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mm: vma_adjust: remove superfluous check for next not NULL
[linux/fpc-iii.git] / drivers / dma / dw / core.c
blobc2c0a613cb7aab53ac5f8e85c6c7441ecc7ef3fc
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 u8 _dms = (_dwc->direction == DMA_MEM_TO_DEV) ? \
49 _dwc->dws.p_master : _dwc->dws.m_master; \
50 u8 _sms = (_dwc->direction == DMA_DEV_TO_MEM) ? \
51 _dwc->dws.p_master : _dwc->dws.m_master; \
52 \
53 (DWC_CTLL_DST_MSIZE(_dmsize) \
54 | DWC_CTLL_SRC_MSIZE(_smsize) \
55 | DWC_CTLL_LLP_D_EN \
56 | DWC_CTLL_LLP_S_EN \
57 | DWC_CTLL_DMS(_dms) \
58 | DWC_CTLL_SMS(_sms)); \
59 })
60
61 /* The set of bus widths supported by the DMA controller */
62 #define DW_DMA_BUSWIDTHS \
63 BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
64 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
65 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
66 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
67
68 /*----------------------------------------------------------------------*/
69
70 static struct device *chan2dev(struct dma_chan *chan)
71 {
72 return &chan->dev->device;
73 }
74
75 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
76 {
77 return to_dw_desc(dwc->active_list.next);
78 }
79
80 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
81 {
82 struct dw_desc *desc = txd_to_dw_desc(tx);
83 struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
84 dma_cookie_t cookie;
85 unsigned long flags;
86
87 spin_lock_irqsave(&dwc->lock, flags);
88 cookie = dma_cookie_assign(tx);
89
90 /*
91 * REVISIT: We should attempt to chain as many descriptors as
92 * possible, perhaps even appending to those already submitted
93 * for DMA. But this is hard to do in a race-free manner.
94 */
95
96 list_add_tail(&desc->desc_node, &dwc->queue);
97 spin_unlock_irqrestore(&dwc->lock, flags);
98 dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n",
99 __func__, desc->txd.cookie);
100
101 return cookie;
102 }
103
104 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
105 {
106 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
107 struct dw_desc *desc;
108 dma_addr_t phys;
109
110 desc = dma_pool_zalloc(dw->desc_pool, GFP_ATOMIC, &phys);
111 if (!desc)
112 return NULL;
113
114 dwc->descs_allocated++;
115 INIT_LIST_HEAD(&desc->tx_list);
116 dma_async_tx_descriptor_init(&desc->txd, &dwc->chan);
117 desc->txd.tx_submit = dwc_tx_submit;
118 desc->txd.flags = DMA_CTRL_ACK;
119 desc->txd.phys = phys;
120 return desc;
121 }
122
123 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
124 {
125 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
126 struct dw_desc *child, *_next;
127
128 if (unlikely(!desc))
129 return;
130
131 list_for_each_entry_safe(child, _next, &desc->tx_list, desc_node) {
132 list_del(&child->desc_node);
133 dma_pool_free(dw->desc_pool, child, child->txd.phys);
134 dwc->descs_allocated--;
135 }
136
137 dma_pool_free(dw->desc_pool, desc, desc->txd.phys);
138 dwc->descs_allocated--;
139 }
140
141 static void dwc_initialize(struct dw_dma_chan *dwc)
142 {
143 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
144 u32 cfghi = DWC_CFGH_FIFO_MODE;
145 u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
146 bool hs_polarity = dwc->dws.hs_polarity;
147
148 if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
149 return;
150
151 cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
152 cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
153
154 /* Set polarity of handshake interface */
155 cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
156
157 channel_writel(dwc, CFG_LO, cfglo);
158 channel_writel(dwc, CFG_HI, cfghi);
159
160 /* Enable interrupts */
161 channel_set_bit(dw, MASK.XFER, dwc->mask);
162 channel_set_bit(dw, MASK.ERROR, dwc->mask);
163
164 set_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
165 }
166
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 = lli_read(desc, ctllo) | DWC_CTLL_INT_EN;
201
202 channel_writel(dwc, SAR, lli_read(desc, sar));
203 channel_writel(dwc, DAR, lli_read(desc, dar));
204 channel_writel(dwc, CTL_LO, ctllo);
205 channel_writel(dwc, CTL_HI, lli_read(desc, 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 u8 lms = DWC_LLP_LMS(dwc->dws.m_master);
217 unsigned long was_soft_llp;
218
219 /* ASSERT: channel is idle */
220 if (dma_readl(dw, CH_EN) & dwc->mask) {
221 dev_err(chan2dev(&dwc->chan),
222 "%s: BUG: Attempted to start non-idle channel\n",
223 __func__);
224 dwc_dump_chan_regs(dwc);
225
226 /* The tasklet will hopefully advance the queue... */
227 return;
228 }
229
230 if (dwc->nollp) {
231 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
232 &dwc->flags);
233 if (was_soft_llp) {
234 dev_err(chan2dev(&dwc->chan),
235 "BUG: Attempted to start new LLP transfer inside ongoing one\n");
236 return;
237 }
238
239 dwc_initialize(dwc);
240
241 first->residue = first->total_len;
242 dwc->tx_node_active = &first->tx_list;
243
244 /* Submit first block */
245 dwc_do_single_block(dwc, first);
246
247 return;
248 }
249
250 dwc_initialize(dwc);
251
252 channel_writel(dwc, LLP, first->txd.phys | lms);
253 channel_writel(dwc, CTL_LO, 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 struct dma_async_tx_descriptor *txd = &desc->txd;
278 struct dw_desc *child;
279 unsigned long flags;
280 struct dmaengine_desc_callback cb;
281
282 dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
283
284 spin_lock_irqsave(&dwc->lock, flags);
285 dma_cookie_complete(txd);
286 if (callback_required)
287 dmaengine_desc_get_callback(txd, &cb);
288 else
289 memset(&cb, 0, sizeof(cb));
290
291 /* async_tx_ack */
292 list_for_each_entry(child, &desc->tx_list, desc_node)
293 async_tx_ack(&child->txd);
294 async_tx_ack(&desc->txd);
295 dwc_desc_put(dwc, desc);
296 spin_unlock_irqrestore(&dwc->lock, flags);
297
298 dmaengine_desc_callback_invoke(&cb, NULL);
299 }
300
301 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
302 {
303 struct dw_desc *desc, *_desc;
304 LIST_HEAD(list);
305 unsigned long flags;
306
307 spin_lock_irqsave(&dwc->lock, flags);
308 if (dma_readl(dw, CH_EN) & dwc->mask) {
309 dev_err(chan2dev(&dwc->chan),
310 "BUG: XFER bit set, but channel not idle!\n");
311
312 /* Try to continue after resetting the channel... */
313 dwc_chan_disable(dw, dwc);
314 }
315
316 /*
317 * Submit queued descriptors ASAP, i.e. before we go through
318 * the completed ones.
