qemu/hw/display/milkymist-tmu2.c
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   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://milkymist.walle.cc/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#include "qapi/error.h"
  33
  34#include <X11/Xlib.h>
  35#include <epoxy/gl.h>
  36#include <epoxy/glx.h>
  37
  38enum {
  39    R_CTL = 0,
  40    R_HMESHLAST,
  41    R_VMESHLAST,
  42    R_BRIGHTNESS,
  43    R_CHROMAKEY,
  44    R_VERTICESADDR,
  45    R_TEXFBUF,
  46    R_TEXHRES,
  47    R_TEXVRES,
  48    R_TEXHMASK,
  49    R_TEXVMASK,
  50    R_DSTFBUF,
  51    R_DSTHRES,
  52    R_DSTVRES,
  53    R_DSTHOFFSET,
  54    R_DSTVOFFSET,
  55    R_DSTSQUAREW,
  56    R_DSTSQUAREH,
  57    R_ALPHA,
  58    R_MAX
  59};
  60
  61enum {
  62    CTL_START_BUSY  = (1<<0),
  63    CTL_CHROMAKEY   = (1<<1),
  64};
  65
  66enum {
  67    MAX_BRIGHTNESS = 63,
  68    MAX_ALPHA      = 63,
  69};
  70
  71enum {
  72    MESH_MAXSIZE = 128,
  73};
  74
  75struct vertex {
  76    int x;
  77    int y;
  78} QEMU_PACKED;
  79
  80#define TYPE_MILKYMIST_TMU2 "milkymist-tmu2"
  81#define MILKYMIST_TMU2(obj) \
  82    OBJECT_CHECK(MilkymistTMU2State, (obj), TYPE_MILKYMIST_TMU2)
  83
  84struct MilkymistTMU2State {
  85    SysBusDevice parent_obj;
  86
  87    MemoryRegion regs_region;
  88    CharDriverState *chr;
  89    qemu_irq irq;
  90
  91    uint32_t regs[R_MAX];
  92
  93    Display *dpy;
  94    GLXFBConfig glx_fb_config;
  95    GLXContext glx_context;
  96};
  97typedef struct MilkymistTMU2State MilkymistTMU2State;
  98
  99static const int glx_fbconfig_attr[] = {
 100    GLX_GREEN_SIZE, 5,
 101    GLX_GREEN_SIZE, 6,
 102    GLX_BLUE_SIZE, 5,
 103    None
 104};
 105
 106static int tmu2_glx_init(MilkymistTMU2State *s)
 107{
 108    GLXFBConfig *configs;
 109    int nelements;
 110
 111    s->dpy = XOpenDisplay(NULL); /* FIXME: call XCloseDisplay() */
 112    if (s->dpy == NULL) {
 113        return 1;
 114    }
 115
 116    configs = glXChooseFBConfig(s->dpy, 0, glx_fbconfig_attr, &nelements);
 117    if (configs == NULL) {
 118        return 1;
 119    }
 120
 121    s->glx_fb_config = *configs;
 122    XFree(configs);
 123
 124    /* FIXME: call glXDestroyContext() */
 125    s->glx_context = glXCreateNewContext(s->dpy, s->glx_fb_config,
 126            GLX_RGBA_TYPE, NULL, 1);
 127    if (s->glx_context == NULL) {
 128        return 1;
 129    }
 130
 131    return 0;
 132}
 133
 134static void tmu2_gl_map(struct vertex *mesh, int texhres, int texvres,
 135        int hmeshlast, int vmeshlast, int ho, int vo, int sw, int sh)
 136{
 137    int x, y;
 138    int x0, y0, x1, y1;
 139    int u0, v0, u1, v1, u2, v2, u3, v3;
 140    double xscale = 1.0 / ((double)(64 * texhres));
 141    double yscale = 1.0 / ((double)(64 * texvres));
 142
 143    glLoadIdentity();
 144    glTranslatef(ho, vo, 0);
 145    glEnable(GL_TEXTURE_2D);
 146    glBegin(GL_QUADS);
 147
 148    for (y = 0; y < vmeshlast; y++) {
 149        y0 = y * sh;
 150        y1 = y0 + sh;
 151        for (x = 0; x < hmeshlast; x++) {
 152            x0 = x * sw;
 153            x1 = x0 + sw;
 154
 155            u0 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x].x);
 156            v0 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x].y);
 157            u1 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x + 1].x);
 158            v1 = be32_to_cpu(mesh[MESH_MAXSIZE * y + x + 1].y);
 159            u2 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x + 1].x);
 160            v2 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x + 1].y);
 161            u3 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x].x);
 162            v3 = be32_to_cpu(mesh[MESH_MAXSIZE * (y + 1) + x].y);
