mpc512x_dma.c revision 463a1f8b3ceebe990ca9a8c7cc2e51ee42cb48eb
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#include "dmaengine.h"
48
49/* Number of DMA Transfer descriptors allocated per channel */
50#define MPC_DMA_DESCRIPTORS	64
51
52/* Macro definitions */
53#define MPC_DMA_CHANNELS	64
54#define MPC_DMA_TCD_OFFSET	0x1000
55
56/* Arbitration mode of group and channel */
57#define MPC_DMA_DMACR_EDCG	(1 << 31)
58#define MPC_DMA_DMACR_ERGA	(1 << 3)
59#define MPC_DMA_DMACR_ERCA	(1 << 2)
60
61/* Error codes */
62#define MPC_DMA_DMAES_VLD	(1 << 31)
63#define MPC_DMA_DMAES_GPE	(1 << 15)
64#define MPC_DMA_DMAES_CPE	(1 << 14)
65#define MPC_DMA_DMAES_ERRCHN(err) \
66				(((err) >> 8) & 0x3f)
67#define MPC_DMA_DMAES_SAE	(1 << 7)
68#define MPC_DMA_DMAES_SOE	(1 << 6)
69#define MPC_DMA_DMAES_DAE	(1 << 5)
70#define MPC_DMA_DMAES_DOE	(1 << 4)
71#define MPC_DMA_DMAES_NCE	(1 << 3)
72#define MPC_DMA_DMAES_SGE	(1 << 2)
73#define MPC_DMA_DMAES_SBE	(1 << 1)
74#define MPC_DMA_DMAES_DBE	(1 << 0)
75
76#define MPC_DMA_DMAGPOR_SNOOP_ENABLE	(1 << 6)
77
78#define MPC_DMA_TSIZE_1		0x00
79#define MPC_DMA_TSIZE_2		0x01
80#define MPC_DMA_TSIZE_4		0x02
81#define MPC_DMA_TSIZE_16	0x04
82#define MPC_DMA_TSIZE_32	0x05
83
84/* MPC5121 DMA engine registers */
85struct __attribute__ ((__packed__)) mpc_dma_regs {
86	/* 0x00 */
87	u32 dmacr;		/* DMA control register */
88	u32 dmaes;		/* DMA error status */
89	/* 0x08 */
90	u32 dmaerqh;		/* DMA enable request high(channels 63~32) */
91	u32 dmaerql;		/* DMA enable request low(channels 31~0) */
92	u32 dmaeeih;		/* DMA enable error interrupt high(ch63~32) */
93	u32 dmaeeil;		/* DMA enable error interrupt low(ch31~0) */
94	/* 0x18 */
95	u8 dmaserq;		/* DMA set enable request */
96	u8 dmacerq;		/* DMA clear enable request */
97	u8 dmaseei;		/* DMA set enable error interrupt */
98	u8 dmaceei;		/* DMA clear enable error interrupt */
99	/* 0x1c */
100	u8 dmacint;		/* DMA clear interrupt request */
101	u8 dmacerr;		/* DMA clear error */
102	u8 dmassrt;		/* DMA set start bit */
103	u8 dmacdne;		/* DMA clear DONE status bit */
104	/* 0x20 */
105	u32 dmainth;		/* DMA interrupt request high(ch63~32) */
106	u32 dmaintl;		/* DMA interrupt request low(ch31~0) */
107	u32 dmaerrh;		/* DMA error high(ch63~32) */
108	u32 dmaerrl;		/* DMA error low(ch31~0) */
109	/* 0x30 */
110	u32 dmahrsh;		/* DMA hw request status high(ch63~32) */
111	u32 dmahrsl;		/* DMA hardware request status low(ch31~0) */
112	union {
113		u32 dmaihsa;	/* DMA interrupt high select AXE(ch63~32) */
114		u32 dmagpor;	/* (General purpose register on MPC8308) */
115	};
116	u32 dmailsa;		/* DMA interrupt low select AXE(ch31~0) */
117	/* 0x40 ~ 0xff */
118	u32 reserve0[48];	/* Reserved */
119	/* 0x100 */
120	u8 dchpri[MPC_DMA_CHANNELS];
121	/* DMA channels(0~63) priority */
122};
123
124struct __attribute__ ((__packed__)) mpc_dma_tcd {
125	/* 0x00 */
126	u32 saddr;		/* Source address */
127
128	u32 smod:5;		/* Source address modulo */
129	u32 ssize:3;		/* Source data transfer size */
130	u32 dmod:5;		/* Destination address modulo */
131	u32 dsize:3;		/* Destination data transfer size */
