xref: /linux/drivers/dma/mmp_pdma.c (revision 3839a7460721b87501134697b7b90c45dcc7825d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2012 Marvell International Ltd.
4  */
5 
6 #include <linux/err.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/types.h>
10 #include <linux/interrupt.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/slab.h>
13 #include <linux/dmaengine.h>
14 #include <linux/platform_device.h>
15 #include <linux/device.h>
16 #include <linux/platform_data/mmp_dma.h>
17 #include <linux/dmapool.h>
18 #include <linux/of_device.h>
19 #include <linux/of_dma.h>
20 #include <linux/of.h>
21 #include <linux/dma/mmp-pdma.h>
22 
23 #include "dmaengine.h"
24 
25 #define DCSR		0x0000
26 #define DALGN		0x00a0
27 #define DINT		0x00f0
28 #define DDADR		0x0200
29 #define DSADR(n)	(0x0204 + ((n) << 4))
30 #define DTADR(n)	(0x0208 + ((n) << 4))
31 #define DCMD		0x020c
32 
33 #define DCSR_RUN	BIT(31)	/* Run Bit (read / write) */
34 #define DCSR_NODESC	BIT(30)	/* No-Descriptor Fetch (read / write) */
35 #define DCSR_STOPIRQEN	BIT(29)	/* Stop Interrupt Enable (read / write) */
36 #define DCSR_REQPEND	BIT(8)	/* Request Pending (read-only) */
37 #define DCSR_STOPSTATE	BIT(3)	/* Stop State (read-only) */
38 #define DCSR_ENDINTR	BIT(2)	/* End Interrupt (read / write) */
39 #define DCSR_STARTINTR	BIT(1)	/* Start Interrupt (read / write) */
40 #define DCSR_BUSERR	BIT(0)	/* Bus Error Interrupt (read / write) */
41 
42 #define DCSR_EORIRQEN	BIT(28)	/* End of Receive Interrupt Enable (R/W) */
43 #define DCSR_EORJMPEN	BIT(27)	/* Jump to next descriptor on EOR */
44 #define DCSR_EORSTOPEN	BIT(26)	/* STOP on an EOR */
45 #define DCSR_SETCMPST	BIT(25)	/* Set Descriptor Compare Status */
46 #define DCSR_CLRCMPST	BIT(24)	/* Clear Descriptor Compare Status */
47 #define DCSR_CMPST	BIT(10)	/* The Descriptor Compare Status */
48 #define DCSR_EORINTR	BIT(9)	/* The end of Receive */
49 
50 #define DRCMR(n)	((((n) < 64) ? 0x0100 : 0x1100) + (((n) & 0x3f) << 2))
51 #define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
52 #define DRCMR_CHLNUM	0x1f	/* mask for Channel Number (read / write) */
53 
54 #define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
55 #define DDADR_STOP	BIT(0)	/* Stop (read / write) */
56 
57 #define DCMD_INCSRCADDR	BIT(31)	/* Source Address Increment Setting. */
58 #define DCMD_INCTRGADDR	BIT(30)	/* Target Address Increment Setting. */
59 #define DCMD_FLOWSRC	BIT(29)	/* Flow Control by the source. */
60 #define DCMD_FLOWTRG	BIT(28)	/* Flow Control by the target. */
61 #define DCMD_STARTIRQEN	BIT(22)	/* Start Interrupt Enable */
62 #define DCMD_ENDIRQEN	BIT(21)	/* End Interrupt Enable */
63 #define DCMD_ENDIAN	BIT(18)	/* Device Endian-ness. */
64 #define DCMD_BURST8	(1 << 16)	/* 8 byte burst */
65 #define DCMD_BURST16	(2 << 16)	/* 16 byte burst */
66 #define DCMD_BURST32	(3 << 16)	/* 32 byte burst */
67 #define DCMD_WIDTH1	(1 << 14)	/* 1 byte width */
68 #define DCMD_WIDTH2	(2 << 14)	/* 2 byte width (HalfWord) */
69 #define DCMD_WIDTH4	(3 << 14)	/* 4 byte width (Word) */
70 #define DCMD_LENGTH	0x01fff		/* length mask (max = 8K - 1) */
71 
72 #define PDMA_MAX_DESC_BYTES	DCMD_LENGTH
73 
74 struct mmp_pdma_desc_hw {
75 	u32 ddadr;	/* Points to the next descriptor + flags */
76 	u32 dsadr;	/* DSADR value for the current transfer */
77 	u32 dtadr;	/* DTADR value for the current transfer */
78 	u32 dcmd;	/* DCMD value for the current transfer */
79 } __aligned(32);
80 
81 struct mmp_pdma_desc_sw {
82 	struct mmp_pdma_desc_hw desc;
83 	struct list_head node;
84 	struct list_head tx_list;
85 	struct dma_async_tx_descriptor async_tx;
86 };
87 
88 struct mmp_pdma_phy;
89 
90 struct mmp_pdma_chan {
91 	struct device *dev;
92 	struct dma_chan chan;
93 	struct dma_async_tx_descriptor desc;
94 	struct mmp_pdma_phy *phy;
95 	enum dma_transfer_direction dir;
96 	struct dma_slave_config slave_config;
97 
98 	struct mmp_pdma_desc_sw *cyclic_first;	/* first desc_sw if channel
99 						 * is in cyclic mode */
100 
101 	/* channel's basic info */
