xref: /openbmc/qemu/hw/sd/bcm2835_sdhost.c (revision 4921d0a7)
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 /* This is reusing the SDBus typedef from SD_BUS */
26 DECLARE_INSTANCE_CHECKER(SDBus, BCM2835_SDHOST_BUS,
27                          TYPE_BCM2835_SDHOST_BUS)
28 
29 #define SDCMD  0x00 /* Command to SD card              - 16 R/W */
30 #define SDARG  0x04 /* Argument to SD card             - 32 R/W */
31 #define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
32 #define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
33 #define SDRSP0 0x10 /* SD card rsp (31:0)         - 32 R   */
34 #define SDRSP1 0x14 /* SD card rsp (63:32)        - 32 R   */
35 #define SDRSP2 0x18 /* SD card rsp (95:64)        - 32 R   */
36 #define SDRSP3 0x1c /* SD card rsp (127:96)       - 32 R   */
37 #define SDHSTS 0x20 /* SD host status                  - 11 R   */
38 #define SDVDD  0x30 /* SD card power control           -  1 R/W */
39 #define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
40 #define SDHCFG 0x38 /* Host configuration              -  2 R/W */
41 #define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
42 #define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
43 #define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
44 
45 #define SDCMD_NEW_FLAG                  0x8000
46 #define SDCMD_FAIL_FLAG                 0x4000
47 #define SDCMD_BUSYWAIT                  0x800
48 #define SDCMD_NO_RESPONSE               0x400
49 #define SDCMD_LONG_RESPONSE             0x200
50 #define SDCMD_WRITE_CMD                 0x80
51 #define SDCMD_READ_CMD                  0x40
52 #define SDCMD_CMD_MASK                  0x3f
53 
54 #define SDCDIV_MAX_CDIV                 0x7ff
55 
56 #define SDHSTS_BUSY_IRPT                0x400
57 #define SDHSTS_BLOCK_IRPT               0x200
58 #define SDHSTS_SDIO_IRPT                0x100
59 #define SDHSTS_REW_TIME_OUT             0x80
60 #define SDHSTS_CMD_TIME_OUT             0x40
61 #define SDHSTS_CRC16_ERROR              0x20
62 #define SDHSTS_CRC7_ERROR               0x10
63 #define SDHSTS_FIFO_ERROR               0x08
64 /* Reserved */
65 /* Reserved */
66 #define SDHSTS_DATA_FLAG                0x01
67 
68 #define SDHCFG_BUSY_IRPT_EN     (1 << 10)
69 #define SDHCFG_BLOCK_IRPT_EN    (1 << 8)
70 #define SDHCFG_SDIO_IRPT_EN     (1 << 5)
71 #define SDHCFG_DATA_IRPT_EN     (1 << 4)
72 #define SDHCFG_SLOW_CARD        (1 << 3)
73 #define SDHCFG_WIDE_EXT_BUS     (1 << 2)
74 #define SDHCFG_WIDE_INT_BUS     (1 << 1)
75 #define SDHCFG_REL_CMD_LINE     (1 << 0)
76 
77 #define SDEDM_FORCE_DATA_MODE   (1 << 19)
78 #define SDEDM_CLOCK_PULSE       (1 << 20)
79 #define SDEDM_BYPASS            (1 << 21)
80 
81 #define SDEDM_WRITE_THRESHOLD_SHIFT 9
82 #define SDEDM_READ_THRESHOLD_SHIFT 14
83 #define SDEDM_THRESHOLD_MASK     0x1f
84 
85 #define SDEDM_FSM_MASK           0xf
86 #define SDEDM_FSM_IDENTMODE      0x0
87 #define SDEDM_FSM_DATAMODE       0x1
88 #define SDEDM_FSM_READDATA       0x2
89 #define SDEDM_FSM_WRITEDATA      0x3
90 #define SDEDM_FSM_READWAIT       0x4
91 #define SDEDM_FSM_READCRC        0x5
92 #define SDEDM_FSM_WRITECRC       0x6
93 #define SDEDM_FSM_WRITEWAIT1     0x7
94 #define SDEDM_FSM_POWERDOWN      0x8
95 #define SDEDM_FSM_POWERUP        0x9
96 #define SDEDM_FSM_WRITESTART1    0xa
97 #define SDEDM_FSM_WRITESTART2    0xb
98 #define SDEDM_FSM_GENPULSES      0xc
99 #define SDEDM_FSM_WRITEWAIT2     0xd
100 #define SDEDM_FSM_STARTPOWDOWN   0xf
101 
102 #define SDDATA_FIFO_WORDS        16
103 
104 static void bcm2835_sdhost_update_irq(BCM2835SDHostState *s)
105 {
106     uint32_t irq = s->status &
107         (SDHSTS_BUSY_IRPT | SDHSTS_BLOCK_IRPT | SDHSTS_SDIO_IRPT);