319 */
320 list_splice_init(&dwc->active_list, &list);
321 dwc_dostart_first_queued(dwc);
322
323 spin_unlock_irqrestore(&dwc->lock, flags);
324
325 list_for_each_entry_safe(desc, _desc, &list, desc_node)
326 dwc_descriptor_complete(dwc, desc, true);
327 }
328
329 /* Returns how many bytes were already received from source */
330 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
331 {
332 u32 ctlhi = channel_readl(dwc, CTL_HI);
333 u32 ctllo = channel_readl(dwc, CTL_LO);
334
335 return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
336 }
337
338 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
339 {
340 dma_addr_t llp;
341 struct dw_desc *desc, *_desc;
342 struct dw_desc *child;
343 u32 status_xfer;
344 unsigned long flags;
345
346 spin_lock_irqsave(&dwc->lock, flags);
347 llp = channel_readl(dwc, LLP);
348 status_xfer = dma_readl(dw, RAW.XFER);
349
350 if (status_xfer & dwc->mask) {
351 /* Everything we've submitted is done */
352 dma_writel(dw, CLEAR.XFER, dwc->mask);
353
354 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
355 struct list_head *head, *active = dwc->tx_node_active;
356
357 /*
358 * We are inside first active descriptor.
359 * Otherwise something is really wrong.
360 */
361 desc = dwc_first_active(dwc);
362
363 head = &desc->tx_list;
364 if (active != head) {
365 /* Update residue to reflect last sent descriptor */
366 if (active == head->next)
367 desc->residue -= desc->len;
368 else
369 desc->residue -= to_dw_desc(active->prev)->len;
370
371 child = to_dw_desc(active);
372
373 /* Submit next block */
374 dwc_do_single_block(dwc, child);
375
376 spin_unlock_irqrestore(&dwc->lock, flags);
377 return;
378 }
379
380 /* We are done here */
381 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
382 }
383
384 spin_unlock_irqrestore(&dwc->lock, flags);
385
386 dwc_complete_all(dw, dwc);
387 return;
388 }
389
390 if (list_empty(&dwc->active_list)) {
391 spin_unlock_irqrestore(&dwc->lock, flags);
392 return;
393 }
394
395 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
396 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
397 spin_unlock_irqrestore(&dwc->lock, flags);
398 return;
399 }
400
401 dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp);
402
403 list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
404 /* Initial residue value */
405 desc->residue = desc->total_len;
406
407 /* Check first descriptors addr */
408 if (desc->txd.phys == DWC_LLP_LOC(llp)) {
409 spin_unlock_irqrestore(&dwc->lock, flags);
410 return;
411 }
412
413 /* Check first descriptors llp */
414 if (lli_read(desc, llp) == llp) {
415 /* This one is currently in progress */
416 desc->residue -= dwc_get_sent(dwc);
417 spin_unlock_irqrestore(&dwc->lock, flags);
418 return;
419 }
420
421 desc->residue -= desc->len;
422 list_for_each_entry(child, &desc->tx_list, desc_node) {
423 if (lli_read(child, llp) == llp) {
424 /* Currently in progress */
425 desc->residue -= dwc_get_sent(dwc);
426 spin_unlock_irqrestore(&dwc->lock, flags);
427 return;
428 }
429 desc->residue -= child->len;
430 }
431
432 /*
433 * No descriptors so far seem to be in progress, i.e.
434 * this one must be done.
435 */
436 spin_unlock_irqrestore(&dwc->lock, flags);
437 dwc_descriptor_complete(dwc, desc, true);
438 spin_lock_irqsave(&dwc->lock, flags);
439 }
440
441 dev_err(chan2dev(&dwc->chan),
442 "BUG: All descriptors done, but channel not idle!\n");
443
444 /* Try to continue after resetting the channel... */
445 dwc_chan_disable(dw, dwc);
446
447 dwc_dostart_first_queued(dwc);
448 spin_unlock_irqrestore(&dwc->lock, flags);
449 }
450
451 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_desc *desc)
452 {
453 dev_crit(chan2dev(&dwc->chan), " desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
454 lli_read(desc, sar),
455 lli_read(desc, dar),
456 lli_read(desc, llp),
457 lli_read(desc, ctlhi),
458 lli_read(desc, ctllo));
459 }
460
461 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
462 {
463 struct dw_desc *bad_desc;
464 struct dw_desc *child;
465 unsigned long flags;
466
467 dwc_scan_descriptors(dw, dwc);
468
469 spin_lock_irqsave(&dwc->lock, flags);
470
471 /*
472 * The descriptor currently at the head of the active list is
473 * borked. Since we don't have any way to report errors, we'll
474 * just have to scream loudly and try to carry on.
475 */
476 bad_desc = dwc_first_active(dwc);
477 list_del_init(&bad_desc->desc_node);
478 list_move(dwc->queue.next, dwc->active_list.prev);
479
480 /* Clear the error flag and try to restart the controller */
481 dma_writel(dw, CLEAR.ERROR, dwc->mask);
482 if (!list_empty(&dwc->active_list))
483 dwc_dostart(dwc, dwc_first_active(dwc));
484
485 /*
486 * WARN may seem harsh, but since this only happens
487 * when someone submits a bad physical address in a
488 * descriptor, we should consider ourselves lucky that the
489 * controller flagged an error instead of scribbling over
490 * random memory locations.
