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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
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License along
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 * with this program; if not, write to the Free Software Foundation, Inc.,
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 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19
 */
20
#include "hw.h"
21
#include "i2c.h"
22
#include "omap.h"
23

    
24
struct omap_i2c_s {
25
    qemu_irq irq;
26
    qemu_irq drq[2];
27
    i2c_slave slave;
28
    i2c_bus *bus;
29

    
30
    uint8_t revision;
31
    uint8_t mask;
32
    uint16_t stat;
33
    uint16_t dma;
34
    uint16_t count;
35
    int count_cur;
36
    uint32_t fifo;
37
    int rxlen;
38
    int txlen;
39
    uint16_t control;
40
    uint16_t addr[2];
41
    uint8_t divider;
42
    uint8_t times[2];
43
    uint16_t test;
44
};
45

    
46
#define OMAP2_INTR_REV        0x34
47
#define OMAP2_GC_REV        0x34
48

    
49
static void omap_i2c_interrupts_update(struct omap_i2c_s *s)
50
{
51
    qemu_set_irq(s->irq, s->stat & s->mask);
52
    if ((s->dma >> 15) & 1)                                        /* RDMA_EN */
53
        qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);                /* RRDY */
54
    if ((s->dma >> 7) & 1)                                        /* XDMA_EN */
55
        qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);                /* XRDY */
56
}
57

    
58
/* These are only stubs now.  */
59
static void omap_i2c_event(i2c_slave *i2c, enum i2c_event event)
60
{
61
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
62

    
63
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
64
        return;
65

    
66
    switch (event) {
67
    case I2C_START_SEND:
68
    case I2C_START_RECV:
69
        s->stat |= 1 << 9;                                        /* AAS */
70
        break;
71
    case I2C_FINISH:
72
        s->stat |= 1 << 2;                                        /* ARDY */
73
        break;
74
    case I2C_NACK:
75
        s->stat |= 1 << 1;                                        /* NACK */
76
        break;
77
    }
78

    
79
    omap_i2c_interrupts_update(s);
80
}
81

    
82
static int omap_i2c_rx(i2c_slave *i2c)
83
{
84
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
85
    uint8_t ret = 0;
86

    
87
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
88
        return -1;
89

    
90
    if (s->txlen)
91
        ret = s->fifo >> ((-- s->txlen) << 3) & 0xff;
92
    else
93
        s->stat |= 1 << 10;                                        /* XUDF */
94
    s->stat |= 1 << 4;                                                /* XRDY */
95

    
96
    omap_i2c_interrupts_update(s);
97
    return ret;
98
}
99

    
100
static int omap_i2c_tx(i2c_slave *i2c, uint8_t data)
101
{
102
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
103

    
104
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
105
        return 1;
106

    
107
    if (s->rxlen < 4)
108
        s->fifo |= data << ((s->rxlen ++) << 3);
109
    else
110
        s->stat |= 1 << 11;                                        /* ROVR */
111
    s->stat |= 1 << 3;                                                /* RRDY */
112

    
113
    omap_i2c_interrupts_update(s);
114
    return 1;
115
}
116

    
117
static void omap_i2c_fifo_run(struct omap_i2c_s *s)
118
{
119
    int ack = 1;
120

