xref: /openbmc/qemu/hw/sd/bcm2835_sdhost.c (revision db1015e92e04835c9eb50c29625fe566d1202dbd)
1 /*
2  * Raspberry Pi (BCM2835) SD Host Controller
3  *
4  * Copyright (c) 2017 Antfield SAS
5  *
6  * Authors:
7  *  Clement Deschamps <clement.deschamps@antfield.fr>
8  *  Luc Michel <luc.michel@antfield.fr>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/log.h"
16 #include "qemu/module.h"
17 #include "sysemu/blockdev.h"
18 #include "hw/irq.h"
19 #include "hw/sd/bcm2835_sdhost.h"
20 #include "migration/vmstate.h"
21 #include "trace.h"
22 #include "qom/object.h"
23 
24 #define TYPE_BCM2835_SDHOST_BUS "bcm2835-sdhost-bus"
25 #define BCM2835_SDHOST_BUS(obj) \
26     OBJECT_CHECK(SDBus, (obj), TYPE_BCM2835_SDHOST_BUS)
27 
28 #define SDCMD  0x00 /* Command to SD card              - 16 R/W */
29 #define SDARG  0x04 /* Argument to SD card             - 32 R/W */
30 #define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
31 #define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
32 #define SDRSP0 0x10 /* SD card rsp (31:0)         - 32 R   */
33 #define SDRSP1 0x14 /* SD card rsp (63:32)        - 32 R   */
34 #define SDRSP2 0x18 /* SD card rsp (95:64)        - 32 R   */
35 #define SDRSP3 0x1c /* SD card rsp (127:96)       - 32 R   */
36 #define SDHSTS 0x20 /* SD host status                  - 11 R   */
37 #define SDVDD  0x30 /* SD card power control           -  1 R/W */
38 #define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
39 #define SDHCFG 0x38 /* Host configuration              -  2 R/W */
40 #define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
41 #define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
42 #define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
43 
44 #define SDCMD_NEW_FLAG                  0x8000
45 #define SDCMD_FAIL_FLAG                 0x4000
46 #define SDCMD_BUSYWAIT                  0x800
47 #define SDCMD_NO_RESPONSE               0x400
48 #define SDCMD_LONG_RESPONSE             0x200
49 #define SDCMD_WRITE_CMD                 0x80
50 #define SDCMD_READ_CMD                  0x40
51 #define SDCMD_CMD_MASK                  0x3f
52 
53 #define SDCDIV_MAX_CDIV                 0x7ff
54 
55 #define SDHSTS_BUSY_IRPT                0x400
56 #define SDHSTS_BLOCK_IRPT               0x200
57 #define SDHSTS_SDIO_IRPT                0x100
58 #define SDHSTS_REW_TIME_OUT             0x80
59 #define SDHSTS_CMD_TIME_OUT             0x40
60 #define SDHSTS_CRC16_ERROR              0x20
61 #define SDHSTS_CRC7_ERROR               0x10
62 #define SDHSTS_FIFO_ERROR               0x08
63 /* Reserved */
64 /* Reserved */
65 #define SDHSTS_DATA_FLAG                0x01
66 
67 #define SDHCFG_BUSY_IRPT_EN     (1 << 10)
68 #define SDHCFG_BLOCK_IRPT_EN    (1 << 8)
69 #define SDHCFG_SDIO_IRPT_EN     (1 << 5)
70 #define SDHCFG_DATA_IRPT_EN     (1 << 4)
71 #define SDHCFG_SLOW_CARD        (1 << 3)
72 #define SDHCFG_WIDE_EXT_BUS     (1 << 2)
73 #define SDHCFG_WIDE_INT_BUS     (1 << 1)
74 #define SDHCFG_REL_CMD_LINE     (1 << 0)
75 
76 #define SDEDM_FORCE_DATA_MODE   (1 << 19)
77 #define SDEDM_CLOCK_PULSE       (1 << 20)
78 #define SDEDM_BYPASS            (1 << 21)
79 
80 #define SDEDM_WRITE_THRESHOLD_SHIFT 9
81 #define SDEDM_READ_THRESHOLD_SHIFT 14
82 #define SDEDM_THRESHOLD_MASK     0x1f
83 
84 #define SDEDM_FSM_MASK           0xf
85 #define SDEDM_FSM_IDENTMODE      0x0
86 #define SDEDM_FSM_DATAMODE       0x1
87 #define SDEDM_FSM_READDATA       0x2
88 #define SDEDM_FSM_WRITEDATA      0x3
89 #define SDEDM_FSM_READWAIT       0x4
90 #define SDEDM_FSM_READCRC        0x5
91 #define SDEDM_FSM_WRITECRC       0x6
92 #define SDEDM_FSM_WRITEWAIT1     0x7
93 #define SDEDM_FSM_POWERDOWN      0x8
94 #define SDEDM_FSM_POWERUP        0x9
95 #define SDEDM_FSM_WRITESTART1    0xa
96 #define SDEDM_FSM_WRITESTART2    0xb
97 #define SDEDM_FSM_GENPULSES      0xc
