hw/milkymist-vgafb.c

   1
   2 /*
   3  *  QEMU model of the Milkymist VGA framebuffer.
   4  *
   5  *  Copyright (c) 2010 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_SOURCE_CLOCK,
  58     R_MAX
  59 };
  60
  61 enum {
  62     CTRL_RESET = (1<<0),
  63 };
  64
  65 struct MilkymistVgafbState {
  66     SysBusDevice busdev;
  67     MemoryRegion regs_region;
  68     DisplayState *ds;
  69
  70     int invalidate;
  71     uint32_t fb_offset;
  72     uint32_t fb_mask;
  73
  74     uint32_t regs[R_MAX];
  75 };
  76 typedef struct MilkymistVgafbState MilkymistVgafbState;
  77
  78 static int vgafb_enabled(MilkymistVgafbState *s)
  79 {
  80     return !(s->regs[R_CTRL] & CTRL_RESET);
  81 }
  82
  83 static void vgafb_update_display(void *opaque)
  84 {
  85     MilkymistVgafbState *s = opaque;
  86     int first = 0;
  87     int last = 0;
  88     drawfn fn;
  89
  90     if (!vgafb_enabled(s)) {
  91         return;
  92     }
  93
  94     int dest_width = s->regs[R_HRES];
  95
  96     switch (ds_get_bits_per_pixel(s->ds)) {
  97     case 0:
  98         return;
  99     case 8:
 100         fn = draw_line_8;
 101         break;
 102     case 15:
 103         fn = draw_line_15;
 104         dest_width *= 2;
 105         break;
 106     case 16:
 107         fn = draw_line_16;
 108         dest_width *= 2;
 109         break;
 110     case 24:
 111         fn = draw_line_24;
 112         dest_width *= 3;
 113         break;
 114     case 32:
 115         fn = draw_line_32;
 116         dest_width *= 4;
 117         break;
 118     default:
 119         hw_error("milkymist_vgafb: bad color depth\n");
 120         break;
 121     }
 122
 123     framebuffer_update_display(s->ds,
 124                                s->regs[R_BASEADDRESS] + s->fb_offset,
 125                                s->regs[R_HRES],
 126                                s->regs[R_VRES],
 127                                s->regs[R_HRES] * 2,
 128                                dest_width,
 129                                0,
 130                                s->invalidate,
 131                                fn,
 132                                NULL,
 133                                &first, &last);
 134
 135     if (first >= 0) {
 136         dpy_update(s->ds, 0, first, s->regs[R_HRES], last - first + 1);
 137     }
 138     s->invalidate = 0;
 139 }
 140
 141 static void vgafb_invalidate_display(void *opaque)
 142 {
 143     MilkymistVgafbState *s = opaque;
 144     s->invalidate = 1;
 145 }
 146
 147 static void vgafb_resize(MilkymistVgafbState *s)
 148 {
 149     if (!vgafb_enabled(s)) {
 150         return;
 151     }
 152
 153     qemu_console_resize(s->ds, s->regs[R_HRES], s->regs[R_VRES]);
 154     s->invalidate = 1;
 155 }
 156
 157 static uint64_t vgafb_read(void *opaque, target_phys_addr_t addr,
 158                            unsigned size)
 159 {
 160     MilkymistVgafbState *s = opaque;
 161     uint32_t r = 0;
 162
 163     addr >>= 2;
 164     switch (addr) {
 165     case R_CTRL:
 166     case R_HRES:
 167     case R_HSYNC_START:
 168     case R_HSYNC_END:
 169     case R_HSCAN:
 170     case R_VRES:
 171     case R_VSYNC_START:
 172     case R_VSYNC_END:
 173     case R_VSCAN:
 174     case R_BASEADDRESS:
 175     case R_BURST_COUNT:
 176     case R_SOURCE_CLOCK:
 177         r = s->regs[addr];
 178     break;
 179     case R_BASEADDRESS_ACT:
 180         r = s->regs[R_BASEADDRESS];
 181     break;
 182
 183     default:
 184         error_report("milkymist_vgafb: read access to unknown register 0x"
 185                 TARGET_FMT_plx, addr << 2);
 186         break;
 187     }
 188
 189     trace_milkymist_vgafb_memory_read(addr << 2, r);
 190
 191     return r;
 192 }
 193
 194 static void vgafb_write(void *opaque, target_phys_addr_t addr, uint64_t value,
 195                         unsigned size)