491 */
492 dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
493 " cookie: %d\n", bad_desc->txd.cookie);
494 dwc_dump_lli(dwc, bad_desc);
495 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
496 dwc_dump_lli(dwc, child);
497
498 spin_unlock_irqrestore(&dwc->lock, flags);
499
500 /* Pretend the descriptor completed successfully */
501 dwc_descriptor_complete(dwc, bad_desc, true);
502 }
503
504 /* --------------------- Cyclic DMA API extensions -------------------- */
505
506 dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
507 {
508 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
509 return channel_readl(dwc, SAR);
510 }
511 EXPORT_SYMBOL(dw_dma_get_src_addr);
512
513 dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
514 {
515 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
516 return channel_readl(dwc, DAR);
517 }
518 EXPORT_SYMBOL(dw_dma_get_dst_addr);
519
520 /* Called with dwc->lock held and all DMAC interrupts disabled */
521 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
522 u32 status_block, u32 status_err, u32 status_xfer)
523 {
524 unsigned long flags;
525
526 if (status_block & dwc->mask) {
527 void (*callback)(void *param);
528 void *callback_param;
529
530 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
531 channel_readl(dwc, LLP));
532 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
533
534 callback = dwc->cdesc->period_callback;
535 callback_param = dwc->cdesc->period_callback_param;
536
537 if (callback)
538 callback(callback_param);
539 }
540
541 /*
542 * Error and transfer complete are highly unlikely, and will most
543 * likely be due to a configuration error by the user.
544 */
545 if (unlikely(status_err & dwc->mask) ||
546 unlikely(status_xfer & dwc->mask)) {
547 unsigned int i;
548
549 dev_err(chan2dev(&dwc->chan),
550 "cyclic DMA unexpected %s interrupt, stopping DMA transfer\n",
551 status_xfer ? "xfer" : "error");
552
553 spin_lock_irqsave(&dwc->lock, flags);
554
555 dwc_dump_chan_regs(dwc);
556
557 dwc_chan_disable(dw, dwc);
558
559 /* Make sure DMA does not restart by loading a new list */
560 channel_writel(dwc, LLP, 0);
561 channel_writel(dwc, CTL_LO, 0);
562 channel_writel(dwc, CTL_HI, 0);
563
564 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
565 dma_writel(dw, CLEAR.ERROR, dwc->mask);
566 dma_writel(dw, CLEAR.XFER, dwc->mask);
567
568 for (i = 0; i < dwc->cdesc->periods; i++)
569 dwc_dump_lli(dwc, dwc->cdesc->desc[i]);
570
571 spin_unlock_irqrestore(&dwc->lock, flags);
572 }
573
574 /* Re-enable interrupts */
575 channel_set_bit(dw, MASK.BLOCK, dwc->mask);
576 }
577
578 /* ------------------------------------------------------------------------- */
579
580 static void dw_dma_tasklet(unsigned long data)
581 {
582 struct dw_dma *dw = (struct dw_dma *)data;
583 struct dw_dma_chan *dwc;
584 u32 status_block;
585 u32 status_xfer;
586 u32 status_err;
587 unsigned int i;
588
589 status_block = dma_readl(dw, RAW.BLOCK);
590 status_xfer = dma_readl(dw, RAW.XFER);
591 status_err = dma_readl(dw, RAW.ERROR);
592
593 dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
594
595 for (i = 0; i < dw->dma.chancnt; i++) {
596 dwc = &dw->chan[i];
597 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
598 dwc_handle_cyclic(dw, dwc, status_block, status_err,
599 status_xfer);
600 else if (status_err & (1 << i))
601 dwc_handle_error(dw, dwc);
602 else if (status_xfer & (1 << i))
603 dwc_scan_descriptors(dw, dwc);
604 }
605
606 /* Re-enable interrupts */
607 channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
608 channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
609 }
610
611 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
612 {
613 struct dw_dma *dw = dev_id;
614 u32 status;
615
616 /* Check if we have any interrupt from the DMAC which is not in use */
617 if (!dw->in_use)
618 return IRQ_NONE;
619
620 status = dma_readl(dw, STATUS_INT);
621 dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);
622
623 /* Check if we have any interrupt from the DMAC */
624 if (!status)
625 return IRQ_NONE;
626
627 /*
628 * Just disable the interrupts. We'll turn them back on in the
629 * softirq handler.
630 */
631 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
632 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
633 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
634
635 status = dma_readl(dw, STATUS_INT);
636 if (status) {
637 dev_err(dw->dma.dev,
638 "BUG: Unexpected interrupts pending: 0x%x\n",
639 status);
640
641 /* Try to recover */
642 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
643 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
644 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
645 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
646 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
647 }
648
649 tasklet_schedule(&dw->tasklet);
650
651 return IRQ_HANDLED;
652 }
653
654 /*----------------------------------------------------------------------*/
655
656 static struct dma_async_tx_descriptor *
657 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
658 size_t len, unsigned long flags)
659 {
660 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
661 struct dw_dma *dw = to_dw_dma(chan->device);
662 struct dw_desc *desc;
663 struct dw_desc *first;
664 struct dw_desc *prev;
665 size_t xfer_count;
666 size_t offset;
667 u8 m_master = dwc->dws.m_master;
668 unsigned int src_width;
669 unsigned int dst_width;
670 unsigned int data_width = dw->pdata->data_width[m_master];
671 u32 ctllo;
672 u8 lms = DWC_LLP_LMS(m_master);
673
674 dev_vdbg(chan2dev(chan),
675 "%s: d%pad s%pad l0x%zx f0x%lx\n", __func__,
676 &dest, &src, len, flags);
677
678 if (unlikely(!len)) {
679 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
680 return NULL;
681 }
682
683 dwc->direction = DMA_MEM_TO_MEM;
684
685 src_width = dst_width = __ffs(data_width | src | dest | len);