108     trace_bcm2835_sdhost_update_irq(irq);
109     qemu_set_irq(s->irq, !!irq);
110 }
111 
112 static void bcm2835_sdhost_send_command(BCM2835SDHostState *s)
113 {
114     SDRequest request;
115     uint8_t rsp[16];
116     int rlen;
117 
118     request.cmd = s->cmd & SDCMD_CMD_MASK;
119     request.arg = s->cmdarg;
120 
121     rlen = sdbus_do_command(&s->sdbus, &request, rsp);
122     if (rlen < 0) {
123         goto error;
124     }
125     if (!(s->cmd & SDCMD_NO_RESPONSE)) {
126         if (rlen == 0 || (rlen == 4 && (s->cmd & SDCMD_LONG_RESPONSE))) {
127             goto error;
128         }
129         if (rlen != 4 && rlen != 16) {
130             goto error;
131         }
132         if (rlen == 4) {
133             s->rsp[0] = ldl_be_p(&rsp[0]);
134             s->rsp[1] = s->rsp[2] = s->rsp[3] = 0;
135         } else {
136             s->rsp[0] = ldl_be_p(&rsp[12]);
137             s->rsp[1] = ldl_be_p(&rsp[8]);
138             s->rsp[2] = ldl_be_p(&rsp[4]);
139             s->rsp[3] = ldl_be_p(&rsp[0]);
140         }
141     }
142     /* We never really delay commands, so if this was a 'busywait' command
143      * then we've completed it now and can raise the interrupt.
144      */
145     if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)) {
146         s->status |= SDHSTS_BUSY_IRPT;
147     }
148     return;
149 
150 error:
151     s->cmd |= SDCMD_FAIL_FLAG;
152     s->status |= SDHSTS_CMD_TIME_OUT;
153 }
154 
155 static void bcm2835_sdhost_fifo_push(BCM2835SDHostState *s, uint32_t value)
156 {
157     int n;
158 
159     if (s->fifo_len == BCM2835_SDHOST_FIFO_LEN) {
160         /* FIFO overflow */
161         return;
162     }
163     n = (s->fifo_pos + s->fifo_len) & (BCM2835_SDHOST_FIFO_LEN - 1);
164     s->fifo_len++;
165     s->fifo[n] = value;
166 }
167 
168 static uint32_t bcm2835_sdhost_fifo_pop(BCM2835SDHostState *s)
169 {
170     uint32_t value;
171 
172     if (s->fifo_len == 0) {
173         /* FIFO underflow */
174         return 0;
175     }
176     value = s->fifo[s->fifo_pos];
177     s->fifo_len--;
178     s->fifo_pos = (s->fifo_pos + 1) & (BCM2835_SDHOST_FIFO_LEN - 1);
179     return value;
180 }
181 
182 static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
183 {
184     uint32_t value = 0;
185     int n;
186     int is_read;
187     int is_write;
188 
189     is_read = (s->cmd & SDCMD_READ_CMD) != 0;
190     is_write = (s->cmd & SDCMD_WRITE_CMD) != 0;
191     if (s->datacnt != 0 && (is_write || sdbus_data_ready(&s->sdbus))) {
192         if (is_read) {
193             n = 0;
194             while (s->datacnt && s->fifo_len < BCM2835_SDHOST_FIFO_LEN) {
195                 value |= (uint32_t)sdbus_read_byte(&s->sdbus) << (n * 8);
196                 s->datacnt--;
197                 n++;
198                 if (n == 4) {
199                     bcm2835_sdhost_fifo_push(s, value);
200                     s->status |= SDHSTS_DATA_FLAG;
201                     if (s->config & SDHCFG_DATA_IRPT_EN) {
202                         s->status |= SDHSTS_SDIO_IRPT;
203                     }
204                     n = 0;
205                     value = 0;
206                 }
207             }
208             if (n != 0) {
209                 bcm2835_sdhost_fifo_push(s, value);
210                 s->status |= SDHSTS_DATA_FLAG;
211                 if (s->config & SDHCFG_DATA_IRPT_EN) {
212                     s->status |= SDHSTS_SDIO_IRPT;
213                 }
214             }
215         } else if (is_write) { /* write */
216             n = 0;
217             while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
218                 if (n == 0) {
