Statistics
| Branch: | Revision:

root / hw / omap_i2c.c @ 02b373ad

History | View | Annotate | Download (14.6 kB)

1
/*
2
 * TI OMAP on-chip I2C controller.  Only "new I2C" mode supported.
3
 *
4
 * Copyright (C) 2007 Andrzej Zaborowski  <balrog@zabor.org>
5
 *
6
 * This program is free software; you can redistribute it and/or
7
 * modify it under the terms of the GNU General Public License as
8
 * published by the Free Software Foundation; either version 2 of
9
 * the License, or (at your option) any later version.
10
 *
11
 * This program is distributed in the hope that it will be useful,
12
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14
 * GNU General Public License for more details.
15
 *
16
 * You should have received a copy of the GNU General Public License
17
 * along with this program; if not, write to the Free Software
18
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
19
 * MA 02111-1307 USA
20
 */
21
#include "hw.h"
22
#include "i2c.h"
23
#include "omap.h"
24

    
25
struct omap_i2c_s {
26
    qemu_irq irq;
27
    qemu_irq drq[2];
28
    i2c_slave slave;
29
    i2c_bus *bus;
30

    
31
    uint8_t revision;
32
    uint8_t mask;
33
    uint16_t stat;
34
    uint16_t dma;
35
    uint16_t count;
36
    int count_cur;
37
    uint32_t fifo;
38
    int rxlen;
39
    int txlen;
40
    uint16_t control;
41
    uint16_t addr[2];
42
    uint8_t divider;
43
    uint8_t times[2];
44
    uint16_t test;
45
};
46

    
47
#define OMAP2_INTR_REV        0x34
48
#define OMAP2_GC_REV        0x34
49

    
50
static void omap_i2c_interrupts_update(struct omap_i2c_s *s)
51
{
52
    qemu_set_irq(s->irq, s->stat & s->mask);
53
    if ((s->dma >> 15) & 1)                                        /* RDMA_EN */
54
        qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);                /* RRDY */
55
    if ((s->dma >> 7) & 1)                                        /* XDMA_EN */
56
        qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);                /* XRDY */
57
}
58

    
59
/* These are only stubs now.  */
60
static void omap_i2c_event(i2c_slave *i2c, enum i2c_event event)
61
{
62
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
63

    
64
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
65
        return;
66

    
67
    switch (event) {
68
    case I2C_START_SEND:
69
    case I2C_START_RECV:
70
        s->stat |= 1 << 9;                                        /* AAS */
71
        break;
72
    case I2C_FINISH:
73
        s->stat |= 1 << 2;                                        /* ARDY */
74
        break;
75
    case I2C_NACK:
76
        s->stat |= 1 << 1;                                        /* NACK */
77
        break;
78
    }
79

    
80
    omap_i2c_interrupts_update(s);
81
}
82

    
83
static int omap_i2c_rx(i2c_slave *i2c)
84
{
85
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
86
    uint8_t ret = 0;
87

    
88
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
89
        return -1;
90

    
91
    if (s->txlen)
92
        ret = s->fifo >> ((-- s->txlen) << 3) & 0xff;
93
    else
94
        s->stat |= 1 << 10;                                        /* XUDF */
95
    s->stat |= 1 << 4;                                                /* XRDY */
96

    
97
    omap_i2c_interrupts_update(s);
98
    return ret;
99
}
100

    
101
static int omap_i2c_tx(i2c_slave *i2c, uint8_t data)
102
{
103
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
104

    
105
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
106
        return 1;
107

    
108
    if (s->rxlen < 4)
109
        s->fifo |= data << ((s->rxlen ++) << 3);
110
    else
111
        s->stat |= 1 << 11;                                        /* ROVR */
112
    s->stat |= 1 << 3;                                                /* RRDY */
113

    
114
    omap_i2c_interrupts_update(s);
115
    return 1;
116
}
117

    
118
static void omap_i2c_fifo_run(struct omap_i2c_s *s)
119
{
120
    int ack = 1;
121

