xref: /openbmc/linux/drivers/dma/dw/core.c (revision d4295e12)
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 	u32 cfghi = DWC_CFGH_FIFO_MODE;
164 	u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
165 	bool hs_polarity = dwc->dws.hs_polarity;
166 
167 	cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
168 	cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
169 
170 	/* Set polarity of handshake interface */
171 	cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
172 
173 	channel_writel(dwc, CFG_LO, cfglo);
174 	channel_writel(dwc, CFG_HI, cfghi);
175 }
176 
177 static void dwc_initialize(struct dw_dma_chan *dwc)
178 {
179 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
180 
181 	if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
182 		return;
183 
184 	if (dw->pdata->is_idma32)
185 		dwc_initialize_chan_idma32(dwc);
186 	else
187 		dwc_initialize_chan_dw(dwc);
188 
189 	/* Enable interrupts */
190 	channel_set_bit(dw, MASK.XFER, dwc->mask);
191 	channel_set_bit(dw, MASK.ERROR, dwc->mask);
192 
193 	set_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
194 }
195 
196 /*----------------------------------------------------------------------*/
197 
198 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
199 {
200 	dev_err(chan2dev(&dwc->chan),
201 		"  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
202 		channel_readl(dwc, SAR),
203 		channel_readl(dwc, DAR),
204 		channel_readl(dwc, LLP),
205 		channel_readl(dwc, CTL_HI),
206 		channel_readl(dwc, CTL_LO));
207 }
208 
209 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
210 {
211 	channel_clear_bit(dw, CH_EN, dwc->mask);
212 	while (dma_readl(dw, CH_EN) & dwc->mask)
213 		cpu_relax();
214 }
215 
216 static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,
217 			  unsigned int width, size_t *len)
218 {
219 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
220 	u32 block;
221 
222 	/* Always in bytes for iDMA 32-bit */
223 	if (dw->pdata->is_idma32)
224 		width = 0;
225 
226 	if ((bytes >> width) > dwc->block_size) {
227 		block = dwc->block_size;
228 		*len = block << width;
229 	} else {
230 		block = bytes >> width;
231 		*len = bytes;
232 	}
233 
234 	return block;
235 }
236 
237 static size_t block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
238 {
239 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
240 
241 	if (dw->pdata->is_idma32)
242 		return IDMA32C_CTLH_BLOCK_TS(block);
243 
244 	return DWC_CTLH_BLOCK_TS(block) << width;
245 }
246 
247 /*----------------------------------------------------------------------*/
248 
249 /* Perform single block transfer */
250 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
251 				       struct dw_desc *desc)
252 {
253 	struct dw_dma	*dw = to_dw_dma(dwc->chan.device);
254 	u32		ctllo;
255 
256 	/*
257 	 * Software emulation of LLP mode relies on interrupts to continue
258 	 * multi block transfer.
259 	 */
260 	ctllo = lli_read(desc, ctllo) | DWC_CTLL_INT_EN;
261 
262 	channel_writel(dwc, SAR, lli_read(desc, sar));
263 	channel_writel(dwc, DAR, lli_read(desc, dar));
264 	channel_writel(dwc, CTL_LO, ctllo);
265 	channel_writel(dwc, CTL_HI, lli_read(desc, ctlhi));
266 	channel_set_bit(dw, CH_EN, dwc->mask);
267 
268 	/* Move pointer to next descriptor */
269 	dwc->tx_node_active = dwc->tx_node_active->next;
270 }
271 
272 /* Called with dwc->lock held and bh disabled */
273 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
274 {
275 	struct dw_dma	*dw = to_dw_dma(dwc->chan.device);
276 	u8		lms = DWC_LLP_LMS(dwc->dws.m_master);
277 	unsigned long	was_soft_llp;
278 
279 	/* ASSERT:  channel is idle */
280 	if (dma_readl(dw, CH_EN) & dwc->mask) {
281 		dev_err(chan2dev(&dwc->chan),
282 			"%s: BUG: Attempted to start non-idle channel\n",
283 			__func__);
284 		dwc_dump_chan_regs(dwc);
285 
286 		/* The tasklet will hopefully advance the queue... */
287 		return;
288 	}
289 
290 	if (dwc->nollp) {
291 		was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
292 						&dwc->flags);
293 		if (was_soft_llp) {
294 			dev_err(chan2dev(&dwc->chan),
295 				"BUG: Attempted to start new LLP transfer inside ongoing one\n");
296 			return;
297 		}
298 
299 		dwc_initialize(dwc);
300 
301 		first->residue = first->total_len;
302 		dwc->tx_node_active = &first->tx_list;
303 
304 		/* Submit first block */
305 		dwc_do_single_block(dwc, first);
306 
307 		return;
308 	}
309 
310 	dwc_initialize(dwc);
311 
312 	channel_writel(dwc, LLP, first->txd.phys | lms);
313 	channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
314 	channel_writel(dwc, CTL_HI, 0);
315 	channel_set_bit(dw, CH_EN, dwc->mask);
316 }
317 
318 static void dwc_dostart_first_queued(struct dw_dma_chan *dwc)
319 {
320 	struct dw_desc *desc;
321 
322 	if (list_empty(&dwc->queue))
323 		return;
324 
325 	list_move(dwc->queue.next, &dwc->active_list);
326 	desc = dwc_first_active(dwc);
