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 #include <common.h> 12 13 /* Information about a matrix keyboard */ 14 struct key_matrix { 15 /* Dimensions of the keyboard matrix, in rows and columns */ 16 int num_rows; 17 int num_cols; 18 int key_count; /* number of keys in the matrix (= rows * cols) */ 19 20 /* 21 * Information about keycode mappings. The plain_keycode array must 22 * exist but fn may be NULL in which case it is not decoded. 23 */ 24 const u8 *plain_keycode; /* key code for each row / column */ 25 const u8 *fn_keycode; /* ...when Fn held down */ 26 int fn_pos; /* position of Fn key in key (or -1) */ 27 int ghost_filter; /* non-zero to enable ghost filter */ 28 }; 29 30 /* Information about a particular key (row, column pair) in the matrix */ 31 struct key_matrix_key { 32 uint8_t row; /* row number (0 = first) */ 33 uint8_t col; /* column number (0 = first) */ 34 uint8_t valid; /* 1 if valid, 0 to ignore this */ 35 }; 36 37 /** 38 * Decode a set of pressed keys into key codes 39 * 40 * Given a list of keys that are pressed, this converts this list into 41 * a list of key codes. Each of the keys has a valid flag, which can be 42 * used to mark a particular key as invalid (so that it is ignored). 43 * 44 * The plain keymap is used, unless the Fn key is detected along the way, 45 * at which point we switch to the Fn key map. 46 * 47 * If key ghosting is detected, we simply ignore the keys and return 0. 48 * 49 * @param config Keyboard matrix config 50 * @param keys List of keys to process (each is row, col) 51 * @param num_keys Number of keys to process 52 * @param keycode Returns a list of key codes, decoded from input 53 * @param max_keycodes Size of key codes array (suggest 8) 54 * 55 */ 56 int key_matrix_decode(struct key_matrix *config, struct key_matrix_key *keys, 57 int num_keys, int keycode[], int max_keycodes); 58 59 /** 60 * Read the keyboard configuration out of the fdt. 61 * 62 * Decode properties of named "linux,<type>keymap" where <type> is either 63 * empty, or "fn-". Then set up the plain key map (and the FN keymap if 64 * present). 65 * 66 * @param config Keyboard matrix config 67 * @param blob FDT blob 68 * @param node Node containing compatible data 69 * @return 0 if ok, -1 on error 70 */ 71 int key_matrix_decode_fdt(struct udevice *dev, struct key_matrix *config); 72 73 /** 74 * Set up a new key matrix. 75 * 76 * @param config Keyboard matrix config 77 * @param rows Number of rows in key matrix 78 * @param cols Number of columns in key matrix 79 * @param ghost_filter Non-zero to enable ghost filtering 80 * @return 0 if ok, -1 on error 81 */ 82 int key_matrix_init(struct key_matrix *config, int rows, int cols, 83 int ghost_filter); 84 85 #endif 86