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[PATCH] w1: Added the triplet w1 master method and changes w1_search() to use it.

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Adds the triplet w1 master method and changes w1_search() to use it.

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Evgeniy Polyakov
2005-06-04 01:30:43 +04:00
committed by Greg Kroah-Hartman
parent be57ce267f
commit 6b72986183
4 changed files with 169 additions and 88 deletions
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43
drivers/w1/w1_io.c
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@ -129,6 +129,47 @@ static u8 w1_read_bit(struct w1_master *dev)
return result & 0x1;
}
/**
* Does a triplet - used for searching ROM addresses.
* Return bits:
* bit 0 = id_bit
* bit 1 = comp_bit
* bit 2 = dir_taken
* If both bits 0 & 1 are set, the search should be restarted.
*
* @param dev the master device
* @param bdir the bit to write if both id_bit and comp_bit are 0
* @return bit fields - see above
*/
u8 w1_triplet(struct w1_master *dev, int bdir)
{
if ( dev->bus_master->triplet )
return(dev->bus_master->triplet(dev->bus_master->data, bdir));
else {
u8 id_bit = w1_touch_bit(dev, 1);
u8 comp_bit = w1_touch_bit(dev, 1);
u8 retval;
if ( id_bit && comp_bit )
return(0x03); /* error */
if ( !id_bit && !comp_bit ) {
/* Both bits are valid, take the direction given */
retval = bdir ? 0x04 : 0;
} else {
/* Only one bit is valid, take that direction */
bdir = id_bit;
retval = id_bit ? 0x05 : 0x02;
}
if ( dev->bus_master->touch_bit )
w1_touch_bit(dev, bdir);
else
w1_write_bit(dev, bdir);
return(retval);
}
}
/**
* Reads 8 bits.
*
@ -233,7 +274,7 @@ void w1_search_devices(struct w1_master *dev, w1_slave_found_callback cb)
if (dev->bus_master->search)
dev->bus_master->search(dev->bus_master->data, cb);
else
w1_search(dev);
w1_search(dev, cb);
}
EXPORT_SYMBOL(w1_touch_bit);