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Merge tag 'gpio-v4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux...
[deliverable/linux.git] / drivers / dma / dw / core.c
1 /*
2 * Core driver for the Synopsys DesignWare DMA Controller
3 *
4 * Copyright (C) 2007-2008 Atmel Corporation
5 * Copyright (C) 2010-2011 ST Microelectronics
6 * Copyright (C) 2013 Intel Corporation
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/bitops.h>
14 #include <linux/delay.h>
15 #include <linux/dmaengine.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/dmapool.h>
18 #include <linux/err.h>
19 #include <linux/init.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/mm.h>
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/pm_runtime.h>
26
27 #include "../dmaengine.h"
28 #include "internal.h"
29
30 /*
31 * This supports the Synopsys "DesignWare AHB Central DMA Controller",
32 * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all
33 * of which use ARM any more). See the "Databook" from Synopsys for
34 * information beyond what licensees probably provide.
35 *
36 * The driver has been tested with the Atmel AT32AP7000, which does not
37 * support descriptor writeback.
38 */
39
40 #define DWC_DEFAULT_CTLLO(_chan) ({ \
41 struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan); \
42 struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \
43 bool _is_slave = is_slave_direction(_dwc->direction); \
44 u8 _smsize = _is_slave ? _sconfig->src_maxburst : \
45 DW_DMA_MSIZE_16; \
46 u8 _dmsize = _is_slave ? _sconfig->dst_maxburst : \
47 DW_DMA_MSIZE_16; \
48 \
49 (DWC_CTLL_DST_MSIZE(_dmsize) \
50 | DWC_CTLL_SRC_MSIZE(_smsize) \
51 | DWC_CTLL_LLP_D_EN \
52 | DWC_CTLL_LLP_S_EN \
53 | DWC_CTLL_DMS(_dwc->dst_master) \
54 | DWC_CTLL_SMS(_dwc->src_master)); \
55 })
56
57 /*
58 * Number of descriptors to allocate for each channel. This should be
59 * made configurable somehow; preferably, the clients (at least the
60 * ones using slave transfers) should be able to give us a hint.
61 */
62 #define NR_DESCS_PER_CHANNEL 64
63
64 /* The set of bus widths supported by the DMA controller */
65 #define DW_DMA_BUSWIDTHS \
66 BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
67 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
68 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
69 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
70
71 /*----------------------------------------------------------------------*/
72
73 static struct device *chan2dev(struct dma_chan *chan)
74 {
75 return &chan->dev->device;
76 }
77
78 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
79 {
80 return to_dw_desc(dwc->active_list.next);
81 }
82
83 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
84 {
85 struct dw_desc *desc, *_desc;
86 struct dw_desc *ret = NULL;
87 unsigned int i = 0;
88 unsigned long flags;
89
90 spin_lock_irqsave(&dwc->lock, flags);
91 list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
92 i++;
93 if (async_tx_test_ack(&desc->txd)) {
94 list_del(&desc->desc_node);
95 ret = desc;
96 break;
97 }
98 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
99 }
100 spin_unlock_irqrestore(&dwc->lock, flags);
101
102 dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
103
104 return ret;
105 }
106
107 /*
108 * Move a descriptor, including any children, to the free list.
109 * `desc' must not be on any lists.
110 */
111 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
112 {
113 unsigned long flags;
114
115 if (desc) {
116 struct dw_desc *child;
117
118 spin_lock_irqsave(&dwc->lock, flags);
119 list_for_each_entry(child, &desc->tx_list, desc_node)
120 dev_vdbg(chan2dev(&dwc->chan),
121 "moving child desc %p to freelist\n",
122 child);
123 list_splice_init(&desc->tx_list, &dwc->free_list);
124 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
125 list_add(&desc->desc_node, &dwc->free_list);
126 spin_unlock_irqrestore(&dwc->lock, flags);
127 }
128 }
129
130 static void dwc_initialize(struct dw_dma_chan *dwc)
131 {
132 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
133 u32 cfghi = DWC_CFGH_FIFO_MODE;
134 u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
135
136 if (dwc->initialized == true)
137 return;
138
139 cfghi |= DWC_CFGH_DST_PER(dwc->dst_id);
140 cfghi |= DWC_CFGH_SRC_PER(dwc->src_id);
141
142 channel_writel(dwc, CFG_LO, cfglo);
143 channel_writel(dwc, CFG_HI, cfghi);
144
145 /* Enable interrupts */
146 channel_set_bit(dw, MASK.XFER, dwc->mask);
147 channel_set_bit(dw, MASK.ERROR, dwc->mask);
148
149 dwc->initialized = true;
150 }
151
152 /*----------------------------------------------------------------------*/
153
154 static inline unsigned int dwc_fast_ffs(unsigned long long v)
155 {
156 /*
157 * We can be a lot more clever here, but this should take care
158 * of the most common optimization.
159 */
160 if (!(v & 7))
161 return 3;
162 else if (!(v & 3))
163 return 2;
164 else if (!(v & 1))
165 return 1;
166 return 0;
167 }
168
169 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
170 {
171 dev_err(chan2dev(&dwc->chan),
172 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
173 channel_readl(dwc, SAR),
174 channel_readl(dwc, DAR),
175 channel_readl(dwc, LLP),
176 channel_readl(dwc, CTL_HI),
177 channel_readl(dwc, CTL_LO));
178 }
179
180 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
181 {
182 channel_clear_bit(dw, CH_EN, dwc->mask);
183 while (dma_readl(dw, CH_EN) & dwc->mask)
184 cpu_relax();
185 }
186
187 /*----------------------------------------------------------------------*/
188
189 /* Perform single block transfer */
190 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
191 struct dw_desc *desc)
192 {
193 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
194 u32 ctllo;
195
196 /*
197 * Software emulation of LLP mode relies on interrupts to continue
198 * multi block transfer.
