mpc512x_dma.c revision a276991357c63bfb8d3ffdf5800054dba4f8d558
1/*
2 * Copyright (C) Freescale Semicondutor, Inc. 2007, 2008.
3 * Copyright (C) Semihalf 2009
4 * Copyright (C) Ilya Yanok, Emcraft Systems 2010
5 *
6 * Written by Piotr Ziecik <kosmo@semihalf.com>. Hardware description
7 * (defines, structures and comments) was taken from MPC5121 DMA driver
8 * written by Hongjun Chen <hong-jun.chen@freescale.com>.
9 *
10 * Approved as OSADL project by a majority of OSADL members and funded
11 * by OSADL membership fees in 2009;  for details see www.osadl.org.
12 *
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms of the GNU General Public License as published by the Free
15 * Software Foundation; either version 2 of the License, or (at your option)
16 * any later version.
17 *
18 * This program is distributed in the hope that it will be useful, but WITHOUT
19 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
20 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
21 * more details.
22 *
23 * You should have received a copy of the GNU General Public License along with
24 * this program; if not, write to the Free Software Foundation, Inc., 59
25 * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
26 *
27 * The full GNU General Public License is included in this distribution in the
28 * file called COPYING.
29 */
30
31/*
32 * This is initial version of MPC5121 DMA driver. Only memory to memory
33 * transfers are supported (tested using dmatest module).
34 */
35
36#include <linux/module.h>
37#include <linux/dmaengine.h>
38#include <linux/dma-mapping.h>
39#include <linux/interrupt.h>
40#include <linux/io.h>
41#include <linux/slab.h>
42#include <linux/of_device.h>
43#include <linux/of_platform.h>
44
45#include <linux/random.h>
46
47/* Number of DMA Transfer descriptors allocated per channel */
48#define MPC_DMA_DESCRIPTORS	64
49
50/* Macro definitions */
51#define MPC_DMA_CHANNELS	64
52#define MPC_DMA_TCD_OFFSET	0x1000
53
54/* Arbitration mode of group and channel */
55#define MPC_DMA_DMACR_EDCG	(1 << 31)
56#define MPC_DMA_DMACR_ERGA	(1 << 3)
57#define MPC_DMA_DMACR_ERCA	(1 << 2)
58
59/* Error codes */
60#define MPC_DMA_DMAES_VLD	(1 << 31)
61#define MPC_DMA_DMAES_GPE	(1 << 15)
62#define MPC_DMA_DMAES_CPE	(1 << 14)
63#define MPC_DMA_DMAES_ERRCHN(err) \
64				(((err) >> 8) & 0x3f)
65#define MPC_DMA_DMAES_SAE	(1 << 7)
66#define MPC_DMA_DMAES_SOE	(1 << 6)
67#define MPC_DMA_DMAES_DAE	(1 << 5)
68#define MPC_DMA_DMAES_DOE	(1 << 4)
69#define MPC_DMA_DMAES_NCE	(1 << 3)
70#define MPC_DMA_DMAES_SGE	(1 << 2)
71#define MPC_DMA_DMAES_SBE	(1 << 1)
72#define MPC_DMA_DMAES_DBE	(1 << 0)
73
74#define MPC_DMA_DMAGPOR_SNOOP_ENABLE	(1 << 6)
75
76#define MPC_DMA_TSIZE_1		0x00
77#define MPC_DMA_TSIZE_2		0x01
78#define MPC_DMA_TSIZE_4		0x02
79#define MPC_DMA_TSIZE_16	0x04
80#define MPC_DMA_TSIZE_32	0x05
81
82/* MPC5121 DMA engine registers */
83struct __attribute__ ((__packed__)) mpc_dma_regs {
84	/* 0x00 */
85	u32 dmacr;		/* DMA control register */
86	u32 dmaes;		/* DMA error status */
87	/* 0x08 */
88	u32 dmaerqh;		/* DMA enable request high(channels 63~32) */
89	u32 dmaerql;		/* DMA enable request low(channels 31~0) */
90	u32 dmaeeih;		/* DMA enable error interrupt high(ch63~32) */
91	u32 dmaeeil;		/* DMA enable error interrupt low(ch31~0) */
92	/* 0x18 */
93	u8 dmaserq;		/* DMA set enable request */
94	u8 dmacerq;		/* DMA clear enable request */
95	u8 dmaseei;		/* DMA set enable error interrupt */
96	u8 dmaceei;		/* DMA clear enable error interrupt */
