staging: add dependencies on PCI for drivers that require it
[linux-2.6.git] / drivers / dma / dw_dmac.c
1 /*
2  * Driver for the Synopsys DesignWare DMA Controller (aka DMACA on
3  * AVR32 systems.)
4  *
5  * Copyright (C) 2007-2008 Atmel Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/clk.h>
12 #include <linux/delay.h>
13 #include <linux/dmaengine.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/mm.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22
23 #include "dw_dmac_regs.h"
24
25 /*
26  * This supports the Synopsys "DesignWare AHB Central DMA Controller",
27  * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all
28  * of which use ARM any more).  See the "Databook" from Synopsys for
29  * information beyond what licensees probably provide.
30  *
31  * The driver has currently been tested only with the Atmel AT32AP7000,
32  * which does not support descriptor writeback.
33  */
34
35 /* NOTE:  DMS+SMS is system-specific. We should get this information
36  * from the platform code somehow.
37  */
38 #define DWC_DEFAULT_CTLLO       (DWC_CTLL_DST_MSIZE(0)          \
39                                 | DWC_CTLL_SRC_MSIZE(0)         \
40                                 | DWC_CTLL_DMS(0)               \
41                                 | DWC_CTLL_SMS(1)               \
42                                 | DWC_CTLL_LLP_D_EN             \
43                                 | DWC_CTLL_LLP_S_EN)
44
45 /*
46  * This is configuration-dependent and usually a funny size like 4095.
47  * Let's round it down to the nearest power of two.
48  *
49  * Note that this is a transfer count, i.e. if we transfer 32-bit
50  * words, we can do 8192 bytes per descriptor.
51  *
52  * This parameter is also system-specific.
53  */
54 #define DWC_MAX_COUNT   2048U
55
56 /*
57  * Number of descriptors to allocate for each channel. This should be
58  * made configurable somehow; preferably, the clients (at least the
59  * ones using slave transfers) should be able to give us a hint.
60  */
61 #define NR_DESCS_PER_CHANNEL    64
62
63 /*----------------------------------------------------------------------*/
64
65 /*
66  * Because we're not relying on writeback from the controller (it may not
67  * even be configured into the core!) we don't need to use dma_pool.  These
68  * descriptors -- and associated data -- are cacheable.  We do need to make
69  * sure their dcache entries are written back before handing them off to
70  * the controller, though.
71  */
72
73 static struct device *chan2dev(struct dma_chan *chan)
74 {
75         return &chan->dev->device;
76 }
77 static struct device *chan2parent(struct dma_chan *chan)
78 {
79         return chan->dev->device.parent;
80 }
81
82 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
83 {
84         return list_entry(dwc->active_list.next, struct dw_desc, desc_node);
85 }
86
87 static struct dw_desc *dwc_first_queued(struct dw_dma_chan *dwc)
88 {
89         return list_entry(dwc->queue.next, struct dw_desc, desc_node);
90 }
91
92 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
93 {
94         struct dw_desc *desc, *_desc;
95         struct dw_desc *ret = NULL;
96         unsigned int i = 0;
97
98         spin_lock_bh(&dwc->lock);
99         list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
100                 if (async_tx_test_ack(&desc->txd)) {
101                         list_del(&desc->desc_node);
102                         ret = desc;
103                         break;
104                 }
105                 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
106                 i++;
107         }
108         spin_unlock_bh(&dwc->lock);
109
110         dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
111
112         return ret;
113 }
114
115 static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc)
116 {
117         struct dw_desc  *child;
118
119         list_for_each_entry(child, &desc->txd.tx_list, desc_node)
120                 dma_sync_single_for_cpu(chan2parent(&dwc->chan),
121                                 child->txd.phys, sizeof(child->lli),
122                                 DMA_TO_DEVICE);
123         dma_sync_single_for_cpu(chan2parent(&dwc->chan),
124                         desc->txd.phys, sizeof(desc->lli),
125                         DMA_TO_DEVICE);
126 }
127
128 /*
129  * Move a descriptor, including any children, to the free list.
130  * `desc' must not be on any lists.
131  */
132 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
133 {
134         if (desc) {
135                 struct dw_desc *child;
136
137                 dwc_sync_desc_for_cpu(dwc, desc);
138
139                 spin_lock_bh(&dwc->lock);
140                 list_for_each_entry(child, &desc->txd.tx_list, desc_node)
141                         dev_vdbg(chan2dev(&dwc->chan),
142                                         "moving child desc %p to freelist\n",
143                                         child);
144                 list_splice_init(&desc->txd.tx_list, &dwc->free_list);
145                 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
146                 list_add(&desc->desc_node, &dwc->free_list);
147                 spin_unlock_bh(&dwc->lock);
148         }
149 }
150
151 /* Called with dwc->lock held and bh disabled */
152 static dma_cookie_t
153 dwc_assign_cookie(struct dw_dma_chan *dwc, struct dw_desc *desc)
154 {
155         dma_cookie_t cookie = dwc->chan.cookie;
156
157         if (++cookie < 0)
158                 cookie = 1;
159
160         dwc->chan.cookie = cookie;
161         desc->txd.cookie = cookie;
162
163         return cookie;
164 }
165
166 /*----------------------------------------------------------------------*/
167
168 /* Called with dwc->lock held and bh disabled */
169 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
170 {
171         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
172
173         /* ASSERT:  channel is idle */
174         if (dma_readl(dw, CH_EN) & dwc->mask) {
175                 dev_err(chan2dev(&dwc->chan),
176                         "BUG: Attempted to start non-idle channel\n");
177                 dev_err(chan2dev(&dwc->chan),
178                         "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
179                         channel_readl(dwc, SAR),
180                         channel_readl(dwc, DAR),
181                         channel_readl(dwc, LLP),
182                         channel_readl(dwc, CTL_HI),
183                         channel_readl(dwc, CTL_LO));
184
185                 /* The tasklet will hopefully advance the queue... */
186                 return;
187         }
188
189         channel_writel(dwc, LLP, first->txd.phys);
190         channel_writel(dwc, CTL_LO,
191                         DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
192         channel_writel(dwc, CTL_HI, 0);
193         channel_set_bit(dw, CH_EN, dwc->mask);
194 }
195
196 /*----------------------------------------------------------------------*/
197
198 static void
199 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc)
200 {
201         dma_async_tx_callback           callback;
202         void                            *param;
203         struct dma_async_tx_descriptor  *txd = &desc->txd;
204
205         dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
206
207         dwc->completed = txd->cookie;
208         callback = txd->callback;
209         param = txd->callback_param;
210
211         dwc_sync_desc_for_cpu(dwc, desc);
212         list_splice_init(&txd->tx_list, &dwc->free_list);
213         list_move(&desc->desc_node, &dwc->free_list);
214
215         /*
216          * We use dma_unmap_page() regardless of how the buffers were
217          * mapped before they were submitted...
