1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates.
4  * Synopsys DesignWare eDMA core driver
5  *
6  * Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/dmaengine.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/dma/edma.h>
18 #include <linux/dma-mapping.h>
19 
20 #include "dw-edma-core.h"
21 #include "dw-edma-v0-core.h"
22 #include "../dmaengine.h"
23 #include "../virt-dma.h"
24 
25 static inline
26 struct device *dchan2dev(struct dma_chan *dchan)
27 {
28 	return &dchan->dev->device;
29 }
30 
31 static inline
32 struct device *chan2dev(struct dw_edma_chan *chan)
33 {
34 	return &chan->vc.chan.dev->device;
35 }
36 
37 static inline
38 struct dw_edma_desc *vd2dw_edma_desc(struct virt_dma_desc *vd)
39 {
40 	return container_of(vd, struct dw_edma_desc, vd);
41 }
42 
43 static struct dw_edma_burst *dw_edma_alloc_burst(struct dw_edma_chunk *chunk)
44 {
45 	struct dw_edma_burst *burst;
46 
47 	burst = kzalloc(sizeof(*burst), GFP_NOWAIT);
48 	if (unlikely(!burst))
49 		return NULL;
50 
51 	INIT_LIST_HEAD(&burst->list);
52 	if (chunk->burst) {
53 		/* Create and add new element into the linked list */
54 		chunk->bursts_alloc++;
55 		list_add_tail(&burst->list, &chunk->burst->list);
56 	} else {
57 		/* List head */
58 		chunk->bursts_alloc = 0;
59 		chunk->burst = burst;
60 	}
61 
62 	return burst;
63 }
64 
65 static struct dw_edma_chunk *dw_edma_alloc_chunk(struct dw_edma_desc *desc)
66 {
67 	struct dw_edma_chan *chan = desc->chan;
68 	struct dw_edma *dw = chan->chip->dw;
69 	struct dw_edma_chunk *chunk;
70 
71 	chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
72 	if (unlikely(!chunk))
73 		return NULL;
74 
75 	INIT_LIST_HEAD(&chunk->list);
76 	chunk->chan = chan;
77 	/* Toggling change bit (CB) in each chunk, this is a mechanism to
78 	 * inform the eDMA HW block that this is a new linked list ready
79 	 * to be consumed.
80 	 *  - Odd chunks originate CB equal to 0
81 	 *  - Even chunks originate CB equal to 1
82 	 */
83 	chunk->cb = !(desc->chunks_alloc % 2);
84 	if (chan->dir == EDMA_DIR_WRITE) {
85 		chunk->ll_region.paddr = dw->ll_region_wr[chan->id].paddr;
86 		chunk->ll_region.vaddr = dw->ll_region_wr[chan->id].vaddr;
87 	} else {
88 		chunk->ll_region.paddr = dw->ll_region_rd[chan->id].paddr;
89 		chunk->ll_region.vaddr = dw->ll_region_rd[chan->id].vaddr;
90 	}
91 
92 	if (desc->chunk) {
93 		/* Create and add new element into the linked list */
94 		if (!dw_edma_alloc_burst(chunk)) {
95 			kfree(chunk);
96 			return NULL;
97 		}
98 		desc->chunks_alloc++;
99 		list_add_tail(&chunk->list, &desc->chunk->list);
100 	} else {
101 		/* List head */
102 		chunk->burst = NULL;
103 		desc->chunks_alloc = 0;
104 		desc->chunk = chunk;
105 	}
106 
107 	return chunk;
108 }
109 
110 static struct dw_edma_desc *dw_edma_alloc_desc(struct dw_edma_chan *chan)
111 {
112 	struct dw_edma_desc *desc;
113 
114 	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
115 	if (unlikely(!desc))
116 		return NULL;
117 
118 	desc->chan = chan;
119 	if (!dw_edma_alloc_chunk(desc)) {
120 		kfree(desc);
121 		return NULL;
122 	}
123 
124 	return desc;
125 }
126 
127 static void dw_edma_free_burst(struct dw_edma_chunk *chunk)
128 {
129 	struct dw_edma_burst *child, *_next;
130 
131 	/* Remove all the list elements */
132 	list_for_each_entry_safe(child, _next, &chunk->burst->list, list) {
133 		list_del(&child->list);
134 		kfree(child);
135 		chunk->bursts_alloc--;
136 	}
137 