98 #define SDEDM_FSM_WRITEWAIT2     0xd
99 #define SDEDM_FSM_STARTPOWDOWN   0xf
100 
101 #define SDDATA_FIFO_WORDS        16
102 
103 static void bcm2835_sdhost_update_irq(BCM2835SDHostState *s)
104 {
105     uint32_t irq = s->status &
106         (SDHSTS_BUSY_IRPT | SDHSTS_BLOCK_IRPT | SDHSTS_SDIO_IRPT);
107     trace_bcm2835_sdhost_update_irq(irq);
108     qemu_set_irq(s->irq, !!irq);
109 }
110 
111 static void bcm2835_sdhost_send_command(BCM2835SDHostState *s)
112 {
113     SDRequest request;
114     uint8_t rsp[16];
115     int rlen;
116 
117     request.cmd = s->cmd & SDCMD_CMD_MASK;
118     request.arg = s->cmdarg;
119 
120     rlen = sdbus_do_command(&s->sdbus, &request, rsp);
121     if (rlen < 0) {
122         goto error;
123     }
124     if (!(s->cmd & SDCMD_NO_RESPONSE)) {
125         if (rlen == 0 || (rlen == 4 && (s->cmd & SDCMD_LONG_RESPONSE))) {
126             goto error;
127         }
128         if (rlen != 4 && rlen != 16) {
129             goto error;
130         }
131         if (rlen == 4) {
132             s->rsp[0] = ldl_be_p(&rsp[0]);
133             s->rsp[1] = s->rsp[2] = s->rsp[3] = 0;
134         } else {
135             s->rsp[0] = ldl_be_p(&rsp[12]);
136             s->rsp[1] = ldl_be_p(&rsp[8]);
137             s->rsp[2] = ldl_be_p(&rsp[4]);
138             s->rsp[3] = ldl_be_p(&rsp[0]);
139         }
140     }
141     /* We never really delay commands, so if this was a 'busywait' command
142      * then we've completed it now and can raise the interrupt.
143      */
144     if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)) {
145         s->status |= SDHSTS_BUSY_IRPT;
146     }
147     return;
148 
149 error:
150     s->cmd |= SDCMD_FAIL_FLAG;
151     s->status |= SDHSTS_CMD_TIME_OUT;
152 }
153 
154 static void bcm2835_sdhost_fifo_push(BCM2835SDHostState *s, uint32_t value)
155 {
156     int n;
157 
158     if (s->fifo_len == BCM2835_SDHOST_FIFO_LEN) {
159         /* FIFO overflow */
160         return;
161     }
162     n = (s->fifo_pos + s->fifo_len) & (BCM2835_SDHOST_FIFO_LEN - 1);
163     s->fifo_len++;
164     s->fifo[n] = value;
165 }
166 
167 static uint32_t bcm2835_sdhost_fifo_pop(BCM2835SDHostState *s)
168 {
169     uint32_t value;
170 
171     if (s->fifo_len == 0) {
172         /* FIFO underflow */
173         return 0;
174     }
175     value = s->fifo[s->fifo_pos];
176     s->fifo_len--;
177     s->fifo_pos = (s->fifo_pos + 1) & (BCM2835_SDHOST_FIFO_LEN - 1);
178     return value;
179 }
180 
181 static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
182 {
183     uint32_t value = 0;
184     int n;
185     int is_read;
186     int is_write;
187 
188     is_read = (s->cmd & SDCMD_READ_CMD) != 0;
189     is_write = (s->cmd & SDCMD_WRITE_CMD) != 0;
190     if (s->datacnt != 0 && (is_write || sdbus_data_ready(&s->sdbus))) {
191         if (is_read) {
192             n = 0;
193             while (s->datacnt && s->fifo_len < BCM2835_SDHOST_FIFO_LEN) {
194                 value |= (uint32_t)sdbus_read_byte(&s->sdbus) << (n * 8);
195                 s->datacnt--;
196                 n++;
197                 if (n == 4) {
198                     bcm2835_sdhost_fifo_push(s, value);
199                     s->status |= SDHSTS_DATA_FLAG;
200                     if (s->config & SDHCFG_DATA_IRPT_EN) {
201                         s->status |= SDHSTS_SDIO_IRPT;
202                     }
203                     n = 0;
204                     value = 0;
205                 }
206             }
207             if (n != 0) {
208                 bcm2835_sdhost_fifo_push(s, value);
209                 s->status |= SDHSTS_DATA_FLAG;
210                 if (s->config & SDHCFG_DATA_IRPT_EN) {
211                     s->status |= SDHSTS_SDIO_IRPT;
212                 }
213             }
214         } else if (is_write) { /* write */
