1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for Audio DMA Controller (ADMAC) on t8103 (M1) and other Apple chips
4 *
5 * Copyright (C) The Asahi Linux Contributors
6 */
7
8 #include <linux/bits.h>
9 #include <linux/bitfield.h>
10 #include <linux/device.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_dma.h>
15 #include <linux/platform_device.h>
16 #include <linux/reset.h>
17 #include <linux/spinlock.h>
18 #include <linux/interrupt.h>
19
20 #include "dmaengine.h"
21
22 #define NCHANNELS_MAX 64
23 #define IRQ_NOUTPUTS 4
24
25 /*
26 * For allocation purposes we split the cache
27 * memory into blocks of fixed size (given in bytes).
28 */
29 #define SRAM_BLOCK 2048
30
31 #define RING_WRITE_SLOT GENMASK(1, 0)
32 #define RING_READ_SLOT GENMASK(5, 4)
33 #define RING_FULL BIT(9)
34 #define RING_EMPTY BIT(8)
35 #define RING_ERR BIT(10)
36
37 #define STATUS_DESC_DONE BIT(0)
38 #define STATUS_ERR BIT(6)
39
40 #define FLAG_DESC_NOTIFY BIT(16)
41
42 #define REG_TX_START 0x0000
43 #define REG_TX_STOP 0x0004
44 #define REG_RX_START 0x0008
45 #define REG_RX_STOP 0x000c
46 #define REG_IMPRINT 0x0090
47 #define REG_TX_SRAM_SIZE 0x0094
48 #define REG_RX_SRAM_SIZE 0x0098
49
50 #define REG_CHAN_CTL(ch) (0x8000 + (ch) * 0x200)
51 #define REG_CHAN_CTL_RST_RINGS BIT(0)
52
53 #define REG_DESC_RING(ch) (0x8070 + (ch) * 0x200)
54 #define REG_REPORT_RING(ch) (0x8074 + (ch) * 0x200)
55
56 #define REG_RESIDUE(ch) (0x8064 + (ch) * 0x200)
57
58 #define REG_BUS_WIDTH(ch) (0x8040 + (ch) * 0x200)
59
60 #define BUS_WIDTH_WORD_SIZE GENMASK(3, 0)
61 #define BUS_WIDTH_FRAME_SIZE GENMASK(7, 4)
62 #define BUS_WIDTH_8BIT 0x00
63 #define BUS_WIDTH_16BIT 0x01
64 #define BUS_WIDTH_32BIT 0x02
65 #define BUS_WIDTH_FRAME_2_WORDS 0x10
66 #define BUS_WIDTH_FRAME_4_WORDS 0x20
67
68 #define REG_CHAN_SRAM_CARVEOUT(ch) (0x8050 + (ch) * 0x200)
69 #define CHAN_SRAM_CARVEOUT_SIZE GENMASK(31, 16)
70 #define CHAN_SRAM_CARVEOUT_BASE GENMASK(15, 0)
71
72 #define REG_CHAN_FIFOCTL(ch) (0x8054 + (ch) * 0x200)
73 #define CHAN_FIFOCTL_LIMIT GENMASK(31, 16)
74 #define CHAN_FIFOCTL_THRESHOLD GENMASK(15, 0)
75
76 #define REG_DESC_WRITE(ch) (0x10000 + ((ch) / 2) * 0x4 + ((ch) & 1) * 0x4000)
77 #define REG_REPORT_READ(ch) (0x10100 + ((ch) / 2) * 0x4 + ((ch) & 1) * 0x4000)
78
79 #define REG_TX_INTSTATE(idx) (0x0030 + (idx) * 4)
80 #define REG_RX_INTSTATE(idx) (0x0040 + (idx) * 4)
81 #define REG_GLOBAL_INTSTATE(idx) (0x0050 + (idx) * 4)
82 #define REG_CHAN_INTSTATUS(ch, idx) (0x8010 + (ch) * 0x200 + (idx) * 4)
83 #define REG_CHAN_INTMASK(ch, idx) (0x8020 + (ch) * 0x200 + (idx) * 4)
84
85 struct admac_data;
86 struct admac_tx;
87
88 struct admac_chan {
89 unsigned int no;
90 struct admac_data *host;
91 struct dma_chan chan;
92 struct tasklet_struct tasklet;
93
94 u32 carveout;
95
96 spinlock_t lock;
97 struct admac_tx *current_tx;
98 int nperiod_acks;
99
100 /*
101 * We maintain a 'submitted' and 'issued' list mainly for interface
102 * correctness. Typical use of the driver (per channel) will be
103 * prepping, submitting and issuing a single cyclic transaction which
104 * will stay current until terminate_all is called.
