1 files changed, 18 insertions, 7 deletions

diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 6fabf584395f..1b632d549e79 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;