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Merge tag 'arm64-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / dma / dw_dmac.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 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/bitops.h>
13 #include <linux/clk.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/of.h>
23 #include <linux/of_dma.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28
29 #include "dw_dmac_regs.h"
30 #include "dmaengine.h"
31
32 /*
33 * This supports the Synopsys "DesignWare AHB Central DMA Controller",
34 * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all
35 * of which use ARM any more). See the "Databook" from Synopsys for
36 * information beyond what licensees probably provide.
37 *
38 * The driver has currently been tested only with the Atmel AT32AP7000,
39 * which does not support descriptor writeback.
40 */
41
42 static inline unsigned int dwc_get_dms(struct dw_dma_slave *slave)
43 {
44 return slave ? slave->dst_master : 0;
45 }
46
47 static inline unsigned int dwc_get_sms(struct dw_dma_slave *slave)
48 {
49 return slave ? slave->src_master : 1;
50 }
51
52 #define SRC_MASTER 0
53 #define DST_MASTER 1
54
55 static inline unsigned int dwc_get_master(struct dma_chan *chan, int master)
56 {
57 struct dw_dma *dw = to_dw_dma(chan->device);
58 struct dw_dma_slave *dws = chan->private;
59 unsigned int m;
60
61 if (master == SRC_MASTER)
62 m = dwc_get_sms(dws);
63 else
64 m = dwc_get_dms(dws);
65
66 return min_t(unsigned int, dw->nr_masters - 1, m);
67 }
68
69 #define DWC_DEFAULT_CTLLO(_chan) ({ \
70 struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan); \
71 struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \
72 bool _is_slave = is_slave_direction(_dwc->direction); \
73 int _dms = dwc_get_master(_chan, DST_MASTER); \
74 int _sms = dwc_get_master(_chan, SRC_MASTER); \
75 u8 _smsize = _is_slave ? _sconfig->src_maxburst : \
76 DW_DMA_MSIZE_16; \
77 u8 _dmsize = _is_slave ? _sconfig->dst_maxburst : \
78 DW_DMA_MSIZE_16; \
79 \
80 (DWC_CTLL_DST_MSIZE(_dmsize) \
81 | DWC_CTLL_SRC_MSIZE(_smsize) \
82 | DWC_CTLL_LLP_D_EN \
83 | DWC_CTLL_LLP_S_EN \
84 | DWC_CTLL_DMS(_dms) \
85 | DWC_CTLL_SMS(_sms)); \
86 })
87
88 /*
89 * Number of descriptors to allocate for each channel. This should be
90 * made configurable somehow; preferably, the clients (at least the
91 * ones using slave transfers) should be able to give us a hint.
92 */
93 #define NR_DESCS_PER_CHANNEL 64
94
95 static inline unsigned int dwc_get_data_width(struct dma_chan *chan, int master)
96 {
97 struct dw_dma *dw = to_dw_dma(chan->device);
98
99 return dw->data_width[dwc_get_master(chan, master)];
100 }
101
102 /*----------------------------------------------------------------------*/
103
104 static struct device *chan2dev(struct dma_chan *chan)
105 {
106 return &chan->dev->device;
107 }
108 static struct device *chan2parent(struct dma_chan *chan)
109 {
110 return chan->dev->device.parent;
111 }
112
113 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
114 {
115 return to_dw_desc(dwc->active_list.next);
116 }
117
118 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
119 {
120 struct dw_desc *desc, *_desc;
121 struct dw_desc *ret = NULL;
122 unsigned int i = 0;
123 unsigned long flags;
124
125 spin_lock_irqsave(&dwc->lock, flags);
126 list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
127 i++;
128 if (async_tx_test_ack(&desc->txd)) {
129 list_del(&desc->desc_node);
130 ret = desc;
131 break;
132 }
133 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
134 }
135 spin_unlock_irqrestore(&dwc->lock, flags);
136
137 dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
138
139 return ret;
140 }
141
142 /*
143 * Move a descriptor, including any children, to the free list.
144 * `desc' must not be on any lists.
145 */
146 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
147 {
148 unsigned long flags;
149
150 if (desc) {
151 struct dw_desc *child;
152
153 spin_lock_irqsave(&dwc->lock, flags);
154 list_for_each_entry(child, &desc->tx_list, desc_node)
155 dev_vdbg(chan2dev(&dwc->chan),
156 "moving child desc %p to freelist\n",
157 child);
158 list_splice_init(&desc->tx_list, &dwc->free_list);
159 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
160 list_add(&desc->desc_node, &dwc->free_list);
161 spin_unlock_irqrestore(&dwc->lock, flags);
162 }
163 }
164
165 static void dwc_initialize(struct dw_dma_chan *dwc)
166 {
167 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
168 struct dw_dma_slave *dws = dwc->chan.private;
169 u32 cfghi = DWC_CFGH_FIFO_MODE;
170 u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
171
172 if (dwc->initialized == true)
173 return;
174
175 if (dws && dws->cfg_hi == ~0 && dws->cfg_lo == ~0) {
176 /* autoconfigure based on request line from DT */
177 if (dwc->direction == DMA_MEM_TO_DEV)
178 cfghi = DWC_CFGH_DST_PER(dwc->request_line);
179 else if (dwc->direction == DMA_DEV_TO_MEM)
180 cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
181 } else if (dws) {
182 /*
183 * We need controller-specific data to set up slave
184 * transfers.
185 */
186 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
187
188 cfghi = dws->cfg_hi;
189 cfglo |= dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
190 } else {
191 if (dwc->direction == DMA_MEM_TO_DEV)
192 cfghi = DWC_CFGH_DST_PER(dwc->dma_sconfig.slave_id);
193 else if (dwc->direction == DMA_DEV_TO_MEM)
194 cfghi = DWC_CFGH_SRC_PER(dwc->dma_sconfig.slave_id);
195 }
196
197 channel_writel(dwc, CFG_LO, cfglo);
198 channel_writel(dwc, CFG_HI, cfghi);
199
200 /* Enable interrupts */
201 channel_set_bit(dw, MASK.XFER, dwc->mask);
202 channel_set_bit(dw, MASK.ERROR, dwc->mask);
203
204 dwc->initialized = true;
205 }
206
207 /*----------------------------------------------------------------------*/
208
209 static inline unsigned int dwc_fast_fls(unsigned long long v)
210 {
211 /*
212 * We can be a lot more clever here, but this should take care
213 * of the most common optimization.
