xref: /openbmc/qemu/hw/sd/pl181.c (revision 135b03cb)
1 /*
2  * Arm PrimeCell PL181 MultiMedia Card Interface
3  *
4  * Copyright (c) 2007 CodeSourcery.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the GPL.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "sysemu/blockdev.h"
12 #include "hw/sysbus.h"
13 #include "migration/vmstate.h"
14 #include "hw/irq.h"
15 #include "hw/sd/sd.h"
16 #include "qemu/log.h"
17 #include "qemu/module.h"
18 #include "qapi/error.h"
19 
20 //#define DEBUG_PL181 1
21 
22 #ifdef DEBUG_PL181
23 #define DPRINTF(fmt, ...) \
24 do { printf("pl181: " fmt , ## __VA_ARGS__); } while (0)
25 #else
26 #define DPRINTF(fmt, ...) do {} while(0)
27 #endif
28 
29 #define PL181_FIFO_LEN 16
30 
31 #define TYPE_PL181 "pl181"
32 #define PL181(obj) OBJECT_CHECK(PL181State, (obj), TYPE_PL181)
33 
34 typedef struct PL181State {
35     SysBusDevice parent_obj;
36 
37     MemoryRegion iomem;
38     SDState *card;
39     uint32_t clock;
40     uint32_t power;
41     uint32_t cmdarg;
42     uint32_t cmd;
43     uint32_t datatimer;
44     uint32_t datalength;
45     uint32_t respcmd;
46     uint32_t response[4];
47     uint32_t datactrl;
48     uint32_t datacnt;
49     uint32_t status;
50     uint32_t mask[2];
51     int32_t fifo_pos;
52     int32_t fifo_len;
53     /* The linux 2.6.21 driver is buggy, and misbehaves if new data arrives
54        while it is reading the FIFO.  We hack around this by deferring
55        subsequent transfers until after the driver polls the status word.
56        http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=4446/1
57      */
58     int32_t linux_hack;
59     uint32_t fifo[PL181_FIFO_LEN];
60     qemu_irq irq[2];
61     /* GPIO outputs for 'card is readonly' and 'card inserted' */
62     qemu_irq cardstatus[2];
63 } PL181State;
64 
65 static const VMStateDescription vmstate_pl181 = {
66     .name = "pl181",
67     .version_id = 1,
68     .minimum_version_id = 1,
69     .fields = (VMStateField[]) {
70         VMSTATE_UINT32(clock, PL181State),
71         VMSTATE_UINT32(power, PL181State),
72         VMSTATE_UINT32(cmdarg, PL181State),
73         VMSTATE_UINT32(cmd, PL181State),
74         VMSTATE_UINT32(datatimer, PL181State),
75         VMSTATE_UINT32(datalength, PL181State),
76         VMSTATE_UINT32(respcmd, PL181State),
77         VMSTATE_UINT32_ARRAY(response, PL181State, 4),
78         VMSTATE_UINT32(datactrl, PL181State),
79         VMSTATE_UINT32(datacnt, PL181State),
80         VMSTATE_UINT32(status, PL181State),
81         VMSTATE_UINT32_ARRAY(mask, PL181State, 2),
82         VMSTATE_INT32(fifo_pos, PL181State),
83         VMSTATE_INT32(fifo_len, PL181State),
84         VMSTATE_INT32(linux_hack, PL181State),
85         VMSTATE_UINT32_ARRAY(fifo, PL181State, PL181_FIFO_LEN),
86         VMSTATE_END_OF_LIST()
87     }
88 };
89 
90 #define PL181_CMD_INDEX     0x3f
91 #define PL181_CMD_RESPONSE  (1 << 6)
92 #define PL181_CMD_LONGRESP  (1 << 7)
93 #define PL181_CMD_INTERRUPT (1 << 8)
94 #define PL181_CMD_PENDING   (1 << 9)
95 #define PL181_CMD_ENABLE    (1 << 10)
96 
97 #define PL181_DATA_ENABLE             (1 << 0)
98 #define PL181_DATA_DIRECTION          (1 << 1)
99 #define PL181_DATA_MODE               (1 << 2)
100 #define PL181_DATA_DMAENABLE          (1 << 3)
101 
102 #define PL181_STATUS_CMDCRCFAIL       (1 << 0)
103 #define PL181_STATUS_DATACRCFAIL      (1 << 1)
104 #define PL181_STATUS_CMDTIMEOUT       (1 << 2)
105 #define PL181_STATUS_DATATIMEOUT      (1 << 3)
106 #define PL181_STATUS_TXUNDERRUN       (1 << 4)
107 #define PL181_STATUS_RXOVERRUN        (1 << 5)
108 #define PL181_STATUS_CMDRESPEND       (1 << 6)
109 #define PL181_STATUS_CMDSENT          (1 << 7)
