xref: /kernel/linux/linux-5.10/drivers/dma/mmp_pdma.c (revision 8c2ecf20)
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
74struct 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
81struct 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
88struct mmp_pdma_phy;
89
90struct 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
117struct mmp_pdma_phy {
118	int idx;
119	void __iomem *base;
120	struct mmp_pdma_chan *vchan;
121};
122
123struct 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
141static int mmp_pdma_config_write(struct dma_chan *dchan,
142			   struct dma_slave_config *cfg,
143			   enum dma_transfer_direction direction);
144
145static 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
152static 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
173static 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
184static 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
202static 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
213static 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 */
240static 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
269out_unlock:
270	spin_unlock_irqrestore(&pdev->phy_lock, flags);
271	return found;
272}
273
274static 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 */
297static 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 */
341static 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
363static struct mmp_pdma_desc_sw *
364mmp_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
392static 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
415static 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
426static 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
444static struct dma_async_tx_descriptor *
445mmp_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
519fail:
520	if (first)
521		mmp_pdma_free_desc_list(chan, &first->tx_list);
522	return NULL;
523}
524
525static struct dma_async_tx_descriptor *
526mmp_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
599fail:
600	if (first)
601		mmp_pdma_free_desc_list(chan, &first->tx_list);
602	return NULL;
603}
604
605static struct dma_async_tx_descriptor *
606mmp_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
686fail:
687	if (first)
688		mmp_pdma_free_desc_list(chan, &first->tx_list);
689	return NULL;
690}
691
692static 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
732	return 0;
733}
734
735static int mmp_pdma_config(struct dma_chan *dchan,
736			   struct dma_slave_config *cfg)
737{
738	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
739
740	memcpy(&chan->slave_config, cfg, sizeof(*cfg));
741	return 0;
742}
743
744static int mmp_pdma_terminate_all(struct dma_chan *dchan)
745{
746	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
747	unsigned long flags;
748
749	if (!dchan)
750		return -EINVAL;
751
752	disable_chan(chan->phy);
753	mmp_pdma_free_phy(chan);
754	spin_lock_irqsave(&chan->desc_lock, flags);
755	mmp_pdma_free_desc_list(chan, &chan->chain_pending);
756	mmp_pdma_free_desc_list(chan, &chan->chain_running);
757	spin_unlock_irqrestore(&chan->desc_lock, flags);
758	chan->idle = true;
759
760	return 0;
761}
762
763static unsigned int mmp_pdma_residue(struct mmp_pdma_chan *chan,
764				     dma_cookie_t cookie)
765{
766	struct mmp_pdma_desc_sw *sw;
767	u32 curr, residue = 0;
768	bool passed = false;
769	bool cyclic = chan->cyclic_first != NULL;
770
771	/*
772	 * If the channel does not have a phy pointer anymore, it has already
773	 * been completed. Therefore, its residue is 0.
774	 */
775	if (!chan->phy)
776		return 0;
777
778	if (chan->dir == DMA_DEV_TO_MEM)
779		curr = readl(chan->phy->base + DTADR(chan->phy->idx));
780	else
781		curr = readl(chan->phy->base + DSADR(chan->phy->idx));
782
783	list_for_each_entry(sw, &chan->chain_running, node) {
784		u32 start, end, len;
785
786		if (chan->dir == DMA_DEV_TO_MEM)
787			start = sw->desc.dtadr;
788		else
789			start = sw->desc.dsadr;
790
791		len = sw->desc.dcmd & DCMD_LENGTH;
792		end = start + len;
793
794		/*
795		 * 'passed' will be latched once we found the descriptor which
796		 * lies inside the boundaries of the curr pointer. All
797		 * descriptors that occur in the list _after_ we found that
798		 * partially handled descriptor are still to be processed and
799		 * are hence added to the residual bytes counter.
800		 */
801
802		if (passed) {
803			residue += len;
804		} else if (curr >= start && curr <= end) {
805			residue += end - curr;
806			passed = true;
807		}
808
809		/*
810		 * Descriptors that have the ENDIRQEN bit set mark the end of a
811		 * transaction chain, and the cookie assigned with it has been
812		 * returned previously from mmp_pdma_tx_submit().
813		 *
814		 * In case we have multiple transactions in the running chain,
815		 * and the cookie does not match the one the user asked us
816		 * about, reset the state variables and start over.