214 */
215 if (!(v & 7))
216 return 3;
217 else if (!(v & 3))
218 return 2;
219 else if (!(v & 1))
220 return 1;
221 return 0;
222 }
223
224 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
225 {
226 dev_err(chan2dev(&dwc->chan),
227 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
228 channel_readl(dwc, SAR),
229 channel_readl(dwc, DAR),
230 channel_readl(dwc, LLP),
231 channel_readl(dwc, CTL_HI),
232 channel_readl(dwc, CTL_LO));
233 }
234
235 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
236 {
237 channel_clear_bit(dw, CH_EN, dwc->mask);
238 while (dma_readl(dw, CH_EN) & dwc->mask)
239 cpu_relax();
240 }
241
242 /*----------------------------------------------------------------------*/
243
244 /* Perform single block transfer */
245 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
246 struct dw_desc *desc)
247 {
248 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
249 u32 ctllo;
250
251 /* Software emulation of LLP mode relies on interrupts to continue
252 * multi block transfer. */
253 ctllo = desc->lli.ctllo | DWC_CTLL_INT_EN;
254
255 channel_writel(dwc, SAR, desc->lli.sar);
256 channel_writel(dwc, DAR, desc->lli.dar);
257 channel_writel(dwc, CTL_LO, ctllo);
258 channel_writel(dwc, CTL_HI, desc->lli.ctlhi);
259 channel_set_bit(dw, CH_EN, dwc->mask);
260
261 /* Move pointer to next descriptor */
262 dwc->tx_node_active = dwc->tx_node_active->next;
263 }
264
265 /* Called with dwc->lock held and bh disabled */
266 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
267 {
268 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
269 unsigned long was_soft_llp;
270
271 /* ASSERT: channel is idle */
272 if (dma_readl(dw, CH_EN) & dwc->mask) {
273 dev_err(chan2dev(&dwc->chan),
274 "BUG: Attempted to start non-idle channel\n");
275 dwc_dump_chan_regs(dwc);
276
277 /* The tasklet will hopefully advance the queue... */
278 return;
279 }
280
281 if (dwc->nollp) {
282 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
283 &dwc->flags);
284 if (was_soft_llp) {
285 dev_err(chan2dev(&dwc->chan),
286 "BUG: Attempted to start new LLP transfer "
287 "inside ongoing one\n");
288 return;
289 }
290
291 dwc_initialize(dwc);
292
293 dwc->residue = first->total_len;
294 dwc->tx_node_active = &first->tx_list;
295
296 /* Submit first block */
297 dwc_do_single_block(dwc, first);
298
299 return;
300 }
301
302 dwc_initialize(dwc);
303
304 channel_writel(dwc, LLP, first->txd.phys);
305 channel_writel(dwc, CTL_LO,
306 DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
307 channel_writel(dwc, CTL_HI, 0);
308 channel_set_bit(dw, CH_EN, dwc->mask);
309 }
310
311 /*----------------------------------------------------------------------*/
312
313 static void
314 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
315 bool callback_required)
316 {
317 dma_async_tx_callback callback = NULL;
318 void *param = NULL;
319 struct dma_async_tx_descriptor *txd = &desc->txd;
320 struct dw_desc *child;
321 unsigned long flags;
322
323 dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
324
325 spin_lock_irqsave(&dwc->lock, flags);
326 dma_cookie_complete(txd);
327 if (callback_required) {
328 callback = txd->callback;
329 param = txd->callback_param;
330 }
331
332 /* async_tx_ack */
333 list_for_each_entry(child, &desc->tx_list, desc_node)
334 async_tx_ack(&child->txd);
335 async_tx_ack(&desc->txd);
336
337 list_splice_init(&desc->tx_list, &dwc->free_list);
338 list_move(&desc->desc_node, &dwc->free_list);
339
340 if (!is_slave_direction(dwc->direction)) {
341 struct device *parent = chan2parent(&dwc->chan);
342 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
343 if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
344 dma_unmap_single(parent, desc->lli.dar,
345 desc->total_len, DMA_FROM_DEVICE);
346 else
347 dma_unmap_page(parent, desc->lli.dar,
348 desc->total_len, DMA_FROM_DEVICE);
349 }
350 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
351 if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
352 dma_unmap_single(parent, desc->lli.sar,
353 desc->total_len, DMA_TO_DEVICE);
354 else
355 dma_unmap_page(parent, desc->lli.sar,
356 desc->total_len, DMA_TO_DEVICE);
357 }
358 }
359
360 spin_unlock_irqrestore(&dwc->lock, flags);
361
362 if (callback)
363 callback(param);
364 }
365
366 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
367 {
368 struct dw_desc *desc, *_desc;
369 LIST_HEAD(list);
370 unsigned long flags;
371
372 spin_lock_irqsave(&dwc->lock, flags);
373 if (dma_readl(dw, CH_EN) & dwc->mask) {
374 dev_err(chan2dev(&dwc->chan),
375 "BUG: XFER bit set, but channel not idle!\n");
376
377 /* Try to continue after resetting the channel... */
378 dwc_chan_disable(dw, dwc);
379 }
380
381 /*
382 * Submit queued descriptors ASAP, i.e. before we go through
383 * the completed ones.
384 */
385 list_splice_init(&dwc->active_list, &list);
386 if (!list_empty(&dwc->queue)) {
387 list_move(dwc->queue.next, &dwc->active_list);
388 dwc_dostart(dwc, dwc_first_active(dwc));
389 }
390
391 spin_unlock_irqrestore(&dwc->lock, flags);
392
393 list_for_each_entry_safe(desc, _desc, &list, desc_node)
394 dwc_descriptor_complete(dwc, desc, true);
395 }
396
397 /* Returns how many bytes were already received from source */
398 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
399 {
400 u32 ctlhi = channel_readl(dwc, CTL_HI);
401 u32 ctllo = channel_readl(dwc, CTL_LO);
402
403 return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
404 }
405
406 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
407 {
408 dma_addr_t llp;
409 struct dw_desc *desc, *_desc;
410 struct dw_desc *child;
411 u32 status_xfer;
412 unsigned long flags;
413
414 spin_lock_irqsave(&dwc->lock, flags);
415 llp = channel_readl(dwc, LLP);
416 status_xfer = dma_readl(dw, RAW.XFER);
417
418 if (status_xfer & dwc->mask) {
419 /* Everything we've submitted is done */
420 dma_writel(dw, CLEAR.XFER, dwc->mask);
421
422 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
423 struct list_head *head, *active = dwc->tx_node_active;
424
425 /*
426 * We are inside first active descriptor.
427 * Otherwise something is really wrong.
428 */
429 desc = dwc_first_active(dwc);
430
431 head = &desc->tx_list;
432 if (active != head) {
433 /* Update desc to reflect last sent one */
434 if (active != head->next)
435 desc = to_dw_desc(active->prev);
436
437 dwc->residue -= desc->len;
438
439 child = to_dw_desc(active);
440
441 /* Submit next block */
442 dwc_do_single_block(dwc, child);
443
444 spin_unlock_irqrestore(&dwc->lock, flags);
445 return;
446 }
447
448 /* We are done here */
449 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
450 }
451
452 dwc->residue = 0;
453
454 spin_unlock_irqrestore(&dwc->lock, flags);
455
456 dwc_complete_all(dw, dwc);
457 return;
458 }
459
460 if (list_empty(&dwc->active_list)) {
461 dwc->residue = 0;
462 spin_unlock_irqrestore(&dwc->lock, flags);
463 return;
464 }
465
466 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
467 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
468 spin_unlock_irqrestore(&dwc->lock, flags);
469 return;
470 }
471
472 dev_vdbg(chan2dev(&dwc->chan), "%s: llp=0x%llx\n", __func__,
473 (unsigned long long)llp);
474
475 list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
476 /* initial residue value */
477 dwc->residue = desc->total_len;
478
479 /* check first descriptors addr */
480 if (desc->txd.phys == llp) {
481 spin_unlock_irqrestore(&dwc->lock, flags);
482 return;
483 }
484
485 /* check first descriptors llp */
486 if (desc->lli.llp == llp) {
487 /* This one is currently in progress */
488 dwc->residue -= dwc_get_sent(dwc);
489 spin_unlock_irqrestore(&dwc->lock, flags);
490 return;
491 }
492
493 dwc->residue -= desc->len;
494 list_for_each_entry(child, &desc->tx_list, desc_node) {
495 if (child->lli.llp == llp) {
496 /* Currently in progress */
497 dwc->residue -= dwc_get_sent(dwc);
498 spin_unlock_irqrestore(&dwc->lock, flags);
499 return;
500 }
501 dwc->residue -= child->len;
502 }
503
504 /*
505 * No descriptors so far seem to be in progress, i.e.