138 	/* Remove the list head */
139 	kfree(child);
140 	chunk->burst = NULL;
141 }
142 
143 static void dw_edma_free_chunk(struct dw_edma_desc *desc)
144 {
145 	struct dw_edma_chunk *child, *_next;
146 
147 	if (!desc->chunk)
148 		return;
149 
150 	/* Remove all the list elements */
151 	list_for_each_entry_safe(child, _next, &desc->chunk->list, list) {
152 		dw_edma_free_burst(child);
153 		list_del(&child->list);
154 		kfree(child);
155 		desc->chunks_alloc--;
156 	}
157 
158 	/* Remove the list head */
159 	kfree(child);
160 	desc->chunk = NULL;
161 }
162 
163 static void dw_edma_free_desc(struct dw_edma_desc *desc)
164 {
165 	dw_edma_free_chunk(desc);
166 	kfree(desc);
167 }
168 
169 static void vchan_free_desc(struct virt_dma_desc *vdesc)
170 {
171 	dw_edma_free_desc(vd2dw_edma_desc(vdesc));
172 }
173 
174 static void dw_edma_start_transfer(struct dw_edma_chan *chan)
175 {
176 	struct dw_edma_chunk *child;
177 	struct dw_edma_desc *desc;
178 	struct virt_dma_desc *vd;
179 
180 	vd = vchan_next_desc(&chan->vc);
181 	if (!vd)
182 		return;
183 
184 	desc = vd2dw_edma_desc(vd);
185 	if (!desc)
186 		return;
187 
188 	child = list_first_entry_or_null(&desc->chunk->list,
189 					 struct dw_edma_chunk, list);
190 	if (!child)
191 		return;
192 
193 	dw_edma_v0_core_start(child, !desc->xfer_sz);
194 	desc->xfer_sz += child->ll_region.sz;
195 	dw_edma_free_burst(child);
196 	list_del(&child->list);
197 	kfree(child);
198 	desc->chunks_alloc--;
199 }
200 
201 static int dw_edma_device_config(struct dma_chan *dchan,
202 				 struct dma_slave_config *config)
203 {
204 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
205 
206 	memcpy(&chan->config, config, sizeof(*config));
207 	chan->configured = true;
208 
209 	return 0;
210 }
211 
212 static int dw_edma_device_pause(struct dma_chan *dchan)
213 {
214 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
215 	int err = 0;
216 
217 	if (!chan->configured)
218 		err = -EPERM;
219 	else if (chan->status != EDMA_ST_BUSY)
220 		err = -EPERM;
221 	else if (chan->request != EDMA_REQ_NONE)
222 		err = -EPERM;
223 	else
224 		chan->request = EDMA_REQ_PAUSE;
225 
226 	return err;
227 }
228 
229 static int dw_edma_device_resume(struct dma_chan *dchan)
230 {
231 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
232 	int err = 0;
233 
234 	if (!chan->configured) {
235 		err = -EPERM;
236 	} else if (chan->status != EDMA_ST_PAUSE) {
237 		err = -EPERM;
238 	} else if (chan->request != EDMA_REQ_NONE) {
239 		err = -EPERM;
240 	} else {
241 		chan->status = EDMA_ST_BUSY;
242 		dw_edma_start_transfer(chan);
243 	}
244 
245 	return err;
246 }
247 
248 static int dw_edma_device_terminate_all(struct dma_chan *dchan)
249 {
250 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
251 	int err = 0;
252 
253 	if (!chan->configured) {
254 		/* Do nothing */
255 	} else if (chan->status == EDMA_ST_PAUSE) {
256 		chan->status = EDMA_ST_IDLE;
257 		chan->configured = false;
258 	} else if (chan->status == EDMA_ST_IDLE) {
259 		chan->configured = false;
260 	} else if (dw_edma_v0_core_ch_status(chan) == DMA_COMPLETE) {
261 		/*
262 		 * The channel is in a false BUSY state, probably didn't
263 		 * receive or lost an interrupt
264 		 */
265 		chan->status = EDMA_ST_IDLE;
266 		chan->configured = false;
267 	} else if (chan->request > EDMA_REQ_PAUSE) {
268 		err = -EPERM;
269 	} else {
270 		chan->request = EDMA_REQ_STOP;
271 	}
272 
273 	return err;
274 }
275 