817		 *
818		 * This logic does not apply to cyclic transactions, where all
819		 * descriptors have the ENDIRQEN bit set, and for which we
820		 * can't have multiple transactions on one channel anyway.
821		 */
822		if (cyclic || !(sw->desc.dcmd & DCMD_ENDIRQEN))
823			continue;
824
825		if (sw->async_tx.cookie == cookie) {
826			return residue;
827		} else {
828			residue = 0;
829			passed = false;
830		}
831	}
832
833	/* We should only get here in case of cyclic transactions */
834	return residue;
835}
836
837static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan,
838					  dma_cookie_t cookie,
839					  struct dma_tx_state *txstate)
840{
841	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
842	enum dma_status ret;
843
844	ret = dma_cookie_status(dchan, cookie, txstate);
845	if (likely(ret != DMA_ERROR))
846		dma_set_residue(txstate, mmp_pdma_residue(chan, cookie));
847
848	return ret;
849}
850
851/*
852 * mmp_pdma_issue_pending - Issue the DMA start command
853 * pending list ==> running list
854 */
855static void mmp_pdma_issue_pending(struct dma_chan *dchan)
856{
857	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
858	unsigned long flags;
859
860	spin_lock_irqsave(&chan->desc_lock, flags);
861	start_pending_queue(chan);
862	spin_unlock_irqrestore(&chan->desc_lock, flags);
863}
864
865/*
866 * dma_do_tasklet
867 * Do call back
868 * Start pending list
869 */
870static void dma_do_tasklet(struct tasklet_struct *t)
871{
872	struct mmp_pdma_chan *chan = from_tasklet(chan, t, tasklet);
873	struct mmp_pdma_desc_sw *desc, *_desc;
874	LIST_HEAD(chain_cleanup);
875	unsigned long flags;
876	struct dmaengine_desc_callback cb;
877
878	if (chan->cyclic_first) {
879		spin_lock_irqsave(&chan->desc_lock, flags);
880		desc = chan->cyclic_first;
881		dmaengine_desc_get_callback(&desc->async_tx, &cb);
882		spin_unlock_irqrestore(&chan->desc_lock, flags);
883
884		dmaengine_desc_callback_invoke(&cb, NULL);
885
886		return;
887	}
888
889	/* submit pending list; callback for each desc; free desc */
890	spin_lock_irqsave(&chan->desc_lock, flags);
891
892	list_for_each_entry_safe(desc, _desc, &chan->chain_running, node) {
893		/*
894		 * move the descriptors to a temporary list so we can drop
895		 * the lock during the entire cleanup operation
896		 */
897		list_move(&desc->node, &chain_cleanup);
898
899		/*
900		 * Look for the first list entry which has the ENDIRQEN flag
901		 * set. That is the descriptor we got an interrupt for, so
902		 * complete that transaction and its cookie.
903		 */
904		if (desc->desc.dcmd & DCMD_ENDIRQEN) {
905			dma_cookie_t cookie = desc->async_tx.cookie;
906			dma_cookie_complete(&desc->async_tx);
907			dev_dbg(chan->dev, "completed_cookie=%d\n", cookie);
908			break;
909		}
910	}
911
912	/*
913	 * The hardware is idle and ready for more when the
914	 * chain_running list is empty.