199 */
200 ctllo = desc->lli.ctllo | DWC_CTLL_INT_EN;
201
202 channel_writel(dwc, SAR, desc->lli.sar);
203 channel_writel(dwc, DAR, desc->lli.dar);
204 channel_writel(dwc, CTL_LO, ctllo);
205 channel_writel(dwc, CTL_HI, desc->lli.ctlhi);
206 channel_set_bit(dw, CH_EN, dwc->mask);
207
208 /* Move pointer to next descriptor */
209 dwc->tx_node_active = dwc->tx_node_active->next;
210 }
211
212 /* Called with dwc->lock held and bh disabled */
213 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
214 {
215 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
216 unsigned long was_soft_llp;
217
218 /* ASSERT: channel is idle */
219 if (dma_readl(dw, CH_EN) & dwc->mask) {
220 dev_err(chan2dev(&dwc->chan),
221 "%s: BUG: Attempted to start non-idle channel\n",
222 __func__);
223 dwc_dump_chan_regs(dwc);
224
225 /* The tasklet will hopefully advance the queue... */
226 return;
227 }
228
229 if (dwc->nollp) {
230 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
231 &dwc->flags);
232 if (was_soft_llp) {
233 dev_err(chan2dev(&dwc->chan),
234 "BUG: Attempted to start new LLP transfer inside ongoing one\n");
235 return;
236 }
237
238 dwc_initialize(dwc);
239
240 dwc->residue = first->total_len;
241 dwc->tx_node_active = &first->tx_list;
242
243 /* Submit first block */
244 dwc_do_single_block(dwc, first);
245
246 return;
247 }
248
249 dwc_initialize(dwc);
250
251 channel_writel(dwc, LLP, first->txd.phys);
252 channel_writel(dwc, CTL_LO,
253 DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
254 channel_writel(dwc, CTL_HI, 0);
255 channel_set_bit(dw, CH_EN, dwc->mask);
256 }
257
258 static void dwc_dostart_first_queued(struct dw_dma_chan *dwc)
259 {
260 struct dw_desc *desc;
261
262 if (list_empty(&dwc->queue))
263 return;
264
265 list_move(dwc->queue.next, &dwc->active_list);
266 desc = dwc_first_active(dwc);
267 dev_vdbg(chan2dev(&dwc->chan), "%s: started %u\n", __func__, desc->txd.cookie);
268 dwc_dostart(dwc, desc);
269 }
270
271 /*----------------------------------------------------------------------*/
272
273 static void
274 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
275 bool callback_required)
276 {
277 dma_async_tx_callback callback = NULL;
278 void *param = NULL;
279 struct dma_async_tx_descriptor *txd = &desc->txd;
280 struct dw_desc *child;
281 unsigned long flags;
282
283 dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
284
285 spin_lock_irqsave(&dwc->lock, flags);
286 dma_cookie_complete(txd);
287 if (callback_required) {
288 callback = txd->callback;
289 param = txd->callback_param;
290 }
291
292 /* async_tx_ack */
293 list_for_each_entry(child, &desc->tx_list, desc_node)
294 async_tx_ack(&child->txd);
295 async_tx_ack(&desc->txd);
296
297 list_splice_init(&desc->tx_list, &dwc->free_list);
298 list_move(&desc->desc_node, &dwc->free_list);
299
300 dma_descriptor_unmap(txd);
301 spin_unlock_irqrestore(&dwc->lock, flags);
302
303 if (callback)
304 callback(param);
305 }
306
307 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
308 {
309 struct dw_desc *desc, *_desc;
310 LIST_HEAD(list);
311 unsigned long flags;
312
313 spin_lock_irqsave(&dwc->lock, flags);
314 if (dma_readl(dw, CH_EN) & dwc->mask) {
315 dev_err(chan2dev(&dwc->chan),
316 "BUG: XFER bit set, but channel not idle!\n");
317
318 /* Try to continue after resetting the channel... */
319 dwc_chan_disable(dw, dwc);
320 }
321
322 /*
323 * Submit queued descriptors ASAP, i.e. before we go through
324 * the completed ones.
325 */
326 list_splice_init(&dwc->active_list, &list);
327 dwc_dostart_first_queued(dwc);
328
329 spin_unlock_irqrestore(&dwc->lock, flags);
330
331 list_for_each_entry_safe(desc, _desc, &list, desc_node)
332 dwc_descriptor_complete(dwc, desc, true);
333 }
334
335 /* Returns how many bytes were already received from source */
336 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
337 {
338 u32 ctlhi = channel_readl(dwc, CTL_HI);
339 u32 ctllo = channel_readl(dwc, CTL_LO);
340
341 return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
342 }
343
344 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
345 {
346 dma_addr_t llp;
347 struct dw_desc *desc, *_desc;
348 struct dw_desc *child;
349 u32 status_xfer;
350 unsigned long flags;
351
352 spin_lock_irqsave(&dwc->lock, flags);
353 llp = channel_readl(dwc, LLP);
354 status_xfer = dma_readl(dw, RAW.XFER);
355
356 if (status_xfer & dwc->mask) {
357 /* Everything we've submitted is done */
358 dma_writel(dw, CLEAR.XFER, dwc->mask);
359
360 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
361 struct list_head *head, *active = dwc->tx_node_active;
362
363 /*
364 * We are inside first active descriptor.
365 * Otherwise something is really wrong.
366 */
367 desc = dwc_first_active(dwc);
368
369 head = &desc->tx_list;
370 if (active != head) {
371 /* Update desc to reflect last sent one */
372 if (active != head->next)
373 desc = to_dw_desc(active->prev);
374
375 dwc->residue -= desc->len;
376
377 child = to_dw_desc(active);
378
379 /* Submit next block */
380 dwc_do_single_block(dwc, child);
381
382 spin_unlock_irqrestore(&dwc->lock, flags);
383 return;
384 }
385
386 /* We are done here */
387 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
388 }
389
390 dwc->residue = 0;
391
392 spin_unlock_irqrestore(&dwc->lock, flags);
393
394 dwc_complete_all(dw, dwc);
395 return;
396 }
397
398 if (list_empty(&dwc->active_list)) {
399 dwc->residue = 0;
400 spin_unlock_irqrestore(&dwc->lock, flags);
401 return;
402 }
403
404 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
405 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
406 spin_unlock_irqrestore(&dwc->lock, flags);
407 return;
408 }
409
410 dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp);
411
412 list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
413 /* Initial residue value */
414 dwc->residue = desc->total_len;
415
416 /* Check first descriptors addr */
417 if (desc->txd.phys == llp) {
418 spin_unlock_irqrestore(&dwc->lock, flags);
419 return;
420 }
421
422 /* Check first descriptors llp */
423 if (desc->lli.llp == llp) {
424 /* This one is currently in progress */
425 dwc->residue -= dwc_get_sent(dwc);
426 spin_unlock_irqrestore(&dwc->lock, flags);
427 return;
428 }
429
430 dwc->residue -= desc->len;
431 list_for_each_entry(child, &desc->tx_list, desc_node) {
432 if (child->lli.llp == llp) {
433 /* Currently in progress */
434 dwc->residue -= dwc_get_sent(dwc);
435 spin_unlock_irqrestore(&dwc->lock, flags);
436 return;
437 }
438 dwc->residue -= child->len;
439 }
440
441 /*
442 * No descriptors so far seem to be in progress, i.e.
443 * this one must be done.
