xref: /linux/drivers/dma/dw/core.c (revision 5ff328836dfde0cef9f28c8b8791a90a36d7a183)
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_chan_idma32(struct dw_dma_chan *dwc)
142 {
143 	u32 cfghi = 0;
144 	u32 cfglo = 0;
145 
146 	/* Set default burst alignment */
147 	cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
148 
149 	/* Low 4 bits of the request lines */
150 	cfghi |= IDMA32C_CFGH_DST_PER(dwc->dws.dst_id & 0xf);
151 	cfghi |= IDMA32C_CFGH_SRC_PER(dwc->dws.src_id & 0xf);
152 
153 	/* Request line extension (2 bits) */
154 	cfghi |= IDMA32C_CFGH_DST_PER_EXT(dwc->dws.dst_id >> 4 & 0x3);
155 	cfghi |= IDMA32C_CFGH_SRC_PER_EXT(dwc->dws.src_id >> 4 & 0x3);
156 
157 	channel_writel(dwc, CFG_LO, cfglo);
158 	channel_writel(dwc, CFG_HI, cfghi);
159 }
160 
161 static void dwc_initialize_chan_dw(struct dw_dma_chan *dwc)
162 {
163 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
164 	u32 cfghi = DWC_CFGH_FIFO_MODE;
165 	u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
166 	bool hs_polarity = dwc->dws.hs_polarity;
167 
168 	cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
169 	cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
170 	cfghi |= DWC_CFGH_PROTCTL(dw->pdata->protctl);
171 
172 	/* Set polarity of handshake interface */
173 	cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
174 
175 	channel_writel(dwc, CFG_LO, cfglo);
176 	channel_writel(dwc, CFG_HI, cfghi);
177 }
178 
179 static void dwc_initialize(struct dw_dma_chan *dwc)
180 {
181 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
182 
183 	if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
184 		return;
185 
186 	if (dw->pdata->is_idma32)
187 		dwc_initialize_chan_idma32(dwc);
188 	else
189 		dwc_initialize_chan_dw(dwc);
190 
191 	/* Enable interrupts */
192 	channel_set_bit(dw, MASK.XFER, dwc->mask);
193 	channel_set_bit(dw, MASK.ERROR, dwc->mask);
194 
195 	set_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
196 }
197 
198 /*----------------------------------------------------------------------*/
199 
200 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
201 {
202 	dev_err(chan2dev(&dwc->chan),
203 		"  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
204 		channel_readl(dwc, SAR),
205 		channel_readl(dwc, DAR),
206 		channel_readl(dwc, LLP),
207 		channel_readl(dwc, CTL_HI),
208 		channel_readl(dwc, CTL_LO));
209 }
210 
211 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
212 {
213 	channel_clear_bit(dw, CH_EN, dwc->mask);
214 	while (dma_readl(dw, CH_EN) & dwc->mask)
215 		cpu_relax();
216 }
217 
218 static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,
219 			  unsigned int width, size_t *len)
220 {
221 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
222 	u32 block;
223 
224 	/* Always in bytes for iDMA 32-bit */
225 	if (dw->pdata->is_idma32)
226 		width = 0;
227 
228 	if ((bytes >> width) > dwc->block_size) {
229 		block = dwc->block_size;
230 		*len = block << width;
231 	} else {
232 		block = bytes >> width;
233 		*len = bytes;
234 	}
235 
236 	return block;
237 }
238 
239 static size_t block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
240 {
241 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
242 
243 	if (dw->pdata->is_idma32)
244 		return IDMA32C_CTLH_BLOCK_TS(block);
245 
246 	return DWC_CTLH_BLOCK_TS(block) << width;
247 }
248 
249 /*----------------------------------------------------------------------*/
250 
251 /* Perform single block transfer */
252 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
253 				       struct dw_desc *desc)
254 {
255 	struct dw_dma	*dw = to_dw_dma(dwc->chan.device);
256 	u32		ctllo;
257 
258 	/*
259 	 * Software emulation of LLP mode relies on interrupts to continue
260 	 * multi block transfer.
