Csi驱动代码

CSI驱动的代码通常需要根据具体的硬件平台和系统架构进行编写，下面是一个简单的CSI驱动代码示例，仅供参考：

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/ioctl.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <asm/io.h>

#define CSI_MAGIC 'c'
#define CSI_START_CAPTURE _IO(CSI_MAGIC, 0)
#define CSI_STOP_CAPTURE _IO(CSI_MAGIC, 1)

#define CSI_BUFFER_SIZE (1024 * 1024)

struct csi_buffer {
    unsigned int size;
    unsigned char *data;
    dma_addr_t dma_addr;
};

struct csi_device {
    struct cdev cdev;
    struct class *class;
    struct device *device;
    struct platform_device *pdev;
    struct device_node *node;
    struct resource *mem;
    struct csi_buffer buffer;
    int irq;
};

static int csi_open(struct inode *inode, struct file *file)
{
    struct csi_device *csi_dev = container_of(inode->i_cdev, struct csi_device, cdev);
    file->private_data = csi_dev;
    return 0;
}

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

static long csi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    struct csi_device *csi_dev = file->private_data;
    switch (cmd) {
        case CSI_START_CAPTURE:
            // 启动采集
            break;
        case CSI_STOP_CAPTURE:
            // 停止采集
            break;
        default:
            return -EINVAL;
    }
    return 0;
}

static ssize_t csi_read(struct file *file, char __user *buf, size_t size, loff_t *offset)
{
    struct csi_device *csi_dev = file->private_data;
    if (size > csi_dev->buffer.size) {
        size = csi_dev->buffer.size;
    }
    if (copy_to_user(buf, csi_dev->buffer.data, size)) {
        return -EFAULT;
    }
    return size;
}

static const struct file_operations csi_fops = {
    .owner = THIS_MODULE,
    .open = csi_open,
    .release = csi_release,
    .read = csi_read,
    .unlocked_ioctl = csi_ioctl,
};

static int csi_probe(struct platform_device *pdev)
{
    struct csi_device *csi_dev;
    struct resource *mem;
    struct device_node *node = pdev->dev.of_node;
    int ret;

    csi_dev = devm_kzalloc(&pdev->dev, sizeof(struct csi_device), GFP_KERNEL);
    if (!csi_dev) {
        dev_err(&pdev->dev, "failed to allocate memory\n");
        return -ENOMEM;
    }

    csi_dev->node = node;
    csi_dev->pdev = pdev;

    mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!mem) {
        dev_err(&pdev->dev, "failed to get memory resource\n");
        return -ENODEV;
    }
    csi_dev->mem = mem;

    csi_dev->buffer.size = CSI_BUFFER_SIZE;
    csi_dev->buffer.data = dma_alloc_coherent(&pdev->dev, csi_dev->buffer.size,
                                               &csi_dev->buffer.dma_addr, GFP_KERNEL);
    if (!csi_dev->buffer.data) {
        dev_err(&pdev->dev, "failed to allocate buffer memory\n");
        return -ENOMEM;
    }

    ret = devm_request_irq(&pdev->dev, csi_dev->irq, csi_isr, 0, "csi", csi_dev);
    if (ret) {
        dev_err(&pdev->dev, "failed to request irq\n");
        return ret;
    }

    cdev_init(&csi_dev->cdev, &csi_fops);
    csi_dev->cdev.owner = THIS_MODULE;
    ret = cdev_add(&csi_dev->cdev, dev, 1);
    if (ret) {
        dev_err(&pdev->dev, "failed to add character device\n");
        return ret;
    }

    csi_dev->class = class_create(THIS_MODULE, "csi");
    if (IS_ERR(csi_dev->class)) {
        dev_err(&pdev->dev, "failed to create class\n");
        return PTR_ERR(csi_dev->class);
    }

    csi_dev->device = device_create(csi_dev->class, NULL, MKDEV(major, 0), NULL, "csi%d", 0);
    if (IS_ERR(csi_dev->device)) {
        dev_err(&pdev->dev, "failed to create device\n");
        return PTR_ERR(csi_dev->device);
    }

    platform_set_drvdata(pdev, csi_dev);

    return 0;
}

static int csi_remove(struct platform_device *pdev)
{
    struct csi_device *csi_dev = platform_get_drvdata(pdev);
    dma_free_coherent(&pdev->dev, csi_dev->buffer.size,
                      csi_dev->buffer.data, csi_dev->buffer.dma_addr);
    device_destroy(csi_dev->class, MKDEV(major, 0));
    class_destroy(csi_dev->class);
    cdev_del(&csi_dev->cdev);
    return 0;
}

static const struct of_device_id csi_of_match[] = {
    { .compatible = "vendor,device-csi", },
    { },
};

MODULE_DEVICE_TABLE(of, csi_of_match);

static struct platform_driver csi_driver = {
    .driver = {
        .name = "csi",
        .of_match_table = csi_of_match,
    },
    .probe = csi_probe,
    .remove = csi_remove,
};

static int __init csi_init(void)
{
    int ret;
    ret = platform_driver_register(&csi_driver);
    if (ret) {
        pr_err("failed to register platform driver\n");
        return ret;
    }
    return 0;
}

static void __exit csi_exit(void)
{
    platform_driver_unregister(&csi_driver);
}

module_init(csi_init);
module_exit(csi_exit);

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

以上代码仅为示例，实际实现中需要根据具体的硬件平台和系统架构进行适当的调整和修改。