src/drivers/pc80/vga/vga.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 #include <pc80/vga.h>
   4 #include <pc80/vga_io.h>
   5
   6 #include <string.h>
   7 #include "vga.h"
   8
   9 /*
  10  * pci io enable should've happened before
  11  */
  12 void
  13 vga_io_init(void)
  14 {
  15         vga_enable_mask(0x01, 0x01);
  16
  17         /* cr io is at 0x3D4/0x3D5 */
  18         vga_misc_mask(0x01, 0x01);
  19
  20         /* clear cr0-7 protection */
  21         vga_cr_mask(0x11, 0x00, 0x80);
  22 }
  23
  24 /*
  25  *
  26  */
  27 static void
  28 vga_fb_init(void)
  29 {
  30         vga_sr_write(0x02, 0x03);
  31         vga_sr_write(0x03, 0x00);
  32         vga_sr_write(0x04, 0x02); /* access all 256kB */
  33
  34         vga_gr_write(0x00, 0x00);
  35         vga_gr_write(0x01, 0x00);
  36         vga_gr_write(0x02, 0x00);
  37         vga_gr_write(0x03, 0x00);
  38         vga_gr_write(0x04, 0x00);
  39         vga_gr_write(0x05, 0x10);
  40         vga_gr_write(0x06, 0x0E); /* map at 0xB8000 */
  41         vga_gr_write(0x07, 0x00);
  42         vga_gr_write(0x08, 0xFF);
  43
  44         /* o/e enable: RAM enable */
  45         vga_misc_mask(0x22, 0x22);
  46 }
  47
  48 /*
  49  *
  50  */
  51 static void
  52 vga_fb_clear(void)
  53 {
  54         memset((void *)VGA_FB, 0x00, 0x8000);
  55 }
  56
  57 /*
  58  *
  59  */
  60 static void
  61 vga_palette_init(void)
  62 {
  63         size_t i;
  64
  65         /* set up attribute registers */
  66         for (i = 0; i < 0x10; i++)
  67                 vga_ar_write(i, i);
  68
  69         vga_ar_write(0x10, 0x0c);
  70         vga_ar_write(0x11, 0x00);
  71         vga_ar_write(0x12, 0x0F);
  72         vga_ar_write(0x13, 0x08);
  73         vga_ar_write(0x14, 0x00);
  74
  75         vga_palette_disable();
  76
  77         /* load actual palette */
  78         vga_dac_mask_write(0xFF);
  79
  80         for (i = 0; i < 0x100; i++) {
  81                 vga_dac_write_address(i);
  82                 vga_dac_data_write(default_vga_palette[i].red);
  83                 vga_dac_data_write(default_vga_palette[i].green);
  84                 vga_dac_data_write(default_vga_palette[i].blue);
  85         }
  86 }
  87
  88 /*
  89  *
  90  */
  91 static void
  92 vga_mode_set(int hdisplay, int hblankstart, int hsyncstart, int hsyncend,
  93              int hblankend, int htotal, int vdisplay, int vblankstart,
  94              int vsyncstart, int vsyncend, int vblankend, int vtotal,
  95              int stride)
  96 {
  97         /* htotal: 2080 */
  98         htotal /= 8;
  99         htotal -= 5;
 100         vga_cr_write(0x00, htotal);
 101
 102         /* hdisplay: 2048 */
 103         hdisplay /= 8;
 104         hdisplay -= 1;
 105         vga_cr_write(0x01, hdisplay);
 106
 107         /* hblankstart: 2048 */
 108         hblankstart /= 8;
 109         hblankstart -= 1;
 110         vga_cr_write(0x02, hblankstart);
 111
 112         /* hblankend: hblankstart + 512 */
 113         hblankend /= 8;
 114         hblankend -= 1;
 115         vga_cr_mask(0x03, hblankend, 0x1F);
 116         vga_cr_mask(0x05, hblankend << 2, 0x80);
 117
 118         /* hsyncstart: 255 * 8: 2040 */
 119         vga_cr_write(0x04, hsyncstart / 8);
 120
 121         /* hsyncend: hsyncstart + 255 */
