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rcu: Make rcu_assign_pointer() unconditionally insert a memory barrier
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / dma / dw_dmac.c
blob4d180ca9a1d86a46e311b25b568e99380c1399a6
1 /*
2 * Driver for the Synopsys DesignWare DMA Controller (aka DMACA on
3 * AVR32 systems.)
4 *
5 * Copyright (C) 2007-2008 Atmel Corporation
6 * Copyright (C) 2010-2011 ST Microelectronics
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/mm.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23
24 #include "dw_dmac_regs.h"
25
26 /*
27 * This supports the Synopsys "DesignWare AHB Central DMA Controller",
28 * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all
29 * of which use ARM any more). See the "Databook" from Synopsys for
30 * information beyond what licensees probably provide.
31 *
32 * The driver has currently been tested only with the Atmel AT32AP7000,
33 * which does not support descriptor writeback.
34 */
35
36 #define DWC_DEFAULT_CTLLO(private) ({ \
37 struct dw_dma_slave *__slave = (private); \
38 int dms = __slave ? __slave->dst_master : 0; \
39 int sms = __slave ? __slave->src_master : 1; \
40 u8 smsize = __slave ? __slave->src_msize : DW_DMA_MSIZE_16; \
41 u8 dmsize = __slave ? __slave->dst_msize : DW_DMA_MSIZE_16; \
42 \
43 (DWC_CTLL_DST_MSIZE(dmsize) \
44 | DWC_CTLL_SRC_MSIZE(smsize) \
45 | DWC_CTLL_LLP_D_EN \
46 | DWC_CTLL_LLP_S_EN \
47 | DWC_CTLL_DMS(dms) \
48 | DWC_CTLL_SMS(sms)); \
49 })
50
51 /*
52 * This is configuration-dependent and usually a funny size like 4095.
53 *
54 * Note that this is a transfer count, i.e. if we transfer 32-bit
55 * words, we can do 16380 bytes per descriptor.
56 *
57 * This parameter is also system-specific.
58 */
59 #define DWC_MAX_COUNT 4095U
60
61 /*
62 * Number of descriptors to allocate for each channel. This should be
63 * made configurable somehow; preferably, the clients (at least the
64 * ones using slave transfers) should be able to give us a hint.
65 */
66 #define NR_DESCS_PER_CHANNEL 64
67
68 /*----------------------------------------------------------------------*/
69
70 /*
71 * Because we're not relying on writeback from the controller (it may not
72 * even be configured into the core!) we don't need to use dma_pool. These
73 * descriptors -- and associated data -- are cacheable. We do need to make
74 * sure their dcache entries are written back before handing them off to
75 * the controller, though.
76 */
77
78 static struct device *chan2dev(struct dma_chan *chan)
79 {
80 return &chan->dev->device;
81 }
82 static struct device *chan2parent(struct dma_chan *chan)
83 {
84 return chan->dev->device.parent;
85 }
86
87 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
88 {
89 return list_entry(dwc->active_list.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 unsigned long flags;
98
99 spin_lock_irqsave(&dwc->lock, flags);
100 list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
101 if (async_tx_test_ack(&desc->txd)) {
102 list_del(&desc->desc_node);
103 ret = desc;
104 break;
105 }
106 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
107 i++;
108 }
109 spin_unlock_irqrestore(&dwc->lock, flags);
110
111 dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
112
113 return ret;
114 }
115
116 static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc)
117 {
118 struct dw_desc *child;
119
120 list_for_each_entry(child, &desc->tx_list, desc_node)
121 dma_sync_single_for_cpu(chan2parent(&dwc->chan),
122 child->txd.phys, sizeof(child->lli),
123 DMA_TO_DEVICE);
124 dma_sync_single_for_cpu(chan2parent(&dwc->chan),
125 desc->txd.phys, sizeof(desc->lli),
126 DMA_TO_DEVICE);
127 }
128
129 /*
130 * Move a descriptor, including any children, to the free list.
131 * `desc' must not be on any lists.
132 */
133 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
134 {
135 unsigned long flags;
136
137 if (desc) {
138 struct dw_desc *child;
139
140 dwc_sync_desc_for_cpu(dwc, desc);
141
142 spin_lock_irqsave(&dwc->lock, flags);
143 list_for_each_entry(child, &desc->tx_list, desc_node)
144 dev_vdbg(chan2dev(&dwc->chan),
145 "moving child desc %p to freelist\n",
146 child);
147 list_splice_init(&desc->tx_list, &dwc->free_list);
148 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
149 list_add(&desc->desc_node, &dwc->free_list);
150 spin_unlock_irqrestore(&dwc->lock, flags);
151 }
152 }
153
154 /* Called with dwc->lock held and bh disabled */
155 static dma_cookie_t
156 dwc_assign_cookie(struct dw_dma_chan *dwc, struct dw_desc *desc)
157 {
158 dma_cookie_t cookie = dwc->chan.cookie;
159
160 if (++cookie < 0)
161 cookie = 1;
162
163 dwc->chan.cookie = cookie;
164 desc->txd.cookie = cookie;
165
166 return cookie;
167 }
168
169 /*----------------------------------------------------------------------*/
170
171 /* Called with dwc->lock held and bh disabled */
172 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
173 {
174 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
175
176 /* ASSERT: channel is idle */
177 if (dma_readl(dw, CH_EN) & dwc->mask) {
178 dev_err(chan2dev(&dwc->chan),
179 "BUG: Attempted to start non-idle channel\n");
180 dev_err(chan2dev(&dwc->chan),
181 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
182 channel_readl(dwc, SAR),
183 channel_readl(dwc, DAR),
184 channel_readl(dwc, LLP),
185 channel_readl(dwc, CTL_HI),
186 channel_readl(dwc, CTL_LO));
187
188 /* The tasklet will hopefully advance the queue... */
189 return;
190 }
191
192 channel_writel(dwc, LLP, first->txd.phys);
193 channel_writel(dwc, CTL_LO,
194 DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
195 channel_writel(dwc, CTL_HI, 0);
