aboutsummaryrefslogtreecommitdiff
path: root/hw/ssi/aspeed_smc.c
blob: 3bd381b13bc2a509e7b82794ecf1ccceaa903a2b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
/*
 * ASPEED AST2400 SMC Controller (SPI Flash Only)
 *
 * Copyright (C) 2016 IBM Corp.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu/osdep.h"
#include "hw/sysbus.h"
#include "sysemu/sysemu.h"
#include "qemu/log.h"
#include "include/qemu/error-report.h"
#include "exec/address-spaces.h"

#include "hw/ssi/aspeed_smc.h"

/* CE Type Setting Register */
#define R_CONF            (0x00 / 4)
#define   CONF_LEGACY_DISABLE  (1 << 31)
#define   CONF_ENABLE_W4       20
#define   CONF_ENABLE_W3       19
#define   CONF_ENABLE_W2       18
#define   CONF_ENABLE_W1       17
#define   CONF_ENABLE_W0       16
#define   CONF_FLASH_TYPE4     8
#define   CONF_FLASH_TYPE3     6
#define   CONF_FLASH_TYPE2     4
#define   CONF_FLASH_TYPE1     2
#define   CONF_FLASH_TYPE0     0
#define      CONF_FLASH_TYPE_NOR   0x0
#define      CONF_FLASH_TYPE_NAND  0x1
#define      CONF_FLASH_TYPE_SPI   0x2

/* CE Control Register */
#define R_CE_CTRL            (0x04 / 4)
#define   CTRL_EXTENDED4       4  /* 32 bit addressing for SPI */
#define   CTRL_EXTENDED3       3  /* 32 bit addressing for SPI */
#define   CTRL_EXTENDED2       2  /* 32 bit addressing for SPI */
#define   CTRL_EXTENDED1       1  /* 32 bit addressing for SPI */
#define   CTRL_EXTENDED0       0  /* 32 bit addressing for SPI */

/* Interrupt Control and Status Register */
#define R_INTR_CTRL       (0x08 / 4)
#define   INTR_CTRL_DMA_STATUS            (1 << 11)
#define   INTR_CTRL_CMD_ABORT_STATUS      (1 << 10)
#define   INTR_CTRL_WRITE_PROTECT_STATUS  (1 << 9)
#define   INTR_CTRL_DMA_EN                (1 << 3)
#define   INTR_CTRL_CMD_ABORT_EN          (1 << 2)
#define   INTR_CTRL_WRITE_PROTECT_EN      (1 << 1)

/* CEx Control Register */
#define R_CTRL0           (0x10 / 4)
#define   CTRL_CMD_SHIFT           16
#define   CTRL_CMD_MASK            0xff
#define   CTRL_CE_STOP_ACTIVE      (1 << 2)
#define   CTRL_CMD_MODE_MASK       0x3
#define     CTRL_READMODE          0x0
#define     CTRL_FREADMODE         0x1
#define     CTRL_WRITEMODE         0x2
#define     CTRL_USERMODE          0x3
#define R_CTRL1           (0x14 / 4)
#define R_CTRL2           (0x18 / 4)
#define R_CTRL3           (0x1C / 4)
#define R_CTRL4           (0x20 / 4)

/* CEx Segment Address Register */
#define R_SEG_ADDR0       (0x30 / 4)
#define   SEG_END_SHIFT        24   /* 8MB units */
#define   SEG_END_MASK         0xff
#define   SEG_START_SHIFT      16   /* address bit [A29-A23] */
#define   SEG_START_MASK       0xff
#define R_SEG_ADDR1       (0x34 / 4)
#define R_SEG_ADDR2       (0x38 / 4)
#define R_SEG_ADDR3       (0x3C / 4)
#define R_SEG_ADDR4       (0x40 / 4)

/* Misc Control Register #1 */
#define R_MISC_CTRL1      (0x50 / 4)

/* Misc Control Register #2 */
#define R_MISC_CTRL2      (0x54 / 4)

