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92c27c51 BT |
1 | /* |
2 | * Manage Keyboard Matrices | |
3 | * | |
4 | * Copyright (c) 2012 The Chromium OS Authors. | |
5 | * (C) Copyright 2004 DENX Software Engineering, Wolfgang Denk, wd@denx.de | |
6 | * | |
7 | * See file CREDITS for list of people who contributed to this | |
8 | * project. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License as | |
12 | * published by the Free Software Foundation; either version 2 of | |
13 | * the License, or (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | * GNU General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
23 | * MA 02111-1307 USA | |
24 | */ | |
25 | ||
c20dbf64 | 26 | #include <common.h> |
92c27c51 BT |
27 | #include <fdtdec.h> |
28 | #include <key_matrix.h> | |
29 | #include <malloc.h> | |
30 | #include <linux/input.h> | |
31 | ||
32 | /** | |
33 | * Determine if the current keypress configuration can cause key ghosting | |
34 | * | |
35 | * We figure this out by seeing if we have two or more keys in the same | |
36 | * column, as well as two or more keys in the same row. | |
37 | * | |
38 | * @param config Keyboard matrix config | |
39 | * @param keys List of keys to check | |
40 | * @param valid Number of valid keypresses to check | |
41 | * @return 0 if no ghosting is possible, 1 if it is | |
42 | */ | |
43 | static int has_ghosting(struct key_matrix *config, struct key_matrix_key *keys, | |
44 | int valid) | |
45 | { | |
46 | int key_in_same_col = 0, key_in_same_row = 0; | |
47 | int i, j; | |
48 | ||
71dc6bca SG |
49 | if (!config->ghost_filter || valid < 3) |
50 | return 0; | |
51 | ||
92c27c51 BT |
52 | for (i = 0; i < valid; i++) { |
53 | /* | |
54 | * Find 2 keys such that one key is in the same row | |
55 | * and the other is in the same column as the i-th key. | |
56 | */ | |
57 | for (j = i + 1; j < valid; j++) { | |
58 | if (keys[j].col == keys[i].col) | |
59 | key_in_same_col = 1; | |
60 | if (keys[j].row == keys[i].row) | |
61 | key_in_same_row = 1; | |
62 | } | |
63 | } | |
64 | ||
65 | if (key_in_same_col && key_in_same_row) | |
66 | return 1; | |
67 | else | |
68 | return 0; | |
69 | } | |
70 | ||
71 | int key_matrix_decode(struct key_matrix *config, struct key_matrix_key keys[], | |
72 | int num_keys, int keycode[], int max_keycodes) | |
73 | { | |
74 | const u8 *keymap; | |
75 | int valid, upto; | |
76 | int pos; | |
77 | ||
78 | debug("%s: num_keys = %d\n", __func__, num_keys); | |
79 | keymap = config->plain_keycode; | |
80 | for (valid = upto = 0; upto < num_keys; upto++) { | |
81 | struct key_matrix_key *key = &keys[upto]; | |
82 | ||
83 | debug(" valid=%d, row=%d, col=%d\n", key->valid, key->row, | |
84 | key->col); | |
85 | if (!key->valid) | |
86 | continue; | |
87 | pos = key->row * config->num_cols + key->col; | |
88 | if (config->fn_keycode && pos == config->fn_pos) | |
89 | keymap = config->fn_keycode; | |
90 | ||
91 | /* Convert the (row, col) values into a keycode */ | |
92 | if (valid < max_keycodes) | |
93 | keycode[valid++] = keymap[pos]; | |
94 | debug(" keycode=%d\n", keymap[pos]); | |
95 | } | |
96 | ||
97 | /* For a ghost key config, ignore the keypresses for this iteration. */ | |
71dc6bca | 98 | if (has_ghosting(config, keys, valid)) { |
92c27c51 BT |
99 | valid = 0; |
100 | debug(" ghosting detected!\n"); | |
101 | } | |
102 | debug(" %d valid keycodes found\n", valid); | |
103 | ||
104 | return valid; | |
105 | } | |
106 | ||
107 | /** | |
108 | * Create a new keycode map from some provided data | |
109 | * | |
110 | * This decodes a keycode map in the format used by the fdt, which is one | |
