xref: /kernel/linux/linux-6.6/drivers/dma/mmp_pdma.c (revision 62306a36)
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
22#include "dmaengine.h"
23
24#define DCSR		0x0000
25#define DALGN		0x00a0
26#define DINT		0x00f0
27#define DDADR		0x0200
28#define DSADR(n)	(0x0204 + ((n) << 4))
29#define DTADR(n)	(0x0208 + ((n) << 4))
30#define DCMD		0x020c
31
32#define DCSR_RUN	BIT(31)	/* Run Bit (read / write) */
33#define DCSR_NODESC	BIT(30)	/* No-Descriptor Fetch (read / write) */
34#define DCSR_STOPIRQEN	BIT(29)	/* Stop Interrupt Enable (read / write) */
35#define DCSR_REQPEND	BIT(8)	/* Request Pending (read-only) */
36#define DCSR_STOPSTATE	BIT(3)	/* Stop State (read-only) */
37#define DCSR_ENDINTR	BIT(2)	/* End Interrupt (read / write) */
38#define DCSR_STARTINTR	BIT(1)	/* Start Interrupt (read / write) */
39#define DCSR_BUSERR	BIT(0)	/* Bus Error Interrupt (read / write) */
40
41#define DCSR_EORIRQEN	BIT(28)	/* End of Receive Interrupt Enable (R/W) */
42#define DCSR_EORJMPEN	BIT(27)	/* Jump to next descriptor on EOR */
43#define DCSR_EORSTOPEN	BIT(26)	/* STOP on an EOR */
44#define DCSR_SETCMPST	BIT(25)	/* Set Descriptor Compare Status */
45#define DCSR_CLRCMPST	BIT(24)	/* Clear Descriptor Compare Status */
46#define DCSR_CMPST	BIT(10)	/* The Descriptor Compare Status */
47#define DCSR_EORINTR	BIT(9)	/* The end of Receive */
48
49#define DRCMR(n)	((((n) < 64) ? 0x0100 : 0x1100) + (((n) & 0x3f) << 2))
50#define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
51#define DRCMR_CHLNUM	0x1f	/* mask for Channel Number (read / write) */
52
53#define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
54#define DDADR_STOP	BIT(0)	/* Stop (read / write) */
55
56#define DCMD_INCSRCADDR	BIT(31)	/* Source Address Increment Setting. */
57#define DCMD_INCTRGADDR	BIT(30)	/* Target Address Increment Setting. */
58#define DCMD_FLOWSRC	BIT(29)	/* Flow Control by the source. */
59#define DCMD_FLOWTRG	BIT(28)	/* Flow Control by the target. */
60#define DCMD_STARTIRQEN	BIT(22)	/* Start Interrupt Enable */
61#define DCMD_ENDIRQEN	BIT(21)	/* End Interrupt Enable */
62#define DCMD_ENDIAN	BIT(18)	/* Device Endian-ness. */
63#define DCMD_BURST8	(1 << 16)	/* 8 byte burst */
64#define DCMD_BURST16	(2 << 16)	/* 16 byte burst */
65#define DCMD_BURST32	(3 << 16)	/* 32 byte burst */
66#define DCMD_WIDTH1	(1 << 14)	/* 1 byte width */
67#define DCMD_WIDTH2	(2 << 14)	/* 2 byte width (HalfWord) */
68#define DCMD_WIDTH4	(3 << 14)	/* 4 byte width (Word) */
69#define DCMD_LENGTH	0x01fff		/* length mask (max = 8K - 1) */
70
71#define PDMA_MAX_DESC_BYTES	DCMD_LENGTH
72
73struct mmp_pdma_desc_hw {
74	u32 ddadr;	/* Points to the next descriptor + flags */
75	u32 dsadr;	/* DSADR value for the current transfer */
76	u32 dtadr;	/* DTADR value for the current transfer */
77	u32 dcmd;	/* DCMD value for the current transfer */
78} __aligned(32);
79
80struct mmp_pdma_desc_sw {
81	struct mmp_pdma_desc_hw desc;
82	struct list_head node;
83	struct list_head tx_list;
84	struct dma_async_tx_descriptor async_tx;
85};
86
87struct mmp_pdma_phy;
88
89struct mmp_pdma_chan {
90	struct device *dev;
91	struct dma_chan chan;
92	struct dma_async_tx_descriptor desc;
93	struct mmp_pdma_phy *phy;
94	enum dma_transfer_direction dir;
95	struct dma_slave_config slave_config;
96
97	struct mmp_pdma_desc_sw *cyclic_first;	/* first desc_sw if channel
98						 * is in cyclic mode */
99
100	/* channel's basic info */
101	struct tasklet_struct tasklet;
102	u32 dcmd;
103	u32 drcmr;
104	u32 dev_addr;
105
106	/* list for desc */
107	spinlock_t desc_lock;		/* Descriptor list lock */
108	struct list_head chain_pending;	/* Link descriptors queue for pending */
109	struct list_head chain_running;	/* Link descriptors queue for running */
