[PATCH 22/30] W1: ds2490.c disable bit read and write

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From: David Fries
Date: Monday, July 28, 2008 - 7:25 pm

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>
---
 drivers/w1/masters/ds2490.c |   25 ++++++++++++++++++-------
 1 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 7acf6d2..6bfd6a9 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;
 }
=20
+#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)
=20
 	return 0;
 }
+#endif
=20
 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;
 }
=20
+#if 0
 static void ds9490r_write_bit(void *data, u8 bit)
 {
 	struct ds_device *dev =3D data;
@@ -729,13 +732,6 @@ static void ds9490r_write_bit(void *data, u8 bit)
 	ds_write_bit(dev, bit);
 }
=20
-static void ds9490r_write_byte(void *data, u8 byte)
-{
-	struct ds_device *dev =3D data;
-
-	ds_write_byte(dev, byte);
-}
-
 static u8 ds9490r_read_bit(void *data)
 {
 	struct ds_device *dev =3D data;
@@ -748,6 +744,14 @@ static u8 ds9490r_read_bit(void *data)
=20
 	return bit & 1;
 }
+#endif
+
+static void ds9490r_write_byte(void *data, u8 byte)
+{
+	struct ds_device *dev =3D data;
+
+	ds_write_byte(dev, byte);
+}
=20
 static u8 ds9490r_read_byte(void *data)
 {
@@ -812,8 +816,15 @@ static int ds_w1_init(struct ds_device *dev)
=20
 	dev->master.data	=3D dev;
 	dev->master.touch_bit	=3D &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	=3D &ds9490r_read_bit;
 	dev->master.write_bit	=3D &ds9490r_write_bit;
+	*/
 	dev->master.read_byte	=3D &ds9490r_read_byte;
 	dev->master.write_byte	=3D &ds9490r_write_byte;
 	dev->master.read_block	=3D &ds9490r_read_block;
--=20
1.4.4.4
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Messages in current thread:
[PATCH 2/30] W1: abort search early on on exit, David Fries, (Mon Jul 28, 7:12 pm)
[PATCH 3/30] W1: don't delay search start, David Fries, (Mon Jul 28, 7:13 pm)
[PATCH 4/30] W1: w1_process, block or sleep, David Fries, (Mon Jul 28, 7:14 pm)
[PATCH 8/30] W1: recode w1_slave_found logic, David Fries, (Mon Jul 28, 7:18 pm)
[PATCH 9/30] W1: new module parameter search_count, David Fries, (Mon Jul 28, 7:19 pm)
[PATCH 16/30] W1: w1.c s/printk/dev_dbg/, David Fries, (Mon Jul 28, 7:23 pm)
[PATCH 17/30] W1: w1_io.c reset comments and msleep, David Fries, (Mon Jul 28, 7:24 pm)
[PATCH 18/30] W1: ds1wm.c msleep for reset, David Fries, (Mon Jul 28, 7:24 pm)
[PATCH 19/30] W1: ds2490.c correct print message, David Fries, (Mon Jul 28, 7:25 pm)
[PATCH 22/30] W1: ds2490.c disable bit read and write, David Fries, (Mon Jul 28, 7:25 pm)
[PATCH 24/30] W1: ds2490.c ds_dump_status rework, David Fries, (Mon Jul 28, 7:26 pm)
[PATCH 26/30] W1: ds2490.c reset ds2490 in init, David Fries, (Mon Jul 28, 7:27 pm)
[PATCH 27/30] W1: ds2490.c magic number work, David Fries, (Mon Jul 28, 7:28 pm)
[PATCH 30/30] W1: ds2490.c optimize ds_set_pullup, David Fries, (Mon Jul 28, 7:30 pm)
[PATCH 2/30] W1: abort search early on on exit, David Fries, (Wed Jul 30, 7:48 pm)
[PATCH 3/30] W1: don't delay search start, David Fries, (Wed Jul 30, 7:48 pm)
[PATCH 4/30] W1: w1_process, block or sleep, David Fries, (Wed Jul 30, 7:48 pm)
[PATCH 8/30] W1: recode w1_slave_found logic, David Fries, (Wed Jul 30, 7:48 pm)
[PATCH 9/30] W1: new module parameter search_count, David Fries, (Wed Jul 30, 7:48 pm)
[PATCH 16/30] W1: w1.c s/printk/dev_dbg/, David Fries, (Wed Jul 30, 7:49 pm)
[PATCH 17/30] W1: w1_io.c reset comments and msleep, David Fries, (Wed Jul 30, 7:49 pm)
[PATCH 18/30] W1: ds1wm.c msleep for reset, David Fries, (Wed Jul 30, 7:49 pm)
[PATCH 19/30] W1: ds2490.c correct print message, David Fries, (Wed Jul 30, 7:49 pm)
[PATCH 22/30] W1: ds2490.c disable bit read and write, David Fries, (Wed Jul 30, 7:50 pm)
[PATCH 24/30] W1: ds2490.c ds_dump_status rework, David Fries, (Wed Jul 30, 7:50 pm)
[PATCH 26/30] W1: ds2490.c reset ds2490 in init, David Fries, (Wed Jul 30, 7:50 pm)
[PATCH 27/30] W1: ds2490.c magic number work, David Fries, (Wed Jul 30, 7:50 pm)
[PATCH 30/30] W1: ds2490.c optimize ds_set_pullup, David Fries, (Wed Jul 30, 7:50 pm)