xref: /linux/drivers/dma/dw-edma/dw-edma-core.c (revision 746680ec6696585e30db3e18c93a63df9cbec39c)
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/dmaengine.h>
13 #include <linux/err.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/dma/edma.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/string_choices.h>
19 
20 #include "dw-edma-core.h"
21 #include "dw-edma-v0-core.h"
22 #include "dw-hdma-v0-core.h"
23 #include "../dmaengine.h"
24 #include "../virt-dma.h"
25 
26 static inline
27 struct dw_edma_desc *vd2dw_edma_desc(struct virt_dma_desc *vd)
28 {
29 	return container_of(vd, struct dw_edma_desc, vd);
30 }
31 
32 static inline
33 u64 dw_edma_get_pci_address(struct dw_edma_chan *chan, phys_addr_t cpu_addr)
34 {
35 	struct dw_edma_chip *chip = chan->dw->chip;
36 
37 	if (chip->ops->pci_address)
38 		return chip->ops->pci_address(chip->dev, cpu_addr);
39 
40 	return cpu_addr;
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_chip *chip = desc->chan->dw->chip;
68 	struct dw_edma_chan *chan = desc->chan;
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 = chip->ll_region_wr[chan->id].paddr;
86 		chunk->ll_region.vaddr = chip->ll_region_wr[chan->id].vaddr;
87 	} else {
88 		chunk->ll_region.paddr = chip->ll_region_rd[chan->id].paddr;
89 		chunk->ll_region.vaddr = chip->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 int dw_edma_start_transfer(struct dw_edma_chan *chan)
175 {
176 	struct dw_edma *dw = chan->dw;
177 	struct dw_edma_chunk *child;
178 	struct dw_edma_desc *desc;
179 	struct virt_dma_desc *vd;
180 
181 	vd = vchan_next_desc(&chan->vc);
182 	if (!vd)
183 		return 0;
184 
185 	desc = vd2dw_edma_desc(vd);
186 	if (!desc)
187 		return 0;
188 
189 	child = list_first_entry_or_null(&desc->chunk->list,
190 					 struct dw_edma_chunk, list);
191 	if (!child)
192 		return 0;
193 
194 	dw_edma_core_start(dw, child, !desc->xfer_sz);
195 	desc->xfer_sz += child->ll_region.sz;
196 	dw_edma_free_burst(child);
197 	list_del(&child->list);
198 	kfree(child);
199 	desc->chunks_alloc--;
200 
201 	return 1;
202 }
203 
204 static void dw_edma_device_caps(struct dma_chan *dchan,
205 				struct dma_slave_caps *caps)
206 {
207 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
208 
209 	if (chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL) {
210 		if (chan->dir == EDMA_DIR_READ)
211 			caps->directions = BIT(DMA_DEV_TO_MEM);
212 		else
213 			caps->directions = BIT(DMA_MEM_TO_DEV);
214 	} else {
215 		if (chan->dir == EDMA_DIR_WRITE)
216 			caps->directions = BIT(DMA_DEV_TO_MEM);
217 		else
218 			caps->directions = BIT(DMA_MEM_TO_DEV);
219 	}
220 }
221 
222 static int dw_edma_device_config(struct dma_chan *dchan,
223 				 struct dma_slave_config *config)
224 {
225 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
226 
227 	memcpy(&chan->config, config, sizeof(*config));
228 	chan->configured = true;
229 
230 	return 0;
231 }
232 
233 static int dw_edma_device_pause(struct dma_chan *dchan)
234 {
235 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
236 	int err = 0;
237 
238 	if (!chan->configured)
239 		err = -EPERM;
240 	else if (chan->status != EDMA_ST_BUSY)
241 		err = -EPERM;
242 	else if (chan->request != EDMA_REQ_NONE)
243 		err = -EPERM;
244 	else
245 		chan->request = EDMA_REQ_PAUSE;
246 
247 	return err;
248 }
249 
250 static int dw_edma_device_resume(struct dma_chan *dchan)
251 {
252 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
253 	int err = 0;
254 
255 	if (!chan->configured) {
256 		err = -EPERM;
257 	} else if (chan->status != EDMA_ST_PAUSE) {
258 		err = -EPERM;
259 	} else if (chan->request != EDMA_REQ_NONE) {
260 		err = -EPERM;
261 	} else {
262 		chan->status = EDMA_ST_BUSY;
