aboutsummaryrefslogtreecommitdiff
path: root/hw/omap_spi.c
blob: df250027fe736bf9ba10e5c30c4a0bad3e0c4dc6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
/*
 * TI OMAP processor's Multichannel SPI emulation.
 *
 * Copyright (C) 2007-2009 Nokia Corporation
 *
 * Original code for OMAP2 by Andrzej Zaborowski <andrew@openedhand.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 or
 * (at your option) any later version of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "hw.h"
#include "omap.h"
#include "sysbus.h"
#include "spi.h"

//#define SPI_DEBUG

#ifdef SPI_DEBUG
#define TRACE(fmt,...) fprintf(stderr, "%s@%d: " fmt "\n", __FUNCTION__, \
                               __LINE__, ##__VA_ARGS__);
#else
#define TRACE(...)
#endif

#define SPI_FIFOSIZE 64
#define SPI_REV_OMAP2420 0x14
#define SPI_REV_OMAP3430 0x21
#define IS_OMAP3_SPI(s) ((s)->revision >= SPI_REV_OMAP3430)

typedef struct omap_mcspi_bus_s {
    SPIBus *bus;
    MemoryRegion iomem;
    qemu_irq irq;
    int chnum;
    uint8_t revision;

    uint32_t sysconfig;
    uint32_t systest;
    uint32_t irqst;
    uint32_t irqen;
    uint32_t wken;
    uint32_t control;

    uint32_t xferlevel;
    struct omap_mcspi_fifo_s {
        int start;
        int len;
        int size;
        uint8_t buf[SPI_FIFOSIZE];
    } tx_fifo, rx_fifo;
    int fifo_ch;
    int fifo_wcnt;

    struct omap_mcspi_ch_s {
        qemu_irq txdrq;
        qemu_irq rxdrq;

        uint32_t tx;
        uint32_t rx;

        uint32_t config;
        uint32_t status;
        uint32_t control;
    } *ch;
} OMAPSPIBusState;

typedef struct omap_mcspi_s {
    SysBusDevice busdev;
    int mpu_model;
    int buscount;
    OMAPSPIBusState *bus;
} OMAPSPIState;

static inline void omap_mcspi_interrupt_update(OMAPSPIBusState *s)
{
    qemu_set_irq(s->irq, s->irqst & s->irqen);
}

static inline void omap_mcspi_dmarequest_update(OMAPSPIBusState *s,
                                                int chnum)
{
    struct omap_mcspi_ch_s *ch = &s->ch[chnum];
    if ((ch->control & 1) &&                         /* EN */
        (ch->config & (1 << 14)) &&                  /* DMAW */
        (ch->status & (1 << 1)) &&                   /* TXS */
        ((ch->config >> 12) & 3) != 1) {             /* TRM */
        if (!IS_OMAP3_SPI(s) ||
            !(ch->config & (1 << 27)) ||             /* FFEW */
            s->tx_fifo.len <= (s->xferlevel & 0x3f)) /* AEL */
            qemu_irq_raise(ch->txdrq);
        else
            qemu_irq_lower(ch->txdrq);
    }
    if ((ch->control & 1) &&                                /* EN */
        (ch->config & (1 << 15)) &&                         /* DMAW */
        (ch->status & (1 << 0)) &&                          /* RXS */
        ((ch->config >> 12) & 3) != 2) {                    /* TRM */
        if (!IS_OMAP3_SPI(s) ||
            !(ch->config & (1 << 28)) ||                    /* FFER */
            s->rx_fifo.len >= ((s->xferlevel >> 8) & 0x3f)) /* AFL */
            qemu_irq_raise(ch->rxdrq);
        else
            qemu_irq_lower(ch->rxdrq);
    }
}

static void omap_mcspi_fifo_reset(OMAPSPIBusState *s)
{
    struct omap_mcspi_ch_s *ch;

    s->tx_fifo.len = 0;
    s->rx_fifo.len = 0;
    s->tx_fifo.start = 0;
    s->rx_fifo.start = 0;
    if (s->fifo_ch < 0) {
        s->tx_fifo.size  = s->rx_fifo.size  = 0;
    } else {
        ch = &s->ch[s->fifo_ch];
        s->tx_fifo.size = ((ch->config >> 27) & 1) ? SPI_FIFOSIZE : 0;
        s->rx_fifo.size = ((ch->config >> 28) & 1) ? SPI_FIFOSIZE : 0;
        if (((ch->config >> 27) & 3) == 3) {
            s->tx_fifo.size >>= 1;
            s->rx_fifo.size >>= 1;
        }
    }
}