261 	 */
262 	ctllo = lli_read(desc, ctllo) | DWC_CTLL_INT_EN;
263 
264 	channel_writel(dwc, SAR, lli_read(desc, sar));
265 	channel_writel(dwc, DAR, lli_read(desc, dar));
266 	channel_writel(dwc, CTL_LO, ctllo);
267 	channel_writel(dwc, CTL_HI, lli_read(desc, ctlhi));
268 	channel_set_bit(dw, CH_EN, dwc->mask);
269 
270 	/* Move pointer to next descriptor */
271 	dwc->tx_node_active = dwc->tx_node_active->next;
272 }
273 
274 /* Called with dwc->lock held and bh disabled */
275 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
276 {
277 	struct dw_dma	*dw = to_dw_dma(dwc->chan.device);
278 	u8		lms = DWC_LLP_LMS(dwc->dws.m_master);
279 	unsigned long	was_soft_llp;
280 
281 	/* ASSERT:  channel is idle */
282 	if (dma_readl(dw, CH_EN) & dwc->mask) {
283 		dev_err(chan2dev(&dwc->chan),
284 			"%s: BUG: Attempted to start non-idle channel\n",
285 			__func__);
286 		dwc_dump_chan_regs(dwc);
287 
288 		/* The tasklet will hopefully advance the queue... */
289 		return;
290 	}
291 
292 	if (dwc->nollp) {
293 		was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
294 						&dwc->flags);
295 		if (was_soft_llp) {
296 			dev_err(chan2dev(&dwc->chan),
297 				"BUG: Attempted to start new LLP transfer inside ongoing one\n");
298 			return;
299 		}
300 
301 		dwc_initialize(dwc);
302 
303 		first->residue = first->total_len;
304 		dwc->tx_node_active = &first->tx_list;
305 
306 		/* Submit first block */
307 		dwc_do_single_block(dwc, first);
308 
309 		return;
310 	}
311 
312 	dwc_initialize(dwc);
313 
314 	channel_writel(dwc, LLP, first->txd.phys | lms);
315 	channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
316 	channel_writel(dwc, CTL_HI, 0);
317 	channel_set_bit(dw, CH_EN, dwc->mask);
318 }
319 
320 static void dwc_dostart_first_queued(struct dw_dma_chan *dwc)
321 {
322 	struct dw_desc *desc;
323 
324 	if (list_empty(&dwc->queue))
325 		return;
326 
327 	list_move(dwc->queue.next, &dwc->active_list);
328 	desc = dwc_first_active(dwc);
329 	dev_vdbg(chan2dev(&dwc->chan), "%s: started %u\n", __func__, desc->txd.cookie);
330 	dwc_dostart(dwc, desc);
331 }
332 
333 /*----------------------------------------------------------------------*/
334 
335 static void
336 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
337 		bool callback_required)
338 {
339 	struct dma_async_tx_descriptor	*txd = &desc->txd;
340 	struct dw_desc			*child;
341 	unsigned long			flags;
342 	struct dmaengine_desc_callback	cb;
343 
344 	dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
345 
346 	spin_lock_irqsave(&dwc->lock, flags);
347 	dma_cookie_complete(txd);
348 	if (callback_required)
349 		dmaengine_desc_get_callback(txd, &cb);
350 	else
351 		memset(&cb, 0, sizeof(cb));
352 
353 	/* async_tx_ack */
354 	list_for_each_entry(child, &desc->tx_list, desc_node)
355 		async_tx_ack(&child->txd);
356 	async_tx_ack(&desc->txd);
357 	dwc_desc_put(dwc, desc);
358 	spin_unlock_irqrestore(&dwc->lock, flags);
359 
360 	dmaengine_desc_callback_invoke(&cb, NULL);
361 }
362 
363 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
364 {
365 	struct dw_desc *desc, *_desc;
366 	LIST_HEAD(list);
367 	unsigned long flags;
368 
369 	spin_lock_irqsave(&dwc->lock, flags);
370 	if (dma_readl(dw, CH_EN) & dwc->mask) {
371 		dev_err(chan2dev(&dwc->chan),
372 			"BUG: XFER bit set, but channel not idle!\n");
373 
374 		/* Try to continue after resetting the channel... */
375 		dwc_chan_disable(dw, dwc);
376 	}
377 
378 	/*
379 	 * Submit queued descriptors ASAP, i.e. before we go through
380 	 * the completed ones.
381 	 */
382 	list_splice_init(&dwc->active_list, &list);
383 	dwc_dostart_first_queued(dwc);
384 
385 	spin_unlock_irqrestore(&dwc->lock, flags);
386 
387 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
388 		dwc_descriptor_complete(dwc, desc, true);
389 }
390 
391 /* Returns how many bytes were already received from source */
392 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
393 {
394 	u32 ctlhi = channel_readl(dwc, CTL_HI);
395 	u32 ctllo = channel_readl(dwc, CTL_LO);
396 
397 	return block2bytes(dwc, ctlhi, ctllo >> 4 & 7);
398 }
399 
400 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
401 {
402 	dma_addr_t llp;
403 	struct dw_desc *desc, *_desc;
404 	struct dw_desc *child;
405 	u32 status_xfer;
406 	unsigned long flags;
407 
408 	spin_lock_irqsave(&dwc->lock, flags);
409 	llp = channel_readl(dwc, LLP);
410 	status_xfer = dma_readl(dw, RAW.XFER);
411 
412 	if (status_xfer & dwc->mask) {
413 		/* Everything we've submitted is done */
414 		dma_writel(dw, CLEAR.XFER, dwc->mask);
415 
416 		if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
417 			struct list_head *head, *active = dwc->tx_node_active;
418 
419 			/*
420 			 * We are inside first active descriptor.
421 			 * Otherwise something is really wrong.
422 			 */
423 			desc = dwc_first_active(dwc);
424 
425 			head = &desc->tx_list;
426 			if (active != head) {
427 				/* Update residue to reflect last sent descriptor */
428 				if (active == head->next)
429 					desc->residue -= desc->len;
430 				else
431 					desc->residue -= to_dw_desc(active->prev)->len;
432 
433 				child = to_dw_desc(active);
434 
435 				/* Submit next block */
436 				dwc_do_single_block(dwc, child);
437 
438 				spin_unlock_irqrestore(&dwc->lock, flags);
439 				return;
440 			}
441 
442 			/* We are done here */
443 			clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
444 		}
445 
446 		spin_unlock_irqrestore(&dwc->lock, flags);
447 
448 		dwc_complete_all(dw, dwc);
449 		return;
450 	}
451 
452 	if (list_empty(&dwc->active_list)) {
453 		spin_unlock_irqrestore(&dwc->lock, flags);
454 		return;
455 	}
456 
457 	if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
458 		dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
459 		spin_unlock_irqrestore(&dwc->lock, flags);
460 		return;
461 	}
462 
463 	dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp);
464 
465 	list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
466 		/* Initial residue value */
467 		desc->residue = desc->total_len;
468 
469 		/* Check first descriptors addr */
470 		if (desc->txd.phys == DWC_LLP_LOC(llp)) {
471 			spin_unlock_irqrestore(&dwc->lock, flags);
472 			return;
473 		}
474 
475 		/* Check first descriptors llp */
476 		if (lli_read(desc, llp) == llp) {
477 			/* This one is currently in progress */
478 			desc->residue -= dwc_get_sent(dwc);
479 			spin_unlock_irqrestore(&dwc->lock, flags);
480 			return;
481 		}
482 
483 		desc->residue -= desc->len;
484 		list_for_each_entry(child, &desc->tx_list, desc_node) {
485 			if (lli_read(child, llp) == llp) {
486 				/* Currently in progress */
487 				desc->residue -= dwc_get_sent(dwc);
488 				spin_unlock_irqrestore(&dwc->lock, flags);
489 				return;
490 			}
491 			desc->residue -= child->len;
492 		}
493 
494 		/*
495 		 * No descriptors so far seem to be in progress, i.e.
