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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 found in several Atmel SoCs. | |
13 | * The only Atmel DMA Controller that is not covered by this driver is the one | |
14 | * found on AT91SAM9263. | |
15 | */ | |
16 | ||
17 | #include <dt-bindings/dma/at91.h> | |
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 | #include <linux/slab.h> | |
26 | #include <linux/of.h> | |
27 | #include <linux/of_device.h> | |
28 | #include <linux/of_dma.h> | |
29 | ||
30 | #include "at_hdmac_regs.h" | |
31 | #include "dmaengine.h" | |
32 | ||
33 | /* | |
34 | * Glossary | |
35 | * -------- | |
36 | * | |
37 | * at_hdmac : Name of the ATmel AHB DMA Controller | |
38 | * at_dma_ / atdma : ATmel DMA controller entity related | |
39 | * atc_ / atchan : ATmel DMA Channel entity related | |
40 | */ | |
41 | ||
42 | #define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO) | |
43 | #define ATC_DEFAULT_CTRLB (ATC_SIF(AT_DMA_MEM_IF) \ | |
44 | |ATC_DIF(AT_DMA_MEM_IF)) | |
45 | #define ATC_DMA_BUSWIDTHS\ | |
46 | (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\ | |
47 | BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\ | |
48 | BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\ | |
49 | BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)) | |
50 | ||
51 | #define ATC_MAX_DSCR_TRIALS 10 | |
52 | ||
53 | /* | |
54 | * Initial number of descriptors to allocate for each channel. This could | |
55 | * be increased during dma usage. | |
56 | */ | |
57 | static unsigned int init_nr_desc_per_channel = 64; | |
58 | module_param(init_nr_desc_per_channel, uint, 0644); | |
59 | MODULE_PARM_DESC(init_nr_desc_per_channel, | |
60 | "initial descriptors per channel (default: 64)"); | |
61 | ||
62 | ||
63 | /* prototypes */ | |
64 | static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx); | |
65 | static void atc_issue_pending(struct dma_chan *chan); | |
66 | ||
67 | ||
68 | /*----------------------------------------------------------------------*/ | |
69 | ||
70 | static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst, | |
71 | size_t len) | |
72 | { | |
73 | unsigned int width; | |
74 | ||
75 | if (!((src | dst | len) & 3)) | |
76 | width = 2; | |
77 | else if (!((src | dst | len) & 1)) | |
78 | width = 1; | |
79 | else | |
80 | width = 0; | |
81 | ||
82 | return width; | |
83 | } | |
84 | ||
85 | static struct at_desc *atc_first_active(struct at_dma_chan *atchan) | |
86 | { | |
87 | return list_first_entry(&atchan->active_list, | |
88 | struct at_desc, desc_node); | |
89 | } | |
90 | ||
91 | static struct at_desc *atc_first_queued(struct at_dma_chan *atchan) | |
92 | { | |
93 | return list_first_entry(&atchan->queue, | |
94 | struct at_desc, desc_node); | |
95 | } | |
96 | ||
97 | /** | |
98 | * atc_alloc_descriptor - allocate and return an initialized descriptor | |
99 | * @chan: the channel to allocate descriptors for | |
100 | * @gfp_flags: GFP allocation flags | |
101 | * | |
102 | * Note: The ack-bit is positioned in the descriptor flag at creation time | |
103 | * to make initial allocation more convenient. This bit will be cleared | |
104 | * and control will be given to client at usage time (during | |
105 | * preparation functions). | |
106 | */ | |
107 | static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan, | |
108 | gfp_t gfp_flags) | |
109 | { | |
110 | struct at_desc *desc = NULL; | |
111 | struct at_dma *atdma = to_at_dma(chan->device); | |
112 | dma_addr_t phys; | |
113 | ||
114 | desc = dma_pool_zalloc(atdma->dma_desc_pool, gfp_flags, &phys); | |
115 | if (desc) { | |
116 | INIT_LIST_HEAD(&desc->tx_list); | |
117 | dma_async_tx_descriptor_init(&desc->txd, chan); | |
118 | /* txd.flags will be overwritten in prep functions */ | |
119 | desc->txd.flags = DMA_CTRL_ACK; | |
120 | desc->txd.tx_submit = atc_tx_submit; | |
121 | desc->txd.phys = phys; | |
122 | } | |
123 | ||
124 | return desc; | |
125 | } | |
126 | ||
127 | /** | |
128 | * atc_desc_get - get an unused descriptor from free_list | |
129 | * @atchan: channel we want a new descriptor for | |
130 | */ | |
131 | static struct at_desc *atc_desc_get(struct at_dma_chan *atchan) | |
132 | { | |
133 | struct at_desc *desc, *_desc; | |
134 | struct at_desc *ret = NULL; | |
135 | unsigned long flags; | |
136 | unsigned int i = 0; | |
137 | LIST_HEAD(tmp_list); | |
138 | ||
139 | spin_lock_irqsave(&atchan->lock, flags); | |
140 | list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) { | |
141 | i++; | |
142 | if (async_tx_test_ack(&desc->txd)) { | |
143 | list_del(&desc->desc_node); | |
144 | ret = desc; | |
145 | break; | |
146 | } | |
147 | dev_dbg(chan2dev(&atchan->chan_common), | |
148 | "desc %p not ACKed\n", desc); | |
149 | } | |
150 | spin_unlock_irqrestore(&atchan->lock, flags); | |
151 | dev_vdbg(chan2dev(&atchan->chan_common), | |
152 | "scanned %u descriptors on freelist\n", i); | |
153 | ||
154 | /* no more descriptor available in initial pool: create one more */ | |
155 | if (!ret) { | |
156 | ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC); | |
157 | if (ret) { | |
158 | spin_lock_irqsave(&atchan->lock, flags); | |
159 | atchan->descs_allocated++; | |
160 | spin_unlock_irqrestore(&atchan->lock, flags); | |
161 | } else { | |
162 | dev_err(chan2dev(&atchan->chan_common), | |
163 | "not enough descriptors available\n"); | |
164 | } | |
165 | } | |
166 | ||
167 | return ret; | |
168 | } | |
169 | ||
170 | /** | |
171 | * atc_desc_put - move a descriptor, including any children, to the free list | |
172 | * @atchan: channel we work on | |
173 | * @desc: descriptor, at the head of a chain, to move to free list | |
174 | */ | |
175 | static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc) | |
176 | { | |
177 | if (desc) { | |
178 | struct at_desc *child; | |
179 | unsigned long flags; | |
180 | ||
181 | spin_lock_irqsave(&atchan->lock, flags); | |
182 | list_for_each_entry(child, &desc->tx_list, desc_node) | |
183 | dev_vdbg(chan2dev(&atchan->chan_common), | |
184 | "moving child desc %p to freelist\n", | |
185 | child); | |
186 | list_splice_init(&desc->tx_list, &atchan->free_list); | |
187 | dev_vdbg(chan2dev(&atchan->chan_common), | |
188 | "moving desc %p to freelist\n", desc); | |
189 | list_add(&desc->desc_node, &atchan->free_list); | |
190 | spin_unlock_irqrestore(&atchan->lock, flags); | |
191 | } | |
192 | } | |
193 | ||
194 | /** | |
195 | * atc_desc_chain - build chain adding a descriptor | |
196 | * @first: address of first descriptor of the chain | |
197 | * @prev: address of previous descriptor of the chain | |
198 | * @desc: descriptor to queue | |
199 | * | |
200 | * Called from prep_* functions | |
201 | */ | |
202 | static void atc_desc_chain(struct at_desc **first, struct at_desc **prev, | |
203 | struct at_desc *desc) | |
204 | { | |
205 | if (!(*first)) { | |
206 | *first = desc; | |
207 | } else { | |
208 | /* inform the HW lli about chaining */ | |
209 | (*prev)->lli.dscr = desc->txd.phys; | |
210 | /* insert the link descriptor to the LD ring */ | |
211 | list_add_tail(&desc->desc_node, | |
212 | &(*first)->tx_list); | |
213 | } | |
214 | *prev = desc; | |
215 | } | |
216 | ||
217 | /** | |
218 | * atc_dostart - starts the DMA engine for real | |
219 | * @atchan: the channel we want to start | |
220 | * @first: first descriptor in the list we want to begin with | |
221 | * | |
222 | * Called with atchan->lock held and bh disabled | |
223 | */ | |
224 | static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first) | |
225 | { | |
226 | struct at_dma *atdma = to_at_dma(atchan->chan_common.device); | |
227 | ||
228 | /* ASSERT: channel is idle */ | |
229 | if (atc_chan_is_enabled(atchan)) { | |
230 | dev_err(chan2dev(&atchan->chan_common), | |
231 | "BUG: Attempted to start non-idle channel\n"); | |
232 | dev_err(chan2dev(&atchan->chan_common), | |
233 | " channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n", | |
234 | channel_readl(atchan, SADDR), | |
235 | channel_readl(atchan, DADDR), | |
236 | channel_readl(atchan, CTRLA), | |
237 | channel_readl(atchan, CTRLB), | |
238 | channel_readl(atchan, DSCR)); | |
239 | ||
240 | /* The tasklet will hopefully advance the queue... */ | |
241 | return; | |
242 | } | |
243 | ||
244 | vdbg_dump_regs(atchan); | |
245 | ||
246 | channel_writel(atchan, SADDR, 0); | |
247 | channel_writel(atchan, DADDR, 0); | |
248 | channel_writel(atchan, CTRLA, 0); | |