105 */
106 struct list_head submitted;
107 struct list_head issued;
108
109 struct list_head to_free;
110 };
111
112 struct admac_sram {
113 u32 size;
114 /*
115 * SRAM_CARVEOUT has 16-bit fields, so the SRAM cannot be larger than
116 * 64K and a 32-bit bitfield over 2K blocks covers it.
117 */
118 u32 allocated;
119 };
120
121 struct admac_data {
122 struct dma_device dma;
123 struct device *dev;
124 __iomem void *base;
125 struct reset_control *rstc;
126
127 struct mutex cache_alloc_lock;
128 struct admac_sram txcache, rxcache;
129
130 int irq;
131 int irq_index;
132 int nchannels;
133 struct admac_chan channels[] __counted_by(nchannels);
134 };
135
136 struct admac_tx {
137 struct dma_async_tx_descriptor tx;
138 bool cyclic;
139 dma_addr_t buf_addr;
140 dma_addr_t buf_end;
141 size_t buf_len;
142 size_t period_len;
143
144 size_t submitted_pos;
145 size_t reclaimed_pos;
146
147 struct list_head node;
148 };
149
admac_alloc_sram_carveout(struct admac_data * ad,enum dma_transfer_direction dir,u32 * out)150 static int admac_alloc_sram_carveout(struct admac_data *ad,
151 enum dma_transfer_direction dir,
152 u32 *out)
153 {
154 struct admac_sram *sram;
155 int i, ret = 0, nblocks;
156
157 if (dir == DMA_MEM_TO_DEV)
158 sram = &ad->txcache;
159 else
160 sram = &ad->rxcache;
161
162 mutex_lock(&ad->cache_alloc_lock);
163
164 nblocks = sram->size / SRAM_BLOCK;
165 for (i = 0; i < nblocks; i++)
166 if (!(sram->allocated & BIT(i)))
167 break;
168
169 if (i < nblocks) {
170 *out = FIELD_PREP(CHAN_SRAM_CARVEOUT_BASE, i * SRAM_BLOCK) |
171 FIELD_PREP(CHAN_SRAM_CARVEOUT_SIZE, SRAM_BLOCK);
172 sram->allocated |= BIT(i);
173 } else {
174 ret = -EBUSY;
175 }
176
177 mutex_unlock(&ad->cache_alloc_lock);
178
179 return ret;
180 }
181
admac_free_sram_carveout(struct admac_data * ad,enum dma_transfer_direction dir,u32 carveout)182 static void admac_free_sram_carveout(struct admac_data *ad,
183 enum dma_transfer_direction dir,
184 u32 carveout)
185 {
186 struct admac_sram *sram;
187 u32 base = FIELD_GET(CHAN_SRAM_CARVEOUT_BASE, carveout);
188 int i;
189
190 if (dir == DMA_MEM_TO_DEV)
191 sram = &ad->txcache;
192 else
193 sram = &ad->rxcache;
194
195 if (WARN_ON(base >= sram->size))
196 return;
197
198 mutex_lock(&ad->cache_alloc_lock);
199 i = base / SRAM_BLOCK;
200 sram->allocated &= ~BIT(i);
201 mutex_unlock(&ad->cache_alloc_lock);
202 }
203
admac_modify(struct admac_data * ad,int reg,u32 mask,u32 val)204 static void admac_modify(struct admac_data *ad, int reg, u32 mask, u32 val)
205 {
206 void __iomem *addr = ad->base + reg;
207 u32 curr = readl_relaxed(addr);
208
209 writel_relaxed((curr & ~mask) | (val & mask), addr);
210 }
211
to_admac_chan(struct dma_chan * chan)212 static struct admac_chan *to_admac_chan(struct dma_chan *chan)
213 {
214 return container_of(chan, struct admac_chan, chan);
215 }
216
to_admac_tx(struct dma_async_tx_descriptor * tx)217 static struct admac_tx *to_admac_tx(struct dma_async_tx_descriptor *tx)
218 {
219 return container_of(tx, struct admac_tx, tx);
220 }
221
admac_chan_direction(int channo)222 static enum dma_transfer_direction admac_chan_direction(int channo)
223 {
224 /* Channel directions are hardwired */
225 return (channo & 1) ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
226 }
227
admac_tx_submit(struct dma_async_tx_descriptor * tx)228 static dma_cookie_t admac_tx_submit(struct dma_async_tx_descriptor *tx)
229 {
230 struct admac_tx *adtx = to_admac_tx(tx);
231 struct admac_chan *adchan = to_admac_chan(tx->chan);
