hw/display/milkymist-tmu2.c

   1 /*
   2  *  QEMU model of the Milkymist texture mapping unit.
   3  *
   4  *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
   5  *  Copyright (c) 2010 Sebastien Bourdeauducq
   6  *                       <sebastien.bourdeauducq@lekernel.net>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  20  *
  21  *
  22  * Specification available at:
  23  *   http://www.milkymist.org/socdoc/tmu2.pdf
  24  *
  25  */
  26
  27 #include "hw/hw.h"
  28 #include "hw/sysbus.h"
  29 #include "trace.h"
  30 #include "qemu/error-report.h"
  31
  32 #include <X11/Xlib.h>
  33 #include <GL/gl.h>
  34 #include <GL/glx.h>
  35
  36 enum {
  37     R_CTL = 0,
  38     R_HMESHLAST,
  39     R_VMESHLAST,
  40     R_BRIGHTNESS,
  41     R_CHROMAKEY,
  42     R_VERTICESADDR,
  43     R_TEXFBUF,
  44     R_TEXHRES,
  45     R_TEXVRES,
  46     R_TEXHMASK,
  47     R_TEXVMASK,
  48     R_DSTFBUF,
  49     R_DSTHRES,
  50     R_DSTVRES,
  51     R_DSTHOFFSET,
  52     R_DSTVOFFSET,
  53     R_DSTSQUAREW,
  54     R_DSTSQUAREH,
  55     R_ALPHA,
  56     R_MAX
  57 };
  58
  59 enum {
  60     CTL_START_BUSY  = (1<<0),
  61     CTL_CHROMAKEY   = (1<<1),
  62 };
  63
  64 enum {
  65     MAX_BRIGHTNESS = 63,
  66     MAX_ALPHA      = 63,
  67 };
  68
  69 enum {
  70     MESH_MAXSIZE = 128,
  71 };
  72
  73 struct vertex {
  74     int x;
  75     int y;
  76 } QEMU_PACKED;
  77
  78 #define TYPE_MILKYMIST_TMU2 "milkymist-tmu2"
  79 #define MILKYMIST_TMU2(obj) \
  80     OBJECT_CHECK(MilkymistTMU2State, (obj), TYPE_MILKYMIST_TMU2)
  81
  82 struct MilkymistTMU2State {
  83     SysBusDevice parent_obj;
  84
  85     MemoryRegion regs_region;
  86     CharDriverState *chr;
  87     qemu_irq irq;
  88
  89     uint32_t regs[R_MAX];
  90
  91     Display *dpy;
  92     GLXFBConfig glx_fb_config;
  93     GLXContext glx_context;
  94 };
  95 typedef struct MilkymistTMU2State MilkymistTMU2State;
  96
  97 static const int glx_fbconfig_attr[] = {
  98     GLX_GREEN_SIZE, 5,
  99     GLX_GREEN_SIZE, 6,
 100     GLX_BLUE_SIZE, 5,
 101     None
 102 };
 103
 104 static int tmu2_glx_init(MilkymistTMU2State *s)
 105 {
 106     GLXFBConfig *configs;
 107     int nelements;
 108
 109     s->dpy = XOpenDisplay(NULL); /* FIXME: call XCloseDisplay() */
 110     if (s->dpy == NULL) {
 111         return 1;
 112     }
 113
 114     configs = glXChooseFBConfig(s->dpy, 0, glx_fbconfig_attr, &nelements);
 115     if (configs == NULL) {
 116         return 1;
 117     }
 118
 119     s->glx_fb_config = *configs;
 120     XFree(configs);
 121
 122     /* FIXME: call glXDestroyContext() */
 123     s->glx_context = glXCreateNewContext(s->dpy, s->glx_fb_config,
 124             GLX_RGBA_TYPE, NULL, 1);
 125     if (s->glx_context == NULL) {
 126         return 1;
 127     }
 128
 129     return 0;
 130 }
 131
 132 static void tmu2_gl_map(struct vertex *mesh, int texhres, int texvres,
 133         int hmeshlast, int vmeshlast, int ho, int vo, int sw, int sh)
 134 {
 135     int x, y;
 136     int x0, y0, x1, y1;
 137     int u0, v0, u1, v1, u2, v2, u3, v3;
 138     double xscale = 1.0 / ((double)(64 * texhres));
 139     double yscale = 1.0 / ((double)(64 * texvres));
 140
 141     glLoadIdentity();
 142     glTranslatef(ho, vo, 0);
 143     glEnable(GL_TEXTURE_2D);
 144     glBegin(GL_QUADS);
