linux driver --- platform框架应用完整实例
作者：互联网
平台设备文件
button_device.c
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
static void button_release(struct device *dev)
{
printk("%s\n", __FUNCTION__);
return;
}
struct resource button_resource[] = {
{
.start = 0x20c406c,
.end = 0x20c406c+3, // IORESOURCE_MEM必须要加上end，不然会报错
.name = "CCGR",
.flags = IORESOURCE_MEM,
},
{
.start = 0x229000c,
.end = 0x229000c+3,
.name = "SW_MUX_CTL",
.flags = IORESOURCE_MEM,
},
{
.start = 0x2290050,
.end = 0x2290050+3,
.name = "SW_PAD_CTL",
.flags = IORESOURCE_MEM,
},
{
.start = 0x20ac004,
.end = 0x20ac004+3,
.name = "GDIR",
.flags = IORESOURCE_MEM,
},
{
.start = 0x20ac008,
.end = 0x20ac008+3,
.name = "PSR",
.flags = IORESOURCE_MEM,
},
{
.start = 1,
.end = 0,
.name = "pin",
.flags = IORESOURCE_IRQ,
},
{
.start = 30,
.end = 0,
.name = "clock_offset",
.flags = IORESOURCE_IRQ,
},
};
struct platform_device button_device = {
.name = "my_button", // 这个名字必须要和设备资源结构体里面的name一致，不然这两个模块匹配不了
.id = -1,
.num_resources = ARRAY_SIZE(button_resource),
.resource = button_resource,
.dev = {
.release = button_release,
},
};
// 入口函数
static int button_platform_device_init(void)
{
int ret = 0;
printk("%s\n", __FUNCTION__);
ret = platform_device_register(&button_device); // 注册设备信息
return ret;
}
// 出口函数
static void button_platform_device_exit(void)
{
printk("%s\n", __FUNCTION__);
platform_device_unregister(&button_device);
}
module_init(button_platform_device_init);
module_exit(button_platform_device_exit);
MODULE_LICENSE("GPL");
平台驱动文件
button_driver.c
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/kmod.h>
#include <linux/gfp.h>
#include <asm/mach/map.h>
#include <linux/platform_device.h>
#include <asm/io.h>
static u32 *vi_ccgr;
static u32 *vi_mux_ctl;
static u32 *vi_pad_ctl;
static u32 *vi_gdir;
static u32 *vi_psr;
static u32 pin;
static u32 clock_offset;
static int major = 0;
static struct class *button_class;
static ssize_t button_drv_read(struct file * file, char __user * buf, size_t size, loff_t *offset)
{
char status = 0;
int ret;
if (*vi_psr & (1<<pin)) {
//printk("按键点击了\n");
status = 1;
} else {
status = 0;
}
ret = copy_to_user(buf, &status, 1);
return 1;
}
static ssize_t button_drv_write(struct file *file, const char __user *buf, size_t size, loff_t *offset)
{
printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
return 0;
}
static int button_drv_open(struct inode *node, struct file *file)
{
// 初始化设备
*(vi_ccgr) |= (3<<clock_offset);
*(vi_mux_ctl) &= ~0xf;
*(vi_mux_ctl) |= 0x5;
*(vi_gdir) &= ~(1<<pin);
printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
return 0;
}
static int button_drv_close(struct inode *node, struct file *file)
{
printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
return 0;
}
static struct file_operations button_opr = {
.open = button_drv_open,
.release = button_drv_close,
.read = button_drv_read,
.write = button_drv_write,
};
static int button_probe(struct platform_device *pdev)
{
int i = 0;
struct resource *res;
u32 ph_addr[5];
int err;
// 获取资源
for (i=0;i<5;i++) {
res = platform_get_resource(pdev, IORESOURCE_MEM, i);
if (res == NULL) {
printk("not get resource\n");
return -1;
}
ph_addr[i] = res->start;
}
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
pin = res->start;
res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
clock_offset = res->start;
// 内存映射
vi_ccgr = ioremap(ph_addr[0], 4);
vi_mux_ctl = ioremap(ph_addr[1], 4);
vi_pad_ctl = ioremap(ph_addr[2], 4);
vi_gdir = ioremap(ph_addr[3], 4);
vi_psr = ioremap(ph_addr[4], 4);
// 完成设备注册的操作
// register_chrdev() class_create() device_create()
major = register_chrdev(0, "my_button", &button_opr);
button_class = class_create(THIS_MODULE, "button_class");
err = PTR_ERR(button_class);
if (IS_ERR(button_class)) {
unregister_chrdev(major, "my_button");
return -1;
}
device_create(button_class, NULL, MKDEV(major, 0), NULL, "my_button");
printk("%s\n", __FUNCTION__);
return 0;
}
static int button_remove(struct platform_device *pdev)
{
printk("%s\n", __FUNCTION__);
// 释放虚拟内存
iounmap(vi_ccgr);
iounmap(vi_mux_ctl);
iounmap(vi_pad_ctl);
iounmap(vi_gdir);
iounmap(vi_psr);
// 完成设备取消注册的操作
device_destroy(button_class, MKDEV(major,0));
class_destroy(button_class);
unregister_chrdev(major, "my_button");
printk("%s\n", __FUNCTION__);
return 0;
}
struct platform_driver button_driver = {
.probe = button_probe,
.remove = button_remove,
.driver = {
.name = "my_button",
},
};
// 入口函数
static int button_platform_driver_init(void)
{
int ret = 0;
printk("%s\n", __FUNCTION__);
ret = platform_driver_register(&button_driver); // 注册设备信息
return ret;
}
// 出口函数
static void button_platform_driver_exit(void)
{
printk("%s\n", __FUNCTION__);
platform_driver_unregister(&button_driver); // 注册设备信息
}
module_init(button_platform_driver_init);
module_exit(button_platform_driver_exit);
MODULE_LICENSE("GPL");
应用层测试程序
button_test.c
#include<stdio.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>
int main(int argc, char **argv)
{
int fd;
char status = 0;
int ret = 0;
int bnt = 0;
if (argc !=2 ) {
printf("Usage: %s <dev-path>\n", argv[0]);
return -1;
}
fd = open(argv[1], O_RDWR);
if (fd < 0) {
perror("open error");
return -1;
}
while(1) {
ret = read(fd, &status, 1);
if (ret < 0) {
perror("read error");
return -1;
} else if (ret == 1 && status == 1) {
printf("button %d\n", bnt++);
}
}
return 0;
}
Makefile文件
Makefile
ARCH=arm
CROSS_COMPILE=arm-linux-gnueabihf- // 该参数与你的交叉编译工具有关
export ARCH CROSS_COMPILE
KERN_DIR = /home/hxd/workdir/ebf_linux_kernel_6ull_depth1/build_image/build // 该目录与你的编译好的内核目录有关
all:
make -C $(KERN_DIR) M=`pwd` modules
$(CROSS_COMPILE)gcc -o button_test button_test.c
clean:
make -C $(KERN_DIR) M=`pwd` modules clean
rm -rf modules.order
rm -f button_test
obj-m += button_device.o button_driver.o
编译运行
编译好后将得到的button_device.ko，button_driver.ko和button_test拷贝到开发板上
标签：__,button,driver,---,platform,static,device,include 来源： https://www.cnblogs.com/god-of-death/p/16656420.html