327 	dev_vdbg(chan2dev(&dwc->chan), "%s: started %u\n", __func__, desc->txd.cookie);
328 	dwc_dostart(dwc, desc);
329 }
330 
331 /*----------------------------------------------------------------------*/
332 
333 static void
334 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
335 		bool callback_required)
336 {
337 	struct dma_async_tx_descriptor	*txd = &desc->txd;
338 	struct dw_desc			*child;
339 	unsigned long			flags;
340 	struct dmaengine_desc_callback	cb;
341 
342 	dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
343 
344 	spin_lock_irqsave(&dwc->lock, flags);
345 	dma_cookie_complete(txd);
346 	if (callback_required)
347 		dmaengine_desc_get_callback(txd, &cb);
348 	else
349 		memset(&cb, 0, sizeof(cb));
350 
351 	/* async_tx_ack */
352 	list_for_each_entry(child, &desc->tx_list, desc_node)
353 		async_tx_ack(&child->txd);
354 	async_tx_ack(&desc->txd);
355 	dwc_desc_put(dwc, desc);
356 	spin_unlock_irqrestore(&dwc->lock, flags);
357 
358 	dmaengine_desc_callback_invoke(&cb, NULL);
359 }
360 
361 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
362 {
363 	struct dw_desc *desc, *_desc;
364 	LIST_HEAD(list);
365 	unsigned long flags;
366 
367 	spin_lock_irqsave(&dwc->lock, flags);
368 	if (dma_readl(dw, CH_EN) & dwc->mask) {
369 		dev_err(chan2dev(&dwc->chan),
370 			"BUG: XFER bit set, but channel not idle!\n");
371 
372 		/* Try to continue after resetting the channel... */
373 		dwc_chan_disable(dw, dwc);
374 	}
375 
376 	/*
377 	 * Submit queued descriptors ASAP, i.e. before we go through
378 	 * the completed ones.
379 	 */
380 	list_splice_init(&dwc->active_list, &list);
381 	dwc_dostart_first_queued(dwc);
382 
383 	spin_unlock_irqrestore(&dwc->lock, flags);
384 
385 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
386 		dwc_descriptor_complete(dwc, desc, true);
387 }
388 
389 /* Returns how many bytes were already received from source */
390 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
391 {
392 	u32 ctlhi = channel_readl(dwc, CTL_HI);
393 	u32 ctllo = channel_readl(dwc, CTL_LO);
394 
395 	return block2bytes(dwc, ctlhi, ctllo >> 4 & 7);
396 }
397 
398 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
399 {
400 	dma_addr_t llp;
401 	struct dw_desc *desc, *_desc;
402 	struct dw_desc *child;
403 	u32 status_xfer;
404 	unsigned long flags;
405 
406 	spin_lock_irqsave(&dwc->lock, flags);
407 	llp = channel_readl(dwc, LLP);
408 	status_xfer = dma_readl(dw, RAW.XFER);
409 
410 	if (status_xfer & dwc->mask) {
411 		/* Everything we've submitted is done */
412 		dma_writel(dw, CLEAR.XFER, dwc->mask);
413 
414 		if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
415 			struct list_head *head, *active = dwc->tx_node_active;
416 
417 			/*
418 			 * We are inside first active descriptor.
419 			 * Otherwise something is really wrong.
420 			 */
421 			desc = dwc_first_active(dwc);
422 
423 			head = &desc->tx_list;
424 			if (active != head) {
425 				/* Update residue to reflect last sent descriptor */
426 				if (active == head->next)
427 					desc->residue -= desc->len;
428 				else
429 					desc->residue -= to_dw_desc(active->prev)->len;
430 
431 				child = to_dw_desc(active);
432 
433 				/* Submit next block */
434 				dwc_do_single_block(dwc, child);
435 
436 				spin_unlock_irqrestore(&dwc->lock, flags);
437 				return;
438 			}
439 
440 			/* We are done here */
441 			clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
442 		}
443 
444 		spin_unlock_irqrestore(&dwc->lock, flags);
445 
446 		dwc_complete_all(dw, dwc);
447 		return;
448 	}
449 
450 	if (list_empty(&dwc->active_list)) {
451 		spin_unlock_irqrestore(&dwc->lock, flags);
452 		return;
453 	}
454 
455 	if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
456 		dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
457 		spin_unlock_irqrestore(&dwc->lock, flags);
458 		return;
459 	}
460 
461 	dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp);
462 
463 	list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
464 		/* Initial residue value */
465 		desc->residue = desc->total_len;
466 
467 		/* Check first descriptors addr */
468 		if (desc->txd.phys == DWC_LLP_LOC(llp)) {
469 			spin_unlock_irqrestore(&dwc->lock, flags);
470 			return;
471 		}
472 
473 		/* Check first descriptors llp */
474 		if (lli_read(desc, llp) == llp) {
475 			/* This one is currently in progress */
476 			desc->residue -= dwc_get_sent(dwc);
477 			spin_unlock_irqrestore(&dwc->lock, flags);
478 			return;
479 		}
480 
481 		desc->residue -= desc->len;
482 		list_for_each_entry(child, &desc->tx_list, desc_node) {
483 			if (lli_read(child, llp) == llp) {
484 				/* Currently in progress */
485 				desc->residue -= dwc_get_sent(dwc);
486 				spin_unlock_irqrestore(&dwc->lock, flags);
487 				return;
488 			}
489 			desc->residue -= child->len;
490 		}
491 
492 		/*
493 		 * No descriptors so far seem to be in progress, i.e.