263 		dw_edma_start_transfer(chan);
264 	}
265 
266 	return err;
267 }
268 
269 static int dw_edma_device_terminate_all(struct dma_chan *dchan)
270 {
271 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
272 	int err = 0;
273 
274 	if (!chan->configured) {
275 		/* Do nothing */
276 	} else if (chan->status == EDMA_ST_PAUSE) {
277 		chan->status = EDMA_ST_IDLE;
278 		chan->configured = false;
279 	} else if (chan->status == EDMA_ST_IDLE) {
280 		chan->configured = false;
281 	} else if (dw_edma_core_ch_status(chan) == DMA_COMPLETE) {
282 		/*
283 		 * The channel is in a false BUSY state, probably didn't
284 		 * receive or lost an interrupt
285 		 */
286 		chan->status = EDMA_ST_IDLE;
287 		chan->configured = false;
288 	} else if (chan->request > EDMA_REQ_PAUSE) {
289 		err = -EPERM;
290 	} else {
291 		chan->request = EDMA_REQ_STOP;
292 	}
293 
294 	return err;
295 }
296 
297 static void dw_edma_device_issue_pending(struct dma_chan *dchan)
298 {
299 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
300 	unsigned long flags;
301 
302 	if (!chan->configured)
303 		return;
304 
305 	spin_lock_irqsave(&chan->vc.lock, flags);
306 	if (vchan_issue_pending(&chan->vc) && chan->request == EDMA_REQ_NONE &&
307 	    chan->status == EDMA_ST_IDLE) {
308 		chan->status = EDMA_ST_BUSY;
309 		dw_edma_start_transfer(chan);
310 	}
311 	spin_unlock_irqrestore(&chan->vc.lock, flags);
312 }
313 
314 static enum dma_status
315 dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
316 			 struct dma_tx_state *txstate)
317 {
318 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
319 	struct dw_edma_desc *desc;
320 	struct virt_dma_desc *vd;
321 	unsigned long flags;
322 	enum dma_status ret;
323 	u32 residue = 0;
324 
325 	ret = dma_cookie_status(dchan, cookie, txstate);
326 	if (ret == DMA_COMPLETE)
327 		return ret;
328 
329 	if (ret == DMA_IN_PROGRESS && chan->status == EDMA_ST_PAUSE)
330 		ret = DMA_PAUSED;
331 
332 	if (!txstate)
333 		goto ret_residue;
334 
335 	spin_lock_irqsave(&chan->vc.lock, flags);
336 	vd = vchan_find_desc(&chan->vc, cookie);
337 	if (vd) {
338 		desc = vd2dw_edma_desc(vd);
339 		if (desc)
340 			residue = desc->alloc_sz - desc->xfer_sz;
341 	}
342 	spin_unlock_irqrestore(&chan->vc.lock, flags);
343 
344 ret_residue:
345 	dma_set_residue(txstate, residue);
346 
347 	return ret;
348 }
349 
350 static struct dma_async_tx_descriptor *
351 dw_edma_device_transfer(struct dw_edma_transfer *xfer)
352 {
353 	struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan);
354 	enum dma_transfer_direction dir = xfer->direction;
355 	struct scatterlist *sg = NULL;
356 	struct dw_edma_chunk *chunk;
357 	struct dw_edma_burst *burst;
358 	struct dw_edma_desc *desc;
359 	u64 src_addr, dst_addr;
360 	size_t fsz = 0;
361 	u32 cnt = 0;
362 	int i;
363 
364 	if (!chan->configured)
365 		return NULL;
366 
367 	/*
368 	 * Local Root Port/End-point              Remote End-point
369 	 * +-----------------------+ PCIe bus +----------------------+
370 	 * |                       |    +-+   |                      |
371 	 * |    DEV_TO_MEM   Rx Ch <----+ +---+ Tx Ch  DEV_TO_MEM    |
372 	 * |                       |    | |   |                      |
373 	 * |    MEM_TO_DEV   Tx Ch +----+ +---> Rx Ch  MEM_TO_DEV    |
374 	 * |                       |    +-+   |                      |
375 	 * +-----------------------+          +----------------------+
376 	 *
377 	 * 1. Normal logic:
378 	 * If eDMA is embedded into the DW PCIe RP/EP and controlled from the
379 	 * CPU/Application side, the Rx channel (EDMA_DIR_READ) will be used
380 	 * for the device read operations (DEV_TO_MEM) and the Tx channel
381 	 * (EDMA_DIR_WRITE) - for the write operations (MEM_TO_DEV).