132	u32 soff:16;		/* Signed source address offset */
133
134	/* 0x08 */
135	u32 nbytes;		/* Inner "minor" byte count */
136	u32 slast;		/* Last source address adjustment */
137	u32 daddr;		/* Destination address */
138
139	/* 0x14 */
140	u32 citer_elink:1;	/* Enable channel-to-channel linking on
141				 * minor loop complete
142				 */
143	u32 citer_linkch:6;	/* Link channel for minor loop complete */
144	u32 citer:9;		/* Current "major" iteration count */
145	u32 doff:16;		/* Signed destination address offset */
146
147	/* 0x18 */
148	u32 dlast_sga;		/* Last Destination address adjustment/scatter
149				 * gather address
150				 */
151
152	/* 0x1c */
153	u32 biter_elink:1;	/* Enable channel-to-channel linking on major
154				 * loop complete
155				 */
156	u32 biter_linkch:6;
157	u32 biter:9;		/* Beginning "major" iteration count */
158	u32 bwc:2;		/* Bandwidth control */
159	u32 major_linkch:6;	/* Link channel number */
160	u32 done:1;		/* Channel done */
161	u32 active:1;		/* Channel active */
162	u32 major_elink:1;	/* Enable channel-to-channel linking on major
163				 * loop complete
164				 */
165	u32 e_sg:1;		/* Enable scatter/gather processing */
166	u32 d_req:1;		/* Disable request */
167	u32 int_half:1;		/* Enable an interrupt when major counter is
168				 * half complete
169				 */
170	u32 int_maj:1;		/* Enable an interrupt when major iteration
171				 * count completes
172				 */
173	u32 start:1;		/* Channel start */
174};
175
176struct mpc_dma_desc {
177	struct dma_async_tx_descriptor	desc;
178	struct mpc_dma_tcd		*tcd;
179	dma_addr_t			tcd_paddr;
180	int				error;
181	struct list_head		node;
182};
183
184struct mpc_dma_chan {
185	struct dma_chan			chan;
186	struct list_head		free;
187	struct list_head		prepared;
188	struct list_head		queued;
189	struct list_head		active;
190	struct list_head		completed;
191	struct mpc_dma_tcd		*tcd;
192	dma_addr_t			tcd_paddr;
193
194	/* Lock for this structure */
195	spinlock_t			lock;
196};
197
198struct mpc_dma {
199	struct dma_device		dma;
200	struct tasklet_struct		tasklet;
201	struct mpc_dma_chan		channels[MPC_DMA_CHANNELS];
202	struct mpc_dma_regs __iomem	*regs;
203	struct mpc_dma_tcd __iomem	*tcd;
204	int				irq;
205	int				irq2;
206	uint				error_status;
207	int				is_mpc8308;
208
209	/* Lock for error_status field in this structure */
210	spinlock_t			error_status_lock;
211};
212
213#define DRV_NAME	"mpc512x_dma"
214
215/* Convert struct dma_chan to struct mpc_dma_chan */
216static inline struct mpc_dma_chan *dma_chan_to_mpc_dma_chan(struct dma_chan *c)
217{
218	return container_of(c, struct mpc_dma_chan, chan);
219}
220
221/* Convert struct dma_chan to struct mpc_dma */
222static inline struct mpc_dma *dma_chan_to_mpc_dma(struct dma_chan *c)
223{
224	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(c);
225	return container_of(mchan, struct mpc_dma, channels[c->chan_id]);
226}
227
228/*
229 * Execute all queued DMA descriptors.
230 *
231 * Following requirements must be met while calling mpc_dma_execute():
232 * 	a) mchan->lock is acquired,
233 * 	b) mchan->active list is empty,
234 * 	c) mchan->queued list contains at least one entry.