219                     value = bcm2835_sdhost_fifo_pop(s);
220                     s->status |= SDHSTS_DATA_FLAG;
221                     if (s->config & SDHCFG_DATA_IRPT_EN) {
222                         s->status |= SDHSTS_SDIO_IRPT;
223                     }
224                     n = 4;
225                 }
226                 n--;
227                 s->datacnt--;
228                 sdbus_write_byte(&s->sdbus, value & 0xff);
229                 value >>= 8;
230             }
231         }
232         if (s->datacnt == 0) {
233             s->edm &= ~SDEDM_FSM_MASK;
234             s->edm |= SDEDM_FSM_DATAMODE;
235             trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm);
236         }
237         if (is_write) {
238             /* set block interrupt at end of each block transfer */
239             if (s->hbct && s->datacnt % s->hbct == 0 &&
240                 (s->config & SDHCFG_BLOCK_IRPT_EN)) {
241                 s->status |= SDHSTS_BLOCK_IRPT;
242             }
243             /* set data interrupt after each transfer */
244             s->status |= SDHSTS_DATA_FLAG;
245             if (s->config & SDHCFG_DATA_IRPT_EN) {
246                 s->status |= SDHSTS_SDIO_IRPT;
247             }
248         }
249     }
250 
251     bcm2835_sdhost_update_irq(s);
252 
253     s->edm &= ~(0x1f << 4);
254     s->edm |= ((s->fifo_len & 0x1f) << 4);
255     trace_bcm2835_sdhost_edm_change("fifo run", s->edm);
256 }
257 
258 static uint64_t bcm2835_sdhost_read(void *opaque, hwaddr offset,
259     unsigned size)
260 {
261     BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
262     uint32_t res = 0;
263 
264     switch (offset) {
265     case SDCMD:
266         res = s->cmd;
267         break;
268     case SDHSTS:
269         res = s->status;
270         break;
271     case SDRSP0:
272         res = s->rsp[0];
273         break;
274     case SDRSP1:
275         res = s->rsp[1];
276         break;
277     case SDRSP2:
278         res = s->rsp[2];
279         break;
280     case SDRSP3:
281         res = s->rsp[3];
282         break;
283     case SDEDM:
284         res = s->edm;
285         break;
286     case SDVDD:
287         res = s->vdd;
288         break;
289     case SDDATA:
290         res = bcm2835_sdhost_fifo_pop(s);
291         bcm2835_sdhost_fifo_run(s);
292         break;
293     case SDHBCT:
294         res = s->hbct;
295         break;
296     case SDHBLC:
297         res = s->hblc;
298         break;
299 
300     default:
301         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
302                       __func__, offset);
303         res = 0;
304         break;
305     }
306 
307     trace_bcm2835_sdhost_read(offset, res, size);
308 
309     return res;
310 }
311 
312 static void bcm2835_sdhost_write(void *opaque, hwaddr offset,
313     uint64_t value, unsigned size)
314 {
315     BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
316 
317     trace_bcm2835_sdhost_write(offset, value, size);
318 
319     switch (offset) {
320     case SDCMD:
321         s->cmd = value;
322         if (value & SDCMD_NEW_FLAG) {
323             bcm2835_sdhost_send_command(s);
324             bcm2835_sdhost_fifo_run(s);
325             s->cmd &= ~SDCMD_NEW_FLAG;
326         }
327         break;
328     case SDTOUT:
329         break;
330     case SDCDIV:
331         break;
332     case SDHSTS:
333         s->status &= ~value;
334         bcm2835_sdhost_update_irq(s);
335         break;
336     case SDARG:
337         s->cmdarg = value;
338         break;
339     case SDEDM:
340         if ((value & 0xf) == 0xf) {
341             /* power down */
342             value &= ~0xf;
343         }
344         s->edm = value;