110	bool idle;			/* channel statue machine */
111	bool byte_align;
112
113	struct dma_pool *desc_pool;	/* Descriptors pool */
114};
115
116struct mmp_pdma_phy {
117	int idx;
118	void __iomem *base;
119	struct mmp_pdma_chan *vchan;
120};
121
122struct mmp_pdma_device {
123	int				dma_channels;
124	void __iomem			*base;
125	struct device			*dev;
126	struct dma_device		device;
127	struct mmp_pdma_phy		*phy;
128	spinlock_t phy_lock; /* protect alloc/free phy channels */
129};
130
131#define tx_to_mmp_pdma_desc(tx)					\
132	container_of(tx, struct mmp_pdma_desc_sw, async_tx)
133#define to_mmp_pdma_desc(lh)					\
134	container_of(lh, struct mmp_pdma_desc_sw, node)
135#define to_mmp_pdma_chan(dchan)					\
136	container_of(dchan, struct mmp_pdma_chan, chan)
137#define to_mmp_pdma_dev(dmadev)					\
138	container_of(dmadev, struct mmp_pdma_device, device)
139
140static int mmp_pdma_config_write(struct dma_chan *dchan,
141			   struct dma_slave_config *cfg,
142			   enum dma_transfer_direction direction);
143
144static void set_desc(struct mmp_pdma_phy *phy, dma_addr_t addr)
145{
146	u32 reg = (phy->idx << 4) + DDADR;
147
148	writel(addr, phy->base + reg);
149}
150
151static void enable_chan(struct mmp_pdma_phy *phy)
152{
153	u32 reg, dalgn;
154
155	if (!phy->vchan)
156		return;
157
158	reg = DRCMR(phy->vchan->drcmr);
159	writel(DRCMR_MAPVLD | phy->idx, phy->base + reg);
160
161	dalgn = readl(phy->base + DALGN);
162	if (phy->vchan->byte_align)
163		dalgn |= 1 << phy->idx;
164	else
165		dalgn &= ~(1 << phy->idx);
166	writel(dalgn, phy->base + DALGN);
167
168	reg = (phy->idx << 2) + DCSR;
169	writel(readl(phy->base + reg) | DCSR_RUN, phy->base + reg);
170}
171
172static void disable_chan(struct mmp_pdma_phy *phy)
173{
174	u32 reg;
175
176	if (!phy)
177		return;
178
179	reg = (phy->idx << 2) + DCSR;
180	writel(readl(phy->base + reg) & ~DCSR_RUN, phy->base + reg);
181}
182
183static int clear_chan_irq(struct mmp_pdma_phy *phy)
184{
185	u32 dcsr;
186	u32 dint = readl(phy->base + DINT);
187	u32 reg = (phy->idx << 2) + DCSR;
188
189	if (!(dint & BIT(phy->idx)))
190		return -EAGAIN;
191
192	/* clear irq */
193	dcsr = readl(phy->base + reg);
194	writel(dcsr, phy->base + reg);
195	if ((dcsr & DCSR_BUSERR) && (phy->vchan))
196		dev_warn(phy->vchan->dev, "DCSR_BUSERR\n");
197
198	return 0;
199}
200
201static irqreturn_t mmp_pdma_chan_handler(int irq, void *dev_id)
202{
203	struct mmp_pdma_phy *phy = dev_id;
204
205	if (clear_chan_irq(phy) != 0)
206		return IRQ_NONE;
207
208	tasklet_schedule(&phy->vchan->tasklet);
209	return IRQ_HANDLED;
210}
211
212static irqreturn_t mmp_pdma_int_handler(int irq, void *dev_id)
213{
214	struct mmp_pdma_device *pdev = dev_id;
215	struct mmp_pdma_phy *phy;
216	u32 dint = readl(pdev->base + DINT);
217	int i, ret;
218	int irq_num = 0;
219
220	while (dint) {
221		i = __ffs(dint);
222		/* only handle interrupts belonging to pdma driver*/
223		if (i >= pdev->dma_channels)
224			break;
225		dint &= (dint - 1);
226		phy = &pdev->phy[i];
227		ret = mmp_pdma_chan_handler(irq, phy);
228		if (ret == IRQ_HANDLED)
229			irq_num++;
230	}
231
232	if (irq_num)
233		return IRQ_HANDLED;
234
235	return IRQ_NONE;
236}
237
238/* lookup free phy channel as descending priority */
239static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan)
240{
241	int prio, i;
242	struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
243	struct mmp_pdma_phy *phy, *found = NULL;
244	unsigned long flags;
245
246	/*
247	 * dma channel priorities
248	 * ch 0 - 3,  16 - 19  <--> (0)
249	 * ch 4 - 7,  20 - 23  <--> (1)
250	 * ch 8 - 11, 24 - 27  <--> (2)
251	 * ch 12 - 15, 28 - 31  <--> (3)
252	 */
253
254	spin_lock_irqsave(&pdev->phy_lock, flags);