249 | channel_writel(atchan, CTRLB, 0); | |
250 | channel_writel(atchan, DSCR, first->txd.phys); | |
251 | channel_writel(atchan, SPIP, ATC_SPIP_HOLE(first->src_hole) | | |
252 | ATC_SPIP_BOUNDARY(first->boundary)); | |
253 | channel_writel(atchan, DPIP, ATC_DPIP_HOLE(first->dst_hole) | | |
254 | ATC_DPIP_BOUNDARY(first->boundary)); | |
255 | dma_writel(atdma, CHER, atchan->mask); | |
256 | ||
257 | vdbg_dump_regs(atchan); | |
258 | } | |
259 | ||
260 | /* | |
261 | * atc_get_desc_by_cookie - get the descriptor of a cookie | |
262 | * @atchan: the DMA channel | |
263 | * @cookie: the cookie to get the descriptor for | |
264 | */ | |
265 | static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan, | |
266 | dma_cookie_t cookie) | |
267 | { | |
268 | struct at_desc *desc, *_desc; | |
269 | ||
270 | list_for_each_entry_safe(desc, _desc, &atchan->queue, desc_node) { | |
271 | if (desc->txd.cookie == cookie) | |
272 | return desc; | |
273 | } | |
274 | ||
275 | list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) { | |
276 | if (desc->txd.cookie == cookie) | |
277 | return desc; | |
278 | } | |
279 | ||
280 | return NULL; | |
281 | } | |
282 | ||
283 | /** | |
284 | * atc_calc_bytes_left - calculates the number of bytes left according to the | |
285 | * value read from CTRLA. | |
286 | * | |
287 | * @current_len: the number of bytes left before reading CTRLA | |
288 | * @ctrla: the value of CTRLA | |
289 | */ | |
290 | static inline int atc_calc_bytes_left(int current_len, u32 ctrla) | |
291 | { | |
292 | u32 btsize = (ctrla & ATC_BTSIZE_MAX); | |
293 | u32 src_width = ATC_REG_TO_SRC_WIDTH(ctrla); | |
294 | ||
295 | /* | |
296 | * According to the datasheet, when reading the Control A Register | |
297 | * (ctrla), the Buffer Transfer Size (btsize) bitfield refers to the | |
298 | * number of transfers completed on the Source Interface. | |
299 | * So btsize is always a number of source width transfers. | |
300 | */ | |
301 | return current_len - (btsize << src_width); | |
302 | } | |
303 | ||
304 | /** | |
305 | * atc_get_bytes_left - get the number of bytes residue for a cookie | |
306 | * @chan: DMA channel | |
307 | * @cookie: transaction identifier to check status of | |
308 | */ | |
309 | static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie) | |
310 | { | |
311 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
312 | struct at_desc *desc_first = atc_first_active(atchan); | |
313 | struct at_desc *desc; | |
314 | int ret; | |
315 | u32 ctrla, dscr, trials; | |
316 | ||
317 | /* | |
318 | * If the cookie doesn't match to the currently running transfer then | |
319 | * we can return the total length of the associated DMA transfer, | |
320 | * because it is still queued. | |
321 | */ | |
322 | desc = atc_get_desc_by_cookie(atchan, cookie); | |
323 | if (desc == NULL) | |
324 | return -EINVAL; | |
325 | else if (desc != desc_first) | |
326 | return desc->total_len; | |
327 | ||
328 | /* cookie matches to the currently running transfer */ | |
329 | ret = desc_first->total_len; | |
330 | ||
331 | if (desc_first->lli.dscr) { | |
332 | /* hardware linked list transfer */ | |
333 | ||
334 | /* | |
335 | * Calculate the residue by removing the length of the child | |
336 | * descriptors already transferred from the total length. | |
337 | * To get the current child descriptor we can use the value of | |
338 | * the channel's DSCR register and compare it against the value | |
339 | * of the hardware linked list structure of each child | |
340 | * descriptor. | |
341 | * | |
342 | * The CTRLA register provides us with the amount of data | |
343 | * already read from the source for the current child | |
344 | * descriptor. So we can compute a more accurate residue by also | |
345 | * removing the number of bytes corresponding to this amount of | |
346 | * data. | |
347 | * | |
348 | * However, the DSCR and CTRLA registers cannot be read both | |
349 | * atomically. Hence a race condition may occur: the first read | |
350 | * register may refer to one child descriptor whereas the second | |
351 | * read may refer to a later child descriptor in the list | |
352 | * because of the DMA transfer progression inbetween the two | |
353 | * reads. | |
354 | * | |
355 | * One solution could have been to pause the DMA transfer, read | |
356 | * the DSCR and CTRLA then resume the DMA transfer. Nonetheless, | |
357 | * this approach presents some drawbacks: | |
358 | * - If the DMA transfer is paused, RX overruns or TX underruns | |
359 | * are more likey to occur depending on the system latency. | |
360 | * Taking the USART driver as an example, it uses a cyclic DMA | |
361 | * transfer to read data from the Receive Holding Register | |
362 | * (RHR) to avoid RX overruns since the RHR is not protected | |
363 | * by any FIFO on most Atmel SoCs. So pausing the DMA transfer | |
364 | * to compute the residue would break the USART driver design. | |
365 | * - The atc_pause() function masks interrupts but we'd rather | |
366 | * avoid to do so for system latency purpose. | |
367 | * | |
368 | * Then we'd rather use another solution: the DSCR is read a | |
369 | * first time, the CTRLA is read in turn, next the DSCR is read | |
370 | * a second time. If the two consecutive read values of the DSCR | |
371 | * are the same then we assume both refers to the very same | |
372 | * child descriptor as well as the CTRLA value read inbetween | |
373 | * does. For cyclic tranfers, the assumption is that a full loop | |
374 | * is "not so fast". | |
375 | * If the two DSCR values are different, we read again the CTRLA | |
376 | * then the DSCR till two consecutive read values from DSCR are | |
377 | * equal or till the maxium trials is reach. | |
378 | * This algorithm is very unlikely not to find a stable value for | |
379 | * DSCR. | |
380 | */ | |
381 | ||
382 | dscr = channel_readl(atchan, DSCR); | |
383 | rmb(); /* ensure DSCR is read before CTRLA */ | |
384 | ctrla = channel_readl(atchan, CTRLA); | |
385 | for (trials = 0; trials < ATC_MAX_DSCR_TRIALS; ++trials) { | |
386 | u32 new_dscr; | |
387 | ||
388 | rmb(); /* ensure DSCR is read after CTRLA */ | |
389 | new_dscr = channel_readl(atchan, DSCR); | |
390 | ||
391 | /* | |
392 | * If the DSCR register value has not changed inside the | |
393 | * DMA controller since the previous read, we assume | |
394 | * that both the dscr and ctrla values refers to the | |
395 | * very same descriptor. | |
396 | */ | |
397 | if (likely(new_dscr == dscr)) | |
398 | break; | |
399 | ||
400 | /* | |
401 | * DSCR has changed inside the DMA controller, so the | |
402 | * previouly read value of CTRLA may refer to an already | |
403 | * processed descriptor hence could be outdated. | |
404 | * We need to update ctrla to match the current | |
405 | * descriptor. | |
406 | */ | |
407 | dscr = new_dscr; | |
408 | rmb(); /* ensure DSCR is read before CTRLA */ | |
409 | ctrla = channel_readl(atchan, CTRLA); | |
410 | } | |
411 | if (unlikely(trials >= ATC_MAX_DSCR_TRIALS)) | |
412 | return -ETIMEDOUT; | |
413 | ||
414 | /* for the first descriptor we can be more accurate */ | |
415 | if (desc_first->lli.dscr == dscr) | |
416 | return atc_calc_bytes_left(ret, ctrla); | |
417 | ||
418 | ret -= desc_first->len; | |
419 | list_for_each_entry(desc, &desc_first->tx_list, desc_node) { | |
420 | if (desc->lli.dscr == dscr) | |
421 | break; | |
422 | ||
423 | ret -= desc->len; | |
424 | } | |
425 | ||
426 | /* | |
427 | * For the current descriptor in the chain we can calculate | |
428 | * the remaining bytes using the channel's register. | |
429 | */ | |
430 | ret = atc_calc_bytes_left(ret, ctrla); | |
431 | } else { | |
432 | /* single transfer */ | |
433 | ctrla = channel_readl(atchan, CTRLA); | |
434 | ret = atc_calc_bytes_left(ret, ctrla); | |
435 | } | |
436 | ||
437 | return ret; | |
438 | } | |
439 | ||
440 | /** | |
441 | * atc_chain_complete - finish work for one transaction chain | |
442 | * @atchan: channel we work on | |
443 | * @desc: descriptor at the head of the chain we want do complete | |
444 | * | |
445 | * Called with atchan->lock held and bh disabled */ | |
446 | static void | |
447 | atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc) | |
448 | { | |
449 | struct dma_async_tx_descriptor *txd = &desc->txd; | |
450 | struct at_dma *atdma = to_at_dma(atchan->chan_common.device); | |
451 | ||
452 | dev_vdbg(chan2dev(&atchan->chan_common), | |
