一、ID匹配之框架代码
id匹配(可想象成八字匹配):一个驱动可以对应多个设备 ------优先级次低(上一章名称匹配只能1对1)
注意事项:
-
device模块中,id的name成员必须与struct platform_device中的name成员内容一致,因此device模块中,struct platform_device中的name成员必须指定
-
driver模块中,struct platform_driver成员driver的name成员必须指定,但与device模块中name可以不相同
1.1 用法展示:
/*platform device框架*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
//定义资源数组
static void device_release(struct device *dev)
{
printk("platform: device release\n");
}
struct platform_device_id test_id = { //<-------------
.name = "test_device",
};
struct platform_device test_device = {
.name = "test_device",//必须初始化 //<------------必须一样
.dev.release = device_release,
.id_entry = &test_id,
};
static int __init platform_device_init(void)
{
platform_device_register(&test_device);
return 0;
}
static void __exit platform_device_exit(void)
{
platform_device_unregister(&test_device);
}
module_init(platform_device_init);
module_exit(platform_device_exit);
MODULE_LICENSE("Dual BSD/GPL");
/*platform driver框架*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
static int driver_probe(struct platform_device *dev)
{
printk("platform: match ok!\n");
return 0;
}
static int driver_remove(struct platform_device *dev)
{
printk("platform: driver remove\n");
return 0;
}
struct platform_device_id testdrv_ids[] = //<---------------
{
[0] = {.name = "test_device"}, //1对多匹配
[1] = {.name = "abcxyz"}, //1对多匹配
[2] = {}, //means ending //结束符
};
struct platform_driver test_driver = {
.probe = driver_probe,
.remove = driver_remove,
.driver = {
.name = "xxxxx", //必须初始化 可以与device不一样
},
.id_table = testdrv_ids, //<------------
};
static int __init platform_driver_init(void)
{
platform_driver_register(&test_driver);
return 0;
}
static void __exit platform_driver_exit(void)
{
platform_driver_unregister(&test_driver);
}
module_init(platform_driver_init);
module_exit(platform_driver_exit);
MODULE_LICENSE("Dual BSD/GPL");
用到结构体数组,一般不指定大小,初始化时最后加{}表示数组结束
设备中增加资源,驱动中访问资源
1.2 test_device和test_driver示例改写
test_device_id.c
/*platform device框架*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
//<---------------设计成数组形式
struct resource test_dev_res [] =
{
[0] = {.start = 0x1000, .end = 0x1003, .name = "reg1", .flags = IORESOURCE_MEM},
[1] = {.start = 0x2000, .end = 0x2003, .name = "reg2", .flags = IORESOURCE_MEM},
[2] = {.start = 10, .end = 10, .name = "irq1", .flags = IORESOURCE_IRQ}, //中断号10
[3] = {.start = 0x3000, .end = 0x3003, .name = "reg3", .flags = IORESOURCE_MEM},
[4] = {.start = 100, .end = 100, .name = "irq2", .flags = IORESOURCE_IRQ},
[5] = {.start = 62, .end = 62, .name = "irq3", .flags = IORESOURCE_IRQ},
};
//定义资源数组
static void device_release(struct device *dev)
{
printk("platform: device release\n");
}
struct platform_device_id test_id = { //<---------------
.name = "test_device",
};
struct platform_device test_device = {
.id_entry = &test_id, //<---------------
.name = "test_device",//必须初始化
.dev.release = device_release,
.resource = test_dev_res,
.num_resources = ARRAY_SIZE(test_dev_res),
};
static int __init platform_device_init(void)
{
platform_device_register(&test_device);
return 0;
}
static void __exit platform_device_exit(void)
{
platform_device_unregister(&test_device);
}
module_init(platform_device_init);
module_exit(platform_device_exit);
MODULE_LICENSE("Dual BSD/GPL");
test_driver_id.c
/*platform driver框架*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
