From 91b28aeb17ce13065d745a1f92c95011c10ba75a Mon Sep 17 00:00:00 2001 From: Cengiz C Date: Tue, 12 Dec 2017 19:43:09 +0300 Subject: i2c: update i2c-dev.h warning in documentation `Documentation/i2c/dev-interface` gives examples for accessing i2c from userspace. There's a note that warns developers about the two `i2c-dev.h` header files which were shipped with the kernel and i2c-tools separately. However, following i2c-tools commits suggest that the header files are now identical (in functionality) and `i2c_*` helper functions are now defined in a separate header called `i2c/smbus.h`, which is distributed with i2c-tools: commit 652619121974 ("Minimize differences with kernel flavor") commit 93caf007f4cb ("Move SMBus helper functions to include/i2c/smbus.h") Thus, I've converted the warning paragraph into a historical note and updated the suggested header files. Signed-off-by: Cengiz Can Cc: Wolfram Sang Signed-off-by: Jonathan Corbet --- Documentation/i2c/dev-interface | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'Documentation/i2c') diff --git a/Documentation/i2c/dev-interface b/Documentation/i2c/dev-interface index 5ff19447ac44..d04e6e4964ee 100644 --- a/Documentation/i2c/dev-interface +++ b/Documentation/i2c/dev-interface @@ -17,13 +17,16 @@ i2c-10, ...). All 256 minor device numbers are reserved for i2c. C example ========= -So let's say you want to access an i2c adapter from a C program. The -first thing to do is "#include ". 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 i2c-tools and is -meant to be included from user-space programs. You obviously want -the second one here. +So let's say you want to access an i2c adapter from a C program. +First, you need to include these two headers: + + #include + #include + +(Please note that there are two files named "i2c-dev.h" out there. One is +distributed with the Linux kernel and the other one is included in the +source tree of i2c-tools. They used to be different in content but since 2012 +they're identical. You should use "linux/i2c-dev.h"). Now, you have to decide which adapter you want to access. You should inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this. -- cgit v1.2.3