276 static void dw_edma_device_issue_pending(struct dma_chan *dchan)
277 {
278 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
279 	unsigned long flags;
280 
281 	spin_lock_irqsave(&chan->vc.lock, flags);
282 	if (chan->configured && chan->request == EDMA_REQ_NONE &&
283 	    chan->status == EDMA_ST_IDLE && vchan_issue_pending(&chan->vc)) {
284 		chan->status = EDMA_ST_BUSY;
285 		dw_edma_start_transfer(chan);
286 	}
287 	spin_unlock_irqrestore(&chan->vc.lock, flags);
288 }
289 
290 static enum dma_status
291 dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
292 			 struct dma_tx_state *txstate)
293 {
294 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
295 	struct dw_edma_desc *desc;
296 	struct virt_dma_desc *vd;
297 	unsigned long flags;
298 	enum dma_status ret;
299 	u32 residue = 0;
300 
301 	ret = dma_cookie_status(dchan, cookie, txstate);
302 	if (ret == DMA_COMPLETE)
303 		return ret;
304 
305 	if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE)
306 		ret = DMA_PAUSED;
307 
308 	if (!txstate)
309 		goto ret_residue;
310 
311 	spin_lock_irqsave(&chan->vc.lock, flags);
312 	vd = vchan_find_desc(&chan->vc, cookie);
313 	if (vd) {
314 		desc = vd2dw_edma_desc(vd);
315 		if (desc)
316 			residue = desc->alloc_sz - desc->xfer_sz;
317 	}
318 	spin_unlock_irqrestore(&chan->vc.lock, flags);
319 
320 ret_residue:
321 	dma_set_residue(txstate, residue);
322 
323 	return ret;
324 }
325 
326 static struct dma_async_tx_descriptor *
327 dw_edma_device_transfer(struct dw_edma_transfer *xfer)
328 {
329 	struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan);
330 	enum dma_transfer_direction dir = xfer->direction;
331 	phys_addr_t src_addr, dst_addr;
332 	struct scatterlist *sg = NULL;
333 	struct dw_edma_chunk *chunk;
334 	struct dw_edma_burst *burst;
335 	struct dw_edma_desc *desc;
336 	u32 cnt = 0;
337 	int i;
338 
339 	if (!chan->configured)
340 		return NULL;
341 
342 	switch (chan->config.direction) {
343 	case DMA_DEV_TO_MEM: /* local DMA */
344 		if (dir == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)
345 			break;
346 		return NULL;
347 	case DMA_MEM_TO_DEV: /* local DMA */
348 		if (dir == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE)
349 			break;
350 		return NULL;
351 	default: /* remote DMA */
352 		if (dir == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_READ)
353 			break;
354 		if (dir == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_WRITE)
355 			break;
356 		return NULL;
357 	}
358 
359 	if (xfer->type == EDMA_XFER_CYCLIC) {
360 		if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt)
361 			return NULL;
362 	} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
363 		if (xfer->xfer.sg.len < 1)
364 			return NULL;
365 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
366 		if (!xfer->xfer.il->numf)
367 			return NULL;
368 		if (xfer->xfer.il->numf > 0 && xfer->xfer.il->frame_size > 0)
369 			return NULL;
370 	} else {
371 		return NULL;
372 	}
373 
374 	desc = dw_edma_alloc_desc(chan);
375 	if (unlikely(!desc))
376 		goto err_alloc;
377 
378 	chunk = dw_edma_alloc_chunk(desc);
379 	if (unlikely(!chunk))
380 		goto err_alloc;
381 
382 	if (xfer->type == EDMA_XFER_INTERLEAVED) {
383 		src_addr = xfer->xfer.il->src_start;
384 		dst_addr = xfer->xfer.il->dst_start;
385 	} else {
386 		src_addr = chan->config.src_addr;
387 		dst_addr = chan->config.dst_addr;
388 	}
389 
390 	if (xfer->type == EDMA_XFER_CYCLIC) {