196 channel_set_bit(dw, CH_EN, dwc->mask);
197 }
198
199 /*----------------------------------------------------------------------*/
200
201 static void
202 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
203 bool callback_required)
204 {
205 dma_async_tx_callback callback = NULL;
206 void *param = NULL;
207 struct dma_async_tx_descriptor *txd = &desc->txd;
208 struct dw_desc *child;
209 unsigned long flags;
210
211 dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
212
213 spin_lock_irqsave(&dwc->lock, flags);
214 dwc->completed = txd->cookie;
215 if (callback_required) {
216 callback = txd->callback;
217 param = txd->callback_param;
218 }
219
220 dwc_sync_desc_for_cpu(dwc, desc);
221
222 /* async_tx_ack */
223 list_for_each_entry(child, &desc->tx_list, desc_node)
224 async_tx_ack(&child->txd);
225 async_tx_ack(&desc->txd);
226
227 list_splice_init(&desc->tx_list, &dwc->free_list);
228 list_move(&desc->desc_node, &dwc->free_list);
229
230 if (!dwc->chan.private) {
231 struct device *parent = chan2parent(&dwc->chan);
232 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
233 if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
234 dma_unmap_single(parent, desc->lli.dar,
235 desc->len, DMA_FROM_DEVICE);
236 else
237 dma_unmap_page(parent, desc->lli.dar,
238 desc->len, DMA_FROM_DEVICE);
239 }
240 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
241 if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
242 dma_unmap_single(parent, desc->lli.sar,
243 desc->len, DMA_TO_DEVICE);
244 else
245 dma_unmap_page(parent, desc->lli.sar,
246 desc->len, DMA_TO_DEVICE);
247 }
248 }
249
250 spin_unlock_irqrestore(&dwc->lock, flags);
251
252 if (callback_required && callback)
253 callback(param);
254 }
255
256 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
257 {
258 struct dw_desc *desc, *_desc;
259 LIST_HEAD(list);
260 unsigned long flags;
261
262 spin_lock_irqsave(&dwc->lock, flags);
263 if (dma_readl(dw, CH_EN) & dwc->mask) {
264 dev_err(chan2dev(&dwc->chan),
265 "BUG: XFER bit set, but channel not idle!\n");
266
267 /* Try to continue after resetting the channel... */
268 channel_clear_bit(dw, CH_EN, dwc->mask);
269 while (dma_readl(dw, CH_EN) & dwc->mask)
270 cpu_relax();
271 }
272
273 /*
274 * Submit queued descriptors ASAP, i.e. before we go through
275 * the completed ones.
276 */
277 list_splice_init(&dwc->active_list, &list);
278 if (!list_empty(&dwc->queue)) {
279 list_move(dwc->queue.next, &dwc->active_list);
280 dwc_dostart(dwc, dwc_first_active(dwc));
281 }
282
283 spin_unlock_irqrestore(&dwc->lock, flags);
284
285 list_for_each_entry_safe(desc, _desc, &list, desc_node)
286 dwc_descriptor_complete(dwc, desc, true);
287 }
288
289 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
290 {
291 dma_addr_t llp;
292 struct dw_desc *desc, *_desc;
293 struct dw_desc *child;
294 u32 status_xfer;
295 unsigned long flags;
296
297 spin_lock_irqsave(&dwc->lock, flags);
298 /*
299 * Clear block interrupt flag before scanning so that we don't
300 * miss any, and read LLP before RAW_XFER to ensure it is
301 * valid if we decide to scan the list.
302 */
303 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
304 llp = channel_readl(dwc, LLP);
305 status_xfer = dma_readl(dw, RAW.XFER);
306
307 if (status_xfer & dwc->mask) {
308 /* Everything we've submitted is done */
309 dma_writel(dw, CLEAR.XFER, dwc->mask);
310 spin_unlock_irqrestore(&dwc->lock, flags);
311
312 dwc_complete_all(dw, dwc);
313 return;
314 }
315
316 if (list_empty(&dwc->active_list)) {
317 spin_unlock_irqrestore(&dwc->lock, flags);
318 return;
319 }
320
321 dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
322
323 list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
324 /* check first descriptors addr */
325 if (desc->txd.phys == llp) {
326 spin_unlock_irqrestore(&dwc->lock, flags);
327 return;
328 }
329
330 /* check first descriptors llp */
331 if (desc->lli.llp == llp) {
332 /* This one is currently in progress */
333 spin_unlock_irqrestore(&dwc->lock, flags);
334 return;
335 }
336
337 list_for_each_entry(child, &desc->tx_list, desc_node)
338 if (child->lli.llp == llp) {
339 /* Currently in progress */
340 spin_unlock_irqrestore(&dwc->lock, flags);
341 return;
342 }
343
344 /*
345 * No descriptors so far seem to be in progress, i.e.
346 * this one must be done.
347 */
348 spin_unlock_irqrestore(&dwc->lock, flags);
349 dwc_descriptor_complete(dwc, desc, true);
350 spin_lock_irqsave(&dwc->lock, flags);
351 }
352
353 dev_err(chan2dev(&dwc->chan),
354 "BUG: All descriptors done, but channel not idle!\n");
355
356 /* Try to continue after resetting the channel... */
357 channel_clear_bit(dw, CH_EN, dwc->mask);
358 while (dma_readl(dw, CH_EN) & dwc->mask)
359 cpu_relax();
360
361 if (!list_empty(&dwc->queue)) {
362 list_move(dwc->queue.next, &dwc->active_list);
363 dwc_dostart(dwc, dwc_first_active(dwc));
364 }
365 spin_unlock_irqrestore(&dwc->lock, flags);
366 }
367
368 static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
369 {
370 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
371 " desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
372 lli->sar, lli->dar, lli->llp,
373 lli->ctlhi, lli->ctllo);
374 }
375
376 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
377 {
378 struct dw_desc *bad_desc;
379 struct dw_desc *child;
380 unsigned long flags;
381
382 dwc_scan_descriptors(dw, dwc);
383
384 spin_lock_irqsave(&dwc->lock, flags);
385
386 /*
387 * The descriptor currently at the head of the active list is
388 * borked. Since we don't have any way to report errors, we'll
389 * just have to scream loudly and try to carry on.
