[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>
diff --git a/Documentation/i2c/dev-interface b/Documentation/i2c/dev-interface
index a78ea62..b849ad6 100644
--- a/Documentation/i2c/dev-interface
+++ b/Documentation/i2c/dev-interface
@@ -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