232 unsigned long flags;
233 dma_cookie_t cookie;
234
235 spin_lock_irqsave(&adchan->lock, flags);
236 cookie = dma_cookie_assign(tx);
237 list_add_tail(&adtx->node, &adchan->submitted);
238 spin_unlock_irqrestore(&adchan->lock, flags);
239
240 return cookie;
241 }
242
admac_desc_free(struct dma_async_tx_descriptor * tx)243 static int admac_desc_free(struct dma_async_tx_descriptor *tx)
244 {
245 kfree(to_admac_tx(tx));
246
247 return 0;
248 }
249
admac_prep_dma_cyclic(struct dma_chan * chan,dma_addr_t buf_addr,size_t buf_len,size_t period_len,enum dma_transfer_direction direction,unsigned long flags)250 static struct dma_async_tx_descriptor *admac_prep_dma_cyclic(
251 struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
252 size_t period_len, enum dma_transfer_direction direction,
253 unsigned long flags)
254 {
255 struct admac_chan *adchan = container_of(chan, struct admac_chan, chan);
256 struct admac_tx *adtx;
257
258 if (direction != admac_chan_direction(adchan->no))
259 return NULL;
260
261 adtx = kzalloc(sizeof(*adtx), GFP_NOWAIT);
262 if (!adtx)
263 return NULL;
264
265 adtx->cyclic = true;
266
267 adtx->buf_addr = buf_addr;
268 adtx->buf_len = buf_len;
269 adtx->buf_end = buf_addr + buf_len;
270 adtx->period_len = period_len;
271
272 adtx->submitted_pos = 0;
273 adtx->reclaimed_pos = 0;
274
275 dma_async_tx_descriptor_init(&adtx->tx, chan);
276 adtx->tx.tx_submit = admac_tx_submit;
277 adtx->tx.desc_free = admac_desc_free;
278
279 return &adtx->tx;
280 }
281
282 /*
283 * Write one hardware descriptor for a dmaengine cyclic transaction.
284 */
admac_cyclic_write_one_desc(struct admac_data * ad,int channo,struct admac_tx * tx)285 static void admac_cyclic_write_one_desc(struct admac_data *ad, int channo,
286 struct admac_tx *tx)
287 {
288 dma_addr_t addr;
289
290 addr = tx->buf_addr + (tx->submitted_pos % tx->buf_len);
291
292 /* If happens means we have buggy code */
293 WARN_ON_ONCE(addr + tx->period_len > tx->buf_end);
294
295 dev_dbg(ad->dev, "ch%d descriptor: addr=0x%pad len=0x%zx flags=0x%lx\n",
296 channo, &addr, tx->period_len, FLAG_DESC_NOTIFY);
297
298 writel_relaxed(lower_32_bits(addr), ad->base + REG_DESC_WRITE(channo));
299 writel_relaxed(upper_32_bits(addr), ad->base + REG_DESC_WRITE(channo));
300 writel_relaxed(tx->period_len, ad->base + REG_DESC_WRITE(channo));
301 writel_relaxed(FLAG_DESC_NOTIFY, ad->base + REG_DESC_WRITE(channo));
302
303 tx->submitted_pos += tx->period_len;
304 tx->submitted_pos %= 2 * tx->buf_len;
305 }
306
307 /*
308 * Write all the hardware descriptors for a dmaengine cyclic
309 * transaction there is space for.
310 */
admac_cyclic_write_desc(struct admac_data * ad,int channo,struct admac_tx * tx)311 static void admac_cyclic_write_desc(struct admac_data *ad, int channo,
312 struct admac_tx *tx)
313 {
314 int i;
315
316 for (i = 0; i < 4; i++) {
317 if (readl_relaxed(ad->base + REG_DESC_RING(channo)) & RING_FULL)
318 break;
319 admac_cyclic_write_one_desc(ad, channo, tx);
320 }
321 }
322
admac_ring_noccupied_slots(int ringval)323 static int admac_ring_noccupied_slots(int ringval)
324 {
325 int wrslot = FIELD_GET(RING_WRITE_SLOT, ringval);
326 int rdslot = FIELD_GET(RING_READ_SLOT, ringval);
327
328 if (wrslot != rdslot) {
329 return (wrslot + 4 - rdslot) % 4;
330 } else {
331 WARN_ON((ringval & (RING_FULL | RING_EMPTY)) == 0);
332
333 if (ringval & RING_FULL)
334 return 4;
335 else
336 return 0;
337 }
338 }
339
340 /*
341 * Read from hardware the residue of a cyclic dmaengine transaction.
