xref: /openbmc/linux/drivers/dma/pl330.c (revision 25985edc)
1 /* linux/drivers/dma/pl330.c
2  *
3  * Copyright (C) 2010 Samsung Electronics Co. Ltd.
4  *	Jaswinder Singh <jassi.brar@samsung.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/io.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/dmaengine.h>
17 #include <linux/interrupt.h>
18 #include <linux/amba/bus.h>
19 #include <linux/amba/pl330.h>
20 
21 #define NR_DEFAULT_DESC	16
22 
23 enum desc_status {
24 	/* In the DMAC pool */
25 	FREE,
26 	/*
27 	 * Allocted to some channel during prep_xxx
28 	 * Also may be sitting on the work_list.
29 	 */
30 	PREP,
31 	/*
32 	 * Sitting on the work_list and already submitted
33 	 * to the PL330 core. Not more than two descriptors
34 	 * of a channel can be BUSY at any time.
35 	 */
36 	BUSY,
37 	/*
38 	 * Sitting on the channel work_list but xfer done
39 	 * by PL330 core
40 	 */
41 	DONE,
42 };
43 
44 struct dma_pl330_chan {
45 	/* Schedule desc completion */
46 	struct tasklet_struct task;
47 
48 	/* DMA-Engine Channel */
49 	struct dma_chan chan;
50 
51 	/* Last completed cookie */
52 	dma_cookie_t completed;
53 
54 	/* List of to be xfered descriptors */
55 	struct list_head work_list;
56 
57 	/* Pointer to the DMAC that manages this channel,
58 	 * NULL if the channel is available to be acquired.
59 	 * As the parent, this DMAC also provides descriptors
60 	 * to the channel.
61 	 */
62 	struct dma_pl330_dmac *dmac;
63 
64 	/* To protect channel manipulation */
65 	spinlock_t lock;
66 
67 	/* Token of a hardware channel thread of PL330 DMAC
68 	 * NULL if the channel is available to be acquired.
69 	 */
70 	void *pl330_chid;
71 };
72 
73 struct dma_pl330_dmac {
74 	struct pl330_info pif;
75 
76 	/* DMA-Engine Device */
77 	struct dma_device ddma;
78 
79 	/* Pool of descriptors available for the DMAC's channels */
80 	struct list_head desc_pool;
81 	/* To protect desc_pool manipulation */
82 	spinlock_t pool_lock;
83 
84 	/* Peripheral channels connected to this DMAC */
85 	struct dma_pl330_chan peripherals[0]; /* keep at end */
86 };
87 
88 struct dma_pl330_desc {
89 	/* To attach to a queue as child */
90 	struct list_head node;
91 
92 	/* Descriptor for the DMA Engine API */
93 	struct dma_async_tx_descriptor txd;
94 
95 	/* Xfer for PL330 core */
96 	struct pl330_xfer px;
97 
98 	struct pl330_reqcfg rqcfg;
99 	struct pl330_req req;
100 
101 	enum desc_status status;
102 
103 	/* The channel which currently holds this desc */
104 	struct dma_pl330_chan *pchan;
105 };
106 
107 static inline struct dma_pl330_chan *
108 to_pchan(struct dma_chan *ch)
109 {
110 	if (!ch)
111 		return NULL;
112 
113 	return container_of(ch, struct dma_pl330_chan, chan);
114 }
115 
116 static inline struct dma_pl330_desc *
117 to_desc(struct dma_async_tx_descriptor *tx)
118 {
119 	return container_of(tx, struct dma_pl330_desc, txd);
120 }
121 
122 static inline void free_desc_list(struct list_head *list)
123 {
124 	struct dma_pl330_dmac *pdmac;
125 	struct dma_pl330_desc *desc;
126 	struct dma_pl330_chan *pch;
127 	unsigned long flags;
128 
129 	if (list_empty(list))
130 		return;
131 
