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block: share request flush fields with elevator_private
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / dma / dw_dmac.c
bloba3991ab0d67e06cf6e99d41d9a1a923109dc1a06
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->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->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->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(&desc->tx_list, &dwc->free_list);
213 list_move(&desc->desc_node, &dwc->free_list);
214
215 if (!dwc->chan.private) {
216 struct device *parent = chan2parent(&dwc->chan);
217 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
218 if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
219 dma_unmap_single(parent, desc->lli.dar,
220 desc->len, DMA_FROM_DEVICE);
221 else
222 dma_unmap_page(parent, desc->lli.dar,
223 desc->len, DMA_FROM_DEVICE);
224 }
225 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
226 if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
227 dma_unmap_single(parent, desc->lli.sar,
228 desc->len, DMA_TO_DEVICE);
229 else
230 dma_unmap_page(parent, desc->lli.sar,
231 desc->len, DMA_TO_DEVICE);
232 }
233 }
234
235 /*
236 * The API requires that no submissions are done from a
237 * callback, so we don't need to drop the lock here
238 */
239 if (callback)
240 callback(param);
241 }
242
243 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
244 {
245 struct dw_desc *desc, *_desc;
246 LIST_HEAD(list);
247
248 if (dma_readl(dw, CH_EN) & dwc->mask) {
249 dev_err(chan2dev(&dwc->chan),
250 "BUG: XFER bit set, but channel not idle!\n");
251
252 /* Try to continue after resetting the channel... */
253 channel_clear_bit(dw, CH_EN, dwc->mask);
254 while (dma_readl(dw, CH_EN) & dwc->mask)
255 cpu_relax();
256 }
257
258 /*
259 * Submit queued descriptors ASAP, i.e. before we go through
260 * the completed ones.
261 */
262 if (!list_empty(&dwc->queue))
263 dwc_dostart(dwc, dwc_first_queued(dwc));
264 list_splice_init(&dwc->active_list, &list);
265 list_splice_init(&dwc->queue, &dwc->active_list);
266
267 list_for_each_entry_safe(desc, _desc, &list, desc_node)
268 dwc_descriptor_complete(dwc, desc);
269 }
270
271 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
272 {
273 dma_addr_t llp;
274 struct dw_desc *desc, *_desc;
275 struct dw_desc *child;
276 u32 status_xfer;
277
278 /*
279 * Clear block interrupt flag before scanning so that we don't
280 * miss any, and read LLP before RAW_XFER to ensure it is
281 * valid if we decide to scan the list.
282 */
283 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
284 llp = channel_readl(dwc, LLP);
285 status_xfer = dma_readl(dw, RAW.XFER);
286
287 if (status_xfer & dwc->mask) {
288 /* Everything we've submitted is done */
289 dma_writel(dw, CLEAR.XFER, dwc->mask);
290 dwc_complete_all(dw, dwc);
291 return;
292 }
293
294 dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
295
296 list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
297 if (desc->lli.llp == llp)
298 /* This one is currently in progress */
299 return;
300
301 list_for_each_entry(child, &desc->tx_list, desc_node)
302 if (child->lli.llp == llp)
303 /* Currently in progress */
304 return;
305
306 /*
307 * No descriptors so far seem to be in progress, i.e.
308 * this one must be done.
309 */
310 dwc_descriptor_complete(dwc, desc);
311 }
312
313 dev_err(chan2dev(&dwc->chan),
314 "BUG: All descriptors done, but channel not idle!\n");
315
316 /* Try to continue after resetting the channel... */
317 channel_clear_bit(dw, CH_EN, dwc->mask);
318 while (dma_readl(dw, CH_EN) & dwc->mask)
319 cpu_relax();
320
321 if (!list_empty(&dwc->queue)) {
322 dwc_dostart(dwc, dwc_first_queued(dwc));
323 list_splice_init(&dwc->queue, &dwc->active_list);
324 }
325 }
326
327 static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
328 {
329 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
330 " desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
331 lli->sar, lli->dar, lli->llp,
332 lli->ctlhi, lli->ctllo);
333 }
334
335 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
336 {
337 struct dw_desc *bad_desc;
338 struct dw_desc *child;
339
340 dwc_scan_descriptors(dw, dwc);
341
342 /*
343 * The descriptor currently at the head of the active list is
344 * borked. Since we don't have any way to report errors, we'll
345 * just have to scream loudly and try to carry on.
346 */
347 bad_desc = dwc_first_active(dwc);
348 list_del_init(&bad_desc->desc_node);
349 list_splice_init(&dwc->queue, dwc->active_list.prev);
350
351 /* Clear the error flag and try to restart the controller */
352 dma_writel(dw, CLEAR.ERROR, dwc->mask);
353 if (!list_empty(&dwc->active_list))
354 dwc_dostart(dwc, dwc_first_active(dwc));
355
356 /*
357 * KERN_CRITICAL may seem harsh, but since this only happens
358 * when someone submits a bad physical address in a
359 * descriptor, we should consider ourselves lucky that the
360 * controller flagged an error instead of scribbling over
361 * random memory locations.
