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dc78baa2 NF |
1 | /* |
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> | |
25 | ||
26 | #include "at_hdmac_regs.h" | |
27 | ||
28 | /* | |
29 | * Glossary | |
30 | * -------- | |
31 | * | |
32 | * at_hdmac : Name of the ATmel AHB DMA Controller | |
33 | * at_dma_ / atdma : ATmel DMA controller entity related | |
34 | * atc_ / atchan : ATmel DMA Channel entity related | |
35 | */ | |
36 | ||
37 | #define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO) | |
38 | #define ATC_DEFAULT_CTRLA (0) | |
39 | #define ATC_DEFAULT_CTRLB (ATC_SIF(0) \ | |
40 | |ATC_DIF(1)) | |
41 | ||
42 | /* | |
43 | * Initial number of descriptors to allocate for each channel. This could | |
44 | * be increased during dma usage. | |
45 | */ | |
46 | static unsigned int init_nr_desc_per_channel = 64; | |
47 | module_param(init_nr_desc_per_channel, uint, 0644); | |
48 | MODULE_PARM_DESC(init_nr_desc_per_channel, | |
49 | "initial descriptors per channel (default: 64)"); | |
50 | ||
51 | ||
52 | /* prototypes */ | |
53 | static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx); | |
54 | ||
55 | ||
56 | /*----------------------------------------------------------------------*/ | |
57 | ||
58 | static struct at_desc *atc_first_active(struct at_dma_chan *atchan) | |
59 | { | |
60 | return list_first_entry(&atchan->active_list, | |
61 | struct at_desc, desc_node); | |
62 | } | |
63 | ||
64 | static struct at_desc *atc_first_queued(struct at_dma_chan *atchan) | |
65 | { | |
66 | return list_first_entry(&atchan->queue, | |
67 | struct at_desc, desc_node); | |
68 | } | |
69 | ||
70 | /** | |
71 | * atc_alloc_descriptor - allocate and return an initilized descriptor | |
72 | * @chan: the channel to allocate descriptors for | |
73 | * @gfp_flags: GFP allocation flags | |
74 | * | |
75 | * Note: The ack-bit is positioned in the descriptor flag at creation time | |
76 | * to make initial allocation more convenient. This bit will be cleared | |
77 | * and control will be given to client at usage time (during | |
78 | * preparation functions). | |
79 | */ | |
80 | static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan, | |
81 | gfp_t gfp_flags) | |
82 | { | |
83 | struct at_desc *desc = NULL; | |
84 | struct at_dma *atdma = to_at_dma(chan->device); | |
85 | dma_addr_t phys; | |
86 | ||
87 | desc = dma_pool_alloc(atdma->dma_desc_pool, gfp_flags, &phys); | |
88 | if (desc) { | |
89 | memset(desc, 0, sizeof(struct at_desc)); | |
90 | dma_async_tx_descriptor_init(&desc->txd, chan); | |
91 | /* txd.flags will be overwritten in prep functions */ | |
92 | desc->txd.flags = DMA_CTRL_ACK; | |
93 | desc->txd.tx_submit = atc_tx_submit; | |
94 | desc->txd.phys = phys; | |
95 | } | |
96 | ||
97 | return desc; | |
98 | } | |
99 | ||
100 | /** | |
101 | * atc_desc_get - get a unsused descriptor from free_list | |
102 | * @atchan: channel we want a new descriptor for | |
103 | */ | |
104 | static struct at_desc *atc_desc_get(struct at_dma_chan *atchan) | |
105 | { | |
106 | struct at_desc *desc, *_desc; | |
107 | struct at_desc *ret = NULL; | |
108 | unsigned int i = 0; | |
109 | LIST_HEAD(tmp_list); | |
110 | ||
111 | spin_lock_bh(&atchan->lock); | |
112 | list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) { | |
113 | i++; | |
114 | if (async_tx_test_ack(&desc->txd)) { | |
115 | list_del(&desc->desc_node); | |
116 | ret = desc; | |
117 | break; | |
118 | } | |
119 | dev_dbg(chan2dev(&atchan->chan_common), | |
120 | "desc %p not ACKed\n", desc); | |
121 | } | |
122 | spin_unlock_bh(&atchan->lock); | |
123 | dev_vdbg(chan2dev(&atchan->chan_common), | |
124 | "scanned %u descriptors on freelist\n", i); | |
125 | ||
126 | /* no more descriptor available in initial pool: create one more */ | |
127 | if (!ret) { | |
128 | ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC); | |
129 | if (ret) { | |
130 | spin_lock_bh(&atchan->lock); | |
131 | atchan->descs_allocated++; | |
132 | spin_unlock_bh(&atchan->lock); | |
133 | } else { | |
134 | dev_err(chan2dev(&atchan->chan_common), | |
135 | "not enough descriptors available\n"); | |
136 | } | |
137 | } | |
138 | ||
139 | return ret; | |
140 | } | |
141 | ||
142 | /** | |
143 | * atc_desc_put - move a descriptor, including any children, to the free list | |
144 | * @atchan: channel we work on | |
