xref: /openbmc/qemu/hw/sd/pl181.c (revision a9ded601)
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/block-backend.h"
12 #include "sysemu/blockdev.h"
13 #include "hw/sysbus.h"
14 #include "hw/sd/sd.h"
15 #include "qemu/log.h"
16 #include "qapi/error.h"
17 
18 //#define DEBUG_PL181 1
19 
20 #ifdef DEBUG_PL181
21 #define DPRINTF(fmt, ...) \
22 do { printf("pl181: " fmt , ## __VA_ARGS__); } while (0)
23 #else
24 #define DPRINTF(fmt, ...) do {} while(0)
25 #endif
26 
27 #define PL181_FIFO_LEN 16
28 
29 #define TYPE_PL181 "pl181"
30 #define PL181(obj) OBJECT_CHECK(PL181State, (obj), TYPE_PL181)
31 
32 typedef struct PL181State {
33     SysBusDevice parent_obj;
34 
35     MemoryRegion iomem;
36     SDState *card;
37     uint32_t clock;
38     uint32_t power;
39     uint32_t cmdarg;
40     uint32_t cmd;
41     uint32_t datatimer;
42     uint32_t datalength;
43     uint32_t respcmd;
44     uint32_t response[4];
45     uint32_t datactrl;
46     uint32_t datacnt;
47     uint32_t status;
48     uint32_t mask[2];
49     int32_t fifo_pos;
50     int32_t fifo_len;
51     /* The linux 2.6.21 driver is buggy, and misbehaves if new data arrives
52        while it is reading the FIFO.  We hack around this by deferring
53        subsequent transfers until after the driver polls the status word.
54        http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=4446/1
55      */
56     int32_t linux_hack;
57     uint32_t fifo[PL181_FIFO_LEN];
58     qemu_irq irq[2];
59     /* GPIO outputs for 'card is readonly' and 'card inserted' */
60     qemu_irq cardstatus[2];
61 } PL181State;
62 
63 static const VMStateDescription vmstate_pl181 = {
64     .name = "pl181",
65     .version_id = 1,
66     .minimum_version_id = 1,
67     .fields = (VMStateField[]) {
68         VMSTATE_UINT32(clock, PL181State),
69         VMSTATE_UINT32(power, PL181State),
70         VMSTATE_UINT32(cmdarg, PL181State),
71         VMSTATE_UINT32(cmd, PL181State),
72         VMSTATE_UINT32(datatimer, PL181State),
73         VMSTATE_UINT32(datalength, PL181State),
74         VMSTATE_UINT32(respcmd, PL181State),
75         VMSTATE_UINT32_ARRAY(response, PL181State, 4),
76         VMSTATE_UINT32(datactrl, PL181State),
77         VMSTATE_UINT32(datacnt, PL181State),
78         VMSTATE_UINT32(status, PL181State),
79         VMSTATE_UINT32_ARRAY(mask, PL181State, 2),
80         VMSTATE_INT32(fifo_pos, PL181State),
81         VMSTATE_INT32(fifo_len, PL181State),
82         VMSTATE_INT32(linux_hack, PL181State),
83         VMSTATE_UINT32_ARRAY(fifo, PL181State, PL181_FIFO_LEN),
84         VMSTATE_END_OF_LIST()
85     }
86 };
87 
88 #define PL181_CMD_INDEX     0x3f
89 #define PL181_CMD_RESPONSE  (1 << 6)
90 #define PL181_CMD_LONGRESP  (1 << 7)
91 #define PL181_CMD_INTERRUPT (1 << 8)
92 #define PL181_CMD_PENDING   (1 << 9)
93 #define PL181_CMD_ENABLE    (1 << 10)
94 
95 #define PL181_DATA_ENABLE             (1 << 0)
96 #define PL181_DATA_DIRECTION          (1 << 1)
97 #define PL181_DATA_MODE               (1 << 2)
98 #define PL181_DATA_DMAENABLE          (1 << 3)
99 
100 #define PL181_STATUS_CMDCRCFAIL       (1 << 0)
101 #define PL181_STATUS_DATACRCFAIL      (1 << 1)
102 #define PL181_STATUS_CMDTIMEOUT       (1 << 2)
103 #define PL181_STATUS_DATATIMEOUT      (1 << 3)
104 #define PL181_STATUS_TXUNDERRUN       (1 << 4)
105 #define PL181_STATUS_RXOVERRUN        (1 << 5)
106 #define PL181_STATUS_CMDRESPEND       (1 << 6)
107 #define PL181_STATUS_CMDSENT          (1 << 7)
108 #define PL181_STATUS_DATAEND          (1 << 8)
109 #define PL181_STATUS_DATABLOCKEND     (1 << 10)
110 #define PL181_STATUS_CMDACTIVE        (1 << 11)