362 */
363 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
364 "Bad descriptor submitted for DMA!\n");
365 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
366 " cookie: %d\n", bad_desc->txd.cookie);
367 dwc_dump_lli(dwc, &bad_desc->lli);
368 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
369 dwc_dump_lli(dwc, &child->lli);
370
371 /* Pretend the descriptor completed successfully */
372 dwc_descriptor_complete(dwc, bad_desc);
373 }
374
375 /* --------------------- Cyclic DMA API extensions -------------------- */
376
377 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
378 {
379 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
380 return channel_readl(dwc, SAR);
381 }
382 EXPORT_SYMBOL(dw_dma_get_src_addr);
383
384 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
385 {
386 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
387 return channel_readl(dwc, DAR);
388 }
389 EXPORT_SYMBOL(dw_dma_get_dst_addr);
390
391 /* called with dwc->lock held and all DMAC interrupts disabled */
392 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
393 u32 status_block, u32 status_err, u32 status_xfer)
394 {
395 if (status_block & dwc->mask) {
396 void (*callback)(void *param);
397 void *callback_param;
398
399 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
400 channel_readl(dwc, LLP));
401 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
402
403 callback = dwc->cdesc->period_callback;
404 callback_param = dwc->cdesc->period_callback_param;
405 if (callback) {
406 spin_unlock(&dwc->lock);
407 callback(callback_param);
408 spin_lock(&dwc->lock);
409 }
410 }
411
412 /*
413 * Error and transfer complete are highly unlikely, and will most
414 * likely be due to a configuration error by the user.
415 */
416 if (unlikely(status_err & dwc->mask) ||
417 unlikely(status_xfer & dwc->mask)) {
418 int i;
419
420 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
421 "interrupt, stopping DMA transfer\n",
422 status_xfer ? "xfer" : "error");
423 dev_err(chan2dev(&dwc->chan),
424 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
425 channel_readl(dwc, SAR),
426 channel_readl(dwc, DAR),
427 channel_readl(dwc, LLP),
428 channel_readl(dwc, CTL_HI),
429 channel_readl(dwc, CTL_LO));
430
431 channel_clear_bit(dw, CH_EN, dwc->mask);
432 while (dma_readl(dw, CH_EN) & dwc->mask)
433 cpu_relax();
434
435 /* make sure DMA does not restart by loading a new list */
436 channel_writel(dwc, LLP, 0);
437 channel_writel(dwc, CTL_LO, 0);
438 channel_writel(dwc, CTL_HI, 0);
439
440 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
441 dma_writel(dw, CLEAR.ERROR, dwc->mask);
442 dma_writel(dw, CLEAR.XFER, dwc->mask);
443
444 for (i = 0; i < dwc->cdesc->periods; i++)
445 dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
446 }
447 }
448
449 /* ------------------------------------------------------------------------- */
450
451 static void dw_dma_tasklet(unsigned long data)
452 {
453 struct dw_dma *dw = (struct dw_dma *)data;
454 struct dw_dma_chan *dwc;
455 u32 status_block;
456 u32 status_xfer;
457 u32 status_err;
458 int i;
459
460 status_block = dma_readl(dw, RAW.BLOCK);
461 status_xfer = dma_readl(dw, RAW.XFER);
462 status_err = dma_readl(dw, RAW.ERROR);
463
464 dev_vdbg(dw->dma.dev, "tasklet: status_block=%x status_err=%x\n",
465 status_block, status_err);
466
467 for (i = 0; i < dw->dma.chancnt; i++) {
468 dwc = &dw->chan[i];
469 spin_lock(&dwc->lock);
470 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
471 dwc_handle_cyclic(dw, dwc, status_block, status_err,
472 status_xfer);
473 else if (status_err & (1 << i))
474 dwc_handle_error(dw, dwc);
475 else if ((status_block | status_xfer) & (1 << i))
476 dwc_scan_descriptors(dw, dwc);
477 spin_unlock(&dwc->lock);
478 }
479
480 /*
481 * Re-enable interrupts. Block Complete interrupts are only
482 * enabled if the INT_EN bit in the descriptor is set. This
483 * will trigger a scan before the whole list is done.
484 */
485 channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
486 channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask);
487 channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
488 }
489
490 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
491 {
492 struct dw_dma *dw = dev_id;
493 u32 status;
494
495 dev_vdbg(dw->dma.dev, "interrupt: status=0x%x\n",
496 dma_readl(dw, STATUS_INT));
497
498 /*
499 * Just disable the interrupts. We'll turn them back on in the
500 * softirq handler.