102 	struct tasklet_struct tasklet;
103 	u32 dcmd;
104 	u32 drcmr;
105 	u32 dev_addr;
106 
107 	/* list for desc */
108 	spinlock_t desc_lock;		/* Descriptor list lock */
109 	struct list_head chain_pending;	/* Link descriptors queue for pending */
110 	struct list_head chain_running;	/* Link descriptors queue for running */
111 	bool idle;			/* channel statue machine */
112 	bool byte_align;
113 
114 	struct dma_pool *desc_pool;	/* Descriptors pool */
115 };
116 
117 struct mmp_pdma_phy {
118 	int idx;
119 	void __iomem *base;
120 	struct mmp_pdma_chan *vchan;
121 };
122 
123 struct mmp_pdma_device {
124 	int				dma_channels;
125 	void __iomem			*base;
126 	struct device			*dev;
127 	struct dma_device		device;
128 	struct mmp_pdma_phy		*phy;
129 	spinlock_t phy_lock; /* protect alloc/free phy channels */
130 };
131 
132 #define tx_to_mmp_pdma_desc(tx)					\
133 	container_of(tx, struct mmp_pdma_desc_sw, async_tx)
134 #define to_mmp_pdma_desc(lh)					\
135 	container_of(lh, struct mmp_pdma_desc_sw, node)
136 #define to_mmp_pdma_chan(dchan)					\
137 	container_of(dchan, struct mmp_pdma_chan, chan)
138 #define to_mmp_pdma_dev(dmadev)					\
139 	container_of(dmadev, struct mmp_pdma_device, device)
140 
141 static int mmp_pdma_config_write(struct dma_chan *dchan,
142 			   struct dma_slave_config *cfg,
143 			   enum dma_transfer_direction direction);
144 
145 static void set_desc(struct mmp_pdma_phy *phy, dma_addr_t addr)
146 {
147 	u32 reg = (phy->idx << 4) + DDADR;
148 
149 	writel(addr, phy->base + reg);
150 }
151 
152 static void enable_chan(struct mmp_pdma_phy *phy)
153 {
154 	u32 reg, dalgn;
155 
156 	if (!phy->vchan)
157 		return;
158 
159 	reg = DRCMR(phy->vchan->drcmr);
160 	writel(DRCMR_MAPVLD | phy->idx, phy->base + reg);
161 
162 	dalgn = readl(phy->base + DALGN);
163 	if (phy->vchan->byte_align)
164 		dalgn |= 1 << phy->idx;
165 	else
166 		dalgn &= ~(1 << phy->idx);
167 	writel(dalgn, phy->base + DALGN);
168 
169 	reg = (phy->idx << 2) + DCSR;
170 	writel(readl(phy->base + reg) | DCSR_RUN, phy->base + reg);
171 }
172 
173 static void disable_chan(struct mmp_pdma_phy *phy)
174 {
175 	u32 reg;
176 
177 	if (!phy)
178 		return;
179 
180 	reg = (phy->idx << 2) + DCSR;
181 	writel(readl(phy->base + reg) & ~DCSR_RUN, phy->base + reg);
182 }
183 
184 static int clear_chan_irq(struct mmp_pdma_phy *phy)
185 {
186 	u32 dcsr;
187 	u32 dint = readl(phy->base + DINT);
188 	u32 reg = (phy->idx << 2) + DCSR;
189 
190 	if (!(dint & BIT(phy->idx)))
191 		return -EAGAIN;
192 
193 	/* clear irq */
194 	dcsr = readl(phy->base + reg);
195 	writel(dcsr, phy->base + reg);
196 	if ((dcsr & DCSR_BUSERR) && (phy->vchan))
197 		dev_warn(phy->vchan->dev, "DCSR_BUSERR\n");
198 
199 	return 0;
200 }
201 
202 static irqreturn_t mmp_pdma_chan_handler(int irq, void *dev_id)
203 {
204 	struct mmp_pdma_phy *phy = dev_id;
205 
206 	if (clear_chan_irq(phy) != 0)
207 		return IRQ_NONE;
208 
209 	tasklet_schedule(&phy->vchan->tasklet);
210 	return IRQ_HANDLED;
211 }
212 
213 static irqreturn_t mmp_pdma_int_handler(int irq, void *dev_id)
214 {
215 	struct mmp_pdma_device *pdev = dev_id;
216 	struct mmp_pdma_phy *phy;
217 	u32 dint = readl(pdev->base + DINT);
218 	int i, ret;
219 	int irq_num = 0;
220 
221 	while (dint) {
222 		i = __ffs(dint);
223 		/* only handle interrupts belonging to pdma driver*/
224 		if (i >= pdev->dma_channels)
225 			break;
226 		dint &= (dint - 1);
227 		phy = &pdev->phy[i];
228 		ret = mmp_pdma_chan_handler(irq, phy);
229 		if (ret == IRQ_HANDLED)
230 			irq_num++;
231 	}
232 
233 	if (irq_num)
234 		return IRQ_HANDLED;
235 
236 	return IRQ_NONE;
237 }
238 
239 /* lookup free phy channel as descending priority */
240 static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan)
241 {
242 	int prio, i;
243 	struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
244 	struct mmp_pdma_phy *phy, *found = NULL;
245 	unsigned long flags;
246 
247 	/*
248 	 * dma channel priorities
249 	 * ch 0 - 3,  16 - 19  <--> (0)