255	for (prio = 0; prio <= ((pdev->dma_channels - 1) & 0xf) >> 2; prio++) {
256		for (i = 0; i < pdev->dma_channels; i++) {
257			if (prio != (i & 0xf) >> 2)
258				continue;
259			phy = &pdev->phy[i];
260			if (!phy->vchan) {
261				phy->vchan = pchan;
262				found = phy;
263				goto out_unlock;
264			}
265		}
266	}
267
268out_unlock:
269	spin_unlock_irqrestore(&pdev->phy_lock, flags);
270	return found;
271}
272
273static void mmp_pdma_free_phy(struct mmp_pdma_chan *pchan)
274{
275	struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
276	unsigned long flags;
277	u32 reg;
278
279	if (!pchan->phy)
280		return;
281
282	/* clear the channel mapping in DRCMR */
283	reg = DRCMR(pchan->drcmr);
284	writel(0, pchan->phy->base + reg);
285
286	spin_lock_irqsave(&pdev->phy_lock, flags);
287	pchan->phy->vchan = NULL;
288	pchan->phy = NULL;
289	spin_unlock_irqrestore(&pdev->phy_lock, flags);
290}
291
292/*
293 * start_pending_queue - transfer any pending transactions
294 * pending list ==> running list
295 */
296static void start_pending_queue(struct mmp_pdma_chan *chan)
297{
298	struct mmp_pdma_desc_sw *desc;
299
300	/* still in running, irq will start the pending list */
301	if (!chan->idle) {
302		dev_dbg(chan->dev, "DMA controller still busy\n");
303		return;
304	}
305
306	if (list_empty(&chan->chain_pending)) {
307		/* chance to re-fetch phy channel with higher prio */
308		mmp_pdma_free_phy(chan);
309		dev_dbg(chan->dev, "no pending list\n");
310		return;
311	}
312
313	if (!chan->phy) {
314		chan->phy = lookup_phy(chan);
315		if (!chan->phy) {
316			dev_dbg(chan->dev, "no free dma channel\n");
317			return;
318		}
319	}
320
321	/*
322	 * pending -> running
323	 * reintilize pending list
324	 */
325	desc = list_first_entry(&chan->chain_pending,
326				struct mmp_pdma_desc_sw, node);
327	list_splice_tail_init(&chan->chain_pending, &chan->chain_running);
328
329	/*
330	 * Program the descriptor's address into the DMA controller,
331	 * then start the DMA transaction
332	 */
333	set_desc(chan->phy, desc->async_tx.phys);
334	enable_chan(chan->phy);
335	chan->idle = false;
336}
337
338
339/* desc->tx_list ==> pending list */
340static dma_cookie_t mmp_pdma_tx_submit(struct dma_async_tx_descriptor *tx)
341{
342	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(tx->chan);
343	struct mmp_pdma_desc_sw *desc = tx_to_mmp_pdma_desc(tx);
344	struct mmp_pdma_desc_sw *child;
345	unsigned long flags;
346	dma_cookie_t cookie = -EBUSY;
347
348	spin_lock_irqsave(&chan->desc_lock, flags);
349
350	list_for_each_entry(child, &desc->tx_list, node) {
351		cookie = dma_cookie_assign(&child->async_tx);
352	}
353
354	/* softly link to pending list - desc->tx_list ==> pending list */
355	list_splice_tail_init(&desc->tx_list, &chan->chain_pending);
356
357	spin_unlock_irqrestore(&chan->desc_lock, flags);
358
359	return cookie;
360}
361
362static struct mmp_pdma_desc_sw *
363mmp_pdma_alloc_descriptor(struct mmp_pdma_chan *chan)
364{
365	struct mmp_pdma_desc_sw *desc;
366	dma_addr_t pdesc;
367
368	desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
369	if (!desc) {
370		dev_err(chan->dev, "out of memory for link descriptor\n");
371		return NULL;
372	}
373
374	INIT_LIST_HEAD(&desc->tx_list);
375	dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan);
376	/* each desc has submit */
377	desc->async_tx.tx_submit = mmp_pdma_tx_submit;
378	desc->async_tx.phys = pdesc;
379
380	return desc;
381}
382
383/*
384 * mmp_pdma_alloc_chan_resources - Allocate resources for DMA channel.
385 *
386 * This function will create a dma pool for descriptor allocation.
387 * Request irq only when channel is requested
388 * Return - The number of allocated descriptors.
389 */
390
391static int mmp_pdma_alloc_chan_resources(struct dma_chan *dchan)
392{
393	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
394
395	if (chan->desc_pool)
396		return 1;
397
398	chan->desc_pool = dma_pool_create(dev_name(&dchan->dev->device),
399					  chan->dev,
400					  sizeof(struct mmp_pdma_desc_sw),
401					  __alignof__(struct mmp_pdma_desc_sw),
402					  0);
403	if (!chan->desc_pool) {
404		dev_err(chan->dev, "unable to allocate descriptor pool\n");
405		return -ENOMEM;
406	}
407
408	mmp_pdma_free_phy(chan);
409	chan->idle = true;
410	chan->dev_addr = 0;
411	return 1;
412}
413
414static void mmp_pdma_free_desc_list(struct mmp_pdma_chan *chan,
415				    struct list_head *list)
416{
417	struct mmp_pdma_desc_sw *desc, *_desc;
418
419	list_for_each_entry_safe(desc, _desc, list, node) {
420		list_del(&desc->node);
421		dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
422	}
423}
424
425static void mmp_pdma_free_chan_resources(struct dma_chan *dchan)
426{
427	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
428	unsigned long flags;
429
430	spin_lock_irqsave(&chan->desc_lock, flags);
431	mmp_pdma_free_desc_list(chan, &chan->chain_pending);
432	mmp_pdma_free_desc_list(chan, &chan->chain_running);
433	spin_unlock_irqrestore(&chan->desc_lock, flags);
434
435	dma_pool_destroy(chan->desc_pool);
436	chan->desc_pool = NULL;
437	chan->idle = true;
438	chan->dev_addr = 0;
439	mmp_pdma_free_phy(chan);
440	return;
441}
442
443static struct dma_async_tx_descriptor *
444mmp_pdma_prep_memcpy(struct dma_chan *dchan,
445		     dma_addr_t dma_dst, dma_addr_t dma_src,
446		     size_t len, unsigned long flags)
447{
448	struct mmp_pdma_chan *chan;
449	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
450	size_t copy = 0;
451
452	if (!dchan)
453		return NULL;
454
455	if (!len)
456		return NULL;
457
458	chan = to_mmp_pdma_chan(dchan);
459	chan->byte_align = false;
460
461	if (!chan->dir) {
462		chan->dir = DMA_MEM_TO_MEM;
463		chan->dcmd = DCMD_INCTRGADDR | DCMD_INCSRCADDR;
464		chan->dcmd |= DCMD_BURST32;
465	}
466
467	do {
468		/* Allocate the link descriptor from DMA pool */
469		new = mmp_pdma_alloc_descriptor(chan);
470		if (!new) {
471			dev_err(chan->dev, "no memory for desc\n");
472			goto fail;
473		}
474
475		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
476		if (dma_src & 0x7 || dma_dst & 0x7)
477			chan->byte_align = true;
478
479		new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & copy);
480		new->desc.dsadr = dma_src;
481		new->desc.dtadr = dma_dst;
482
483		if (!first)
484			first = new;
485		else
486			prev->desc.ddadr = new->async_tx.phys;
487
488		new->async_tx.cookie = 0;
489		async_tx_ack(&new->async_tx);
490
491		prev = new;
492		len -= copy;
493
494		if (chan->dir == DMA_MEM_TO_DEV) {
495			dma_src += copy;
496		} else if (chan->dir == DMA_DEV_TO_MEM) {
497			dma_dst += copy;
498		} else if (chan->dir == DMA_MEM_TO_MEM) {
499			dma_src += copy;
500			dma_dst += copy;
501		}
502
503		/* Insert the link descriptor to the LD ring */
504		list_add_tail(&new->node, &first->tx_list);
505	} while (len);
506
507	first->async_tx.flags = flags; /* client is in control of this ack */
508	first->async_tx.cookie = -EBUSY;
509
510	/* last desc and fire IRQ */
511	new->desc.ddadr = DDADR_STOP;
512	new->desc.dcmd |= DCMD_ENDIRQEN;
513
514	chan->cyclic_first = NULL;
515
516	return &first->async_tx;
517
518fail:
519	if (first)
520		mmp_pdma_free_desc_list(chan, &first->tx_list);
521	return NULL;
522}
523
524static struct dma_async_tx_descriptor *
525mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
526		       unsigned int sg_len, enum dma_transfer_direction dir,
527		       unsigned long flags, void *context)
528{
529	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
530	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new = NULL;
531	size_t len, avail;
532	struct scatterlist *sg;
533	dma_addr_t addr;
534	int i;
535
536	if ((sgl == NULL) || (sg_len == 0))
537		return NULL;
538
539	chan->byte_align = false;
540
541	mmp_pdma_config_write(dchan, &chan->slave_config, dir);
542
543	for_each_sg(sgl, sg, sg_len, i) {
544		addr = sg_dma_address(sg);
545		avail = sg_dma_len(sgl);
546
547		do {
548			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
549			if (addr & 0x7)
550				chan->byte_align = true;
551
552			/* allocate and populate the descriptor */
553			new = mmp_pdma_alloc_descriptor(chan);
554			if (!new) {
555				dev_err(chan->dev, "no memory for desc\n");
556				goto fail;
557			}
558
559			new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & len);
560			if (dir == DMA_MEM_TO_DEV) {
561				new->desc.dsadr = addr;
562				new->desc.dtadr = chan->dev_addr;
563			} else {
564				new->desc.dsadr = chan->dev_addr;
565				new->desc.dtadr = addr;
566			}
567
568			if (!first)
569				first = new;
570			else
571				prev->desc.ddadr = new->async_tx.phys;
572
573			new->async_tx.cookie = 0;
574			async_tx_ack(&new->async_tx);
575			prev = new;
576
577			/* Insert the link descriptor to the LD ring */
578			list_add_tail(&new->node, &first->tx_list);
579
580			/* update metadata */
581			addr += len;
582			avail -= len;
583		} while (avail);
584	}
585
586	first->async_tx.cookie = -EBUSY;
587	first->async_tx.flags = flags;
588
589	/* last desc and fire IRQ */
590	new->desc.ddadr = DDADR_STOP;
591	new->desc.dcmd |= DCMD_ENDIRQEN;
592
593	chan->dir = dir;
594	chan->cyclic_first = NULL;
595
596	return &first->async_tx;
597
598fail:
599	if (first)
600		mmp_pdma_free_desc_list(chan, &first->tx_list);
601	return NULL;
602}
603
604static struct dma_async_tx_descriptor *
605mmp_pdma_prep_dma_cyclic(struct dma_chan *dchan,
606			 dma_addr_t buf_addr, size_t len, size_t period_len,
607			 enum dma_transfer_direction direction,
608			 unsigned long flags)
609{
610	struct mmp_pdma_chan *chan;
611	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
612	dma_addr_t dma_src, dma_dst;
613
614	if (!dchan || !len || !period_len)
615		return NULL;
616
617	/* the buffer length must be a multiple of period_len */
618	if (len % period_len != 0)
619		return NULL;
620
621	if (period_len > PDMA_MAX_DESC_BYTES)
622		return NULL;
623
624	chan = to_mmp_pdma_chan(dchan);
625	mmp_pdma_config_write(dchan, &chan->slave_config, direction);
626
627	switch (direction) {
628	case DMA_MEM_TO_DEV:
629		dma_src = buf_addr;
630		dma_dst = chan->dev_addr;
631		break;
632	case DMA_DEV_TO_MEM:
633		dma_dst = buf_addr;
634		dma_src = chan->dev_addr;
635		break;
636	default:
637		dev_err(chan->dev, "Unsupported direction for cyclic DMA\n");
638		return NULL;
639	}
640
641	chan->dir = direction;
642
643	do {
644		/* Allocate the link descriptor from DMA pool */
645		new = mmp_pdma_alloc_descriptor(chan);
646		if (!new) {
647			dev_err(chan->dev, "no memory for desc\n");
648			goto fail;
649		}
650
651		new->desc.dcmd = (chan->dcmd | DCMD_ENDIRQEN |
652				  (DCMD_LENGTH & period_len));
653		new->desc.dsadr = dma_src;
654		new->desc.dtadr = dma_dst;
655
656		if (!first)
657			first = new;
658		else
659			prev->desc.ddadr = new->async_tx.phys;
660
661		new->async_tx.cookie = 0;
662		async_tx_ack(&new->async_tx);
663
664		prev = new;
665		len -= period_len;
666
667		if (chan->dir == DMA_MEM_TO_DEV)
668			dma_src += period_len;
669		else
670			dma_dst += period_len;
671
672		/* Insert the link descriptor to the LD ring */
673		list_add_tail(&new->node, &first->tx_list);
674	} while (len);
675
676	first->async_tx.flags = flags; /* client is in control of this ack */
677	first->async_tx.cookie = -EBUSY;
678
679	/* make the cyclic link */
680	new->desc.ddadr = first->async_tx.phys;
681	chan->cyclic_first = first;
682
683	return &first->async_tx;
684
685fail:
686	if (first)
687		mmp_pdma_free_desc_list(chan, &first->tx_list);
688	return NULL;
689}
690
691static int mmp_pdma_config_write(struct dma_chan *dchan,
692			   struct dma_slave_config *cfg,
693			   enum dma_transfer_direction direction)
694{
695	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
696	u32 maxburst = 0, addr = 0;
697	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
698
699	if (!dchan)
700		return -EINVAL;
701
702	if (direction == DMA_DEV_TO_MEM) {
703		chan->dcmd = DCMD_INCTRGADDR | DCMD_FLOWSRC;
704		maxburst = cfg->src_maxburst;
705		width = cfg->src_addr_width;
706		addr = cfg->src_addr;
707	} else if (direction == DMA_MEM_TO_DEV) {
708		chan->dcmd = DCMD_INCSRCADDR | DCMD_FLOWTRG;
709		maxburst = cfg->dst_maxburst;
710		width = cfg->dst_addr_width;
711		addr = cfg->dst_addr;
712	}
713
714	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
715		chan->dcmd |= DCMD_WIDTH1;
716	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
717		chan->dcmd |= DCMD_WIDTH2;
718	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
719		chan->dcmd |= DCMD_WIDTH4;
720
721	if (maxburst == 8)
722		chan->dcmd |= DCMD_BURST8;
723	else if (maxburst == 16)
724		chan->dcmd |= DCMD_BURST16;
725	else if (maxburst == 32)
726		chan->dcmd |= DCMD_BURST32;
727
728	chan->dir = direction;
729	chan->dev_addr = addr;
730
731	return 0;
732}
733
734static int mmp_pdma_config(struct dma_chan *dchan,
735			   struct dma_slave_config *cfg)
736{
737	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
738
739	memcpy(&chan->slave_config, cfg, sizeof(*cfg));
740	return 0;
741}
742
743static int mmp_pdma_terminate_all(struct dma_chan *dchan)
744{
745	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
746	unsigned long flags;
747
748	if (!dchan)
749		return -EINVAL;
750
751	disable_chan(chan->phy);
752	mmp_pdma_free_phy(chan);
753	spin_lock_irqsave(&chan->desc_lock, flags);
754	mmp_pdma_free_desc_list(chan, &chan->chain_pending);
755	mmp_pdma_free_desc_list(chan, &chan->chain_running);
756	spin_unlock_irqrestore(&chan->desc_lock, flags);
757	chan->idle = true;
758
759	return 0;
760}
761
762static unsigned int mmp_pdma_residue(struct mmp_pdma_chan *chan,
763				     dma_cookie_t cookie)
764{
765	struct mmp_pdma_desc_sw *sw;
766	u32 curr, residue = 0;
767	bool passed = false;
768	bool cyclic = chan->cyclic_first != NULL;
769
770	/*
771	 * If the channel does not have a phy pointer anymore, it has already
772	 * been completed. Therefore, its residue is 0.
