From: Asier Llano Palacios <a.llano@usyscom.com>
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.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/w1/w1.c | 7 ++++---
25-akpm/drivers/w1/w1.h | 8 ++++++++
2 files changed, 12 insertions(+), 3 deletions(-)
diff -puN drivers/w1/w1.c~fix-1-wire-dallas-in-bigendian-machines drivers/w1/w1.c
--- 25/drivers/w1/w1.c~fix-1-wire-dallas-in-bigendian-machines 2005-03-07 20:41:41.000000000 -0800
+++ 25-akpm/drivers/w1/w1.c 2005-03-07 20:41:41.000000000 -0800
@@ -521,9 +521,10 @@ void w1_slave_found(unsigned long data,
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);
}
atomic_dec(&dev->refcnt);
diff -puN drivers/w1/w1.h~fix-1-wire-dallas-in-bigendian-machines drivers/w1/w1.h
--- 25/drivers/w1/w1.h~fix-1-wire-dallas-in-bigendian-machines 2005-03-07 20:41:41.000000000 -0800
+++ 25-akpm/drivers/w1/w1.h 2005-03-07 20:41:41.000000000 -0800
@@ -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__
_