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OMAPDSS: VENC: fix NULL pointer dereference in DSS2 VENC sysfs debug attr on OMAP4
[zen-stable.git] / drivers / dma / dw_dmac.c
blob9b592b02b5f49a3023cdc883322af7c451448a0a
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 static void dwc_initialize(struct dw_dma_chan *dwc)
170 {
171 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
172 struct dw_dma_slave *dws = dwc->chan.private;
173 u32 cfghi = DWC_CFGH_FIFO_MODE;
174 u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
175
176 if (dwc->initialized == true)
177 return;
178
179 if (dws) {
180 /*
181 * We need controller-specific data to set up slave
182 * transfers.
183 */
184 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
185
186 cfghi = dws->cfg_hi;
187 cfglo |= dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
188 }
189
190 channel_writel(dwc, CFG_LO, cfglo);
191 channel_writel(dwc, CFG_HI, cfghi);
192
193 /* Enable interrupts */
194 channel_set_bit(dw, MASK.XFER, dwc->mask);
195 channel_set_bit(dw, MASK.BLOCK, dwc->mask);
196 channel_set_bit(dw, MASK.ERROR, dwc->mask);
197
198 dwc->initialized = true;
199 }
200
201 /*----------------------------------------------------------------------*/
202
203 /* Called with dwc->lock held and bh disabled */
204 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
205 {
206 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
207
208 /* ASSERT: channel is idle */
209 if (dma_readl(dw, CH_EN) & dwc->mask) {
210 dev_err(chan2dev(&dwc->chan),
211 "BUG: Attempted to start non-idle channel\n");
212 dev_err(chan2dev(&dwc->chan),
213 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
214 channel_readl(dwc, SAR),
215 channel_readl(dwc, DAR),
216 channel_readl(dwc, LLP),
217 channel_readl(dwc, CTL_HI),
218 channel_readl(dwc, CTL_LO));
219
220 /* The tasklet will hopefully advance the queue... */
221 return;
222 }
223
224 dwc_initialize(dwc);
225
226 channel_writel(dwc, LLP, first->txd.phys);
227 channel_writel(dwc, CTL_LO,
228 DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
229 channel_writel(dwc, CTL_HI, 0);
230 channel_set_bit(dw, CH_EN, dwc->mask);
231 }
232
233 /*----------------------------------------------------------------------*/
234
235 static void
236 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
237 bool callback_required)
238 {
239 dma_async_tx_callback callback = NULL;
240 void *param = NULL;
241 struct dma_async_tx_descriptor *txd = &desc->txd;
242 struct dw_desc *child;
243 unsigned long flags;
244
245 dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
246
247 spin_lock_irqsave(&dwc->lock, flags);
248 dwc->completed = txd->cookie;
249 if (callback_required) {
250 callback = txd->callback;
251 param = txd->callback_param;
252 }
253
254 dwc_sync_desc_for_cpu(dwc, desc);
255
256 /* async_tx_ack */
257 list_for_each_entry(child, &desc->tx_list, desc_node)
258 async_tx_ack(&child->txd);
259 async_tx_ack(&desc->txd);
260
261 list_splice_init(&desc->tx_list, &dwc->free_list);
262 list_move(&desc->desc_node, &dwc->free_list);
263
264 if (!dwc->chan.private) {
265 struct device *parent = chan2parent(&dwc->chan);
266 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
267 if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
268 dma_unmap_single(parent, desc->lli.dar,
269 desc->len, DMA_FROM_DEVICE);
270 else
271 dma_unmap_page(parent, desc->lli.dar,
272 desc->len, DMA_FROM_DEVICE);
273 }
274 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
275 if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
276 dma_unmap_single(parent, desc->lli.sar,
277 desc->len, DMA_TO_DEVICE);
278 else
279 dma_unmap_page(parent, desc->lli.sar,
280 desc->len, DMA_TO_DEVICE);
281 }
282 }
283
284 spin_unlock_irqrestore(&dwc->lock, flags);
285
286 if (callback_required && callback)
287 callback(param);
288 }
289
290 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
291 {
292 struct dw_desc *desc, *_desc;
293 LIST_HEAD(list);
294 unsigned long flags;
295
296 spin_lock_irqsave(&dwc->lock, flags);
297 if (dma_readl(dw, CH_EN) & dwc->mask) {
298 dev_err(chan2dev(&dwc->chan),
299 "BUG: XFER bit set, but channel not idle!\n");
300
301 /* Try to continue after resetting the channel... */
302 channel_clear_bit(dw, CH_EN, dwc->mask);
303 while (dma_readl(dw, CH_EN) & dwc->mask)
304 cpu_relax();
305 }
306
307 /*
308 * Submit queued descriptors ASAP, i.e. before we go through
309 * the completed ones.
310 */
311 list_splice_init(&dwc->active_list, &list);
312 if (!list_empty(&dwc->queue)) {
313 list_move(dwc->queue.next, &dwc->active_list);
314 dwc_dostart(dwc, dwc_first_active(dwc));
315 }
316
317 spin_unlock_irqrestore(&dwc->lock, flags);
318
319 list_for_each_entry_safe(desc, _desc, &list, desc_node)
320 dwc_descriptor_complete(dwc, desc, true);
321 }
322
323 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
324 {
325 dma_addr_t llp;
326 struct dw_desc *desc, *_desc;
327 struct dw_desc *child;
328 u32 status_xfer;
329 unsigned long flags;
330
331 spin_lock_irqsave(&dwc->lock, flags);
332 /*
333 * Clear block interrupt flag before scanning so that we don't
334 * miss any, and read LLP before RAW_XFER to ensure it is
335 * valid if we decide to scan the list.
