CCSPI bug fixes.

[goodfet] / firmware / apps / radios / ccspi.c

diff --git a/firmware/apps/radios/ccspi.c b/firmware/apps/radios/ccspi.c
index 54b155c..9a9c13d 100644 (file)
--- a/firmware/apps/radios/ccspi.c
+++ b/firmware/apps/radios/ccspi.c
@@ -154,7 +154,43 @@ void ccspireflexjam(u16 delay){
 #endif
 }
 
+//! Writes bytes into the CC2420's RAM.  Untested.
+void ccspi_pokeram(u8 addr, char *data, int len){
+  CLRSS;
+  //Begin with the start address.
+  ccspitrans8(0x80 | (addr & 0x7F)); 
+  ccspitrans8(((addr>>1)&0xC0) // MSBits are high bits of 9-bit address.
+                              // Read/!Write bit should be clear to write.
+             );
+  
+  //Data goes here.
+  while(len--)
+    ccspitrans8(*data++);
+  
+  SETSS;
+}
+
+//! Read bytes from the CC2420's RAM.  Untested.
+void ccspi_peekram(u16 addr, u8 *data, u16 len){
+  CLRSS;
+  
+  //Begin with the start address.
+  ccspitrans8(0x80 | (addr & 0x7F));
+  ccspitrans8(((addr>>1)&0xC0) // MSBits are high bits of 9-bit address.
+             | BIT5           // Read/!Write bit should be set to read.
+             ); 
+  
+  //Data goes here.
+  while(len--)
+    *data++=ccspitrans8(0);
+  
+  SETSS;
+}
 
+//! Updates the Nonce's sequence number.
+void ccspi_updaterxnonce(u32 seq){
+  
+}
 
 //! Writes a register
 u8 ccspi_regwrite(u8 reg, const u8 *buf, int len){
@@ -207,18 +243,42 @@ void ccspi_handle_fn( uint8_t const app,
     ccspisetup();
     txdata(app,verb,0);
     break;
+  case CCSPI_PEEK_RAM:
+    i=cmddataword[1]; // Backup length.
+    ccspi_peekram(cmddataword[0], // First word is the address.
+                  cmddata,        // Return in the same buffer.
+                  cmddataword[1]  // Second word is the length.
+                  );
+    txdata(app,verb,i);
+    break;
+  case CCSPI_POKE_RAM:
+    ccspi_pokeram(cmddataword[0], //First word is address
+                 cmddata+2,      //Remainder of buffer is dat.
+                 len-2           //Length implied by packet length.
+                 );
+    txdata(app,verb,0);
+    break;
   case CCSPI_RX:
 #ifdef FIFOP
     //Has there been an overflow?
     if((!FIFO)&&FIFOP){
-      //debugstr("Clearing overflow");
+      debugstr("Clearing overflow");
       CLRSS;
       ccspitrans8(0x08); //SFLUSHRX
+      ccspitrans8(0x08); //SFLUSHRX
       SETSS;
+      txdata(app,verb,0); //no packet
+      return;
     }
-
+    
+    /* Uncomment this to wait around a bit for the packet.
+       Might reduce dropped packet count.
+    i=1000; //Number of tries.
+    while(!(FIFOP&&FIFO) && i--);
+    */
+    
     //Is there a packet?
-    if(FIFOP&&FIFO){
+    if (FIFOP && FIFO){
       //Wait for completion.
       while(SFD);
       
@@ -226,20 +286,101 @@ void ccspi_handle_fn( uint8_t const app,
       CLRSS;
       ccspitrans8(CCSPI_RXFIFO | 0x40);
       //ccspitrans8(0x3F|0x40);
-      cmddata[0]=0xff; //to be replaced with length
-      for(i=0;i<cmddata[0]+2;i++)
-        cmddata[i]=ccspitrans8(0xde);
+      cmddata[0]=0x20; //to be replaced with length
+      
+      
+      /* This reads too far on some CC2420 revisions, but on others it
+        works fine.  It probably has to do with whether FIFO drops
+        before or after the SPI clocking.
+        
+        A software fix is to reset the CC2420 between packets.  This
+        works, but a better solution is desired.
+      */
+      //for(i=0;i<cmddata[0]+1;i++)
+      for(i=0;FIFO && i<0x80;i++)
+        cmddata[i]=ccspitrans8(0x00);
       SETSS;
 
-      //Flush buffer.
+      /* We used to flush the RX buffer after receive. No longer.
+      CLRSS;
+      ccspitrans8(0x08); //SFLUSHRX
+      SETSS;
+      */
+      
+      //Only transmit a packet if the length is legal.
+      if(cmddata[0]&0x80 || cmddata[0]==0) i=0;
+      txdata(app,verb,i);
+    }else{
+      
+      //No packet.
+      txdata(app,verb,0);
+    }
+#else
+    debugstr("Can't RX a packet with SFD and FIFOP definitions.");
+    txdata(app,NOK,0);
+#endif
+    break;
+  case CCSPI_RXDEC:
+#ifdef FIFOP
+    //Has there been an overflow?
+    if((!FIFO)&&FIFOP){
+      debugstr("Clearing overflow");
       CLRSS;
       ccspitrans8(0x08); //SFLUSHRX
       SETSS;
+      txdata(app,verb,0); //no packet
+      return;
+    }
+
+    //Is there a packet?
+    if(FIFOP&&FIFO){
+      //Wait for completion.
+      while(SFD);
+      
+      CLRSS;
+      ccspitrans8(CCSPI_RXFIFO | 0x40);
+      // Grab the length.
+      cmddata[0]=ccspitrans8(0x00);
+      
+      //Read the header first.
+      for(i=1;i<cmddata[0]+1 && i<0x11;i++)
+        cmddata[i]=ccspitrans8(0x00);
+      SETSS;
+      
+      //Is the frame encrypted?
+      if(cmddata[1]&BIT3){
+       //Copy the sequence number to the Nonce.
+       
+       
+       //Decrypt the rest of the packet.
+       CLRSS; ccspitrans8(CCSPI_SRXDEC); SETSS;
+       
+       //Wait for decryption to complete.
+       while(!FIFO);
+      
+      }
+      
+      
+      //Get the packet, which is now decrypted in position.
+      CLRSS;
+      ccspitrans8(CCSPI_RXFIFO | 0x40);
+      //ccspitrans8(0x3F|0x40);
       
       
-      //Only should transmit length of one more than the reported
-      // length of the frame, which holds the length byte:
-      txdata(app,verb,cmddata[0]+1);
+      /* This reads too far on some CC2420 revisions, but on others it
+        works fine.  It probably has to do with whether FIFO drops
+        before or after the SPI clocking.
+        
+        A software fix is to reset the CC2420 between packets.  This
+        works, but a better solution is desired.
+      */
+      for(;i<cmddata[0]+1;i++)
+        cmddata[i]=ccspitrans8(0x00);
+      SETSS;
+      
+      //Only forward a packet if the length is legal.
+      if(cmddata[0]&0x80) i=0;
+      txdata(app,verb,i);
     }else{
       //No packet.
       txdata(app,verb,0);