linux内核添加spi驱动

#include <linux/module.h>
#include <linux/spi/spidev.h>
#include <linux/fs.h>

static struct spi_device *spi_dev;

static int spi_open(struct inode *inode, struct file *file) {
    return 0;
}

static ssize_t spi_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) {
    int ret;
    char tx_buf[] = {0x01, 0x80, 0x00};
    char rx_buf[3];

    ret = spi_sync_transfer(spi_dev, tx_buf, rx_buf, sizeof(tx_buf));
    if (ret < 0) {
        return ret;
    }

    if (copy_to_user(buf, rx_buf, sizeof(rx_buf))) {
        return -EFAULT;
    }

    return sizeof(rx_buf);
}

static struct file_operations spi_fops = {
    .owner = THIS_MODULE,
    .open = spi_open,
    .read = spi_read,
};

static int __init spi_init(void) {
    struct spi_master *master;
    int ret;

    master = spi_busnum_to_master(0); // 假设SPI总线号为0
    spi_dev = spi_new_device(master, &spi_dev_info);
    if (!spi_dev) {
        return -ENODEV;
    }

    ret = register_chrdev(240, "spi_device", &spi_fops);
    if (ret < 0) {
        spi_unregister_device(spi_dev);
        return ret;
    }

    return 0;
}

static void __exit spi_exit(void) {
    unregister_chrdev(240, "spi_device");
    spi_unregister_device(spi_dev);
}

module_init(spi_init);
module_exit(spi_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Simple SPI Driver");
MODULE_AUTHOR("Your Name");