qemu/hw/dma/etraxfs_dma.c
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   1/*
   2 * QEMU ETRAX DMA Controller.
   3 *
   4 * Copyright (c) 2008 Edgar E. Iglesias, Axis Communications AB.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24
  25#include "qemu/osdep.h"
  26#include "hw/hw.h"
  27#include "hw/irq.h"
  28#include "qemu/main-loop.h"
  29#include "sysemu/runstate.h"
  30#include "exec/address-spaces.h"
  31
  32#include "hw/cris/etraxfs_dma.h"
  33
  34#define D(x)
  35
  36#define RW_DATA           (0x0 / 4)
  37#define RW_SAVED_DATA     (0x58 / 4)
  38#define RW_SAVED_DATA_BUF (0x5c / 4)
  39#define RW_GROUP          (0x60 / 4)
  40#define RW_GROUP_DOWN     (0x7c / 4)
  41#define RW_CMD            (0x80 / 4)
  42#define RW_CFG            (0x84 / 4)
  43#define RW_STAT           (0x88 / 4)
  44#define RW_INTR_MASK      (0x8c / 4)
  45#define RW_ACK_INTR       (0x90 / 4)
  46#define R_INTR            (0x94 / 4)
  47#define R_MASKED_INTR     (0x98 / 4)
  48#define RW_STREAM_CMD     (0x9c / 4)
  49
  50#define DMA_REG_MAX       (0x100 / 4)
  51
  52/* descriptors */
  53
  54// ------------------------------------------------------------ dma_descr_group
  55typedef struct dma_descr_group {
  56  uint32_t                      next;
  57  unsigned                      eol        : 1;
  58  unsigned                      tol        : 1;
  59  unsigned                      bol        : 1;
  60  unsigned                                 : 1;
  61  unsigned                      intr       : 1;
  62  unsigned                                 : 2;
  63  unsigned                      en         : 1;
  64  unsigned                                 : 7;
  65  unsigned                      dis        : 1;
  66  unsigned                      md         : 16;
  67  struct dma_descr_group       *up;
  68  union {
  69    struct dma_descr_context   *context;
  70    struct dma_descr_group     *group;
  71  }                             down;
  72} dma_descr_group;
  73
  74// ---------------------------------------------------------- dma_descr_context
  75typedef struct dma_descr_context {
  76  uint32_t                      next;
  77  unsigned                      eol        : 1;
  78  unsigned                                 : 3;
  79  unsigned                      intr       : 1;
  80  unsigned                                 : 1;
  81  unsigned                      store_mode : 1;
  82  unsigned                      en         : 1;
  83  unsigned                                 : 7;
  84  unsigned                      dis        : 1;
  85  unsigned                      md0        : 16;
  86  unsigned                      md1;
  87  unsigned                      md2;
  88  unsigned                      md3;
  89  unsigned                      md4;
  90  uint32_t                      saved_data;
  91  uint32_t                      saved_data_buf;
  92} dma_descr_context;
  93
  94// ------------------------------------------------------------- dma_descr_data
  95typedef struct dma_descr_data {
  96  uint32_t                      next;
  97  uint32_t                      buf;
  98  unsigned                      eol        : 1;
  99  unsigned                                 : 2;
 100  unsigned                      out_eop    : 1;
 101  unsigned                      intr       : 1;
 102  unsigned                      wait       : 1;
 103  unsigned                                 : 2;
 104  unsigned                                 : 3;
 105  unsigned                      in_eop     : 1;
 106  unsigned                                 : 4;
 107  unsigned                      md         : 16;
 108  uint32_t                      after;
 109} dma_descr_data;
 110
 111/* Constants */
 112enum {
 113  regk_dma_ack_pkt                         = 0x00000100,
 114  regk_dma_anytime                         = 0x00000001,
 115  regk_dma_array                           = 0x00000008,
 116  regk_dma_burst                           = 0x00000020,
 117  regk_dma_client                          = 0x00000002,
 118  regk_dma_copy_next                       = 0x00000010,
 119  regk_dma_copy_up                         = 0x00000020,
 120  regk_dma_data_at_eol                     = 0x00000001,
 121  regk_dma_dis_c                           = 0x00000010,
