xref: /openbmc/qemu/hw/sd/bcm2835_sdhost.c (revision ba632924)
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 "sysemu/blockdev.h"
17 #include "hw/sd/bcm2835_sdhost.h"
18 #include "trace.h"
19 
20 #define TYPE_BCM2835_SDHOST_BUS "bcm2835-sdhost-bus"
21 #define BCM2835_SDHOST_BUS(obj) \
22     OBJECT_CHECK(SDBus, (obj), TYPE_BCM2835_SDHOST_BUS)
23 
24 #define SDCMD  0x00 /* Command to SD card              - 16 R/W */
25 #define SDARG  0x04 /* Argument to SD card             - 32 R/W */
26 #define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
27 #define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
28 #define SDRSP0 0x10 /* SD card rsp (31:0)         - 32 R   */
29 #define SDRSP1 0x14 /* SD card rsp (63:32)        - 32 R   */
30 #define SDRSP2 0x18 /* SD card rsp (95:64)        - 32 R   */
31 #define SDRSP3 0x1c /* SD card rsp (127:96)       - 32 R   */
32 #define SDHSTS 0x20 /* SD host status                  - 11 R   */
33 #define SDVDD  0x30 /* SD card power control           -  1 R/W */
34 #define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
35 #define SDHCFG 0x38 /* Host configuration              -  2 R/W */
36 #define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
37 #define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
38 #define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
39 
40 #define SDCMD_NEW_FLAG                  0x8000
41 #define SDCMD_FAIL_FLAG                 0x4000
42 #define SDCMD_BUSYWAIT                  0x800
43 #define SDCMD_NO_RESPONSE               0x400
44 #define SDCMD_LONG_RESPONSE             0x200
45 #define SDCMD_WRITE_CMD                 0x80
46 #define SDCMD_READ_CMD                  0x40
47 #define SDCMD_CMD_MASK                  0x3f
48 
49 #define SDCDIV_MAX_CDIV                 0x7ff
50 
51 #define SDHSTS_BUSY_IRPT                0x400
52 #define SDHSTS_BLOCK_IRPT               0x200
53 #define SDHSTS_SDIO_IRPT                0x100
54 #define SDHSTS_REW_TIME_OUT             0x80
55 #define SDHSTS_CMD_TIME_OUT             0x40
56 #define SDHSTS_CRC16_ERROR              0x20
57 #define SDHSTS_CRC7_ERROR               0x10
58 #define SDHSTS_FIFO_ERROR               0x08
59 /* Reserved */
60 /* Reserved */
61 #define SDHSTS_DATA_FLAG                0x01
62 
63 #define SDHCFG_BUSY_IRPT_EN     (1 << 10)
64 #define SDHCFG_BLOCK_IRPT_EN    (1 << 8)
65 #define SDHCFG_SDIO_IRPT_EN     (1 << 5)
66 #define SDHCFG_DATA_IRPT_EN     (1 << 4)
67 #define SDHCFG_SLOW_CARD        (1 << 3)
68 #define SDHCFG_WIDE_EXT_BUS     (1 << 2)
69 #define SDHCFG_WIDE_INT_BUS     (1 << 1)
70 #define SDHCFG_REL_CMD_LINE     (1 << 0)
71 
72 #define SDEDM_FORCE_DATA_MODE   (1 << 19)
73 #define SDEDM_CLOCK_PULSE       (1 << 20)
74 #define SDEDM_BYPASS            (1 << 21)
75 
76 #define SDEDM_WRITE_THRESHOLD_SHIFT 9
77 #define SDEDM_READ_THRESHOLD_SHIFT 14
78 #define SDEDM_THRESHOLD_MASK     0x1f
79 
80 #define SDEDM_FSM_MASK           0xf
81 #define SDEDM_FSM_IDENTMODE      0x0
82 #define SDEDM_FSM_DATAMODE       0x1
83 #define SDEDM_FSM_READDATA       0x2
84 #define SDEDM_FSM_WRITEDATA      0x3
85 #define SDEDM_FSM_READWAIT       0x4
86 #define SDEDM_FSM_READCRC        0x5
87 #define SDEDM_FSM_WRITECRC       0x6
88 #define SDEDM_FSM_WRITEWAIT1     0x7
89 #define SDEDM_FSM_POWERDOWN      0x8
90 #define SDEDM_FSM_POWERUP        0x9
91 #define SDEDM_FSM_WRITESTART1    0xa
92 #define SDEDM_FSM_WRITESTART2    0xb
93 #define SDEDM_FSM_GENPULSES      0xc
94 #define SDEDM_FSM_WRITEWAIT2     0xd
95 #define SDEDM_FSM_STARTPOWDOWN   0xf
96 
97 #define SDDATA_FIFO_WORDS        16
98 
99 static void bcm2835_sdhost_update_irq(BCM2835SDHostState *s)
100 {
101     uint32_t irq = s->status &
102         (SDHSTS_BUSY_IRPT | SDHSTS_BLOCK_IRPT | SDHSTS_SDIO_IRPT);