111 | * word per entry, with the row, col and keycode encoded in that word. | |
112 | * | |
113 | * We create a (row x col) size byte array with each entry containing the | |
114 | * keycode for that (row, col). We also search for map_keycode and return | |
115 | * its position if found (this is used for finding the Fn key). | |
116 | * | |
117 | * @param config Key matrix dimensions structure | |
118 | * @param data Keycode data | |
119 | * @param len Number of entries in keycode table | |
120 | * @param map_keycode Key code to find in the map | |
121 | * @param pos Returns position of map_keycode, if found, else -1 | |
122 | * @return map Pointer to allocated map | |
123 | */ | |
124 | static uchar *create_keymap(struct key_matrix *config, u32 *data, int len, | |
125 | int map_keycode, int *pos) | |
126 | { | |
127 | uchar *map; | |
128 | ||
129 | if (pos) | |
130 | *pos = -1; | |
131 | map = (uchar *)calloc(1, config->key_count); | |
132 | if (!map) { | |
133 | debug("%s: failed to malloc %d bytes\n", __func__, | |
134 | config->key_count); | |
135 | return NULL; | |
136 | } | |
137 | ||
138 | for (; len >= sizeof(u32); data++, len -= 4) { | |
139 | u32 tmp = fdt32_to_cpu(*data); | |
140 | int key_code, row, col; | |
141 | int entry; | |
142 | ||
143 | row = (tmp >> 24) & 0xff; | |
144 | col = (tmp >> 16) & 0xff; | |
145 | key_code = tmp & 0xffff; | |
146 | entry = row * config->num_cols + col; | |
147 | map[entry] = key_code; | |
14813f19 SG |
148 | debug(" map %d, %d: pos=%d, keycode=%d\n", row, col, |
149 | entry, key_code); | |
92c27c51 BT |
150 | if (pos && map_keycode == key_code) |
151 | *pos = entry; | |
152 | } | |
153 | ||
154 | return map; | |
155 | } | |
156 | ||
df637fa6 | 157 | int key_matrix_decode_fdt(struct key_matrix *config, const void *blob, int node) |
92c27c51 BT |
158 | { |
159 | const struct fdt_property *prop; | |
df637fa6 SW |
160 | int proplen; |
161 | uchar *plain_keycode; | |
92c27c51 | 162 | |
df637fa6 SW |
163 | prop = fdt_get_property(blob, node, "linux,keymap", &proplen); |
164 | /* Basic keymap is required */ | |
374e8370 SW |
165 | if (!prop) { |
166 | debug("%s: cannot find keycode-plain map\n", __func__); | |
df637fa6 | 167 | return -1; |
374e8370 | 168 | } |
92c27c51 | 169 | |
df637fa6 SW |
170 | plain_keycode = create_keymap(config, (u32 *)prop->data, |
171 | proplen, KEY_FN, &config->fn_pos); | |
172 | config->plain_keycode = plain_keycode; | |
173 | /* Conversion error -> fail */ | |
174 | if (!config->plain_keycode) | |
175 | return -1; | |
176 | ||
177 | prop = fdt_get_property(blob, node, "linux,fn-keymap", &proplen); | |
178 | /* fn keymap is optional */ | |
179 | if (!prop) | |
180 | goto done; | |
181 | ||
182 | config->fn_keycode = create_keymap(config, (u32 *)prop->data, | |
183 | proplen, -1, NULL); | |
184 | /* Conversion error -> fail */ | |
374e8370 | 185 | if (!config->fn_keycode) { |
df637fa6 | 186 | free(plain_keycode); |
92c27c51 BT |
187 | return -1; |
188 | } | |
189 | ||
df637fa6 SW |
190 | done: |
191 | debug("%s: Decoded key maps %p, %p from fdt\n", __func__, | |
192 | config->plain_keycode, config->fn_keycode); | |
92c27c51 BT |
193 | return 0; |
194 | } | |
195 | ||
71dc6bca SG |
196 | int key_matrix_init(struct key_matrix *config, int rows, int cols, |
197 | int ghost_filter) | |
92c27c51 BT |
198 | { |
199 | memset(config, '\0', sizeof(*config)); | |
200 | config->num_rows = rows; | |
201 | config->num_cols = cols; | |
202 | config->key_count = rows * cols; | |
71dc6bca | 203 | config->ghost_filter = ghost_filter; |
92c27c51 BT |
204 | assert(config->key_count > 0); |
205 | ||
206 | return 0; | |
207 | } |