 145
 146     for (y = 0; y < vmeshlast; y++) {
 147         y0 = y * sh;
 148         y1 = y0 + sh;
 149         for (x = 0; x < hmeshlast; x++) {
 150             x0 = x * sw;
 151             x1 = x0 + sw;
 152
 153             u0 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x].x);
 154             v0 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x].y);
 155             u1 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x + 1].x);
 156             v1 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x + 1].y);
 157             u2 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x + 1].x);
 158             v2 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x + 1].y);
 159             u3 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x].x);
 160             v3 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x].y);
 161
 162             glTexCoord2d(((double)u0) * xscale, ((double)v0) * yscale);
 163             glVertex3i(x0, y0, 0);
 164             glTexCoord2d(((double)u1) * xscale, ((double)v1) * yscale);
 165             glVertex3i(x1, y0, 0);
 166             glTexCoord2d(((double)u2) * xscale, ((double)v2) * yscale);
 167             glVertex3i(x1, y1, 0);
 168             glTexCoord2d(((double)u3) * xscale, ((double)v3) * yscale);
 169             glVertex3i(x0, y1, 0);
 170         }
 171     }
 172
 173     glEnd();
 174 }
 175
 176 static void tmu2_start(MilkymistTMU2State *s)
 177 {
 178     int pbuffer_attrib[6] = {
 179         GLX_PBUFFER_WIDTH,
 180         0,
 181         GLX_PBUFFER_HEIGHT,
 182         0,
 183         GLX_PRESERVED_CONTENTS,
 184         True
 185     };
 186
 187     GLXPbuffer pbuffer;
 188     GLuint texture;
 189     void *fb;
 190     hwaddr fb_len;
 191     void *mesh;
 192     hwaddr mesh_len;
 193     float m;
 194
 195     trace_milkymist_tmu2_start();
 196
 197     /* Create and set up a suitable OpenGL context */
 198     pbuffer_attrib[1] = s->regs[R_DSTHRES];
 199     pbuffer_attrib[3] = s->regs[R_DSTVRES];
 200     pbuffer = glXCreatePbuffer(s->dpy, s->glx_fb_config, pbuffer_attrib);
 201     glXMakeContextCurrent(s->dpy, pbuffer, pbuffer, s->glx_context);
 202
 203     /* Fixup endianness. TODO: would it work on BE hosts? */
 204     glPixelStorei(GL_UNPACK_SWAP_BYTES, 1);
 205     glPixelStorei(GL_PACK_SWAP_BYTES, 1);
 206
 207     /* Row alignment */
 208     glPixelStorei(GL_UNPACK_ALIGNMENT, 2);
 209     glPixelStorei(GL_PACK_ALIGNMENT, 2);
 210
 211     /* Read the QEMU source framebuffer into an OpenGL texture */
 212     glGenTextures(1, &texture);
 213     glBindTexture(GL_TEXTURE_2D, texture);
 214     fb_len = 2*s->regs[R_TEXHRES]*s->regs[R_TEXVRES];
 215     fb = cpu_physical_memory_map(s->regs[R_TEXFBUF], &fb_len, 0);
 216     if (fb == NULL) {
 217         glDeleteTextures(1, &texture);
 218         glXMakeContextCurrent(s->dpy, None, None, NULL);
 219         glXDestroyPbuffer(s->dpy, pbuffer);
 220         return;
 221     }
 222     glTexImage2D(GL_TEXTURE_2D, 0, 3, s->regs[R_TEXHRES], s->regs[R_TEXVRES],
 223             0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, fb);
 224     cpu_physical_memory_unmap(fb, fb_len, 0, fb_len);
 225
 226     /* Set up texturing options */
 227     /* WARNING:
 228      * Many cases of TMU2 masking are not supported by OpenGL.
