X-Git-Url: http://git.rot13.org/?p=goodfet;a=blobdiff_plain;f=firmware%2Fapps%2Fi2c%2Fi2c.c;h=6e1dfdea058437b79d83b98749146d0f2bde1a17;hp=6ee1623b041826219441a9cb4e0709c92bb22062;hb=027937b9bed208a4a79b7e9d89a7326747b52a9e;hpb=ae09939eb8c62c83f244527e7916cee5f9145e6c

diff --git a/firmware/apps/i2c/i2c.c b/firmware/apps/i2c/i2c.c
index 6ee1623..6e1dfde 100644
--- a/firmware/apps/i2c/i2c.c
+++ b/firmware/apps/i2c/i2c.c
@@ -11,28 +11,59 @@
 
 #include "platform.h"
 #include "command.h"
+#include "i2c.h"
 
-#include <signal.h>
-#include <io.h>
-#include <iomacros.h>
-
+#ifndef _GNU_ASSEMBLER_
+#include <msp430.h>
+#endif
 
 //Pins and I/O
 #include <jtag.h>
-#define SDA TDI
-#define SCL TDO
+
+//! Handles an i2c command.
+void i2c_handle_fn( uint8_t const app,
+					uint8_t const verb,
+					uint32_t const len);
+
+// define the i2c app's app_t
+app_t const i2c_app = {
+
+	/* app number */
+	I2C_APP,
+
+	/* handle fn */
+	i2c_handle_fn,
+
+	/* name */
+	"I2C",
+
+	/* desc */
+	"\tThe I2C app implements the i2c bus protocol thus\n"
+	"\tturning your GoodFET into a USB-to-i2c adapter.\n"
+};
 
 #define I2CDELAY(x) delay(x<<4)
 
 
 //2xx only, need 1xx compat code
-#define CLRSDA P5OUT&=~SDA
-#define SETSDA P5OUT|=SDA
-#define CLRSCL P5OUT&=~SCL
-#define SETSCL P5OUT|=SCL
+#define SDA TDI
+#define SCL TDO
+
+#define SDAINPUT SPIDIR&=~SDA
+#define SDAOUTPUT SPIDIR|=SDA
+#define SCLINPUT SPIDIR&=~SCL
+#define SCLOUTPUT SPIDIR|=SCL
+
+#define PULLON SPIREN|=(SDA|SCL)
+#define PULLOFF SPIREN&=~(SDA|SCL)
 
-#define READSDA (P5IN&SDA?1:0)
-#define SETBOTH P5OUT|=(SDA|SCL)
+#define CLRSDA SPIOUT&=~SDA
+#define SETSDA SPIOUT|=SDA
+#define CLRSCL SPIOUT&=~SCL
+#define SETSCL SPIOUT|=SCL
+
+#define READSDA (SPIIN&SDA?1:0)
+#define SETBOTH SPIOUT|=(SDA|SCL)
 
 #define I2C_DATA_HI() SETSDA
 #define I2C_DATA_LO() CLRSDA
@@ -42,24 +73,36 @@
 
 //#warning "Using internal resistors.  Won't work on 161x devices."
 
-//! Inits bitbanging port, must be called before using the functions below
-void I2C_Init()
+// Take control of the bus
+void I2C_Take()
 {
-  
-  //Clear SDA and SCL.
-  //Direction, not value, is used to set the value.
-  //(Pull-up or 0.)
-  
-  P5DIR|=(SDA|SCL);
-  P5REN|=SDA|SCL;
-  
-  
   I2C_CLOCK_HI();
   I2C_DATA_HI();
+  SCLOUTPUT;
+  SDAOUTPUT;
+}
 
+void I2C_Release()
+{
+  SDAINPUT;
+  SCLINPUT;
+}
+
+//! Inits bitbanging port, must be called before using the functions below
+void I2C_Init()
+{
+  I2C_Take();
+  //PULLON;
   I2CDELAY(1);
 }
 
+// XXX This is never called...
+void I2C_Exit()
+{
+  I2C_Release();
+  PULLOFF;
+}
+
 //! Write an I2C bit.
 void I2C_WriteBit( unsigned char c )
 {
@@ -73,39 +116,64 @@ void I2C_WriteBit( unsigned char c )
 
   I2C_CLOCK_LO();
   I2CDELAY(1);
-
-  if(c>0)
-    I2C_DATA_LO();
-
-  I2CDELAY(1);
 }
 
 //! Read an I2C bit.
 unsigned char I2C_ReadBit()
 {
-  I2C_DATA_HI();
-
+  SDAINPUT;
   I2C_CLOCK_HI();
-  I2CDELAY(1);
   
   unsigned char c = READSDA;
+  if(c)
+    I2C_DATA_HI();
+  else
+    I2C_DATA_LO();
 
+  SDAOUTPUT;
+  I2CDELAY(1);
   I2C_CLOCK_LO();
   I2CDELAY(1);
 
   return c;
 }
 
+unsigned char I2C_ReadBit_Wait()
+{
+  SDAINPUT;
+  I2C_CLOCK_HI();
+  
+  unsigned int i = 0;
+  unsigned char c = READSDA;
+
+  while(c>0 && i<=35)
+  {
+    I2CDELAY(1);
+    c = READSDA;
+    i++;
+  }
+
+  if(c)
+    I2C_DATA_HI();
+  else
+    I2C_DATA_LO();
+
+  SDAOUTPUT;
+  I2CDELAY(1);
+  I2C_CLOCK_LO();
+  I2CDELAY(1);
+
+  return c?0:1;	// return true on ACK (0)
+}
 
 //! Send a START Condition
 void I2C_Start()
 {
-  // set both to high at the same time
-  SETBOTH;
-  I2CDELAY(1);
+  I2C_Take();	// XXX Should probably check to see if someone else is using the bus before we do this
+  I2CDELAY(3);
   
   I2C_DATA_LO();
-  I2CDELAY(1);
+  I2CDELAY(3);
   
   I2C_CLOCK_LO();
   I2CDELAY(1);
@@ -114,11 +182,15 @@ void I2C_Start()
 //! Send a STOP Condition
 void I2C_Stop()
 {
+  I2C_DATA_LO();
+  I2CDELAY(3);
+
   I2C_CLOCK_HI();
-  I2CDELAY(1);
+  I2CDELAY(3);
 
   I2C_DATA_HI();
   I2CDELAY(1);
+  I2C_Release();
 }
 
 //! write a byte to the I2C slave device
@@ -130,7 +202,7 @@ unsigned char I2C_Write( unsigned char c )
     c<<=1;
   }
   
-  return I2C_ReadBit();
+  return I2C_ReadBit_Wait();
 }
 
 
@@ -155,45 +227,68 @@ unsigned char I2C_Read( unsigned char ack )
   return res;
 }
 
-
-//! Handles a monitor command.
-void i2chandle(unsigned char app,
-	       unsigned char verb,
-	       unsigned char len){
-  unsigned char i;
-  switch(verb){
-    
-  case PEEK:
-    break;
-  case POKE:
-    break;
-    
-  case READ:
-    if(len>0)          //optional parameter of length
-      len=cmddata[0];
-    if(!len)           //default value of 1
-      len=1;
-    for(i=0;i<len;i++)
-      cmddata[i]=I2C_Read(1);  //Always acknowledge
-    txdata(app,verb,len);
-    break;
-  case WRITE:
-    cmddata[0]=0;
-    for(i=0;i<len;i++)
-      cmddata[0]+=I2C_Write(cmddata[i]);
-    txdata(app,verb,1);
-    break;
-  case START:
-    I2C_Start();
-    txdata(app,verb,0);
-    break;
-  case STOP:
-    I2C_Stop();
-    txdata(app,verb,0);
-    break;
-  case SETUP:
-    I2C_Init();
-    txdata(app,verb,0);
-    break;
-  }
+//! Handles an i2c command.
+void i2c_handle_fn( uint8_t const app,
+					uint8_t const verb,
+					uint32_t const len)
+{
+	unsigned char i;
+	unsigned long l;
+	switch(verb)
+	{
+	case READ:
+		l = len;
+		if(l > 0)					//optional parameter of length
+			l=cmddata[0];
+		if(!l)						//default value of 1
+			l=1;
+		I2C_Start();
+		for(i=0; i < l; i++)
+			cmddata[i]=I2C_Read(i<l?1:0);
+		I2C_Stop();
+		txdata(app,verb,l);
+		break;
+	case WRITE:
+		I2C_Start();
+		cmddata[0] = cmddata[0] << 1;
+		for(i=0; i<len; i++) {
+			if (!I2C_Write(cmddata[i]))		//if NACK
+				break;
+		}
+		I2C_Stop();
+		cmddata[0] = i;
+		txdata(app,verb,1);
+		break;
+	case PEEK:
+		l = cmddata[0];
+		I2C_Start();
+		unsigned char address = cmddata[1] << 1;
+		I2C_Write(address);
+		for(i=2; i < len; i++){
+			I2C_Write(cmddata[i]);
+		}
+		I2C_Start();
+		I2C_Write(address|1);				// spit out the target address again and flip the read bit
+		I2CDELAY(1);	// XXX We should wait for clock to go high here XXX
+		for(i=0; i < l; i++)
+			cmddata[i]=I2C_Read(i+1<l?1:0);		// If the next i is still less than l, then ACK
+		I2C_Stop();
+		txdata(app,verb,l);
+		break;
+	case POKE:
+		break;
+
+	case START:
+		I2C_Start();
+		txdata(app,verb,0);
+		break;
+	case STOP:
+		I2C_Stop();
+		txdata(app,verb,0);
+		break;
+	case SETUP:
+		I2C_Init();
+		txdata(app,verb,0);
+		break;
+	}
 }