250 	 * ch 4 - 7,  20 - 23  <--> (1)
251 	 * ch 8 - 11, 24 - 27  <--> (2)
252 	 * ch 12 - 15, 28 - 31  <--> (3)
253 	 */
254 
255 	spin_lock_irqsave(&pdev->phy_lock, flags);
256 	for (prio = 0; prio <= ((pdev->dma_channels - 1) & 0xf) >> 2; prio++) {
257 		for (i = 0; i < pdev->dma_channels; i++) {
258 			if (prio != (i & 0xf) >> 2)
259 				continue;
260 			phy = &pdev->phy[i];
261 			if (!phy->vchan) {
262 				phy->vchan = pchan;
263 				found = phy;
264 				goto out_unlock;
265 			}
266 		}
267 	}
268 
269 out_unlock:
270 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
271 	return found;
272 }
273 
274 static void mmp_pdma_free_phy(struct mmp_pdma_chan *pchan)
275 {
276 	struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
277 	unsigned long flags;
278 	u32 reg;
279 
280 	if (!pchan->phy)
281 		return;
282 
283 	/* clear the channel mapping in DRCMR */
284 	reg = DRCMR(pchan->drcmr);
285 	writel(0, pchan->phy->base + reg);
286 
287 	spin_lock_irqsave(&pdev->phy_lock, flags);
288 	pchan->phy->vchan = NULL;
289 	pchan->phy = NULL;
290 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
291 }
292 
293 /**
294  * start_pending_queue - transfer any pending transactions
295  * pending list ==> running list
296  */
297 static void start_pending_queue(struct mmp_pdma_chan *chan)
298 {
299 	struct mmp_pdma_desc_sw *desc;
300 
301 	/* still in running, irq will start the pending list */
302 	if (!chan->idle) {
303 		dev_dbg(chan->dev, "DMA controller still busy\n");
304 		return;
305 	}
306 
307 	if (list_empty(&chan->chain_pending)) {
308 		/* chance to re-fetch phy channel with higher prio */
309 		mmp_pdma_free_phy(chan);
310 		dev_dbg(chan->dev, "no pending list\n");
311 		return;
312 	}
313 
314 	if (!chan->phy) {
315 		chan->phy = lookup_phy(chan);
316 		if (!chan->phy) {
317 			dev_dbg(chan->dev, "no free dma channel\n");
318 			return;
319 		}
320 	}
321 
322 	/*
323 	 * pending -> running
324 	 * reintilize pending list
325 	 */
326 	desc = list_first_entry(&chan->chain_pending,
327 				struct mmp_pdma_desc_sw, node);
328 	list_splice_tail_init(&chan->chain_pending, &chan->chain_running);
329 
330 	/*
331 	 * Program the descriptor's address into the DMA controller,
332 	 * then start the DMA transaction
333 	 */
334 	set_desc(chan->phy, desc->async_tx.phys);
335 	enable_chan(chan->phy);
336 	chan->idle = false;
337 }
338 
339 
340 /* desc->tx_list ==> pending list */
341 static dma_cookie_t mmp_pdma_tx_submit(struct dma_async_tx_descriptor *tx)
342 {
343 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(tx->chan);
344 	struct mmp_pdma_desc_sw *desc = tx_to_mmp_pdma_desc(tx);
345 	struct mmp_pdma_desc_sw *child;
346 	unsigned long flags;
347 	dma_cookie_t cookie = -EBUSY;
348 
349 	spin_lock_irqsave(&chan->desc_lock, flags);
350 
351 	list_for_each_entry(child, &desc->tx_list, node) {
352 		cookie = dma_cookie_assign(&child->async_tx);
353 	}
354 
355 	/* softly link to pending list - desc->tx_list ==> pending list */
356 	list_splice_tail_init(&desc->tx_list, &chan->chain_pending);
357 
358 	spin_unlock_irqrestore(&chan->desc_lock, flags);
359 
360 	return cookie;
361 }
362 
363 static struct mmp_pdma_desc_sw *
364 mmp_pdma_alloc_descriptor(struct mmp_pdma_chan *chan)
365 {
366 	struct mmp_pdma_desc_sw *desc;
367 	dma_addr_t pdesc;
368 
369 	desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
370 	if (!desc) {
371 		dev_err(chan->dev, "out of memory for link descriptor\n");
372 		return NULL;
373 	}
374 
375 	INIT_LIST_HEAD(&desc->tx_list);
376 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan);
377 	/* each desc has submit */
378 	desc->async_tx.tx_submit = mmp_pdma_tx_submit;
379 	desc->async_tx.phys = pdesc;
380 
381 	return desc;
382 }
383 
384 /**
385  * mmp_pdma_alloc_chan_resources - Allocate resources for DMA channel.
386  *
387  * This function will create a dma pool for descriptor allocation.
388  * Request irq only when channel is requested
389  * Return - The number of allocated descriptors.
