1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Filename: cfag12864b-example.c
4 * Version: 0.1.0
5 * Description: cfag12864b LCD userspace example program
6 *
7 * Author: Copyright (C) Miguel Ojeda <ojeda@kernel.org>
8 * Date: 2006-10-31
9 */
10
11 /*
12 * ------------------------
13 * start of cfag12864b code
14 * ------------------------
15 */
16
17 #include <string.h>
18 #include <fcntl.h>
19 #include <unistd.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/mman.h>
23
24 #define CFAG12864B_WIDTH (128)
25 #define CFAG12864B_HEIGHT (64)
26 #define CFAG12864B_SIZE (128 * 64 / 8)
27 #define CFAG12864B_BPB (8)
28 #define CFAG12864B_ADDRESS(x, y) ((y) * CFAG12864B_WIDTH / \
29 CFAG12864B_BPB + (x) / CFAG12864B_BPB)
30 #define CFAG12864B_BIT(n) (((unsigned char) 1) << (n))
31
32 #undef CFAG12864B_DOCHECK
33 #ifdef CFAG12864B_DOCHECK
34 #define CFAG12864B_CHECK(x, y) ((x) < CFAG12864B_WIDTH && \
35 (y) < CFAG12864B_HEIGHT)
36 #else
37 #define CFAG12864B_CHECK(x, y) (1)
38 #endif
39
40 int cfag12864b_fd;
41 unsigned char * cfag12864b_mem;
42 unsigned char cfag12864b_buffer[CFAG12864B_SIZE];
43
44 /*
45 * init a cfag12864b framebuffer device
46 *
47 * No error: return = 0
48 * Unable to open: return = -1
49 * Unable to mmap: return = -2
50 */
cfag12864b_init(char * path)51 static int cfag12864b_init(char *path)
52 {
53 cfag12864b_fd = open(path, O_RDWR);
54 if (cfag12864b_fd == -1)
55 return -1;
56
57 cfag12864b_mem = mmap(0, CFAG12864B_SIZE, PROT_READ | PROT_WRITE,
58 MAP_SHARED, cfag12864b_fd, 0);
59 if (cfag12864b_mem == MAP_FAILED) {
60 close(cfag12864b_fd);
61 return -2;
62 }
63
64 return 0;
65 }
66
67 /*
68 * exit a cfag12864b framebuffer device
69 */
cfag12864b_exit(void)70 static void cfag12864b_exit(void)
71 {
72 munmap(cfag12864b_mem, CFAG12864B_SIZE);
73 close(cfag12864b_fd);
74 }
75
76 /*
77 * set (x, y) pixel
78 */
cfag12864b_set(unsigned char x,unsigned char y)79 static void cfag12864b_set(unsigned char x, unsigned char y)
80 {
81 if (CFAG12864B_CHECK(x, y))
82 cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] |=
83 CFAG12864B_BIT(x % CFAG12864B_BPB);
84 }
85
86 /*
87 * unset (x, y) pixel
88 */
cfag12864b_unset(unsigned char x,unsigned char y)89 static void cfag12864b_unset(unsigned char x, unsigned char y)
90 {
91 if (CFAG12864B_CHECK(x, y))
92 cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &=
93 ~CFAG12864B_BIT(x % CFAG12864B_BPB);
94 }
95
96 /*
97 * is set (x, y) pixel?