686
687 ctllo = DWC_DEFAULT_CTLLO(chan)
688 | DWC_CTLL_DST_WIDTH(dst_width)
689 | DWC_CTLL_SRC_WIDTH(src_width)
690 | DWC_CTLL_DST_INC
691 | DWC_CTLL_SRC_INC
692 | DWC_CTLL_FC_M2M;
693 prev = first = NULL;
694
695 for (offset = 0; offset < len; offset += xfer_count << src_width) {
696 xfer_count = min_t(size_t, (len - offset) >> src_width,
697 dwc->block_size);
698
699 desc = dwc_desc_get(dwc);
700 if (!desc)
701 goto err_desc_get;
702
703 lli_write(desc, sar, src + offset);
704 lli_write(desc, dar, dest + offset);
705 lli_write(desc, ctllo, ctllo);
706 lli_write(desc, ctlhi, xfer_count);
707 desc->len = xfer_count << src_width;
708
709 if (!first) {
710 first = desc;
711 } else {
712 lli_write(prev, llp, desc->txd.phys | lms);
713 list_add_tail(&desc->desc_node, &first->tx_list);
714 }
715 prev = desc;
716 }
717
718 if (flags & DMA_PREP_INTERRUPT)
719 /* Trigger interrupt after last block */
720 lli_set(prev, ctllo, DWC_CTLL_INT_EN);
721
722 prev->lli.llp = 0;
723 lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
724 first->txd.flags = flags;
725 first->total_len = len;
726
727 return &first->txd;
728
729 err_desc_get:
730 dwc_desc_put(dwc, first);
731 return NULL;
732 }
733
734 static struct dma_async_tx_descriptor *
735 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
736 unsigned int sg_len, enum dma_transfer_direction direction,
737 unsigned long flags, void *context)
738 {
739 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
740 struct dw_dma *dw = to_dw_dma(chan->device);
741 struct dma_slave_config *sconfig = &dwc->dma_sconfig;
742 struct dw_desc *prev;
743 struct dw_desc *first;
744 u32 ctllo;
745 u8 m_master = dwc->dws.m_master;
746 u8 lms = DWC_LLP_LMS(m_master);
747 dma_addr_t reg;
748 unsigned int reg_width;
749 unsigned int mem_width;
750 unsigned int data_width = dw->pdata->data_width[m_master];
751 unsigned int i;
752 struct scatterlist *sg;
753 size_t total_len = 0;
754
755 dev_vdbg(chan2dev(chan), "%s\n", __func__);
756
757 if (unlikely(!is_slave_direction(direction) || !sg_len))
758 return NULL;
759
760 dwc->direction = direction;
761
762 prev = first = NULL;
763
764 switch (direction) {
765 case DMA_MEM_TO_DEV:
766 reg_width = __ffs(sconfig->dst_addr_width);
767 reg = sconfig->dst_addr;
768 ctllo = (DWC_DEFAULT_CTLLO(chan)
769 | DWC_CTLL_DST_WIDTH(reg_width)
770 | DWC_CTLL_DST_FIX
771 | DWC_CTLL_SRC_INC);
772
773 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
774 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
775
776 for_each_sg(sgl, sg, sg_len, i) {
777 struct dw_desc *desc;
778 u32 len, dlen, mem;
779
780 mem = sg_dma_address(sg);
781 len = sg_dma_len(sg);
782
783 mem_width = __ffs(data_width | mem | len);
784
785 slave_sg_todev_fill_desc:
786 desc = dwc_desc_get(dwc);
787 if (!desc)
788 goto err_desc_get;
789
790 lli_write(desc, sar, mem);
791 lli_write(desc, dar, reg);
792 lli_write(desc, ctllo, ctllo | DWC_CTLL_SRC_WIDTH(mem_width));
793 if ((len >> mem_width) > dwc->block_size) {
794 dlen = dwc->block_size << mem_width;
795 mem += dlen;
796 len -= dlen;
797 } else {
798 dlen = len;
799 len = 0;
800 }
801
802 lli_write(desc, ctlhi, dlen >> mem_width);
803 desc->len = dlen;
804
805 if (!first) {
806 first = desc;
807 } else {
808 lli_write(prev, llp, desc->txd.phys | lms);
809 list_add_tail(&desc->desc_node, &first->tx_list);
810 }
811 prev = desc;
812 total_len += dlen;
813
814 if (len)
815 goto slave_sg_todev_fill_desc;
816 }
817 break;
818 case DMA_DEV_TO_MEM:
819 reg_width = __ffs(sconfig->src_addr_width);
820 reg = sconfig->src_addr;
821 ctllo = (DWC_DEFAULT_CTLLO(chan)
822 | DWC_CTLL_SRC_WIDTH(reg_width)
823 | DWC_CTLL_DST_INC
824 | DWC_CTLL_SRC_FIX);
825
826 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
827 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
828
829 for_each_sg(sgl, sg, sg_len, i) {
830 struct dw_desc *desc;
831 u32 len, dlen, mem;
832
833 mem = sg_dma_address(sg);
834 len = sg_dma_len(sg);
835
836 mem_width = __ffs(data_width | mem | len);
837
838 slave_sg_fromdev_fill_desc:
839 desc = dwc_desc_get(dwc);
840 if (!desc)
841 goto err_desc_get;
842
843 lli_write(desc, sar, reg);
844 lli_write(desc, dar, mem);
845 lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width));
846 if ((len >> reg_width) > dwc->block_size) {
847 dlen = dwc->block_size << reg_width;
848 mem += dlen;
849 len -= dlen;
850 } else {
851 dlen = len;
852 len = 0;
853 }
854 lli_write(desc, ctlhi, dlen >> reg_width);
855 desc->len = dlen;
856
857 if (!first) {
858 first = desc;
859 } else {
860 lli_write(prev, llp, desc->txd.phys | lms);
861 list_add_tail(&desc->desc_node, &first->tx_list);
862 }
863 prev = desc;
864 total_len += dlen;
865
866 if (len)
867 goto slave_sg_fromdev_fill_desc;
868 }
869 break;
870 default:
871 return NULL;
872 }
873
874 if (flags & DMA_PREP_INTERRUPT)
875 /* Trigger interrupt after last block */
876 lli_set(prev, ctllo, DWC_CTLL_INT_EN);
877
878 prev->lli.llp = 0;
879 lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
880 first->total_len = total_len;
881
882 return &first->txd;
883
884 err_desc_get:
885 dev_err(chan2dev(chan),
886 "not enough descriptors available. Direction %d\n", direction);
887 dwc_desc_put(dwc, first);
888 return NULL;
889 }
890
891 bool dw_dma_filter(struct dma_chan *chan, void *param)
892 {
893 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
894 struct dw_dma_slave *dws = param;
895
896 if (dws->dma_dev != chan->device->dev)
897 return false;
898
899 /* We have to copy data since dws can be temporary storage */
900 memcpy(&dwc->dws, dws, sizeof(struct dw_dma_slave));
901
902 return true;
903 }
904 EXPORT_SYMBOL_GPL(dw_dma_filter);
905
906 /*
907 * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
908 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
909 *
910 * NOTE: burst size 2 is not supported by controller.