494 		 * this one must be done.
495 		 */
496 		spin_unlock_irqrestore(&dwc->lock, flags);
497 		dwc_descriptor_complete(dwc, desc, true);
498 		spin_lock_irqsave(&dwc->lock, flags);
499 	}
500 
501 	dev_err(chan2dev(&dwc->chan),
502 		"BUG: All descriptors done, but channel not idle!\n");
503 
504 	/* Try to continue after resetting the channel... */
505 	dwc_chan_disable(dw, dwc);
506 
507 	dwc_dostart_first_queued(dwc);
508 	spin_unlock_irqrestore(&dwc->lock, flags);
509 }
510 
511 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_desc *desc)
512 {
513 	dev_crit(chan2dev(&dwc->chan), "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
514 		 lli_read(desc, sar),
515 		 lli_read(desc, dar),
516 		 lli_read(desc, llp),
517 		 lli_read(desc, ctlhi),
518 		 lli_read(desc, ctllo));
519 }
520 
521 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
522 {
523 	struct dw_desc *bad_desc;
524 	struct dw_desc *child;
525 	unsigned long flags;
526 
527 	dwc_scan_descriptors(dw, dwc);
528 
529 	spin_lock_irqsave(&dwc->lock, flags);
530 
531 	/*
532 	 * The descriptor currently at the head of the active list is
533 	 * borked. Since we don't have any way to report errors, we'll
534 	 * just have to scream loudly and try to carry on.
535 	 */
536 	bad_desc = dwc_first_active(dwc);
537 	list_del_init(&bad_desc->desc_node);
538 	list_move(dwc->queue.next, dwc->active_list.prev);
539 
540 	/* Clear the error flag and try to restart the controller */
541 	dma_writel(dw, CLEAR.ERROR, dwc->mask);
542 	if (!list_empty(&dwc->active_list))
543 		dwc_dostart(dwc, dwc_first_active(dwc));
544 
545 	/*
546 	 * WARN may seem harsh, but since this only happens
547 	 * when someone submits a bad physical address in a
548 	 * descriptor, we should consider ourselves lucky that the
549 	 * controller flagged an error instead of scribbling over
550 	 * random memory locations.
551 	 */
552 	dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
553 				       "  cookie: %d\n", bad_desc->txd.cookie);
554 	dwc_dump_lli(dwc, bad_desc);
555 	list_for_each_entry(child, &bad_desc->tx_list, desc_node)
556 		dwc_dump_lli(dwc, child);
557 
558 	spin_unlock_irqrestore(&dwc->lock, flags);
559 
560 	/* Pretend the descriptor completed successfully */
561 	dwc_descriptor_complete(dwc, bad_desc, true);
562 }
563 
564 static void dw_dma_tasklet(unsigned long data)
565 {
566 	struct dw_dma *dw = (struct dw_dma *)data;
567 	struct dw_dma_chan *dwc;
568 	u32 status_xfer;
569 	u32 status_err;
570 	unsigned int i;
571 
572 	status_xfer = dma_readl(dw, RAW.XFER);
573 	status_err = dma_readl(dw, RAW.ERROR);
574 
575 	dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
576 
577 	for (i = 0; i < dw->dma.chancnt; i++) {
578 		dwc = &dw->chan[i];
579 		if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
580 			dev_vdbg(dw->dma.dev, "Cyclic xfer is not implemented\n");
581 		else if (status_err & (1 << i))
582 			dwc_handle_error(dw, dwc);
583 		else if (status_xfer & (1 << i))
584 			dwc_scan_descriptors(dw, dwc);
585 	}
586 
587 	/* Re-enable interrupts */
588 	channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
589 	channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
590 }
591 
592 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
593 {
594 	struct dw_dma *dw = dev_id;
595 	u32 status;
596 
597 	/* Check if we have any interrupt from the DMAC which is not in use */
598 	if (!dw->in_use)
599 		return IRQ_NONE;
600 
601 	status = dma_readl(dw, STATUS_INT);
602 	dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);
603 
604 	/* Check if we have any interrupt from the DMAC */
605 	if (!status)
606 		return IRQ_NONE;
607 
608 	/*
609 	 * Just disable the interrupts. We'll turn them back on in the
610 	 * softirq handler.