496 		 * this one must be done.
497 		 */
498 		spin_unlock_irqrestore(&dwc->lock, flags);
499 		dwc_descriptor_complete(dwc, desc, true);
500 		spin_lock_irqsave(&dwc->lock, flags);
501 	}
502 
503 	dev_err(chan2dev(&dwc->chan),
504 		"BUG: All descriptors done, but channel not idle!\n");
505 
506 	/* Try to continue after resetting the channel... */
507 	dwc_chan_disable(dw, dwc);
508 
509 	dwc_dostart_first_queued(dwc);
510 	spin_unlock_irqrestore(&dwc->lock, flags);
511 }
512 
513 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_desc *desc)
514 {
515 	dev_crit(chan2dev(&dwc->chan), "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
516 		 lli_read(desc, sar),
517 		 lli_read(desc, dar),
518 		 lli_read(desc, llp),
519 		 lli_read(desc, ctlhi),
520 		 lli_read(desc, ctllo));
521 }
522 
523 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
524 {
525 	struct dw_desc *bad_desc;
526 	struct dw_desc *child;
527 	unsigned long flags;
528 
529 	dwc_scan_descriptors(dw, dwc);
530 
531 	spin_lock_irqsave(&dwc->lock, flags);
532 
533 	/*
534 	 * The descriptor currently at the head of the active list is
535 	 * borked. Since we don't have any way to report errors, we'll
536 	 * just have to scream loudly and try to carry on.
537 	 */
538 	bad_desc = dwc_first_active(dwc);
539 	list_del_init(&bad_desc->desc_node);
540 	list_move(dwc->queue.next, dwc->active_list.prev);
541 
542 	/* Clear the error flag and try to restart the controller */
543 	dma_writel(dw, CLEAR.ERROR, dwc->mask);
544 	if (!list_empty(&dwc->active_list))
545 		dwc_dostart(dwc, dwc_first_active(dwc));
546 
547 	/*
548 	 * WARN may seem harsh, but since this only happens
549 	 * when someone submits a bad physical address in a
550 	 * descriptor, we should consider ourselves lucky that the
551 	 * controller flagged an error instead of scribbling over
552 	 * random memory locations.
553 	 */
554 	dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
555 				       "  cookie: %d\n", bad_desc->txd.cookie);
556 	dwc_dump_lli(dwc, bad_desc);
557 	list_for_each_entry(child, &bad_desc->tx_list, desc_node)
558 		dwc_dump_lli(dwc, child);
559 
560 	spin_unlock_irqrestore(&dwc->lock, flags);
561 
562 	/* Pretend the descriptor completed successfully */
563 	dwc_descriptor_complete(dwc, bad_desc, true);
564 }
565 
566 static void dw_dma_tasklet(unsigned long data)
567 {
568 	struct dw_dma *dw = (struct dw_dma *)data;
569 	struct dw_dma_chan *dwc;
570 	u32 status_xfer;
571 	u32 status_err;
572 	unsigned int i;
573 
574 	status_xfer = dma_readl(dw, RAW.XFER);
575 	status_err = dma_readl(dw, RAW.ERROR);
576 
577 	dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
578 
579 	for (i = 0; i < dw->dma.chancnt; i++) {
580 		dwc = &dw->chan[i];
581 		if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
582 			dev_vdbg(dw->dma.dev, "Cyclic xfer is not implemented\n");
583 		else if (status_err & (1 << i))
584 			dwc_handle_error(dw, dwc);
585 		else if (status_xfer & (1 << i))
586 			dwc_scan_descriptors(dw, dwc);
587 	}
588 
589 	/* Re-enable interrupts */
590 	channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
591 	channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
592 }
593 
594 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
595 {
596 	struct dw_dma *dw = dev_id;
597 	u32 status;
598 
599 	/* Check if we have any interrupt from the DMAC which is not in use */
600 	if (!dw->in_use)
601 		return IRQ_NONE;
602 
603 	status = dma_readl(dw, STATUS_INT);
604 	dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);
605 
606 	/* Check if we have any interrupt from the DMAC */
607 	if (!status)
608 		return IRQ_NONE;
609 
610 	/*
611 	 * Just disable the interrupts. We'll turn them back on in the
612 	 * softirq handler.
