学习ALINX_ZYNQ(7Z020开发板SDK)第二天——RS485串口

/* Definitions for peripheral PS7_GPIO_0 */
//串口器件ID
#define RS485_DEVICE_ID      		XPAR_PS7_UART_0_DEVICE_ID
#define RS485_INTC_DEVICE_ID		XPAR_SCUGIC_SINGLE_DEVICE_ID//中断的设备ID
#define RS485_UART_INT_IRQ_ID		XPAR_XUARTPS_0_INTR//串口的中断号
#define XPAR_PS7_GPIO_0_DEVICE_ID 0
XUartPsFormat UartFormat =
{
		9600,
		XUARTPS_FORMAT_8_BITS,
		XUARTPS_FORMAT_NO_PARITY,
		XUARTPS_FORMAT_1_STOP_BIT
};

//串口
int uart_init(void)
{
	static int status;
	//设置RS485
	PsGpioSetup();
	//串口初始化
    status = uart_config();
    //串口中断初始化
    uart_intr(); 
    return status;
}

int PsGpioSetup(void)
{
	int Status;
	/* Initial RS485_0 DE */
	XGpioPs_Config *GPIO_CONFIG ;
	GPIO_CONFIG = XGpioPs_LookupConfig(XPAR_PS7_GPIO_0_DEVICE_ID) ;
	Status = XGpioPs_CfgInitialize(&rs485_0_de, GPIO_CONFIG, GPIO_CONFIG->BaseAddr) ;
	if (Status != XST_SUCCESS)
	{
		return XST_FAILURE ;
	}
	/* set MIO 9 as output */
	XGpioPs_SetDirectionPin(&rs485_0_de, 9, 1) ;
	/* enable MIO 9 output */
	XGpioPs_SetOutputEnablePin(&rs485_0_de, 9, 1) ;
	return XST_SUCCESS ;
}

//串口初始化
int uart_config(void)
{
		int Status;
		XUartPs_Config *Config;
		//根据器件ID查找配置信息
		Config = XUartPs_LookupConfig(RS485_DEVICE_ID);
		if (NULL == Config) {
			return XST_FAILURE;
		}
		//根据配置信息对PS UART进行初始化
		Status = XUartPs_CfgInitialize(&Uart_PS, Config, Config->BaseAddress);
		if (Status != XST_SUCCESS) {
			return XST_FAILURE;
		}
		/* Check hardware build./检查硬件搭配是否正确 */
		Status = XUartPs_SelfTest(&Uart_PS);
		if (Status != XST_SUCCESS) {
			return XST_FAILURE;
		}
		/* Use Normal mode. */
		XUartPs_SetOperMode(&Uart_PS, XUARTPS_OPER_MODE_NORMAL);
		/* Set uart mode Baud Rate 115200, 8bits, no parity, 1 stop bit */
		XUartPs_SetDataFormat(&Uart_PS, &UartFormat) ;
		return 1;
}

//串口中断初始化
int uart_intr(void)
{
	/*Set receiver FIFO interrupt trigger level, here set to 32*/
	XUartPs_SetFifoThreshold(&Uart_PS,32);
	//超时时间
	XUartPs_SetRecvTimeout(&Uart_PS,10);
	//RX FIFO trigger interrupt Timeout error interrupt
	XUartPs_SetInterruptMask(&Uart_PS,XUARTPS_IXR_RXOVR|XUARTPS_IXR_TOUT);
	SetupInterruptSystem(&IntcInstPtr, &Uart_PS, RS485_UART_INT_IRQ_ID) ;
	XGpioPs_WritePin(&rs485_0_de, 9, 0) ;
	return 2;
}

int SetupInterruptSystem(XScuGic *IntcInstancePtr,	XUartPs *UartInstancePtr, u16 UartIntrId)
{
	int Status;
	/* Configuration for interrupt controller */
	XScuGic_Config *IntcConfig;
	/* Initialize the interrupt controller driver */
	IntcConfig = XScuGic_LookupConfig(RS485_INTC_DEVICE_ID);
	if (NULL == IntcConfig) {
		return XST_FAILURE;
	}
	Status = XScuGic_CfgInitialize(IntcInstancePtr, IntcConfig,
			IntcConfig->CpuBaseAddress);
	if (Status != XST_SUCCESS) {
		return XST_FAILURE;
	}
	   //设置并打开中断异常处理功能
	    Xil_ExceptionInit();
	/*
	 * Connect the interrupt controller interrupt handler to the
	 * hardware interrupt handling logic in the processor.
	 */
	Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
			(Xil_ExceptionHandler) XScuGic_InterruptHandler,
			IntcInstancePtr);
	Status = XScuGic_Connect(IntcInstancePtr, UartIntrId,
			(Xil_ExceptionHandler) Handler,
			(void *) UartInstancePtr);
	if (Status != XST_SUCCESS) {
		return XST_FAILURE;
	}
	XScuGic_Enable(IntcInstancePtr, UartIntrId);
	Xil_ExceptionEnable();
	return Status ;
}