hw/milkymist-vgafb.c

   1
   2 /*
   3  *  QEMU model of the Milkymist VGA framebuffer.
   4  *
   5  *  Copyright (c) 2010-2012 Michael Walle <michael@walle.cc>
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  *
  20  *
  21  * Specification available at:
  22  *   http://www.milkymist.org/socdoc/vgafb.pdf
  23  */
  24
  25 #include "hw.h"
  26 #include "sysbus.h"
  27 #include "trace.h"
  28 #include "console.h"
  29 #include "framebuffer.h"
  30 #include "pixel_ops.h"
  31 #include "qemu-error.h"
  32
  33 #define BITS 8
  34 #include "milkymist-vgafb_template.h"
  35 #define BITS 15
  36 #include "milkymist-vgafb_template.h"
  37 #define BITS 16
  38 #include "milkymist-vgafb_template.h"
  39 #define BITS 24
  40 #include "milkymist-vgafb_template.h"
  41 #define BITS 32
  42 #include "milkymist-vgafb_template.h"
  43
  44 enum {
  45     R_CTRL = 0,
  46     R_HRES,
  47     R_HSYNC_START,
  48     R_HSYNC_END,
  49     R_HSCAN,
  50     R_VRES,
  51     R_VSYNC_START,
  52     R_VSYNC_END,
  53     R_VSCAN,
  54     R_BASEADDRESS,
  55     R_BASEADDRESS_ACT,
  56     R_BURST_COUNT,
  57     R_DDC,
  58     R_SOURCE_CLOCK,
  59     R_MAX
  60 };
  61
  62 enum {
  63     CTRL_RESET = (1<<0),
  64 };
  65
  66 struct MilkymistVgafbState {
  67     SysBusDevice busdev;
  68     MemoryRegion regs_region;
  69     DisplayState *ds;
  70
  71     int invalidate;
  72     uint32_t fb_offset;
  73     uint32_t fb_mask;
  74
  75     uint32_t regs[R_MAX];
  76 };
  77 typedef struct MilkymistVgafbState MilkymistVgafbState;
  78
  79 static int vgafb_enabled(MilkymistVgafbState *s)
  80 {
  81     return !(s->regs[R_CTRL] & CTRL_RESET);
  82 }
  83
  84 static void vgafb_update_display(void *opaque)
  85 {
  86     MilkymistVgafbState *s = opaque;
  87     int first = 0;
  88     int last = 0;
  89     drawfn fn;
  90
  91     if (!vgafb_enabled(s)) {
  92         return;
  93     }
  94
  95     int dest_width = s->regs[R_HRES];
  96
  97     switch (ds_get_bits_per_pixel(s->ds)) {
  98     case 0:
  99         return;
 100     case 8:
 101         fn = draw_line_8;
 102         break;
 103     case 15:
 104         fn = draw_line_15;
 105         dest_width *= 2;
 106         break;
 107     case 16:
 108         fn = draw_line_16;
 109         dest_width *= 2;
 110         break;
 111     case 24:
 112         fn = draw_line_24;
 113         dest_width *= 3;
 114         break;
 115     case 32:
 116         fn = draw_line_32;
 117         dest_width *= 4;
 118         break;
 119     default:
 120         hw_error("milkymist_vgafb: bad color depth\n");
 121         break;
 122     }
 123
 124     framebuffer_update_display(s->ds, sysbus_address_space(&s->busdev),
 125                                s->regs[R_BASEADDRESS] + s->fb_offset,
 126                                s->regs[R_HRES],
 127                                s->regs[R_VRES],
 128                                s->regs[R_HRES] * 2,
 129                                dest_width,
 130                                0,
 131                                s->invalidate,
 132                                fn,
 133                                NULL,
 134                                &first, &last);
 135
 136     if (first >= 0) {
 137         dpy_gfx_update(s->ds, 0, first, s->regs[R_HRES], last - first + 1);
 138     }
 139     s->invalidate = 0;
 140 }
 141
 142 static void vgafb_invalidate_display(void *opaque)
 143 {
 144     MilkymistVgafbState *s = opaque;
 145     s->invalidate = 1;
 146 }
 147
 148 static void vgafb_resize(MilkymistVgafbState *s)
 149 {
 150     if (!vgafb_enabled(s)) {
 151         return;
 152     }
 153
 154     qemu_console_resize(s->ds, s->regs[R_HRES], s->regs[R_VRES]);
 155     s->invalidate = 1;
 156 }
 157
 158 static uint64_t vgafb_read(void *opaque, hwaddr addr,
 159                            unsigned size)
 160 {
 161     MilkymistVgafbState *s = opaque;
 162     uint32_t r = 0;
 163
 164     addr >>= 2;
 165     switch (addr) {
 166     case R_CTRL:
 167     case R_HRES:
 168     case R_HSYNC_START:
 169     case R_HSYNC_END:
 170     case R_HSCAN:
 171     case R_VRES:
 172     case R_VSYNC_START:
 173     case R_VSYNC_END:
 174     case R_VSCAN:
 175     case R_BASEADDRESS:
 176     case R_BURST_COUNT:
 177     case R_DDC:
 178     case R_SOURCE_CLOCK:
 179         r = s->regs[addr];
 180     break;
 181     case R_BASEADDRESS_ACT:
 182         r = s->regs[R_BASEADDRESS];
 183     break;
 184
 185     default:
 186         error_report("milkymist_vgafb: read access to unknown register 0x"