 122         vga_cr_mask(0x05, hsyncend / 8, 0x1F);
 123
 124         /* vtotal: 1025 */
 125         vtotal -= 2;
 126         vga_cr_write(0x06, vtotal);
 127         vga_cr_mask(0x07, vtotal >> 8, 0x01);
 128         vga_cr_mask(0x07, vtotal >> 4, 0x20);
 129
 130         /* vdisplay: 1024 */
 131         vdisplay -= 1;
 132         vga_cr_write(0x12, vdisplay);
 133         vga_cr_mask(0x07, vdisplay >> 7, 0x02);
 134         vga_cr_mask(0x07, vdisplay >> 3, 0x40);
 135
 136         /* vblankstart: 1024 */
 137         vblankstart -= 1;
 138         vga_cr_write(0x15, vblankstart);
 139         vga_cr_mask(0x07, vblankstart >> 5, 0x08);
 140         vga_cr_mask(0x09, vblankstart >> 4, 0x20);
 141
 142         /* vblankend: vblankstart + 256 */
 143         vblankend -= 1;
 144         vga_cr_write(0x16, vblankend);
 145
 146         /* vsyncstart: 1023 */
 147         vga_cr_write(0x10, vsyncstart);
 148         vga_cr_mask(0x07, vsyncstart >> 6, 0x04);
 149         vga_cr_mask(0x07, vsyncstart >> 2, 0x80);
 150
 151         /* vsyncend: vsyncstart + 16 */
 152         vga_cr_mask(0x11, vsyncend, 0x0F);
 153
 154         /* stride */
 155         vga_cr_write(0x13, stride / 8);
 156
 157         /* line compare */
 158         vga_cr_write(0x18, 0xFF);
 159         vga_cr_mask(0x07, 0x10, 0x10);
 160         vga_cr_mask(0x09, 0x40, 0x40);
 161
 162         vga_misc_mask(0x44, 0xCC); /* set up clock: 27mhz and h/vsync */
 163
 164         vga_cr_mask(0x09, 0x00, 0x80); /* disable doublescan */
 165 }
 166
 167 static void
 168 vga_font_8x16_load(void)
 169 {
 170         unsigned char *p;
 171         size_t i, j;
 172         unsigned char sr2, sr4, gr5, gr6;
 173
 174 #define height 16
 175 #define count 256
 176
 177         sr2 = vga_sr_read(0x02);
 178         sr4 = vga_sr_read(0x04);
 179         gr5 = vga_gr_read(0x05);
 180         gr6 = vga_gr_read(0x06);
 181
 182         /* disable odd/even */
 183         vga_sr_mask(0x04, 0x04, 0x04);
 184         vga_gr_mask(0x05, 0x00, 0x10);
 185         vga_gr_mask(0x06, 0x00, 0x02);
 186
 187         /* plane 2 */
 188         vga_sr_write(0x02, 0x04);
 189         p = (unsigned char *)VGA_FB;
 190         for (i = 0; i < count; i++) {
 191                 for (j = 0; j < 32; j++) {
 192                         if (j < height)
 193                                 *p = vga_font_8x16[i][j];
 194                         else
 195                                 *p = 0x00;
 196                         p++;
 197                 }
 198         }
 199
 200         vga_gr_write(0x06, gr6);
 201         vga_gr_write(0x05, gr5);
 202         vga_sr_write(0x04, sr4);
 203         vga_sr_write(0x02, sr2);
 204
 205         /* set up font size */
 206         vga_cr_mask(0x09, 16 - 1, 0x1F);
 207 }
 208
 209 /*
 210  *
 211  */
 212 void
 213 vga_cursor_enable(int enable)
 214 {
 215         if (enable)
 216                 vga_cr_mask(0x0A, 0x00, 0x20);
 217         else
 218                 vga_cr_mask(0x0A, 0x20, 0x20);
 219 }
 220
 221 /*
 222  *
 223  */
 224 void
 225 vga_cursor_reset(void)
 226 {
 227         vga_cr_write(0x0A, 0x2E);
 228         vga_cr_write(0x0B, 0x0E);
 229         vga_cr_write(0x0E, 0x00);
 230         vga_cr_write(0x0F, 0x00);
 231 }
 232
 233 /*
 234  *
 235  */
 236 void
 237 vga_cursor_set(unsigned int line, unsigned int character)
