| .TH I2CGET 8 "May 2008" |
| .SH "NAME" |
| i2cget \- read from I2C/SMBus chip registers |
| |
| .SH SYNOPSIS |
| .B i2cget |
| .RB [ -f ] |
| .RB [ -y ] |
| .I i2cbus |
| .I chip-address |
| .RI [ "data-address " [ mode ]] |
| .br |
| .B i2cget |
| .B -V |
| |
| .SH DESCRIPTION |
| i2cget is a small helper program to read registers visible through the I2C |
| bus (or SMBus). |
| |
| .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, i2cget |
| 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 i2cget to return an invalid |
| value. So use at your own risk and only if you know what you're doing. |
| .TP |
| .B -y |
| Disable interactive mode. By default, i2cget 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. Use with caution. |
| .PP |
| There are two required options to i2cget. \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. |
| .PP |
| \fIdata-address\fR specifies the address on that chip to read from, and is |
| an integer between 0x00 and 0xFF. If omitted, the currently active register |
| will be read (if that makes sense for the considered chip). |
| .PP |
| The \fImode\fR parameter, if specified, is one of the letters \fBb\fP, |
| \fBw\fP or \fBc\fP, corresponding to a read byte data, a read word data or a |
| write byte/read byte transaction, respectively. A \fBp\fP can also be appended |
| to the \fImode\fR parameter to enable PEC. If the \fImode\fR parameter is omitted, |
| i2cget defaults to a read byte data transaction, unless \fIdata-address\fR is |
| also omitted, in which case the default (and only valid) transaction is a |
| single read byte. |
| |
| .SH WARNING |
| i2cget can be extremely dangerous if used improperly. I2C and SMBus are designed |
| in such a way that an SMBus read transaction can be seen as a write transaction by |
| certain chips. This is particularly true if setting \fImode\fR to \fBcp\fP (write byte/read |
| byte with PEC). Be extremely careful using this program. |
| |
| .SH SEE ALSO |
| i2cdump(8), i2cset(8) |
| |
| .SH AUTHOR |
| Jean Delvare |
| |
| This manual page was strongly inspired from those written by David Z Maze |
| for i2cset. |