static int driver_probe(struct platform_device *dev)
{
struct resource * pres = NULL;
printk("platform: match ok!\n");
pres = platform_get_resource(dev,IORESOURCE_MEM,2);
printk("res.start = 0x%x\n",(unsigned int)pres->start);
pres = platform_get_resource(dev,IORESOURCE_IRQ,1);
printk("res.start = %d\n",(int)pres->start);
return 0;
}
static int driver_remove(struct platform_device *dev)
{
printk("platform: driver remove\n");
return 0;
}
struct platform_device_id testdrv_ids[] = //<---------------
{
[0] = {.name = "test_device"},
[1] = {.name = "xyz"},
[2] = {}, //表示结束符
};
struct platform_driver test_driver = {
.probe = driver_probe,
.remove = driver_remove,
.driver = {
.name = "abc", //必须初始化 //<------名字故意与device不一样
},
.id_table = testdrv_ids, //<---------------
};
static int __init platform_driver_init(void)
{
platform_driver_register(&test_driver);
return 0;
}
static void __exit platform_driver_exit(void)
{
platform_driver_unregister(&test_driver);
}
module_init(platform_driver_init);
module_exit(platform_driver_exit);
MODULE_LICENSE("Dual BSD/GPL");
Makefile
ifeq ($(KERNELRELEASE),)
ifeq ($(ARCH),arm)
KERNELDIR ?= /home/linux/Linux_4412/kernel/linux-3.14
ROOTFS ?= /opt/4412/rootfs
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
endif
PWD := $(shell pwd)
modules:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules INSTALL_MOD_PATH=$(ROOTFS) modules_install
clean:
rm -rf *.o *.ko .*.cmd *.mod.* modules.order Module.symvers .tmp_versions
else
CONFIG_MODULE_SIG=n
#obj-m += fs4412_led_device.o
#obj-m += fs4412_led_driver.o
obj-m += test_driver_id.o
obj-m += test_device_id.o
endif
编译测试
二、ID匹配之led驱动
改写fs4412_led_device_idmatch.c
/*platform device框架*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include "leddrv.h"
#define GPX1CON 0x11000C20
#define GPX1DAT 0x11000C24
#define GPX2CON 0x11000C40
#define GPX2DAT 0x11000C44
#define GPF3CON 0x114001E0
#define GPF3DAT 0x114001E4
//<---------------修改寄存器地址
struct resource fs4412led_dev_res [] =
{
[0] = {.start = GPX1CON, .end = GPX1CON+3, .name = "GPX1CON", .flags = IORESOURCE_MEM},
[1] = {.start = GPX1DAT, .end = GPX1DAT+3, .name = "GPX1DAT", .flags = IORESOURCE_MEM},
[2] = {.start = GPX2CON, .end = GPX2CON+3, .name = "GPX2CON", .flags = IORESOURCE_MEM},
[3] = {.start = GPX2DAT, .end = GPX2DAT+3, .name = "GPX2DAT", .flags = IORESOURCE_MEM},
[4] = {.start = GPF3CON, .end = GPF3CON+3, .name = "GPF3CON", .flags = IORESOURCE_MEM},
[5] = {.start = GPF3DAT, .end = GPF3DAT+3, .name = "GPF3DAT", .flags = IORESOURCE_MEM},
};
//定义资源数组
static void fs4412led_dev_release(struct device *dev)
{
printk("platform: fs4412led_dev_release is called\n");
}
struct platform_device_id fs4412led_id = { //<----------
.name = "fs4412led",
};
struct platform_device fs4412led_device = {
.id_entry = &fs4412led_id, //<-------------
.name = "fs4412led",//必须初始化
.dev.release = fs4412led_dev_release,
.resource = fs4412led_dev_res,
.num_resources = ARRAY_SIZE(fs4412led_dev_res),
};
static int __init fs4412led_dev_init(void)
{
platform_device_register(&fs4412led_device);
return 0;
}
static void __exit fs4412led_dev_exit(void)
{
platform_device_unregister(&fs4412led_device);
}
module_init(fs4412led_dev_init);
module_exit(fs4412led_dev_exit);
MODULE_LICENSE("Dual BSD/GPL");
改写改写fs4412_led_driver_idmatch.c
/*platform driver框架*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include "leddrv.h"
int major = 11;
int minor = 0;