453 | "descriptor %u complete\n", txd->cookie); | |
454 | ||
455 | /* mark the descriptor as complete for non cyclic cases only */ | |
456 | if (!atc_chan_is_cyclic(atchan)) | |
457 | dma_cookie_complete(txd); | |
458 | ||
459 | /* If the transfer was a memset, free our temporary buffer */ | |
460 | if (desc->memset_buffer) { | |
461 | dma_pool_free(atdma->memset_pool, desc->memset_vaddr, | |
462 | desc->memset_paddr); | |
463 | desc->memset_buffer = false; | |
464 | } | |
465 | ||
466 | /* move children to free_list */ | |
467 | list_splice_init(&desc->tx_list, &atchan->free_list); | |
468 | /* move myself to free_list */ | |
469 | list_move(&desc->desc_node, &atchan->free_list); | |
470 | ||
471 | dma_descriptor_unmap(txd); | |
472 | /* for cyclic transfers, | |
473 | * no need to replay callback function while stopping */ | |
474 | if (!atc_chan_is_cyclic(atchan)) { | |
475 | /* | |
476 | * The API requires that no submissions are done from a | |
477 | * callback, so we don't need to drop the lock here | |
478 | */ | |
479 | dmaengine_desc_get_callback_invoke(txd, NULL); | |
480 | } | |
481 | ||
482 | dma_run_dependencies(txd); | |
483 | } | |
484 | ||
485 | /** | |
486 | * atc_complete_all - finish work for all transactions | |
487 | * @atchan: channel to complete transactions for | |
488 | * | |
489 | * Eventually submit queued descriptors if any | |
490 | * | |
491 | * Assume channel is idle while calling this function | |
492 | * Called with atchan->lock held and bh disabled | |
493 | */ | |
494 | static void atc_complete_all(struct at_dma_chan *atchan) | |
495 | { | |
496 | struct at_desc *desc, *_desc; | |
497 | LIST_HEAD(list); | |
498 | ||
499 | dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n"); | |
500 | ||
501 | /* | |
502 | * Submit queued descriptors ASAP, i.e. before we go through | |
503 | * the completed ones. | |
504 | */ | |
505 | if (!list_empty(&atchan->queue)) | |
506 | atc_dostart(atchan, atc_first_queued(atchan)); | |
507 | /* empty active_list now it is completed */ | |
508 | list_splice_init(&atchan->active_list, &list); | |
509 | /* empty queue list by moving descriptors (if any) to active_list */ | |
510 | list_splice_init(&atchan->queue, &atchan->active_list); | |
511 | ||
512 | list_for_each_entry_safe(desc, _desc, &list, desc_node) | |
513 | atc_chain_complete(atchan, desc); | |
514 | } | |
515 | ||
516 | /** | |
517 | * atc_advance_work - at the end of a transaction, move forward | |
518 | * @atchan: channel where the transaction ended | |
519 | * | |
520 | * Called with atchan->lock held and bh disabled | |
521 | */ | |
522 | static void atc_advance_work(struct at_dma_chan *atchan) | |
523 | { | |
524 | dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n"); | |
525 | ||
526 | if (atc_chan_is_enabled(atchan)) | |
527 | return; | |
528 | ||
529 | if (list_empty(&atchan->active_list) || | |
530 | list_is_singular(&atchan->active_list)) { | |
531 | atc_complete_all(atchan); | |
532 | } else { | |
533 | atc_chain_complete(atchan, atc_first_active(atchan)); | |
534 | /* advance work */ | |
535 | atc_dostart(atchan, atc_first_active(atchan)); | |
536 | } | |
537 | } | |
538 | ||
539 | ||
540 | /** | |
541 | * atc_handle_error - handle errors reported by DMA controller | |
542 | * @atchan: channel where error occurs | |
543 | * | |
544 | * Called with atchan->lock held and bh disabled | |
545 | */ | |
546 | static void atc_handle_error(struct at_dma_chan *atchan) | |
547 | { | |
548 | struct at_desc *bad_desc; | |
549 | struct at_desc *child; | |
550 | ||
551 | /* | |
552 | * The descriptor currently at the head of the active list is | |
553 | * broked. Since we don't have any way to report errors, we'll | |
554 | * just have to scream loudly and try to carry on. | |
555 | */ | |
556 | bad_desc = atc_first_active(atchan); | |
557 | list_del_init(&bad_desc->desc_node); | |
558 | ||
559 | /* As we are stopped, take advantage to push queued descriptors | |
560 | * in active_list */ | |
561 | list_splice_init(&atchan->queue, atchan->active_list.prev); | |
562 | ||
563 | /* Try to restart the controller */ | |
564 | if (!list_empty(&atchan->active_list)) | |
565 | atc_dostart(atchan, atc_first_active(atchan)); | |
566 | ||
567 | /* | |
568 | * KERN_CRITICAL may seem harsh, but since this only happens | |
569 | * when someone submits a bad physical address in a | |
570 | * descriptor, we should consider ourselves lucky that the | |
571 | * controller flagged an error instead of scribbling over | |
572 | * random memory locations. | |
573 | */ | |
574 | dev_crit(chan2dev(&atchan->chan_common), | |
575 | "Bad descriptor submitted for DMA!\n"); | |
576 | dev_crit(chan2dev(&atchan->chan_common), | |
577 | " cookie: %d\n", bad_desc->txd.cookie); | |
578 | atc_dump_lli(atchan, &bad_desc->lli); | |
579 | list_for_each_entry(child, &bad_desc->tx_list, desc_node) | |
580 | atc_dump_lli(atchan, &child->lli); | |
581 | ||
582 | /* Pretend the descriptor completed successfully */ | |
583 | atc_chain_complete(atchan, bad_desc); | |
584 | } | |
585 | ||
586 | /** | |
587 | * atc_handle_cyclic - at the end of a period, run callback function | |
588 | * @atchan: channel used for cyclic operations | |
589 | * | |
590 | * Called with atchan->lock held and bh disabled | |
591 | */ | |
592 | static void atc_handle_cyclic(struct at_dma_chan *atchan) | |
593 | { | |
594 | struct at_desc *first = atc_first_active(atchan); | |
595 | struct dma_async_tx_descriptor *txd = &first->txd; | |
596 | ||
597 | dev_vdbg(chan2dev(&atchan->chan_common), | |
598 | "new cyclic period llp 0x%08x\n", | |
599 | channel_readl(atchan, DSCR)); | |
600 | ||
601 | dmaengine_desc_get_callback_invoke(txd, NULL); | |
602 | } | |
603 | ||
604 | /*-- IRQ & Tasklet ---------------------------------------------------*/ | |
605 | ||
606 | static void atc_tasklet(unsigned long data) | |
607 | { | |
608 | struct at_dma_chan *atchan = (struct at_dma_chan *)data; | |
609 | unsigned long flags; | |
610 | ||
611 | spin_lock_irqsave(&atchan->lock, flags); | |
612 | if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status)) | |
613 | atc_handle_error(atchan); | |
614 | else if (atc_chan_is_cyclic(atchan)) | |
615 | atc_handle_cyclic(atchan); | |
616 | else | |
617 | atc_advance_work(atchan); | |
618 | ||
619 | spin_unlock_irqrestore(&atchan->lock, flags); | |
620 | } | |
621 | ||
622 | static irqreturn_t at_dma_interrupt(int irq, void *dev_id) | |
623 | { | |
624 | struct at_dma *atdma = (struct at_dma *)dev_id; | |
625 | struct at_dma_chan *atchan; | |
626 | int i; | |
627 | u32 status, pending, imr; | |
628 | int ret = IRQ_NONE; | |
629 | ||
630 | do { | |
631 | imr = dma_readl(atdma, EBCIMR); | |
632 | status = dma_readl(atdma, EBCISR); | |
633 | pending = status & imr; | |
634 | ||
635 | if (!pending) | |
636 | break; | |
637 | ||
638 | dev_vdbg(atdma->dma_common.dev, | |
639 | "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n", | |
640 | status, imr, pending); | |
641 | ||
642 | for (i = 0; i < atdma->dma_common.chancnt; i++) { | |
643 | atchan = &atdma->chan[i]; | |
644 | if (pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))) { | |
645 | if (pending & AT_DMA_ERR(i)) { | |
646 | /* Disable channel on AHB error */ | |
647 | dma_writel(atdma, CHDR, | |
648 | AT_DMA_RES(i) | atchan->mask); | |
649 | /* Give information to tasklet */ | |
650 | set_bit(ATC_IS_ERROR, &atchan->status); | |
651 | } | |
652 | tasklet_schedule(&atchan->tasklet); | |
653 | ret = IRQ_HANDLED; | |
654 | } | |
655 | } | |
656 | ||
657 | } while (pending); | |
658 | ||
659 | return ret; | |
660 | } | |
661 | ||
662 | ||
663 | /*-- DMA Engine API --------------------------------------------------*/ | |
664 | ||
665 | /** | |
666 | * atc_tx_submit - set the prepared descriptor(s) to be executed by the engine | |
667 | * @desc: descriptor at the head of the transaction chain | |
668 | * | |
669 | * Queue chain if DMA engine is working already | |
670 | * | |
671 | * Cookie increment and adding to active_list or queue must be atomic | |
672 | */ | |
673 | static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx) | |
674 | { | |
675 | struct at_desc *desc = txd_to_at_desc(tx); | |
676 | struct at_dma_chan *atchan = to_at_dma_chan(tx->chan); | |
677 | dma_cookie_t cookie; | |
678 | unsigned long flags; | |
679 | ||
680 | spin_lock_irqsave(&atchan->lock, flags); | |
681 | cookie = dma_cookie_assign(tx); | |
682 | ||
683 | if (list_empty(&atchan->active_list)) { | |
