1 /*
2  * Copyright (c) 2005 Henk Vergonet <Henk.Vergonet@gmail.com>
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of
7  * the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  */
18 
19 #ifndef MAP_TO_7SEGMENT_H
20 #define MAP_TO_7SEGMENT_H
21 
22 /* This file provides translation primitives and tables for the conversion
23  * of (ASCII) characters to a 7-segments notation.
24  *
25  * The 7 segment's wikipedia notation below is used as standard.
26  * See: http://en.wikipedia.org/wiki/Seven_segment_display
27  *
28  * Notation:	+-a-+
29  *		f   b
30  *		+-g-+
31  *		e   c
32  *		+-d-+
33  *
34  * Usage:
35  *
36  *   Register a map variable, and fill it with a character set:
37  *	static SEG7_DEFAULT_MAP(map_seg7);
38  *
39  *
40  *   Then use for conversion:
41  *	seg7 = map_to_seg7(&map_seg7, some_char);
42  *	...
43  *
44  * In device drivers it is recommended, if required, to make the char map
45  * accessible via the sysfs interface using the following scheme:
46  *
47  * static ssize_t show_map(struct device *dev, char *buf) {
48  *	memcpy(buf, &map_seg7, sizeof(map_seg7));
49  *	return sizeof(map_seg7);
50  * }
51  * static ssize_t store_map(struct device *dev, const char *buf, size_t cnt) {
52  *	if(cnt != sizeof(map_seg7))
53  *		return -EINVAL;
54  *	memcpy(&map_seg7, buf, cnt);
55  *	return cnt;
56  * }
57  * static DEVICE_ATTR(map_seg7, PERMS_RW, show_map, store_map);
58  *
59  * History:
60  * 2005-05-31	RFC linux-kernel@vger.kernel.org
61  */
62 #include <linux/errno.h>
63 
64 
65 #define BIT_SEG7_A		0
66 #define BIT_SEG7_B		1
67 #define BIT_SEG7_C		2
68 #define BIT_SEG7_D		3
69 #define BIT_SEG7_E		4
70 #define BIT_SEG7_F		5
71 #define BIT_SEG7_G		6
72 #define BIT_SEG7_RESERVED	7
73 
74 struct seg7_conversion_map {
75 	unsigned char	table[128];
76 };
77 
map_to_seg7(struct seg7_conversion_map * map,int c)78 static __inline__ int map_to_seg7(struct seg7_conversion_map *map, int c)
79 {
80 	return c >= 0 && c < sizeof(map->table) ? map->table[c] : -EINVAL;
81 }
82 
83 #define SEG7_CONVERSION_MAP(_name, _map)	\
84 	struct seg7_conversion_map _name = { .table = { _map } }
85 
86 /*
87  * It is recommended to use a facility that allows user space to redefine
88  * custom character sets for LCD devices. Please use a sysfs interface
89  * as described above.
90  */
91 #define MAP_TO_SEG7_SYSFS_FILE	"map_seg7"
92 
93 /*******************************************************************************
94  * ASCII conversion table
95  ******************************************************************************/
96 
97 #define _SEG7(l,a,b,c,d,e,f,g)	\
98       (	a<<BIT_SEG7_A |	b<<BIT_SEG7_B |	c<<BIT_SEG7_C |	d<<BIT_SEG7_D |	\
99 	e<<BIT_SEG7_E |	f<<BIT_SEG7_F |	g<<BIT_SEG7_G )
100 
101 #define _MAP_0_32_ASCII_SEG7_NON_PRINTABLE	\
102 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
103 
104 #define _MAP_33_47_ASCII_SEG7_SYMBOL		\
105  _SEG7('!',0,0,0,0,1,1,0), _SEG7('"',0,1,0,0,0,1,0), _SEG7('#',0,1,1,0,1,1,0),\
106  _SEG7('$',1,0,1,1,0,1,1), _SEG7('%',0,0,1,0,0,1,0), _SEG7('&',1,0,1,1,1,1,1),\
107  _SEG7('\'',0,0,0,0,0,1,0),_SEG7('(',1,0,0,1,1,1,0), _SEG7(')',1,1,1,1,0,0,0),\
108  _SEG7('*',0,1,1,0,1,1,1), _SEG7('+',0,1,1,0,0,0,1), _SEG7(',',0,0,0,0,1,0,0),\
109  _SEG7('-',0,0,0,0,0,0,1), _SEG7('.',0,0,0,0,1,0,0), _SEG7('/',0,1,0,0,1,0,1),
110 
111 #define _MAP_48_57_ASCII_SEG7_NUMERIC		\
112  _SEG7('0',1,1,1,1,1,1,0), _SEG7('1',0,1,1,0,0,0,0), _SEG7('2',1,1,0,1,1,0,1),\
113  _SEG7('3',1,1,1,1,0,0,1), _SEG7('4',0,1,1,0,0,1,1), _SEG7('5',1,0,1,1,0,1,1),\
114  _SEG7('6',1,0,1,1,1,1,1), _SEG7('7',1,1,1,0,0,0,0), _SEG7('8',1,1,1,1,1,1,1),\
115  _SEG7('9',1,1,1,1,0,1,1),
116 
117 #define _MAP_58_64_ASCII_SEG7_SYMBOL		\
118  _SEG7(':',0,0,0,1,0,0,1), _SEG7(';',0,0,0,1,0,0,1), _SEG7('<',1,0,0,0,0,1,1),\
119  _SEG7('=',0,0,0,1,0,0,1), _SEG7('>',1,1,0,0,0,0,1), _SEG7('?',1,1,1,0,0,1,0),\
120  _SEG7('@',1,1,0,1,1,1,1),
121 
122 #define _MAP_65_90_ASCII_SEG7_ALPHA_UPPR	\
123  _SEG7('A',1,1,1,0,1,1,1), _SEG7('B',1,1,1,1,1,1,1), _SEG7('C',1,0,0,1,1,1,0),\
124  _SEG7('D',1,1,1,1,1,1,0), _SEG7('E',1,0,0,1,1,1,1), _SEG7('F',1,0,0,0,1,1,1),\
125  _SEG7('G',1,1,1,1,0,1,1), _SEG7('H',0,1,1,0,1,1,1), _SEG7('I',0,1,1,0,0,0,0),\
126  _SEG7('J',0,1,1,1,0,0,0), _SEG7('K',0,1,1,0,1,1,1), _SEG7('L',0,0,0,1,1,1,0),\
127  _SEG7('M',1,1,1,0,1,1,0), _SEG7('N',1,1,1,0,1,1,0), _SEG7('O',1,1,1,1,1,1,0),\
128  _SEG7('P',1,1,0,0,1,1,1), _SEG7('Q',1,1,1,1,1,1,0), _SEG7('R',1,1,1,0,1,1,1),\
129  _SEG7('S',1,0,1,1,0,1,1), _SEG7('T',0,0,0,1,1,1,1), _SEG7('U',0,1,1,1,1,1,0),\
130  _SEG7('V',0,1,1,1,1,1,0), _SEG7('W',0,1,1,1,1,1,1), _SEG7('X',0,1,1,0,1,1,1),\
131  _SEG7('Y',0,1,1,0,0,1,1), _SEG7('Z',1,1,0,1,1,0,1),
132 
133 #define _MAP_91_96_ASCII_SEG7_SYMBOL		\
134  _SEG7('[',1,0,0,1,1,1,0), _SEG7('\\',0,0,1,0,0,1,1),_SEG7(']',1,1,1,1,0,0,0),\