103     trace_bcm2835_sdhost_update_irq(irq);
104     qemu_set_irq(s->irq, !!irq);
105 }
106 
107 static void bcm2835_sdhost_send_command(BCM2835SDHostState *s)
108 {
109     SDRequest request;
110     uint8_t rsp[16];
111     int rlen;
112 
113     request.cmd = s->cmd & SDCMD_CMD_MASK;
114     request.arg = s->cmdarg;
115 
116     rlen = sdbus_do_command(&s->sdbus, &request, rsp);
117     if (rlen < 0) {
118         goto error;
119     }
120     if (!(s->cmd & SDCMD_NO_RESPONSE)) {
121         if (rlen == 0 || (rlen == 4 && (s->cmd & SDCMD_LONG_RESPONSE))) {
122             goto error;
123         }
124         if (rlen != 4 && rlen != 16) {
125             goto error;
126         }
127         if (rlen == 4) {
128             s->rsp[0] = ldl_be_p(&rsp[0]);
129             s->rsp[1] = s->rsp[2] = s->rsp[3] = 0;
130         } else {
131             s->rsp[0] = ldl_be_p(&rsp[12]);
132             s->rsp[1] = ldl_be_p(&rsp[8]);
133             s->rsp[2] = ldl_be_p(&rsp[4]);
134             s->rsp[3] = ldl_be_p(&rsp[0]);
135         }
136     }
137     /* We never really delay commands, so if this was a 'busywait' command
138      * then we've completed it now and can raise the interrupt.
139      */
140     if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)) {
141         s->status |= SDHSTS_BUSY_IRPT;
142     }
143     return;
144 
145 error:
146     s->cmd |= SDCMD_FAIL_FLAG;
147     s->status |= SDHSTS_CMD_TIME_OUT;
148 }
149 
150 static void bcm2835_sdhost_fifo_push(BCM2835SDHostState *s, uint32_t value)
151 {
152     int n;
153 
154     if (s->fifo_len == BCM2835_SDHOST_FIFO_LEN) {
155         /* FIFO overflow */
156         return;
157     }
158     n = (s->fifo_pos + s->fifo_len) & (BCM2835_SDHOST_FIFO_LEN - 1);
159     s->fifo_len++;
160     s->fifo[n] = value;
161 }
162 
163 static uint32_t bcm2835_sdhost_fifo_pop(BCM2835SDHostState *s)
164 {
165     uint32_t value;
166 
167     if (s->fifo_len == 0) {
168         /* FIFO underflow */
169         return 0;
170     }
171     value = s->fifo[s->fifo_pos];
172     s->fifo_len--;
173     s->fifo_pos = (s->fifo_pos + 1) & (BCM2835_SDHOST_FIFO_LEN - 1);
174     return value;
175 }
176 
177 static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
178 {
179     uint32_t value = 0;
180     int n;
181     int is_read;
182     int is_write;
183 
184     is_read = (s->cmd & SDCMD_READ_CMD) != 0;
185     is_write = (s->cmd & SDCMD_WRITE_CMD) != 0;
186     if (s->datacnt != 0 && (is_write || sdbus_data_ready(&s->sdbus))) {
187         if (is_read) {
188             n = 0;
189             while (s->datacnt && s->fifo_len < BCM2835_SDHOST_FIFO_LEN) {
190                 value |= (uint32_t)sdbus_read_data(&s->sdbus) << (n * 8);
191                 s->datacnt--;
192                 n++;
193                 if (n == 4) {
194                     bcm2835_sdhost_fifo_push(s, value);
195                     s->status |= SDHSTS_DATA_FLAG;
196                     if (s->config & SDHCFG_DATA_IRPT_EN) {
197                         s->status |= SDHSTS_SDIO_IRPT;
198                     }
199                     n = 0;
200                     value = 0;
201                 }
202             }
203             if (n != 0) {
204                 bcm2835_sdhost_fifo_push(s, value);
205                 s->status |= SDHSTS_DATA_FLAG;
206                 if (s->config & SDHCFG_DATA_IRPT_EN) {
207                     s->status |= SDHSTS_SDIO_IRPT;
208                 }
209             }
210         } else if (is_write) { /* write */
211             n = 0;
212             while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
213                 if (n == 0) {
214                     value = bcm2835_sdhost_fifo_pop(s);