336 */
337 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
338 llp = channel_readl(dwc, LLP);
339 status_xfer = dma_readl(dw, RAW.XFER);
340
341 if (status_xfer & dwc->mask) {
342 /* Everything we've submitted is done */
343 dma_writel(dw, CLEAR.XFER, dwc->mask);
344 spin_unlock_irqrestore(&dwc->lock, flags);
345
346 dwc_complete_all(dw, dwc);
347 return;
348 }
349
350 if (list_empty(&dwc->active_list)) {
351 spin_unlock_irqrestore(&dwc->lock, flags);
352 return;
353 }
354
355 dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
356
357 list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
358 /* check first descriptors addr */
359 if (desc->txd.phys == llp) {
360 spin_unlock_irqrestore(&dwc->lock, flags);
361 return;
362 }
363
364 /* check first descriptors llp */
365 if (desc->lli.llp == llp) {
366 /* This one is currently in progress */
367 spin_unlock_irqrestore(&dwc->lock, flags);
368 return;
369 }
370
371 list_for_each_entry(child, &desc->tx_list, desc_node)
372 if (child->lli.llp == llp) {
373 /* Currently in progress */
374 spin_unlock_irqrestore(&dwc->lock, flags);
375 return;
376 }
377
378 /*
379 * No descriptors so far seem to be in progress, i.e.
380 * this one must be done.
381 */
382 spin_unlock_irqrestore(&dwc->lock, flags);
383 dwc_descriptor_complete(dwc, desc, true);
384 spin_lock_irqsave(&dwc->lock, flags);
385 }
386
387 dev_err(chan2dev(&dwc->chan),
388 "BUG: All descriptors done, but channel not idle!\n");
389
390 /* Try to continue after resetting the channel... */
391 channel_clear_bit(dw, CH_EN, dwc->mask);
392 while (dma_readl(dw, CH_EN) & dwc->mask)
393 cpu_relax();
394
395 if (!list_empty(&dwc->queue)) {
396 list_move(dwc->queue.next, &dwc->active_list);
397 dwc_dostart(dwc, dwc_first_active(dwc));
398 }
399 spin_unlock_irqrestore(&dwc->lock, flags);
400 }
401
402 static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
403 {
404 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
405 " desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
406 lli->sar, lli->dar, lli->llp,
407 lli->ctlhi, lli->ctllo);
408 }
409
410 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
411 {
412 struct dw_desc *bad_desc;
413 struct dw_desc *child;
414 unsigned long flags;
415
416 dwc_scan_descriptors(dw, dwc);
417
418 spin_lock_irqsave(&dwc->lock, flags);
419
420 /*
421 * The descriptor currently at the head of the active list is
422 * borked. Since we don't have any way to report errors, we'll
423 * just have to scream loudly and try to carry on.
424 */
425 bad_desc = dwc_first_active(dwc);
426 list_del_init(&bad_desc->desc_node);
427 list_move(dwc->queue.next, dwc->active_list.prev);
428
429 /* Clear the error flag and try to restart the controller */
430 dma_writel(dw, CLEAR.ERROR, dwc->mask);
431 if (!list_empty(&dwc->active_list))
432 dwc_dostart(dwc, dwc_first_active(dwc));
433
434 /*
435 * KERN_CRITICAL may seem harsh, but since this only happens
436 * when someone submits a bad physical address in a
437 * descriptor, we should consider ourselves lucky that the
438 * controller flagged an error instead of scribbling over
439 * random memory locations.
440 */
441 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
442 "Bad descriptor submitted for DMA!\n");
443 dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
444 " cookie: %d\n", bad_desc->txd.cookie);
445 dwc_dump_lli(dwc, &bad_desc->lli);
446 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
447 dwc_dump_lli(dwc, &child->lli);
448
449 spin_unlock_irqrestore(&dwc->lock, flags);
450
451 /* Pretend the descriptor completed successfully */
452 dwc_descriptor_complete(dwc, bad_desc, true);
453 }
454
455 /* --------------------- Cyclic DMA API extensions -------------------- */
456
457 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
458 {
459 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
460 return channel_readl(dwc, SAR);
461 }
462 EXPORT_SYMBOL(dw_dma_get_src_addr);
463
464 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
465 {
466 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
467 return channel_readl(dwc, DAR);
468 }
469 EXPORT_SYMBOL(dw_dma_get_dst_addr);
470
471 /* called with dwc->lock held and all DMAC interrupts disabled */
472 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
473 u32 status_block, u32 status_err, u32 status_xfer)
474 {
475 unsigned long flags;
476
477 if (status_block & dwc->mask) {
478 void (*callback)(void *param);
479 void *callback_param;
480
481 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
482 channel_readl(dwc, LLP));
483 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
484
485 callback = dwc->cdesc->period_callback;
486 callback_param = dwc->cdesc->period_callback_param;
487
488 if (callback)
489 callback(callback_param);
490 }
491
492 /*
493 * Error and transfer complete are highly unlikely, and will most
494 * likely be due to a configuration error by the user.