773	 */
774	if (!chan->phy)
775		return 0;
776
777	if (chan->dir == DMA_DEV_TO_MEM)
778		curr = readl(chan->phy->base + DTADR(chan->phy->idx));
779	else
780		curr = readl(chan->phy->base + DSADR(chan->phy->idx));
781
782	list_for_each_entry(sw, &chan->chain_running, node) {
783		u32 start, end, len;
784
785		if (chan->dir == DMA_DEV_TO_MEM)
786			start = sw->desc.dtadr;
787		else
788			start = sw->desc.dsadr;
789
790		len = sw->desc.dcmd & DCMD_LENGTH;
791		end = start + len;
792
793		/*
794		 * 'passed' will be latched once we found the descriptor which
795		 * lies inside the boundaries of the curr pointer. All
796		 * descriptors that occur in the list _after_ we found that
797		 * partially handled descriptor are still to be processed and
798		 * are hence added to the residual bytes counter.
799		 */
800
801		if (passed) {
802			residue += len;
803		} else if (curr >= start && curr <= end) {
804			residue += end - curr;
805			passed = true;
806		}
807
808		/*
809		 * Descriptors that have the ENDIRQEN bit set mark the end of a
810		 * transaction chain, and the cookie assigned with it has been
811		 * returned previously from mmp_pdma_tx_submit().
812		 *
813		 * In case we have multiple transactions in the running chain,
814		 * and the cookie does not match the one the user asked us
815		 * about, reset the state variables and start over.
816		 *
817		 * This logic does not apply to cyclic transactions, where all
818		 * descriptors have the ENDIRQEN bit set, and for which we
819		 * can't have multiple transactions on one channel anyway.
820		 */
821		if (cyclic || !(sw->desc.dcmd & DCMD_ENDIRQEN))
822			continue;
823
824		if (sw->async_tx.cookie == cookie) {
825			return residue;
826		} else {
827			residue = 0;
828			passed = false;
829		}
830	}
831
832	/* We should only get here in case of cyclic transactions */
833	return residue;
834}
835
836static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan,
837					  dma_cookie_t cookie,
838					  struct dma_tx_state *txstate)
839{
840	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
841	enum dma_status ret;
842
843	ret = dma_cookie_status(dchan, cookie, txstate);
844	if (likely(ret != DMA_ERROR))
845		dma_set_residue(txstate, mmp_pdma_residue(chan, cookie));
846
847	return ret;
848}
849
850/*
851 * mmp_pdma_issue_pending - Issue the DMA start command
852 * pending list ==> running list
853 */
854static void mmp_pdma_issue_pending(struct dma_chan *dchan)
855{
856	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
857	unsigned long flags;
858
859	spin_lock_irqsave(&chan->desc_lock, flags);
860	start_pending_queue(chan);
861	spin_unlock_irqrestore(&chan->desc_lock, flags);
862}
863
864/*
865 * dma_do_tasklet
866 * Do call back
867 * Start pending list
868 */
869static void dma_do_tasklet(struct tasklet_struct *t)
870{
871	struct mmp_pdma_chan *chan = from_tasklet(chan, t, tasklet);
872	struct mmp_pdma_desc_sw *desc, *_desc;
873	LIST_HEAD(chain_cleanup);
874	unsigned long flags;
875	struct dmaengine_desc_callback cb;
876
877	if (chan->cyclic_first) {
878		spin_lock_irqsave(&chan->desc_lock, flags);
879		desc = chan->cyclic_first;
880		dmaengine_desc_get_callback(&desc->async_tx, &cb);
881		spin_unlock_irqrestore(&chan->desc_lock, flags);
882
883		dmaengine_desc_callback_invoke(&cb, NULL);
884
885		return;
886	}
887
888	/* submit pending list; callback for each desc; free desc */
889	spin_lock_irqsave(&chan->desc_lock, flags);
890
891	list_for_each_entry_safe(desc, _desc, &chan->chain_running, node) {
892		/*
893		 * move the descriptors to a temporary list so we can drop
894		 * the lock during the entire cleanup operation
895		 */
896		list_move(&desc->node, &chain_cleanup);
897
898		/*
899		 * Look for the first list entry which has the ENDIRQEN flag
900		 * set. That is the descriptor we got an interrupt for, so
901		 * complete that transaction and its cookie.
