1 /* 2 * Keyboard matrix helper functions 3 * 4 * Copyright (c) 2012 The Chromium OS Authors. 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 */ 23 24 #ifndef _KEY_MATRIX_H 25 #define _KEY_MATRIX_H 26 27 #include <common.h> 28 29 /* Information about a matrix keyboard */ 30 struct key_matrix { 31 /* Dimensions of the keyboard matrix, in rows and columns */ 32 int num_rows; 33 int num_cols; 34 int key_count; /* number of keys in the matrix (= rows * cols) */ 35 36 /* 37 * Information about keycode mappings. The plain_keycode array must 38 * exist but fn may be NULL in which case it is not decoded. 39 */ 40 const u8 *plain_keycode; /* key code for each row / column */ 41 const u8 *fn_keycode; /* ...when Fn held down */ 42 int fn_pos; /* position of Fn key in key (or -1) */ 43 int ghost_filter; /* non-zero to enable ghost filter */ 44 }; 45 46 /* Information about a particular key (row, column pair) in the matrix */ 47 struct key_matrix_key { 48 uint8_t row; /* row number (0 = first) */ 49 uint8_t col; /* column number (0 = first) */ 50 uint8_t valid; /* 1 if valid, 0 to ignore this */ 51 }; 52 53 /** 54 * Decode a set of pressed keys into key codes 55 * 56 * Given a list of keys that are pressed, this converts this list into 57 * a list of key codes. Each of the keys has a valid flag, which can be 58 * used to mark a particular key as invalid (so that it is ignored). 59 * 60 * The plain keymap is used, unless the Fn key is detected along the way, 61 * at which point we switch to the Fn key map. 62 * 63 * If key ghosting is detected, we simply ignore the keys and return 0. 64 * 65 * @param config Keyboard matrix config 66 * @param keys List of keys to process (each is row, col) 67 * @param num_keys Number of keys to process 68 * @param keycode Returns a list of key codes, decoded from input 69 * @param max_keycodes Size of key codes array (suggest 8) 70 * 71 */ 72 int key_matrix_decode(struct key_matrix *config, struct key_matrix_key *keys, 73 int num_keys, int keycode[], int max_keycodes); 74 75 /** 76 * Read the keyboard configuration out of the fdt. 77 * 78 * Decode properties of named "linux,<type>keymap" where <type> is either 79 * empty, or "fn-". Then set up the plain key map (and the FN keymap if 80 * present). 81 * 82 * @param config Keyboard matrix config 83 * @param blob FDT blob 84 * @param node Node containing compatible data 85 * @return 0 if ok, -1 on error 86 */ 87 int key_matrix_decode_fdt(struct key_matrix *config, const void *blob, 88 int node); 89 90 /** 91 * Set up a new key matrix. 92 * 93 * @param config Keyboard matrix config 94 * @param rows Number of rows in key matrix 95 * @param cols Number of columns in key matrix 96 * @param ghost_filter Non-zero to enable ghost filtering 97 * @return 0 if ok, -1 on error 98 */ 99 int key_matrix_init(struct key_matrix *config, int rows, int cols, 100 int ghost_filter); 101 102 #endif 103