spi驱动

SPI驱动使用直接调用内核函数是否合适？

发布于 2022-11-28 16:21:13 浏览：257 订阅该版

硬件平台：GD32F4xx

在使用SPI驱动时，发现应用层调用SPI配置，其实还是直接调用`spi_core.c`内的函数，而不是通过通用的`read` `write` `control`接口

且如果采用目前的`read` `write`接口不适用，因为通常的SPI通讯都是发送完一个地址之后读取数据，但是现在的read和write都是单独的纯写或者纯读
```c

rt_size_t rt_spi_transfer(struct rt_spi_device *device,
                          const void           *send_buf,
                          void                 *recv_buf,
                          rt_size_t             length)
{
    rt_err_t result;
    struct rt_spi_message message;

RT_ASSERT(device != RT_NULL);
    RT_ASSERT(device->bus != RT_NULL);

result = rt_mutex_take(&(device->bus->lock), RT_WAITING_FOREVER);
    if (result == RT_EOK)
    {
        if (device->bus->owner != device)
        {
            /* not the same owner as current, re-configure SPI bus */
            result = device->bus->ops->configure(device, &device->config);
            if (result == RT_EOK)
            {
                /* set SPI bus owner */
                device->bus->owner = device;
            }
            else
            {
                /* configure SPI bus failed */
                rt_set_errno(-RT_EIO);
                result = 0;
                goto __exit;
            }
        }

/* initial message */
        message.send_buf   = send_buf;
        message.recv_buf   = recv_buf;
        message.length     = length;
        message.cs_take    = 1;
        message.cs_release = 1;
        message.next       = RT_NULL;

/* transfer message */
        result = device->bus->ops->xfer(device, &message);
        if (result == 0)
        {
            rt_set_errno(-RT_EIO);
            goto __exit;
        }
    }
    else
    {
        rt_set_errno(-RT_EIO);

return 0;
    }

__exit:
    rt_mutex_release(&(device->bus->lock));

return result;
}
```

个人觉得可以修改`spi_dev.c`和`spi_core.c`来完善此驱动，大家觉得有必要吗？