506 * this one must be done.
507 */
508 spin_unlock_irqrestore(&dwc->lock, flags);
509 dwc_descriptor_complete(dwc, desc, true);
510 spin_lock_irqsave(&dwc->lock, flags);
511 }
512
513 dev_err(chan2dev(&dwc->chan),
514 "BUG: All descriptors done, but channel not idle!\n");
515
516 /* Try to continue after resetting the channel... */
517 dwc_chan_disable(dw, dwc);
518
519 if (!list_empty(&dwc->queue)) {
520 list_move(dwc->queue.next, &dwc->active_list);
521 dwc_dostart(dwc, dwc_first_active(dwc));
522 }
523 spin_unlock_irqrestore(&dwc->lock, flags);
524 }
525
526 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
527 {
528 dev_crit(chan2dev(&dwc->chan), " desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
529 lli->sar, lli->dar, lli->llp, lli->ctlhi, lli->ctllo);
530 }
531
532 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
533 {
534 struct dw_desc *bad_desc;
535 struct dw_desc *child;
536 unsigned long flags;
537
538 dwc_scan_descriptors(dw, dwc);
539
540 spin_lock_irqsave(&dwc->lock, flags);
541
542 /*
543 * The descriptor currently at the head of the active list is
544 * borked. Since we don't have any way to report errors, we'll
545 * just have to scream loudly and try to carry on.
546 */
547 bad_desc = dwc_first_active(dwc);
548 list_del_init(&bad_desc->desc_node);
549 list_move(dwc->queue.next, dwc->active_list.prev);
550
551 /* Clear the error flag and try to restart the controller */
552 dma_writel(dw, CLEAR.ERROR, dwc->mask);
553 if (!list_empty(&dwc->active_list))
554 dwc_dostart(dwc, dwc_first_active(dwc));
555
556 /*
557 * WARN may seem harsh, but since this only happens
558 * when someone submits a bad physical address in a
559 * descriptor, we should consider ourselves lucky that the
560 * controller flagged an error instead of scribbling over
561 * random memory locations.
562 */
563 dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
564 " cookie: %d\n", bad_desc->txd.cookie);
565 dwc_dump_lli(dwc, &bad_desc->lli);
566 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
567 dwc_dump_lli(dwc, &child->lli);
568
569 spin_unlock_irqrestore(&dwc->lock, flags);
570
571 /* Pretend the descriptor completed successfully */
572 dwc_descriptor_complete(dwc, bad_desc, true);
573 }
574
575 /* --------------------- Cyclic DMA API extensions -------------------- */
576
577 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
578 {
579 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
580 return channel_readl(dwc, SAR);
581 }
582 EXPORT_SYMBOL(dw_dma_get_src_addr);
583
584 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
585 {
586 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
587 return channel_readl(dwc, DAR);
588 }
589 EXPORT_SYMBOL(dw_dma_get_dst_addr);
590
591 /* called with dwc->lock held and all DMAC interrupts disabled */
592 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
593 u32 status_err, u32 status_xfer)
594 {
595 unsigned long flags;
596
597 if (dwc->mask) {
598 void (*callback)(void *param);
599 void *callback_param;
600
601 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
602 channel_readl(dwc, LLP));
603
604 callback = dwc->cdesc->period_callback;
605 callback_param = dwc->cdesc->period_callback_param;
606
607 if (callback)
608 callback(callback_param);
609 }
610
611 /*
612 * Error and transfer complete are highly unlikely, and will most
613 * likely be due to a configuration error by the user.
614 */
615 if (unlikely(status_err & dwc->mask) ||
616 unlikely(status_xfer & dwc->mask)) {
617 int i;
618
619 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
620 "interrupt, stopping DMA transfer\n",
621 status_xfer ? "xfer" : "error");
622
623 spin_lock_irqsave(&dwc->lock, flags);
624
625 dwc_dump_chan_regs(dwc);
626
627 dwc_chan_disable(dw, dwc);
628
629 /* make sure DMA does not restart by loading a new list */
630 channel_writel(dwc, LLP, 0);
631 channel_writel(dwc, CTL_LO, 0);
632 channel_writel(dwc, CTL_HI, 0);
633
634 dma_writel(dw, CLEAR.ERROR, dwc->mask);
635 dma_writel(dw, CLEAR.XFER, dwc->mask);
636
637 for (i = 0; i < dwc->cdesc->periods; i++)
638 dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
639
640 spin_unlock_irqrestore(&dwc->lock, flags);
641 }
642 }
643
644 /* ------------------------------------------------------------------------- */
645
646 static void dw_dma_tasklet(unsigned long data)
647 {
648 struct dw_dma *dw = (struct dw_dma *)data;
649 struct dw_dma_chan *dwc;
650 u32 status_xfer;
651 u32 status_err;
652 int i;
653
654 status_xfer = dma_readl(dw, RAW.XFER);
655 status_err = dma_readl(dw, RAW.ERROR);
656
657 dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
658
659 for (i = 0; i < dw->dma.chancnt; i++) {
660 dwc = &dw->chan[i];
661 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
662 dwc_handle_cyclic(dw, dwc, status_err, status_xfer);
663 else if (status_err & (1 << i))
664 dwc_handle_error(dw, dwc);
665 else if (status_xfer & (1 << i))
666 dwc_scan_descriptors(dw, dwc);
667 }
668
669 /*
670 * Re-enable interrupts.
671 */
672 channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
673 channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
674 }
675
676 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
677 {
678 struct dw_dma *dw = dev_id;
679 u32 status;
680
681 dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__,
682 dma_readl(dw, STATUS_INT));
683
684 /*
685 * Just disable the interrupts. We'll turn them back on in the
686 * softirq handler.
687 */
688 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
689 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
690
691 status = dma_readl(dw, STATUS_INT);
692 if (status) {
693 dev_err(dw->dma.dev,
694 "BUG: Unexpected interrupts pending: 0x%x\n",
695 status);
696
697 /* Try to recover */
698 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
699 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
700 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
701 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
702 }
703
704 tasklet_schedule(&dw->tasklet);
705
706 return IRQ_HANDLED;
707 }
708
709 /*----------------------------------------------------------------------*/
710
711 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
712 {
713 struct dw_desc *desc = txd_to_dw_desc(tx);
714 struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
715 dma_cookie_t cookie;
716 unsigned long flags;
717
718 spin_lock_irqsave(&dwc->lock, flags);
719 cookie = dma_cookie_assign(tx);
720
721 /*
722 * REVISIT: We should attempt to chain as many descriptors as
723 * possible, perhaps even appending to those already submitted
724 * for DMA. But this is hard to do in a race-free manner.