495 */
496 if (unlikely(status_err & dwc->mask) ||
497 unlikely(status_xfer & dwc->mask)) {
498 int i;
499
500 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
501 "interrupt, stopping DMA transfer\n",
502 status_xfer ? "xfer" : "error");
503
504 spin_lock_irqsave(&dwc->lock, flags);
505
506 dev_err(chan2dev(&dwc->chan),
507 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
508 channel_readl(dwc, SAR),
509 channel_readl(dwc, DAR),
510 channel_readl(dwc, LLP),
511 channel_readl(dwc, CTL_HI),
512 channel_readl(dwc, CTL_LO));
513
514 channel_clear_bit(dw, CH_EN, dwc->mask);
515 while (dma_readl(dw, CH_EN) & dwc->mask)
516 cpu_relax();
517
518 /* make sure DMA does not restart by loading a new list */
519 channel_writel(dwc, LLP, 0);
520 channel_writel(dwc, CTL_LO, 0);
521 channel_writel(dwc, CTL_HI, 0);
522
523 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
524 dma_writel(dw, CLEAR.ERROR, dwc->mask);
525 dma_writel(dw, CLEAR.XFER, dwc->mask);
526
527 for (i = 0; i < dwc->cdesc->periods; i++)
528 dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
529
530 spin_unlock_irqrestore(&dwc->lock, flags);
531 }
532 }
533
534 /* ------------------------------------------------------------------------- */
535
536 static void dw_dma_tasklet(unsigned long data)
537 {
538 struct dw_dma *dw = (struct dw_dma *)data;
539 struct dw_dma_chan *dwc;
540 u32 status_block;
541 u32 status_xfer;
542 u32 status_err;
543 int i;
544
545 status_block = dma_readl(dw, RAW.BLOCK);
546 status_xfer = dma_readl(dw, RAW.XFER);
547 status_err = dma_readl(dw, RAW.ERROR);
548
549 dev_vdbg(dw->dma.dev, "tasklet: status_block=%x status_err=%x\n",
550 status_block, status_err);
551
552 for (i = 0; i < dw->dma.chancnt; i++) {
553 dwc = &dw->chan[i];
554 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
555 dwc_handle_cyclic(dw, dwc, status_block, status_err,
556 status_xfer);
557 else if (status_err & (1 << i))
558 dwc_handle_error(dw, dwc);
559 else if ((status_block | status_xfer) & (1 << i))
560 dwc_scan_descriptors(dw, dwc);
561 }
562
563 /*
564 * Re-enable interrupts. Block Complete interrupts are only
565 * enabled if the INT_EN bit in the descriptor is set. This
566 * will trigger a scan before the whole list is done.
567 */
568 channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
569 channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask);
570 channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
571 }
572
573 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
574 {
575 struct dw_dma *dw = dev_id;
576 u32 status;
577
578 dev_vdbg(dw->dma.dev, "interrupt: status=0x%x\n",
579 dma_readl(dw, STATUS_INT));
580
581 /*
582 * Just disable the interrupts. We'll turn them back on in the
583 * softirq handler.
584 */
585 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
586 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
587 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
588
589 status = dma_readl(dw, STATUS_INT);
590 if (status) {
591 dev_err(dw->dma.dev,
592 "BUG: Unexpected interrupts pending: 0x%x\n",
593 status);
594
595 /* Try to recover */
596 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
597 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
598 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
599 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
600 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
601 }
602
603 tasklet_schedule(&dw->tasklet);
604
605 return IRQ_HANDLED;
606 }
607
608 /*----------------------------------------------------------------------*/
609
610 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
611 {
612 struct dw_desc *desc = txd_to_dw_desc(tx);
613 struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
614 dma_cookie_t cookie;
615 unsigned long flags;
616
617 spin_lock_irqsave(&dwc->lock, flags);
618 cookie = dwc_assign_cookie(dwc, desc);
619
620 /*
621 * REVISIT: We should attempt to chain as many descriptors as
622 * possible, perhaps even appending to those already submitted
623 * for DMA. But this is hard to do in a race-free manner.
624 */
625 if (list_empty(&dwc->active_list)) {
626 dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
627 desc->txd.cookie);
628 list_add_tail(&desc->desc_node, &dwc->active_list);
629 dwc_dostart(dwc, dwc_first_active(dwc));
630 } else {
631 dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
632 desc->txd.cookie);
633
634 list_add_tail(&desc->desc_node, &dwc->queue);
635 }
636
637 spin_unlock_irqrestore(&dwc->lock, flags);
638
639 return cookie;
640 }
641
642 static struct dma_async_tx_descriptor *
643 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
644 size_t len, unsigned long flags)
645 {
646 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
647 struct dw_desc *desc;
648 struct dw_desc *first;
649 struct dw_desc *prev;
650 size_t xfer_count;
651 size_t offset;
652 unsigned int src_width;
653 unsigned int dst_width;
654 u32 ctllo;
655
656 dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
657 dest, src, len, flags);
658
659 if (unlikely(!len)) {
660 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
661 return NULL;
662 }
663
664 /*
665 * We can be a lot more clever here, but this should take care
666 * of the most common optimization.