97	/* 0x1c */
98	u8 dmacint;		/* DMA clear interrupt request */
99	u8 dmacerr;		/* DMA clear error */
100	u8 dmassrt;		/* DMA set start bit */
101	u8 dmacdne;		/* DMA clear DONE status bit */
102	/* 0x20 */
103	u32 dmainth;		/* DMA interrupt request high(ch63~32) */
104	u32 dmaintl;		/* DMA interrupt request low(ch31~0) */
105	u32 dmaerrh;		/* DMA error high(ch63~32) */
106	u32 dmaerrl;		/* DMA error low(ch31~0) */
107	/* 0x30 */
108	u32 dmahrsh;		/* DMA hw request status high(ch63~32) */
109	u32 dmahrsl;		/* DMA hardware request status low(ch31~0) */
110	union {
111		u32 dmaihsa;	/* DMA interrupt high select AXE(ch63~32) */
112		u32 dmagpor;	/* (General purpose register on MPC8308) */
113	};
114	u32 dmailsa;		/* DMA interrupt low select AXE(ch31~0) */
115	/* 0x40 ~ 0xff */
116	u32 reserve0[48];	/* Reserved */
117	/* 0x100 */
118	u8 dchpri[MPC_DMA_CHANNELS];
119	/* DMA channels(0~63) priority */
120};
121
122struct __attribute__ ((__packed__)) mpc_dma_tcd {
123	/* 0x00 */
124	u32 saddr;		/* Source address */
125
126	u32 smod:5;		/* Source address modulo */
127	u32 ssize:3;		/* Source data transfer size */
128	u32 dmod:5;		/* Destination address modulo */
129	u32 dsize:3;		/* Destination data transfer size */
130	u32 soff:16;		/* Signed source address offset */
131
132	/* 0x08 */
133	u32 nbytes;		/* Inner "minor" byte count */
134	u32 slast;		/* Last source address adjustment */
135	u32 daddr;		/* Destination address */
136
137	/* 0x14 */
138	u32 citer_elink:1;	/* Enable channel-to-channel linking on
139				 * minor loop complete
140				 */
141	u32 citer_linkch:6;	/* Link channel for minor loop complete */
142	u32 citer:9;		/* Current "major" iteration count */
143	u32 doff:16;		/* Signed destination address offset */
144
145	/* 0x18 */
146	u32 dlast_sga;		/* Last Destination address adjustment/scatter
147				 * gather address
148				 */
149
150	/* 0x1c */
151	u32 biter_elink:1;	/* Enable channel-to-channel linking on major
152				 * loop complete
153				 */
154	u32 biter_linkch:6;
155	u32 biter:9;		/* Beginning "major" iteration count */
156	u32 bwc:2;		/* Bandwidth control */
157	u32 major_linkch:6;	/* Link channel number */
158	u32 done:1;		/* Channel done */
159	u32 active:1;		/* Channel active */
160	u32 major_elink:1;	/* Enable channel-to-channel linking on major
161				 * loop complete
162				 */
163	u32 e_sg:1;		/* Enable scatter/gather processing */
164	u32 d_req:1;		/* Disable request */
165	u32 int_half:1;		/* Enable an interrupt when major counter is
166				 * half complete
167				 */
168	u32 int_maj:1;		/* Enable an interrupt when major iteration
169				 * count completes
170				 */
171	u32 start:1;		/* Channel start */
172};
173
174struct mpc_dma_desc {
175	struct dma_async_tx_descriptor	desc;
176	struct mpc_dma_tcd		*tcd;
177	dma_addr_t			tcd_paddr;
178	int				error;
179	struct list_head		node;
180};
181
182struct mpc_dma_chan {
183	struct dma_chan			chan;
184	struct list_head		free;
185	struct list_head		prepared;
186	struct list_head		queued;
187	struct list_head		active;
188	struct list_head		completed;
189	struct mpc_dma_tcd		*tcd;
190	dma_addr_t			tcd_paddr;
191	dma_cookie_t			completed_cookie;
192
193	/* Lock for this structure */
194	spinlock_t			lock;
195};
196
197struct mpc_dma {
198	struct dma_device		dma;
199	struct tasklet_struct		tasklet;
200	struct mpc_dma_chan		channels[MPC_DMA_CHANNELS];
201	struct mpc_dma_regs __iomem	*regs;
202	struct mpc_dma_tcd __iomem	*tcd;
203	int				irq;