int myled_num = 1;
struct myled_dev
{
struct cdev mydev;
volatile unsigned long *pled2_con;
volatile unsigned long *pled2_dat;
volatile unsigned long *pled3_con;
volatile unsigned long *pled3_dat;
volatile unsigned long *pled4_con;
volatile unsigned long *pled4_dat;
volatile unsigned long *pled5_con;
volatile unsigned long *pled5_dat;
/*
volatile 防止优化。对这块指针指向的内存,有时候cpu会把外设寄存器中的值读到内部寄存器中,方便下次读的时候更快.加了voltatile就不会优化,否则cpu可能会从内部寄存器中读取,而不是去外设寄存器中读取。
*/
struct class *cls; //<-----------------
struct device *dvs; //<-----------------
};
struct myled_dev *pgmydev = NULL;
int myled_open(struct inode *pnode,struct file *pfile)
{
pfile->private_data =(void *) (container_of(pnode->i_cdev,struct myled_dev,mydev));
return 0;
}
int myled_close(struct inode *pnode,struct file *pfile)
{
return 0;
}
void led_on(struct myled_dev *pmydev,int ledno)
{
switch(ledno)
{
case 2:
writel(readl(pmydev->pled2_dat) | (0x1 << 7),pmydev->pled2_dat);
break;
case 3:
writel(readl(pmydev->pled3_dat) | (0x1),pmydev->pled3_dat);
break;
case 4:
writel(readl(pmydev->pled4_dat) | (0x1 << 4),pmydev->pled4_dat);
break;
case 5:
writel(readl(pmydev->pled5_dat) | (0x1 << 5),pmydev->pled5_dat);
break;
}
}
void led_off(struct myled_dev *pmydev,int ledno)
{
switch(ledno)
{
case 2:
writel(readl(pmydev->pled2_dat) & (~(0x1 << 7)),pmydev->pled2_dat);
break;
case 3:
writel(readl(pmydev->pled3_dat) & (~(0x1)),pmydev->pled3_dat);
break;
case 4:
writel(readl(pmydev->pled4_dat) & (~(0x1 << 4)),pmydev->pled4_dat);
break;
case 5:
writel(readl(pmydev->pled5_dat) & (~(0x1 << 5)),pmydev->pled5_dat);
break;
}
}
long myled_ioctl(struct file *pfile,unsigned int cmd,unsigned long arg)
{
struct myled_dev *pmydev = (struct myled_dev *)pfile->private_data;
if(arg < 2 || arg > 5)
{
return -1;
}
switch(cmd)
{
case MY_LED_ON:
led_on(pmydev,arg);
break;
case MY_LED_OFF:
led_off(pmydev,arg);
break;
default:
return -1;
}
return 0;
}
void ioremap_ledreg(struct myled_dev *pmydev,struct platform_device *p_pltdev)
{
struct resource *pres = NULL;
pres = platform_get_resource(p_pltdev,IORESOURCE_MEM,2);
pmydev->pled2_con = ioremap(pres->start,4);
pres = platform_get_resource(p_pltdev,IORESOURCE_MEM,3);
pmydev->pled2_dat = ioremap(pres->start,4);
pres = platform_get_resource(p_pltdev,IORESOURCE_MEM,0);
pmydev->pled3_con = ioremap(pres->start,4);
pres = platform_get_resource(p_pltdev,IORESOURCE_MEM,1);
pmydev->pled3_dat = ioremap(pres->start,4);
pres = platform_get_resource(p_pltdev,IORESOURCE_MEM,4);
pmydev->pled4_con = ioremap(pres->start,4);
pres = platform_get_resource(p_pltdev,IORESOURCE_MEM,5);
pmydev->pled4_dat = ioremap(pres->start,4);
pmydev->pled5_con = pmydev->pled4_con;
pmydev->pled5_dat = pmydev->pled4_dat;
}
void iounmap_ledreg(struct myled_dev *pmydev)
{
iounmap(pmydev->pled2_con);
pmydev->pled2_con = NULL;
iounmap(pmydev->pled2_dat);
pmydev->pled2_dat = NULL;
iounmap(pmydev->pled3_con);
pmydev->pled3_con = NULL;
iounmap(pmydev->pled3_dat);
pmydev->pled3_dat = NULL;
iounmap(pmydev->pled4_con);
pmydev->pled4_con = NULL;
iounmap(pmydev->pled4_dat);
pmydev->pled4_dat = NULL;
pmydev->pled5_con = NULL;
pmydev->pled5_dat = NULL;
}
void set_output_ledconreg(struct myled_dev *pmydev)
{
writel((readl(pmydev->pled2_con) & (~(0xF << 28))) | (0x1 << 28),pmydev->pled2_con);
writel((readl(pmydev->pled3_con) & (~(0xF))) | (0x1),pmydev->pled3_con);
writel((readl(pmydev->pled4_con) & (~(0xF << 16))) | (0x1 << 16),pmydev->pled4_con);