667 */
668 if (!((src | dest | len) & 7))
669 src_width = dst_width = 3;
670 else if (!((src | dest | len) & 3))
671 src_width = dst_width = 2;
672 else if (!((src | dest | len) & 1))
673 src_width = dst_width = 1;
674 else
675 src_width = dst_width = 0;
676
677 ctllo = DWC_DEFAULT_CTLLO(chan->private)
678 | DWC_CTLL_DST_WIDTH(dst_width)
679 | DWC_CTLL_SRC_WIDTH(src_width)
680 | DWC_CTLL_DST_INC
681 | DWC_CTLL_SRC_INC
682 | DWC_CTLL_FC_M2M;
683 prev = first = NULL;
684
685 for (offset = 0; offset < len; offset += xfer_count << src_width) {
686 xfer_count = min_t(size_t, (len - offset) >> src_width,
687 DWC_MAX_COUNT);
688
689 desc = dwc_desc_get(dwc);
690 if (!desc)
691 goto err_desc_get;
692
693 desc->lli.sar = src + offset;
694 desc->lli.dar = dest + offset;
695 desc->lli.ctllo = ctllo;
696 desc->lli.ctlhi = xfer_count;
697
698 if (!first) {
699 first = desc;
700 } else {
701 prev->lli.llp = desc->txd.phys;
702 dma_sync_single_for_device(chan2parent(chan),
703 prev->txd.phys, sizeof(prev->lli),
704 DMA_TO_DEVICE);
705 list_add_tail(&desc->desc_node,
706 &first->tx_list);
707 }
708 prev = desc;
709 }
710
711
712 if (flags & DMA_PREP_INTERRUPT)
713 /* Trigger interrupt after last block */
714 prev->lli.ctllo |= DWC_CTLL_INT_EN;
715
716 prev->lli.llp = 0;
717 dma_sync_single_for_device(chan2parent(chan),
718 prev->txd.phys, sizeof(prev->lli),
719 DMA_TO_DEVICE);
720
721 first->txd.flags = flags;
722 first->len = len;
723
724 return &first->txd;
725
726 err_desc_get:
727 dwc_desc_put(dwc, first);
728 return NULL;
729 }
730
731 static struct dma_async_tx_descriptor *
732 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
733 unsigned int sg_len, enum dma_transfer_direction direction,
734 unsigned long flags)
735 {
736 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
737 struct dw_dma_slave *dws = chan->private;
738 struct dw_desc *prev;
739 struct dw_desc *first;
740 u32 ctllo;
741 dma_addr_t reg;
742 unsigned int reg_width;
743 unsigned int mem_width;
744 unsigned int i;
745 struct scatterlist *sg;
746 size_t total_len = 0;
747
748 dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
749
750 if (unlikely(!dws || !sg_len))
751 return NULL;
752
753 reg_width = dws->reg_width;
754 prev = first = NULL;
755
756 switch (direction) {
757 case DMA_MEM_TO_DEV:
758 ctllo = (DWC_DEFAULT_CTLLO(chan->private)
759 | DWC_CTLL_DST_WIDTH(reg_width)
760 | DWC_CTLL_DST_FIX
761 | DWC_CTLL_SRC_INC
762 | DWC_CTLL_FC(dws->fc));
763 reg = dws->tx_reg;
764 for_each_sg(sgl, sg, sg_len, i) {
765 struct dw_desc *desc;
766 u32 len, dlen, mem;
767
768 mem = sg_phys(sg);
769 len = sg_dma_len(sg);
770 mem_width = 2;
771 if (unlikely(mem & 3 || len & 3))
772 mem_width = 0;
773
774 slave_sg_todev_fill_desc:
775 desc = dwc_desc_get(dwc);
776 if (!desc) {
777 dev_err(chan2dev(chan),
778 "not enough descriptors available\n");
779 goto err_desc_get;
780 }
781
782 desc->lli.sar = mem;
783 desc->lli.dar = reg;
784 desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
785 if ((len >> mem_width) > DWC_MAX_COUNT) {
786 dlen = DWC_MAX_COUNT << mem_width;
787 mem += dlen;
788 len -= dlen;
789 } else {
790 dlen = len;
791 len = 0;
792 }
793
794 desc->lli.ctlhi = dlen >> mem_width;
795
796 if (!first) {
797 first = desc;
798 } else {
799 prev->lli.llp = desc->txd.phys;
800 dma_sync_single_for_device(chan2parent(chan),
801 prev->txd.phys,
802 sizeof(prev->lli),
803 DMA_TO_DEVICE);
804 list_add_tail(&desc->desc_node,
805 &first->tx_list);
806 }
807 prev = desc;
808 total_len += dlen;
809
810 if (len)
811 goto slave_sg_todev_fill_desc;
812 }
813 break;
814 case DMA_DEV_TO_MEM:
815 ctllo = (DWC_DEFAULT_CTLLO(chan->private)
816 | DWC_CTLL_SRC_WIDTH(reg_width)
817 | DWC_CTLL_DST_INC
818 | DWC_CTLL_SRC_FIX
819 | DWC_CTLL_FC(dws->fc));
820
821 reg = dws->rx_reg;
822 for_each_sg(sgl, sg, sg_len, i) {
823 struct dw_desc *desc;
824 u32 len, dlen, mem;
825
826 mem = sg_phys(sg);
827 len = sg_dma_len(sg);
828 mem_width = 2;
829 if (unlikely(mem & 3 || len & 3))
830 mem_width = 0;
831
832 slave_sg_fromdev_fill_desc:
833 desc = dwc_desc_get(dwc);
834 if (!desc) {
835 dev_err(chan2dev(chan),
836 "not enough descriptors available\n");
837 goto err_desc_get;
838 }
839
840 desc->lli.sar = reg;
841 desc->lli.dar = mem;
842 desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
843 if ((len >> reg_width) > DWC_MAX_COUNT) {
844 dlen = DWC_MAX_COUNT << reg_width;
845 mem += dlen;
846 len -= dlen;
847 } else {
848 dlen = len;
849 len = 0;
850 }
851 desc->lli.ctlhi = dlen >> reg_width;
852
853 if (!first) {
854 first = desc;
855 } else {
856 prev->lli.llp = desc->txd.phys;
857 dma_sync_single_for_device(chan2parent(chan),
858 prev->txd.phys,
859 sizeof(prev->lli),
860 DMA_TO_DEVICE);
861 list_add_tail(&desc->desc_node,
862 &first->tx_list);
863 }
864 prev = desc;
865 total_len += dlen;
866
867 if (len)
868 goto slave_sg_fromdev_fill_desc;
869 }
870 break;
871 default:
872 return NULL;
873 }
874
875 if (flags & DMA_PREP_INTERRUPT)
876 /* Trigger interrupt after last block */
877 prev->lli.ctllo |= DWC_CTLL_INT_EN;
878
879 prev->lli.llp = 0;
880 dma_sync_single_for_device(chan2parent(chan),
881 prev->txd.phys, sizeof(prev->lli),
882 DMA_TO_DEVICE);
883
884 first->len = total_len;
885
886 return &first->txd;
887
888 err_desc_get:
889 dwc_desc_put(dwc, first);
890 return NULL;
891 }
892
893 static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
894 unsigned long arg)
895 {
896 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
897 struct dw_dma *dw = to_dw_dma(chan->device);
898 struct dw_desc *desc, *_desc;
899 unsigned long flags;
900 u32 cfglo;
901 LIST_HEAD(list);
902
903 if (cmd == DMA_PAUSE) {
904 spin_lock_irqsave(&dwc->lock, flags);