390 */
391 bad_desc = dwc_first_active(dwc);
392 list_del_init(&bad_desc->desc_node);
393 list_move(dwc->queue.next, dwc->active_list.prev);
394
395 /* Clear the error flag and try to restart the controller */
396 dma_writel(dw, CLEAR.ERROR, dwc->mask);
397 if (!list_empty(&dwc->active_list))
398 dwc_dostart(dwc, dwc_first_active(dwc));
399
400 /*
401 * KERN_CRITICAL may seem harsh, but since this only happens
402 * when someone submits a bad physical address in a
403 * descriptor, we should consider ourselves lucky that the
404 * controller flagged an error instead of scribbling over
405 * random memory locations.
406 */
407 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
408 "Bad descriptor submitted for DMA!\n");
409 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
410 " cookie: %d\n", bad_desc->txd.cookie);
411 dwc_dump_lli(dwc, &bad_desc->lli);
412 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
413 dwc_dump_lli(dwc, &child->lli);
414
415 spin_unlock_irqrestore(&dwc->lock, flags);
416
417 /* Pretend the descriptor completed successfully */
418 dwc_descriptor_complete(dwc, bad_desc, true);
419 }
420
421 /* --------------------- Cyclic DMA API extensions -------------------- */
422
423 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
424 {
425 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
426 return channel_readl(dwc, SAR);
427 }
428 EXPORT_SYMBOL(dw_dma_get_src_addr);
429
430 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
431 {
432 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
433 return channel_readl(dwc, DAR);
434 }
435 EXPORT_SYMBOL(dw_dma_get_dst_addr);
436
437 /* called with dwc->lock held and all DMAC interrupts disabled */
438 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
439 u32 status_block, u32 status_err, u32 status_xfer)
440 {
441 unsigned long flags;
442
443 if (status_block & dwc->mask) {
444 void (*callback)(void *param);
445 void *callback_param;
446
447 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
448 channel_readl(dwc, LLP));
449 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
450
451 callback = dwc->cdesc->period_callback;
452 callback_param = dwc->cdesc->period_callback_param;
453
454 if (callback)
455 callback(callback_param);
456 }
457
458 /*
459 * Error and transfer complete are highly unlikely, and will most
460 * likely be due to a configuration error by the user.
461 */
462 if (unlikely(status_err & dwc->mask) ||
463 unlikely(status_xfer & dwc->mask)) {
464 int i;
465
466 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
467 "interrupt, stopping DMA transfer\n",
468 status_xfer ? "xfer" : "error");
469
470 spin_lock_irqsave(&dwc->lock, flags);
471
472 dev_err(chan2dev(&dwc->chan),
473 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
474 channel_readl(dwc, SAR),
475 channel_readl(dwc, DAR),
476 channel_readl(dwc, LLP),
477 channel_readl(dwc, CTL_HI),
478 channel_readl(dwc, CTL_LO));
479
480 channel_clear_bit(dw, CH_EN, dwc->mask);
481 while (dma_readl(dw, CH_EN) & dwc->mask)
482 cpu_relax();
483
484 /* make sure DMA does not restart by loading a new list */
485 channel_writel(dwc, LLP, 0);
486 channel_writel(dwc, CTL_LO, 0);
487 channel_writel(dwc, CTL_HI, 0);
488
489 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
490 dma_writel(dw, CLEAR.ERROR, dwc->mask);
491 dma_writel(dw, CLEAR.XFER, dwc->mask);
492
493 for (i = 0; i < dwc->cdesc->periods; i++)
494 dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
495
496 spin_unlock_irqrestore(&dwc->lock, flags);
497 }
498 }
499
500 /* ------------------------------------------------------------------------- */
501
502 static void dw_dma_tasklet(unsigned long data)
503 {
504 struct dw_dma *dw = (struct dw_dma *)data;
505 struct dw_dma_chan *dwc;
506 u32 status_block;
507 u32 status_xfer;
508 u32 status_err;
509 int i;
510
511 status_block = dma_readl(dw, RAW.BLOCK);
512 status_xfer = dma_readl(dw, RAW.XFER);
513 status_err = dma_readl(dw, RAW.ERROR);
514
515 dev_vdbg(dw->dma.dev, "tasklet: status_block=%x status_err=%x\n",
516 status_block, status_err);
517
518 for (i = 0; i < dw->dma.chancnt; i++) {
519 dwc = &dw->chan[i];
520 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
521 dwc_handle_cyclic(dw, dwc, status_block, status_err,
522 status_xfer);
523 else if (status_err & (1 << i))
524 dwc_handle_error(dw, dwc);
525 else if ((status_block | status_xfer) & (1 << i))
526 dwc_scan_descriptors(dw, dwc);
527 }
528
529 /*
530 * Re-enable interrupts. Block Complete interrupts are only
531 * enabled if the INT_EN bit in the descriptor is set. This
532 * will trigger a scan before the whole list is done.
533 */
534 channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
535 channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask);
536 channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
537 }
538
539 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
540 {
541 struct dw_dma *dw = dev_id;
542 u32 status;
543
544 dev_vdbg(dw->dma.dev, "interrupt: status=0x%x\n",
545 dma_readl(dw, STATUS_INT));
546
547 /*
548 * Just disable the interrupts. We'll turn them back on in the
549 * softirq handler.
550 */
551 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
552 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
553 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
554
555 status = dma_readl(dw, STATUS_INT);
556 if (status) {
557 dev_err(dw->dma.dev,
558 "BUG: Unexpected interrupts pending: 0x%x\n",
559 status);
560
561 /* Try to recover */
562 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
563 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
564 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
565 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
566 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
567 }
568
569 tasklet_schedule(&dw->tasklet);
570
571 return IRQ_HANDLED;
572 }
573
574 /*----------------------------------------------------------------------*/
575
576 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
577 {
578 struct dw_desc *desc = txd_to_dw_desc(tx);
579 struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
580 dma_cookie_t cookie;
581 unsigned long flags;
582
583 spin_lock_irqsave(&dwc->lock, flags);
584 cookie = dwc_assign_cookie(dwc, desc);
585
586 /*
587 * REVISIT: We should attempt to chain as many descriptors as
588 * possible, perhaps even appending to those already submitted
589 * for DMA. But this is hard to do in a race-free manner.