/* returns next word in FIFO or the n first bytes if there is not
 * enough data in FIFO */
static uint32_t omap_mcspi_fifo_get(struct omap_mcspi_fifo_s *s, int wl)
{
    uint32_t v, sh;

    for (v = 0, sh = 0; wl > 0 && s->len; wl -= 8, s->len--, sh += 8) {
        v |= ((uint32_t)s->buf[s->start++]) << sh;
        if (s->start >= s->size)
            s->start = 0;
    }
    return v;
}

/* pushes a word to FIFO or the first n bytes of the word if the FIFO
 * is too full to hold the full word */
static void omap_mcspi_fifo_put(struct omap_mcspi_fifo_s *s, int wl,
                                uint32_t v)
{
    int p = s->start + s->len;

    for (; wl > 0 && s->len < s->size; wl -=8, v >>= 8, s->len++) {
        if (p >= s->size)
            p -= s->size;
        s->buf[p++] = (uint8_t)(v & 0xff);
    }
}

static void omap_mcspi_transfer_run(OMAPSPIBusState *s, int chnum)
{
    struct omap_mcspi_ch_s *ch = s->ch + chnum;
    int trm = (ch->config >> 12) & 3;
    int wl;

    if (!(ch->control & 1))                  /* EN */
        return;
    if ((ch->status & 1) && trm != 2 &&      /* RXS */
        !(ch->config & (1 << 19)))           /* TURBO */
        goto intr_update;
    if ((ch->status & (1 << 1)) && trm != 1) /* TXS */
        goto intr_update;

    if (!(s->control & 1) ||        /* SINGLE */
        (ch->config & (1 << 20))) { /* FORCE */
        wl = 1 + (0x1f & (ch->config >> 7)); /* WL */
        if (!IS_OMAP3_SPI(s) || s->fifo_ch != chnum ||
            !((ch->config >> 27) & 3)) {     /* FFER | FFEW */
            ch->rx = spi_txrx(s->bus, chnum, ch->tx, wl);
        } else {
            switch ((ch->config >> 27) & 3) {
            case 1: /* !FFER, FFEW */
                if (trm != 1)
                    ch->tx = omap_mcspi_fifo_get(&s->tx_fifo, wl);
                ch->rx = spi_txrx(s->bus, chnum, ch->tx, wl);
                s->fifo_wcnt--;
                break;
            case 2: /* FFER, !FFEW */
                ch->rx = spi_txrx(s->bus, chnum, ch->tx, wl);
                if (trm != 2)
                    omap_mcspi_fifo_put(&s->rx_fifo, wl, ch->rx);
                s->fifo_wcnt--;
                break;
            case 3: /* FFER, FFEW */
                while (s->rx_fifo.len < s->rx_fifo.size &&
                       s->tx_fifo.len && s->fifo_wcnt) {
                    if (trm != 1)
                        ch->tx = omap_mcspi_fifo_get(&s->tx_fifo, wl);
                    ch->rx = spi_txrx(s->bus, chnum, ch->tx, wl);
                    if (trm != 2)
                        omap_mcspi_fifo_put(&s->rx_fifo, wl, ch->rx);
                    s->fifo_wcnt--;
                }
                break;
            default:
                break;
            }
            if ((ch->config & (1 << 28)) &&        /* FFER */
                s->rx_fifo.len >= s->rx_fifo.size)
                ch->status |= 1 << 6;              /* RXFFF */
            ch->status &= ~(1 << 5);               /* RXFFE */
            ch->status &= ~(1 << 4);               /* TXFFF */
            if ((ch->config & (1 << 27)) &&        /* FFEW */
                !s->tx_fifo.len)
                ch->status |= 1 << 3;              /* TXFFE */
            if (!s->fifo_wcnt &&
                ((s->xferlevel >> 16) & 0xffff))   /* WCNT */
                s->irqst |= 1 << 17;               /* EOW */
        }
    }

    ch->tx = 0;
    ch->status |= 1 << 2;               /* EOT */
    ch->status |= 1 << 1;               /* TXS */
    if (trm != 2) {
        ch->status |= 1;                /* RXS */
    } else {
        ch->status &= ~1;               /* RXS */
    }