382 	 *
383 	 * 2. Inverted logic:
384 	 * If eDMA is embedded into a Remote PCIe EP and is controlled by the
385 	 * MWr/MRd TLPs sent from the CPU's PCIe host controller, the Tx
386 	 * channel (EDMA_DIR_WRITE) will be used for the device read operations
387 	 * (DEV_TO_MEM) and the Rx channel (EDMA_DIR_READ) - for the write
388 	 * operations (MEM_TO_DEV).
389 	 *
390 	 * It is the client driver responsibility to choose a proper channel
391 	 * for the DMA transfers.
392 	 */
393 	if (chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL) {
394 		if ((chan->dir == EDMA_DIR_READ && dir != DMA_DEV_TO_MEM) ||
395 		    (chan->dir == EDMA_DIR_WRITE && dir != DMA_MEM_TO_DEV))
396 			return NULL;
397 	} else {
398 		if ((chan->dir == EDMA_DIR_WRITE && dir != DMA_DEV_TO_MEM) ||
399 		    (chan->dir == EDMA_DIR_READ && dir != DMA_MEM_TO_DEV))
400 			return NULL;
401 	}
402 
403 	if (xfer->type == EDMA_XFER_CYCLIC) {
404 		if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt)
405 			return NULL;
406 	} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
407 		if (xfer->xfer.sg.len < 1)
408 			return NULL;
409 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
410 		if (!xfer->xfer.il->numf || xfer->xfer.il->frame_size < 1)
411 			return NULL;
412 		if (!xfer->xfer.il->src_inc || !xfer->xfer.il->dst_inc)
413 			return NULL;
414 	} else {
415 		return NULL;
416 	}
417 
418 	desc = dw_edma_alloc_desc(chan);
419 	if (unlikely(!desc))
420 		goto err_alloc;
421 
422 	chunk = dw_edma_alloc_chunk(desc);
423 	if (unlikely(!chunk))
424 		goto err_alloc;
425 
426 	if (xfer->type == EDMA_XFER_INTERLEAVED) {
427 		src_addr = xfer->xfer.il->src_start;
428 		dst_addr = xfer->xfer.il->dst_start;
429 	} else {
430 		src_addr = chan->config.src_addr;
431 		dst_addr = chan->config.dst_addr;
432 	}
433 
434 	if (dir == DMA_DEV_TO_MEM)
435 		src_addr = dw_edma_get_pci_address(chan, (phys_addr_t)src_addr);
436 	else
437 		dst_addr = dw_edma_get_pci_address(chan, (phys_addr_t)dst_addr);
438 
439 	if (xfer->type == EDMA_XFER_CYCLIC) {
440 		cnt = xfer->xfer.cyclic.cnt;
441 	} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
442 		cnt = xfer->xfer.sg.len;
443 		sg = xfer->xfer.sg.sgl;
444 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
445 		cnt = xfer->xfer.il->numf * xfer->xfer.il->frame_size;
446 		fsz = xfer->xfer.il->frame_size;
447 	}
448 
449 	for (i = 0; i < cnt; i++) {
450 		if (xfer->type == EDMA_XFER_SCATTER_GATHER && !sg)
451 			break;
452 
453 		if (chunk->bursts_alloc == chan->ll_max) {
454 			chunk = dw_edma_alloc_chunk(desc);
455 			if (unlikely(!chunk))
456 				goto err_alloc;
457 		}
458 
459 		burst = dw_edma_alloc_burst(chunk);
460 		if (unlikely(!burst))
461 			goto err_alloc;
462 
463 		if (xfer->type == EDMA_XFER_CYCLIC)
464 			burst->sz = xfer->xfer.cyclic.len;
465 		else if (xfer->type == EDMA_XFER_SCATTER_GATHER)
