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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
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 * published by the Free Software Foundation; either version 2 of
9
 * the License, or (at your option) any later version.
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 *
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 * 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
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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 * MA 02111-1307 USA
20
 */
21
#include "hw.h"
22
#include "i2c.h"
23
#include "omap.h"
24

    
25
struct omap_i2c_s {
26
    target_phys_addr_t base;
27
    qemu_irq irq;
28
    qemu_irq drq[2];
29
    i2c_slave slave;
30
    i2c_bus *bus;
31

    
32
    uint8_t revision;
33
    uint8_t mask;
34
    uint16_t stat;
35
    uint16_t dma;
36
    uint16_t count;
37
    int count_cur;
38
    uint32_t fifo;
39
    int rxlen;
40
    int txlen;
41
    uint16_t control;
42
    uint16_t addr[2];
43
    uint8_t divider;
44
    uint8_t times[2];
45
    uint16_t test;
46
};
47

    
48
#define OMAP2_INTR_REV        0x34
49
#define OMAP2_GC_REV        0x34
50

    
51
static void omap_i2c_interrupts_update(struct omap_i2c_s *s)
52
{
53
    qemu_set_irq(s->irq, s->stat & s->mask);
54
    if ((s->dma >> 15) & 1)                                        /* RDMA_EN */
55
        qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);                /* RRDY */
56
    if ((s->dma >> 7) & 1)                                        /* XDMA_EN */
57
        qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);                /* XRDY */
58
}
59

    
60
/* These are only stubs now.  */
61
static void omap_i2c_event(i2c_slave *i2c, enum i2c_event event)
62
{
63
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
64

    
65
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
66
        return;
67

    
68
    switch (event) {
69
    case I2C_START_SEND:
70
    case I2C_START_RECV:
71
        s->stat |= 1 << 9;                                        /* AAS */
72
        break;
73
    case I2C_FINISH:
74
        s->stat |= 1 << 2;                                        /* ARDY */
75
        break;
76
    case I2C_NACK:
77
        s->stat |= 1 << 1;                                        /* NACK */
78
        break;
79
    }
80

    
81
    omap_i2c_interrupts_update(s);
82
}
83

    
84
static int omap_i2c_rx(i2c_slave *i2c)
85
{
86
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
87
    uint8_t ret = 0;
88

    
89
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
90
        return -1;
91

    
92
    if (s->txlen)
93
        ret = s->fifo >> ((-- s->txlen) << 3) & 0xff;
94
    else
95
        s->stat |= 1 << 10;                                        /* XUDF */
96
    s->stat |= 1 << 4;                                                /* XRDY */
97

    
98
    omap_i2c_interrupts_update(s);
99
    return ret;
100
}
101

    
102
static int omap_i2c_tx(i2c_slave *i2c, uint8_t data)
103
{
104
    struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
105

    
106
    if ((~s->control >> 15) & 1)                                /* I2C_EN */
107
        return 1;
108

    
109
    if (s->rxlen < 4)
110
        s->fifo |= data << ((s->rxlen ++) << 3);
111
    else
112
        s->stat |= 1 << 11;                                        /* ROVR */
113
    s->stat |= 1 << 3;                                                /* RRDY */
114

    
115
    omap_i2c_interrupts_update(s);
116
    return 1;
117
}
118

    
119
static void omap_i2c_fifo_run(struct omap_i2c_s *s)
120
{
121
    int ack = 1;
122

