blob: a0f3e6a06e06532b3701ade73b110d823eec591f [file] [log] [blame]
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001/*
2 * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
3 *
4 * Copyright (C) 2008 Atmel Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 *
12 * This supports the Atmel AHB DMA Controller,
13 *
14 * The driver has currently been tested with the Atmel AT91SAM9RL
15 * and AT91SAM9G45 series.
16 */
17
18#include <linux/clk.h>
19#include <linux/dmaengine.h>
20#include <linux/dma-mapping.h>
21#include <linux/dmapool.h>
22#include <linux/interrupt.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090025#include <linux/slab.h>
Nicolas Ferredc78baa2009-07-03 19:24:33 +020026
27#include "at_hdmac_regs.h"
28
29/*
30 * Glossary
31 * --------
32 *
33 * at_hdmac : Name of the ATmel AHB DMA Controller
34 * at_dma_ / atdma : ATmel DMA controller entity related
35 * atc_ / atchan : ATmel DMA Channel entity related
36 */
37
38#define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO)
39#define ATC_DEFAULT_CTRLA (0)
40#define ATC_DEFAULT_CTRLB (ATC_SIF(0) \
41 |ATC_DIF(1))
42
43/*
44 * Initial number of descriptors to allocate for each channel. This could
45 * be increased during dma usage.
46 */
47static unsigned int init_nr_desc_per_channel = 64;
48module_param(init_nr_desc_per_channel, uint, 0644);
49MODULE_PARM_DESC(init_nr_desc_per_channel,
50 "initial descriptors per channel (default: 64)");
51
52
53/* prototypes */
54static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
55
56
57/*----------------------------------------------------------------------*/
58
59static struct at_desc *atc_first_active(struct at_dma_chan *atchan)
60{
61 return list_first_entry(&atchan->active_list,
62 struct at_desc, desc_node);
63}
64
65static struct at_desc *atc_first_queued(struct at_dma_chan *atchan)
66{
67 return list_first_entry(&atchan->queue,
68 struct at_desc, desc_node);
69}
70
71/**
Uwe Kleine-König421f91d2010-06-11 12:17:00 +020072 * atc_alloc_descriptor - allocate and return an initialized descriptor
Nicolas Ferredc78baa2009-07-03 19:24:33 +020073 * @chan: the channel to allocate descriptors for
74 * @gfp_flags: GFP allocation flags
75 *
76 * Note: The ack-bit is positioned in the descriptor flag at creation time
77 * to make initial allocation more convenient. This bit will be cleared
78 * and control will be given to client at usage time (during
79 * preparation functions).
80 */
81static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan,
82 gfp_t gfp_flags)
83{
84 struct at_desc *desc = NULL;
85 struct at_dma *atdma = to_at_dma(chan->device);
86 dma_addr_t phys;
87
88 desc = dma_pool_alloc(atdma->dma_desc_pool, gfp_flags, &phys);
89 if (desc) {
90 memset(desc, 0, sizeof(struct at_desc));
Dan Williams285a3c72009-09-08 17:53:03 -070091 INIT_LIST_HEAD(&desc->tx_list);
Nicolas Ferredc78baa2009-07-03 19:24:33 +020092 dma_async_tx_descriptor_init(&desc->txd, chan);
93 /* txd.flags will be overwritten in prep functions */
94 desc->txd.flags = DMA_CTRL_ACK;
95 desc->txd.tx_submit = atc_tx_submit;
96 desc->txd.phys = phys;
97 }
98
99 return desc;
100}
101
102/**
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200103 * atc_desc_get - get an unused descriptor from free_list
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200104 * @atchan: channel we want a new descriptor for
105 */
106static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
107{
108 struct at_desc *desc, *_desc;
109 struct at_desc *ret = NULL;
110 unsigned int i = 0;
111 LIST_HEAD(tmp_list);
112
113 spin_lock_bh(&atchan->lock);
114 list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
115 i++;
116 if (async_tx_test_ack(&desc->txd)) {
117 list_del(&desc->desc_node);
118 ret = desc;
119 break;
120 }
121 dev_dbg(chan2dev(&atchan->chan_common),
122 "desc %p not ACKed\n", desc);
123 }
124 spin_unlock_bh(&atchan->lock);
125 dev_vdbg(chan2dev(&atchan->chan_common),
126 "scanned %u descriptors on freelist\n", i);
127
128 /* no more descriptor available in initial pool: create one more */
129 if (!ret) {
130 ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC);
131 if (ret) {
132 spin_lock_bh(&atchan->lock);
133 atchan->descs_allocated++;
134 spin_unlock_bh(&atchan->lock);
135 } else {
136 dev_err(chan2dev(&atchan->chan_common),
137 "not enough descriptors available\n");
138 }
139 }
140
141 return ret;
142}
143
144/**
145 * atc_desc_put - move a descriptor, including any children, to the free list
146 * @atchan: channel we work on
147 * @desc: descriptor, at the head of a chain, to move to free list
148 */
149static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
150{
151 if (desc) {
152 struct at_desc *child;
153
154 spin_lock_bh(&atchan->lock);
Dan Williams285a3c72009-09-08 17:53:03 -0700155 list_for_each_entry(child, &desc->tx_list, desc_node)
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200156 dev_vdbg(chan2dev(&atchan->chan_common),
157 "moving child desc %p to freelist\n",
158 child);
Dan Williams285a3c72009-09-08 17:53:03 -0700159 list_splice_init(&desc->tx_list, &atchan->free_list);
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200160 dev_vdbg(chan2dev(&atchan->chan_common),
161 "moving desc %p to freelist\n", desc);
162 list_add(&desc->desc_node, &atchan->free_list);
163 spin_unlock_bh(&atchan->lock);
164 }
165}
166
167/**
168 * atc_assign_cookie - compute and assign new cookie
169 * @atchan: channel we work on
170 * @desc: descriptor to asign cookie for
171 *
172 * Called with atchan->lock held and bh disabled
173 */
174static dma_cookie_t
175atc_assign_cookie(struct at_dma_chan *atchan, struct at_desc *desc)
176{
177 dma_cookie_t cookie = atchan->chan_common.cookie;
178
179 if (++cookie < 0)
180 cookie = 1;
181
182 atchan->chan_common.cookie = cookie;
183 desc->txd.cookie = cookie;
184
185 return cookie;
186}
187
188/**
189 * atc_dostart - starts the DMA engine for real
190 * @atchan: the channel we want to start
191 * @first: first descriptor in the list we want to begin with
192 *
193 * Called with atchan->lock held and bh disabled
194 */
195static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
196{
197 struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
198
199 /* ASSERT: channel is idle */
200 if (atc_chan_is_enabled(atchan)) {
201 dev_err(chan2dev(&atchan->chan_common),
202 "BUG: Attempted to start non-idle channel\n");
203 dev_err(chan2dev(&atchan->chan_common),
204 " channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
205 channel_readl(atchan, SADDR),
206 channel_readl(atchan, DADDR),
207 channel_readl(atchan, CTRLA),
208 channel_readl(atchan, CTRLB),
209 channel_readl(atchan, DSCR));
210
211 /* The tasklet will hopefully advance the queue... */
212 return;
213 }
214
215 vdbg_dump_regs(atchan);
216
217 /* clear any pending interrupt */
218 while (dma_readl(atdma, EBCISR))
219 cpu_relax();
220
221 channel_writel(atchan, SADDR, 0);
222 channel_writel(atchan, DADDR, 0);
223 channel_writel(atchan, CTRLA, 0);
224 channel_writel(atchan, CTRLB, 0);
225 channel_writel(atchan, DSCR, first->txd.phys);
226 dma_writel(atdma, CHER, atchan->mask);
227
228 vdbg_dump_regs(atchan);
229}
230
231/**
232 * atc_chain_complete - finish work for one transaction chain
233 * @atchan: channel we work on
234 * @desc: descriptor at the head of the chain we want do complete
235 *
236 * Called with atchan->lock held and bh disabled */
237static void
238atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
239{
240 dma_async_tx_callback callback;
241 void *param;
242 struct dma_async_tx_descriptor *txd = &desc->txd;
243
244 dev_vdbg(chan2dev(&atchan->chan_common),
245 "descriptor %u complete\n", txd->cookie);
246
247 atchan->completed_cookie = txd->cookie;
248 callback = txd->callback;
249 param = txd->callback_param;
250
251 /* move children to free_list */
Dan Williams285a3c72009-09-08 17:53:03 -0700252 list_splice_init(&desc->tx_list, &atchan->free_list);
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200253 /* move myself to free_list */
254 list_move(&desc->desc_node, &atchan->free_list);
255
256 /* unmap dma addresses */
Atsushi Nemoto657a77f2009-09-08 17:53:05 -0700257 if (!atchan->chan_common.private) {
258 struct device *parent = chan2parent(&atchan->chan_common);
259 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
260 if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
261 dma_unmap_single(parent,
262 desc->lli.daddr,
263 desc->len, DMA_FROM_DEVICE);
264 else
265 dma_unmap_page(parent,
266 desc->lli.daddr,
267 desc->len, DMA_FROM_DEVICE);
268 }
269 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
270 if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
271 dma_unmap_single(parent,
272 desc->lli.saddr,
273 desc->len, DMA_TO_DEVICE);
274 else
275 dma_unmap_page(parent,
276 desc->lli.saddr,
277 desc->len, DMA_TO_DEVICE);
278 }
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200279 }
280
281 /*
282 * The API requires that no submissions are done from a
283 * callback, so we don't need to drop the lock here
284 */
285 if (callback)
286 callback(param);
287
288 dma_run_dependencies(txd);
289}
290
291/**
292 * atc_complete_all - finish work for all transactions
293 * @atchan: channel to complete transactions for
294 *
295 * Eventually submit queued descriptors if any
296 *
297 * Assume channel is idle while calling this function
298 * Called with atchan->lock held and bh disabled
299 */
300static void atc_complete_all(struct at_dma_chan *atchan)
301{
302 struct at_desc *desc, *_desc;
303 LIST_HEAD(list);
304
305 dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
306
307 BUG_ON(atc_chan_is_enabled(atchan));
308
309 /*
310 * Submit queued descriptors ASAP, i.e. before we go through
311 * the completed ones.
312 */
313 if (!list_empty(&atchan->queue))
314 atc_dostart(atchan, atc_first_queued(atchan));
315 /* empty active_list now it is completed */
316 list_splice_init(&atchan->active_list, &list);
317 /* empty queue list by moving descriptors (if any) to active_list */
318 list_splice_init(&atchan->queue, &atchan->active_list);
319
320 list_for_each_entry_safe(desc, _desc, &list, desc_node)
321 atc_chain_complete(atchan, desc);
322}
323
324/**
325 * atc_cleanup_descriptors - cleanup up finished descriptors in active_list
326 * @atchan: channel to be cleaned up
327 *
328 * Called with atchan->lock held and bh disabled
329 */
330static void atc_cleanup_descriptors(struct at_dma_chan *atchan)
331{
332 struct at_desc *desc, *_desc;
333 struct at_desc *child;
334
335 dev_vdbg(chan2dev(&atchan->chan_common), "cleanup descriptors\n");
336
337 list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
338 if (!(desc->lli.ctrla & ATC_DONE))
339 /* This one is currently in progress */
340 return;
341
Dan Williams285a3c72009-09-08 17:53:03 -0700342 list_for_each_entry(child, &desc->tx_list, desc_node)
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200343 if (!(child->lli.ctrla & ATC_DONE))
344 /* Currently in progress */
345 return;
346
347 /*
348 * No descriptors so far seem to be in progress, i.e.
349 * this chain must be done.
350 */
351 atc_chain_complete(atchan, desc);
352 }
353}
354
355/**
356 * atc_advance_work - at the end of a transaction, move forward
357 * @atchan: channel where the transaction ended
358 *
359 * Called with atchan->lock held and bh disabled
360 */
361static void atc_advance_work(struct at_dma_chan *atchan)
362{
363 dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
364
365 if (list_empty(&atchan->active_list) ||
366 list_is_singular(&atchan->active_list)) {
367 atc_complete_all(atchan);
368 } else {
369 atc_chain_complete(atchan, atc_first_active(atchan));
370 /* advance work */
371 atc_dostart(atchan, atc_first_active(atchan));
372 }
373}
374
375
376/**
377 * atc_handle_error - handle errors reported by DMA controller
378 * @atchan: channel where error occurs
379 *
380 * Called with atchan->lock held and bh disabled
381 */
382static void atc_handle_error(struct at_dma_chan *atchan)
383{
384 struct at_desc *bad_desc;
385 struct at_desc *child;
386
387 /*
388 * The descriptor currently at the head of the active list is
389 * broked. Since we don't have any way to report errors, we'll
390 * just have to scream loudly and try to carry on.
391 */
392 bad_desc = atc_first_active(atchan);
393 list_del_init(&bad_desc->desc_node);
394
395 /* As we are stopped, take advantage to push queued descriptors
396 * in active_list */
397 list_splice_init(&atchan->queue, atchan->active_list.prev);
398
399 /* Try to restart the controller */
400 if (!list_empty(&atchan->active_list))
401 atc_dostart(atchan, atc_first_active(atchan));
402
403 /*
404 * KERN_CRITICAL may seem harsh, but since this only happens
405 * when someone submits a bad physical address in a
406 * descriptor, we should consider ourselves lucky that the
407 * controller flagged an error instead of scribbling over
408 * random memory locations.
409 */
410 dev_crit(chan2dev(&atchan->chan_common),
411 "Bad descriptor submitted for DMA!\n");
412 dev_crit(chan2dev(&atchan->chan_common),
413 " cookie: %d\n", bad_desc->txd.cookie);
414 atc_dump_lli(atchan, &bad_desc->lli);
Dan Williams285a3c72009-09-08 17:53:03 -0700415 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200416 atc_dump_lli(atchan, &child->lli);
417
418 /* Pretend the descriptor completed successfully */
419 atc_chain_complete(atchan, bad_desc);
420}
421
422
423/*-- IRQ & Tasklet ---------------------------------------------------*/
424
425static void atc_tasklet(unsigned long data)
426{
427 struct at_dma_chan *atchan = (struct at_dma_chan *)data;
428
429 /* Channel cannot be enabled here */
430 if (atc_chan_is_enabled(atchan)) {
431 dev_err(chan2dev(&atchan->chan_common),
432 "BUG: channel enabled in tasklet\n");
433 return;
434 }
435
436 spin_lock(&atchan->lock);
437 if (test_and_clear_bit(0, &atchan->error_status))
438 atc_handle_error(atchan);
439 else
440 atc_advance_work(atchan);
441
442 spin_unlock(&atchan->lock);
443}
444
445static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
446{
447 struct at_dma *atdma = (struct at_dma *)dev_id;
448 struct at_dma_chan *atchan;
449 int i;
450 u32 status, pending, imr;
451 int ret = IRQ_NONE;
452
453 do {
454 imr = dma_readl(atdma, EBCIMR);
455 status = dma_readl(atdma, EBCISR);
456 pending = status & imr;
457
458 if (!pending)
459 break;
460
461 dev_vdbg(atdma->dma_common.dev,
462 "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n",
463 status, imr, pending);
464
465 for (i = 0; i < atdma->dma_common.chancnt; i++) {
466 atchan = &atdma->chan[i];
467 if (pending & (AT_DMA_CBTC(i) | AT_DMA_ERR(i))) {
468 if (pending & AT_DMA_ERR(i)) {
469 /* Disable channel on AHB error */
470 dma_writel(atdma, CHDR, atchan->mask);
471 /* Give information to tasklet */
472 set_bit(0, &atchan->error_status);
473 }
474 tasklet_schedule(&atchan->tasklet);
475 ret = IRQ_HANDLED;
476 }
477 }
478
479 } while (pending);
480
481 return ret;
482}
483
484
485/*-- DMA Engine API --------------------------------------------------*/
486
487/**
488 * atc_tx_submit - set the prepared descriptor(s) to be executed by the engine
489 * @desc: descriptor at the head of the transaction chain
490 *
491 * Queue chain if DMA engine is working already
492 *
493 * Cookie increment and adding to active_list or queue must be atomic
494 */
495static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx)
496{
497 struct at_desc *desc = txd_to_at_desc(tx);
498 struct at_dma_chan *atchan = to_at_dma_chan(tx->chan);
499 dma_cookie_t cookie;
500
501 spin_lock_bh(&atchan->lock);
502 cookie = atc_assign_cookie(atchan, desc);
503
504 if (list_empty(&atchan->active_list)) {
505 dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
506 desc->txd.cookie);
507 atc_dostart(atchan, desc);
508 list_add_tail(&desc->desc_node, &atchan->active_list);
509 } else {
510 dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
511 desc->txd.cookie);
512 list_add_tail(&desc->desc_node, &atchan->queue);
513 }
514
515 spin_unlock_bh(&atchan->lock);
516
517 return cookie;
518}
519
520/**
521 * atc_prep_dma_memcpy - prepare a memcpy operation
522 * @chan: the channel to prepare operation on
523 * @dest: operation virtual destination address
524 * @src: operation virtual source address
525 * @len: operation length
526 * @flags: tx descriptor status flags
527 */
528static struct dma_async_tx_descriptor *
529atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
530 size_t len, unsigned long flags)
531{
532 struct at_dma_chan *atchan = to_at_dma_chan(chan);
533 struct at_desc *desc = NULL;
534 struct at_desc *first = NULL;
535 struct at_desc *prev = NULL;
536 size_t xfer_count;
537 size_t offset;
538 unsigned int src_width;
539 unsigned int dst_width;
540 u32 ctrla;
541 u32 ctrlb;
542
543 dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d0x%x s0x%x l0x%zx f0x%lx\n",
544 dest, src, len, flags);
545
546 if (unlikely(!len)) {
547 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
548 return NULL;
549 }
550
551 ctrla = ATC_DEFAULT_CTRLA;
552 ctrlb = ATC_DEFAULT_CTRLB
553 | ATC_SRC_ADDR_MODE_INCR
554 | ATC_DST_ADDR_MODE_INCR
555 | ATC_FC_MEM2MEM;
556
557 /*
558 * We can be a lot more clever here, but this should take care
559 * of the most common optimization.
560 */
561 if (!((src | dest | len) & 3)) {
562 ctrla |= ATC_SRC_WIDTH_WORD | ATC_DST_WIDTH_WORD;
563 src_width = dst_width = 2;
564 } else if (!((src | dest | len) & 1)) {
565 ctrla |= ATC_SRC_WIDTH_HALFWORD | ATC_DST_WIDTH_HALFWORD;
566 src_width = dst_width = 1;
567 } else {
568 ctrla |= ATC_SRC_WIDTH_BYTE | ATC_DST_WIDTH_BYTE;
569 src_width = dst_width = 0;
570 }
571
572 for (offset = 0; offset < len; offset += xfer_count << src_width) {
573 xfer_count = min_t(size_t, (len - offset) >> src_width,
574 ATC_BTSIZE_MAX);
575
576 desc = atc_desc_get(atchan);
577 if (!desc)
578 goto err_desc_get;
579
580 desc->lli.saddr = src + offset;
581 desc->lli.daddr = dest + offset;
582 desc->lli.ctrla = ctrla | xfer_count;
583 desc->lli.ctrlb = ctrlb;
584
585 desc->txd.cookie = 0;
586 async_tx_ack(&desc->txd);
587
588 if (!first) {
589 first = desc;
590 } else {
591 /* inform the HW lli about chaining */
592 prev->lli.dscr = desc->txd.phys;
593 /* insert the link descriptor to the LD ring */
594 list_add_tail(&desc->desc_node,
Dan Williams285a3c72009-09-08 17:53:03 -0700595 &first->tx_list);
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200596 }
597 prev = desc;
598 }
599
600 /* First descriptor of the chain embedds additional information */
601 first->txd.cookie = -EBUSY;
602 first->len = len;
603
604 /* set end-of-link to the last link descriptor of list*/
605 set_desc_eol(desc);
606
607 desc->txd.flags = flags; /* client is in control of this ack */
608
609 return &first->txd;
610
611err_desc_get:
612 atc_desc_put(atchan, first);
613 return NULL;
614}
615
Nicolas Ferre808347f2009-07-22 20:04:45 +0200616
617/**
618 * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
619 * @chan: DMA channel
620 * @sgl: scatterlist to transfer to/from
621 * @sg_len: number of entries in @scatterlist
622 * @direction: DMA direction
623 * @flags: tx descriptor status flags
624 */
625static struct dma_async_tx_descriptor *
626atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
627 unsigned int sg_len, enum dma_data_direction direction,
628 unsigned long flags)
629{
630 struct at_dma_chan *atchan = to_at_dma_chan(chan);
631 struct at_dma_slave *atslave = chan->private;
632 struct at_desc *first = NULL;
633 struct at_desc *prev = NULL;
634 u32 ctrla;
635 u32 ctrlb;
636 dma_addr_t reg;
637 unsigned int reg_width;
638 unsigned int mem_width;
639 unsigned int i;
640 struct scatterlist *sg;
641 size_t total_len = 0;
642
643 dev_vdbg(chan2dev(chan), "prep_slave_sg: %s f0x%lx\n",
644 direction == DMA_TO_DEVICE ? "TO DEVICE" : "FROM DEVICE",
645 flags);
646
647 if (unlikely(!atslave || !sg_len)) {
648 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
649 return NULL;
650 }
651
652 reg_width = atslave->reg_width;
653
Nicolas Ferre808347f2009-07-22 20:04:45 +0200654 ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla;
655 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN;
656
657 switch (direction) {
658 case DMA_TO_DEVICE:
659 ctrla |= ATC_DST_WIDTH(reg_width);
660 ctrlb |= ATC_DST_ADDR_MODE_FIXED
661 | ATC_SRC_ADDR_MODE_INCR
662 | ATC_FC_MEM2PER;
663 reg = atslave->tx_reg;
664 for_each_sg(sgl, sg, sg_len, i) {
665 struct at_desc *desc;
666 u32 len;
667 u32 mem;
668
669 desc = atc_desc_get(atchan);
670 if (!desc)
671 goto err_desc_get;
672
673 mem = sg_phys(sg);
674 len = sg_dma_len(sg);
675 mem_width = 2;
676 if (unlikely(mem & 3 || len & 3))
677 mem_width = 0;
678
679 desc->lli.saddr = mem;
680 desc->lli.daddr = reg;
681 desc->lli.ctrla = ctrla
682 | ATC_SRC_WIDTH(mem_width)
683 | len >> mem_width;
684 desc->lli.ctrlb = ctrlb;
685
686 if (!first) {
687 first = desc;
688 } else {
689 /* inform the HW lli about chaining */
690 prev->lli.dscr = desc->txd.phys;
691 /* insert the link descriptor to the LD ring */
692 list_add_tail(&desc->desc_node,
Dan Williams285a3c72009-09-08 17:53:03 -0700693 &first->tx_list);
Nicolas Ferre808347f2009-07-22 20:04:45 +0200694 }
695 prev = desc;
696 total_len += len;
697 }
698 break;
699 case DMA_FROM_DEVICE:
700 ctrla |= ATC_SRC_WIDTH(reg_width);
701 ctrlb |= ATC_DST_ADDR_MODE_INCR
702 | ATC_SRC_ADDR_MODE_FIXED
703 | ATC_FC_PER2MEM;
704
705 reg = atslave->rx_reg;
706 for_each_sg(sgl, sg, sg_len, i) {
707 struct at_desc *desc;
708 u32 len;
709 u32 mem;
710
711 desc = atc_desc_get(atchan);
712 if (!desc)
713 goto err_desc_get;
714
715 mem = sg_phys(sg);
716 len = sg_dma_len(sg);
717 mem_width = 2;
718 if (unlikely(mem & 3 || len & 3))
719 mem_width = 0;
720
721 desc->lli.saddr = reg;
722 desc->lli.daddr = mem;
723 desc->lli.ctrla = ctrla
724 | ATC_DST_WIDTH(mem_width)
725 | len >> mem_width;
726 desc->lli.ctrlb = ctrlb;
727
728 if (!first) {
729 first = desc;
730 } else {
731 /* inform the HW lli about chaining */
732 prev->lli.dscr = desc->txd.phys;
733 /* insert the link descriptor to the LD ring */
734 list_add_tail(&desc->desc_node,
Dan Williams285a3c72009-09-08 17:53:03 -0700735 &first->tx_list);
Nicolas Ferre808347f2009-07-22 20:04:45 +0200736 }
737 prev = desc;
738 total_len += len;
739 }
740 break;
741 default:
742 return NULL;
743 }
744
745 /* set end-of-link to the last link descriptor of list*/
746 set_desc_eol(prev);
747
748 /* First descriptor of the chain embedds additional information */
749 first->txd.cookie = -EBUSY;
750 first->len = total_len;
751
752 /* last link descriptor of list is responsible of flags */
753 prev->txd.flags = flags; /* client is in control of this ack */
754
755 return &first->txd;
756
757err_desc_get:
758 dev_err(chan2dev(chan), "not enough descriptors available\n");
759 atc_desc_put(atchan, first);
760 return NULL;
761}
762
Linus Walleij05827632010-05-17 16:30:42 -0700763static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
764 unsigned long arg)
Nicolas Ferre808347f2009-07-22 20:04:45 +0200765{
766 struct at_dma_chan *atchan = to_at_dma_chan(chan);
767 struct at_dma *atdma = to_at_dma(chan->device);
768 struct at_desc *desc, *_desc;
769 LIST_HEAD(list);
770
Linus Walleijc3635c72010-03-26 16:44:01 -0700771 /* Only supports DMA_TERMINATE_ALL */
772 if (cmd != DMA_TERMINATE_ALL)
773 return -ENXIO;
774
Nicolas Ferre808347f2009-07-22 20:04:45 +0200775 /*
776 * This is only called when something went wrong elsewhere, so
777 * we don't really care about the data. Just disable the
778 * channel. We still have to poll the channel enable bit due
779 * to AHB/HSB limitations.
780 */
781 spin_lock_bh(&atchan->lock);
782
783 dma_writel(atdma, CHDR, atchan->mask);
784
785 /* confirm that this channel is disabled */
786 while (dma_readl(atdma, CHSR) & atchan->mask)
787 cpu_relax();
788
789 /* active_list entries will end up before queued entries */
790 list_splice_init(&atchan->queue, &list);
791 list_splice_init(&atchan->active_list, &list);
792
Nicolas Ferre808347f2009-07-22 20:04:45 +0200793 /* Flush all pending and queued descriptors */
794 list_for_each_entry_safe(desc, _desc, &list, desc_node)
795 atc_chain_complete(atchan, desc);
Linus Walleijc3635c72010-03-26 16:44:01 -0700796
Yong Wangb0ebeb92010-08-05 10:40:08 +0800797 spin_unlock_bh(&atchan->lock);
798
Linus Walleijc3635c72010-03-26 16:44:01 -0700799 return 0;
Nicolas Ferre808347f2009-07-22 20:04:45 +0200800}
801
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200802/**
Linus Walleij07934482010-03-26 16:50:49 -0700803 * atc_tx_status - poll for transaction completion
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200804 * @chan: DMA channel
805 * @cookie: transaction identifier to check status of
Linus Walleij07934482010-03-26 16:50:49 -0700806 * @txstate: if not %NULL updated with transaction state
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200807 *
Linus Walleij07934482010-03-26 16:50:49 -0700808 * If @txstate is passed in, upon return it reflect the driver
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200809 * internal state and can be used with dma_async_is_complete() to check
810 * the status of multiple cookies without re-checking hardware state.
811 */
812static enum dma_status
Linus Walleij07934482010-03-26 16:50:49 -0700813atc_tx_status(struct dma_chan *chan,
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200814 dma_cookie_t cookie,
Linus Walleij07934482010-03-26 16:50:49 -0700815 struct dma_tx_state *txstate)
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200816{
817 struct at_dma_chan *atchan = to_at_dma_chan(chan);
818 dma_cookie_t last_used;
819 dma_cookie_t last_complete;
820 enum dma_status ret;
821
Nicolas Ferre4297a462009-12-16 16:28:03 +0100822 spin_lock_bh(&atchan->lock);
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200823
824 last_complete = atchan->completed_cookie;
825 last_used = chan->cookie;
826
827 ret = dma_async_is_complete(cookie, last_complete, last_used);
828 if (ret != DMA_SUCCESS) {
829 atc_cleanup_descriptors(atchan);
830
831 last_complete = atchan->completed_cookie;
832 last_used = chan->cookie;
833
834 ret = dma_async_is_complete(cookie, last_complete, last_used);
835 }
836
Nicolas Ferre4297a462009-12-16 16:28:03 +0100837 spin_unlock_bh(&atchan->lock);
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200838
Dan Williamsbca34692010-03-26 16:52:10 -0700839 dma_set_tx_state(txstate, last_complete, last_used, 0);
Linus Walleij07934482010-03-26 16:50:49 -0700840 dev_vdbg(chan2dev(chan), "tx_status: %d (d%d, u%d)\n",
841 cookie, last_complete ? last_complete : 0,
842 last_used ? last_used : 0);
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200843
844 return ret;
845}
846
847/**
848 * atc_issue_pending - try to finish work
849 * @chan: target DMA channel
850 */
851static void atc_issue_pending(struct dma_chan *chan)
852{
853 struct at_dma_chan *atchan = to_at_dma_chan(chan);
854
855 dev_vdbg(chan2dev(chan), "issue_pending\n");
856
857 if (!atc_chan_is_enabled(atchan)) {
858 spin_lock_bh(&atchan->lock);
859 atc_advance_work(atchan);
860 spin_unlock_bh(&atchan->lock);
861 }
862}
863
864/**
865 * atc_alloc_chan_resources - allocate resources for DMA channel
866 * @chan: allocate descriptor resources for this channel
867 * @client: current client requesting the channel be ready for requests
868 *
869 * return - the number of allocated descriptors
870 */
871static int atc_alloc_chan_resources(struct dma_chan *chan)
872{
873 struct at_dma_chan *atchan = to_at_dma_chan(chan);
874 struct at_dma *atdma = to_at_dma(chan->device);
875 struct at_desc *desc;
Nicolas Ferre808347f2009-07-22 20:04:45 +0200876 struct at_dma_slave *atslave;
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200877 int i;
Nicolas Ferre808347f2009-07-22 20:04:45 +0200878 u32 cfg;
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200879 LIST_HEAD(tmp_list);
880
881 dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
882
883 /* ASSERT: channel is idle */
884 if (atc_chan_is_enabled(atchan)) {
885 dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
886 return -EIO;
887 }
888
Nicolas Ferre808347f2009-07-22 20:04:45 +0200889 cfg = ATC_DEFAULT_CFG;
890
891 atslave = chan->private;
892 if (atslave) {
893 /*
894 * We need controller-specific data to set up slave
895 * transfers.
896 */
897 BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_common.dev);
898
899 /* if cfg configuration specified take it instad of default */
900 if (atslave->cfg)
901 cfg = atslave->cfg;
902 }
903
904 /* have we already been set up?
905 * reconfigure channel but no need to reallocate descriptors */
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200906 if (!list_empty(&atchan->free_list))
907 return atchan->descs_allocated;
908
909 /* Allocate initial pool of descriptors */
910 for (i = 0; i < init_nr_desc_per_channel; i++) {
911 desc = atc_alloc_descriptor(chan, GFP_KERNEL);
912 if (!desc) {
913 dev_err(atdma->dma_common.dev,
914 "Only %d initial descriptors\n", i);
915 break;
916 }
917 list_add_tail(&desc->desc_node, &tmp_list);
918 }
919
920 spin_lock_bh(&atchan->lock);
921 atchan->descs_allocated = i;
922 list_splice(&tmp_list, &atchan->free_list);
923 atchan->completed_cookie = chan->cookie = 1;
924 spin_unlock_bh(&atchan->lock);
925
926 /* channel parameters */
Nicolas Ferre808347f2009-07-22 20:04:45 +0200927 channel_writel(atchan, CFG, cfg);
Nicolas Ferredc78baa2009-07-03 19:24:33 +0200928
929 dev_dbg(chan2dev(chan),
930 "alloc_chan_resources: allocated %d descriptors\n",
931 atchan->descs_allocated);
932
933 return atchan->descs_allocated;
934}
935
936/**
937 * atc_free_chan_resources - free all channel resources
938 * @chan: DMA channel
939 */
940static void atc_free_chan_resources(struct dma_chan *chan)
941{
942 struct at_dma_chan *atchan = to_at_dma_chan(chan);
943 struct at_dma *atdma = to_at_dma(chan->device);
944 struct at_desc *desc, *_desc;
945 LIST_HEAD(list);
946
947 dev_dbg(chan2dev(chan), "free_chan_resources: (descs allocated=%u)\n",
948 atchan->descs_allocated);
949
950 /* ASSERT: channel is idle */
951 BUG_ON(!list_empty(&atchan->active_list));
952 BUG_ON(!list_empty(&atchan->queue));
953 BUG_ON(atc_chan_is_enabled(atchan));
954
955 list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
956 dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
957 list_del(&desc->desc_node);
958 /* free link descriptor */
959 dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
960 }
961 list_splice_init(&atchan->free_list, &list);
962 atchan->descs_allocated = 0;
963
964 dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
965}
966
967
968/*-- Module Management -----------------------------------------------*/
969
970/**
971 * at_dma_off - disable DMA controller
972 * @atdma: the Atmel HDAMC device
973 */
974static void at_dma_off(struct at_dma *atdma)
975{
976 dma_writel(atdma, EN, 0);
977
978 /* disable all interrupts */
979 dma_writel(atdma, EBCIDR, -1L);
980
981 /* confirm that all channels are disabled */
982 while (dma_readl(atdma, CHSR) & atdma->all_chan_mask)
983 cpu_relax();
984}
985
986static int __init at_dma_probe(struct platform_device *pdev)
987{
988 struct at_dma_platform_data *pdata;
989 struct resource *io;
990 struct at_dma *atdma;
991 size_t size;
992 int irq;
993 int err;
994 int i;
995
996 /* get DMA Controller parameters from platform */
997 pdata = pdev->dev.platform_data;
998 if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS)
999 return -EINVAL;
1000
1001 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1002 if (!io)
1003 return -EINVAL;
1004
1005 irq = platform_get_irq(pdev, 0);
1006 if (irq < 0)
1007 return irq;
1008
1009 size = sizeof(struct at_dma);
1010 size += pdata->nr_channels * sizeof(struct at_dma_chan);
1011 atdma = kzalloc(size, GFP_KERNEL);
1012 if (!atdma)
1013 return -ENOMEM;
1014
1015 /* discover transaction capabilites from the platform data */
1016 atdma->dma_common.cap_mask = pdata->cap_mask;
1017 atdma->all_chan_mask = (1 << pdata->nr_channels) - 1;
1018
1019 size = io->end - io->start + 1;
1020 if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
1021 err = -EBUSY;
1022 goto err_kfree;
1023 }
1024
1025 atdma->regs = ioremap(io->start, size);
1026 if (!atdma->regs) {
1027 err = -ENOMEM;
1028 goto err_release_r;
1029 }
1030
1031 atdma->clk = clk_get(&pdev->dev, "dma_clk");
1032 if (IS_ERR(atdma->clk)) {
1033 err = PTR_ERR(atdma->clk);
1034 goto err_clk;
1035 }
1036 clk_enable(atdma->clk);
1037
1038 /* force dma off, just in case */
1039 at_dma_off(atdma);
1040
1041 err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma);
1042 if (err)
1043 goto err_irq;
1044
1045 platform_set_drvdata(pdev, atdma);
1046
1047 /* create a pool of consistent memory blocks for hardware descriptors */
1048 atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool",
1049 &pdev->dev, sizeof(struct at_desc),
1050 4 /* word alignment */, 0);
1051 if (!atdma->dma_desc_pool) {
1052 dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
1053 err = -ENOMEM;
1054 goto err_pool_create;
1055 }
1056
1057 /* clear any pending interrupt */
1058 while (dma_readl(atdma, EBCISR))
1059 cpu_relax();
1060
1061 /* initialize channels related values */
1062 INIT_LIST_HEAD(&atdma->dma_common.channels);
1063 for (i = 0; i < pdata->nr_channels; i++, atdma->dma_common.chancnt++) {
1064 struct at_dma_chan *atchan = &atdma->chan[i];
1065
1066 atchan->chan_common.device = &atdma->dma_common;
1067 atchan->chan_common.cookie = atchan->completed_cookie = 1;
1068 atchan->chan_common.chan_id = i;
1069 list_add_tail(&atchan->chan_common.device_node,
1070 &atdma->dma_common.channels);
1071
1072 atchan->ch_regs = atdma->regs + ch_regs(i);
1073 spin_lock_init(&atchan->lock);
1074 atchan->mask = 1 << i;
1075
1076 INIT_LIST_HEAD(&atchan->active_list);
1077 INIT_LIST_HEAD(&atchan->queue);
1078 INIT_LIST_HEAD(&atchan->free_list);
1079
1080 tasklet_init(&atchan->tasklet, atc_tasklet,
1081 (unsigned long)atchan);
1082 atc_enable_irq(atchan);
1083 }
1084
1085 /* set base routines */
1086 atdma->dma_common.device_alloc_chan_resources = atc_alloc_chan_resources;
1087 atdma->dma_common.device_free_chan_resources = atc_free_chan_resources;
Linus Walleij07934482010-03-26 16:50:49 -07001088 atdma->dma_common.device_tx_status = atc_tx_status;
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001089 atdma->dma_common.device_issue_pending = atc_issue_pending;
1090 atdma->dma_common.dev = &pdev->dev;
1091
1092 /* set prep routines based on capability */
1093 if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask))
1094 atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy;
1095
Nicolas Ferre808347f2009-07-22 20:04:45 +02001096 if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {
1097 atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;
Linus Walleijc3635c72010-03-26 16:44:01 -07001098 atdma->dma_common.device_control = atc_control;
Nicolas Ferre808347f2009-07-22 20:04:45 +02001099 }
1100
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001101 dma_writel(atdma, EN, AT_DMA_ENABLE);
1102
1103 dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s), %d channels\n",
1104 dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
1105 dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask) ? "slave " : "",
1106 atdma->dma_common.chancnt);
1107
1108 dma_async_device_register(&atdma->dma_common);
1109
1110 return 0;
1111
1112err_pool_create:
1113 platform_set_drvdata(pdev, NULL);
1114 free_irq(platform_get_irq(pdev, 0), atdma);
1115err_irq:
1116 clk_disable(atdma->clk);
1117 clk_put(atdma->clk);
1118err_clk:
1119 iounmap(atdma->regs);
1120 atdma->regs = NULL;
1121err_release_r:
1122 release_mem_region(io->start, size);
1123err_kfree:
1124 kfree(atdma);
1125 return err;
1126}
1127
1128static int __exit at_dma_remove(struct platform_device *pdev)
1129{
1130 struct at_dma *atdma = platform_get_drvdata(pdev);
1131 struct dma_chan *chan, *_chan;
1132 struct resource *io;
1133
1134 at_dma_off(atdma);
1135 dma_async_device_unregister(&atdma->dma_common);
1136
1137 dma_pool_destroy(atdma->dma_desc_pool);
1138 platform_set_drvdata(pdev, NULL);
1139 free_irq(platform_get_irq(pdev, 0), atdma);
1140
1141 list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
1142 device_node) {
1143 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1144
1145 /* Disable interrupts */
1146 atc_disable_irq(atchan);
1147 tasklet_disable(&atchan->tasklet);
1148
1149 tasklet_kill(&atchan->tasklet);
1150 list_del(&chan->device_node);
1151 }
1152
1153 clk_disable(atdma->clk);
1154 clk_put(atdma->clk);
1155
1156 iounmap(atdma->regs);
1157 atdma->regs = NULL;
1158
1159 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1160 release_mem_region(io->start, io->end - io->start + 1);
1161
1162 kfree(atdma);
1163
1164 return 0;
1165}
1166
1167static void at_dma_shutdown(struct platform_device *pdev)
1168{
1169 struct at_dma *atdma = platform_get_drvdata(pdev);
1170
1171 at_dma_off(platform_get_drvdata(pdev));
1172 clk_disable(atdma->clk);
1173}
1174
Dan Williams33f82d12009-09-10 00:06:44 +02001175static int at_dma_suspend_noirq(struct device *dev)
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001176{
Dan Williams33f82d12009-09-10 00:06:44 +02001177 struct platform_device *pdev = to_platform_device(dev);
1178 struct at_dma *atdma = platform_get_drvdata(pdev);
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001179
1180 at_dma_off(platform_get_drvdata(pdev));
1181 clk_disable(atdma->clk);
1182 return 0;
1183}
1184
Dan Williams33f82d12009-09-10 00:06:44 +02001185static int at_dma_resume_noirq(struct device *dev)
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001186{
Dan Williams33f82d12009-09-10 00:06:44 +02001187 struct platform_device *pdev = to_platform_device(dev);
1188 struct at_dma *atdma = platform_get_drvdata(pdev);
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001189
1190 clk_enable(atdma->clk);
1191 dma_writel(atdma, EN, AT_DMA_ENABLE);
1192 return 0;
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001193}
1194
Alexey Dobriyan47145212009-12-14 18:00:08 -08001195static const struct dev_pm_ops at_dma_dev_pm_ops = {
Dan Williams33f82d12009-09-10 00:06:44 +02001196 .suspend_noirq = at_dma_suspend_noirq,
1197 .resume_noirq = at_dma_resume_noirq,
1198};
1199
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001200static struct platform_driver at_dma_driver = {
1201 .remove = __exit_p(at_dma_remove),
1202 .shutdown = at_dma_shutdown,
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001203 .driver = {
1204 .name = "at_hdmac",
Dan Williams33f82d12009-09-10 00:06:44 +02001205 .pm = &at_dma_dev_pm_ops,
Nicolas Ferredc78baa2009-07-03 19:24:33 +02001206 },
1207};
1208
1209static int __init at_dma_init(void)
1210{
1211 return platform_driver_probe(&at_dma_driver, at_dma_probe);
1212}
1213module_init(at_dma_init);
1214
1215static void __exit at_dma_exit(void)
1216{
1217 platform_driver_unregister(&at_dma_driver);
1218}
1219module_exit(at_dma_exit);
1220
1221MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
1222MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
1223MODULE_LICENSE("GPL");
1224MODULE_ALIAS("platform:at_hdmac");