342 */
admac_cyclic_read_residue(struct admac_data * ad,int channo,struct admac_tx * adtx)343 static u32 admac_cyclic_read_residue(struct admac_data *ad, int channo,
344 struct admac_tx *adtx)
345 {
346 u32 ring1, ring2;
347 u32 residue1, residue2;
348 int nreports;
349 size_t pos;
350
351 ring1 = readl_relaxed(ad->base + REG_REPORT_RING(channo));
352 residue1 = readl_relaxed(ad->base + REG_RESIDUE(channo));
353 ring2 = readl_relaxed(ad->base + REG_REPORT_RING(channo));
354 residue2 = readl_relaxed(ad->base + REG_RESIDUE(channo));
355
356 if (residue2 > residue1) {
357 /*
358 * Controller must have loaded next descriptor between
359 * the two residue reads
360 */
361 nreports = admac_ring_noccupied_slots(ring1) + 1;
362 } else {
363 /* No descriptor load between the two reads, ring2 is safe to use */
364 nreports = admac_ring_noccupied_slots(ring2);
365 }
366
367 pos = adtx->reclaimed_pos + adtx->period_len * (nreports + 1) - residue2;
368
369 return adtx->buf_len - pos % adtx->buf_len;
370 }
371
admac_tx_status(struct dma_chan * chan,dma_cookie_t cookie,struct dma_tx_state * txstate)372 static enum dma_status admac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
373 struct dma_tx_state *txstate)
374 {
375 struct admac_chan *adchan = to_admac_chan(chan);
376 struct admac_data *ad = adchan->host;
377 struct admac_tx *adtx;
378
379 enum dma_status ret;
380 size_t residue;
381 unsigned long flags;
382
383 ret = dma_cookie_status(chan, cookie, txstate);
384 if (ret == DMA_COMPLETE || !txstate)
385 return ret;
386
387 spin_lock_irqsave(&adchan->lock, flags);
388 adtx = adchan->current_tx;
389
390 if (adtx && adtx->tx.cookie == cookie) {
391 ret = DMA_IN_PROGRESS;
392 residue = admac_cyclic_read_residue(ad, adchan->no, adtx);
393 } else {
394 ret = DMA_IN_PROGRESS;
395 residue = 0;
396 list_for_each_entry(adtx, &adchan->issued, node) {
397 if (adtx->tx.cookie == cookie) {
398 residue = adtx->buf_len;
399 break;
400 }
401 }
402 }
403 spin_unlock_irqrestore(&adchan->lock, flags);
404
405 dma_set_residue(txstate, residue);
406 return ret;
407 }
408
admac_start_chan(struct admac_chan * adchan)409 static void admac_start_chan(struct admac_chan *adchan)
410 {
411 struct admac_data *ad = adchan->host;
412 u32 startbit = 1 << (adchan->no / 2);
413
414 writel_relaxed(STATUS_DESC_DONE | STATUS_ERR,
415 ad->base + REG_CHAN_INTSTATUS(adchan->no, ad->irq_index));
416 writel_relaxed(STATUS_DESC_DONE | STATUS_ERR,
417 ad->base + REG_CHAN_INTMASK(adchan->no, ad->irq_index));
418
419 switch (admac_chan_direction(adchan->no)) {
420 case DMA_MEM_TO_DEV:
421 writel_relaxed(startbit, ad->base + REG_TX_START);
422 break;
423 case DMA_DEV_TO_MEM:
424 writel_relaxed(startbit, ad->base + REG_RX_START);
425 break;
426 default:
427 break;
428 }
429 dev_dbg(adchan->host->dev, "ch%d start\n", adchan->no);
430 }
431
admac_stop_chan(struct admac_chan * adchan)432 static void admac_stop_chan(struct admac_chan *adchan)
433 {
434 struct admac_data *ad = adchan->host;
435 u32 stopbit = 1 << (adchan->no / 2);
436
437 switch (admac_chan_direction(adchan->no)) {
438 case DMA_MEM_TO_DEV:
439 writel_relaxed(stopbit, ad->base + REG_TX_STOP);
440 break;
441 case DMA_DEV_TO_MEM:
442 writel_relaxed(stopbit, ad->base + REG_RX_STOP);
443 break;
444 default:
445 break;
446 }
447 dev_dbg(adchan->host->dev, "ch%d stop\n", adchan->no);
448 }
449
admac_reset_rings(struct admac_chan * adchan)450 static void admac_reset_rings(struct admac_chan *adchan)
451 {
452 struct admac_data *ad = adchan->host;
453
454 writel_relaxed(REG_CHAN_CTL_RST_RINGS,
455 ad->base + REG_CHAN_CTL(adchan->no));
456 writel_relaxed(0, ad->base + REG_CHAN_CTL(adchan->no));
457 }
458
admac_start_current_tx(struct admac_chan * adchan)459 static void admac_start_current_tx(struct admac_chan *adchan)
460 {
461 struct admac_data *ad = adchan->host;