905
906 cfglo = channel_readl(dwc, CFG_LO);
907 channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
908 while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY))
909 cpu_relax();
910
911 dwc->paused = true;
912 spin_unlock_irqrestore(&dwc->lock, flags);
913 } else if (cmd == DMA_RESUME) {
914 if (!dwc->paused)
915 return 0;
916
917 spin_lock_irqsave(&dwc->lock, flags);
918
919 cfglo = channel_readl(dwc, CFG_LO);
920 channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
921 dwc->paused = false;
922
923 spin_unlock_irqrestore(&dwc->lock, flags);
924 } else if (cmd == DMA_TERMINATE_ALL) {
925 spin_lock_irqsave(&dwc->lock, flags);
926
927 channel_clear_bit(dw, CH_EN, dwc->mask);
928 while (dma_readl(dw, CH_EN) & dwc->mask)
929 cpu_relax();
930
931 dwc->paused = false;
932
933 /* active_list entries will end up before queued entries */
934 list_splice_init(&dwc->queue, &list);
935 list_splice_init(&dwc->active_list, &list);
936
937 spin_unlock_irqrestore(&dwc->lock, flags);
938
939 /* Flush all pending and queued descriptors */
940 list_for_each_entry_safe(desc, _desc, &list, desc_node)
941 dwc_descriptor_complete(dwc, desc, false);
942 } else
943 return -ENXIO;
944
945 return 0;
946 }
947
948 static enum dma_status
949 dwc_tx_status(struct dma_chan *chan,
950 dma_cookie_t cookie,
951 struct dma_tx_state *txstate)
952 {
953 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
954 dma_cookie_t last_used;
955 dma_cookie_t last_complete;
956 int ret;
957
958 last_complete = dwc->completed;
959 last_used = chan->cookie;
960
961 ret = dma_async_is_complete(cookie, last_complete, last_used);
962 if (ret != DMA_SUCCESS) {
963 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
964
965 last_complete = dwc->completed;
966 last_used = chan->cookie;
967
968 ret = dma_async_is_complete(cookie, last_complete, last_used);
969 }
970
971 if (ret != DMA_SUCCESS)
972 dma_set_tx_state(txstate, last_complete, last_used,
973 dwc_first_active(dwc)->len);
974 else
975 dma_set_tx_state(txstate, last_complete, last_used, 0);
976
977 if (dwc->paused)
978 return DMA_PAUSED;
979
980 return ret;
981 }
982
983 static void dwc_issue_pending(struct dma_chan *chan)
984 {
985 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
986
987 if (!list_empty(&dwc->queue))
988 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
989 }
990
991 static int dwc_alloc_chan_resources(struct dma_chan *chan)
992 {
993 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
994 struct dw_dma *dw = to_dw_dma(chan->device);
995 struct dw_desc *desc;
996 int i;
997 unsigned long flags;
998
999 dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
1000
1001 /* ASSERT: channel is idle */
1002 if (dma_readl(dw, CH_EN) & dwc->mask) {
1003 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1004 return -EIO;
1005 }
1006
1007 dwc->completed = chan->cookie = 1;
1008
1009 /*
1010 * NOTE: some controllers may have additional features that we
1011 * need to initialize here, like "scatter-gather" (which
1012 * doesn't mean what you think it means), and status writeback.
1013 */
1014
1015 spin_lock_irqsave(&dwc->lock, flags);
1016 i = dwc->descs_allocated;
1017 while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1018 spin_unlock_irqrestore(&dwc->lock, flags);
1019
1020 desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
1021 if (!desc) {
1022 dev_info(chan2dev(chan),
1023 "only allocated %d descriptors\n", i);
1024 spin_lock_irqsave(&dwc->lock, flags);
1025 break;
1026 }
1027
1028 INIT_LIST_HEAD(&desc->tx_list);
1029 dma_async_tx_descriptor_init(&desc->txd, chan);
1030 desc->txd.tx_submit = dwc_tx_submit;
1031 desc->txd.flags = DMA_CTRL_ACK;
1032 desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,
1033 sizeof(desc->lli), DMA_TO_DEVICE);
1034 dwc_desc_put(dwc, desc);
1035
1036 spin_lock_irqsave(&dwc->lock, flags);
1037 i = ++dwc->descs_allocated;
1038 }
1039
1040 spin_unlock_irqrestore(&dwc->lock, flags);
1041
1042 dev_dbg(chan2dev(chan),
1043 "alloc_chan_resources allocated %d descriptors\n", i);
1044
1045 return i;
1046 }
1047
1048 static void dwc_free_chan_resources(struct dma_chan *chan)
1049 {
1050 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1051 struct dw_dma *dw = to_dw_dma(chan->device);
1052 struct dw_desc *desc, *_desc;
1053 unsigned long flags;
1054 LIST_HEAD(list);
1055
1056 dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
1057 dwc->descs_allocated);
1058
1059 /* ASSERT: channel is idle */
1060 BUG_ON(!list_empty(&dwc->active_list));
1061 BUG_ON(!list_empty(&dwc->queue));
1062 BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1063
1064 spin_lock_irqsave(&dwc->lock, flags);
1065 list_splice_init(&dwc->free_list, &list);
1066 dwc->descs_allocated = 0;
1067 dwc->initialized = false;
1068
1069 /* Disable interrupts */
1070 channel_clear_bit(dw, MASK.XFER, dwc->mask);
1071 channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1072 channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1073
1074 spin_unlock_irqrestore(&dwc->lock, flags);
1075
1076 list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1077 dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
1078 dma_unmap_single(chan2parent(chan), desc->txd.phys,
1079 sizeof(desc->lli), DMA_TO_DEVICE);
1080 kfree(desc);
1081 }
1082
1083 dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
1084 }
1085
1086 /* --------------------- Cyclic DMA API extensions -------------------- */
1087
1088 /**
1089 * dw_dma_cyclic_start - start the cyclic DMA transfer
1090 * @chan: the DMA channel to start
1091 *
1092 * Must be called with soft interrupts disabled. Returns zero on success or
1093 * -errno on failure.