390  */
391 
392 static int mmp_pdma_alloc_chan_resources(struct dma_chan *dchan)
393 {
394 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
395 
396 	if (chan->desc_pool)
397 		return 1;
398 
399 	chan->desc_pool = dma_pool_create(dev_name(&dchan->dev->device),
400 					  chan->dev,
401 					  sizeof(struct mmp_pdma_desc_sw),
402 					  __alignof__(struct mmp_pdma_desc_sw),
403 					  0);
404 	if (!chan->desc_pool) {
405 		dev_err(chan->dev, "unable to allocate descriptor pool\n");
406 		return -ENOMEM;
407 	}
408 
409 	mmp_pdma_free_phy(chan);
410 	chan->idle = true;
411 	chan->dev_addr = 0;
412 	return 1;
413 }
414 
415 static void mmp_pdma_free_desc_list(struct mmp_pdma_chan *chan,
416 				    struct list_head *list)
417 {
418 	struct mmp_pdma_desc_sw *desc, *_desc;
419 
420 	list_for_each_entry_safe(desc, _desc, list, node) {
421 		list_del(&desc->node);
422 		dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
423 	}
424 }
425 
426 static void mmp_pdma_free_chan_resources(struct dma_chan *dchan)
427 {
428 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
429 	unsigned long flags;
430 
431 	spin_lock_irqsave(&chan->desc_lock, flags);
432 	mmp_pdma_free_desc_list(chan, &chan->chain_pending);
433 	mmp_pdma_free_desc_list(chan, &chan->chain_running);
434 	spin_unlock_irqrestore(&chan->desc_lock, flags);
435 
436 	dma_pool_destroy(chan->desc_pool);
437 	chan->desc_pool = NULL;
438 	chan->idle = true;
439 	chan->dev_addr = 0;
440 	mmp_pdma_free_phy(chan);
441 	return;
442 }
443 
444 static struct dma_async_tx_descriptor *
445 mmp_pdma_prep_memcpy(struct dma_chan *dchan,
446 		     dma_addr_t dma_dst, dma_addr_t dma_src,
447 		     size_t len, unsigned long flags)
448 {
449 	struct mmp_pdma_chan *chan;
450 	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
451 	size_t copy = 0;
452 
453 	if (!dchan)
454 		return NULL;
455 
456 	if (!len)
457 		return NULL;
458 
459 	chan = to_mmp_pdma_chan(dchan);
460 	chan->byte_align = false;
461 
462 	if (!chan->dir) {
463 		chan->dir = DMA_MEM_TO_MEM;
464 		chan->dcmd = DCMD_INCTRGADDR | DCMD_INCSRCADDR;
465 		chan->dcmd |= DCMD_BURST32;
466 	}
467 
468 	do {
469 		/* Allocate the link descriptor from DMA pool */
470 		new = mmp_pdma_alloc_descriptor(chan);
471 		if (!new) {
472 			dev_err(chan->dev, "no memory for desc\n");
473 			goto fail;
474 		}
475 
476 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
477 		if (dma_src & 0x7 || dma_dst & 0x7)
478 			chan->byte_align = true;
479 
480 		new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & copy);
481 		new->desc.dsadr = dma_src;
482 		new->desc.dtadr = dma_dst;
483 
484 		if (!first)
485 			first = new;
486 		else
487 			prev->desc.ddadr = new->async_tx.phys;
488 
489 		new->async_tx.cookie = 0;
490 		async_tx_ack(&new->async_tx);
491 
492 		prev = new;
493 		len -= copy;
494 
495 		if (chan->dir == DMA_MEM_TO_DEV) {
496 			dma_src += copy;
497 		} else if (chan->dir == DMA_DEV_TO_MEM) {
498 			dma_dst += copy;
499 		} else if (chan->dir == DMA_MEM_TO_MEM) {
500 			dma_src += copy;
501 			dma_dst += copy;
502 		}
503 
504 		/* Insert the link descriptor to the LD ring */
505 		list_add_tail(&new->node, &first->tx_list);
506 	} while (len);
507 
508 	first->async_tx.flags = flags; /* client is in control of this ack */
509 	first->async_tx.cookie = -EBUSY;
510 
511 	/* last desc and fire IRQ */
512 	new->desc.ddadr = DDADR_STOP;
513 	new->desc.dcmd |= DCMD_ENDIRQEN;
514 
515 	chan->cyclic_first = NULL;
516 
517 	return &first->async_tx;
518 
519 fail:
520 	if (first)
521 		mmp_pdma_free_desc_list(chan, &first->tx_list);
522 	return NULL;
523 }
524 
525 static struct dma_async_tx_descriptor *
526 mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
527 		       unsigned int sg_len, enum dma_transfer_direction dir,
528 		       unsigned long flags, void *context)
529 {
530 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
531 	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new = NULL;
532 	size_t len, avail;
533 	struct scatterlist *sg;
534 	dma_addr_t addr;
535 	int i;
536 
537 	if ((sgl == NULL) || (sg_len == 0))
538 		return NULL;
539 
540 	chan->byte_align = false;
541 
542 	mmp_pdma_config_write(dchan, &chan->slave_config, dir);
543 
544 	for_each_sg(sgl, sg, sg_len, i) {
545 		addr = sg_dma_address(sg);
546 		avail = sg_dma_len(sgl);
547 
548 		do {
549 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
550 			if (addr & 0x7)
551 				chan->byte_align = true;
552 
553 			/* allocate and populate the descriptor */
554 			new = mmp_pdma_alloc_descriptor(chan);
555 			if (!new) {
556 				dev_err(chan->dev, "no memory for desc\n");
557 				goto fail;
558 			}
559 
560 			new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & len);
