帮我写一段TMS320F28335要通过spi读写cav25128芯片，spi的初始化代码，要兼容普通gpio模拟spi

好的，以下是TMS320F28335通过SPI读写cav25128芯片的初始化代码，同时兼容普通GPIO模拟SPI：

#include "F28335_spi.h"

#define GPIO_SIM_SPI_MISO       GPIO_Number_0
#define GPIO_SIM_SPI_MOSI       GPIO_Number_1
#define GPIO_SIM_SPI_SCLK       GPIO_Number_2
#define GPIO_SIM_SPI_CS         GPIO_Number_3

void GPIO_SIM_SPI_Init(void)
{
    EALLOW;
    GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 0;  // Configure GPIO0 as MISO
    GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 0;  // Configure GPIO1 as MOSI
    GpioCtrlRegs.GPAMUX1.bit.GPIO2 = 0;  // Configure GPIO2 as SCLK
    GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 0;  // Configure GPIO3 as CS
    GpioCtrlRegs.GPADIR.bit.GPIO0 = 0;   // Configure GPIO0 as input
    GpioCtrlRegs.GPADIR.bit.GPIO1 = 1;   // Configure GPIO1 as output
    GpioCtrlRegs.GPADIR.bit.GPIO2 = 1;   // Configure GPIO2 as output
    GpioCtrlRegs.GPADIR.bit.GPIO3 = 1;   // Configure GPIO3 as output
    EDIS;
}

void SPI_Init(void)
{
    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.SPIAENCLK = 1;  // Enable SPI clock

    SpiaRegs.SPICCR.bit.SPISWRESET = 0;    // Reset SPI
    SpiaRegs.SPICCR.bit.CLKPOLARITY = 0;   // Set clock polarity
    SpiaRegs.SPICCR.bit.SPICHAR = 7;       // Set character length
    SpiaRegs.SPICCR.bit.SPILBK = 0;        // Disable loopback mode
    SpiaRegs.SPICCR.bit.HS_MODE = 0;       // Set low speed mode
    SpiaRegs.SPICCR.bit.SPICHAR = 7;       // Set character length
    SpiaRegs.SPICCR.bit.SPISWRESET = 1;    // Enable SPI

    SpiaRegs.SPICTL.bit.SPIINTENA = 0;     // Disable interrupts
    SpiaRegs.SPICTL.bit.SPIRXINTENA = 0;   // Disable RX interrupts
    SpiaRegs.SPICTL.bit.MASTER_SLAVE = 1;  // Set as master
    SpiaRegs.SPICTL.bit.TALK = 1;          // Enable transmission
    SpiaRegs.SPICTL.bit.CLK_PHASE = 0;     // Set clock phase
    SpiaRegs.SPICTL.bit.OVERRUNINTENA = 0; // Disable overrun interrupts
    SpiaRegs.SPICTL.bit.CLK_MODE = 1;      // Set to 16-bit mode

    SpiaRegs.SPIBRR.bit.SPI_BIT_RATE = 255; // Set baud rate (adjust as needed)

    SpiaRegs.SPIPRI.bit.FREE = 1;          // Free run mode
    SpiaRegs.SPIPRI.bit.SOFT = 1;          // Set software control
    SpiaRegs.SPIPRI.bit.TRIWIRE = 0;       // Set to 4-wire mode
    SpiaRegs.SPIPRI.bit.STEINV = 1;        // Invert enable signal

    SpiaRegs.SPICCR.bit.SPILBK = 0;        // Disable loopback mode
    SpiaRegs.SPICCR.bit.HS_MODE = 0;       // Set low speed mode
    SpiaRegs.SPICCR.bit.SPICHAR = 7;       // Set character length
    SpiaRegs.SPICCR.bit.SPISWRESET = 1;    // Enable SPI

    GPIO_SIM_SPI_Init();

    EDIS;
}

void SPI_Write(uint16_t data)
{
    GpioDataRegs.GPACLEAR.bit.GPIO3 = 1;   // Assert CS
    SpiaRegs.SPITXBUF = data;              // Send data
    while(SpiaRegs.SPISTS.bit.INT_FLAG == 0); // Wait for transmission to complete
    GpioDataRegs.GPASET.bit.GPIO3 = 1;     // Deassert CS
}

uint16_t SPI_Read(void)
{
    uint16_t data;
    GpioDataRegs.GPACLEAR.bit.GPIO3 = 1;   // Assert CS
    SpiaRegs.SPITXBUF = 0xFF;              // Dummy write to start SPI
    while(SpiaRegs.SPISTS.bit.INT_FLAG == 0); // Wait for transmission to complete
    data = SpiaRegs.SPIRXBUF;              // Read data
    GpioDataRegs.GPASET.bit.GPIO3 = 1;     // Deassert CS
    return data;
}

以上代码中，`GPIO_SIM_SPI_Init()`函数用于初始化GPIO口，将4个GPIO口分别配置为MISO、MOSI、SCLK和CS，并设置方向；`SPI_Init()`函数用于初始化SPI，并设置为主机模式，设置传输参数、时钟等；`SPI_Write()`和`SPI_Read()`函数分别用于写入和读取数据，通过`SpiaRegs.SPITXBUF`和`SpiaRegs.SPIRXBUF`寄存器进行数据交换，同时对CS进行控制。

需要注意的是，以上代码中的SPI读写函数只适用于硬件SPI模式，如果需要在GPIO口上模拟SPI，需要进行相应的修改。