w1: add fast search for single slave bus

This enables a much more efficient way of device searching. It uses the
1-wire read-rom operation which allows the direct reading of the slave
address. BUT this works only with exactly one slave on the bus.

Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>

index c374978..9761950 100644
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Evgeniy Polyakov 2011-12-10 04:36:11 +03:00 committed by Greg Kroah-Hartman
parent 74099b18b8
commit c9cbf558e7

View File

@ -892,6 +892,16 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
break;
}
/* Do fast search on single slave bus */
if (dev->max_slave_count == 1) {
w1_write_8(dev, W1_READ_ROM);
if (w1_read_block(dev, (u8 *)&rn, 8) == 8 && rn)
cb(dev, rn);
break;
}
/* Start the search */
w1_write_8(dev, search_type);
for (i = 0; i < 64; ++i) {