444 */
445 spin_unlock_irqrestore(&dwc->lock, flags);
446 dwc_descriptor_complete(dwc, desc, true);
447 spin_lock_irqsave(&dwc->lock, flags);
448 }
449
450 dev_err(chan2dev(&dwc->chan),
451 "BUG: All descriptors done, but channel not idle!\n");
452
453 /* Try to continue after resetting the channel... */
454 dwc_chan_disable(dw, dwc);
455
456 dwc_dostart_first_queued(dwc);
457 spin_unlock_irqrestore(&dwc->lock, flags);
458 }
459
460 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
461 {
462 dev_crit(chan2dev(&dwc->chan), " desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
463 lli->sar, lli->dar, lli->llp, lli->ctlhi, lli->ctllo);
464 }
465
466 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
467 {
468 struct dw_desc *bad_desc;
469 struct dw_desc *child;
470 unsigned long flags;
471
472 dwc_scan_descriptors(dw, dwc);
473
474 spin_lock_irqsave(&dwc->lock, flags);
475
476 /*
477 * The descriptor currently at the head of the active list is
478 * borked. Since we don't have any way to report errors, we'll
479 * just have to scream loudly and try to carry on.
480 */
481 bad_desc = dwc_first_active(dwc);
482 list_del_init(&bad_desc->desc_node);
483 list_move(dwc->queue.next, dwc->active_list.prev);
484
485 /* Clear the error flag and try to restart the controller */
486 dma_writel(dw, CLEAR.ERROR, dwc->mask);
487 if (!list_empty(&dwc->active_list))
488 dwc_dostart(dwc, dwc_first_active(dwc));
489
490 /*
491 * WARN may seem harsh, but since this only happens
492 * when someone submits a bad physical address in a
493 * descriptor, we should consider ourselves lucky that the
494 * controller flagged an error instead of scribbling over
495 * random memory locations.
496 */
497 dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
498 " cookie: %d\n", bad_desc->txd.cookie);
499 dwc_dump_lli(dwc, &bad_desc->lli);
500 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
501 dwc_dump_lli(dwc, &child->lli);
502
503 spin_unlock_irqrestore(&dwc->lock, flags);
504
505 /* Pretend the descriptor completed successfully */
506 dwc_descriptor_complete(dwc, bad_desc, true);
507 }
508
509 /* --------------------- Cyclic DMA API extensions -------------------- */
510
511 dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
512 {
513 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
514 return channel_readl(dwc, SAR);
515 }
516 EXPORT_SYMBOL(dw_dma_get_src_addr);
517
518 dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
519 {
520 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
521 return channel_readl(dwc, DAR);
522 }
523 EXPORT_SYMBOL(dw_dma_get_dst_addr);
524
525 /* Called with dwc->lock held and all DMAC interrupts disabled */
526 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
527 u32 status_block, u32 status_err, u32 status_xfer)
528 {
529 unsigned long flags;
530
531 if (status_block & dwc->mask) {
532 void (*callback)(void *param);
533 void *callback_param;
534
535 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
536 channel_readl(dwc, LLP));
537 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
538
539 callback = dwc->cdesc->period_callback;
540 callback_param = dwc->cdesc->period_callback_param;
541
542 if (callback)
543 callback(callback_param);
544 }
545
546 /*
547 * Error and transfer complete are highly unlikely, and will most
548 * likely be due to a configuration error by the user.
549 */
550 if (unlikely(status_err & dwc->mask) ||
551 unlikely(status_xfer & dwc->mask)) {
552 int i;
553
554 dev_err(chan2dev(&dwc->chan),
555 "cyclic DMA unexpected %s interrupt, stopping DMA transfer\n",
556 status_xfer ? "xfer" : "error");
557
558 spin_lock_irqsave(&dwc->lock, flags);
559
560 dwc_dump_chan_regs(dwc);
561
562 dwc_chan_disable(dw, dwc);
563
564 /* Make sure DMA does not restart by loading a new list */
565 channel_writel(dwc, LLP, 0);
566 channel_writel(dwc, CTL_LO, 0);
567 channel_writel(dwc, CTL_HI, 0);
568
569 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
570 dma_writel(dw, CLEAR.ERROR, dwc->mask);
571 dma_writel(dw, CLEAR.XFER, dwc->mask);
572
573 for (i = 0; i < dwc->cdesc->periods; i++)
574 dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
575
576 spin_unlock_irqrestore(&dwc->lock, flags);
577 }
578
579 /* Re-enable interrupts */
580 channel_set_bit(dw, MASK.BLOCK, dwc->mask);
581 }
582
583 /* ------------------------------------------------------------------------- */
584
585 static void dw_dma_tasklet(unsigned long data)
586 {
587 struct dw_dma *dw = (struct dw_dma *)data;
588 struct dw_dma_chan *dwc;
589 u32 status_block;
590 u32 status_xfer;
591 u32 status_err;
592 int i;
593
594 status_block = dma_readl(dw, RAW.BLOCK);
595 status_xfer = dma_readl(dw, RAW.XFER);
596 status_err = dma_readl(dw, RAW.ERROR);
597
598 dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
599
600 for (i = 0; i < dw->dma.chancnt; i++) {
601 dwc = &dw->chan[i];
602 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
603 dwc_handle_cyclic(dw, dwc, status_block, status_err,
604 status_xfer);
605 else if (status_err & (1 << i))
606 dwc_handle_error(dw, dwc);
607 else if (status_xfer & (1 << i))
608 dwc_scan_descriptors(dw, dwc);
609 }
610
611 /* Re-enable interrupts */
612 channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
613 channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
614 }
615
616 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
617 {
618 struct dw_dma *dw = dev_id;
619 u32 status;
620
621 /* Check if we have any interrupt from the DMAC which is not in use */
622 if (!dw->in_use)
623 return IRQ_NONE;
624
625 status = dma_readl(dw, STATUS_INT);
626 dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);
627
628 /* Check if we have any interrupt from the DMAC */
629 if (!status)
630 return IRQ_NONE;
631
632 /*
633 * Just disable the interrupts. We'll turn them back on in the
634 * softirq handler.
635 */
636 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
637 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
638 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
639
640 status = dma_readl(dw, STATUS_INT);
641 if (status) {
642 dev_err(dw->dma.dev,
643 "BUG: Unexpected interrupts pending: 0x%x\n",
644 status);
645
646 /* Try to recover */
647 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
648 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
649 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
650 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
651 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
652 }
653
654 tasklet_schedule(&dw->tasklet);
655
656 return IRQ_HANDLED;
657 }
658
659 /*----------------------------------------------------------------------*/
660
661 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
662 {
663 struct dw_desc *desc = txd_to_dw_desc(tx);
664 struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
665 dma_cookie_t cookie;
666 unsigned long flags;
667
668 spin_lock_irqsave(&dwc->lock, flags);
669 cookie = dma_cookie_assign(tx);
670
671 /*
672 * REVISIT: We should attempt to chain as many descriptors as
673 * possible, perhaps even appending to those already submitted
674 * for DMA. But this is hard to do in a race-free manner.