466 			burst->sz = sg_dma_len(sg);
467 		else if (xfer->type == EDMA_XFER_INTERLEAVED)
468 			burst->sz = xfer->xfer.il->sgl[i % fsz].size;
469 
470 		chunk->ll_region.sz += burst->sz;
471 		desc->alloc_sz += burst->sz;
472 
473 		if (dir == DMA_DEV_TO_MEM) {
474 			burst->sar = src_addr;
475 			if (xfer->type == EDMA_XFER_CYCLIC) {
476 				burst->dar = xfer->xfer.cyclic.paddr;
477 			} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
478 				src_addr += sg_dma_len(sg);
479 				burst->dar = sg_dma_address(sg);
480 				/* Unlike the typical assumption by other
481 				 * drivers/IPs the peripheral memory isn't
482 				 * a FIFO memory, in this case, it's a
483 				 * linear memory and that why the source
484 				 * and destination addresses are increased
485 				 * by the same portion (data length)
486 				 */
487 			} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
488 				burst->dar = dst_addr;
489 			}
490 		} else {
491 			burst->dar = dst_addr;
492 			if (xfer->type == EDMA_XFER_CYCLIC) {
493 				burst->sar = xfer->xfer.cyclic.paddr;
494 			} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
495 				dst_addr += sg_dma_len(sg);
496 				burst->sar = sg_dma_address(sg);
497 				/* Unlike the typical assumption by other
498 				 * drivers/IPs the peripheral memory isn't
499 				 * a FIFO memory, in this case, it's a
500 				 * linear memory and that why the source
501 				 * and destination addresses are increased
502 				 * by the same portion (data length)
503 				 */
504 			}  else if (xfer->type == EDMA_XFER_INTERLEAVED) {
505 				burst->sar = src_addr;
506 			}
507 		}
508 
509 		if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
510 			sg = sg_next(sg);
511 		} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
512 			struct dma_interleaved_template *il = xfer->xfer.il;
513 			struct data_chunk *dc = &il->sgl[i % fsz];
514 
515 			src_addr += burst->sz;
516 			if (il->src_sgl)
517 				src_addr += dmaengine_get_src_icg(il, dc);
518 
519 			dst_addr += burst->sz;
520 			if (il->dst_sgl)
521 				dst_addr += dmaengine_get_dst_icg(il, dc);
522 		}
523 	}
524 
525 	return vchan_tx_prep(&chan->vc, &desc->vd, xfer->flags);
526 
527 err_alloc:
528 	if (desc)
529 		dw_edma_free_desc(desc);
530 
531 	return NULL;
532 }
533 
534 static struct dma_async_tx_descriptor *
535 dw_edma_device_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
536 			     unsigned int len,
537 			     enum dma_transfer_direction direction,
538 			     unsigned long flags, void *context)
539 {
540 	struct dw_edma_transfer xfer;
541 
542 	xfer.dchan = dchan;
543 	xfer.direction = direction;
544 	xfer.xfer.sg.sgl = sgl;
545 	xfer.xfer.sg.len = len;
546 	xfer.flags = flags;
547 	xfer.type = EDMA_XFER_SCATTER_GATHER;
548 
549 	return dw_edma_device_transfer(&xfer);
550 }
551 
552 static struct dma_async_tx_descriptor *