235 */
236static void mpc_dma_execute(struct mpc_dma_chan *mchan)
237{
238	struct mpc_dma *mdma = dma_chan_to_mpc_dma(&mchan->chan);
239	struct mpc_dma_desc *first = NULL;
240	struct mpc_dma_desc *prev = NULL;
241	struct mpc_dma_desc *mdesc;
242	int cid = mchan->chan.chan_id;
243
244	/* Move all queued descriptors to active list */
245	list_splice_tail_init(&mchan->queued, &mchan->active);
246
247	/* Chain descriptors into one transaction */
248	list_for_each_entry(mdesc, &mchan->active, node) {
249		if (!first)
250			first = mdesc;
251
252		if (!prev) {
253			prev = mdesc;
254			continue;
255		}
256
257		prev->tcd->dlast_sga = mdesc->tcd_paddr;
258		prev->tcd->e_sg = 1;
259		mdesc->tcd->start = 1;
260
261		prev = mdesc;
262	}
263
264	prev->tcd->int_maj = 1;
265
266	/* Send first descriptor in chain into hardware */
267	memcpy_toio(&mdma->tcd[cid], first->tcd, sizeof(struct mpc_dma_tcd));
268
269	if (first != prev)
270		mdma->tcd[cid].e_sg = 1;
271	out_8(&mdma->regs->dmassrt, cid);
272}
273
274/* Handle interrupt on one half of DMA controller (32 channels) */
275static void mpc_dma_irq_process(struct mpc_dma *mdma, u32 is, u32 es, int off)
276{
277	struct mpc_dma_chan *mchan;
278	struct mpc_dma_desc *mdesc;
279	u32 status = is | es;
280	int ch;
281
282	while ((ch = fls(status) - 1) >= 0) {
283		status &= ~(1 << ch);
284		mchan = &mdma->channels[ch + off];
285
286		spin_lock(&mchan->lock);
287
288		out_8(&mdma->regs->dmacint, ch + off);
289		out_8(&mdma->regs->dmacerr, ch + off);
290
291		/* Check error status */
292		if (es & (1 << ch))
293			list_for_each_entry(mdesc, &mchan->active, node)
294				mdesc->error = -EIO;
295
296		/* Execute queued descriptors */
297		list_splice_tail_init(&mchan->active, &mchan->completed);
298		if (!list_empty(&mchan->queued))
299			mpc_dma_execute(mchan);
300
301		spin_unlock(&mchan->lock);
302	}
303}
304
305/* Interrupt handler */
306static irqreturn_t mpc_dma_irq(int irq, void *data)
307{
308	struct mpc_dma *mdma = data;
309	uint es;
310
311	/* Save error status register */
312	es = in_be32(&mdma->regs->dmaes);
313	spin_lock(&mdma->error_status_lock);
314	if ((es & MPC_DMA_DMAES_VLD) && mdma->error_status == 0)
315		mdma->error_status = es;
316	spin_unlock(&mdma->error_status_lock);
317
318	/* Handle interrupt on each channel */
319	if (mdma->dma.chancnt > 32) {
320		mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmainth),
321					in_be32(&mdma->regs->dmaerrh), 32);
322	}
323	mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmaintl),
324					in_be32(&mdma->regs->dmaerrl), 0);
325
326	/* Schedule tasklet */
327	tasklet_schedule(&mdma->tasklet);
328
329	return IRQ_HANDLED;
330}
331
332/* process completed descriptors */
333static void mpc_dma_process_completed(struct mpc_dma *mdma)
334{
335	dma_cookie_t last_cookie = 0;
336	struct mpc_dma_chan *mchan;
337	struct mpc_dma_desc *mdesc;
338	struct dma_async_tx_descriptor *desc;
339	unsigned long flags;
340	LIST_HEAD(list);
341	int i;
342
343	for (i = 0; i < mdma->dma.chancnt; i++) {
344		mchan = &mdma->channels[i];
345
346		/* Get all completed descriptors */
347		spin_lock_irqsave(&mchan->lock, flags);
348		if (!list_empty(&mchan->completed))
349			list_splice_tail_init(&mchan->completed, &list);
350		spin_unlock_irqrestore(&mchan->lock, flags);
351
352		if (list_empty(&list))
353			continue;
354
355		/* Execute callbacks and run dependencies */
356		list_for_each_entry(mdesc, &list, node) {
357			desc = &mdesc->desc;
358
359			if (desc->callback)