561 			if (dir == DMA_MEM_TO_DEV) {
562 				new->desc.dsadr = addr;
563 				new->desc.dtadr = chan->dev_addr;
564 			} else {
565 				new->desc.dsadr = chan->dev_addr;
566 				new->desc.dtadr = addr;
567 			}
568 
569 			if (!first)
570 				first = new;
571 			else
572 				prev->desc.ddadr = new->async_tx.phys;
573 
574 			new->async_tx.cookie = 0;
575 			async_tx_ack(&new->async_tx);
576 			prev = new;
577 
578 			/* Insert the link descriptor to the LD ring */
579 			list_add_tail(&new->node, &first->tx_list);
580 
581 			/* update metadata */
582 			addr += len;
583 			avail -= len;
584 		} while (avail);
585 	}
586 
587 	first->async_tx.cookie = -EBUSY;
588 	first->async_tx.flags = flags;
589 
590 	/* last desc and fire IRQ */
591 	new->desc.ddadr = DDADR_STOP;
592 	new->desc.dcmd |= DCMD_ENDIRQEN;
593 
594 	chan->dir = dir;
595 	chan->cyclic_first = NULL;
596 
597 	return &first->async_tx;
598 
599 fail:
600 	if (first)
601 		mmp_pdma_free_desc_list(chan, &first->tx_list);
602 	return NULL;
603 }
604 
605 static struct dma_async_tx_descriptor *
606 mmp_pdma_prep_dma_cyclic(struct dma_chan *dchan,
607 			 dma_addr_t buf_addr, size_t len, size_t period_len,
608 			 enum dma_transfer_direction direction,
609 			 unsigned long flags)
610 {
611 	struct mmp_pdma_chan *chan;
612 	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
613 	dma_addr_t dma_src, dma_dst;
614 
615 	if (!dchan || !len || !period_len)
616 		return NULL;
617 
618 	/* the buffer length must be a multiple of period_len */
619 	if (len % period_len != 0)
620 		return NULL;
621 
622 	if (period_len > PDMA_MAX_DESC_BYTES)
623 		return NULL;
624 
625 	chan = to_mmp_pdma_chan(dchan);
626 	mmp_pdma_config_write(dchan, &chan->slave_config, direction);
627 
628 	switch (direction) {
629 	case DMA_MEM_TO_DEV:
630 		dma_src = buf_addr;
631 		dma_dst = chan->dev_addr;
632 		break;
633 	case DMA_DEV_TO_MEM:
634 		dma_dst = buf_addr;
635 		dma_src = chan->dev_addr;
636 		break;
637 	default:
638 		dev_err(chan->dev, "Unsupported direction for cyclic DMA\n");
639 		return NULL;
640 	}
641 
642 	chan->dir = direction;
643 
644 	do {
645 		/* Allocate the link descriptor from DMA pool */
646 		new = mmp_pdma_alloc_descriptor(chan);
647 		if (!new) {
648 			dev_err(chan->dev, "no memory for desc\n");
649 			goto fail;
650 		}
651 
652 		new->desc.dcmd = (chan->dcmd | DCMD_ENDIRQEN |
653 				  (DCMD_LENGTH & period_len));
654 		new->desc.dsadr = dma_src;
655 		new->desc.dtadr = dma_dst;
656 
657 		if (!first)
658 			first = new;
659 		else
660 			prev->desc.ddadr = new->async_tx.phys;
661 
662 		new->async_tx.cookie = 0;
663 		async_tx_ack(&new->async_tx);
664 
665 		prev = new;
666 		len -= period_len;
667 
668 		if (chan->dir == DMA_MEM_TO_DEV)
669 			dma_src += period_len;
670 		else
671 			dma_dst += period_len;
672 
673 		/* Insert the link descriptor to the LD ring */
674 		list_add_tail(&new->node, &first->tx_list);
675 	} while (len);
676 
677 	first->async_tx.flags = flags; /* client is in control of this ack */
678 	first->async_tx.cookie = -EBUSY;
679 
680 	/* make the cyclic link */
681 	new->desc.ddadr = first->async_tx.phys;
682 	chan->cyclic_first = first;
683 
684 	return &first->async_tx;
685 
686 fail:
687 	if (first)
688 		mmp_pdma_free_desc_list(chan, &first->tx_list);
689 	return NULL;
690 }
691 
692 static int mmp_pdma_config_write(struct dma_chan *dchan,
693 			   struct dma_slave_config *cfg,
694 			   enum dma_transfer_direction direction)
695 {
696 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
697 	u32 maxburst = 0, addr = 0;
698 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
699 
700 	if (!dchan)
701 		return -EINVAL;
702 
703 	if (direction == DMA_DEV_TO_MEM) {
704 		chan->dcmd = DCMD_INCTRGADDR | DCMD_FLOWSRC;
705 		maxburst = cfg->src_maxburst;
706 		width = cfg->src_addr_width;
707 		addr = cfg->src_addr;
708 	} else if (direction == DMA_MEM_TO_DEV) {
709 		chan->dcmd = DCMD_INCSRCADDR | DCMD_FLOWTRG;
710 		maxburst = cfg->dst_maxburst;
711 		width = cfg->dst_addr_width;
712 		addr = cfg->dst_addr;
713 	}
714 
715 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
716 		chan->dcmd |= DCMD_WIDTH1;
717 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
718 		chan->dcmd |= DCMD_WIDTH2;
719 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
720 		chan->dcmd |= DCMD_WIDTH4;
721 
722 	if (maxburst == 8)
723 		chan->dcmd |= DCMD_BURST8;
724 	else if (maxburst == 16)
725 		chan->dcmd |= DCMD_BURST16;
726 	else if (maxburst == 32)
727 		chan->dcmd |= DCMD_BURST32;
728 
729 	chan->dir = direction;
730 	chan->dev_addr = addr;
731 	/* FIXME: drivers should be ported over to use the filter
732 	 * function. Once that's done, the following two lines can
733 	 * be removed.