 122  regk_dma_dis_g                           = 0x00000020,
 123  regk_dma_idle                            = 0x00000001,
 124  regk_dma_intern                          = 0x00000004,
 125  regk_dma_load_c                          = 0x00000200,
 126  regk_dma_load_c_n                        = 0x00000280,
 127  regk_dma_load_c_next                     = 0x00000240,
 128  regk_dma_load_d                          = 0x00000140,
 129  regk_dma_load_g                          = 0x00000300,
 130  regk_dma_load_g_down                     = 0x000003c0,
 131  regk_dma_load_g_next                     = 0x00000340,
 132  regk_dma_load_g_up                       = 0x00000380,
 133  regk_dma_next_en                         = 0x00000010,
 134  regk_dma_next_pkt                        = 0x00000010,
 135  regk_dma_no                              = 0x00000000,
 136  regk_dma_only_at_wait                    = 0x00000000,
 137  regk_dma_restore                         = 0x00000020,
 138  regk_dma_rst                             = 0x00000001,
 139  regk_dma_running                         = 0x00000004,
 140  regk_dma_rw_cfg_default                  = 0x00000000,
 141  regk_dma_rw_cmd_default                  = 0x00000000,
 142  regk_dma_rw_intr_mask_default            = 0x00000000,
 143  regk_dma_rw_stat_default                 = 0x00000101,
 144  regk_dma_rw_stream_cmd_default           = 0x00000000,
 145  regk_dma_save_down                       = 0x00000020,
 146  regk_dma_save_up                         = 0x00000020,
 147  regk_dma_set_reg                         = 0x00000050,
 148  regk_dma_set_w_size1                     = 0x00000190,
 149  regk_dma_set_w_size2                     = 0x000001a0,
 150  regk_dma_set_w_size4                     = 0x000001c0,
 151  regk_dma_stopped                         = 0x00000002,
 152  regk_dma_store_c                         = 0x00000002,
 153  regk_dma_store_descr                     = 0x00000000,
 154  regk_dma_store_g                         = 0x00000004,
 155  regk_dma_store_md                        = 0x00000001,
 156  regk_dma_sw                              = 0x00000008,
 157  regk_dma_update_down                     = 0x00000020,
 158  regk_dma_yes                             = 0x00000001
 159};
 160
 161enum dma_ch_state
 162{
 163        RST = 1,
 164        STOPPED = 2,
 165        RUNNING = 4
 166};
 167
 168struct fs_dma_channel
 169{
 170        qemu_irq irq;
 171        struct etraxfs_dma_client *client;
 172
 173        /* Internal status.  */
 174        int stream_cmd_src;
 175        enum dma_ch_state state;
 176
 177        unsigned int input : 1;
 178        unsigned int eol : 1;
 179
 180        struct dma_descr_group current_g;
 181        struct dma_descr_context current_c;
 182        struct dma_descr_data current_d;
 183
 184        /* Control registers.  */
 185        uint32_t regs[DMA_REG_MAX];
 186};
 187
 188struct fs_dma_ctrl
 189{
 190        MemoryRegion mmio;
 191        int nr_channels;
 192        struct fs_dma_channel *channels;
 193
 194        QEMUBH *bh;
 195};
 196
 197static void DMA_run(void *opaque);
 198static int channel_out_run(struct fs_dma_ctrl *ctrl, int c);
 199
 200static inline uint32_t channel_reg(struct fs_dma_ctrl *ctrl, int c, int reg)
 201{
 202        return ctrl->channels[c].regs[reg];
 203}
 204
 205static inline int channel_stopped(struct fs_dma_ctrl *ctrl, int c)
 206{
 207        return channel_reg(ctrl, c, RW_CFG) & 2;
 208}
 209
 210static inline int channel_en(struct fs_dma_ctrl *ctrl, int c)
 211{
 212        return (channel_reg(ctrl, c, RW_CFG) & 1)
 213                && ctrl->channels[c].client;
 214}
 215
 216static inline int fs_channel(hwaddr addr)
 217{
 218        /* Every channel has a 0x2000 ctrl register map.  */
 219        return addr >> 13;
 220}
 221
 222#ifdef USE_THIS_DEAD_CODE
 223static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
 224{
 225        hwaddr addr = channel_reg(ctrl, c, RW_GROUP);
 226
 227        /* Load and decode. FIXME: handle endianness.  */
 228    cpu_physical_memory_read(addr, &ctrl->channels[c].current_g,
 229                             sizeof(ctrl->channels[c].current_g));
 230}
 231
 232static void dump_c(int ch, struct dma_descr_context *c)
 233{
 234        printf("%s ch=%d\n", __func__, ch);
 235        printf("next=%x\n", c->next);