501 */
502 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
503 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
504 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
505
506 status = dma_readl(dw, STATUS_INT);
507 if (status) {
508 dev_err(dw->dma.dev,
509 "BUG: Unexpected interrupts pending: 0x%x\n",
510 status);
511
512 /* Try to recover */
513 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
514 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
515 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
516 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
517 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
518 }
519
520 tasklet_schedule(&dw->tasklet);
521
522 return IRQ_HANDLED;
523 }
524
525 /*----------------------------------------------------------------------*/
526
527 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
528 {
529 struct dw_desc *desc = txd_to_dw_desc(tx);
530 struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
531 dma_cookie_t cookie;
532
533 spin_lock_bh(&dwc->lock);
534 cookie = dwc_assign_cookie(dwc, desc);
535
536 /*
537 * REVISIT: We should attempt to chain as many descriptors as
538 * possible, perhaps even appending to those already submitted
539 * for DMA. But this is hard to do in a race-free manner.
540 */
541 if (list_empty(&dwc->active_list)) {
542 dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
543 desc->txd.cookie);
544 dwc_dostart(dwc, desc);
545 list_add_tail(&desc->desc_node, &dwc->active_list);
546 } else {
547 dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
548 desc->txd.cookie);
549
550 list_add_tail(&desc->desc_node, &dwc->queue);
551 }
552
553 spin_unlock_bh(&dwc->lock);
554
555 return cookie;
556 }
557
558 static struct dma_async_tx_descriptor *
559 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
560 size_t len, unsigned long flags)
561 {
562 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
563 struct dw_desc *desc;
564 struct dw_desc *first;
565 struct dw_desc *prev;
566 size_t xfer_count;
567 size_t offset;
568 unsigned int src_width;
569 unsigned int dst_width;
570 u32 ctllo;
571
572 dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
573 dest, src, len, flags);
574
575 if (unlikely(!len)) {
576 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
577 return NULL;
578 }
579
580 /*
581 * We can be a lot more clever here, but this should take care
582 * of the most common optimization.
583 */
584 if (!((src | dest | len) & 3))
585 src_width = dst_width = 2;
586 else if (!((src | dest | len) & 1))
587 src_width = dst_width = 1;
588 else
589 src_width = dst_width = 0;
590
591 ctllo = DWC_DEFAULT_CTLLO
592 | DWC_CTLL_DST_WIDTH(dst_width)
593 | DWC_CTLL_SRC_WIDTH(src_width)
594 | DWC_CTLL_DST_INC
595 | DWC_CTLL_SRC_INC
596 | DWC_CTLL_FC_M2M;
597 prev = first = NULL;
598
599 for (offset = 0; offset < len; offset += xfer_count << src_width) {
600 xfer_count = min_t(size_t, (len - offset) >> src_width,
601 DWC_MAX_COUNT);
602
603 desc = dwc_desc_get(dwc);
604 if (!desc)
605 goto err_desc_get;
606
607 desc->lli.sar = src + offset;
608 desc->lli.dar = dest + offset;
609 desc->lli.ctllo = ctllo;
610 desc->lli.ctlhi = xfer_count;
611
612 if (!first) {
613 first = desc;
614 } else {
615 prev->lli.llp = desc->txd.phys;
616 dma_sync_single_for_device(chan2parent(chan),
617 prev->txd.phys, sizeof(prev->lli),
618 DMA_TO_DEVICE);
619 list_add_tail(&desc->desc_node,
620 &first->tx_list);
621 }
622 prev = desc;
623 }
624
625
626 if (flags & DMA_PREP_INTERRUPT)
627 /* Trigger interrupt after last block */
628 prev->lli.ctllo |= DWC_CTLL_INT_EN;
629
630 prev->lli.llp = 0;
631 dma_sync_single_for_device(chan2parent(chan),
632 prev->txd.phys, sizeof(prev->lli),
633 DMA_TO_DEVICE);
634
635 first->txd.flags = flags;
636 first->len = len;
637
638 return &first->txd;
639
640 err_desc_get:
641 dwc_desc_put(dwc, first);
642 return NULL;
643 }
644
645 static struct dma_async_tx_descriptor *
646 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
647 unsigned int sg_len, enum dma_data_direction direction,
648 unsigned long flags)
649 {
650 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
651 struct dw_dma_slave *dws = chan->private;
652 struct dw_desc *prev;
653 struct dw_desc *first;
654 u32 ctllo;
655 dma_addr_t reg;
656 unsigned int reg_width;
657 unsigned int mem_width;
658 unsigned int i;
659 struct scatterlist *sg;
660 size_t total_len = 0;
661
662 dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
663
664 if (unlikely(!dws || !sg_len))
665 return NULL;
666
667 reg_width = dws->reg_width;
668 prev = first = NULL;
669
670 switch (direction) {
671 case DMA_TO_DEVICE:
672 ctllo = (DWC_DEFAULT_CTLLO
673 | DWC_CTLL_DST_WIDTH(reg_width)
674 | DWC_CTLL_DST_FIX
675 | DWC_CTLL_SRC_INC
676 | DWC_CTLL_FC_M2P);
677 reg = dws->tx_reg;
678 for_each_sg(sgl, sg, sg_len, i) {
679 struct dw_desc *desc;
680 u32 len;
681 u32 mem;
682
683 desc = dwc_desc_get(dwc);
684 if (!desc) {
685 dev_err(chan2dev(chan),
686 "not enough descriptors available\n");
687 goto err_desc_get;
688 }
689
690 mem = sg_phys(sg);
691 len = sg_dma_len(sg);
692 mem_width = 2;
693 if (unlikely(mem & 3 || len & 3))
694 mem_width = 0;
695
696 desc->lli.sar = mem;
697 desc->lli.dar = reg;
698 desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
699 desc->lli.ctlhi = len >> mem_width;
700
701 if (!first) {
702 first = desc;
703 } else {
704 prev->lli.llp = desc->txd.phys;
705 dma_sync_single_for_device(chan2parent(chan),
706 prev->txd.phys,
707 sizeof(prev->lli),
708 DMA_TO_DEVICE);
709 list_add_tail(&desc->desc_node,
710 &first->tx_list);
711 }
712 prev = desc;
713 total_len += len;
714 }
715 break;
716 case DMA_FROM_DEVICE:
717 ctllo = (DWC_DEFAULT_CTLLO
718 | DWC_CTLL_SRC_WIDTH(reg_width)
719 | DWC_CTLL_DST_INC
720 | DWC_CTLL_SRC_FIX
721 | DWC_CTLL_FC_P2M);
722
723 reg = dws->rx_reg;
724 for_each_sg(sgl, sg, sg_len, i) {
725 struct dw_desc *desc;
726 u32 len;
727 u32 mem;
728
729 desc = dwc_desc_get(dwc);
730 if (!desc) {
731 dev_err(chan2dev(chan),
732 "not enough descriptors available\n");
733 goto err_desc_get;
734 }
735
736 mem = sg_phys(sg);
737 len = sg_dma_len(sg);
738 mem_width = 2;
739 if (unlikely(mem & 3 || len & 3))
740 mem_width = 0;
741
742 desc->lli.sar = reg;
743 desc->lli.dar = mem;
744 desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
745 desc->lli.ctlhi = len >> reg_width;
746
747 if (!first) {
748 first = desc;
749 } else {
750 prev->lli.llp = desc->txd.phys;
751 dma_sync_single_for_device(chan2parent(chan),
752 prev->txd.phys,
753 sizeof(prev->lli),
754 DMA_TO_DEVICE);
755 list_add_tail(&desc->desc_node,
756 &first->tx_list);
757 }
758 prev = desc;
759 total_len += len;
760 }
761 break;
762 default:
763 return NULL;
764 }
765
766 if (flags & DMA_PREP_INTERRUPT)
767 /* Trigger interrupt after last block */
768 prev->lli.ctllo |= DWC_CTLL_INT_EN;
769
770 prev->lli.llp = 0;
771 dma_sync_single_for_device(chan2parent(chan),
772 prev->txd.phys, sizeof(prev->lli),
773 DMA_TO_DEVICE);
774
775 first->len = total_len;
776
777 return &first->txd;
778
779 err_desc_get:
780 dwc_desc_put(dwc, first);
781 return NULL;
782 }
783
784 static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
785 unsigned long arg)
786 {
787 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
788 struct dw_dma *dw = to_dw_dma(chan->device);
789 struct dw_desc *desc, *_desc;
790 LIST_HEAD(list);
791
792 /* Only supports DMA_TERMINATE_ALL */
793 if (cmd != DMA_TERMINATE_ALL)
794 return -ENXIO;
795
796 /*
797 * This is only called when something went wrong elsewhere, so
798 * we don't really care about the data. Just disable the
799 * channel. We still have to poll the channel enable bit due
800 * to AHB/HSB limitations.