553 dw_edma_device_prep_dma_cyclic(struct dma_chan *dchan, dma_addr_t paddr,
554 			       size_t len, size_t count,
555 			       enum dma_transfer_direction direction,
556 			       unsigned long flags)
557 {
558 	struct dw_edma_transfer xfer;
559 
560 	xfer.dchan = dchan;
561 	xfer.direction = direction;
562 	xfer.xfer.cyclic.paddr = paddr;
563 	xfer.xfer.cyclic.len = len;
564 	xfer.xfer.cyclic.cnt = count;
565 	xfer.flags = flags;
566 	xfer.type = EDMA_XFER_CYCLIC;
567 
568 	return dw_edma_device_transfer(&xfer);
569 }
570 
571 static struct dma_async_tx_descriptor *
572 dw_edma_device_prep_interleaved_dma(struct dma_chan *dchan,
573 				    struct dma_interleaved_template *ilt,
574 				    unsigned long flags)
575 {
576 	struct dw_edma_transfer xfer;
577 
578 	xfer.dchan = dchan;
579 	xfer.direction = ilt->dir;
580 	xfer.xfer.il = ilt;
581 	xfer.flags = flags;
582 	xfer.type = EDMA_XFER_INTERLEAVED;
583 
584 	return dw_edma_device_transfer(&xfer);
585 }
586 
587 static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
588 {
589 	struct dw_edma_desc *desc;
590 	struct virt_dma_desc *vd;
591 	unsigned long flags;
592 
593 	spin_lock_irqsave(&chan->vc.lock, flags);
594 	vd = vchan_next_desc(&chan->vc);
595 	if (vd) {
596 		switch (chan->request) {
597 		case EDMA_REQ_NONE:
598 			desc = vd2dw_edma_desc(vd);
599 			if (!desc->chunks_alloc) {
600 				list_del(&vd->node);
601 				vchan_cookie_complete(vd);
602 			}
603 
604 			/* Continue transferring if there are remaining chunks or issued requests.
605 			 */
606 			chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
607 			break;
608 
609 		case EDMA_REQ_STOP:
610 			list_del(&vd->node);
611 			vchan_cookie_complete(vd);
612 			chan->request = EDMA_REQ_NONE;
613 			chan->status = EDMA_ST_IDLE;
614 			break;
615 
616 		case EDMA_REQ_PAUSE:
617 			chan->request = EDMA_REQ_NONE;
618 			chan->status = EDMA_ST_PAUSE;
619 			break;
620 
621 		default:
622 			break;
623 		}
624 	}
625 	spin_unlock_irqrestore(&chan->vc.lock, flags);
626 }
627 
628 static void dw_edma_abort_interrupt(struct dw_edma_chan *chan)
629 {
630 	struct virt_dma_desc *vd;
631 	unsigned long flags;
632 
633 	spin_lock_irqsave(&chan->vc.lock, flags);
634 	vd = vchan_next_desc(&chan->vc);
635 	if (vd) {
636 		list_del(&vd->node);
637 		vchan_cookie_complete(vd);
638 	}
639 	spin_unlock_irqrestore(&chan->vc.lock, flags);
640 	chan->request = EDMA_REQ_NONE;
641 	chan->status = EDMA_ST_IDLE;
642 }
643 
644 static inline irqreturn_t dw_edma_interrupt_write(int irq, void *data)
645 {
646 	struct dw_edma_irq *dw_irq = data;
647 
648 	return dw_edma_core_handle_int(dw_irq, EDMA_DIR_WRITE,
649 				       dw_edma_done_interrupt,
650 				       dw_edma_abort_interrupt);
651 }
652 
653 static inline irqreturn_t dw_edma_interrupt_read(int irq, void *data)
654 {
655 	struct dw_edma_irq *dw_irq = data;
656 
657 	return dw_edma_core_handle_int(dw_irq, EDMA_DIR_READ,