    
121
    if (!i2c_bus_busy(s->bus))
122
        return;
123

    
124
    if ((s->control >> 2) & 1) {                                /* RM */
125
        if ((s->control >> 1) & 1) {                                /* STP */
126
            i2c_end_transfer(s->bus);
127
            s->control &= ~(1 << 1);                                /* STP */
128
            s->count_cur = s->count;
129
            s->txlen = 0;
130
        } else if ((s->control >> 9) & 1) {                        /* TRX */
131
            while (ack && s->txlen)
132
                ack = (i2c_send(s->bus,
133
                                        (s->fifo >> ((-- s->txlen) << 3)) &
134
                                        0xff) >= 0);
135
            s->stat |= 1 << 4;                                        /* XRDY */
136
        } else {
137
            while (s->rxlen < 4)
138
                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
139
            s->stat |= 1 << 3;                                        /* RRDY */
140
        }
141
    } else {
142
        if ((s->control >> 9) & 1) {                                /* TRX */
143
            while (ack && s->count_cur && s->txlen) {
144
                ack = (i2c_send(s->bus,
145
                                        (s->fifo >> ((-- s->txlen) << 3)) &
146
                                        0xff) >= 0);
147
                s->count_cur --;
148
            }
149
            if (ack && s->count_cur)
150
                s->stat |= 1 << 4;                                /* XRDY */
151
            else
152
                s->stat &= ~(1 << 4);                                /* XRDY */
153
            if (!s->count_cur) {
154
                s->stat |= 1 << 2;                                /* ARDY */
155
                s->control &= ~(1 << 10);                        /* MST */
156
            }
157
        } else {
158
            while (s->count_cur && s->rxlen < 4) {
159
                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
160
                s->count_cur --;
161
            }
162
            if (s->rxlen)
163
                s->stat |= 1 << 3;                                /* RRDY */
164
            else
165
                s->stat &= ~(1 << 3);                                /* RRDY */
166
        }
167
        if (!s->count_cur) {
168
            if ((s->control >> 1) & 1) {                        /* STP */
169
                i2c_end_transfer(s->bus);
170
                s->control &= ~(1 << 1);                        /* STP */
171
                s->count_cur = s->count;
172
                s->txlen = 0;
173
            } else {
174
                s->stat |= 1 << 2;                                /* ARDY */
175
                s->control &= ~(1 << 10);                        /* MST */
176
            }
177
        }
178
    }
179

    
180
    s->stat |= (!ack) << 1;                                        /* NACK */
181
    if (!ack)
182
        s->control &= ~(1 << 1);                                /* STP */
183
}
184

    
185
void omap_i2c_reset(struct omap_i2c_s *s)
186
{
187
    s->mask = 0;
188
    s->stat = 0;
189
    s->dma = 0;
190
    s->count = 0;
191
    s->count_cur = 0;
192
    s->fifo = 0;
193
    s->rxlen = 0;
194
    s->txlen = 0;
195
    s->control = 0;
196
    s->addr[0] = 0;
197
    s->addr[1] = 0;
198
    s->divider = 0;
199
    s->times[0] = 0;
200
    s->times[1] = 0;
201
    s->test = 0;
202
}
203

    
204
static uint32_t omap_i2c_read(void *opaque, target_phys_addr_t addr)
205
{
206
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
207
    int offset = addr & OMAP_MPUI_REG_MASK;
208
    uint16_t ret;
209

    
210
    switch (offset) {
211
    case 0x00:        /* I2C_REV */
212
        return s->revision;                                        /* REV */
213

    
214
    case 0x04:        /* I2C_IE */
215
        return s->mask;
216

    
217
    case 0x08:        /* I2C_STAT */
218
        return s->stat | (i2c_bus_busy(s->bus) << 12);
219

    
220
    case 0x0c:        /* I2C_IV */
221
        if (s->revision >= OMAP2_INTR_REV)
222
            break;
223
        ret = ffs(s->stat & s->mask);
224
        if (ret)
225
            s->stat ^= 1 << (ret - 1);
226
        omap_i2c_interrupts_update(s);
227
        return ret;
228

    
229
    case 0x10:        /* I2C_SYSS */
230
        return (s->control >> 15) & 1;                                /* I2C_EN */
231

    
232
    case 0x14:        /* I2C_BUF */
233
        return s->dma;
234

    
235
    case 0x18:        /* I2C_CNT */
236
        return s->count_cur;                                        /* DCOUNT */
237

