xref: /openbmc/linux/drivers/dma/mmp_pdma.c (revision 97da55fc)
1 /*
2  * Copyright 2012 Marvell International Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 #include <linux/err.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/types.h>
12 #include <linux/interrupt.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/slab.h>
15 #include <linux/dmaengine.h>
16 #include <linux/platform_device.h>
17 #include <linux/device.h>
18 #include <linux/platform_data/mmp_dma.h>
19 #include <linux/dmapool.h>
20 #include <linux/of_device.h>
21 #include <linux/of.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		0x0204
30 #define DTADR		0x0208
31 #define DCMD		0x020c
32 
33 #define DCSR_RUN	(1 << 31)	/* Run Bit (read / write) */
34 #define DCSR_NODESC	(1 << 30)	/* No-Descriptor Fetch (read / write) */
35 #define DCSR_STOPIRQEN	(1 << 29)	/* Stop Interrupt Enable (read / write) */
36 #define DCSR_REQPEND	(1 << 8)	/* Request Pending (read-only) */
37 #define DCSR_STOPSTATE	(1 << 3)	/* Stop State (read-only) */
38 #define DCSR_ENDINTR	(1 << 2)	/* End Interrupt (read / write) */
39 #define DCSR_STARTINTR	(1 << 1)	/* Start Interrupt (read / write) */
40 #define DCSR_BUSERR	(1 << 0)	/* Bus Error Interrupt (read / write) */
41 
42 #define DCSR_EORIRQEN	(1 << 28)       /* End of Receive Interrupt Enable (R/W) */
43 #define DCSR_EORJMPEN	(1 << 27)       /* Jump to next descriptor on EOR */
44 #define DCSR_EORSTOPEN	(1 << 26)       /* STOP on an EOR */
45 #define DCSR_SETCMPST	(1 << 25)       /* Set Descriptor Compare Status */
46 #define DCSR_CLRCMPST	(1 << 24)       /* Clear Descriptor Compare Status */
47 #define DCSR_CMPST	(1 << 10)       /* The Descriptor Compare Status */
48 #define DCSR_EORINTR	(1 << 9)        /* The end of Receive */
49 
50 #define DRCMR_MAPVLD	(1 << 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	(1 << 0)	/* Stop (read / write) */
55 
56 #define DCMD_INCSRCADDR	(1 << 31)	/* Source Address Increment Setting. */
57 #define DCMD_INCTRGADDR	(1 << 30)	/* Target Address Increment Setting. */
58 #define DCMD_FLOWSRC	(1 << 29)	/* Flow Control by the source. */
59 #define DCMD_FLOWTRG	(1 << 28)	/* Flow Control by the target. */
60 #define DCMD_STARTIRQEN	(1 << 22)	/* Start Interrupt Enable */
61 #define DCMD_ENDIRQEN	(1 << 21)	/* End Interrupt Enable */
62 #define DCMD_ENDIAN	(1 << 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_ALIGNMENT		3
72 #define PDMA_MAX_DESC_BYTES	0x1000
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 
97 	/* channel's basic info */
98 	struct tasklet_struct tasklet;
99 	u32 dcmd;
100 	u32 drcmr;
101 	u32 dev_addr;
102 
103 	/* list for desc */
104 	spinlock_t desc_lock;		/* Descriptor list lock */
105 	struct list_head chain_pending;	/* Link descriptors queue for pending */
106 	struct list_head chain_running;	/* Link descriptors queue for running */
107 	bool idle;			/* channel statue machine */
108 
109 	struct dma_pool *desc_pool;	/* Descriptors pool */
110 };
111 
112 struct mmp_pdma_phy {
113 	int idx;
114 	void __iomem *base;
115 	struct mmp_pdma_chan *vchan;
116 };
117 
118 struct mmp_pdma_device {
119 	int				dma_channels;
120 	void __iomem			*base;
121 	struct device			*dev;
122 	struct dma_device		device;
123 	struct mmp_pdma_phy		*phy;
124 };
125 
126 #define tx_to_mmp_pdma_desc(tx) container_of(tx, struct mmp_pdma_desc_sw, async_tx)
127 #define to_mmp_pdma_desc(lh) container_of(lh, struct mmp_pdma_desc_sw, node)
128 #define to_mmp_pdma_chan(dchan) container_of(dchan, struct mmp_pdma_chan, chan)
129 #define to_mmp_pdma_dev(dmadev) container_of(dmadev, struct mmp_pdma_device, device)
130 
131 static void set_desc(struct mmp_pdma_phy *phy, dma_addr_t addr)
132 {
133 	u32 reg = (phy->idx << 4) + DDADR;
134 
135 	writel(addr, phy->base + reg);
136 }
137 
138 static void enable_chan(struct mmp_pdma_phy *phy)
139 {
140 	u32 reg;
141 
142 	if (!phy->vchan)
143 		return;
144 
145 	reg = phy->vchan->drcmr;
146 	reg = (((reg) < 64) ? 0x0100 : 0x1100) + (((reg) & 0x3f) << 2);
147 	writel(DRCMR_MAPVLD | phy->idx, phy->base + reg);
148 
149 	reg = (phy->idx << 2) + DCSR;
150 	writel(readl(phy->base + reg) | DCSR_RUN,
151 					phy->base + reg);
152 }
153 
154 static void disable_chan(struct mmp_pdma_phy *phy)
155 {
156 	u32 reg;
157 
158 	if (phy) {
159 		reg = (phy->idx << 2) + DCSR;
160 		writel(readl(phy->base + reg) & ~DCSR_RUN,
161 						phy->base + reg);
162 	}
163 }
164 
165 static int clear_chan_irq(struct mmp_pdma_phy *phy)
166 {
167 	u32 dcsr;
168 	u32 dint = readl(phy->base + DINT);
169 	u32 reg = (phy->idx << 2) + DCSR;
170 
171 	if (dint & BIT(phy->idx)) {
172 		/* clear irq */
173 		dcsr = readl(phy->base + reg);
174 		writel(dcsr, phy->base + reg);
175 		if ((dcsr & DCSR_BUSERR) && (phy->vchan))
176 			dev_warn(phy->vchan->dev, "DCSR_BUSERR\n");
177 		return 0;
178 	}
179 	return -EAGAIN;
180 }
181 
182 static irqreturn_t mmp_pdma_chan_handler(int irq, void *dev_id)
183 {
184 	struct mmp_pdma_phy *phy = dev_id;
185 
186 	if (clear_chan_irq(phy) == 0) {
187 		tasklet_schedule(&phy->vchan->tasklet);
188 		return IRQ_HANDLED;
189 	} else
190 		return IRQ_NONE;
191 }
192 
193 static irqreturn_t mmp_pdma_int_handler(int irq, void *dev_id)
194 {
195 	struct mmp_pdma_device *pdev = dev_id;
196 	struct mmp_pdma_phy *phy;
197 	u32 dint = readl(pdev->base + DINT);
198 	int i, ret;
199 	int irq_num = 0;
200 
201 	while (dint) {
202 		i = __ffs(dint);
203 		dint &= (dint - 1);
204 		phy = &pdev->phy[i];
205 		ret = mmp_pdma_chan_handler(irq, phy);
206 		if (ret == IRQ_HANDLED)
207 			irq_num++;
208 	}
209 
210 	if (irq_num)
211 		return IRQ_HANDLED;
212 	else
213 		return IRQ_NONE;
214 }
215 
216 /* lookup free phy channel as descending priority */
217 static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan)
218 {
219 	int prio, i;
220 	struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
221 	struct mmp_pdma_phy *phy;
222 
223 	/*
224 	 * dma channel priorities
225 	 * ch 0 - 3,  16 - 19  <--> (0)
226 	 * ch 4 - 7,  20 - 23  <--> (1)
227 	 * ch 8 - 11, 24 - 27  <--> (2)
228 	 * ch 12 - 15, 28 - 31  <--> (3)
229 	 */
230 	for (prio = 0; prio <= (((pdev->dma_channels - 1) & 0xf) >> 2); prio++) {
231 		for (i = 0; i < pdev->dma_channels; i++) {
232 			if (prio != ((i & 0xf) >> 2))
233 				continue;
234 			phy = &pdev->phy[i];
235 			if (!phy->vchan) {
236 				phy->vchan = pchan;
237 				return phy;
238 			}
239 		}
240 	}
241 
242 	return NULL;
243 }
244 
245 /* desc->tx_list ==> pending list */
