1/*
2 * Freescale MPC85xx, MPC83xx DMA Engine support
3 *
4 * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
5 *
6 * Author:
7 *   Zhang Wei <wei.zhang@freescale.com>, Jul 2007
8 *   Ebony Zhu <ebony.zhu@freescale.com>, May 2007
9 *
10 * Description:
11 *   DMA engine driver for Freescale MPC8540 DMA controller, which is
12 *   also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
13 *   The support for MPC8349 DMA controller is also added.
14 *
15 * This driver instructs the DMA controller to issue the PCI Read Multiple
16 * command for PCI read operations, instead of using the default PCI Read Line
17 * command. Please be aware that this setting may result in read pre-fetching
18 * on some platforms.
19 *
20 * This is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; either version 2 of the License, or
23 * (at your option) any later version.
24 *
25 */
26
27#include <linux/init.h>
28#include <linux/module.h>
29#include <linux/pci.h>
30#include <linux/slab.h>
31#include <linux/interrupt.h>
32#include <linux/dmaengine.h>
33#include <linux/delay.h>
34#include <linux/dma-mapping.h>
35#include <linux/dmapool.h>
36#include <linux/of_address.h>
37#include <linux/of_irq.h>
38#include <linux/of_platform.h>
39#include <linux/fsldma.h>
40#include "dmaengine.h"
41#include "fsldma.h"
42
43#define chan_dbg(chan, fmt, arg...)					\
44	dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
45#define chan_err(chan, fmt, arg...)					\
46	dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
47
48static const char msg_ld_oom[] = "No free memory for link descriptor";
49
50/*
51 * Register Helpers
52 */
53
54static void set_sr(struct fsldma_chan *chan, u32 val)
55{
56	DMA_OUT(chan, &chan->regs->sr, val, 32);
57}
58
59static u32 get_sr(struct fsldma_chan *chan)
60{
61	return DMA_IN(chan, &chan->regs->sr, 32);
62}
63
64static void set_mr(struct fsldma_chan *chan, u32 val)
65{
66	DMA_OUT(chan, &chan->regs->mr, val, 32);
67}
68
69static u32 get_mr(struct fsldma_chan *chan)
70{
71	return DMA_IN(chan, &chan->regs->mr, 32);
72}
73
74static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
75{
76	DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
77}
78
79static dma_addr_t get_cdar(struct fsldma_chan *chan)
80{
81	return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
82}
83
84static void set_bcr(struct fsldma_chan *chan, u32 val)
85{
86	DMA_OUT(chan, &chan->regs->bcr, val, 32);
87}
88
89static u32 get_bcr(struct fsldma_chan *chan)
90{
91	return DMA_IN(chan, &chan->regs->bcr, 32);
92}
93
94/*
95 * Descriptor Helpers
96 */
97
98static void set_desc_cnt(struct fsldma_chan *chan,
99				struct fsl_dma_ld_hw *hw, u32 count)
100{
101	hw->count = CPU_TO_DMA(chan, count, 32);
102}
103
104static void set_desc_src(struct fsldma_chan *chan,
105			 struct fsl_dma_ld_hw *hw, dma_addr_t src)
106{
107	u64 snoop_bits;
108
109	snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
110		? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
111	hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
112}
113
114static void set_desc_dst(struct fsldma_chan *chan,
115			 struct fsl_dma_ld_hw *hw, dma_addr_t dst)
116{
117	u64 snoop_bits;
118
119	snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
120		? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
121	hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
122}
123
124static void set_desc_next(struct fsldma_chan *chan,
125			  struct fsl_dma_ld_hw *hw, dma_addr_t next)
126{
127	u64 snoop_bits;
128
129	snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
130		? FSL_DMA_SNEN : 0;
131	hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
132}
133
134static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
135{
136	u64 snoop_bits;
137
138	snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
139		? FSL_DMA_SNEN : 0;
140
141	desc->hw.next_ln_addr = CPU_TO_DMA(chan,
142		DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
143			| snoop_bits, 64);
144}
145
146/*
147 * DMA Engine Hardware Control Helpers
148 */
149
150static void dma_init(struct fsldma_chan *chan)
151{
152	/* Reset the channel */
153	set_mr(chan, 0);
154
155	switch (chan->feature & FSL_DMA_IP_MASK) {
156	case FSL_DMA_IP_85XX:
157		/* Set the channel to below modes:
158		 * EIE - Error interrupt enable
159		 * EOLNIE - End of links interrupt enable
160		 * BWC - Bandwidth sharing among channels
161		 */
162		set_mr(chan, FSL_DMA_MR_BWC | FSL_DMA_MR_EIE
163			| FSL_DMA_MR_EOLNIE);
164		break;
165	case FSL_DMA_IP_83XX:
166		/* Set the channel to below modes:
167		 * EOTIE - End-of-transfer interrupt enable
168		 * PRC_RM - PCI read multiple
169		 */
170		set_mr(chan, FSL_DMA_MR_EOTIE | FSL_DMA_MR_PRC_RM);
171		break;
172	}
173}
174
175static int dma_is_idle(struct fsldma_chan *chan)
176{
177	u32 sr = get_sr(chan);
178	return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
179}
180
181/*
182 * Start the DMA controller
183 *
184 * Preconditions:
185 * - the CDAR register must point to the start descriptor
186 * - the MRn[CS] bit must be cleared
187 */
188static void dma_start(struct fsldma_chan *chan)
189{
190	u32 mode;
191
192	mode = get_mr(chan);
193
194	if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
195		set_bcr(chan, 0);
196		mode |= FSL_DMA_MR_EMP_EN;
197	} else {
198		mode &= ~FSL_DMA_MR_EMP_EN;
199	}
200
201	if (chan->feature & FSL_DMA_CHAN_START_EXT) {
202		mode |= FSL_DMA_MR_EMS_EN;
203	} else {
204		mode &= ~FSL_DMA_MR_EMS_EN;
205		mode |= FSL_DMA_MR_CS;
206	}
207
208	set_mr(chan, mode);
209}
210
211static void dma_halt(struct fsldma_chan *chan)
212{
213	u32 mode;
214	int i;
215
216	/* read the mode register */
217	mode = get_mr(chan);
218
219	/*
220	 * The 85xx controller supports channel abort, which will stop
221	 * the current transfer. On 83xx, this bit is the transfer error
222	 * mask bit, which should not be changed.