462 int ch = adchan->no;
463
464 admac_reset_rings(adchan);
465 writel_relaxed(0, ad->base + REG_CHAN_CTL(ch));
466
467 admac_cyclic_write_one_desc(ad, ch, adchan->current_tx);
468 admac_start_chan(adchan);
469 admac_cyclic_write_desc(ad, ch, adchan->current_tx);
470 }
471
admac_issue_pending(struct dma_chan * chan)472 static void admac_issue_pending(struct dma_chan *chan)
473 {
474 struct admac_chan *adchan = to_admac_chan(chan);
475 struct admac_tx *tx;
476 unsigned long flags;
477
478 spin_lock_irqsave(&adchan->lock, flags);
479 list_splice_tail_init(&adchan->submitted, &adchan->issued);
480 if (!list_empty(&adchan->issued) && !adchan->current_tx) {
481 tx = list_first_entry(&adchan->issued, struct admac_tx, node);
482 list_del(&tx->node);
483
484 adchan->current_tx = tx;
485 adchan->nperiod_acks = 0;
486 admac_start_current_tx(adchan);
487 }
488 spin_unlock_irqrestore(&adchan->lock, flags);
489 }
490
admac_pause(struct dma_chan * chan)491 static int admac_pause(struct dma_chan *chan)
492 {
493 struct admac_chan *adchan = to_admac_chan(chan);
494
495 admac_stop_chan(adchan);
496
497 return 0;
498 }
499
admac_resume(struct dma_chan * chan)500 static int admac_resume(struct dma_chan *chan)
501 {
502 struct admac_chan *adchan = to_admac_chan(chan);
503
504 admac_start_chan(adchan);
505
506 return 0;
507 }
508
admac_terminate_all(struct dma_chan * chan)509 static int admac_terminate_all(struct dma_chan *chan)
510 {
511 struct admac_chan *adchan = to_admac_chan(chan);
512 unsigned long flags;
513
514 spin_lock_irqsave(&adchan->lock, flags);
515 admac_stop_chan(adchan);
516 admac_reset_rings(adchan);
517
518 if (adchan->current_tx) {
519 list_add_tail(&adchan->current_tx->node, &adchan->to_free);
520 adchan->current_tx = NULL;
521 }
522 /*
523 * Descriptors can only be freed after the tasklet
524 * has been killed (in admac_synchronize).
525 */
526 list_splice_tail_init(&adchan->submitted, &adchan->to_free);
527 list_splice_tail_init(&adchan->issued, &adchan->to_free);
528 spin_unlock_irqrestore(&adchan->lock, flags);
529
530 return 0;
531 }
532
admac_synchronize(struct dma_chan * chan)533 static void admac_synchronize(struct dma_chan *chan)
534 {
535 struct admac_chan *adchan = to_admac_chan(chan);
536 struct admac_tx *adtx, *_adtx;
537 unsigned long flags;
538 LIST_HEAD(head);
539
540 spin_lock_irqsave(&adchan->lock, flags);
541 list_splice_tail_init(&adchan->to_free, &head);
542 spin_unlock_irqrestore(&adchan->lock, flags);
543
544 tasklet_kill(&adchan->tasklet);
545
546 list_for_each_entry_safe(adtx, _adtx, &head, node) {
547 list_del(&adtx->node);
548 admac_desc_free(&adtx->tx);
549 }
550 }
551
admac_alloc_chan_resources(struct dma_chan * chan)552 static int admac_alloc_chan_resources(struct dma_chan *chan)
553 {
554 struct admac_chan *adchan = to_admac_chan(chan);
555 struct admac_data *ad = adchan->host;
556 int ret;
557
558 dma_cookie_init(&adchan->chan);
559 ret = admac_alloc_sram_carveout(ad, admac_chan_direction(adchan->no),
560 &adchan->carveout);
561 if (ret < 0)
562 return ret;
563
564 writel_relaxed(adchan->carveout,
565 ad->base + REG_CHAN_SRAM_CARVEOUT(adchan->no));
566 return 0;
567 }
568
admac_free_chan_resources(struct dma_chan * chan)569 static void admac_free_chan_resources(struct dma_chan *chan)
570 {
571 struct admac_chan *adchan = to_admac_chan(chan);
572
573 admac_terminate_all(chan);
574 admac_synchronize(chan);
575 admac_free_sram_carveout(adchan->host, admac_chan_direction(adchan->no),
576 adchan->carveout);
577 }
578
admac_dma_of_xlate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)579 static struct dma_chan *admac_dma_of_xlate(struct of_phandle_args *dma_spec,
580 struct of_dma *ofdma)
581 {
582 struct admac_data *ad = (struct admac_data *) ofdma->of_dma_data;
583 unsigned int index;
584
585 if (dma_spec->args_count != 1)
