linux dma应用程序

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>

static int dma_transfer(struct device *dev, struct scatterlist *sg, unsigned int num_sg)
{
    struct dma_chan *chan;
    struct dma_async_tx_descriptor *tx;
    dma_cookie_t cookie;

    chan = dma_request_channel(dev, "dma_channel", NULL);
    if (!chan) {
        printk(KERN_ERR "Failed to request DMA channel
");
        return -ENODEV;
    }

    tx = dmaengine_prep_slave_sg(chan, sg, num_sg, DMA_MEM_TO_DEV, NULL);
    if (!tx) {
        printk(KERN_ERR "Failed to prepare DMA transaction
");
        dma_release_channel(chan);
        return -EIO;
    }

    cookie = dmaengine_submit(tx);
    if (dma_submit_error(cookie)) {
        printk(KERN_ERR "Failed to submit DMA transaction
");
        dmaengine_terminate(chan);
        dma_release_channel(chan);
        return -EIO;
    }

    dma_async_issue_pending(chan);
    dma_release_channel(chan);

    return 0;
}

static int __init dma_init(void)
{
    printk(KERN_INFO "DMA module loaded
");
    return 0;
}

static void __exit dma_exit(void)
{
    printk(KERN_INFO "DMA module unloaded
");
}

module_init(dma_init);
module_exit(dma_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("DMA Transfer Example");
MODULE_AUTHOR("Your Name");