658 				       dw_edma_done_interrupt,
659 				       dw_edma_abort_interrupt);
660 }
661 
662 static irqreturn_t dw_edma_interrupt_common(int irq, void *data)
663 {
664 	irqreturn_t ret = IRQ_NONE;
665 
666 	ret |= dw_edma_interrupt_write(irq, data);
667 	ret |= dw_edma_interrupt_read(irq, data);
668 
669 	return ret;
670 }
671 
672 static int dw_edma_alloc_chan_resources(struct dma_chan *dchan)
673 {
674 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
675 
676 	if (chan->status != EDMA_ST_IDLE)
677 		return -EBUSY;
678 
679 	return 0;
680 }
681 
682 static void dw_edma_free_chan_resources(struct dma_chan *dchan)
683 {
684 	unsigned long timeout = jiffies + msecs_to_jiffies(5000);
685 	int ret;
686 
687 	while (time_before(jiffies, timeout)) {
688 		ret = dw_edma_device_terminate_all(dchan);
689 		if (!ret)
690 			break;
691 
692 		if (time_after_eq(jiffies, timeout))
693 			return;
694 
695 		cpu_relax();
696 	}
697 }
698 
699 static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
700 {
701 	struct dw_edma_chip *chip = dw->chip;
702 	struct device *dev = chip->dev;
703 	struct dw_edma_chan *chan;
704 	struct dw_edma_irq *irq;
705 	struct dma_device *dma;
706 	u32 i, ch_cnt;
707 	u32 pos;
708 
709 	ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
710 	dma = &dw->dma;
711 
712 	INIT_LIST_HEAD(&dma->channels);
713 
714 	for (i = 0; i < ch_cnt; i++) {
715 		chan = &dw->chan[i];
716 
717 		chan->dw = dw;
718 
719 		if (i < dw->wr_ch_cnt) {
720 			chan->id = i;
721 			chan->dir = EDMA_DIR_WRITE;
722 		} else {
723 			chan->id = i - dw->wr_ch_cnt;
724 			chan->dir = EDMA_DIR_READ;
725 		}
726 
727 		chan->configured = false;
728 		chan->request = EDMA_REQ_NONE;
729 		chan->status = EDMA_ST_IDLE;
730 
731 		if (chan->dir == EDMA_DIR_WRITE)
732 			chan->ll_max = (chip->ll_region_wr[chan->id].sz / EDMA_LL_SZ);
733 		else
734 			chan->ll_max = (chip->ll_region_rd[chan->id].sz / EDMA_LL_SZ);
735 		chan->ll_max -= 1;
736 
737 		dev_vdbg(dev, "L. List:\tChannel %s[%u] max_cnt=%u\n",
738 			 str_write_read(chan->dir == EDMA_DIR_WRITE),
739 			 chan->id, chan->ll_max);
740 
741 		if (dw->nr_irqs == 1)
742 			pos = 0;
743 		else if (chan->dir == EDMA_DIR_WRITE)
744 			pos = chan->id % wr_alloc;
745 		else
746 			pos = wr_alloc + chan->id % rd_alloc;
747 
748 		irq = &dw->irq[pos];
749 
750 		if (chan->dir == EDMA_DIR_WRITE)
751 			irq->wr_mask |= BIT(chan->id);
752 		else
753 			irq->rd_mask |= BIT(chan->id);
754 
755 		irq->dw = dw;
756 		memcpy(&chan->msi, &irq->msi, sizeof(chan->msi));
757 
758 		dev_vdbg(dev, "MSI:\t\tChannel %s[%u] addr=0x%.8x%.8x, data=0x%.8x\n",
759 			 str_write_read(chan->dir == EDMA_DIR_WRITE),
760 			 chan->id,
761 			 chan->msi.address_hi, chan->msi.address_lo,
762 			 chan->msi.data);
763 
764 		chan->vc.desc_free = vchan_free_desc;
765 		chan->vc.chan.private = chan->dir == EDMA_DIR_WRITE ?