145 | * @desc: descriptor, at the head of a chain, to move to free list | |
146 | */ | |
147 | static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc) | |
148 | { | |
149 | if (desc) { | |
150 | struct at_desc *child; | |
151 | ||
152 | spin_lock_bh(&atchan->lock); | |
153 | list_for_each_entry(child, &desc->txd.tx_list, desc_node) | |
154 | dev_vdbg(chan2dev(&atchan->chan_common), | |
155 | "moving child desc %p to freelist\n", | |
156 | child); | |
157 | list_splice_init(&desc->txd.tx_list, &atchan->free_list); | |
158 | dev_vdbg(chan2dev(&atchan->chan_common), | |
159 | "moving desc %p to freelist\n", desc); | |
160 | list_add(&desc->desc_node, &atchan->free_list); | |
161 | spin_unlock_bh(&atchan->lock); | |
162 | } | |
163 | } | |
164 | ||
165 | /** | |
166 | * atc_assign_cookie - compute and assign new cookie | |
167 | * @atchan: channel we work on | |
168 | * @desc: descriptor to asign cookie for | |
169 | * | |
170 | * Called with atchan->lock held and bh disabled | |
171 | */ | |
172 | static dma_cookie_t | |
173 | atc_assign_cookie(struct at_dma_chan *atchan, struct at_desc *desc) | |
174 | { | |
175 | dma_cookie_t cookie = atchan->chan_common.cookie; | |
176 | ||
177 | if (++cookie < 0) | |
178 | cookie = 1; | |
179 | ||
180 | atchan->chan_common.cookie = cookie; | |
181 | desc->txd.cookie = cookie; | |
182 | ||
183 | return cookie; | |
184 | } | |
185 | ||
186 | /** | |
187 | * atc_dostart - starts the DMA engine for real | |
188 | * @atchan: the channel we want to start | |
189 | * @first: first descriptor in the list we want to begin with | |
190 | * | |
191 | * Called with atchan->lock held and bh disabled | |
192 | */ | |
193 | static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first) | |
194 | { | |
195 | struct at_dma *atdma = to_at_dma(atchan->chan_common.device); | |
196 | ||
197 | /* ASSERT: channel is idle */ | |
198 | if (atc_chan_is_enabled(atchan)) { | |
199 | dev_err(chan2dev(&atchan->chan_common), | |
200 | "BUG: Attempted to start non-idle channel\n"); | |
201 | dev_err(chan2dev(&atchan->chan_common), | |
202 | " channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n", | |
203 | channel_readl(atchan, SADDR), | |
204 | channel_readl(atchan, DADDR), | |
205 | channel_readl(atchan, CTRLA), | |
206 | channel_readl(atchan, CTRLB), | |
207 | channel_readl(atchan, DSCR)); | |
208 | ||
209 | /* The tasklet will hopefully advance the queue... */ | |
210 | return; | |
211 | } | |
212 | ||
213 | vdbg_dump_regs(atchan); | |
214 | ||
215 | /* clear any pending interrupt */ | |
216 | while (dma_readl(atdma, EBCISR)) | |
217 | cpu_relax(); | |
218 | ||
219 | channel_writel(atchan, SADDR, 0); | |
220 | channel_writel(atchan, DADDR, 0); | |
221 | channel_writel(atchan, CTRLA, 0); | |
222 | channel_writel(atchan, CTRLB, 0); | |
223 | channel_writel(atchan, DSCR, first->txd.phys); | |
224 | dma_writel(atdma, CHER, atchan->mask); | |
225 | ||
226 | vdbg_dump_regs(atchan); | |
227 | } | |
228 | ||
229 | /** | |
230 | * atc_chain_complete - finish work for one transaction chain | |
231 | * @atchan: channel we work on | |
232 | * @desc: descriptor at the head of the chain we want do complete | |
233 | * | |
234 | * Called with atchan->lock held and bh disabled */ | |
235 | static void | |
236 | atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc) | |
237 | { | |
238 | dma_async_tx_callback callback; | |
239 | void *param; | |
240 | struct dma_async_tx_descriptor *txd = &desc->txd; | |
241 | ||
242 | dev_vdbg(chan2dev(&atchan->chan_common), | |
243 | "descriptor %u complete\n", txd->cookie); | |
244 | ||
245 | atchan->completed_cookie = txd->cookie; | |
246 | callback = txd->callback; | |
247 | param = txd->callback_param; | |
248 | ||
249 | /* move children to free_list */ | |
250 | list_splice_init(&txd->tx_list, &atchan->free_list); | |
251 | /* move myself to free_list */ | |
252 | list_move(&desc->desc_node, &atchan->free_list); | |
253 | ||
254 | /* unmap dma addresses */ | |
255 | if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) { | |
256 | if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE) | |
257 | dma_unmap_single(chan2parent(&atchan->chan_common), | |
258 | desc->lli.daddr, | |
259 | desc->len, DMA_FROM_DEVICE); | |
260 | else | |
261 | dma_unmap_page(chan2parent(&atchan->chan_common), | |
262 | desc->lli.daddr, | |
263 | desc->len, DMA_FROM_DEVICE); | |
264 | } | |
265 | if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) { | |
266 | if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE) | |
267 | dma_unmap_single(chan2parent(&atchan->chan_common), | |
268 | desc->lli.saddr, | |
269 | desc->len, DMA_TO_DEVICE); | |
270 | else | |
271 | dma_unmap_page(chan2parent(&atchan->chan_common), | |
272 | desc->lli.saddr, | |
273 | desc->len, DMA_TO_DEVICE); | |
274 | } | |
275 | ||
276 | /* | |
277 | * The API requires that no submissions are done from a | |
278 | * callback, so we don't need to drop the lock here | |
279 | */ | |
280 | if (callback) | |
281 | callback(param); | |
282 | ||
283 | dma_run_dependencies(txd); | |
284 | } | |
285 | ||
286 | /** | |
287 | * atc_complete_all - finish work for all transactions | |
288 | * @atchan: channel to complete transactions for | |
289 | * | |
290 | * Eventually submit queued descriptors if any | |
291 | * | |
292 | * Assume channel is idle while calling this function | |
293 | * Called with atchan->lock held and bh disabled | |
294 | */ | |
295 | static void atc_complete_all(struct at_dma_chan *atchan) | |
296 | { | |
297 | struct at_desc *desc, *_desc; | |
298 | LIST_HEAD(list); | |
299 | ||
300 | dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n"); | |
301 | ||
302 | BUG_ON(atc_chan_is_enabled(atchan)); | |
303 | ||
304 | /* | |
305 | * Submit queued descriptors ASAP, i.e. before we go through | |
306 | * the completed ones. | |
307 | */ | |
308 | if (!list_empty(&atchan->queue)) | |
309 | atc_dostart(atchan, atc_first_queued(atchan)); | |
310 | /* empty active_list now it is completed */ | |
311 | list_splice_init(&atchan->active_list, &list); | |
312 | /* empty queue list by moving descriptors (if any) to active_list */ | |
313 | list_splice_init(&atchan->queue, &atchan->active_list); | |
314 | ||
315 | list_for_each_entry_safe(desc, _desc, &list, desc_node) | |
316 | atc_chain_complete(atchan, desc); | |
317 | } | |
318 | ||
319 | /** | |
320 | * atc_cleanup_descriptors - cleanup up finished descriptors in active_list | |
321 | * @atchan: channel to be cleaned up | |
322 | * | |
323 | * Called with atchan->lock held and bh disabled | |
324 | */ | |
325 | static void atc_cleanup_descriptors(struct at_dma_chan *atchan) | |
326 | { | |
327 | struct at_desc *desc, *_desc; | |
328 | struct at_desc *child; | |
329 | ||
330 | dev_vdbg(chan2dev(&atchan->chan_common), "cleanup descriptors\n"); | |
331 | ||
332 | list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) { | |
333 | if (!(desc->lli.ctrla & ATC_DONE)) | |
334 | /* This one is currently in progress */ | |
335 | return; | |
336 | ||
337 | list_for_each_entry(child, &desc->txd.tx_list, desc_node) | |
338 | if (!(child->lli.ctrla & ATC_DONE)) | |
339 | /* Currently in progress */ | |
340 | return; | |
341 | ||
342 | /* | |
343 | * No descriptors so far seem to be in progress, i.e. | |
344 | * this chain must be done. | |
345 | */ | |
346 | atc_chain_complete(atchan, desc); | |
347 | } | |
348 | } | |
349 | ||
350 | /** | |
351 | * atc_advance_work - at the end of a transaction, move forward | |
352 | * @atchan: channel where the transaction ended | |
353 | * | |
354 | * Called with atchan->lock held and bh disabled | |
355 | */ | |
356 | static void atc_advance_work(struct at_dma_chan *atchan) | |
357 | { | |
358 | dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n"); | |
359 | ||
360 | if (list_empty(&atchan->active_list) || | |
361 | list_is_singular(&atchan->active_list)) { | |
362 | atc_complete_all(atchan); | |
363 | } else { | |
364 | atc_chain_complete(atchan, atc_first_active(atchan)); | |
365 | /* advance work */ | |
366 | atc_dostart(atchan, atc_first_active(atchan)); | |
367 | } | |
368 | } | |
369 | ||
370 | ||
371 | /** | |
372 | * atc_handle_error - handle errors reported by DMA controller | |
373 | * @atchan: channel where error occurs | |
374 | * | |
375 | * Called with atchan->lock held and bh disabled | |
376 | */ | |
377 | static void atc_handle_error(struct at_dma_chan *atchan) | |
378 | { | |
379 | struct at_desc *bad_desc; | |
380 | struct at_desc *child; | |
381 | ||
382 | /* | |
383 | * The descriptor currently at the head of the active list is | |
384 | * broked. Since we don't have any way to report errors, we'll | |
385 | * just have to scream loudly and try to carry on. | |
386 | */ | |
387 | bad_desc = atc_first_active(atchan); | |
388 | list_del_init(&bad_desc->desc_node); | |
389 | ||
390 | /* As we are stopped, take advantage to push queued descriptors | |
391 | * in active_list */ | |
392 | list_splice_init(&atchan->queue, atchan->active_list.prev); | |
393 | ||
394 | /* Try to restart the controller */ | |
395 | if (!list_empty(&atchan->active_list)) | |
396 | atc_dostart(atchan, atc_first_active(atchan)); | |
397 | ||
398 | /* | |
399 | * KERN_CRITICAL may seem harsh, but since this only happens | |
400 | * when someone submits a bad physical address in a | |
401 | * descriptor, we should consider ourselves lucky that the | |
402 | * controller flagged an error instead of scribbling over | |
403 | * random memory locations. | |
404 | */ | |
405 | dev_crit(chan2dev(&atchan->chan_common), | |
406 | "Bad descriptor submitted for DMA!\n"); | |
407 | dev_crit(chan2dev(&atchan->chan_common), | |
408 | " cookie: %d\n", bad_desc->txd.cookie); | |
409 | atc_dump_lli(atchan, &bad_desc->lli); | |
410 | list_for_each_entry(child, &bad_desc->txd.tx_list, desc_node) | |
411 | atc_dump_lli(atchan, &child->lli); | |
412 | ||
413 | /* Pretend the descriptor completed successfully */ | |
414 | atc_chain_complete(atchan, bad_desc); | |
415 | } | |
416 | ||
417 | ||
418 | /*-- IRQ & Tasklet ---------------------------------------------------*/ | |
419 | ||
420 | static void atc_tasklet(unsigned long data) | |
421 | { | |
422 | struct at_dma_chan *atchan = (struct at_dma_chan *)data; | |
423 | ||
424 | /* Channel cannot be enabled here */ | |
425 | if (atc_chan_is_enabled(atchan)) { | |
426 | dev_err(chan2dev(&atchan->chan_common), | |
427 | "BUG: channel enabled in tasklet\n"); | |
428 | return; | |
429 | } | |
430 | ||
431 | spin_lock(&atchan->lock); | |
432 | if (test_and_clear_bit(0, &atchan->error_status)) | |
433 | atc_handle_error(atchan); | |
434 | else | |
435 | atc_advance_work(atchan); | |
436 | ||
437 | spin_unlock(&atchan->lock); | |
438 | } | |
439 | ||
440 | static irqreturn_t at_dma_interrupt(int irq, void *dev_id) | |
441 | { | |
442 | struct at_dma *atdma = (struct at_dma *)dev_id; | |
443 | struct at_dma_chan *atchan; | |
444 | int i; | |
445 | u32 status, pending, imr; | |
446 | int ret = IRQ_NONE; | |
447 | ||
448 | do { | |
449 | imr = dma_readl(atdma, EBCIMR); | |
450 | status = dma_readl(atdma, EBCISR); | |
451 | pending = status & imr; | |
452 | ||
453 | if (!pending) | |
454 | break; | |
455 | ||
456 | dev_vdbg(atdma->dma_common.dev, | |
457 | "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n", | |
458 | status, imr, pending); | |
459 | ||
460 | for (i = 0; i < atdma->dma_common.chancnt; i++) { | |
461 | atchan = &atdma->chan[i]; | |
462 | if (pending & (AT_DMA_CBTC(i) | AT_DMA_ERR(i))) { | |
463 | if (pending & AT_DMA_ERR(i)) { | |
464 | /* Disable channel on AHB error */ | |
465 | dma_writel(atdma, CHDR, atchan->mask); | |
466 | /* Give information to tasklet */ | |
467 | set_bit(0, &atchan->error_status); | |
468 | } | |
469 | tasklet_schedule(&atchan->tasklet); | |
470 | ret = IRQ_HANDLED; | |
471 | } | |
472 | } | |
473 | ||
474 | } while (pending); | |
475 | ||
476 | return ret; | |
477 | } | |
478 | ||
479 | ||
480 | /*-- DMA Engine API --------------------------------------------------*/ | |
481 | ||
482 | /** | |
483 | * atc_tx_submit - set the prepared descriptor(s) to be executed by the engine | |
484 | * @desc: descriptor at the head of the transaction chain | |
485 | * | |
486 | * Queue chain if DMA engine is working already | |
487 | * | |
488 | * Cookie increment and adding to active_list or queue must be atomic | |
489 | */ | |
490 | static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx) | |
491 | { | |
492 | struct at_desc *desc = txd_to_at_desc(tx); | |
493 | struct at_dma_chan *atchan = to_at_dma_chan(tx->chan); | |
494 | dma_cookie_t cookie; | |
495 | ||
496 | spin_lock_bh(&atchan->lock); | |
497 | cookie = atc_assign_cookie(atchan, desc); | |
498 | ||
499 | if (list_empty(&atchan->active_list)) { | |
500 | dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n", | |
501 | desc->txd.cookie); | |
502 | atc_dostart(atchan, desc); | |
503 | list_add_tail(&desc->desc_node, &atchan->active_list); | |
504 | } else { | |