215                     s->status |= SDHSTS_DATA_FLAG;
216                     if (s->config & SDHCFG_DATA_IRPT_EN) {
217                         s->status |= SDHSTS_SDIO_IRPT;
218                     }
219                     n = 4;
220                 }
221                 n--;
222                 s->datacnt--;
223                 sdbus_write_data(&s->sdbus, value & 0xff);
224                 value >>= 8;
225             }
226         }
227         if (s->datacnt == 0) {
228             s->edm &= ~SDEDM_FSM_MASK;
229             s->edm |= SDEDM_FSM_DATAMODE;
230             trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm);
231         }
232         if (is_write) {
233             /* set block interrupt at end of each block transfer */
234             if (s->hbct && s->datacnt % s->hbct == 0 &&
235                 (s->config & SDHCFG_BLOCK_IRPT_EN)) {
236                 s->status |= SDHSTS_BLOCK_IRPT;
237             }
238             /* set data interrupt after each transfer */
239             s->status |= SDHSTS_DATA_FLAG;
240             if (s->config & SDHCFG_DATA_IRPT_EN) {
241                 s->status |= SDHSTS_SDIO_IRPT;
242             }
243         }
244     }
245 
246     bcm2835_sdhost_update_irq(s);
247 
248     s->edm &= ~(0x1f << 4);
249     s->edm |= ((s->fifo_len & 0x1f) << 4);
250     trace_bcm2835_sdhost_edm_change("fifo run", s->edm);
251 }
252 
253 static uint64_t bcm2835_sdhost_read(void *opaque, hwaddr offset,
254     unsigned size)
255 {
256     BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
257     uint32_t res = 0;
258 
259     switch (offset) {
260     case SDCMD:
261         res = s->cmd;
262         break;
263     case SDHSTS:
264         res = s->status;
265         break;
266     case SDRSP0:
267         res = s->rsp[0];
268         break;
269     case SDRSP1:
270         res = s->rsp[1];
271         break;
272     case SDRSP2:
273         res = s->rsp[2];
274         break;
275     case SDRSP3:
276         res = s->rsp[3];
277         break;
278     case SDEDM:
279         res = s->edm;
280         break;
281     case SDVDD:
282         res = s->vdd;
283         break;
284     case SDDATA:
285         res = bcm2835_sdhost_fifo_pop(s);
286         bcm2835_sdhost_fifo_run(s);
287         break;
288     case SDHBCT:
289         res = s->hbct;
290         break;
291     case SDHBLC:
292         res = s->hblc;
293         break;
294 
295     default:
296         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
297                       __func__, offset);
298         res = 0;
299         break;
300     }
301 
302     trace_bcm2835_sdhost_read(offset, res, size);
303 
304     return res;
305 }
306 
307 static void bcm2835_sdhost_write(void *opaque, hwaddr offset,
308     uint64_t value, unsigned size)
309 {
310     BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
311 
312     trace_bcm2835_sdhost_write(offset, value, size);
313 
314     switch (offset) {
315     case SDCMD:
316         s->cmd = value;
317         if (value & SDCMD_NEW_FLAG) {
318             bcm2835_sdhost_send_command(s);
319             bcm2835_sdhost_fifo_run(s);
320             s->cmd &= ~SDCMD_NEW_FLAG;
321         }
322         break;
323     case SDTOUT:
324         break;
325     case SDCDIV:
326         break;
327     case SDHSTS:
328         s->status &= ~value;
329         bcm2835_sdhost_update_irq(s);
330         break;
331     case SDARG:
332         s->cmdarg = value;
333         break;
334     case SDEDM:
335         if ((value & 0xf) == 0xf) {
336             /* power down */
337             value &= ~0xf;
338         }
339         s->edm = value;
340         trace_bcm2835_sdhost_edm_change("guest register write", s->edm);
341         break;