611 	 */
612 	channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
613 	channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
614 	channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
615 
616 	status = dma_readl(dw, STATUS_INT);
617 	if (status) {
618 		dev_err(dw->dma.dev,
619 			"BUG: Unexpected interrupts pending: 0x%x\n",
620 			status);
621 
622 		/* Try to recover */
623 		channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
624 		channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
625 		channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
626 		channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
627 		channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
628 	}
629 
630 	tasklet_schedule(&dw->tasklet);
631 
632 	return IRQ_HANDLED;
633 }
634 
635 /*----------------------------------------------------------------------*/
636 
637 static struct dma_async_tx_descriptor *
638 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
639 		size_t len, unsigned long flags)
640 {
641 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
642 	struct dw_dma		*dw = to_dw_dma(chan->device);
643 	struct dw_desc		*desc;
644 	struct dw_desc		*first;
645 	struct dw_desc		*prev;
646 	size_t			xfer_count;
647 	size_t			offset;
648 	u8			m_master = dwc->dws.m_master;
649 	unsigned int		src_width;
650 	unsigned int		dst_width;
651 	unsigned int		data_width = dw->pdata->data_width[m_master];
652 	u32			ctllo;
653 	u8			lms = DWC_LLP_LMS(m_master);
654 
655 	dev_vdbg(chan2dev(chan),
656 			"%s: d%pad s%pad l0x%zx f0x%lx\n", __func__,
657 			&dest, &src, len, flags);
658 
659 	if (unlikely(!len)) {
660 		dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
661 		return NULL;
662 	}
663 
664 	dwc->direction = DMA_MEM_TO_MEM;
665 
666 	src_width = dst_width = __ffs(data_width | src | dest | len);
667 
668 	ctllo = DWC_DEFAULT_CTLLO(chan)
669 			| DWC_CTLL_DST_WIDTH(dst_width)
670 			| DWC_CTLL_SRC_WIDTH(src_width)
671 			| DWC_CTLL_DST_INC
672 			| DWC_CTLL_SRC_INC
673 			| DWC_CTLL_FC_M2M;
674 	prev = first = NULL;
675 
676 	for (offset = 0; offset < len; offset += xfer_count) {
677 		desc = dwc_desc_get(dwc);
678 		if (!desc)
679 			goto err_desc_get;
680 
681 		lli_write(desc, sar, src + offset);
682 		lli_write(desc, dar, dest + offset);
683 		lli_write(desc, ctllo, ctllo);
684 		lli_write(desc, ctlhi, bytes2block(dwc, len - offset, src_width, &xfer_count));
685 		desc->len = xfer_count;
686 
687 		if (!first) {
688 			first = desc;
689 		} else {
690 			lli_write(prev, llp, desc->txd.phys | lms);
691 			list_add_tail(&desc->desc_node, &first->tx_list);
692 		}
693 		prev = desc;
694 	}
695 
696 	if (flags & DMA_PREP_INTERRUPT)
697 		/* Trigger interrupt after last block */
698 		lli_set(prev, ctllo, DWC_CTLL_INT_EN);
699 
700 	prev->lli.llp = 0;
701 	lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
702 	first->txd.flags = flags;
703 	first->total_len = len;
704 
705 	return &first->txd;
706 
707 err_desc_get:
708 	dwc_desc_put(dwc, first);
709 	return NULL;
710 }
711 
712 static struct dma_async_tx_descriptor *
713 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
714 		unsigned int sg_len, enum dma_transfer_direction direction,
715 		unsigned long flags, void *context)
716 {
717 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
718 	struct dw_dma		*dw = to_dw_dma(chan->device);
719 	struct dma_slave_config	*sconfig = &dwc->dma_sconfig;
720 	struct dw_desc		*prev;
721 	struct dw_desc		*first;
722 	u32			ctllo;
723 	u8			m_master = dwc->dws.m_master;
724 	u8			lms = DWC_LLP_LMS(m_master);
725 	dma_addr_t		reg;
726 	unsigned int		reg_width;
727 	unsigned int		mem_width;
728 	unsigned int		data_width = dw->pdata->data_width[m_master];
729 	unsigned int		i;
730 	struct scatterlist	*sg;
731 	size_t			total_len = 0;
732 
733 	dev_vdbg(chan2dev(chan), "%s\n", __func__);
734 
735 	if (unlikely(!is_slave_direction(direction) || !sg_len))
736 		return NULL;
737 
738 	dwc->direction = direction;
739 
740 	prev = first = NULL;
741 
742 	switch (direction) {
743 	case DMA_MEM_TO_DEV:
744 		reg_width = __ffs(sconfig->dst_addr_width);
745 		reg = sconfig->dst_addr;
746 		ctllo = (DWC_DEFAULT_CTLLO(chan)
747 				| DWC_CTLL_DST_WIDTH(reg_width)
748 				| DWC_CTLL_DST_FIX
749 				| DWC_CTLL_SRC_INC);
750 
751 		ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
752 			DWC_CTLL_FC(DW_DMA_FC_D_M2P);
753 
754 		for_each_sg(sgl, sg, sg_len, i) {
755 			struct dw_desc	*desc;
756 			u32		len, mem;
757 			size_t		dlen;
758 
759 			mem = sg_dma_address(sg);
760 			len = sg_dma_len(sg);
761 
762 			mem_width = __ffs(data_width | mem | len);
763 
764 slave_sg_todev_fill_desc:
765 			desc = dwc_desc_get(dwc);
766 			if (!desc)
767 				goto err_desc_get;
768 
769 			lli_write(desc, sar, mem);
770 			lli_write(desc, dar, reg);
771 			lli_write(desc, ctlhi, bytes2block(dwc, len, mem_width, &dlen));
772 			lli_write(desc, ctllo, ctllo | DWC_CTLL_SRC_WIDTH(mem_width));
773 			desc->len = dlen;
774 
775 			if (!first) {
776 				first = desc;
777 			} else {
