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author | Graydon, Tracy <tracy.graydon@intel.com> | 2013-01-31 18:44:07 -0800 |
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committer | Graydon, Tracy <tracy.graydon@intel.com> | 2013-01-31 18:44:07 -0800 |
commit | b19d79bf9028f58e3e4226bd9410b59f19fe3c8d (patch) | |
tree | a84dec919322f3d19c7c0cf3050c8c134a0d4fc6 /tools/i2cset.8 | |
download | i2c-tools-accepted/tizen_common.tar.gz i2c-tools-accepted/tizen_common.tar.bz2 i2c-tools-accepted/tizen_common.zip |
Initial commitHEADsubmit/tizen_common/20150126.093738submit/tizen_3.0_common/20161104.104000submit/2.0alpha/20130201.222745accepted/tizen/common/20150126.100451accepted/tizen/3.0/common/20161114.112238accepted/2.0alpha/20130201.222208tizen_3.0.m2tizen_3.0.2015.q2_commontizen_3.0.2014.q4_commonaccepted/tizen_commonaccepted/tizen_3.0_common2.0alpha
Diffstat (limited to 'tools/i2cset.8')
-rw-r--r-- | tools/i2cset.8 | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/tools/i2cset.8 b/tools/i2cset.8 new file mode 100644 index 0000000..2b4ce3a --- /dev/null +++ b/tools/i2cset.8 @@ -0,0 +1,91 @@ +.TH I2CSET 8 "November 2008" +.SH "NAME" +i2cset \- set I2C registers + +.SH SYNOPSIS +.B i2cset +.RB [ -f ] +.RB [ -y ] +.RB [ "-m mask" ] +.RB [ -r ] +.I i2cbus +.I chip-address +.I data-address +.RI [ "value " [ "mode" ]] +.br +.B i2cset +.B -V + +.SH DESCRIPTION +i2cset is a small helper program to set registers visible through the I2C +bus. + +.SH OPTIONS +.TP +.B -V +Display the version and exit. +.TP +.B -f +Force access to the device even if it is already busy. By default, i2cset +will refuse to access a device which is already under the control of a +kernel driver. Using this flag is dangerous, it can seriously confuse the +kernel driver in question. It can also cause i2cset to silently write to +the wrong register. So use at your own risk and only if you know what +you're doing. +.TP +.B -y +Disable interactive mode. By default, i2cset will wait for a confirmation +from the user before messing with the I2C bus. When this flag is used, it +will perform the operation directly. This is mainly meant to be used in +scripts. +.TP +.B -m mask +The \fImask\fR parameter, if specified, describes which bits of \fIvalue\fR +will be actually written to \fIdata-address\fR. Bits set to 1 in the mask +are taken from \fIvalue\fR, while bits set to 0 will be read from +\fIdata-address\fR and thus preserved by the operation. Please note that +this parameter assumes that the read and write operations for the specified +mode are symmetrical for the device you are accessing. This may or may not +be the case, as neither I2C nor SMBus guarantees this. +.TP +.B -r +Read back the value right after writing it, and compare the result with the +value written. This used to be the default behavior. The same limitations +apply as those of option \fB-m\fR. +.PP +There are three required options to i2cset. \fIi2cbus\fR indicates the number +or name of the I2C bus to be scanned. This number should correspond to one of +the busses listed by \fIi2cdetect -l\fR. \fIchip-address\fR specifies the +address of the chip on that bus, and is an integer between 0x03 and 0x77. +\fIdata-address\fR specifies the address on that chip to write to, and is an +integer between 0x00 and 0xFF. +.PP +The \fIvalue\fR parameter, if specified, is the value to write to that +location on the chip. If this parameter is omited, then a short write is +issued. For most chips, it simply sets an internal pointer to the target +location, but doesn't actually write to that location. For a few chips +though, in particular simple ones with a single register, this short write +is an actual write. +.PP +The \fImode\fR parameter, if specified, is one of the letters \fBb\fP or +\fBw\fP, corresponding to a write size of a single byte or a 16-bit word, +respectively. A \fBp\fP can also be appended to the \fImode\fR parameter to +enable PEC. If the \fImode\fR parameter is omitted, i2cset defaults to byte +mode without PEC. The \fIvalue\fR provided must be within range for the +specified data type (0x00-0xFF for bytes, 0x0000-0xFFFF for words). + +.SH WARNING +i2cset can be extremely dangerous if used improperly. It can confuse your +I2C bus, cause data loss, or have more serious side effects. Writing to +a serial EEPROM on a memory DIMM (chip addresses between 0x50 and 0x57) may +DESTROY your memory, leaving your system unbootable! Be extremely careful +using this program. + +.SH SEE ALSO +i2cdump(8), isaset(8) + +.SH AUTHOR +Frodo Looijaard, Mark D. Studebaker and Jean Delvare + +This manual page was originally written by David Z Maze <dmaze@debian.org> for +the Debian GNU/Linux system. |