345         trace_bcm2835_sdhost_edm_change("guest register write", s->edm);
346         break;
347     case SDHCFG:
348         s->config = value;
349         bcm2835_sdhost_fifo_run(s);
350         break;
351     case SDVDD:
352         s->vdd = value;
353         break;
354     case SDDATA:
355         bcm2835_sdhost_fifo_push(s, value);
356         bcm2835_sdhost_fifo_run(s);
357         break;
358     case SDHBCT:
359         s->hbct = value;
360         break;
361     case SDHBLC:
362         s->hblc = value;
363         s->datacnt = s->hblc * s->hbct;
364         bcm2835_sdhost_fifo_run(s);
365         break;
366 
367     default:
368         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
369                       __func__, offset);
370         break;
371     }
372 }
373 
374 static const MemoryRegionOps bcm2835_sdhost_ops = {
375     .read = bcm2835_sdhost_read,
376     .write = bcm2835_sdhost_write,
377     .endianness = DEVICE_NATIVE_ENDIAN,
378 };
379 
380 static const VMStateDescription vmstate_bcm2835_sdhost = {
381     .name = TYPE_BCM2835_SDHOST,
382     .version_id = 1,
383     .minimum_version_id = 1,
384     .fields = (const VMStateField[]) {
385         VMSTATE_UINT32(cmd, BCM2835SDHostState),
386         VMSTATE_UINT32(cmdarg, BCM2835SDHostState),
387         VMSTATE_UINT32(status, BCM2835SDHostState),
388         VMSTATE_UINT32_ARRAY(rsp, BCM2835SDHostState, 4),
389         VMSTATE_UINT32(config, BCM2835SDHostState),
390         VMSTATE_UINT32(edm, BCM2835SDHostState),
391         VMSTATE_UINT32(vdd, BCM2835SDHostState),
392         VMSTATE_UINT32(hbct, BCM2835SDHostState),
393         VMSTATE_UINT32(hblc, BCM2835SDHostState),
394         VMSTATE_INT32(fifo_pos, BCM2835SDHostState),
395         VMSTATE_INT32(fifo_len, BCM2835SDHostState),
396         VMSTATE_UINT32_ARRAY(fifo, BCM2835SDHostState, BCM2835_SDHOST_FIFO_LEN),
397         VMSTATE_UINT32(datacnt, BCM2835SDHostState),
398         VMSTATE_END_OF_LIST()
399     }
400 };
401 
402 static void bcm2835_sdhost_init(Object *obj)
403 {
404     BCM2835SDHostState *s = BCM2835_SDHOST(obj);
405 
406     qbus_init(&s->sdbus, sizeof(s->sdbus),
407               TYPE_BCM2835_SDHOST_BUS, DEVICE(s), "sd-bus");
408 
409     memory_region_init_io(&s->iomem, obj, &bcm2835_sdhost_ops, s,
410                           TYPE_BCM2835_SDHOST, 0x1000);
411     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
412     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
413 }
414 
415 static void bcm2835_sdhost_reset(DeviceState *dev)
416 {
417     BCM2835SDHostState *s = BCM2835_SDHOST(dev);
418 
419     s->cmd = 0;
420     s->cmdarg = 0;
421     s->edm = 0x0000c60f;
422     trace_bcm2835_sdhost_edm_change("device reset", s->edm);
423     s->config = 0;
424     s->hbct = 0;
425     s->hblc = 0;
426     s->datacnt = 0;
427     s->fifo_pos = 0;
428     s->fifo_len = 0;
429 }
430 
431 static void bcm2835_sdhost_class_init(ObjectClass *klass, void *data)
432 {
433     DeviceClass *dc = DEVICE_CLASS(klass);
434 
435     dc->reset = bcm2835_sdhost_reset;
436     dc->vmsd = &vmstate_bcm2835_sdhost;
437 }
438 
439 static const TypeInfo bcm2835_sdhost_types[] = {
440     {
441         .name           = TYPE_BCM2835_SDHOST,
442         .parent         = TYPE_SYS_BUS_DEVICE,
443         .instance_size  = sizeof(BCM2835SDHostState),
444         .class_init     = bcm2835_sdhost_class_init,
445         .instance_init  = bcm2835_sdhost_init,
446     },
447     {
448         .name           = TYPE_BCM2835_SDHOST_BUS,
449         .parent         = TYPE_SD_BUS,
450         .instance_size  = sizeof(SDBus),
451     },
452 };
453 
454 DEFINE_TYPES(bcm2835_sdhost_types)
455