684 | dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n", | |
685 | desc->txd.cookie); | |
686 | atc_dostart(atchan, desc); | |
687 | list_add_tail(&desc->desc_node, &atchan->active_list); | |
688 | } else { | |
689 | dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n", | |
690 | desc->txd.cookie); | |
691 | list_add_tail(&desc->desc_node, &atchan->queue); | |
692 | } | |
693 | ||
694 | spin_unlock_irqrestore(&atchan->lock, flags); | |
695 | ||
696 | return cookie; | |
697 | } | |
698 | ||
699 | /** | |
700 | * atc_prep_dma_interleaved - prepare memory to memory interleaved operation | |
701 | * @chan: the channel to prepare operation on | |
702 | * @xt: Interleaved transfer template | |
703 | * @flags: tx descriptor status flags | |
704 | */ | |
705 | static struct dma_async_tx_descriptor * | |
706 | atc_prep_dma_interleaved(struct dma_chan *chan, | |
707 | struct dma_interleaved_template *xt, | |
708 | unsigned long flags) | |
709 | { | |
710 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
711 | struct data_chunk *first; | |
712 | struct at_desc *desc = NULL; | |
713 | size_t xfer_count; | |
714 | unsigned int dwidth; | |
715 | u32 ctrla; | |
716 | u32 ctrlb; | |
717 | size_t len = 0; | |
718 | int i; | |
719 | ||
720 | if (unlikely(!xt || xt->numf != 1 || !xt->frame_size)) | |
721 | return NULL; | |
722 | ||
723 | first = xt->sgl; | |
724 | ||
725 | dev_info(chan2dev(chan), | |
726 | "%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n", | |
727 | __func__, &xt->src_start, &xt->dst_start, xt->numf, | |
728 | xt->frame_size, flags); | |
729 | ||
730 | /* | |
731 | * The controller can only "skip" X bytes every Y bytes, so we | |
732 | * need to make sure we are given a template that fit that | |
733 | * description, ie a template with chunks that always have the | |
734 | * same size, with the same ICGs. | |
735 | */ | |
736 | for (i = 0; i < xt->frame_size; i++) { | |
737 | struct data_chunk *chunk = xt->sgl + i; | |
738 | ||
739 | if ((chunk->size != xt->sgl->size) || | |
740 | (dmaengine_get_dst_icg(xt, chunk) != dmaengine_get_dst_icg(xt, first)) || | |
741 | (dmaengine_get_src_icg(xt, chunk) != dmaengine_get_src_icg(xt, first))) { | |
742 | dev_err(chan2dev(chan), | |
743 | "%s: the controller can transfer only identical chunks\n", | |
744 | __func__); | |
745 | return NULL; | |
746 | } | |
747 | ||
748 | len += chunk->size; | |
749 | } | |
750 | ||
751 | dwidth = atc_get_xfer_width(xt->src_start, | |
752 | xt->dst_start, len); | |
753 | ||
754 | xfer_count = len >> dwidth; | |
755 | if (xfer_count > ATC_BTSIZE_MAX) { | |
756 | dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__); | |
757 | return NULL; | |
758 | } | |
759 | ||
760 | ctrla = ATC_SRC_WIDTH(dwidth) | | |
761 | ATC_DST_WIDTH(dwidth); | |
762 | ||
763 | ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | |
764 | | ATC_SRC_ADDR_MODE_INCR | |
765 | | ATC_DST_ADDR_MODE_INCR | |
766 | | ATC_SRC_PIP | |
767 | | ATC_DST_PIP | |
768 | | ATC_FC_MEM2MEM; | |
769 | ||
770 | /* create the transfer */ | |
771 | desc = atc_desc_get(atchan); | |
772 | if (!desc) { | |
773 | dev_err(chan2dev(chan), | |
774 | "%s: couldn't allocate our descriptor\n", __func__); | |
775 | return NULL; | |
776 | } | |
777 | ||
778 | desc->lli.saddr = xt->src_start; | |
779 | desc->lli.daddr = xt->dst_start; | |
780 | desc->lli.ctrla = ctrla | xfer_count; | |
781 | desc->lli.ctrlb = ctrlb; | |
782 | ||
783 | desc->boundary = first->size >> dwidth; | |
784 | desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1; | |
785 | desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1; | |
786 | ||
787 | desc->txd.cookie = -EBUSY; | |
788 | desc->total_len = desc->len = len; | |
789 | ||
790 | /* set end-of-link to the last link descriptor of list*/ | |
791 | set_desc_eol(desc); | |
792 | ||
793 | desc->txd.flags = flags; /* client is in control of this ack */ | |
794 | ||
795 | return &desc->txd; | |
796 | } | |
797 | ||
798 | /** | |
799 | * atc_prep_dma_memcpy - prepare a memcpy operation | |
800 | * @chan: the channel to prepare operation on | |
801 | * @dest: operation virtual destination address | |
802 | * @src: operation virtual source address | |
803 | * @len: operation length | |
804 | * @flags: tx descriptor status flags | |
805 | */ | |
806 | static struct dma_async_tx_descriptor * | |
807 | atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, | |
808 | size_t len, unsigned long flags) | |
809 | { | |
810 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
811 | struct at_desc *desc = NULL; | |
812 | struct at_desc *first = NULL; | |
813 | struct at_desc *prev = NULL; | |
814 | size_t xfer_count; | |
815 | size_t offset; | |
816 | unsigned int src_width; | |
817 | unsigned int dst_width; | |
818 | u32 ctrla; | |
819 | u32 ctrlb; | |
820 | ||
821 | dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n", | |
822 | &dest, &src, len, flags); | |
823 | ||
824 | if (unlikely(!len)) { | |
825 | dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n"); | |
826 | return NULL; | |
827 | } | |
828 | ||
829 | ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | |
830 | | ATC_SRC_ADDR_MODE_INCR | |
831 | | ATC_DST_ADDR_MODE_INCR | |
832 | | ATC_FC_MEM2MEM; | |
833 | ||
834 | /* | |
835 | * We can be a lot more clever here, but this should take care | |
836 | * of the most common optimization. | |
837 | */ | |
838 | src_width = dst_width = atc_get_xfer_width(src, dest, len); | |
839 | ||
840 | ctrla = ATC_SRC_WIDTH(src_width) | | |
841 | ATC_DST_WIDTH(dst_width); | |
842 | ||
843 | for (offset = 0; offset < len; offset += xfer_count << src_width) { | |
844 | xfer_count = min_t(size_t, (len - offset) >> src_width, | |
845 | ATC_BTSIZE_MAX); | |
846 | ||
847 | desc = atc_desc_get(atchan); | |
848 | if (!desc) | |
849 | goto err_desc_get; | |
850 | ||
851 | desc->lli.saddr = src + offset; | |
852 | desc->lli.daddr = dest + offset; | |
853 | desc->lli.ctrla = ctrla | xfer_count; | |
854 | desc->lli.ctrlb = ctrlb; | |
855 | ||
856 | desc->txd.cookie = 0; | |
857 | desc->len = xfer_count << src_width; | |
858 | ||
859 | atc_desc_chain(&first, &prev, desc); | |
860 | } | |
861 | ||
862 | /* First descriptor of the chain embedds additional information */ | |
863 | first->txd.cookie = -EBUSY; | |
864 | first->total_len = len; | |
865 | ||
866 | /* set end-of-link to the last link descriptor of list*/ | |
867 | set_desc_eol(desc); | |
868 | ||
869 | first->txd.flags = flags; /* client is in control of this ack */ | |
870 | ||
871 | return &first->txd; | |
872 | ||
873 | err_desc_get: | |
874 | atc_desc_put(atchan, first); | |
875 | return NULL; | |
876 | } | |
877 | ||
878 | static struct at_desc *atc_create_memset_desc(struct dma_chan *chan, | |
879 | dma_addr_t psrc, | |
880 | dma_addr_t pdst, | |
881 | size_t len) | |
882 | { | |
883 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
884 | struct at_desc *desc; | |
885 | size_t xfer_count; | |
886 | ||
887 | u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2); | |
888 | u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | | |
889 | ATC_SRC_ADDR_MODE_FIXED | | |
890 | ATC_DST_ADDR_MODE_INCR | | |
891 | ATC_FC_MEM2MEM; | |
892 | ||
893 | xfer_count = len >> 2; | |
894 | if (xfer_count > ATC_BTSIZE_MAX) { | |
895 | dev_err(chan2dev(chan), "%s: buffer is too big\n", | |
896 | __func__); | |
897 | return NULL; | |
898 | } | |
899 | ||
900 | desc = atc_desc_get(atchan); | |
901 | if (!desc) { | |
902 | dev_err(chan2dev(chan), "%s: can't get a descriptor\n", | |
903 | __func__); | |
904 | return NULL; | |
905 | } | |
906 | ||
907 | desc->lli.saddr = psrc; | |
908 | desc->lli.daddr = pdst; | |
909 | desc->lli.ctrla = ctrla | xfer_count; | |
910 | desc->lli.ctrlb = ctrlb; | |
911 | ||
912 | desc->txd.cookie = 0; | |
913 | desc->len = len; | |
914 | ||
915 | return desc; | |
916 | } | |
917 | ||
918 | /** | |
919 | * atc_prep_dma_memset - prepare a memcpy operation | |
920 | * @chan: the channel to prepare operation on | |
921 | * @dest: operation virtual destination address | |
922 | * @value: value to set memory buffer to | |
923 | * @len: operation length | |
924 | * @flags: tx descriptor status flags | |
925 | */ | |
926 | static struct dma_async_tx_descriptor * | |
927 | atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value, | |
928 | size_t len, unsigned long flags) | |
929 | { | |
930 | struct at_dma *atdma = to_at_dma(chan->device); | |
931 | struct at_desc *desc; | |
932 | void __iomem *vaddr; | |
933 | dma_addr_t paddr; | |
934 | ||
935 | dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__, | |
936 | &dest, value, len, flags); | |
937 | ||
938 | if (unlikely(!len)) { | |
939 | dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__); | |
940 | return NULL; | |
941 | } | |
942 | ||
943 | if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { | |
944 | dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n", | |
945 | __func__); | |
946 | return NULL; | |
947 | } | |
948 | ||
949 | vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr); | |
950 | if (!vaddr) { | |
951 | dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", | |
952 | __func__); | |
953 | return NULL; | |
954 | } | |
955 | *(u32*)vaddr = value; | |
956 | ||
957 | desc = atc_create_memset_desc(chan, paddr, dest, len); | |
958 | if (!desc) { | |
959 | dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n", | |
960 | __func__); | |
961 | goto err_free_buffer; | |
962 | } | |
963 | ||
964 | desc->memset_paddr = paddr; | |
965 | desc->memset_vaddr = vaddr; | |
966 | desc->memset_buffer = true; | |
967 | ||
968 | desc->txd.cookie = -EBUSY; | |
969 | desc->total_len = len; | |
970 | ||
971 | /* set end-of-link on the descriptor */ | |
972 | set_desc_eol(desc); | |
973 | ||
974 | desc->txd.flags = flags; | |
975 | ||
976 | return &desc->txd; | |
977 | ||
978 | err_free_buffer: | |
979 | dma_pool_free(atdma->memset_pool, vaddr, paddr); | |
980 | return NULL; | |
981 | } | |
982 | ||
983 | static struct dma_async_tx_descriptor * | |
984 | atc_prep_dma_memset_sg(struct dma_chan *chan, | |
985 | struct scatterlist *sgl, | |
986 | unsigned int sg_len, int value, | |
987 | unsigned long flags) | |
988 | { | |
989 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
990 | struct at_dma *atdma = to_at_dma(chan->device); | |
991 | struct at_desc *desc = NULL, *first = NULL, *prev = NULL; | |
992 | struct scatterlist *sg; | |
993 | void __iomem *vaddr; | |
994 | dma_addr_t paddr; | |
995 | size_t total_len = 0; | |
996 | int i; | |
997 | ||
998 | dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__, | |
999 | value, sg_len, flags); | |
1000 | ||
1001 | if (unlikely(!sgl || !sg_len)) { | |
1002 | dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n", | |
1003 | __func__); | |
1004 | return NULL; | |
1005 | } | |
1006 | ||
1007 | vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr); | |
1008 | if (!vaddr) { | |
1009 | dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", | |
1010 | __func__); | |
1011 | return NULL; | |
1012 | } | |
1013 | *(u32*)vaddr = value; | |
1014 | ||
1015 | for_each_sg(sgl, sg, sg_len, i) { | |
1016 | dma_addr_t dest = sg_dma_address(sg); | |
1017 | size_t len = sg_dma_len(sg); | |
1018 | ||
1019 | dev_vdbg(chan2dev(chan), "%s: d%pad, l0x%zx\n", | |
1020 | __func__, &dest, len); | |
1021 | ||
1022 | if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { | |
1023 | dev_err(chan2dev(chan), "%s: buffer is not aligned\n", | |
1024 | __func__); | |
1025 | goto err_put_desc; | |
1026 | } | |
1027 | ||
1028 | desc = atc_create_memset_desc(chan, paddr, dest, len); | |
1029 | if (!desc) | |
1030 | goto err_put_desc; | |
1031 | ||
1032 | atc_desc_chain(&first, &prev, desc); | |
1033 | ||
1034 | total_len += len; | |
1035 | } | |
1036 | ||
1037 | /* | |
1038 | * Only set the buffer pointers on the last descriptor to | |
1039 | * avoid free'ing while we have our transfer still going | |
1040 | */ | |
1041 | desc->memset_paddr = paddr; | |
1042 | desc->memset_vaddr = vaddr; | |
1043 | desc->memset_buffer = true; | |
1044 | ||
1045 | first->txd.cookie = -EBUSY; | |
1046 | first->total_len = total_len; | |
1047 | ||
1048 | /* set end-of-link on the descriptor */ | |
1049 | set_desc_eol(desc); | |
1050 | ||
1051 | first->txd.flags = flags; | |
1052 | ||
1053 | return &first->txd; | |
1054 | ||
1055 | err_put_desc: | |
1056 | atc_desc_put(atchan, first); | |
1057 | return NULL; | |
1058 | } | |
1059 | ||
1060 | /** | |
1061 | * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction | |
1062 | * @chan: DMA channel | |
1063 | * @sgl: scatterlist to transfer to/from | |
1064 | * @sg_len: number of entries in @scatterlist | |
1065 | * @direction: DMA direction | |
1066 | * @flags: tx descriptor status flags | |
1067 | * @context: transaction context (ignored) | |
1068 | */ | |
1069 | static struct dma_async_tx_descriptor * | |
1070 | atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, | |
1071 | unsigned int sg_len, enum dma_transfer_direction direction, | |
1072 | unsigned long flags, void *context) | |
1073 | { | |
1074 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1075 | struct at_dma_slave *atslave = chan->private; | |
1076 | struct dma_slave_config *sconfig = &atchan->dma_sconfig; | |
1077 | struct at_desc *first = NULL; | |
1078 | struct at_desc *prev = NULL; | |
1079 | u32 ctrla; | |
1080 | u32 ctrlb; | |
1081 | dma_addr_t reg; | |
1082 | unsigned int reg_width; | |
1083 | unsigned int mem_width; | |
1084 | unsigned int i; | |
1085 | struct scatterlist *sg; | |
1086 | size_t total_len = 0; | |
1087 | ||
1088 | dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n", | |
1089 | sg_len, | |
1090 | direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", | |
1091 | flags); | |
1092 | ||
1093 | if (unlikely(!atslave || !sg_len)) { | |
1094 | dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n"); | |
1095 | return NULL; | |
1096 | } | |
1097 | ||
1098 | ctrla = ATC_SCSIZE(sconfig->src_maxburst) | |
1099 | | ATC_DCSIZE(sconfig->dst_maxburst); | |
1100 | ctrlb = ATC_IEN; | |
1101 | ||
1102 | switch (direction) { | |
1103 | case DMA_MEM_TO_DEV: | |
1104 | reg_width = convert_buswidth(sconfig->dst_addr_width); | |
1105 | ctrla |= ATC_DST_WIDTH(reg_width); | |
1106 | ctrlb |= ATC_DST_ADDR_MODE_FIXED | |
1107 | | ATC_SRC_ADDR_MODE_INCR | |
1108 | | ATC_FC_MEM2PER | |
1109 | | ATC_SIF(atchan->mem_if) | ATC_DIF(atchan->per_if); | |
1110 | reg = sconfig->dst_addr; | |
1111 | for_each_sg(sgl, sg, sg_len, i) { | |
1112 | struct at_desc *desc; | |
1113 | u32 len; | |
1114 | u32 mem; | |
1115 | ||
1116 | desc = atc_desc_get(atchan); | |
1117 | if (!desc) | |
1118 | goto err_desc_get; | |
1119 | ||
1120 | mem = sg_dma_address(sg); | |
1121 | len = sg_dma_len(sg); | |
1122 | if (unlikely(!len)) { | |
1123 | dev_dbg(chan2dev(chan), | |
1124 | "prep_slave_sg: sg(%d) data length is zero\n", i); | |
1125 | goto err; | |
1126 | } | |
1127 | mem_width = 2; | |
1128 | if (unlikely(mem & 3 || len & 3)) | |
1129 | mem_width = 0; | |
1130 | ||
1131 | desc->lli.saddr = mem; | |
1132 | desc->lli.daddr = reg; | |
1133 | desc->lli.ctrla = ctrla | |
1134 | | ATC_SRC_WIDTH(mem_width) | |
1135 | | len >> mem_width; | |
1136 | desc->lli.ctrlb = ctrlb; | |
1137 | desc->len = len; | |
1138 | ||
1139 | atc_desc_chain(&first, &prev, desc); | |
1140 | total_len += len; | |
1141 | } | |
1142 | break; | |
1143 | case DMA_DEV_TO_MEM: | |
1144 | reg_width = convert_buswidth(sconfig->src_addr_width); | |
1145 | ctrla |= ATC_SRC_WIDTH(reg_width); | |
1146 | ctrlb |= ATC_DST_ADDR_MODE_INCR | |
1147 | | ATC_SRC_ADDR_MODE_FIXED | |
1148 | | ATC_FC_PER2MEM | |
1149 | | ATC_SIF(atchan->per_if) | ATC_DIF(atchan->mem_if); | |
1150 | ||
1151 | reg = sconfig->src_addr; | |
1152 | for_each_sg(sgl, sg, sg_len, i) { | |
1153 | struct at_desc *desc; | |
1154 | u32 len; | |
1155 | u32 mem; | |
1156 | ||
1157 | desc = atc_desc_get(atchan); | |
1158 | if (!desc) | |
1159 | goto err_desc_get; | |
1160 | ||
1161 | mem = sg_dma_address(sg); | |
1162 | len = sg_dma_len(sg); | |
1163 | if (unlikely(!len)) { | |
1164 | dev_dbg(chan2dev(chan), | |
1165 | "prep_slave_sg: sg(%d) data length is zero\n", i); | |
1166 | goto err; | |
1167 | } | |
1168 | mem_width = 2; | |
1169 | if (unlikely(mem & 3 || len & 3)) | |
1170 | mem_width = 0; | |
1171 | ||
1172 | desc->lli.saddr = reg; | |
1173 | desc->lli.daddr = mem; | |
1174 | desc->lli.ctrla = ctrla | |
1175 | | ATC_DST_WIDTH(mem_width) | |
1176 | | len >> reg_width; | |
1177 | desc->lli.ctrlb = ctrlb; | |
1178 | desc->len = len; | |
1179 | ||
1180 | atc_desc_chain(&first, &prev, desc); | |
1181 | total_len += len; | |
1182 | } | |
1183 | break; | |
1184 | default: | |
1185 | return NULL; | |
1186 | } | |
1187 | ||
1188 | /* set end-of-link to the last link descriptor of list*/ | |
1189 | set_desc_eol(prev); | |
1190 | ||
1191 | /* First descriptor of the chain embedds additional information */ | |
1192 | first->txd.cookie = -EBUSY; | |
1193 | first->total_len = total_len; | |
1194 | ||
1195 | /* first link descriptor of list is responsible of flags */ | |
1196 | first->txd.flags = flags; /* client is in control of this ack */ | |
1197 | ||
1198 | return &first->txd; | |
1199 | ||
1200 | err_desc_get: | |
1201 | dev_err(chan2dev(chan), "not enough descriptors available\n"); | |
1202 | err: | |
1203 | atc_desc_put(atchan, first); | |
1204 | return NULL; | |
1205 | } | |
1206 | ||
1207 | /** | |
1208 | * atc_dma_cyclic_check_values | |
1209 | * Check for too big/unaligned periods and unaligned DMA buffer | |
1210 | */ | |
1211 | static int | |
1212 | atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr, | |
1213 | size_t period_len) | |
1214 | { | |
1215 | if (period_len > (ATC_BTSIZE_MAX << reg_width)) | |
1216 | goto err_out; | |
1217 | if (unlikely(period_len & ((1 << reg_width) - 1))) | |
1218 | goto err_out; | |
1219 | if (unlikely(buf_addr & ((1 << reg_width) - 1))) | |
1220 | goto err_out; | |
1221 | ||
1222 | return 0; | |
1223 | ||
1224 | err_out: | |
1225 | return -EINVAL; | |
1226 | } | |
1227 | ||
1228 | /** | |
1229 | * atc_dma_cyclic_fill_desc - Fill one period descriptor | |
1230 | */ | |
1231 | static int | |
1232 | atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc, | |
1233 | unsigned int period_index, dma_addr_t buf_addr, | |
1234 | unsigned int reg_width, size_t period_len, | |
1235 | enum dma_transfer_direction direction) | |
1236 | { | |
1237 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1238 | struct dma_slave_config *sconfig = &atchan->dma_sconfig; | |
1239 | u32 ctrla; | |
1240 | ||
1241 | /* prepare common CRTLA value */ | |
1242 | ctrla = ATC_SCSIZE(sconfig->src_maxburst) | |
1243 | | ATC_DCSIZE(sconfig->dst_maxburst) | |
1244 | | ATC_DST_WIDTH(reg_width) | |
1245 | | ATC_SRC_WIDTH(reg_width) | |
1246 | | period_len >> reg_width; | |
1247 | ||
1248 | switch (direction) { | |
1249 | case DMA_MEM_TO_DEV: | |
1250 | desc->lli.saddr = buf_addr + (period_len * period_index); | |
1251 | desc->lli.daddr = sconfig->dst_addr; | |
1252 | desc->lli.ctrla = ctrla; | |
1253 | desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED | |
1254 | | ATC_SRC_ADDR_MODE_INCR | |
1255 | | ATC_FC_MEM2PER | |
1256 | | ATC_SIF(atchan->mem_if) | |
1257 | | ATC_DIF(atchan->per_if); | |
1258 | desc->len = period_len; | |
1259 | break; | |
1260 | ||
1261 | case DMA_DEV_TO_MEM: | |
1262 | desc->lli.saddr = sconfig->src_addr; | |
1263 | desc->lli.daddr = buf_addr + (period_len * period_index); | |
1264 | desc->lli.ctrla = ctrla; | |
1265 | desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR | |
1266 | | ATC_SRC_ADDR_MODE_FIXED | |
1267 | | ATC_FC_PER2MEM | |
1268 | | ATC_SIF(atchan->per_if) | |
1269 | | ATC_DIF(atchan->mem_if); | |
1270 | desc->len = period_len; | |
1271 | break; | |
1272 | ||
1273 | default: | |
1274 | return -EINVAL; | |
1275 | } | |
1276 | ||
1277 | return 0; | |
1278 | } | |
1279 | ||
1280 | /** | |
1281 | * atc_prep_dma_cyclic - prepare the cyclic DMA transfer | |
1282 | * @chan: the DMA channel to prepare | |
1283 | * @buf_addr: physical DMA address where the buffer starts | |
1284 | * @buf_len: total number of bytes for the entire buffer | |
1285 | * @period_len: number of bytes for each period | |
1286 | * @direction: transfer direction, to or from device | |
1287 | * @flags: tx descriptor status flags | |
1288 | */ | |
1289 | static struct dma_async_tx_descriptor * | |
1290 | atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, | |
1291 | size_t period_len, enum dma_transfer_direction direction, | |
1292 | unsigned long flags) | |
1293 | { | |
1294 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1295 | struct at_dma_slave *atslave = chan->private; | |
1296 | struct dma_slave_config *sconfig = &atchan->dma_sconfig; | |
1297 | struct at_desc *first = NULL; | |
1298 | struct at_desc *prev = NULL; | |
1299 | unsigned long was_cyclic; | |
1300 | unsigned int reg_width; | |
1301 | unsigned int periods = buf_len / period_len; | |
1302 | unsigned int i; | |
1303 | ||
1304 | dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@%pad - %d (%d/%d)\n", | |
1305 | direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", | |
1306 | &buf_addr, | |
1307 | periods, buf_len, period_len); | |
1308 | ||
1309 | if (unlikely(!atslave || !buf_len || !period_len)) { | |
1310 | dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n"); | |
1311 | return NULL; | |
1312 | } | |
1313 | ||
1314 | was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status); | |
1315 | if (was_cyclic) { | |
1316 | dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n"); | |
1317 | return NULL; | |
1318 | } | |
1319 | ||
1320 | if (unlikely(!is_slave_direction(direction))) | |
1321 | goto err_out; | |
1322 | ||
1323 | if (sconfig->direction == DMA_MEM_TO_DEV) | |
1324 | reg_width = convert_buswidth(sconfig->dst_addr_width); | |
1325 | else | |
1326 | reg_width = convert_buswidth(sconfig->src_addr_width); | |
1327 | ||
1328 | /* Check for too big/unaligned periods and unaligned DMA buffer */ | |
1329 | if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len)) | |
1330 | goto err_out; | |
1331 | ||
1332 | /* build cyclic linked list */ | |
1333 | for (i = 0; i < periods; i++) { | |
1334 | struct at_desc *desc; | |
1335 | ||
1336 | desc = atc_desc_get(atchan); | |
1337 | if (!desc) | |
1338 | goto err_desc_get; | |
1339 | ||
1340 | if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr, | |
1341 | reg_width, period_len, direction)) | |
1342 | goto err_desc_get; | |
1343 | ||
1344 | atc_desc_chain(&first, &prev, desc); | |
1345 | } | |
1346 | ||
1347 | /* lets make a cyclic list */ | |
1348 | prev->lli.dscr = first->txd.phys; | |
1349 | ||
1350 | /* First descriptor of the chain embedds additional information */ | |
1351 | first->txd.cookie = -EBUSY; | |
1352 | first->total_len = buf_len; | |
1353 | ||
1354 | return &first->txd; | |
1355 | ||
1356 | err_desc_get: | |
1357 | dev_err(chan2dev(chan), "not enough descriptors available\n"); | |
1358 | atc_desc_put(atchan, first); | |
1359 | err_out: | |
1360 | clear_bit(ATC_IS_CYCLIC, &atchan->status); | |
1361 | return NULL; | |
1362 | } | |
1363 | ||
1364 | static int atc_config(struct dma_chan *chan, | |
1365 | struct dma_slave_config *sconfig) | |
1366 | { | |
1367 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1368 | ||
1369 | dev_vdbg(chan2dev(chan), "%s\n", __func__); | |
1370 | ||
1371 | /* Check if it is chan is configured for slave transfers */ | |
1372 | if (!chan->private) | |
1373 | return -EINVAL; | |
1374 | ||
1375 | memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig)); | |
1376 | ||
1377 | convert_burst(&atchan->dma_sconfig.src_maxburst); | |
1378 | convert_burst(&atchan->dma_sconfig.dst_maxburst); | |
1379 | ||
1380 | return 0; | |
1381 | } | |
1382 | ||
1383 | static int atc_pause(struct dma_chan *chan) | |
1384 | { | |
1385 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1386 | struct at_dma *atdma = to_at_dma(chan->device); | |
1387 | int chan_id = atchan->chan_common.chan_id; | |
1388 | unsigned long flags; | |
1389 | ||
1390 | LIST_HEAD(list); | |
1391 | ||
1392 | dev_vdbg(chan2dev(chan), "%s\n", __func__); | |
1393 | ||
1394 | spin_lock_irqsave(&atchan->lock, flags); | |
1395 | ||
1396 | dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id)); | |
1397 | set_bit(ATC_IS_PAUSED, &atchan->status); | |
1398 | ||
1399 | spin_unlock_irqrestore(&atchan->lock, flags); | |
1400 | ||
1401 | return 0; | |
1402 | } | |
1403 | ||
1404 | static int atc_resume(struct dma_chan *chan) | |
1405 | { | |
1406 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1407 | struct at_dma *atdma = to_at_dma(chan->device); | |
1408 | int chan_id = atchan->chan_common.chan_id; | |
1409 | unsigned long flags; | |
1410 | ||
1411 | LIST_HEAD(list); | |
1412 | ||
1413 | dev_vdbg(chan2dev(chan), "%s\n", __func__); | |
1414 | ||
1415 | if (!atc_chan_is_paused(atchan)) | |
1416 | return 0; | |
1417 | ||
1418 | spin_lock_irqsave(&atchan->lock, flags); | |
1419 | ||
1420 | dma_writel(atdma, CHDR, AT_DMA_RES(chan_id)); | |
1421 | clear_bit(ATC_IS_PAUSED, &atchan->status); | |
1422 | ||
1423 | spin_unlock_irqrestore(&atchan->lock, flags); | |
1424 | ||
1425 | return 0; | |
1426 | } | |
1427 | ||
1428 | static int atc_terminate_all(struct dma_chan *chan) | |
1429 | { | |
1430 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1431 | struct at_dma *atdma = to_at_dma(chan->device); | |
1432 | int chan_id = atchan->chan_common.chan_id; | |
1433 | struct at_desc *desc, *_desc; | |
1434 | unsigned long flags; | |
1435 | ||
1436 | LIST_HEAD(list); | |
1437 | ||
1438 | dev_vdbg(chan2dev(chan), "%s\n", __func__); | |
1439 | ||
1440 | /* | |
1441 | * This is only called when something went wrong elsewhere, so | |
1442 | * we don't really care about the data. Just disable the | |
1443 | * channel. We still have to poll the channel enable bit due | |
1444 | * to AHB/HSB limitations. | |
1445 | */ | |
1446 | spin_lock_irqsave(&atchan->lock, flags); | |
1447 | ||
1448 | /* disabling channel: must also remove suspend state */ | |
1449 | dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask); | |
1450 | ||
1451 | /* confirm that this channel is disabled */ | |
1452 | while (dma_readl(atdma, CHSR) & atchan->mask) | |
1453 | cpu_relax(); | |
1454 | ||
1455 | /* active_list entries will end up before queued entries */ | |
1456 | list_splice_init(&atchan->queue, &list); | |
1457 | list_splice_init(&atchan->active_list, &list); | |
1458 | ||
1459 | /* Flush all pending and queued descriptors */ | |
1460 | list_for_each_entry_safe(desc, _desc, &list, desc_node) | |
1461 | atc_chain_complete(atchan, desc); | |
1462 | ||
1463 | clear_bit(ATC_IS_PAUSED, &atchan->status); | |
1464 | /* if channel dedicated to cyclic operations, free it */ | |
1465 | clear_bit(ATC_IS_CYCLIC, &atchan->status); | |
1466 | ||
1467 | spin_unlock_irqrestore(&atchan->lock, flags); | |
1468 | ||
1469 | return 0; | |
1470 | } | |
1471 | ||
1472 | /** | |
1473 | * atc_tx_status - poll for transaction completion | |
1474 | * @chan: DMA channel | |
1475 | * @cookie: transaction identifier to check status of | |
1476 | * @txstate: if not %NULL updated with transaction state | |
1477 | * | |
1478 | * If @txstate is passed in, upon return it reflect the driver | |
1479 | * internal state and can be used with dma_async_is_complete() to check | |
1480 | * the status of multiple cookies without re-checking hardware state. | |
1481 | */ | |
1482 | static enum dma_status | |
1483 | atc_tx_status(struct dma_chan *chan, | |
1484 | dma_cookie_t cookie, | |
1485 | struct dma_tx_state *txstate) | |
1486 | { | |
1487 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1488 | unsigned long flags; | |
1489 | enum dma_status ret; | |
1490 | int bytes = 0; | |
1491 | ||
1492 | ret = dma_cookie_status(chan, cookie, txstate); | |
1493 | if (ret == DMA_COMPLETE) | |
1494 | return ret; | |
1495 | /* | |
1496 | * There's no point calculating the residue if there's | |
1497 | * no txstate to store the value. | |
1498 | */ | |
1499 | if (!txstate) | |
1500 | return DMA_ERROR; | |
1501 | ||
1502 | spin_lock_irqsave(&atchan->lock, flags); | |
1503 | ||
1504 | /* Get number of bytes left in the active transactions */ | |
1505 | bytes = atc_get_bytes_left(chan, cookie); | |
1506 | ||
1507 | spin_unlock_irqrestore(&atchan->lock, flags); | |
1508 | ||
1509 | if (unlikely(bytes < 0)) { | |
1510 | dev_vdbg(chan2dev(chan), "get residual bytes error\n"); | |
1511 | return DMA_ERROR; | |
1512 | } else { | |
1513 | dma_set_residue(txstate, bytes); | |
1514 | } | |
1515 | ||
1516 | dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %d\n", | |
1517 | ret, cookie, bytes); | |
1518 | ||
1519 | return ret; | |
1520 | } | |
1521 | ||
1522 | /** | |
1523 | * atc_issue_pending - try to finish work | |
1524 | * @chan: target DMA channel | |
1525 | */ | |
1526 | static void atc_issue_pending(struct dma_chan *chan) | |
1527 | { | |
1528 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1529 | unsigned long flags; | |
1530 | ||
1531 | dev_vdbg(chan2dev(chan), "issue_pending\n"); | |
1532 | ||
1533 | /* Not needed for cyclic transfers */ | |
1534 | if (atc_chan_is_cyclic(atchan)) | |
1535 | return; | |
1536 | ||
1537 | spin_lock_irqsave(&atchan->lock, flags); | |
1538 | atc_advance_work(atchan); | |
1539 | spin_unlock_irqrestore(&atchan->lock, flags); | |
1540 | } | |
1541 | ||
1542 | /** | |
1543 | * atc_alloc_chan_resources - allocate resources for DMA channel | |
1544 | * @chan: allocate descriptor resources for this channel | |
1545 | * @client: current client requesting the channel be ready for requests | |
1546 | * | |
1547 | * return - the number of allocated descriptors | |
1548 | */ | |
1549 | static int atc_alloc_chan_resources(struct dma_chan *chan) | |
1550 | { | |
1551 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1552 | struct at_dma *atdma = to_at_dma(chan->device); | |
1553 | struct at_desc *desc; | |
1554 | struct at_dma_slave *atslave; | |
1555 | unsigned long flags; | |
1556 | int i; | |
1557 | u32 cfg; | |
1558 | LIST_HEAD(tmp_list); | |
1559 | ||
1560 | dev_vdbg(chan2dev(chan), "alloc_chan_resources\n"); | |
1561 | ||
1562 | /* ASSERT: channel is idle */ | |
1563 | if (atc_chan_is_enabled(atchan)) { | |
1564 | dev_dbg(chan2dev(chan), "DMA channel not idle ?\n"); | |
1565 | return -EIO; | |
1566 | } | |
1567 | ||
1568 | cfg = ATC_DEFAULT_CFG; | |
1569 | ||
1570 | atslave = chan->private; | |
1571 | if (atslave) { | |
1572 | /* | |
1573 | * We need controller-specific data to set up slave | |
1574 | * transfers. | |
1575 | */ | |
1576 | BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_common.dev); | |
1577 | ||
1578 | /* if cfg configuration specified take it instead of default */ | |
1579 | if (atslave->cfg) | |
1580 | cfg = atslave->cfg; | |
1581 | } | |
1582 | ||
1583 | /* have we already been set up? | |
1584 | * reconfigure channel but no need to reallocate descriptors */ | |
1585 | if (!list_empty(&atchan->free_list)) | |
1586 | return atchan->descs_allocated; | |
1587 | ||
1588 | /* Allocate initial pool of descriptors */ | |
1589 | for (i = 0; i < init_nr_desc_per_channel; i++) { | |
1590 | desc = atc_alloc_descriptor(chan, GFP_KERNEL); | |
1591 | if (!desc) { | |
1592 | dev_err(atdma->dma_common.dev, | |
1593 | "Only %d initial descriptors\n", i); | |
1594 | break; | |
1595 | } | |
1596 | list_add_tail(&desc->desc_node, &tmp_list); | |
1597 | } | |
1598 | ||
1599 | spin_lock_irqsave(&atchan->lock, flags); | |
1600 | atchan->descs_allocated = i; | |
1601 | list_splice(&tmp_list, &atchan->free_list); | |
1602 | dma_cookie_init(chan); | |
1603 | spin_unlock_irqrestore(&atchan->lock, flags); | |
1604 | ||
1605 | /* channel parameters */ | |
1606 | channel_writel(atchan, CFG, cfg); | |
1607 | ||
1608 | dev_dbg(chan2dev(chan), | |
1609 | "alloc_chan_resources: allocated %d descriptors\n", | |
1610 | atchan->descs_allocated); | |
1611 | ||
1612 | return atchan->descs_allocated; | |
1613 | } | |
1614 | ||
1615 | /** | |
1616 | * atc_free_chan_resources - free all channel resources | |
1617 | * @chan: DMA channel | |
1618 | */ | |
1619 | static void atc_free_chan_resources(struct dma_chan *chan) | |
1620 | { | |
1621 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
1622 | struct at_dma *atdma = to_at_dma(chan->device); | |
1623 | struct at_desc *desc, *_desc; | |
1624 | LIST_HEAD(list); | |
1625 | ||
1626 | dev_dbg(chan2dev(chan), "free_chan_resources: (descs allocated=%u)\n", | |
1627 | atchan->descs_allocated); | |
1628 | ||
1629 | /* ASSERT: channel is idle */ | |
1630 | BUG_ON(!list_empty(&atchan->active_list)); | |
1631 | BUG_ON(!list_empty(&atchan->queue)); | |
1632 | BUG_ON(atc_chan_is_enabled(atchan)); | |
1633 | ||
1634 | list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) { | |
1635 | dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc); | |
1636 | list_del(&desc->desc_node); | |
1637 | /* free link descriptor */ | |
1638 | dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys); | |
1639 | } | |
1640 | list_splice_init(&atchan->free_list, &list); | |
1641 | atchan->descs_allocated = 0; | |
1642 | atchan->status = 0; | |
1643 | ||
1644 | dev_vdbg(chan2dev(chan), "free_chan_resources: done\n"); | |
1645 | } | |
1646 | ||
1647 | #ifdef CONFIG_OF | |
1648 | static bool at_dma_filter(struct dma_chan *chan, void *slave) | |
1649 | { | |
1650 | struct at_dma_slave *atslave = slave; | |
1651 | ||
1652 | if (atslave->dma_dev == chan->device->dev) { | |
1653 | chan->private = atslave; | |
1654 | return true; | |
1655 | } else { | |
1656 | return false; | |
1657 | } | |
1658 | } | |
1659 | ||
1660 | static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, | |