218          */
219         if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP))
220                 dma_unmap_page(chan2parent(&dwc->chan), desc->lli.dar,
221                                desc->len, DMA_FROM_DEVICE);
222         if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP))
223                 dma_unmap_page(chan2parent(&dwc->chan), desc->lli.sar,
224                                desc->len, DMA_TO_DEVICE);
225
226         /*
227          * The API requires that no submissions are done from a
228          * callback, so we don't need to drop the lock here
229          */
230         if (callback)
231                 callback(param);
232 }
233
234 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
235 {
236         struct dw_desc *desc, *_desc;
237         LIST_HEAD(list);
238
239         if (dma_readl(dw, CH_EN) & dwc->mask) {
240                 dev_err(chan2dev(&dwc->chan),
241                         "BUG: XFER bit set, but channel not idle!\n");
242
243                 /* Try to continue after resetting the channel... */
244                 channel_clear_bit(dw, CH_EN, dwc->mask);
245                 while (dma_readl(dw, CH_EN) & dwc->mask)
246                         cpu_relax();
247         }
248
249         /*
250          * Submit queued descriptors ASAP, i.e. before we go through
251          * the completed ones.
252          */
253         if (!list_empty(&dwc->queue))
254                 dwc_dostart(dwc, dwc_first_queued(dwc));
255         list_splice_init(&dwc->active_list, &list);
256         list_splice_init(&dwc->queue, &dwc->active_list);
257
258         list_for_each_entry_safe(desc, _desc, &list, desc_node)
259                 dwc_descriptor_complete(dwc, desc);
260 }
261
262 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
263 {
264         dma_addr_t llp;
265         struct dw_desc *desc, *_desc;
266         struct dw_desc *child;
267         u32 status_xfer;
268
269         /*
270          * Clear block interrupt flag before scanning so that we don't
271          * miss any, and read LLP before RAW_XFER to ensure it is
272          * valid if we decide to scan the list.
273          */
274         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
275         llp = channel_readl(dwc, LLP);
276         status_xfer = dma_readl(dw, RAW.XFER);
277
278         if (status_xfer & dwc->mask) {
279                 /* Everything we've submitted is done */
280                 dma_writel(dw, CLEAR.XFER, dwc->mask);
281                 dwc_complete_all(dw, dwc);
282                 return;
283         }
284
285         dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
286
287         list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
288                 if (desc->lli.llp == llp)
289                         /* This one is currently in progress */
290                         return;
291
292                 list_for_each_entry(child, &desc->txd.tx_list, desc_node)
293                         if (child->lli.llp == llp)
294                                 /* Currently in progress */
295                                 return;
296
297                 /*
298                  * No descriptors so far seem to be in progress, i.e.
299                  * this one must be done.
300                  */
301                 dwc_descriptor_complete(dwc, desc);
302         }
303
304         dev_err(chan2dev(&dwc->chan),
305                 "BUG: All descriptors done, but channel not idle!\n");
306
307         /* Try to continue after resetting the channel... */
308         channel_clear_bit(dw, CH_EN, dwc->mask);
309         while (dma_readl(dw, CH_EN) & dwc->mask)
310                 cpu_relax();
311
312         if (!list_empty(&dwc->queue)) {
313                 dwc_dostart(dwc, dwc_first_queued(dwc));
314                 list_splice_init(&dwc->queue, &dwc->active_list);
315         }
316 }
317
318 static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
319 {
320         dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
321                         "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
322                         lli->sar, lli->dar, lli->llp,
323                         lli->ctlhi, lli->ctllo);
324 }
325
326 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
327 {
328         struct dw_desc *bad_desc;
329         struct dw_desc *child;
330
331         dwc_scan_descriptors(dw, dwc);
332
333         /*
334          * The descriptor currently at the head of the active list is
335          * borked. Since we don't have any way to report errors, we'll
336          * just have to scream loudly and try to carry on.
337          */
338         bad_desc = dwc_first_active(dwc);
339         list_del_init(&bad_desc->desc_node);
340         list_splice_init(&dwc->queue, dwc->active_list.prev);
341
342         /* Clear the error flag and try to restart the controller */
343         dma_writel(dw, CLEAR.ERROR, dwc->mask);
344         if (!list_empty(&dwc->active_list))
345                 dwc_dostart(dwc, dwc_first_active(dwc));
346
347         /*
348          * KERN_CRITICAL may seem harsh, but since this only happens
349          * when someone submits a bad physical address in a
350          * descriptor, we should consider ourselves lucky that the
351          * controller flagged an error instead of scribbling over
352          * random memory locations.