    
123
    if (!i2c_bus_busy(s->bus))
124
        return;
125

    
126
    if ((s->control >> 2) & 1) {                                /* RM */
127
        if ((s->control >> 1) & 1) {                                /* STP */
128
            i2c_end_transfer(s->bus);
129
            s->control &= ~(1 << 1);                                /* STP */
130
            s->count_cur = s->count;
131
            s->txlen = 0;
132
        } else if ((s->control >> 9) & 1) {                        /* TRX */
133
            while (ack && s->txlen)
134
                ack = (i2c_send(s->bus,
135
                                        (s->fifo >> ((-- s->txlen) << 3)) &
136
                                        0xff) >= 0);
137
            s->stat |= 1 << 4;                                        /* XRDY */
138
        } else {
139
            while (s->rxlen < 4)
140
                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
141
            s->stat |= 1 << 3;                                        /* RRDY */
142
        }
143
    } else {
144
        if ((s->control >> 9) & 1) {                                /* TRX */
145
            while (ack && s->count_cur && s->txlen) {
146
                ack = (i2c_send(s->bus,
147
                                        (s->fifo >> ((-- s->txlen) << 3)) &
148
                                        0xff) >= 0);
149
                s->count_cur --;
150
            }
151
            if (ack && s->count_cur)
152
                s->stat |= 1 << 4;                                /* XRDY */
153
            else
154
                s->stat &= ~(1 << 4);                                /* XRDY */
155
            if (!s->count_cur) {
156
                s->stat |= 1 << 2;                                /* ARDY */
157
                s->control &= ~(1 << 10);                        /* MST */
158
            }
159
        } else {
160
            while (s->count_cur && s->rxlen < 4) {
161
                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
162
                s->count_cur --;
163
            }
164
            if (s->rxlen)
165
                s->stat |= 1 << 3;                                /* RRDY */
166
            else
167
                s->stat &= ~(1 << 3);                                /* RRDY */
168
        }
169
        if (!s->count_cur) {
170
            if ((s->control >> 1) & 1) {                        /* STP */
171
                i2c_end_transfer(s->bus);
172
                s->control &= ~(1 << 1);                        /* STP */
173
                s->count_cur = s->count;
174
                s->txlen = 0;
175
            } else {
176
                s->stat |= 1 << 2;                                /* ARDY */
177
                s->control &= ~(1 << 10);                        /* MST */
178
            }
179
        }
180
    }
181

    
182
    s->stat |= (!ack) << 1;                                        /* NACK */
183
    if (!ack)
184
        s->control &= ~(1 << 1);                                /* STP */
185
}
186

    
187
void omap_i2c_reset(struct omap_i2c_s *s)
188
{
189
    s->mask = 0;
190
    s->stat = 0;
191
    s->dma = 0;
192
    s->count = 0;
193
    s->count_cur = 0;
194
    s->fifo = 0;
195
    s->rxlen = 0;
196
    s->txlen = 0;
197
    s->control = 0;
198
    s->addr[0] = 0;
199
    s->addr[1] = 0;
200
    s->divider = 0;
201
    s->times[0] = 0;
202
    s->times[1] = 0;
203
    s->test = 0;
204
}
205

    
206
static uint32_t omap_i2c_read(void *opaque, target_phys_addr_t addr)
207
{
208
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
209
    int offset = addr & OMAP_MPUI_REG_MASK;
210
    uint16_t ret;
211

    
212
    switch (offset) {
213
    case 0x00:        /* I2C_REV */
214
        return s->revision;                                        /* REV */
215

    
216
    case 0x04:        /* I2C_IE */
217
        return s->mask;
218

    
219
    case 0x08:        /* I2C_STAT */
220
        return s->stat | (i2c_bus_busy(s->bus) << 12);
221

    
222
    case 0x0c:        /* I2C_IV */
223
        if (s->revision >= OMAP2_INTR_REV)
224
            break;
225
        ret = ffs(s->stat & s->mask);
226
        if (ret)
227
            s->stat ^= 1 << (ret - 1);
228
        omap_i2c_interrupts_update(s);
229
        return ret;
230

    
231
    case 0x10:        /* I2C_SYSS */
232
        return (s->control >> 15) & 1;                                /* I2C_EN */
233

    
234
    case 0x14:        /* I2C_BUF */
235
        return s->dma;
236

    
237
    case 0x18:        /* I2C_CNT */
238
        return s->count_cur;                                        /* DCOUNT */
239

