summaryrefslogtreecommitdiffstats
path: root/drivers/w1/w1.c
diff options
context:
space:
mode:
authorEvgeniy Polyakov <zbr@ioremap.net>2011-12-10 02:36:11 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2011-12-10 04:19:18 +0100
commitc9cbf558e7793d312a4dd5d839ad7eae1aa8bd12 (patch)
tree5a06a20dc0de4365b2d385662dd5fa178d9d3a61 /drivers/w1/w1.c
parentdriver-core: skip uevent generation when nobody is listening (diff)
downloadlinux-c9cbf558e7793d312a4dd5d839ad7eae1aa8bd12.tar.xz
linux-c9cbf558e7793d312a4dd5d839ad7eae1aa8bd12.zip
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>
Diffstat (limited to '')
-rw-r--r--drivers/w1/w1.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index c37497823851..9761950697b4 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -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) {