246 static void append_pending_queue(struct mmp_pdma_chan *chan,
247 					struct mmp_pdma_desc_sw *desc)
248 {
249 	struct mmp_pdma_desc_sw *tail =
250 				to_mmp_pdma_desc(chan->chain_pending.prev);
251 
252 	if (list_empty(&chan->chain_pending))
253 		goto out_splice;
254 
255 	/* one irq per queue, even appended */
256 	tail->desc.ddadr = desc->async_tx.phys;
257 	tail->desc.dcmd &= ~DCMD_ENDIRQEN;
258 
259 	/* softly link to pending list */
260 out_splice:
261 	list_splice_tail_init(&desc->tx_list, &chan->chain_pending);
262 }
263 
264 /**
265  * start_pending_queue - transfer any pending transactions
266  * pending list ==> running list
267  */
268 static void start_pending_queue(struct mmp_pdma_chan *chan)
269 {
270 	struct mmp_pdma_desc_sw *desc;
271 
272 	/* still in running, irq will start the pending list */
273 	if (!chan->idle) {
274 		dev_dbg(chan->dev, "DMA controller still busy\n");
275 		return;
276 	}
277 
278 	if (list_empty(&chan->chain_pending)) {
279 		/* chance to re-fetch phy channel with higher prio */
280 		if (chan->phy) {
281 			chan->phy->vchan = NULL;
282 			chan->phy = NULL;
283 		}
284 		dev_dbg(chan->dev, "no pending list\n");
285 		return;
286 	}
287 
288 	if (!chan->phy) {
289 		chan->phy = lookup_phy(chan);
290 		if (!chan->phy) {
291 			dev_dbg(chan->dev, "no free dma channel\n");
292 			return;
293 		}
294 	}
295 
296 	/*
297 	 * pending -> running
298 	 * reintilize pending list
299 	 */
300 	desc = list_first_entry(&chan->chain_pending,
301 				struct mmp_pdma_desc_sw, node);
302 	list_splice_tail_init(&chan->chain_pending, &chan->chain_running);
303 
304 	/*
305 	 * Program the descriptor's address into the DMA controller,
306 	 * then start the DMA transaction
307 	 */
308 	set_desc(chan->phy, desc->async_tx.phys);
309 	enable_chan(chan->phy);
310 	chan->idle = false;
311 }
312 
313 
314 /* desc->tx_list ==> pending list */
315 static dma_cookie_t mmp_pdma_tx_submit(struct dma_async_tx_descriptor *tx)
316 {
317 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(tx->chan);
318 	struct mmp_pdma_desc_sw *desc = tx_to_mmp_pdma_desc(tx);
319 	struct mmp_pdma_desc_sw *child;
320 	unsigned long flags;
321 	dma_cookie_t cookie = -EBUSY;
322 
323 	spin_lock_irqsave(&chan->desc_lock, flags);
324 
325 	list_for_each_entry(child, &desc->tx_list, node) {
326 		cookie = dma_cookie_assign(&child->async_tx);
327 	}
328 
329 	append_pending_queue(chan, desc);
330 
331 	spin_unlock_irqrestore(&chan->desc_lock, flags);
332 
333 	return cookie;
334 }
335 
336 struct mmp_pdma_desc_sw *mmp_pdma_alloc_descriptor(struct mmp_pdma_chan *chan)
337 {
338 	struct mmp_pdma_desc_sw *desc;
339 	dma_addr_t pdesc;
340 
341 	desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
342 	if (!desc) {
343 		dev_err(chan->dev, "out of memory for link descriptor\n");
344 		return NULL;
345 	}
346 
347 	memset(desc, 0, sizeof(*desc));
348 	INIT_LIST_HEAD(&desc->tx_list);
349 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan);
350 	/* each desc has submit */
351 	desc->async_tx.tx_submit = mmp_pdma_tx_submit;
352 	desc->async_tx.phys = pdesc;
353 
354 	return desc;
355 }
356 
357 /**
358  * mmp_pdma_alloc_chan_resources - Allocate resources for DMA channel.
359  *
360  * This function will create a dma pool for descriptor allocation.
361  * Request irq only when channel is requested
362  * Return - The number of allocated descriptors.
363  */
364 
365 static int mmp_pdma_alloc_chan_resources(struct dma_chan *dchan)
366 {
367 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
368 
369 	if (chan->desc_pool)
370 		return 1;
371 
372 	chan->desc_pool =
373 		dma_pool_create(dev_name(&dchan->dev->device), chan->dev,
374 				  sizeof(struct mmp_pdma_desc_sw),
375 				  __alignof__(struct mmp_pdma_desc_sw), 0);
376 	if (!chan->desc_pool) {
377 		dev_err(chan->dev, "unable to allocate descriptor pool\n");
378 		return -ENOMEM;
379 	}
380 	if (chan->phy) {
381 		chan->phy->vchan = NULL;
382 		chan->phy = NULL;
383 	}
384 	chan->idle = true;
385 	chan->dev_addr = 0;
386 	return 1;
387 }
388 
389 static void mmp_pdma_free_desc_list(struct mmp_pdma_chan *chan,
390 				  struct list_head *list)
391 {
392 	struct mmp_pdma_desc_sw *desc, *_desc;
393 
394 	list_for_each_entry_safe(desc, _desc, list, node) {
395 		list_del(&desc->node);
396 		dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
397 	}
398 }
399 
400 static void mmp_pdma_free_chan_resources(struct dma_chan *dchan)
401 {
402 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
403 	unsigned long flags;
404 
405 	spin_lock_irqsave(&chan->desc_lock, flags);
406 	mmp_pdma_free_desc_list(chan, &chan->chain_pending);
407 	mmp_pdma_free_desc_list(chan, &chan->chain_running);
408 	spin_unlock_irqrestore(&chan->desc_lock, flags);
409 
410 	dma_pool_destroy(chan->desc_pool);
411 	chan->desc_pool = NULL;
412 	chan->idle = true;
413 	chan->dev_addr = 0;
414 	if (chan->phy) {
415 		chan->phy->vchan = NULL;
416 		chan->phy = NULL;
417 	}
418 	return;
419 }
420 
421 static struct dma_async_tx_descriptor *
422 mmp_pdma_prep_memcpy(struct dma_chan *dchan,
423 	dma_addr_t dma_dst, dma_addr_t dma_src,
424 	size_t len, unsigned long flags)
425 {
426 	struct mmp_pdma_chan *chan;
427 	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
428 	size_t copy = 0;
429 
430 	if (!dchan)
431 		return NULL;
432 
433 	if (!len)
434 		return NULL;
435 
436 	chan = to_mmp_pdma_chan(dchan);
437 
438 	if (!chan->dir) {
439 		chan->dir = DMA_MEM_TO_MEM;
440 		chan->dcmd = DCMD_INCTRGADDR | DCMD_INCSRCADDR;
441 		chan->dcmd |= DCMD_BURST32;
442 	}
443 
444 	do {
445 		/* Allocate the link descriptor from DMA pool */
446 		new = mmp_pdma_alloc_descriptor(chan);
447 		if (!new) {
448 			dev_err(chan->dev, "no memory for desc\n");
449 			goto fail;
450 		}
451 
452 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
453 
454 		new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & copy);
455 		new->desc.dsadr = dma_src;
456 		new->desc.dtadr = dma_dst;
457 
458 		if (!first)
459 			first = new;
460 		else
461 			prev->desc.ddadr = new->async_tx.phys;
462 
463 		new->async_tx.cookie = 0;
464 		async_tx_ack(&new->async_tx);
465 
466 		prev = new;
467 		len -= copy;
468 
469 		if (chan->dir == DMA_MEM_TO_DEV) {