391 		cnt = xfer->xfer.cyclic.cnt;
392 	} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
393 		cnt = xfer->xfer.sg.len;
394 		sg = xfer->xfer.sg.sgl;
395 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
396 		if (xfer->xfer.il->numf > 0)
397 			cnt = xfer->xfer.il->numf;
398 		else
399 			cnt = xfer->xfer.il->frame_size;
400 	}
401 
402 	for (i = 0; i < cnt; i++) {
403 		if (xfer->type == EDMA_XFER_SCATTER_GATHER && !sg)
404 			break;
405 
406 		if (chunk->bursts_alloc == chan->ll_max) {
407 			chunk = dw_edma_alloc_chunk(desc);
408 			if (unlikely(!chunk))
409 				goto err_alloc;
410 		}
411 
412 		burst = dw_edma_alloc_burst(chunk);
413 		if (unlikely(!burst))
414 			goto err_alloc;
415 
416 		if (xfer->type == EDMA_XFER_CYCLIC)
417 			burst->sz = xfer->xfer.cyclic.len;
418 		else if (xfer->type == EDMA_XFER_SCATTER_GATHER)
419 			burst->sz = sg_dma_len(sg);
420 		else if (xfer->type == EDMA_XFER_INTERLEAVED)
421 			burst->sz = xfer->xfer.il->sgl[i].size;
422 
423 		chunk->ll_region.sz += burst->sz;
424 		desc->alloc_sz += burst->sz;
425 
426 		if (chan->dir == EDMA_DIR_WRITE) {
427 			burst->sar = src_addr;
428 			if (xfer->type == EDMA_XFER_CYCLIC) {
429 				burst->dar = xfer->xfer.cyclic.paddr;
430 			} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
431 				src_addr += sg_dma_len(sg);
432 				burst->dar = sg_dma_address(sg);
433 				/* Unlike the typical assumption by other
434 				 * drivers/IPs the peripheral memory isn't
435 				 * a FIFO memory, in this case, it's a
436 				 * linear memory and that why the source
437 				 * and destination addresses are increased
438 				 * by the same portion (data length)
439 				 */
440 			}
441 		} else {
442 			burst->dar = dst_addr;
443 			if (xfer->type == EDMA_XFER_CYCLIC) {
444 				burst->sar = xfer->xfer.cyclic.paddr;
445 			} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
446 				dst_addr += sg_dma_len(sg);
447 				burst->sar = sg_dma_address(sg);
448 				/* Unlike the typical assumption by other
449 				 * drivers/IPs the peripheral memory isn't
450 				 * a FIFO memory, in this case, it's a
451 				 * linear memory and that why the source
452 				 * and destination addresses are increased
453 				 * by the same portion (data length)
454 				 */
455 			}
456 		}
457 
458 		if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
459 			sg = sg_next(sg);
460 		} else if (xfer->type == EDMA_XFER_INTERLEAVED &&
461 			   xfer->xfer.il->frame_size > 0) {
462 			struct dma_interleaved_template *il = xfer->xfer.il;
463 			struct data_chunk *dc = &il->sgl[i];
464 
465 			if (il->src_sgl) {
466 				src_addr += burst->sz;
467 				src_addr += dmaengine_get_src_icg(il, dc);
468 			}
469 
470 			if (il->dst_sgl) {
471 				dst_addr += burst->sz;
472 				dst_addr += dmaengine_get_dst_icg(il, dc);
473 			}
474 		}
475 	}
476 
477 	return vchan_tx_prep(&chan->vc, &desc->vd, xfer->flags);
478 
479 err_alloc:
480 	if (desc)
481 		dw_edma_free_desc(desc);
482 
483 	return NULL;
484 }
485 
486 static struct dma_async_tx_descriptor *
487 dw_edma_device_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
488 			     unsigned int len,
489 			     enum dma_transfer_direction direction,
490 			     unsigned long flags, void *context)
491 {
492 	struct dw_edma_transfer xfer;
493 
494 	xfer.dchan = dchan;
495 	xfer.direction = direction;
496 	xfer.xfer.sg.sgl = sgl;
497 	xfer.xfer.sg.len = len;
498 	xfer.flags = flags;