590 */
591 if (list_empty(&dwc->active_list)) {
592 dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
593 desc->txd.cookie);
594 list_add_tail(&desc->desc_node, &dwc->active_list);
595 dwc_dostart(dwc, dwc_first_active(dwc));
596 } else {
597 dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
598 desc->txd.cookie);
599
600 list_add_tail(&desc->desc_node, &dwc->queue);
601 }
602
603 spin_unlock_irqrestore(&dwc->lock, flags);
604
605 return cookie;
606 }
607
608 static struct dma_async_tx_descriptor *
609 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
610 size_t len, unsigned long flags)
611 {
612 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
613 struct dw_desc *desc;
614 struct dw_desc *first;
615 struct dw_desc *prev;
616 size_t xfer_count;
617 size_t offset;
618 unsigned int src_width;
619 unsigned int dst_width;
620 u32 ctllo;
621
622 dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
623 dest, src, len, flags);
624
625 if (unlikely(!len)) {
626 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
627 return NULL;
628 }
629
630 /*
631 * We can be a lot more clever here, but this should take care
632 * of the most common optimization.
633 */
634 if (!((src | dest | len) & 7))
635 src_width = dst_width = 3;
636 else if (!((src | dest | len) & 3))
637 src_width = dst_width = 2;
638 else if (!((src | dest | len) & 1))
639 src_width = dst_width = 1;
640 else
641 src_width = dst_width = 0;
642
643 ctllo = DWC_DEFAULT_CTLLO(chan->private)
644 | DWC_CTLL_DST_WIDTH(dst_width)
645 | DWC_CTLL_SRC_WIDTH(src_width)
646 | DWC_CTLL_DST_INC
647 | DWC_CTLL_SRC_INC
648 | DWC_CTLL_FC_M2M;
649 prev = first = NULL;
650
651 for (offset = 0; offset < len; offset += xfer_count << src_width) {
652 xfer_count = min_t(size_t, (len - offset) >> src_width,
653 DWC_MAX_COUNT);
654
655 desc = dwc_desc_get(dwc);
656 if (!desc)
657 goto err_desc_get;
658
659 desc->lli.sar = src + offset;
660 desc->lli.dar = dest + offset;
661 desc->lli.ctllo = ctllo;
662 desc->lli.ctlhi = xfer_count;
663
664 if (!first) {
665 first = desc;
666 } else {
667 prev->lli.llp = desc->txd.phys;
668 dma_sync_single_for_device(chan2parent(chan),
669 prev->txd.phys, sizeof(prev->lli),
670 DMA_TO_DEVICE);
671 list_add_tail(&desc->desc_node,
672 &first->tx_list);
673 }
674 prev = desc;
675 }
676
677
678 if (flags & DMA_PREP_INTERRUPT)
679 /* Trigger interrupt after last block */
680 prev->lli.ctllo |= DWC_CTLL_INT_EN;
681
682 prev->lli.llp = 0;
683 dma_sync_single_for_device(chan2parent(chan),
684 prev->txd.phys, sizeof(prev->lli),
685 DMA_TO_DEVICE);
686
687 first->txd.flags = flags;
688 first->len = len;
689
690 return &first->txd;
691
692 err_desc_get:
693 dwc_desc_put(dwc, first);
694 return NULL;
695 }
696
697 static struct dma_async_tx_descriptor *
698 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
699 unsigned int sg_len, enum dma_data_direction direction,
700 unsigned long flags)
701 {
702 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
703 struct dw_dma_slave *dws = chan->private;
704 struct dw_desc *prev;
705 struct dw_desc *first;
706 u32 ctllo;
707 dma_addr_t reg;
708 unsigned int reg_width;
709 unsigned int mem_width;
710 unsigned int i;
711 struct scatterlist *sg;
712 size_t total_len = 0;
713
714 dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
715
716 if (unlikely(!dws || !sg_len))
717 return NULL;
718
719 reg_width = dws->reg_width;
720 prev = first = NULL;
721
722 switch (direction) {
723 case DMA_TO_DEVICE:
724 ctllo = (DWC_DEFAULT_CTLLO(chan->private)
725 | DWC_CTLL_DST_WIDTH(reg_width)
726 | DWC_CTLL_DST_FIX
727 | DWC_CTLL_SRC_INC
728 | DWC_CTLL_FC(dws->fc));
729 reg = dws->tx_reg;
730 for_each_sg(sgl, sg, sg_len, i) {
731 struct dw_desc *desc;
732 u32 len, dlen, mem;
733
734 mem = sg_phys(sg);
735 len = sg_dma_len(sg);
736 mem_width = 2;
737 if (unlikely(mem & 3 || len & 3))
738 mem_width = 0;
739
740 slave_sg_todev_fill_desc:
741 desc = dwc_desc_get(dwc);
742 if (!desc) {
743 dev_err(chan2dev(chan),
744 "not enough descriptors available\n");
745 goto err_desc_get;
746 }
747
748 desc->lli.sar = mem;
749 desc->lli.dar = reg;
750 desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
751 if ((len >> mem_width) > DWC_MAX_COUNT) {
752 dlen = DWC_MAX_COUNT << mem_width;
753 mem += dlen;
754 len -= dlen;
755 } else {
756 dlen = len;
757 len = 0;
758 }
759
760 desc->lli.ctlhi = dlen >> mem_width;
761
762 if (!first) {
763 first = desc;
764 } else {
765 prev->lli.llp = desc->txd.phys;
766 dma_sync_single_for_device(chan2parent(chan),
767 prev->txd.phys,
768 sizeof(prev->lli),
769 DMA_TO_DEVICE);
770 list_add_tail(&desc->desc_node,
771 &first->tx_list);
772 }
773 prev = desc;
774 total_len += dlen;
775
776 if (len)
777 goto slave_sg_todev_fill_desc;
778 }
779 break;
780 case DMA_FROM_DEVICE:
781 ctllo = (DWC_DEFAULT_CTLLO(chan->private)
782 | DWC_CTLL_SRC_WIDTH(reg_width)
783 | DWC_CTLL_DST_INC
784 | DWC_CTLL_SRC_FIX
785 | DWC_CTLL_FC(dws->fc));
786
787 reg = dws->rx_reg;
788 for_each_sg(sgl, sg, sg_len, i) {
789 struct dw_desc *desc;
790 u32 len, dlen, mem;
791
792 mem = sg_phys(sg);
793 len = sg_dma_len(sg);
794 mem_width = 2;
795 if (unlikely(mem & 3 || len & 3))
796 mem_width = 0;
797