675 */
676
677 dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__, desc->txd.cookie);
678 list_add_tail(&desc->desc_node, &dwc->queue);
679
680 spin_unlock_irqrestore(&dwc->lock, flags);
681
682 return cookie;
683 }
684
685 static struct dma_async_tx_descriptor *
686 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
687 size_t len, unsigned long flags)
688 {
689 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
690 struct dw_dma *dw = to_dw_dma(chan->device);
691 struct dw_desc *desc;
692 struct dw_desc *first;
693 struct dw_desc *prev;
694 size_t xfer_count;
695 size_t offset;
696 unsigned int src_width;
697 unsigned int dst_width;
698 unsigned int data_width;
699 u32 ctllo;
700
701 dev_vdbg(chan2dev(chan),
702 "%s: d%pad s%pad l0x%zx f0x%lx\n", __func__,
703 &dest, &src, len, flags);
704
705 if (unlikely(!len)) {
706 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
707 return NULL;
708 }
709
710 dwc->direction = DMA_MEM_TO_MEM;
711
712 data_width = min_t(unsigned int, dw->data_width[dwc->src_master],
713 dw->data_width[dwc->dst_master]);
714
715 src_width = dst_width = min_t(unsigned int, data_width,
716 dwc_fast_ffs(src | dest | len));
717
718 ctllo = DWC_DEFAULT_CTLLO(chan)
719 | DWC_CTLL_DST_WIDTH(dst_width)
720 | DWC_CTLL_SRC_WIDTH(src_width)
721 | DWC_CTLL_DST_INC
722 | DWC_CTLL_SRC_INC
723 | DWC_CTLL_FC_M2M;
724 prev = first = NULL;
725
726 for (offset = 0; offset < len; offset += xfer_count << src_width) {
727 xfer_count = min_t(size_t, (len - offset) >> src_width,
728 dwc->block_size);
729
730 desc = dwc_desc_get(dwc);
731 if (!desc)
732 goto err_desc_get;
733
734 desc->lli.sar = src + offset;
735 desc->lli.dar = dest + offset;
736 desc->lli.ctllo = ctllo;
737 desc->lli.ctlhi = xfer_count;
738 desc->len = xfer_count << src_width;
739
740 if (!first) {
741 first = desc;
742 } else {
743 prev->lli.llp = desc->txd.phys;
744 list_add_tail(&desc->desc_node,
745 &first->tx_list);
746 }
747 prev = desc;
748 }
749
750 if (flags & DMA_PREP_INTERRUPT)
751 /* Trigger interrupt after last block */
752 prev->lli.ctllo |= DWC_CTLL_INT_EN;
753
754 prev->lli.llp = 0;
755 first->txd.flags = flags;
756 first->total_len = len;
757
758 return &first->txd;
759
760 err_desc_get:
761 dwc_desc_put(dwc, first);
762 return NULL;
763 }
764
765 static struct dma_async_tx_descriptor *
766 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
767 unsigned int sg_len, enum dma_transfer_direction direction,
768 unsigned long flags, void *context)
769 {
770 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
771 struct dw_dma *dw = to_dw_dma(chan->device);
772 struct dma_slave_config *sconfig = &dwc->dma_sconfig;
773 struct dw_desc *prev;
774 struct dw_desc *first;
775 u32 ctllo;
776 dma_addr_t reg;
777 unsigned int reg_width;
778 unsigned int mem_width;
779 unsigned int data_width;
780 unsigned int i;
781 struct scatterlist *sg;
782 size_t total_len = 0;
783
784 dev_vdbg(chan2dev(chan), "%s\n", __func__);
785
786 if (unlikely(!is_slave_direction(direction) || !sg_len))
787 return NULL;
788
789 dwc->direction = direction;
790
791 prev = first = NULL;
792
793 switch (direction) {
794 case DMA_MEM_TO_DEV:
795 reg_width = __ffs(sconfig->dst_addr_width);
796 reg = sconfig->dst_addr;
797 ctllo = (DWC_DEFAULT_CTLLO(chan)
798 | DWC_CTLL_DST_WIDTH(reg_width)
799 | DWC_CTLL_DST_FIX
800 | DWC_CTLL_SRC_INC);
801
802 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
803 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
804
805 data_width = dw->data_width[dwc->src_master];
806
807 for_each_sg(sgl, sg, sg_len, i) {
808 struct dw_desc *desc;
809 u32 len, dlen, mem;
810
811 mem = sg_dma_address(sg);
812 len = sg_dma_len(sg);
813
814 mem_width = min_t(unsigned int,
815 data_width, dwc_fast_ffs(mem | len));
816
817 slave_sg_todev_fill_desc:
818 desc = dwc_desc_get(dwc);
819 if (!desc)
820 goto err_desc_get;
821
822 desc->lli.sar = mem;
823 desc->lli.dar = reg;
824 desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
825 if ((len >> mem_width) > dwc->block_size) {
826 dlen = dwc->block_size << mem_width;
827 mem += dlen;
828 len -= dlen;
829 } else {
830 dlen = len;
831 len = 0;
832 }
833
834 desc->lli.ctlhi = dlen >> mem_width;
835 desc->len = dlen;
836
837 if (!first) {
838 first = desc;
839 } else {
840 prev->lli.llp = desc->txd.phys;
841 list_add_tail(&desc->desc_node,
842 &first->tx_list);
843 }
844 prev = desc;
845 total_len += dlen;
846
847 if (len)
848 goto slave_sg_todev_fill_desc;
849 }
850 break;
851 case DMA_DEV_TO_MEM:
852 reg_width = __ffs(sconfig->src_addr_width);
853 reg = sconfig->src_addr;
854 ctllo = (DWC_DEFAULT_CTLLO(chan)
855 | DWC_CTLL_SRC_WIDTH(reg_width)
856 | DWC_CTLL_DST_INC
857 | DWC_CTLL_SRC_FIX);
858
859 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
860 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
861
862 data_width = dw->data_width[dwc->dst_master];
863
864 for_each_sg(sgl, sg, sg_len, i) {
865 struct dw_desc *desc;
866 u32 len, dlen, mem;
867
868 mem = sg_dma_address(sg);
869 len = sg_dma_len(sg);
870
871 mem_width = min_t(unsigned int,
872 data_width, dwc_fast_ffs(mem | len));
873
874 slave_sg_fromdev_fill_desc:
875 desc = dwc_desc_get(dwc);
876 if (!desc)
877 goto err_desc_get;
878
879 desc->lli.sar = reg;
880 desc->lli.dar = mem;
881 desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
882 if ((len >> reg_width) > dwc->block_size) {
883 dlen = dwc->block_size << reg_width;
884 mem += dlen;
885 len -= dlen;
886 } else {
887 dlen = len;
888 len = 0;
889 }
890 desc->lli.ctlhi = dlen >> reg_width;
891 desc->len = dlen;
892
893 if (!first) {
894 first = desc;
895 } else {
896 prev->lli.llp = desc->txd.phys;
897 list_add_tail(&desc->desc_node,
898 &first->tx_list);
899 }
900 prev = desc;
901 total_len += dlen;
902
903 if (len)
904 goto slave_sg_fromdev_fill_desc;
905 }
906 break;
907 default:
908 return NULL;
909 }
910
911 if (flags & DMA_PREP_INTERRUPT)
912 /* Trigger interrupt after last block */
913 prev->lli.ctllo |= DWC_CTLL_INT_EN;
914
915 prev->lli.llp = 0;
916 first->total_len = total_len;
917
918 return &first->txd;
919
920 err_desc_get:
921 dev_err(chan2dev(chan),
922 "not enough descriptors available. Direction %d\n", direction);
923 dwc_desc_put(dwc, first);
924 return NULL;
925 }
926
