mirror of
https://e.coding.net/weidongshan/linux/doc_and_source_for_drivers.git
synced 2025-12-02 04:41:19 +08:00
add 09_UART/07
This commit is contained in:
weidongshan
@@ -0,0 +1,21 @@
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# 1. 使用不同的开发板内核时, 一定要修改KERN_DIR
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# 2. KERN_DIR中的内核要事先配置、编译, 为了能编译内核, 要先设置下列环境变量:
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# 2.1 ARCH, 比如: export ARCH=arm64
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# 2.2 CROSS_COMPILE, 比如: export CROSS_COMPILE=aarch64-linux-gnu-
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# 2.3 PATH, 比如: export PATH=$PATH:/home/book/100ask_roc-rk3399-pc/ToolChain-6.3.1/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu/bin
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# 注意: 不同的开发板不同的编译器上述3个环境变量不一定相同,
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# 请参考各开发板的高级用户使用手册
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KERN_DIR = /home/book/100ask_imx6ull-sdk/Linux-4.9.88
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all:
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make -C $(KERN_DIR) M=`pwd` modules
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$(CROSS_COMPILE)gcc -o hello_drv_test hello_drv_test.c
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clean:
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make -C $(KERN_DIR) M=`pwd` modules clean
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rm -rf modules.order
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rm -f hello_drv_test
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obj-m += hello_drv.o
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@@ -0,0 +1,104 @@
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/errno.h>
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#include <linux/miscdevice.h>
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#include <linux/kernel.h>
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#include <linux/major.h>
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#include <linux/mutex.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/stat.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/tty.h>
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#include <linux/kmod.h>
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#include <linux/gfp.h>
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/* 1. 确定主设备号 */
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static int major = 0;
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static char kernel_buf[1024];
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static struct class *hello_class;
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#define MIN(a, b) (a < b ? a : b)
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/* 3. 实现对应的open/read/write等函数，填入file_operations结构体 */
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static ssize_t hello_drv_read (struct file *file, char __user *buf, size_t size, loff_t *offset)
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{
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int err;
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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err = copy_to_user(buf, kernel_buf, MIN(1024, size));
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return MIN(1024, size);
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}
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static ssize_t hello_drv_write (struct file *file, const char __user *buf, size_t size, loff_t *offset)
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{
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int err;
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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err = copy_from_user(kernel_buf, buf, MIN(1024, size));
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return MIN(1024, size);
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}
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static int hello_drv_open (struct inode *node, struct file *file)
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{
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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return 0;
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}
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static int hello_drv_close (struct inode *node, struct file *file)
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{
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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return 0;
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}
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/* 2. 定义自己的file_operations结构体 */
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static struct file_operations hello_drv = {
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.owner = THIS_MODULE,
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.open = hello_drv_open,
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.read = hello_drv_read,
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.write = hello_drv_write,
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.release = hello_drv_close,
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};
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/* 4. 把file_operations结构体告诉内核：注册驱动程序 */
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/* 5. 谁来注册驱动程序啊？得有一个入口函数：安装驱动程序时，就会去调用这个入口函数 */
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static int __init hello_init(void)
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{
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int err;
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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major = register_chrdev(0, "hello", &hello_drv); /* /dev/hello */
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hello_class = class_create(THIS_MODULE, "hello_class");
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err = PTR_ERR(hello_class);
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if (IS_ERR(hello_class)) {
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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unregister_chrdev(major, "hello");
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return -1;
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}
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device_create(hello_class, NULL, MKDEV(major, 0), NULL, "hello"); /* /dev/hello */
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return 0;
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}
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/* 6. 有入口函数就应该有出口函数：卸载驱动程序时，就会去调用这个出口函数 */
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static void __exit hello_exit(void)
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{
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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device_destroy(hello_class, MKDEV(major, 0));
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class_destroy(hello_class);
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unregister_chrdev(major, "hello");
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}
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/* 7. 其他完善：提供设备信息，自动创建设备节点 */
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module_init(hello_init);
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module_exit(hello_exit);
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MODULE_LICENSE("GPL");
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@@ -0,0 +1,54 @@
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <string.h>
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/*
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* ./hello_drv_test -w abc
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* ./hello_drv_test -r
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*/
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int main(int argc, char **argv)
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{
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int fd;
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char buf[1024];
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int len;
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/* 1. 判断参数 */
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if (argc < 2)
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{
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printf("Usage: %s -w <string>\n", argv[0]);
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printf(" %s -r\n", argv[0]);
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return -1;
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}
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/* 2. 打开文件 */
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fd = open("/dev/hello", O_RDWR);
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if (fd == -1)
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{
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printf("can not open file /dev/hello\n");
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return -1;
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}
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/* 3. 写文件或读文件 */
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if ((0 == strcmp(argv[1], "-w")) && (argc == 3))
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{
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len = strlen(argv[2]) + 1;
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len = len < 1024 ? len : 1024;
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write(fd, argv[2], len);
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}
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else
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{
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len = read(fd, buf, 1024);
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buf[1023] = '\0';
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printf("APP read : %s\n", buf);
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}
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close(fd);
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return 0;
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}
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@@ -0,0 +1,21 @@
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# 1. 使用不同的开发板内核时, 一定要修改KERN_DIR
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# 2. KERN_DIR中的内核要事先配置、编译, 为了能编译内核, 要先设置下列环境变量:
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# 2.1 ARCH, 比如: export ARCH=arm64
