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

source code of linux/drivers/dma/apple-admac.c