801 */
802 spin_lock_bh(&dwc->lock);
803
804 channel_clear_bit(dw, CH_EN, dwc->mask);
805
806 while (dma_readl(dw, CH_EN) & dwc->mask)
807 cpu_relax();
808
809 /* active_list entries will end up before queued entries */
810 list_splice_init(&dwc->queue, &list);
811 list_splice_init(&dwc->active_list, &list);
812
813 spin_unlock_bh(&dwc->lock);
814
815 /* Flush all pending and queued descriptors */
816 list_for_each_entry_safe(desc, _desc, &list, desc_node)
817 dwc_descriptor_complete(dwc, desc);
818
819 return 0;
820 }
821
822 static enum dma_status
823 dwc_tx_status(struct dma_chan *chan,
824 dma_cookie_t cookie,
825 struct dma_tx_state *txstate)
826 {
827 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
828 dma_cookie_t last_used;
829 dma_cookie_t last_complete;
830 int ret;
831
832 last_complete = dwc->completed;
833 last_used = chan->cookie;
834
835 ret = dma_async_is_complete(cookie, last_complete, last_used);
836 if (ret != DMA_SUCCESS) {
837 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
838
839 last_complete = dwc->completed;
840 last_used = chan->cookie;
841
842 ret = dma_async_is_complete(cookie, last_complete, last_used);
843 }
844
845 dma_set_tx_state(txstate, last_complete, last_used, 0);
846
847 return ret;
848 }
849
850 static void dwc_issue_pending(struct dma_chan *chan)
851 {
852 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
853
854 spin_lock_bh(&dwc->lock);
855 if (!list_empty(&dwc->queue))
856 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
857 spin_unlock_bh(&dwc->lock);
858 }
859
860 static int dwc_alloc_chan_resources(struct dma_chan *chan)
861 {
862 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
863 struct dw_dma *dw = to_dw_dma(chan->device);
864 struct dw_desc *desc;
865 struct dw_dma_slave *dws;
866 int i;
867 u32 cfghi;
868 u32 cfglo;
869
870 dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
871
872 /* ASSERT: channel is idle */
873 if (dma_readl(dw, CH_EN) & dwc->mask) {
874 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
875 return -EIO;
876 }
877
878 dwc->completed = chan->cookie = 1;
879
880 cfghi = DWC_CFGH_FIFO_MODE;
881 cfglo = 0;
882
883 dws = chan->private;
884 if (dws) {
885 /*
886 * We need controller-specific data to set up slave
887 * transfers.
888 */
889 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
890
891 cfghi = dws->cfg_hi;
892 cfglo = dws->cfg_lo;
893 }
894 channel_writel(dwc, CFG_LO, cfglo);
895 channel_writel(dwc, CFG_HI, cfghi);
896
897 /*
898 * NOTE: some controllers may have additional features that we
899 * need to initialize here, like "scatter-gather" (which
900 * doesn't mean what you think it means), and status writeback.
901 */
902
903 spin_lock_bh(&dwc->lock);
904 i = dwc->descs_allocated;
905 while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
906 spin_unlock_bh(&dwc->lock);
907
908 desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
909 if (!desc) {
910 dev_info(chan2dev(chan),
911 "only allocated %d descriptors\n", i);
912 spin_lock_bh(&dwc->lock);
913 break;
914 }
915
916 INIT_LIST_HEAD(&desc->tx_list);
917 dma_async_tx_descriptor_init(&desc->txd, chan);
918 desc->txd.tx_submit = dwc_tx_submit;
919 desc->txd.flags = DMA_CTRL_ACK;
920 desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,
921 sizeof(desc->lli), DMA_TO_DEVICE);
922 dwc_desc_put(dwc, desc);
923
924 spin_lock_bh(&dwc->lock);
925 i = ++dwc->descs_allocated;
926 }
927
928 /* Enable interrupts */
929 channel_set_bit(dw, MASK.XFER, dwc->mask);
930 channel_set_bit(dw, MASK.BLOCK, dwc->mask);
931 channel_set_bit(dw, MASK.ERROR, dwc->mask);
932
933 spin_unlock_bh(&dwc->lock);
934
935 dev_dbg(chan2dev(chan),
936 "alloc_chan_resources allocated %d descriptors\n", i);
937
938 return i;
939 }
940
941 static void dwc_free_chan_resources(struct dma_chan *chan)
942 {
943 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
944 struct dw_dma *dw = to_dw_dma(chan->device);
945 struct dw_desc *desc, *_desc;
946 LIST_HEAD(list);
947
948 dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
949 dwc->descs_allocated);
950
951 /* ASSERT: channel is idle */
952 BUG_ON(!list_empty(&dwc->active_list));
953 BUG_ON(!list_empty(&dwc->queue));
954 BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
955
956 spin_lock_bh(&dwc->lock);
957 list_splice_init(&dwc->free_list, &list);
958 dwc->descs_allocated = 0;
959
960 /* Disable interrupts */
961 channel_clear_bit(dw, MASK.XFER, dwc->mask);
962 channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
963 channel_clear_bit(dw, MASK.ERROR, dwc->mask);
964
965 spin_unlock_bh(&dwc->lock);
966
967 list_for_each_entry_safe(desc, _desc, &list, desc_node) {
968 dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
969 dma_unmap_single(chan2parent(chan), desc->txd.phys,
970 sizeof(desc->lli), DMA_TO_DEVICE);
971 kfree(desc);
972 }
973
974 dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
975 }
976
977 /* --------------------- Cyclic DMA API extensions -------------------- */
978
979 /**
980 * dw_dma_cyclic_start - start the cyclic DMA transfer
981 * @chan: the DMA channel to start
982 *
983 * Must be called with soft interrupts disabled. Returns zero on success or
984 * -errno on failure.