499 	xfer.type = EDMA_XFER_SCATTER_GATHER;
500 
501 	return dw_edma_device_transfer(&xfer);
502 }
503 
504 static struct dma_async_tx_descriptor *
505 dw_edma_device_prep_dma_cyclic(struct dma_chan *dchan, dma_addr_t paddr,
506 			       size_t len, size_t count,
507 			       enum dma_transfer_direction direction,
508 			       unsigned long flags)
509 {
510 	struct dw_edma_transfer xfer;
511 
512 	xfer.dchan = dchan;
513 	xfer.direction = direction;
514 	xfer.xfer.cyclic.paddr = paddr;
515 	xfer.xfer.cyclic.len = len;
516 	xfer.xfer.cyclic.cnt = count;
517 	xfer.flags = flags;
518 	xfer.type = EDMA_XFER_CYCLIC;
519 
520 	return dw_edma_device_transfer(&xfer);
521 }
522 
523 static struct dma_async_tx_descriptor *
524 dw_edma_device_prep_interleaved_dma(struct dma_chan *dchan,
525 				    struct dma_interleaved_template *ilt,
526 				    unsigned long flags)
527 {
528 	struct dw_edma_transfer xfer;
529 
530 	xfer.dchan = dchan;
531 	xfer.direction = ilt->dir;
532 	xfer.xfer.il = ilt;
533 	xfer.flags = flags;
534 	xfer.type = EDMA_XFER_INTERLEAVED;
535 
536 	return dw_edma_device_transfer(&xfer);
537 }
538 
539 static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
540 {
541 	struct dw_edma_desc *desc;
542 	struct virt_dma_desc *vd;
543 	unsigned long flags;
544 
545 	dw_edma_v0_core_clear_done_int(chan);
546 
547 	spin_lock_irqsave(&chan->vc.lock, flags);
548 	vd = vchan_next_desc(&chan->vc);
549 	if (vd) {
550 		switch (chan->request) {
551 		case EDMA_REQ_NONE:
552 			desc = vd2dw_edma_desc(vd);
553 			if (desc->chunks_alloc) {
554 				chan->status = EDMA_ST_BUSY;
555 				dw_edma_start_transfer(chan);
556 			} else {
557 				list_del(&vd->node);
558 				vchan_cookie_complete(vd);
559 				chan->status = EDMA_ST_IDLE;
560 			}
561 			break;
562 
563 		case EDMA_REQ_STOP:
564 			list_del(&vd->node);
565 			vchan_cookie_complete(vd);
566 			chan->request = EDMA_REQ_NONE;
567 			chan->status = EDMA_ST_IDLE;
568 			break;
569 
570 		case EDMA_REQ_PAUSE:
571 			chan->request = EDMA_REQ_NONE;
572 			chan->status = EDMA_ST_PAUSE;
573 			break;
574 
575 		default:
576 			break;
577 		}
578 	}
579 	spin_unlock_irqrestore(&chan->vc.lock, flags);
580 }
581 
582 static void dw_edma_abort_interrupt(struct dw_edma_chan *chan)
583 {
584 	struct virt_dma_desc *vd;
585 	unsigned long flags;
586 
587 	dw_edma_v0_core_clear_abort_int(chan);
588 
589 	spin_lock_irqsave(&chan->vc.lock, flags);
590 	vd = vchan_next_desc(&chan->vc);
591 	if (vd) {
592 		list_del(&vd->node);
593 		vchan_cookie_complete(vd);
594 	}
595 	spin_unlock_irqrestore(&chan->vc.lock, flags);
596 	chan->request = EDMA_REQ_NONE;
597 	chan->status = EDMA_ST_IDLE;
598 }
599 
600 static irqreturn_t dw_edma_interrupt(int irq, void *data, bool write)
601 {
602 	struct dw_edma_irq *dw_irq = data;
603 	struct dw_edma *dw = dw_irq->dw;
604 	unsigned long total, pos, val;
605 	unsigned long off;
606 	u32 mask;
607 
608 	if (write) {
609 		total = dw->wr_ch_cnt;
610 		off = 0;
611 		mask = dw_irq->wr_mask;
612 	} else {
613 		total = dw->rd_ch_cnt;
614 		off = dw->wr_ch_cnt;
615 		mask = dw_irq->rd_mask;
616 	}
617 
618 	val = dw_edma_v0_core_status_done_int(dw, write ?
619 							  EDMA_DIR_WRITE :
620 							  EDMA_DIR_READ);
621 	val &= mask;
622 	for_each_set_bit(pos, &val, total) {
623 		struct dw_edma_chan *chan = &dw->chan[pos + off];
624 
625 		dw_edma_done_interrupt(chan);
626 	}
627 
628 	val = dw_edma_v0_core_status_abort_int(dw, write ?