223	 */
224	if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
225		mode |= FSL_DMA_MR_CA;
226		set_mr(chan, mode);
227
228		mode &= ~FSL_DMA_MR_CA;
229	}
230
231	/* stop the DMA controller */
232	mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
233	set_mr(chan, mode);
234
235	/* wait for the DMA controller to become idle */
236	for (i = 0; i < 100; i++) {
237		if (dma_is_idle(chan))
238			return;
239
240		udelay(10);
241	}
242
243	if (!dma_is_idle(chan))
244		chan_err(chan, "DMA halt timeout!\n");
245}
246
247/**
248 * fsl_chan_set_src_loop_size - Set source address hold transfer size
249 * @chan : Freescale DMA channel
250 * @size     : Address loop size, 0 for disable loop
251 *
252 * The set source address hold transfer size. The source
253 * address hold or loop transfer size is when the DMA transfer
254 * data from source address (SA), if the loop size is 4, the DMA will
255 * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
256 * SA + 1 ... and so on.
257 */
258static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
259{
260	u32 mode;
261
262	mode = get_mr(chan);
263
264	switch (size) {
265	case 0:
266		mode &= ~FSL_DMA_MR_SAHE;
267		break;
268	case 1:
269	case 2:
270	case 4:
271	case 8:
272		mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
273		break;
274	}
275
276	set_mr(chan, mode);
277}
278
279/**
280 * fsl_chan_set_dst_loop_size - Set destination address hold transfer size
281 * @chan : Freescale DMA channel
282 * @size     : Address loop size, 0 for disable loop
283 *
284 * The set destination address hold transfer size. The destination
285 * address hold or loop transfer size is when the DMA transfer
286 * data to destination address (TA), if the loop size is 4, the DMA will
287 * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
288 * TA + 1 ... and so on.
289 */
290static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
291{
292	u32 mode;
293
294	mode = get_mr(chan);
295
296	switch (size) {
297	case 0:
298		mode &= ~FSL_DMA_MR_DAHE;
299		break;
300	case 1:
301	case 2:
302	case 4:
303	case 8:
304		mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
305		break;
306	}
307
308	set_mr(chan, mode);
309}
310
311/**
312 * fsl_chan_set_request_count - Set DMA Request Count for external control
313 * @chan : Freescale DMA channel
314 * @size     : Number of bytes to transfer in a single request
315 *
316 * The Freescale DMA channel can be controlled by the external signal DREQ#.
317 * The DMA request count is how many bytes are allowed to transfer before
318 * pausing the channel, after which a new assertion of DREQ# resumes channel
319 * operation.
320 *
321 * A size of 0 disables external pause control. The maximum size is 1024.
322 */
323static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
324{
325	u32 mode;
326
327	BUG_ON(size > 1024);
328
329	mode = get_mr(chan);
330	mode |= (__ilog2(size) << 24) & 0x0f000000;
331
332	set_mr(chan, mode);
333}
334
335/**
336 * fsl_chan_toggle_ext_pause - Toggle channel external pause status
337 * @chan : Freescale DMA channel
338 * @enable   : 0 is disabled, 1 is enabled.
339 *
340 * The Freescale DMA channel can be controlled by the external signal DREQ#.
341 * The DMA Request Count feature should be used in addition to this feature
342 * to set the number of bytes to transfer before pausing the channel.
343 */
344static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
345{
346	if (enable)
347		chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
348	else
349		chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
350}
351
352/**
353 * fsl_chan_toggle_ext_start - Toggle channel external start status
354 * @chan : Freescale DMA channel
355 * @enable   : 0 is disabled, 1 is enabled.
356 *
357 * If enable the external start, the channel can be started by an
358 * external DMA start pin. So the dma_start() does not start the
359 * transfer immediately. The DMA channel will wait for the
360 * control pin asserted.
361 */
362static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
363{
364	if (enable)
365		chan->feature |= FSL_DMA_CHAN_START_EXT;
366	else
367		chan->feature &= ~FSL_DMA_CHAN_START_EXT;
368}
369
370int fsl_dma_external_start(struct dma_chan *dchan, int enable)
371{
372	struct fsldma_chan *chan;
373
374	if (!dchan)
375		return -EINVAL;
376
377	chan = to_fsl_chan(dchan);
378
379	fsl_chan_toggle_ext_start(chan, enable);
380	return 0;
381}
382EXPORT_SYMBOL_GPL(fsl_dma_external_start);
383
384static void append_ld_queue(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
385{
386	struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
387
388	if (list_empty(&chan->ld_pending))
389		goto out_splice;
390
391	/*
392	 * Add the hardware descriptor to the chain of hardware descriptors
393	 * that already exists in memory.
394	 *
395	 * This will un-set the EOL bit of the existing transaction, and the
396	 * last link in this transaction will become the EOL descriptor.