 196 {
 197     MilkymistVgafbState *s = opaque;
 198
 199     trace_milkymist_vgafb_memory_write(addr, value);
 200
 201     addr >>= 2;
 202     switch (addr) {
 203     case R_CTRL:
 204         s->regs[addr] = value;
 205         vgafb_resize(s);
 206         break;
 207     case R_HSYNC_START:
 208     case R_HSYNC_END:
 209     case R_HSCAN:
 210     case R_VSYNC_START:
 211     case R_VSYNC_END:
 212     case R_VSCAN:
 213     case R_BURST_COUNT:
 214     case R_SOURCE_CLOCK:
 215         s->regs[addr] = value;
 216         break;
 217     case R_BASEADDRESS:
 218         if (value & 0x1f) {
 219             error_report("milkymist_vgafb: framebuffer base address have to "
 220                      "be 32 byte aligned");
 221             break;
 222         }
 223         s->regs[addr] = value & s->fb_mask;
 224         s->invalidate = 1;
 225         break;
 226     case R_HRES:
 227     case R_VRES:
 228         s->regs[addr] = value;
 229         vgafb_resize(s);
 230         break;
 231     case R_BASEADDRESS_ACT:
 232         error_report("milkymist_vgafb: write to read-only register 0x"
 233                 TARGET_FMT_plx, addr << 2);
 234         break;
 235
 236     default:
 237         error_report("milkymist_vgafb: write access to unknown register 0x"
 238                 TARGET_FMT_plx, addr << 2);
 239         break;
 240     }
 241 }
 242
 243 static const MemoryRegionOps vgafb_mmio_ops = {
 244     .read = vgafb_read,
 245     .write = vgafb_write,
 246     .valid = {
 247         .min_access_size = 4,
 248         .max_access_size = 4,
 249     },
 250     .endianness = DEVICE_NATIVE_ENDIAN,
 251 };
 252
 253 static void milkymist_vgafb_reset(DeviceState *d)
 254 {
 255     MilkymistVgafbState *s = container_of(d, MilkymistVgafbState, busdev.qdev);
 256     int i;
 257
 258     for (i = 0; i < R_MAX; i++) {
 259         s->regs[i] = 0;
 260     }
 261
 262     /* defaults */
 263     s->regs[R_CTRL] = CTRL_RESET;
 264     s->regs[R_HRES] = 640;
 265     s->regs[R_VRES] = 480;
 266     s->regs[R_BASEADDRESS] = 0;
 267 }
 268
 269 static int milkymist_vgafb_init(SysBusDevice *dev)
 270 {
 271     MilkymistVgafbState *s = FROM_SYSBUS(typeof(*s), dev);
 272
 273     memory_region_init_io(&s->regs_region, &vgafb_mmio_ops, s,
 274             "milkymist-vgafb", R_MAX * 4);
 275     sysbus_init_mmio_region(dev, &s->regs_region);
 276
 277     s->ds = graphic_console_init(vgafb_update_display,
 278                                  vgafb_invalidate_display,
 279                                  NULL, NULL, s);
 280
 281     return 0;
 282 }
 283
 284 static int vgafb_post_load(void *opaque, int version_id)
 285 {
 286     vgafb_invalidate_display(opaque);
 287     return 0;
 288 }
 289
 290 static const VMStateDescription vmstate_milkymist_vgafb = {
 291     .name = "milkymist-vgafb",
 292     .version_id = 1,
 293     .minimum_version_id = 1,
 294     .minimum_version_id_old = 1,
 295     .post_load = vgafb_post_load,
 296     .fields      = (VMStateField[]) {
 297         VMSTATE_UINT32_ARRAY(regs, MilkymistVgafbState, R_MAX),
 298         VMSTATE_END_OF_LIST()
 299     }
 300 };
 301
 302 static SysBusDeviceInfo milkymist_vgafb_info = {
 303     .init = milkymist_vgafb_init,
 304     .qdev.name  = "milkymist-vgafb",
 305     .qdev.size  = sizeof(MilkymistVgafbState),
 306     .qdev.vmsd  = &vmstate_milkymist_vgafb,
 307     .qdev.reset = milkymist_vgafb_reset,
 308     .qdev.props = (Property[]) {
 309         DEFINE_PROP_UINT32("fb_offset", MilkymistVgafbState, fb_offset, 0x0),
 310         DEFINE_PROP_UINT32("fb_mask", MilkymistVgafbState, fb_mask, 0xffffffff),
 311         DEFINE_PROP_END_OF_LIST(),
 312     }
 313 };
 314
 315 static void milkymist_vgafb_register(void)
 316 {
 317     sysbus_register_withprop(&milkymist_vgafb_info);
 318 }
 319
 320 device_init(milkymist_vgafb_register)