586 return NULL;
587
588 index = dma_spec->args[0];
589
590 if (index >= ad->nchannels) {
591 dev_err(ad->dev, "channel index %u out of bounds\n", index);
592 return NULL;
593 }
594
595 return dma_get_slave_channel(&ad->channels[index].chan);
596 }
597
admac_drain_reports(struct admac_data * ad,int channo)598 static int admac_drain_reports(struct admac_data *ad, int channo)
599 {
600 int count;
601
602 for (count = 0; count < 4; count++) {
603 u32 countval_hi, countval_lo, unk1, flags;
604
605 if (readl_relaxed(ad->base + REG_REPORT_RING(channo)) & RING_EMPTY)
606 break;
607
608 countval_lo = readl_relaxed(ad->base + REG_REPORT_READ(channo));
609 countval_hi = readl_relaxed(ad->base + REG_REPORT_READ(channo));
610 unk1 = readl_relaxed(ad->base + REG_REPORT_READ(channo));
611 flags = readl_relaxed(ad->base + REG_REPORT_READ(channo));
612
613 dev_dbg(ad->dev, "ch%d report: countval=0x%llx unk1=0x%x flags=0x%x\n",
614 channo, ((u64) countval_hi) << 32 | countval_lo, unk1, flags);
615 }
616
617 return count;
618 }
619
admac_handle_status_err(struct admac_data * ad,int channo)620 static void admac_handle_status_err(struct admac_data *ad, int channo)
621 {
622 bool handled = false;
623
624 if (readl_relaxed(ad->base + REG_DESC_RING(channo)) & RING_ERR) {
625 writel_relaxed(RING_ERR, ad->base + REG_DESC_RING(channo));
626 dev_err_ratelimited(ad->dev, "ch%d descriptor ring error\n", channo);
627 handled = true;
628 }
629
630 if (readl_relaxed(ad->base + REG_REPORT_RING(channo)) & RING_ERR) {
631 writel_relaxed(RING_ERR, ad->base + REG_REPORT_RING(channo));
632 dev_err_ratelimited(ad->dev, "ch%d report ring error\n", channo);
633 handled = true;
634 }
635
636 if (unlikely(!handled)) {
637 dev_err(ad->dev, "ch%d unknown error, masking errors as cause of IRQs\n", channo);
638 admac_modify(ad, REG_CHAN_INTMASK(channo, ad->irq_index),
639 STATUS_ERR, 0);
640 }
641 }
642
admac_handle_status_desc_done(struct admac_data * ad,int channo)643 static void admac_handle_status_desc_done(struct admac_data *ad, int channo)
644 {
645 struct admac_chan *adchan = &ad->channels[channo];
646 unsigned long flags;
647 int nreports;
648
649 writel_relaxed(STATUS_DESC_DONE,
650 ad->base + REG_CHAN_INTSTATUS(channo, ad->irq_index));
651
652 spin_lock_irqsave(&adchan->lock, flags);
653 nreports = admac_drain_reports(ad, channo);
654
655 if (adchan->current_tx) {
656 struct admac_tx *tx = adchan->current_tx;
657
658 adchan->nperiod_acks += nreports;
659 tx->reclaimed_pos += nreports * tx->period_len;
660 tx->reclaimed_pos %= 2 * tx->buf_len;
661
662 admac_cyclic_write_desc(ad, channo, tx);
663 tasklet_schedule(&adchan->tasklet);
664 }
665 spin_unlock_irqrestore(&adchan->lock, flags);
666 }
667
admac_handle_chan_int(struct admac_data * ad,int no)668 static void admac_handle_chan_int(struct admac_data *ad, int no)
669 {
670 u32 cause = readl_relaxed(ad->base + REG_CHAN_INTSTATUS(no, ad->irq_index));
671
672 if (cause & STATUS_ERR)
673 admac_handle_status_err(ad, no);
674
675 if (cause & STATUS_DESC_DONE)
676 admac_handle_status_desc_done(ad, no);
677 }
678
admac_interrupt(int irq,void * devid)679 static irqreturn_t admac_interrupt(int irq, void *devid)
680 {
681 struct admac_data *ad = devid;
682 u32 rx_intstate, tx_intstate, global_intstate;
683 int i;
684
685 rx_intstate = readl_relaxed(ad->base + REG_RX_INTSTATE(ad->irq_index));
686 tx_intstate = readl_relaxed(ad->base + REG_TX_INTSTATE(ad->irq_index));
687 global_intstate = readl_relaxed(ad->base + REG_GLOBAL_INTSTATE(ad->irq_index));
688
689 if (!tx_intstate && !rx_intstate && !global_intstate)
690 return IRQ_NONE;
691
692 for (i = 0; i < ad->nchannels; i += 2) {
693 if (tx_intstate & 1)
694 admac_handle_chan_int(ad, i);
695 tx_intstate >>= 1;
696 }
697
698 for (i = 1; i < ad->nchannels; i += 2) {
699 if (rx_intstate & 1)
700 admac_handle_chan_int(ad, i);
