实现Linux内核UART驱动架构教程

整体流程

在实现Linux内核UART驱动架构时，主要涉及以下几个步骤：

步骤 操作
1 编写UART驱动的核心模块代码
2 注册UART驱动模块
3 实现UART设备的Probe和Remove函数
4 设置串口参数和中断处理
5 编译内核并加载模块

操作指引

步骤一：编写UART驱动的核心模块代码

// uart_driver.c

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/serial_core.h>

static int uart_open(struct inode *inode, struct file *filp) {
    // 打开串口
}

static int uart_release(struct inode *inode, struct file *filp) {
    // 关闭串口
}

static ssize_t uart_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) {
    // 读取数据
}

static ssize_t uart_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) {
    // 写入数据
}

static struct file_operations uart_fops = {
    .owner = THIS_MODULE,
    .open = uart_open,
    .release = uart_release,
    .read = uart_read,
    .write = uart_write,
};

static int __init uart_init(void) {
    // 初始化串口驱动
}

static void __exit uart_exit(void) {
    // 退出串口驱动
}

module_init(uart_init);
module_exit(uart_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("UART Driver");

步骤二：注册UART驱动模块

// uart_driver.c

static struct platform_driver uart_driver = {
    .driver = {
        .name = "uart_driver",
        .owner = THIS_MODULE,
    },
};

static int __init uart_init(void) {
    // 注册串口驱动
}

static void __exit uart_exit(void) {
    // 注销串口驱动
}

步骤三：实现UART设备的Probe和Remove函数

// uart_driver.c

static int uart_probe(struct platform_device *pdev) {
    // 探测串口设备
}

static int uart_remove(struct platform_device *pdev) {
    // 移除串口设备
}

static struct platform_driver uart_driver = {
    .driver = {
        .name = "uart_driver",
        .owner = THIS_MODULE,
    },
    .probe = uart_probe,
    .remove = uart_remove,
};

步骤四：设置串口参数和中断处理

// uart_driver.c

static void uart_set_params(struct uart_port *port) {
    // 设置串口参数
}

static irqreturn_t uart_interrupt(int irq, void *dev_id) {
    // 中断处理
}

static struct uart_driver uart_drv = {
    .driver_name = "uart_driver",
    .setup_port = uart_set_params,
    .handle_irq = uart_interrupt,
};

步骤五：编译内核并加载模块

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- menuconfig
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- zImage
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- modules
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- dtbs
$ sudo make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- INSTALL_MOD_PATH=/path/to/rootfs modules_install
$ sudo cp arch/arm/boot/zImage /path/to/boot
$ sudo cp arch/arm/boot/dts/*.dtb /path/to/boot/dtbs
$ sudo cp arch/arm/boot/dts/*.dtb /path/to/boot/dtbs
$ sudo cp drivers/uart/uart_driver.ko /path/to/rootfs/lib/modules/4.14.75/extra
$ sudo depmod -a -b /path/to/rootfs/ 4.14.75
$ sudo chroot /path/to/rootfs
# insmod /lib/modules/4.14.75/extra/uart_driver.ko

类图

classDiagram
    class UARTDriver {
        -uart_open()
        -uart_release()
        -uart_read()
        -uart_write()
        +uart_init()
        +uart_exit()
    }
    class PlatformDriver {
        +uart_probe()
        +uart_remove()
    }
    class UARTDriver {
        +uart_set_params()
        +uart