734 	 */
735 	if (cfg->slave_id)
736 		chan->drcmr = cfg->slave_id;
737 
738 	return 0;
739 }
740 
741 static int mmp_pdma_config(struct dma_chan *dchan,
742 			   struct dma_slave_config *cfg)
743 {
744 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
745 
746 	memcpy(&chan->slave_config, cfg, sizeof(*cfg));
747 	return 0;
748 }
749 
750 static int mmp_pdma_terminate_all(struct dma_chan *dchan)
751 {
752 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
753 	unsigned long flags;
754 
755 	if (!dchan)
756 		return -EINVAL;
757 
758 	disable_chan(chan->phy);
759 	mmp_pdma_free_phy(chan);
760 	spin_lock_irqsave(&chan->desc_lock, flags);
761 	mmp_pdma_free_desc_list(chan, &chan->chain_pending);
762 	mmp_pdma_free_desc_list(chan, &chan->chain_running);
763 	spin_unlock_irqrestore(&chan->desc_lock, flags);
764 	chan->idle = true;
765 
766 	return 0;
767 }
768 
769 static unsigned int mmp_pdma_residue(struct mmp_pdma_chan *chan,
770 				     dma_cookie_t cookie)
771 {
772 	struct mmp_pdma_desc_sw *sw;
773 	u32 curr, residue = 0;
774 	bool passed = false;
775 	bool cyclic = chan->cyclic_first != NULL;
776 
777 	/*
778 	 * If the channel does not have a phy pointer anymore, it has already
779 	 * been completed. Therefore, its residue is 0.
780 	 */
781 	if (!chan->phy)
782 		return 0;
783 
784 	if (chan->dir == DMA_DEV_TO_MEM)
785 		curr = readl(chan->phy->base + DTADR(chan->phy->idx));
786 	else
787 		curr = readl(chan->phy->base + DSADR(chan->phy->idx));
788 
789 	list_for_each_entry(sw, &chan->chain_running, node) {
790 		u32 start, end, len;
791 
792 		if (chan->dir == DMA_DEV_TO_MEM)
793 			start = sw->desc.dtadr;
794 		else
795 			start = sw->desc.dsadr;
796 
797 		len = sw->desc.dcmd & DCMD_LENGTH;
798 		end = start + len;
799 
800 		/*
801 		 * 'passed' will be latched once we found the descriptor which
802 		 * lies inside the boundaries of the curr pointer. All
803 		 * descriptors that occur in the list _after_ we found that
804 		 * partially handled descriptor are still to be processed and
805 		 * are hence added to the residual bytes counter.
806 		 */
807 
808 		if (passed) {
809 			residue += len;
810 		} else if (curr >= start && curr <= end) {
811 			residue += end - curr;
812 			passed = true;
813 		}
814 
815 		/*
816 		 * Descriptors that have the ENDIRQEN bit set mark the end of a
817 		 * transaction chain, and the cookie assigned with it has been
818 		 * returned previously from mmp_pdma_tx_submit().
819 		 *
820 		 * In case we have multiple transactions in the running chain,
821 		 * and the cookie does not match the one the user asked us
822 		 * about, reset the state variables and start over.
823 		 *
824 		 * This logic does not apply to cyclic transactions, where all
825 		 * descriptors have the ENDIRQEN bit set, and for which we
826 		 * can't have multiple transactions on one channel anyway.
827 		 */
828 		if (cyclic || !(sw->desc.dcmd & DCMD_ENDIRQEN))
829 			continue;
830 
831 		if (sw->async_tx.cookie == cookie) {
832 			return residue;
833 		} else {
834 			residue = 0;
835 			passed = false;
836 		}
837 	}
838 
839 	/* We should only get here in case of cyclic transactions */
840 	return residue;
841 }
842 
843 static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan,
844 					  dma_cookie_t cookie,
845 					  struct dma_tx_state *txstate)
846 {
847 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
848 	enum dma_status ret;
849 
850 	ret = dma_cookie_status(dchan, cookie, txstate);
851 	if (likely(ret != DMA_ERROR))
852 		dma_set_residue(txstate, mmp_pdma_residue(chan, cookie));
853 
854 	return ret;
855 }
856 
857 /**
858  * mmp_pdma_issue_pending - Issue the DMA start command
859  * pending list ==> running list
860  */
861 static void mmp_pdma_issue_pending(struct dma_chan *dchan)
862 {
863 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
864 	unsigned long flags;
865 
866 	spin_lock_irqsave(&chan->desc_lock, flags);
867 	start_pending_queue(chan);
868 	spin_unlock_irqrestore(&chan->desc_lock, flags);
869 }
870 
871 /*
872  * dma_do_tasklet
873  * Do call back
874  * Start pending list
875  */
876 static void dma_do_tasklet(unsigned long data)
877 {
878 	struct mmp_pdma_chan *chan = (struct mmp_pdma_chan *)data;
879 	struct mmp_pdma_desc_sw *desc, *_desc;
880 	LIST_HEAD(chain_cleanup);
881 	unsigned long flags;
882 	struct dmaengine_desc_callback cb;
883 
884 	if (chan->cyclic_first) {
885 		spin_lock_irqsave(&chan->desc_lock, flags);
886 		desc = chan->cyclic_first;
887 		dmaengine_desc_get_callback(&desc->async_tx, &cb);
888 		spin_unlock_irqrestore(&chan->desc_lock, flags);
889 
890 		dmaengine_desc_callback_invoke(&cb, NULL);
891 
892 		return;
893 	}
894 
895 	/* submit pending list; callback for each desc; free desc */
896 	spin_lock_irqsave(&chan->desc_lock, flags);
897 
898 	list_for_each_entry_safe(desc, _desc, &chan->chain_running, node) {
899 		/*
900 		 * move the descriptors to a temporary list so we can drop
901 		 * the lock during the entire cleanup operation
902 		 */
903 		list_move(&desc->node, &chain_cleanup);
904 
905 		/*
906 		 * Look for the first list entry which has the ENDIRQEN flag
907 		 * set. That is the descriptor we got an interrupt for, so
908 		 * complete that transaction and its cookie.