    
240
    case 0x1c:        /* I2C_DATA */
241
        ret = 0;
242
        if (s->control & (1 << 14)) {                                /* BE */
243
            ret |= ((s->fifo >> 0) & 0xff) << 8;
244
            ret |= ((s->fifo >> 8) & 0xff) << 0;
245
        } else {
246
            ret |= ((s->fifo >> 8) & 0xff) << 8;
247
            ret |= ((s->fifo >> 0) & 0xff) << 0;
248
        }
249
        if (s->rxlen == 1) {
250
            s->stat |= 1 << 15;                                        /* SBD */
251
            s->rxlen = 0;
252
        } else if (s->rxlen > 1) {
253
            if (s->rxlen > 2)
254
                s->fifo >>= 16;
255
            s->rxlen -= 2;
256
        } else
257
            /* XXX: remote access (qualifier) error - what's that?  */;
258
        if (!s->rxlen) {
259
            s->stat &= ~(1 << 3);                                /* RRDY */
260
            if (((s->control >> 10) & 1) &&                        /* MST */
261
                            ((~s->control >> 9) & 1)) {                /* TRX */
262
                s->stat |= 1 << 2;                                /* ARDY */
263
                s->control &= ~(1 << 10);                        /* MST */
264
            }
265
        }
266
        s->stat &= ~(1 << 11);                                        /* ROVR */
267
        omap_i2c_fifo_run(s);
268
        omap_i2c_interrupts_update(s);
269
        return ret;
270

    
271
    case 0x20:        /* I2C_SYSC */
272
        return 0;
273

    
274
    case 0x24:        /* I2C_CON */
275
        return s->control;
276

    
277
    case 0x28:        /* I2C_OA */
278
        return s->addr[0];
279

    
280
    case 0x2c:        /* I2C_SA */
281
        return s->addr[1];
282

    
283
    case 0x30:        /* I2C_PSC */
284
        return s->divider;
285

    
286
    case 0x34:        /* I2C_SCLL */
287
        return s->times[0];
288

    
289
    case 0x38:        /* I2C_SCLH */
290
        return s->times[1];
291

    
292
    case 0x3c:        /* I2C_SYSTEST */
293
        if (s->test & (1 << 15)) {                                /* ST_EN */
294
            s->test ^= 0xa;
295
            return s->test;
296
        } else
297
            return s->test & ~0x300f;
298
    }
299

    
300
    OMAP_BAD_REG(addr);
301
    return 0;
302
}
303

    
304
static void omap_i2c_write(void *opaque, target_phys_addr_t addr,
305
                uint32_t value)
306
{
307
    struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
308
    int offset = addr & OMAP_MPUI_REG_MASK;
309
    int nack;
310

    
311
    switch (offset) {
312
    case 0x00:        /* I2C_REV */
313
    case 0x0c:        /* I2C_IV */
314
    case 0x10:        /* I2C_SYSS */
315
        OMAP_RO_REG(addr);
316
        return;
317

    
318
    case 0x04:        /* I2C_IE */
319
        s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
320
        break;
321

    
322
    case 0x08:        /* I2C_STAT */
323
        if (s->revision < OMAP2_INTR_REV) {
324
            OMAP_RO_REG(addr);
325
            return;
326
        }
327

    
328
        /* RRDY and XRDY are reset by hardware. (in all versions???) */
329
        s->stat &= ~(value & 0x27);
330
        omap_i2c_interrupts_update(s);
331
        break;
332

    
333
    case 0x14:        /* I2C_BUF */
334
        s->dma = value & 0x8080;
335
        if (value & (1 << 15))                                        /* RDMA_EN */
336
            s->mask &= ~(1 << 3);                                /* RRDY_IE */
337
        if (value & (1 << 7))                                        /* XDMA_EN */
338
            s->mask &= ~(1 << 4);                                /* XRDY_IE */
339
        break;
340

    
341
    case 0x18:        /* I2C_CNT */
342
        s->count = value;                                        /* DCOUNT */
343
        break;
344