915	 */
916	chan->idle = list_empty(&chan->chain_running);
917
918	/* Start any pending transactions automatically */
919	start_pending_queue(chan);
920	spin_unlock_irqrestore(&chan->desc_lock, flags);
921
922	/* Run the callback for each descriptor, in order */
923	list_for_each_entry_safe(desc, _desc, &chain_cleanup, node) {
924		struct dma_async_tx_descriptor *txd = &desc->async_tx;
925
926		/* Remove from the list of transactions */
927		list_del(&desc->node);
928		/* Run the link descriptor callback function */
929		dmaengine_desc_get_callback(txd, &cb);
930		dmaengine_desc_callback_invoke(&cb, NULL);
931
932		dma_pool_free(chan->desc_pool, desc, txd->phys);
933	}
934}
935
936static int mmp_pdma_remove(struct platform_device *op)
937{
938	struct mmp_pdma_device *pdev = platform_get_drvdata(op);
939	struct mmp_pdma_phy *phy;
940	int i, irq = 0, irq_num = 0;
941
942	if (op->dev.of_node)
943		of_dma_controller_free(op->dev.of_node);
944
945	for (i = 0; i < pdev->dma_channels; i++) {
946		if (platform_get_irq(op, i) > 0)
947			irq_num++;
948	}
949
950	if (irq_num != pdev->dma_channels) {
951		irq = platform_get_irq(op, 0);
952		devm_free_irq(&op->dev, irq, pdev);
953	} else {
954		for (i = 0; i < pdev->dma_channels; i++) {
955			phy = &pdev->phy[i];
956			irq = platform_get_irq(op, i);
957			devm_free_irq(&op->dev, irq, phy);
958		}
959	}
960
961	dma_async_device_unregister(&pdev->device);
962	return 0;
963}
964
965static int mmp_pdma_chan_init(struct mmp_pdma_device *pdev, int idx, int irq)
966{
967	struct mmp_pdma_phy *phy  = &pdev->phy[idx];
968	struct mmp_pdma_chan *chan;
969	int ret;
970
971	chan = devm_kzalloc(pdev->dev, sizeof(*chan), GFP_KERNEL);
972	if (chan == NULL)
973		return -ENOMEM;
974
975	phy->idx = idx;
976	phy->base = pdev->base;
977
978	if (irq) {
979		ret = devm_request_irq(pdev->dev, irq, mmp_pdma_chan_handler,
980				       IRQF_SHARED, "pdma", phy);
981		if (ret) {
982			dev_err(pdev->dev, "channel request irq fail!\n");
983			return ret;
984		}
985	}
986
987	spin_lock_init(&chan->desc_lock);
988	chan->dev = pdev->dev;
989	chan->chan.device = &pdev->device;
990	tasklet_setup(&chan->tasklet, dma_do_tasklet);
991	INIT_LIST_HEAD(&chan->chain_pending);
992	INIT_LIST_HEAD(&chan->chain_running);
993
994	/* register virt channel to dma engine */
995	list_add_tail(&chan->chan.device_node, &pdev->device.channels);
996
997	return 0;
998}
999
1000static const struct of_device_id mmp_pdma_dt_ids[] = {
1001	{ .compatible = "marvell,pdma-1.0", },
1002	{}
1003};
1004MODULE_DEVICE_TABLE(of, mmp_pdma_dt_ids);
1005
1006static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec,
1007					   struct of_dma *ofdma)
1008{
1009	struct mmp_pdma_device *d = ofdma->of_dma_data;
1010	struct dma_chan *chan;
1011
1012	chan = dma_get_any_slave_channel(&d->device);
1013	if (!chan)
1014		return NULL;
1015
1016	to_mmp_pdma_chan(chan)->drcmr = dma_spec->args[0];
1017
1018	return chan;
1019}
1020
1021static int mmp_pdma_probe(struct platform_device *op)
1022{
1023	struct mmp_pdma_device *pdev;
1024	const struct of_device_id *of_id;
1025	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1026	struct resource *iores;
1027	int i, ret, irq = 0;
1028	int dma_channels = 0, irq_num = 0;
1029	const enum dma_slave_buswidth widths =
1030		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1031		DMA_SLAVE_BUSWIDTH_4_BYTES;
1032
1033	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1034	if (!pdev)
1035		return -ENOMEM;
1036
1037	pdev->dev = &op->dev;
1038
1039	spin_lock_init(&pdev->phy_lock);
1040
1041	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1042	pdev->base = devm_ioremap_resource(pdev->dev, iores);
1043	if (IS_ERR(pdev->base))
1044		return PTR_ERR(pdev->base);
1045
1046	of_id = of_match_device(mmp_pdma_dt_ids, pdev->dev);
1047	if (of_id)
1048		of_property_read_u32(pdev->dev->of_node, "#dma-channels",
