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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
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 * 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,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * 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, see <http://www.gnu.org/licenses/>.
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 */
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#include "hw/hw.h"
20
#include "hw/i2c/i2c.h"
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#include "hw/arm/omap.h"
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#include "hw/sysbus.h"
23

    
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#define TYPE_OMAP_I2C "omap_i2c"
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#define OMAP_I2C(obj) OBJECT_CHECK(OMAPI2CState, (obj), TYPE_OMAP_I2C)
26

    
27
typedef struct OMAPI2CState {
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    SysBusDevice parent_obj;
29

    
30
    MemoryRegion iomem;
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    qemu_irq irq;
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    qemu_irq drq[2];
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    i2c_bus *bus;
34

    
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    uint8_t revision;
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    void *iclk;
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    void *fclk;
38

    
39
    uint8_t mask;
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    uint16_t stat;
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    uint16_t dma;
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    uint16_t count;
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    int count_cur;
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    uint32_t fifo;
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    int rxlen;
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    int txlen;
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    uint16_t control;
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    uint16_t addr[2];
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    uint8_t divider;
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    uint8_t times[2];
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    uint16_t test;
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} OMAPI2CState;
53

    
54
#define OMAP2_INTR_REV        0x34
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#define OMAP2_GC_REV        0x34
56

    
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static void omap_i2c_interrupts_update(OMAPI2CState *s)
58
{
59
    qemu_set_irq(s->irq, s->stat & s->mask);
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    if ((s->dma >> 15) & 1)                                        /* RDMA_EN */
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        qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);                /* RRDY */
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    if ((s->dma >> 7) & 1)                                        /* XDMA_EN */
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        qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);                /* XRDY */
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}
65

    
66
static void omap_i2c_fifo_run(OMAPI2CState *s)
67
{
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    int ack = 1;
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    if (!i2c_bus_busy(s->bus))
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        return;
72

    
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    if ((s->control >> 2) & 1) {                                /* RM */
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        if ((s->control >> 1) & 1) {                                /* STP */
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            i2c_end_transfer(s->bus);
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            s->control &= ~(1 << 1);                                /* STP */
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            s->count_cur = s->count;
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            s->txlen = 0;
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        } else if ((s->control >> 9) & 1) {                        /* TRX */
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            while (ack && s->txlen)
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                ack = (i2c_send(s->bus,
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                                        (s->fifo >> ((-- s->txlen) << 3)) &
83
                                        0xff) >= 0);
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            s->stat |= 1 << 4;                                        /* XRDY */
85
        } else {
86
            while (s->rxlen < 4)
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                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
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            s->stat |= 1 << 3;                                        /* RRDY */
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        }
90
    } else {
91
        if ((s->control >> 9) & 1) {                                /* TRX */
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            while (ack && s->count_cur && s->txlen) {
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                ack = (i2c_send(s->bus,
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                                        (s->fifo >> ((-- s->txlen) << 3)) &
95
                                        0xff) >= 0);
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                s->count_cur --;
97
            }
98
            if (ack && s->count_cur)
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                s->stat |= 1 << 4;                                /* XRDY */
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            else
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                s->stat &= ~(1 << 4);                                /* XRDY */
102
            if (!s->count_cur) {
103
                s->stat |= 1 << 2;                                /* ARDY */
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                s->control &= ~(1 << 10);                        /* MST */
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            }
106
        } else {
107
            while (s->count_cur && s->rxlen < 4) {
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                s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
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                s->count_cur --;
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            }
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            if (s->rxlen)
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                s->stat |= 1 << 3;                                /* RRDY */
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            else
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                s->stat &= ~(1 << 3);                                /* RRDY */
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        }
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        if (!s->count_cur) {
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            if ((s->control >> 1) & 1) {                        /* STP */
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                i2c_end_transfer(s->bus);
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                s->control &= ~(1 << 1);                        /* STP */
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                s->count_cur = s->count;
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                s->txlen = 0;
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            } else {
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                s->stat |= 1 << 2;                                /* ARDY */
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                s->control &= ~(1 << 10);                        /* MST */
125
            }
126
        }
127
    }
128

    
129
    s->stat |= (!ack) << 1;                                        /* NACK */
130
    if (!ack)
131
        s->control &= ~(1 << 1);                                /* STP */
132
}
133

    
134
static void omap_i2c_reset(DeviceState *dev)
135
{
136
    OMAPI2CState *s = OMAP_I2C(dev);
137

    
138
    s->mask = 0;
139
    s->stat = 0;
140
    s->dma = 0;
141
    s->count = 0;
142
    s->count_cur = 0;
143
    s->fifo = 0;
144
    s->rxlen = 0;
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    s->txlen = 0;
146
    s->control = 0;
147
    s->addr[0] = 0;
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    s->addr[1] = 0;
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    s->divider = 0;
150
    s->times[0] = 0;
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    s->times[1] = 0;
152
    s->test = 0;
153
}
154

    
155
static uint32_t omap_i2c_read(void *opaque, hwaddr addr)
156
{
157
    OMAPI2CState *s = opaque;
158
    int offset = addr & OMAP_MPUI_REG_MASK;
159
    uint16_t ret;
160

    
161
    switch (offset) {
162
    case 0x00:        /* I2C_REV */
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        return s->revision;                                        /* REV */
164

    
165
    case 0x04:        /* I2C_IE */
166
        return s->mask;
167

    
168
    case 0x08:        /* I2C_STAT */
169
        return s->stat | (i2c_bus_busy(s->bus) << 12);
170

    
171
    case 0x0c:        /* I2C_IV */
172
        if (s->revision >= OMAP2_INTR_REV)
173
            break;
174
        ret = ffs(s->stat & s->mask);
175
        if (ret)
176
            s->stat ^= 1 << (ret - 1);
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        omap_i2c_interrupts_update(s);
178
        return ret;
179

    
180
    case 0x10:        /* I2C_SYSS */
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        return (s->control >> 15) & 1;                                /* I2C_EN */
182

    
183
    case 0x14:        /* I2C_BUF */
184
        return s->dma;
185

    
186
    case 0x18:        /* I2C_CNT */
187
        return s->count_cur;                                        /* DCOUNT */
188

    
189
    case 0x1c:        /* I2C_DATA */
190
        ret = 0;
191
        if (s->control & (1 << 14)) {                                /* BE */
192
            ret |= ((s->fifo >> 0) & 0xff) << 8;
193
            ret |= ((s->fifo >> 8) & 0xff) << 0;
194
        } else {
195
            ret |= ((s->fifo >> 8) & 0xff) << 8;
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            ret |= ((s->fifo >> 0) & 0xff) << 0;
197
        }
198
        if (s->rxlen == 1) {
199
            s->stat |= 1 << 15;                                        /* SBD */
200
            s->rxlen = 0;
201
        } else if (s->rxlen > 1) {
202
            if (s->rxlen > 2)
203
                s->fifo >>= 16;
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            s->rxlen -= 2;
205
        } else {
206
            /* XXX: remote access (qualifier) error - what's that?  */
207
        }
208
        if (!s->rxlen) {
209
            s->stat &= ~(1 << 3);                                /* RRDY */
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            if (((s->control >> 10) & 1) &&                        /* MST */
211
                            ((~s->control >> 9) & 1)) {                /* TRX */
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                s->stat |= 1 << 2;                                /* ARDY */
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                s->control &= ~(1 << 10);                        /* MST */
214
            }
215
        }
216
        s->stat &= ~(1 << 11);                                        /* ROVR */
217
        omap_i2c_fifo_run(s);
218
        omap_i2c_interrupts_update(s);
219
        return ret;
220

    
221
    case 0x20:        /* I2C_SYSC */
222
        return 0;
223

    
224
    case 0x24:        /* I2C_CON */
225
        return s->control;
226

    
227
    case 0x28:        /* I2C_OA */
228
        return s->addr[0];
229

    
230
    case 0x2c:        /* I2C_SA */
231
        return s->addr[1];
232

    
233
    case 0x30:        /* I2C_PSC */
234
        return s->divider;
235

    
236
    case 0x34:        /* I2C_SCLL */
237
        return s->times[0];
238

    
239
    case 0x38:        /* I2C_SCLH */
240
        return s->times[1];
241

    
242
    case 0x3c:        /* I2C_SYSTEST */
243
        if (s->test & (1 << 15)) {                                /* ST_EN */
244
            s->test ^= 0xa;
245
            return s->test;
246
        } else
247
            return s->test & ~0x300f;
248
    }
249

    
250
    OMAP_BAD_REG(addr);
251
    return 0;
252
}
253

    
254
static void omap_i2c_write(void *opaque, hwaddr addr,
255
                uint32_t value)
256
{
257
    OMAPI2CState *s = opaque;
258
    int offset = addr & OMAP_MPUI_REG_MASK;
259
    int nack;
260

    
261
    switch (offset) {
262
    case 0x00:        /* I2C_REV */
263
    case 0x0c:        /* I2C_IV */
264
    case 0x10:        /* I2C_SYSS */
265
        OMAP_RO_REG(addr);
266
        return;
267

    
268
    case 0x04:        /* I2C_IE */
269
        s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
270
        break;
271

    
272
    case 0x08:        /* I2C_STAT */
273
        if (s->revision < OMAP2_INTR_REV) {
274
            OMAP_RO_REG(addr);
275
            return;
276
        }
277

    
278
        /* RRDY and XRDY are reset by hardware. (in all versions???) */
279
        s->stat &= ~(value & 0x27);
280
        omap_i2c_interrupts_update(s);
281
        break;
282

    
283
    case 0x14:        /* I2C_BUF */
284
        s->dma = value & 0x8080;
285
        if (value & (1 << 15))                                        /* RDMA_EN */
286
            s->mask &= ~(1 << 3);                                /* RRDY_IE */
287
        if (value & (1 << 7))                                        /* XDMA_EN */
288
            s->mask &= ~(1 << 4);                                /* XRDY_IE */
289
        break;
290

    
291
    case 0x18:        /* I2C_CNT */
292
        s->count = value;                                        /* DCOUNT */
293
        break;
294

    
295
    case 0x1c:        /* I2C_DATA */
296
        if (s->txlen > 2) {
297
            /* XXX: remote access (qualifier) error - what's that?  */
298
            break;
299
        }
300
        s->fifo <<= 16;
301
        s->txlen += 2;
302
        if (s->control & (1 << 14)) {                                /* BE */
303
            s->fifo |= ((value >> 8) & 0xff) << 8;
304
            s->fifo |= ((value >> 0) & 0xff) << 0;
305
        } else {
306
            s->fifo |= ((value >> 0) & 0xff) << 8;
307
            s->fifo |= ((value >> 8) & 0xff) << 0;
308
        }
309
        s->stat &= ~(1 << 10);                                        /* XUDF */
310
        if (s->txlen > 2)
311
            s->stat &= ~(1 << 4);                                /* XRDY */
312
        omap_i2c_fifo_run(s);
313
        omap_i2c_interrupts_update(s);
314
        break;
315

    
316
    case 0x20:        /* I2C_SYSC */
317
        if (s->revision < OMAP2_INTR_REV) {
318
            OMAP_BAD_REG(addr);
319
            return;
320
        }
321

    
322
        if (value & 2) {
323
            omap_i2c_reset(DEVICE(s));
324
        }
325
        break;
326

    
327
    case 0x24:        /* I2C_CON */
328
        s->control = value & 0xcf87;
329
        if (~value & (1 << 15)) {                                /* I2C_EN */
330
            if (s->revision < OMAP2_INTR_REV) {
331
                omap_i2c_reset(DEVICE(s));
332
            }
333
            break;
334
        }
335
        if ((value & (1 << 15)) && !(value & (1 << 10))) {        /* MST */
336
            fprintf(stderr, "%s: I^2C slave mode not supported\n",
337
                            __FUNCTION__);
338
            break;
339
        }
340
        if ((value & (1 << 15)) && value & (1 << 8)) {                /* XA */
341
            fprintf(stderr, "%s: 10-bit addressing mode not supported\n",
342
                            __FUNCTION__);
343
            break;
344
        }
345
        if ((value & (1 << 15)) && value & (1 << 0)) {                /* STT */
346
            nack = !!i2c_start_transfer(s->bus, s->addr[1],        /* SA */
347
                            (~value >> 9) & 1);                        /* TRX */
348
            s->stat |= nack << 1;                                /* NACK */
349
            s->control &= ~(1 << 0);                                /* STT */
350
            s->fifo = 0;
351
            if (nack)
352
                s->control &= ~(1 << 1);                        /* STP */
353
            else {
354
                s->count_cur = s->count;
355
                omap_i2c_fifo_run(s);
356
            }
357
            omap_i2c_interrupts_update(s);
358
        }
359
        break;
360

    
361
    case 0x28:        /* I2C_OA */
362
        s->addr[0] = value & 0x3ff;
363
        break;
364

    
365
    case 0x2c:        /* I2C_SA */
366
        s->addr[1] = value & 0x3ff;
367
        break;
368

    
369
    case 0x30:        /* I2C_PSC */
370
        s->divider = value;
371
        break;
372

    
373
    case 0x34:        /* I2C_SCLL */
374
        s->times[0] = value;
375
        break;
376

    
377
    case 0x38:        /* I2C_SCLH */
378
        s->times[1] = value;
379
        break;
380