725 */
726 if (list_empty(&dwc->active_list)) {
727 dev_vdbg(chan2dev(tx->chan), "%s: started %u\n", __func__,
728 desc->txd.cookie);
729 list_add_tail(&desc->desc_node, &dwc->active_list);
730 dwc_dostart(dwc, dwc_first_active(dwc));
731 } else {
732 dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__,
733 desc->txd.cookie);
734
735 list_add_tail(&desc->desc_node, &dwc->queue);
736 }
737
738 spin_unlock_irqrestore(&dwc->lock, flags);
739
740 return cookie;
741 }
742
743 static struct dma_async_tx_descriptor *
744 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
745 size_t len, unsigned long flags)
746 {
747 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
748 struct dw_desc *desc;
749 struct dw_desc *first;
750 struct dw_desc *prev;
751 size_t xfer_count;
752 size_t offset;
753 unsigned int src_width;
754 unsigned int dst_width;
755 unsigned int data_width;
756 u32 ctllo;
757
758 dev_vdbg(chan2dev(chan),
759 "%s: d0x%llx s0x%llx l0x%zx f0x%lx\n", __func__,
760 (unsigned long long)dest, (unsigned long long)src,
761 len, flags);
762
763 if (unlikely(!len)) {
764 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
765 return NULL;
766 }
767
768 dwc->direction = DMA_MEM_TO_MEM;
769
770 data_width = min_t(unsigned int, dwc_get_data_width(chan, SRC_MASTER),
771 dwc_get_data_width(chan, DST_MASTER));
772
773 src_width = dst_width = min_t(unsigned int, data_width,
774 dwc_fast_fls(src | dest | len));
775
776 ctllo = DWC_DEFAULT_CTLLO(chan)
777 | DWC_CTLL_DST_WIDTH(dst_width)
778 | DWC_CTLL_SRC_WIDTH(src_width)
779 | DWC_CTLL_DST_INC
780 | DWC_CTLL_SRC_INC
781 | DWC_CTLL_FC_M2M;
782 prev = first = NULL;
783
784 for (offset = 0; offset < len; offset += xfer_count << src_width) {
785 xfer_count = min_t(size_t, (len - offset) >> src_width,
786 dwc->block_size);
787
788 desc = dwc_desc_get(dwc);
789 if (!desc)
790 goto err_desc_get;
791
792 desc->lli.sar = src + offset;
793 desc->lli.dar = dest + offset;
794 desc->lli.ctllo = ctllo;
795 desc->lli.ctlhi = xfer_count;
796 desc->len = xfer_count << src_width;
797
798 if (!first) {
799 first = desc;
800 } else {
801 prev->lli.llp = desc->txd.phys;
802 list_add_tail(&desc->desc_node,
803 &first->tx_list);
804 }
805 prev = desc;
806 }
807
808 if (flags & DMA_PREP_INTERRUPT)
809 /* Trigger interrupt after last block */
810 prev->lli.ctllo |= DWC_CTLL_INT_EN;
811
812 prev->lli.llp = 0;
813 first->txd.flags = flags;
814 first->total_len = len;
815
816 return &first->txd;
817
818 err_desc_get:
819 dwc_desc_put(dwc, first);
820 return NULL;
821 }
822
823 static struct dma_async_tx_descriptor *
824 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
825 unsigned int sg_len, enum dma_transfer_direction direction,
826 unsigned long flags, void *context)
827 {
828 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
829 struct dma_slave_config *sconfig = &dwc->dma_sconfig;
830 struct dw_desc *prev;
831 struct dw_desc *first;
832 u32 ctllo;
833 dma_addr_t reg;
834 unsigned int reg_width;
835 unsigned int mem_width;
836 unsigned int data_width;
837 unsigned int i;
838 struct scatterlist *sg;
839 size_t total_len = 0;
840
841 dev_vdbg(chan2dev(chan), "%s\n", __func__);
842
843 if (unlikely(!is_slave_direction(direction) || !sg_len))
844 return NULL;
845
846 dwc->direction = direction;
847
848 prev = first = NULL;
849
850 switch (direction) {
851 case DMA_MEM_TO_DEV:
852 reg_width = __fls(sconfig->dst_addr_width);
853 reg = sconfig->dst_addr;
854 ctllo = (DWC_DEFAULT_CTLLO(chan)
855 | DWC_CTLL_DST_WIDTH(reg_width)
856 | DWC_CTLL_DST_FIX
857 | DWC_CTLL_SRC_INC);
858
859 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
860 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
861
862 data_width = dwc_get_data_width(chan, SRC_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_fls(mem | len));
873
874 slave_sg_todev_fill_desc:
875 desc = dwc_desc_get(dwc);
876 if (!desc) {
877 dev_err(chan2dev(chan),
878 "not enough descriptors available\n");
879 goto err_desc_get;
880 }
881
882 desc->lli.sar = mem;
883 desc->lli.dar = reg;
884 desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
885 if ((len >> mem_width) > dwc->block_size) {
886 dlen = dwc->block_size << mem_width;
887 mem += dlen;
888 len -= dlen;
889 } else {
890 dlen = len;
891 len = 0;
892 }
893
894 desc->lli.ctlhi = dlen >> mem_width;
895 desc->len = dlen;
896
897 if (!first) {
898 first = desc;
899 } else {
900 prev->lli.llp = desc->txd.phys;
901 list_add_tail(&desc->desc_node,
902 &first->tx_list);
903 }
904 prev = desc;
905 total_len += dlen;
906
907 if (len)
908 goto slave_sg_todev_fill_desc;
909 }
910 break;
911 case DMA_DEV_TO_MEM:
912 reg_width = __fls(sconfig->src_addr_width);
913 reg = sconfig->src_addr;
914 ctllo = (DWC_DEFAULT_CTLLO(chan)
915 | DWC_CTLL_SRC_WIDTH(reg_width)
916 | DWC_CTLL_DST_INC
917 | DWC_CTLL_SRC_FIX);
918
919 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
920 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
921
922 data_width = dwc_get_data_width(chan, DST_MASTER);
923
924 for_each_sg(sgl, sg, sg_len, i) {
925 struct dw_desc *desc;
926 u32 len, dlen, mem;
927
928 mem = sg_dma_address(sg);
929 len = sg_dma_len(sg);
930
931 mem_width = min_t(unsigned int,
932 data_width, dwc_fast_fls(mem | len));
933
934 slave_sg_fromdev_fill_desc:
935 desc = dwc_desc_get(dwc);
936 if (!desc) {
937 dev_err(chan2dev(chan),
938 "not enough descriptors available\n");
939 goto err_desc_get;
940 }
941
942 desc->lli.sar = reg;
943 desc->lli.dar = mem;
944 desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
945 if ((len >> reg_width) > dwc->block_size) {
946 dlen = dwc->block_size << reg_width;
947 mem += dlen;
948 len -= dlen;
949 } else {
950 dlen = len;
951 len = 0;
952 }
953 desc->lli.ctlhi = dlen >> reg_width;
954 desc->len = dlen;
955
956 if (!first) {
957 first = desc;
958 } else {
959 prev->lli.llp = desc->txd.phys;
960 list_add_tail(&desc->desc_node,
961 &first->tx_list);
962 }
963 prev = desc;
964 total_len += dlen;
965
966 if (len)
967 goto slave_sg_fromdev_fill_desc;
968 }
969 break;
970 default:
971 return NULL;
972 }
973
974 if (flags & DMA_PREP_INTERRUPT)
975 /* Trigger interrupt after last block */
976 prev->lli.ctllo |= DWC_CTLL_INT_EN;
977
978 prev->lli.llp = 0;
979 first->total_len = total_len;
980
981 return &first->txd;
982
983 err_desc_get:
984 dwc_desc_put(dwc, first);
985 return NULL;
986 }
987
988 /*
989 * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
990 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
991 *
992 * NOTE: burst size 2 is not supported by controller.
993 *
994 * This can be done by finding least significant bit set: n & (n - 1)
995 */
996 static inline void convert_burst(u32 *maxburst)
997 {
998 if (*maxburst > 1)
999 *maxburst = fls(*maxburst) - 2;
1000 else
1001 *maxburst = 0;
1002 }
1003
1004 static inline void convert_slave_id(struct dw_dma_chan *dwc)
1005 {
1006 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1007
1008 dwc->dma_sconfig.slave_id -= dw->request_line_base;
1009 }
1010
1011 static int
1012 set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
1013 {
1014 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1015
1016 /* Check if chan will be configured for slave transfers */
1017 if (!is_slave_direction(sconfig->direction))
1018 return -EINVAL;
1019
1020 memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
1021 dwc->direction = sconfig->direction;
1022
1023 convert_burst(&dwc->dma_sconfig.src_maxburst);
1024 convert_burst(&dwc->dma_sconfig.dst_maxburst);
1025 convert_slave_id(dwc);
1026
1027 return 0;
1028 }
1029
1030 static inline void dwc_chan_pause(struct dw_dma_chan *dwc)
1031 {
1032 u32 cfglo = channel_readl(dwc, CFG_LO);
1033
1034 channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
1035 while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY))
1036 cpu_relax();
1037
1038 dwc->paused = true;
1039 }
1040
1041 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
1042 {
1043 u32 cfglo = channel_readl(dwc, CFG_LO);
1044
1045 channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
1046
1047 dwc->paused = false;
1048 }
1049
1050 static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
1051 unsigned long arg)
1052 {
1053 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1054 struct dw_dma *dw = to_dw_dma(chan->device);
1055 struct dw_desc *desc, *_desc;
1056 unsigned long flags;
1057 LIST_HEAD(list);
1058
1059 if (cmd == DMA_PAUSE) {
1060 spin_lock_irqsave(&dwc->lock, flags);
1061
1062 dwc_chan_pause(dwc);
1063
1064 spin_unlock_irqrestore(&dwc->lock, flags);
1065 } else if (cmd == DMA_RESUME) {
1066 if (!dwc->paused)
1067 return 0;
1068
1069 spin_lock_irqsave(&dwc->lock, flags);
1070
1071 dwc_chan_resume(dwc);
1072
1073 spin_unlock_irqrestore(&dwc->lock, flags);
1074 } else if (cmd == DMA_TERMINATE_ALL) {
1075 spin_lock_irqsave(&dwc->lock, flags);
1076
1077 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
1078
1079 dwc_chan_disable(dw, dwc);
1080
1081 dwc_chan_resume(dwc);
1082
1083 /* active_list entries will end up before queued entries */
1084 list_splice_init(&dwc->queue, &list);
1085 list_splice_init(&dwc->active_list, &list);
1086
1087 spin_unlock_irqrestore(&dwc->lock, flags);
1088
1089 /* Flush all pending and queued descriptors */
1090 list_for_each_entry_safe(desc, _desc, &list, desc_node)
1091 dwc_descriptor_complete(dwc, desc, false);
1092 } else if (cmd == DMA_SLAVE_CONFIG) {
1093 return set_runtime_config(chan, (struct dma_slave_config *)arg);
1094 } else {
1095 return -ENXIO;
1096 }
1097
1098 return 0;
1099 }
1100
1101 static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
1102 {
1103 unsigned long flags;
1104 u32 residue;
1105
1106 spin_lock_irqsave(&dwc->lock, flags);
1107
1108 residue = dwc->residue;
1109 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1110 residue -= dwc_get_sent(dwc);
1111
1112 spin_unlock_irqrestore(&dwc->lock, flags);
1113 return residue;
1114 }
1115
1116 static enum dma_status
1117 dwc_tx_status(struct dma_chan *chan,
1118 dma_cookie_t cookie,
1119 struct dma_tx_state *txstate)
1120 {
1121 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1122 enum dma_status ret;
1123
1124 ret = dma_cookie_status(chan, cookie, txstate);
1125 if (ret != DMA_SUCCESS) {
1126 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1127
1128 ret = dma_cookie_status(chan, cookie, txstate);
1129 }
1130
1131 if (ret != DMA_SUCCESS)
1132 dma_set_residue(txstate, dwc_get_residue(dwc));
1133
1134 if (dwc->paused)
1135 return DMA_PAUSED;
1136
1137 return ret;
1138 }
1139
1140 static void dwc_issue_pending(struct dma_chan *chan)
1141 {
1142 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1143
1144 if (!list_empty(&dwc->queue))
1145 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1146 }
1147
1148 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1149 {
1150 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1151 struct dw_dma *dw = to_dw_dma(chan->device);
1152 struct dw_desc *desc;
1153 int i;
1154 unsigned long flags;
1155
1156 dev_vdbg(chan2dev(chan), "%s\n", __func__);
1157
1158 /* ASSERT: channel is idle */
1159 if (dma_readl(dw, CH_EN) & dwc->mask) {
1160 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1161 return -EIO;
1162 }
1163
1164 dma_cookie_init(chan);
1165
1166 /*
1167 * NOTE: some controllers may have additional features that we
1168 * need to initialize here, like "scatter-gather" (which
1169 * doesn't mean what you think it means), and status writeback.
1170 */
1171
1172 spin_lock_irqsave(&dwc->lock, flags);
1173 i = dwc->descs_allocated;
1174 while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1175 dma_addr_t phys;
1176
1177 spin_unlock_irqrestore(&dwc->lock, flags);
1178
1179 desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys);
1180 if (!desc)
1181 goto err_desc_alloc;
1182
1183 memset(desc, 0, sizeof(struct dw_desc));
1184
1185 INIT_LIST_HEAD(&desc->tx_list);
1186 dma_async_tx_descriptor_init(&desc->txd, chan);
1187 desc->txd.tx_submit = dwc_tx_submit;
1188 desc->txd.flags = DMA_CTRL_ACK;
1189 desc->txd.phys = phys;
1190
1191 dwc_desc_put(dwc, desc);
1192
1193 spin_lock_irqsave(&dwc->lock, flags);
1194 i = ++dwc->descs_allocated;
1195 }
1196
1197 spin_unlock_irqrestore(&dwc->lock, flags);
1198
1199 dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
1200
1201 return i;
1202
1203 err_desc_alloc:
1204 dev_info(chan2dev(chan), "only allocated %d descriptors\n", i);
1205
1206 return i;
1207 }
1208
1209 static void dwc_free_chan_resources(struct dma_chan *chan)
1210 {
1211 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1212 struct dw_dma *dw = to_dw_dma(chan->device);
1213 struct dw_desc *desc, *_desc;
1214 unsigned long flags;
1215 LIST_HEAD(list);
1216
1217 dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1218 dwc->descs_allocated);
1219
1220 /* ASSERT: channel is idle */
1221 BUG_ON(!list_empty(&dwc->active_list));
1222 BUG_ON(!list_empty(&dwc->queue));
1223 BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1224
1225 spin_lock_irqsave(&dwc->lock, flags);
1226 list_splice_init(&dwc->free_list, &list);
1227 dwc->descs_allocated = 0;
1228 dwc->initialized = false;
1229
1230 /* Disable interrupts */
1231 channel_clear_bit(dw, MASK.XFER, dwc->mask);
1232 channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1233
1234 spin_unlock_irqrestore(&dwc->lock, flags);
1235
1236 list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1237 dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
1238 dma_pool_free(dw->desc_pool, desc, desc->txd.phys);
1239 }
1240
1241 dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1242 }
1243
1244 struct dw_dma_filter_args {
1245 struct dw_dma *dw;
1246 unsigned int req;
1247 unsigned int src;
1248 unsigned int dst;
1249 };
1250
1251 static bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
1252 {
1253 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1254 struct dw_dma *dw = to_dw_dma(chan->device);
1255 struct dw_dma_filter_args *fargs = param;
1256 struct dw_dma_slave *dws = &dwc->slave;
1257
1258 /* ensure the device matches our channel */
1259 if (chan->device != &fargs->dw->dma)
1260 return false;
1261
1262 dws->dma_dev = dw->dma.dev;
1263 dws->cfg_hi = ~0;
1264 dws->cfg_lo = ~0;
1265 dws->src_master = fargs->src;
1266 dws->dst_master = fargs->dst;
1267
1268 dwc->request_line = fargs->req;
1269
1270 chan->private = dws;
1271
1272 return true;
1273 }
1274
1275 static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec,
1276 struct of_dma *ofdma)
1277 {
1278 struct dw_dma *dw = ofdma->of_dma_data;
1279 struct dw_dma_filter_args fargs = {
1280 .dw = dw,
1281 };
1282 dma_cap_mask_t cap;
1283
1284 if (dma_spec->args_count != 3)
1285 return NULL;
1286
1287 fargs.req = dma_spec->args[0];
1288 fargs.src = dma_spec->args[1];
1289 fargs.dst = dma_spec->args[2];
1290
1291 if (WARN_ON(fargs.req >= DW_DMA_MAX_NR_REQUESTS ||
1292 fargs.src >= dw->nr_masters ||
1293 fargs.dst >= dw->nr_masters))
1294 return NULL;
1295
1296 dma_cap_zero(cap);
1297 dma_cap_set(DMA_SLAVE, cap);
1298
1299 /* TODO: there should be a simpler way to do this */
1300 return dma_request_channel(cap, dw_dma_generic_filter, &fargs);
1301 }
1302
1303 /* --------------------- Cyclic DMA API extensions -------------------- */
1304
1305 /**
1306 * dw_dma_cyclic_start - start the cyclic DMA transfer
1307 * @chan: the DMA channel to start
1308 *
1309 * Must be called with soft interrupts disabled. Returns zero on success or
1310 * -errno on failure.