 229      * We only implement the most common ones:
 230      *  - full bilinear filtering vs. nearest texel
 231      *  - texture clamping vs. texture wrapping
 232      */
 233     if ((s->regs[R_TEXHMASK] & 0x3f) > 0x20) {
 234         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 235         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 236     } else {
 237         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 238         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 239     }
 240     if ((s->regs[R_TEXHMASK] >> 6) & s->regs[R_TEXHRES]) {
 241         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 242     } else {
 243         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 244     }
 245     if ((s->regs[R_TEXVMASK] >> 6) & s->regs[R_TEXVRES]) {
 246         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 247     } else {
 248         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 249     }
 250
 251     /* Translucency and decay */
 252     glEnable(GL_BLEND);
 253     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 254     m = (float)(s->regs[R_BRIGHTNESS] + 1) / 64.0f;
 255     glColor4f(m, m, m, (float)(s->regs[R_ALPHA] + 1) / 64.0f);
 256
 257     /* Read the QEMU dest. framebuffer into the OpenGL framebuffer */
 258     fb_len = 2 * s->regs[R_DSTHRES] * s->regs[R_DSTVRES];
 259     fb = cpu_physical_memory_map(s->regs[R_DSTFBUF], &fb_len, 0);
 260     if (fb == NULL) {
 261         glDeleteTextures(1, &texture);
 262         glXMakeContextCurrent(s->dpy, None, None, NULL);
 263         glXDestroyPbuffer(s->dpy, pbuffer);
 264         return;
 265     }
 266
 267     glDrawPixels(s->regs[R_DSTHRES], s->regs[R_DSTVRES], GL_RGB,
 268             GL_UNSIGNED_SHORT_5_6_5, fb);
 269     cpu_physical_memory_unmap(fb, fb_len, 0, fb_len);
 270     glViewport(0, 0, s->regs[R_DSTHRES], s->regs[R_DSTVRES]);
 271     glMatrixMode(GL_PROJECTION);
 272     glLoadIdentity();
 273     glOrtho(0.0, s->regs[R_DSTHRES], 0.0, s->regs[R_DSTVRES], -1.0, 1.0);
 274     glMatrixMode(GL_MODELVIEW);
 275
 276     /* Map the texture */
 277     mesh_len = MESH_MAXSIZE*MESH_MAXSIZE*sizeof(struct vertex);
 278     mesh = cpu_physical_memory_map(s->regs[R_VERTICESADDR], &mesh_len, 0);
 279     if (mesh == NULL) {
 280         glDeleteTextures(1, &texture);
 281         glXMakeContextCurrent(s->dpy, None, None, NULL);
 282         glXDestroyPbuffer(s->dpy, pbuffer);
 283         return;
 284     }
 285
 286     tmu2_gl_map((struct vertex *)mesh,
 287         s->regs[R_TEXHRES], s->regs[R_TEXVRES],
 288         s->regs[R_HMESHLAST], s->regs[R_VMESHLAST],
 289         s->regs[R_DSTHOFFSET], s->regs[R_DSTVOFFSET],
 290         s->regs[R_DSTSQUAREW], s->regs[R_DSTSQUAREH]);
 291     cpu_physical_memory_unmap(mesh, mesh_len, 0, mesh_len);
 292
 293     /* Write back the OpenGL framebuffer to the QEMU framebuffer */
 294     fb_len = 2 * s->regs[R_DSTHRES] * s->regs[R_DSTVRES];
 295     fb = cpu_physical_memory_map(s->regs[R_DSTFBUF], &fb_len, 1);
 296     if (fb == NULL) {
 297         glDeleteTextures(1, &texture);
 298         glXMakeContextCurrent(s->dpy, None, None, NULL);
 299         glXDestroyPbuffer(s->dpy, pbuffer);
 300         return;
 301     }
 302
 303     glReadPixels(0, 0, s->regs[R_DSTHRES], s->regs[R_DSTVRES], GL_RGB,
 304             GL_UNSIGNED_SHORT_5_6_5, fb);
 305     cpu_physical_memory_unmap(fb, fb_len, 1, fb_len);
 306
 307     /* Free OpenGL allocs */
 308     glDeleteTextures(1, &texture);
 309     glXMakeContextCurrent(s->dpy, None, None, NULL);
 310     glXDestroyPbuffer(s->dpy, pbuffer);
 311
 312     s->regs[R_CTL] &= ~CTL_START_BUSY;
 313
 314     trace_milkymist_tmu2_pulse_irq();
 315     qemu_irq_pulse(s->irq);
 316 }
 317
 318 static uint64_t tmu2_read(void *opaque, hwaddr addr,
 319                           unsigned size)
 320 {
 321     MilkymistTMU2State *s = opaque;
 322     uint32_t r = 0;
 323
 324     addr >>= 2;
 325     switch (addr) {
 326     case R_CTL:
 327     case R_HMESHLAST:
 328     case R_VMESHLAST:
 329     case R_BRIGHTNESS:
 330     case R_CHROMAKEY:
 331     case R_VERTICESADDR:
 332     case R_TEXFBUF:
 333     case R_TEXHRES:
 334     case R_TEXVRES:
 335     case R_TEXHMASK:
 336     case R_TEXVMASK:
 337     case R_DSTFBUF:
 338     case R_DSTHRES:
 339     case R_DSTVRES:
 340     case R_DSTHOFFSET:
 341     case R_DSTVOFFSET:
 342     case R_DSTSQUAREW:
 343     case R_DSTSQUAREH:
 344     case R_ALPHA:
 345         r = s->regs[addr];
 346         break;
 347
 348     default:
 349         error_report("milkymist_tmu2: read access to unknown register 0x"
 350                 TARGET_FMT_plx, addr << 2);
 351         break;
 352     }
 353
 354     trace_milkymist_tmu2_memory_read(addr << 2, r);
 355
 356     return r;
 357 }
 358
 359 static void tmu2_check_registers(MilkymistTMU2State *s)
 360 {
 361     if (s->regs[R_BRIGHTNESS] > MAX_BRIGHTNESS) {
 362         error_report("milkymist_tmu2: max brightness is %d", MAX_BRIGHTNESS);
 363     }
 364
 365     if (s->regs[R_ALPHA] > MAX_ALPHA) {
 366         error_report("milkymist_tmu2: max alpha is %d", MAX_ALPHA);
 367     }
 368
 369     if (s->regs[R_VERTICESADDR] & 0x07) {
 370         error_report("milkymist_tmu2: vertex mesh address has to be 64-bit "
 371                 "aligned");
 372     }
 373
 374     if (s->regs[R_TEXFBUF] & 0x01) {
 375         error_report("milkymist_tmu2: texture buffer address has to be "
 376                 "16-bit aligned");
 377     }
 378 }
 379
 380 static void tmu2_write(void *opaque, hwaddr addr, uint64_t value,
 381                        unsigned size)
 382 {
 383     MilkymistTMU2State *s = opaque;
 384
 385     trace_milkymist_tmu2_memory_write(addr, value);
 386
 387     addr >>= 2;
 388     switch (addr) {
 389     case R_CTL:
 390         s->regs[addr] = value;
 391         if (value & CTL_START_BUSY) {
 392             tmu2_start(s);
 393         }
 394         break;
 395     case R_BRIGHTNESS:
 396     case R_HMESHLAST:
 397     case R_VMESHLAST:
 398     case R_CHROMAKEY:
 399     case R_VERTICESADDR:
 400     case R_TEXFBUF:
 401     case R_TEXHRES:
 402     case R_TEXVRES:
 403     case R_TEXHMASK:
 404     case R_TEXVMASK:
 405     case R_DSTFBUF:
 406     case R_DSTHRES:
 407     case R_DSTVRES:
 408     case R_DSTHOFFSET:
 409     case R_DSTVOFFSET:
 410     case R_DSTSQUAREW:
 411     case R_DSTSQUAREH:
 412     case R_ALPHA:
 413         s->regs[addr] = value;
 414         break;
 415
 416     default:
 417         error_report("milkymist_tmu2: write access to unknown register 0x"
 418                 TARGET_FMT_plx, addr << 2);
 419         break;
 420     }
 421
 422     tmu2_check_registers(s);
 423 }
 424
 425 static const MemoryRegionOps tmu2_mmio_ops = {
 426     .read = tmu2_read,
 427     .write = tmu2_write,
 428     .valid = {
 429         .min_access_size = 4,
 430         .max_access_size = 4,
 431     },
 432     .endianness = DEVICE_NATIVE_ENDIAN,
 433 };
 434
 435 static void milkymist_tmu2_reset(DeviceState *d)
 436 {
 437     MilkymistTMU2State *s = MILKYMIST_TMU2(d);
 438     int i;
 439
 440     for (i = 0; i < R_MAX; i++) {
 441         s->regs[i] = 0;
 442     }
 443 }
 444
 445 static int milkymist_tmu2_init(SysBusDevice *dev)
 446 {
 447     MilkymistTMU2State *s = MILKYMIST_TMU2(dev);
 448
 449     if (tmu2_glx_init(s)) {
 450         return 1;
 451     }
 452
 453     sysbus_init_irq(dev, &s->irq);
 454
 455     memory_region_init_io(&s->regs_region, OBJECT(s), &tmu2_mmio_ops, s,
 456             "milkymist-tmu2", R_MAX * 4);
 457     sysbus_init_mmio(dev, &s->regs_region);
 458
 459     return 0;
 460 }
 461
 462 static const VMStateDescription vmstate_milkymist_tmu2 = {
 463     .name = "milkymist-tmu2",
 464     .version_id = 1,
 465     .minimum_version_id = 1,
 466     .fields = (VMStateField[]) {
 467         VMSTATE_UINT32_ARRAY(regs, MilkymistTMU2State, R_MAX),
 468         VMSTATE_END_OF_LIST()
 469     }
 470 };
 471
 472 static void milkymist_tmu2_class_init(ObjectClass *klass, void *data)
 473 {
 474     DeviceClass *dc = DEVICE_CLASS(klass);
 475     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 476
 477     k->init = milkymist_tmu2_init;
 478     dc->reset = milkymist_tmu2_reset;
 479     dc->vmsd = &vmstate_milkymist_tmu2;
 480 }
 481
 482 static const TypeInfo milkymist_tmu2_info = {
 483     .name          = TYPE_MILKYMIST_TMU2,
 484     .parent        = TYPE_SYS_BUS_DEVICE,
 485     .instance_size = sizeof(MilkymistTMU2State),
 486     .class_init    = milkymist_tmu2_class_init,
 487 };
 488
 489 static void milkymist_tmu2_register_types(void)
 490 {
 491     type_register_static(&milkymist_tmu2_info);
 492 }
 493
 494 type_init(milkymist_tmu2_register_types)