613 	 */
614 	channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
615 	channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
616 	channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
617 
618 	status = dma_readl(dw, STATUS_INT);
619 	if (status) {
620 		dev_err(dw->dma.dev,
621 			"BUG: Unexpected interrupts pending: 0x%x\n",
622 			status);
623 
624 		/* Try to recover */
625 		channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
626 		channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
627 		channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
628 		channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
629 		channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
630 	}
631 
632 	tasklet_schedule(&dw->tasklet);
633 
634 	return IRQ_HANDLED;
635 }
636 
637 /*----------------------------------------------------------------------*/
638 
639 static struct dma_async_tx_descriptor *
640 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
641 		size_t len, unsigned long flags)
642 {
643 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
644 	struct dw_dma		*dw = to_dw_dma(chan->device);
645 	struct dw_desc		*desc;
646 	struct dw_desc		*first;
647 	struct dw_desc		*prev;
648 	size_t			xfer_count;
649 	size_t			offset;
650 	u8			m_master = dwc->dws.m_master;
651 	unsigned int		src_width;
652 	unsigned int		dst_width;
653 	unsigned int		data_width = dw->pdata->data_width[m_master];
654 	u32			ctllo;
655 	u8			lms = DWC_LLP_LMS(m_master);
656 
657 	dev_vdbg(chan2dev(chan),
658 			"%s: d%pad s%pad l0x%zx f0x%lx\n", __func__,
659 			&dest, &src, len, flags);
660 
661 	if (unlikely(!len)) {
662 		dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
663 		return NULL;
664 	}
665 
666 	dwc->direction = DMA_MEM_TO_MEM;
667 
668 	src_width = dst_width = __ffs(data_width | src | dest | len);
669 
670 	ctllo = DWC_DEFAULT_CTLLO(chan)
671 			| DWC_CTLL_DST_WIDTH(dst_width)
672 			| DWC_CTLL_SRC_WIDTH(src_width)
673 			| DWC_CTLL_DST_INC
674 			| DWC_CTLL_SRC_INC
675 			| DWC_CTLL_FC_M2M;
676 	prev = first = NULL;
677 
678 	for (offset = 0; offset < len; offset += xfer_count) {
679 		desc = dwc_desc_get(dwc);
680 		if (!desc)
681 			goto err_desc_get;
682 
683 		lli_write(desc, sar, src + offset);
684 		lli_write(desc, dar, dest + offset);
685 		lli_write(desc, ctllo, ctllo);
686 		lli_write(desc, ctlhi, bytes2block(dwc, len - offset, src_width, &xfer_count));
687 		desc->len = xfer_count;
688 
689 		if (!first) {
690 			first = desc;
691 		} else {
692 			lli_write(prev, llp, desc->txd.phys | lms);
693 			list_add_tail(&desc->desc_node, &first->tx_list);
694 		}
695 		prev = desc;
696 	}
697 
698 	if (flags & DMA_PREP_INTERRUPT)
699 		/* Trigger interrupt after last block */
700 		lli_set(prev, ctllo, DWC_CTLL_INT_EN);
701 
702 	prev->lli.llp = 0;
703 	lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
704 	first->txd.flags = flags;
705 	first->total_len = len;
706 
707 	return &first->txd;
708 
709 err_desc_get:
710 	dwc_desc_put(dwc, first);
711 	return NULL;
712 }
713 
714 static struct dma_async_tx_descriptor *
715 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
716 		unsigned int sg_len, enum dma_transfer_direction direction,
717 		unsigned long flags, void *context)
718 {
719 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
720 	struct dw_dma		*dw = to_dw_dma(chan->device);
721 	struct dma_slave_config	*sconfig = &dwc->dma_sconfig;
722 	struct dw_desc		*prev;
723 	struct dw_desc		*first;
724 	u32			ctllo;
725 	u8			m_master = dwc->dws.m_master;
726 	u8			lms = DWC_LLP_LMS(m_master);
727 	dma_addr_t		reg;
728 	unsigned int		reg_width;
729 	unsigned int		mem_width;
730 	unsigned int		data_width = dw->pdata->data_width[m_master];
731 	unsigned int		i;
732 	struct scatterlist	*sg;
733 	size_t			total_len = 0;
734 
735 	dev_vdbg(chan2dev(chan), "%s\n", __func__);
736 
737 	if (unlikely(!is_slave_direction(direction) || !sg_len))
738 		return NULL;
739 
740 	dwc->direction = direction;
741 
742 	prev = first = NULL;
743 
744 	switch (direction) {
745 	case DMA_MEM_TO_DEV:
746 		reg_width = __ffs(sconfig->dst_addr_width);
747 		reg = sconfig->dst_addr;
748 		ctllo = (DWC_DEFAULT_CTLLO(chan)
749 				| DWC_CTLL_DST_WIDTH(reg_width)
750 				| DWC_CTLL_DST_FIX
751 				| DWC_CTLL_SRC_INC);
752 
753 		ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
754 			DWC_CTLL_FC(DW_DMA_FC_D_M2P);
755 
756 		for_each_sg(sgl, sg, sg_len, i) {
757 			struct dw_desc	*desc;
758 			u32		len, mem;
759 			size_t		dlen;
760 
761 			mem = sg_dma_address(sg);
762 			len = sg_dma_len(sg);
763 
764 			mem_width = __ffs(data_width | mem | len);
765 
766 slave_sg_todev_fill_desc:
767 			desc = dwc_desc_get(dwc);
768 			if (!desc)
769 				goto err_desc_get;
770 
771 			lli_write(desc, sar, mem);
772 			lli_write(desc, dar, reg);
773 			lli_write(desc, ctlhi, bytes2block(dwc, len, mem_width, &dlen));
774 			lli_write(desc, ctllo, ctllo | DWC_CTLL_SRC_WIDTH(mem_width));
775 			desc->len = dlen;
776 
777 			if (!first) {
778 				first = desc;
779 			} else {