    
122
    if (!i2c_bus_busy(s->bus))
123
        return;
124

    
125
    if ((s->control >> 2) & 1) {                                /* RM */
126
        if ((s->control >> 1) & 1) {                                /* STP */
127
            i2c_end_transfer(s->bus);
128
            s->control &= ~(1 << 1);                                /* STP */
129
            s->count_cur = s->count;
130
            s->txlen = 0;
131
        } else if ((s->control >> 9) & 1) {                        /* TRX */
132
            while (ack && s->txlen)
133
                ack = (i2c_send(s->bus,
134
                                        (s->fifo >> ((-- s->txlen) << 3)) &
135
                                        0xff) >= 0);
136
            s->stat |= 1 << 4;                                        /* XRDY */
137
        } else {
138
            while (s->rxlen < 4)
139
                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
140
            s->stat |= 1 << 3;                                        /* RRDY */
141
        }
142
    } else {
143
        if ((s->control >> 9) & 1) {                                /* TRX */
144
            while (ack && s->count_cur && s->txlen) {
145
                ack = (i2c_send(s->bus,
146
                                        (s->fifo >> ((-- s->txlen) << 3)) &
147
                                        0xff) >= 0);
148
                s->count_cur --;
149
            }
150
            if (ack && s->count_cur)
151
                s->stat |= 1 << 4;                                /* XRDY */
152
            else
153
                s->stat &= ~(1 << 4);                                /* XRDY */
154
            if (!s->count_cur) {
155
                s->stat |= 1 << 2;                                /* ARDY */
156
                s->control &= ~(1 << 10);                        /* MST */
157
            }
158
        } else {
159
            while (s->count_cur && s->rxlen < 4) {
160
                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
161
                s->count_cur --;
162
            }
163
            if (s->rxlen)
164
                s->stat |= 1 << 3;                                /* RRDY */
165
            else
166
                s->stat &= ~(1 << 3);                                /* RRDY */
167
        }
168
        if (!s->count_cur) {
169
            if ((s->control >> 1) & 1) {                        /* STP */
170
                i2c_end_transfer(s->bus);
171
                s->control &= ~(1 << 1);                        /* STP */
172
                s->count_cur = s->count;
173
                s->txlen = 0;
174
            } else {
175
                s->stat |= 1 << 2;                                /* ARDY */
176
                s->control &= ~(1 << 10);                        /* MST */
177
            }
178
        }
179
    }
180

    
181
    s->stat |= (!ack) << 1;                                        /* NACK */
182
    if (!ack)
183
        s->control &= ~(1 << 1);                                /* STP */
184
}
185

    
186
void omap_i2c_reset(struct omap_i2c_s *s)
187
{
188
    s->mask = 0;
189
    s->stat = 0;
190
    s->dma = 0;
191
    s->count = 0;
192
    s->count_cur = 0;
193
    s->fifo = 0;
194
    s->rxlen = 0;
195
    s->txlen = 0;
196
    s->control = 0;
197
    s->addr[0] = 0;
198
    s->addr[1] = 0;
199
    s->divider = 0;
200
    s->times[0] = 0;
201
    s->times[1] = 0;
202
    s->test = 0;
203
}
204

    
205
static uint32_t omap_i2c_read(void *opaque, target_phys_addr_t addr)
206
{
207
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
208
    int offset = addr & OMAP_MPUI_REG_MASK;
209
    uint16_t ret;
210

    
211
    switch (offset) {
212
    case 0x00:        /* I2C_REV */
213
        return s->revision;                                        /* REV */
214

    
215
    case 0x04:        /* I2C_IE */
216
        return s->mask;
217

    
218
    case 0x08:        /* I2C_STAT */
219
        return s->stat | (i2c_bus_busy(s->bus) << 12);
220

    
221
    case 0x0c:        /* I2C_IV */
222
        if (s->revision >= OMAP2_INTR_REV)
223
            break;
224
        ret = ffs(s->stat & s->mask);
225
        if (ret)
226
            s->stat ^= 1 << (ret - 1);
227
        omap_i2c_interrupts_update(s);
228
        return ret;
229

    
230
    case 0x10:        /* I2C_SYSS */
231
        return (s->control >> 15) & 1;                                /* I2C_EN */
232

    
233
    case 0x14:        /* I2C_BUF */
234
        return s->dma;
235

    
236
    case 0x18:        /* I2C_CNT */
237
        return s->count_cur;                                        /* DCOUNT */
238

    
239
    case 0x1c:        /* I2C_DATA */
240
        ret = 0;
241
        if (s->control & (1 << 14)) {                                /* BE */
242
            ret |= ((s->fifo >> 0) & 0xff) << 8;
243
            ret |= ((s->fifo >> 8) & 0xff) << 0;
244
        } else {
245
            ret |= ((s->fifo >> 8) & 0xff) << 8;
246
            ret |= ((s->fifo >> 0) & 0xff) << 0;
247
        }
248
        if (s->rxlen == 1) {
249
            s->stat |= 1 << 15;                                        /* SBD */
250
            s->rxlen = 0;
251
        } else if (s->rxlen > 1) {
252
            if (s->rxlen > 2)
253
                s->fifo >>= 16;
254
            s->rxlen -= 2;
255
        } else
256
            /* XXX: remote access (qualifier) error - what's that?  */;
257
        if (!s->rxlen) {
258
            s->stat &= ~(1 << 3);                                /* RRDY */
259
            if (((s->control >> 10) & 1) &&                        /* MST */
260
                            ((~s->control >> 9) & 1)) {                /* TRX */
261
                s->stat |= 1 << 2;                                /* ARDY */
262
                s->control &= ~(1 << 10);                        /* MST */
263
            }
264
        }
265
        s->stat &= ~(1 << 11);                                        /* ROVR */
266
        omap_i2c_fifo_run(s);
267
        omap_i2c_interrupts_update(s);
268
        return ret;
269

    
270
    case 0x20:        /* I2C_SYSC */
271
        return 0;
272

    
273
    case 0x24:        /* I2C_CON */
274
        return s->control;
275

    
276
    case 0x28:        /* I2C_OA */
277
        return s->addr[0];
278

    
279
    case 0x2c:        /* I2C_SA */
280
        return s->addr[1];
281

    
282
    case 0x30:        /* I2C_PSC */
283
        return s->divider;
284

    
285
    case 0x34:        /* I2C_SCLL */
286
        return s->times[0];
287

    
288
    case 0x38:        /* I2C_SCLH */
289
        return s->times[1];
290

    
291
    case 0x3c:        /* I2C_SYSTEST */
292
        if (s->test & (1 << 15)) {                                /* ST_EN */
293
            s->test ^= 0xa;
294
            return s->test;
295
        } else
296
            return s->test & ~0x300f;
297
    }
298

    
299
    OMAP_BAD_REG(addr);
300
    return 0;
301
}
302

    
303
static void omap_i2c_write(void *opaque, target_phys_addr_t addr,
304
                uint32_t value)
305
{
306
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
307
    int offset = addr & OMAP_MPUI_REG_MASK;
308
    int nack;
309

    
310
    switch (offset) {
311
    case 0x00:        /* I2C_REV */
312
    case 0x0c:        /* I2C_IV */
313
    case 0x10:        /* I2C_SYSS */
314
        OMAP_RO_REG(addr);
315
        return;
316

    
317
    case 0x04:        /* I2C_IE */
318
        s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
319
        break;
320

    
321
    case 0x08:        /* I2C_STAT */
322
        if (s->revision < OMAP2_INTR_REV) {
323
            OMAP_RO_REG(addr);
324
            return;
325
        }
326

    
327
        /* RRDY and XRDY are reset by hardware. (in all versions???) */
328
        s->stat &= ~(value & 0x27);
329
        omap_i2c_interrupts_update(s);
330
        break;
331

    
332
    case 0x14:        /* I2C_BUF */
333
        s->dma = value & 0x8080;
334
        if (value & (1 << 15))                                        /* RDMA_EN */
335
            s->mask &= ~(1 << 3);                                /* RRDY_IE */
336
        if (value & (1 << 7))                                        /* XDMA_EN */
337
            s->mask &= ~(1 << 4);                                /* XRDY_IE */
338
        break;
339

    
340
    case 0x18:        /* I2C_CNT */
341
        s->count = value;                                        /* DCOUNT */
342
        break;
343

    
344
    case 0x1c:        /* I2C_DATA */
345
        if (s->txlen > 2) {
346
            /* XXX: remote access (qualifier) error - what's that?  */
347
            break;
348
        }
349
        s->fifo <<= 16;
350
        s->txlen += 2;
351
        if (s->control & (1 << 14)) {                                /* BE */
352
            s->fifo |= ((value >> 8) & 0xff) << 8;
353
            s->fifo |= ((value >> 0) & 0xff) << 0;
354
        } else {
355
            s->fifo |= ((value >> 0) & 0xff) << 8;
356
            s->fifo |= ((value >> 8) & 0xff) << 0;
357
        }
358
        s->stat &= ~(1 << 10);                                        /* XUDF */
359
        if (s->txlen > 2)
360
            s->stat &= ~(1 << 4);                                /* XRDY */
361
        omap_i2c_fifo_run(s);
362
        omap_i2c_interrupts_update(s);
363
        break;
364

    
365
    case 0x20:        /* I2C_SYSC */
366
        if (s->revision < OMAP2_INTR_REV) {
367
            OMAP_BAD_REG(addr);
368
            return;
369
        }
370

    
371
        if (value & 2)
372
            omap_i2c_reset(s);
373
        break;
374

    
375
    case 0x24:        /* I2C_CON */
376
        s->control = value & 0xcf87;
377
        if (~value & (1 << 15)) {                                /* I2C_EN */
378
            if (s->revision < OMAP2_INTR_REV)
379
                omap_i2c_reset(s);
380
            break;
381
        }
382
        if ((value & (1 << 15)) && !(value & (1 << 10))) {        /* MST */
383
            fprintf(stderr, "%s: I^2C slave mode not supported\n",
384
                            __FUNCTION__);
385
            break;
386
        }
387
        if ((value & (1 << 15)) && value & (1 << 8)) {                /* XA */
388
            fprintf(stderr, "%s: 10-bit addressing mode not supported\n",
389
                            __FUNCTION__);
390
            break;
391
        }
392
        if ((value & (1 << 15)) && value & (1 << 0)) {                /* STT */
393
            nack = !!i2c_start_transfer(s->bus, s->addr[1],        /* SA */
394
                            (~value >> 9) & 1);                        /* TRX */
395
            s->stat |= nack << 1;                                /* NACK */
396
            s->control &= ~(1 << 0);                                /* STT */
397
            s->fifo = 0;
398
            if (nack)
399
                s->control &= ~(1 << 1);                        /* STP */
400
            else {
401
                s->count_cur = s->count;
402
                omap_i2c_fifo_run(s);
403
            }
404
            omap_i2c_interrupts_update(s);
405
        }
406
        break;
407

    
408
    case 0x28:        /* I2C_OA */
409
        s->addr[0] = value & 0x3ff;
410
        i2c_set_slave_address(&s->slave, value & 0x7f);
411
        break;
412

    
413
    case 0x2c:        /* I2C_SA */
414
        s->addr[1] = value & 0x3ff;
415
        break;
416

    
417
    case 0x30:        /* I2C_PSC */
418
        s->divider = value;
419
        break;
420

    
421
    case 0x34:        /* I2C_SCLL */
422
        s->times[0] = value;
423
        break;
424

    
425
    case 0x38:        /* I2C_SCLH */
426
        s->times[1] = value;
427
        break;
428

    
429
    case 0x3c:        /* I2C_SYSTEST */
430
        s->test = value & 0xf80f;
431
        if (value & (1 << 11))                                        /* SBB */
432
            if (s->revision >= OMAP2_INTR_REV) {
433
                s->stat |= 0x3f;
434
                omap_i2c_interrupts_update(s);
435
            }
436
        if (value & (1 << 15))                                        /* ST_EN */
437
            fprintf(stderr, "%s: System Test not supported\n", __FUNCTION__);
438
        break;
439

