Steps toward plugin support.

[goodfet] / firmware / apps / spi / spi.c

diff --git a/firmware/apps/spi/spi.c b/firmware/apps/spi/spi.c
index 2b53914..f4c6560 100644 (file)
--- a/firmware/apps/spi/spi.c
+++ b/firmware/apps/spi/spi.c
@@ -17,6 +17,7 @@
 #define MISO BIT2
 #define SCK  BIT3
 
+
 //This could be more accurate.
 //Does it ever need to be?
 #define SPISPEED 0
@@ -31,20 +32,23 @@
 
 
 //! Set up the pins for SPI mode.
-unsigned char spisetup(){
+void spisetup(){
+  P5OUT|=SS;
   P5DIR|=MOSI+SCK+SS;
   P5DIR&=~MISO;
+  
+  //Begin a new transaction.
+  P5OUT&=~SS; 
   P5OUT|=SS;
 }
 
+
 //! Read and write an SPI bit.
 unsigned char spitrans8(unsigned char byte){
   unsigned int bit;
   //This function came from the SPI Wikipedia article.
   //Minor alterations.
   
-  P5OUT&=~SS;
-  
   for (bit = 0; bit < 8; bit++) {
     /* write MOSI on trailing edge of previous clock */
     if (byte & 0x80)
@@ -65,25 +69,145 @@ unsigned char spitrans8(unsigned char byte){
     CLRCLK;
   }
   
-  P5OUT|=SS;
- 
   return byte;
 }
 
+
+//! Enable SPI writing
+void spiflash_wrten(){
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x04);//Write Disable
+  P5OUT|=SS;  //Raise !SS to end transaction.
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x06);//Write Enable
+  P5OUT|=SS;  //Raise !SS to end transaction.
+}
+
+
+//! Grab the SPI flash status byte.
+unsigned char spiflash_status(){
+  unsigned char c;
+  P5OUT|=SS;  //Raise !SS to end transaction.
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x05);//GET STATUS
+  c=spitrans8(0xFF);
+  P5OUT|=SS;  //Raise !SS to end transaction.
+  return c;
+}
+
+
+//! Grab the SPI flash status byte.
+void spiflash_setstatus(unsigned char c){
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x01);//SET STATUS
+  spitrans8(c);
+  P5OUT|=SS;  //Raise !SS to end transaction.
+  //return c;
+}
+
+//! Peek some blocks.
+void spiflash_peek(unsigned char app,
+                  unsigned char verb,
+                  unsigned char len){
+  register char blocks=(len>3?cmddata[3]:1);
+  unsigned char i,j;
+  
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x03);//Flash Read Command
+  len=3;//write 3 byte pointer
+  for(i=0;i<len;i++)
+    spitrans8(cmddata[i]);
+  
+  //Send reply header
+  len=0x80;//128 byte chunk, repeated for each block
+  serial_tx(app);
+  serial_tx(verb);
+  serial_tx(len); //multiplied by block count.
+  
+  while(blocks--){
+    for(i=0;i<len;i++)
+      serial_tx(spitrans8(0));
+    
+    /* old fashioned
+    for(i=0;i<len;i++)
+      cmddata[i]=spitrans8(0);
+    txdata(app,verb,len);
+    */
+  }
+  P5OUT|=SS;  //Raise !SS to end transaction.
+}
+
 //! Handles a monitor command.
 void spihandle(unsigned char app,
               unsigned char verb,
               unsigned char len){
+  unsigned char i;
+  
+  
+  //Raise !SS to end transaction, just in case we forgot.
+  P5OUT|=SS;  
+  
   switch(verb){
     //PEEK and POKE might come later.
   case READ:
   case WRITE:
-    cmddata[0]=spitrans8(cmddata[0]);
-    txdata(app,verb,1);
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    for(i=0;i<len;i++)
+      cmddata[i]=spitrans8(cmddata[i]);
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    txdata(app,verb,len);
+    break;
+
+
+  case SPI_JEDEC://Grab 3-byte JEDEC ID.
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    spitrans8(0x9f);
+    len=3;
+    for(i=0;i<len;i++)
+      cmddata[i]=spitrans8(cmddata[i]);
+    txdata(app,verb,len);
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    break;
+
+
+  case PEEK://Grab 128 bytes from an SPI Flash ROM
+    spiflash_peek(app,verb,len);
     break;
+
+
+  case POKE://Poke up bytes from an SPI Flash ROM.
+    spiflash_setstatus(0x02);
+    spiflash_wrten();
+    
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    spitrans8(0x02); //Poke command.
+    
+    //First three bytes are address, then data.
+    for(i=0;i<len;i++)
+      spitrans8(cmddata[i]);
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    
+    while(spiflash_status()&0x01)//while busy
+      P1OUT^=1;
+    P1OUT&=~1;
+    
+    txdata(app,verb,len);
+    break;
+
+
+  case SPI_ERASE://Erase the SPI Flash ROM.
+    spiflash_wrten();
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    spitrans8(0xC7);//Chip Erase
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    txdata(app,verb,0);
+    break;
+
+
   case SETUP:
     spisetup();
     txdata(app,verb,0);
     break;
   }
+  
 }