    
345
    case 0x1c:        /* I2C_DATA */
346
        if (s->txlen > 2) {
347
            /* XXX: remote access (qualifier) error - what's that?  */
348
            break;
349
        }
350
        s->fifo <<= 16;
351
        s->txlen += 2;
352
        if (s->control & (1 << 14)) {                                /* BE */
353
            s->fifo |= ((value >> 8) & 0xff) << 8;
354
            s->fifo |= ((value >> 0) & 0xff) << 0;
355
        } else {
356
            s->fifo |= ((value >> 0) & 0xff) << 8;
357
            s->fifo |= ((value >> 8) & 0xff) << 0;
358
        }
359
        s->stat &= ~(1 << 10);                                        /* XUDF */
360
        if (s->txlen > 2)
361
            s->stat &= ~(1 << 4);                                /* XRDY */
362
        omap_i2c_fifo_run(s);
363
        omap_i2c_interrupts_update(s);
364
        break;
365

    
366
    case 0x20:        /* I2C_SYSC */
367
        if (s->revision < OMAP2_INTR_REV) {
368
            OMAP_BAD_REG(addr);
369
            return;
370
        }
371

    
372
        if (value & 2)
373
            omap_i2c_reset(s);
374
        break;
375

    
376
    case 0x24:        /* I2C_CON */
377
        s->control = value & 0xcf87;
378
        if (~value & (1 << 15)) {                                /* I2C_EN */
379
            if (s->revision < OMAP2_INTR_REV)
380
                omap_i2c_reset(s);
381
            break;
382
        }
383
        if ((value & (1 << 15)) && !(value & (1 << 10))) {        /* MST */
384
            fprintf(stderr, "%s: I^2C slave mode not supported\n",
385
                            __FUNCTION__);
386
            break;
387
        }
388
        if ((value & (1 << 15)) && value & (1 << 8)) {                /* XA */
389
            fprintf(stderr, "%s: 10-bit addressing mode not supported\n",
390
                            __FUNCTION__);
391
            break;
392
        }
393
        if ((value & (1 << 15)) && value & (1 << 0)) {                /* STT */
394
            nack = !!i2c_start_transfer(s->bus, s->addr[1],        /* SA */
395
                            (~value >> 9) & 1);                        /* TRX */
396
            s->stat |= nack << 1;                                /* NACK */
397
            s->control &= ~(1 << 0);                                /* STT */
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->base = base;
496
    s->irq = irq;
497
    s->drq[0] = dma[0];
498
    s->drq[1] = dma[1];
499
    s->slave.event = omap_i2c_event;
500
    s->slave.recv = omap_i2c_rx;
501
    s->slave.send = omap_i2c_tx;
502
    s->bus = i2c_init_bus();
503
    omap_i2c_reset(s);
504

    
505
    iomemtype = cpu_register_io_memory(0, omap_i2c_readfn,
506
                    omap_i2c_writefn, s);
507
    cpu_register_physical_memory(s->base, 0x800, iomemtype);
508

    
509
    return s;
510
}
511

    
512
struct omap_i2c_s *omap2_i2c_init(struct omap_target_agent_s *ta,
513
                qemu_irq irq, qemu_irq *dma, omap_clk fclk, omap_clk iclk)
514
{
515
    int iomemtype;
516
    struct omap_i2c_s *s = (struct omap_i2c_s *)
517
            qemu_mallocz(sizeof(struct omap_i2c_s));
518

    
519
    s->revision = 0x34;
520
    s->irq = irq;
521
    s->drq[0] = dma[0];
522
    s->drq[1] = dma[1];
523
    s->slave.event = omap_i2c_event;
524
    s->slave.recv = omap_i2c_rx;
525
    s->slave.send = omap_i2c_tx;
526
    s->bus = i2c_init_bus();
527
    omap_i2c_reset(s);
528

    
529
    iomemtype = cpu_register_io_memory(0, omap_i2c_readfn,
530
                    omap_i2c_writefn, s);
531
    s->base = omap_l4_attach(ta, 0, iomemtype);
532

    
533
    return s;
534
}
535

    
536
i2c_bus *omap_i2c_bus(struct omap_i2c_s *s)
537
{
538
    return s->bus;
539
}