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| author | Evgeniy Polyakov <zbr@ioremap.net> | 2011-12-10 04:36:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-12-09 19:19:18 -0800 |
| commit | c9cbf558e7793d312a4dd5d839ad7eae1aa8bd12 (patch) | |
| tree | 5a06a20dc0de4365b2d385662dd5fa178d9d3a61 /drivers/w1/w1.c | |
| parent | 74099b18b8db0670484e0caeb3425fb29ff3144e (diff) | |
| download | lwn-c9cbf558e7793d312a4dd5d839ad7eae1aa8bd12.tar.gz lwn-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 'drivers/w1/w1.c')
| -rw-r--r-- | drivers/w1/w1.c | 10 |
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) { |