/* DMA Control/Status Register */
#define R_DMA_CTRL        (0x80 / 4)
#define   DMA_CTRL_DELAY_MASK   0xf
#define   DMA_CTRL_DELAY_SHIFT  8
#define   DMA_CTRL_FREQ_MASK    0xf
#define   DMA_CTRL_FREQ_SHIFT   4
#define   DMA_CTRL_MODE         (1 << 3)
#define   DMA_CTRL_CKSUM        (1 << 2)
#define   DMA_CTRL_DIR          (1 << 1)
#define   DMA_CTRL_EN           (1 << 0)

/* DMA Flash Side Address */
#define R_DMA_FLASH_ADDR  (0x84 / 4)

/* DMA DRAM Side Address */
#define R_DMA_DRAM_ADDR   (0x88 / 4)

/* DMA Length Register */
#define R_DMA_LEN         (0x8C / 4)

/* Checksum Calculation Result */
#define R_DMA_CHECKSUM    (0x90 / 4)

/* Misc Control Register #2 */
#define R_TIMINGS         (0x94 / 4)

/* SPI controller registers and bits */
#define R_SPI_CONF        (0x00 / 4)
#define   SPI_CONF_ENABLE_W0   0
#define R_SPI_CTRL0       (0x4 / 4)
#define R_SPI_MISC_CTRL   (0x10 / 4)
#define R_SPI_TIMINGS     (0x14 / 4)

#define ASPEED_SOC_SMC_FLASH_BASE   0x10000000
#define ASPEED_SOC_FMC_FLASH_BASE   0x20000000
#define ASPEED_SOC_SPI_FLASH_BASE   0x30000000
#define ASPEED_SOC_SPI2_FLASH_BASE  0x38000000

/*
 * Default segments mapping addresses and size for each slave per
 * controller. These can be changed when board is initialized with the
 * Segment Address Registers.
 */
static const AspeedSegments aspeed_segments_legacy[] = {
    { 0x10000000, 32 * 1024 * 1024 },
};

static const AspeedSegments aspeed_segments_fmc[] = {
    { 0x20000000, 64 * 1024 * 1024 }, /* start address is readonly */
    { 0x24000000, 32 * 1024 * 1024 },
    { 0x26000000, 32 * 1024 * 1024 },
    { 0x28000000, 32 * 1024 * 1024 },
    { 0x2A000000, 32 * 1024 * 1024 }
};

static const AspeedSegments aspeed_segments_spi[] = {
    { 0x30000000, 64 * 1024 * 1024 },
};

static const AspeedSegments aspeed_segments_ast2500_fmc[] = {
    { 0x20000000, 128 * 1024 * 1024 }, /* start address is readonly */
    { 0x28000000,  32 * 1024 * 1024 },
    { 0x2A000000,  32 * 1024 * 1024 },
};

static const AspeedSegments aspeed_segments_ast2500_spi1[] = {
    { 0x30000000, 32 * 1024 * 1024 }, /* start address is readonly */
    { 0x32000000, 96 * 1024 * 1024 }, /* end address is readonly */
};

static const AspeedSegments aspeed_segments_ast2500_spi2[] = {
    { 0x38000000, 32 * 1024 * 1024 }, /* start address is readonly */
    { 0x3A000000, 96 * 1024 * 1024 }, /* end address is readonly */
};