902		 */
903		if (desc->desc.dcmd & DCMD_ENDIRQEN) {
904			dma_cookie_t cookie = desc->async_tx.cookie;
905			dma_cookie_complete(&desc->async_tx);
906			dev_dbg(chan->dev, "completed_cookie=%d\n", cookie);
907			break;
908		}
909	}
910
911	/*
912	 * The hardware is idle and ready for more when the
913	 * chain_running list is empty.
914	 */
915	chan->idle = list_empty(&chan->chain_running);
916
917	/* Start any pending transactions automatically */
918	start_pending_queue(chan);
919	spin_unlock_irqrestore(&chan->desc_lock, flags);
920
921	/* Run the callback for each descriptor, in order */
922	list_for_each_entry_safe(desc, _desc, &chain_cleanup, node) {
923		struct dma_async_tx_descriptor *txd = &desc->async_tx;
924
925		/* Remove from the list of transactions */
926		list_del(&desc->node);
927		/* Run the link descriptor callback function */
928		dmaengine_desc_get_callback(txd, &cb);
929		dmaengine_desc_callback_invoke(&cb, NULL);
930
931		dma_pool_free(chan->desc_pool, desc, txd->phys);
932	}
933}
934
935static int mmp_pdma_remove(struct platform_device *op)
936{
937	struct mmp_pdma_device *pdev = platform_get_drvdata(op);
938	struct mmp_pdma_phy *phy;
939	int i, irq = 0, irq_num = 0;
940
941	if (op->dev.of_node)
942		of_dma_controller_free(op->dev.of_node);
943
944	for (i = 0; i < pdev->dma_channels; i++) {
945		if (platform_get_irq(op, i) > 0)
946			irq_num++;
947	}
948
949	if (irq_num != pdev->dma_channels) {
950		irq = platform_get_irq(op, 0);
951		devm_free_irq(&op->dev, irq, pdev);
952	} else {
953		for (i = 0; i < pdev->dma_channels; i++) {
954			phy = &pdev->phy[i];
955			irq = platform_get_irq(op, i);
956			devm_free_irq(&op->dev, irq, phy);
957		}
958	}
959
960	dma_async_device_unregister(&pdev->device);
961	return 0;
962}
963
964static int mmp_pdma_chan_init(struct mmp_pdma_device *pdev, int idx, int irq)
965{
966	struct mmp_pdma_phy *phy  = &pdev->phy[idx];
967	struct mmp_pdma_chan *chan;
968	int ret;
969
970	chan = devm_kzalloc(pdev->dev, sizeof(*chan), GFP_KERNEL);
971	if (chan == NULL)
972		return -ENOMEM;
973
974	phy->idx = idx;
975	phy->base = pdev->base;
976
977	if (irq) {
978		ret = devm_request_irq(pdev->dev, irq, mmp_pdma_chan_handler,
979				       IRQF_SHARED, "pdma", phy);
980		if (ret) {
981			dev_err(pdev->dev, "channel request irq fail!\n");
982			return ret;
983		}
984	}
985
986	spin_lock_init(&chan->desc_lock);
987	chan->dev = pdev->dev;
988	chan->chan.device = &pdev->device;
989	tasklet_setup(&chan->tasklet, dma_do_tasklet);
990	INIT_LIST_HEAD(&chan->chain_pending);
991	INIT_LIST_HEAD(&chan->chain_running);
992
993	/* register virt channel to dma engine */
994	list_add_tail(&chan->chan.device_node, &pdev->device.channels);
995
996	return 0;
997}
998
999static const struct of_device_id mmp_pdma_dt_ids[] = {
1000	{ .compatible = "marvell,pdma-1.0", },
1001	{}
1002};
1003MODULE_DEVICE_TABLE(of, mmp_pdma_dt_ids);
1004
1005static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec,
1006					   struct of_dma *ofdma)
1007{
1008	struct mmp_pdma_device *d = ofdma->of_dma_data;
1009	struct dma_chan *chan;
1010
1011	chan = dma_get_any_slave_channel(&d->device);
1012	if (!chan)
1013		return NULL;
1014
1015	to_mmp_pdma_chan(chan)->drcmr = dma_spec->args[0];
1016
1017	return chan;
1018}
1019
1020static int mmp_pdma_probe(struct platform_device *op)
1021{
1022	struct mmp_pdma_device *pdev;
1023	const struct of_device_id *of_id;
1024	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1025	int i, ret, irq = 0;
1026	int dma_channels = 0, irq_num = 0;
1027	const enum dma_slave_buswidth widths =
1028		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1029		DMA_SLAVE_BUSWIDTH_4_BYTES;
1030
1031	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1032	if (!pdev)
1033		return -ENOMEM;
1034
1035	pdev->dev = &op->dev;