701 rx_intstate >>= 1;
702 }
703
704 if (global_intstate) {
705 dev_warn(ad->dev, "clearing unknown global interrupt flag: %x\n",
706 global_intstate);
707 writel_relaxed(~(u32) 0, ad->base + REG_GLOBAL_INTSTATE(ad->irq_index));
708 }
709
710 return IRQ_HANDLED;
711 }
712
admac_chan_tasklet(struct tasklet_struct * t)713 static void admac_chan_tasklet(struct tasklet_struct *t)
714 {
715 struct admac_chan *adchan = from_tasklet(adchan, t, tasklet);
716 struct admac_tx *adtx;
717 struct dmaengine_desc_callback cb;
718 struct dmaengine_result tx_result;
719 int nacks;
720
721 spin_lock_irq(&adchan->lock);
722 adtx = adchan->current_tx;
723 nacks = adchan->nperiod_acks;
724 adchan->nperiod_acks = 0;
725 spin_unlock_irq(&adchan->lock);
726
727 if (!adtx || !nacks)
728 return;
729
730 tx_result.result = DMA_TRANS_NOERROR;
731 tx_result.residue = 0;
732
733 dmaengine_desc_get_callback(&adtx->tx, &cb);
734 while (nacks--)
735 dmaengine_desc_callback_invoke(&cb, &tx_result);
736 }
737
admac_device_config(struct dma_chan * chan,struct dma_slave_config * config)738 static int admac_device_config(struct dma_chan *chan,
739 struct dma_slave_config *config)
740 {
741 struct admac_chan *adchan = to_admac_chan(chan);
742 struct admac_data *ad = adchan->host;
743 bool is_tx = admac_chan_direction(adchan->no) == DMA_MEM_TO_DEV;
744 int wordsize = 0;
745 u32 bus_width = readl_relaxed(ad->base + REG_BUS_WIDTH(adchan->no)) &
746 ~(BUS_WIDTH_WORD_SIZE | BUS_WIDTH_FRAME_SIZE);
747
748 switch (is_tx ? config->dst_addr_width : config->src_addr_width) {
749 case DMA_SLAVE_BUSWIDTH_1_BYTE:
750 wordsize = 1;
751 bus_width |= BUS_WIDTH_8BIT;
752 break;
753 case DMA_SLAVE_BUSWIDTH_2_BYTES:
754 wordsize = 2;
755 bus_width |= BUS_WIDTH_16BIT;
756 break;
757 case DMA_SLAVE_BUSWIDTH_4_BYTES:
758 wordsize = 4;
759 bus_width |= BUS_WIDTH_32BIT;
760 break;
761 default:
762 return -EINVAL;
763 }
764
765 /*
766 * We take port_window_size to be the number of words in a frame.
767 *
768 * The controller has some means of out-of-band signalling, to the peripheral,
769 * of words position in a frame. That's where the importance of this control
770 * comes from.
771 */
772 switch (is_tx ? config->dst_port_window_size : config->src_port_window_size) {
773 case 0 ... 1:
774 break;
775 case 2:
776 bus_width |= BUS_WIDTH_FRAME_2_WORDS;
777 break;
778 case 4:
779 bus_width |= BUS_WIDTH_FRAME_4_WORDS;
780 break;
781 default:
782 return -EINVAL;
783 }
784
785 writel_relaxed(bus_width, ad->base + REG_BUS_WIDTH(adchan->no));
786
787 /*
788 * By FIFOCTL_LIMIT we seem to set the maximal number of bytes allowed to be
789 * held in controller's per-channel FIFO. Transfers seem to be triggered
790 * around the time FIFO occupancy touches FIFOCTL_THRESHOLD.
791 *
792 * The numbers we set are more or less arbitrary.
793 */
794 writel_relaxed(FIELD_PREP(CHAN_FIFOCTL_LIMIT, 0x30 * wordsize)
795 | FIELD_PREP(CHAN_FIFOCTL_THRESHOLD, 0x18 * wordsize),
796 ad->base + REG_CHAN_FIFOCTL(adchan->no));
797
798 return 0;
799 }
800
admac_probe(struct platform_device * pdev)801 static int admac_probe(struct platform_device *pdev)
802 {
803 struct device_node *np = pdev->dev.of_node;
804 struct admac_data *ad;
805 struct dma_device *dma;
806 int nchannels;
807 int err, irq, i;
808
809 err = of_property_read_u32(np, "dma-channels", &nchannels);
810 if (err || nchannels > NCHANNELS_MAX) {
811 dev_err(&pdev->dev, "missing or invalid dma-channels property\n");
812 return -EINVAL;
813 }
814
815 ad = devm_kzalloc(&pdev->dev, struct_size(ad, channels, nchannels), GFP_KERNEL);
816 if (!ad)
817 return -ENOMEM;
818
819 platform_set_drvdata(pdev, ad);
820 ad->dev = &pdev->dev;
821 ad->nchannels = nchannels;
822 mutex_init(&ad->cache_alloc_lock);
823
824 /*
825 * The controller has 4 IRQ outputs. Try them all until
826 * we find one we can use.
