GNU Linux-libre 5.19-rc6-gnu
[releases.git] / samples / auxdisplay / cfag12864b-example.c
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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
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
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 }