static const AspeedSMCController controllers[] = {
    { "aspeed.smc.smc", R_CONF, R_CE_CTRL, R_CTRL0, R_TIMINGS,
      CONF_ENABLE_W0, 5, aspeed_segments_legacy,
      ASPEED_SOC_SMC_FLASH_BASE, 0x6000000 },
    { "aspeed.smc.fmc", R_CONF, R_CE_CTRL, R_CTRL0, R_TIMINGS,
      CONF_ENABLE_W0, 5, aspeed_segments_fmc,
      ASPEED_SOC_FMC_FLASH_BASE, 0x10000000 },
    { "aspeed.smc.spi", R_SPI_CONF, 0xff, R_SPI_CTRL0, R_SPI_TIMINGS,
      SPI_CONF_ENABLE_W0, 1, aspeed_segments_spi,
      ASPEED_SOC_SPI_FLASH_BASE, 0x10000000 },
    { "aspeed.smc.ast2500-fmc", R_CONF, R_CE_CTRL, R_CTRL0, R_TIMINGS,
      CONF_ENABLE_W0, 3, aspeed_segments_ast2500_fmc,
      ASPEED_SOC_FMC_FLASH_BASE, 0x10000000 },
    { "aspeed.smc.ast2500-spi1", R_CONF, R_CE_CTRL, R_CTRL0, R_TIMINGS,
      CONF_ENABLE_W0, 2, aspeed_segments_ast2500_spi1,
      ASPEED_SOC_SPI_FLASH_BASE, 0x8000000 },
    { "aspeed.smc.ast2500-spi2", R_CONF, R_CE_CTRL, R_CTRL0, R_TIMINGS,
      CONF_ENABLE_W0, 2, aspeed_segments_ast2500_spi2,
      ASPEED_SOC_SPI2_FLASH_BASE, 0x8000000 },
};

/*
 * The Segment Register uses a 8MB unit to encode the start address
 * and the end address of the mapping window of a flash SPI slave :
 *
 *        | byte 1 | byte 2 | byte 3 | byte 4 |
 *        +--------+--------+--------+--------+
 *        |  end   |  start |   0    |   0    |
 *
 */
static inline uint32_t aspeed_smc_segment_to_reg(const AspeedSegments *seg)
{
    uint32_t reg = 0;
    reg |= ((seg->addr >> 23) & SEG_START_MASK) << SEG_START_SHIFT;
    reg |= (((seg->addr + seg->size) >> 23) & SEG_END_MASK) << SEG_END_SHIFT;
    return reg;
}

static inline void aspeed_smc_reg_to_segment(uint32_t reg, AspeedSegments *seg)
{
    seg->addr = ((reg >> SEG_START_SHIFT) & SEG_START_MASK) << 23;
    seg->size = (((reg >> SEG_END_SHIFT) & SEG_END_MASK) << 23) - seg->addr;
}

static bool aspeed_smc_flash_overlap(const AspeedSMCState *s,
                                     const AspeedSegments *new,
                                     int cs)
{
    AspeedSegments seg;
    int i;

    for (i = 0; i < s->ctrl->max_slaves; i++) {
        if (i == cs) {
            continue;
        }

        aspeed_smc_reg_to_segment(s->regs[R_SEG_ADDR0 + i], &seg);

        if (new->addr + new->size > seg.addr &&
            new->addr < seg.addr + seg.size) {
            qemu_log_mask(LOG_GUEST_ERROR, "%s: new segment CS%d [ 0x%"
                          HWADDR_PRIx" - 0x%"HWADDR_PRIx" ] overlaps with "
                          "CS%d [ 0x%"HWADDR_PRIx" - 0x%"HWADDR_PRIx" ]\n",
                          s->ctrl->name, cs, new->addr, new->addr + new->size,
                          i, seg.addr, seg.addr + seg.size);
            return true;
        }
    }
    return false;
}

static void aspeed_smc_flash_set_segment(AspeedSMCState *s, int cs,
                                         uint64_t new)
{
    AspeedSMCFlash *fl = &s->flashes[cs];
    AspeedSegments seg;

    aspeed_smc_reg_to_segment(new, &seg);

    /* The start address of CS0 is read-only */
    if (cs == 0 && seg.addr != s->ctrl->flash_window_base) {
        qemu_log_mask(LOG_GUEST_ERROR,
                      "%s: Tried to change CS0 start address to 0x%"
                      HWADDR_PRIx "\n", s->ctrl->name, seg.addr);
        seg.addr = s->ctrl->flash_window_base;
        new = aspeed_smc_segment_to_reg(&seg);
    }