927 bool dw_dma_filter(struct dma_chan *chan, void *param)
928 {
929 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
930 struct dw_dma_slave *dws = param;
931
932 if (dws->dma_dev != chan->device->dev)
933 return false;
934
935 /* We have to copy data since dws can be temporary storage */
936
937 dwc->src_id = dws->src_id;
938 dwc->dst_id = dws->dst_id;
939
940 dwc->src_master = dws->src_master;
941 dwc->dst_master = dws->dst_master;
942
943 return true;
944 }
945 EXPORT_SYMBOL_GPL(dw_dma_filter);
946
947 /*
948 * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
949 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
950 *
951 * NOTE: burst size 2 is not supported by controller.
952 *
953 * This can be done by finding least significant bit set: n & (n - 1)
954 */
955 static inline void convert_burst(u32 *maxburst)
956 {
957 if (*maxburst > 1)
958 *maxburst = fls(*maxburst) - 2;
959 else
960 *maxburst = 0;
961 }
962
963 static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
964 {
965 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
966
967 /* Check if chan will be configured for slave transfers */
968 if (!is_slave_direction(sconfig->direction))
969 return -EINVAL;
970
971 memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
972 dwc->direction = sconfig->direction;
973
974 convert_burst(&dwc->dma_sconfig.src_maxburst);
975 convert_burst(&dwc->dma_sconfig.dst_maxburst);
976
977 return 0;
978 }
979
980 static int dwc_pause(struct dma_chan *chan)
981 {
982 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
983 unsigned long flags;
984 unsigned int count = 20; /* timeout iterations */
985 u32 cfglo;
986
987 spin_lock_irqsave(&dwc->lock, flags);
988
989 cfglo = channel_readl(dwc, CFG_LO);
990 channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
991 while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
992 udelay(2);
993
994 dwc->paused = true;
995
996 spin_unlock_irqrestore(&dwc->lock, flags);
997
998 return 0;
999 }
1000
1001 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
1002 {
1003 u32 cfglo = channel_readl(dwc, CFG_LO);
1004
1005 channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
1006
1007 dwc->paused = false;
1008 }
1009
1010 static int dwc_resume(struct dma_chan *chan)
1011 {
1012 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1013 unsigned long flags;
1014
1015 if (!dwc->paused)
1016 return 0;
1017
1018 spin_lock_irqsave(&dwc->lock, flags);
1019
1020 dwc_chan_resume(dwc);
1021
1022 spin_unlock_irqrestore(&dwc->lock, flags);
1023
1024 return 0;
1025 }
1026
1027 static int dwc_terminate_all(struct dma_chan *chan)
1028 {
1029 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1030 struct dw_dma *dw = to_dw_dma(chan->device);
1031 struct dw_desc *desc, *_desc;
1032 unsigned long flags;
1033 LIST_HEAD(list);
1034
1035 spin_lock_irqsave(&dwc->lock, flags);
1036
1037 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
1038
1039 dwc_chan_disable(dw, dwc);
1040
1041 dwc_chan_resume(dwc);
1042
1043 /* active_list entries will end up before queued entries */
1044 list_splice_init(&dwc->queue, &list);
1045 list_splice_init(&dwc->active_list, &list);
1046
1047 spin_unlock_irqrestore(&dwc->lock, flags);
1048
1049 /* Flush all pending and queued descriptors */
1050 list_for_each_entry_safe(desc, _desc, &list, desc_node)
1051 dwc_descriptor_complete(dwc, desc, false);
1052
1053 return 0;
1054 }
1055
1056 static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
1057 {
1058 unsigned long flags;
1059 u32 residue;
1060
1061 spin_lock_irqsave(&dwc->lock, flags);
1062
1063 residue = dwc->residue;
1064 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1065 residue -= dwc_get_sent(dwc);
1066
1067 spin_unlock_irqrestore(&dwc->lock, flags);
1068 return residue;
1069 }
1070
1071 static enum dma_status
1072 dwc_tx_status(struct dma_chan *chan,
1073 dma_cookie_t cookie,
1074 struct dma_tx_state *txstate)
1075 {
1076 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1077 enum dma_status ret;
1078
1079 ret = dma_cookie_status(chan, cookie, txstate);
1080 if (ret == DMA_COMPLETE)
1081 return ret;
1082
1083 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1084
1085 ret = dma_cookie_status(chan, cookie, txstate);
1086 if (ret != DMA_COMPLETE)
1087 dma_set_residue(txstate, dwc_get_residue(dwc));
1088
1089 if (dwc->paused && ret == DMA_IN_PROGRESS)
1090 return DMA_PAUSED;
1091
1092 return ret;
1093 }
1094
1095 static void dwc_issue_pending(struct dma_chan *chan)
1096 {
1097 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1098 unsigned long flags;
1099
1100 spin_lock_irqsave(&dwc->lock, flags);
1101 if (list_empty(&dwc->active_list))
1102 dwc_dostart_first_queued(dwc);
1103 spin_unlock_irqrestore(&dwc->lock, flags);
1104 }
1105
1106 /*----------------------------------------------------------------------*/
1107
1108 static void dw_dma_off(struct dw_dma *dw)
1109 {
1110 int i;
1111
1112 dma_writel(dw, CFG, 0);
1113
1114 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1115 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1116 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1117 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1118 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1119
1120 while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1121 cpu_relax();
1122
1123 for (i = 0; i < dw->dma.chancnt; i++)
1124 dw->chan[i].initialized = false;
1125 }
1126
1127 static void dw_dma_on(struct dw_dma *dw)
1128 {
1129 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1130 }
1131
1132 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1133 {
1134 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1135 struct dw_dma *dw = to_dw_dma(chan->device);
1136 struct dw_desc *desc;
1137 int i;
1138 unsigned long flags;
1139
1140 dev_vdbg(chan2dev(chan), "%s\n", __func__);
1141
1142 /* ASSERT: channel is idle */
1143 if (dma_readl(dw, CH_EN) & dwc->mask) {
1144 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1145 return -EIO;
1146 }
1147
1148 dma_cookie_init(chan);
1149
1150 /*
1151 * NOTE: some controllers may have additional features that we
1152 * need to initialize here, like "scatter-gather" (which
1153 * doesn't mean what you think it means), and status writeback.