397	 */
398	set_desc_next(chan, &tail->hw, desc->async_tx.phys);
399
400	/*
401	 * Add the software descriptor and all children to the list
402	 * of pending transactions
403	 */
404out_splice:
405	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
406}
407
408static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
409{
410	struct fsldma_chan *chan = to_fsl_chan(tx->chan);
411	struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
412	struct fsl_desc_sw *child;
413	dma_cookie_t cookie = -EINVAL;
414
415	spin_lock_bh(&chan->desc_lock);
416
417#ifdef CONFIG_PM
418	if (unlikely(chan->pm_state != RUNNING)) {
419		chan_dbg(chan, "cannot submit due to suspend\n");
420		spin_unlock_bh(&chan->desc_lock);
421		return -1;
422	}
423#endif
424
425	/*
426	 * assign cookies to all of the software descriptors
427	 * that make up this transaction
428	 */
429	list_for_each_entry(child, &desc->tx_list, node) {
430		cookie = dma_cookie_assign(&child->async_tx);
431	}
432
433	/* put this transaction onto the tail of the pending queue */
434	append_ld_queue(chan, desc);
435
436	spin_unlock_bh(&chan->desc_lock);
437
438	return cookie;
439}
440
441/**
442 * fsl_dma_free_descriptor - Free descriptor from channel's DMA pool.
443 * @chan : Freescale DMA channel
444 * @desc: descriptor to be freed
445 */
446static void fsl_dma_free_descriptor(struct fsldma_chan *chan,
447		struct fsl_desc_sw *desc)
448{
449	list_del(&desc->node);
450	chan_dbg(chan, "LD %p free\n", desc);
451	dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
452}
453
454/**
455 * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
456 * @chan : Freescale DMA channel
457 *
458 * Return - The descriptor allocated. NULL for failed.
459 */
460static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
461{
462	struct fsl_desc_sw *desc;
463	dma_addr_t pdesc;
464
465	desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
466	if (!desc) {
467		chan_dbg(chan, "out of memory for link descriptor\n");
468		return NULL;
469	}
470
471	memset(desc, 0, sizeof(*desc));
472	INIT_LIST_HEAD(&desc->tx_list);
473	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
474	desc->async_tx.tx_submit = fsl_dma_tx_submit;
475	desc->async_tx.phys = pdesc;
476
477	chan_dbg(chan, "LD %p allocated\n", desc);
478
479	return desc;
480}
481
482/**
483 * fsldma_clean_completed_descriptor - free all descriptors which
484 * has been completed and acked
485 * @chan: Freescale DMA channel
486 *
487 * This function is used on all completed and acked descriptors.
488 * All descriptors should only be freed in this function.
489 */
490static void fsldma_clean_completed_descriptor(struct fsldma_chan *chan)
491{
492	struct fsl_desc_sw *desc, *_desc;
493
494	/* Run the callback for each descriptor, in order */
495	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node)
496		if (async_tx_test_ack(&desc->async_tx))
497			fsl_dma_free_descriptor(chan, desc);
498}
499
500/**
501 * fsldma_run_tx_complete_actions - cleanup a single link descriptor
502 * @chan: Freescale DMA channel
503 * @desc: descriptor to cleanup and free
504 * @cookie: Freescale DMA transaction identifier
505 *
506 * This function is used on a descriptor which has been executed by the DMA
507 * controller. It will run any callbacks, submit any dependencies.
508 */
509static dma_cookie_t fsldma_run_tx_complete_actions(struct fsldma_chan *chan,
510		struct fsl_desc_sw *desc, dma_cookie_t cookie)
511{
512	struct dma_async_tx_descriptor *txd = &desc->async_tx;
513	dma_cookie_t ret = cookie;
514
515	BUG_ON(txd->cookie < 0);
516
517	if (txd->cookie > 0) {
518		ret = txd->cookie;
519
520		/* Run the link descriptor callback function */
521		if (txd->callback) {
522			chan_dbg(chan, "LD %p callback\n", desc);
523			txd->callback(txd->callback_param);
524		}
525	}
526
527	/* Run any dependencies */
528	dma_run_dependencies(txd);
529
530	return ret;
531}
532
533/**
534 * fsldma_clean_running_descriptor - move the completed descriptor from
535 * ld_running to ld_completed
536 * @chan: Freescale DMA channel
537 * @desc: the descriptor which is completed
538 *
539 * Free the descriptor directly if acked by async_tx api, or move it to
540 * queue ld_completed.
541 */
542static void fsldma_clean_running_descriptor(struct fsldma_chan *chan,
543		struct fsl_desc_sw *desc)
544{
545	/* Remove from the list of transactions */
546	list_del(&desc->node);
547
548	/*
549	 * the client is allowed to attach dependent operations
550	 * until 'ack' is set
551	 */
552	if (!async_tx_test_ack(&desc->async_tx)) {
553		/*
554		 * Move this descriptor to the list of descriptors which is
555		 * completed, but still awaiting the 'ack' bit to be set.
556		 */
557		list_add_tail(&desc->node, &chan->ld_completed);
558		return;
559	}
560
561	dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
562}
563
564/**
565 * fsl_chan_xfer_ld_queue - transfer any pending transactions
566 * @chan : Freescale DMA channel
567 *
568 * HARDWARE STATE: idle
569 * LOCKING: must hold chan->desc_lock
570 */
571static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
572{
573	struct fsl_desc_sw *desc;
574
575	/*
576	 * If the list of pending descriptors is empty, then we
577	 * don't need to do any work at all
578	 */
579	if (list_empty(&chan->ld_pending)) {
580		chan_dbg(chan, "no pending LDs\n");
581		return;
582	}
583
584	/*
585	 * The DMA controller is not idle, which means that the interrupt
586	 * handler will start any queued transactions when it runs after
587	 * this transaction finishes
588	 */
589	if (!chan->idle) {
590		chan_dbg(chan, "DMA controller still busy\n");
591		return;
592	}
593
594	/*
595	 * If there are some link descriptors which have not been
596	 * transferred, we need to start the controller
597	 */
598
599	/*
600	 * Move all elements from the queue of pending transactions
601	 * onto the list of running transactions
602	 */
603	chan_dbg(chan, "idle, starting controller\n");
604	desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
605	list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
606
607	/*
608	 * The 85xx DMA controller doesn't clear the channel start bit
609	 * automatically at the end of a transfer. Therefore we must clear
610	 * it in software before starting the transfer.