798 slave_sg_fromdev_fill_desc:
799 desc = dwc_desc_get(dwc);
800 if (!desc) {
801 dev_err(chan2dev(chan),
802 "not enough descriptors available\n");
803 goto err_desc_get;
804 }
805
806 desc->lli.sar = reg;
807 desc->lli.dar = mem;
808 desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
809 if ((len >> reg_width) > DWC_MAX_COUNT) {
810 dlen = DWC_MAX_COUNT << reg_width;
811 mem += dlen;
812 len -= dlen;
813 } else {
814 dlen = len;
815 len = 0;
816 }
817 desc->lli.ctlhi = dlen >> reg_width;
818
819 if (!first) {
820 first = desc;
821 } else {
822 prev->lli.llp = desc->txd.phys;
823 dma_sync_single_for_device(chan2parent(chan),
824 prev->txd.phys,
825 sizeof(prev->lli),
826 DMA_TO_DEVICE);
827 list_add_tail(&desc->desc_node,
828 &first->tx_list);
829 }
830 prev = desc;
831 total_len += dlen;
832
833 if (len)
834 goto slave_sg_fromdev_fill_desc;
835 }
836 break;
837 default:
838 return NULL;
839 }
840
841 if (flags & DMA_PREP_INTERRUPT)
842 /* Trigger interrupt after last block */
843 prev->lli.ctllo |= DWC_CTLL_INT_EN;
844
845 prev->lli.llp = 0;
846 dma_sync_single_for_device(chan2parent(chan),
847 prev->txd.phys, sizeof(prev->lli),
848 DMA_TO_DEVICE);
849
850 first->len = total_len;
851
852 return &first->txd;
853
854 err_desc_get:
855 dwc_desc_put(dwc, first);
856 return NULL;
857 }
858
859 static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
860 unsigned long arg)
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, *_desc;
865 unsigned long flags;
866 u32 cfglo;
867 LIST_HEAD(list);
868
869 if (cmd == DMA_PAUSE) {
870 spin_lock_irqsave(&dwc->lock, flags);
871
872 cfglo = channel_readl(dwc, CFG_LO);
873 channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
874 while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY))
875 cpu_relax();
876
877 dwc->paused = true;
878 spin_unlock_irqrestore(&dwc->lock, flags);
879 } else if (cmd == DMA_RESUME) {
880 if (!dwc->paused)
881 return 0;
882
883 spin_lock_irqsave(&dwc->lock, flags);
884
885 cfglo = channel_readl(dwc, CFG_LO);
886 channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
887 dwc->paused = false;
888
889 spin_unlock_irqrestore(&dwc->lock, flags);
890 } else if (cmd == DMA_TERMINATE_ALL) {
891 spin_lock_irqsave(&dwc->lock, flags);
892
893 channel_clear_bit(dw, CH_EN, dwc->mask);
894 while (dma_readl(dw, CH_EN) & dwc->mask)
895 cpu_relax();
896
897 dwc->paused = false;
898
899 /* active_list entries will end up before queued entries */
900 list_splice_init(&dwc->queue, &list);
901 list_splice_init(&dwc->active_list, &list);
902
903 spin_unlock_irqrestore(&dwc->lock, flags);
904
905 /* Flush all pending and queued descriptors */
906 list_for_each_entry_safe(desc, _desc, &list, desc_node)
907 dwc_descriptor_complete(dwc, desc, false);
908 } else
909 return -ENXIO;
910
911 return 0;
912 }
913
914 static enum dma_status
915 dwc_tx_status(struct dma_chan *chan,
916 dma_cookie_t cookie,
917 struct dma_tx_state *txstate)
918 {
919 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
920 dma_cookie_t last_used;
921 dma_cookie_t last_complete;
922 int ret;
923
924 last_complete = dwc->completed;
925 last_used = chan->cookie;
926
927 ret = dma_async_is_complete(cookie, last_complete, last_used);
928 if (ret != DMA_SUCCESS) {
929 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
930
931 last_complete = dwc->completed;
932 last_used = chan->cookie;
933
934 ret = dma_async_is_complete(cookie, last_complete, last_used);
935 }
936
937 if (ret != DMA_SUCCESS)
938 dma_set_tx_state(txstate, last_complete, last_used,
939 dwc_first_active(dwc)->len);
940 else
941 dma_set_tx_state(txstate, last_complete, last_used, 0);
942
943 if (dwc->paused)
944 return DMA_PAUSED;
945
946 return ret;
947 }
948
949 static void dwc_issue_pending(struct dma_chan *chan)
950 {
951 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
952
953 if (!list_empty(&dwc->queue))
954 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
955 }
956
957 static int dwc_alloc_chan_resources(struct dma_chan *chan)
958 {
959 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
960 struct dw_dma *dw = to_dw_dma(chan->device);
961 struct dw_desc *desc;
962 struct dw_dma_slave *dws;
963 int i;
964 u32 cfghi;
965 u32 cfglo;
966 unsigned long flags;
967
968 dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
969
970 /* ASSERT: channel is idle */
971 if (dma_readl(dw, CH_EN) & dwc->mask) {
972 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
973 return -EIO;
974 }
975
976 dwc->completed = chan->cookie = 1;
977
978 cfghi = DWC_CFGH_FIFO_MODE;
979 cfglo = 0;
980
981 dws = chan->private;
982 if (dws) {
983 /*
984 * We need controller-specific data to set up slave
985 * transfers.
986 */
987 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
988
989 cfghi = dws->cfg_hi;
990 cfglo = dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
991 }
992
993 cfglo |= DWC_CFGL_CH_PRIOR(dwc->priority);
994
995 channel_writel(dwc, CFG_LO, cfglo);
996 channel_writel(dwc, CFG_HI, cfghi);
997
998 /*
999 * NOTE: some controllers may have additional features that we
1000 * need to initialize here, like "scatter-gather" (which
1001 * doesn't mean what you think it means), and status writeback.