1154 */
1155
1156 /*
1157 * We need controller-specific data to set up slave transfers.
1158 */
1159 if (chan->private && !dw_dma_filter(chan, chan->private)) {
1160 dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
1161 return -EINVAL;
1162 }
1163
1164 /* Enable controller here if needed */
1165 if (!dw->in_use)
1166 dw_dma_on(dw);
1167 dw->in_use |= dwc->mask;
1168
1169 spin_lock_irqsave(&dwc->lock, flags);
1170 i = dwc->descs_allocated;
1171 while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1172 dma_addr_t phys;
1173
1174 spin_unlock_irqrestore(&dwc->lock, flags);
1175
1176 desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys);
1177 if (!desc)
1178 goto err_desc_alloc;
1179
1180 memset(desc, 0, sizeof(struct dw_desc));
1181
1182 INIT_LIST_HEAD(&desc->tx_list);
1183 dma_async_tx_descriptor_init(&desc->txd, chan);
1184 desc->txd.tx_submit = dwc_tx_submit;
1185 desc->txd.flags = DMA_CTRL_ACK;
1186 desc->txd.phys = phys;
1187
1188 dwc_desc_put(dwc, desc);
1189
1190 spin_lock_irqsave(&dwc->lock, flags);
1191 i = ++dwc->descs_allocated;
1192 }
1193
1194 spin_unlock_irqrestore(&dwc->lock, flags);
1195
1196 dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
1197
1198 return i;
1199
1200 err_desc_alloc:
1201 dev_info(chan2dev(chan), "only allocated %d descriptors\n", i);
1202
1203 return i;
1204 }
1205
1206 static void dwc_free_chan_resources(struct dma_chan *chan)
1207 {
1208 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1209 struct dw_dma *dw = to_dw_dma(chan->device);
1210 struct dw_desc *desc, *_desc;
1211 unsigned long flags;
1212 LIST_HEAD(list);
1213
1214 dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1215 dwc->descs_allocated);
1216
1217 /* ASSERT: channel is idle */
1218 BUG_ON(!list_empty(&dwc->active_list));
1219 BUG_ON(!list_empty(&dwc->queue));
1220 BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1221
1222 spin_lock_irqsave(&dwc->lock, flags);
1223 list_splice_init(&dwc->free_list, &list);
1224 dwc->descs_allocated = 0;
1225
1226 /* Clear custom channel configuration */
1227 dwc->src_id = 0;
1228 dwc->dst_id = 0;
1229
1230 dwc->src_master = 0;
1231 dwc->dst_master = 0;
1232
1233 dwc->initialized = false;
1234
1235 /* Disable interrupts */
1236 channel_clear_bit(dw, MASK.XFER, dwc->mask);
1237 channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1238 channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1239
1240 spin_unlock_irqrestore(&dwc->lock, flags);
1241
1242 /* Disable controller in case it was a last user */
1243 dw->in_use &= ~dwc->mask;
1244 if (!dw->in_use)
1245 dw_dma_off(dw);
1246
1247 list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1248 dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
1249 dma_pool_free(dw->desc_pool, desc, desc->txd.phys);
1250 }
1251
1252 dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1253 }
1254
1255 /* --------------------- Cyclic DMA API extensions -------------------- */
1256
1257 /**
1258 * dw_dma_cyclic_start - start the cyclic DMA transfer
1259 * @chan: the DMA channel to start
1260 *
1261 * Must be called with soft interrupts disabled. Returns zero on success or
1262 * -errno on failure.
1263 */
1264 int dw_dma_cyclic_start(struct dma_chan *chan)
1265 {
1266 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1267 struct dw_dma *dw = to_dw_dma(chan->device);
1268 unsigned long flags;
1269
1270 if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1271 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1272 return -ENODEV;
1273 }
1274
1275 spin_lock_irqsave(&dwc->lock, flags);
1276
1277 /* Enable interrupts to perform cyclic transfer */
1278 channel_set_bit(dw, MASK.BLOCK, dwc->mask);
1279
1280 dwc_dostart(dwc, dwc->cdesc->desc[0]);
1281
1282 spin_unlock_irqrestore(&dwc->lock, flags);
1283
1284 return 0;
1285 }
1286 EXPORT_SYMBOL(dw_dma_cyclic_start);
1287
1288 /**
1289 * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1290 * @chan: the DMA channel to stop
1291 *
1292 * Must be called with soft interrupts disabled.