353          */
354         dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
355                         "Bad descriptor submitted for DMA!\n");
356         dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
357                         "  cookie: %d\n", bad_desc->txd.cookie);
358         dwc_dump_lli(dwc, &bad_desc->lli);
359         list_for_each_entry(child, &bad_desc->txd.tx_list, desc_node)
360                 dwc_dump_lli(dwc, &child->lli);
361
362         /* Pretend the descriptor completed successfully */
363         dwc_descriptor_complete(dwc, bad_desc);
364 }
365
366 /* --------------------- Cyclic DMA API extensions -------------------- */
367
368 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
369 {
370         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
371         return channel_readl(dwc, SAR);
372 }
373 EXPORT_SYMBOL(dw_dma_get_src_addr);
374
375 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
376 {
377         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
378         return channel_readl(dwc, DAR);
379 }
380 EXPORT_SYMBOL(dw_dma_get_dst_addr);
381
382 /* called with dwc->lock held and all DMAC interrupts disabled */
383 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
384                 u32 status_block, u32 status_err, u32 status_xfer)
385 {
386         if (status_block & dwc->mask) {
387                 void (*callback)(void *param);
388                 void *callback_param;
389
390                 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
391                                 channel_readl(dwc, LLP));
392                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
393
394                 callback = dwc->cdesc->period_callback;
395                 callback_param = dwc->cdesc->period_callback_param;
396                 if (callback) {
397                         spin_unlock(&dwc->lock);
398                         callback(callback_param);
399                         spin_lock(&dwc->lock);
400                 }
401         }
402
403         /*
404          * Error and transfer complete are highly unlikely, and will most
405          * likely be due to a configuration error by the user.
406          */
407         if (unlikely(status_err & dwc->mask) ||
408                         unlikely(status_xfer & dwc->mask)) {
409                 int i;
410
411                 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
412                                 "interrupt, stopping DMA transfer\n",
413                                 status_xfer ? "xfer" : "error");
414                 dev_err(chan2dev(&dwc->chan),
415                         "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
416                         channel_readl(dwc, SAR),
417                         channel_readl(dwc, DAR),
418                         channel_readl(dwc, LLP),
419                         channel_readl(dwc, CTL_HI),
420                         channel_readl(dwc, CTL_LO));
421
422                 channel_clear_bit(dw, CH_EN, dwc->mask);
423                 while (dma_readl(dw, CH_EN) & dwc->mask)
424                         cpu_relax();
425
426                 /* make sure DMA does not restart by loading a new list */
427                 channel_writel(dwc, LLP, 0);
428                 channel_writel(dwc, CTL_LO, 0);
429                 channel_writel(dwc, CTL_HI, 0);
430
431                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
432                 dma_writel(dw, CLEAR.ERROR, dwc->mask);
433                 dma_writel(dw, CLEAR.XFER, dwc->mask);
434
435                 for (i = 0; i < dwc->cdesc->periods; i++)
436                         dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
437         }
438 }
439
440 /* ------------------------------------------------------------------------- */
441
442 static void dw_dma_tasklet(unsigned long data)
443 {
444         struct dw_dma *dw = (struct dw_dma *)data;
445         struct dw_dma_chan *dwc;
446         u32 status_block;
447         u32 status_xfer;
448         u32 status_err;
449         int i;
450
451         status_block = dma_readl(dw, RAW.BLOCK);
452         status_xfer = dma_readl(dw, RAW.XFER);
453         status_err = dma_readl(dw, RAW.ERROR);
454
455         dev_vdbg(dw->dma.dev, "tasklet: status_block=%x status_err=%x\n",
456                         status_block, status_err);
457
458         for (i = 0; i < dw->dma.chancnt; i++) {
459                 dwc = &dw->chan[i];
460                 spin_lock(&dwc->lock);
461                 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
462                         dwc_handle_cyclic(dw, dwc, status_block, status_err,
463                                         status_xfer);
464                 else if (status_err & (1 << i))
465                         dwc_handle_error(dw, dwc);
466                 else if ((status_block | status_xfer) & (1 << i))
467                         dwc_scan_descriptors(dw, dwc);
468                 spin_unlock(&dwc->lock);
469         }
470
471         /*
472          * Re-enable interrupts. Block Complete interrupts are only
473          * enabled if the INT_EN bit in the descriptor is set. This
474          * will trigger a scan before the whole list is done.
475          */
476         channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
477         channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask);
478         channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
479 }
480
481 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
482 {
483         struct dw_dma *dw = dev_id;
484         u32 status;
485
486         dev_vdbg(dw->dma.dev, "interrupt: status=0x%x\n",
487                         dma_readl(dw, STATUS_INT));
488
489         /*
490          * Just disable the interrupts. We'll turn them back on in the
491          * softirq handler.
492          */
493         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
494         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
495         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
496
497         status = dma_readl(dw, STATUS_INT);
498         if (status) {
499                 dev_err(dw->dma.dev,
500                         "BUG: Unexpected interrupts pending: 0x%x\n",
501                         status);
502
503                 /* Try to recover */
504                 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
505                 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
506                 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
507                 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
508                 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
509         }
510
511         tasklet_schedule(&dw->tasklet);
512
513         return IRQ_HANDLED;
514 }
515
516 /*----------------------------------------------------------------------*/
517
518 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
519 {
520         struct dw_desc          *desc = txd_to_dw_desc(tx);
521         struct dw_dma_chan      *dwc = to_dw_dma_chan(tx->chan);
522         dma_cookie_t            cookie;
523
524         spin_lock_bh(&dwc->lock);
525         cookie = dwc_assign_cookie(dwc, desc);
526
527         /*
528          * REVISIT: We should attempt to chain as many descriptors as
529          * possible, perhaps even appending to those already submitted
530          * for DMA. But this is hard to do in a race-free manner.
