// SPDX-License-Identifier: GPL-2.0+
/*
* Front panel driver for Linux
* Copyright (C) 2000-2008, Willy Tarreau <w@1wt.eu>
* Copyright (C) 2016-2017 Glider bvba
*
* This code drives an LCD module (/dev/lcd), and a keypad (/dev/keypad)
* connected to a parallel printer port.
*
* The LCD module may either be an HD44780-like 8-bit parallel LCD, or a 1-bit
* serial module compatible with Samsung's KS0074. The pins may be connected in
* any combination, everything is programmable.
*
* The keypad consists in a matrix of push buttons connecting input pins to
* data output pins or to the ground. The combinations have to be hard-coded
* in the driver, though several profiles exist and adding new ones is easy.
*
* Several profiles are provided for commonly found LCD+keypad modules on the
* market, such as those found in Nexcom's appliances.
*
* FIXME:
* - the initialization/deinitialization process is very dirty and should
* be rewritten. It may even be buggy.
*
* TODO:
* - document 24 keys keyboard (3 rows of 8 cols, 32 diodes + 2 inputs)
* - make the LCD a part of a virtual screen of Vx*Vy
* - make the inputs list smp-safe
* - change the keyboard to a double mapping : signals -> key_id -> values
* so that applications can change values without knowing signals
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include
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