204	int				irq2;
205	uint				error_status;
206	int				is_mpc8308;
207
208	/* Lock for error_status field in this structure */
209	spinlock_t			error_status_lock;
210};
211
212#define DRV_NAME	"mpc512x_dma"
213
214/* Convert struct dma_chan to struct mpc_dma_chan */
215static inline struct mpc_dma_chan *dma_chan_to_mpc_dma_chan(struct dma_chan *c)
216{
217	return container_of(c, struct mpc_dma_chan, chan);
218}
219
220/* Convert struct dma_chan to struct mpc_dma */
221static inline struct mpc_dma *dma_chan_to_mpc_dma(struct dma_chan *c)
222{
223	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(c);
224	return container_of(mchan, struct mpc_dma, channels[c->chan_id]);
225}
226
227/*
228 * Execute all queued DMA descriptors.
229 *
230 * Following requirements must be met while calling mpc_dma_execute():
231 * 	a) mchan->lock is acquired,
232 * 	b) mchan->active list is empty,
233 * 	c) mchan->queued list contains at least one entry.
234 */
235static void mpc_dma_execute(struct mpc_dma_chan *mchan)
236{
237	struct mpc_dma *mdma = dma_chan_to_mpc_dma(&mchan->chan);
238	struct mpc_dma_desc *first = NULL;
239	struct mpc_dma_desc *prev = NULL;
240	struct mpc_dma_desc *mdesc;
241	int cid = mchan->chan.chan_id;
242
243	/* Move all queued descriptors to active list */
244	list_splice_tail_init(&mchan->queued, &mchan->active);
245
246	/* Chain descriptors into one transaction */
247	list_for_each_entry(mdesc, &mchan->active, node) {
248		if (!first)
249			first = mdesc;
250
251		if (!prev) {
252			prev = mdesc;
253			continue;
254		}
255
256		prev->tcd->dlast_sga = mdesc->tcd_paddr;
257		prev->tcd->e_sg = 1;
258		mdesc->tcd->start = 1;
259
260		prev = mdesc;
261	}
262
263	prev->tcd->int_maj = 1;
264
265	/* Send first descriptor in chain into hardware */
266	memcpy_toio(&mdma->tcd[cid], first->tcd, sizeof(struct mpc_dma_tcd));
267
268	if (first != prev)
269		mdma->tcd[cid].e_sg = 1;
270	out_8(&mdma->regs->dmassrt, cid);
271}
272
273/* Handle interrupt on one half of DMA controller (32 channels) */
274static void mpc_dma_irq_process(struct mpc_dma *mdma, u32 is, u32 es, int off)
275{
276	struct mpc_dma_chan *mchan;
277	struct mpc_dma_desc *mdesc;
278	u32 status = is | es;
279	int ch;
280
281	while ((ch = fls(status) - 1) >= 0) {
282		status &= ~(1 << ch);
283		mchan = &mdma->channels[ch + off];
284
285		spin_lock(&mchan->lock);
286
287		out_8(&mdma->regs->dmacint, ch + off);
288		out_8(&mdma->regs->dmacerr, ch + off);
289
290		/* Check error status */
291		if (es & (1 << ch))
292			list_for_each_entry(mdesc, &mchan->active, node)
293				mdesc->error = -EIO;
294
295		/* Execute queued descriptors */
296		list_splice_tail_init(&mchan->active, &mchan->completed);
297		if (!list_empty(&mchan->queued))
298			mpc_dma_execute(mchan);
299
300		spin_unlock(&mchan->lock);
301	}
302}
303
304/* Interrupt handler */
305static irqreturn_t mpc_dma_irq(int irq, void *data)
306{
307	struct mpc_dma *mdma = data;
308	uint es;
309
310	/* Save error status register */
311	es = in_be32(&mdma->regs->dmaes);
312	spin_lock(&mdma->error_status_lock);
313	if ((es & MPC_DMA_DMAES_VLD) && mdma->error_status == 0)
314		mdma->error_status = es;
315	spin_unlock(&mdma->error_status_lock);
316
317	/* Handle interrupt on each channel */
318	if (mdma->dma.chancnt > 32) {
319		mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmainth),
320					in_be32(&mdma->regs->dmaerrh), 32);
321	}
322	mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmaintl),
