1/* SPDX-License-Identifier: GPL-2.0+ */ 2/* 3 * Keyboard matrix helper functions 4 * 5 * Copyright (c) 2012 The Chromium OS Authors. 6 */ 7 8#ifndef _KEY_MATRIX_H 9#define _KEY_MATRIX_H 10 11 12/* Information about a matrix keyboard */ 13struct key_matrix { 14 /* Dimensions of the keyboard matrix, in rows and columns */ 15 int num_rows; 16 int num_cols; 17 int key_count; /* number of keys in the matrix (= rows * cols) */ 18 19 /* 20 * Information about keycode mappings. The plain_keycode array must 21 * exist but fn may be NULL in which case it is not decoded. 22 */ 23 const u8 *plain_keycode; /* key code for each row / column */ 24 const u8 *fn_keycode; /* ...when Fn held down */ 25 int fn_pos; /* position of Fn key in key (or -1) */ 26 int ghost_filter; /* non-zero to enable ghost filter */ 27}; 28 29/* Information about a particular key (row, column pair) in the matrix */ 30struct key_matrix_key { 31 uint8_t row; /* row number (0 = first) */ 32 uint8_t col; /* column number (0 = first) */ 33 uint8_t valid; /* 1 if valid, 0 to ignore this */ 34}; 35 36/** 37 * Decode a set of pressed keys into key codes 38 * 39 * Given a list of keys that are pressed, this converts this list into 40 * a list of key codes. Each of the keys has a valid flag, which can be 41 * used to mark a particular key as invalid (so that it is ignored). 42 * 43 * The plain keymap is used, unless the Fn key is detected along the way, 44 * at which point we switch to the Fn key map. 45 * 46 * If key ghosting is detected, we simply ignore the keys and return 0. 47 * 48 * @param config Keyboard matrix config 49 * @param keys List of keys to process (each is row, col) 50 * @param num_keys Number of keys to process 51 * @param keycode Returns a list of key codes, decoded from input 52 * @param max_keycodes Size of key codes array (suggest 8) 53 * 54 */ 55int key_matrix_decode(struct key_matrix *config, struct key_matrix_key *keys, 56 int num_keys, int keycode[], int max_keycodes); 57 58/** 59 * Read the keyboard configuration out of the fdt. 60 * 61 * Decode properties of named "linux,<type>keymap" where <type> is either 62 * empty, or "fn-". Then set up the plain key map (and the FN keymap if 63 * present). 64 * 65 * @param config Keyboard matrix config 66 * @param blob FDT blob 67 * @param node Node containing compatible data 68 * Return: 0 if ok, -1 on error 69 */ 70int key_matrix_decode_fdt(struct udevice *dev, struct key_matrix *config); 71 72/** 73 * Set up a new key matrix. 74 * 75 * @param config Keyboard matrix config 76 * @param rows Number of rows in key matrix 77 * @param cols Number of columns in key matrix 78 * @param ghost_filter Non-zero to enable ghost filtering 79 * Return: 0 if ok, -1 on error 80 */ 81int key_matrix_init(struct key_matrix *config, int rows, int cols, 82 int ghost_filter); 83 84#endif 85