629 							   EDMA_DIR_WRITE :
630 							   EDMA_DIR_READ);
631 	val &= mask;
632 	for_each_set_bit(pos, &val, total) {
633 		struct dw_edma_chan *chan = &dw->chan[pos + off];
634 
635 		dw_edma_abort_interrupt(chan);
636 	}
637 
638 	return IRQ_HANDLED;
639 }
640 
641 static inline irqreturn_t dw_edma_interrupt_write(int irq, void *data)
642 {
643 	return dw_edma_interrupt(irq, data, true);
644 }
645 
646 static inline irqreturn_t dw_edma_interrupt_read(int irq, void *data)
647 {
648 	return dw_edma_interrupt(irq, data, false);
649 }
650 
651 static irqreturn_t dw_edma_interrupt_common(int irq, void *data)
652 {
653 	dw_edma_interrupt(irq, data, true);
654 	dw_edma_interrupt(irq, data, false);
655 
656 	return IRQ_HANDLED;
657 }
658 
659 static int dw_edma_alloc_chan_resources(struct dma_chan *dchan)
660 {
661 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
662 
663 	if (chan->status != EDMA_ST_IDLE)
664 		return -EBUSY;
665 
666 	pm_runtime_get(chan->chip->dev);
667 
668 	return 0;
669 }
670 
671 static void dw_edma_free_chan_resources(struct dma_chan *dchan)
672 {
673 	unsigned long timeout = jiffies + msecs_to_jiffies(5000);
674 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
675 	int ret;
676 
677 	while (time_before(jiffies, timeout)) {
678 		ret = dw_edma_device_terminate_all(dchan);
679 		if (!ret)
680 			break;
681 
682 		if (time_after_eq(jiffies, timeout))
683 			return;
684 
685 		cpu_relax();
686 	}
687 
688 	pm_runtime_put(chan->chip->dev);
689 }
690 
691 static int dw_edma_channel_setup(struct dw_edma_chip *chip, bool write,
692 				 u32 wr_alloc, u32 rd_alloc)
693 {
694 	struct dw_edma_region *dt_region;
695 	struct device *dev = chip->dev;
696 	struct dw_edma *dw = chip->dw;
697 	struct dw_edma_chan *chan;
698 	struct dw_edma_irq *irq;
699 	struct dma_device *dma;
700 	u32 alloc, off_alloc;
701 	u32 i, j, cnt;
702 	int err = 0;
703 	u32 pos;
704 
705 	if (write) {
706 		i = 0;
707 		cnt = dw->wr_ch_cnt;
708 		dma = &dw->wr_edma;
709 		alloc = wr_alloc;
710 		off_alloc = 0;
711 	} else {
712 		i = dw->wr_ch_cnt;
713 		cnt = dw->rd_ch_cnt;
714 		dma = &dw->rd_edma;
715 		alloc = rd_alloc;
716 		off_alloc = wr_alloc;
717 	}
718 
719 	INIT_LIST_HEAD(&dma->channels);
720 	for (j = 0; (alloc || dw->nr_irqs == 1) && j < cnt; j++, i++) {
721 		chan = &dw->chan[i];
722 
723 		dt_region = devm_kzalloc(dev, sizeof(*dt_region), GFP_KERNEL);
724 		if (!dt_region)
725 			return -ENOMEM;
726 
727 		chan->vc.chan.private = dt_region;
728 
729 		chan->chip = chip;
730 		chan->id = j;
731 		chan->dir = write ? EDMA_DIR_WRITE : EDMA_DIR_READ;
732 		chan->configured = false;
733 		chan->request = EDMA_REQ_NONE;
734 		chan->status = EDMA_ST_IDLE;
735 
736 		if (write)
737 			chan->ll_max = (dw->ll_region_wr[j].sz / EDMA_LL_SZ);
738 		else
739 			chan->ll_max = (dw->ll_region_rd[j].sz / EDMA_LL_SZ);
740 		chan->ll_max -= 1;
741 
742 		dev_vdbg(dev, "L. List:\tChannel %s[%u] max_cnt=%u\n",
743 			 write ? "write" : "read", j, chan->ll_max);
744 
745 		if (dw->nr_irqs == 1)
746 			pos = 0;
747 		else
748 			pos = off_alloc + (j % alloc);
749 
750 		irq = &dw->irq[pos];
751 
752 		if (write)
753 			irq->wr_mask |= BIT(j);
754 		else
755 			irq->rd_mask |= BIT(j);
756 
757 		irq->dw = dw;
758 		memcpy(&chan->msi, &irq->msi, sizeof(chan->msi));
759 
760 		dev_vdbg(dev, "MSI:\t\tChannel %s[%u] addr=0x%.8x%.8x, data=0x%.8x\n",
761 			 write ? "write" : "read", j,
762 			 chan->msi.address_hi, chan->msi.address_lo,
763 			 chan->msi.data);
764 
765 		chan->vc.desc_free = vchan_free_desc;
766 		vchan_init(&chan->vc, dma);