110 #define PL181_STATUS_DATAEND          (1 << 8)
111 #define PL181_STATUS_DATABLOCKEND     (1 << 10)
112 #define PL181_STATUS_CMDACTIVE        (1 << 11)
113 #define PL181_STATUS_TXACTIVE         (1 << 12)
114 #define PL181_STATUS_RXACTIVE         (1 << 13)
115 #define PL181_STATUS_TXFIFOHALFEMPTY  (1 << 14)
116 #define PL181_STATUS_RXFIFOHALFFULL   (1 << 15)
117 #define PL181_STATUS_TXFIFOFULL       (1 << 16)
118 #define PL181_STATUS_RXFIFOFULL       (1 << 17)
119 #define PL181_STATUS_TXFIFOEMPTY      (1 << 18)
120 #define PL181_STATUS_RXFIFOEMPTY      (1 << 19)
121 #define PL181_STATUS_TXDATAAVLBL      (1 << 20)
122 #define PL181_STATUS_RXDATAAVLBL      (1 << 21)
123 
124 #define PL181_STATUS_TX_FIFO (PL181_STATUS_TXACTIVE \
125                              |PL181_STATUS_TXFIFOHALFEMPTY \
126                              |PL181_STATUS_TXFIFOFULL \
127                              |PL181_STATUS_TXFIFOEMPTY \
128                              |PL181_STATUS_TXDATAAVLBL)
129 #define PL181_STATUS_RX_FIFO (PL181_STATUS_RXACTIVE \
130                              |PL181_STATUS_RXFIFOHALFFULL \
131                              |PL181_STATUS_RXFIFOFULL \
132                              |PL181_STATUS_RXFIFOEMPTY \
133                              |PL181_STATUS_RXDATAAVLBL)
134 
135 static const unsigned char pl181_id[] =
136 { 0x81, 0x11, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
137 
138 static void pl181_update(PL181State *s)
139 {
140     int i;
141     for (i = 0; i < 2; i++) {
142         qemu_set_irq(s->irq[i], (s->status & s->mask[i]) != 0);
143     }
144 }
145 
146 static void pl181_fifo_push(PL181State *s, uint32_t value)
147 {
148     int n;
149 
150     if (s->fifo_len == PL181_FIFO_LEN) {
151         fprintf(stderr, "pl181: FIFO overflow\n");
152         return;
153     }
154     n = (s->fifo_pos + s->fifo_len) & (PL181_FIFO_LEN - 1);
155     s->fifo_len++;
156     s->fifo[n] = value;
157     DPRINTF("FIFO push %08x\n", (int)value);
158 }
159 
160 static uint32_t pl181_fifo_pop(PL181State *s)
161 {
162     uint32_t value;
163 
164     if (s->fifo_len == 0) {
165         fprintf(stderr, "pl181: FIFO underflow\n");
166         return 0;
167     }
168     value = s->fifo[s->fifo_pos];
169     s->fifo_len--;
170     s->fifo_pos = (s->fifo_pos + 1) & (PL181_FIFO_LEN - 1);
171     DPRINTF("FIFO pop %08x\n", (int)value);
172     return value;
173 }
174 
175 static void pl181_send_command(PL181State *s)
176 {
177     SDRequest request;
178     uint8_t response[16];
179     int rlen;
180 
181     request.cmd = s->cmd & PL181_CMD_INDEX;
182     request.arg = s->cmdarg;
183     DPRINTF("Command %d %08x\n", request.cmd, request.arg);
184     rlen = sd_do_command(s->card, &request, response);
185     if (rlen < 0)
186         goto error;
187     if (s->cmd & PL181_CMD_RESPONSE) {
188         if (rlen == 0 || (rlen == 4 && (s->cmd & PL181_CMD_LONGRESP)))
189             goto error;
190         if (rlen != 4 && rlen != 16)
191             goto error;
192         s->response[0] = ldl_be_p(&response[0]);
193         if (rlen == 4) {
194             s->response[1] = s->response[2] = s->response[3] = 0;
195         } else {
196             s->response[1] = ldl_be_p(&response[4]);
197             s->response[2] = ldl_be_p(&response[8]);
198             s->response[3] = ldl_be_p(&response[12]) & ~1;
199         }
200         DPRINTF("Response received\n");
201         s->status |= PL181_STATUS_CMDRESPEND;
202     } else {
203         DPRINTF("Command sent\n");
204         s->status |= PL181_STATUS_CMDSENT;
205     }
206     return;
207 
208 error:
209     DPRINTF("Timeout\n");
210     s->status |= PL181_STATUS_CMDTIMEOUT;
211 }
212 