911 *
912 * This can be done by finding least significant bit set: n & (n - 1)
913 */
914 static inline void convert_burst(u32 *maxburst)
915 {
916 if (*maxburst > 1)
917 *maxburst = fls(*maxburst) - 2;
918 else
919 *maxburst = 0;
920 }
921
922 static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
923 {
924 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
925
926 /* Check if chan will be configured for slave transfers */
927 if (!is_slave_direction(sconfig->direction))
928 return -EINVAL;
929
930 memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
931 dwc->direction = sconfig->direction;
932
933 convert_burst(&dwc->dma_sconfig.src_maxburst);
934 convert_burst(&dwc->dma_sconfig.dst_maxburst);
935
936 return 0;
937 }
938
939 static int dwc_pause(struct dma_chan *chan)
940 {
941 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
942 unsigned long flags;
943 unsigned int count = 20; /* timeout iterations */
944 u32 cfglo;
945
946 spin_lock_irqsave(&dwc->lock, flags);
947
948 cfglo = channel_readl(dwc, CFG_LO);
949 channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
950 while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
951 udelay(2);
952
953 set_bit(DW_DMA_IS_PAUSED, &dwc->flags);
954
955 spin_unlock_irqrestore(&dwc->lock, flags);
956
957 return 0;
958 }
959
960 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
961 {
962 u32 cfglo = channel_readl(dwc, CFG_LO);
963
964 channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
965
966 clear_bit(DW_DMA_IS_PAUSED, &dwc->flags);
967 }
968
969 static int dwc_resume(struct dma_chan *chan)
970 {
971 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
972 unsigned long flags;
973
974 spin_lock_irqsave(&dwc->lock, flags);
975
976 if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags))
977 dwc_chan_resume(dwc);
978
979 spin_unlock_irqrestore(&dwc->lock, flags);
980
981 return 0;
982 }
983
984 static int dwc_terminate_all(struct dma_chan *chan)
985 {
986 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
987 struct dw_dma *dw = to_dw_dma(chan->device);
988 struct dw_desc *desc, *_desc;
989 unsigned long flags;
990 LIST_HEAD(list);
991
992 spin_lock_irqsave(&dwc->lock, flags);
993
994 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
995
996 dwc_chan_disable(dw, dwc);
997
998 dwc_chan_resume(dwc);
999
1000 /* active_list entries will end up before queued entries */
1001 list_splice_init(&dwc->queue, &list);
1002 list_splice_init(&dwc->active_list, &list);
1003
1004 spin_unlock_irqrestore(&dwc->lock, flags);
1005
1006 /* Flush all pending and queued descriptors */
1007 list_for_each_entry_safe(desc, _desc, &list, desc_node)
1008 dwc_descriptor_complete(dwc, desc, false);
1009
1010 return 0;
1011 }
1012
1013 static struct dw_desc *dwc_find_desc(struct dw_dma_chan *dwc, dma_cookie_t c)
1014 {
1015 struct dw_desc *desc;
1016
1017 list_for_each_entry(desc, &dwc->active_list, desc_node)
1018 if (desc->txd.cookie == c)
1019 return desc;
1020
1021 return NULL;
1022 }
1023
1024 static u32 dwc_get_residue(struct dw_dma_chan *dwc, dma_cookie_t cookie)
1025 {
1026 struct dw_desc *desc;
1027 unsigned long flags;
1028 u32 residue;
1029
1030 spin_lock_irqsave(&dwc->lock, flags);
1031
1032 desc = dwc_find_desc(dwc, cookie);
1033 if (desc) {
1034 if (desc == dwc_first_active(dwc)) {
1035 residue = desc->residue;
1036 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1037 residue -= dwc_get_sent(dwc);
1038 } else {
1039 residue = desc->total_len;
1040 }
1041 } else {
1042 residue = 0;
1043 }
1044
1045 spin_unlock_irqrestore(&dwc->lock, flags);
1046 return residue;
1047 }
1048
1049 static enum dma_status
1050 dwc_tx_status(struct dma_chan *chan,
1051 dma_cookie_t cookie,
1052 struct dma_tx_state *txstate)
1053 {
1054 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1055 enum dma_status ret;
1056
1057 ret = dma_cookie_status(chan, cookie, txstate);
1058 if (ret == DMA_COMPLETE)
1059 return ret;
1060
1061 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1062
1063 ret = dma_cookie_status(chan, cookie, txstate);
1064 if (ret == DMA_COMPLETE)
1065 return ret;
1066
1067 dma_set_residue(txstate, dwc_get_residue(dwc, cookie));
1068
1069 if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags) && ret == DMA_IN_PROGRESS)
1070 return DMA_PAUSED;
1071
1072 return ret;
1073 }
1074
1075 static void dwc_issue_pending(struct dma_chan *chan)
1076 {
1077 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1078 unsigned long flags;
1079
1080 spin_lock_irqsave(&dwc->lock, flags);
1081 if (list_empty(&dwc->active_list))
1082 dwc_dostart_first_queued(dwc);
1083 spin_unlock_irqrestore(&dwc->lock, flags);
1084 }
1085
1086 /*----------------------------------------------------------------------*/
1087
1088 static void dw_dma_off(struct dw_dma *dw)
1089 {
1090 unsigned int i;
1091
1092 dma_writel(dw, CFG, 0);
1093
1094 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1095 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1096 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1097 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1098 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1099
1100 while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1101 cpu_relax();
1102
1103 for (i = 0; i < dw->dma.chancnt; i++)
1104 clear_bit(DW_DMA_IS_INITIALIZED, &dw->chan[i].flags);
1105 }
1106
1107 static void dw_dma_on(struct dw_dma *dw)
1108 {
1109 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1110 }
1111
1112 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1113 {
1114 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1115 struct dw_dma *dw = to_dw_dma(chan->device);
1116
1117 dev_vdbg(chan2dev(chan), "%s\n", __func__);
1118
1119 /* ASSERT: channel is idle */
1120 if (dma_readl(dw, CH_EN) & dwc->mask) {
1121 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1122 return -EIO;
1123 }
1124
1125 dma_cookie_init(chan);
1126
1127 /*
1128 * NOTE: some controllers may have additional features that we
1129 * need to initialize here, like "scatter-gather" (which
1130 * doesn't mean what you think it means), and status writeback.