766 					&dw->chip->dt_region_wr[chan->id] :
767 					&dw->chip->dt_region_rd[chan->id];
768 
769 		vchan_init(&chan->vc, dma);
770 
771 		dw_edma_core_ch_config(chan);
772 	}
773 
774 	/* Set DMA channel capabilities */
775 	dma_cap_zero(dma->cap_mask);
776 	dma_cap_set(DMA_SLAVE, dma->cap_mask);
777 	dma_cap_set(DMA_CYCLIC, dma->cap_mask);
778 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
779 	dma_cap_set(DMA_INTERLEAVE, dma->cap_mask);
780 	dma->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
781 	dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
782 	dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
783 	dma->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
784 
785 	/* Set DMA channel callbacks */
786 	dma->dev = chip->dev;
787 	dma->device_alloc_chan_resources = dw_edma_alloc_chan_resources;
788 	dma->device_free_chan_resources = dw_edma_free_chan_resources;
789 	dma->device_caps = dw_edma_device_caps;
790 	dma->device_config = dw_edma_device_config;
791 	dma->device_pause = dw_edma_device_pause;
792 	dma->device_resume = dw_edma_device_resume;
793 	dma->device_terminate_all = dw_edma_device_terminate_all;
794 	dma->device_issue_pending = dw_edma_device_issue_pending;
795 	dma->device_tx_status = dw_edma_device_tx_status;
796 	dma->device_prep_slave_sg = dw_edma_device_prep_slave_sg;
797 	dma->device_prep_dma_cyclic = dw_edma_device_prep_dma_cyclic;
798 	dma->device_prep_interleaved_dma = dw_edma_device_prep_interleaved_dma;
799 
800 	dma_set_max_seg_size(dma->dev, U32_MAX);
801 
802 	/* Register DMA device */
803 	return dma_async_device_register(dma);
804 }
805 
806 static inline void dw_edma_dec_irq_alloc(int *nr_irqs, u32 *alloc, u16 cnt)
807 {
808 	if (*nr_irqs && *alloc < cnt) {
809 		(*alloc)++;
810 		(*nr_irqs)--;
811 	}
812 }
813 
814 static inline void dw_edma_add_irq_mask(u32 *mask, u32 alloc, u16 cnt)
815 {
816 	while (*mask * alloc < cnt)
817 		(*mask)++;
818 }
819 
820 static int dw_edma_irq_request(struct dw_edma *dw,
821 			       u32 *wr_alloc, u32 *rd_alloc)
822 {
823 	struct dw_edma_chip *chip = dw->chip;
824 	struct device *dev = dw->chip->dev;
825 	u32 wr_mask = 1;
826 	u32 rd_mask = 1;
827 	int i, err = 0;
828 	u32 ch_cnt;
829 	int irq;
830 
831 	ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
832 
833 	if (chip->nr_irqs < 1 || !chip->ops->irq_vector)
834 		return -EINVAL;
835 
836 	dw->irq = devm_kcalloc(dev, chip->nr_irqs, sizeof(*dw->irq), GFP_KERNEL);
837 	if (!dw->irq)
838 		return -ENOMEM;
839 
840 	if (chip->nr_irqs == 1) {
841 		/* Common IRQ shared among all channels */
842 		irq = chip->ops->irq_vector(dev, 0);
843 		err = request_irq(irq, dw_edma_interrupt_common,
844 				  IRQF_SHARED, dw->name, &dw->irq[0]);
845 		if (err) {
846 			dw->nr_irqs = 0;
847 			return err;
848 		}
849 
850 		if (irq_get_msi_desc(irq))
851 			get_cached_msi_msg(irq, &dw->irq[0].msi);
852 
853 		dw->nr_irqs = 1;
854 	} else {
855 		/* Distribute IRQs equally among all channels */
856 		int tmp = chip->nr_irqs;
857 
858 		while (tmp && (*wr_alloc + *rd_alloc) < ch_cnt) {
859 			dw_edma_dec_irq_alloc(&tmp, wr_alloc, dw->wr_ch_cnt);
860 			dw_edma_dec_irq_alloc(&tmp, rd_alloc, dw->rd_ch_cnt);
861 		}
862 
863 		dw_edma_add_irq_mask(&wr_mask, *wr_alloc, dw->wr_ch_cnt);
864 		dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt);
865 
866 		for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
867 			irq = chip->ops->irq_vector(dev, i);
868 			err = request_irq(irq,
869 					  i < *wr_alloc ?