1002 */
1003
1004 spin_lock_irqsave(&dwc->lock, flags);
1005 i = dwc->descs_allocated;
1006 while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1007 spin_unlock_irqrestore(&dwc->lock, flags);
1008
1009 desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
1010 if (!desc) {
1011 dev_info(chan2dev(chan),
1012 "only allocated %d descriptors\n", i);
1013 spin_lock_irqsave(&dwc->lock, flags);
1014 break;
1015 }
1016
1017 INIT_LIST_HEAD(&desc->tx_list);
1018 dma_async_tx_descriptor_init(&desc->txd, chan);
1019 desc->txd.tx_submit = dwc_tx_submit;
1020 desc->txd.flags = DMA_CTRL_ACK;
1021 desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,
1022 sizeof(desc->lli), DMA_TO_DEVICE);
1023 dwc_desc_put(dwc, desc);
1024
1025 spin_lock_irqsave(&dwc->lock, flags);
1026 i = ++dwc->descs_allocated;
1027 }
1028
1029 /* Enable interrupts */
1030 channel_set_bit(dw, MASK.XFER, dwc->mask);
1031 channel_set_bit(dw, MASK.BLOCK, dwc->mask);
1032 channel_set_bit(dw, MASK.ERROR, dwc->mask);
1033
1034 spin_unlock_irqrestore(&dwc->lock, flags);
1035
1036 dev_dbg(chan2dev(chan),
1037 "alloc_chan_resources allocated %d descriptors\n", i);
1038
1039 return i;
1040 }
1041
1042 static void dwc_free_chan_resources(struct dma_chan *chan)
1043 {
1044 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1045 struct dw_dma *dw = to_dw_dma(chan->device);
1046 struct dw_desc *desc, *_desc;
1047 unsigned long flags;
1048 LIST_HEAD(list);
1049
1050 dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
1051 dwc->descs_allocated);
1052
1053 /* ASSERT: channel is idle */
1054 BUG_ON(!list_empty(&dwc->active_list));
1055 BUG_ON(!list_empty(&dwc->queue));
1056 BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1057
1058 spin_lock_irqsave(&dwc->lock, flags);
1059 list_splice_init(&dwc->free_list, &list);
1060 dwc->descs_allocated = 0;
1061
1062 /* Disable interrupts */
1063 channel_clear_bit(dw, MASK.XFER, dwc->mask);
1064 channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1065 channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1066
1067 spin_unlock_irqrestore(&dwc->lock, flags);
1068
1069 list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1070 dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
1071 dma_unmap_single(chan2parent(chan), desc->txd.phys,
1072 sizeof(desc->lli), DMA_TO_DEVICE);
1073 kfree(desc);
1074 }
1075
1076 dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
1077 }
1078
1079 /* --------------------- Cyclic DMA API extensions -------------------- */
1080
1081 /**
1082 * dw_dma_cyclic_start - start the cyclic DMA transfer
1083 * @chan: the DMA channel to start
1084 *
1085 * Must be called with soft interrupts disabled. Returns zero on success or
1086 * -errno on failure.
1087 */
1088 int dw_dma_cyclic_start(struct dma_chan *chan)
1089 {
1090 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1091 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1092 unsigned long flags;
1093
1094 if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1095 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1096 return -ENODEV;
1097 }
1098
1099 spin_lock_irqsave(&dwc->lock, flags);
1100
1101 /* assert channel is idle */
1102 if (dma_readl(dw, CH_EN) & dwc->mask) {
1103 dev_err(chan2dev(&dwc->chan),
1104 "BUG: Attempted to start non-idle channel\n");
1105 dev_err(chan2dev(&dwc->chan),
1106 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
1107 channel_readl(dwc, SAR),
1108 channel_readl(dwc, DAR),
1109 channel_readl(dwc, LLP),
1110 channel_readl(dwc, CTL_HI),
1111 channel_readl(dwc, CTL_LO));
1112 spin_unlock_irqrestore(&dwc->lock, flags);
1113 return -EBUSY;
1114 }
1115
1116 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1117 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1118 dma_writel(dw, CLEAR.XFER, dwc->mask);
1119
1120 /* setup DMAC channel registers */
1121 channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1122 channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1123 channel_writel(dwc, CTL_HI, 0);
1124
1125 channel_set_bit(dw, CH_EN, dwc->mask);
1126
1127 spin_unlock_irqrestore(&dwc->lock, flags);
1128
1129 return 0;
1130 }
1131 EXPORT_SYMBOL(dw_dma_cyclic_start);
1132
1133 /**
1134 * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1135 * @chan: the DMA channel to stop
1136 *
1137 * Must be called with soft interrupts disabled.