111 #define PL181_STATUS_TXACTIVE         (1 << 12)
112 #define PL181_STATUS_RXACTIVE         (1 << 13)
113 #define PL181_STATUS_TXFIFOHALFEMPTY  (1 << 14)
114 #define PL181_STATUS_RXFIFOHALFFULL   (1 << 15)
115 #define PL181_STATUS_TXFIFOFULL       (1 << 16)
116 #define PL181_STATUS_RXFIFOFULL       (1 << 17)
117 #define PL181_STATUS_TXFIFOEMPTY      (1 << 18)
118 #define PL181_STATUS_RXFIFOEMPTY      (1 << 19)
119 #define PL181_STATUS_TXDATAAVLBL      (1 << 20)
120 #define PL181_STATUS_RXDATAAVLBL      (1 << 21)
121 
122 #define PL181_STATUS_TX_FIFO (PL181_STATUS_TXACTIVE \
123                              |PL181_STATUS_TXFIFOHALFEMPTY \
124                              |PL181_STATUS_TXFIFOFULL \
125                              |PL181_STATUS_TXFIFOEMPTY \
126                              |PL181_STATUS_TXDATAAVLBL)
127 #define PL181_STATUS_RX_FIFO (PL181_STATUS_RXACTIVE \
128                              |PL181_STATUS_RXFIFOHALFFULL \
129                              |PL181_STATUS_RXFIFOFULL \
130                              |PL181_STATUS_RXFIFOEMPTY \
131                              |PL181_STATUS_RXDATAAVLBL)
132 
133 static const unsigned char pl181_id[] =
134 { 0x81, 0x11, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
135 
136 static void pl181_update(PL181State *s)
137 {
138     int i;
139     for (i = 0; i < 2; i++) {
140         qemu_set_irq(s->irq[i], (s->status & s->mask[i]) != 0);
141     }
142 }
143 
144 static void pl181_fifo_push(PL181State *s, uint32_t value)
145 {
146     int n;
147 
148     if (s->fifo_len == PL181_FIFO_LEN) {
149         fprintf(stderr, "pl181: FIFO overflow\n");
150         return;
151     }
152     n = (s->fifo_pos + s->fifo_len) & (PL181_FIFO_LEN - 1);
153     s->fifo_len++;
154     s->fifo[n] = value;
155     DPRINTF("FIFO push %08x\n", (int)value);
156 }
157 
158 static uint32_t pl181_fifo_pop(PL181State *s)
159 {
160     uint32_t value;
161 
162     if (s->fifo_len == 0) {
163         fprintf(stderr, "pl181: FIFO underflow\n");
164         return 0;
165     }
166     value = s->fifo[s->fifo_pos];
167     s->fifo_len--;
168     s->fifo_pos = (s->fifo_pos + 1) & (PL181_FIFO_LEN - 1);
169     DPRINTF("FIFO pop %08x\n", (int)value);
170     return value;
171 }
172 
173 static void pl181_send_command(PL181State *s)
174 {
175     SDRequest request;
176     uint8_t response[16];
177     int rlen;
178 
179     request.cmd = s->cmd & PL181_CMD_INDEX;
180     request.arg = s->cmdarg;
181     DPRINTF("Command %d %08x\n", request.cmd, request.arg);
182     rlen = sd_do_command(s->card, &request, response);
183     if (rlen < 0)
184         goto error;
185     if (s->cmd & PL181_CMD_RESPONSE) {
186 #define RWORD(n) (((uint32_t)response[n] << 24) | (response[n + 1] << 16) \
187                   | (response[n + 2] << 8) | response[n + 3])
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] = RWORD(0);
193         if (rlen == 4) {
194             s->response[1] = s->response[2] = s->response[3] = 0;
195         } else {
196             s->response[1] = RWORD(4);
197             s->response[2] = RWORD(8);
198             s->response[3] = RWORD(12) & ~1;
199         }
200         DPRINTF("Response received\n");
201         s->status |= PL181_STATUS_CMDRESPEND;
202 #undef RWORD
203     } else {
204         DPRINTF("Command sent\n");
205         s->status |= PL181_STATUS_CMDSENT;
206     }
207     return;
208 
209 error:
210     DPRINTF("Timeout\n");
211     s->status |= PL181_STATUS_CMDTIMEOUT;
212 }
213 
214 /* Transfer data between the card and the FIFO.  This is complicated by