1094 */
1095 int dw_dma_cyclic_start(struct dma_chan *chan)
1096 {
1097 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1098 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1099 unsigned long flags;
1100
1101 if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1102 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1103 return -ENODEV;
1104 }
1105
1106 spin_lock_irqsave(&dwc->lock, flags);
1107
1108 /* assert channel is idle */
1109 if (dma_readl(dw, CH_EN) & dwc->mask) {
1110 dev_err(chan2dev(&dwc->chan),
1111 "BUG: Attempted to start non-idle channel\n");
1112 dev_err(chan2dev(&dwc->chan),
1113 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
1114 channel_readl(dwc, SAR),
1115 channel_readl(dwc, DAR),
1116 channel_readl(dwc, LLP),
1117 channel_readl(dwc, CTL_HI),
1118 channel_readl(dwc, CTL_LO));
1119 spin_unlock_irqrestore(&dwc->lock, flags);
1120 return -EBUSY;
1121 }
1122
1123 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1124 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1125 dma_writel(dw, CLEAR.XFER, dwc->mask);
1126
1127 /* setup DMAC channel registers */
1128 channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1129 channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1130 channel_writel(dwc, CTL_HI, 0);
1131
1132 channel_set_bit(dw, CH_EN, dwc->mask);
1133
1134 spin_unlock_irqrestore(&dwc->lock, flags);
1135
1136 return 0;
1137 }
1138 EXPORT_SYMBOL(dw_dma_cyclic_start);
1139
1140 /**
1141 * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1142 * @chan: the DMA channel to stop
1143 *
1144 * Must be called with soft interrupts disabled.
1145 */
1146 void dw_dma_cyclic_stop(struct dma_chan *chan)
1147 {
1148 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1149 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1150 unsigned long flags;
1151
1152 spin_lock_irqsave(&dwc->lock, flags);
1153
1154 channel_clear_bit(dw, CH_EN, dwc->mask);
1155 while (dma_readl(dw, CH_EN) & dwc->mask)
1156 cpu_relax();
1157
1158 spin_unlock_irqrestore(&dwc->lock, flags);
1159 }
1160 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1161
1162 /**
1163 * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1164 * @chan: the DMA channel to prepare
1165 * @buf_addr: physical DMA address where the buffer starts
1166 * @buf_len: total number of bytes for the entire buffer
1167 * @period_len: number of bytes for each period
1168 * @direction: transfer direction, to or from device
1169 *
1170 * Must be called before trying to start the transfer. Returns a valid struct
1171 * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1172 */
1173 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1174 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1175 enum dma_transfer_direction direction)
1176 {
1177 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1178 struct dw_cyclic_desc *cdesc;
1179 struct dw_cyclic_desc *retval = NULL;
1180 struct dw_desc *desc;
1181 struct dw_desc *last = NULL;
1182 struct dw_dma_slave *dws = chan->private;
1183 unsigned long was_cyclic;
1184 unsigned int reg_width;
1185 unsigned int periods;
1186 unsigned int i;
1187 unsigned long flags;
1188
1189 spin_lock_irqsave(&dwc->lock, flags);
1190 if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1191 spin_unlock_irqrestore(&dwc->lock, flags);
1192 dev_dbg(chan2dev(&dwc->chan),
1193 "queue and/or active list are not empty\n");
1194 return ERR_PTR(-EBUSY);
1195 }
1196
1197 was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1198 spin_unlock_irqrestore(&dwc->lock, flags);
1199 if (was_cyclic) {
1200 dev_dbg(chan2dev(&dwc->chan),
1201 "channel already prepared for cyclic DMA\n");
1202 return ERR_PTR(-EBUSY);
1203 }
1204
1205 retval = ERR_PTR(-EINVAL);
1206 reg_width = dws->reg_width;
1207 periods = buf_len / period_len;
1208
1209 /* Check for too big/unaligned periods and unaligned DMA buffer. */
1210 if (period_len > (DWC_MAX_COUNT << reg_width))
1211 goto out_err;
1212 if (unlikely(period_len & ((1 << reg_width) - 1)))
1213 goto out_err;
1214 if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1215 goto out_err;
1216 if (unlikely(!(direction & (DMA_MEM_TO_DEV | DMA_DEV_TO_MEM))))
1217 goto out_err;
1218
1219 retval = ERR_PTR(-ENOMEM);
1220
1221 if (periods > NR_DESCS_PER_CHANNEL)
1222 goto out_err;
1223
1224 cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1225 if (!cdesc)
1226 goto out_err;
1227
1228 cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1229 if (!cdesc->desc)
1230 goto out_err_alloc;
1231
1232 for (i = 0; i < periods; i++) {
1233 desc = dwc_desc_get(dwc);
1234 if (!desc)
1235 goto out_err_desc_get;
1236
1237 switch (direction) {
1238 case DMA_MEM_TO_DEV:
1239 desc->lli.dar = dws->tx_reg;
1240 desc->lli.sar = buf_addr + (period_len * i);
1241 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
1242 | DWC_CTLL_DST_WIDTH(reg_width)
1243 | DWC_CTLL_SRC_WIDTH(reg_width)