611	 */
612	if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
613		u32 mode;
614
615		mode = get_mr(chan);
616		mode &= ~FSL_DMA_MR_CS;
617		set_mr(chan, mode);
618	}
619
620	/*
621	 * Program the descriptor's address into the DMA controller,
622	 * then start the DMA transaction
623	 */
624	set_cdar(chan, desc->async_tx.phys);
625	get_cdar(chan);
626
627	dma_start(chan);
628	chan->idle = false;
629}
630
631/**
632 * fsldma_cleanup_descriptors - cleanup link descriptors which are completed
633 * and move them to ld_completed to free until flag 'ack' is set
634 * @chan: Freescale DMA channel
635 *
636 * This function is used on descriptors which have been executed by the DMA
637 * controller. It will run any callbacks, submit any dependencies, then
638 * free these descriptors if flag 'ack' is set.
639 */
640static void fsldma_cleanup_descriptors(struct fsldma_chan *chan)
641{
642	struct fsl_desc_sw *desc, *_desc;
643	dma_cookie_t cookie = 0;
644	dma_addr_t curr_phys = get_cdar(chan);
645	int seen_current = 0;
646
647	fsldma_clean_completed_descriptor(chan);
648
649	/* Run the callback for each descriptor, in order */
650	list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
651		/*
652		 * do not advance past the current descriptor loaded into the
653		 * hardware channel, subsequent descriptors are either in
654		 * process or have not been submitted
655		 */
656		if (seen_current)
657			break;
658
659		/*
660		 * stop the search if we reach the current descriptor and the
661		 * channel is busy
662		 */
663		if (desc->async_tx.phys == curr_phys) {
664			seen_current = 1;
665			if (!dma_is_idle(chan))
666				break;
667		}
668
669		cookie = fsldma_run_tx_complete_actions(chan, desc, cookie);
670
671		fsldma_clean_running_descriptor(chan, desc);
672	}
673
674	/*
675	 * Start any pending transactions automatically
676	 *
677	 * In the ideal case, we keep the DMA controller busy while we go
678	 * ahead and free the descriptors below.
679	 */
680	fsl_chan_xfer_ld_queue(chan);
681
682	if (cookie > 0)
683		chan->common.completed_cookie = cookie;
684}
685
686/**
687 * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
688 * @chan : Freescale DMA channel
689 *
690 * This function will create a dma pool for descriptor allocation.
691 *
692 * Return - The number of descriptors allocated.
693 */
694static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
695{
696	struct fsldma_chan *chan = to_fsl_chan(dchan);
697
698	/* Has this channel already been allocated? */
699	if (chan->desc_pool)
700		return 1;
701
702	/*
703	 * We need the descriptor to be aligned to 32bytes
704	 * for meeting FSL DMA specification requirement.
705	 */
706	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
707					  sizeof(struct fsl_desc_sw),
708					  __alignof__(struct fsl_desc_sw), 0);
709	if (!chan->desc_pool) {
710		chan_err(chan, "unable to allocate descriptor pool\n");
711		return -ENOMEM;
712	}
713
714	/* there is at least one descriptor free to be allocated */
715	return 1;
716}
717
718/**
719 * fsldma_free_desc_list - Free all descriptors in a queue
720 * @chan: Freescae DMA channel
721 * @list: the list to free
722 *
723 * LOCKING: must hold chan->desc_lock
724 */
725static void fsldma_free_desc_list(struct fsldma_chan *chan,
726				  struct list_head *list)
727{
728	struct fsl_desc_sw *desc, *_desc;
729
730	list_for_each_entry_safe(desc, _desc, list, node)
731		fsl_dma_free_descriptor(chan, desc);
732}
733
734static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
735					  struct list_head *list)
736{
737	struct fsl_desc_sw *desc, *_desc;
738
739	list_for_each_entry_safe_reverse(desc, _desc, list, node)
740		fsl_dma_free_descriptor(chan, desc);
741}
742
743/**
744 * fsl_dma_free_chan_resources - Free all resources of the channel.
745 * @chan : Freescale DMA channel
746 */
747static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
748{
749	struct fsldma_chan *chan = to_fsl_chan(dchan);
750
751	chan_dbg(chan, "free all channel resources\n");
752	spin_lock_bh(&chan->desc_lock);
753	fsldma_cleanup_descriptors(chan);
754	fsldma_free_desc_list(chan, &chan->ld_pending);
755	fsldma_free_desc_list(chan, &chan->ld_running);
756	fsldma_free_desc_list(chan, &chan->ld_completed);
757	spin_unlock_bh(&chan->desc_lock);
758
759	dma_pool_destroy(chan->desc_pool);
760	chan->desc_pool = NULL;
761}
762
763static struct dma_async_tx_descriptor *
764fsl_dma_prep_memcpy(struct dma_chan *dchan,
765	dma_addr_t dma_dst, dma_addr_t dma_src,
766	size_t len, unsigned long flags)
767{
768	struct fsldma_chan *chan;
769	struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
770	size_t copy;
771
772	if (!dchan)
773		return NULL;
774
775	if (!len)
776		return NULL;
777
778	chan = to_fsl_chan(dchan);
779
780	do {
781
782		/* Allocate the link descriptor from DMA pool */
783		new = fsl_dma_alloc_descriptor(chan);
784		if (!new) {
785			chan_err(chan, "%s\n", msg_ld_oom);
786			goto fail;
787		}
788
789		copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
790
791		set_desc_cnt(chan, &new->hw, copy);
792		set_desc_src(chan, &new->hw, dma_src);
793		set_desc_dst(chan, &new->hw, dma_dst);
794
795		if (!first)
796			first = new;
797		else
798			set_desc_next(chan, &prev->hw, new->async_tx.phys);
799
800		new->async_tx.cookie = 0;
801		async_tx_ack(&new->async_tx);
802
803		prev = new;
804		len -= copy;
805		dma_src += copy;
806		dma_dst += copy;
807
808		/* Insert the link descriptor to the LD ring */
809		list_add_tail(&new->node, &first->tx_list);
810	} while (len);
811
812	new->async_tx.flags = flags; /* client is in control of this ack */
813	new->async_tx.cookie = -EBUSY;
814
815	/* Set End-of-link to the last link descriptor of new list */
816	set_ld_eol(chan, new);
817
818	return &first->async_tx;
819
820fail:
821	if (!first)
822		return NULL;
823
824	fsldma_free_desc_list_reverse(chan, &first->tx_list);
825	return NULL;
826}
827
828static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
829	struct scatterlist *dst_sg, unsigned int dst_nents,
830	struct scatterlist *src_sg, unsigned int src_nents,
831	unsigned long flags)
832{
833	struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
834	struct fsldma_chan *chan = to_fsl_chan(dchan);
835	size_t dst_avail, src_avail;
836	dma_addr_t dst, src;
837	size_t len;
838
839	/* basic sanity checks */
840	if (dst_nents == 0 || src_nents == 0)
841		return NULL;
842
843	if (dst_sg == NULL || src_sg == NULL)
844		return NULL;
845
846	/*
847	 * TODO: should we check that both scatterlists have the same
848	 * TODO: number of bytes in total? Is that really an error?
849	 */
850
851	/* get prepared for the loop */
852	dst_avail = sg_dma_len(dst_sg);
853	src_avail = sg_dma_len(src_sg);
854
855	/* run until we are out of scatterlist entries */
856	while (true) {
857
858		/* create the largest transaction possible */
859		len = min_t(size_t, src_avail, dst_avail);
860		len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
861		if (len == 0)
862			goto fetch;
863
864		dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
865		src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
866
867		/* allocate and populate the descriptor */
868		new = fsl_dma_alloc_descriptor(chan);
869		if (!new) {
870			chan_err(chan, "%s\n", msg_ld_oom);
871			goto fail;
872		}
873
874		set_desc_cnt(chan, &new->hw, len);
875		set_desc_src(chan, &new->hw, src);
876		set_desc_dst(chan, &new->hw, dst);
877
878		if (!first)
879			first = new;
880		else
881			set_desc_next(chan, &prev->hw, new->async_tx.phys);
882
883		new->async_tx.cookie = 0;
884		async_tx_ack(&new->async_tx);
885		prev = new;
886
887		/* Insert the link descriptor to the LD ring */
888		list_add_tail(&new->node, &first->tx_list);
889
890		/* update metadata */
891		dst_avail -= len;
892		src_avail -= len;
893
894fetch:
895		/* fetch the next dst scatterlist entry */
896		if (dst_avail == 0) {
897
898			/* no more entries: we're done */
899			if (dst_nents == 0)
900				break;
901
902			/* fetch the next entry: if there are no more: done */
903			dst_sg = sg_next(dst_sg);
904			if (dst_sg == NULL)
905				break;
906
907			dst_nents--;
908			dst_avail = sg_dma_len(dst_sg);
909		}
910
911		/* fetch the next src scatterlist entry */
912		if (src_avail == 0) {
913
914			/* no more entries: we're done */
915			if (src_nents == 0)
916				break;
917
918			/* fetch the next entry: if there are no more: done */
919			src_sg = sg_next(src_sg);
920			if (src_sg == NULL)
921				break;
922
923			src_nents--;
924			src_avail = sg_dma_len(src_sg);
925		}
926	}
927
928	new->async_tx.flags = flags; /* client is in control of this ack */
929	new->async_tx.cookie = -EBUSY;
930
931	/* Set End-of-link to the last link descriptor of new list */
932	set_ld_eol(chan, new);
933
934	return &first->async_tx;
935
936fail:
937	if (!first)
938		return NULL;
939
940	fsldma_free_desc_list_reverse(chan, &first->tx_list);
941	return NULL;
942}
943
944static int fsl_dma_device_terminate_all(struct dma_chan *dchan)
945{
946	struct fsldma_chan *chan;
947
948	if (!dchan)
949		return -EINVAL;
950
951	chan = to_fsl_chan(dchan);
952
953	spin_lock_bh(&chan->desc_lock);
954
955	/* Halt the DMA engine */
956	dma_halt(chan);
957
958	/* Remove and free all of the descriptors in the LD queue */
959	fsldma_free_desc_list(chan, &chan->ld_pending);
960	fsldma_free_desc_list(chan, &chan->ld_running);
961	fsldma_free_desc_list(chan, &chan->ld_completed);
962	chan->idle = true;
963
964	spin_unlock_bh(&chan->desc_lock);
965	return 0;
966}
967
968static int fsl_dma_device_config(struct dma_chan *dchan,
969				 struct dma_slave_config *config)
970{
971	struct fsldma_chan *chan;
972	int size;
973
974	if (!dchan)
975		return -EINVAL;
976
977	chan = to_fsl_chan(dchan);
978
979	/* make sure the channel supports setting burst size */
980	if (!chan->set_request_count)
981		return -ENXIO;
982
983	/* we set the controller burst size depending on direction */
984	if (config->direction == DMA_MEM_TO_DEV)
985		size = config->dst_addr_width * config->dst_maxburst;
986	else
987		size = config->src_addr_width * config->src_maxburst;
988
989	chan->set_request_count(chan, size);
990	return 0;
991}
992
993
994/**
995 * fsl_dma_memcpy_issue_pending - Issue the DMA start command
996 * @chan : Freescale DMA channel
997 */
998static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
999{
1000	struct fsldma_chan *chan = to_fsl_chan(dchan);
1001
1002	spin_lock_bh(&chan->desc_lock);
1003	fsl_chan_xfer_ld_queue(chan);
1004	spin_unlock_bh(&chan->desc_lock);
1005}
1006
1007/**
1008 * fsl_tx_status - Determine the DMA status
1009 * @chan : Freescale DMA channel
1010 */
1011static enum dma_status fsl_tx_status(struct dma_chan *dchan,
1012					dma_cookie_t cookie,
1013					struct dma_tx_state *txstate)
1014{
1015	struct fsldma_chan *chan = to_fsl_chan(dchan);
1016	enum dma_status ret;
1017
1018	ret = dma_cookie_status(dchan, cookie, txstate);
1019	if (ret == DMA_COMPLETE)
1020		return ret;
1021
1022	spin_lock_bh(&chan->desc_lock);
1023	fsldma_cleanup_descriptors(chan);
1024	spin_unlock_bh(&chan->desc_lock);
1025
1026	return dma_cookie_status(dchan, cookie, txstate);
1027}
1028
1029/*----------------------------------------------------------------------------*/
1030/* Interrupt Handling                                                         */
1031/*----------------------------------------------------------------------------*/
1032
1033static irqreturn_t fsldma_chan_irq(int irq, void *data)
1034{
1035	struct fsldma_chan *chan = data;
1036	u32 stat;
1037
1038	/* save and clear the status register */
1039	stat = get_sr(chan);
1040	set_sr(chan, stat);
1041	chan_dbg(chan, "irq: stat = 0x%x\n", stat);
1042
1043	/* check that this was really our device */
1044	stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
1045	if (!stat)
1046		return IRQ_NONE;
1047
1048	if (stat & FSL_DMA_SR_TE)
1049		chan_err(chan, "Transfer Error!\n");
1050
1051	/*
1052	 * Programming Error
1053	 * The DMA_INTERRUPT async_tx is a NULL transfer, which will
1054	 * trigger a PE interrupt.