1293 */
1294 void dw_dma_cyclic_stop(struct dma_chan *chan)
1295 {
1296 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1297 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1298 unsigned long flags;
1299
1300 spin_lock_irqsave(&dwc->lock, flags);
1301
1302 dwc_chan_disable(dw, dwc);
1303
1304 spin_unlock_irqrestore(&dwc->lock, flags);
1305 }
1306 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1307
1308 /**
1309 * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1310 * @chan: the DMA channel to prepare
1311 * @buf_addr: physical DMA address where the buffer starts
1312 * @buf_len: total number of bytes for the entire buffer
1313 * @period_len: number of bytes for each period
1314 * @direction: transfer direction, to or from device
1315 *
1316 * Must be called before trying to start the transfer. Returns a valid struct
1317 * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1318 */
1319 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1320 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1321 enum dma_transfer_direction direction)
1322 {
1323 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1324 struct dma_slave_config *sconfig = &dwc->dma_sconfig;
1325 struct dw_cyclic_desc *cdesc;
1326 struct dw_cyclic_desc *retval = NULL;
1327 struct dw_desc *desc;
1328 struct dw_desc *last = NULL;
1329 unsigned long was_cyclic;
1330 unsigned int reg_width;
1331 unsigned int periods;
1332 unsigned int i;
1333 unsigned long flags;
1334
1335 spin_lock_irqsave(&dwc->lock, flags);
1336 if (dwc->nollp) {
1337 spin_unlock_irqrestore(&dwc->lock, flags);
1338 dev_dbg(chan2dev(&dwc->chan),
1339 "channel doesn't support LLP transfers\n");
1340 return ERR_PTR(-EINVAL);
1341 }
1342
1343 if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1344 spin_unlock_irqrestore(&dwc->lock, flags);
1345 dev_dbg(chan2dev(&dwc->chan),
1346 "queue and/or active list are not empty\n");
1347 return ERR_PTR(-EBUSY);
1348 }
1349
1350 was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1351 spin_unlock_irqrestore(&dwc->lock, flags);
1352 if (was_cyclic) {
1353 dev_dbg(chan2dev(&dwc->chan),
1354 "channel already prepared for cyclic DMA\n");
1355 return ERR_PTR(-EBUSY);
1356 }
1357
1358 retval = ERR_PTR(-EINVAL);
1359
1360 if (unlikely(!is_slave_direction(direction)))
1361 goto out_err;
1362
1363 dwc->direction = direction;
1364
1365 if (direction == DMA_MEM_TO_DEV)
1366 reg_width = __ffs(sconfig->dst_addr_width);
1367 else
1368 reg_width = __ffs(sconfig->src_addr_width);
1369
1370 periods = buf_len / period_len;
1371
1372 /* Check for too big/unaligned periods and unaligned DMA buffer. */
1373 if (period_len > (dwc->block_size << reg_width))
1374 goto out_err;
1375 if (unlikely(period_len & ((1 << reg_width) - 1)))
1376 goto out_err;
1377 if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1378 goto out_err;
1379
1380 retval = ERR_PTR(-ENOMEM);
1381
1382 if (periods > NR_DESCS_PER_CHANNEL)
1383 goto out_err;
1384
1385 cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1386 if (!cdesc)
1387 goto out_err;
1388
1389 cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1390 if (!cdesc->desc)
1391 goto out_err_alloc;
1392
1393 for (i = 0; i < periods; i++) {
1394 desc = dwc_desc_get(dwc);
1395 if (!desc)
1396 goto out_err_desc_get;
1397
1398 switch (direction) {
1399 case DMA_MEM_TO_DEV:
1400 desc->lli.dar = sconfig->dst_addr;
1401 desc->lli.sar = buf_addr + (period_len * i);
1402 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1403 | DWC_CTLL_DST_WIDTH(reg_width)
1404 | DWC_CTLL_SRC_WIDTH(reg_width)
1405 | DWC_CTLL_DST_FIX
1406 | DWC_CTLL_SRC_INC
1407 | DWC_CTLL_INT_EN);
1408
1409 desc->lli.ctllo |= sconfig->device_fc ?
1410 DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
1411 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
1412
1413 break;
1414 case DMA_DEV_TO_MEM:
1415 desc->lli.dar = buf_addr + (period_len * i);
1416 desc->lli.sar = sconfig->src_addr;
1417 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1418 | DWC_CTLL_SRC_WIDTH(reg_width)
1419 | DWC_CTLL_DST_WIDTH(reg_width)
1420 | DWC_CTLL_DST_INC
1421 | DWC_CTLL_SRC_FIX
1422 | DWC_CTLL_INT_EN);
1423
1424 desc->lli.ctllo |= sconfig->device_fc ?
1425 DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
1426 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
1427
1428 break;
1429 default:
1430 break;
1431 }
1432
1433 desc->lli.ctlhi = (period_len >> reg_width);
1434 cdesc->desc[i] = desc;
1435
1436 if (last)
1437 last->lli.llp = desc->txd.phys;
1438
1439 last = desc;
1440 }
1441
1442 /* Let's make a cyclic list */
1443 last->lli.llp = cdesc->desc[0]->txd.phys;
1444
1445 dev_dbg(chan2dev(&dwc->chan),
1446 "cyclic prepared buf %pad len %zu period %zu periods %d\n",
1447 &buf_addr, buf_len, period_len, periods);
1448
1449 cdesc->periods = periods;
1450 dwc->cdesc = cdesc;
1451
1452 return cdesc;
1453
1454 out_err_desc_get:
1455 while (i--)
1456 dwc_desc_put(dwc, cdesc->desc[i]);
1457 out_err_alloc:
1458 kfree(cdesc);
1459 out_err:
1460 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1461 return (struct dw_cyclic_desc *)retval;
1462 }
1463 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1464
1465 /**
1466 * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1467 * @chan: the DMA channel to free
1468 */
1469 void dw_dma_cyclic_free(struct dma_chan *chan)
1470 {
1471 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1472 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1473 struct dw_cyclic_desc *cdesc = dwc->cdesc;
1474 int i;
1475 unsigned long flags;
1476
1477 dev_dbg(chan2dev(&dwc->chan), "%s\n", __func__);
1478
1479 if (!cdesc)
1480 return;
1481
1482 spin_lock_irqsave(&dwc->lock, flags);
1483
1484 dwc_chan_disable(dw, dwc);
1485
1486 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1487 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1488 dma_writel(dw, CLEAR.XFER, dwc->mask);
1489
1490 spin_unlock_irqrestore(&dwc->lock, flags);
1491
1492 for (i = 0; i < cdesc->periods; i++)
1493 dwc_desc_put(dwc, cdesc->desc[i]);
1494
1495 kfree(cdesc->desc);
1496 kfree(cdesc);
1497
1498 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1499 }
1500 EXPORT_SYMBOL(dw_dma_cyclic_free);
1501
1502 /*----------------------------------------------------------------------*/
1503
1504 int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
1505 {
1506 struct dw_dma *dw;
1507 bool autocfg = false;
1508 unsigned int dw_params;
1509 unsigned int max_blk_size = 0;
1510 int err;
1511 int i;
1512
1513 dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
1514 if (!dw)
1515 return -ENOMEM;
1516
1517 dw->regs = chip->regs;
1518 chip->dw = dw;
1519
1520 pm_runtime_get_sync(chip->dev);
1521
1522 if (!pdata) {
1523 dw_params = dma_read_byaddr(chip->regs, DW_PARAMS);
1524 dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1525
1526 autocfg = dw_params >> DW_PARAMS_EN & 1;
1527 if (!autocfg) {
1528 err = -EINVAL;
1529 goto err_pdata;
1530 }
