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