1055	 */
1056	if (stat & FSL_DMA_SR_PE) {
1057		chan_dbg(chan, "irq: Programming Error INT\n");
1058		stat &= ~FSL_DMA_SR_PE;
1059		if (get_bcr(chan) != 0)
1060			chan_err(chan, "Programming Error!\n");
1061	}
1062
1063	/*
1064	 * For MPC8349, EOCDI event need to update cookie
1065	 * and start the next transfer if it exist.
1066	 */
1067	if (stat & FSL_DMA_SR_EOCDI) {
1068		chan_dbg(chan, "irq: End-of-Chain link INT\n");
1069		stat &= ~FSL_DMA_SR_EOCDI;
1070	}
1071
1072	/*
1073	 * If it current transfer is the end-of-transfer,
1074	 * we should clear the Channel Start bit for
1075	 * prepare next transfer.
1076	 */
1077	if (stat & FSL_DMA_SR_EOLNI) {
1078		chan_dbg(chan, "irq: End-of-link INT\n");
1079		stat &= ~FSL_DMA_SR_EOLNI;
1080	}
1081
1082	/* check that the DMA controller is really idle */
1083	if (!dma_is_idle(chan))
1084		chan_err(chan, "irq: controller not idle!\n");
1085
1086	/* check that we handled all of the bits */
1087	if (stat)
1088		chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
1089
1090	/*
1091	 * Schedule the tasklet to handle all cleanup of the current
1092	 * transaction. It will start a new transaction if there is
1093	 * one pending.
1094	 */
1095	tasklet_schedule(&chan->tasklet);
1096	chan_dbg(chan, "irq: Exit\n");
1097	return IRQ_HANDLED;
1098}
1099
1100static void dma_do_tasklet(unsigned long data)
1101{
1102	struct fsldma_chan *chan = (struct fsldma_chan *)data;
1103
1104	chan_dbg(chan, "tasklet entry\n");
1105
1106	spin_lock_bh(&chan->desc_lock);
1107
1108	/* the hardware is now idle and ready for more */
1109	chan->idle = true;
1110
1111	/* Run all cleanup for descriptors which have been completed */
1112	fsldma_cleanup_descriptors(chan);
1113
1114	spin_unlock_bh(&chan->desc_lock);
1115
1116	chan_dbg(chan, "tasklet exit\n");
1117}
1118
1119static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
1120{
1121	struct fsldma_device *fdev = data;
1122	struct fsldma_chan *chan;
1123	unsigned int handled = 0;
1124	u32 gsr, mask;
1125	int i;
1126
1127	gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
1128						   : in_le32(fdev->regs);
1129	mask = 0xff000000;
1130	dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
1131
1132	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1133		chan = fdev->chan[i];
1134		if (!chan)
1135			continue;
1136
1137		if (gsr & mask) {
1138			dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
1139			fsldma_chan_irq(irq, chan);
1140			handled++;
1141		}
1142
1143		gsr &= ~mask;
1144		mask >>= 8;
1145	}
1146
1147	return IRQ_RETVAL(handled);
1148}
1149
1150static void fsldma_free_irqs(struct fsldma_device *fdev)
1151{
1152	struct fsldma_chan *chan;
1153	int i;
1154
1155	if (fdev->irq != NO_IRQ) {
1156		dev_dbg(fdev->dev, "free per-controller IRQ\n");
1157		free_irq(fdev->irq, fdev);
1158		return;
1159	}
1160
1161	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1162		chan = fdev->chan[i];
1163		if (chan && chan->irq != NO_IRQ) {
1164			chan_dbg(chan, "free per-channel IRQ\n");
1165			free_irq(chan->irq, chan);
1166		}
1167	}
1168}
1169
1170static int fsldma_request_irqs(struct fsldma_device *fdev)
1171{
1172	struct fsldma_chan *chan;
1173	int ret;
1174	int i;
1175
1176	/* if we have a per-controller IRQ, use that */
1177	if (fdev->irq != NO_IRQ) {
1178		dev_dbg(fdev->dev, "request per-controller IRQ\n");
1179		ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED,
1180				  "fsldma-controller", fdev);
1181		return ret;
1182	}
1183
1184	/* no per-controller IRQ, use the per-channel IRQs */
1185	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1186		chan = fdev->chan[i];
1187		if (!chan)
1188			continue;
1189
1190		if (chan->irq == NO_IRQ) {
1191			chan_err(chan, "interrupts property missing in device tree\n");
1192			ret = -ENODEV;
1193			goto out_unwind;
1194		}
1195
1196		chan_dbg(chan, "request per-channel IRQ\n");
1197		ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
1198				  "fsldma-chan", chan);
1199		if (ret) {
1200			chan_err(chan, "unable to request per-channel IRQ\n");
1201			goto out_unwind;
1202		}
1203	}
1204
1205	return 0;
1206
1207out_unwind:
1208	for (/* none */; i >= 0; i--) {
1209		chan = fdev->chan[i];
1210		if (!chan)
1211			continue;
1212
1213		if (chan->irq == NO_IRQ)
1214			continue;
1215
1216		free_irq(chan->irq, chan);
1217	}
1218
1219	return ret;
1220}
1221
1222/*----------------------------------------------------------------------------*/
1223/* OpenFirmware Subsystem                                                     */
1224/*----------------------------------------------------------------------------*/
1225
1226static int fsl_dma_chan_probe(struct fsldma_device *fdev,
1227	struct device_node *node, u32 feature, const char *compatible)
1228{
1229	struct fsldma_chan *chan;
1230	struct resource res;
1231	int err;
1232
1233	/* alloc channel */
1234	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1235	if (!chan) {