360				desc->callback(desc->callback_param);
361
362			last_cookie = desc->cookie;
363			dma_run_dependencies(desc);
364		}
365
366		/* Free descriptors */
367		spin_lock_irqsave(&mchan->lock, flags);
368		list_splice_tail_init(&list, &mchan->free);
369		mchan->chan.completed_cookie = last_cookie;
370		spin_unlock_irqrestore(&mchan->lock, flags);
371	}
372}
373
374/* DMA Tasklet */
375static void mpc_dma_tasklet(unsigned long data)
376{
377	struct mpc_dma *mdma = (void *)data;
378	unsigned long flags;
379	uint es;
380
381	spin_lock_irqsave(&mdma->error_status_lock, flags);
382	es = mdma->error_status;
383	mdma->error_status = 0;
384	spin_unlock_irqrestore(&mdma->error_status_lock, flags);
385
386	/* Print nice error report */
387	if (es) {
388		dev_err(mdma->dma.dev,
389			"Hardware reported following error(s) on channel %u:\n",
390						      MPC_DMA_DMAES_ERRCHN(es));
391
392		if (es & MPC_DMA_DMAES_GPE)
393			dev_err(mdma->dma.dev, "- Group Priority Error\n");
394		if (es & MPC_DMA_DMAES_CPE)
395			dev_err(mdma->dma.dev, "- Channel Priority Error\n");
396		if (es & MPC_DMA_DMAES_SAE)
397			dev_err(mdma->dma.dev, "- Source Address Error\n");
398		if (es & MPC_DMA_DMAES_SOE)
399			dev_err(mdma->dma.dev, "- Source Offset"
400						" Configuration Error\n");
401		if (es & MPC_DMA_DMAES_DAE)
402			dev_err(mdma->dma.dev, "- Destination Address"
403								" Error\n");
404		if (es & MPC_DMA_DMAES_DOE)
405			dev_err(mdma->dma.dev, "- Destination Offset"
406						" Configuration Error\n");
407		if (es & MPC_DMA_DMAES_NCE)
408			dev_err(mdma->dma.dev, "- NBytes/Citter"
409						" Configuration Error\n");
410		if (es & MPC_DMA_DMAES_SGE)
411			dev_err(mdma->dma.dev, "- Scatter/Gather"
412						" Configuration Error\n");
413		if (es & MPC_DMA_DMAES_SBE)
414			dev_err(mdma->dma.dev, "- Source Bus Error\n");
415		if (es & MPC_DMA_DMAES_DBE)
416			dev_err(mdma->dma.dev, "- Destination Bus Error\n");
417	}
418
419	mpc_dma_process_completed(mdma);
420}
421
422/* Submit descriptor to hardware */
423static dma_cookie_t mpc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
424{
425	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(txd->chan);
426	struct mpc_dma_desc *mdesc;
427	unsigned long flags;
428	dma_cookie_t cookie;
429
430	mdesc = container_of(txd, struct mpc_dma_desc, desc);
431
432	spin_lock_irqsave(&mchan->lock, flags);
433
434	/* Move descriptor to queue */
435	list_move_tail(&mdesc->node, &mchan->queued);
436
437	/* If channel is idle, execute all queued descriptors */
438	if (list_empty(&mchan->active))
439		mpc_dma_execute(mchan);
440
441	/* Update cookie */
442	cookie = dma_cookie_assign(txd);
443	spin_unlock_irqrestore(&mchan->lock, flags);
444
445	return cookie;
446}
447
448/* Alloc channel resources */
449static int mpc_dma_alloc_chan_resources(struct dma_chan *chan)
450{
451	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
452	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
453	struct mpc_dma_desc *mdesc;
454	struct mpc_dma_tcd *tcd;
455	dma_addr_t tcd_paddr;
456	unsigned long flags;
457	LIST_HEAD(descs);
458	int i;
459
460	/* Alloc DMA memory for Transfer Control Descriptors */
461	tcd = dma_alloc_coherent(mdma->dma.dev,
462			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
463							&tcd_paddr, GFP_KERNEL);
464	if (!tcd)
465		return -ENOMEM;
466
467	/* Alloc descriptors for this channel */
468	for (i = 0; i < MPC_DMA_DESCRIPTORS; i++) {
469		mdesc = kzalloc(sizeof(struct mpc_dma_desc), GFP_KERNEL);
470		if (!mdesc) {
471			dev_notice(mdma->dma.dev, "Memory allocation error. "
472					"Allocated only %u descriptors\n", i);
473			break;
474		}
475
476		dma_async_tx_descriptor_init(&mdesc->desc, chan);
477		mdesc->desc.flags = DMA_CTRL_ACK;
478		mdesc->desc.tx_submit = mpc_dma_tx_submit;
479
480		mdesc->tcd = &tcd[i];
481		mdesc->tcd_paddr = tcd_paddr + (i * sizeof(struct mpc_dma_tcd));
482
483		list_add_tail(&mdesc->node, &descs);
484	}
485
486	/* Return error only if no descriptors were allocated */
487	if (i == 0) {
488		dma_free_coherent(mdma->dma.dev,
489			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
490								tcd, tcd_paddr);
491		return -ENOMEM;
492	}
493
494	spin_lock_irqsave(&mchan->lock, flags);
495	mchan->tcd = tcd;
496	mchan->tcd_paddr = tcd_paddr;
497	list_splice_tail_init(&descs, &mchan->free);
498	spin_unlock_irqrestore(&mchan->lock, flags);
499
500	/* Enable Error Interrupt */
501	out_8(&mdma->regs->dmaseei, chan->chan_id);
502
503	return 0;
504}
505
506/* Free channel resources */
507static void mpc_dma_free_chan_resources(struct dma_chan *chan)
508{
509	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
510	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
511	struct mpc_dma_desc *mdesc, *tmp;
512	struct mpc_dma_tcd *tcd;
513	dma_addr_t tcd_paddr;
514	unsigned long flags;
515	LIST_HEAD(descs);
516
517	spin_lock_irqsave(&mchan->lock, flags);
518
519	/* Channel must be idle */
520	BUG_ON(!list_empty(&mchan->prepared));
521	BUG_ON(!list_empty(&mchan->queued));
522	BUG_ON(!list_empty(&mchan->active));
523	BUG_ON(!list_empty(&mchan->completed));
524
525	/* Move data */
526	list_splice_tail_init(&mchan->free, &descs);
527	tcd = mchan->tcd;
528	tcd_paddr = mchan->tcd_paddr;
529
530	spin_unlock_irqrestore(&mchan->lock, flags);
531
532	/* Free DMA memory used by descriptors */
533	dma_free_coherent(mdma->dma.dev,
534			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
535								tcd, tcd_paddr);
536
537	/* Free descriptors */
538	list_for_each_entry_safe(mdesc, tmp, &descs, node)
539		kfree(mdesc);
540
541	/* Disable Error Interrupt */
542	out_8(&mdma->regs->dmaceei, chan->chan_id);
543}
544
545/* Send all pending descriptor to hardware */
546static void mpc_dma_issue_pending(struct dma_chan *chan)
547{
548	/*
549	 * We are posting descriptors to the hardware as soon as
550	 * they are ready, so this function does nothing.
551	 */
552}
553
554/* Check request completion status */
555static enum dma_status
556mpc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
557	       struct dma_tx_state *txstate)
558{
559	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
560	enum dma_status ret;
561	unsigned long flags;
562
563	spin_lock_irqsave(&mchan->lock, flags);
564	ret = dma_cookie_status(chan, cookie, txstate);
565	spin_unlock_irqrestore(&mchan->lock, flags);
566
567	return ret;
568}
569
570/* Prepare descriptor for memory to memory copy */
571static struct dma_async_tx_descriptor *
572mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
573					size_t len, unsigned long flags)
574{
575	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
576	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
577	struct mpc_dma_desc *mdesc = NULL;
578	struct mpc_dma_tcd *tcd;
579	unsigned long iflags;
580
581	/* Get free descriptor */
582	spin_lock_irqsave(&mchan->lock, iflags);
583	if (!list_empty(&mchan->free)) {
584		mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc,
585									node);