    /*
     * The end address of the AST2500 spi controllers is also
     * read-only.
     */
    if ((s->ctrl->segments == aspeed_segments_ast2500_spi1 ||
         s->ctrl->segments == aspeed_segments_ast2500_spi2) &&
        cs == s->ctrl->max_slaves &&
        seg.addr + seg.size != s->ctrl->segments[cs].addr +
        s->ctrl->segments[cs].size) {
        qemu_log_mask(LOG_GUEST_ERROR,
                      "%s: Tried to change CS%d end address to 0x%"
                      HWADDR_PRIx "\n", s->ctrl->name, cs, seg.addr + seg.size);
        seg.size = s->ctrl->segments[cs].addr + s->ctrl->segments[cs].size -
            seg.addr;
        new = aspeed_smc_segment_to_reg(&seg);
    }

    /* Keep the segment in the overall flash window */
    if (seg.addr + seg.size <= s->ctrl->flash_window_base ||
        seg.addr > s->ctrl->flash_window_base + s->ctrl->flash_window_size) {
        qemu_log_mask(LOG_GUEST_ERROR, "%s: new segment for CS%d is invalid : "
                      "[ 0x%"HWADDR_PRIx" - 0x%"HWADDR_PRIx" ]\n",
                      s->ctrl->name, cs, seg.addr, seg.addr + seg.size);
        return;
    }

    /* Check start address vs. alignment */
    if (seg.size && !QEMU_IS_ALIGNED(seg.addr, seg.size)) {
        qemu_log_mask(LOG_GUEST_ERROR, "%s: new segment for CS%d is not "
                      "aligned : [ 0x%"HWADDR_PRIx" - 0x%"HWADDR_PRIx" ]\n",
                      s->ctrl->name, cs, seg.addr, seg.addr + seg.size);
    }

    /* And segments should not overlap (in the specs) */
    aspeed_smc_flash_overlap(s, &seg, cs);

    /* All should be fine now to move the region */
    memory_region_transaction_begin();
    memory_region_set_size(&fl->mmio, seg.size);
    memory_region_set_address(&fl->mmio, seg.addr - s->ctrl->flash_window_base);
    memory_region_set_enabled(&fl->mmio, true);
    memory_region_transaction_commit();

    s->regs[R_SEG_ADDR0 + cs] = new;
}

static uint64_t aspeed_smc_flash_default_read(void *opaque, hwaddr addr,
                                              unsigned size)
{
    qemu_log_mask(LOG_GUEST_ERROR, "%s: To 0x%" HWADDR_PRIx " of size %u"
                  PRIx64 "\n", __func__, addr, size);
    return 0;
}

static void aspeed_smc_flash_default_write(void *opaque, hwaddr addr,
                                           uint64_t data, unsigned size)
{
   qemu_log_mask(LOG_GUEST_ERROR, "%s: To 0x%" HWADDR_PRIx " of size %u: 0x%"
                 PRIx64 "\n", __func__, addr, size, data);
}

static const MemoryRegionOps aspeed_smc_flash_default_ops = {
    .read = aspeed_smc_flash_default_read,
    .write = aspeed_smc_flash_default_write,
    .endianness = DEVICE_LITTLE_ENDIAN,
    .valid = {
        .min_access_size = 1,
        .max_access_size = 4,
    },
};

static inline int aspeed_smc_flash_mode(const AspeedSMCFlash *fl)
{
    const AspeedSMCState *s = fl->controller;

    return s->regs[s->r_ctrl0 + fl->id] & CTRL_CMD_MODE_MASK;
}

static inline bool aspeed_smc_is_usermode(const AspeedSMCFlash *fl)
{
    return aspeed_smc_flash_mode(fl) == CTRL_USERMODE;
}

static inline bool aspeed_smc_is_writable(const AspeedSMCFlash *fl)
{
    const AspeedSMCState *s = fl->controller;