1236		dev_err(fdev->dev, "no free memory for DMA channels!\n");
1237		err = -ENOMEM;
1238		goto out_return;
1239	}
1240
1241	/* ioremap registers for use */
1242	chan->regs = of_iomap(node, 0);
1243	if (!chan->regs) {
1244		dev_err(fdev->dev, "unable to ioremap registers\n");
1245		err = -ENOMEM;
1246		goto out_free_chan;
1247	}
1248
1249	err = of_address_to_resource(node, 0, &res);
1250	if (err) {
1251		dev_err(fdev->dev, "unable to find 'reg' property\n");
1252		goto out_iounmap_regs;
1253	}
1254
1255	chan->feature = feature;
1256	if (!fdev->feature)
1257		fdev->feature = chan->feature;
1258
1259	/*
1260	 * If the DMA device's feature is different than the feature
1261	 * of its channels, report the bug
1262	 */
1263	WARN_ON(fdev->feature != chan->feature);
1264
1265	chan->dev = fdev->dev;
1266	chan->id = (res.start & 0xfff) < 0x300 ?
1267		   ((res.start - 0x100) & 0xfff) >> 7 :
1268		   ((res.start - 0x200) & 0xfff) >> 7;
1269	if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
1270		dev_err(fdev->dev, "too many channels for device\n");
1271		err = -EINVAL;
1272		goto out_iounmap_regs;
1273	}
1274
1275	fdev->chan[chan->id] = chan;
1276	tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
1277	snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
1278
1279	/* Initialize the channel */
1280	dma_init(chan);
1281
1282	/* Clear cdar registers */
1283	set_cdar(chan, 0);
1284
1285	switch (chan->feature & FSL_DMA_IP_MASK) {
1286	case FSL_DMA_IP_85XX:
1287		chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
1288	case FSL_DMA_IP_83XX:
1289		chan->toggle_ext_start = fsl_chan_toggle_ext_start;
1290		chan->set_src_loop_size = fsl_chan_set_src_loop_size;
1291		chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
1292		chan->set_request_count = fsl_chan_set_request_count;
1293	}
1294
1295	spin_lock_init(&chan->desc_lock);
1296	INIT_LIST_HEAD(&chan->ld_pending);
1297	INIT_LIST_HEAD(&chan->ld_running);
1298	INIT_LIST_HEAD(&chan->ld_completed);
1299	chan->idle = true;
1300#ifdef CONFIG_PM
1301	chan->pm_state = RUNNING;
1302#endif
1303
1304	chan->common.device = &fdev->common;
1305	dma_cookie_init(&chan->common);
1306
1307	/* find the IRQ line, if it exists in the device tree */
1308	chan->irq = irq_of_parse_and_map(node, 0);
1309
1310	/* Add the channel to DMA device channel list */
1311	list_add_tail(&chan->common.device_node, &fdev->common.channels);
1312
1313	dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
1314		 chan->irq != NO_IRQ ? chan->irq : fdev->irq);
1315
1316	return 0;
1317
1318out_iounmap_regs:
1319	iounmap(chan->regs);
1320out_free_chan:
1321	kfree(chan);
1322out_return:
1323	return err;
1324}
1325
1326static void fsl_dma_chan_remove(struct fsldma_chan *chan)
1327{
1328	irq_dispose_mapping(chan->irq);
1329	list_del(&chan->common.device_node);
1330	iounmap(chan->regs);
1331	kfree(chan);
1332}
1333
1334static int fsldma_of_probe(struct platform_device *op)
1335{
1336	struct fsldma_device *fdev;
1337	struct device_node *child;
1338	int err;
1339
1340	fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
1341	if (!fdev) {
1342		dev_err(&op->dev, "No enough memory for 'priv'\n");
1343		err = -ENOMEM;
1344		goto out_return;
1345	}
1346
1347	fdev->dev = &op->dev;
1348	INIT_LIST_HEAD(&fdev->common.channels);
1349
1350	/* ioremap the registers for use */
1351	fdev->regs = of_iomap(op->dev.of_node, 0);
1352	if (!fdev->regs) {
1353		dev_err(&op->dev, "unable to ioremap registers\n");
1354		err = -ENOMEM;
1355		goto out_free_fdev;
1356	}
1357
1358	/* map the channel IRQ if it exists, but don't hookup the handler yet */
1359	fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
1360
1361	dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
1362	dma_cap_set(DMA_SG, fdev->common.cap_mask);
1363	dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
1364	fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
1365	fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
1366	fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
1367	fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
1368	fdev->common.device_tx_status = fsl_tx_status;
1369	fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
1370	fdev->common.device_config = fsl_dma_device_config;
1371	fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
1372	fdev->common.dev = &op->dev;
1373
1374	fdev->common.src_addr_widths = FSL_DMA_BUSWIDTHS;
1375	fdev->common.dst_addr_widths = FSL_DMA_BUSWIDTHS;
1376	fdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1377	fdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1378
1379	dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
1380
1381	platform_set_drvdata(op, fdev);
1382
1383	/*
1384	 * We cannot use of_platform_bus_probe() because there is no
1385	 * of_platform_bus_remove(). Instead, we manually instantiate every DMA
1386	 * channel object.