586		list_del(&mdesc->node);
587	}
588	spin_unlock_irqrestore(&mchan->lock, iflags);
589
590	if (!mdesc) {
591		/* try to free completed descriptors */
592		mpc_dma_process_completed(mdma);
593		return NULL;
594	}
595
596	mdesc->error = 0;
597	tcd = mdesc->tcd;
598
599	/* Prepare Transfer Control Descriptor for this transaction */
600	memset(tcd, 0, sizeof(struct mpc_dma_tcd));
601
602	if (IS_ALIGNED(src | dst | len, 32)) {
603		tcd->ssize = MPC_DMA_TSIZE_32;
604		tcd->dsize = MPC_DMA_TSIZE_32;
605		tcd->soff = 32;
606		tcd->doff = 32;
607	} else if (!mdma->is_mpc8308 && IS_ALIGNED(src | dst | len, 16)) {
608		/* MPC8308 doesn't support 16 byte transfers */
609		tcd->ssize = MPC_DMA_TSIZE_16;
610		tcd->dsize = MPC_DMA_TSIZE_16;
611		tcd->soff = 16;
612		tcd->doff = 16;
613	} else if (IS_ALIGNED(src | dst | len, 4)) {
614		tcd->ssize = MPC_DMA_TSIZE_4;
615		tcd->dsize = MPC_DMA_TSIZE_4;
616		tcd->soff = 4;
617		tcd->doff = 4;
618	} else if (IS_ALIGNED(src | dst | len, 2)) {
619		tcd->ssize = MPC_DMA_TSIZE_2;
620		tcd->dsize = MPC_DMA_TSIZE_2;
621		tcd->soff = 2;
622		tcd->doff = 2;
623	} else {
624		tcd->ssize = MPC_DMA_TSIZE_1;
625		tcd->dsize = MPC_DMA_TSIZE_1;
626		tcd->soff = 1;
627		tcd->doff = 1;
628	}
629
630	tcd->saddr = src;
631	tcd->daddr = dst;
632	tcd->nbytes = len;
633	tcd->biter = 1;
634	tcd->citer = 1;
635
636	/* Place descriptor in prepared list */
637	spin_lock_irqsave(&mchan->lock, iflags);
638	list_add_tail(&mdesc->node, &mchan->prepared);
639	spin_unlock_irqrestore(&mchan->lock, iflags);
640
641	return &mdesc->desc;
642}
643
644static int mpc_dma_probe(struct platform_device *op)
645{
646	struct device_node *dn = op->dev.of_node;
647	struct device *dev = &op->dev;
648	struct dma_device *dma;
649	struct mpc_dma *mdma;
650	struct mpc_dma_chan *mchan;
651	struct resource res;
652	ulong regs_start, regs_size;
653	int retval, i;
654
655	mdma = devm_kzalloc(dev, sizeof(struct mpc_dma), GFP_KERNEL);
656	if (!mdma) {
657		dev_err(dev, "Memory exhausted!\n");
658		return -ENOMEM;
659	}
660
661	mdma->irq = irq_of_parse_and_map(dn, 0);
662	if (mdma->irq == NO_IRQ) {
663		dev_err(dev, "Error mapping IRQ!\n");
664		return -EINVAL;
665	}
666
667	if (of_device_is_compatible(dn, "fsl,mpc8308-dma")) {
668		mdma->is_mpc8308 = 1;
669		mdma->irq2 = irq_of_parse_and_map(dn, 1);
670		if (mdma->irq2 == NO_IRQ) {
671			dev_err(dev, "Error mapping IRQ!\n");
672			return -EINVAL;
673		}
674	}
675
676	retval = of_address_to_resource(dn, 0, &res);
677	if (retval) {
678		dev_err(dev, "Error parsing memory region!\n");
679		return retval;
680	}
681
682	regs_start = res.start;
683	regs_size = resource_size(&res);
684
685	if (!devm_request_mem_region(dev, regs_start, regs_size, DRV_NAME)) {
686		dev_err(dev, "Error requesting memory region!\n");
687		return -EBUSY;
688	}
689
690	mdma->regs = devm_ioremap(dev, regs_start, regs_size);
691	if (!mdma->regs) {
692		dev_err(dev, "Error mapping memory region!\n");
693		return -ENOMEM;
694	}
695
696	mdma->tcd = (struct mpc_dma_tcd *)((u8 *)(mdma->regs)
697							+ MPC_DMA_TCD_OFFSET);
698
699	retval = devm_request_irq(dev, mdma->irq, &mpc_dma_irq, 0, DRV_NAME,
700									mdma);
701	if (retval) {
702		dev_err(dev, "Error requesting IRQ!\n");
703		return -EINVAL;
704	}
705
706	if (mdma->is_mpc8308) {
707		retval = devm_request_irq(dev, mdma->irq2, &mpc_dma_irq, 0,
708				DRV_NAME, mdma);
709		if (retval) {
710			dev_err(dev, "Error requesting IRQ2!\n");
711			return -EINVAL;
712		}
713	}
714