909 		 */
910 		if (desc->desc.dcmd & DCMD_ENDIRQEN) {
911 			dma_cookie_t cookie = desc->async_tx.cookie;
912 			dma_cookie_complete(&desc->async_tx);
913 			dev_dbg(chan->dev, "completed_cookie=%d\n", cookie);
914 			break;
915 		}
916 	}
917 
918 	/*
919 	 * The hardware is idle and ready for more when the
920 	 * chain_running list is empty.
921 	 */
922 	chan->idle = list_empty(&chan->chain_running);
923 
924 	/* Start any pending transactions automatically */
925 	start_pending_queue(chan);
926 	spin_unlock_irqrestore(&chan->desc_lock, flags);
927 
928 	/* Run the callback for each descriptor, in order */
929 	list_for_each_entry_safe(desc, _desc, &chain_cleanup, node) {
930 		struct dma_async_tx_descriptor *txd = &desc->async_tx;
931 
932 		/* Remove from the list of transactions */
933 		list_del(&desc->node);
934 		/* Run the link descriptor callback function */
935 		dmaengine_desc_get_callback(txd, &cb);
936 		dmaengine_desc_callback_invoke(&cb, NULL);
937 
938 		dma_pool_free(chan->desc_pool, desc, txd->phys);
939 	}
940 }
941 
942 static int mmp_pdma_remove(struct platform_device *op)
943 {
944 	struct mmp_pdma_device *pdev = platform_get_drvdata(op);
945 	struct mmp_pdma_phy *phy;
946 	int i, irq = 0, irq_num = 0;
947 
948 	if (op->dev.of_node)
949 		of_dma_controller_free(op->dev.of_node);
950 
951 	for (i = 0; i < pdev->dma_channels; i++) {
952 		if (platform_get_irq(op, i) > 0)
953 			irq_num++;
954 	}
955 
956 	if (irq_num != pdev->dma_channels) {
957 		irq = platform_get_irq(op, 0);
958 		devm_free_irq(&op->dev, irq, pdev);
959 	} else {
960 		for (i = 0; i < pdev->dma_channels; i++) {
961 			phy = &pdev->phy[i];
962 			irq = platform_get_irq(op, i);
963 			devm_free_irq(&op->dev, irq, phy);
964 		}
965 	}
966 
967 	dma_async_device_unregister(&pdev->device);
968 	return 0;
969 }
970 
971 static int mmp_pdma_chan_init(struct mmp_pdma_device *pdev, int idx, int irq)
972 {
973 	struct mmp_pdma_phy *phy  = &pdev->phy[idx];
974 	struct mmp_pdma_chan *chan;
975 	int ret;
976 
977 	chan = devm_kzalloc(pdev->dev, sizeof(*chan), GFP_KERNEL);
978 	if (chan == NULL)
979 		return -ENOMEM;
980 
981 	phy->idx = idx;
982 	phy->base = pdev->base;
983 
984 	if (irq) {
985 		ret = devm_request_irq(pdev->dev, irq, mmp_pdma_chan_handler,
986 				       IRQF_SHARED, "pdma", phy);
987 		if (ret) {
988 			dev_err(pdev->dev, "channel request irq fail!\n");
989 			return ret;
990 		}
991 	}
992 
993 	spin_lock_init(&chan->desc_lock);
994 	chan->dev = pdev->dev;
995 	chan->chan.device = &pdev->device;
996 	tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
997 	INIT_LIST_HEAD(&chan->chain_pending);
998 	INIT_LIST_HEAD(&chan->chain_running);
999 
1000 	/* register virt channel to dma engine */
1001 	list_add_tail(&chan->chan.device_node, &pdev->device.channels);
1002 
1003 	return 0;
1004 }
1005 
1006 static const struct of_device_id mmp_pdma_dt_ids[] = {
1007 	{ .compatible = "marvell,pdma-1.0", },
1008 	{}
1009 };
1010 MODULE_DEVICE_TABLE(of, mmp_pdma_dt_ids);
1011 
1012 static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec,
1013 					   struct of_dma *ofdma)
1014 {
1015 	struct mmp_pdma_device *d = ofdma->of_dma_data;
1016 	struct dma_chan *chan;
1017 
1018 	chan = dma_get_any_slave_channel(&d->device);
1019 	if (!chan)
1020 		return NULL;
1021 
1022 	to_mmp_pdma_chan(chan)->drcmr = dma_spec->args[0];
1023 
1024 	return chan;
1025 }
1026 
1027 static int mmp_pdma_probe(struct platform_device *op)
1028 {
1029 	struct mmp_pdma_device *pdev;
1030 	const struct of_device_id *of_id;
1031 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1032 	struct resource *iores;
1033 	int i, ret, irq = 0;
1034 	int dma_channels = 0, irq_num = 0;
1035 	const enum dma_slave_buswidth widths =
1036 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1037 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1038 
1039 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1040 	if (!pdev)
1041 		return -ENOMEM;
1042 
1043 	pdev->dev = &op->dev;
1044 
1045 	spin_lock_init(&pdev->phy_lock);
1046 
1047 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1048 	pdev->base = devm_ioremap_resource(pdev->dev, iores);