213 /* Transfer data between the card and the FIFO.  This is complicated by
214    the FIFO holding 32-bit words and the card taking data in single byte
215    chunks.  FIFO bytes are transferred in little-endian order.  */
216 
217 static void pl181_fifo_run(PL181State *s)
218 {
219     uint32_t bits;
220     uint32_t value = 0;
221     int n;
222     int is_read;
223 
224     is_read = (s->datactrl & PL181_DATA_DIRECTION) != 0;
225     if (s->datacnt != 0 && (!is_read || sd_data_ready(s->card))
226             && !s->linux_hack) {
227         if (is_read) {
228             n = 0;
229             while (s->datacnt && s->fifo_len < PL181_FIFO_LEN) {
230                 value |= (uint32_t)sd_read_data(s->card) << (n * 8);
231                 s->datacnt--;
232                 n++;
233                 if (n == 4) {
234                     pl181_fifo_push(s, value);
235                     n = 0;
236                     value = 0;
237                 }
238             }
239             if (n != 0) {
240                 pl181_fifo_push(s, value);
241             }
242         } else { /* write */
243             n = 0;
244             while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
245                 if (n == 0) {
246                     value = pl181_fifo_pop(s);
247                     n = 4;
248                 }
249                 n--;
250                 s->datacnt--;
251                 sd_write_data(s->card, value & 0xff);
252                 value >>= 8;
253             }
254         }
255     }
256     s->status &= ~(PL181_STATUS_RX_FIFO | PL181_STATUS_TX_FIFO);
257     if (s->datacnt == 0) {
258         s->status |= PL181_STATUS_DATAEND;
259         /* HACK: */
260         s->status |= PL181_STATUS_DATABLOCKEND;
261         DPRINTF("Transfer Complete\n");
262     }
263     if (s->datacnt == 0 && s->fifo_len == 0) {
264         s->datactrl &= ~PL181_DATA_ENABLE;
265         DPRINTF("Data engine idle\n");
266     } else {
267         /* Update FIFO bits.  */
268         bits = PL181_STATUS_TXACTIVE | PL181_STATUS_RXACTIVE;
269         if (s->fifo_len == 0) {
270             bits |= PL181_STATUS_TXFIFOEMPTY;
271             bits |= PL181_STATUS_RXFIFOEMPTY;
272         } else {
273             bits |= PL181_STATUS_TXDATAAVLBL;
274             bits |= PL181_STATUS_RXDATAAVLBL;
275         }
276         if (s->fifo_len == 16) {
277             bits |= PL181_STATUS_TXFIFOFULL;
278             bits |= PL181_STATUS_RXFIFOFULL;
279         }
280         if (s->fifo_len <= 8) {
281             bits |= PL181_STATUS_TXFIFOHALFEMPTY;
282         }
283         if (s->fifo_len >= 8) {
284             bits |= PL181_STATUS_RXFIFOHALFFULL;
285         }
286         if (s->datactrl & PL181_DATA_DIRECTION) {
287             bits &= PL181_STATUS_RX_FIFO;
288         } else {
289             bits &= PL181_STATUS_TX_FIFO;
290         }
291         s->status |= bits;
292     }
293 }
294 
295 static uint64_t pl181_read(void *opaque, hwaddr offset,
296                            unsigned size)
297 {
298     PL181State *s = (PL181State *)opaque;
299     uint32_t tmp;
300 
301     if (offset >= 0xfe0 && offset < 0x1000) {
302         return pl181_id[(offset - 0xfe0) >> 2];
303     }
304     switch (offset) {
305     case 0x00: /* Power */
306         return s->power;
307     case 0x04: /* Clock */
308         return s->clock;
309     case 0x08: /* Argument */
310         return s->cmdarg;
311     case 0x0c: /* Command */
312         return s->cmd;
313     case 0x10: /* RespCmd */
314         return s->respcmd;
315     case 0x14: /* Response0 */
316         return s->response[0];
317     case 0x18: /* Response1 */
318         return s->response[1];