778 				lli_write(prev, llp, desc->txd.phys | lms);
779 				list_add_tail(&desc->desc_node, &first->tx_list);
780 			}
781 			prev = desc;
782 
783 			mem += dlen;
784 			len -= dlen;
785 			total_len += dlen;
786 
787 			if (len)
788 				goto slave_sg_todev_fill_desc;
789 		}
790 		break;
791 	case DMA_DEV_TO_MEM:
792 		reg_width = __ffs(sconfig->src_addr_width);
793 		reg = sconfig->src_addr;
794 		ctllo = (DWC_DEFAULT_CTLLO(chan)
795 				| DWC_CTLL_SRC_WIDTH(reg_width)
796 				| DWC_CTLL_DST_INC
797 				| DWC_CTLL_SRC_FIX);
798 
799 		ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
800 			DWC_CTLL_FC(DW_DMA_FC_D_P2M);
801 
802 		for_each_sg(sgl, sg, sg_len, i) {
803 			struct dw_desc	*desc;
804 			u32		len, mem;
805 			size_t		dlen;
806 
807 			mem = sg_dma_address(sg);
808 			len = sg_dma_len(sg);
809 
810 slave_sg_fromdev_fill_desc:
811 			desc = dwc_desc_get(dwc);
812 			if (!desc)
813 				goto err_desc_get;
814 
815 			lli_write(desc, sar, reg);
816 			lli_write(desc, dar, mem);
817 			lli_write(desc, ctlhi, bytes2block(dwc, len, reg_width, &dlen));
818 			mem_width = __ffs(data_width | mem | dlen);
819 			lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width));
820 			desc->len = dlen;
821 
822 			if (!first) {
823 				first = desc;
824 			} else {
825 				lli_write(prev, llp, desc->txd.phys | lms);
826 				list_add_tail(&desc->desc_node, &first->tx_list);
827 			}
828 			prev = desc;
829 
830 			mem += dlen;
831 			len -= dlen;
832 			total_len += dlen;
833 
834 			if (len)
835 				goto slave_sg_fromdev_fill_desc;
836 		}
837 		break;
838 	default:
839 		return NULL;
840 	}
841 
842 	if (flags & DMA_PREP_INTERRUPT)
843 		/* Trigger interrupt after last block */
844 		lli_set(prev, ctllo, DWC_CTLL_INT_EN);
845 
846 	prev->lli.llp = 0;
847 	lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
848 	first->total_len = total_len;
849 
850 	return &first->txd;
851 
852 err_desc_get:
853 	dev_err(chan2dev(chan),
854 		"not enough descriptors available. Direction %d\n", direction);
855 	dwc_desc_put(dwc, first);
856 	return NULL;
857 }
858 
859 bool dw_dma_filter(struct dma_chan *chan, void *param)
860 {
861 	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
862 	struct dw_dma_slave *dws = param;
863 
864 	if (dws->dma_dev != chan->device->dev)
865 		return false;
866 
867 	/* We have to copy data since dws can be temporary storage */
868 	memcpy(&dwc->dws, dws, sizeof(struct dw_dma_slave));
869 
870 	return true;
871 }
872 EXPORT_SYMBOL_GPL(dw_dma_filter);
873 
874 static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
875 {
876 	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
877 	struct dma_slave_config *sc = &dwc->dma_sconfig;
878 	struct dw_dma *dw = to_dw_dma(chan->device);
879 	/*
880 	 * Fix sconfig's burst size according to dw_dmac. We need to convert
881 	 * them as:
882 	 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
883 	 *
884 	 * NOTE: burst size 2 is not supported by DesignWare controller.
885 	 *       iDMA 32-bit supports it.
886 	 */
887 	u32 s = dw->pdata->is_idma32 ? 1 : 2;
888 
889 	memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
890 
891 	sc->src_maxburst = sc->src_maxburst > 1 ? fls(sc->src_maxburst) - s : 0;
892 	sc->dst_maxburst = sc->dst_maxburst > 1 ? fls(sc->dst_maxburst) - s : 0;
893 
894 	return 0;
895 }
896 
897 static void dwc_chan_pause(struct dw_dma_chan *dwc, bool drain)
898 {
899 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
900 	unsigned int		count = 20;	/* timeout iterations */
901 	u32			cfglo;
902 
903 	cfglo = channel_readl(dwc, CFG_LO);
904 	if (dw->pdata->is_idma32) {
905 		if (drain)
906 			cfglo |= IDMA32C_CFGL_CH_DRAIN;
907 		else
908 			cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
909 	}
910 	channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
911 	while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
912 		udelay(2);
913 
914 	set_bit(DW_DMA_IS_PAUSED, &dwc->flags);
915 }
916 
917 static int dwc_pause(struct dma_chan *chan)
918 {
919 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
920 	unsigned long		flags;
921 
922 	spin_lock_irqsave(&dwc->lock, flags);
923 	dwc_chan_pause(dwc, false);
924 	spin_unlock_irqrestore(&dwc->lock, flags);
925 
926 	return 0;
927 }
928 
929 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
930 {
931 	u32 cfglo = channel_readl(dwc, CFG_LO);
932 
933 	channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
934 
935 	clear_bit(DW_DMA_IS_PAUSED, &dwc->flags);
936 }
937 
938 static int dwc_resume(struct dma_chan *chan)
939 {
940 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
941 	unsigned long		flags;
942 
943 	spin_lock_irqsave(&dwc->lock, flags);
944 
945 	if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags))
946 		dwc_chan_resume(dwc);
947 
948 	spin_unlock_irqrestore(&dwc->lock, flags);
949 
950 	return 0;
951 }
952 
953 static int dwc_terminate_all(struct dma_chan *chan)
954 {
955 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
956 	struct dw_dma		*dw = to_dw_dma(chan->device);
957 	struct dw_desc		*desc, *_desc;