1049 	if (IS_ERR(pdev->base))
1050 		return PTR_ERR(pdev->base);
1051 
1052 	of_id = of_match_device(mmp_pdma_dt_ids, pdev->dev);
1053 	if (of_id)
1054 		of_property_read_u32(pdev->dev->of_node, "#dma-channels",
1055 				     &dma_channels);
1056 	else if (pdata && pdata->dma_channels)
1057 		dma_channels = pdata->dma_channels;
1058 	else
1059 		dma_channels = 32;	/* default 32 channel */
1060 	pdev->dma_channels = dma_channels;
1061 
1062 	for (i = 0; i < dma_channels; i++) {
1063 		if (platform_get_irq(op, i) > 0)
1064 			irq_num++;
1065 	}
1066 
1067 	pdev->phy = devm_kcalloc(pdev->dev, dma_channels, sizeof(*pdev->phy),
1068 				 GFP_KERNEL);
1069 	if (pdev->phy == NULL)
1070 		return -ENOMEM;
1071 
1072 	INIT_LIST_HEAD(&pdev->device.channels);
1073 
1074 	if (irq_num != dma_channels) {
1075 		/* all chan share one irq, demux inside */
1076 		irq = platform_get_irq(op, 0);
1077 		ret = devm_request_irq(pdev->dev, irq, mmp_pdma_int_handler,
1078 				       IRQF_SHARED, "pdma", pdev);
1079 		if (ret)
1080 			return ret;
1081 	}
1082 
1083 	for (i = 0; i < dma_channels; i++) {
1084 		irq = (irq_num != dma_channels) ? 0 : platform_get_irq(op, i);
1085 		ret = mmp_pdma_chan_init(pdev, i, irq);
1086 		if (ret)
1087 			return ret;
1088 	}
1089 
1090 	dma_cap_set(DMA_SLAVE, pdev->device.cap_mask);
1091 	dma_cap_set(DMA_MEMCPY, pdev->device.cap_mask);
1092 	dma_cap_set(DMA_CYCLIC, pdev->device.cap_mask);
1093 	dma_cap_set(DMA_PRIVATE, pdev->device.cap_mask);
1094 	pdev->device.dev = &op->dev;
1095 	pdev->device.device_alloc_chan_resources = mmp_pdma_alloc_chan_resources;
1096 	pdev->device.device_free_chan_resources = mmp_pdma_free_chan_resources;
1097 	pdev->device.device_tx_status = mmp_pdma_tx_status;
1098 	pdev->device.device_prep_dma_memcpy = mmp_pdma_prep_memcpy;
1099 	pdev->device.device_prep_slave_sg = mmp_pdma_prep_slave_sg;
1100 	pdev->device.device_prep_dma_cyclic = mmp_pdma_prep_dma_cyclic;
1101 	pdev->device.device_issue_pending = mmp_pdma_issue_pending;
1102 	pdev->device.device_config = mmp_pdma_config;
1103 	pdev->device.device_terminate_all = mmp_pdma_terminate_all;
1104 	pdev->device.copy_align = DMAENGINE_ALIGN_8_BYTES;
1105 	pdev->device.src_addr_widths = widths;
1106 	pdev->device.dst_addr_widths = widths;
1107 	pdev->device.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1108 	pdev->device.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1109 
1110 	if (pdev->dev->coherent_dma_mask)
1111 		dma_set_mask(pdev->dev, pdev->dev->coherent_dma_mask);
1112 	else
1113 		dma_set_mask(pdev->dev, DMA_BIT_MASK(64));
1114 
1115 	ret = dma_async_device_register(&pdev->device);
1116 	if (ret) {
1117 		dev_err(pdev->device.dev, "unable to register\n");
1118 		return ret;
1119 	}
1120 
1121 	if (op->dev.of_node) {
1122 		/* Device-tree DMA controller registration */
1123 		ret = of_dma_controller_register(op->dev.of_node,
1124 						 mmp_pdma_dma_xlate, pdev);
1125 		if (ret < 0) {
1126 			dev_err(&op->dev, "of_dma_controller_register failed\n");
1127 			return ret;
1128 		}
1129 	}
1130 
1131 	platform_set_drvdata(op, pdev);
1132 	dev_info(pdev->device.dev, "initialized %d channels\n", dma_channels);
1133 	return 0;
1134 }
1135 
1136 static const struct platform_device_id mmp_pdma_id_table[] = {
1137 	{ "mmp-pdma", },
1138 	{ },
1139 };
1140 
1141 static struct platform_driver mmp_pdma_driver = {
1142 	.driver		= {
1143 		.name	= "mmp-pdma",
1144 		.of_match_table = mmp_pdma_dt_ids,
1145 	},
1146 	.id_table	= mmp_pdma_id_table,
1147 	.probe		= mmp_pdma_probe,
1148 	.remove		= mmp_pdma_remove,
1149 };
1150 
1151 bool mmp_pdma_filter_fn(struct dma_chan *chan, void *param)
1152 {
1153 	struct mmp_pdma_chan *c = to_mmp_pdma_chan(chan);
1154 
1155 	if (chan->device->dev->driver != &mmp_pdma_driver.driver)
1156 		return false;
1157 
1158 	c->drcmr = *(unsigned int *)param;
1159 
1160 	return true;
1161 }
1162 EXPORT_SYMBOL_GPL(mmp_pdma_filter_fn);
1163 
1164 module_platform_driver(mmp_pdma_driver);
1165 
1166 MODULE_DESCRIPTION("MARVELL MMP Peripheral DMA Driver");
1167 MODULE_AUTHOR("Marvell International Ltd.");
1168 MODULE_LICENSE("GPL v2");
1169