1244 | DWC_CTLL_DST_FIX
1245 | DWC_CTLL_SRC_INC
1246 | DWC_CTLL_FC(dws->fc)
1247 | DWC_CTLL_INT_EN);
1248 break;
1249 case DMA_DEV_TO_MEM:
1250 desc->lli.dar = buf_addr + (period_len * i);
1251 desc->lli.sar = dws->rx_reg;
1252 desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
1253 | DWC_CTLL_SRC_WIDTH(reg_width)
1254 | DWC_CTLL_DST_WIDTH(reg_width)
1255 | DWC_CTLL_DST_INC
1256 | DWC_CTLL_SRC_FIX
1257 | DWC_CTLL_FC(dws->fc)
1258 | DWC_CTLL_INT_EN);
1259 break;
1260 default:
1261 break;
1262 }
1263
1264 desc->lli.ctlhi = (period_len >> reg_width);
1265 cdesc->desc[i] = desc;
1266
1267 if (last) {
1268 last->lli.llp = desc->txd.phys;
1269 dma_sync_single_for_device(chan2parent(chan),
1270 last->txd.phys, sizeof(last->lli),
1271 DMA_TO_DEVICE);
1272 }
1273
1274 last = desc;
1275 }
1276
1277 /* lets make a cyclic list */
1278 last->lli.llp = cdesc->desc[0]->txd.phys;
1279 dma_sync_single_for_device(chan2parent(chan), last->txd.phys,
1280 sizeof(last->lli), DMA_TO_DEVICE);
1281
1282 dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%08x len %zu "
1283 "period %zu periods %d\n", buf_addr, buf_len,
1284 period_len, periods);
1285
1286 cdesc->periods = periods;
1287 dwc->cdesc = cdesc;
1288
1289 return cdesc;
1290
1291 out_err_desc_get:
1292 while (i--)
1293 dwc_desc_put(dwc, cdesc->desc[i]);
1294 out_err_alloc:
1295 kfree(cdesc);
1296 out_err:
1297 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1298 return (struct dw_cyclic_desc *)retval;
1299 }
1300 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1301
1302 /**
1303 * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1304 * @chan: the DMA channel to free
1305 */
1306 void dw_dma_cyclic_free(struct dma_chan *chan)
1307 {
1308 struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1309 struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1310 struct dw_cyclic_desc *cdesc = dwc->cdesc;
1311 int i;
1312 unsigned long flags;
1313
1314 dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
1315
1316 if (!cdesc)
1317 return;
1318
1319 spin_lock_irqsave(&dwc->lock, flags);
1320
1321 channel_clear_bit(dw, CH_EN, dwc->mask);
1322 while (dma_readl(dw, CH_EN) & dwc->mask)
1323 cpu_relax();
1324
1325 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1326 dma_writel(dw, CLEAR.ERROR, dwc->mask);
1327 dma_writel(dw, CLEAR.XFER, dwc->mask);
1328
1329 spin_unlock_irqrestore(&dwc->lock, flags);
1330
1331 for (i = 0; i < cdesc->periods; i++)
1332 dwc_desc_put(dwc, cdesc->desc[i]);
1333
1334 kfree(cdesc->desc);
1335 kfree(cdesc);
1336
1337 clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1338 }
1339 EXPORT_SYMBOL(dw_dma_cyclic_free);
1340
1341 /*----------------------------------------------------------------------*/
1342
1343 static void dw_dma_off(struct dw_dma *dw)
1344 {
1345 int i;
1346
1347 dma_writel(dw, CFG, 0);
1348
1349 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1350 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1351 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1352 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1353 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1354
1355 while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1356 cpu_relax();
1357
1358 for (i = 0; i < dw->dma.chancnt; i++)
1359 dw->chan[i].initialized = false;
1360 }
1361
1362 static int __init dw_probe(struct platform_device *pdev)
1363 {
1364 struct dw_dma_platform_data *pdata;
1365 struct resource *io;
1366 struct dw_dma *dw;
1367 size_t size;
1368 int irq;
1369 int err;
1370 int i;
1371
1372 pdata = pdev->dev.platform_data;
1373 if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1374 return -EINVAL;
1375
1376 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1377 if (!io)
1378 return -EINVAL;
1379
1380 irq = platform_get_irq(pdev, 0);
1381 if (irq < 0)
1382 return irq;
1383
1384 size = sizeof(struct dw_dma);
1385 size += pdata->nr_channels * sizeof(struct dw_dma_chan);
1386 dw = kzalloc(size, GFP_KERNEL);
1387 if (!dw)
1388 return -ENOMEM;
1389
1390 if (!request_mem_region(io->start, DW_REGLEN, pdev->dev.driver->name)) {
1391 err = -EBUSY;
1392 goto err_kfree;
1393 }
1394
1395 dw->regs = ioremap(io->start, DW_REGLEN);
1396 if (!dw->regs) {
1397 err = -ENOMEM;
1398 goto err_release_r;
1399 }
1400
1401 dw->clk = clk_get(&pdev->dev, "hclk");
1402 if (IS_ERR(dw->clk)) {
1403 err = PTR_ERR(dw->clk);
1404 goto err_clk;
1405 }
1406 clk_enable(dw->clk);
1407
1408 /* force dma off, just in case */
1409 dw_dma_off(dw);
1410
1411 err = request_irq(irq, dw_dma_interrupt, 0, "dw_dmac", dw);
1412 if (err)
1413 goto err_irq;
1414
1415 platform_set_drvdata(pdev, dw);
1416
1417 tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1418
1419 dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1420
1421 INIT_LIST_HEAD(&dw->dma.channels);
1422 for (i = 0; i < pdata->nr_channels; i++) {
1423 struct dw_dma_chan *dwc = &dw->chan[i];
1424