505 | dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n", | |
506 | desc->txd.cookie); | |
507 | list_add_tail(&desc->desc_node, &atchan->queue); | |
508 | } | |
509 | ||
510 | spin_unlock_bh(&atchan->lock); | |
511 | ||
512 | return cookie; | |
513 | } | |
514 | ||
515 | /** | |
516 | * atc_prep_dma_memcpy - prepare a memcpy operation | |
517 | * @chan: the channel to prepare operation on | |
518 | * @dest: operation virtual destination address | |
519 | * @src: operation virtual source address | |
520 | * @len: operation length | |
521 | * @flags: tx descriptor status flags | |
522 | */ | |
523 | static struct dma_async_tx_descriptor * | |
524 | atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, | |
525 | size_t len, unsigned long flags) | |
526 | { | |
527 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
528 | struct at_desc *desc = NULL; | |
529 | struct at_desc *first = NULL; | |
530 | struct at_desc *prev = NULL; | |
531 | size_t xfer_count; | |
532 | size_t offset; | |
533 | unsigned int src_width; | |
534 | unsigned int dst_width; | |
535 | u32 ctrla; | |
536 | u32 ctrlb; | |
537 | ||
538 | dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d0x%x s0x%x l0x%zx f0x%lx\n", | |
539 | dest, src, len, flags); | |
540 | ||
541 | if (unlikely(!len)) { | |
542 | dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n"); | |
543 | return NULL; | |
544 | } | |
545 | ||
546 | ctrla = ATC_DEFAULT_CTRLA; | |
547 | ctrlb = ATC_DEFAULT_CTRLB | |
548 | | ATC_SRC_ADDR_MODE_INCR | |
549 | | ATC_DST_ADDR_MODE_INCR | |
550 | | ATC_FC_MEM2MEM; | |
551 | ||
552 | /* | |
553 | * We can be a lot more clever here, but this should take care | |
554 | * of the most common optimization. | |
555 | */ | |
556 | if (!((src | dest | len) & 3)) { | |
557 | ctrla |= ATC_SRC_WIDTH_WORD | ATC_DST_WIDTH_WORD; | |
558 | src_width = dst_width = 2; | |
559 | } else if (!((src | dest | len) & 1)) { | |
560 | ctrla |= ATC_SRC_WIDTH_HALFWORD | ATC_DST_WIDTH_HALFWORD; | |
561 | src_width = dst_width = 1; | |
562 | } else { | |
563 | ctrla |= ATC_SRC_WIDTH_BYTE | ATC_DST_WIDTH_BYTE; | |
564 | src_width = dst_width = 0; | |
565 | } | |
566 | ||
567 | for (offset = 0; offset < len; offset += xfer_count << src_width) { | |
568 | xfer_count = min_t(size_t, (len - offset) >> src_width, | |
569 | ATC_BTSIZE_MAX); | |
570 | ||
571 | desc = atc_desc_get(atchan); | |
572 | if (!desc) | |
573 | goto err_desc_get; | |
574 | ||
575 | desc->lli.saddr = src + offset; | |
576 | desc->lli.daddr = dest + offset; | |
577 | desc->lli.ctrla = ctrla | xfer_count; | |
578 | desc->lli.ctrlb = ctrlb; | |
579 | ||
580 | desc->txd.cookie = 0; | |
581 | async_tx_ack(&desc->txd); | |
582 | ||
583 | if (!first) { | |
584 | first = desc; | |
585 | } else { | |
586 | /* inform the HW lli about chaining */ | |
587 | prev->lli.dscr = desc->txd.phys; | |
588 | /* insert the link descriptor to the LD ring */ | |
589 | list_add_tail(&desc->desc_node, | |
590 | &first->txd.tx_list); | |
591 | } | |
592 | prev = desc; | |
593 | } | |
594 | ||
595 | /* First descriptor of the chain embedds additional information */ | |
596 | first->txd.cookie = -EBUSY; | |
597 | first->len = len; | |
598 | ||
599 | /* set end-of-link to the last link descriptor of list*/ | |
600 | set_desc_eol(desc); | |
601 | ||
602 | desc->txd.flags = flags; /* client is in control of this ack */ | |
603 | ||
604 | return &first->txd; | |
605 | ||
606 | err_desc_get: | |
607 | atc_desc_put(atchan, first); | |
608 | return NULL; | |
609 | } | |
610 | ||
611 | /** | |
612 | * atc_is_tx_complete - poll for transaction completion | |
613 | * @chan: DMA channel | |
614 | * @cookie: transaction identifier to check status of | |
615 | * @done: if not %NULL, updated with last completed transaction | |
616 | * @used: if not %NULL, updated with last used transaction | |
617 | * | |
618 | * If @done and @used are passed in, upon return they reflect the driver | |
619 | * internal state and can be used with dma_async_is_complete() to check | |
620 | * the status of multiple cookies without re-checking hardware state. | |
621 | */ | |
622 | static enum dma_status | |
623 | atc_is_tx_complete(struct dma_chan *chan, | |
624 | dma_cookie_t cookie, | |
625 | dma_cookie_t *done, dma_cookie_t *used) | |
626 | { | |
627 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