323					in_be32(&mdma->regs->dmaerrl), 0);
324
325	/* Schedule tasklet */
326	tasklet_schedule(&mdma->tasklet);
327
328	return IRQ_HANDLED;
329}
330
331/* proccess completed descriptors */
332static void mpc_dma_process_completed(struct mpc_dma *mdma)
333{
334	dma_cookie_t last_cookie = 0;
335	struct mpc_dma_chan *mchan;
336	struct mpc_dma_desc *mdesc;
337	struct dma_async_tx_descriptor *desc;
338	unsigned long flags;
339	LIST_HEAD(list);
340	int i;
341
342	for (i = 0; i < mdma->dma.chancnt; i++) {
343		mchan = &mdma->channels[i];
344
345		/* Get all completed descriptors */
346		spin_lock_irqsave(&mchan->lock, flags);
347		if (!list_empty(&mchan->completed))
348			list_splice_tail_init(&mchan->completed, &list);
349		spin_unlock_irqrestore(&mchan->lock, flags);
350
351		if (list_empty(&list))
352			continue;
353
354		/* Execute callbacks and run dependencies */
355		list_for_each_entry(mdesc, &list, node) {
356			desc = &mdesc->desc;
357
358			if (desc->callback)
359				desc->callback(desc->callback_param);
360
361			last_cookie = desc->cookie;
362			dma_run_dependencies(desc);
363		}
364
365		/* Free descriptors */
366		spin_lock_irqsave(&mchan->lock, flags);
367		list_splice_tail_init(&list, &mchan->free);
368		mchan->completed_cookie = last_cookie;
369		spin_unlock_irqrestore(&mchan->lock, flags);
370	}
371}
372
373/* DMA Tasklet */
374static void mpc_dma_tasklet(unsigned long data)
375{
376	struct mpc_dma *mdma = (void *)data;
377	unsigned long flags;
378	uint es;
379
380	spin_lock_irqsave(&mdma->error_status_lock, flags);
381	es = mdma->error_status;
382	mdma->error_status = 0;
383	spin_unlock_irqrestore(&mdma->error_status_lock, flags);
384
385	/* Print nice error report */
386	if (es) {
387		dev_err(mdma->dma.dev,
388			"Hardware reported following error(s) on channel %u:\n",
389						      MPC_DMA_DMAES_ERRCHN(es));
390
391		if (es & MPC_DMA_DMAES_GPE)
392			dev_err(mdma->dma.dev, "- Group Priority Error\n");
393		if (es & MPC_DMA_DMAES_CPE)
394			dev_err(mdma->dma.dev, "- Channel Priority Error\n");
395		if (es & MPC_DMA_DMAES_SAE)
396			dev_err(mdma->dma.dev, "- Source Address Error\n");
397		if (es & MPC_DMA_DMAES_SOE)
398			dev_err(mdma->dma.dev, "- Source Offset"
399						" Configuration Error\n");
400		if (es & MPC_DMA_DMAES_DAE)
401			dev_err(mdma->dma.dev, "- Destination Address"
402								" Error\n");
403		if (es & MPC_DMA_DMAES_DOE)
404			dev_err(mdma->dma.dev, "- Destination Offset"
405						" Configuration Error\n");
406		if (es & MPC_DMA_DMAES_NCE)
407			dev_err(mdma->dma.dev, "- NBytes/Citter"
408						" Configuration Error\n");
409		if (es & MPC_DMA_DMAES_SGE)
410			dev_err(mdma->dma.dev, "- Scatter/Gather"
411						" Configuration Error\n");
412		if (es & MPC_DMA_DMAES_SBE)
413			dev_err(mdma->dma.dev, "- Source Bus Error\n");
414		if (es & MPC_DMA_DMAES_DBE)
415			dev_err(mdma->dma.dev, "- Destination Bus Error\n");
416	}
417
418	mpc_dma_process_completed(mdma);
419}
420
421/* Submit descriptor to hardware */
422static dma_cookie_t mpc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
423{
424	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(txd->chan);
425	struct mpc_dma_desc *mdesc;
426	unsigned long flags;
427	dma_cookie_t cookie;
428
429	mdesc = container_of(txd, struct mpc_dma_desc, desc);
430
431	spin_lock_irqsave(&mchan->lock, flags);
432
433	/* Move descriptor to queue */
434	list_move_tail(&mdesc->node, &mchan->queued);
435
436	/* If channel is idle, execute all queued descriptors */
437	if (list_empty(&mchan->active))
438		mpc_dma_execute(mchan);
439
440	/* Update cookie */
441	cookie = mchan->chan.cookie + 1;
442	if (cookie <= 0)
443		cookie = 1;
444
445	mchan->chan.cookie = cookie;
446	mdesc->desc.cookie = cookie;
447
448	spin_unlock_irqrestore(&mchan->lock, flags);
449
450	return cookie;
451}
452
453/* Alloc channel resources */
454static int mpc_dma_alloc_chan_resources(struct dma_chan *chan)
455{
456	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
457	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
458	struct mpc_dma_desc *mdesc;
459	struct mpc_dma_tcd *tcd;
460	dma_addr_t tcd_paddr;
461	unsigned long flags;
462	LIST_HEAD(descs);
463	int i;
464
465	/* Alloc DMA memory for Transfer Control Descriptors */
466	tcd = dma_alloc_coherent(mdma->dma.dev,
467			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
468							&tcd_paddr, GFP_KERNEL);
469	if (!tcd)
470		return -ENOMEM;
471
472	/* Alloc descriptors for this channel */
473	for (i = 0; i < MPC_DMA_DESCRIPTORS; i++) {
474		mdesc = kzalloc(sizeof(struct mpc_dma_desc), GFP_KERNEL);
475		if (!mdesc) {
476			dev_notice(mdma->dma.dev, "Memory allocation error. "
477					"Allocated only %u descriptors\n", i);
478			break;
479		}
480
481		dma_async_tx_descriptor_init(&mdesc->desc, chan);
482		mdesc->desc.flags = DMA_CTRL_ACK;
483		mdesc->desc.tx_submit = mpc_dma_tx_submit;
484
485		mdesc->tcd = &tcd[i];
486		mdesc->tcd_paddr = tcd_paddr + (i * sizeof(struct mpc_dma_tcd));
487
488		list_add_tail(&mdesc->node, &descs);
489	}
490
491	/* Return error only if no descriptors were allocated */
492	if (i == 0) {
493		dma_free_coherent(mdma->dma.dev,
494			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
495								tcd, tcd_paddr);
496		return -ENOMEM;
497	}
498
499	spin_lock_irqsave(&mchan->lock, flags);
500	mchan->tcd = tcd;
501	mchan->tcd_paddr = tcd_paddr;
502	list_splice_tail_init(&descs, &mchan->free);
503	spin_unlock_irqrestore(&mchan->lock, flags);
504
505	/* Enable Error Interrupt */
506	out_8(&mdma->regs->dmaseei, chan->chan_id);
507
508	return 0;
509}
510
511/* Free channel resources */
512static void mpc_dma_free_chan_resources(struct dma_chan *chan)
513{
514	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
515	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
516	struct mpc_dma_desc *mdesc, *tmp;
517	struct mpc_dma_tcd *tcd;
518	dma_addr_t tcd_paddr;
519	unsigned long flags;
520	LIST_HEAD(descs);
521
522	spin_lock_irqsave(&mchan->lock, flags);
523
524	/* Channel must be idle */
525	BUG_ON(!list_empty(&mchan->prepared));
526	BUG_ON(!list_empty(&mchan->queued));
527	BUG_ON(!list_empty(&mchan->active));
528	BUG_ON(!list_empty(&mchan->completed));
529
530	/* Move data */
531	list_splice_tail_init(&mchan->free, &descs);
532	tcd = mchan->tcd;
533	tcd_paddr = mchan->tcd_paddr;
534
535	spin_unlock_irqrestore(&mchan->lock, flags);
536
537	/* Free DMA memory used by descriptors */
538	dma_free_coherent(mdma->dma.dev,
539			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
540								tcd, tcd_paddr);
541
542	/* Free descriptors */
543	list_for_each_entry_safe(mdesc, tmp, &descs, node)
544		kfree(mdesc);
545
546	/* Disable Error Interrupt */
547	out_8(&mdma->regs->dmaceei, chan->chan_id);
548}
549
550/* Send all pending descriptor to hardware */
551static void mpc_dma_issue_pending(struct dma_chan *chan)
552{
553	/*
554	 * We are posting descriptors to the hardware as soon as
555	 * they are ready, so this function does nothing.