 187                 TARGET_FMT_plx, addr << 2);
 188         break;
 189     }
 190
 191     trace_milkymist_vgafb_memory_read(addr << 2, r);
 192
 193     return r;
 194 }
 195
 196 static void vgafb_write(void *opaque, hwaddr addr, uint64_t value,
 197                         unsigned size)
 198 {
 199     MilkymistVgafbState *s = opaque;
 200
 201     trace_milkymist_vgafb_memory_write(addr, value);
 202
 203     addr >>= 2;
 204     switch (addr) {
 205     case R_CTRL:
 206         s->regs[addr] = value;
 207         vgafb_resize(s);
 208         break;
 209     case R_HSYNC_START:
 210     case R_HSYNC_END:
 211     case R_HSCAN:
 212     case R_VSYNC_START:
 213     case R_VSYNC_END:
 214     case R_VSCAN:
 215     case R_BURST_COUNT:
 216     case R_DDC:
 217     case R_SOURCE_CLOCK:
 218         s->regs[addr] = value;
 219         break;
 220     case R_BASEADDRESS:
 221         if (value & 0x1f) {
 222             error_report("milkymist_vgafb: framebuffer base address have to "
 223                      "be 32 byte aligned");
 224             break;
 225         }
 226         s->regs[addr] = value & s->fb_mask;
 227         s->invalidate = 1;
 228         break;
 229     case R_HRES:
 230     case R_VRES:
 231         s->regs[addr] = value;
 232         vgafb_resize(s);
 233         break;
 234     case R_BASEADDRESS_ACT:
 235         error_report("milkymist_vgafb: write to read-only register 0x"
 236                 TARGET_FMT_plx, addr << 2);
 237         break;
 238
 239     default:
 240         error_report("milkymist_vgafb: write access to unknown register 0x"
 241                 TARGET_FMT_plx, addr << 2);
 242         break;
 243     }
 244 }
 245
 246 static const MemoryRegionOps vgafb_mmio_ops = {
 247     .read = vgafb_read,
 248     .write = vgafb_write,
 249     .valid = {
 250         .min_access_size = 4,
 251         .max_access_size = 4,
 252     },
 253     .endianness = DEVICE_NATIVE_ENDIAN,
 254 };
 255
 256 static void milkymist_vgafb_reset(DeviceState *d)
 257 {
 258     MilkymistVgafbState *s = container_of(d, MilkymistVgafbState, busdev.qdev);
 259     int i;
 260
 261     for (i = 0; i < R_MAX; i++) {
 262         s->regs[i] = 0;
 263     }
 264
 265     /* defaults */
 266     s->regs[R_CTRL] = CTRL_RESET;
 267     s->regs[R_HRES] = 640;
 268     s->regs[R_VRES] = 480;
 269     s->regs[R_BASEADDRESS] = 0;
 270 }
 271
 272 static int milkymist_vgafb_init(SysBusDevice *dev)
 273 {
 274     MilkymistVgafbState *s = FROM_SYSBUS(typeof(*s), dev);
 275
 276     memory_region_init_io(&s->regs_region, &vgafb_mmio_ops, s,
 277             "milkymist-vgafb", R_MAX * 4);
 278     sysbus_init_mmio(dev, &s->regs_region);
 279
 280     s->ds = graphic_console_init(vgafb_update_display,
 281                                  vgafb_invalidate_display,
 282                                  NULL, NULL, s);
 283
 284     return 0;
 285 }
 286
 287 static int vgafb_post_load(void *opaque, int version_id)
 288 {
 289     vgafb_invalidate_display(opaque);
 290     return 0;
 291 }
 292
 293 static const VMStateDescription vmstate_milkymist_vgafb = {
 294     .name = "milkymist-vgafb",
 295     .version_id = 1,
 296     .minimum_version_id = 1,
 297     .minimum_version_id_old = 1,
 298     .post_load = vgafb_post_load,
 299     .fields      = (VMStateField[]) {
 300         VMSTATE_UINT32_ARRAY(regs, MilkymistVgafbState, R_MAX),
 301         VMSTATE_END_OF_LIST()
 302     }
 303 };
 304
 305 static Property milkymist_vgafb_properties[] = {
 306     DEFINE_PROP_UINT32("fb_offset", MilkymistVgafbState, fb_offset, 0x0),
 307     DEFINE_PROP_UINT32("fb_mask", MilkymistVgafbState, fb_mask, 0xffffffff),
 308     DEFINE_PROP_END_OF_LIST(),
 309 };
 310
 311 static void milkymist_vgafb_class_init(ObjectClass *klass, void *data)
 312 {
 313     DeviceClass *dc = DEVICE_CLASS(klass);
 314     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 315
 316     k->init = milkymist_vgafb_init;
 317     dc->reset = milkymist_vgafb_reset;
 318     dc->vmsd = &vmstate_milkymist_vgafb;
 319     dc->props = milkymist_vgafb_properties;
 320 }
 321
 322 static TypeInfo milkymist_vgafb_info = {
 323     .name          = "milkymist-vgafb",
 324     .parent        = TYPE_SYS_BUS_DEVICE,
 325     .instance_size = sizeof(MilkymistVgafbState),
 326     .class_init    = milkymist_vgafb_class_init,
 327 };
 328
 329 static void milkymist_vgafb_register_types(void)
 330 {
 331     type_register_static(&milkymist_vgafb_info);
 332 }
 333
 334 type_init(milkymist_vgafb_register_types)