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