1049				     &dma_channels);
1050	else if (pdata && pdata->dma_channels)
1051		dma_channels = pdata->dma_channels;
1052	else
1053		dma_channels = 32;	/* default 32 channel */
1054	pdev->dma_channels = dma_channels;
1055
1056	for (i = 0; i < dma_channels; i++) {
1057		if (platform_get_irq_optional(op, i) > 0)
1058			irq_num++;
1059	}
1060
1061	pdev->phy = devm_kcalloc(pdev->dev, dma_channels, sizeof(*pdev->phy),
1062				 GFP_KERNEL);
1063	if (pdev->phy == NULL)
1064		return -ENOMEM;
1065
1066	INIT_LIST_HEAD(&pdev->device.channels);
1067
1068	if (irq_num != dma_channels) {
1069		/* all chan share one irq, demux inside */
1070		irq = platform_get_irq(op, 0);
1071		ret = devm_request_irq(pdev->dev, irq, mmp_pdma_int_handler,
1072				       IRQF_SHARED, "pdma", pdev);
1073		if (ret)
1074			return ret;
1075	}
1076
1077	for (i = 0; i < dma_channels; i++) {
1078		irq = (irq_num != dma_channels) ? 0 : platform_get_irq(op, i);
1079		ret = mmp_pdma_chan_init(pdev, i, irq);
1080		if (ret)
1081			return ret;
1082	}
1083
1084	dma_cap_set(DMA_SLAVE, pdev->device.cap_mask);
1085	dma_cap_set(DMA_MEMCPY, pdev->device.cap_mask);
1086	dma_cap_set(DMA_CYCLIC, pdev->device.cap_mask);
1087	dma_cap_set(DMA_PRIVATE, pdev->device.cap_mask);
1088	pdev->device.dev = &op->dev;
1089	pdev->device.device_alloc_chan_resources = mmp_pdma_alloc_chan_resources;
1090	pdev->device.device_free_chan_resources = mmp_pdma_free_chan_resources;
1091	pdev->device.device_tx_status = mmp_pdma_tx_status;
1092	pdev->device.device_prep_dma_memcpy = mmp_pdma_prep_memcpy;
1093	pdev->device.device_prep_slave_sg = mmp_pdma_prep_slave_sg;
1094	pdev->device.device_prep_dma_cyclic = mmp_pdma_prep_dma_cyclic;
1095	pdev->device.device_issue_pending = mmp_pdma_issue_pending;
1096	pdev->device.device_config = mmp_pdma_config;
1097	pdev->device.device_terminate_all = mmp_pdma_terminate_all;
1098	pdev->device.copy_align = DMAENGINE_ALIGN_8_BYTES;
1099	pdev->device.src_addr_widths = widths;
1100	pdev->device.dst_addr_widths = widths;
1101	pdev->device.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1102	pdev->device.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1103
1104	if (pdev->dev->coherent_dma_mask)
1105		dma_set_mask(pdev->dev, pdev->dev->coherent_dma_mask);
1106	else
1107		dma_set_mask(pdev->dev, DMA_BIT_MASK(64));
1108
1109	ret = dma_async_device_register(&pdev->device);
1110	if (ret) {
1111		dev_err(pdev->device.dev, "unable to register\n");
1112		return ret;
1113	}
1114
1115	if (op->dev.of_node) {
1116		/* Device-tree DMA controller registration */
1117		ret = of_dma_controller_register(op->dev.of_node,
1118						 mmp_pdma_dma_xlate, pdev);
1119		if (ret < 0) {
1120			dev_err(&op->dev, "of_dma_controller_register failed\n");
1121			return ret;
1122		}
1123	}
1124
1125	platform_set_drvdata(op, pdev);
1126	dev_info(pdev->device.dev, "initialized %d channels\n", dma_channels);
1127	return 0;
1128}
1129
1130static const struct platform_device_id mmp_pdma_id_table[] = {
1131	{ "mmp-pdma", },
1132	{ },
1133};
1134
1135static struct platform_driver mmp_pdma_driver = {
1136	.driver		= {
1137		.name	= "mmp-pdma",
1138		.of_match_table = mmp_pdma_dt_ids,
1139	},
1140	.id_table	= mmp_pdma_id_table,
1141	.probe		= mmp_pdma_probe,
1142	.remove		= mmp_pdma_remove,
1143};
1144
1145bool mmp_pdma_filter_fn(struct dma_chan *chan, void *param)
1146{
1147	struct mmp_pdma_chan *c = to_mmp_pdma_chan(chan);
1148
1149	if (chan->device->dev->driver != &mmp_pdma_driver.driver)
1150		return false;
1151
1152	c->drcmr = *(unsigned int *)param;
1153
1154	return true;
1155}
1156EXPORT_SYMBOL_GPL(mmp_pdma_filter_fn);
1157
1158module_platform_driver(mmp_pdma_driver);
1159
1160MODULE_DESCRIPTION("MARVELL MMP Peripheral DMA Driver");
1161MODULE_AUTHOR("Marvell International Ltd.");
1162MODULE_LICENSE("GPL v2");
1163