215             n = 0;
216             while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
217                 if (n == 0) {
218                     value = bcm2835_sdhost_fifo_pop(s);
219                     s->status |= SDHSTS_DATA_FLAG;
220                     if (s->config & SDHCFG_DATA_IRPT_EN) {
221                         s->status |= SDHSTS_SDIO_IRPT;
222                     }
223                     n = 4;
224                 }
225                 n--;
226                 s->datacnt--;
227                 sdbus_write_byte(&s->sdbus, value & 0xff);
228                 value >>= 8;
229             }
230         }
231         if (s->datacnt == 0) {
232             s->edm &= ~SDEDM_FSM_MASK;
233             s->edm |= SDEDM_FSM_DATAMODE;
234             trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm);
235         }
236         if (is_write) {
237             /* set block interrupt at end of each block transfer */
238             if (s->hbct && s->datacnt % s->hbct == 0 &&
239                 (s->config & SDHCFG_BLOCK_IRPT_EN)) {
240                 s->status |= SDHSTS_BLOCK_IRPT;
241             }
242             /* set data interrupt after each transfer */
243             s->status |= SDHSTS_DATA_FLAG;
244             if (s->config & SDHCFG_DATA_IRPT_EN) {
245                 s->status |= SDHSTS_SDIO_IRPT;
246             }
247         }
248     }
249 
250     bcm2835_sdhost_update_irq(s);
251 
252     s->edm &= ~(0x1f << 4);
253     s->edm |= ((s->fifo_len & 0x1f) << 4);
254     trace_bcm2835_sdhost_edm_change("fifo run", s->edm);
255 }
256 
257 static uint64_t bcm2835_sdhost_read(void *opaque, hwaddr offset,
258     unsigned size)
259 {
260     BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
261     uint32_t res = 0;
262 
263     switch (offset) {
264     case SDCMD:
265         res = s->cmd;
266         break;
267     case SDHSTS:
268         res = s->status;
269         break;
270     case SDRSP0:
271         res = s->rsp[0];
272         break;
273     case SDRSP1:
274         res = s->rsp[1];
275         break;
276     case SDRSP2:
277         res = s->rsp[2];
278         break;
279     case SDRSP3:
280         res = s->rsp[3];
281         break;
282     case SDEDM:
283         res = s->edm;
284         break;
285     case SDVDD:
286         res = s->vdd;
287         break;
288     case SDDATA:
289         res = bcm2835_sdhost_fifo_pop(s);
290         bcm2835_sdhost_fifo_run(s);
291         break;
292     case SDHBCT:
293         res = s->hbct;
294         break;
295     case SDHBLC:
296         res = s->hblc;
297         break;
298 
299     default:
300         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
301                       __func__, offset);
302         res = 0;
303         break;
304     }
305 
306     trace_bcm2835_sdhost_read(offset, res, size);
307 
308     return res;
309 }
310 
311 static void bcm2835_sdhost_write(void *opaque, hwaddr offset,
312     uint64_t value, unsigned size)
313 {
314     BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
315 
316     trace_bcm2835_sdhost_write(offset, value, size);
317 
318     switch (offset) {
319     case SDCMD:
320         s->cmd = value;
321         if (value & SDCMD_NEW_FLAG) {
322             bcm2835_sdhost_send_command(s);
323             bcm2835_sdhost_fifo_run(s);
324             s->cmd &= ~SDCMD_NEW_FLAG;
325         }
326         break;
327     case SDTOUT:
328         break;
329     case SDCDIV:
330         break;
331     case SDHSTS:
332         s->status &= ~value;
333         bcm2835_sdhost_update_irq(s);
334         break;
335     case SDARG:
336         s->cmdarg = value;
337         break;
338     case SDEDM:
339         if ((value & 0xf) == 0xf) {
340             /* power down */
341             value &= ~0xf;
342         }
343         s->edm = value;