intr_update:
    if ((ch->status & 1) &&	trm != 2 &&                     /* RXS */
        !(ch->config & (1 << 19)))                          /* TURBO */
        if (!IS_OMAP3_SPI(s) || s->fifo_ch != chnum ||
            !((ch->config >> 28) & 1) ||                    /* FFER */
            s->rx_fifo.len >= ((s->xferlevel >> 8) & 0x3f)) /* AFL */
            s->irqst |= 1 << (2 + 4 * chnum);               /* RX_FULL */
    if ((ch->status & (1 << 1)) && trm != 1)                /* TXS */
        if (!IS_OMAP3_SPI(s) || s->fifo_ch != chnum ||
            !((ch->config >> 27) & 1) ||                    /* FFEW */
            s->tx_fifo.len <= (s->xferlevel & 0x3f))        /* AEL */
            s->irqst |= 1 << (4 * chnum);                   /* TX_EMPTY */
    omap_mcspi_interrupt_update(s);
    omap_mcspi_dmarequest_update(s, chnum);
}

static void omap_mcspi_bus_reset(OMAPSPIBusState *s)
{
    int ch;

    s->sysconfig = 0;
    s->systest = 0;
    s->irqst = 0;
    s->irqen = 0;
    s->wken = 0;
    s->control = 4;

    s->fifo_ch = -1;
    omap_mcspi_fifo_reset(s);

    for (ch = 0; ch < s->chnum; ch ++) {
        s->ch[ch].config = 0x060000;
        s->ch[ch].status = 2;				/* TXS */
        s->ch[ch].control = 0;

        omap_mcspi_dmarequest_update(s, ch);
    }

    omap_mcspi_interrupt_update(s);
}

static uint64_t omap_mcspi_read(void *opaque, target_phys_addr_t addr,
                                unsigned size)
{
    OMAPSPIBusState *s = (OMAPSPIBusState *) opaque;
    int ch = 0;
    uint32_t ret;

    if (size != 4) {
        return omap_badwidth_read32(opaque, addr);
    }

    switch (addr) {
    case 0x00:	/* MCSPI_REVISION */
        TRACE("REVISION = 0x%08x", s->revision);
        return s->revision;

    case 0x10:	/* MCSPI_SYSCONFIG */
        TRACE("SYSCONFIG = 0x%08x", s->sysconfig);
        return s->sysconfig;

    case 0x14:	/* MCSPI_SYSSTATUS */
        TRACE("SYSSTATUS = 0x00000001");
        return 1;					/* RESETDONE */

    case 0x18:	/* MCSPI_IRQSTATUS */
        TRACE("IRQSTATUS = 0x%08x", s->irqst);
        return s->irqst;

    case 0x1c:	/* MCSPI_IRQENABLE */
        TRACE("IRQENABLE = 0x%08x", s->irqen);
        return s->irqen;

    case 0x20:	/* MCSPI_WAKEUPENABLE */
        TRACE("WAKEUPENABLE = 0x%08x", s->wken);
        return s->wken;

    case 0x24:	/* MCSPI_SYST */
        TRACE("SYST = 0x%08x", s->systest);
        return s->systest;

    case 0x28:	/* MCSPI_MODULCTRL */
        TRACE("MODULCTRL = 0x%08x", s->control);
        return s->control;

    case 0x68: ch ++;
    case 0x54: ch ++;
    case 0x40: ch ++;
    case 0x2c:	/* MCSPI_CHCONF */
        TRACE("CHCONF%d = 0x%08x", ch,
              (ch < s->chnum) ? s->ch[ch].config : 0);
        return (ch < s->chnum) ? s->ch[ch].config : 0;

    case 0x6c: ch ++;
    case 0x58: ch ++;
    case 0x44: ch ++;
    case 0x30:	/* MCSPI_CHSTAT */
        TRACE("CHSTAT%d = 0x%08x", ch,
              (ch < s->chnum) ? s->ch[ch].status : 0);
        return (ch < s->chnum) ? s->ch[ch].status : 0;

    case 0x70: ch ++;
    case 0x5c: ch ++;
    case 0x48: ch ++;
    case 0x34:	/* MCSPI_CHCTRL */
        TRACE("CHCTRL%d = 0x%08x", ch,
              (ch < s->chnum) ? s->ch[ch].control : 0);
        return (ch < s->chnum) ? s->ch[ch].control : 0;

    case 0x74: ch ++;
    case 0x60: ch ++;
    case 0x4c: ch ++;
    case 0x38:	/* MCSPI_TX */
        TRACE("TX%d = 0x%08x", ch,
              (ch < s->chnum) ? s->ch[ch].tx : 0);
        return (ch < s->chnum) ? s->ch[ch].tx : 0;

    case 0x78: ch ++;
    case 0x64: ch ++;
    case 0x50: ch ++;
    case 0x3c:	/* MCSPI_RX */
        if (ch < s->chnum) {
            if (!IS_OMAP3_SPI(s) || ch != s->fifo_ch ||
                !(s->ch[ch].config & (1 << 28))) { /* FFER */
                s->ch[ch].status &= ~1;            /* RXS */
                ret = s->ch[ch].rx;
                TRACE("RX%d = 0x%08x", ch, ret);
                omap_mcspi_transfer_run(s, ch);
                return ret;
            }
            if (!s->rx_fifo.len) {
                TRACE("rxfifo underflow!");
            } else {
                qemu_irq_lower(s->ch[ch].rxdrq);
                s->ch[ch].status &= ~(1 << 6);                 /* RXFFF */
                if (((s->ch[ch].config >> 12) & 3) != 2)        /* TRM */
                    ret = omap_mcspi_fifo_get(&s->rx_fifo,
                        1 + ((s->ch[ch].config >> 7) & 0x1f)); /* WL */
                else
                    ret = s->ch[ch].rx;
                TRACE("RX%d = 0x%08x", ch, ret);
                if (!s->rx_fifo.len) {
                    s->ch[ch].status &= ~1;     /* RXS */
                    s->ch[ch].status |= 1 << 5; /* RXFFE */
                    omap_mcspi_transfer_run(s, ch);
                }
                return ret;
            }
        }
        TRACE("RX%d = 0x00000000", ch);
        return 0;

    case 0x7c: /* MCSPI_XFERLEVEL */
        if (IS_OMAP3_SPI(s)) {
            if ((s->xferlevel >> 16) & 0xffff) /* WCNT */
                ret = ((s->xferlevel & 0xffff0000) - (s->fifo_wcnt << 16));
            else
                ret = ((-s->fifo_wcnt) & 0xffff) << 16;
            TRACE("XFERLEVEL = 0x%08x", (s->xferlevel & 0xffff) | ret);
            return (s->xferlevel & 0xffff) | ret;
        }
        break;

    default:
        break;
    }

    OMAP_BAD_REG(addr);
    return 0;
}

static void omap_mcspi_write(void *opaque, target_phys_addr_t addr,
                             uint64_t value, unsigned size)
{
    OMAPSPIBusState *s = (OMAPSPIBusState *) opaque;
    uint32_t old;
    int ch = 0;

    if (size != 4) {
        return omap_badwidth_write32(opaque, addr, value);
    }

    switch (addr) {
    case 0x00:	/* MCSPI_REVISION */
    case 0x14:	/* MCSPI_SYSSTATUS */
    case 0x30:	/* MCSPI_CHSTAT0 */
    case 0x3c:	/* MCSPI_RX0 */
    case 0x44:	/* MCSPI_CHSTAT1 */
    case 0x50:	/* MCSPI_RX1 */
    case 0x58:	/* MCSPI_CHSTAT2 */
    case 0x64:	/* MCSPI_RX2 */
    case 0x6c:	/* MCSPI_CHSTAT3 */
    case 0x78:	/* MCSPI_RX3 */
        /* silently ignore */
        //OMAP_RO_REGV(addr, value);
        return;

    case 0x10:	/* MCSPI_SYSCONFIG */
        TRACE("SYSCONFIG = 0x%08x", value);
        if (value & (1 << 1))				/* SOFTRESET */
            omap_mcspi_bus_reset(s);
        s->sysconfig = value & 0x31d;
        break;

    case 0x18:	/* MCSPI_IRQSTATUS */
        TRACE("IRQSTATUS = 0x%08x", value);
        if (!((s->control & (1 << 3)) && (s->systest & (1 << 11)))) {
            s->irqst &= ~value;
            omap_mcspi_interrupt_update(s);
        }
        break;

    case 0x1c:	/* MCSPI_IRQENABLE */
        TRACE("IRQENABLE = 0x%08x", value);
        s->irqen = value & (IS_OMAP3_SPI(s) ? 0x3777f : 0x1777f);
        omap_mcspi_interrupt_update(s);
        break;

    case 0x20:	/* MCSPI_WAKEUPENABLE */
        TRACE("WAKEUPENABLE = 0x%08x", value);
        s->wken = value & 1;
        break;

    case 0x24:	/* MCSPI_SYST */
        TRACE("SYST = 0x%08x", value);
        if (s->control & (1 << 3))			/* SYSTEM_TEST */
            if (value & (1 << 11)) {			/* SSB */
                s->irqst |= 0x1777f;
                omap_mcspi_interrupt_update(s);
            }
        s->systest = value & 0xfff;
        break;

    case 0x28:	/* MCSPI_MODULCTRL */
        TRACE("MODULCTRL = 0x%08x", value);
        if (value & (1 << 3))				/* SYSTEM_TEST */
            if (s->systest & (1 << 11)) {		/* SSB */
                s->irqst |= IS_OMAP3_SPI(s) ? 0x3777f : 0x1777f;
                omap_mcspi_interrupt_update(s);
            }
        s->control = value & 0xf;
        break;

    case 0x68: ch ++;
    case 0x54: ch ++;
    case 0x40: ch ++;
    case 0x2c:	/* MCSPI_CHCONF */
        TRACE("CHCONF%d = 0x%08x", ch, value);
        if (ch < s->chnum) {
            old = s->ch[ch].config;
            s->ch[ch].config = value & (IS_OMAP3_SPI(s)
                                        ? 0x3fffffff : 0x7fffff);
            if (IS_OMAP3_SPI(s) &&
                ((value ^ old) & (3 << 27))) { /* FFER | FFEW */
                s->fifo_ch = ((value & (3 << 27))) ? ch : -1;
                omap_mcspi_fifo_reset(s);
            }
            if (((value ^ old) & (3 << 14)) || /* DMAR | DMAW */
                (IS_OMAP3_SPI(s) &&
                 ((value ^ old) & (3 << 27)))) /* FFER | FFEW */
                omap_mcspi_dmarequest_update(s, ch);
            if (((value >> 12) & 3) == 3) {   /* TRM */
                TRACE("invalid TRM value (3)");
            }
                if (((value >> 7) & 0x1f) < 3) {  /* WL */
                TRACE("invalid WL value (%" PRIx64 ")", (value >> 7) & 0x1f);
                }
            if (IS_OMAP3_SPI(s) && ((value >> 23) & 1)) { /* SBE */
                TRACE("start-bit mode is not supported");
            }
        }
        break;

    case 0x70: ch ++;
    case 0x5c: ch ++;
    case 0x48: ch ++;
    case 0x34:	/* MCSPI_CHCTRL */
        TRACE("CHCTRL%d = 0x%08x", ch, value);
        if (ch < s->chnum) {
            old = s->ch[ch].control;
            s->ch[ch].control = value & (IS_OMAP3_SPI(s) ? 0xff01 : 1);
            if (value & ~old & 1) { /* EN */
                if (IS_OMAP3_SPI(s) && s->fifo_ch == ch)
                    omap_mcspi_fifo_reset(s);
                omap_mcspi_transfer_run(s, ch);
            }
        }
        break;

    case 0x74: ch ++;
    case 0x60: ch ++;
    case 0x4c: ch ++;
    case 0x38:	/* MCSPI_TX */
        TRACE("TX%d = 0x%08x", ch, value);
        if (ch < s->chnum) {
            if (!IS_OMAP3_SPI(s) || s->fifo_ch != ch ||
                !(s->ch[ch].config & (1 << 27))) { /* FFEW */
                s->ch[ch].tx = value;
                s->ch[ch].status &= ~0x06;         /* EOT | TXS */
                omap_mcspi_transfer_run(s, ch);
            } else {
                if (s->tx_fifo.len >= s->tx_fifo.size) {
                    TRACE("txfifo overflow!");
                } else {
                    qemu_irq_lower(s->ch[ch].txdrq);
                    s->ch[ch].status &= ~0x0e;      /* TXFFE | EOT | TXS */
                    if (((s->ch[ch].config >> 12) & 3) != 1) {    /* TRM */
                        omap_mcspi_fifo_put(
                            &s->tx_fifo,
                            1 + ((s->ch[ch].config >> 7) & 0x1f), /* WL */
                            value);
                        if (s->tx_fifo.len >= s->tx_fifo.size)
                            s->ch[ch].status |= 1 << 4;        /* TXFFF */
                        if (s->tx_fifo.len >= (s->xferlevel & 0x3f))
                            omap_mcspi_transfer_run(s, ch);
                    } else {
                        s->ch[ch].tx = value;
                        omap_mcspi_transfer_run(s, ch);
                    }
                }
            }
        }
        break;