870 						dw_edma_interrupt_write :
871 						dw_edma_interrupt_read,
872 					  IRQF_SHARED, dw->name,
873 					  &dw->irq[i]);
874 			if (err)
875 				goto err_irq_free;
876 
877 			if (irq_get_msi_desc(irq))
878 				get_cached_msi_msg(irq, &dw->irq[i].msi);
879 		}
880 
881 		dw->nr_irqs = i;
882 	}
883 
884 	return 0;
885 
886 err_irq_free:
887 	for  (i--; i >= 0; i--) {
888 		irq = chip->ops->irq_vector(dev, i);
889 		free_irq(irq, &dw->irq[i]);
890 	}
891 
892 	return err;
893 }
894 
895 int dw_edma_probe(struct dw_edma_chip *chip)
896 {
897 	struct device *dev;
898 	struct dw_edma *dw;
899 	u32 wr_alloc = 0;
900 	u32 rd_alloc = 0;
901 	int i, err;
902 
903 	if (!chip)
904 		return -EINVAL;
905 
906 	dev = chip->dev;
907 	if (!dev || !chip->ops)
908 		return -EINVAL;
909 
910 	dw = devm_kzalloc(dev, sizeof(*dw), GFP_KERNEL);
911 	if (!dw)
912 		return -ENOMEM;
913 
914 	dw->chip = chip;
915 
916 	if (dw->chip->mf == EDMA_MF_HDMA_NATIVE)
917 		dw_hdma_v0_core_register(dw);
918 	else
919 		dw_edma_v0_core_register(dw);
920 
921 	raw_spin_lock_init(&dw->lock);
922 
923 	dw->wr_ch_cnt = min_t(u16, chip->ll_wr_cnt,
924 			      dw_edma_core_ch_count(dw, EDMA_DIR_WRITE));
925 	dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt, EDMA_MAX_WR_CH);
926 
927 	dw->rd_ch_cnt = min_t(u16, chip->ll_rd_cnt,
928 			      dw_edma_core_ch_count(dw, EDMA_DIR_READ));
929 	dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt, EDMA_MAX_RD_CH);
930 
931 	if (!dw->wr_ch_cnt && !dw->rd_ch_cnt)
932 		return -EINVAL;
933 
934 	dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n",
935 		 dw->wr_ch_cnt, dw->rd_ch_cnt);
936 
937 	/* Allocate channels */
938 	dw->chan = devm_kcalloc(dev, dw->wr_ch_cnt + dw->rd_ch_cnt,
939 				sizeof(*dw->chan), GFP_KERNEL);
940 	if (!dw->chan)
941 		return -ENOMEM;
942 
943 	snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%s",
944 		 dev_name(chip->dev));
945 
946 	/* Disable eDMA, only to establish the ideal initial conditions */
947 	dw_edma_core_off(dw);
948 
949 	/* Request IRQs */
950 	err = dw_edma_irq_request(dw, &wr_alloc, &rd_alloc);
951 	if (err)
952 		return err;
953 
954 	/* Setup write/read channels */
955 	err = dw_edma_channel_setup(dw, wr_alloc, rd_alloc);
956 	if (err)
957 		goto err_irq_free;
958 
959 	/* Turn debugfs on */
960 	dw_edma_core_debugfs_on(dw);
961 
962 	chip->dw = dw;
963 
964 	return 0;
965 
966 err_irq_free:
967 	for (i = (dw->nr_irqs - 1); i >= 0; i--)
968 		free_irq(chip->ops->irq_vector(dev, i), &dw->irq[i]);
969 
970 	return err;
971 }
972 EXPORT_SYMBOL_GPL(dw_edma_probe);
973 
974 int dw_edma_remove(struct dw_edma_chip *chip)
975 {
976 	struct dw_edma_chan *chan, *_chan;
977 	struct device *dev = chip->dev;
978 	struct dw_edma *dw = chip->dw;
979 	int i;
980 
981 	/* Skip removal if no private data found */
982 	if (!dw)
983 		return -ENODEV;
984 
985 	/* Disable eDMA */
986 	dw_edma_core_off(dw);
987 
988 	/* Free irqs */
989 	for (i = (dw->nr_irqs - 1); i >= 0; i--)
990 		free_irq(chip->ops->irq_vector(dev, i), &dw->irq[i]);
991 
992 	/* Deregister eDMA device */
993 	dma_async_device_unregister(&dw->dma);
994 	list_for_each_entry_safe(chan, _chan, &dw->dma.channels,
995 				 vc.chan.device_node) {
996 		tasklet_kill(&chan->vc.task);
997 		list_del(&chan->vc.chan.device_node);
998 	}
999 
1000 	return 0;
1001 }
1002 EXPORT_SYMBOL_GPL(dw_edma_remove);
1003 
1004 MODULE_LICENSE("GPL v2");
1005 MODULE_DESCRIPTION("Synopsys DesignWare eDMA controller core driver");
1006 MODULE_AUTHOR("Gustavo Pimentel <gustavo.pimentel@synopsys.com>");
1007