1387	 */
1388	for_each_child_of_node(op->dev.of_node, child) {
1389		if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
1390			fsl_dma_chan_probe(fdev, child,
1391				FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
1392				"fsl,eloplus-dma-channel");
1393		}
1394
1395		if (of_device_is_compatible(child, "fsl,elo-dma-channel")) {
1396			fsl_dma_chan_probe(fdev, child,
1397				FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
1398				"fsl,elo-dma-channel");
1399		}
1400	}
1401
1402	/*
1403	 * Hookup the IRQ handler(s)
1404	 *
1405	 * If we have a per-controller interrupt, we prefer that to the
1406	 * per-channel interrupts to reduce the number of shared interrupt
1407	 * handlers on the same IRQ line
1408	 */
1409	err = fsldma_request_irqs(fdev);
1410	if (err) {
1411		dev_err(fdev->dev, "unable to request IRQs\n");
1412		goto out_free_fdev;
1413	}
1414
1415	dma_async_device_register(&fdev->common);
1416	return 0;
1417
1418out_free_fdev:
1419	irq_dispose_mapping(fdev->irq);
1420	kfree(fdev);
1421out_return:
1422	return err;
1423}
1424
1425static int fsldma_of_remove(struct platform_device *op)
1426{
1427	struct fsldma_device *fdev;
1428	unsigned int i;
1429
1430	fdev = platform_get_drvdata(op);
1431	dma_async_device_unregister(&fdev->common);
1432
1433	fsldma_free_irqs(fdev);
1434
1435	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1436		if (fdev->chan[i])
1437			fsl_dma_chan_remove(fdev->chan[i]);
1438	}
1439
1440	iounmap(fdev->regs);
1441	kfree(fdev);
1442
1443	return 0;
1444}
1445
1446#ifdef CONFIG_PM
1447static int fsldma_suspend_late(struct device *dev)
1448{
1449	struct platform_device *pdev = to_platform_device(dev);
1450	struct fsldma_device *fdev = platform_get_drvdata(pdev);
1451	struct fsldma_chan *chan;
1452	int i;
1453
1454	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1455		chan = fdev->chan[i];
1456		if (!chan)
1457			continue;
1458
1459		spin_lock_bh(&chan->desc_lock);
1460		if (unlikely(!chan->idle))
1461			goto out;
1462		chan->regs_save.mr = get_mr(chan);
1463		chan->pm_state = SUSPENDED;
1464		spin_unlock_bh(&chan->desc_lock);
1465	}
1466	return 0;
1467
1468out:
1469	for (; i >= 0; i--) {
1470		chan = fdev->chan[i];
1471		if (!chan)
1472			continue;
1473		chan->pm_state = RUNNING;
1474		spin_unlock_bh(&chan->desc_lock);
1475	}
1476	return -EBUSY;
1477}
1478
1479static int fsldma_resume_early(struct device *dev)
1480{
1481	struct platform_device *pdev = to_platform_device(dev);
1482	struct fsldma_device *fdev = platform_get_drvdata(pdev);
1483	struct fsldma_chan *chan;
1484	u32 mode;
1485	int i;
1486
1487	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1488		chan = fdev->chan[i];
1489		if (!chan)
1490			continue;
1491
1492		spin_lock_bh(&chan->desc_lock);
1493		mode = chan->regs_save.mr
1494			& ~FSL_DMA_MR_CS & ~FSL_DMA_MR_CC & ~FSL_DMA_MR_CA;
1495		set_mr(chan, mode);
1496		chan->pm_state = RUNNING;
1497		spin_unlock_bh(&chan->desc_lock);
1498	}
1499
1500	return 0;
1501}
1502
1503static const struct dev_pm_ops fsldma_pm_ops = {
1504	.suspend_late	= fsldma_suspend_late,
1505	.resume_early	= fsldma_resume_early,
1506};
1507#endif
1508
1509static const struct of_device_id fsldma_of_ids[] = {
1510	{ .compatible = "fsl,elo3-dma", },
1511	{ .compatible = "fsl,eloplus-dma", },
1512	{ .compatible = "fsl,elo-dma", },
1513	{}
1514};
1515
1516static struct platform_driver fsldma_of_driver = {
1517	.driver = {
1518		.name = "fsl-elo-dma",
1519		.of_match_table = fsldma_of_ids,
1520#ifdef CONFIG_PM
1521		.pm = &fsldma_pm_ops,
1522#endif
1523	},
1524	.probe = fsldma_of_probe,
1525	.remove = fsldma_of_remove,
1526};
1527
1528/*----------------------------------------------------------------------------*/
1529/* Module Init / Exit                                                         */
1530/*----------------------------------------------------------------------------*/
1531
1532static __init int fsldma_init(void)
1533{
1534	pr_info("Freescale Elo series DMA driver\n");
1535	return platform_driver_register(&fsldma_of_driver);
1536}
1537
1538static void __exit fsldma_exit(void)
1539{
1540	platform_driver_unregister(&fsldma_of_driver);
1541}
1542
1543subsys_initcall(fsldma_init);
1544module_exit(fsldma_exit);
1545
1546MODULE_DESCRIPTION("Freescale Elo series DMA driver");
1547MODULE_LICENSE("GPL");
1548