1138 */
1139 void dw_dma_cyclic_stop(struct dma_chan *chan)
1140 {
1141 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1142 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1143 unsigned long flags;
1144
1145 spin_lock_irqsave(&dwc->lock, flags);
1146
1147 channel_clear_bit(dw, CH_EN, dwc->mask);
1148 while (dma_readl(dw, CH_EN) & dwc->mask)
1149 cpu_relax();
1150
1151 spin_unlock_irqrestore(&dwc->lock, flags);
1152 }
1153 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1154
1155 /**
1156 * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1157 * @chan: the DMA channel to prepare
1158 * @buf_addr: physical DMA address where the buffer starts
1159 * @buf_len: total number of bytes for the entire buffer
1160 * @period_len: number of bytes for each period
1161 * @direction: transfer direction, to or from device
1162 *
1163 * Must be called before trying to start the transfer. Returns a valid struct
1164 * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1165 */
1166 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1167 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1168 enum dma_data_direction direction)
1169 {
1170 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1171 struct dw_cyclic_desc *cdesc;
1172 struct dw_cyclic_desc *retval = NULL;
1173 struct dw_desc *desc;
1174 struct dw_desc *last = NULL;
1175 struct dw_dma_slave *dws = chan->private;
1176 unsigned long was_cyclic;
1177 unsigned int reg_width;
1178 unsigned int periods;
1179 unsigned int i;
1180 unsigned long flags;
1181
1182 spin_lock_irqsave(&dwc->lock, flags);
1183 if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1184 spin_unlock_irqrestore(&dwc->lock, flags);
1185 dev_dbg(chan2dev(&dwc->chan),
1186 "queue and/or active list are not empty\n");
1187 return ERR_PTR(-EBUSY);
1188 }
1189
1190 was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1191 spin_unlock_irqrestore(&dwc->lock, flags);
1192 if (was_cyclic) {
1193 dev_dbg(chan2dev(&dwc->chan),
1194 "channel already prepared for cyclic DMA\n");
1195 return ERR_PTR(-EBUSY);
1196 }
1197
1198 retval = ERR_PTR(-EINVAL);
1199 reg_width = dws->reg_width;
1200 periods = buf_len / period_len;
1201
1202 /* Check for too big/unaligned periods and unaligned DMA buffer. */
1203 if (period_len > (DWC_MAX_COUNT << reg_width))
1204 goto out_err;
1205 if (unlikely(period_len & ((1 << reg_width) - 1)))
1206 goto out_err;
1207 if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1208 goto out_err;
1209 if (unlikely(!(direction & (DMA_TO_DEVICE | DMA_FROM_DEVICE))))
1210 goto out_err;
1211
1212 retval = ERR_PTR(-ENOMEM);
1213
1214 if (periods > NR_DESCS_PER_CHANNEL)
1215 goto out_err;
1216
1217 cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1218 if (!cdesc)
1219 goto out_err;
1220
1221 cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1222 if (!cdesc->desc)
1223 goto out_err_alloc;
1224
1225 for (i = 0; i < periods; i++) {
1226 desc = dwc_desc_get(dwc);
1227 if (!desc)
1228 goto out_err_desc_get;
1229
1230 switch (direction) {
1231 case DMA_TO_DEVICE:
1232 desc->lli.dar = dws->tx_reg;
1233 desc->lli.sar = buf_addr + (period_len * i);
1234 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
1235 | DWC_CTLL_DST_WIDTH(reg_width)
1236 | DWC_CTLL_SRC_WIDTH(reg_width)
1237 | DWC_CTLL_DST_FIX
1238 | DWC_CTLL_SRC_INC
1239 | DWC_CTLL_FC(dws->fc)
1240 | DWC_CTLL_INT_EN);
1241 break;
1242 case DMA_FROM_DEVICE:
1243 desc->lli.dar = buf_addr + (period_len * i);
1244 desc->lli.sar = dws->rx_reg;
1245 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
1246 | DWC_CTLL_SRC_WIDTH(reg_width)
1247 | DWC_CTLL_DST_WIDTH(reg_width)
1248 | DWC_CTLL_DST_INC
1249 | DWC_CTLL_SRC_FIX
1250 | DWC_CTLL_FC(dws->fc)
1251 | DWC_CTLL_INT_EN);
1252 break;
1253 default:
1254 break;
1255 }
1256
1257 desc->lli.ctlhi = (period_len >> reg_width);
1258 cdesc->desc[i] = desc;
1259
1260 if (last) {
1261 last->lli.llp = desc->txd.phys;
1262 dma_sync_single_for_device(chan2parent(chan),
1263 last->txd.phys, sizeof(last->lli),
1264 DMA_TO_DEVICE);
1265 }
1266
1267 last = desc;
1268 }
1269
1270 /* lets make a cyclic list */
1271 last->lli.llp = cdesc->desc[0]->txd.phys;
1272 dma_sync_single_for_device(chan2parent(chan), last->txd.phys,
1273 sizeof(last->lli), DMA_TO_DEVICE);
1274
1275 dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%08x len %zu "
1276 "period %zu periods %d\n", buf_addr, buf_len,
1277 period_len, periods);
1278
1279 cdesc->periods = periods;
1280 dwc->cdesc = cdesc;
1281
1282 return cdesc;
1283
1284 out_err_desc_get:
1285 while (i--)
1286 dwc_desc_put(dwc, cdesc->desc[i]);
1287 out_err_alloc:
1288 kfree(cdesc);
1289 out_err:
1290 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1291 return (struct dw_cyclic_desc *)retval;
1292 }
1293 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1294
1295 /**
1296 * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1297 * @chan: the DMA channel to free
1298 */
1299 void dw_dma_cyclic_free(struct dma_chan *chan)
1300 {
1301 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1302 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1303 struct dw_cyclic_desc *cdesc = dwc->cdesc;
1304 int i;
1305 unsigned long flags;
1306
1307 dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
1308
1309 if (!cdesc)
1310 return;
1311
1312 spin_lock_irqsave(&dwc->lock, flags);
1313
1314 channel_clear_bit(dw, CH_EN, dwc->mask);
1315 while (dma_readl(dw, CH_EN) & dwc->mask)
1316 cpu_relax();
1317
1318 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1319 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1320 dma_writel(dw, CLEAR.XFER, dwc->mask);
1321
1322 spin_unlock_irqrestore(&dwc->lock, flags);
1323
1324 for (i = 0; i < cdesc->periods; i++)
1325 dwc_desc_put(dwc, cdesc->desc[i]);
1326
1327 kfree(cdesc->desc);
1328 kfree(cdesc);
1329
1330 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1331 }
1332 EXPORT_SYMBOL(dw_dma_cyclic_free);
1333
1334 /*----------------------------------------------------------------------*/
1335
1336 static void dw_dma_off(struct dw_dma *dw)
1337 {
1338 dma_writel(dw, CFG, 0);
1339
1340 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1341 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1342 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1343 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1344 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1345
1346 while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1347 cpu_relax();
1348 }
1349
1350 static int __init dw_probe(struct platform_device *pdev)