    
238
    case 0x1c:        /* I2C_DATA */
239
        ret = 0;
240
        if (s->control & (1 << 14)) {                                /* BE */
241
            ret |= ((s->fifo >> 0) & 0xff) << 8;
242
            ret |= ((s->fifo >> 8) & 0xff) << 0;
243
        } else {
244
            ret |= ((s->fifo >> 8) & 0xff) << 8;
245
            ret |= ((s->fifo >> 0) & 0xff) << 0;
246
        }
247
        if (s->rxlen == 1) {
248
            s->stat |= 1 << 15;                                        /* SBD */
249
            s->rxlen = 0;
250
        } else if (s->rxlen > 1) {
251
            if (s->rxlen > 2)
252
                s->fifo >>= 16;
253
            s->rxlen -= 2;
254
        } else
255
            /* XXX: remote access (qualifier) error - what's that?  */;
256
        if (!s->rxlen) {
257
            s->stat &= ~(1 << 3);                                /* RRDY */
258
            if (((s->control >> 10) & 1) &&                        /* MST */
259
                            ((~s->control >> 9) & 1)) {                /* TRX */
260
                s->stat |= 1 << 2;                                /* ARDY */
261
                s->control &= ~(1 << 10);                        /* MST */
262
            }
263
        }
264
        s->stat &= ~(1 << 11);                                        /* ROVR */
265
        omap_i2c_fifo_run(s);
266
        omap_i2c_interrupts_update(s);
267
        return ret;
268

    
269
    case 0x20:        /* I2C_SYSC */
270
        return 0;
271

    
272
    case 0x24:        /* I2C_CON */
273
        return s->control;
274

    
275
    case 0x28:        /* I2C_OA */
276
        return s->addr[0];
277

    
278
    case 0x2c:        /* I2C_SA */
279
        return s->addr[1];
280

    
281
    case 0x30:        /* I2C_PSC */
282
        return s->divider;
283

    
284
    case 0x34:        /* I2C_SCLL */
285
        return s->times[0];
286

    
287
    case 0x38:        /* I2C_SCLH */
288
        return s->times[1];
289

    
290
    case 0x3c:        /* I2C_SYSTEST */
291
        if (s->test & (1 << 15)) {                                /* ST_EN */
292
            s->test ^= 0xa;
293
            return s->test;
294
        } else
295
            return s->test & ~0x300f;
296
    }
297

    
298
    OMAP_BAD_REG(addr);
299
    return 0;
300
}
301

    
302
static void omap_i2c_write(void *opaque, target_phys_addr_t addr,
303
                uint32_t value)
304
{
305
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
306
    int offset = addr & OMAP_MPUI_REG_MASK;
307
    int nack;
308

    
309
    switch (offset) {
310
    case 0x00:        /* I2C_REV */
311
    case 0x0c:        /* I2C_IV */
312
    case 0x10:        /* I2C_SYSS */
313
        OMAP_RO_REG(addr);
314
        return;
315

    
316
    case 0x04:        /* I2C_IE */
317
        s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
318
        break;
319

    
320
    case 0x08:        /* I2C_STAT */
321
        if (s->revision < OMAP2_INTR_REV) {
322
            OMAP_RO_REG(addr);
323
            return;
324
        }
325

    
326
        /* RRDY and XRDY are reset by hardware. (in all versions???) */
327
        s->stat &= ~(value & 0x27);
328
        omap_i2c_interrupts_update(s);
329
        break;
330

    
331
    case 0x14:        /* I2C_BUF */
332
        s->dma = value & 0x8080;
333
        if (value & (1 << 15))                                        /* RDMA_EN */
334
            s->mask &= ~(1 << 3);                                /* RRDY_IE */
335
        if (value & (1 << 7))                                        /* XDMA_EN */
336
            s->mask &= ~(1 << 4);                                /* XRDY_IE */
337
        break;
338

    
339
    case 0x18:        /* I2C_CNT */
340
        s->count = value;                                        /* DCOUNT */
341
        break;
342