556	 */
557}
558
559/* Check request completion status */
560static enum dma_status
561mpc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
562	       struct dma_tx_state *txstate)
563{
564	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
565	unsigned long flags;
566	dma_cookie_t last_used;
567	dma_cookie_t last_complete;
568
569	spin_lock_irqsave(&mchan->lock, flags);
570	last_used = mchan->chan.cookie;
571	last_complete = mchan->completed_cookie;
572	spin_unlock_irqrestore(&mchan->lock, flags);
573
574	dma_set_tx_state(txstate, last_complete, last_used, 0);
575	return dma_async_is_complete(cookie, last_complete, last_used);
576}
577
578/* Prepare descriptor for memory to memory copy */
579static struct dma_async_tx_descriptor *
580mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
581					size_t len, unsigned long flags)
582{
583	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
584	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
585	struct mpc_dma_desc *mdesc = NULL;
586	struct mpc_dma_tcd *tcd;
587	unsigned long iflags;
588
589	/* Get free descriptor */
590	spin_lock_irqsave(&mchan->lock, iflags);
591	if (!list_empty(&mchan->free)) {
592		mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc,
593									node);
594		list_del(&mdesc->node);
595	}
596	spin_unlock_irqrestore(&mchan->lock, iflags);
597
598	if (!mdesc) {
599		/* try to free completed descriptors */
600		mpc_dma_process_completed(mdma);
601		return NULL;
602	}
603
604	mdesc->error = 0;
605	tcd = mdesc->tcd;
606
607	/* Prepare Transfer Control Descriptor for this transaction */
608	memset(tcd, 0, sizeof(struct mpc_dma_tcd));
609
610	if (IS_ALIGNED(src | dst | len, 32)) {
611		tcd->ssize = MPC_DMA_TSIZE_32;
612		tcd->dsize = MPC_DMA_TSIZE_32;
613		tcd->soff = 32;
614		tcd->doff = 32;
615	} else if (!mdma->is_mpc8308 && IS_ALIGNED(src | dst | len, 16)) {
616		/* MPC8308 doesn't support 16 byte transfers */
617		tcd->ssize = MPC_DMA_TSIZE_16;
618		tcd->dsize = MPC_DMA_TSIZE_16;
619		tcd->soff = 16;
620		tcd->doff = 16;
621	} else if (IS_ALIGNED(src | dst | len, 4)) {
622		tcd->ssize = MPC_DMA_TSIZE_4;
623		tcd->dsize = MPC_DMA_TSIZE_4;
624		tcd->soff = 4;
625		tcd->doff = 4;
626	} else if (IS_ALIGNED(src | dst | len, 2)) {
627		tcd->ssize = MPC_DMA_TSIZE_2;
628		tcd->dsize = MPC_DMA_TSIZE_2;
629		tcd->soff = 2;
630		tcd->doff = 2;
631	} else {
632		tcd->ssize = MPC_DMA_TSIZE_1;
633		tcd->dsize = MPC_DMA_TSIZE_1;
634		tcd->soff = 1;
635		tcd->doff = 1;
636	}
637
638	tcd->saddr = src;
639	tcd->daddr = dst;
640	tcd->nbytes = len;
641	tcd->biter = 1;
642	tcd->citer = 1;
643
644	/* Place descriptor in prepared list */
645	spin_lock_irqsave(&mchan->lock, iflags);
646	list_add_tail(&mdesc->node, &mchan->prepared);
647	spin_unlock_irqrestore(&mchan->lock, iflags);
648
649	return &mdesc->desc;
650}
651
652static int __devinit mpc_dma_probe(struct platform_device *op,
653					const struct of_device_id *match)
654{
655	struct device_node *dn = op->dev.of_node;
656	struct device *dev = &op->dev;
657	struct dma_device *dma;
658	struct mpc_dma *mdma;