985 */
986 int dw_dma_cyclic_start(struct dma_chan *chan)
987 {
988 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
989 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
990
991 if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
992 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
993 return -ENODEV;
994 }
995
996 spin_lock(&dwc->lock);
997
998 /* assert channel is idle */
999 if (dma_readl(dw, CH_EN) & dwc->mask) {
1000 dev_err(chan2dev(&dwc->chan),
1001 "BUG: Attempted to start non-idle channel\n");
1002 dev_err(chan2dev(&dwc->chan),
1003 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
1004 channel_readl(dwc, SAR),
1005 channel_readl(dwc, DAR),
1006 channel_readl(dwc, LLP),
1007 channel_readl(dwc, CTL_HI),
1008 channel_readl(dwc, CTL_LO));
1009 spin_unlock(&dwc->lock);
1010 return -EBUSY;
1011 }
1012
1013 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1014 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1015 dma_writel(dw, CLEAR.XFER, dwc->mask);
1016
1017 /* setup DMAC channel registers */
1018 channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1019 channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1020 channel_writel(dwc, CTL_HI, 0);
1021
1022 channel_set_bit(dw, CH_EN, dwc->mask);
1023
1024 spin_unlock(&dwc->lock);
1025
1026 return 0;
1027 }
1028 EXPORT_SYMBOL(dw_dma_cyclic_start);
1029
1030 /**
1031 * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1032 * @chan: the DMA channel to stop
1033 *
1034 * Must be called with soft interrupts disabled.
1035 */
1036 void dw_dma_cyclic_stop(struct dma_chan *chan)
1037 {
1038 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1039 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1040
1041 spin_lock(&dwc->lock);
1042
1043 channel_clear_bit(dw, CH_EN, dwc->mask);
1044 while (dma_readl(dw, CH_EN) & dwc->mask)
1045 cpu_relax();
1046
1047 spin_unlock(&dwc->lock);
1048 }
1049 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1050
1051 /**
1052 * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1053 * @chan: the DMA channel to prepare
1054 * @buf_addr: physical DMA address where the buffer starts
1055 * @buf_len: total number of bytes for the entire buffer
1056 * @period_len: number of bytes for each period
1057 * @direction: transfer direction, to or from device
1058 *
1059 * Must be called before trying to start the transfer. Returns a valid struct
1060 * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1061 */
1062 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1063 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1064 enum dma_data_direction direction)
1065 {
1066 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1067 struct dw_cyclic_desc *cdesc;
1068 struct dw_cyclic_desc *retval = NULL;
1069 struct dw_desc *desc;
1070 struct dw_desc *last = NULL;
1071 struct dw_dma_slave *dws = chan->private;
1072 unsigned long was_cyclic;
1073 unsigned int reg_width;
1074 unsigned int periods;
1075 unsigned int i;
1076
1077 spin_lock_bh(&dwc->lock);
1078 if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1079 spin_unlock_bh(&dwc->lock);
1080 dev_dbg(chan2dev(&dwc->chan),
1081 "queue and/or active list are not empty\n");
1082 return ERR_PTR(-EBUSY);
1083 }
1084
1085 was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1086 spin_unlock_bh(&dwc->lock);
1087 if (was_cyclic) {
1088 dev_dbg(chan2dev(&dwc->chan),
1089 "channel already prepared for cyclic DMA\n");
1090 return ERR_PTR(-EBUSY);
1091 }
1092
1093 retval = ERR_PTR(-EINVAL);
1094 reg_width = dws->reg_width;
1095 periods = buf_len / period_len;
1096
1097 /* Check for too big/unaligned periods and unaligned DMA buffer. */
1098 if (period_len > (DWC_MAX_COUNT << reg_width))
1099 goto out_err;
1100 if (unlikely(period_len & ((1 << reg_width) - 1)))
1101 goto out_err;
1102 if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1103 goto out_err;
1104 if (unlikely(!(direction & (DMA_TO_DEVICE | DMA_FROM_DEVICE))))
1105 goto out_err;
1106
1107 retval = ERR_PTR(-ENOMEM);
1108
1109 if (periods > NR_DESCS_PER_CHANNEL)
1110 goto out_err;
1111
1112 cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1113 if (!cdesc)
1114 goto out_err;
1115
1116 cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1117 if (!cdesc->desc)
1118 goto out_err_alloc;
1119
1120 for (i = 0; i < periods; i++) {
1121 desc = dwc_desc_get(dwc);
1122 if (!desc)
1123 goto out_err_desc_get;
1124
1125 switch (direction) {
1126 case DMA_TO_DEVICE:
1127 desc->lli.dar = dws->tx_reg;
1128 desc->lli.sar = buf_addr + (period_len * i);
1129 desc->lli.ctllo = (DWC_DEFAULT_CTLLO
1130 | DWC_CTLL_DST_WIDTH(reg_width)
1131 | DWC_CTLL_SRC_WIDTH(reg_width)
1132 | DWC_CTLL_DST_FIX
1133 | DWC_CTLL_SRC_INC
1134 | DWC_CTLL_FC_M2P
1135 | DWC_CTLL_INT_EN);
1136 break;
1137 case DMA_FROM_DEVICE:
1138 desc->lli.dar = buf_addr + (period_len * i);
1139 desc->lli.sar = dws->rx_reg;
1140 desc->lli.ctllo = (DWC_DEFAULT_CTLLO
1141 | DWC_CTLL_SRC_WIDTH(reg_width)
1142 | DWC_CTLL_DST_WIDTH(reg_width)
1143 | DWC_CTLL_DST_INC
1144 | DWC_CTLL_SRC_FIX
1145 | DWC_CTLL_FC_P2M
1146 | DWC_CTLL_INT_EN);
1147 break;
1148 default:
1149 break;
1150 }
1151
1152 desc->lli.ctlhi = (period_len >> reg_width);
1153 cdesc->desc[i] = desc;
1154
1155 if (last) {
1156 last->lli.llp = desc->txd.phys;
1157 dma_sync_single_for_device(chan2parent(chan),
1158 last->txd.phys, sizeof(last->lli),
1159 DMA_TO_DEVICE);
1160 }
1161
1162 last = desc;
1163 }
1164
1165 /* lets make a cyclic list */
1166 last->lli.llp = cdesc->desc[0]->txd.phys;
1167 dma_sync_single_for_device(chan2parent(chan), last->txd.phys,
1168 sizeof(last->lli), DMA_TO_DEVICE);
1169
1170 dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%08x len %zu "
1171 "period %zu periods %d\n", buf_addr, buf_len,
1172 period_len, periods);
1173
1174 cdesc->periods = periods;
1175 dwc->cdesc = cdesc;
1176
1177 return cdesc;
1178
1179 out_err_desc_get:
1180 while (i--)
1181 dwc_desc_put(dwc, cdesc->desc[i]);
1182 out_err_alloc:
1183 kfree(cdesc);
1184 out_err:
1185 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1186 return (struct dw_cyclic_desc *)retval;
1187 }
1188 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1189
1190 /**
1191 * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1192 * @chan: the DMA channel to free
1193 */
1194 void dw_dma_cyclic_free(struct dma_chan *chan)
1195 {
1196 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1197 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1198 struct dw_cyclic_desc *cdesc = dwc->cdesc;
1199 int i;
1200
1201 dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
1202
1203 if (!cdesc)
1204 return;
1205
1206 spin_lock_bh(&dwc->lock);
1207
1208 channel_clear_bit(dw, CH_EN, dwc->mask);
1209 while (dma_readl(dw, CH_EN) & dwc->mask)
1210 cpu_relax();
1211
1212 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1213 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1214 dma_writel(dw, CLEAR.XFER, dwc->mask);
1215
1216 spin_unlock_bh(&dwc->lock);
1217
1218 for (i = 0; i < cdesc->periods; i++)
1219 dwc_desc_put(dwc, cdesc->desc[i]);
1220
1221 kfree(cdesc->desc);
1222 kfree(cdesc);
1223
1224 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1225 }
1226 EXPORT_SYMBOL(dw_dma_cyclic_free);
1227
1228 /*----------------------------------------------------------------------*/
1229
1230 static void dw_dma_off(struct dw_dma *dw)
1231 {
1232 dma_writel(dw, CFG, 0);
1233
1234 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1235 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1236 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1237 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1238 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1239
1240 while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1241 cpu_relax();
1242 }
1243
1244 static int __init dw_probe(struct platform_device *pdev)
1245 {
1246 struct dw_dma_platform_data *pdata;
1247 struct resource *io;
1248 struct dw_dma *dw;
1249 size_t size;
1250 int irq;
1251 int err;
1252 int i;
1253
1254 pdata = pdev->dev.platform_data;
1255 if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1256 return -EINVAL;
1257
1258 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1259 if (!io)
1260 return -EINVAL;
1261
1262 irq = platform_get_irq(pdev, 0);
1263 if (irq < 0)
1264 return irq;
1265
1266 size = sizeof(struct dw_dma);
1267 size += pdata->nr_channels * sizeof(struct dw_dma_chan);
1268 dw = kzalloc(size, GFP_KERNEL);
1269 if (!dw)
1270 return -ENOMEM;
1271
1272 if (!request_mem_region(io->start, DW_REGLEN, pdev->dev.driver->name)) {
1273 err = -EBUSY;
1274 goto err_kfree;
1275 }
1276
1277 dw->regs = ioremap(io->start, DW_REGLEN);
1278 if (!dw->regs) {
1279 err = -ENOMEM;
1280 goto err_release_r;
1281 }
1282
1283 dw->clk = clk_get(&pdev->dev, "hclk");
1284 if (IS_ERR(dw->clk)) {
1285 err = PTR_ERR(dw->clk);
1286 goto err_clk;
1287 }
1288 clk_enable(dw->clk);
1289
1290 /* force dma off, just in case */
1291 dw_dma_off(dw);
1292
1293 err = request_irq(irq, dw_dma_interrupt, 0, "dw_dmac", dw);
1294 if (err)
1295 goto err_irq;
1296
1297 platform_set_drvdata(pdev, dw);
1298
1299 tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1300
1301 dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1302