 236        printf("saved_data=%x\n", c->saved_data);
 237        printf("saved_data_buf=%x\n", c->saved_data_buf);
 238        printf("eol=%x\n", (uint32_t) c->eol);
 239}
 240
 241static void dump_d(int ch, struct dma_descr_data *d)
 242{
 243        printf("%s ch=%d\n", __func__, ch);
 244        printf("next=%x\n", d->next);
 245        printf("buf=%x\n", d->buf);
 246        printf("after=%x\n", d->after);
 247        printf("intr=%x\n", (uint32_t) d->intr);
 248        printf("out_eop=%x\n", (uint32_t) d->out_eop);
 249        printf("in_eop=%x\n", (uint32_t) d->in_eop);
 250        printf("eol=%x\n", (uint32_t) d->eol);
 251}
 252#endif
 253
 254static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
 255{
 256        hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
 257
 258        /* Load and decode. FIXME: handle endianness.  */
 259    cpu_physical_memory_read(addr, &ctrl->channels[c].current_c,
 260                             sizeof(ctrl->channels[c].current_c));
 261
 262        D(dump_c(c, &ctrl->channels[c].current_c));
 263        /* I guess this should update the current pos.  */
 264        ctrl->channels[c].regs[RW_SAVED_DATA] =
 265                (uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data;
 266        ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
 267                (uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data_buf;
 268}
 269
 270static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
 271{
 272        hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
 273
 274        /* Load and decode. FIXME: handle endianness.  */
 275        D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
 276    cpu_physical_memory_read(addr, &ctrl->channels[c].current_d,
 277                             sizeof(ctrl->channels[c].current_d));
 278
 279        D(dump_d(c, &ctrl->channels[c].current_d));
 280        ctrl->channels[c].regs[RW_DATA] = addr;
 281}
 282
 283static void channel_store_c(struct fs_dma_ctrl *ctrl, int c)
 284{
 285        hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
 286
 287        /* Encode and store. FIXME: handle endianness.  */
 288        D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
 289        D(dump_d(c, &ctrl->channels[c].current_d));
 290    cpu_physical_memory_write(addr, &ctrl->channels[c].current_c,
 291                              sizeof(ctrl->channels[c].current_c));
 292}
 293
 294static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
 295{
 296        hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
 297
 298        /* Encode and store. FIXME: handle endianness.  */
 299        D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
 300    cpu_physical_memory_write(addr, &ctrl->channels[c].current_d,
 301                              sizeof(ctrl->channels[c].current_d));
 302}
 303
 304static inline void channel_stop(struct fs_dma_ctrl *ctrl, int c)
 305{
 306        /* FIXME:  */
 307}
 308
 309static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
 310{
 311        if (ctrl->channels[c].client)
 312        {
 313                ctrl->channels[c].eol = 0;
 314                ctrl->channels[c].state = RUNNING;
 315                if (!ctrl->channels[c].input)
 316                        channel_out_run(ctrl, c);
 317        } else
 318                printf("WARNING: starting DMA ch %d with no client\n", c);
 319
 320        qemu_bh_schedule_idle(ctrl->bh);
 321}
 322
 323static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
 324{
 325        if (!channel_en(ctrl, c) 
 326            || channel_stopped(ctrl, c)
 327            || ctrl->channels[c].state != RUNNING
 328            /* Only reload the current data descriptor if it has eol set.  */
 329            || !ctrl->channels[c].current_d.eol) {
 330                D(printf("continue failed ch=%d state=%d stopped=%d en=%d eol=%d\n", 
 331                         c, ctrl->channels[c].state,
 332                         channel_stopped(ctrl, c),
 333                         channel_en(ctrl,c),
 334                         ctrl->channels[c].eol));
 335                D(dump_d(c, &ctrl->channels[c].current_d));
 336                return;
 337        }
 338
 339        /* Reload the current descriptor.  */
 340        channel_load_d(ctrl, c);
 341