715	spin_lock_init(&mdma->error_status_lock);
716
717	dma = &mdma->dma;
718	dma->dev = dev;
719	if (!mdma->is_mpc8308)
720		dma->chancnt = MPC_DMA_CHANNELS;
721	else
722		dma->chancnt = 16; /* MPC8308 DMA has only 16 channels */
723	dma->device_alloc_chan_resources = mpc_dma_alloc_chan_resources;
724	dma->device_free_chan_resources = mpc_dma_free_chan_resources;
725	dma->device_issue_pending = mpc_dma_issue_pending;
726	dma->device_tx_status = mpc_dma_tx_status;
727	dma->device_prep_dma_memcpy = mpc_dma_prep_memcpy;
728
729	INIT_LIST_HEAD(&dma->channels);
730	dma_cap_set(DMA_MEMCPY, dma->cap_mask);
731
732	for (i = 0; i < dma->chancnt; i++) {
733		mchan = &mdma->channels[i];
734
735		mchan->chan.device = dma;
736		dma_cookie_init(&mchan->chan);
737
738		INIT_LIST_HEAD(&mchan->free);
739		INIT_LIST_HEAD(&mchan->prepared);
740		INIT_LIST_HEAD(&mchan->queued);
741		INIT_LIST_HEAD(&mchan->active);
742		INIT_LIST_HEAD(&mchan->completed);
743
744		spin_lock_init(&mchan->lock);
745		list_add_tail(&mchan->chan.device_node, &dma->channels);
746	}
747
748	tasklet_init(&mdma->tasklet, mpc_dma_tasklet, (unsigned long)mdma);
749
750	/*
751	 * Configure DMA Engine:
752	 * - Dynamic clock,
753	 * - Round-robin group arbitration,
754	 * - Round-robin channel arbitration.
755	 */
756	if (!mdma->is_mpc8308) {
757		out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_EDCG |
758					MPC_DMA_DMACR_ERGA | MPC_DMA_DMACR_ERCA);
759
760		/* Disable hardware DMA requests */
761		out_be32(&mdma->regs->dmaerqh, 0);
762		out_be32(&mdma->regs->dmaerql, 0);
763
764		/* Disable error interrupts */
765		out_be32(&mdma->regs->dmaeeih, 0);
766		out_be32(&mdma->regs->dmaeeil, 0);
767
768		/* Clear interrupts status */
769		out_be32(&mdma->regs->dmainth, 0xFFFFFFFF);
770		out_be32(&mdma->regs->dmaintl, 0xFFFFFFFF);
771		out_be32(&mdma->regs->dmaerrh, 0xFFFFFFFF);
772		out_be32(&mdma->regs->dmaerrl, 0xFFFFFFFF);
773
774		/* Route interrupts to IPIC */
775		out_be32(&mdma->regs->dmaihsa, 0);
776		out_be32(&mdma->regs->dmailsa, 0);
777	} else {
778		/* MPC8308 has 16 channels and lacks some registers */
779		out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA);
780
781		/* enable snooping */
782		out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE);
783		/* Disable error interrupts */
784		out_be32(&mdma->regs->dmaeeil, 0);
785
786		/* Clear interrupts status */
787		out_be32(&mdma->regs->dmaintl, 0xFFFF);
788		out_be32(&mdma->regs->dmaerrl, 0xFFFF);
789	}
790
791	/* Register DMA engine */
792	dev_set_drvdata(dev, mdma);
793	retval = dma_async_device_register(dma);
794	if (retval) {
795		devm_free_irq(dev, mdma->irq, mdma);
796		irq_dispose_mapping(mdma->irq);
797	}
798
799	return retval;
800}
801
802static int __devexit mpc_dma_remove(struct platform_device *op)
803{
804	struct device *dev = &op->dev;
805	struct mpc_dma *mdma = dev_get_drvdata(dev);
806
807	dma_async_device_unregister(&mdma->dma);
808	devm_free_irq(dev, mdma->irq, mdma);
809	irq_dispose_mapping(mdma->irq);
810
811	return 0;
812}
813
814static struct of_device_id mpc_dma_match[] = {
815	{ .compatible = "fsl,mpc5121-dma", },
816	{},
817};
818
819static struct platform_driver mpc_dma_driver = {
820	.probe		= mpc_dma_probe,
821	.remove		= mpc_dma_remove,
822	.driver = {
823		.name = DRV_NAME,
824		.owner = THIS_MODULE,
825		.of_match_table	= mpc_dma_match,
826	},
827};
828
829module_platform_driver(mpc_dma_driver);
830
831MODULE_LICENSE("GPL");
832MODULE_AUTHOR("Piotr Ziecik <kosmo@semihalf.com>");
833