780 				lli_write(prev, llp, desc->txd.phys | lms);
781 				list_add_tail(&desc->desc_node, &first->tx_list);
782 			}
783 			prev = desc;
784 
785 			mem += dlen;
786 			len -= dlen;
787 			total_len += dlen;
788 
789 			if (len)
790 				goto slave_sg_todev_fill_desc;
791 		}
792 		break;
793 	case DMA_DEV_TO_MEM:
794 		reg_width = __ffs(sconfig->src_addr_width);
795 		reg = sconfig->src_addr;
796 		ctllo = (DWC_DEFAULT_CTLLO(chan)
797 				| DWC_CTLL_SRC_WIDTH(reg_width)
798 				| DWC_CTLL_DST_INC
799 				| DWC_CTLL_SRC_FIX);
800 
801 		ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
802 			DWC_CTLL_FC(DW_DMA_FC_D_P2M);
803 
804 		for_each_sg(sgl, sg, sg_len, i) {
805 			struct dw_desc	*desc;
806 			u32		len, mem;
807 			size_t		dlen;
808 
809 			mem = sg_dma_address(sg);
810 			len = sg_dma_len(sg);
811 
812 slave_sg_fromdev_fill_desc:
813 			desc = dwc_desc_get(dwc);
814 			if (!desc)
815 				goto err_desc_get;
816 
817 			lli_write(desc, sar, reg);
818 			lli_write(desc, dar, mem);
819 			lli_write(desc, ctlhi, bytes2block(dwc, len, reg_width, &dlen));
820 			mem_width = __ffs(data_width | mem | dlen);
821 			lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width));
822 			desc->len = dlen;
823 
824 			if (!first) {
825 				first = desc;
826 			} else {
827 				lli_write(prev, llp, desc->txd.phys | lms);
828 				list_add_tail(&desc->desc_node, &first->tx_list);
829 			}
830 			prev = desc;
831 
832 			mem += dlen;
833 			len -= dlen;
834 			total_len += dlen;
835 
836 			if (len)
837 				goto slave_sg_fromdev_fill_desc;
838 		}
839 		break;
840 	default:
841 		return NULL;
842 	}
843 
844 	if (flags & DMA_PREP_INTERRUPT)
845 		/* Trigger interrupt after last block */
846 		lli_set(prev, ctllo, DWC_CTLL_INT_EN);
847 
848 	prev->lli.llp = 0;
849 	lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
850 	first->total_len = total_len;
851 
852 	return &first->txd;
853 
854 err_desc_get:
855 	dev_err(chan2dev(chan),
856 		"not enough descriptors available. Direction %d\n", direction);
857 	dwc_desc_put(dwc, first);
858 	return NULL;
859 }
860 
861 bool dw_dma_filter(struct dma_chan *chan, void *param)
862 {
863 	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
864 	struct dw_dma_slave *dws = param;
865 
866 	if (dws->dma_dev != chan->device->dev)
867 		return false;
868 
869 	/* We have to copy data since dws can be temporary storage */
870 	memcpy(&dwc->dws, dws, sizeof(struct dw_dma_slave));
871 
872 	return true;
873 }
874 EXPORT_SYMBOL_GPL(dw_dma_filter);
875 
876 static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
877 {
878 	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
879 	struct dma_slave_config *sc = &dwc->dma_sconfig;
880 	struct dw_dma *dw = to_dw_dma(chan->device);
881 	/*
882 	 * Fix sconfig's burst size according to dw_dmac. We need to convert
883 	 * them as:
884 	 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
885 	 *
886 	 * NOTE: burst size 2 is not supported by DesignWare controller.
887 	 *       iDMA 32-bit supports it.
888 	 */
889 	u32 s = dw->pdata->is_idma32 ? 1 : 2;
890 
891 	memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
892 
893 	sc->src_maxburst = sc->src_maxburst > 1 ? fls(sc->src_maxburst) - s : 0;
894 	sc->dst_maxburst = sc->dst_maxburst > 1 ? fls(sc->dst_maxburst) - s : 0;
895 
896 	return 0;
897 }
898 
899 static void dwc_chan_pause(struct dw_dma_chan *dwc, bool drain)
900 {
901 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
902 	unsigned int		count = 20;	/* timeout iterations */
903 	u32			cfglo;
904 
905 	cfglo = channel_readl(dwc, CFG_LO);
906 	if (dw->pdata->is_idma32) {
907 		if (drain)
908 			cfglo |= IDMA32C_CFGL_CH_DRAIN;
909 		else
910 			cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
911 	}
912 	channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
913 	while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
914 		udelay(2);
915 
916 	set_bit(DW_DMA_IS_PAUSED, &dwc->flags);
917 }
918 
919 static int dwc_pause(struct dma_chan *chan)
920 {
921 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
922 	unsigned long		flags;
923 
924 	spin_lock_irqsave(&dwc->lock, flags);
925 	dwc_chan_pause(dwc, false);
926 	spin_unlock_irqrestore(&dwc->lock, flags);
927 
928 	return 0;
929 }
930 
931 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
932 {
933 	u32 cfglo = channel_readl(dwc, CFG_LO);
934 
935 	channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
936 
937 	clear_bit(DW_DMA_IS_PAUSED, &dwc->flags);
938 }
939 
940 static int dwc_resume(struct dma_chan *chan)
941 {
942 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
943 	unsigned long		flags;
944 
945 	spin_lock_irqsave(&dwc->lock, flags);
946 
947 	if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags))
948 		dwc_chan_resume(dwc);
949 
950 	spin_unlock_irqrestore(&dwc->lock, flags);
951 
952 	return 0;
953 }
954 
955 static int dwc_terminate_all(struct dma_chan *chan)
956 {
957 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
958 	struct dw_dma		*dw = to_dw_dma(chan->device);