writel((readl(pmydev->pled5_con) & (~(0xF << 20))) | (0x1 << 20),pmydev->pled5_con);
writel(readl(pmydev->pled2_dat) & (~(0x1 << 7)),pmydev->pled2_dat);
writel(readl(pmydev->pled3_dat) & (~(0x1)),pmydev->pled3_dat);
writel(readl(pmydev->pled4_dat) & (~(0x1 << 4)),pmydev->pled4_dat);
writel(readl(pmydev->pled5_dat) & (~(0x1 << 5)),pmydev->pled5_dat);
}
struct file_operations myops = {
.owner = THIS_MODULE,
.open = myled_open,
.release = myled_close,
.unlocked_ioctl = myled_ioctl,
};
static int fs4412led_driver_probe(struct platform_device *p_pltdev)
{
int ret = 0;
dev_t devno = MKDEV(major,minor);
/*申请设备号*/
ret = register_chrdev_region(devno,myled_num,"myled");
if(ret)
{
ret = alloc_chrdev_region(&devno,minor,myled_num,"myled");
if(ret)
{
printk("get devno failed\n");
return -1;
}
major = MAJOR(devno);//容易遗漏,注意
}
pgmydev = (struct myled_dev *)kmalloc(sizeof(struct myled_dev),GFP_KERNEL);
if(NULL == pgmydev)
{
unregister_chrdev_region(devno,myled_num);
printk("kmalloc failed\n");
return -1;
}
memset(pgmydev,0,sizeof(struct myled_dev)); //这里的memset并非c库的函数,而是内核自己实现的memset函数
/*给struct cdev对象指定操作函数集*/
cdev_init(&pgmydev->mydev,&myops);
/*将struct cdev对象添加到内核对应的数据结构里*/
pgmydev->mydev.owner = THIS_MODULE;
cdev_add(&pgmydev->mydev,devno,myled_num);
/*ioremap*/
ioremap_ledreg(pgmydev,p_pltdev);
/*con-register set output*/
set_output_ledconreg(pgmydev);
pgmydev->cls = class_create(THIS_MODULE, "myled");
if(IS_ERR(pgmydev->cls))
{
printk("class_create failed\n");
cdev_del(&pgmydev->mydev);
unregister_chrdev_region(devno,myled_num);
return -1;
}
pgmydev->dvs = device_create(pgmydev->cls, NULL, devno, NULL,"myled");
if(pgmydev->dvs == NULL)
{
printk("device_create failed\n");
class_destroy(pgmydev->cls);
cdev_del(&pgmydev->mydev);
unregister_chrdev_region(devno,myled_num);
return -1;
}
return 0;
}
static int fs4412led_driver_remove(struct platform_device *dev)
{
dev_t devno = MKDEV(major,minor);
/*iounmap*/
iounmap_ledreg(pgmydev);
cdev_del(&pgmydev->mydev);
unregister_chrdev_region(devno,myled_num);
kfree(pgmydev);
pgmydev = NULL;
printk("platform: driver remove\n");
return 0;
}
struct platform_device_id fs4412led_ids[] = //<---------------------
{
[0] = {.name = "fs4412led"},
[1] = {.name = "xyz"},
[2] = {},
};
struct platform_driver fs4412led_driver = {
.probe = fs4412led_driver_probe,
.remove = fs4412led_driver_remove,
.driver = {
.name = "abc", //必须初始化
},
.id_table = fs4412led_ids, //<-------------------------
};
static int __init fs4412led_driver_init(void)
{
platform_driver_register(&fs4412led_driver);
return 0;
}
static void __exit fs4412led_driver_exit(void)
{
platform_driver_unregister(&fs4412led_driver);
return;
}
module_init(fs4412led_driver_init);
module_exit(fs4412led_driver_exit);
MODULE_LICENSE("Dual BSD/GPL");
改写Makefile
ifeq ($(KERNELRELEASE),)
ifeq ($(ARCH),arm)
KERNELDIR ?= /home/linux/Linux_4412/kernel/linux-3.14
ROOTFS ?= /opt/4412/rootfs
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
endif
PWD := $(shell pwd)
modules:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules INSTALL_MOD_PATH=$(ROOTFS) modules_install
clean:
rm -rf *.o *.ko .*.cmd *.mod.* modules.order Module.symvers .tmp_versions
else
CONFIG_MODULE_SIG=n
obj-m += fs4412_led_device_idmatch.o
obj-m += fs4412_led_driver_idmatch.o
endif
编译测试
三、设备树匹配
设备树匹配:内核启动时根据设备树自动产生的设备 ------ 优先级最高(大部分设备的方法)
注意事项:
-