344         trace_bcm2835_sdhost_edm_change("guest register write", s->edm);
345         break;
346     case SDHCFG:
347         s->config = value;
348         bcm2835_sdhost_fifo_run(s);
349         break;
350     case SDVDD:
351         s->vdd = value;
352         break;
353     case SDDATA:
354         bcm2835_sdhost_fifo_push(s, value);
355         bcm2835_sdhost_fifo_run(s);
356         break;
357     case SDHBCT:
358         s->hbct = value;
359         break;
360     case SDHBLC:
361         s->hblc = value;
362         s->datacnt = s->hblc * s->hbct;
363         bcm2835_sdhost_fifo_run(s);
364         break;
365 
366     default:
367         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
368                       __func__, offset);
369         break;
370     }
371 }
372 
373 static const MemoryRegionOps bcm2835_sdhost_ops = {
374     .read = bcm2835_sdhost_read,
375     .write = bcm2835_sdhost_write,
376     .endianness = DEVICE_NATIVE_ENDIAN,
377 };
378 
379 static const VMStateDescription vmstate_bcm2835_sdhost = {
380     .name = TYPE_BCM2835_SDHOST,
381     .version_id = 1,
382     .minimum_version_id = 1,
383     .fields = (VMStateField[]) {
384         VMSTATE_UINT32(cmd, BCM2835SDHostState),
385         VMSTATE_UINT32(cmdarg, BCM2835SDHostState),
386         VMSTATE_UINT32(status, BCM2835SDHostState),
387         VMSTATE_UINT32_ARRAY(rsp, BCM2835SDHostState, 4),
388         VMSTATE_UINT32(config, BCM2835SDHostState),
389         VMSTATE_UINT32(edm, BCM2835SDHostState),
390         VMSTATE_UINT32(vdd, BCM2835SDHostState),
391         VMSTATE_UINT32(hbct, BCM2835SDHostState),
392         VMSTATE_UINT32(hblc, BCM2835SDHostState),
393         VMSTATE_INT32(fifo_pos, BCM2835SDHostState),
394         VMSTATE_INT32(fifo_len, BCM2835SDHostState),
395         VMSTATE_UINT32_ARRAY(fifo, BCM2835SDHostState, BCM2835_SDHOST_FIFO_LEN),
396         VMSTATE_UINT32(datacnt, BCM2835SDHostState),
397         VMSTATE_END_OF_LIST()
398     }
399 };
400 
401 static void bcm2835_sdhost_init(Object *obj)
402 {
403     BCM2835SDHostState *s = BCM2835_SDHOST(obj);
404 
405     qbus_create_inplace(&s->sdbus, sizeof(s->sdbus),
406                         TYPE_BCM2835_SDHOST_BUS, DEVICE(s), "sd-bus");
407 
408     memory_region_init_io(&s->iomem, obj, &bcm2835_sdhost_ops, s,
409                           TYPE_BCM2835_SDHOST, 0x1000);
410     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
411     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
412 }
413 
414 static void bcm2835_sdhost_reset(DeviceState *dev)
415 {
416     BCM2835SDHostState *s = BCM2835_SDHOST(dev);
417 
418     s->cmd = 0;
419     s->cmdarg = 0;
420     s->edm = 0x0000c60f;
421     trace_bcm2835_sdhost_edm_change("device reset", s->edm);
422     s->config = 0;
423     s->hbct = 0;
424     s->hblc = 0;
425     s->datacnt = 0;
426     s->fifo_pos = 0;
427     s->fifo_len = 0;
428 }
429 
430 static void bcm2835_sdhost_class_init(ObjectClass *klass, void *data)
431 {
432     DeviceClass *dc = DEVICE_CLASS(klass);
433 
434     dc->reset = bcm2835_sdhost_reset;
435     dc->vmsd = &vmstate_bcm2835_sdhost;
436 }
437 
438 static TypeInfo bcm2835_sdhost_info = {
439     .name          = TYPE_BCM2835_SDHOST,
440     .parent        = TYPE_SYS_BUS_DEVICE,
441     .instance_size = sizeof(BCM2835SDHostState),
442     .class_init    = bcm2835_sdhost_class_init,
443     .instance_init = bcm2835_sdhost_init,
444 };
445 
446 static const TypeInfo bcm2835_sdhost_bus_info = {
447     .name = TYPE_BCM2835_SDHOST_BUS,
448     .parent = TYPE_SD_BUS,
449     .instance_size = sizeof(SDBus),
450 };
451 
452 static void bcm2835_sdhost_register_types(void)
453 {
454     type_register_static(&bcm2835_sdhost_info);
455     type_register_static(&bcm2835_sdhost_bus_info);
456 }
457 
458 type_init(bcm2835_sdhost_register_types)
459