写一个linux下lpc_matster控制器的驱动

LPC Master Controller是一种用于Linux系统中的串行总线控制器，常被用于I2C和SPI总线。以下是一个简单的LPC Master Controller驱动程序示例：

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/delay.h>

#define DEVICE_NAME "lpc_master"
#define CLASS_NAME "lpc_class"

static struct class *lpc_class;
static struct device *lpc_device;

static struct i2c_adapter *lpc_adapter;
static struct i2c_client *lpc_client;

static int lpc_open(struct inode *inode, struct file *file)
{
    printk(KERN_INFO "lpc_master: Device opened.\n");
    return 0;
}

static int lpc_release(struct inode *inode, struct file *file)
{
    printk(KERN_INFO "lpc_master: Device closed.\n");
    return 0;
}

static ssize_t lpc_read(struct file *file, char *buffer, size_t length, loff_t *offset)
{
    // Read data from I2C/SPI bus using lpc_client
    return length;
}

static ssize_t lpc_write(struct file *file, const char *buffer, size_t length, loff_t *offset)
{
    // Write data to I2C/SPI bus using lpc_client
    return length;
}

static struct file_operations lpc_fops = {
    .owner = THIS_MODULE,
    .open = lpc_open,
    .release = lpc_release,
    .read = lpc_read,
    .write = lpc_write,
};

static int __init lpc_init(void)
{
    int ret = 0;
    printk(KERN_INFO "lpc_master: Initializing driver.\n");

    // Create class
    lpc_class = class_create(THIS_MODULE, CLASS_NAME);
    if (IS_ERR(lpc_class)) {
        printk(KERN_ALERT "lpc_master: Failed to create class.\n");
        return PTR_ERR(lpc_class);
    }

    // Create device
    lpc_device = device_create(lpc_class, NULL, MKDEV(0,0), NULL, DEVICE_NAME);
    if (IS_ERR(lpc_device)) {
        printk(KERN_ALERT "lpc_master: Failed to create device.\n");
        class_destroy(lpc_class);
        return PTR_ERR(lpc_device);
    }

    // Get I2C adapter
    lpc_adapter = i2c_get_adapter(0);
    if (!lpc_adapter) {
        printk(KERN_ALERT "lpc_master: Failed to get I2C adapter.\n");
        device_destroy(lpc_class, MKDEV(0,0));
        class_destroy(lpc_class);
        return -ENODEV;
    }

    // Create I2C client
    lpc_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
    if (!lpc_client) {
        printk(KERN_ALERT "lpc_master: Failed to allocate memory for I2C client.\n");
        i2c_put_adapter(lpc_adapter);
        device_destroy(lpc_class, MKDEV(0,0));
        class_destroy(lpc_class);
        return -ENOMEM;
    }

    // Set I2C client properties
    strlcpy(lpc_client->name, "lpc_slave", I2C_NAME_SIZE);
    lpc_client->addr = 0x50;

    // Attach I2C client to adapter
    lpc_client->adapter = lpc_adapter;
    ret = i2c_add_client(lpc_client);
    if (ret) {
        printk(KERN_ALERT "lpc_master: Failed to add I2C client to adapter.\n");
        kfree(lpc_client);
        i2c_put_adapter(lpc_adapter);
        device_destroy(lpc_class, MKDEV(0,0));
        class_destroy(lpc_class);
        return ret;
    }

    // Register device
    ret = register_chrdev(0, DEVICE_NAME, &lpc_fops);
    if (ret < 0) {
        printk(KERN_ALERT "lpc_master: Failed to register device.\n");
        i2c_del_client(lpc_client);
        kfree(lpc_client);
        i2c_put_adapter(lpc_adapter);
        device_destroy(lpc_class, MKDEV(0,0));
        class_destroy(lpc_class);
        return ret;
    }

    printk(KERN_INFO "lpc_master: Driver initialized.\n");
    return 0;
}

static void __exit lpc_exit(void)
{
    printk(KERN_INFO "lpc_master: Exiting driver.\n");

    // Unregister device
    unregister_chrdev(0, DEVICE_NAME);

    // Remove I2C client
    i2c_del_client(lpc_client);
    kfree(lpc_client);

    // Release I2C adapter
    i2c_put_adapter(lpc_adapter);

    // Destroy device
    device_destroy(lpc_class, MKDEV(0,0));

    // Destroy class
    class_destroy(lpc_class);
}

module_init(lpc_init);
module_exit(lpc_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("LPC Master Controller Driver");

以上代码仅作为驱动程序的示例，具体实现可能需要根据硬件和应用场景进行修改。