u-boot/include/key_matrix.h
Simon Glass 71dc6bca4e input: Allow key ghosting filter to be disabled
Some keyboards will not need a key ghosting filter, so make this feature
optional.

Signed-off-by: Simon Glass <sjg@chromium.org>
2012-10-15 11:54:04 -07:00

102 lines
3.5 KiB
C

/*
* Keyboard matrix helper functions
*
* Copyright (c) 2012 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifndef _KEY_MATRIX_H
#define _KEY_MATRIX_H
#include <common.h>
/* Information about a matrix keyboard */
struct key_matrix {
/* Dimensions of the keyboard matrix, in rows and columns */
int num_rows;
int num_cols;
int key_count; /* number of keys in the matrix (= rows * cols) */
/*
* Information about keycode mappings. The plain_keycode array must
* exist but fn may be NULL in which case it is not decoded.
*/
const u8 *plain_keycode; /* key code for each row / column */
const u8 *fn_keycode; /* ...when Fn held down */
int fn_pos; /* position of Fn key in key (or -1) */
int ghost_filter; /* non-zero to enable ghost filter */
};
/* Information about a particular key (row, column pair) in the matrix */
struct key_matrix_key {
uint8_t row; /* row number (0 = first) */
uint8_t col; /* column number (0 = first) */
uint8_t valid; /* 1 if valid, 0 to ignore this */
};
/**
* Decode a set of pressed keys into key codes
*
* Given a list of keys that are pressed, this converts this list into
* a list of key codes. Each of the keys has a valid flag, which can be
* used to mark a particular key as invalid (so that it is ignored).
*
* The plain keymap is used, unless the Fn key is detected along the way,
* at which point we switch to the Fn key map.
*
* If key ghosting is detected, we simply ignore the keys and return 0.
*
* @param config Keyboard matrix config
* @param keys List of keys to process (each is row, col)
* @param num_keys Number of keys to process
* @param keycode Returns a list of key codes, decoded from input
* @param max_keycodes Size of key codes array (suggest 8)
*
*/
int key_matrix_decode(struct key_matrix *config, struct key_matrix_key *keys,
int num_keys, int keycode[], int max_keycodes);
/**
* Read the keyboard configuration out of the fdt.
*
* Decode properties of named "linux,<type>keymap" where <type> is either
* empty, or "fn-". Then set up the plain key map (and the FN keymap if
* present).
*
* @param config Keyboard matrix config
* @param blob FDT blob
* @param node Node containing compatible data
* @return 0 if ok, -1 on error
*/
int key_matrix_decode_fdt(struct key_matrix *config, const void *blob,
int node);
/**
* Set up a new key matrix.
*
* @param config Keyboard matrix config
* @param rows Number of rows in key matrix
* @param cols Number of columns in key matrix
* @param ghost_filter Non-zero to enable ghost filtering
* @return 0 if ok, -1 on error
*/
int key_matrix_init(struct key_matrix *config, int rows, int cols,
int ghost_filter);
#endif