1311 */
1312 int dw_dma_cyclic_start(struct dma_chan *chan)
1313 {
1314 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1315 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1316 unsigned long flags;
1317
1318 if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1319 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1320 return -ENODEV;
1321 }
1322
1323 spin_lock_irqsave(&dwc->lock, flags);
1324
1325 /* assert channel is idle */
1326 if (dma_readl(dw, CH_EN) & dwc->mask) {
1327 dev_err(chan2dev(&dwc->chan),
1328 "BUG: Attempted to start non-idle channel\n");
1329 dwc_dump_chan_regs(dwc);
1330 spin_unlock_irqrestore(&dwc->lock, flags);
1331 return -EBUSY;
1332 }
1333
1334 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1335 dma_writel(dw, CLEAR.XFER, dwc->mask);
1336
1337 /* setup DMAC channel registers */
1338 channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1339 channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1340 channel_writel(dwc, CTL_HI, 0);
1341
1342 channel_set_bit(dw, CH_EN, dwc->mask);
1343
1344 spin_unlock_irqrestore(&dwc->lock, flags);
1345
1346 return 0;
1347 }
1348 EXPORT_SYMBOL(dw_dma_cyclic_start);
1349
1350 /**
1351 * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1352 * @chan: the DMA channel to stop
1353 *
1354 * Must be called with soft interrupts disabled.
1355 */
1356 void dw_dma_cyclic_stop(struct dma_chan *chan)
1357 {
1358 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1359 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1360 unsigned long flags;
1361
1362 spin_lock_irqsave(&dwc->lock, flags);
1363
1364 dwc_chan_disable(dw, dwc);
1365
1366 spin_unlock_irqrestore(&dwc->lock, flags);
1367 }
1368 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1369
1370 /**
1371 * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1372 * @chan: the DMA channel to prepare
1373 * @buf_addr: physical DMA address where the buffer starts
1374 * @buf_len: total number of bytes for the entire buffer
1375 * @period_len: number of bytes for each period
1376 * @direction: transfer direction, to or from device
1377 *
1378 * Must be called before trying to start the transfer. Returns a valid struct
1379 * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1380 */
1381 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1382 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1383 enum dma_transfer_direction direction)
1384 {
1385 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1386 struct dma_slave_config *sconfig = &dwc->dma_sconfig;
1387 struct dw_cyclic_desc *cdesc;
1388 struct dw_cyclic_desc *retval = NULL;
1389 struct dw_desc *desc;
1390 struct dw_desc *last = NULL;
1391 unsigned long was_cyclic;
1392 unsigned int reg_width;
1393 unsigned int periods;
1394 unsigned int i;
1395 unsigned long flags;
1396
1397 spin_lock_irqsave(&dwc->lock, flags);
1398 if (dwc->nollp) {
1399 spin_unlock_irqrestore(&dwc->lock, flags);
1400 dev_dbg(chan2dev(&dwc->chan),
1401 "channel doesn't support LLP transfers\n");
1402 return ERR_PTR(-EINVAL);
1403 }
1404
1405 if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1406 spin_unlock_irqrestore(&dwc->lock, flags);
1407 dev_dbg(chan2dev(&dwc->chan),
1408 "queue and/or active list are not empty\n");
1409 return ERR_PTR(-EBUSY);
1410 }
1411
1412 was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1413 spin_unlock_irqrestore(&dwc->lock, flags);
1414 if (was_cyclic) {
1415 dev_dbg(chan2dev(&dwc->chan),
1416 "channel already prepared for cyclic DMA\n");
1417 return ERR_PTR(-EBUSY);
1418 }
1419
1420 retval = ERR_PTR(-EINVAL);
1421
1422 if (unlikely(!is_slave_direction(direction)))
1423 goto out_err;
1424
1425 dwc->direction = direction;
1426
1427 if (direction == DMA_MEM_TO_DEV)
1428 reg_width = __ffs(sconfig->dst_addr_width);
1429 else
1430 reg_width = __ffs(sconfig->src_addr_width);
1431
1432 periods = buf_len / period_len;
1433
1434 /* Check for too big/unaligned periods and unaligned DMA buffer. */
1435 if (period_len > (dwc->block_size << reg_width))
1436 goto out_err;
1437 if (unlikely(period_len & ((1 << reg_width) - 1)))
1438 goto out_err;
1439 if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1440 goto out_err;
1441
1442 retval = ERR_PTR(-ENOMEM);
1443
1444 if (periods > NR_DESCS_PER_CHANNEL)
1445 goto out_err;
1446
1447 cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1448 if (!cdesc)
1449 goto out_err;
1450
1451 cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1452 if (!cdesc->desc)
1453 goto out_err_alloc;
1454
1455 for (i = 0; i < periods; i++) {
1456 desc = dwc_desc_get(dwc);
1457 if (!desc)
1458 goto out_err_desc_get;
1459
1460 switch (direction) {
1461 case DMA_MEM_TO_DEV:
1462 desc->lli.dar = sconfig->dst_addr;
1463 desc->lli.sar = buf_addr + (period_len * i);
1464 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1465 | DWC_CTLL_DST_WIDTH(reg_width)
1466 | DWC_CTLL_SRC_WIDTH(reg_width)
1467 | DWC_CTLL_DST_FIX
1468 | DWC_CTLL_SRC_INC
1469 | DWC_CTLL_INT_EN);
1470
1471 desc->lli.ctllo |= sconfig->device_fc ?