628 | dma_cookie_t last_used; | |
629 | dma_cookie_t last_complete; | |
630 | enum dma_status ret; | |
631 | ||
632 | dev_vdbg(chan2dev(chan), "is_tx_complete: %d (d%d, u%d)\n", | |
633 | cookie, done ? *done : 0, used ? *used : 0); | |
634 | ||
635 | spin_lock_bh(atchan->lock); | |
636 | ||
637 | last_complete = atchan->completed_cookie; | |
638 | last_used = chan->cookie; | |
639 | ||
640 | ret = dma_async_is_complete(cookie, last_complete, last_used); | |
641 | if (ret != DMA_SUCCESS) { | |
642 | atc_cleanup_descriptors(atchan); | |
643 | ||
644 | last_complete = atchan->completed_cookie; | |
645 | last_used = chan->cookie; | |
646 | ||
647 | ret = dma_async_is_complete(cookie, last_complete, last_used); | |
648 | } | |
649 | ||
650 | spin_unlock_bh(atchan->lock); | |
651 | ||
652 | if (done) | |
653 | *done = last_complete; | |
654 | if (used) | |
655 | *used = last_used; | |
656 | ||
657 | return ret; | |
658 | } | |
659 | ||
660 | /** | |
661 | * atc_issue_pending - try to finish work | |
662 | * @chan: target DMA channel | |
663 | */ | |
664 | static void atc_issue_pending(struct dma_chan *chan) | |
665 | { | |
666 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
667 | ||
668 | dev_vdbg(chan2dev(chan), "issue_pending\n"); | |
669 | ||
670 | if (!atc_chan_is_enabled(atchan)) { | |
671 | spin_lock_bh(&atchan->lock); | |
672 | atc_advance_work(atchan); | |
673 | spin_unlock_bh(&atchan->lock); | |
674 | } | |
675 | } | |
676 | ||
677 | /** | |
678 | * atc_alloc_chan_resources - allocate resources for DMA channel | |
679 | * @chan: allocate descriptor resources for this channel | |
680 | * @client: current client requesting the channel be ready for requests | |
681 | * | |
682 | * return - the number of allocated descriptors | |
683 | */ | |
684 | static int atc_alloc_chan_resources(struct dma_chan *chan) | |
685 | { | |
686 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
687 | struct at_dma *atdma = to_at_dma(chan->device); | |
688 | struct at_desc *desc; | |
689 | int i; | |
690 | LIST_HEAD(tmp_list); | |
691 | ||
692 | dev_vdbg(chan2dev(chan), "alloc_chan_resources\n"); | |
693 | ||
694 | /* ASSERT: channel is idle */ | |
695 | if (atc_chan_is_enabled(atchan)) { | |
696 | dev_dbg(chan2dev(chan), "DMA channel not idle ?\n"); | |
697 | return -EIO; | |
698 | } | |
699 | ||
700 | /* have we already been set up? */ | |
701 | if (!list_empty(&atchan->free_list)) | |
702 | return atchan->descs_allocated; | |
703 | ||
704 | /* Allocate initial pool of descriptors */ | |
705 | for (i = 0; i < init_nr_desc_per_channel; i++) { | |
706 | desc = atc_alloc_descriptor(chan, GFP_KERNEL); | |
707 | if (!desc) { | |
708 | dev_err(atdma->dma_common.dev, | |
709 | "Only %d initial descriptors\n", i); | |
710 | break; | |
711 | } | |
712 | list_add_tail(&desc->desc_node, &tmp_list); | |
713 | } | |
714 | ||
715 | spin_lock_bh(&atchan->lock); | |
716 | atchan->descs_allocated = i; | |
717 | list_splice(&tmp_list, &atchan->free_list); | |
718 | atchan->completed_cookie = chan->cookie = 1; | |
719 | spin_unlock_bh(&atchan->lock); | |
720 | ||
721 | /* channel parameters */ | |
722 | channel_writel(atchan, CFG, ATC_DEFAULT_CFG); | |
723 | ||
724 | dev_dbg(chan2dev(chan), | |
725 | "alloc_chan_resources: allocated %d descriptors\n", | |
726 | atchan->descs_allocated); | |
727 | ||
728 | return atchan->descs_allocated; | |
729 | } | |
730 | ||
731 | /** | |
732 | * atc_free_chan_resources - free all channel resources | |
733 | * @chan: DMA channel | |
734 | */ | |
735 | static void atc_free_chan_resources(struct dma_chan *chan) | |
736 | { | |
737 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
738 | struct at_dma *atdma = to_at_dma(chan->device); | |
739 | struct at_desc *desc, *_desc; | |
740 | LIST_HEAD(list); | |
741 | ||
742 | dev_dbg(chan2dev(chan), "free_chan_resources: (descs allocated=%u)\n", | |
743 | atchan->descs_allocated); | |
744 | ||
745 | /* ASSERT: channel is idle */ | |
746 | BUG_ON(!list_empty(&atchan->active_list)); | |
747 | BUG_ON(!list_empty(&atchan->queue)); | |
748 | BUG_ON(atc_chan_is_enabled(atchan)); | |
749 | ||
750 | list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) { | |
751 | dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc); | |
752 | list_del(&desc->desc_node); | |
753 | /* free link descriptor */ | |
754 | dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys); | |
755 | } | |
756 | list_splice_init(&atchan->free_list, &list); | |
757 | atchan->descs_allocated = 0; | |
758 | ||
759 | dev_vdbg(chan2dev(chan), "free_chan_resources: done\n"); | |
760 | } | |
761 | ||
762 | ||
763 | /*-- Module Management -----------------------------------------------*/ | |
764 | ||
765 | /** | |
766 | * at_dma_off - disable DMA controller | |
767 | * @atdma: the Atmel HDAMC device | |
768 | */ | |
769 | static void at_dma_off(struct at_dma *atdma) | |
770 | { | |
771 | dma_writel(atdma, EN, 0); | |
772 | ||
773 | /* disable all interrupts */ | |
774 | dma_writel(atdma, EBCIDR, -1L); | |
775 | ||
776 | /* confirm that all channels are disabled */ | |
777 | while (dma_readl(atdma, CHSR) & atdma->all_chan_mask) | |
778 | cpu_relax(); | |
779 | } | |
780 | ||
781 | static int __init at_dma_probe(struct platform_device *pdev) | |
782 | { | |
783 | struct at_dma_platform_data *pdata; | |
784 | struct resource *io; | |
785 | struct at_dma *atdma; | |
786 | size_t size; | |
787 | int irq; | |
788 | int err; | |
789 | int i; | |
790 | ||
791 | /* get DMA Controller parameters from platform */ | |
792 | pdata = pdev->dev.platform_data; | |
793 | if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS) | |
794 | return -EINVAL; | |
795 | ||
796 | io = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
797 | if (!io) | |
798 | return -EINVAL; | |
799 | ||
800 | irq = platform_get_irq(pdev, 0); | |
801 | if (irq < 0) | |
802 | return irq; | |
803 | ||
804 | size = sizeof(struct at_dma); | |
805 | size += pdata->nr_channels * sizeof(struct at_dma_chan); | |
806 | atdma = kzalloc(size, GFP_KERNEL); | |
807 | if (!atdma) | |
808 | return -ENOMEM; | |
809 | ||
810 | /* discover transaction capabilites from the platform data */ | |
811 | atdma->dma_common.cap_mask = pdata->cap_mask; | |
812 | atdma->all_chan_mask = (1 << pdata->nr_channels) - 1; | |
813 | ||
814 | size = io->end - io->start + 1; | |
815 | if (!request_mem_region(io->start, size, pdev->dev.driver->name)) { | |
816 | err = -EBUSY; | |
817 | goto err_kfree; | |
818 | } | |
819 | ||
820 | atdma->regs = ioremap(io->start, size); | |
821 | if (!atdma->regs) { | |
822 | err = -ENOMEM; | |
823 | goto err_release_r; | |
824 | } | |
825 | ||
826 | atdma->clk = clk_get(&pdev->dev, "dma_clk"); | |
827 | if (IS_ERR(atdma->clk)) { | |
828 | err = PTR_ERR(atdma->clk); | |
829 | goto err_clk; | |
830 | } | |
831 | clk_enable(atdma->clk); | |
832 | ||
833 | /* force dma off, just in case */ | |
834 | at_dma_off(atdma); | |
835 | ||
836 | err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma); | |
837 | if (err) | |
838 | goto err_irq; | |
839 | ||
840 | platform_set_drvdata(pdev, atdma); | |
841 | ||
842 | /* create a pool of consistent memory blocks for hardware descriptors */ | |
843 | atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool", | |
844 | &pdev->dev, sizeof(struct at_desc), | |
845 | 4 /* word alignment */, 0); | |
846 | if (!atdma->dma_desc_pool) { | |
847 | dev_err(&pdev->dev, "No memory for descriptors dma pool\n"); | |
848 | err = -ENOMEM; | |
849 | goto err_pool_create; | |
850 | } | |
851 | ||
852 | /* clear any pending interrupt */ | |
853 | while (dma_readl(atdma, EBCISR)) | |
854 | cpu_relax(); | |
855 | ||
856 | /* initialize channels related values */ | |
857 | INIT_LIST_HEAD(&atdma->dma_common.channels); | |
858 | for (i = 0; i < pdata->nr_channels; i++, atdma->dma_common.chancnt++) { | |
859 | struct at_dma_chan *atchan = &atdma->chan[i]; | |
860 | ||
861 | atchan->chan_common.device = &atdma->dma_common; | |
862 | atchan->chan_common.cookie = atchan->completed_cookie = 1; | |
863 | atchan->chan_common.chan_id = i; | |
864 | list_add_tail(&atchan->chan_common.device_node, | |
865 | &atdma->dma_common.channels); | |
866 | ||
867 | atchan->ch_regs = atdma->regs + ch_regs(i); | |
868 | spin_lock_init(&atchan->lock); | |
869 | atchan->mask = 1 << i; | |
870 | ||
871 | INIT_LIST_HEAD(&atchan->active_list); | |
872 | INIT_LIST_HEAD(&atchan->queue); | |
873 | INIT_LIST_HEAD(&atchan->free_list); | |
874 | ||
875 | tasklet_init(&atchan->tasklet, atc_tasklet, | |
876 | (unsigned long)atchan); | |
877 | atc_enable_irq(atchan); | |
878 | } | |
879 | ||
880 | /* set base routines */ | |
881 | atdma->dma_common.device_alloc_chan_resources = atc_alloc_chan_resources; | |
