Beginning Chipcon SPI support.

git-svn-id: https://svn.code.sf.net/p/goodfet/code/trunk@629 12e2690d-a6be-4b82-a7b7-67c4a43b65c8

diff --git a/firmware/apps/radios/cc.c b/firmware/apps/radios/cc.c
new file mode 100644 (file)
index 0000000..e1cb9bb
--- /dev/null
+++ b/firmware/apps/radios/cc.c
@@ -0,0 +1,158 @@
+/*! \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;
+}