无需编写device模块,只需编写driver模块
-
使用compatible属性进行匹配,注意设备树中compatible属性值不要包含空白字符(空格tab键不可以有)
-
id_table可不设置,但struct platform_driver成员driver的name成员必须设置
-
可以1对多
/*platform driver框架*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
static int driver_probe(struct platform_device *dev)
{
printk("platform: match ok!\n");
return 0;
}
static int driver_remove(struct platform_device *dev)
{
printk("platform: driver remove\n");
return 0;
}
struct platform_device_id testdrv_ids[] =
{
[0] = {.name = "test_device"},
[1] = {.name = "abcxyz"},
[2] = {}, //means ending
};
struct of_device_id test_of_ids[] = //<---------------------也可以1对多
{
[0] = {.compatible = "xyz,abc"},
[1] = {.compatible = "qwe,opq"},
[2] = {},
};
struct platform_driver test_driver = {
.probe = driver_probe,
.remove = driver_remove,
.driver = {
.name = "xxxxx", //必须初始化
.of_match_table = test_of_ids, //<---------------------
},
};
static int __init platform_driver_init(void)
{
platform_driver_register(&test_driver);
return 0;
}
static void __exit platform_driver_exit(void)
{
platform_driver_unregister(&test_driver);
}
module_init(platform_driver_init);
module_exit(platform_driver_exit);
MODULE_LICENSE("Dual BSD/GPL");
四、设备树匹配之led驱动
改写leddrv_dt.c为fs4412_led_driver_treecmatch.c
改写重点创建struct platform_driver结构体,把init和exit改为probe和remove方式
j
这个成员匹配成功后的pnode成员
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include "leddrv.h"
int major = 11;
int minor = 0;
int myled_num = 1;
//不会对寄存器直接操作,改为对设备编号操作
struct myled_dev
{
struct cdev mydev;
unsigned int led2gpio;
unsigned int led3gpio;
unsigned int led4gpio;
unsigned int led5gpio;
};
struct myled_dev *pgmydev = NULL;
int myled_open(struct inode *pnode,struct file *pfile)
{
pfile->private_data =(void *) (container_of(pnode->i_cdev,struct myled_dev,mydev));
return 0;
}
int myled_close(struct inode *pnode,struct file *pfile)
{
return 0;
}
void led_on(struct myled_dev *pmydev,int ledno)
{
switch(ledno)
{
case 2:
gpio_set_value(pmydev->led2gpio,1);
break;
case 3:
gpio_set_value(pmydev->led3gpio,1);
break;
case 4:
gpio_set_value(pmydev->led4gpio,1);
break;
case 5:
gpio_set_value(pmydev->led5gpio,1);
break;
}
}
void led_off(struct myled_dev *pmydev,int ledno)
{
switch(ledno)
{
case 2:
gpio_set_value(pmydev->led2gpio,0);
break;
case 3:
gpio_set_value(pmydev->led3gpio,0);
break;
case 4:
gpio_set_value(pmydev->led4gpio,0);
break;
case 5:
gpio_set_value(pmydev->led5gpio,0);
break;
}
}
long myled_ioctl(struct file *pfile,unsigned int cmd,unsigned long arg)
{
struct myled_dev *pmydev = (struct myled_dev *)pfile->private_data;
if(arg < 2 || arg > 5)
{
return -1;
}
switch(cmd)
{
case MY_LED_ON:
led_on(pmydev,arg);
break;
case MY_LED_OFF:
led_off(pmydev,arg);
break;
default:
return -1;
}
return 0;
}
struct file_operations myops = {
.owner = THIS_MODULE,
.open = myled_open,
.release = myled_close,
.unlocked_ioctl = myled_ioctl,
};
//申请gpio编号,init中会调用
void request_leds_gpio(struct myled_dev *pmydev,struct device_node *pnode)
{
pmydev->led2gpio = of_get_named_gpio(pnode,"led2-gpio",0);
gpio_request(pmydev->led2gpio,"led2");
pmydev->led3gpio = of_get_named_gpio(pnode,"led3-gpio",0);
gpio_request(pmydev->led3gpio,"led3");
pmydev->led4gpio = of_get_named_gpio(pnode,"led4-gpio",0);
gpio_request(pmydev->led4gpio,"led4");
pmydev->led5gpio = of_get_named_gpio(pnode,"led5-gpio",0);
gpio_request(pmydev->led5gpio,"led5");
}
void set_leds_gpio_output(struct myled_dev *pmydev)
