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diff --git a/tools/i2cdump.8 b/tools/i2cdump.8 new file mode 100644 index 0000000..7a02a47 --- /dev/null +++ b/tools/i2cdump.8 @@ -0,0 +1,84 @@ +.TH I2CDUMP 8 "May 2008" +.SH NAME +i2cdump \- examine I2C registers + +.SH SYNOPSIS +.B i2cdump +.RB [ -f ] +.RB [ "-r first-last" ] +.RB [ -y ] +.I i2cbus +.I address +.RI [ "mode " [ "bank " [ bankreg ]]] +.br +.B i2cdump +.B -V + +.SH DESCRIPTION +i2cdump is a small helper program to examine 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, i2cdump +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 i2cdump to return invalid +results. So use at your own risk and only if you know what you're doing. +.TP +.B -r first-last +Limit the range of registers being accessed. This option is only available +with modes \fBb\fP, \fBw\fP, \fBc\fP and \fBW\fP. For mode \fBW\fP, +\fBfirst\fR must be even and \fBlast\fR must be odd. +.TP +.B -y +Disable interactive mode. By default, i2cdump 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. +.PP +At least two options must be provided to i2cdump. \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. \fIaddress\fR indicates the +address to be scanned on that bus, and is an integer between 0x03 and 0x77. +.PP +The \fImode\fR parameter, if specified, is one of the letters \fBb\fP, \fBw\fP, +\fBs\fP, or \fBi\fP, corresponding to a read size of a single byte, a 16-bit +word, an SMBus block, an I2C block, respectively. The \fBc\fP mode is a +little different, it reads all bytes consecutively, and is useful for chips that +have an address auto-increment feature, such as EEPROMs. The \fBW\fP mode is +also special, it is similar to \fBw\fP except that a read command will only +be issued on even register addresses; this is again mainly useful for EEPROMs. +.PP +A \fBp\fP can also be appended to the \fImode\fR parameter (except for +\fBi\fP and \fBW\fP) to enable PEC. If the \fImode\fR parameter is omitted, +i2cdump defaults to byte access without PEC. +.PP +The \fIbank\fR and \fIbankreg\fR parameters are useful on the W83781D and +similar chips (at the time of writing, all Winbond and Asus chips). +\fIbank\fR is an integer between 0 and 7, and \fIbankreg\fR is an integer +between 0x00 and 0xFF (default value: 0x4E). The W83781D data sheet has more +information on bank selection. + +.SH WARNING +i2cdump can be dangerous if used improperly. Most notably, the \fBc\fP mode +starts with WRITING a byte to the chip. On most chips it will be stored in the +address pointer register, which is OK, but some chips with a single register +or no (visible) register at all will most likely see this as a real WRITE, +resulting in possible misbehavior or corruption. Do not use i2cdump +on random addresses. Anyway, it is of little use unless you have good +knowledge of the chip you're working with and an idea of what you are looking +for. + +.SH SEE ALSO +i2cset(8), i2cdetect(8), isadump(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. |