1131 */
1132
1133 /*
1134 * We need controller-specific data to set up slave transfers.
1135 */
1136 if (chan->private && !dw_dma_filter(chan, chan->private)) {
1137 dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
1138 return -EINVAL;
1139 }
1140
1141 /* Enable controller here if needed */
1142 if (!dw->in_use)
1143 dw_dma_on(dw);
1144 dw->in_use |= dwc->mask;
1145
1146 return 0;
1147 }
1148
1149 static void dwc_free_chan_resources(struct dma_chan *chan)
1150 {
1151 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1152 struct dw_dma *dw = to_dw_dma(chan->device);
1153 unsigned long flags;
1154 LIST_HEAD(list);
1155
1156 dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1157 dwc->descs_allocated);
1158
1159 /* ASSERT: channel is idle */
1160 BUG_ON(!list_empty(&dwc->active_list));
1161 BUG_ON(!list_empty(&dwc->queue));
1162 BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1163
1164 spin_lock_irqsave(&dwc->lock, flags);
1165
1166 /* Clear custom channel configuration */
1167 memset(&dwc->dws, 0, sizeof(struct dw_dma_slave));
1168
1169 clear_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
1170
1171 /* Disable interrupts */
1172 channel_clear_bit(dw, MASK.XFER, dwc->mask);
1173 channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1174 channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1175
1176 spin_unlock_irqrestore(&dwc->lock, flags);
1177
1178 /* Disable controller in case it was a last user */
1179 dw->in_use &= ~dwc->mask;
1180 if (!dw->in_use)
1181 dw_dma_off(dw);
1182
1183 dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1184 }
1185
1186 /* --------------------- Cyclic DMA API extensions -------------------- */
1187
1188 /**
1189 * dw_dma_cyclic_start - start the cyclic DMA transfer
1190 * @chan: the DMA channel to start
1191 *
1192 * Must be called with soft interrupts disabled. Returns zero on success or
1193 * -errno on failure.
1194 */
1195 int dw_dma_cyclic_start(struct dma_chan *chan)
1196 {
1197 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1198 struct dw_dma *dw = to_dw_dma(chan->device);
1199 unsigned long flags;
1200
1201 if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1202 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1203 return -ENODEV;
1204 }
1205
1206 spin_lock_irqsave(&dwc->lock, flags);
1207
1208 /* Enable interrupts to perform cyclic transfer */
1209 channel_set_bit(dw, MASK.BLOCK, dwc->mask);
1210
1211 dwc_dostart(dwc, dwc->cdesc->desc[0]);
1212
1213 spin_unlock_irqrestore(&dwc->lock, flags);
1214
1215 return 0;
1216 }
1217 EXPORT_SYMBOL(dw_dma_cyclic_start);
1218
1219 /**
1220 * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1221 * @chan: the DMA channel to stop
1222 *
1223 * Must be called with soft interrupts disabled.
1224 */
1225 void dw_dma_cyclic_stop(struct dma_chan *chan)
1226 {
1227 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1228 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1229 unsigned long flags;
1230
1231 spin_lock_irqsave(&dwc->lock, flags);
1232
1233 dwc_chan_disable(dw, dwc);
1234
1235 spin_unlock_irqrestore(&dwc->lock, flags);
1236 }
1237 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1238
1239 /**
1240 * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1241 * @chan: the DMA channel to prepare
1242 * @buf_addr: physical DMA address where the buffer starts
1243 * @buf_len: total number of bytes for the entire buffer
1244 * @period_len: number of bytes for each period
1245 * @direction: transfer direction, to or from device
1246 *
1247 * Must be called before trying to start the transfer. Returns a valid struct
1248 * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1249 */
1250 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1251 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1252 enum dma_transfer_direction direction)
1253 {
1254 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1255 struct dma_slave_config *sconfig = &dwc->dma_sconfig;
1256 struct dw_cyclic_desc *cdesc;
1257 struct dw_cyclic_desc *retval = NULL;
1258 struct dw_desc *desc;
1259 struct dw_desc *last = NULL;
1260 u8 lms = DWC_LLP_LMS(dwc->dws.m_master);
1261 unsigned long was_cyclic;
1262 unsigned int reg_width;
1263 unsigned int periods;
1264 unsigned int i;
1265 unsigned long flags;
1266
1267 spin_lock_irqsave(&dwc->lock, flags);
1268 if (dwc->nollp) {
1269 spin_unlock_irqrestore(&dwc->lock, flags);
1270 dev_dbg(chan2dev(&dwc->chan),
1271 "channel doesn't support LLP transfers\n");
1272 return ERR_PTR(-EINVAL);
1273 }
1274
1275 if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1276 spin_unlock_irqrestore(&dwc->lock, flags);
1277 dev_dbg(chan2dev(&dwc->chan),
1278 "queue and/or active list are not empty\n");
1279 return ERR_PTR(-EBUSY);
1280 }
1281
1282 was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1283 spin_unlock_irqrestore(&dwc->lock, flags);
1284 if (was_cyclic) {
1285 dev_dbg(chan2dev(&dwc->chan),
1286 "channel already prepared for cyclic DMA\n");
1287 return ERR_PTR(-EBUSY);
1288 }
1289
1290 retval = ERR_PTR(-EINVAL);
1291
1292 if (unlikely(!is_slave_direction(direction)))
1293 goto out_err;
1294
1295 dwc->direction = direction;
1296
1297 if (direction == DMA_MEM_TO_DEV)
1298 reg_width = __ffs(sconfig->dst_addr_width);
1299 else
1300 reg_width = __ffs(sconfig->src_addr_width);
1301
1302 periods = buf_len / period_len;
1303
1304 /* Check for too big/unaligned periods and unaligned DMA buffer. */
1305 if (period_len > (dwc->block_size << reg_width))
1306 goto out_err;
1307 if (unlikely(period_len & ((1 << reg_width) - 1)))
1308 goto out_err;
1309 if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1310 goto out_err;
1311
1312 retval = ERR_PTR(-ENOMEM);
1313
1314 cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1315 if (!cdesc)
1316 goto out_err;
1317
1318 cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1319 if (!cdesc->desc)
1320 goto out_err_alloc;
1321
1322 for (i = 0; i < periods; i++) {
1323 desc = dwc_desc_get(dwc);
1324 if (!desc)
1325 goto out_err_desc_get;
1326
1327 switch (direction) {
1328 case DMA_MEM_TO_DEV:
1329 lli_write(desc, dar, sconfig->dst_addr);
1330 lli_write(desc, sar, buf_addr + period_len * i);
1331 lli_write(desc, ctllo, (DWC_DEFAULT_CTLLO(chan)
1332 | DWC_CTLL_DST_WIDTH(reg_width)
1333 | DWC_CTLL_SRC_WIDTH(reg_width)
1334 | DWC_CTLL_DST_FIX
1335 | DWC_CTLL_SRC_INC
1336 | DWC_CTLL_INT_EN));
1337
1338 lli_set(desc, ctllo, sconfig->device_fc ?
