From khali@linux-fr.org Sat Jun 25 02:39:22 2005 Date: Sat, 25 Jun 2005 11:37:40 +0200 From: Jean Delvare <khali@linux-fr.org> To: Greg KH <greg@kroah.com> Cc: LM Sensors <lm-sensors@lm-sensors.org>, Nils Roeder <nroeder@inf.ed.ac.uk> Subject: I2C: Clarify the usage of i2c-dev.h Message-Id: <20050625113740.29b08918.khali@linux-fr.org> Upon suggestion by Nils Roeder, here is an update to the i2c documentation to clarify which header files user-space applications relying on the i2c-dev interface should include. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- Documentation/i2c/dev-interface | 11 +++++++---- 1 files changed, 7 insertions(+), 4 deletions(-) --- gregkh-2.6.orig/Documentation/i2c/dev-interface 2005-07-01 14:44:13.000000000 -0700 +++ gregkh-2.6/Documentation/i2c/dev-interface 2005-07-01 14:44:14.000000000 -0700 @@ -14,9 +14,12 @@ ========= So let's say you want to access an i2c adapter from a C program. The -first thing to do is `#include <linux/i2c.h>" and "#include <linux/i2c-dev.h>. -Yes, I know, you should never include kernel header files, but until glibc -knows about i2c, there is not much choice. +first thing to do is "#include <linux/i2c-dev.h>". Please note that +there are two files named "i2c-dev.h" out there, one is distributed +with the Linux kernel and is meant to be included from kernel +driver code, the other one is distributed with lm_sensors and is +meant to be included from user-space programs. You obviously want +the second one here. Now, you have to decide which adapter you want to access. You should inspect /sys/class/i2c-dev/ to decide this. Adapter numbers are assigned @@ -78,7 +81,7 @@ ========================== The following IOCTLs are defined and fully supported -(see also i2c-dev.h and i2c.h): +(see also i2c-dev.h): ioctl(file,I2C_SLAVE,long addr) Change slave address. The address is passed in the 7 lower bits of the