blob: 8db686040d393b0352c647cc5c77cfe5e9b65840
1 | /* |
2 | * Keyboard matrix helper functions |
3 | * |
4 | * Copyright (c) 2012 The Chromium OS Authors. |
5 | * |
6 | * SPDX-License-Identifier: GPL-2.0+ |
7 | */ |
8 | |
9 | #ifndef _KEY_MATRIX_H |
10 | #define _KEY_MATRIX_H |
11 | |
12 | #include <common.h> |
13 | |
14 | /* Information about a matrix keyboard */ |
15 | struct key_matrix { |
16 | /* Dimensions of the keyboard matrix, in rows and columns */ |
17 | int num_rows; |
18 | int num_cols; |
19 | int key_count; /* number of keys in the matrix (= rows * cols) */ |
20 | |
21 | /* |
22 | * Information about keycode mappings. The plain_keycode array must |
23 | * exist but fn may be NULL in which case it is not decoded. |
24 | */ |
25 | const u8 *plain_keycode; /* key code for each row / column */ |
26 | const u8 *fn_keycode; /* ...when Fn held down */ |
27 | int fn_pos; /* position of Fn key in key (or -1) */ |
28 | int ghost_filter; /* non-zero to enable ghost filter */ |
29 | }; |
30 | |
31 | /* Information about a particular key (row, column pair) in the matrix */ |
32 | struct key_matrix_key { |
33 | uint8_t row; /* row number (0 = first) */ |
34 | uint8_t col; /* column number (0 = first) */ |
35 | uint8_t valid; /* 1 if valid, 0 to ignore this */ |
36 | }; |
37 | |
38 | /** |
39 | * Decode a set of pressed keys into key codes |
40 | * |
41 | * Given a list of keys that are pressed, this converts this list into |
42 | * a list of key codes. Each of the keys has a valid flag, which can be |
43 | * used to mark a particular key as invalid (so that it is ignored). |
44 | * |
45 | * The plain keymap is used, unless the Fn key is detected along the way, |
46 | * at which point we switch to the Fn key map. |
47 | * |
48 | * If key ghosting is detected, we simply ignore the keys and return 0. |
49 | * |
50 | * @param config Keyboard matrix config |
51 | * @param keys List of keys to process (each is row, col) |
52 | * @param num_keys Number of keys to process |
53 | * @param keycode Returns a list of key codes, decoded from input |
54 | * @param max_keycodes Size of key codes array (suggest 8) |
55 | * |
56 | */ |
57 | int key_matrix_decode(struct key_matrix *config, struct key_matrix_key *keys, |
58 | int num_keys, int keycode[], int max_keycodes); |
59 | |
60 | /** |
61 | * Read the keyboard configuration out of the fdt. |
62 | * |
63 | * Decode properties of named "linux,<type>keymap" where <type> is either |
64 | * empty, or "fn-". Then set up the plain key map (and the FN keymap if |
65 | * present). |
66 | * |
67 | * @param config Keyboard matrix config |
68 | * @param blob FDT blob |
69 | * @param node Node containing compatible data |
70 | * @return 0 if ok, -1 on error |
71 | */ |
72 | int key_matrix_decode_fdt(struct key_matrix *config, const void *blob, |
73 | int node); |
74 | |
75 | /** |
76 | * Set up a new key matrix. |
77 | * |
78 | * @param config Keyboard matrix config |
79 | * @param rows Number of rows in key matrix |
80 | * @param cols Number of columns in key matrix |
81 | * @param ghost_filter Non-zero to enable ghost filtering |
82 | * @return 0 if ok, -1 on error |
83 | */ |
84 | int key_matrix_init(struct key_matrix *config, int rows, int cols, |
85 | int ghost_filter); |
86 | |
87 | #endif |
88 |