215    the FIFO holding 32-bit words and the card taking data in single byte
216    chunks.  FIFO bytes are transferred in little-endian order.  */
217 
218 static void pl181_fifo_run(PL181State *s)
219 {
220     uint32_t bits;
221     uint32_t value = 0;
222     int n;
223     int is_read;
224 
225     is_read = (s->datactrl & PL181_DATA_DIRECTION) != 0;
226     if (s->datacnt != 0 && (!is_read || sd_data_ready(s->card))
227             && !s->linux_hack) {
228         if (is_read) {
229             n = 0;
230             while (s->datacnt && s->fifo_len < PL181_FIFO_LEN) {
231                 value |= (uint32_t)sd_read_data(s->card) << (n * 8);
232                 s->datacnt--;
233                 n++;
234                 if (n == 4) {
235                     pl181_fifo_push(s, value);
236                     n = 0;
237                     value = 0;
238                 }
239             }
240             if (n != 0) {
241                 pl181_fifo_push(s, value);
242             }
243         } else { /* write */
244             n = 0;
245             while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
246                 if (n == 0) {
247                     value = pl181_fifo_pop(s);
248                     n = 4;
249                 }
250                 n--;
251                 s->datacnt--;
252                 sd_write_data(s->card, value & 0xff);
253                 value >>= 8;
254             }
255         }
256     }
257     s->status &= ~(PL181_STATUS_RX_FIFO | PL181_STATUS_TX_FIFO);
258     if (s->datacnt == 0) {
259         s->status |= PL181_STATUS_DATAEND;
260         /* HACK: */
261         s->status |= PL181_STATUS_DATABLOCKEND;
262         DPRINTF("Transfer Complete\n");
263     }
264     if (s->datacnt == 0 && s->fifo_len == 0) {
265         s->datactrl &= ~PL181_DATA_ENABLE;
266         DPRINTF("Data engine idle\n");
267     } else {
268         /* Update FIFO bits.  */
269         bits = PL181_STATUS_TXACTIVE | PL181_STATUS_RXACTIVE;
270         if (s->fifo_len == 0) {
271             bits |= PL181_STATUS_TXFIFOEMPTY;
272             bits |= PL181_STATUS_RXFIFOEMPTY;
273         } else {
274             bits |= PL181_STATUS_TXDATAAVLBL;
275             bits |= PL181_STATUS_RXDATAAVLBL;
276         }
277         if (s->fifo_len == 16) {
278             bits |= PL181_STATUS_TXFIFOFULL;
279             bits |= PL181_STATUS_RXFIFOFULL;
280         }
281         if (s->fifo_len <= 8) {
282             bits |= PL181_STATUS_TXFIFOHALFEMPTY;
283         }
284         if (s->fifo_len >= 8) {
285             bits |= PL181_STATUS_RXFIFOHALFFULL;
286         }
287         if (s->datactrl & PL181_DATA_DIRECTION) {
288             bits &= PL181_STATUS_RX_FIFO;
289         } else {
290             bits &= PL181_STATUS_TX_FIFO;
291         }
292         s->status |= bits;
293     }
294 }
295 
296 static uint64_t pl181_read(void *opaque, hwaddr offset,
297                            unsigned size)
298 {
299     PL181State *s = (PL181State *)opaque;
300     uint32_t tmp;
301 
302     if (offset >= 0xfe0 && offset < 0x1000) {
303         return pl181_id[(offset - 0xfe0) >> 2];
304     }
305     switch (offset) {
306     case 0x00: /* Power */
307         return s->power;
308     case 0x04: /* Clock */
309         return s->clock;
310     case 0x08: /* Argument */
311         return s->cmdarg;
312     case 0x0c: /* Command */
313         return s->cmd;
314     case 0x10: /* RespCmd */
315         return s->respcmd;
316     case 0x14: /* Response0 */
317         return s->response[0];
318     case 0x18: /* Response1 */
319         return s->response[1];
