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authorkhali <khali@7894878c-1315-0410-8ee3-d5d059ff63e0>2012-12-21 16:46:31 +0000
committerkhali <khali@7894878c-1315-0410-8ee3-d5d059ff63e0>2012-12-21 16:46:31 +0000
commit8a8f32a2fc439ea1caca97e0742d392dcdfdc7f3 (patch)
tree21aeb0053aab2e9271af640d79171753571b4972
parent7b2debbc565c6fb1dbcf06bdfd512e8e708046e5 (diff)
downloadi2c-tools-8a8f32a2fc439ea1caca97e0742d392dcdfdc7f3.tar.gz
i2cdetect: Clarify the SMBus commands used for probing by default.
git-svn-id: http://lm-sensors.org/svn/i2c-tools/branches/i2c-tools-3.1@6110 7894878c-1315-0410-8ee3-d5d059ff63e0
-rw-r--r--CHANGES1
-rw-r--r--tools/i2cdetect.812
2 files changed, 9 insertions, 4 deletions
diff --git a/CHANGES b/CHANGES
index c97ddbc..eddc335 100644
--- a/CHANGES
+++ b/CHANGES
@@ -8,6 +8,7 @@ SVN HEAD
Update manufacturer IDs
Remove duplicate "ns" in SDR timings
Fix decoding of SDR SPD revision
+ i2cdetect: Clarify the SMBus commands used for probing by default
i2c-dev.h: Minimize differences with kernel flavor
Move SMBus helper functions to include/i2c/smbus.h
i2c-stub-from-dump: Be more tolerant on input dump format
diff --git a/tools/i2cdetect.8 b/tools/i2cdetect.8
index 47cad04..ef5cda2 100644
--- a/tools/i2cdetect.8
+++ b/tools/i2cdetect.8
@@ -28,6 +28,12 @@ should correspond to one of the busses listed by \fIi2cdetect -l\fR.
The optional parameters \fIfirst\fR and \fIlast\fR restrict the scanning
range (default: from 0x03 to 0x77).
.PP
+As there is no standard I2C detection command, i2cdetect uses arbitrary
+SMBus commands (namely SMBus quick write and SMBus receive byte) to probe
+for devices. By default, the command used is the one believed to be the
+safest for each address. See options \fI-q\fR and \fI-r\fR to change this
+behavior.
+.PP
i2cdetect can also be used to query the functionalities of an I2C bus
(see option \fB-F\fP.)
@@ -57,14 +63,12 @@ scripts.
Force scanning of non-regular addresses. Not recommended.
.TP
.B "\-q"
-Use SMBus "quick write" commands for probing (by default, the command
-used is the one believed to be the safest for each address).
+Use SMBus "quick write" command for probing.
Not recommended. This is known to corrupt the Atmel AT24RF08 EEPROM
found on many IBM Thinkpad laptops.
.TP
.B "\-r"
-Use SMBus "read byte" commands for probing (by default, the command
-used is the one believed to be the safest for each address).
+Use SMBus "receive byte" command for probing.
Not recommended. This is known to lock SMBus on various write-only
chips (most notably clock chips at address 0x69).
.TP