 342        /* If the current descriptor cleared the eol flag and we had already
 343           reached eol state, do the continue.  */
 344        if (!ctrl->channels[c].current_d.eol && ctrl->channels[c].eol) {
 345                D(printf("continue %d ok %x\n", c,
 346                         ctrl->channels[c].current_d.next));
 347                ctrl->channels[c].regs[RW_SAVED_DATA] =
 348                        (uint32_t)(unsigned long)ctrl->channels[c].current_d.next;
 349                channel_load_d(ctrl, c);
 350                ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
 351                        (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
 352
 353                channel_start(ctrl, c);
 354        }
 355        ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
 356                (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
 357}
 358
 359static void channel_stream_cmd(struct fs_dma_ctrl *ctrl, int c, uint32_t v)
 360{
 361        unsigned int cmd = v & ((1 << 10) - 1);
 362
 363        D(printf("%s ch=%d cmd=%x\n",
 364                 __func__, c, cmd));
 365        if (cmd & regk_dma_load_d) {
 366                channel_load_d(ctrl, c);
 367                if (cmd & regk_dma_burst)
 368                        channel_start(ctrl, c);
 369        }
 370
 371        if (cmd & regk_dma_load_c) {
 372                channel_load_c(ctrl, c);
 373        }
 374}
 375
 376static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
 377{
 378        D(printf("%s %d\n", __func__, c));
 379        ctrl->channels[c].regs[R_INTR] &=
 380                ~(ctrl->channels[c].regs[RW_ACK_INTR]);
 381
 382        ctrl->channels[c].regs[R_MASKED_INTR] =
 383                ctrl->channels[c].regs[R_INTR]
 384                & ctrl->channels[c].regs[RW_INTR_MASK];
 385
 386        D(printf("%s: chan=%d masked_intr=%x\n", __func__, 
 387                 c,
 388                 ctrl->channels[c].regs[R_MASKED_INTR]));
 389
 390        qemu_set_irq(ctrl->channels[c].irq,
 391                     !!ctrl->channels[c].regs[R_MASKED_INTR]);
 392}
 393
 394static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
 395{
 396        uint32_t len;
 397        uint32_t saved_data_buf;
 398        unsigned char buf[2 * 1024];
 399
 400        struct dma_context_metadata meta;
 401        bool send_context = true;
 402
 403        if (ctrl->channels[c].eol)
 404                return 0;
 405
 406        do {
 407                bool out_eop;
 408                D(printf("ch=%d buf=%x after=%x\n",
 409                         c,
 410                         (uint32_t)ctrl->channels[c].current_d.buf,
 411                         (uint32_t)ctrl->channels[c].current_d.after));
 412
 413                if (send_context) {
 414                        if (ctrl->channels[c].client->client.metadata_push) {
 415                                meta.metadata = ctrl->channels[c].current_d.md;
 416                                ctrl->channels[c].client->client.metadata_push(
 417                                        ctrl->channels[c].client->client.opaque,
 418                                        &meta);
 419                        }
 420                        send_context = false;
 421                }
 422
 423                channel_load_d(ctrl, c);
 424                saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
 425                len = (uint32_t)(unsigned long)
 426                        ctrl->channels[c].current_d.after;
 427                len -= saved_data_buf;
 428
 429                if (len > sizeof buf)
 430                        len = sizeof buf;
 431                cpu_physical_memory_read (saved_data_buf, buf, len);
 432
 433                out_eop = ((saved_data_buf + len) ==
 434                           ctrl->channels[c].current_d.after) &&
 435                        ctrl->channels[c].current_d.out_eop;
 436
 437                D(printf("channel %d pushes %x %u bytes eop=%u\n", c,
 438                         saved_data_buf, len, out_eop));
 439
 440                if (ctrl->channels[c].client->client.push) {
 441                        if (len > 0) {
 442                                ctrl->channels[c].client->client.push(
 443                                        ctrl->channels[c].client->client.opaque,