    return s->regs[s->r_conf] & (1 << (s->conf_enable_w0 + fl->id));
}

static uint64_t aspeed_smc_flash_read(void *opaque, hwaddr addr, unsigned size)
{
    AspeedSMCFlash *fl = opaque;
    const AspeedSMCState *s = fl->controller;
    uint64_t ret = 0;
    int i;

    if (aspeed_smc_is_usermode(fl)) {
        for (i = 0; i < size; i++) {
            ret |= ssi_transfer(s->spi, 0x0) << (8 * i);
        }
    } else {
        qemu_log_mask(LOG_UNIMP, "%s: usermode not implemented\n",
                      __func__);
        ret = -1;
    }

    return ret;
}

static void aspeed_smc_flash_write(void *opaque, hwaddr addr, uint64_t data,
                           unsigned size)
{
    AspeedSMCFlash *fl = opaque;
    const AspeedSMCState *s = fl->controller;
    int i;

    if (!aspeed_smc_is_writable(fl)) {
        qemu_log_mask(LOG_GUEST_ERROR, "%s: flash is not writable at 0x%"
                      HWADDR_PRIx "\n", __func__, addr);
        return;
    }

    if (!aspeed_smc_is_usermode(fl)) {
        qemu_log_mask(LOG_UNIMP, "%s: usermode not implemented\n",
                      __func__);
        return;
    }

    for (i = 0; i < size; i++) {
        ssi_transfer(s->spi, (data >> (8 * i)) & 0xff);
    }
}

static const MemoryRegionOps aspeed_smc_flash_ops = {
    .read = aspeed_smc_flash_read,
    .write = aspeed_smc_flash_write,
    .endianness = DEVICE_LITTLE_ENDIAN,
    .valid = {
        .min_access_size = 1,
        .max_access_size = 4,
    },
};

static inline bool aspeed_smc_is_ce_stop_active(const AspeedSMCFlash *fl)
{
    const AspeedSMCState *s = fl->controller;

    return s->regs[s->r_ctrl0 + fl->id] & CTRL_CE_STOP_ACTIVE;
}

static void aspeed_smc_flash_update_cs(AspeedSMCFlash *fl)
{
    const AspeedSMCState *s = fl->controller;

    qemu_set_irq(s->cs_lines[fl->id], aspeed_smc_is_ce_stop_active(fl));
}

static void aspeed_smc_reset(DeviceState *d)
{
    AspeedSMCState *s = ASPEED_SMC(d);
    int i;

    memset(s->regs, 0, sizeof s->regs);

    /* Pretend DMA is done (u-boot initialization) */
    s->regs[R_INTR_CTRL] = INTR_CTRL_DMA_STATUS;

    /* Unselect all slaves */
    for (i = 0; i < s->num_cs; ++i) {
        s->regs[s->r_ctrl0 + i] |= CTRL_CE_STOP_ACTIVE;
        qemu_set_irq(s->cs_lines[i], true);
    }

    /* setup default segment register values for all */
    for (i = 0; i < s->ctrl->max_slaves; ++i) {
        s->regs[R_SEG_ADDR0 + i] =
            aspeed_smc_segment_to_reg(&s->ctrl->segments[i]);
    }

    /* HW strapping for AST2500 FMC controllers  */
    if (s->ctrl->segments == aspeed_segments_ast2500_fmc) {
        /* flash type is fixed to SPI for CE0 and CE1 */
        s->regs[s->r_conf] |= (CONF_FLASH_TYPE_SPI << CONF_FLASH_TYPE0);
        s->regs[s->r_conf] |= (CONF_FLASH_TYPE_SPI << CONF_FLASH_TYPE1);

        /* 4BYTE mode is autodetected for CE0. Let's force it to 1 for
         * now */
        s->regs[s->r_ce_ctrl] |= (1 << (CTRL_EXTENDED0));
    }