958 	unsigned long		flags;
959 	LIST_HEAD(list);
960 
961 	spin_lock_irqsave(&dwc->lock, flags);
962 
963 	clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
964 
965 	dwc_chan_pause(dwc, true);
966 
967 	dwc_chan_disable(dw, dwc);
968 
969 	dwc_chan_resume(dwc);
970 
971 	/* active_list entries will end up before queued entries */
972 	list_splice_init(&dwc->queue, &list);
973 	list_splice_init(&dwc->active_list, &list);
974 
975 	spin_unlock_irqrestore(&dwc->lock, flags);
976 
977 	/* Flush all pending and queued descriptors */
978 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
979 		dwc_descriptor_complete(dwc, desc, false);
980 
981 	return 0;
982 }
983 
984 static struct dw_desc *dwc_find_desc(struct dw_dma_chan *dwc, dma_cookie_t c)
985 {
986 	struct dw_desc *desc;
987 
988 	list_for_each_entry(desc, &dwc->active_list, desc_node)
989 		if (desc->txd.cookie == c)
990 			return desc;
991 
992 	return NULL;
993 }
994 
995 static u32 dwc_get_residue(struct dw_dma_chan *dwc, dma_cookie_t cookie)
996 {
997 	struct dw_desc *desc;
998 	unsigned long flags;
999 	u32 residue;
1000 
1001 	spin_lock_irqsave(&dwc->lock, flags);
1002 
1003 	desc = dwc_find_desc(dwc, cookie);
1004 	if (desc) {
1005 		if (desc == dwc_first_active(dwc)) {
1006 			residue = desc->residue;
1007 			if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1008 				residue -= dwc_get_sent(dwc);
1009 		} else {
1010 			residue = desc->total_len;
1011 		}
1012 	} else {
1013 		residue = 0;
1014 	}
1015 
1016 	spin_unlock_irqrestore(&dwc->lock, flags);
1017 	return residue;
1018 }
1019 
1020 static enum dma_status
1021 dwc_tx_status(struct dma_chan *chan,
1022 	      dma_cookie_t cookie,
1023 	      struct dma_tx_state *txstate)
1024 {
1025 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
1026 	enum dma_status		ret;
1027 
1028 	ret = dma_cookie_status(chan, cookie, txstate);
1029 	if (ret == DMA_COMPLETE)
1030 		return ret;
1031 
1032 	dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1033 
1034 	ret = dma_cookie_status(chan, cookie, txstate);
1035 	if (ret == DMA_COMPLETE)
1036 		return ret;
1037 
1038 	dma_set_residue(txstate, dwc_get_residue(dwc, cookie));
1039 
1040 	if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags) && ret == DMA_IN_PROGRESS)
1041 		return DMA_PAUSED;
1042 
1043 	return ret;
1044 }
1045 
1046 static void dwc_issue_pending(struct dma_chan *chan)
1047 {
1048 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
1049 	unsigned long		flags;
1050 
1051 	spin_lock_irqsave(&dwc->lock, flags);
1052 	if (list_empty(&dwc->active_list))
1053 		dwc_dostart_first_queued(dwc);
1054 	spin_unlock_irqrestore(&dwc->lock, flags);
1055 }
1056 
1057 /*----------------------------------------------------------------------*/
1058 
1059 /*
1060  * Program FIFO size of channels.
1061  *
1062  * By default full FIFO (1024 bytes) is assigned to channel 0. Here we
1063  * slice FIFO on equal parts between channels.
1064  */
1065 static void idma32_fifo_partition(struct dw_dma *dw)
1066 {
1067 	u64 value = IDMA32C_FP_PSIZE_CH0(128) | IDMA32C_FP_PSIZE_CH1(128) |
1068 		    IDMA32C_FP_UPDATE;
1069 	u64 fifo_partition = 0;
1070 
1071 	if (!dw->pdata->is_idma32)
1072 		return;
1073 
1074 	/* Fill FIFO_PARTITION low bits (Channels 0..1, 4..5) */
1075 	fifo_partition |= value << 0;
1076 
1077 	/* Fill FIFO_PARTITION high bits (Channels 2..3, 6..7) */
1078 	fifo_partition |= value << 32;
1079 
1080 	/* Program FIFO Partition registers - 128 bytes for each channel */
1081 	idma32_writeq(dw, FIFO_PARTITION1, fifo_partition);
1082 	idma32_writeq(dw, FIFO_PARTITION0, fifo_partition);
1083 }
1084 
1085 static void dw_dma_off(struct dw_dma *dw)
1086 {
1087 	unsigned int i;
1088 
1089 	dma_writel(dw, CFG, 0);
1090 
1091 	channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1092 	channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1093 	channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1094 	channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1095 	channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1096 
1097 	while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1098 		cpu_relax();
1099 
1100 	for (i = 0; i < dw->dma.chancnt; i++)
1101 		clear_bit(DW_DMA_IS_INITIALIZED, &dw->chan[i].flags);
1102 }
1103 
1104 static void dw_dma_on(struct dw_dma *dw)
1105 {
1106 	dma_writel(dw, CFG, DW_CFG_DMA_EN);
1107 }
1108 
1109 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1110 {
1111 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
1112 	struct dw_dma		*dw = to_dw_dma(chan->device);
1113 
1114 	dev_vdbg(chan2dev(chan), "%s\n", __func__);
1115 
1116 	/* ASSERT:  channel is idle */
1117 	if (dma_readl(dw, CH_EN) & dwc->mask) {
1118 		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1119 		return -EIO;
1120 	}
1121 
1122 	dma_cookie_init(chan);
1123 
1124 	/*
1125 	 * NOTE: some controllers may have additional features that we
1126 	 * need to initialize here, like "scatter-gather" (which
1127 	 * doesn't mean what you think it means), and status writeback.