 163
 164            glTexCoord2d(((double)u0) * xscale, ((double)v0) * yscale);
 165            glVertex3i(x0, y0, 0);
 166            glTexCoord2d(((double)u1) * xscale, ((double)v1) * yscale);
 167            glVertex3i(x1, y0, 0);
 168            glTexCoord2d(((double)u2) * xscale, ((double)v2) * yscale);
 169            glVertex3i(x1, y1, 0);
 170            glTexCoord2d(((double)u3) * xscale, ((double)v3) * yscale);
 171            glVertex3i(x0, y1, 0);
 172        }
 173    }
 174
 175    glEnd();
 176}
 177
 178static void tmu2_start(MilkymistTMU2State *s)
 179{
 180    int pbuffer_attrib[6] = {
 181        GLX_PBUFFER_WIDTH,
 182        0,
 183        GLX_PBUFFER_HEIGHT,
 184        0,
 185        GLX_PRESERVED_CONTENTS,
 186        True
 187    };
 188
 189    GLXPbuffer pbuffer;
 190    GLuint texture;
 191    void *fb;
 192    hwaddr fb_len;
 193    void *mesh;
 194    hwaddr mesh_len;
 195    float m;
 196
 197    trace_milkymist_tmu2_start();
 198
 199    /* Create and set up a suitable OpenGL context */
 200    pbuffer_attrib[1] = s->regs[R_DSTHRES];
 201    pbuffer_attrib[3] = s->regs[R_DSTVRES];
 202    pbuffer = glXCreatePbuffer(s->dpy, s->glx_fb_config, pbuffer_attrib);
 203    glXMakeContextCurrent(s->dpy, pbuffer, pbuffer, s->glx_context);
 204
 205    /* Fixup endianness. TODO: would it work on BE hosts? */
 206    glPixelStorei(GL_UNPACK_SWAP_BYTES, 1);
 207    glPixelStorei(GL_PACK_SWAP_BYTES, 1);
 208
 209    /* Row alignment */
 210    glPixelStorei(GL_UNPACK_ALIGNMENT, 2);
 211    glPixelStorei(GL_PACK_ALIGNMENT, 2);
 212
 213    /* Read the QEMU source framebuffer into an OpenGL texture */
 214    glGenTextures(1, &texture);
 215    glBindTexture(GL_TEXTURE_2D, texture);
 216    fb_len = 2ULL * s->regs[R_TEXHRES] * s->regs[R_TEXVRES];
 217    fb = cpu_physical_memory_map(s->regs[R_TEXFBUF], &fb_len, 0);
 218    if (fb == NULL) {
 219        glDeleteTextures(1, &texture);
 220        glXMakeContextCurrent(s->dpy, None, None, NULL);
 221        glXDestroyPbuffer(s->dpy, pbuffer);
 222        return;
 223    }
 224    glTexImage2D(GL_TEXTURE_2D, 0, 3, s->regs[R_TEXHRES], s->regs[R_TEXVRES],
 225            0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, fb);
 226    cpu_physical_memory_unmap(fb, fb_len, 0, fb_len);
 227
 228    /* Set up texturing options */
 229    /* WARNING:
 230     * Many cases of TMU2 masking are not supported by OpenGL.
 231     * We only implement the most common ones:
 232     *  - full bilinear filtering vs. nearest texel
 233     *  - texture clamping vs. texture wrapping
 234     */
 235    if ((s->regs[R_TEXHMASK] & 0x3f) > 0x20) {
 236        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 237        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 238    } else {
 239        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 240        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 241    }
 242    if ((s->regs[R_TEXHMASK] >> 6) & s->regs[R_TEXHRES]) {
 243        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 244    } else {
 245        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 246    }
 247    if ((s->regs[R_TEXVMASK] >> 6) & s->regs[R_TEXVRES]) {
 248        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 249    } else {
 250        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 251    }
 252
 253    /* Translucency and decay */
 254    glEnable(GL_BLEND);
 255    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 256    m = (float)(s->regs[R_BRIGHTNESS] + 1) / 64.0f;
 257    glColor4f(m, m, m, (float)(s->regs[R_ALPHA] + 1) / 64.0f);
 258
 259    /* Read the QEMU dest. framebuffer into the OpenGL framebuffer */