1425 dwc->chan.device = &dw->dma;
1426 dwc->chan.cookie = dwc->completed = 1;
1427 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1428 list_add_tail(&dwc->chan.device_node,
1429 &dw->dma.channels);
1430 else
1431 list_add(&dwc->chan.device_node, &dw->dma.channels);
1432
1433 /* 7 is highest priority & 0 is lowest. */
1434 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1435 dwc->priority = 7 - i;
1436 else
1437 dwc->priority = i;
1438
1439 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1440 spin_lock_init(&dwc->lock);
1441 dwc->mask = 1 << i;
1442
1443 INIT_LIST_HEAD(&dwc->active_list);
1444 INIT_LIST_HEAD(&dwc->queue);
1445 INIT_LIST_HEAD(&dwc->free_list);
1446
1447 channel_clear_bit(dw, CH_EN, dwc->mask);
1448 }
1449
1450 /* Clear/disable all interrupts on all channels. */
1451 dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1452 dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1453 dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1454 dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1455 dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1456
1457 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1458 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1459 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1460 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1461 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1462
1463 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1464 dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1465 if (pdata->is_private)
1466 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1467 dw->dma.dev = &pdev->dev;
1468 dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1469 dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1470
1471 dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1472
1473 dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1474 dw->dma.device_control = dwc_control;
1475
1476 dw->dma.device_tx_status = dwc_tx_status;
1477 dw->dma.device_issue_pending = dwc_issue_pending;
1478
1479 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1480
1481 printk(KERN_INFO "%s: DesignWare DMA Controller, %d channels\n",
1482 dev_name(&pdev->dev), pdata->nr_channels);
1483
1484 dma_async_device_register(&dw->dma);
1485
1486 return 0;
1487
1488 err_irq:
1489 clk_disable(dw->clk);
1490 clk_put(dw->clk);
1491 err_clk:
1492 iounmap(dw->regs);
1493 dw->regs = NULL;
1494 err_release_r:
1495 release_resource(io);
1496 err_kfree:
1497 kfree(dw);
1498 return err;
1499 }
1500
1501 static int __exit dw_remove(struct platform_device *pdev)
1502 {
1503 struct dw_dma *dw = platform_get_drvdata(pdev);
1504 struct dw_dma_chan *dwc, *_dwc;
1505 struct resource *io;
1506
1507 dw_dma_off(dw);
1508 dma_async_device_unregister(&dw->dma);
1509
1510 free_irq(platform_get_irq(pdev, 0), dw);
1511 tasklet_kill(&dw->tasklet);
1512
1513 list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1514 chan.device_node) {
1515 list_del(&dwc->chan.device_node);
1516 channel_clear_bit(dw, CH_EN, dwc->mask);
1517 }
1518
1519 clk_disable(dw->clk);
1520 clk_put(dw->clk);
1521
1522 iounmap(dw->regs);
1523 dw->regs = NULL;
1524
1525 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1526 release_mem_region(io->start, DW_REGLEN);
1527
1528 kfree(dw);
1529
1530 return 0;
1531 }
1532
1533 static void dw_shutdown(struct platform_device *pdev)
1534 {
1535 struct dw_dma *dw = platform_get_drvdata(pdev);
1536
1537 dw_dma_off(platform_get_drvdata(pdev));
1538 clk_disable(dw->clk);
1539 }
1540
1541 static int dw_suspend_noirq(struct device *dev)
1542 {
1543 struct platform_device *pdev = to_platform_device(dev);
1544 struct dw_dma *dw = platform_get_drvdata(pdev);
1545
1546 dw_dma_off(platform_get_drvdata(pdev));
1547 clk_disable(dw->clk);
1548
1549 return 0;
1550 }
1551
1552 static int dw_resume_noirq(struct device *dev)
1553 {
1554 struct platform_device *pdev = to_platform_device(dev);
1555 struct dw_dma *dw = platform_get_drvdata(pdev);
1556
1557 clk_enable(dw->clk);
1558 dma_writel(dw, CFG, DW_CFG_DMA_EN);
1559 return 0;
1560 }
1561
1562 static const struct dev_pm_ops dw_dev_pm_ops = {
1563 .suspend_noirq = dw_suspend_noirq,
1564 .resume_noirq = dw_resume_noirq,
1565 };
1566
1567 static struct platform_driver dw_driver = {
1568 .remove = __exit_p(dw_remove),
1569 .shutdown = dw_shutdown,
1570 .driver = {
1571 .name = "dw_dmac",
1572 .pm = &dw_dev_pm_ops,
1573 },
1574 };
1575
1576 static int __init dw_init(void)
1577 {
1578 return platform_driver_probe(&dw_driver, dw_probe);
1579 }
1580 subsys_initcall(dw_init);
1581
1582 static void __exit dw_exit(void)
1583 {
1584 platform_driver_unregister(&dw_driver);
1585 }
1586 module_exit(dw_exit);
1587
1588 MODULE_LICENSE("GPL v2");
1589 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1590 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1591 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");