320     case 0x1c: /* Response2 */
321         return s->response[2];
322     case 0x20: /* Response3 */
323         return s->response[3];
324     case 0x24: /* DataTimer */
325         return s->datatimer;
326     case 0x28: /* DataLength */
327         return s->datalength;
328     case 0x2c: /* DataCtrl */
329         return s->datactrl;
330     case 0x30: /* DataCnt */
331         return s->datacnt;
332     case 0x34: /* Status */
333         tmp = s->status;
334         if (s->linux_hack) {
335             s->linux_hack = 0;
336             pl181_fifo_run(s);
337             pl181_update(s);
338         }
339         return tmp;
340     case 0x3c: /* Mask0 */
341         return s->mask[0];
342     case 0x40: /* Mask1 */
343         return s->mask[1];
344     case 0x48: /* FifoCnt */
345         /* The documentation is somewhat vague about exactly what FifoCnt
346            does.  On real hardware it appears to be when decrememnted
347            when a word is transferred between the FIFO and the serial
348            data engine.  DataCnt is decremented after each byte is
349            transferred between the serial engine and the card.
350            We don't emulate this level of detail, so both can be the same.  */
351         tmp = (s->datacnt + 3) >> 2;
352         if (s->linux_hack) {
353             s->linux_hack = 0;
354             pl181_fifo_run(s);
355             pl181_update(s);
356         }
357         return tmp;
358     case 0x80: case 0x84: case 0x88: case 0x8c: /* FifoData */
359     case 0x90: case 0x94: case 0x98: case 0x9c:
360     case 0xa0: case 0xa4: case 0xa8: case 0xac:
361     case 0xb0: case 0xb4: case 0xb8: case 0xbc:
362         if (s->fifo_len == 0) {
363             qemu_log_mask(LOG_GUEST_ERROR, "pl181: Unexpected FIFO read\n");
364             return 0;
365         } else {
366             uint32_t value;
367             value = pl181_fifo_pop(s);
368             s->linux_hack = 1;
369             pl181_fifo_run(s);
370             pl181_update(s);
371             return value;
372         }
373     default:
374         qemu_log_mask(LOG_GUEST_ERROR,
375                       "pl181_read: Bad offset %x\n", (int)offset);
376         return 0;
377     }
378 }
379 
380 static void pl181_write(void *opaque, hwaddr offset,
381                         uint64_t value, unsigned size)
382 {
383     PL181State *s = (PL181State *)opaque;
384 
385     switch (offset) {
386     case 0x00: /* Power */
387         s->power = value & 0xff;
388         break;
389     case 0x04: /* Clock */
390         s->clock = value & 0xff;
391         break;
392     case 0x08: /* Argument */
393         s->cmdarg = value;
394         break;
395     case 0x0c: /* Command */
396         s->cmd = value;
397         if (s->cmd & PL181_CMD_ENABLE) {
398             if (s->cmd & PL181_CMD_INTERRUPT) {
399                 qemu_log_mask(LOG_UNIMP,
400                               "pl181: Interrupt mode not implemented\n");
401             } if (s->cmd & PL181_CMD_PENDING) {
402                 qemu_log_mask(LOG_UNIMP,
403                               "pl181: Pending commands not implemented\n");
404             } else {
405                 pl181_send_command(s);
406                 pl181_fifo_run(s);
407             }
408             /* The command has completed one way or the other.  */
409             s->cmd &= ~PL181_CMD_ENABLE;
410         }
411         break;
412     case 0x24: /* DataTimer */
413         s->datatimer = value;
414         break;
415     case 0x28: /* DataLength */
416         s->datalength = value & 0xffff;