531          */
532         if (list_empty(&dwc->active_list)) {
533                 dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
534                                 desc->txd.cookie);
535                 dwc_dostart(dwc, desc);
536                 list_add_tail(&desc->desc_node, &dwc->active_list);
537         } else {
538                 dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
539                                 desc->txd.cookie);
540
541                 list_add_tail(&desc->desc_node, &dwc->queue);
542         }
543
544         spin_unlock_bh(&dwc->lock);
545
546         return cookie;
547 }
548
549 static struct dma_async_tx_descriptor *
550 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
551                 size_t len, unsigned long flags)
552 {
553         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
554         struct dw_desc          *desc;
555         struct dw_desc          *first;
556         struct dw_desc          *prev;
557         size_t                  xfer_count;
558         size_t                  offset;
559         unsigned int            src_width;
560         unsigned int            dst_width;
561         u32                     ctllo;
562
563         dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
564                         dest, src, len, flags);
565
566         if (unlikely(!len)) {
567                 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
568                 return NULL;
569         }
570
571         /*
572          * We can be a lot more clever here, but this should take care
573          * of the most common optimization.
574          */
575         if (!((src | dest  | len) & 3))
576                 src_width = dst_width = 2;
577         else if (!((src | dest | len) & 1))
578                 src_width = dst_width = 1;
579         else
580                 src_width = dst_width = 0;
581
582         ctllo = DWC_DEFAULT_CTLLO
583                         | DWC_CTLL_DST_WIDTH(dst_width)
584                         | DWC_CTLL_SRC_WIDTH(src_width)
585                         | DWC_CTLL_DST_INC
586                         | DWC_CTLL_SRC_INC
587                         | DWC_CTLL_FC_M2M;
588         prev = first = NULL;
589
590         for (offset = 0; offset < len; offset += xfer_count << src_width) {
591                 xfer_count = min_t(size_t, (len - offset) >> src_width,
592                                 DWC_MAX_COUNT);
593
594                 desc = dwc_desc_get(dwc);
595                 if (!desc)
596                         goto err_desc_get;
597
598                 desc->lli.sar = src + offset;
599                 desc->lli.dar = dest + offset;
600                 desc->lli.ctllo = ctllo;
601                 desc->lli.ctlhi = xfer_count;
602
603                 if (!first) {
604                         first = desc;
605                 } else {
606                         prev->lli.llp = desc->txd.phys;
607                         dma_sync_single_for_device(chan2parent(chan),
608                                         prev->txd.phys, sizeof(prev->lli),
609                                         DMA_TO_DEVICE);
610                         list_add_tail(&desc->desc_node,
611                                         &first->txd.tx_list);
612                 }
613                 prev = desc;
614         }
615
616
617         if (flags & DMA_PREP_INTERRUPT)
618                 /* Trigger interrupt after last block */
619                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
620
621         prev->lli.llp = 0;
622         dma_sync_single_for_device(chan2parent(chan),
623                         prev->txd.phys, sizeof(prev->lli),
624                         DMA_TO_DEVICE);
625
626         first->txd.flags = flags;
627         first->len = len;
628
629         return &first->txd;
630
631 err_desc_get:
632         dwc_desc_put(dwc, first);
633         return NULL;
634 }
635
636 static struct dma_async_tx_descriptor *
637 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
638                 unsigned int sg_len, enum dma_data_direction direction,
639                 unsigned long flags)
640 {
641         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
642         struct dw_dma_slave     *dws = chan->private;
643         struct dw_desc          *prev;
644         struct dw_desc          *first;
645         u32                     ctllo;
646         dma_addr_t              reg;
647         unsigned int            reg_width;
648         unsigned int            mem_width;
649         unsigned int            i;
650         struct scatterlist      *sg;
651         size_t                  total_len = 0;
652
653         dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
654
655         if (unlikely(!dws || !sg_len))
656                 return NULL;
657
658         reg_width = dws->reg_width;
659         prev = first = NULL;
660
661         sg_len = dma_map_sg(chan2parent(chan), sgl, sg_len, direction);
662
663         switch (direction) {
664         case DMA_TO_DEVICE:
665                 ctllo = (DWC_DEFAULT_CTLLO
666                                 | DWC_CTLL_DST_WIDTH(reg_width)
667                                 | DWC_CTLL_DST_FIX
668                                 | DWC_CTLL_SRC_INC
669                                 | DWC_CTLL_FC_M2P);
670                 reg = dws->tx_reg;
671                 for_each_sg(sgl, sg, sg_len, i) {
672                         struct dw_desc  *desc;
673                         u32             len;
674                         u32             mem;
675
676                         desc = dwc_desc_get(dwc);
677                         if (!desc) {
678                                 dev_err(chan2dev(chan),
679                                         "not enough descriptors available\n");
680                                 goto err_desc_get;
681                         }
682
683                         mem = sg_phys(sg);
684                         len = sg_dma_len(sg);
685                         mem_width = 2;
686                         if (unlikely(mem & 3 || len & 3))
687                                 mem_width = 0;
688
689                         desc->lli.sar = mem;
690                         desc->lli.dar = reg;
691                         desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
692                         desc->lli.ctlhi = len >> mem_width;
693
694                         if (!first) {
695                                 first = desc;
696                         } else {
697                                 prev->lli.llp = desc->txd.phys;
698                                 dma_sync_single_for_device(chan2parent(chan),
699                                                 prev->txd.phys,
700                                                 sizeof(prev->lli),
701                                                 DMA_TO_DEVICE);
702                                 list_add_tail(&desc->desc_node,
703                                                 &first->txd.tx_list);
704                         }
705                         prev = desc;
706                         total_len += len;
707                 }
708                 break;
709         case DMA_FROM_DEVICE:
710                 ctllo = (DWC_DEFAULT_CTLLO
711                                 | DWC_CTLL_SRC_WIDTH(reg_width)
712                                 | DWC_CTLL_DST_INC
713                                 | DWC_CTLL_SRC_FIX
714                                 | DWC_CTLL_FC_P2M);
715
716                 reg = dws->rx_reg;
717                 for_each_sg(sgl, sg, sg_len, i) {
718                         struct dw_desc  *desc;
719                         u32             len;
720                         u32             mem;
721
722                         desc = dwc_desc_get(dwc);
723                         if (!desc) {
724                                 dev_err(chan2dev(chan),
725                                         "not enough descriptors available\n");
726                                 goto err_desc_get;
727                         }
728
729                         mem = sg_phys(sg);
730                         len = sg_dma_len(sg);
731                         mem_width = 2;
732                         if (unlikely(mem & 3 || len & 3))
733                                 mem_width = 0;
734
735                         desc->lli.sar = reg;
736                         desc->lli.dar = mem;
737                         desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
738                         desc->lli.ctlhi = len >> reg_width;
739
740                         if (!first) {
741                                 first = desc;
742                         } else {
743                                 prev->lli.llp = desc->txd.phys;
744                                 dma_sync_single_for_device(chan2parent(chan),
745                                                 prev->txd.phys,
746                                                 sizeof(prev->lli),
747                                                 DMA_TO_DEVICE);
748                                 list_add_tail(&desc->desc_node,
749                                                 &first->txd.tx_list);
750                         }
751                         prev = desc;
752                         total_len += len;
753                 }
754                 break;
755         default:
756                 return NULL;
757         }
758
759         if (flags & DMA_PREP_INTERRUPT)
760                 /* Trigger interrupt after last block */
761                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
762
763         prev->lli.llp = 0;
764         dma_sync_single_for_device(chan2parent(chan),
765                         prev->txd.phys, sizeof(prev->lli),
766                         DMA_TO_DEVICE);
767
768         first->len = total_len;
769
770         return &first->txd;
771
772 err_desc_get:
773         dwc_desc_put(dwc, first);
774         return NULL;
775 }
776
777 static void dwc_terminate_all(struct dma_chan *chan)
778 {
779         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
780         struct dw_dma           *dw = to_dw_dma(chan->device);
781         struct dw_desc          *desc, *_desc;
782         LIST_HEAD(list);
783
784         /*
785          * This is only called when something went wrong elsewhere, so
786          * we don't really care about the data. Just disable the
787          * channel. We still have to poll the channel enable bit due
788          * to AHB/HSB limitations.
789          */
790         spin_lock_bh(&dwc->lock);
791
792         channel_clear_bit(dw, CH_EN, dwc->mask);
793
794         while (dma_readl(dw, CH_EN) & dwc->mask)
795                 cpu_relax();
796
797         /* active_list entries will end up before queued entries */
798         list_splice_init(&dwc->queue, &list);
799         list_splice_init(&dwc->active_list, &list);
800
801         spin_unlock_bh(&dwc->lock);
802
803         /* Flush all pending and queued descriptors */
804         list_for_each_entry_safe(desc, _desc, &list, desc_node)
805                 dwc_descriptor_complete(dwc, desc);
806 }
807
808 static enum dma_status
809 dwc_is_tx_complete(struct dma_chan *chan,
810                 dma_cookie_t cookie,
811                 dma_cookie_t *done, dma_cookie_t *used)
812 {
813         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
814         dma_cookie_t            last_used;
815         dma_cookie_t            last_complete;
816         int                     ret;
817
818         last_complete = dwc->completed;
819         last_used = chan->cookie;
820
821         ret = dma_async_is_complete(cookie, last_complete, last_used);
822         if (ret != DMA_SUCCESS) {
823                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
824
825                 last_complete = dwc->completed;
826                 last_used = chan->cookie;
827
828                 ret = dma_async_is_complete(cookie, last_complete, last_used);
829         }
830
831         if (done)
832                 *done = last_complete;
833         if (used)
834                 *used = last_used;
835
836         return ret;
837 }
838
839 static void dwc_issue_pending(struct dma_chan *chan)
840 {
841         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
842
843         spin_lock_bh(&dwc->lock);
844         if (!list_empty(&dwc->queue))
845                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
846         spin_unlock_bh(&dwc->lock);
847 }
848
849 static int dwc_alloc_chan_resources(struct dma_chan *chan)
850 {
851         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
852         struct dw_dma           *dw = to_dw_dma(chan->device);
853         struct dw_desc          *desc;
854         struct dw_dma_slave     *dws;
855         int                     i;
856         u32                     cfghi;
857         u32                     cfglo;
858
859         dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
860
861         /* ASSERT:  channel is idle */
862         if (dma_readl(dw, CH_EN) & dwc->mask) {
863                 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
864                 return -EIO;
865         }
866
867         dwc->completed = chan->cookie = 1;
868
869         cfghi = DWC_CFGH_FIFO_MODE;
870         cfglo = 0;
871
872         dws = chan->private;
873         if (dws) {
874                 /*
875                  * We need controller-specific data to set up slave
876                  * transfers.
877                  */
878                 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
879
880                 cfghi = dws->cfg_hi;
881                 cfglo = dws->cfg_lo;
882         }
883         channel_writel(dwc, CFG_LO, cfglo);
884         channel_writel(dwc, CFG_HI, cfghi);
885
886         /*
887          * NOTE: some controllers may have additional features that we
888          * need to initialize here, like "scatter-gather" (which
889          * doesn't mean what you think it means), and status writeback.
890          */
891
892         spin_lock_bh(&dwc->lock);
893         i = dwc->descs_allocated;
894         while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
895                 spin_unlock_bh(&dwc->lock);
896
897                 desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
898                 if (!desc) {
899                         dev_info(chan2dev(chan),
900                                 "only allocated %d descriptors\n", i);
901                         spin_lock_bh(&dwc->lock);
902                         break;
903                 }
904
905                 dma_async_tx_descriptor_init(&desc->txd, chan);
906                 desc->txd.tx_submit = dwc_tx_submit;
907                 desc->txd.flags = DMA_CTRL_ACK;
908                 desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,
909                                 sizeof(desc->lli), DMA_TO_DEVICE);
910                 dwc_desc_put(dwc, desc);
911
912                 spin_lock_bh(&dwc->lock);
913                 i = ++dwc->descs_allocated;
914         }
915
916         /* Enable interrupts */
917         channel_set_bit(dw, MASK.XFER, dwc->mask);
918         channel_set_bit(dw, MASK.BLOCK, dwc->mask);
919         channel_set_bit(dw, MASK.ERROR, dwc->mask);
920
921         spin_unlock_bh(&dwc->lock);
922
923         dev_dbg(chan2dev(chan),
924                 "alloc_chan_resources allocated %d descriptors\n", i);
925
926         return i;
927 }
928
929 static void dwc_free_chan_resources(struct dma_chan *chan)
930 {
931         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
932         struct dw_dma           *dw = to_dw_dma(chan->device);
933         struct dw_desc          *desc, *_desc;
934         LIST_HEAD(list);
935
936         dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
937                         dwc->descs_allocated);
938
939         /* ASSERT:  channel is idle */
940         BUG_ON(!list_empty(&dwc->active_list));
941         BUG_ON(!list_empty(&dwc->queue));
942         BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
943
944         spin_lock_bh(&dwc->lock);
945         list_splice_init(&dwc->free_list, &list);
946         dwc->descs_allocated = 0;
947
948         /* Disable interrupts */
949         channel_clear_bit(dw, MASK.XFER, dwc->mask);
950         channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
951         channel_clear_bit(dw, MASK.ERROR, dwc->mask);
952
953         spin_unlock_bh(&dwc->lock);
954
955         list_for_each_entry_safe(desc, _desc, &list, desc_node) {
956                 dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
957                 dma_unmap_single(chan2parent(chan), desc->txd.phys,
958                                 sizeof(desc->lli), DMA_TO_DEVICE);
959                 kfree(desc);
960         }
961
962         dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
963 }
964
965 /* --------------------- Cyclic DMA API extensions -------------------- */
966
967 /**
968  * dw_dma_cyclic_start - start the cyclic DMA transfer
969  * @chan: the DMA channel to start
970  *
971  * Must be called with soft interrupts disabled. Returns zero on success or
972  * -errno on failure.
973  */
974 int dw_dma_cyclic_start(struct dma_chan *chan)
975 {
976         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
977         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
978
979         if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
980                 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
981                 return -ENODEV;
982         }
983
984         spin_lock(&dwc->lock);
985
986         /* assert channel is idle */
987         if (dma_readl(dw, CH_EN) & dwc->mask) {
988                 dev_err(chan2dev(&dwc->chan),
989                         "BUG: Attempted to start non-idle channel\n");
990                 dev_err(chan2dev(&dwc->chan),
991                         "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
992                         channel_readl(dwc, SAR),
993                         channel_readl(dwc, DAR),
994                         channel_readl(dwc, LLP),
995                         channel_readl(dwc, CTL_HI),
996                         channel_readl(dwc, CTL_LO));
997                 spin_unlock(&dwc->lock);
998                 return -EBUSY;
999         }
1000
1001         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1002         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1003         dma_writel(dw, CLEAR.XFER, dwc->mask);
1004
1005         /* setup DMAC channel registers */
1006         channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1007         channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1008         channel_writel(dwc, CTL_HI, 0);
1009
1010         channel_set_bit(dw, CH_EN, dwc->mask);
1011
1012         spin_unlock(&dwc->lock);
1013
1014         return 0;
1015 }
1016 EXPORT_SYMBOL(dw_dma_cyclic_start);
1017
1018 /**
1019  * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1020  * @chan: the DMA channel to stop
1021  *
1022  * Must be called with soft interrupts disabled.
1023  */
1024 void dw_dma_cyclic_stop(struct dma_chan *chan)
1025 {
1026         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1027         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1028
1029         spin_lock(&dwc->lock);
1030
1031         channel_clear_bit(dw, CH_EN, dwc->mask);
1032         while (dma_readl(dw, CH_EN) & dwc->mask)
1033                 cpu_relax();
1034
1035         spin_unlock(&dwc->lock);
1036 }
1037 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1038
1039 /**
1040  * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1041  * @chan: the DMA channel to prepare
1042  * @buf_addr: physical DMA address where the buffer starts
1043  * @buf_len: total number of bytes for the entire buffer
1044  * @period_len: number of bytes for each period
1045  * @direction: transfer direction, to or from device
1046  *
1047  * Must be called before trying to start the transfer. Returns a valid struct
1048  * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1049  */
1050 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1051                 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1052                 enum dma_data_direction direction)
1053 {
1054         struct dw_dma_chan              *dwc = to_dw_dma_chan(chan);
1055         struct dw_cyclic_desc           *cdesc;
1056         struct dw_cyclic_desc           *retval = NULL;
1057         struct dw_desc                  *desc;
1058         struct dw_desc                  *last = NULL;
1059         struct dw_dma_slave             *dws = chan->private;
1060         unsigned long                   was_cyclic;
1061         unsigned int                    reg_width;
1062         unsigned int                    periods;
1063         unsigned int                    i;
1064
1065         spin_lock_bh(&dwc->lock);
1066         if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1067                 spin_unlock_bh(&dwc->lock);