319     case 0x1c: /* Response2 */
320         return s->response[2];
321     case 0x20: /* Response3 */
322         return s->response[3];
323     case 0x24: /* DataTimer */
324         return s->datatimer;
325     case 0x28: /* DataLength */
326         return s->datalength;
327     case 0x2c: /* DataCtrl */
328         return s->datactrl;
329     case 0x30: /* DataCnt */
330         return s->datacnt;
331     case 0x34: /* Status */
332         tmp = s->status;
333         if (s->linux_hack) {
334             s->linux_hack = 0;
335             pl181_fifo_run(s);
336             pl181_update(s);
337         }
338         return tmp;
339     case 0x3c: /* Mask0 */
340         return s->mask[0];
341     case 0x40: /* Mask1 */
342         return s->mask[1];
343     case 0x48: /* FifoCnt */
344         /* The documentation is somewhat vague about exactly what FifoCnt
345            does.  On real hardware it appears to be when decrememnted
346            when a word is transferred between the FIFO and the serial
347            data engine.  DataCnt is decremented after each byte is
348            transferred between the serial engine and the card.
349            We don't emulate this level of detail, so both can be the same.  */
350         tmp = (s->datacnt + 3) >> 2;
351         if (s->linux_hack) {
352             s->linux_hack = 0;
353             pl181_fifo_run(s);
354             pl181_update(s);
355         }
356         return tmp;
357     case 0x80: case 0x84: case 0x88: case 0x8c: /* FifoData */
358     case 0x90: case 0x94: case 0x98: case 0x9c:
359     case 0xa0: case 0xa4: case 0xa8: case 0xac:
360     case 0xb0: case 0xb4: case 0xb8: case 0xbc:
361         if (s->fifo_len == 0) {
362             qemu_log_mask(LOG_GUEST_ERROR, "pl181: Unexpected FIFO read\n");
363             return 0;
364         } else {
365             uint32_t value;
366             value = pl181_fifo_pop(s);
367             s->linux_hack = 1;
368             pl181_fifo_run(s);
369             pl181_update(s);
370             return value;
371         }
372     default:
373         qemu_log_mask(LOG_GUEST_ERROR,
374                       "pl181_read: Bad offset %x\n", (int)offset);
375         return 0;
376     }
377 }
378 
379 static void pl181_write(void *opaque, hwaddr offset,
380                         uint64_t value, unsigned size)
381 {
382     PL181State *s = (PL181State *)opaque;
383 
384     switch (offset) {
385     case 0x00: /* Power */
386         s->power = value & 0xff;
387         break;
388     case 0x04: /* Clock */
389         s->clock = value & 0xff;
390         break;
391     case 0x08: /* Argument */
392         s->cmdarg = value;
393         break;
394     case 0x0c: /* Command */
395         s->cmd = value;
396         if (s->cmd & PL181_CMD_ENABLE) {
397             if (s->cmd & PL181_CMD_INTERRUPT) {
398                 qemu_log_mask(LOG_UNIMP,
399                               "pl181: Interrupt mode not implemented\n");
400             } if (s->cmd & PL181_CMD_PENDING) {
401                 qemu_log_mask(LOG_UNIMP,
402                               "pl181: Pending commands not implemented\n");
403             } else {
404                 pl181_send_command(s);
405                 pl181_fifo_run(s);
406             }
407             /* The command has completed one way or the other.  */
408             s->cmd &= ~PL181_CMD_ENABLE;
409         }
410         break;
411     case 0x24: /* DataTimer */
412         s->datatimer = value;
413         break;
414     case 0x28: /* DataLength */
415         s->datalength = value & 0xffff;
416         break;
417     case 0x2c: /* DataCtrl */
418         s->datactrl = value & 0xff;