    /* HW strapping for AST2400 FMC controllers (SCU70). Let's use the
     * configuration of the palmetto-bmc machine */
    if (s->ctrl->segments == aspeed_segments_fmc) {
        s->regs[s->r_conf] |= (CONF_FLASH_TYPE_SPI << CONF_FLASH_TYPE0);

        s->regs[s->r_ce_ctrl] |= (1 << (CTRL_EXTENDED0));
    }
}

static uint64_t aspeed_smc_read(void *opaque, hwaddr addr, unsigned int size)
{
    AspeedSMCState *s = ASPEED_SMC(opaque);

    addr >>= 2;

    if (addr >= ARRAY_SIZE(s->regs)) {
        qemu_log_mask(LOG_GUEST_ERROR,
                      "%s: Out-of-bounds read at 0x%" HWADDR_PRIx "\n",
                      __func__, addr);
        return 0;
    }

    if (addr == s->r_conf ||
        addr == s->r_timings ||
        addr == s->r_ce_ctrl ||
        addr == R_INTR_CTRL ||
        (addr >= R_SEG_ADDR0 && addr < R_SEG_ADDR0 + s->ctrl->max_slaves) ||
        (addr >= s->r_ctrl0 && addr < s->r_ctrl0 + s->num_cs)) {
        return s->regs[addr];
    } else {
        qemu_log_mask(LOG_UNIMP, "%s: not implemented: 0x%" HWADDR_PRIx "\n",
                      __func__, addr);
        return 0;
    }
}

static void aspeed_smc_write(void *opaque, hwaddr addr, uint64_t data,
                             unsigned int size)
{
    AspeedSMCState *s = ASPEED_SMC(opaque);
    uint32_t value = data;

    addr >>= 2;

    if (addr >= ARRAY_SIZE(s->regs)) {
        qemu_log_mask(LOG_GUEST_ERROR,
                      "%s: Out-of-bounds write at 0x%" HWADDR_PRIx "\n",
                      __func__, addr);
        return;
    }

    if (addr == s->r_conf ||
        addr == s->r_timings ||
        addr == s->r_ce_ctrl) {
        s->regs[addr] = value;
    } else if (addr >= s->r_ctrl0 && addr < s->r_ctrl0 + s->num_cs) {
        int cs = addr - s->r_ctrl0;
        s->regs[addr] = value;
        aspeed_smc_flash_update_cs(&s->flashes[cs]);
    } else if (addr >= R_SEG_ADDR0 &&
               addr < R_SEG_ADDR0 + s->ctrl->max_slaves) {
        int cs = addr - R_SEG_ADDR0;

        if (value != s->regs[R_SEG_ADDR0 + cs]) {
            aspeed_smc_flash_set_segment(s, cs, value);
        }
    } else {
        qemu_log_mask(LOG_UNIMP, "%s: not implemented: 0x%" HWADDR_PRIx "\n",
                      __func__, addr);
        return;
    }
}

static const MemoryRegionOps aspeed_smc_ops = {
    .read = aspeed_smc_read,
    .write = aspeed_smc_write,
    .endianness = DEVICE_LITTLE_ENDIAN,
    .valid.unaligned = true,
};

static void aspeed_smc_realize(DeviceState *dev, Error **errp)
{
    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
    AspeedSMCState *s = ASPEED_SMC(dev);
    AspeedSMCClass *mc = ASPEED_SMC_GET_CLASS(s);
    int i;
    char name[32];
    hwaddr offset = 0;

    s->ctrl = mc->ctrl;

    /* keep a copy under AspeedSMCState to speed up accesses */
    s->r_conf = s->ctrl->r_conf;
    s->r_ce_ctrl = s->ctrl->r_ce_ctrl;
    s->r_ctrl0 = s->ctrl->r_ctrl0;
    s->r_timings = s->ctrl->r_timings;
    s->conf_enable_w0 = s->ctrl->conf_enable_w0;

    /* Enforce some real HW limits */
    if (s->num_cs > s->ctrl->max_slaves) {
        qemu_log_mask(LOG_GUEST_ERROR, "%s: num_cs cannot exceed: %d\n",
                      __func__, s->ctrl->max_slaves);
        s->num_cs = s->ctrl->max_slaves;
    }

    s->spi = ssi_create_bus(dev, "spi");