 238 {
 239         unsigned int offset = (VGA_COLUMNS * line + character) & 0xFFFF;
 240
 241         vga_cr_write(0x0A, 0x0E);
 242         vga_cr_write(0x0B, 0x0E);
 243         vga_cr_write(0x0E, offset >> 8);
 244         vga_cr_write(0x0F, offset & 0xFF);
 245 }
 246
 247 /*
 248  *
 249  */
 250 void
 251 vga_frame_set(unsigned int line, unsigned int character)
 252 {
 253         unsigned int offset = (VGA_COLUMNS * line + character) & 0xFFFF;
 254
 255         vga_cr_write(0x0C, offset >> 8);
 256         vga_cr_write(0x0D, offset & 0xFF);
 257 }
 258
 259 static void
 260 vga_write_at_offset(unsigned int line, unsigned int offset, const char *string)
 261 {
 262         if (!string)
 263                 return;
 264
 265         unsigned short *p = (unsigned short *)VGA_FB + (VGA_COLUMNS * line) + offset;
 266         size_t i, len = strlen(string);
 267
 268         for (i = 0; i < (VGA_COLUMNS - offset); i++) {
 269                 if (i < len)
 270                         p[i] = 0x0F00 | (unsigned char)string[i];
 271                 else
 272                         p[i] = 0x0F00;
 273         }
 274 }
 275
 276 /*
 277  * simply fills a line with the given string.
 278  */
 279 void
 280 vga_line_write(unsigned int line, const char *string)
 281 {
 282         vga_write_at_offset(line, 0, string);
 283 }
 284
 285 void
 286 vga_write_text(enum VGA_TEXT_ALIGNMENT alignment, unsigned int line, const char *string)
 287 {
 288         char str[VGA_COLUMNS * VGA_LINES] = {0};
 289         memcpy(str, string, strnlen(string, sizeof(str) - 1));
 290
 291         char *token = strtok(str, "\n");
 292
 293         while (token != NULL) {
 294                 size_t offset = VGA_COLUMNS - strnlen(token, VGA_COLUMNS);
 295                 switch (alignment) {
 296                 case VGA_TEXT_CENTER:
 297                         vga_write_at_offset(line++, offset/2, token);
 298                         break;
 299                 case VGA_TEXT_RIGHT:
 300                         vga_write_at_offset(line++, offset, token);
 301                         break;
 302                 case VGA_TEXT_LEFT:
 303                 default:
 304                         vga_write_at_offset(line++, 0, token);
 305                         break;
 306                 }
 307                 token = strtok(NULL, "\n");
 308         }
 309 }
 310
 311 /*
 312  * set up everything to get a basic 80x25 textmode.
 313  */
 314 void
 315 vga_textmode_init(void)
 316 {
 317         vga_sr_write(0x00, 0x01); /* clear reset */
 318         vga_sr_write(0x01, 0x00);
 319
 320         /* set up cr */
 321         vga_cr_mask(0x03, 0x80, 0xE0);
 322         vga_cr_mask(0x05, 0x00, 0x60);
 323
 324         vga_cr_write(0x08, 0x00);
 325
 326         vga_cr_write(0x14, 0x00); /* */
 327
 328         vga_cr_write(0x17, 0x23);
 329
 330         vga_palette_init();
 331
 332         vga_mode_set(640, 648, 680, 776, 792, 800,
 333                      400, 407, 412, 414, 442, 449, 320);
 334
 335         vga_cursor_reset();
 336         vga_frame_set(0, 0);
 337
 338         vga_fb_init();
 339         vga_fb_clear();
 340         vga_font_8x16_load();
 341
 342         vga_sr_mask(0x00, 0x02, 0x02); /* take us out of reset */
 343         vga_cr_mask(0x17, 0x80, 0x80); /* sync! */
 344 }