[FE training-materials-updates] Add details about misc vs raw character devices

Michael Opdenacker michael.opdenacker at free-electrons.com
Wed Dec 7 23:14:28 CET 2016


Repository : git://git.free-electrons.com/training-materials.git
On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=bd30cc1afeb5b01989e506a342d7d2619e5b4782

>---------------------------------------------------------------

commit bd30cc1afeb5b01989e506a342d7d2619e5b4782
Author: Michael Opdenacker <michael.opdenacker at free-electrons.com>
Date:   Wed Dec 7 23:14:28 2016 +0100

    Add details about misc vs raw character devices
    
    Signed-off-by: Michael Opdenacker <michael.opdenacker at free-electrons.com>


>---------------------------------------------------------------

bd30cc1afeb5b01989e506a342d7d2619e5b4782
 slides/kernel-misc-subsystem/kernel-misc-subsystem.tex | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/slides/kernel-misc-subsystem/kernel-misc-subsystem.tex b/slides/kernel-misc-subsystem/kernel-misc-subsystem.tex
index 64b5c3c..0fde3a5 100644
--- a/slides/kernel-misc-subsystem/kernel-misc-subsystem.tex
+++ b/slides/kernel-misc-subsystem/kernel-misc-subsystem.tex
@@ -18,12 +18,16 @@
       useful.
     \end{itemize}
   \item The drivers for such devices could be implemented directly as
-    raw {\em character drivers}.
+    raw {\em character drivers} (with \kfunc{cdev_init} and
+    \kfunc{cdev_add}).
   \item But there is a subsystem that makes this work a little bit
     easier: the {\bf misc subsystem}.
     \begin{itemize}
     \item It is really only a {\bf thin layer} above the {\em character
         driver} API.
+    \item Another advantage is that devices are integrated in the Device
+        Model (device files appearing in {\em devtmpfs}, which you don't
+	have with raw character devices).
     \end{itemize}
   \end{itemize}
 \end{frame}




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