 444                                        buf, len, out_eop);
 445                        }
 446                } else {
 447                        printf("WARNING: DMA ch%d dataloss,"
 448                               " no attached client.\n", c);
 449                }
 450
 451                saved_data_buf += len;
 452
 453                if (saved_data_buf == (uint32_t)(unsigned long)
 454                                ctrl->channels[c].current_d.after) {
 455                        /* Done. Step to next.  */
 456                        if (ctrl->channels[c].current_d.out_eop) {
 457                                send_context = true;
 458                        }
 459                        if (ctrl->channels[c].current_d.intr) {
 460                                /* data intr.  */
 461                                D(printf("signal intr %d eol=%d\n",
 462                                        len, ctrl->channels[c].current_d.eol));
 463                                ctrl->channels[c].regs[R_INTR] |= (1 << 2);
 464                                channel_update_irq(ctrl, c);
 465                        }
 466                        channel_store_d(ctrl, c);
 467                        if (ctrl->channels[c].current_d.eol) {
 468                                D(printf("channel %d EOL\n", c));
 469                                ctrl->channels[c].eol = 1;
 470
 471                                /* Mark the context as disabled.  */
 472                                ctrl->channels[c].current_c.dis = 1;
 473                                channel_store_c(ctrl, c);
 474
 475                                channel_stop(ctrl, c);
 476                        } else {
 477                                ctrl->channels[c].regs[RW_SAVED_DATA] =
 478                                        (uint32_t)(unsigned long)ctrl->
 479                                                channels[c].current_d.next;
 480                                /* Load new descriptor.  */
 481                                channel_load_d(ctrl, c);
 482                                saved_data_buf = (uint32_t)(unsigned long)
 483                                        ctrl->channels[c].current_d.buf;
 484                        }
 485
 486                        ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
 487                                                        saved_data_buf;
 488                        D(dump_d(c, &ctrl->channels[c].current_d));
 489                }
 490                ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
 491        } while (!ctrl->channels[c].eol);
 492        return 1;
 493}
 494
 495static int channel_in_process(struct fs_dma_ctrl *ctrl, int c, 
 496                              unsigned char *buf, int buflen, int eop)
 497{
 498        uint32_t len;
 499        uint32_t saved_data_buf;
 500
 501        if (ctrl->channels[c].eol == 1)
 502                return 0;
 503
 504        channel_load_d(ctrl, c);
 505        saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
 506        len = (uint32_t)(unsigned long)ctrl->channels[c].current_d.after;
 507        len -= saved_data_buf;
 508        
 509        if (len > buflen)
 510                len = buflen;
 511
 512        cpu_physical_memory_write (saved_data_buf, buf, len);
 513        saved_data_buf += len;
 514
 515        if (saved_data_buf ==
 516            (uint32_t)(unsigned long)ctrl->channels[c].current_d.after
 517            || eop) {
 518                uint32_t r_intr = ctrl->channels[c].regs[R_INTR];
 519
 520                D(printf("in dscr end len=%d\n", 
 521                         ctrl->channels[c].current_d.after
 522                         - ctrl->channels[c].current_d.buf));
 523                ctrl->channels[c].current_d.after = saved_data_buf;
 524
 525                /* Done. Step to next.  */
 526                if (ctrl->channels[c].current_d.intr) {
 527                        /* TODO: signal eop to the client.  */
 528                        /* data intr.  */
 529                        ctrl->channels[c].regs[R_INTR] |= 3;
 530                }
 531                if (eop) {
 532                        ctrl->channels[c].current_d.in_eop = 1;
 533                        ctrl->channels[c].regs[R_INTR] |= 8;
 534                }
