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[]; 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 }; 149 150 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 } 181 182 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 } 203 204 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 } 211 212 static struct admac_chan *to_admac_chan(struct dma_chan *chan) 213 { 214 return container_of(chan, struct admac_chan, chan); 215 } 216 217 static struct admac_tx *to_admac_tx(struct dma_async_tx_descriptor *tx) 218 { 219 return container_of(tx, struct admac_tx, tx); 220 } 221 222 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 } 227 228 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 } 242 243 static int admac_desc_free(struct dma_async_tx_descriptor *tx) 244 { 245 kfree(to_admac_tx(tx)); 246 247 return 0; 248 } 249 250 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 */ 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 */ 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 } 322 323 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 */ 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 } 371 372 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 } 408 409 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 } 431 432 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 } 449 450 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 } 458 459 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 } 471 472 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 } 490 491 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 } 499 500 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 } 508 509 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 } 532 533 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 } 551 552 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 } 568 569 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 } 578 579 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 } 597 598 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 } 619 620 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 } 642 643 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 } 667 668 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 } 678 679 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 } 712 713 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 } 737 738 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 } 800 801 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 } 930 931 static int 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 return 0; 941 } 942 943 static const struct of_device_id admac_of_match[] = { 944 { .compatible = "apple,admac", }, 945 { } 946 }; 947 MODULE_DEVICE_TABLE(of, admac_of_match); 948 949 static struct platform_driver apple_admac_driver = { 950 .driver = { 951 .name = "apple-admac", 952 .of_match_table = admac_of_match, 953 }, 954 .probe = admac_probe, 955 .remove = admac_remove, 956 }; 957 module_platform_driver(apple_admac_driver); 958 959 MODULE_AUTHOR("Martin Povišer <povik+lin@cutebit.org>"); 960 MODULE_DESCRIPTION("Driver for Audio DMA Controller (ADMAC) on Apple SoCs"); 961 MODULE_LICENSE("GPL"); 962