[PATCH] 1-Wire Dallas in bigendian machines

[PATCH] 1-Wire Dallas in bigendian machines

[Asier Llano Palacios]

I've been testing the 1-Wire Dallas in a bigendian machine (through a
GPIO) and I've found some problems that can easily addressed with the
provided patch. (inline at the end of the message).

I have a question about the implementation of w1_smem.
In the line 90 of drivers/w1/w1_smem.c.
  for (i = 0; i < 9; ++i)
     count += sprintf(buf + count, "%02x ", ((u8 *)&sl->reg_num)[i]);
I don't see why this loop is execute 9 times when the provided reg_num
is 8 bytes long. I don't understand the purpose of the last byte.

Thank you very much.

-- 
Asier Llano Palacios <a.llano@usyscom.com>



diff -urP linux-2.6.10/drivers/w1/w1.c
linux-2.6.10-w1-bigendian/drivers/w1/w1.c
--- linux-2.6.10/drivers/w1/w1.c	2004-12-24 22:34:30.000000000 +0100
+++ linux-2.6.10-w1-bigendian/drivers/w1/w1.c	2005-01-28
12:54:39.000000000 +0100
@@ -579,9 +579,10 @@
 			slave_count++;
 		}
 
-		if (slave_count == dev->slave_count &&
-			rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
-			w1_attach_slave_device(dev, (struct w1_reg_num *) &rn);
+		if (slave_count == dev->slave_count && rn ) {
+			tmp = cpu_to_le64(rn);
+			if(((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&tmp, 7))
+				w1_attach_slave_device(dev, (struct w1_reg_num *) &rn);
 		}
 	}
 }
diff -urP linux-2.6.10/drivers/w1/w1.h
linux-2.6.10-w1-bigendian/drivers/w1/w1.h
--- linux-2.6.10/drivers/w1/w1.h	2004-12-24 22:35:50.000000000 +0100
+++ linux-2.6.10-w1-bigendian/drivers/w1/w1.h	2005-01-28
13:05:47.000000000 +0100
@@ -24,9 +24,17 @@
 
 struct w1_reg_num
 {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
 	__u64	family:8,
 		id:48,
 		crc:8;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	__u64	crc:8,
+		id:48,
+		family:8;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
 };
 
 #ifdef __KERNEL__