平台设备驱动包括两部分:平台设别驱动模块和平台设备模块,平台设备包含设备占用的资源,比如说端口、中断等,而平台设备驱动则是正真的设备驱动,通过设备名称完成匹配,需要完成设备操作接口。下面是MINI2440的设备模块和设备驱动模块以及测试模块代码:
led_device.c:
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <mach/irqs.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <linux/cdev.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
MODULE_AUTHOR("WK") ;
MODULE_LICENSE("GPL") ;
static void led_release()
{
printk("led device is released!\n") ;
}
static struct resource led_resource[]={
[0]={
.start=0x56000010,
.end=0x56000018,
.flags=IORESOURCE_MEM,
},
[1]={
.start=5 ,
.end=5 ,
.flags=IORESOURCE_IRQ,
},
};
static struct platform_device led_device={
.name="led_platform" ,
.id = -1 ,
.dev = {
.release= led_release,
},
.num_resources =ARRAY_SIZE(led_resource) ,
.resource = led_resource ,
} ;
static int __init led_init()
{
platform_device_register(&led_device) ;
return 0 ;
}
static void __exit led_exit()
{
platform_device_unregister(&led_device) ;
}
module_init(led_init) ;
module_exit(led_exit) ;
led_driver.c
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/io.h>
MODULE_AUTHOR("WK") ;
MODULE_LICENSE("Dual BSD/GPL") ;
volatile static unsigned int *gpb_con=NULL ;
volatile static unsigned int *gpb_dat=NULL ;
static int led_ioctl(
struct inode *inode,
struct file * file,
unsigned int cmd,
unsigned int arg
)
{
if(cmd>1||arg>3){
return -EINVAL ;
}
switch(cmd){
case 0:
*gpb_dat |=(0b01<<(5+arg)) ;
break ;
case 1:
*gpb_dat &= (~(0b01<<(5+arg))) ;
break ;
default:
return -EINVAL ;
}
return 0 ;
}
static struct file_operations led_fops={
.owner = THIS_MODULE ,
.ioctl = led_ioctl,
} ;
static struct miscdevice led_dev={
.minor = MISC_DYNAMIC_MINOR,
.name = "led_platform",
.fops = &led_fops,
};
static int led_probe(struct platform_device *dev)
{
int ret = -1 ;
struct resource *ptr_res = NULL ;
ptr_res = platform_get_resource(dev,IORESOURCE_MEM,0) ;
if(ptr_res == NULL) {
dev_err(dev, "no memory resource specified!\n") ;
return -ENOENT ;
}
int mem_size=ptr_res->end-ptr_res->start+1 ;
gpb_con = ioremap(ptr_res->start, mem_size) ;
gpb_dat =gpb_con + 1 ;
ret = misc_register(&led_dev) ;
// /*
*gpb_con &= (~(0b11111111<<5*2)) ;
*gpb_con |= (0b01010101<<2*5);
*gpb_dat &= (~(0b1111<<5)) ;
// */
/*
*gpb_con &= (~((0x11<<5*2) | (0x11<<6*2) | (0x11<<7*2) | (0x11<<8*2))) ;
*gpb_con |= (0x01<<5*2) | (0x01<<6*2) | (0x01<<7*2) | (0x01<<8*2) ;
*gpb_dat &= (~((0x01<<5) | (0x01<<6) | (0x01<<7) | (0x01<<8) )) ;
*/
printk("led deivce is probed!\n") ;
return ret ;
}
static int led_remove(
struct platform_device *dev
)
{
misc_deregister(&led_dev) ;
iounmap(gpb_con) ;
printk("led device is removed!\n") ;
}
static struct platform_driver led_driver={
.probe = led_probe ,
.remove = led_remove ,
.driver = {
.name = "led_platform" ,
.owner = THIS_MODULE ,
},
} ;
static int __init init_led_drv(void)
{
platform_driver_register(&led_driver) ;
return 0 ;
}
static void __exit exit_led_drv(void)
{
platform_driver_unregister(&led_driver) ;
}
module_init(init_led_drv) ;
module_exit(exit_led_drv) ;
测试代码:
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include "sys/types.h"
#include "sys/ioctl.h"
#include "fcntl.h"
int main() {
int fd=-1 ;
int i,j ;
fd=open("/dev/led_platform",O_RDWR) ;
if(fd<0) {
printf("open led device failed!\n") ;
return -1 ;
}
i=0 ;
while(1) {
if(i%2) {
ioctl(fd,0,0) ;
ioctl(fd,1,1) ;
ioctl(fd,0,2) ;
ioctl(fd,1,3) ;
}else {
ioctl(fd,1,0) ;
ioctl(fd,0,1) ;
ioctl(fd,1,2) ;
ioctl(fd,0,3) ;
}
sleep(1) ;
i++ ;
}
close(fd) ;
return 0 ;
}
Makefile:
CC=arm-linux-gcc
KDIR=/root/workspace/mini2440/linux-2.6.32.2
ifeq ($(driver),1)
ifneq ($(KERNELRELEASE),)
obj-m:=led_device.o led_driver.o
else
PWD=$(shell pwd)
module:
$(MAKE) -C $(KDIR) M=$(PWD) modules
endif
install:
insmod led_device.ko led_driver.ko
uninstall:
rmmod led_device led_driver
endif
ifeq ($(driver),0)
OBJS=main.o
CFLAGS=-Wall -g -O
CFLAGS+=-I $(KDIR)
CFLAGS+=-static
main:$(OBJS)
$(CC) $(OBJS) -o main
$(OBJS):%o:%c
$(CC) -c $(CFLAGS) $< -o $@
endif
clean:
rm -fr *.o *.ko main *.order *.symvers *.mod*
通过make driver=1命令编译驱动,通过make driver=0编译测试文件