470 			dma_src += copy;
471 		} else if (chan->dir == DMA_DEV_TO_MEM) {
472 			dma_dst += copy;
473 		} else if (chan->dir == DMA_MEM_TO_MEM) {
474 			dma_src += copy;
475 			dma_dst += copy;
476 		}
477 
478 		/* Insert the link descriptor to the LD ring */
479 		list_add_tail(&new->node, &first->tx_list);
480 	} while (len);
481 
482 	first->async_tx.flags = flags; /* client is in control of this ack */
483 	first->async_tx.cookie = -EBUSY;
484 
485 	/* last desc and fire IRQ */
486 	new->desc.ddadr = DDADR_STOP;
487 	new->desc.dcmd |= DCMD_ENDIRQEN;
488 
489 	return &first->async_tx;
490 
491 fail:
492 	if (first)
493 		mmp_pdma_free_desc_list(chan, &first->tx_list);
494 	return NULL;
495 }
496 
497 static struct dma_async_tx_descriptor *
498 mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
499 			 unsigned int sg_len, enum dma_transfer_direction dir,
500 			 unsigned long flags, void *context)
501 {
502 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
503 	struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new = NULL;
504 	size_t len, avail;
505 	struct scatterlist *sg;
506 	dma_addr_t addr;
507 	int i;
508 
509 	if ((sgl == NULL) || (sg_len == 0))
510 		return NULL;
511 
512 	for_each_sg(sgl, sg, sg_len, i) {
513 		addr = sg_dma_address(sg);
514 		avail = sg_dma_len(sgl);
515 
516 		do {
517 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
518 
519 			/* allocate and populate the descriptor */
520 			new = mmp_pdma_alloc_descriptor(chan);
521 			if (!new) {
522 				dev_err(chan->dev, "no memory for desc\n");
523 				goto fail;
524 			}
525 
526 			new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & len);
527 			if (dir == DMA_MEM_TO_DEV) {
528 				new->desc.dsadr = addr;
529 				new->desc.dtadr = chan->dev_addr;
530 			} else {
531 				new->desc.dsadr = chan->dev_addr;
532 				new->desc.dtadr = addr;
533 			}
534 
535 			if (!first)
536 				first = new;
537 			else
538 				prev->desc.ddadr = new->async_tx.phys;
539 
540 			new->async_tx.cookie = 0;
541 			async_tx_ack(&new->async_tx);
542 			prev = new;
543 
544 			/* Insert the link descriptor to the LD ring */
545 			list_add_tail(&new->node, &first->tx_list);
546 
547 			/* update metadata */
548 			addr += len;
549 			avail -= len;
550 		} while (avail);
551 	}
552 
553 	first->async_tx.cookie = -EBUSY;
554 	first->async_tx.flags = flags;
555 
556 	/* last desc and fire IRQ */
557 	new->desc.ddadr = DDADR_STOP;
558 	new->desc.dcmd |= DCMD_ENDIRQEN;
559 
560 	return &first->async_tx;
561 
562 fail:
563 	if (first)
564 		mmp_pdma_free_desc_list(chan, &first->tx_list);
565 	return NULL;
566 }
567 
568 static int mmp_pdma_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd,
569 		unsigned long arg)
570 {
571 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
572 	struct dma_slave_config *cfg = (void *)arg;
573 	unsigned long flags;
574 	int ret = 0;
575 	u32 maxburst = 0, addr = 0;
576 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
577 
578 	if (!dchan)
579 		return -EINVAL;
580 
581 	switch (cmd) {
582 	case DMA_TERMINATE_ALL:
583 		disable_chan(chan->phy);
584 		if (chan->phy) {
585 			chan->phy->vchan = NULL;
586 			chan->phy = NULL;
587 		}
588 		spin_lock_irqsave(&chan->desc_lock, flags);
589 		mmp_pdma_free_desc_list(chan, &chan->chain_pending);
590 		mmp_pdma_free_desc_list(chan, &chan->chain_running);
591 		spin_unlock_irqrestore(&chan->desc_lock, flags);
592 		chan->idle = true;
593 		break;
594 	case DMA_SLAVE_CONFIG:
595 		if (cfg->direction == DMA_DEV_TO_MEM) {
596 			chan->dcmd = DCMD_INCTRGADDR | DCMD_FLOWSRC;
597 			maxburst = cfg->src_maxburst;
598 			width = cfg->src_addr_width;
599 			addr = cfg->src_addr;
600 		} else if (cfg->direction == DMA_MEM_TO_DEV) {
601 			chan->dcmd = DCMD_INCSRCADDR | DCMD_FLOWTRG;
602 			maxburst = cfg->dst_maxburst;
603 			width = cfg->dst_addr_width;
604 			addr = cfg->dst_addr;
605 		}
606 
607 		if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
608 			chan->dcmd |= DCMD_WIDTH1;
609 		else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
610 			chan->dcmd |= DCMD_WIDTH2;
611 		else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
612 			chan->dcmd |= DCMD_WIDTH4;
613 
614 		if (maxburst == 8)
615 			chan->dcmd |= DCMD_BURST8;
616 		else if (maxburst == 16)
617 			chan->dcmd |= DCMD_BURST16;
618 		else if (maxburst == 32)
619 			chan->dcmd |= DCMD_BURST32;
620 
621 		chan->dir = cfg->direction;
622 		chan->drcmr = cfg->slave_id;
623 		chan->dev_addr = addr;
624 		break;
625 	default:
626 		return -ENOSYS;
627 	}
628 
629 	return ret;
630 }
631 
632 static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan,
633 			dma_cookie_t cookie, struct dma_tx_state *txstate)
634 {
635 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
636 	enum dma_status ret;
637 	unsigned long flags;
638 
639 	spin_lock_irqsave(&chan->desc_lock, flags);
640 	ret = dma_cookie_status(dchan, cookie, txstate);
641 	spin_unlock_irqrestore(&chan->desc_lock, flags);
642 
643 	return ret;
644 }
645 
646 /**
647  * mmp_pdma_issue_pending - Issue the DMA start command
648  * pending list ==> running list
649  */
650 static void mmp_pdma_issue_pending(struct dma_chan *dchan)
651 {
652 	struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
653 	unsigned long flags;
654 
655 	spin_lock_irqsave(&chan->desc_lock, flags);
656 	start_pending_queue(chan);
657 	spin_unlock_irqrestore(&chan->desc_lock, flags);
658 }
659 
660 /*
661  * dma_do_tasklet
662  * Do call back
663  * Start pending list
664  */
665 static void dma_do_tasklet(unsigned long data)
666 {
667 	struct mmp_pdma_chan *chan = (struct mmp_pdma_chan *)data;
668 	struct mmp_pdma_desc_sw *desc, *_desc;
669 	LIST_HEAD(chain_cleanup);
670 	unsigned long flags;
671 
672 	/* submit pending list; callback for each desc; free desc */
673 
674 	spin_lock_irqsave(&chan->desc_lock, flags);
675 
676 	/* update the cookie if we have some descriptors to cleanup */
677 	if (!list_empty(&chan->chain_running)) {
678 		dma_cookie_t cookie;
679 
680 		desc = to_mmp_pdma_desc(chan->chain_running.prev);
681 		cookie = desc->async_tx.cookie;
682 		dma_cookie_complete(&desc->async_tx);
683 
684 		dev_dbg(chan->dev, "completed_cookie=%d\n", cookie);
685 	}
686 
687 	/*
688 	 * move the descriptors to a temporary list so we can drop the lock
689 	 * during the entire cleanup operation
690 	 */
691 	list_splice_tail_init(&chan->chain_running, &chain_cleanup);
692 
693 	/* the hardware is now idle and ready for more */
694 	chan->idle = true;
695 
696 	/* Start any pending transactions automatically */
697 	start_pending_queue(chan);
698 	spin_unlock_irqrestore(&chan->desc_lock, flags);
699 
700 	/* Run the callback for each descriptor, in order */
701 	list_for_each_entry_safe(desc, _desc, &chain_cleanup, node) {
702 		struct dma_async_tx_descriptor *txd = &desc->async_tx;
703 
704 		/* Remove from the list of transactions */
705 		list_del(&desc->node);
706 		/* Run the link descriptor callback function */
707 		if (txd->callback)
708 			txd->callback(txd->callback_param);
709 
710 		dma_pool_free(chan->desc_pool, desc, txd->phys);
711 	}
712 }
713 
714 static int mmp_pdma_remove(struct platform_device *op)
715 {
716 	struct mmp_pdma_device *pdev = platform_get_drvdata(op);
717 
718 	dma_async_device_unregister(&pdev->device);
719 	return 0;
720 }
721 
722 static int mmp_pdma_chan_init(struct mmp_pdma_device *pdev,
723 							int idx, int irq)
724 {
725 	struct mmp_pdma_phy *phy  = &pdev->phy[idx];
726 	struct mmp_pdma_chan *chan;
727 	int ret;
728 
729 	chan = devm_kzalloc(pdev->dev,
730 			sizeof(struct mmp_pdma_chan), GFP_KERNEL);
731 	if (chan == NULL)
732 		return -ENOMEM;
733 
734 	phy->idx = idx;
735 	phy->base = pdev->base;
736 
737 	if (irq) {
738 		ret = devm_request_irq(pdev->dev, irq,
739 			mmp_pdma_chan_handler, IRQF_DISABLED, "pdma", phy);
740 		if (ret) {
741 			dev_err(pdev->dev, "channel request irq fail!\n");
742 			return ret;
743 		}
744 	}
745 
746 	spin_lock_init(&chan->desc_lock);
747 	chan->dev = pdev->dev;
748 	chan->chan.device = &pdev->device;
749 	tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
750 	INIT_LIST_HEAD(&chan->chain_pending);
751 	INIT_LIST_HEAD(&chan->chain_running);
752 
753 	/* register virt channel to dma engine */
754 	list_add_tail(&chan->chan.device_node,
755 			&pdev->device.channels);
756 
757 	return 0;
758 }
759 
760 static struct of_device_id mmp_pdma_dt_ids[] = {
761 	{ .compatible = "marvell,pdma-1.0", },
762 	{}
763 };
764 MODULE_DEVICE_TABLE(of, mmp_pdma_dt_ids);
765 
766 static int mmp_pdma_probe(struct platform_device *op)
767 {
768 	struct mmp_pdma_device *pdev;
769 	const struct of_device_id *of_id;
770 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
771 	struct resource *iores;
772 	int i, ret, irq = 0;
773 	int dma_channels = 0, irq_num = 0;
774 
775 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
776 	if (!pdev)
777 		return -ENOMEM;
778 	pdev->dev = &op->dev;
779 
780 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
781 	if (!iores)
782 		return -EINVAL;
783 
784 	pdev->base = devm_ioremap_resource(pdev->dev, iores);
785 	if (IS_ERR(pdev->base))
786 		return PTR_ERR(pdev->base);
787 
788 	of_id = of_match_device(mmp_pdma_dt_ids, pdev->dev);
789 	if (of_id)
790 		of_property_read_u32(pdev->dev->of_node,
791 				"#dma-channels", &dma_channels);
792 	else if (pdata && pdata->dma_channels)
793 		dma_channels = pdata->dma_channels;
794 	else
795 		dma_channels = 32;	/* default 32 channel */
796 	pdev->dma_channels = dma_channels;
797 
798 	for (i = 0; i < dma_channels; i++) {
799 		if (platform_get_irq(op, i) > 0)
800 			irq_num++;
801 	}
802 
803 	pdev->phy = devm_kzalloc(pdev->dev,
804 		dma_channels * sizeof(struct mmp_pdma_chan), GFP_KERNEL);
805 	if (pdev->phy == NULL)
806 		return -ENOMEM;
807 
808 	INIT_LIST_HEAD(&pdev->device.channels);
809 
810 	if (irq_num != dma_channels) {
811 		/* all chan share one irq, demux inside */
812 		irq = platform_get_irq(op, 0);
813 		ret = devm_request_irq(pdev->dev, irq,
814 			mmp_pdma_int_handler, IRQF_DISABLED, "pdma", pdev);
815 		if (ret)
816 			return ret;
817 	}
818 
819 	for (i = 0; i < dma_channels; i++) {
820 		irq = (irq_num != dma_channels) ? 0 : platform_get_irq(op, i);
821 		ret = mmp_pdma_chan_init(pdev, i, irq);
822 		if (ret)
823 			return ret;
824 	}
825 
826 	dma_cap_set(DMA_SLAVE, pdev->device.cap_mask);
827 	dma_cap_set(DMA_MEMCPY, pdev->device.cap_mask);
828 	dma_cap_set(DMA_SLAVE, pdev->device.cap_mask);
829 	pdev->device.dev = &op->dev;
830 	pdev->device.device_alloc_chan_resources = mmp_pdma_alloc_chan_resources;
831 	pdev->device.device_free_chan_resources = mmp_pdma_free_chan_resources;
832 	pdev->device.device_tx_status = mmp_pdma_tx_status;
833 	pdev->device.device_prep_dma_memcpy = mmp_pdma_prep_memcpy;
834 	pdev->device.device_prep_slave_sg = mmp_pdma_prep_slave_sg;
835 	pdev->device.device_issue_pending = mmp_pdma_issue_pending;
836 	pdev->device.device_control = mmp_pdma_control;
837 	pdev->device.copy_align = PDMA_ALIGNMENT;
838 
839 	if (pdev->dev->coherent_dma_mask)
840 		dma_set_mask(pdev->dev, pdev->dev->coherent_dma_mask);
841 	else
842 		dma_set_mask(pdev->dev, DMA_BIT_MASK(64));
843 
844 	ret = dma_async_device_register(&pdev->device);
845 	if (ret) {
846 		dev_err(pdev->device.dev, "unable to register\n");
847 		return ret;
848 	}
849 
850 	dev_info(pdev->device.dev, "initialized\n");
851 	return 0;
852 }
853 
854 static const struct platform_device_id mmp_pdma_id_table[] = {
855 	{ "mmp-pdma", },
856 	{ },
857 };
858 
859 static struct platform_driver mmp_pdma_driver = {
860 	.driver		= {
861 		.name	= "mmp-pdma",
862 		.owner  = THIS_MODULE,
863 		.of_match_table = mmp_pdma_dt_ids,
864 	},
865 	.id_table	= mmp_pdma_id_table,
866 	.probe		= mmp_pdma_probe,
867 	.remove		= mmp_pdma_remove,
868 };
869 
870 module_platform_driver(mmp_pdma_driver);
871 
872 MODULE_DESCRIPTION("MARVELL MMP Periphera DMA Driver");
873 MODULE_AUTHOR("Marvell International Ltd.");
874 MODULE_LICENSE("GPL v2");
875