Dear Gerhard Sittig,

- add comments about individual routines' purpose and their interaction,
  pre-conditions and consequences
- mark a few spots which may need some more attention or clarification
- rephrase some diagnostics messages

Signed-off-by: Gerhard Sittig <redacted>
---
 drivers/input/keyboard/matrix_keypad.c |   81
+++++++++++++++++++++++++++++--- drivers/input/matrix-keymap.c          | 
  4 +-
 include/linux/input/matrix_keypad.h    |   17 ++++---
 3 files changed, 89 insertions(+), 13 deletions(-)

You might want to use kerneldoc for this , see Documentation/kernel-doc-nano-
HOWTO.txt

Best regards,
Marek Vasut