lkml.org 
[lkml]   [2011]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] w1: add fast search for single slave bus
Date
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>
---
drivers/w1/Kconfig | 8 ++++++++
drivers/w1/w1.c | 11 +++++++++++
2 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/drivers/w1/Kconfig b/drivers/w1/Kconfig
index fd2c7bd..e5006bc 100644
--- a/drivers/w1/Kconfig
+++ b/drivers/w1/Kconfig
@@ -25,6 +25,14 @@ config W1_CON
2. Userspace commands. Includes read/write and search/alarm search commands.
3. Replies to userspace commands.

+config W1_FAST_SEARCH
+ bool "Fast search (single slave bus only!)"
+ ---help---
+ 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.
+ If unsure, say 'N'.
+
source drivers/w1/masters/Kconfig
source drivers/w1/slaves/Kconfig

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index c374978..7c648ec 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -892,6 +892,17 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
break;
}

+#ifdef CONFIG_W1_FAST_SEARCH
+ 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;
+ }
+#endif
+
/* Start the search */
w1_write_8(dev, search_type);
for (i = 0; i < 64; ++i) {
--
1.7.4.1


\
 
 \ /
  Last update: 2011-11-28 21:11    [W:0.158 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site