帮我用rt thread写一段gd32的spi驱动代码

以下是使用RT-Thread编写的GD32的SPI驱动代码示例：

#include <rtthread.h>
#include "gd32_spi.h"

#define SPI_BUS_NAME    "spi1"

static struct rt_spi_device spi_device;

static void gd32_spi_bus_init(void)
{
    /* 初始化SPI总线 */
    rcu_periph_clock_enable(RCU_GPIOA);
    rcu_periph_clock_enable(RCU_SPI1);

    gpio_init(GPIOA, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_5 | GPIO_PIN_6 | GPIO_PIN_7);
    spi_parameter_struct spi_init_struct;
    spi_init_struct.trans_mode           = SPI_TRANSMODE_FULLDUPLEX;
    spi_init_struct.device_mode          = SPI_MASTER;
    spi_init_struct.frame_size           = SPI_FRAMESIZE_8BIT;
    spi_init_struct.clock_polarity_phase = SPI_CK_PL_HIGH_PH_2EDGE;
    spi_init_struct.nss                  = SPI_NSS_SOFT;
    spi_init_struct.prescale             = SPI_PSC_32;
    spi_init(SPI1, &spi_init_struct);

    spi_enable(SPI1);
}

static rt_err_t gd32_spi_bus_configure(struct rt_spi_device *device, struct rt_spi_configuration *configuration)
{
    rt_uint32_t spi_crc = 0;

    struct rt_spi_configuration *cfg = (struct rt_spi_configuration *)configuration;

    if (cfg->data_width > 8)
    {
        return -RT_ERROR;
    }

    if (cfg->mode & RT_SPI_CPOL)
    {
        spi_crc |= SPI_CK_PL_LOW;
    }
    else
    {
        spi_crc |= SPI_CK_PL_HIGH;
    }

    if (cfg->mode & RT_SPI_CPHA)
    {
        spi_crc |= SPI_CK_PH_2EDGE;
    }
    else
    {
        spi_crc |= SPI_CK_PH_1EDGE;
    }

    switch (cfg->data_width)
    {
        case 8:
            spi_crc |= SPI_FRAMESIZE_8BIT;
            break;
        case 16:
            spi_crc |= SPI_FRAMESIZE_16BIT;
            break;
        case 32:
            spi_crc |= SPI_FRAMESIZE_32BIT;
            break;
        default:
            spi_crc |= SPI_FRAMESIZE_8BIT;
            break;
    }

    /* 配置SPI设备 */
    spi_device.dev_id = (void *)device;
    spi_device.spi_device.cs_pin = device->chip_select;
    spi_device.spi_device.mode = cfg->mode;
    spi_device.spi_device.data_width = cfg->data_width;

    return RT_EOK;
}

static rt_uint32_t gd32_spi_bus_xfer(struct rt_spi_device *device, struct rt_spi_message *message)
{
    rt_uint32_t i;
    rt_uint32_t length = message->length;
    rt_uint8_t *send_ptr = message->send_buf;
    rt_uint8_t *recv_ptr = message->recv_buf;

    if (message->cs_take)
    {
        /* 选中SPI设备 */
        rt_pin_write(device->chip_select, PIN_LOW);
    }

    /* 发送数据 */
    for (i = 0; i < length; i++)
    {
        while (RESET == spi_i2s_flag_get(SPI1, SPI_FLAG_TBE));
        spi_i2s_data_transmit(SPI1, *send_ptr);
        while (RESET == spi_i2s_flag_get(SPI1, SPI_FLAG_RBNE));
        *recv_ptr = spi_i2s_data_receive(SPI1);

        send_ptr++;
        recv_ptr++;
    }

    if (message->cs_release)
    {
        /* 取消选中SPI设备 */
        rt_pin_write(device->chip_select, PIN_HIGH);
    }

    return i;
}

static struct rt_spi_ops gd32_spi_ops =
{
    .configure = gd32_spi_bus_configure,
    .xfer = gd32_spi_bus_xfer,
};

int rt_hw_spi_init(void)
{
    /* 初始化SPI总线 */
    gd32_spi_bus_init();

    /* 注册SPI总线 */
    rt_spi_bus_register(&spi_bus, SPI_BUS_NAME, &gd32_spi_ops);

    return RT_EOK;
}

在这个示例中，我们首先定义了一个SPI总线名称，然后定义了一个名为spi_device的结构体，用于存储SPI设备的信息。接着，我们实现了gd32_spi_bus_init函数，用于初始化SPI总线；然后实现了gd32_spi_bus_configure和gd32_spi_bus_xfer函数，用于配置和传输数据。最后，我们通过gd32_spi_ops结构体定义了SPI操作函数，然后调用rt_spi_bus_register函数注册SPI总线。

需要注意的是，以上代码中的某些宏定义和函数调用可能需要根据具体的GD32芯片型号进行调整。