342     case SDHCFG:
343         s->config = value;
344         bcm2835_sdhost_fifo_run(s);
345         break;
346     case SDVDD:
347         s->vdd = value;
348         break;
349     case SDDATA:
350         bcm2835_sdhost_fifo_push(s, value);
351         bcm2835_sdhost_fifo_run(s);
352         break;
353     case SDHBCT:
354         s->hbct = value;
355         break;
356     case SDHBLC:
357         s->hblc = value;
358         s->datacnt = s->hblc * s->hbct;
359         bcm2835_sdhost_fifo_run(s);
360         break;
361 
362     default:
363         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
364                       __func__, offset);
365         break;
366     }
367 }
368 
369 static const MemoryRegionOps bcm2835_sdhost_ops = {
370     .read = bcm2835_sdhost_read,
371     .write = bcm2835_sdhost_write,
372     .endianness = DEVICE_NATIVE_ENDIAN,
373 };
374 
375 static const VMStateDescription vmstate_bcm2835_sdhost = {
376     .name = TYPE_BCM2835_SDHOST,
377     .version_id = 1,
378     .minimum_version_id = 1,
379     .fields = (VMStateField[]) {
380         VMSTATE_UINT32(cmd, BCM2835SDHostState),
381         VMSTATE_UINT32(cmdarg, BCM2835SDHostState),
382         VMSTATE_UINT32(status, BCM2835SDHostState),
383         VMSTATE_UINT32_ARRAY(rsp, BCM2835SDHostState, 4),
384         VMSTATE_UINT32(config, BCM2835SDHostState),
385         VMSTATE_UINT32(edm, BCM2835SDHostState),
386         VMSTATE_UINT32(vdd, BCM2835SDHostState),
387         VMSTATE_UINT32(hbct, BCM2835SDHostState),
388         VMSTATE_UINT32(hblc, BCM2835SDHostState),
389         VMSTATE_INT32(fifo_pos, BCM2835SDHostState),
390         VMSTATE_INT32(fifo_len, BCM2835SDHostState),
391         VMSTATE_UINT32_ARRAY(fifo, BCM2835SDHostState, BCM2835_SDHOST_FIFO_LEN),
392         VMSTATE_UINT32(datacnt, BCM2835SDHostState),
393         VMSTATE_END_OF_LIST()
394     }
395 };
396 
397 static void bcm2835_sdhost_init(Object *obj)
398 {
399     BCM2835SDHostState *s = BCM2835_SDHOST(obj);
400 
401     qbus_create_inplace(&s->sdbus, sizeof(s->sdbus),
402                         TYPE_BCM2835_SDHOST_BUS, DEVICE(s), "sd-bus");
403 
404     memory_region_init_io(&s->iomem, obj, &bcm2835_sdhost_ops, s,
405                           TYPE_BCM2835_SDHOST, 0x1000);
406     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
407     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
408 }
409 
410 static void bcm2835_sdhost_reset(DeviceState *dev)
411 {
412     BCM2835SDHostState *s = BCM2835_SDHOST(dev);
413 
414     s->cmd = 0;
415     s->cmdarg = 0;
416     s->edm = 0x0000c60f;
417     trace_bcm2835_sdhost_edm_change("device reset", s->edm);
418     s->config = 0;
419     s->hbct = 0;
420     s->hblc = 0;
421     s->datacnt = 0;
422     s->fifo_pos = 0;
423     s->fifo_len = 0;
424 }
425 
426 static void bcm2835_sdhost_class_init(ObjectClass *klass, void *data)
427 {
428     DeviceClass *dc = DEVICE_CLASS(klass);
429 
430     dc->reset = bcm2835_sdhost_reset;
431     dc->vmsd = &vmstate_bcm2835_sdhost;
432 }
433 
434 static TypeInfo bcm2835_sdhost_info = {
435     .name          = TYPE_BCM2835_SDHOST,
436     .parent        = TYPE_SYS_BUS_DEVICE,
437     .instance_size = sizeof(BCM2835SDHostState),
438     .class_init    = bcm2835_sdhost_class_init,
439     .instance_init = bcm2835_sdhost_init,
440 };
441 
442 static const TypeInfo bcm2835_sdhost_bus_info = {
443     .name = TYPE_BCM2835_SDHOST_BUS,
444     .parent = TYPE_SD_BUS,
445     .instance_size = sizeof(SDBus),
446 };
447 
448 static void bcm2835_sdhost_register_types(void)
449 {
450     type_register_static(&bcm2835_sdhost_info);
451     type_register_static(&bcm2835_sdhost_bus_info);
452 }
453 
454 type_init(bcm2835_sdhost_register_types)
455