419         if (value & PL181_DATA_ENABLE) {
420             s->datacnt = s->datalength;
421             pl181_fifo_run(s);
422         }
423         break;
424     case 0x38: /* Clear */
425         s->status &= ~(value & 0x7ff);
426         break;
427     case 0x3c: /* Mask0 */
428         s->mask[0] = value;
429         break;
430     case 0x40: /* Mask1 */
431         s->mask[1] = value;
432         break;
433     case 0x80: case 0x84: case 0x88: case 0x8c: /* FifoData */
434     case 0x90: case 0x94: case 0x98: case 0x9c:
435     case 0xa0: case 0xa4: case 0xa8: case 0xac:
436     case 0xb0: case 0xb4: case 0xb8: case 0xbc:
437         if (s->datacnt == 0) {
438             qemu_log_mask(LOG_GUEST_ERROR, "pl181: Unexpected FIFO write\n");
439         } else {
440             pl181_fifo_push(s, value);
441             pl181_fifo_run(s);
442         }
443         break;
444     default:
445         qemu_log_mask(LOG_GUEST_ERROR,
446                       "pl181_write: Bad offset %x\n", (int)offset);
447     }
448     pl181_update(s);
449 }
450 
451 static const MemoryRegionOps pl181_ops = {
452     .read = pl181_read,
453     .write = pl181_write,
454     .endianness = DEVICE_NATIVE_ENDIAN,
455 };
456 
457 static void pl181_reset(DeviceState *d)
458 {
459     PL181State *s = PL181(d);
460 
461     s->power = 0;
462     s->cmdarg = 0;
463     s->cmd = 0;
464     s->datatimer = 0;
465     s->datalength = 0;
466     s->respcmd = 0;
467     s->response[0] = 0;
468     s->response[1] = 0;
469     s->response[2] = 0;
470     s->response[3] = 0;
471     s->datatimer = 0;
472     s->datalength = 0;
473     s->datactrl = 0;
474     s->datacnt = 0;
475     s->status = 0;
476     s->linux_hack = 0;
477     s->mask[0] = 0;
478     s->mask[1] = 0;
479 
480     /* We can assume our GPIO outputs have been wired up now */
481     sd_set_cb(s->card, s->cardstatus[0], s->cardstatus[1]);
482     /* Since we're still using the legacy SD API the card is not plugged
483      * into any bus, and we must reset it manually.
484      */
485     device_reset(DEVICE(s->card));
486 }
487 
488 static void pl181_init(Object *obj)
489 {
490     DeviceState *dev = DEVICE(obj);
491     PL181State *s = PL181(obj);
492     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
493 
494     memory_region_init_io(&s->iomem, obj, &pl181_ops, s, "pl181", 0x1000);
495     sysbus_init_mmio(sbd, &s->iomem);
496     sysbus_init_irq(sbd, &s->irq[0]);
497     sysbus_init_irq(sbd, &s->irq[1]);
498     qdev_init_gpio_out(dev, s->cardstatus, 2);
499 }
500 
501 static void pl181_realize(DeviceState *dev, Error **errp)
502 {
503     PL181State *s = PL181(dev);
504     DriveInfo *dinfo;
505 
506     /* FIXME use a qdev drive property instead of drive_get_next() */
507     dinfo = drive_get_next(IF_SD);
508     s->card = sd_init(dinfo ? blk_by_legacy_dinfo(dinfo) : NULL, false);
509     if (s->card == NULL) {
510         error_setg(errp, "sd_init failed");
511     }
512 }
513 
514 static void pl181_class_init(ObjectClass *klass, void *data)
515 {
516     DeviceClass *k = DEVICE_CLASS(klass);
517 
518     k->vmsd = &vmstate_pl181;
519     k->reset = pl181_reset;
520     /* Reason: init() method uses drive_get_next() */
521     k->user_creatable = false;
522     k->realize = pl181_realize;
523 }
524 
525 static const TypeInfo pl181_info = {
526     .name          = TYPE_PL181,
527     .parent        = TYPE_SYS_BUS_DEVICE,
528     .instance_size = sizeof(PL181State),
529     .instance_init = pl181_init,
530     .class_init    = pl181_class_init,
531 };
532 
533 static void pl181_register_types(void)
534 {
535     type_register_static(&pl181_info);
536 }
537 
538 type_init(pl181_register_types)
539