1339 DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
1340 DWC_CTLL_FC(DW_DMA_FC_D_M2P));
1341
1342 break;
1343 case DMA_DEV_TO_MEM:
1344 lli_write(desc, dar, buf_addr + period_len * i);
1345 lli_write(desc, sar, sconfig->src_addr);
1346 lli_write(desc, ctllo, (DWC_DEFAULT_CTLLO(chan)
1347 | DWC_CTLL_SRC_WIDTH(reg_width)
1348 | DWC_CTLL_DST_WIDTH(reg_width)
1349 | DWC_CTLL_DST_INC
1350 | DWC_CTLL_SRC_FIX
1351 | DWC_CTLL_INT_EN));
1352
1353 lli_set(desc, ctllo, sconfig->device_fc ?
1354 DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
1355 DWC_CTLL_FC(DW_DMA_FC_D_P2M));
1356
1357 break;
1358 default:
1359 break;
1360 }
1361
1362 lli_write(desc, ctlhi, period_len >> reg_width);
1363 cdesc->desc[i] = desc;
1364
1365 if (last)
1366 lli_write(last, llp, desc->txd.phys | lms);
1367
1368 last = desc;
1369 }
1370
1371 /* Let's make a cyclic list */
1372 lli_write(last, llp, cdesc->desc[0]->txd.phys | lms);
1373
1374 dev_dbg(chan2dev(&dwc->chan),
1375 "cyclic prepared buf %pad len %zu period %zu periods %d\n",
1376 &buf_addr, buf_len, period_len, periods);
1377
1378 cdesc->periods = periods;
1379 dwc->cdesc = cdesc;
1380
1381 return cdesc;
1382
1383 out_err_desc_get:
1384 while (i--)
1385 dwc_desc_put(dwc, cdesc->desc[i]);
1386 out_err_alloc:
1387 kfree(cdesc);
1388 out_err:
1389 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1390 return (struct dw_cyclic_desc *)retval;
1391 }
1392 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1393
1394 /**
1395 * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1396 * @chan: the DMA channel to free
1397 */
1398 void dw_dma_cyclic_free(struct dma_chan *chan)
1399 {
1400 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1401 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1402 struct dw_cyclic_desc *cdesc = dwc->cdesc;
1403 unsigned int i;
1404 unsigned long flags;
1405
1406 dev_dbg(chan2dev(&dwc->chan), "%s\n", __func__);
1407
1408 if (!cdesc)
1409 return;
1410
1411 spin_lock_irqsave(&dwc->lock, flags);
1412
1413 dwc_chan_disable(dw, dwc);
1414
1415 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1416 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1417 dma_writel(dw, CLEAR.XFER, dwc->mask);
1418
1419 spin_unlock_irqrestore(&dwc->lock, flags);
1420
1421 for (i = 0; i < cdesc->periods; i++)
1422 dwc_desc_put(dwc, cdesc->desc[i]);
1423
1424 kfree(cdesc->desc);
1425 kfree(cdesc);
1426
1427 dwc->cdesc = NULL;
1428
1429 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1430 }
1431 EXPORT_SYMBOL(dw_dma_cyclic_free);
1432
1433 /*----------------------------------------------------------------------*/
1434
1435 int dw_dma_probe(struct dw_dma_chip *chip)
1436 {
1437 struct dw_dma_platform_data *pdata;
1438 struct dw_dma *dw;
1439 bool autocfg = false;
1440 unsigned int dw_params;
1441 unsigned int i;
1442 int err;
1443
1444 dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
1445 if (!dw)
1446 return -ENOMEM;
1447
1448 dw->pdata = devm_kzalloc(chip->dev, sizeof(*dw->pdata), GFP_KERNEL);
1449 if (!dw->pdata)
1450 return -ENOMEM;
1451
1452 dw->regs = chip->regs;
1453 chip->dw = dw;
1454
1455 pm_runtime_get_sync(chip->dev);
1456
1457 if (!chip->pdata) {
1458 dw_params = dma_readl(dw, DW_PARAMS);
1459 dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1460
1461 autocfg = dw_params >> DW_PARAMS_EN & 1;
1462 if (!autocfg) {
1463 err = -EINVAL;
1464 goto err_pdata;
1465 }
1466
1467 /* Reassign the platform data pointer */
1468 pdata = dw->pdata;
1469
1470 /* Get hardware configuration parameters */
1471 pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1;
1472 pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1473 for (i = 0; i < pdata->nr_masters; i++) {
1474 pdata->data_width[i] =
1475 4 << (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3);
1476 }
1477 pdata->block_size = dma_readl(dw, MAX_BLK_SIZE);
1478
1479 /* Fill platform data with the default values */
1480 pdata->is_private = true;
1481 pdata->is_memcpy = true;
1482 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1483 pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1484 } else if (chip->pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
1485 err = -EINVAL;
1486 goto err_pdata;
1487 } else {
1488 memcpy(dw->pdata, chip->pdata, sizeof(*dw->pdata));
1489
1490 /* Reassign the platform data pointer */
1491 pdata = dw->pdata;
1492 }
1493
1494 dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
1495 GFP_KERNEL);
1496 if (!dw->chan) {
1497 err = -ENOMEM;
1498 goto err_pdata;
1499 }
1500
1501 /* Calculate all channel mask before DMA setup */
1502 dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1503
1504 /* Force dma off, just in case */
1505 dw_dma_off(dw);
1506
1507 /* Create a pool of consistent memory blocks for hardware descriptors */
1508 dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev,
1509 sizeof(struct dw_desc), 4, 0);
1510 if (!dw->desc_pool) {
1511 dev_err(chip->dev, "No memory for descriptors dma pool\n");
1512 err = -ENOMEM;