767 
768 		if (write) {
769 			dt_region->paddr = dw->dt_region_wr[j].paddr;
770 			dt_region->vaddr = dw->dt_region_wr[j].vaddr;
771 			dt_region->sz = dw->dt_region_wr[j].sz;
772 		} else {
773 			dt_region->paddr = dw->dt_region_rd[j].paddr;
774 			dt_region->vaddr = dw->dt_region_rd[j].vaddr;
775 			dt_region->sz = dw->dt_region_rd[j].sz;
776 		}
777 
778 		dw_edma_v0_core_device_config(chan);
779 	}
780 
781 	/* Set DMA channel capabilities */
782 	dma_cap_zero(dma->cap_mask);
783 	dma_cap_set(DMA_SLAVE, dma->cap_mask);
784 	dma_cap_set(DMA_CYCLIC, dma->cap_mask);
785 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
786 	dma_cap_set(DMA_INTERLEAVE, dma->cap_mask);
787 	dma->directions = BIT(write ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV);
788 	dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
789 	dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
790 	dma->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
791 	dma->chancnt = cnt;
792 
793 	/* Set DMA channel callbacks */
794 	dma->dev = chip->dev;
795 	dma->device_alloc_chan_resources = dw_edma_alloc_chan_resources;
796 	dma->device_free_chan_resources = dw_edma_free_chan_resources;
797 	dma->device_config = dw_edma_device_config;
798 	dma->device_pause = dw_edma_device_pause;
799 	dma->device_resume = dw_edma_device_resume;
800 	dma->device_terminate_all = dw_edma_device_terminate_all;
801 	dma->device_issue_pending = dw_edma_device_issue_pending;
802 	dma->device_tx_status = dw_edma_device_tx_status;
803 	dma->device_prep_slave_sg = dw_edma_device_prep_slave_sg;
804 	dma->device_prep_dma_cyclic = dw_edma_device_prep_dma_cyclic;
805 	dma->device_prep_interleaved_dma = dw_edma_device_prep_interleaved_dma;
806 
807 	dma_set_max_seg_size(dma->dev, U32_MAX);
808 
809 	/* Register DMA device */
810 	err = dma_async_device_register(dma);
811 
812 	return err;
813 }
814 
815 static inline void dw_edma_dec_irq_alloc(int *nr_irqs, u32 *alloc, u16 cnt)
816 {
817 	if (*nr_irqs && *alloc < cnt) {
818 		(*alloc)++;
819 		(*nr_irqs)--;
820 	}
821 }
822 
823 static inline void dw_edma_add_irq_mask(u32 *mask, u32 alloc, u16 cnt)
824 {
825 	while (*mask * alloc < cnt)
826 		(*mask)++;
827 }
828 
829 static int dw_edma_irq_request(struct dw_edma_chip *chip,
830 			       u32 *wr_alloc, u32 *rd_alloc)
831 {
832 	struct device *dev = chip->dev;
833 	struct dw_edma *dw = chip->dw;
834 	u32 wr_mask = 1;
835 	u32 rd_mask = 1;
836 	int i, err = 0;
837 	u32 ch_cnt;
838 	int irq;
839 
840 	ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
841 
842 	if (dw->nr_irqs < 1)
843 		return -EINVAL;
844 
845 	if (dw->nr_irqs == 1) {
846 		/* Common IRQ shared among all channels */
847 		irq = dw->ops->irq_vector(dev, 0);
848 		err = request_irq(irq, dw_edma_interrupt_common,
849 				  IRQF_SHARED, dw->name, &dw->irq[0]);
850 		if (err) {
851 			dw->nr_irqs = 0;
852 			return err;
853 		}
854 
855 		if (irq_get_msi_desc(irq))
856 			get_cached_msi_msg(irq, &dw->irq[0].msi);
857 	} else {
858 		/* Distribute IRQs equally among all channels */
859 		int tmp = dw->nr_irqs;
860 
861 		while (tmp && (*wr_alloc + *rd_alloc) < ch_cnt) {
862 			dw_edma_dec_irq_alloc(&tmp, wr_alloc, dw->wr_ch_cnt);
863 			dw_edma_dec_irq_alloc(&tmp, rd_alloc, dw->rd_ch_cnt);
864 		}
865 
866 		dw_edma_add_irq_mask(&wr_mask, *wr_alloc, dw->wr_ch_cnt);
867 		dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt);
868 
869 		for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
870 			irq = dw->ops->irq_vector(dev, i);
871 			err = request_irq(irq,
872 					  i < *wr_alloc ?