 260    fb_len = 2 * s->regs[R_DSTHRES] * s->regs[R_DSTVRES];
 261    fb = cpu_physical_memory_map(s->regs[R_DSTFBUF], &fb_len, 0);
 262    if (fb == NULL) {
 263        glDeleteTextures(1, &texture);
 264        glXMakeContextCurrent(s->dpy, None, None, NULL);
 265        glXDestroyPbuffer(s->dpy, pbuffer);
 266        return;
 267    }
 268
 269    glDrawPixels(s->regs[R_DSTHRES], s->regs[R_DSTVRES], GL_RGB,
 270            GL_UNSIGNED_SHORT_5_6_5, fb);
 271    cpu_physical_memory_unmap(fb, fb_len, 0, fb_len);
 272    glViewport(0, 0, s->regs[R_DSTHRES], s->regs[R_DSTVRES]);
 273    glMatrixMode(GL_PROJECTION);
 274    glLoadIdentity();
 275    glOrtho(0.0, s->regs[R_DSTHRES], 0.0, s->regs[R_DSTVRES], -1.0, 1.0);
 276    glMatrixMode(GL_MODELVIEW);
 277
 278    /* Map the texture */
 279    mesh_len = MESH_MAXSIZE*MESH_MAXSIZE*sizeof(struct vertex);
 280    mesh = cpu_physical_memory_map(s->regs[R_VERTICESADDR], &mesh_len, 0);
 281    if (mesh == NULL) {
 282        glDeleteTextures(1, &texture);
 283        glXMakeContextCurrent(s->dpy, None, None, NULL);
 284        glXDestroyPbuffer(s->dpy, pbuffer);
 285        return;
 286    }
 287
 288    tmu2_gl_map((struct vertex *)mesh,
 289        s->regs[R_TEXHRES], s->regs[R_TEXVRES],
 290        s->regs[R_HMESHLAST], s->regs[R_VMESHLAST],
 291        s->regs[R_DSTHOFFSET], s->regs[R_DSTVOFFSET],
 292        s->regs[R_DSTSQUAREW], s->regs[R_DSTSQUAREH]);
 293    cpu_physical_memory_unmap(mesh, mesh_len, 0, mesh_len);
 294
 295    /* Write back the OpenGL framebuffer to the QEMU framebuffer */
 296    fb_len = 2 * s->regs[R_DSTHRES] * s->regs[R_DSTVRES];
 297    fb = cpu_physical_memory_map(s->regs[R_DSTFBUF], &fb_len, 1);
 298    if (fb == NULL) {
 299        glDeleteTextures(1, &texture);
 300        glXMakeContextCurrent(s->dpy, None, None, NULL);
 301        glXDestroyPbuffer(s->dpy, pbuffer);
 302        return;
 303    }
 304
 305    glReadPixels(0, 0, s->regs[R_DSTHRES], s->regs[R_DSTVRES], GL_RGB,
 306            GL_UNSIGNED_SHORT_5_6_5, fb);
 307    cpu_physical_memory_unmap(fb, fb_len, 1, fb_len);
 308
 309    /* Free OpenGL allocs */
 310    glDeleteTextures(1, &texture);
 311    glXMakeContextCurrent(s->dpy, None, None, NULL);
 312    glXDestroyPbuffer(s->dpy, pbuffer);
 313
 314    s->regs[R_CTL] &= ~CTL_START_BUSY;
 315
 316    trace_milkymist_tmu2_pulse_irq();
 317    qemu_irq_pulse(s->irq);
 318}
 319
 320static uint64_t tmu2_read(void *opaque, hwaddr addr,
 321                          unsigned size)
 322{
 323    MilkymistTMU2State *s = opaque;
 324    uint32_t r = 0;
 325
 326    addr >>= 2;
 327    switch (addr) {
 328    case R_CTL:
 329    case R_HMESHLAST:
 330    case R_VMESHLAST:
 331    case R_BRIGHTNESS:
 332    case R_CHROMAKEY:
 333    case R_VERTICESADDR:
 334    case R_TEXFBUF:
 335    case R_TEXHRES:
 336    case R_TEXVRES:
 337    case R_TEXHMASK:
 338    case R_TEXVMASK:
 339    case R_DSTFBUF:
 340    case R_DSTHRES:
 341    case R_DSTVRES:
 342    case R_DSTHOFFSET:
 343    case R_DSTVOFFSET:
 344    case R_DSTSQUAREW:
 345    case R_DSTSQUAREH:
 346    case R_ALPHA:
 347        r = s->regs[addr];
 348        break;
 349
 350    default:
 351        error_report("milkymist_tmu2: read access to unknown register 0x"
 352                TARGET_FMT_plx, addr << 2);
 353        break;
 354    }
 355
 356    trace_milkymist_tmu2_memory_read(addr << 2, r);
 357
 358    return r;
 359}
 360
 361static void tmu2_check_registers(MilkymistTMU2State *s)
 362{
 363    if (s->regs[R_BRIGHTNESS] > MAX_BRIGHTNESS) {
 364        error_report("milkymist_tmu2: max brightness is %d", MAX_BRIGHTNESS);
 365    }
 366
 367    if (s->regs[R_ALPHA] > MAX_ALPHA) {
 368        error_report("milkymist_tmu2: max alpha is %d", MAX_ALPHA);