659	struct mpc_dma_chan *mchan;
660	struct resource res;
661	ulong regs_start, regs_size;
662	int retval, i;
663
664	mdma = devm_kzalloc(dev, sizeof(struct mpc_dma), GFP_KERNEL);
665	if (!mdma) {
666		dev_err(dev, "Memory exhausted!\n");
667		return -ENOMEM;
668	}
669
670	mdma->irq = irq_of_parse_and_map(dn, 0);
671	if (mdma->irq == NO_IRQ) {
672		dev_err(dev, "Error mapping IRQ!\n");
673		return -EINVAL;
674	}
675
676	if (of_device_is_compatible(dn, "fsl,mpc8308-dma")) {
677		mdma->is_mpc8308 = 1;
678		mdma->irq2 = irq_of_parse_and_map(dn, 1);
679		if (mdma->irq2 == NO_IRQ) {
680			dev_err(dev, "Error mapping IRQ!\n");
681			return -EINVAL;
682		}
683	}
684
685	retval = of_address_to_resource(dn, 0, &res);
686	if (retval) {
687		dev_err(dev, "Error parsing memory region!\n");
688		return retval;
689	}
690
691	regs_start = res.start;
692	regs_size = resource_size(&res);
693
694	if (!devm_request_mem_region(dev, regs_start, regs_size, DRV_NAME)) {
695		dev_err(dev, "Error requesting memory region!\n");
696		return -EBUSY;
697	}
698
699	mdma->regs = devm_ioremap(dev, regs_start, regs_size);
700	if (!mdma->regs) {
701		dev_err(dev, "Error mapping memory region!\n");
702		return -ENOMEM;
703	}
704
705	mdma->tcd = (struct mpc_dma_tcd *)((u8 *)(mdma->regs)
706							+ MPC_DMA_TCD_OFFSET);
707
708	retval = devm_request_irq(dev, mdma->irq, &mpc_dma_irq, 0, DRV_NAME,
709									mdma);
710	if (retval) {
711		dev_err(dev, "Error requesting IRQ!\n");
712		return -EINVAL;
713	}
714
715	if (mdma->is_mpc8308) {
716		retval = devm_request_irq(dev, mdma->irq2, &mpc_dma_irq, 0,
717				DRV_NAME, mdma);
718		if (retval) {
719			dev_err(dev, "Error requesting IRQ2!\n");
720			return -EINVAL;
721		}
722	}
723
724	spin_lock_init(&mdma->error_status_lock);
725
726	dma = &mdma->dma;
727	dma->dev = dev;
728	if (!mdma->is_mpc8308)
729		dma->chancnt = MPC_DMA_CHANNELS;
730	else
731		dma->chancnt = 16; /* MPC8308 DMA has only 16 channels */
732	dma->device_alloc_chan_resources = mpc_dma_alloc_chan_resources;
733	dma->device_free_chan_resources = mpc_dma_free_chan_resources;
734	dma->device_issue_pending = mpc_dma_issue_pending;
735	dma->device_tx_status = mpc_dma_tx_status;
736	dma->device_prep_dma_memcpy = mpc_dma_prep_memcpy;
737
738	INIT_LIST_HEAD(&dma->channels);
739	dma_cap_set(DMA_MEMCPY, dma->cap_mask);
740
741	for (i = 0; i < dma->chancnt; i++) {
742		mchan = &mdma->channels[i];
743
744		mchan->chan.device = dma;
745		mchan->chan.chan_id = i;
746		mchan->chan.cookie = 1;
747		mchan->completed_cookie = mchan->chan.cookie;
748
749		INIT_LIST_HEAD(&mchan->free);
750		INIT_LIST_HEAD(&mchan->prepared);
751		INIT_LIST_HEAD(&mchan->queued);
752		INIT_LIST_HEAD(&mchan->active);
753		INIT_LIST_HEAD(&mchan->completed);
754
755		spin_lock_init(&mchan->lock);
756		list_add_tail(&mchan->chan.device_node, &dma->channels);
757	}
758
759	tasklet_init(&mdma->tasklet, mpc_dma_tasklet, (unsigned long)mdma);
760
761	/*
762	 * Configure DMA Engine:
763	 * - Dynamic clock,
764	 * - Round-robin group arbitration,
765	 * - Round-robin channel arbitration.