 535                if (r_intr != ctrl->channels[c].regs[R_INTR])
 536                        channel_update_irq(ctrl, c);
 537
 538                channel_store_d(ctrl, c);
 539                D(dump_d(c, &ctrl->channels[c].current_d));
 540
 541                if (ctrl->channels[c].current_d.eol) {
 542                        D(printf("channel %d EOL\n", c));
 543                        ctrl->channels[c].eol = 1;
 544
 545                        /* Mark the context as disabled.  */
 546                        ctrl->channels[c].current_c.dis = 1;
 547                        channel_store_c(ctrl, c);
 548
 549                        channel_stop(ctrl, c);
 550                } else {
 551                        ctrl->channels[c].regs[RW_SAVED_DATA] =
 552                                (uint32_t)(unsigned long)ctrl->
 553                                        channels[c].current_d.next;
 554                        /* Load new descriptor.  */
 555                        channel_load_d(ctrl, c);
 556                        saved_data_buf = (uint32_t)(unsigned long)
 557                                ctrl->channels[c].current_d.buf;
 558                }
 559        }
 560
 561        ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
 562        return len;
 563}
 564
 565static inline int channel_in_run(struct fs_dma_ctrl *ctrl, int c)
 566{
 567        if (ctrl->channels[c].client->client.pull) {
 568                ctrl->channels[c].client->client.pull(
 569                        ctrl->channels[c].client->client.opaque);
 570                return 1;
 571        } else
 572                return 0;
 573}
 574
 575static uint32_t dma_rinvalid (void *opaque, hwaddr addr)
 576{
 577        hw_error("Unsupported short raccess. reg=" TARGET_FMT_plx "\n", addr);
 578        return 0;
 579}
 580
 581static uint64_t
 582dma_read(void *opaque, hwaddr addr, unsigned int size)
 583{
 584        struct fs_dma_ctrl *ctrl = opaque;
 585        int c;
 586        uint32_t r = 0;
 587
 588        if (size != 4) {
 589                dma_rinvalid(opaque, addr);
 590        }
 591
 592        /* Make addr relative to this channel and bounded to nr regs.  */
 593        c = fs_channel(addr);
 594        addr &= 0xff;
 595        addr >>= 2;
 596        switch (addr)
 597        {
 598                case RW_STAT:
 599                        r = ctrl->channels[c].state & 7;
 600                        r |= ctrl->channels[c].eol << 5;
 601                        r |= ctrl->channels[c].stream_cmd_src << 8;
 602                        break;
 603
 604                default:
 605                        r = ctrl->channels[c].regs[addr];
 606                        D(printf ("%s c=%d addr=" TARGET_FMT_plx "\n",
 607                                  __func__, c, addr));
 608                        break;
 609        }
 610        return r;
 611}
 612
 613static void
 614dma_winvalid (void *opaque, hwaddr addr, uint32_t value)
 615{
 616        hw_error("Unsupported short waccess. reg=" TARGET_FMT_plx "\n", addr);
 617}
 618
 619static void
 620dma_update_state(struct fs_dma_ctrl *ctrl, int c)
 621{
 622        if (ctrl->channels[c].regs[RW_CFG] & 2)
 623                ctrl->channels[c].state = STOPPED;
 624        if (!(ctrl->channels[c].regs[RW_CFG] & 1))
 625                ctrl->channels[c].state = RST;
 626}
 627
 628static void
 629dma_write(void *opaque, hwaddr addr,
 630          uint64_t val64, unsigned int size)
 631{
 632        struct fs_dma_ctrl *ctrl = opaque;
 633        uint32_t value = val64;
 634        int c;
 635
 636        if (size != 4) {
 637                dma_winvalid(opaque, addr, value);
 638        }
 639
 640        /* Make addr relative to this channel and bounded to nr regs.  */
 641        c = fs_channel(addr);
 642        addr &= 0xff;
 643        addr >>= 2;
 644        switch (addr)
 645        {
 646                case RW_DATA:
 647                        ctrl->channels[c].regs[addr] = value;
 648                        break;
 649
 650                case RW_CFG:
 651                        ctrl->channels[c].regs[addr] = value;
 652                        dma_update_state(ctrl, c);
 653                        break;
 654                case RW_CMD:
 655                        /* continue.  */
 656                        if (value & ~1)