132 	/* Finish off the work list */
133 	list_for_each_entry(desc, list, node) {
134 		dma_async_tx_callback callback;
135 		void *param;
136 
137 		/* All desc in a list belong to same channel */
138 		pch = desc->pchan;
139 		callback = desc->txd.callback;
140 		param = desc->txd.callback_param;
141 
142 		if (callback)
143 			callback(param);
144 
145 		desc->pchan = NULL;
146 	}
147 
148 	pdmac = pch->dmac;
149 
150 	spin_lock_irqsave(&pdmac->pool_lock, flags);
151 	list_splice_tail_init(list, &pdmac->desc_pool);
152 	spin_unlock_irqrestore(&pdmac->pool_lock, flags);
153 }
154 
155 static inline void fill_queue(struct dma_pl330_chan *pch)
156 {
157 	struct dma_pl330_desc *desc;
158 	int ret;
159 
160 	list_for_each_entry(desc, &pch->work_list, node) {
161 
162 		/* If already submitted */
163 		if (desc->status == BUSY)
164 			break;
165 
166 		ret = pl330_submit_req(pch->pl330_chid,
167 						&desc->req);
168 		if (!ret) {
169 			desc->status = BUSY;
170 			break;
171 		} else if (ret == -EAGAIN) {
172 			/* QFull or DMAC Dying */
173 			break;
174 		} else {
175 			/* Unacceptable request */
176 			desc->status = DONE;
177 			dev_err(pch->dmac->pif.dev, "%s:%d Bad Desc(%d)\n",
178 					__func__, __LINE__, desc->txd.cookie);
179 			tasklet_schedule(&pch->task);
180 		}
181 	}
182 }
183 
184 static void pl330_tasklet(unsigned long data)
185 {
186 	struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data;
187 	struct dma_pl330_desc *desc, *_dt;
188 	unsigned long flags;
189 	LIST_HEAD(list);
190 
191 	spin_lock_irqsave(&pch->lock, flags);
192 
193 	/* Pick up ripe tomatoes */
194 	list_for_each_entry_safe(desc, _dt, &pch->work_list, node)
195 		if (desc->status == DONE) {
196 			pch->completed = desc->txd.cookie;
197 			list_move_tail(&desc->node, &list);
198 		}
199 
200 	/* Try to submit a req imm. next to the last completed cookie */
201 	fill_queue(pch);
202 
203 	/* Make sure the PL330 Channel thread is active */
204 	pl330_chan_ctrl(pch->pl330_chid, PL330_OP_START);
205 
206 	spin_unlock_irqrestore(&pch->lock, flags);
207 
208 	free_desc_list(&list);
209 }
210 
211 static void dma_pl330_rqcb(void *token, enum pl330_op_err err)
212 {
213 	struct dma_pl330_desc *desc = token;
214 	struct dma_pl330_chan *pch = desc->pchan;
215 	unsigned long flags;
216 
217 	/* If desc aborted */
218 	if (!pch)
219 		return;
220 
221 	spin_lock_irqsave(&pch->lock, flags);
222 
223 	desc->status = DONE;
224 
225 	spin_unlock_irqrestore(&pch->lock, flags);
226 
227 	tasklet_schedule(&pch->task);
228 }
229 
230 static int pl330_alloc_chan_resources(struct dma_chan *chan)
231 {
232 	struct dma_pl330_chan *pch = to_pchan(chan);
233 	struct dma_pl330_dmac *pdmac = pch->dmac;
234 	unsigned long flags;
235 
236 	spin_lock_irqsave(&pch->lock, flags);
237 
238 	pch->completed = chan->cookie = 1;
239 
240 	pch->pl330_chid = pl330_request_channel(&pdmac->pif);
241 	if (!pch->pl330_chid) {
242 		spin_unlock_irqrestore(&pch->lock, flags);
243 		return 0;
244 	}
245 
246 	tasklet_init(&pch->task, pl330_tasklet, (unsigned long) pch);
247 
248 	spin_unlock_irqrestore(&pch->lock, flags);
249 
250 	return 1;
251 }
252 
253 static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg)
254 {
255 	struct dma_pl330_chan *pch = to_pchan(chan);
256 	struct dma_pl330_desc *desc;
257 	unsigned long flags;
258 
259 	/* Only supports DMA_TERMINATE_ALL */
260 	if (cmd != DMA_TERMINATE_ALL)
261 		return -ENXIO;
262 
263 	spin_lock_irqsave(&pch->lock, flags);
264 
265 	/* FLUSH the PL330 Channel thread */
266 	pl330_chan_ctrl(pch->pl330_chid, PL330_OP_FLUSH);
267 
268 	/* Mark all desc done */
269 	list_for_each_entry(desc, &pch->work_list, node)
270 		desc->status = DONE;
271 
272 	spin_unlock_irqrestore(&pch->lock, flags);
273 
274 	pl330_tasklet((unsigned long) pch);
275 
276 	return 0;
277 }
278 
279 static void pl330_free_chan_resources(struct dma_chan *chan)
280 {
281 	struct dma_pl330_chan *pch = to_pchan(chan);
282 	unsigned long flags;
283 
284 	spin_lock_irqsave(&pch->lock, flags);
285 
286 	tasklet_kill(&pch->task);
287 
288 	pl330_release_channel(pch->pl330_chid);
289 	pch->pl330_chid = NULL;
290 
291 	spin_unlock_irqrestore(&pch->lock, flags);
292 }
293 
294 static enum dma_status
295 pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
296 		 struct dma_tx_state *txstate)
297 {
298 	struct dma_pl330_chan *pch = to_pchan(chan);
299 	dma_cookie_t last_done, last_used;
300 	int ret;
301 
302 	last_done = pch->completed;
303 	last_used = chan->cookie;
304 
305 	ret = dma_async_is_complete(cookie, last_done, last_used);
306 
307 	dma_set_tx_state(txstate, last_done, last_used, 0);
308 
309 	return ret;
310 }
311 
312 static void pl330_issue_pending(struct dma_chan *chan)
313 {
314 	pl330_tasklet((unsigned long) to_pchan(chan));
315 }
316 
317 /*
318  * We returned the last one of the circular list of descriptor(s)
319  * from prep_xxx, so the argument to submit corresponds to the last
320  * descriptor of the list.
321  */
322 static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
323 {
324 	struct dma_pl330_desc *desc, *last = to_desc(tx);
325 	struct dma_pl330_chan *pch = to_pchan(tx->chan);
326 	dma_cookie_t cookie;
327 	unsigned long flags;
328 
329 	spin_lock_irqsave(&pch->lock, flags);
330 
331 	/* Assign cookies to all nodes */
332 	cookie = tx->chan->cookie;
333 
334 	while (!list_empty(&last->node)) {
335 		desc = list_entry(last->node.next, struct dma_pl330_desc, node);
336 
337 		if (++cookie < 0)
338 			cookie = 1;
339 		desc->txd.cookie = cookie;
340 
341 		list_move_tail(&desc->node, &pch->work_list);
342 	}
343 
344 	if (++cookie < 0)
345 		cookie = 1;
346 	last->txd.cookie = cookie;
347 
348 	list_add_tail(&last->node, &pch->work_list);
349 
350 	tx->chan->cookie = cookie;
351 
352 	spin_unlock_irqrestore(&pch->lock, flags);
353 
354 	return cookie;
355 }
356 
357 static inline void _init_desc(struct dma_pl330_desc *desc)
358 {
359 	desc->pchan = NULL;
360 	desc->req.x = &desc->px;
361 	desc->req.token = desc;
362 	desc->rqcfg.swap = SWAP_NO;
363 	desc->rqcfg.privileged = 0;
364 	desc->rqcfg.insnaccess = 0;
365 	desc->rqcfg.scctl = SCCTRL0;
366 	desc->rqcfg.dcctl = DCCTRL0;
367 	desc->req.cfg = &desc->rqcfg;
368 	desc->req.xfer_cb = dma_pl330_rqcb;
369 	desc->txd.tx_submit = pl330_tx_submit;
370 
371 	INIT_LIST_HEAD(&desc->node);
372 }
373 
374 /* Returns the number of descriptors added to the DMAC pool */
375 int add_desc(struct dma_pl330_dmac *pdmac, gfp_t flg, int count)
376 {
377 	struct dma_pl330_desc *desc;
378 	unsigned long flags;
379 	int i;
380 
381 	if (!pdmac)
382 		return 0;
383 
384 	desc = kmalloc(count * sizeof(*desc), flg);
385 	if (!desc)
386 		return 0;
387 
388 	spin_lock_irqsave(&pdmac->pool_lock, flags);
389 
390 	for (i = 0; i < count; i++) {
391 		_init_desc(&desc[i]);
392 		list_add_tail(&desc[i].node, &pdmac->desc_pool);
393 	}
394 
395 	spin_unlock_irqrestore(&pdmac->pool_lock, flags);
396 
397 	return count;
398 }
399 
400 static struct dma_pl330_desc *
401 pluck_desc(struct dma_pl330_dmac *pdmac)
402 {
403 	struct dma_pl330_desc *desc = NULL;
404 	unsigned long flags;
405 
406 	if (!pdmac)
407 		return NULL;
408 
409 	spin_lock_irqsave(&pdmac->pool_lock, flags);
410 
411 	if (!list_empty(&pdmac->desc_pool)) {
412 		desc = list_entry(pdmac->desc_pool.next,
413 				struct dma_pl330_desc, node);
414 
415 		list_del_init(&desc->node);
416 
417 		desc->status = PREP;
418 		desc->txd.callback = NULL;
419 	}
420 
421 	spin_unlock_irqrestore(&pdmac->pool_lock, flags);
422 
423 	return desc;
424 }
425 
426 static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan *pch)
427 {
428 	struct dma_pl330_dmac *pdmac = pch->dmac;
429 	struct dma_pl330_peri *peri = pch->chan.private;
430 	struct dma_pl330_desc *desc;
431 
432 	/* Pluck one desc from the pool of DMAC */
433 	desc = pluck_desc(pdmac);
434 
435 	/* If the DMAC pool is empty, alloc new */
436 	if (!desc) {
437 		if (!add_desc(pdmac, GFP_ATOMIC, 1))
438 			return NULL;
439 
440 		/* Try again */
441 		desc = pluck_desc(pdmac);
442 		if (!desc) {
443 			dev_err(pch->dmac->pif.dev,
444 				"%s:%d ALERT!\n", __func__, __LINE__);
445 			return NULL;
446 		}
447 	}
448 
449 	/* Initialize the descriptor */
450 	desc->pchan = pch;
451 	desc->txd.cookie = 0;
452 	async_tx_ack(&desc->txd);
453 
454 	desc->req.rqtype = peri->rqtype;
455 	desc->req.peri = peri->peri_id;
456 
457 	dma_async_tx_descriptor_init(&desc->txd, &pch->chan);
458 
459 	return desc;
460 }
461 
462 static inline void fill_px(struct pl330_xfer *px,
463 		dma_addr_t dst, dma_addr_t src, size_t len)
464 {
465 	px->next = NULL;
466 	px->bytes = len;
467 	px->dst_addr = dst;
468 	px->src_addr = src;
469 }
470 
471 static struct dma_pl330_desc *
472 __pl330_prep_dma_memcpy(struct dma_pl330_chan *pch, dma_addr_t dst,
473 		dma_addr_t src, size_t len)
474 {
475 	struct dma_pl330_desc *desc = pl330_get_desc(pch);
476 
477 	if (!desc) {
478 		dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n",
479 			__func__, __LINE__);
480 		return NULL;
481 	}
482 
483 	/*
484 	 * Ideally we should lookout for reqs bigger than
485 	 * those that can be programmed with 256 bytes of
486 	 * MC buffer, but considering a req size is seldom
487 	 * going to be word-unaligned and more than 200MB,
488 	 * we take it easy.
489 	 * Also, should the limit is reached we'd rather
490 	 * have the platform increase MC buffer size than
491 	 * complicating this API driver.
492 	 */
493 	fill_px(&desc->px, dst, src, len);
494 
495 	return desc;
496 }
497 
498 /* Call after fixing burst size */
499 static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len)
500 {
501 	struct dma_pl330_chan *pch = desc->pchan;
502 	struct pl330_info *pi = &pch->dmac->pif;
503 	int burst_len;
504 
505 	burst_len = pi->pcfg.data_bus_width / 8;
506 	burst_len *= pi->pcfg.data_buf_dep;
507 	burst_len >>= desc->rqcfg.brst_size;
508 
509 	/* src/dst_burst_len can't be more than 16 */
510 	if (burst_len > 16)
511 		burst_len = 16;
512 
513 	while (burst_len > 1) {
514 		if (!(len % (burst_len << desc->rqcfg.brst_size)))
515 			break;
516 		burst_len--;
517 	}
518 
519 	return burst_len;
520 }
521 
522 static struct dma_async_tx_descriptor *
523 pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst,
524 		dma_addr_t src, size_t len, unsigned long flags)
525 {
526 	struct dma_pl330_desc *desc;
527 	struct dma_pl330_chan *pch = to_pchan(chan);
528 	struct dma_pl330_peri *peri = chan->private;
529 	struct pl330_info *pi;
530 	int burst;
531 
532 	if (unlikely(!pch || !len || !peri))
533 		return NULL;
534 
535 	if (peri->rqtype != MEMTOMEM)
536 		return NULL;
537 
538 	pi = &pch->dmac->pif;
539 
540 	desc = __pl330_prep_dma_memcpy(pch, dst, src, len);
541 	if (!desc)
542 		return NULL;
543 
544 	desc->rqcfg.src_inc = 1;
545 	desc->rqcfg.dst_inc = 1;
546 
547 	/* Select max possible burst size */
548 	burst = pi->pcfg.data_bus_width / 8;
549 
550 	while (burst > 1) {
551 		if (!(len % burst))
552 			break;
553 		burst /= 2;
554 	}
555 
556 	desc->rqcfg.brst_size = 0;
557 	while (burst != (1 << desc->rqcfg.brst_size))
558 		desc->rqcfg.brst_size++;
559 
560 	desc->rqcfg.brst_len = get_burst_len(desc, len);
561 
562 	desc->txd.flags = flags;
563 
564 	return &desc->txd;
565 }
566 
567 static struct dma_async_tx_descriptor *
568 pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
569 		unsigned int sg_len, enum dma_data_direction direction,
570 		unsigned long flg)
571 {
572 	struct dma_pl330_desc *first, *desc = NULL;
573 	struct dma_pl330_chan *pch = to_pchan(chan);
574 	struct dma_pl330_peri *peri = chan->private;
575 	struct scatterlist *sg;
576 	unsigned long flags;
577 	int i, burst_size;
578 	dma_addr_t addr;
579 
580 	if (unlikely(!pch || !sgl || !sg_len))
581 		return NULL;
582 
583 	/* Make sure the direction is consistent */
584 	if ((direction == DMA_TO_DEVICE &&
585 				peri->rqtype != MEMTODEV) ||
586 			(direction == DMA_FROM_DEVICE &&
587 				peri->rqtype != DEVTOMEM)) {
588 		dev_err(pch->dmac->pif.dev, "%s:%d Invalid Direction\n",
589 				__func__, __LINE__);
590 		return NULL;
591 	}
592 
593 	addr = peri->fifo_addr;
594 	burst_size = peri->burst_sz;
595 
596 	first = NULL;
597 
598 	for_each_sg(sgl, sg, sg_len, i) {
599 
600 		desc = pl330_get_desc(pch);
601 		if (!desc) {
602 			struct dma_pl330_dmac *pdmac = pch->dmac;
603 
604 			dev_err(pch->dmac->pif.dev,
605 				"%s:%d Unable to fetch desc\n",
606 				__func__, __LINE__);
607 			if (!first)
608 				return NULL;
609 
610 			spin_lock_irqsave(&pdmac->pool_lock, flags);
611 
612 			while (!list_empty(&first->node)) {
613 				desc = list_entry(first->node.next,
614 						struct dma_pl330_desc, node);
615 				list_move_tail(&desc->node, &pdmac->desc_pool);
616 			}
617 
618 			list_move_tail(&first->node, &pdmac->desc_pool);
619 
620 			spin_unlock_irqrestore(&pdmac->pool_lock, flags);
621 
622 			return NULL;
623 		}
624 
625 		if (!first)
626 			first = desc;
627 		else
628 			list_add_tail(&desc->node, &first->node);
629 
630 		if (direction == DMA_TO_DEVICE) {
631 			desc->rqcfg.src_inc = 1;
632 			desc->rqcfg.dst_inc = 0;
633 			fill_px(&desc->px,
634 				addr, sg_dma_address(sg), sg_dma_len(sg));
635 		} else {
636 			desc->rqcfg.src_inc = 0;
637 			desc->rqcfg.dst_inc = 1;
638 			fill_px(&desc->px,
639 				sg_dma_address(sg), addr, sg_dma_len(sg));
640 		}
641 
642 		desc->rqcfg.brst_size = burst_size;
643 		desc->rqcfg.brst_len = 1;
644 	}
645 
646 	/* Return the last desc in the chain */
647 	desc->txd.flags = flg;
648 	return &desc->txd;
649 }
650 
651 static irqreturn_t pl330_irq_handler(int irq, void *data)
652 {
653 	if (pl330_update(data))
654 		return IRQ_HANDLED;
655 	else
656 		return IRQ_NONE;
657 }
658 
659 static int __devinit
660 pl330_probe(struct amba_device *adev, const struct amba_id *id)
661 {
662 	struct dma_pl330_platdata *pdat;
663 	struct dma_pl330_dmac *pdmac;
664 	struct dma_pl330_chan *pch;
665 	struct pl330_info *pi;
666 	struct dma_device *pd;
667 	struct resource *res;
668 	int i, ret, irq;
669 
670 	pdat = adev->dev.platform_data;
671 
672 	if (!pdat || !pdat->nr_valid_peri) {
673 		dev_err(&adev->dev, "platform data missing\n");
674 		return -ENODEV;
675 	}
676 
677 	/* Allocate a new DMAC and its Channels */
678 	pdmac = kzalloc(pdat->nr_valid_peri * sizeof(*pch)
679 				+ sizeof(*pdmac), GFP_KERNEL);
680 	if (!pdmac) {
681 		dev_err(&adev->dev, "unable to allocate mem\n");
682 		return -ENOMEM;
683 	}
684 
685 	pi = &pdmac->pif;
686 	pi->dev = &adev->dev;
687 	pi->pl330_data = NULL;
688 	pi->mcbufsz = pdat->mcbuf_sz;
689 
690 	res = &adev->res;
691 	request_mem_region(res->start, resource_size(res), "dma-pl330");
692 
693 	pi->base = ioremap(res->start, resource_size(res));
694 	if (!pi->base) {
695 		ret = -ENXIO;
696 		goto probe_err1;
697 	}
698 
699 	irq = adev->irq[0];
700 	ret = request_irq(irq, pl330_irq_handler, 0,
701 			dev_name(&adev->dev), pi);
702 	if (ret)
703 		goto probe_err2;
704 
705 	ret = pl330_add(pi);
706 	if (ret)
707 		goto probe_err3;
708 
709 	INIT_LIST_HEAD(&pdmac->desc_pool);
710 	spin_lock_init(&pdmac->pool_lock);
711 
712 	/* Create a descriptor pool of default size */
713 	if (!add_desc(pdmac, GFP_KERNEL, NR_DEFAULT_DESC))
714 		dev_warn(&adev->dev, "unable to allocate desc\n");
715 
716 	pd = &pdmac->ddma;
717 	INIT_LIST_HEAD(&pd->channels);
718 
719 	/* Initialize channel parameters */
720 	for (i = 0; i < pdat->nr_valid_peri; i++) {
721 		struct dma_pl330_peri *peri = &pdat->peri[i];
722 		pch = &pdmac->peripherals[i];
723 
724 		switch (peri->rqtype) {
725 		case MEMTOMEM:
726 			dma_cap_set(DMA_MEMCPY, pd->cap_mask);
727 			break;
728 		case MEMTODEV:
729 		case DEVTOMEM:
730 			dma_cap_set(DMA_SLAVE, pd->cap_mask);
731 			break;
732 		default:
733 			dev_err(&adev->dev, "DEVTODEV Not Supported\n");
734 			continue;
735 		}
736 
737 		INIT_LIST_HEAD(&pch->work_list);
738 		spin_lock_init(&pch->lock);
739 		pch->pl330_chid = NULL;
740 		pch->chan.private = peri;
741 		pch->chan.device = pd;
742 		pch->chan.chan_id = i;
743 		pch->dmac = pdmac;
744 
745 		/* Add the channel to the DMAC list */
746 		pd->chancnt++;
747 		list_add_tail(&pch->chan.device_node, &pd->channels);
748 	}
749 
750 	pd->dev = &adev->dev;
751 
752 	pd->device_alloc_chan_resources = pl330_alloc_chan_resources;
753 	pd->device_free_chan_resources = pl330_free_chan_resources;
754 	pd->device_prep_dma_memcpy = pl330_prep_dma_memcpy;
755 	pd->device_tx_status = pl330_tx_status;
756 	pd->device_prep_slave_sg = pl330_prep_slave_sg;
757 	pd->device_control = pl330_control;
758 	pd->device_issue_pending = pl330_issue_pending;
759 
760 	ret = dma_async_device_register(pd);
761 	if (ret) {
762 		dev_err(&adev->dev, "unable to register DMAC\n");
763 		goto probe_err4;
764 	}
765 
766 	amba_set_drvdata(adev, pdmac);
767 
768 	dev_info(&adev->dev,
769 		"Loaded driver for PL330 DMAC-%d\n", adev->periphid);
770 	dev_info(&adev->dev,
771 		"\tDBUFF-%ux%ubytes Num_Chans-%u Num_Peri-%u Num_Events-%u\n",
772 		pi->pcfg.data_buf_dep,
773 		pi->pcfg.data_bus_width / 8, pi->pcfg.num_chan,
774 		pi->pcfg.num_peri, pi->pcfg.num_events);
775 
776 	return 0;
777 
778 probe_err4:
779 	pl330_del(pi);
780 probe_err3:
781 	free_irq(irq, pi);
782 probe_err2:
783 	iounmap(pi->base);
784 probe_err1:
785 	release_mem_region(res->start, resource_size(res));
786 	kfree(pdmac);
787 
788 	return ret;
789 }
790 
791 static int __devexit pl330_remove(struct amba_device *adev)
792 {
793 	struct dma_pl330_dmac *pdmac = amba_get_drvdata(adev);
794 	struct dma_pl330_chan *pch, *_p;
795 	struct pl330_info *pi;
796 	struct resource *res;
797 	int irq;
798 
799 	if (!pdmac)
800 		return 0;
801 
802 	amba_set_drvdata(adev, NULL);
803 
804 	/* Idle the DMAC */
805 	list_for_each_entry_safe(pch, _p, &pdmac->ddma.channels,
806 			chan.device_node) {
807 
808 		/* Remove the channel */
809 		list_del(&pch->chan.device_node);
810 
811 		/* Flush the channel */
812 		pl330_control(&pch->chan, DMA_TERMINATE_ALL, 0);
813 		pl330_free_chan_resources(&pch->chan);
814 	}
815 
816 	pi = &pdmac->pif;
817 
818 	pl330_del(pi);
819 
820 	irq = adev->irq[0];
821 	free_irq(irq, pi);
822 
823 	iounmap(pi->base);
824 
825 	res = &adev->res;
826 	release_mem_region(res->start, resource_size(res));
827 
828 	kfree(pdmac);
829 
830 	return 0;
831 }
832 
833 static struct amba_id pl330_ids[] = {
834 	{
835 		.id	= 0x00041330,
836 		.mask	= 0x000fffff,
837 	},
838 	{ 0, 0 },
839 };
840 
841 static struct amba_driver pl330_driver = {
842 	.drv = {
843 		.owner = THIS_MODULE,
844 		.name = "dma-pl330",
845 	},
846 	.id_table = pl330_ids,
847 	.probe = pl330_probe,
848 	.remove = pl330_remove,
849 };
850 
851 static int __init pl330_init(void)
852 {
853 	return amba_driver_register(&pl330_driver);
854 }
855 module_init(pl330_init);
856 
857 static void __exit pl330_exit(void)
858 {
859 	amba_driver_unregister(&pl330_driver);
860 	return;
861 }
862 module_exit(pl330_exit);
863 
864 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
865 MODULE_DESCRIPTION("API Driver for PL330 DMAC");
866 MODULE_LICENSE("GPL");
867