766	 */
767	if (!mdma->is_mpc8308) {
768		out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_EDCG |
769					MPC_DMA_DMACR_ERGA | MPC_DMA_DMACR_ERCA);
770
771		/* Disable hardware DMA requests */
772		out_be32(&mdma->regs->dmaerqh, 0);
773		out_be32(&mdma->regs->dmaerql, 0);
774
775		/* Disable error interrupts */
776		out_be32(&mdma->regs->dmaeeih, 0);
777		out_be32(&mdma->regs->dmaeeil, 0);
778
779		/* Clear interrupts status */
780		out_be32(&mdma->regs->dmainth, 0xFFFFFFFF);
781		out_be32(&mdma->regs->dmaintl, 0xFFFFFFFF);
782		out_be32(&mdma->regs->dmaerrh, 0xFFFFFFFF);
783		out_be32(&mdma->regs->dmaerrl, 0xFFFFFFFF);
784
785		/* Route interrupts to IPIC */
786		out_be32(&mdma->regs->dmaihsa, 0);
787		out_be32(&mdma->regs->dmailsa, 0);
788	} else {
789		/* MPC8308 has 16 channels and lacks some registers */
790		out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA);
791
792		/* enable snooping */
793		out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE);
794		/* Disable error interrupts */
795		out_be32(&mdma->regs->dmaeeil, 0);
796
797		/* Clear interrupts status */
798		out_be32(&mdma->regs->dmaintl, 0xFFFF);
799		out_be32(&mdma->regs->dmaerrl, 0xFFFF);
800	}
801
802	/* Register DMA engine */
803	dev_set_drvdata(dev, mdma);
804	retval = dma_async_device_register(dma);
805	if (retval) {
806		devm_free_irq(dev, mdma->irq, mdma);
807		irq_dispose_mapping(mdma->irq);
808	}
809
810	return retval;
811}
812
813static int __devexit mpc_dma_remove(struct platform_device *op)
814{
815	struct device *dev = &op->dev;
816	struct mpc_dma *mdma = dev_get_drvdata(dev);
817
818	dma_async_device_unregister(&mdma->dma);
819	devm_free_irq(dev, mdma->irq, mdma);
820	irq_dispose_mapping(mdma->irq);
821
822	return 0;
823}
824
825static struct of_device_id mpc_dma_match[] = {
826	{ .compatible = "fsl,mpc5121-dma", },
827	{},
828};
829
830static struct of_platform_driver mpc_dma_driver = {
831	.probe		= mpc_dma_probe,
832	.remove		= __devexit_p(mpc_dma_remove),
833	.driver = {
834		.name = DRV_NAME,
835		.owner = THIS_MODULE,
836		.of_match_table	= mpc_dma_match,
837	},
838};
839
840static int __init mpc_dma_init(void)
841{
842	return of_register_platform_driver(&mpc_dma_driver);
843}
844module_init(mpc_dma_init);
845
846static void __exit mpc_dma_exit(void)
847{
848	of_unregister_platform_driver(&mpc_dma_driver);
849}
850module_exit(mpc_dma_exit);
851
852MODULE_LICENSE("GPL");
853MODULE_AUTHOR("Piotr Ziecik <kosmo@semihalf.com>");
854