873 						dw_edma_interrupt_write :
874 						dw_edma_interrupt_read,
875 					  IRQF_SHARED, dw->name,
876 					  &dw->irq[i]);
877 			if (err) {
878 				dw->nr_irqs = i;
879 				return err;
880 			}
881 
882 			if (irq_get_msi_desc(irq))
883 				get_cached_msi_msg(irq, &dw->irq[i].msi);
884 		}
885 
886 		dw->nr_irqs = i;
887 	}
888 
889 	return err;
890 }
891 
892 int dw_edma_probe(struct dw_edma_chip *chip)
893 {
894 	struct device *dev;
895 	struct dw_edma *dw;
896 	u32 wr_alloc = 0;
897 	u32 rd_alloc = 0;
898 	int i, err;
899 
900 	if (!chip)
901 		return -EINVAL;
902 
903 	dev = chip->dev;
904 	if (!dev)
905 		return -EINVAL;
906 
907 	dw = chip->dw;
908 	if (!dw || !dw->irq || !dw->ops || !dw->ops->irq_vector)
909 		return -EINVAL;
910 
911 	raw_spin_lock_init(&dw->lock);
912 
913 	dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt,
914 			      dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE));
915 	dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt, EDMA_MAX_WR_CH);
916 
917 	dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt,
918 			      dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ));
919 	dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt, EDMA_MAX_RD_CH);
920 
921 	if (!dw->wr_ch_cnt && !dw->rd_ch_cnt)
922 		return -EINVAL;
923 
924 	dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n",
925 		 dw->wr_ch_cnt, dw->rd_ch_cnt);
926 
927 	/* Allocate channels */
928 	dw->chan = devm_kcalloc(dev, dw->wr_ch_cnt + dw->rd_ch_cnt,
929 				sizeof(*dw->chan), GFP_KERNEL);
930 	if (!dw->chan)
931 		return -ENOMEM;
932 
933 	snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%d", chip->id);
934 
935 	/* Disable eDMA, only to establish the ideal initial conditions */
936 	dw_edma_v0_core_off(dw);
937 
938 	/* Request IRQs */
939 	err = dw_edma_irq_request(chip, &wr_alloc, &rd_alloc);
940 	if (err)
941 		return err;
942 
943 	/* Setup write channels */
944 	err = dw_edma_channel_setup(chip, true, wr_alloc, rd_alloc);
945 	if (err)
946 		goto err_irq_free;
947 
948 	/* Setup read channels */
949 	err = dw_edma_channel_setup(chip, false, wr_alloc, rd_alloc);
950 	if (err)
951 		goto err_irq_free;
952 
953 	/* Power management */
954 	pm_runtime_enable(dev);
955 
956 	/* Turn debugfs on */
957 	dw_edma_v0_core_debugfs_on(chip);
958 
959 	return 0;
960 
961 err_irq_free:
962 	for (i = (dw->nr_irqs - 1); i >= 0; i--)
963 		free_irq(dw->ops->irq_vector(dev, i), &dw->irq[i]);
964 
965 	dw->nr_irqs = 0;
966 
967 	return err;
968 }
969 EXPORT_SYMBOL_GPL(dw_edma_probe);
970 
971 int dw_edma_remove(struct dw_edma_chip *chip)
972 {
973 	struct dw_edma_chan *chan, *_chan;
974 	struct device *dev = chip->dev;
975 	struct dw_edma *dw = chip->dw;
976 	int i;
977 
978 	/* Disable eDMA */
979 	dw_edma_v0_core_off(dw);
980 
981 	/* Free irqs */
982 	for (i = (dw->nr_irqs - 1); i >= 0; i--)
983 		free_irq(dw->ops->irq_vector(dev, i), &dw->irq[i]);
984 
985 	/* Power management */
986 	pm_runtime_disable(dev);
987 
988 	/* Deregister eDMA device */
989 	dma_async_device_unregister(&dw->wr_edma);
990 	list_for_each_entry_safe(chan, _chan, &dw->wr_edma.channels,
991 				 vc.chan.device_node) {
992 		tasklet_kill(&chan->vc.task);
993 		list_del(&chan->vc.chan.device_node);
994 	}
995 
996 	dma_async_device_unregister(&dw->rd_edma);
997 	list_for_each_entry_safe(chan, _chan, &dw->rd_edma.channels,
998 				 vc.chan.device_node) {
999 		tasklet_kill(&chan->vc.task);
1000 		list_del(&chan->vc.chan.device_node);
1001 	}
1002 
1003 	/* Turn debugfs off */
1004 	dw_edma_v0_core_debugfs_off(chip);
1005 
1006 	return 0;
1007 }
1008 EXPORT_SYMBOL_GPL(dw_edma_remove);
1009 
1010 MODULE_LICENSE("GPL v2");
1011 MODULE_DESCRIPTION("Synopsys DesignWare eDMA controller core driver");
1012 MODULE_AUTHOR("Gustavo Pimentel <gustavo.pimentel@synopsys.com>");
1013