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authorDavid Fries <david@fries.net>2008-10-15 22:05:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 11:21:50 -0700
commita08e2d338bab17ac5c51a8f2f25185da18f6710c (patch)
tree91e61effbb0db1c1b4652ad3e761184caa07fca8
parente1c86d226daf95407d66246ced8fe087055acc6b (diff)
W1: ds2490.c disable bit read and write
Don't export read and write bit operations, they didn't work, they weren't used, and they can't be made to work. The one wire low level bit operations expect to set high or low levels, the ds2490 hardware only supports complete read or write time slots, better to just comment them out. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/w1/masters/ds2490.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 6fabf584395..1b632d549e7 100644
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -520,6 +520,7 @@ static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
return 0;
}
+#if 0
static int ds_write_bit(struct ds_device *dev, u8 bit)
{
int err;
@@ -538,6 +539,7 @@ static int ds_write_bit(struct ds_device *dev, u8 bit)
return 0;
}
+#endif
static int ds_write_byte(struct ds_device *dev, u8 byte)
{
@@ -722,6 +724,7 @@ static u8 ds9490r_touch_bit(void *data, u8 bit)
return ret;
}
+#if 0
static void ds9490r_write_bit(void *data, u8 bit)
{
struct ds_device *dev = data;
@@ -729,13 +732,6 @@ static void ds9490r_write_bit(void *data, u8 bit)
ds_write_bit(dev, bit);
}
-static void ds9490r_write_byte(void *data, u8 byte)
-{
- struct ds_device *dev = data;
-
- ds_write_byte(dev, byte);
-}
-
static u8 ds9490r_read_bit(void *data)
{
struct ds_device *dev = data;
@@ -748,6 +744,14 @@ static u8 ds9490r_read_bit(void *data)
return bit & 1;
}
+#endif
+
+static void ds9490r_write_byte(void *data, u8 byte)
+{
+ struct ds_device *dev = data;
+
+ ds_write_byte(dev, byte);
+}
static u8 ds9490r_read_byte(void *data)
{
@@ -812,8 +816,15 @@ static int ds_w1_init(struct ds_device *dev)
dev->master.data = dev;
dev->master.touch_bit = &ds9490r_touch_bit;
+ /* read_bit and write_bit in w1_bus_master are expected to set and
+ * sample the line level. For write_bit that means it is expected to
+ * set it to that value and leave it there. ds2490 only supports an
+ * individual time slot at the lowest level. The requirement from
+ * pulling the bus state down to reading the state is 15us, something
+ * that isn't realistic on the USB bus anyway.
dev->master.read_bit = &ds9490r_read_bit;
dev->master.write_bit = &ds9490r_write_bit;
+ */
dev->master.read_byte = &ds9490r_read_byte;
dev->master.write_byte = &ds9490r_write_byte;
dev->master.read_block = &ds9490r_read_block;