 657                                printf("Invalid store to ch=%d RW_CMD %x\n",
 658                                       c, value);
 659                        ctrl->channels[c].regs[addr] = value;
 660                        channel_continue(ctrl, c);
 661                        break;
 662
 663                case RW_SAVED_DATA:
 664                case RW_SAVED_DATA_BUF:
 665                case RW_GROUP:
 666                case RW_GROUP_DOWN:
 667                        ctrl->channels[c].regs[addr] = value;
 668                        break;
 669
 670                case RW_ACK_INTR:
 671                case RW_INTR_MASK:
 672                        ctrl->channels[c].regs[addr] = value;
 673                        channel_update_irq(ctrl, c);
 674                        if (addr == RW_ACK_INTR)
 675                                ctrl->channels[c].regs[RW_ACK_INTR] = 0;
 676                        break;
 677
 678                case RW_STREAM_CMD:
 679                        if (value & ~1023)
 680                                printf("Invalid store to ch=%d "
 681                                       "RW_STREAMCMD %x\n",
 682                                       c, value);
 683                        ctrl->channels[c].regs[addr] = value;
 684                        D(printf("stream_cmd ch=%d\n", c));
 685                        channel_stream_cmd(ctrl, c, value);
 686                        break;
 687
 688                default:
 689                        D(printf ("%s c=%d " TARGET_FMT_plx "\n",
 690                                __func__, c, addr));
 691                        break;
 692        }
 693}
 694
 695static const MemoryRegionOps dma_ops = {
 696        .read = dma_read,
 697        .write = dma_write,
 698        .endianness = DEVICE_NATIVE_ENDIAN,
 699        .valid = {
 700                .min_access_size = 1,
 701                .max_access_size = 4
 702        }
 703};
 704
 705static int etraxfs_dmac_run(void *opaque)
 706{
 707        struct fs_dma_ctrl *ctrl = opaque;
 708        int i;
 709        int p = 0;
 710
 711        for (i = 0; 
 712             i < ctrl->nr_channels;
 713             i++)
 714        {
 715                if (ctrl->channels[i].state == RUNNING)
 716                {
 717                        if (ctrl->channels[i].input) {
 718                                p += channel_in_run(ctrl, i);
 719                        } else {
 720                                p += channel_out_run(ctrl, i);
 721                        }
 722                }
 723        }
 724        return p;
 725}
 726
 727int etraxfs_dmac_input(struct etraxfs_dma_client *client, 
 728                       void *buf, int len, int eop)
 729{
 730        return channel_in_process(client->ctrl, client->channel, 
 731                                  buf, len, eop);
 732}
 733
 734/* Connect an IRQ line with a channel.  */
 735void etraxfs_dmac_connect(void *opaque, int c, qemu_irq *line, int input)
 736{
 737        struct fs_dma_ctrl *ctrl = opaque;
 738        ctrl->channels[c].irq = *line;
 739        ctrl->channels[c].input = input;
 740}
 741
 742void etraxfs_dmac_connect_client(void *opaque, int c, 
 743                                 struct etraxfs_dma_client *cl)
 744{
 745        struct fs_dma_ctrl *ctrl = opaque;
 746        cl->ctrl = ctrl;
 747        cl->channel = c;
 748        ctrl->channels[c].client = cl;
 749}
 750
 751
 752static void DMA_run(void *opaque)
 753{
 754    struct fs_dma_ctrl *etraxfs_dmac = opaque;
 755    int p = 1;
 756
 757    if (runstate_is_running())
 758        p = etraxfs_dmac_run(etraxfs_dmac);
 759
 760    if (p)
 761        qemu_bh_schedule_idle(etraxfs_dmac->bh);
 762}
 763
 764void *etraxfs_dmac_init(hwaddr base, int nr_channels)
 765{
 766        struct fs_dma_ctrl *ctrl = NULL;
 767
 768        ctrl = g_malloc0(sizeof *ctrl);
 769
 770        ctrl->bh = qemu_bh_new(DMA_run, ctrl);
 771
 772        ctrl->nr_channels = nr_channels;
 773        ctrl->channels = g_malloc0(sizeof ctrl->channels[0] * nr_channels);
 774
 775        memory_region_init_io(&ctrl->mmio, NULL, &dma_ops, ctrl, "etraxfs-dma",
 776                              nr_channels * 0x2000);
 777        memory_region_add_subregion(get_system_memory(), base, &ctrl->mmio);
 778
 779        return ctrl;
 780}
 781