1513 goto err_pdata;
1514 }
1515
1516 tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1517
1518 err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
1519 "dw_dmac", dw);
1520 if (err)
1521 goto err_pdata;
1522
1523 INIT_LIST_HEAD(&dw->dma.channels);
1524 for (i = 0; i < pdata->nr_channels; i++) {
1525 struct dw_dma_chan *dwc = &dw->chan[i];
1526
1527 dwc->chan.device = &dw->dma;
1528 dma_cookie_init(&dwc->chan);
1529 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1530 list_add_tail(&dwc->chan.device_node,
1531 &dw->dma.channels);
1532 else
1533 list_add(&dwc->chan.device_node, &dw->dma.channels);
1534
1535 /* 7 is highest priority & 0 is lowest. */
1536 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1537 dwc->priority = pdata->nr_channels - i - 1;
1538 else
1539 dwc->priority = i;
1540
1541 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1542 spin_lock_init(&dwc->lock);
1543 dwc->mask = 1 << i;
1544
1545 INIT_LIST_HEAD(&dwc->active_list);
1546 INIT_LIST_HEAD(&dwc->queue);
1547
1548 channel_clear_bit(dw, CH_EN, dwc->mask);
1549
1550 dwc->direction = DMA_TRANS_NONE;
1551
1552 /* Hardware configuration */
1553 if (autocfg) {
1554 unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
1555 void __iomem *addr = &__dw_regs(dw)->DWC_PARAMS[r];
1556 unsigned int dwc_params = dma_readl_native(addr);
1557
1558 dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1559 dwc_params);
1560
1561 /*
1562 * Decode maximum block size for given channel. The
1563 * stored 4 bit value represents blocks from 0x00 for 3
1564 * up to 0x0a for 4095.
1565 */
1566 dwc->block_size =
1567 (4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1;
1568 dwc->nollp =
1569 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1570 } else {
1571 dwc->block_size = pdata->block_size;
1572 dwc->nollp = pdata->is_nollp;
1573 }
1574 }
1575
1576 /* Clear all interrupts on all channels. */
1577 dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1578 dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1579 dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1580 dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1581 dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1582
1583 /* Set capabilities */
1584 dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1585 if (pdata->is_private)
1586 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1587 if (pdata->is_memcpy)
1588 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1589
1590 dw->dma.dev = chip->dev;
1591 dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1592 dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1593
1594 dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1595 dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1596
1597 dw->dma.device_config = dwc_config;
1598 dw->dma.device_pause = dwc_pause;
1599 dw->dma.device_resume = dwc_resume;
1600 dw->dma.device_terminate_all = dwc_terminate_all;
1601
1602 dw->dma.device_tx_status = dwc_tx_status;
1603 dw->dma.device_issue_pending = dwc_issue_pending;
1604
1605 /* DMA capabilities */
1606 dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
1607 dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
1608 dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1609 BIT(DMA_MEM_TO_MEM);
1610 dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1611
1612 err = dma_async_device_register(&dw->dma);
1613 if (err)
1614 goto err_dma_register;
1615
1616 dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
1617 pdata->nr_channels);
1618
1619 pm_runtime_put_sync_suspend(chip->dev);
1620
1621 return 0;
1622
1623 err_dma_register:
1624 free_irq(chip->irq, dw);
1625 err_pdata:
1626 pm_runtime_put_sync_suspend(chip->dev);
1627 return err;
1628 }
1629 EXPORT_SYMBOL_GPL(dw_dma_probe);
1630
1631 int dw_dma_remove(struct dw_dma_chip *chip)
1632 {
1633 struct dw_dma *dw = chip->dw;
1634 struct dw_dma_chan *dwc, *_dwc;
1635
1636 pm_runtime_get_sync(chip->dev);
1637
1638 dw_dma_off(dw);
1639 dma_async_device_unregister(&dw->dma);
1640
1641 free_irq(chip->irq, dw);
1642 tasklet_kill(&dw->tasklet);
1643
1644 list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1645 chan.device_node) {
1646 list_del(&dwc->chan.device_node);
1647 channel_clear_bit(dw, CH_EN, dwc->mask);
1648 }
1649
1650 pm_runtime_put_sync_suspend(chip->dev);
1651 return 0;
1652 }
1653 EXPORT_SYMBOL_GPL(dw_dma_remove);
1654
1655 int dw_dma_disable(struct dw_dma_chip *chip)
1656 {
1657 struct dw_dma *dw = chip->dw;
1658
1659 dw_dma_off(dw);
1660 return 0;
1661 }
1662 EXPORT_SYMBOL_GPL(dw_dma_disable);
1663
1664 int dw_dma_enable(struct dw_dma_chip *chip)
1665 {
1666 struct dw_dma *dw = chip->dw;
1667
1668 dw_dma_on(dw);
1669 return 0;
1670 }
1671 EXPORT_SYMBOL_GPL(dw_dma_enable);
1672
1673 MODULE_LICENSE("GPL v2");
1674 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver");
1675 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1676 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
Linux with added FPC-III support