    /* Setup cs_lines for slaves */
    sysbus_init_irq(sbd, &s->irq);
    s->cs_lines = g_new0(qemu_irq, s->num_cs);
    ssi_auto_connect_slaves(dev, s->cs_lines, s->spi);

    for (i = 0; i < s->num_cs; ++i) {
        sysbus_init_irq(sbd, &s->cs_lines[i]);
    }

    /* The memory region for the controller registers */
    memory_region_init_io(&s->mmio, OBJECT(s), &aspeed_smc_ops, s,
                          s->ctrl->name, ASPEED_SMC_R_MAX * 4);
    sysbus_init_mmio(sbd, &s->mmio);

    /*
     * The container memory region representing the address space
     * window in which the flash modules are mapped. The size and
     * address depends on the SoC model and controller type.
     */
    snprintf(name, sizeof(name), "%s.flash", s->ctrl->name);

    memory_region_init_io(&s->mmio_flash, OBJECT(s),
                          &aspeed_smc_flash_default_ops, s, name,
                          s->ctrl->flash_window_size);
    sysbus_init_mmio(sbd, &s->mmio_flash);

    s->flashes = g_new0(AspeedSMCFlash, s->ctrl->max_slaves);

    /*
     * Let's create a sub memory region for each possible slave. All
     * have a configurable memory segment in the overall flash mapping
     * window of the controller but, there is not necessarily a flash
     * module behind to handle the memory accesses. This depends on
     * the board configuration.
     */
    for (i = 0; i < s->ctrl->max_slaves; ++i) {
        AspeedSMCFlash *fl = &s->flashes[i];

        snprintf(name, sizeof(name), "%s.%d", s->ctrl->name, i);

        fl->id = i;
        fl->controller = s;
        fl->size = s->ctrl->segments[i].size;
        memory_region_init_io(&fl->mmio, OBJECT(s), &aspeed_smc_flash_ops,
                              fl, name, fl->size);
        memory_region_add_subregion(&s->mmio_flash, offset, &fl->mmio);
        offset += fl->size;
    }
}

static const VMStateDescription vmstate_aspeed_smc = {
    .name = "aspeed.smc",
    .version_id = 1,
    .minimum_version_id = 1,
    .fields = (VMStateField[]) {
        VMSTATE_UINT32_ARRAY(regs, AspeedSMCState, ASPEED_SMC_R_MAX),
        VMSTATE_END_OF_LIST()
    }
};

static Property aspeed_smc_properties[] = {
    DEFINE_PROP_UINT32("num-cs", AspeedSMCState, num_cs, 1),
    DEFINE_PROP_END_OF_LIST(),
};

static void aspeed_smc_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    AspeedSMCClass *mc = ASPEED_SMC_CLASS(klass);

    dc->realize = aspeed_smc_realize;
    dc->reset = aspeed_smc_reset;
    dc->props = aspeed_smc_properties;
    dc->vmsd = &vmstate_aspeed_smc;
    mc->ctrl = data;
}

static const TypeInfo aspeed_smc_info = {
    .name           = TYPE_ASPEED_SMC,
    .parent         = TYPE_SYS_BUS_DEVICE,
    .instance_size  = sizeof(AspeedSMCState),
    .class_size     = sizeof(AspeedSMCClass),
    .abstract       = true,
};

static void aspeed_smc_register_types(void)
{
    int i;

    type_register_static(&aspeed_smc_info);
    for (i = 0; i < ARRAY_SIZE(controllers); ++i) {
        TypeInfo ti = {
            .name       = controllers[i].name,
            .parent     = TYPE_ASPEED_SMC,
            .class_init = aspeed_smc_class_init,
            .class_data = (void *)&controllers[i],
        };
        type_register(&ti);
    }
}

type_init(aspeed_smc_register_types)