    
440
    default:
441
        OMAP_BAD_REG(addr);
442
        return;
443
    }
444
}
445

    
446
static void omap_i2c_writeb(void *opaque, target_phys_addr_t addr,
447
                uint32_t value)
448
{
449
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
450
    int offset = addr & OMAP_MPUI_REG_MASK;
451

    
452
    switch (offset) {
453
    case 0x1c:        /* I2C_DATA */
454
        if (s->txlen > 2) {
455
            /* XXX: remote access (qualifier) error - what's that?  */
456
            break;
457
        }
458
        s->fifo <<= 8;
459
        s->txlen += 1;
460
        s->fifo |= value & 0xff;
461
        s->stat &= ~(1 << 10);                                        /* XUDF */
462
        if (s->txlen > 2)
463
            s->stat &= ~(1 << 4);                                /* XRDY */
464
        omap_i2c_fifo_run(s);
465
        omap_i2c_interrupts_update(s);
466
        break;
467

    
468
    default:
469
        OMAP_BAD_REG(addr);
470
        return;
471
    }
472
}
473

    
474
static CPUReadMemoryFunc *omap_i2c_readfn[] = {
475
    omap_badwidth_read16,
476
    omap_i2c_read,
477
    omap_badwidth_read16,
478
};
479

    
480
static CPUWriteMemoryFunc *omap_i2c_writefn[] = {
481
    omap_i2c_writeb,        /* Only the last fifo write can be 8 bit.  */
482
    omap_i2c_write,
483
    omap_badwidth_write16,
484
};
485

    
486
struct omap_i2c_s *omap_i2c_init(target_phys_addr_t base,
487
                qemu_irq irq, qemu_irq *dma, omap_clk clk)
488
{
489
    int iomemtype;
490
    struct omap_i2c_s *s = (struct omap_i2c_s *)
491
            qemu_mallocz(sizeof(struct omap_i2c_s));
492

    
493
    /* TODO: set a value greater or equal to real hardware */
494
    s->revision = 0x11;
495
    s->irq = irq;
496
    s->drq[0] = dma[0];
497
    s->drq[1] = dma[1];
498
    s->slave.event = omap_i2c_event;
499
    s->slave.recv = omap_i2c_rx;
500
    s->slave.send = omap_i2c_tx;
501
    s->bus = i2c_init_bus();
502
    omap_i2c_reset(s);
503

    
504
    iomemtype = cpu_register_io_memory(0, omap_i2c_readfn,
505
                    omap_i2c_writefn, s);
506
    cpu_register_physical_memory(base, 0x800, iomemtype);
507

    
508
    return s;
509
}
510

    
511
struct omap_i2c_s *omap2_i2c_init(struct omap_target_agent_s *ta,
512
                qemu_irq irq, qemu_irq *dma, omap_clk fclk, omap_clk iclk)
513
{
514
    int iomemtype;
515
    struct omap_i2c_s *s = (struct omap_i2c_s *)
516
            qemu_mallocz(sizeof(struct omap_i2c_s));
517

    
518
    s->revision = 0x34;
519
    s->irq = irq;
520
    s->drq[0] = dma[0];
521
    s->drq[1] = dma[1];
522
    s->slave.event = omap_i2c_event;
523
    s->slave.recv = omap_i2c_rx;
524
    s->slave.send = omap_i2c_tx;
525
    s->bus = i2c_init_bus();
526
    omap_i2c_reset(s);
527

    
528
    iomemtype = l4_register_io_memory(0, omap_i2c_readfn,
529
                    omap_i2c_writefn, s);
530
    omap_l4_attach(ta, 0, iomemtype);
531

    
532
    return s;
533
}
534

    
535
i2c_bus *omap_i2c_bus(struct omap_i2c_s *s)
536
{
537
    return s->bus;
538
}