-/*! \file ccspi.c
- \author Travis Goodspeed
- \brief Chipcon SPI Register Interface
-*/
-
-//Higher level left to client application.
-
-#include "platform.h"
-#include "command.h"
-
-#include <signal.h>
-#include <io.h>
-#include <iomacros.h>
-
-#include "ccspi.h"
-#include "spi.h"
-
-
-#define RADIOACTIVE SETCE
-#define RADIOPASSIVE CLRCE
-
-//! Set up the pins for CCSPI mode.
-void ccspisetup(){
- SETSS;
- P5DIR&=~MISO;
- P5DIR|=MOSI+SCK;
- DIRSS;
- DIRCE;
-
- //Begin a new transaction.
- CLRSS;
- SETSS;
-}
-
-//! Read and write an CCSPI byte.
-u8 ccspitrans8(u8 byte){
- register unsigned int bit;
- //This function came from the CCSPI Wikipedia article.
- //Minor alterations.
-
- for (bit = 0; bit < 8; bit++) {
- /* write MOSI on trailing edge of previous clock */
- if (byte & 0x80)
- SETMOSI;
- else
- CLRMOSI;
- byte <<= 1;
-
- SETCLK;
-
- /* read MISO on trailing edge */
- byte |= READMISO;
- CLRCLK;
- }
-
- return byte;
-}
-
-
-//! Writes a register
-u8 ccspi_regwrite(u8 reg, const u8 *buf, int len){
- CLRSS;
-
- reg=ccspitrans8(reg);
- while(len--)
- ccspitrans8(*buf++);
-
- SETSS;
- return reg;//status
-}
-//! Reads a register
-u8 ccspi_regread(u8 reg, u8 *buf, int len){
- CLRSS;
-
- reg=ccspitrans8(reg);
- while(len--)
- *buf++=ccspitrans8(0);
-
- SETSS;
- return reg;//status
-}
-
-//! Handles a Chipcon SPI command.
-void ccspihandle(unsigned char app,
- unsigned char verb,
- unsigned long len){
- unsigned long i;
-
- //Drop CE to passify radio.
- RADIOPASSIVE;
- //Raise !SS to end transaction, just in case we forgot.
- SETSS;
- ccspisetup();
-
- switch(verb){
- //PEEK and POKE might come later.
- case READ:
- case WRITE:
- CLRSS; //Drop !SS to begin transaction.
- for(i=0;i<len;i++)
- cmddata[i]=ccspitrans8(cmddata[i]);
- SETSS; //Raise !SS to end transaction.
- txdata(app,verb,len);
- break;
-
- case PEEK://Grab CCSPI Register
- CLRSS; //Drop !SS to begin transaction.
- ccspitrans8(CCSPI_R_REGISTER | cmddata[0]); //000A AAAA
- for(i=1;i<len;i++)
- cmddata[i]=ccspitrans8(cmddata[i]);
- SETSS; //Raise !SS to end transaction.
- txdata(app,verb,len);
- break;
-
- case POKE://Poke CCSPI Register
- CLRSS; //Drop !SS to begin transaction.
- ccspitrans8(CCSPI_W_REGISTER | cmddata[0]); //001A AAAA
- for(i=1;i<len;i++)
- cmddata[i]=ccspitrans8(cmddata[i]);
- SETSS; //Raise !SS to end transaction.
- txdata(app,verb,len);
- break;
- case SETUP:
- ccspisetup();
- txdata(app,verb,0);
- break;
- case CCSPI_RX:
- RADIOPASSIVE;
- //Get the packet.
- CLRSS;
- ccspitrans8(CCSPI_R_RX_PAYLOAD);
- for(i=0;i<32;i++)
- cmddata[i]=ccspitrans8(0xde);
- SETSS;
- //no break
- txdata(app,verb,32);
- break;
- case CCSPI_RX_FLUSH:
- //Flush the buffer.
- CLRSS;
- ccspitrans8(CCSPI_FLUSH_RX);
- SETSS;
-
- //Return the packet.
- txdata(app,verb,32);
- break;
- case CCSPI_TX:
- case CCSPI_TX_FLUSH:
- default:
- debugstr("Not yet supported.");
- txdata(app,verb,0);
- break;
- }
-
-
- SETSS;//End session
- RADIOACTIVE;
-}