959 	struct dw_desc		*desc, *_desc;
960 	unsigned long		flags;
961 	LIST_HEAD(list);
962 
963 	spin_lock_irqsave(&dwc->lock, flags);
964 
965 	clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
966 
967 	dwc_chan_pause(dwc, true);
968 
969 	dwc_chan_disable(dw, dwc);
970 
971 	dwc_chan_resume(dwc);
972 
973 	/* active_list entries will end up before queued entries */
974 	list_splice_init(&dwc->queue, &list);
975 	list_splice_init(&dwc->active_list, &list);
976 
977 	spin_unlock_irqrestore(&dwc->lock, flags);
978 
979 	/* Flush all pending and queued descriptors */
980 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
981 		dwc_descriptor_complete(dwc, desc, false);
982 
983 	return 0;
984 }
985 
986 static struct dw_desc *dwc_find_desc(struct dw_dma_chan *dwc, dma_cookie_t c)
987 {
988 	struct dw_desc *desc;
989 
990 	list_for_each_entry(desc, &dwc->active_list, desc_node)
991 		if (desc->txd.cookie == c)
992 			return desc;
993 
994 	return NULL;
995 }
996 
997 static u32 dwc_get_residue(struct dw_dma_chan *dwc, dma_cookie_t cookie)
998 {
999 	struct dw_desc *desc;
1000 	unsigned long flags;
1001 	u32 residue;
1002 
1003 	spin_lock_irqsave(&dwc->lock, flags);
1004 
1005 	desc = dwc_find_desc(dwc, cookie);
1006 	if (desc) {
1007 		if (desc == dwc_first_active(dwc)) {
1008 			residue = desc->residue;
1009 			if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1010 				residue -= dwc_get_sent(dwc);
1011 		} else {
1012 			residue = desc->total_len;
1013 		}
1014 	} else {
1015 		residue = 0;
1016 	}
1017 
1018 	spin_unlock_irqrestore(&dwc->lock, flags);
1019 	return residue;
1020 }
1021 
1022 static enum dma_status
1023 dwc_tx_status(struct dma_chan *chan,
1024 	      dma_cookie_t cookie,
1025 	      struct dma_tx_state *txstate)
1026 {
1027 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
1028 	enum dma_status		ret;
1029 
1030 	ret = dma_cookie_status(chan, cookie, txstate);
1031 	if (ret == DMA_COMPLETE)
1032 		return ret;
1033 
1034 	dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1035 
1036 	ret = dma_cookie_status(chan, cookie, txstate);
1037 	if (ret == DMA_COMPLETE)
1038 		return ret;
1039 
1040 	dma_set_residue(txstate, dwc_get_residue(dwc, cookie));
1041 
1042 	if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags) && ret == DMA_IN_PROGRESS)
1043 		return DMA_PAUSED;
1044 
1045 	return ret;
1046 }
1047 
1048 static void dwc_issue_pending(struct dma_chan *chan)
1049 {
1050 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
1051 	unsigned long		flags;
1052 
1053 	spin_lock_irqsave(&dwc->lock, flags);
1054 	if (list_empty(&dwc->active_list))
1055 		dwc_dostart_first_queued(dwc);
1056 	spin_unlock_irqrestore(&dwc->lock, flags);
1057 }
1058 
1059 /*----------------------------------------------------------------------*/
1060 
1061 /*
1062  * Program FIFO size of channels.
1063  *
1064  * By default full FIFO (512 bytes) is assigned to channel 0. Here we
1065  * slice FIFO on equal parts between channels.
1066  */
1067 static void idma32_fifo_partition(struct dw_dma *dw)
1068 {
1069 	u64 value = IDMA32C_FP_PSIZE_CH0(64) | IDMA32C_FP_PSIZE_CH1(64) |
1070 		    IDMA32C_FP_UPDATE;
1071 	u64 fifo_partition = 0;
1072 
1073 	if (!dw->pdata->is_idma32)
1074 		return;
1075 
1076 	/* Fill FIFO_PARTITION low bits (Channels 0..1, 4..5) */
1077 	fifo_partition |= value << 0;
1078 
1079 	/* Fill FIFO_PARTITION high bits (Channels 2..3, 6..7) */
1080 	fifo_partition |= value << 32;
1081 
1082 	/* Program FIFO Partition registers - 64 bytes per channel */
1083 	idma32_writeq(dw, FIFO_PARTITION1, fifo_partition);
1084 	idma32_writeq(dw, FIFO_PARTITION0, fifo_partition);
1085 }
1086 
1087 static void dw_dma_off(struct dw_dma *dw)
1088 {
1089 	unsigned int i;
1090 
1091 	dma_writel(dw, CFG, 0);
1092 
1093 	channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1094 	channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1095 	channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1096 	channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1097 	channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1098 
1099 	while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1100 		cpu_relax();
1101 
1102 	for (i = 0; i < dw->dma.chancnt; i++)
1103 		clear_bit(DW_DMA_IS_INITIALIZED, &dw->chan[i].flags);
1104 }
1105 
1106 static void dw_dma_on(struct dw_dma *dw)
1107 {
1108 	dma_writel(dw, CFG, DW_CFG_DMA_EN);
1109 }
1110 
1111 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1112 {
1113 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
1114 	struct dw_dma		*dw = to_dw_dma(chan->device);
1115 
1116 	dev_vdbg(chan2dev(chan), "%s\n", __func__);
1117 
1118 	/* ASSERT:  channel is idle */
1119 	if (dma_readl(dw, CH_EN) & dwc->mask) {
1120 		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1121 		return -EIO;
1122 	}
1123 
1124 	dma_cookie_init(chan);
1125 
1126 	/*
1127 	 * NOTE: some controllers may have additional features that we
1128 	 * need to initialize here, like "scatter-gather" (which
1129 	 * doesn't mean what you think it means), and status writeback.