1036
1037	spin_lock_init(&pdev->phy_lock);
1038
1039	pdev->base = devm_platform_ioremap_resource(op, 0);
1040	if (IS_ERR(pdev->base))
1041		return PTR_ERR(pdev->base);
1042
1043	of_id = of_match_device(mmp_pdma_dt_ids, pdev->dev);
1044	if (of_id) {
1045		/* Parse new and deprecated dma-channels properties */
1046		if (of_property_read_u32(pdev->dev->of_node, "dma-channels",
1047					 &dma_channels))
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	}
1055	pdev->dma_channels = dma_channels;
1056
1057	for (i = 0; i < dma_channels; i++) {
1058		if (platform_get_irq_optional(op, i) > 0)
1059			irq_num++;
1060	}
1061
1062	pdev->phy = devm_kcalloc(pdev->dev, dma_channels, sizeof(*pdev->phy),
1063				 GFP_KERNEL);
1064	if (pdev->phy == NULL)
1065		return -ENOMEM;
1066
1067	INIT_LIST_HEAD(&pdev->device.channels);
1068
1069	if (irq_num != dma_channels) {
1070		/* all chan share one irq, demux inside */
1071		irq = platform_get_irq(op, 0);
1072		ret = devm_request_irq(pdev->dev, irq, mmp_pdma_int_handler,
1073				       IRQF_SHARED, "pdma", pdev);
1074		if (ret)
1075			return ret;
1076	}
1077
1078	for (i = 0; i < dma_channels; i++) {
1079		irq = (irq_num != dma_channels) ? 0 : platform_get_irq(op, i);
1080		ret = mmp_pdma_chan_init(pdev, i, irq);
1081		if (ret)
1082			return ret;
1083	}
1084
1085	dma_cap_set(DMA_SLAVE, pdev->device.cap_mask);
1086	dma_cap_set(DMA_MEMCPY, pdev->device.cap_mask);
1087	dma_cap_set(DMA_CYCLIC, pdev->device.cap_mask);
1088	dma_cap_set(DMA_PRIVATE, pdev->device.cap_mask);
1089	pdev->device.dev = &op->dev;
1090	pdev->device.device_alloc_chan_resources = mmp_pdma_alloc_chan_resources;
1091	pdev->device.device_free_chan_resources = mmp_pdma_free_chan_resources;
1092	pdev->device.device_tx_status = mmp_pdma_tx_status;
1093	pdev->device.device_prep_dma_memcpy = mmp_pdma_prep_memcpy;
1094	pdev->device.device_prep_slave_sg = mmp_pdma_prep_slave_sg;
1095	pdev->device.device_prep_dma_cyclic = mmp_pdma_prep_dma_cyclic;
1096	pdev->device.device_issue_pending = mmp_pdma_issue_pending;
1097	pdev->device.device_config = mmp_pdma_config;
1098	pdev->device.device_terminate_all = mmp_pdma_terminate_all;
1099	pdev->device.copy_align = DMAENGINE_ALIGN_8_BYTES;
1100	pdev->device.src_addr_widths = widths;
1101	pdev->device.dst_addr_widths = widths;
1102	pdev->device.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1103	pdev->device.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1104
1105	if (pdev->dev->coherent_dma_mask)
1106		dma_set_mask(pdev->dev, pdev->dev->coherent_dma_mask);
1107	else
1108		dma_set_mask(pdev->dev, DMA_BIT_MASK(64));
1109
1110	ret = dma_async_device_register(&pdev->device);
1111	if (ret) {
1112		dev_err(pdev->device.dev, "unable to register\n");
1113		return ret;
1114	}
1115
1116	if (op->dev.of_node) {
1117		/* Device-tree DMA controller registration */
1118		ret = of_dma_controller_register(op->dev.of_node,
1119						 mmp_pdma_dma_xlate, pdev);
1120		if (ret < 0) {
1121			dev_err(&op->dev, "of_dma_controller_register failed\n");
1122			dma_async_device_unregister(&pdev->device);
1123			return ret;
1124		}
1125	}
1126
1127	platform_set_drvdata(op, pdev);
1128	dev_info(pdev->device.dev, "initialized %d channels\n", dma_channels);
1129	return 0;
1130}
1131
1132static const struct platform_device_id mmp_pdma_id_table[] = {
1133	{ "mmp-pdma", },
1134	{ },
1135};
1136
1137static struct platform_driver mmp_pdma_driver = {
1138	.driver		= {
1139		.name	= "mmp-pdma",
1140		.of_match_table = mmp_pdma_dt_ids,
1141	},
1142	.id_table	= mmp_pdma_id_table,
1143	.probe		= mmp_pdma_probe,
1144	.remove		= mmp_pdma_remove,
1145};
1146
1147module_platform_driver(mmp_pdma_driver);
1148
1149MODULE_DESCRIPTION("MARVELL MMP Peripheral DMA Driver");
1150MODULE_AUTHOR("Marvell International Ltd.");
1151MODULE_LICENSE("GPL v2");
1152