1351 {
1352 struct dw_dma_platform_data *pdata;
1353 struct resource *io;
1354 struct dw_dma *dw;
1355 size_t size;
1356 int irq;
1357 int err;
1358 int i;
1359
1360 pdata = pdev->dev.platform_data;
1361 if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1362 return -EINVAL;
1363
1364 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1365 if (!io)
1366 return -EINVAL;
1367
1368 irq = platform_get_irq(pdev, 0);
1369 if (irq < 0)
1370 return irq;
1371
1372 size = sizeof(struct dw_dma);
1373 size += pdata->nr_channels * sizeof(struct dw_dma_chan);
1374 dw = kzalloc(size, GFP_KERNEL);
1375 if (!dw)
1376 return -ENOMEM;
1377
1378 if (!request_mem_region(io->start, DW_REGLEN, pdev->dev.driver->name)) {
1379 err = -EBUSY;
1380 goto err_kfree;
1381 }
1382
1383 dw->regs = ioremap(io->start, DW_REGLEN);
1384 if (!dw->regs) {
1385 err = -ENOMEM;
1386 goto err_release_r;
1387 }
1388
1389 dw->clk = clk_get(&pdev->dev, "hclk");
1390 if (IS_ERR(dw->clk)) {
1391 err = PTR_ERR(dw->clk);
1392 goto err_clk;
1393 }
1394 clk_enable(dw->clk);
1395
1396 /* force dma off, just in case */
1397 dw_dma_off(dw);
1398
1399 err = request_irq(irq, dw_dma_interrupt, 0, "dw_dmac", dw);
1400 if (err)
1401 goto err_irq;
1402
1403 platform_set_drvdata(pdev, dw);
1404
1405 tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1406
1407 dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1408
1409 INIT_LIST_HEAD(&dw->dma.channels);
1410 for (i = 0; i < pdata->nr_channels; i++, dw->dma.chancnt++) {
1411 struct dw_dma_chan *dwc = &dw->chan[i];
1412
1413 dwc->chan.device = &dw->dma;
1414 dwc->chan.cookie = dwc->completed = 1;
1415 dwc->chan.chan_id = i;
1416 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1417 list_add_tail(&dwc->chan.device_node,
1418 &dw->dma.channels);
1419 else
1420 list_add(&dwc->chan.device_node, &dw->dma.channels);
1421
1422 /* 7 is highest priority & 0 is lowest. */
1423 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1424 dwc->priority = 7 - i;
1425 else
1426 dwc->priority = i;
1427
1428 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1429 spin_lock_init(&dwc->lock);
1430 dwc->mask = 1 << i;
1431
1432 INIT_LIST_HEAD(&dwc->active_list);
1433 INIT_LIST_HEAD(&dwc->queue);
1434 INIT_LIST_HEAD(&dwc->free_list);
1435
1436 channel_clear_bit(dw, CH_EN, dwc->mask);
1437 }
1438
1439 /* Clear/disable all interrupts on all channels. */
1440 dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1441 dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1442 dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1443 dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1444 dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1445
1446 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1447 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1448 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1449 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1450 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1451
1452 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1453 dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1454 if (pdata->is_private)
1455 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1456 dw->dma.dev = &pdev->dev;
1457 dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1458 dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1459
1460 dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1461
1462 dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1463 dw->dma.device_control = dwc_control;
1464
1465 dw->dma.device_tx_status = dwc_tx_status;
1466 dw->dma.device_issue_pending = dwc_issue_pending;
1467
1468 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1469
1470 printk(KERN_INFO "%s: DesignWare DMA Controller, %d channels\n",
1471 dev_name(&pdev->dev), dw->dma.chancnt);
1472
1473 dma_async_device_register(&dw->dma);
1474
1475 return 0;
1476
1477 err_irq:
1478 clk_disable(dw->clk);
1479 clk_put(dw->clk);
1480 err_clk:
1481 iounmap(dw->regs);
1482 dw->regs = NULL;
1483 err_release_r:
1484 release_resource(io);
1485 err_kfree:
1486 kfree(dw);
1487 return err;
1488 }
1489
1490 static int __exit dw_remove(struct platform_device *pdev)
1491 {
1492 struct dw_dma *dw = platform_get_drvdata(pdev);
1493 struct dw_dma_chan *dwc, *_dwc;
1494 struct resource *io;
1495
1496 dw_dma_off(dw);
1497 dma_async_device_unregister(&dw->dma);
1498
1499 free_irq(platform_get_irq(pdev, 0), dw);
1500 tasklet_kill(&dw->tasklet);
1501
1502 list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1503 chan.device_node) {
1504 list_del(&dwc->chan.device_node);
1505 channel_clear_bit(dw, CH_EN, dwc->mask);
1506 }
1507
1508 clk_disable(dw->clk);
1509 clk_put(dw->clk);
1510
1511 iounmap(dw->regs);
1512 dw->regs = NULL;
1513
1514 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1515 release_mem_region(io->start, DW_REGLEN);
1516
1517 kfree(dw);
1518
1519 return 0;
1520 }
1521
1522 static void dw_shutdown(struct platform_device *pdev)
1523 {
1524 struct dw_dma *dw = platform_get_drvdata(pdev);
1525
1526 dw_dma_off(platform_get_drvdata(pdev));
1527 clk_disable(dw->clk);
1528 }
1529
1530 static int dw_suspend_noirq(struct device *dev)
1531 {
1532 struct platform_device *pdev = to_platform_device(dev);
1533 struct dw_dma *dw = platform_get_drvdata(pdev);
1534
1535 dw_dma_off(platform_get_drvdata(pdev));
1536 clk_disable(dw->clk);
1537 return 0;
1538 }
1539
1540 static int dw_resume_noirq(struct device *dev)
1541 {
1542 struct platform_device *pdev = to_platform_device(dev);
1543 struct dw_dma *dw = platform_get_drvdata(pdev);
1544
1545 clk_enable(dw->clk);
1546 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1547 return 0;
1548 }
1549
1550 static const struct dev_pm_ops dw_dev_pm_ops = {
1551 .suspend_noirq = dw_suspend_noirq,
1552 .resume_noirq = dw_resume_noirq,
1553 };
1554
1555 static struct platform_driver dw_driver = {
1556 .remove = __exit_p(dw_remove),
1557 .shutdown = dw_shutdown,
1558 .driver = {
1559 .name = "dw_dmac",
1560 .pm = &dw_dev_pm_ops,
1561 },
1562 };
1563
1564 static int __init dw_init(void)
1565 {
1566 return platform_driver_probe(&dw_driver, dw_probe);
1567 }
1568 subsys_initcall(dw_init);
1569
1570 static void __exit dw_exit(void)
1571 {
1572 platform_driver_unregister(&dw_driver);
1573 }
1574 module_exit(dw_exit);
1575
1576 MODULE_LICENSE("GPL v2");
1577 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1578 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1579 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree