Documentation/auxdisplay/cfag12864b-example.c

   1 /*
   2  *    Filename: cfag12864b-example.c
   3  *     Version: 0.1.0
   4  * Description: cfag12864b LCD userspace example program
   5  *     License: GPLv2
   6  *
   7  *      Author: Copyright (C) Miguel Ojeda Sandonis
   8  *        Date: 2006-10-31
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2 as
  12  *  published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  *
  23  */
  24
  25 /*
  26  * ------------------------
  27  * start of cfag12864b code
  28  * ------------------------
  29  */
  30
  31 #include <string.h>
  32 #include <fcntl.h>
  33 #include <unistd.h>
  34 #include <sys/types.h>
  35 #include <sys/stat.h>
  36 #include <sys/mman.h>
  37
  38 #define CFAG12864B_WIDTH                (128)
  39 #define CFAG12864B_HEIGHT               (64)
  40 #define CFAG12864B_SIZE                 (128 * 64 / 8)
  41 #define CFAG12864B_BPB                  (8)
  42 #define CFAG12864B_ADDRESS(x, y)        ((y) * CFAG12864B_WIDTH / \
  43                                         CFAG12864B_BPB + (x) / CFAG12864B_BPB)
  44 #define CFAG12864B_BIT(n)               (((unsigned char) 1) << (n))
  45
  46 #undef CFAG12864B_DOCHECK
  47 #ifdef CFAG12864B_DOCHECK
  48         #define CFAG12864B_CHECK(x, y)          ((x) < CFAG12864B_WIDTH && \
  49                                                 (y) < CFAG12864B_HEIGHT)
  50 #else
  51         #define CFAG12864B_CHECK(x, y)          (1)
  52 #endif
  53
  54 int cfag12864b_fd;
  55 unsigned char * cfag12864b_mem;
  56 unsigned char cfag12864b_buffer[CFAG12864B_SIZE];
  57
  58 /*
  59  * init a cfag12864b framebuffer device
  60  *
  61  * No error:       return = 0
  62  * Unable to open: return = -1
  63  * Unable to mmap: return = -2
  64  */
  65 static int cfag12864b_init(char *path)
  66 {
  67         cfag12864b_fd = open(path, O_RDWR);
  68         if (cfag12864b_fd == -1)
  69                 return -1;
  70
  71         cfag12864b_mem = mmap(0, CFAG12864B_SIZE, PROT_READ | PROT_WRITE,
  72                 MAP_SHARED, cfag12864b_fd, 0);
  73         if (cfag12864b_mem == MAP_FAILED) {
  74                 close(cfag12864b_fd);
  75                 return -2;
  76         }
  77
  78         return 0;
  79 }
  80
  81 /*
  82  * exit a cfag12864b framebuffer device
  83  */
  84 static void cfag12864b_exit(void)
  85 {
  86         munmap(cfag12864b_mem, CFAG12864B_SIZE);
  87         close(cfag12864b_fd);
  88 }
  89
  90 /*
  91  * set (x, y) pixel
  92  */
  93 static void cfag12864b_set(unsigned char x, unsigned char y)
  94 {
  95         if (CFAG12864B_CHECK(x, y))
  96                 cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] |=
  97                         CFAG12864B_BIT(x % CFAG12864B_BPB);
  98 }
  99
 100 /*
 101  * unset (x, y) pixel
 102  */
 103 static void cfag12864b_unset(unsigned char x, unsigned char y)
 104 {
 105         if (CFAG12864B_CHECK(x, y))
 106                 cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &=
 107                         ~CFAG12864B_BIT(x % CFAG12864B_BPB);
 108 }
 109
 110 /*
 111  * is set (x, y) pixel?
 112  *
 113  * Pixel off: return = 0
 114  * Pixel on:  return = 1
 115  */
 116 static unsigned char cfag12864b_isset(unsigned char x, unsigned char y)
 117 {
 118         if (CFAG12864B_CHECK(x, y))
 119                 if (cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &
 120                         CFAG12864B_BIT(x % CFAG12864B_BPB))
 121                         return 1;
 122
 123         return 0;
 124 }
 125
 126 /*
 127  * not (x, y) pixel
 128  */
 129 static void cfag12864b_not(unsigned char x, unsigned char y)
 130 {
 131         if (cfag12864b_isset(x, y))
 132                 cfag12864b_unset(x, y);
 133         else
 134                 cfag12864b_set(x, y);
 135 }
 136
 137 /*
 138  * fill (set all pixels)
 139  */
 140 static void cfag12864b_fill(void)
 141 {
 142         unsigned short i;
 143
 144         for (i = 0; i < CFAG12864B_SIZE; i++)
 145                 cfag12864b_buffer[i] = 0xFF;
 146 }
 147
 148 /*
 149  * clear (unset all pixels)
 150  */
 151 static void cfag12864b_clear(void)
 152 {
 153         unsigned short i;
 154
 155         for (i = 0; i < CFAG12864B_SIZE; i++)
 156                 cfag12864b_buffer[i] = 0;
 157 }
 158
 159 /*
 160  * format a [128*64] matrix
 161  *
 162  * Pixel off: src[i] = 0
 163  * Pixel on:  src[i] > 0
 164  */
 165 static void cfag12864b_format(unsigned char * matrix)
 166 {
 167         unsigned char i, j, n;
 168
 169         for (i = 0; i < CFAG12864B_HEIGHT; i++)
 170         for (j = 0; j < CFAG12864B_WIDTH / CFAG12864B_BPB; j++) {
 171                 cfag12864b_buffer[i * CFAG12864B_WIDTH / CFAG12864B_BPB +
 172                         j] = 0;
 173                 for (n = 0; n < CFAG12864B_BPB; n++)
 174                         if (matrix[i * CFAG12864B_WIDTH +
 175                                 j * CFAG12864B_BPB + n])
 176                                 cfag12864b_buffer[i * CFAG12864B_WIDTH /
 177                                         CFAG12864B_BPB + j] |=
 178                                         CFAG12864B_BIT(n);
 179         }
 180 }
 181
 182 /*
 183  * blit buffer to lcd
 184  */
 185 static void cfag12864b_blit(void)
 186 {
 187         memcpy(cfag12864b_mem, cfag12864b_buffer, CFAG12864B_SIZE);
 188 }
 189
 190 /*
 191  * ----------------------
 192  * end of cfag12864b code
 193  * ----------------------
 194  */
 195
 196 #include <stdio.h>
 197
 198 #define EXAMPLES        6
 199
 200 static void example(unsigned char n)
 201 {
 202         unsigned short i, j;
 203         unsigned char matrix[CFAG12864B_WIDTH * CFAG12864B_HEIGHT];
 204
 205         if (n > EXAMPLES)
 206                 return;
 207
 208         printf("Example %i/%i - ", n, EXAMPLES);
 209
 210         switch (n) {
 211         case 1:
 212                 printf("Draw points setting bits");
 213                 cfag12864b_clear();
 214                 for (i = 0; i < CFAG12864B_WIDTH; i += 2)
 215                         for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
 216                                 cfag12864b_set(i, j);
 217                 break;
 218
 219         case 2:
 220                 printf("Clear the LCD");
 221                 cfag12864b_clear();
 222                 break;
 223
 224         case 3:
 225                 printf("Draw rows formatting a [128*64] matrix");
 226                 memset(matrix, 0, CFAG12864B_WIDTH * CFAG12864B_HEIGHT);
 227                 for (i = 0; i < CFAG12864B_WIDTH; i++)
 228                         for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
 229                                 matrix[j * CFAG12864B_WIDTH + i] = 1;
 230                 cfag12864b_format(matrix);
 231                 break;
 232
 233         case 4:
 234                 printf("Fill the lcd");
 235                 cfag12864b_fill();
 236                 break;
 237
 238         case 5:
 239                 printf("Draw columns unsetting bits");
 240                 for (i = 0; i < CFAG12864B_WIDTH; i += 2)
 241                         for (j = 0; j < CFAG12864B_HEIGHT; j++)
 242                                 cfag12864b_unset(i, j);
 243                 break;
 244
 245         case 6:
 246                 printf("Do negative not-ing all bits");
 247                 for (i = 0; i < CFAG12864B_WIDTH; i++)
 248                         for (j = 0; j < CFAG12864B_HEIGHT; j ++)
 249                                 cfag12864b_not(i, j);
 250                 break;
 251         }
 252
 253         puts(" - [Press Enter]");
 254 }
 255
 256 int main(int argc, char *argv[])
 257 {
 258         unsigned char n;
 259
 260         if (argc != 2) {
 261                 printf(
 262                         "Sintax:  %s fbdev\n"
 263                         "Usually: /dev/fb0, /dev/fb1...\n", argv[0]);
 264                 return -1;
 265         }
 266
 267         if (cfag12864b_init(argv[1])) {
 268                 printf("Can't init %s fbdev\n", argv[1]);
 269                 return -2;
 270         }
 271
 272         for (n = 1; n <= EXAMPLES; n++) {
 273                 example(n);
 274                 cfag12864b_blit();
 275                 while (getchar() != '\n');
 276         }
 277
 278         cfag12864b_exit();
 279
 280         return 0;
 281 }