    
343
    case 0x1c:        /* I2C_DATA */
344
        if (s->txlen > 2) {
345
            /* XXX: remote access (qualifier) error - what's that?  */
346
            break;
347
        }
348
        s->fifo <<= 16;
349
        s->txlen += 2;
350
        if (s->control & (1 << 14)) {                                /* BE */
351
            s->fifo |= ((value >> 8) & 0xff) << 8;
352
            s->fifo |= ((value >> 0) & 0xff) << 0;
353
        } else {
354
            s->fifo |= ((value >> 0) & 0xff) << 8;
355
            s->fifo |= ((value >> 8) & 0xff) << 0;
356
        }
357
        s->stat &= ~(1 << 10);                                        /* XUDF */
358
        if (s->txlen > 2)
359
            s->stat &= ~(1 << 4);                                /* XRDY */
360
        omap_i2c_fifo_run(s);
361
        omap_i2c_interrupts_update(s);
362
        break;
363

    
364
    case 0x20:        /* I2C_SYSC */
365
        if (s->revision < OMAP2_INTR_REV) {
366
            OMAP_BAD_REG(addr);
367
            return;
368
        }
369

    
370
        if (value & 2)
371
            omap_i2c_reset(s);
372
        break;
373

    
374
    case 0x24:        /* I2C_CON */
375
        s->control = value & 0xcf87;
376
        if (~value & (1 << 15)) {                                /* I2C_EN */
377
            if (s->revision < OMAP2_INTR_REV)
378
                omap_i2c_reset(s);
379
            break;
380
        }
381
        if ((value & (1 << 15)) && !(value & (1 << 10))) {        /* MST */
382
            fprintf(stderr, "%s: I^2C slave mode not supported\n",
383
                            __FUNCTION__);
384
            break;
385
        }
386
        if ((value & (1 << 15)) && value & (1 << 8)) {                /* XA */
387
            fprintf(stderr, "%s: 10-bit addressing mode not supported\n",
388
                            __FUNCTION__);
389
            break;
390
        }
391
        if ((value & (1 << 15)) && value & (1 << 0)) {                /* STT */
392
            nack = !!i2c_start_transfer(s->bus, s->addr[1],        /* SA */
393
                            (~value >> 9) & 1);                        /* TRX */
394
            s->stat |= nack << 1;                                /* NACK */
395
            s->control &= ~(1 << 0);                                /* STT */
396
            s->fifo = 0;
397
            if (nack)
398
                s->control &= ~(1 << 1);                        /* STP */
399
            else {
400
                s->count_cur = s->count;
401
                omap_i2c_fifo_run(s);
402
            }
403
            omap_i2c_interrupts_update(s);
404
        }
405
        break;
406

    
407
    case 0x28:        /* I2C_OA */
408
        s->addr[0] = value & 0x3ff;
409
        i2c_set_slave_address(&s->slave, value & 0x7f);
410
        break;
411

    
412
    case 0x2c:        /* I2C_SA */
413
        s->addr[1] = value & 0x3ff;
414
        break;
415

    
416
    case 0x30:        /* I2C_PSC */
417
        s->divider = value;
418
        break;
419

    
420
    case 0x34:        /* I2C_SCLL */
421
        s->times[0] = value;
422
        break;
423

    
424
    case 0x38:        /* I2C_SCLH */
425
        s->times[1] = value;
426
        break;
427

    
428
    case 0x3c:        /* I2C_SYSTEST */
429
        s->test = value & 0xf80f;
430
        if (value & (1 << 11))                                        /* SBB */
431
            if (s->revision >= OMAP2_INTR_REV) {
432
                s->stat |= 0x3f;
433
                omap_i2c_interrupts_update(s);
434
            }
435
        if (value & (1 << 15))                                        /* ST_EN */
436
            fprintf(stderr, "%s: System Test not supported\n", __FUNCTION__);
437
        break;
438