1472 DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
1473 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
1474
1475 break;
1476 case DMA_DEV_TO_MEM:
1477 desc->lli.dar = buf_addr + (period_len * i);
1478 desc->lli.sar = sconfig->src_addr;
1479 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1480 | DWC_CTLL_SRC_WIDTH(reg_width)
1481 | DWC_CTLL_DST_WIDTH(reg_width)
1482 | DWC_CTLL_DST_INC
1483 | DWC_CTLL_SRC_FIX
1484 | DWC_CTLL_INT_EN);
1485
1486 desc->lli.ctllo |= sconfig->device_fc ?
1487 DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
1488 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
1489
1490 break;
1491 default:
1492 break;
1493 }
1494
1495 desc->lli.ctlhi = (period_len >> reg_width);
1496 cdesc->desc[i] = desc;
1497
1498 if (last)
1499 last->lli.llp = desc->txd.phys;
1500
1501 last = desc;
1502 }
1503
1504 /* lets make a cyclic list */
1505 last->lli.llp = cdesc->desc[0]->txd.phys;
1506
1507 dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%llx len %zu "
1508 "period %zu periods %d\n", (unsigned long long)buf_addr,
1509 buf_len, period_len, periods);
1510
1511 cdesc->periods = periods;
1512 dwc->cdesc = cdesc;
1513
1514 return cdesc;
1515
1516 out_err_desc_get:
1517 while (i--)
1518 dwc_desc_put(dwc, cdesc->desc[i]);
1519 out_err_alloc:
1520 kfree(cdesc);
1521 out_err:
1522 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1523 return (struct dw_cyclic_desc *)retval;
1524 }
1525 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1526
1527 /**
1528 * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1529 * @chan: the DMA channel to free
1530 */
1531 void dw_dma_cyclic_free(struct dma_chan *chan)
1532 {
1533 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1534 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1535 struct dw_cyclic_desc *cdesc = dwc->cdesc;
1536 int i;
1537 unsigned long flags;
1538
1539 dev_dbg(chan2dev(&dwc->chan), "%s\n", __func__);
1540
1541 if (!cdesc)
1542 return;
1543
1544 spin_lock_irqsave(&dwc->lock, flags);
1545
1546 dwc_chan_disable(dw, dwc);
1547
1548 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1549 dma_writel(dw, CLEAR.XFER, dwc->mask);
1550
1551 spin_unlock_irqrestore(&dwc->lock, flags);
1552
1553 for (i = 0; i < cdesc->periods; i++)
1554 dwc_desc_put(dwc, cdesc->desc[i]);
1555
1556 kfree(cdesc->desc);
1557 kfree(cdesc);
1558
1559 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1560 }
1561 EXPORT_SYMBOL(dw_dma_cyclic_free);
1562
1563 /*----------------------------------------------------------------------*/
1564
1565 static void dw_dma_off(struct dw_dma *dw)
1566 {
1567 int i;
1568
1569 dma_writel(dw, CFG, 0);
1570
1571 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1572 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1573 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1574 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1575
1576 while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1577 cpu_relax();
1578
1579 for (i = 0; i < dw->dma.chancnt; i++)
1580 dw->chan[i].initialized = false;
1581 }
1582
1583 #ifdef CONFIG_OF
1584 static struct dw_dma_platform_data *
1585 dw_dma_parse_dt(struct platform_device *pdev)
1586 {
1587 struct device_node *np = pdev->dev.of_node;
1588 struct dw_dma_platform_data *pdata;
1589 u32 tmp, arr[4];
1590
1591 if (!np) {
1592 dev_err(&pdev->dev, "Missing DT data\n");
1593 return NULL;
1594 }
1595
1596 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1597 if (!pdata)
1598 return NULL;
1599
1600 if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
1601 return NULL;
1602
1603 if (of_property_read_bool(np, "is_private"))
1604 pdata->is_private = true;
1605
1606 if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
1607 pdata->chan_allocation_order = (unsigned char)tmp;
1608
1609 if (!of_property_read_u32(np, "chan_priority", &tmp))
1610 pdata->chan_priority = tmp;
1611
1612 if (!of_property_read_u32(np, "block_size", &tmp))
1613 pdata->block_size = tmp;
1614
1615 if (!of_property_read_u32(np, "dma-masters", &tmp)) {
1616 if (tmp > 4)
1617 return NULL;
1618
1619 pdata->nr_masters = tmp;
1620 }
1621
1622 if (!of_property_read_u32_array(np, "data_width", arr,
1623 pdata->nr_masters))
1624 for (tmp = 0; tmp < pdata->nr_masters; tmp++)
1625 pdata->data_width[tmp] = arr[tmp];
1626
1627 return pdata;
1628 }
1629 #else
1630 static inline struct dw_dma_platform_data *
1631 dw_dma_parse_dt(struct platform_device *pdev)
1632 {
1633 return NULL;
1634 }
1635 #endif
1636
1637 static int dw_probe(struct platform_device *pdev)
1638 {
1639 const struct platform_device_id *match;
1640 struct dw_dma_platform_data *pdata;
1641 struct resource *io;
1642 struct dw_dma *dw;
1643 size_t size;
1644 void __iomem *regs;
1645 bool autocfg;
1646 unsigned int dw_params;
1647 unsigned int nr_channels;
1648 unsigned int max_blk_size = 0;
1649 int irq;
1650 int err;
1651 int i;
1652
1653 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1654 if (!io)
1655 return -EINVAL;
1656
1657 irq = platform_get_irq(pdev, 0);
1658 if (irq < 0)
1659 return irq;
1660
1661 regs = devm_ioremap_resource(&pdev->dev, io);
1662 if (IS_ERR(regs))
1663 return PTR_ERR(regs);
1664
1665 /* Apply default dma_mask if needed */
1666 if (!pdev->dev.dma_mask) {
1667 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
1668 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
1669 }
1670
1671 dw_params = dma_read_byaddr(regs, DW_PARAMS);
1672 autocfg = dw_params >> DW_PARAMS_EN & 0x1;
1673
1674 dev_dbg(&pdev->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1675
1676 pdata = dev_get_platdata(&pdev->dev);
1677 if (!pdata)
1678 pdata = dw_dma_parse_dt(pdev);
1679
1680 if (!pdata && autocfg) {
1681 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1682 if (!pdata)
1683 return -ENOMEM;
1684
1685 /* Fill platform data with the default values */
1686 pdata->is_private = true;
1687 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1688 pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1689 } else if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1690 return -EINVAL;
1691
1692 if (autocfg)
1693 nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 0x7) + 1;
1694 else
1695 nr_channels = pdata->nr_channels;
1696
1697 size = sizeof(struct dw_dma) + nr_channels * sizeof(struct dw_dma_chan);
1698 dw = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
1699 if (!dw)
1700 return -ENOMEM;
1701
1702 dw->clk = devm_clk_get(&pdev->dev, "hclk");
1703 if (IS_ERR(dw->clk))
1704 return PTR_ERR(dw->clk);
1705 clk_prepare_enable(dw->clk);
1706
1707 dw->regs = regs;
1708
1709 /* get hardware configuration parameters */
1710 if (autocfg) {
1711 max_blk_size = dma_readl(dw, MAX_BLK_SIZE);
1712
1713 dw->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1714 for (i = 0; i < dw->nr_masters; i++) {
1715 dw->data_width[i] =
1716 (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3) + 2;
1717 }
1718 } else {
1719 dw->nr_masters = pdata->nr_masters;
1720 memcpy(dw->data_width, pdata->data_width, 4);
1721 }