 369    }
 370
 371    if (s->regs[R_VERTICESADDR] & 0x07) {
 372        error_report("milkymist_tmu2: vertex mesh address has to be 64-bit "
 373                "aligned");
 374    }
 375
 376    if (s->regs[R_TEXFBUF] & 0x01) {
 377        error_report("milkymist_tmu2: texture buffer address has to be "
 378                "16-bit aligned");
 379    }
 380}
 381
 382static void tmu2_write(void *opaque, hwaddr addr, uint64_t value,
 383                       unsigned size)
 384{
 385    MilkymistTMU2State *s = opaque;
 386
 387    trace_milkymist_tmu2_memory_write(addr, value);
 388
 389    addr >>= 2;
 390    switch (addr) {
 391    case R_CTL:
 392        s->regs[addr] = value;
 393        if (value & CTL_START_BUSY) {
 394            tmu2_start(s);
 395        }
 396        break;
 397    case R_BRIGHTNESS:
 398    case R_HMESHLAST:
 399    case R_VMESHLAST:
 400    case R_CHROMAKEY:
 401    case R_VERTICESADDR:
 402    case R_TEXFBUF:
 403    case R_TEXHRES:
 404    case R_TEXVRES:
 405    case R_TEXHMASK:
 406    case R_TEXVMASK:
 407    case R_DSTFBUF:
 408    case R_DSTHRES:
 409    case R_DSTVRES:
 410    case R_DSTHOFFSET:
 411    case R_DSTVOFFSET:
 412    case R_DSTSQUAREW:
 413    case R_DSTSQUAREH:
 414    case R_ALPHA:
 415        s->regs[addr] = value;
 416        break;
 417
 418    default:
 419        error_report("milkymist_tmu2: write access to unknown register 0x"
 420                TARGET_FMT_plx, addr << 2);
 421        break;
 422    }
 423
 424    tmu2_check_registers(s);
 425}
 426
 427static const MemoryRegionOps tmu2_mmio_ops = {
 428    .read = tmu2_read,
 429    .write = tmu2_write,
 430    .valid = {
 431        .min_access_size = 4,
 432        .max_access_size = 4,
 433    },
 434    .endianness = DEVICE_NATIVE_ENDIAN,
 435};
 436
 437static void milkymist_tmu2_reset(DeviceState *d)
 438{
 439    MilkymistTMU2State *s = MILKYMIST_TMU2(d);
 440    int i;
 441
 442    for (i = 0; i < R_MAX; i++) {
 443        s->regs[i] = 0;
 444    }
 445}
 446
 447static void milkymist_tmu2_init(Object *obj)
 448{
 449    MilkymistTMU2State *s = MILKYMIST_TMU2(obj);
 450    SysBusDevice *dev = SYS_BUS_DEVICE(obj);
 451
 452    sysbus_init_irq(dev, &s->irq);
 453
 454    memory_region_init_io(&s->regs_region, obj, &tmu2_mmio_ops, s,
 455            "milkymist-tmu2", R_MAX * 4);
 456    sysbus_init_mmio(dev, &s->regs_region);
 457}
 458
 459static void milkymist_tmu2_realize(DeviceState *dev, Error **errp)
 460{
 461    MilkymistTMU2State *s = MILKYMIST_TMU2(dev);
 462
 463    if (tmu2_glx_init(s)) {
 464        error_setg(errp, "tmu2_glx_init failed");
 465    }
 466}
 467
 468static const VMStateDescription vmstate_milkymist_tmu2 = {
 469    .name = "milkymist-tmu2",
 470    .version_id = 1,
 471    .minimum_version_id = 1,
 472    .fields = (VMStateField[]) {
 473        VMSTATE_UINT32_ARRAY(regs, MilkymistTMU2State, R_MAX),
 474        VMSTATE_END_OF_LIST()
 475    }
 476};
 477
 478static void milkymist_tmu2_class_init(ObjectClass *klass, void *data)
 479{
 480    DeviceClass *dc = DEVICE_CLASS(klass);
 481
 482    dc->realize = milkymist_tmu2_realize;
 483    dc->reset = milkymist_tmu2_reset;
 484    dc->vmsd = &vmstate_milkymist_tmu2;
 485}
 486
 487static const TypeInfo milkymist_tmu2_info = {
 488    .name          = TYPE_MILKYMIST_TMU2,
 489    .parent        = TYPE_SYS_BUS_DEVICE,
 490    .instance_size = sizeof(MilkymistTMU2State),
 491    .instance_init = milkymist_tmu2_init,
 492    .class_init    = milkymist_tmu2_class_init,
 493};
 494
 495static void milkymist_tmu2_register_types(void)
 496{
 497    type_register_static(&milkymist_tmu2_info);
 498}
 499
 500type_init(milkymist_tmu2_register_types)
 501