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[PATCH] I2C: Clarify the usage of i2c-dev.h 

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>
This commit is contained in:
Jean Delvare 2005-06-25 11:37:40 +02:00 committed by Greg Kroah-Hartman
parent a68e2f4895
commit 1d772e2587
1 changed files with 7 additions and 4 deletions
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11
Documentation/i2c/dev-interface
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@ -14,9 +14,12 @@ C example
========= =========
So let's say you want to access an i2c adapter from a C program. The 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>. first thing to do is "#include <linux/i2c-dev.h>". Please note that
Yes, I know, you should never include kernel header files, but until glibc there are two files named "i2c-dev.h" out there, one is distributed
knows about i2c, there is not much choice. 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 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 inspect /sys/class/i2c-dev/ to decide this. Adapter numbers are assigned
@ -78,7 +81,7 @@ Full interface description
========================== ==========================
The following IOCTLs are defined and fully supported 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) ioctl(file,I2C_SLAVE,long addr)
Change slave address. The address is passed in the 7 lower bits of the Change slave address. The address is passed in the 7 lower bits of the