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# 2.2 CROSS_COMPILE, 比如: export CROSS_COMPILE=aarch64-linux-gnu-
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# 2.3 PATH, 比如: export PATH=$PATH:/home/book/100ask_roc-rk3399-pc/ToolChain-6.3.1/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu/bin
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# 注意: 不同的开发板不同的编译器上述3个环境变量不一定相同,
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# 请参考各开发板的高级用户使用手册
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KERN_DIR = /home/book/100ask_imx6ull-sdk/Linux-4.9.88
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all:
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make -C $(KERN_DIR) M=`pwd` modules
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$(CROSS_COMPILE)gcc -o hello_drv_test hello_drv_test.c
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clean:
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make -C $(KERN_DIR) M=`pwd` modules clean
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rm -rf modules.order
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rm -f hello_drv_test
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obj-m += hello_drv.o
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@@ -0,0 +1,114 @@
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/errno.h>
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#include <linux/miscdevice.h>
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#include <linux/kernel.h>
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#include <linux/major.h>
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#include <linux/mutex.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/stat.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/tty.h>
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#include <linux/kmod.h>
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#include <linux/gfp.h>
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/* 1. 确定主设备号 */
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static int major = 0;
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static struct cdev hello_cdev;
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static char kernel_buf[1024];
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static struct class *hello_class;
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#define MIN(a, b) (a < b ? a : b)
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/* 3. 实现对应的open/read/write等函数，填入file_operations结构体 */
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static ssize_t hello_drv_read (struct file *file, char __user *buf, size_t size, loff_t *offset)
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{
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int err;
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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err = copy_to_user(buf, kernel_buf, MIN(1024, size));
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return MIN(1024, size);
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}
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static ssize_t hello_drv_write (struct file *file, const char __user *buf, size_t size, loff_t *offset)
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{
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int err;
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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err = copy_from_user(kernel_buf, buf, MIN(1024, size));
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return MIN(1024, size);
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}
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static int hello_drv_open (struct inode *node, struct file *file)
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{
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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return 0;
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}
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static int hello_drv_close (struct inode *node, struct file *file)
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{
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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return 0;
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}
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/* 2. 定义自己的file_operations结构体 */
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static struct file_operations hello_drv = {
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.owner = THIS_MODULE,
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.open = hello_drv_open,
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.read = hello_drv_read,
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.write = hello_drv_write,
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.release = hello_drv_close,
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};
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/* 4. 把file_operations结构体告诉内核：注册驱动程序 */
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/* 5. 谁来注册驱动程序啊？得有一个入口函数：安装驱动程序时，就会去调用这个入口函数 */
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static int __init hello_init(void)
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{
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int err;
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int rc;
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dev_t devid;
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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//major = register_chrdev(0, "hello", &hello_drv); /* /dev/hello */
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rc = alloc_chrdev_region(&devid, 0, 1, "hello");
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major = MAJOR(devid);
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cdev_init(&hello_cdev, &hello_drv);
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cdev_add(&hello_cdev, devid, 1);
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hello_class = class_create(THIS_MODULE, "hello_class");
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err = PTR_ERR(hello_class);
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if (IS_ERR(hello_class)) {
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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unregister_chrdev(major, "hello");
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return -1;
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}
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device_create(hello_class, NULL, MKDEV(major, 0), NULL, "hello"); /* /dev/hello */
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return 0;
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}
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/* 6. 有入口函数就应该有出口函数：卸载驱动程序时，就会去调用这个出口函数 */
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static void __exit hello_exit(void)
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{
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printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
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device_destroy(hello_class, MKDEV(major, 0));
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class_destroy(hello_class);
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//unregister_chrdev(major, "hello");
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cdev_del(&hello_cdev);
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unregister_chrdev_region(MKDEV(major,0), 1);
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}
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/* 7. 其他完善：提供设备信息，自动创建设备节点 */
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module_init(hello_init);
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module_exit(hello_exit);
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MODULE_LICENSE("GPL");
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@@ -0,0 +1,54 @@
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <string.h>
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/*
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* ./hello_drv_test -w abc
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* ./hello_drv_test -r
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*/
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int main(int argc, char **argv)
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{
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int fd;
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char buf[1024];
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int len;
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/* 1. 判断参数 */
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if (argc < 2)
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{
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printf("Usage: %s -w <string>\n", argv[0]);
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printf(" %s -r\n", argv[0]);
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return -1;
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}
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/* 2. 打开文件 */
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fd = open("/dev/hello", O_RDWR);
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if (fd == -1)
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{
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printf("can not open file /dev/hello\n");
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return -1;
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}
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/* 3. 写文件或读文件 */
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if ((0 == strcmp(argv[1], "-w")) && (argc == 3))
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{
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len = strlen(argv[2]) + 1;
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len = len < 1024 ? len : 1024;
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write(fd, argv[2], len);
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}
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else
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{
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len = read(fd, buf, 1024);
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buf[1023] = '\0';
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printf("APP read : %s\n", buf);
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}
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close(fd);
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return 0;
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}
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Reference in New Issue
Block a user