882 | atdma->dma_common.device_free_chan_resources = atc_free_chan_resources; | |
883 | atdma->dma_common.device_is_tx_complete = atc_is_tx_complete; | |
884 | atdma->dma_common.device_issue_pending = atc_issue_pending; | |
885 | atdma->dma_common.dev = &pdev->dev; | |
886 | ||
887 | /* set prep routines based on capability */ | |
888 | if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask)) | |
889 | atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy; | |
890 | ||
891 | dma_writel(atdma, EN, AT_DMA_ENABLE); | |
892 | ||
893 | dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s), %d channels\n", | |
894 | dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "", | |
895 | dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask) ? "slave " : "", | |
896 | atdma->dma_common.chancnt); | |
897 | ||
898 | dma_async_device_register(&atdma->dma_common); | |
899 | ||
900 | return 0; | |
901 | ||
902 | err_pool_create: | |
903 | platform_set_drvdata(pdev, NULL); | |
904 | free_irq(platform_get_irq(pdev, 0), atdma); | |
905 | err_irq: | |
906 | clk_disable(atdma->clk); | |
907 | clk_put(atdma->clk); | |
908 | err_clk: | |
909 | iounmap(atdma->regs); | |
910 | atdma->regs = NULL; | |
911 | err_release_r: | |
912 | release_mem_region(io->start, size); | |
913 | err_kfree: | |
914 | kfree(atdma); | |
915 | return err; | |
916 | } | |
917 | ||
918 | static int __exit at_dma_remove(struct platform_device *pdev) | |
919 | { | |
920 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
921 | struct dma_chan *chan, *_chan; | |
922 | struct resource *io; | |
923 | ||
924 | at_dma_off(atdma); | |
925 | dma_async_device_unregister(&atdma->dma_common); | |
926 | ||
927 | dma_pool_destroy(atdma->dma_desc_pool); | |
928 | platform_set_drvdata(pdev, NULL); | |
929 | free_irq(platform_get_irq(pdev, 0), atdma); | |
930 | ||
931 | list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, | |
932 | device_node) { | |
933 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
934 | ||
935 | /* Disable interrupts */ | |
936 | atc_disable_irq(atchan); | |
937 | tasklet_disable(&atchan->tasklet); | |
938 | ||
939 | tasklet_kill(&atchan->tasklet); | |
940 | list_del(&chan->device_node); | |
941 | } | |
942 | ||
943 | clk_disable(atdma->clk); | |
944 | clk_put(atdma->clk); | |
945 | ||
946 | iounmap(atdma->regs); | |
947 | atdma->regs = NULL; | |
948 | ||
949 | io = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
950 | release_mem_region(io->start, io->end - io->start + 1); | |
951 | ||
952 | kfree(atdma); | |
953 | ||
954 | return 0; | |
955 | } | |
956 | ||
957 | static void at_dma_shutdown(struct platform_device *pdev) | |
958 | { | |
959 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
960 | ||
961 | at_dma_off(platform_get_drvdata(pdev)); | |
962 | clk_disable(atdma->clk); | |
963 | } | |
964 | ||
965 | static int at_dma_suspend_late(struct platform_device *pdev, pm_message_t mesg) | |
966 | { | |
967 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
968 | ||
969 | at_dma_off(platform_get_drvdata(pdev)); | |
970 | clk_disable(atdma->clk); | |
971 | return 0; | |
972 | } | |
973 | ||
974 | static int at_dma_resume_early(struct platform_device *pdev) | |
975 | { | |
976 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
977 | ||
978 | clk_enable(atdma->clk); | |
979 | dma_writel(atdma, EN, AT_DMA_ENABLE); | |
980 | return 0; | |
981 | ||
982 | } | |
983 | ||
984 | static struct platform_driver at_dma_driver = { | |
985 | .remove = __exit_p(at_dma_remove), | |
986 | .shutdown = at_dma_shutdown, | |
987 | .suspend_late = at_dma_suspend_late, | |
988 | .resume_early = at_dma_resume_early, | |
989 | .driver = { | |
990 | .name = "at_hdmac", | |
991 | }, | |
992 | }; | |
993 | ||
994 | static int __init at_dma_init(void) | |
995 | { | |
996 | return platform_driver_probe(&at_dma_driver, at_dma_probe); | |
997 | } | |
998 | module_init(at_dma_init); | |
999 | ||
1000 | static void __exit at_dma_exit(void) | |
1001 | { | |
1002 | platform_driver_unregister(&at_dma_driver); | |
1003 | } | |
1004 | module_exit(at_dma_exit); | |
1005 | ||
1006 | MODULE_DESCRIPTION("Atmel AHB DMA Controller driver"); | |
1007 | MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>"); | |
1008 | MODULE_LICENSE("GPL"); | |
1009 | MODULE_ALIAS("platform:at_hdmac"); |