{
gpio_direction_output(pmydev->led2gpio,0);
gpio_direction_output(pmydev->led3gpio,0);
gpio_direction_output(pmydev->led4gpio,0);
gpio_direction_output(pmydev->led5gpio,0);
}
void free_leds_gpio(struct myled_dev *pmydev)
{
gpio_free(pmydev->led2gpio);
gpio_free(pmydev->led3gpio);
gpio_free(pmydev->led4gpio);
gpio_free(pmydev->led5gpio);
}
int fs4412led_driver_probe(struct platform_device *p_pltdev)
{
int ret = 0;
dev_t devno = MKDEV(major,minor);
struct device_node *pnode = NULL;
// pnode = of_find_node_by_path("/fs4412-leds");
// if(NULL == pnode)
// {
// printk("find node by path failed\n");
// return -1;
// }
pnode = p_pltdev->dev.of_node; //<---------------------------修改为此种方式获取pnode
/*申请设备号*/
ret = register_chrdev_region(devno,myled_num,"myled");
if(ret)
{
ret = alloc_chrdev_region(&devno,minor,myled_num,"myled");
if(ret)
{
printk("get devno failed\n");
return -1;
}
major = MAJOR(devno);//容易遗漏,注意
}
pgmydev = (struct myled_dev *)kmalloc(sizeof(struct myled_dev),GFP_KERNEL);
if(NULL == pgmydev)
{
unregister_chrdev_region(devno,myled_num);
printk("kmalloc failed\n");
return -1;
}
memset(pgmydev,0,sizeof(struct myled_dev)); //这里的memset并非c库的函数,而是内核自己实现的memset函数
/*给struct cdev对象指定操作函数集*/
cdev_init(&pgmydev->mydev,&myops);
/*将struct cdev对象添加到内核对应的数据结构里*/
pgmydev->mydev.owner = THIS_MODULE;
cdev_add(&pgmydev->mydev,devno,myled_num);
/*ioremap*/
request_leds_gpio(pgmydev,pnode);
/*con-register set output*/
set_leds_gpio_output(pgmydev);
return 0;
}
void fs4412led_driver_remove(struct platform_device *p_pltdev)
{
dev_t devno = MKDEV(major,minor);
/*iounmap*/
free_leds_gpio(pgmydev);
cdev_del(&pgmydev->mydev);
unregister_chrdev_region(devno,myled_num);
kfree(pgmydev);
pgmydev = NULL;
}
struct of_device_id fs4412_of_ids[]= //<--------------------
{
[0] = {.compatible = "fs4412,led2-5"}, //<-----------------
[1] = {.compatible = "qwe,led6-10"},
[2] = {},
};
struct platform_driver fs4412led_driver =
{
.probe = fs4412led_driver_probe,
.remove = fs4412led_driver_remove,
.driver = {
.name = "abcdef",
.of_match_table = fs4412_of_ids, //<-----------------------
},
};
int __init myled_init(void)
{
platform_driver_register(&fs4412led_driver);
return 0;
}
void __exit myled_exit(void)
{
platform_driver_unregister(&fs4412led_driver);
return;
}
MODULE_LICENSE("GPL");
module_init(myled_init);
module_exit(myled_exit);
改写Makefie
ifeq ($(KERNELRELEASE),)
ifeq ($(ARCH),arm)
KERNELDIR ?= /home/linux/Linux_4412/kernel/linux-3.14
ROOTFS ?= /opt/4412/rootfs
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
endif
PWD := $(shell pwd)
modules:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules INSTALL_MOD_PATH=$(ROOTFS) modules_install
clean:
rm -rf *.o *.ko .*.cmd *.mod.* modules.order Module.symvers .tmp_versions
else
CONFIG_MODULE_SIG=n
#obj-m += fs4412_led_device_idmatch.o
#obj-m += fs4412_led_driver_idmatch.o
obj-m += fs4412_led_driver_treematch.o
endif
测试
文章来源:https://www.toymoban.com/news/detail-831244.html
五、一个编写驱动用的宏
熟悉这样的写法,等同于init和exit文章来源地址https://www.toymoban.com/news/detail-831244.html
struct platform_driver xxx = {
...
};
module_platform_driver(xxx);
//最终展开后就是如下形式:
static int __init xxx_init(void)
{
return platform_driver_register(&xxx);
}
module_init(xxx_init);
static void __exit xxx_init(void)
{
return platform_driver_unregister(&xxx);
}
module_exit(xxx_exit)
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