98 *
99 * Pixel off: return = 0
100 * Pixel on: return = 1
101 */
cfag12864b_isset(unsigned char x,unsigned char y)102 static unsigned char cfag12864b_isset(unsigned char x, unsigned char y)
103 {
104 if (CFAG12864B_CHECK(x, y))
105 if (cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &
106 CFAG12864B_BIT(x % CFAG12864B_BPB))
107 return 1;
108
109 return 0;
110 }
111
112 /*
113 * not (x, y) pixel
114 */
cfag12864b_not(unsigned char x,unsigned char y)115 static void cfag12864b_not(unsigned char x, unsigned char y)
116 {
117 if (cfag12864b_isset(x, y))
118 cfag12864b_unset(x, y);
119 else
120 cfag12864b_set(x, y);
121 }
122
123 /*
124 * fill (set all pixels)
125 */
cfag12864b_fill(void)126 static void cfag12864b_fill(void)
127 {
128 unsigned short i;
129
130 for (i = 0; i < CFAG12864B_SIZE; i++)
131 cfag12864b_buffer[i] = 0xFF;
132 }
133
134 /*
135 * clear (unset all pixels)
136 */
cfag12864b_clear(void)137 static void cfag12864b_clear(void)
138 {
139 unsigned short i;
140
141 for (i = 0; i < CFAG12864B_SIZE; i++)
142 cfag12864b_buffer[i] = 0;
143 }
144
145 /*
146 * format a [128*64] matrix
147 *
148 * Pixel off: src[i] = 0
149 * Pixel on: src[i] > 0
150 */
cfag12864b_format(unsigned char * matrix)151 static void cfag12864b_format(unsigned char * matrix)
152 {
153 unsigned char i, j, n;
154
155 for (i = 0; i < CFAG12864B_HEIGHT; i++)
156 for (j = 0; j < CFAG12864B_WIDTH / CFAG12864B_BPB; j++) {
157 cfag12864b_buffer[i * CFAG12864B_WIDTH / CFAG12864B_BPB +
158 j] = 0;
159 for (n = 0; n < CFAG12864B_BPB; n++)
160 if (matrix[i * CFAG12864B_WIDTH +
161 j * CFAG12864B_BPB + n])
162 cfag12864b_buffer[i * CFAG12864B_WIDTH /
163 CFAG12864B_BPB + j] |=
164 CFAG12864B_BIT(n);
165 }
166 }
167
168 /*
169 * blit buffer to lcd
170 */
cfag12864b_blit(void)171 static void cfag12864b_blit(void)
172 {
173 memcpy(cfag12864b_mem, cfag12864b_buffer, CFAG12864B_SIZE);
174 }
175
176 /*
177 * ----------------------
178 * end of cfag12864b code
179 * ----------------------
180 */
181
182 #include <stdio.h>
183
184 #define EXAMPLES 6
185
example(unsigned char n)186 static void example(unsigned char n)
187 {
188 unsigned short i, j;
189 unsigned char matrix[CFAG12864B_WIDTH * CFAG12864B_HEIGHT];
190
191 if (n > EXAMPLES)
192 return;
193
194 printf("Example %i/%i - ", n, EXAMPLES);
195
196 switch (n) {
197 case 1:
198 printf("Draw points setting bits");
199 cfag12864b_clear();
200 for (i = 0; i < CFAG12864B_WIDTH; i += 2)
201 for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
202 cfag12864b_set(i, j);
203 break;
204
205 case 2:
206 printf("Clear the LCD");
207 cfag12864b_clear();
208 break;
209
210 case 3:
211 printf("Draw rows formatting a [128*64] matrix");
212 memset(matrix, 0, CFAG12864B_WIDTH * CFAG12864B_HEIGHT);
213 for (i = 0; i < CFAG12864B_WIDTH; i++)
214 for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
215 matrix[j * CFAG12864B_WIDTH + i] = 1;
216 cfag12864b_format(matrix);
217 break;
218
219 case 4:
220 printf("Fill the lcd");
221 cfag12864b_fill();
222 break;
223
224 case 5:
225 printf("Draw columns unsetting bits");
226 for (i = 0; i < CFAG12864B_WIDTH; i += 2)
227 for (j = 0; j < CFAG12864B_HEIGHT; j++)
228 cfag12864b_unset(i, j);
229 break;
230
231 case 6:
232 printf("Do negative not-ing all bits");
233 for (i = 0; i < CFAG12864B_WIDTH; i++)
234 for (j = 0; j < CFAG12864B_HEIGHT; j ++)
235 cfag12864b_not(i, j);
236 break;
237 }
238
239 puts(" - [Press Enter]");
240 }
241
main(int argc,char * argv[])242 int main(int argc, char *argv[])
243 {
244 unsigned char n;
245
246 if (argc != 2) {
247 printf(
248 "Syntax: %s fbdev\n"
249 "Usually: /dev/fb0, /dev/fb1...\n", argv[0]);
250 return -1;
251 }
252
253 if (cfag12864b_init(argv[1])) {
254 printf("Can't init %s fbdev\n", argv[1]);
255 return -2;
256 }
257
258 for (n = 1; n <= EXAMPLES; n++) {
259 example(n);
260 cfag12864b_blit();
261 while (getchar() != '\n');
262 }
263
264 cfag12864b_exit();
265
266 return 0;
267 }
268