417         break;
418     case 0x2c: /* DataCtrl */
419         s->datactrl = value & 0xff;
420         if (value & PL181_DATA_ENABLE) {
421             s->datacnt = s->datalength;
422             pl181_fifo_run(s);
423         }
424         break;
425     case 0x38: /* Clear */
426         s->status &= ~(value & 0x7ff);
427         break;
428     case 0x3c: /* Mask0 */
429         s->mask[0] = value;
430         break;
431     case 0x40: /* Mask1 */
432         s->mask[1] = value;
433         break;
434     case 0x80: case 0x84: case 0x88: case 0x8c: /* FifoData */
435     case 0x90: case 0x94: case 0x98: case 0x9c:
436     case 0xa0: case 0xa4: case 0xa8: case 0xac:
437     case 0xb0: case 0xb4: case 0xb8: case 0xbc:
438         if (s->datacnt == 0) {
439             qemu_log_mask(LOG_GUEST_ERROR, "pl181: Unexpected FIFO write\n");
440         } else {
441             pl181_fifo_push(s, value);
442             pl181_fifo_run(s);
443         }
444         break;
445     default:
446         qemu_log_mask(LOG_GUEST_ERROR,
447                       "pl181_write: Bad offset %x\n", (int)offset);
448     }
449     pl181_update(s);
450 }
451 
452 static const MemoryRegionOps pl181_ops = {
453     .read = pl181_read,
454     .write = pl181_write,
455     .endianness = DEVICE_NATIVE_ENDIAN,
456 };
457 
458 static void pl181_reset(DeviceState *d)
459 {
460     PL181State *s = PL181(d);
461 
462     s->power = 0;
463     s->cmdarg = 0;
464     s->cmd = 0;
465     s->datatimer = 0;
466     s->datalength = 0;
467     s->respcmd = 0;
468     s->response[0] = 0;
469     s->response[1] = 0;
470     s->response[2] = 0;
471     s->response[3] = 0;
472     s->datatimer = 0;
473     s->datalength = 0;
474     s->datactrl = 0;
475     s->datacnt = 0;
476     s->status = 0;
477     s->linux_hack = 0;
478     s->mask[0] = 0;
479     s->mask[1] = 0;
480 
481     /* We can assume our GPIO outputs have been wired up now */
482     sd_set_cb(s->card, s->cardstatus[0], s->cardstatus[1]);
483 }
484 
485 static void pl181_init(Object *obj)
486 {
487     DeviceState *dev = DEVICE(obj);
488     PL181State *s = PL181(obj);
489     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
490 
491     memory_region_init_io(&s->iomem, obj, &pl181_ops, s, "pl181", 0x1000);
492     sysbus_init_mmio(sbd, &s->iomem);
493     sysbus_init_irq(sbd, &s->irq[0]);
494     sysbus_init_irq(sbd, &s->irq[1]);
495     qdev_init_gpio_out(dev, s->cardstatus, 2);
496 }
497 
498 static void pl181_realize(DeviceState *dev, Error **errp)
499 {
500     PL181State *s = PL181(dev);
501     DriveInfo *dinfo;
502 
503     /* FIXME use a qdev drive property instead of drive_get_next() */
504     dinfo = drive_get_next(IF_SD);
505     s->card = sd_init(dinfo ? blk_by_legacy_dinfo(dinfo) : NULL, false);
506     if (s->card == NULL) {
507         error_setg(errp, "sd_init failed");
508     }
509 }
510 
511 static void pl181_class_init(ObjectClass *klass, void *data)
512 {
513     DeviceClass *k = DEVICE_CLASS(klass);
514 
515     k->vmsd = &vmstate_pl181;
516     k->reset = pl181_reset;
517     /* Reason: init() method uses drive_get_next() */
518     k->user_creatable = false;
519     k->realize = pl181_realize;
520 }
521 
522 static const TypeInfo pl181_info = {
523     .name          = TYPE_PL181,
524     .parent        = TYPE_SYS_BUS_DEVICE,
525     .instance_size = sizeof(PL181State),
526     .instance_init = pl181_init,
527     .class_init    = pl181_class_init,
528 };
529 
530 static void pl181_register_types(void)
531 {
532     type_register_static(&pl181_info);
533 }
534 
535 type_init(pl181_register_types)
536