1130 	 */
1131 
1132 	/*
1133 	 * We need controller-specific data to set up slave transfers.
1134 	 */
1135 	if (chan->private && !dw_dma_filter(chan, chan->private)) {
1136 		dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
1137 		return -EINVAL;
1138 	}
1139 
1140 	/* Enable controller here if needed */
1141 	if (!dw->in_use)
1142 		dw_dma_on(dw);
1143 	dw->in_use |= dwc->mask;
1144 
1145 	return 0;
1146 }
1147 
1148 static void dwc_free_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 	unsigned long		flags;
1153 	LIST_HEAD(list);
1154 
1155 	dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1156 			dwc->descs_allocated);
1157 
1158 	/* ASSERT:  channel is idle */
1159 	BUG_ON(!list_empty(&dwc->active_list));
1160 	BUG_ON(!list_empty(&dwc->queue));
1161 	BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1162 
1163 	spin_lock_irqsave(&dwc->lock, flags);
1164 
1165 	/* Clear custom channel configuration */
1166 	memset(&dwc->dws, 0, sizeof(struct dw_dma_slave));
1167 
1168 	clear_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
1169 
1170 	/* Disable interrupts */
1171 	channel_clear_bit(dw, MASK.XFER, dwc->mask);
1172 	channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1173 	channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1174 
1175 	spin_unlock_irqrestore(&dwc->lock, flags);
1176 
1177 	/* Disable controller in case it was a last user */
1178 	dw->in_use &= ~dwc->mask;
1179 	if (!dw->in_use)
1180 		dw_dma_off(dw);
1181 
1182 	dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1183 }
1184 
1185 int dw_dma_probe(struct dw_dma_chip *chip)
1186 {
1187 	struct dw_dma_platform_data *pdata;
1188 	struct dw_dma		*dw;
1189 	bool			autocfg = false;
1190 	unsigned int		dw_params;
1191 	unsigned int		i;
1192 	int			err;
1193 
1194 	dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
1195 	if (!dw)
1196 		return -ENOMEM;
1197 
1198 	dw->pdata = devm_kzalloc(chip->dev, sizeof(*dw->pdata), GFP_KERNEL);
1199 	if (!dw->pdata)
1200 		return -ENOMEM;
1201 
1202 	dw->regs = chip->regs;
1203 	chip->dw = dw;
1204 
1205 	pm_runtime_get_sync(chip->dev);
1206 
1207 	if (!chip->pdata) {
1208 		dw_params = dma_readl(dw, DW_PARAMS);
1209 		dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1210 
1211 		autocfg = dw_params >> DW_PARAMS_EN & 1;
1212 		if (!autocfg) {
1213 			err = -EINVAL;
1214 			goto err_pdata;
1215 		}
1216 
1217 		/* Reassign the platform data pointer */
1218 		pdata = dw->pdata;
1219 
1220 		/* Get hardware configuration parameters */
1221 		pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1;
1222 		pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1223 		for (i = 0; i < pdata->nr_masters; i++) {
1224 			pdata->data_width[i] =
1225 				4 << (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3);
1226 		}
1227 		pdata->block_size = dma_readl(dw, MAX_BLK_SIZE);
1228 
1229 		/* Fill platform data with the default values */
1230 		pdata->is_private = true;
1231 		pdata->is_memcpy = true;
1232 		pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1233 		pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1234 	} else if (chip->pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
1235 		err = -EINVAL;
1236 		goto err_pdata;
1237 	} else {
1238 		memcpy(dw->pdata, chip->pdata, sizeof(*dw->pdata));
1239 
1240 		/* Reassign the platform data pointer */
1241 		pdata = dw->pdata;
1242 	}
1243 
1244 	dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
1245 				GFP_KERNEL);
1246 	if (!dw->chan) {
1247 		err = -ENOMEM;
1248 		goto err_pdata;
1249 	}
1250 
1251 	/* Calculate all channel mask before DMA setup */
1252 	dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1253 
1254 	/* Force dma off, just in case */
1255 	dw_dma_off(dw);
1256 
1257 	idma32_fifo_partition(dw);
1258 
1259 	/* Device and instance ID for IRQ and DMA pool */
1260 	if (pdata->is_idma32)
1261 		snprintf(dw->name, sizeof(dw->name), "idma32:dmac%d", chip->id);
1262 	else
1263 		snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", chip->id);
1264 
1265 	/* Create a pool of consistent memory blocks for hardware descriptors */
1266 	dw->desc_pool = dmam_pool_create(dw->name, chip->dev,
1267 					 sizeof(struct dw_desc), 4, 0);
1268 	if (!dw->desc_pool) {
1269 		dev_err(chip->dev, "No memory for descriptors dma pool\n");
1270 		err = -ENOMEM;
1271 		goto err_pdata;
1272 	}
1273 
1274 	tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1275 
1276 	err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
1277 			  dw->name, dw);
1278 	if (err)
1279 		goto err_pdata;
1280 
1281 	INIT_LIST_HEAD(&dw->dma.channels);
1282 	for (i = 0; i < pdata->nr_channels; i++) {
1283 		struct dw_dma_chan	*dwc = &dw->chan[i];
1284 
1285 		dwc->chan.device = &dw->dma;
1286 		dma_cookie_init(&dwc->chan);