1068                 dev_dbg(chan2dev(&dwc->chan),
1069                                 "queue and/or active list are not empty\n");
1070                 return ERR_PTR(-EBUSY);
1071         }
1072
1073         was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1074         spin_unlock_bh(&dwc->lock);
1075         if (was_cyclic) {
1076                 dev_dbg(chan2dev(&dwc->chan),
1077                                 "channel already prepared for cyclic DMA\n");
1078                 return ERR_PTR(-EBUSY);
1079         }
1080
1081         retval = ERR_PTR(-EINVAL);
1082         reg_width = dws->reg_width;
1083         periods = buf_len / period_len;
1084
1085         /* Check for too big/unaligned periods and unaligned DMA buffer. */
1086         if (period_len > (DWC_MAX_COUNT << reg_width))
1087                 goto out_err;
1088         if (unlikely(period_len & ((1 << reg_width) - 1)))
1089                 goto out_err;
1090         if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1091                 goto out_err;
1092         if (unlikely(!(direction & (DMA_TO_DEVICE | DMA_FROM_DEVICE))))
1093                 goto out_err;
1094
1095         retval = ERR_PTR(-ENOMEM);
1096
1097         if (periods > NR_DESCS_PER_CHANNEL)
1098                 goto out_err;
1099
1100         cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1101         if (!cdesc)
1102                 goto out_err;
1103
1104         cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1105         if (!cdesc->desc)
1106                 goto out_err_alloc;
1107
1108         for (i = 0; i < periods; i++) {
1109                 desc = dwc_desc_get(dwc);
1110                 if (!desc)
1111                         goto out_err_desc_get;
1112
1113                 switch (direction) {
1114                 case DMA_TO_DEVICE:
1115                         desc->lli.dar = dws->tx_reg;
1116                         desc->lli.sar = buf_addr + (period_len * i);
1117                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO
1118                                         | DWC_CTLL_DST_WIDTH(reg_width)
1119                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1120                                         | DWC_CTLL_DST_FIX
1121                                         | DWC_CTLL_SRC_INC
1122                                         | DWC_CTLL_FC_M2P
1123                                         | DWC_CTLL_INT_EN);
1124                         break;
1125                 case DMA_FROM_DEVICE:
1126                         desc->lli.dar = buf_addr + (period_len * i);
1127                         desc->lli.sar = dws->rx_reg;
1128                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO
1129                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1130                                         | DWC_CTLL_DST_WIDTH(reg_width)
1131                                         | DWC_CTLL_DST_INC
1132                                         | DWC_CTLL_SRC_FIX
1133                                         | DWC_CTLL_FC_P2M
1134                                         | DWC_CTLL_INT_EN);
1135                         break;
1136                 default:
1137                         break;
1138                 }
1139
1140                 desc->lli.ctlhi = (period_len >> reg_width);
1141                 cdesc->desc[i] = desc;
1142
1143                 if (last) {
1144                         last->lli.llp = desc->txd.phys;
1145                         dma_sync_single_for_device(chan2parent(chan),
1146                                         last->txd.phys, sizeof(last->lli),
1147                                         DMA_TO_DEVICE);
1148                 }
1149
1150                 last = desc;
1151         }
1152
1153         /* lets make a cyclic list */
1154         last->lli.llp = cdesc->desc[0]->txd.phys;
1155         dma_sync_single_for_device(chan2parent(chan), last->txd.phys,
1156                         sizeof(last->lli), DMA_TO_DEVICE);
1157
1158         dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%08x len %zu "
1159                         "period %zu periods %d\n", buf_addr, buf_len,
1160                         period_len, periods);
1161
1162         cdesc->periods = periods;
1163         dwc->cdesc = cdesc;
1164
1165         return cdesc;
1166
1167 out_err_desc_get:
1168         while (i--)
1169                 dwc_desc_put(dwc, cdesc->desc[i]);
1170 out_err_alloc:
1171         kfree(cdesc);
1172 out_err:
1173         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1174         return (struct dw_cyclic_desc *)retval;
1175 }
1176 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1177
1178 /**
1179  * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1180  * @chan: the DMA channel to free
1181  */
1182 void dw_dma_cyclic_free(struct dma_chan *chan)
1183 {
1184         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1185         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1186         struct dw_cyclic_desc   *cdesc = dwc->cdesc;
1187         int                     i;
1188
1189         dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
1190
1191         if (!cdesc)
1192                 return;
1193
1194         spin_lock_bh(&dwc->lock);
1195
1196         channel_clear_bit(dw, CH_EN, dwc->mask);
1197         while (dma_readl(dw, CH_EN) & dwc->mask)
1198                 cpu_relax();
1199
1200         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1201         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1202         dma_writel(dw, CLEAR.XFER, dwc->mask);
1203
1204         spin_unlock_bh(&dwc->lock);
1205
1206         for (i = 0; i < cdesc->periods; i++)
1207                 dwc_desc_put(dwc, cdesc->desc[i]);
1208
1209         kfree(cdesc->desc);
1210         kfree(cdesc);
1211
1212         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1213 }
1214 EXPORT_SYMBOL(dw_dma_cyclic_free);
1215
1216 /*----------------------------------------------------------------------*/
1217
1218 static void dw_dma_off(struct dw_dma *dw)
1219 {
1220         dma_writel(dw, CFG, 0);
1221
1222         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1223         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1224         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1225         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1226         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1227
1228         while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1229                 cpu_relax();
1230 }
1231
1232 static int __init dw_probe(struct platform_device *pdev)
1233 {
1234         struct dw_dma_platform_data *pdata;
1235         struct resource         *io;
1236         struct dw_dma           *dw;
1237         size_t                  size;
1238         int                     irq;
1239         int                     err;
1240         int                     i;
1241
1242         pdata = pdev->dev.platform_data;
1243         if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1244                 return -EINVAL;
1245
1246         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1247         if (!io)
1248                 return -EINVAL;
1249
1250         irq = platform_get_irq(pdev, 0);
1251         if (irq < 0)
1252                 return irq;
1253
1254         size = sizeof(struct dw_dma);
1255         size += pdata->nr_channels * sizeof(struct dw_dma_chan);
1256         dw = kzalloc(size, GFP_KERNEL);
1257         if (!dw)
1258                 return -ENOMEM;
1259
1260         if (!request_mem_region(io->start, DW_REGLEN, pdev->dev.driver->name)) {
1261                 err = -EBUSY;
1262                 goto err_kfree;
1263         }
1264
1265         memset(dw, 0, sizeof *dw);
1266
1267         dw->regs = ioremap(io->start, DW_REGLEN);
1268         if (!dw->regs) {
1269                 err = -ENOMEM;
1270                 goto err_release_r;
1271         }
1272
1273         dw->clk = clk_get(&pdev->dev, "hclk");
1274         if (IS_ERR(dw->clk)) {
1275                 err = PTR_ERR(dw->clk);
1276                 goto err_clk;
1277         }
1278         clk_enable(dw->clk);
1279
1280         /* force dma off, just in case */
1281         dw_dma_off(dw);
1282
1283         err = request_irq(irq, dw_dma_interrupt, 0, "dw_dmac", dw);
1284         if (err)
1285                 goto err_irq;
1286
1287         platform_set_drvdata(pdev, dw);
1288
1289         tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1290
1291         dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1292
1293         INIT_LIST_HEAD(&dw->dma.channels);
1294         for (i = 0; i < pdata->nr_channels; i++, dw->dma.chancnt++) {
1295                 struct dw_dma_chan      *dwc = &dw->chan[i];
1296
1297                 dwc->chan.device = &dw->dma;
1298                 dwc->chan.cookie = dwc->completed = 1;
1299                 dwc->chan.chan_id = i;
1300                 list_add_tail(&dwc->chan.device_node, &dw->dma.channels);
1301
1302                 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1303                 spin_lock_init(&dwc->lock);
1304                 dwc->mask = 1 << i;
1305
1306                 INIT_LIST_HEAD(&dwc->active_list);
1307                 INIT_LIST_HEAD(&dwc->queue);
1308                 INIT_LIST_HEAD(&dwc->free_list);
1309
1310                 channel_clear_bit(dw, CH_EN, dwc->mask);
1311         }
1312
1313         /* Clear/disable all interrupts on all channels. */
1314         dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1315         dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1316         dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1317         dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1318         dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1319
1320         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1321         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1322         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1323         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1324         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1325
1326         dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1327         dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1328         dw->dma.dev = &pdev->dev;
1329         dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1330         dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1331
1332         dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1333
1334         dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1335         dw->dma.device_terminate_all = dwc_terminate_all;
1336
1337         dw->dma.device_is_tx_complete = dwc_is_tx_complete;
1338         dw->dma.device_issue_pending = dwc_issue_pending;
1339
1340         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1341
1342         printk(KERN_INFO "%s: DesignWare DMA Controller, %d channels\n",
1343                         dev_name(&pdev->dev), dw->dma.chancnt);
1344
1345         dma_async_device_register(&dw->dma);
1346
1347         return 0;
1348
1349 err_irq:
1350         clk_disable(dw->clk);
1351         clk_put(dw->clk);
1352 err_clk:
1353         iounmap(dw->regs);
1354         dw->regs = NULL;
1355 err_release_r:
1356         release_resource(io);
1357 err_kfree:
1358         kfree(dw);
1359         return err;
1360 }
1361
1362 static int __exit dw_remove(struct platform_device *pdev)
1363 {
1364         struct dw_dma           *dw = platform_get_drvdata(pdev);
1365         struct dw_dma_chan      *dwc, *_dwc;
1366         struct resource         *io;
1367
1368         dw_dma_off(dw);
1369         dma_async_device_unregister(&dw->dma);
1370
1371         free_irq(platform_get_irq(pdev, 0), dw);
1372         tasklet_kill(&dw->tasklet);
1373
1374         list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1375                         chan.device_node) {
1376                 list_del(&dwc->chan.device_node);
1377                 channel_clear_bit(dw, CH_EN, dwc->mask);
1378         }
1379
1380         clk_disable(dw->clk);
1381         clk_put(dw->clk);
1382
1383         iounmap(dw->regs);
1384         dw->regs = NULL;
1385
1386         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1387         release_mem_region(io->start, DW_REGLEN);
1388
1389         kfree(dw);
1390
1391         return 0;
1392 }
1393
1394 static void dw_shutdown(struct platform_device *pdev)
1395 {
1396         struct dw_dma   *dw = platform_get_drvdata(pdev);
1397
1398         dw_dma_off(platform_get_drvdata(pdev));
1399         clk_disable(dw->clk);
1400 }
1401
1402 static int dw_suspend_late(struct platform_device *pdev, pm_message_t mesg)
1403 {
1404         struct dw_dma   *dw = platform_get_drvdata(pdev);
1405
1406         dw_dma_off(platform_get_drvdata(pdev));
1407         clk_disable(dw->clk);
1408         return 0;
1409 }
1410
1411 static int dw_resume_early(struct platform_device *pdev)
1412 {
1413         struct dw_dma   *dw = platform_get_drvdata(pdev);
1414
1415         clk_enable(dw->clk);
1416         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1417         return 0;
1418
1419 }
1420
1421 static struct platform_driver dw_driver = {
1422         .remove         = __exit_p(dw_remove),
1423         .shutdown       = dw_shutdown,
1424         .suspend_late   = dw_suspend_late,
1425         .resume_early   = dw_resume_early,
1426         .driver = {
1427                 .name   = "dw_dmac",
1428         },
1429 };
1430
1431 static int __init dw_init(void)
1432 {
1433         return platform_driver_probe(&dw_driver, dw_probe);
1434 }
1435 module_init(dw_init);
1436
1437 static void __exit dw_exit(void)
1438 {
1439         platform_driver_unregister(&dw_driver);
1440 }
1441 module_exit(dw_exit);
1442
1443 MODULE_LICENSE("GPL v2");
1444 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1445 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");