    
381
    case 0x3c:        /* I2C_SYSTEST */
382
        s->test = value & 0xf80f;
383
        if (value & (1 << 11))                                        /* SBB */
384
            if (s->revision >= OMAP2_INTR_REV) {
385
                s->stat |= 0x3f;
386
                omap_i2c_interrupts_update(s);
387
            }
388
        if (value & (1 << 15))                                        /* ST_EN */
389
            fprintf(stderr, "%s: System Test not supported\n", __FUNCTION__);
390
        break;
391

    
392
    default:
393
        OMAP_BAD_REG(addr);
394
        return;
395
    }
396
}
397

    
398
static void omap_i2c_writeb(void *opaque, hwaddr addr,
399
                uint32_t value)
400
{
401
    OMAPI2CState *s = opaque;
402
    int offset = addr & OMAP_MPUI_REG_MASK;
403

    
404
    switch (offset) {
405
    case 0x1c:        /* I2C_DATA */
406
        if (s->txlen > 2) {
407
            /* XXX: remote access (qualifier) error - what's that?  */
408
            break;
409
        }
410
        s->fifo <<= 8;
411
        s->txlen += 1;
412
        s->fifo |= value & 0xff;
413
        s->stat &= ~(1 << 10);                                        /* XUDF */
414
        if (s->txlen > 2)
415
            s->stat &= ~(1 << 4);                                /* XRDY */
416
        omap_i2c_fifo_run(s);
417
        omap_i2c_interrupts_update(s);
418
        break;
419

    
420
    default:
421
        OMAP_BAD_REG(addr);
422
        return;
423
    }
424
}
425

    
426
static const MemoryRegionOps omap_i2c_ops = {
427
    .old_mmio = {
428
        .read = {
429
            omap_badwidth_read16,
430
            omap_i2c_read,
431
            omap_badwidth_read16,
432
        },
433
        .write = {
434
            omap_i2c_writeb, /* Only the last fifo write can be 8 bit.  */
435
            omap_i2c_write,
436
            omap_badwidth_write16,
437
        },
438
    },
439
    .endianness = DEVICE_NATIVE_ENDIAN,
440
};
441

    
442
static int omap_i2c_init(SysBusDevice *sbd)
443
{
444
    DeviceState *dev = DEVICE(sbd);
445
    OMAPI2CState *s = OMAP_I2C(dev);
446

    
447
    if (!s->fclk) {
448
        hw_error("omap_i2c: fclk not connected\n");
449
    }
450
    if (s->revision >= OMAP2_INTR_REV && !s->iclk) {
451
        /* Note that OMAP1 doesn't have a separate interface clock */
452
        hw_error("omap_i2c: iclk not connected\n");
453
    }
454
    sysbus_init_irq(sbd, &s->irq);
455
    sysbus_init_irq(sbd, &s->drq[0]);
456
    sysbus_init_irq(sbd, &s->drq[1]);
457
    memory_region_init_io(&s->iomem, OBJECT(s), &omap_i2c_ops, s, "omap.i2c",
458
                          (s->revision < OMAP2_INTR_REV) ? 0x800 : 0x1000);
459
    sysbus_init_mmio(sbd, &s->iomem);
460
    s->bus = i2c_init_bus(dev, NULL);
461
    return 0;
462
}
463

    
464
static Property omap_i2c_properties[] = {
465
    DEFINE_PROP_UINT8("revision", OMAPI2CState, revision, 0),
466
    DEFINE_PROP_PTR("iclk", OMAPI2CState, iclk),
467
    DEFINE_PROP_PTR("fclk", OMAPI2CState, fclk),
468
    DEFINE_PROP_END_OF_LIST(),
469
};
470

    
471
static void omap_i2c_class_init(ObjectClass *klass, void *data)
472
{
473
    DeviceClass *dc = DEVICE_CLASS(klass);
474
    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
475
    k->init = omap_i2c_init;
476
    dc->props = omap_i2c_properties;
477
    dc->reset = omap_i2c_reset;
478
    /* Reason: pointer properties "iclk", "fclk" */
479
    dc->cannot_instantiate_with_device_add_yet = true;
480
}
481

    
482
static const TypeInfo omap_i2c_info = {
483
    .name = TYPE_OMAP_I2C,
484
    .parent = TYPE_SYS_BUS_DEVICE,
485
    .instance_size = sizeof(OMAPI2CState),
486
    .class_init = omap_i2c_class_init,
487
};
488

    
489
static void omap_i2c_register_types(void)
490
{
491
    type_register_static(&omap_i2c_info);
492
}
493

    
494
i2c_bus *omap_i2c_bus(DeviceState *omap_i2c)
495
{
496
    OMAPI2CState *s = OMAP_I2C(omap_i2c);
497
    return s->bus;
498
}
499

    
500
type_init(omap_i2c_register_types)