1722
1723 /* Get the base request line if set */
1724 match = platform_get_device_id(pdev);
1725 if (match)
1726 dw->request_line_base = (unsigned int)match->driver_data;
1727
1728 /* Calculate all channel mask before DMA setup */
1729 dw->all_chan_mask = (1 << nr_channels) - 1;
1730
1731 /* force dma off, just in case */
1732 dw_dma_off(dw);
1733
1734 /* disable BLOCK interrupts as well */
1735 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1736
1737 err = devm_request_irq(&pdev->dev, irq, dw_dma_interrupt, 0,
1738 "dw_dmac", dw);
1739 if (err)
1740 return err;
1741
1742 platform_set_drvdata(pdev, dw);
1743
1744 /* create a pool of consistent memory blocks for hardware descriptors */
1745 dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", &pdev->dev,
1746 sizeof(struct dw_desc), 4, 0);
1747 if (!dw->desc_pool) {
1748 dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
1749 return -ENOMEM;
1750 }
1751
1752 tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1753
1754 INIT_LIST_HEAD(&dw->dma.channels);
1755 for (i = 0; i < nr_channels; i++) {
1756 struct dw_dma_chan *dwc = &dw->chan[i];
1757 int r = nr_channels - i - 1;
1758
1759 dwc->chan.device = &dw->dma;
1760 dma_cookie_init(&dwc->chan);
1761 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1762 list_add_tail(&dwc->chan.device_node,
1763 &dw->dma.channels);
1764 else
1765 list_add(&dwc->chan.device_node, &dw->dma.channels);
1766
1767 /* 7 is highest priority & 0 is lowest. */
1768 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1769 dwc->priority = r;
1770 else
1771 dwc->priority = i;
1772
1773 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1774 spin_lock_init(&dwc->lock);
1775 dwc->mask = 1 << i;
1776
1777 INIT_LIST_HEAD(&dwc->active_list);
1778 INIT_LIST_HEAD(&dwc->queue);
1779 INIT_LIST_HEAD(&dwc->free_list);
1780
1781 channel_clear_bit(dw, CH_EN, dwc->mask);
1782
1783 dwc->direction = DMA_TRANS_NONE;
1784
1785 /* hardware configuration */
1786 if (autocfg) {
1787 unsigned int dwc_params;
1788
1789 dwc_params = dma_read_byaddr(regs + r * sizeof(u32),
1790 DWC_PARAMS);
1791
1792 dev_dbg(&pdev->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1793 dwc_params);
1794
1795 /* Decode maximum block size for given channel. The
1796 * stored 4 bit value represents blocks from 0x00 for 3
1797 * up to 0x0a for 4095. */
1798 dwc->block_size =
1799 (4 << ((max_blk_size >> 4 * i) & 0xf)) - 1;
1800 dwc->nollp =
1801 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1802 } else {
1803 dwc->block_size = pdata->block_size;
1804
1805 /* Check if channel supports multi block transfer */
1806 channel_writel(dwc, LLP, 0xfffffffc);
1807 dwc->nollp =
1808 (channel_readl(dwc, LLP) & 0xfffffffc) == 0;
1809 channel_writel(dwc, LLP, 0);
1810 }
1811 }
1812
1813 /* Clear all interrupts on all channels. */
1814 dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1815 dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1816 dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1817 dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1818 dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1819
1820 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1821 dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1822 if (pdata->is_private)
1823 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1824 dw->dma.dev = &pdev->dev;
1825 dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1826 dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1827
1828 dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1829
1830 dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1831 dw->dma.device_control = dwc_control;
1832
1833 dw->dma.device_tx_status = dwc_tx_status;
1834 dw->dma.device_issue_pending = dwc_issue_pending;
1835
1836 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1837
1838 dev_info(&pdev->dev, "DesignWare DMA Controller, %d channels\n",
1839 nr_channels);
1840
1841 dma_async_device_register(&dw->dma);
1842
1843 if (pdev->dev.of_node) {
1844 err = of_dma_controller_register(pdev->dev.of_node,
1845 dw_dma_xlate, dw);
1846 if (err && err != -ENODEV)
1847 dev_err(&pdev->dev,
1848 "could not register of_dma_controller\n");
1849 }
1850
1851 return 0;
1852 }
1853
1854 static int dw_remove(struct platform_device *pdev)
1855 {
1856 struct dw_dma *dw = platform_get_drvdata(pdev);
1857 struct dw_dma_chan *dwc, *_dwc;
1858
1859 if (pdev->dev.of_node)
1860 of_dma_controller_free(pdev->dev.of_node);
1861 dw_dma_off(dw);
1862 dma_async_device_unregister(&dw->dma);
1863
1864 tasklet_kill(&dw->tasklet);
1865
1866 list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1867 chan.device_node) {
1868 list_del(&dwc->chan.device_node);
1869 channel_clear_bit(dw, CH_EN, dwc->mask);
1870 }
1871
1872 return 0;
1873 }
1874
1875 static void dw_shutdown(struct platform_device *pdev)
1876 {
1877 struct dw_dma *dw = platform_get_drvdata(pdev);
1878
1879 dw_dma_off(dw);
1880 clk_disable_unprepare(dw->clk);
1881 }
1882
1883 static int dw_suspend_noirq(struct device *dev)
1884 {
1885 struct platform_device *pdev = to_platform_device(dev);
1886 struct dw_dma *dw = platform_get_drvdata(pdev);
1887
1888 dw_dma_off(dw);
1889 clk_disable_unprepare(dw->clk);
1890
1891 return 0;
1892 }
1893
1894 static int dw_resume_noirq(struct device *dev)
1895 {
1896 struct platform_device *pdev = to_platform_device(dev);
1897 struct dw_dma *dw = platform_get_drvdata(pdev);
1898
1899 clk_prepare_enable(dw->clk);
1900 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1901
1902 return 0;
1903 }
1904
1905 static const struct dev_pm_ops dw_dev_pm_ops = {
1906 .suspend_noirq = dw_suspend_noirq,
1907 .resume_noirq = dw_resume_noirq,
1908 .freeze_noirq = dw_suspend_noirq,
1909 .thaw_noirq = dw_resume_noirq,
1910 .restore_noirq = dw_resume_noirq,
1911 .poweroff_noirq = dw_suspend_noirq,
1912 };
1913
1914 #ifdef CONFIG_OF
1915 static const struct of_device_id dw_dma_id_table[] = {
1916 { .compatible = "snps,dma-spear1340" },
1917 {}
1918 };
1919 MODULE_DEVICE_TABLE(of, dw_dma_id_table);
1920 #endif
1921
1922 static const struct platform_device_id dw_dma_ids[] = {
1923 /* Name, Request Line Base */
1924 { "INTL9C60", (kernel_ulong_t)16 },
1925 { }
1926 };
1927
1928 static struct platform_driver dw_driver = {
1929 .probe = dw_probe,
1930 .remove = dw_remove,
1931 .shutdown = dw_shutdown,
1932 .driver = {
1933 .name = "dw_dmac",
1934 .pm = &dw_dev_pm_ops,
1935 .of_match_table = of_match_ptr(dw_dma_id_table),
1936 },
1937 .id_table = dw_dma_ids,
1938 };
1939
1940 static int __init dw_init(void)
1941 {
1942 return platform_driver_register(&dw_driver);
1943 }
1944 subsys_initcall(dw_init);
1945
1946 static void __exit dw_exit(void)
1947 {
1948 platform_driver_unregister(&dw_driver);
1949 }
1950 module_exit(dw_exit);
1951
1952 MODULE_LICENSE("GPL v2");
1953 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1954 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1955 MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");
kernel source for telekom puls (alcatel/mediatek)