135  _SEG7('^',1,1,0,0,0,1,0), _SEG7('_',0,0,0,1,0,0,0), _SEG7('`',0,1,0,0,0,0,0),
136 
137 #define _MAP_97_122_ASCII_SEG7_ALPHA_LOWER	\
138  _SEG7('A',1,1,1,0,1,1,1), _SEG7('b',0,0,1,1,1,1,1), _SEG7('c',0,0,0,1,1,0,1),\
139  _SEG7('d',0,1,1,1,1,0,1), _SEG7('E',1,0,0,1,1,1,1), _SEG7('F',1,0,0,0,1,1,1),\
140  _SEG7('G',1,1,1,1,0,1,1), _SEG7('h',0,0,1,0,1,1,1), _SEG7('i',0,0,1,0,0,0,0),\
141  _SEG7('j',0,0,1,1,0,0,0), _SEG7('k',0,0,1,0,1,1,1), _SEG7('L',0,0,0,1,1,1,0),\
142  _SEG7('M',1,1,1,0,1,1,0), _SEG7('n',0,0,1,0,1,0,1), _SEG7('o',0,0,1,1,1,0,1),\
143  _SEG7('P',1,1,0,0,1,1,1), _SEG7('q',1,1,1,0,0,1,1), _SEG7('r',0,0,0,0,1,0,1),\
144  _SEG7('S',1,0,1,1,0,1,1), _SEG7('T',0,0,0,1,1,1,1), _SEG7('u',0,0,1,1,1,0,0),\
145  _SEG7('v',0,0,1,1,1,0,0), _SEG7('W',0,1,1,1,1,1,1), _SEG7('X',0,1,1,0,1,1,1),\
146  _SEG7('y',0,1,1,1,0,1,1), _SEG7('Z',1,1,0,1,1,0,1),
147 
148 #define _MAP_123_126_ASCII_SEG7_SYMBOL		\
149  _SEG7('{',1,0,0,1,1,1,0), _SEG7('|',0,0,0,0,1,1,0), _SEG7('}',1,1,1,1,0,0,0),\
150  _SEG7('~',1,0,0,0,0,0,0),
151 
152 /* Maps */
153 
154 /* This set tries to map as close as possible to the visible characteristics
155  * of the ASCII symbol, lowercase and uppercase letters may differ in
156  * presentation on the display.
157  */
158 #define MAP_ASCII7SEG_ALPHANUM			\
159 	_MAP_0_32_ASCII_SEG7_NON_PRINTABLE	\
160 	_MAP_33_47_ASCII_SEG7_SYMBOL		\
161 	_MAP_48_57_ASCII_SEG7_NUMERIC		\
162 	_MAP_58_64_ASCII_SEG7_SYMBOL		\
163 	_MAP_65_90_ASCII_SEG7_ALPHA_UPPR	\
164 	_MAP_91_96_ASCII_SEG7_SYMBOL		\
165 	_MAP_97_122_ASCII_SEG7_ALPHA_LOWER	\
166 	_MAP_123_126_ASCII_SEG7_SYMBOL
167 
168 /* This set tries to map as close as possible to the symbolic characteristics
169  * of the ASCII character for maximum discrimination.
170  * For now this means all alpha chars are in lower case representations.
171  * (This for example facilitates the use of hex numbers with uppercase input.)
172  */
173 #define MAP_ASCII7SEG_ALPHANUM_LC			\
174 	_MAP_0_32_ASCII_SEG7_NON_PRINTABLE	\
175 	_MAP_33_47_ASCII_SEG7_SYMBOL		\
176 	_MAP_48_57_ASCII_SEG7_NUMERIC		\
177 	_MAP_58_64_ASCII_SEG7_SYMBOL		\
178 	_MAP_97_122_ASCII_SEG7_ALPHA_LOWER	\
179 	_MAP_91_96_ASCII_SEG7_SYMBOL		\
180 	_MAP_97_122_ASCII_SEG7_ALPHA_LOWER	\
181 	_MAP_123_126_ASCII_SEG7_SYMBOL
182 
183 #define SEG7_DEFAULT_MAP(_name)		\
184 	SEG7_CONVERSION_MAP(_name,MAP_ASCII7SEG_ALPHANUM)
185 
186 #endif	/* MAP_TO_7SEGMENT_H */
187 
188