rs485.c

zigbee 飞思卡尔 音频传输 基于ucos的所有源码

/*
 * File:        rs485.c
 * Purpose:     Provide common ColdFire rs485 routines for serial IO
 *
 * Notes:		99% of this code stolen/borrowed from the uart.c and uart.h
 *				examples.
 *	author:		michael.chen
 *	e-mail:		[e-mail]	
 */ 


#include "common.h"
#include "rs485.h"
#define MCF_GPIO_PTD_PAR_PWM7 (0x08)
#define MCF_GPIO_DDR_PWM7	(0x08)
#define MCF_GPIO_OUT_SET	(0x08)

/*
 * To do -- enhance to a more complete driver with interrupts, dma, etc.
 */

/********************************************************************/
/*
 * Initialize the rs485 for 8N1 operation, interrupts disabled, and
 * no hardware flow-control
 *
 * Parameters:
 *  uartch      UART channel to initialize
 *  sysclk      UART System Clock (in KHz)
 *  baud        UART baud rate
 *  settings    Initialization parameters
 * 
 *
 *Note : firstly we should set RXD1 and TXD1 .at hhcf521x-r1-kirin board we use PWM7 to control RS485's ~RE and DE.
 *       here we initialize the rs485 under receive mode.
 */
void 
rs485_init (int uartch, int sysclk, int baud, int settings)
{ 
	register uint16 ubgs;
	/*
	*IPSBAR+005A:PUBPAR
	* 7    6	5	4	 3	2	1	0
	*|	PAR3 |	PAR2  |   PAR1|  PAR0|
*RESET0    0    0   0    0   0  0   0
	*	GPIO	GPIO	 RXD1	TXD1
	* 0    0    0    0   0   1   0   1
	*/
	
    MCF_GPIO_PUBPAR |= 0x05; //set RXD1 and TXD1
    
    /* 
     * Reset Transmitter 
     */
    MCF_UART_UCR(uartch) = MCF_UART_UCR_RESET_TX;

    /* 
     * Reset Receiver 
     */
    MCF_UART_UCR(uartch) = MCF_UART_UCR_RESET_RX;

    /* 
     * Reset Mode Register 
     */
    MCF_UART_UCR(uartch) = MCF_UART_UCR_RESET_MR;

    /* 
     * No parity, 8-bits per character 
     */
    MCF_UART_UMR(uartch) = (0
        | MCF_UART_UMR_PM_NONE
        | MCF_UART_UMR_BC_8);

    /* 
     * No echo or loopback, 1 stop bit 
     */
    MCF_UART_UMR(uartch) = (0
        | MCF_UART_UMR_CM_NORMAL
        | MCF_UART_UMR_SB_STOP_BITS_1);

    /* 
     * Set Rx and Tx baud by timer 
     */
    MCF_UART_UCSR(uartch) = (0
        | MCF_UART_UCSR_RCS_SYS_CLK
        | MCF_UART_UCSR_TCS_SYS_CLK);

    /* 
     * Mask all UART interrupts 
     */
    MCF_UART_UIMR(uartch) = 0;
                 
    /* 
     * Calculate baud settings 
     */
    ubgs = (uint16)((sysclk*1000)/(baud * 32));

    MCF_UART_UBG1(uartch) = (uint8)((ubgs & 0xFF00) >> 8);
    MCF_UART_UBG2(uartch) = (uint8)(ubgs & 0x00FF);

    
    /* 
     * set PWM7 as GPIO, clr PWM7 port,let rs485 into recieve mode
     */
     MCF_GPIO_PTDPAR &= ~MCF_GPIO_PTD_PAR_PWM7; //set pwm7 as GPIO
     MCF_GPIO_DDRTD |=  MCF_GPIO_DDR_PWM7;	//PWM7 is GPIO output
     MCF_GPIO_PORTTD	&= ~MCF_GPIO_OUT_SET;	//PWM7 output have been clear
    
    
    /* 
     * Enable receiver and transmitter 
     */
    MCF_UART_UCR(uartch) = (0
        | MCF_UART_UCR_TX_ENABLED
        | MCF_UART_UCR_RX_ENABLED);
        
        
}
/********************************************************************/
/*
 * Wait for a character to be received on the specified UART
 *
 * Return Values:
 *  the received character
 */
char
rs485_getchar (int channel)
{
    /* Wait until character has been received */
    while (!(MCF_UART_USR(channel) & MCF_UART_USR_RXRDY))
        ; 
    return MCF_UART_URB(channel);
}
/********************************************************************/
/*
 * Wait for space in the UART Tx FIFO and then send a character
 *	finally make UART into receive mode.
 */ 
void
rs485_putchar (int channel, char ch)
{
    
    char i;
    /*set transfer mode*/
    MCF_GPIO_PORTTD	|= MCF_GPIO_OUT_SET;
    
    /* Wait until space is available in the FIFO */
    while (!(MCF_UART_USR(channel) & MCF_UART_USR_TXRDY))
        ;
    /* Send the character */
    MCF_UART_UTB(channel) = (uint8)ch;
        
    
    /*set recieve mode*/
    MCF_GPIO_PORTTD	&= ~MCF_GPIO_OUT_SET;
	

}
/********************************************************************/
/*
 * Check to see if a character has been received
 *
 * Return values:
 *  0       No character received
 *  1       Character has been received
 */
int
rs485_getchar_present (int channel)
{
    return (MCF_UART_USR(channel) & MCF_UART_USR_RXRDY);
}
/********************************************************************/



/*******************************************************************/
/*
 *
 *the task of test the rs485 module
 *  
 *function: sent from "a" to "z" into 485 module.and then wait for 
 *			the 485's input for output 26 characters again.
 *				
 *
 *
 *
 *
 *
 */
OS_STK	AppTaskRs485Stk[256];			// The TaskStack for the rs485 Task 
void  AppTaskRs485 (void * pdata)
{
	char i = 0;
	rs485_init(1,SYS_CLK_KHZ,115200,NULL);
	while(1)
	{
		printf("\nstart to output 26 charater in 485 port!\n");
		for(i=0;i<26;i++)
		{
			rs485_putchar (1,'a'+i);	//output 26 charaters
		}
		
	
		
		/*
		 * Special chars like
		 * '\n' or '\t' are normally converted to the appropriate
		 * character by the __compiler__.  Thus, no need for this
		 * routine to account for the '\' character.
		 */
		 
			/*
			 * This needs to be replaced with something like
			 * 'out_char()' or call an OS routine.
			 */
#ifndef UNIX_DEBUG							//out '\n'

	 	rs485_putchar (1,0x0D /* CR */);
		rs485_putchar (1,0x0A /* LF */);
	
#else
		rs485_putchar (1,'\n');				
#endif

		printf("\ninput a charater in 485 port! let 485 port these 26 charaters again!\n");
		
		i = rs485_getchar (1);			//wait for rs485 intput


#ifndef UNIX_DEBUG							//out '\n'

	 	rs485_putchar (1,0x0D /* CR */);
		rs485_putchar (1,0x0A /* LF */);
	
#else
		rs485_putchar (1,'\n');				
#endif		
		
		OSTimeDly(50);
		
	}
}