1128 	 */
1129 
1130 	/*
1131 	 * We need controller-specific data to set up slave transfers.
1132 	 */
1133 	if (chan->private && !dw_dma_filter(chan, chan->private)) {
1134 		dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
1135 		return -EINVAL;
1136 	}
1137 
1138 	/* Enable controller here if needed */
1139 	if (!dw->in_use)
1140 		dw_dma_on(dw);
1141 	dw->in_use |= dwc->mask;
1142 
1143 	return 0;
1144 }
1145 
1146 static void dwc_free_chan_resources(struct dma_chan *chan)
1147 {
1148 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
1149 	struct dw_dma		*dw = to_dw_dma(chan->device);
1150 	unsigned long		flags;
1151 	LIST_HEAD(list);
1152 
1153 	dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1154 			dwc->descs_allocated);
1155 
1156 	/* ASSERT:  channel is idle */
1157 	BUG_ON(!list_empty(&dwc->active_list));
1158 	BUG_ON(!list_empty(&dwc->queue));
1159 	BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1160 
1161 	spin_lock_irqsave(&dwc->lock, flags);
1162 
1163 	/* Clear custom channel configuration */
1164 	memset(&dwc->dws, 0, sizeof(struct dw_dma_slave));
1165 
1166 	clear_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
1167 
1168 	/* Disable interrupts */
1169 	channel_clear_bit(dw, MASK.XFER, dwc->mask);
1170 	channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1171 	channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1172 
1173 	spin_unlock_irqrestore(&dwc->lock, flags);
1174 
1175 	/* Disable controller in case it was a last user */
1176 	dw->in_use &= ~dwc->mask;
1177 	if (!dw->in_use)
1178 		dw_dma_off(dw);
1179 
1180 	dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1181 }
1182 
1183 int dw_dma_probe(struct dw_dma_chip *chip)
1184 {
1185 	struct dw_dma_platform_data *pdata;
1186 	struct dw_dma		*dw;
1187 	bool			autocfg = false;
1188 	unsigned int		dw_params;
1189 	unsigned int		i;
1190 	int			err;
1191 
1192 	dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
1193 	if (!dw)
1194 		return -ENOMEM;
1195 
1196 	dw->pdata = devm_kzalloc(chip->dev, sizeof(*dw->pdata), GFP_KERNEL);
1197 	if (!dw->pdata)
1198 		return -ENOMEM;
1199 
1200 	dw->regs = chip->regs;
1201 	chip->dw = dw;
1202 
1203 	pm_runtime_get_sync(chip->dev);
1204 
1205 	if (!chip->pdata) {
1206 		dw_params = dma_readl(dw, DW_PARAMS);
1207 		dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1208 
1209 		autocfg = dw_params >> DW_PARAMS_EN & 1;
1210 		if (!autocfg) {
1211 			err = -EINVAL;
1212 			goto err_pdata;
1213 		}
1214 
1215 		/* Reassign the platform data pointer */
1216 		pdata = dw->pdata;
1217 
1218 		/* Get hardware configuration parameters */
1219 		pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1;
1220 		pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1221 		for (i = 0; i < pdata->nr_masters; i++) {
1222 			pdata->data_width[i] =
1223 				4 << (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3);
1224 		}
1225 		pdata->block_size = dma_readl(dw, MAX_BLK_SIZE);
1226 
1227 		/* Fill platform data with the default values */
1228 		pdata->is_private = true;
1229 		pdata->is_memcpy = true;
1230 		pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1231 		pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1232 	} else if (chip->pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
1233 		err = -EINVAL;
1234 		goto err_pdata;
1235 	} else {
1236 		memcpy(dw->pdata, chip->pdata, sizeof(*dw->pdata));
1237 
1238 		/* Reassign the platform data pointer */
1239 		pdata = dw->pdata;
1240 	}
1241 
1242 	dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
1243 				GFP_KERNEL);
1244 	if (!dw->chan) {
1245 		err = -ENOMEM;
1246 		goto err_pdata;
1247 	}
1248 
1249 	/* Calculate all channel mask before DMA setup */
1250 	dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1251 
1252 	/* Force dma off, just in case */
1253 	dw_dma_off(dw);
1254 
1255 	idma32_fifo_partition(dw);
1256 
1257 	/* Device and instance ID for IRQ and DMA pool */
1258 	if (pdata->is_idma32)
1259 		snprintf(dw->name, sizeof(dw->name), "idma32:dmac%d", chip->id);
1260 	else
1261 		snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", chip->id);
1262 
1263 	/* Create a pool of consistent memory blocks for hardware descriptors */
1264 	dw->desc_pool = dmam_pool_create(dw->name, chip->dev,
1265 					 sizeof(struct dw_desc), 4, 0);
1266 	if (!dw->desc_pool) {
1267 		dev_err(chip->dev, "No memory for descriptors dma pool\n");
1268 		err = -ENOMEM;
1269 		goto err_pdata;
1270 	}
1271 
1272 	tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1273 
1274 	err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
1275 			  dw->name, dw);
1276 	if (err)
1277 		goto err_pdata;
1278 
1279 	INIT_LIST_HEAD(&dw->dma.channels);
1280 	for (i = 0; i < pdata->nr_channels; i++) {
1281 		struct dw_dma_chan	*dwc = &dw->chan[i];
1282 