1531
1532 pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
1533 if (!pdata) {
1534 err = -ENOMEM;
1535 goto err_pdata;
1536 }
1537
1538 /* Get hardware configuration parameters */
1539 pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1;
1540 pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1541 for (i = 0; i < pdata->nr_masters; i++) {
1542 pdata->data_width[i] =
1543 (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3) + 2;
1544 }
1545 max_blk_size = dma_readl(dw, MAX_BLK_SIZE);
1546
1547 /* Fill platform data with the default values */
1548 pdata->is_private = true;
1549 pdata->is_memcpy = true;
1550 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1551 pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1552 } else if (pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
1553 err = -EINVAL;
1554 goto err_pdata;
1555 }
1556
1557 dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
1558 GFP_KERNEL);
1559 if (!dw->chan) {
1560 err = -ENOMEM;
1561 goto err_pdata;
1562 }
1563
1564 /* Get hardware configuration parameters */
1565 dw->nr_masters = pdata->nr_masters;
1566 for (i = 0; i < dw->nr_masters; i++)
1567 dw->data_width[i] = pdata->data_width[i];
1568
1569 /* Calculate all channel mask before DMA setup */
1570 dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1571
1572 /* Force dma off, just in case */
1573 dw_dma_off(dw);
1574
1575 /* Create a pool of consistent memory blocks for hardware descriptors */
1576 dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev,
1577 sizeof(struct dw_desc), 4, 0);
1578 if (!dw->desc_pool) {
1579 dev_err(chip->dev, "No memory for descriptors dma pool\n");
1580 err = -ENOMEM;
1581 goto err_pdata;
1582 }
1583
1584 tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1585
1586 err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
1587 "dw_dmac", dw);
1588 if (err)
1589 goto err_pdata;
1590
1591 INIT_LIST_HEAD(&dw->dma.channels);
1592 for (i = 0; i < pdata->nr_channels; i++) {
1593 struct dw_dma_chan *dwc = &dw->chan[i];
1594
1595 dwc->chan.device = &dw->dma;
1596 dma_cookie_init(&dwc->chan);
1597 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1598 list_add_tail(&dwc->chan.device_node,
1599 &dw->dma.channels);
1600 else
1601 list_add(&dwc->chan.device_node, &dw->dma.channels);
1602
1603 /* 7 is highest priority & 0 is lowest. */
1604 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1605 dwc->priority = pdata->nr_channels - i - 1;
1606 else
1607 dwc->priority = i;
1608
1609 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1610 spin_lock_init(&dwc->lock);
1611 dwc->mask = 1 << i;
1612
1613 INIT_LIST_HEAD(&dwc->active_list);
1614 INIT_LIST_HEAD(&dwc->queue);
1615 INIT_LIST_HEAD(&dwc->free_list);
1616
1617 channel_clear_bit(dw, CH_EN, dwc->mask);
1618
1619 dwc->direction = DMA_TRANS_NONE;
1620
1621 /* Hardware configuration */
1622 if (autocfg) {
1623 unsigned int dwc_params;
1624 unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
1625 void __iomem *addr = chip->regs + r * sizeof(u32);
1626
1627 dwc_params = dma_read_byaddr(addr, DWC_PARAMS);
1628
1629 dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1630 dwc_params);
1631
1632 /*
1633 * Decode maximum block size for given channel. The
1634 * stored 4 bit value represents blocks from 0x00 for 3
1635 * up to 0x0a for 4095.
1636 */
1637 dwc->block_size =
1638 (4 << ((max_blk_size >> 4 * i) & 0xf)) - 1;
1639 dwc->nollp =
1640 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1641 } else {
1642 dwc->block_size = pdata->block_size;
1643
1644 /* Check if channel supports multi block transfer */
1645 channel_writel(dwc, LLP, 0xfffffffc);
1646 dwc->nollp =
1647 (channel_readl(dwc, LLP) & 0xfffffffc) == 0;
1648 channel_writel(dwc, LLP, 0);
1649 }
1650 }
1651
1652 /* Clear all interrupts on all channels. */
1653 dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1654 dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1655 dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1656 dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1657 dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1658
1659 /* Set capabilities */
1660 dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1661 if (pdata->is_private)
1662 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1663 if (pdata->is_memcpy)
1664 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1665
1666 dw->dma.dev = chip->dev;
1667 dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1668 dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1669
1670 dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1671 dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1672
1673 dw->dma.device_config = dwc_config;
1674 dw->dma.device_pause = dwc_pause;
1675 dw->dma.device_resume = dwc_resume;
1676 dw->dma.device_terminate_all = dwc_terminate_all;
1677
1678 dw->dma.device_tx_status = dwc_tx_status;
1679 dw->dma.device_issue_pending = dwc_issue_pending;
1680
1681 /* DMA capabilities */
1682 dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
1683 dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
1684 dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1685 BIT(DMA_MEM_TO_MEM);
1686 dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1687
1688 err = dma_async_device_register(&dw->dma);
1689 if (err)
1690 goto err_dma_register;
1691
1692 dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
1693 pdata->nr_channels);
1694
1695 pm_runtime_put_sync_suspend(chip->dev);
1696
1697 return 0;
1698
1699 err_dma_register:
1700 free_irq(chip->irq, dw);
1701 err_pdata:
1702 pm_runtime_put_sync_suspend(chip->dev);
1703 return err;
1704 }
1705 EXPORT_SYMBOL_GPL(dw_dma_probe);
1706
1707 int dw_dma_remove(struct dw_dma_chip *chip)
1708 {
1709 struct dw_dma *dw = chip->dw;
1710 struct dw_dma_chan *dwc, *_dwc;
1711
1712 pm_runtime_get_sync(chip->dev);
1713
1714 dw_dma_off(dw);
1715 dma_async_device_unregister(&dw->dma);
1716
1717 free_irq(chip->irq, dw);
1718 tasklet_kill(&dw->tasklet);
1719
1720 list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1721 chan.device_node) {
1722 list_del(&dwc->chan.device_node);
1723 channel_clear_bit(dw, CH_EN, dwc->mask);
1724 }
1725
1726 pm_runtime_put_sync_suspend(chip->dev);
1727 return 0;
1728 }
1729 EXPORT_SYMBOL_GPL(dw_dma_remove);
1730
1731 int dw_dma_disable(struct dw_dma_chip *chip)
1732 {
1733 struct dw_dma *dw = chip->dw;
1734
1735 dw_dma_off(dw);
1736 return 0;
1737 }
1738 EXPORT_SYMBOL_GPL(dw_dma_disable);
1739
1740 int dw_dma_enable(struct dw_dma_chip *chip)
1741 {
1742 struct dw_dma *dw = chip->dw;
1743
1744 dw_dma_on(dw);
1745 return 0;
1746 }
1747 EXPORT_SYMBOL_GPL(dw_dma_enable);
1748
1749 MODULE_LICENSE("GPL v2");
1750 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver");
1751 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1752 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
Linux kernel - Deliverables
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