827 */
828 for (i = 0; i < IRQ_NOUTPUTS; i++) {
829 irq = platform_get_irq_optional(pdev, i);
830 if (irq >= 0) {
831 ad->irq_index = i;
832 break;
833 }
834 }
835
836 if (irq < 0)
837 return dev_err_probe(&pdev->dev, irq, "no usable interrupt\n");
838 ad->irq = irq;
839
840 ad->base = devm_platform_ioremap_resource(pdev, 0);
841 if (IS_ERR(ad->base))
842 return dev_err_probe(&pdev->dev, PTR_ERR(ad->base),
843 "unable to obtain MMIO resource\n");
844
845 ad->rstc = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
846 if (IS_ERR(ad->rstc))
847 return PTR_ERR(ad->rstc);
848
849 dma = &ad->dma;
850
851 dma_cap_set(DMA_PRIVATE, dma->cap_mask);
852 dma_cap_set(DMA_CYCLIC, dma->cap_mask);
853
854 dma->dev = &pdev->dev;
855 dma->device_alloc_chan_resources = admac_alloc_chan_resources;
856 dma->device_free_chan_resources = admac_free_chan_resources;
857 dma->device_tx_status = admac_tx_status;
858 dma->device_issue_pending = admac_issue_pending;
859 dma->device_terminate_all = admac_terminate_all;
860 dma->device_synchronize = admac_synchronize;
861 dma->device_prep_dma_cyclic = admac_prep_dma_cyclic;
862 dma->device_config = admac_device_config;
863 dma->device_pause = admac_pause;
864 dma->device_resume = admac_resume;
865
866 dma->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
867 dma->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
868 dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
869 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
870 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
871 dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
872 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
873 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
874
875 INIT_LIST_HEAD(&dma->channels);
876 for (i = 0; i < nchannels; i++) {
877 struct admac_chan *adchan = &ad->channels[i];
878
879 adchan->host = ad;
880 adchan->no = i;
881 adchan->chan.device = &ad->dma;
882 spin_lock_init(&adchan->lock);
883 INIT_LIST_HEAD(&adchan->submitted);
884 INIT_LIST_HEAD(&adchan->issued);
885 INIT_LIST_HEAD(&adchan->to_free);
886 list_add_tail(&adchan->chan.device_node, &dma->channels);
887 tasklet_setup(&adchan->tasklet, admac_chan_tasklet);
888 }
889
890 err = reset_control_reset(ad->rstc);
891 if (err)
892 return dev_err_probe(&pdev->dev, err,
893 "unable to trigger reset\n");
894
895 err = request_irq(irq, admac_interrupt, 0, dev_name(&pdev->dev), ad);
896 if (err) {
897 dev_err_probe(&pdev->dev, err,
898 "unable to register interrupt\n");
899 goto free_reset;
900 }
901
902 err = dma_async_device_register(&ad->dma);
903 if (err) {
904 dev_err_probe(&pdev->dev, err, "failed to register DMA device\n");
905 goto free_irq;
906 }
907
908 err = of_dma_controller_register(pdev->dev.of_node, admac_dma_of_xlate, ad);
909 if (err) {
910 dma_async_device_unregister(&ad->dma);
911 dev_err_probe(&pdev->dev, err, "failed to register with OF\n");
912 goto free_irq;
913 }
914
915 ad->txcache.size = readl_relaxed(ad->base + REG_TX_SRAM_SIZE);
916 ad->rxcache.size = readl_relaxed(ad->base + REG_RX_SRAM_SIZE);
917
918 dev_info(&pdev->dev, "Audio DMA Controller\n");
919 dev_info(&pdev->dev, "imprint %x TX cache %u RX cache %u\n",
920 readl_relaxed(ad->base + REG_IMPRINT), ad->txcache.size, ad->rxcache.size);
921
922 return 0;
923
924 free_irq:
925 free_irq(ad->irq, ad);
926 free_reset:
927 reset_control_rearm(ad->rstc);
928 return err;
929 }
930
admac_remove(struct platform_device * pdev)931 static void admac_remove(struct platform_device *pdev)
932 {
933 struct admac_data *ad = platform_get_drvdata(pdev);
934
935 of_dma_controller_free(pdev->dev.of_node);
936 dma_async_device_unregister(&ad->dma);
937 free_irq(ad->irq, ad);
938 reset_control_rearm(ad->rstc);
939 }
940
941 static const struct of_device_id admac_of_match[] = {
942 { .compatible = "apple,admac", },
943 { }
944 };
945 MODULE_DEVICE_TABLE(of, admac_of_match);
946
947 static struct platform_driver apple_admac_driver = {
948 .driver = {
949 .name = "apple-admac",
950 .of_match_table = admac_of_match,
951 },
952 .probe = admac_probe,
953 .remove_new = admac_remove,
954 };
955 module_platform_driver(apple_admac_driver);
956
957 MODULE_AUTHOR("Martin Povišer <povik+lin@cutebit.org>");
958 MODULE_DESCRIPTION("Driver for Audio DMA Controller (ADMAC) on Apple SoCs");
959 MODULE_LICENSE("GPL");
960