1303 INIT_LIST_HEAD(&dw->dma.channels);
1304 for (i = 0; i < pdata->nr_channels; i++, dw->dma.chancnt++) {
1305 struct dw_dma_chan *dwc = &dw->chan[i];
1306
1307 dwc->chan.device = &dw->dma;
1308 dwc->chan.cookie = dwc->completed = 1;
1309 dwc->chan.chan_id = i;
1310 list_add_tail(&dwc->chan.device_node, &dw->dma.channels);
1311
1312 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1313 spin_lock_init(&dwc->lock);
1314 dwc->mask = 1 << i;
1315
1316 INIT_LIST_HEAD(&dwc->active_list);
1317 INIT_LIST_HEAD(&dwc->queue);
1318 INIT_LIST_HEAD(&dwc->free_list);
1319
1320 channel_clear_bit(dw, CH_EN, dwc->mask);
1321 }
1322
1323 /* Clear/disable all interrupts on all channels. */
1324 dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1325 dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1326 dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1327 dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1328 dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1329
1330 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1331 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1332 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1333 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1334 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1335
1336 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1337 dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1338 dw->dma.dev = &pdev->dev;
1339 dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1340 dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1341
1342 dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1343
1344 dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1345 dw->dma.device_control = dwc_control;
1346
1347 dw->dma.device_tx_status = dwc_tx_status;
1348 dw->dma.device_issue_pending = dwc_issue_pending;
1349
1350 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1351
1352 printk(KERN_INFO "%s: DesignWare DMA Controller, %d channels\n",
1353 dev_name(&pdev->dev), dw->dma.chancnt);
1354
1355 dma_async_device_register(&dw->dma);
1356
1357 return 0;
1358
1359 err_irq:
1360 clk_disable(dw->clk);
1361 clk_put(dw->clk);
1362 err_clk:
1363 iounmap(dw->regs);
1364 dw->regs = NULL;
1365 err_release_r:
1366 release_resource(io);
1367 err_kfree:
1368 kfree(dw);
1369 return err;
1370 }
1371
1372 static int __exit dw_remove(struct platform_device *pdev)
1373 {
1374 struct dw_dma *dw = platform_get_drvdata(pdev);
1375 struct dw_dma_chan *dwc, *_dwc;
1376 struct resource *io;
1377
1378 dw_dma_off(dw);
1379 dma_async_device_unregister(&dw->dma);
1380
1381 free_irq(platform_get_irq(pdev, 0), dw);
1382 tasklet_kill(&dw->tasklet);
1383
1384 list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1385 chan.device_node) {
1386 list_del(&dwc->chan.device_node);
1387 channel_clear_bit(dw, CH_EN, dwc->mask);
1388 }
1389
1390 clk_disable(dw->clk);
1391 clk_put(dw->clk);
1392
1393 iounmap(dw->regs);
1394 dw->regs = NULL;
1395
1396 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1397 release_mem_region(io->start, DW_REGLEN);
1398
1399 kfree(dw);
1400
1401 return 0;
1402 }
1403
1404 static void dw_shutdown(struct platform_device *pdev)
1405 {
1406 struct dw_dma *dw = platform_get_drvdata(pdev);
1407
1408 dw_dma_off(platform_get_drvdata(pdev));
1409 clk_disable(dw->clk);
1410 }
1411
1412 static int dw_suspend_noirq(struct device *dev)
1413 {
1414 struct platform_device *pdev = to_platform_device(dev);
1415 struct dw_dma *dw = platform_get_drvdata(pdev);
1416
1417 dw_dma_off(platform_get_drvdata(pdev));
1418 clk_disable(dw->clk);
1419 return 0;
1420 }
1421
1422 static int dw_resume_noirq(struct device *dev)
1423 {
1424 struct platform_device *pdev = to_platform_device(dev);
1425 struct dw_dma *dw = platform_get_drvdata(pdev);
1426
1427 clk_enable(dw->clk);
1428 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1429 return 0;
1430 }
1431
1432 static const struct dev_pm_ops dw_dev_pm_ops = {
1433 .suspend_noirq = dw_suspend_noirq,
1434 .resume_noirq = dw_resume_noirq,
1435 };
1436
1437 static struct platform_driver dw_driver = {
1438 .remove = __exit_p(dw_remove),
1439 .shutdown = dw_shutdown,
1440 .driver = {
1441 .name = "dw_dmac",
1442 .pm = &dw_dev_pm_ops,
1443 },
1444 };
1445
1446 static int __init dw_init(void)
1447 {
1448 return platform_driver_probe(&dw_driver, dw_probe);
1449 }
1450 module_init(dw_init);
1451
1452 static void __exit dw_exit(void)
1453 {
1454 platform_driver_unregister(&dw_driver);
1455 }
1456 module_exit(dw_exit);
1457
1458 MODULE_LICENSE("GPL v2");
1459 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1460 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree