Fix i2c-algo-bit for adapers that cannot read SCL back

@@ -18,10 +18,8 @@
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     */
 /* ------------------------------------------------------------------------- */
 
-/* With some changes from Ky?sti M?lkki <[email protected]> and even
-   Frodo Looijaard <[email protected]> */
-
-/* $Id: i2c-algo-bit.c,v 1.44 2003/01/21 08:08:16 kmalkki Exp $ */
+/* With some changes from Frodo Looijaard <[email protected]>, Ky?sti M?lkki
+   <[email protected]> and Jean Delvare <[email protected]> */
 
 /* #define DEBUG 1 */
 

@@ -87,8 +85,10 @@
 	setscl(adap,1);
 
 	/* Not all adapters have scl sense line... */
-	if (adap->getscl = NULL )
+	if (adap->getscl = NULL ) {
+		udelay(adap->udelay);
 		return 0;
+	}
 
 	start=jiffies;
 	while (! getscl(adap) ) {	

@@ -222,68 +222,72 @@
  */
 static int test_bus(struct i2c_algo_bit_data *adap, char* name) {
 	int scl,sda;
+
+	if (adap->getscl=NULL)
+		printk(KERN_INFO "i2c-algo-bit.o: Testing SDA only, "
+			"SCL is not readable.\n");
+
 	sda=getsda(adap);
-	if (adap->getscl=NULL) {
-		printk(KERN_WARNING "i2c-algo-bit.o: Warning: Adapter can't read from clock line - skipping test.\n");
-		return 0;		
-	}
-	scl=getscl(adap);
-	printk(KERN_INFO "i2c-algo-bit.o: Adapter: %s scl: %d  sda: %d -- testing...\n",
-	       name,getscl(adap),getsda(adap));
+	scl=(adap->getscl=NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (0) scl=%d, sda=%d\n",scl,sda);
 	if (!scl || !sda ) {
-		printk(KERN_INFO " i2c-algo-bit.o: %s seems to be busy.\n",name);
+		printk(KERN_WARNING "i2c-algo-bit.o: %s seems to be busy.\n", name);
 		goto bailout;
 	}
+
 	sdalo(adap);
-	printk(KERN_DEBUG "i2c-algo-bit.o:1 scl: %d  sda: %d \n",getscl(adap),
-	       getsda(adap));
-	if ( 0 != getsda(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SDA stuck high!\n",name);
-		sdahi(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl=NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (1) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 != sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA stuck high!\n");
 		goto bailout;
 	}
-	if ( 0 = getscl(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SCL unexpected low while pulling SDA low!\n",
-			name);
+	if ( 0 = scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL unexpected low "
+			"while pulling SDA low!\n");
 		goto bailout;
 	}		
+
 	sdahi(adap);
-	printk(KERN_DEBUG "i2c-algo-bit.o:2 scl: %d  sda: %d \n",getscl(adap),
-	       getsda(adap));
-	if ( 0 = getsda(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SDA stuck low!\n",name);
-		sdahi(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl=NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (2) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 = sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA stuck low!\n");
 		goto bailout;
 	}
-	if ( 0 = getscl(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SCL unexpected low while SDA high!\n",
-		       name);
-	goto bailout;
+	if ( 0 = scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL unexpected low "
+			"while pulling SDA high!\n");
+		goto bailout;
 	}
+
 	scllo(adap);
-	printk(KERN_DEBUG "i2c-algo-bit.o:3 scl: %d  sda: %d \n",getscl(adap),
-	       getsda(adap));
-	if ( 0 != getscl(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SCL stuck high!\n",name);
-		sclhi(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl=NULL?0:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (3) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 != scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL stuck high!\n");
 		goto bailout;
 	}
-	if ( 0 = getsda(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SDA unexpected low while pulling SCL low!\n",
-			name);
+	if ( 0 = sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA unexpected low "
+			"while pulling SCL low!\n");
 		goto bailout;
 	}
+	
 	sclhi(adap);
-	printk(KERN_DEBUG "i2c-algo-bit.o:4 scl: %d  sda: %d \n",getscl(adap),
-	       getsda(adap));
-	if ( 0 = getscl(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SCL stuck low!\n",name);
-		sclhi(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl=NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (4) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 = scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL stuck low!\n");
 		goto bailout;
 	}
-	if ( 0 = getsda(adap) ) {
-		printk(KERN_WARNING "i2c-algo-bit.o: %s SDA unexpected low while SCL high!\n",
-			name);
+	if ( 0 = sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA unexpected low "
+			"while pulling SCL high!\n");
 		goto bailout;
 	}
 	printk(KERN_INFO "i2c-algo-bit.o: %s passed test.\n",name);