

——————————————

device

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include "mydevinfo.h"

struct mydev_info  info = {
.name = "s5pv210_mydev",
.addr = 0xE0000060,
.irqno = 456,
.gpionum = 123,
};

extern struct bus_type  mybus; //为了编译

void    mydev_release(struct device *dev)
{

}

struct device mydev = {
.init_name = "s5pv210_devdrv", // /sys/bus/my_bus/devices/my_dev
// /sys/devices/my_dev
.bus = &mybus,
.release = mydev_release,
.platform_data = &info,
};

static int __init mydev_init(void)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
int ret;
//注册一个device到总线上
ret = device_register(&mydev);
if(ret < 0)
{
printk("device_register error");
return ret;
}

return 0;

}

static void __exit mydev_exit(void)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
device_unregister(&mydev);

}
module_init(mydev_init);
module_exit(mydev_exit);
MODULE_LICENSE("GPL");

——————————————

driver

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include "mydevinfo.h"

extern struct bus_type  mybus; //为了编译

int mydrv_probe (struct device *dev)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
//获取到device中的数据
struct mydev_info *p = dev->platform_data;

printk("name = %s\n", p->name);
printk("addr = 0x%x\n", p->addr);
printk("gpio = %d\n", p->gpionum);
printk("irq = %d\n", p->irqno);

return 0;
}
int mydrv_remove (struct device *dev)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
return 0;

}

struct device_driver mydrv = {
.name = "s5pv210_devdrv", //  /sys/bus/my_bus/drivers/my_drv
.bus = &mybus,
.probe = mydrv_probe,
.remove = mydrv_remove,
};

static int __init mydrv_init(void)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
int ret;
//注册一个driver到总线上

ret = driver_register(&mydrv);
if(ret < 0)
{
printk("device_register error");
return ret;
}

return 0;

}

static void __exit mydrv_exit(void)
{
printk("-------^_^   %s-----------\n", __FUNCTION__);
driver_unregister(&mydrv);

}
module_init(mydrv_init);
module_exit(mydrv_exit);
MODULE_LICENSE("GPL");