    case 0x7c: /* MCSPI_XFERLEVEL */
        TRACE("XFERLEVEL = 0x%08x", value);
        if (IS_OMAP3_SPI(s)) {
            if (value != s->xferlevel) {
                s->fifo_wcnt = (value >> 16) & 0xffff;
                s->xferlevel = value & 0xffff3f3f;
                omap_mcspi_fifo_reset(s);
            }
        } else
            OMAP_BAD_REG(addr);
        break;

    default:
        OMAP_BAD_REG(addr);
        return;
    }
}

static const MemoryRegionOps omap_mcspi_ops = {
    .read = omap_mcspi_read,
    .write = omap_mcspi_write,
    .endianness = DEVICE_NATIVE_ENDIAN,
};

static void omap_mcspi_reset(DeviceState *qdev)
{
    int i;
    OMAPSPIState *s = FROM_SYSBUS(OMAPSPIState, sysbus_from_qdev(qdev));
    for (i = 0; i < s->buscount; i++) {
        omap_mcspi_bus_reset(&s->bus[i]);
    }
}

static int omap_mcspi_init(SysBusDevice *busdev)
{
    int i, j;
    OMAPSPIBusState *bs;
    OMAPSPIState *s = FROM_SYSBUS(OMAPSPIState, busdev);
    
    s->buscount = (s->mpu_model < omap3430) ? 2 : 4;
    s->bus = g_new0(OMAPSPIBusState, s->buscount);
    for (i = 0; i < s->buscount; i++) {
        bs = &s->bus[i];
        if (s->mpu_model < omap3430) {
            bs->revision = SPI_REV_OMAP2420;
            bs->chnum = i ? 2 : 4;
        } else {
            bs->revision = SPI_REV_OMAP3430;
            bs->chnum = (i > 2) ? 1 : (i ? 2 : 4);
        }
        sysbus_init_irq(busdev, &bs->irq);
        bs->bus = spi_init_bus(&busdev->qdev, NULL, bs->chnum);
        bs->ch = g_new0(struct omap_mcspi_ch_s, bs->chnum);
        for (j = 0; j < bs->chnum; j++) {
            sysbus_init_irq(busdev, &bs->ch[j].txdrq);
            sysbus_init_irq(busdev, &bs->ch[j].rxdrq);
        }
        memory_region_init_io(&bs->iomem, &omap_mcspi_ops, bs, "omap.mcspi",
                              0x1000);
        sysbus_init_mmio(busdev, &bs->iomem);
    }
    return 0;
}

SPIBus *omap_mcspi_bus(DeviceState *qdev, int bus_number)
{
    OMAPSPIState *s = FROM_SYSBUS(OMAPSPIState, sysbus_from_qdev(qdev));
    if (bus_number < s->buscount) {
        return s->bus[bus_number].bus;
    }
    hw_error("%s: invalid bus number %d\n", __FUNCTION__, bus_number);
}

static Property omap_mcspi_properties[] = {
    DEFINE_PROP_INT32("mpu_model", OMAPSPIState, mpu_model, 0),
    DEFINE_PROP_END_OF_LIST()
};

static void omap_mcspi_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
    k->init = omap_mcspi_init;
    dc->props = omap_mcspi_properties;
    dc->reset = omap_mcspi_reset;
}

static TypeInfo omap_mcspi_info = {
    .name = "omap_mcspi",
    .parent = TYPE_SYS_BUS_DEVICE,
    .instance_size = sizeof(OMAPSPIState),
    .class_init = omap_mcspi_class_init,
};

static void omap_mcspi_register_types(void)
{
    type_register_static(&omap_mcspi_info);
}

type_init(omap_mcspi_register_types)