1287 		if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1288 			list_add_tail(&dwc->chan.device_node,
1289 					&dw->dma.channels);
1290 		else
1291 			list_add(&dwc->chan.device_node, &dw->dma.channels);
1292 
1293 		/* 7 is highest priority & 0 is lowest. */
1294 		if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1295 			dwc->priority = pdata->nr_channels - i - 1;
1296 		else
1297 			dwc->priority = i;
1298 
1299 		dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1300 		spin_lock_init(&dwc->lock);
1301 		dwc->mask = 1 << i;
1302 
1303 		INIT_LIST_HEAD(&dwc->active_list);
1304 		INIT_LIST_HEAD(&dwc->queue);
1305 
1306 		channel_clear_bit(dw, CH_EN, dwc->mask);
1307 
1308 		dwc->direction = DMA_TRANS_NONE;
1309 
1310 		/* Hardware configuration */
1311 		if (autocfg) {
1312 			unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
1313 			void __iomem *addr = &__dw_regs(dw)->DWC_PARAMS[r];
1314 			unsigned int dwc_params = readl(addr);
1315 
1316 			dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1317 					   dwc_params);
1318 
1319 			/*
1320 			 * Decode maximum block size for given channel. The
1321 			 * stored 4 bit value represents blocks from 0x00 for 3
1322 			 * up to 0x0a for 4095.
1323 			 */
1324 			dwc->block_size =
1325 				(4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1;
1326 			dwc->nollp =
1327 				(dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1328 		} else {
1329 			dwc->block_size = pdata->block_size;
1330 			dwc->nollp = !pdata->multi_block[i];
1331 		}
1332 	}
1333 
1334 	/* Clear all interrupts on all channels. */
1335 	dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1336 	dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1337 	dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1338 	dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1339 	dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1340 
1341 	/* Set capabilities */
1342 	dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1343 	if (pdata->is_private)
1344 		dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1345 	if (pdata->is_memcpy)
1346 		dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1347 
1348 	dw->dma.dev = chip->dev;
1349 	dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1350 	dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1351 
1352 	dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1353 	dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1354 
1355 	dw->dma.device_config = dwc_config;
1356 	dw->dma.device_pause = dwc_pause;
1357 	dw->dma.device_resume = dwc_resume;
1358 	dw->dma.device_terminate_all = dwc_terminate_all;
1359 
1360 	dw->dma.device_tx_status = dwc_tx_status;
1361 	dw->dma.device_issue_pending = dwc_issue_pending;
1362 
1363 	/* DMA capabilities */
1364 	dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
1365 	dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
1366 	dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1367 			     BIT(DMA_MEM_TO_MEM);
1368 	dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1369 
1370 	err = dma_async_device_register(&dw->dma);
1371 	if (err)
1372 		goto err_dma_register;
1373 
1374 	dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
1375 		 pdata->nr_channels);
1376 
1377 	pm_runtime_put_sync_suspend(chip->dev);
1378 
1379 	return 0;
1380 
1381 err_dma_register:
1382 	free_irq(chip->irq, dw);
1383 err_pdata:
1384 	pm_runtime_put_sync_suspend(chip->dev);
1385 	return err;
1386 }
1387 EXPORT_SYMBOL_GPL(dw_dma_probe);
1388 
1389 int dw_dma_remove(struct dw_dma_chip *chip)
1390 {
1391 	struct dw_dma		*dw = chip->dw;
1392 	struct dw_dma_chan	*dwc, *_dwc;
1393 
1394 	pm_runtime_get_sync(chip->dev);
1395 
1396 	dw_dma_off(dw);
1397 	dma_async_device_unregister(&dw->dma);
1398 
1399 	free_irq(chip->irq, dw);
1400 	tasklet_kill(&dw->tasklet);
1401 
1402 	list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1403 			chan.device_node) {
1404 		list_del(&dwc->chan.device_node);
1405 		channel_clear_bit(dw, CH_EN, dwc->mask);
1406 	}
1407 
1408 	pm_runtime_put_sync_suspend(chip->dev);
1409 	return 0;
1410 }
1411 EXPORT_SYMBOL_GPL(dw_dma_remove);
1412 
1413 int dw_dma_disable(struct dw_dma_chip *chip)
1414 {
1415 	struct dw_dma *dw = chip->dw;
1416 
1417 	dw_dma_off(dw);
1418 	return 0;
1419 }
1420 EXPORT_SYMBOL_GPL(dw_dma_disable);
1421 
1422 int dw_dma_enable(struct dw_dma_chip *chip)
1423 {
1424 	struct dw_dma *dw = chip->dw;
1425 
1426 	idma32_fifo_partition(dw);
1427 
1428 	dw_dma_on(dw);
1429 	return 0;
1430 }
1431 EXPORT_SYMBOL_GPL(dw_dma_enable);
1432 
1433 MODULE_LICENSE("GPL v2");
1434 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver");
1435 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1436 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
1437