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 }