1283 		dwc->chan.device = &dw->dma;
1284 		dma_cookie_init(&dwc->chan);
1285 		if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1286 			list_add_tail(&dwc->chan.device_node,
1287 					&dw->dma.channels);
1288 		else
1289 			list_add(&dwc->chan.device_node, &dw->dma.channels);
1290 
1291 		/* 7 is highest priority & 0 is lowest. */
1292 		if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1293 			dwc->priority = pdata->nr_channels - i - 1;
1294 		else
1295 			dwc->priority = i;
1296 
1297 		dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1298 		spin_lock_init(&dwc->lock);
1299 		dwc->mask = 1 << i;
1300 
1301 		INIT_LIST_HEAD(&dwc->active_list);
1302 		INIT_LIST_HEAD(&dwc->queue);
1303 
1304 		channel_clear_bit(dw, CH_EN, dwc->mask);
1305 
1306 		dwc->direction = DMA_TRANS_NONE;
1307 
1308 		/* Hardware configuration */
1309 		if (autocfg) {
1310 			unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
1311 			void __iomem *addr = &__dw_regs(dw)->DWC_PARAMS[r];
1312 			unsigned int dwc_params = readl(addr);
1313 
1314 			dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1315 					   dwc_params);
1316 
1317 			/*
1318 			 * Decode maximum block size for given channel. The
1319 			 * stored 4 bit value represents blocks from 0x00 for 3
1320 			 * up to 0x0a for 4095.
1321 			 */
1322 			dwc->block_size =
1323 				(4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1;
1324 			dwc->nollp =
1325 				(dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1326 		} else {
1327 			dwc->block_size = pdata->block_size;
1328 			dwc->nollp = !pdata->multi_block[i];
1329 		}
1330 	}
1331 
1332 	/* Clear all interrupts on all channels. */
1333 	dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1334 	dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1335 	dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1336 	dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1337 	dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1338 
1339 	/* Set capabilities */
1340 	dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1341 	if (pdata->is_private)
1342 		dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1343 	if (pdata->is_memcpy)
1344 		dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1345 
1346 	dw->dma.dev = chip->dev;
1347 	dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1348 	dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1349 
1350 	dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1351 	dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1352 
1353 	dw->dma.device_config = dwc_config;
1354 	dw->dma.device_pause = dwc_pause;
1355 	dw->dma.device_resume = dwc_resume;
1356 	dw->dma.device_terminate_all = dwc_terminate_all;
1357 
1358 	dw->dma.device_tx_status = dwc_tx_status;
1359 	dw->dma.device_issue_pending = dwc_issue_pending;
1360 
1361 	/* DMA capabilities */
1362 	dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
1363 	dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
1364 	dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1365 			     BIT(DMA_MEM_TO_MEM);
1366 	dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1367 
1368 	err = dma_async_device_register(&dw->dma);
1369 	if (err)
1370 		goto err_dma_register;
1371 
1372 	dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
1373 		 pdata->nr_channels);
1374 
1375 	pm_runtime_put_sync_suspend(chip->dev);
1376 
1377 	return 0;
1378 
1379 err_dma_register:
1380 	free_irq(chip->irq, dw);
1381 err_pdata:
1382 	pm_runtime_put_sync_suspend(chip->dev);
1383 	return err;
1384 }
1385 EXPORT_SYMBOL_GPL(dw_dma_probe);
1386 
1387 int dw_dma_remove(struct dw_dma_chip *chip)
1388 {
1389 	struct dw_dma		*dw = chip->dw;
1390 	struct dw_dma_chan	*dwc, *_dwc;
1391 
1392 	pm_runtime_get_sync(chip->dev);
1393 
1394 	dw_dma_off(dw);
1395 	dma_async_device_unregister(&dw->dma);
1396 
1397 	free_irq(chip->irq, dw);
1398 	tasklet_kill(&dw->tasklet);
1399 
1400 	list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1401 			chan.device_node) {
1402 		list_del(&dwc->chan.device_node);
1403 		channel_clear_bit(dw, CH_EN, dwc->mask);
1404 	}
1405 
1406 	pm_runtime_put_sync_suspend(chip->dev);
1407 	return 0;
1408 }
1409 EXPORT_SYMBOL_GPL(dw_dma_remove);
1410 
1411 int dw_dma_disable(struct dw_dma_chip *chip)
1412 {
1413 	struct dw_dma *dw = chip->dw;
1414 
1415 	dw_dma_off(dw);
1416 	return 0;
1417 }
1418 EXPORT_SYMBOL_GPL(dw_dma_disable);
1419 
1420 int dw_dma_enable(struct dw_dma_chip *chip)
1421 {
1422 	struct dw_dma *dw = chip->dw;
1423 
1424 	idma32_fifo_partition(dw);
1425 
1426 	dw_dma_on(dw);
1427 	return 0;
1428 }
1429 EXPORT_SYMBOL_GPL(dw_dma_enable);
1430 
1431 MODULE_LICENSE("GPL v2");
1432 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver");
1433 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1434 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
1435