    
439
    default:
440
        OMAP_BAD_REG(addr);
441
        return;
442
    }
443
}
444

    
445
static void omap_i2c_writeb(void *opaque, target_phys_addr_t addr,
446
                uint32_t value)
447
{
448
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
449
    int offset = addr & OMAP_MPUI_REG_MASK;
450

    
451
    switch (offset) {
452
    case 0x1c:        /* I2C_DATA */
453
        if (s->txlen > 2) {
454
            /* XXX: remote access (qualifier) error - what's that?  */
455
            break;
456
        }
457
        s->fifo <<= 8;
458
        s->txlen += 1;
459
        s->fifo |= value & 0xff;
460
        s->stat &= ~(1 << 10);                                        /* XUDF */
461
        if (s->txlen > 2)
462
            s->stat &= ~(1 << 4);                                /* XRDY */
463
        omap_i2c_fifo_run(s);
464
        omap_i2c_interrupts_update(s);
465
        break;
466

    
467
    default:
468
        OMAP_BAD_REG(addr);
469
        return;
470
    }
471
}
472

    
473
static CPUReadMemoryFunc *omap_i2c_readfn[] = {
474
    omap_badwidth_read16,
475
    omap_i2c_read,
476
    omap_badwidth_read16,
477
};
478

    
479
static CPUWriteMemoryFunc *omap_i2c_writefn[] = {
480
    omap_i2c_writeb,        /* Only the last fifo write can be 8 bit.  */
481
    omap_i2c_write,
482
    omap_badwidth_write16,
483
};
484

    
485
struct omap_i2c_s *omap_i2c_init(target_phys_addr_t base,
486
                qemu_irq irq, qemu_irq *dma, omap_clk clk)
487
{
488
    int iomemtype;
489
    struct omap_i2c_s *s = (struct omap_i2c_s *)
490
            qemu_mallocz(sizeof(struct omap_i2c_s));
491

    
492
    /* TODO: set a value greater or equal to real hardware */
493
    s->revision = 0x11;
494
    s->irq = irq;
495
    s->drq[0] = dma[0];
496
    s->drq[1] = dma[1];
497
    s->slave.event = omap_i2c_event;
498
    s->slave.recv = omap_i2c_rx;
499
    s->slave.send = omap_i2c_tx;
500
    s->bus = i2c_init_bus();
501
    omap_i2c_reset(s);
502

    
503
    iomemtype = cpu_register_io_memory(0, omap_i2c_readfn,
504
                    omap_i2c_writefn, s);
505
    cpu_register_physical_memory(base, 0x800, iomemtype);
506

    
507
    return s;
508
}
509

    
510
struct omap_i2c_s *omap2_i2c_init(struct omap_target_agent_s *ta,
511
                qemu_irq irq, qemu_irq *dma, omap_clk fclk, omap_clk iclk)
512
{
513
    int iomemtype;
514
    struct omap_i2c_s *s = (struct omap_i2c_s *)
515
            qemu_mallocz(sizeof(struct omap_i2c_s));
516

    
517
    s->revision = 0x34;
518
    s->irq = irq;
519
    s->drq[0] = dma[0];
520
    s->drq[1] = dma[1];
521
    s->slave.event = omap_i2c_event;
522
    s->slave.recv = omap_i2c_rx;
523
    s->slave.send = omap_i2c_tx;
524
    s->bus = i2c_init_bus();
525
    omap_i2c_reset(s);
526

    
527
    iomemtype = l4_register_io_memory(0, omap_i2c_readfn,
528
                    omap_i2c_writefn, s);
529
    omap_l4_attach(ta, 0, iomemtype);
530

    
531
    return s;
532
}
533

    
534
i2c_bus *omap_i2c_bus(struct omap_i2c_s *s)
535
{
536
    return s->bus;
537
}