1661 | struct of_dma *of_dma) | |
1662 | { | |
1663 | struct dma_chan *chan; | |
1664 | struct at_dma_chan *atchan; | |
1665 | struct at_dma_slave *atslave; | |
1666 | dma_cap_mask_t mask; | |
1667 | unsigned int per_id; | |
1668 | struct platform_device *dmac_pdev; | |
1669 | ||
1670 | if (dma_spec->args_count != 2) | |
1671 | return NULL; | |
1672 | ||
1673 | dmac_pdev = of_find_device_by_node(dma_spec->np); | |
1674 | ||
1675 | dma_cap_zero(mask); | |
1676 | dma_cap_set(DMA_SLAVE, mask); | |
1677 | ||
1678 | atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL); | |
1679 | if (!atslave) | |
1680 | return NULL; | |
1681 | ||
1682 | atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW; | |
1683 | /* | |
1684 | * We can fill both SRC_PER and DST_PER, one of these fields will be | |
1685 | * ignored depending on DMA transfer direction. | |
1686 | */ | |
1687 | per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK; | |
1688 | atslave->cfg |= ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id) | |
1689 | | ATC_SRC_PER_MSB(per_id) | ATC_SRC_PER(per_id); | |
1690 | /* | |
1691 | * We have to translate the value we get from the device tree since | |
1692 | * the half FIFO configuration value had to be 0 to keep backward | |
1693 | * compatibility. | |
1694 | */ | |
1695 | switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) { | |
1696 | case AT91_DMA_CFG_FIFOCFG_ALAP: | |
1697 | atslave->cfg |= ATC_FIFOCFG_LARGESTBURST; | |
1698 | break; | |
1699 | case AT91_DMA_CFG_FIFOCFG_ASAP: | |
1700 | atslave->cfg |= ATC_FIFOCFG_ENOUGHSPACE; | |
1701 | break; | |
1702 | case AT91_DMA_CFG_FIFOCFG_HALF: | |
1703 | default: | |
1704 | atslave->cfg |= ATC_FIFOCFG_HALFFIFO; | |
1705 | } | |
1706 | atslave->dma_dev = &dmac_pdev->dev; | |
1707 | ||
1708 | chan = dma_request_channel(mask, at_dma_filter, atslave); | |
1709 | if (!chan) | |
1710 | return NULL; | |
1711 | ||
1712 | atchan = to_at_dma_chan(chan); | |
1713 | atchan->per_if = dma_spec->args[0] & 0xff; | |
1714 | atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff; | |
1715 | ||
1716 | return chan; | |
1717 | } | |
1718 | #else | |
1719 | static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, | |
1720 | struct of_dma *of_dma) | |
1721 | { | |
1722 | return NULL; | |
1723 | } | |
1724 | #endif | |
1725 | ||
1726 | /*-- Module Management -----------------------------------------------*/ | |
1727 | ||
1728 | /* cap_mask is a multi-u32 bitfield, fill it with proper C code. */ | |
1729 | static struct at_dma_platform_data at91sam9rl_config = { | |
1730 | .nr_channels = 2, | |
1731 | }; | |
1732 | static struct at_dma_platform_data at91sam9g45_config = { | |
1733 | .nr_channels = 8, | |
1734 | }; | |
1735 | ||
1736 | #if defined(CONFIG_OF) | |
1737 | static const struct of_device_id atmel_dma_dt_ids[] = { | |
1738 | { | |
1739 | .compatible = "atmel,at91sam9rl-dma", | |
1740 | .data = &at91sam9rl_config, | |
1741 | }, { | |
1742 | .compatible = "atmel,at91sam9g45-dma", | |
1743 | .data = &at91sam9g45_config, | |
1744 | }, { | |
1745 | /* sentinel */ | |
1746 | } | |
1747 | }; | |
1748 | ||
1749 | MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids); | |
1750 | #endif | |
1751 | ||
1752 | static const struct platform_device_id atdma_devtypes[] = { | |
1753 | { | |
1754 | .name = "at91sam9rl_dma", | |
1755 | .driver_data = (unsigned long) &at91sam9rl_config, | |
1756 | }, { | |
1757 | .name = "at91sam9g45_dma", | |
1758 | .driver_data = (unsigned long) &at91sam9g45_config, | |
1759 | }, { | |
1760 | /* sentinel */ | |
1761 | } | |
1762 | }; | |
1763 | ||
1764 | static inline const struct at_dma_platform_data * __init at_dma_get_driver_data( | |
1765 | struct platform_device *pdev) | |
1766 | { | |
1767 | if (pdev->dev.of_node) { | |
1768 | const struct of_device_id *match; | |
1769 | match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node); | |
1770 | if (match == NULL) | |
1771 | return NULL; | |
1772 | return match->data; | |
1773 | } | |
1774 | return (struct at_dma_platform_data *) | |
1775 | platform_get_device_id(pdev)->driver_data; | |
1776 | } | |
1777 | ||
1778 | /** | |
1779 | * at_dma_off - disable DMA controller | |
1780 | * @atdma: the Atmel HDAMC device | |
1781 | */ | |
1782 | static void at_dma_off(struct at_dma *atdma) | |
1783 | { | |
1784 | dma_writel(atdma, EN, 0); | |
1785 | ||
1786 | /* disable all interrupts */ | |
1787 | dma_writel(atdma, EBCIDR, -1L); | |
1788 | ||
1789 | /* confirm that all channels are disabled */ | |
1790 | while (dma_readl(atdma, CHSR) & atdma->all_chan_mask) | |
1791 | cpu_relax(); | |
1792 | } | |
1793 | ||
1794 | static int __init at_dma_probe(struct platform_device *pdev) | |
1795 | { | |
1796 | struct resource *io; | |
1797 | struct at_dma *atdma; | |
1798 | size_t size; | |
1799 | int irq; | |
1800 | int err; | |
1801 | int i; | |
1802 | const struct at_dma_platform_data *plat_dat; | |
1803 | ||
1804 | /* setup platform data for each SoC */ | |
1805 | dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask); | |
1806 | dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask); | |
1807 | dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask); | |
1808 | dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask); | |
1809 | dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask); | |
1810 | dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask); | |
1811 | dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask); | |
1812 | ||
1813 | /* get DMA parameters from controller type */ | |
1814 | plat_dat = at_dma_get_driver_data(pdev); | |
1815 | if (!plat_dat) | |
1816 | return -ENODEV; | |
1817 | ||
1818 | io = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
1819 | if (!io) | |
1820 | return -EINVAL; | |
1821 | ||
1822 | irq = platform_get_irq(pdev, 0); | |
1823 | if (irq < 0) | |
1824 | return irq; | |
1825 | ||
1826 | size = sizeof(struct at_dma); | |
1827 | size += plat_dat->nr_channels * sizeof(struct at_dma_chan); | |
1828 | atdma = kzalloc(size, GFP_KERNEL); | |
1829 | if (!atdma) | |
1830 | return -ENOMEM; | |
1831 | ||
1832 | /* discover transaction capabilities */ | |
1833 | atdma->dma_common.cap_mask = plat_dat->cap_mask; | |
1834 | atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1; | |
1835 | ||
1836 | size = resource_size(io); | |
1837 | if (!request_mem_region(io->start, size, pdev->dev.driver->name)) { | |
1838 | err = -EBUSY; | |
1839 | goto err_kfree; | |
1840 | } | |
1841 | ||
1842 | atdma->regs = ioremap(io->start, size); | |
1843 | if (!atdma->regs) { | |
1844 | err = -ENOMEM; | |
1845 | goto err_release_r; | |
1846 | } | |
1847 | ||
1848 | atdma->clk = clk_get(&pdev->dev, "dma_clk"); | |
1849 | if (IS_ERR(atdma->clk)) { | |
1850 | err = PTR_ERR(atdma->clk); | |
1851 | goto err_clk; | |
1852 | } | |
1853 | err = clk_prepare_enable(atdma->clk); | |
1854 | if (err) | |
1855 | goto err_clk_prepare; | |
1856 | ||
1857 | /* force dma off, just in case */ | |
1858 | at_dma_off(atdma); | |
1859 | ||
1860 | err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma); | |
1861 | if (err) | |
1862 | goto err_irq; | |
1863 | ||
1864 | platform_set_drvdata(pdev, atdma); | |
1865 | ||
1866 | /* create a pool of consistent memory blocks for hardware descriptors */ | |
1867 | atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool", | |
1868 | &pdev->dev, sizeof(struct at_desc), | |
1869 | 4 /* word alignment */, 0); | |
1870 | if (!atdma->dma_desc_pool) { | |
1871 | dev_err(&pdev->dev, "No memory for descriptors dma pool\n"); | |
1872 | err = -ENOMEM; | |
1873 | goto err_desc_pool_create; | |
1874 | } | |
1875 | ||
1876 | /* create a pool of consistent memory blocks for memset blocks */ | |
1877 | atdma->memset_pool = dma_pool_create("at_hdmac_memset_pool", | |
1878 | &pdev->dev, sizeof(int), 4, 0); | |
1879 | if (!atdma->memset_pool) { | |
1880 | dev_err(&pdev->dev, "No memory for memset dma pool\n"); | |
1881 | err = -ENOMEM; | |
1882 | goto err_memset_pool_create; | |
1883 | } | |
1884 | ||
1885 | /* clear any pending interrupt */ | |
1886 | while (dma_readl(atdma, EBCISR)) | |
1887 | cpu_relax(); | |
1888 | ||
1889 | /* initialize channels related values */ | |
1890 | INIT_LIST_HEAD(&atdma->dma_common.channels); | |
1891 | for (i = 0; i < plat_dat->nr_channels; i++) { | |
1892 | struct at_dma_chan *atchan = &atdma->chan[i]; | |
1893 | ||
1894 | atchan->mem_if = AT_DMA_MEM_IF; | |
1895 | atchan->per_if = AT_DMA_PER_IF; | |
1896 | atchan->chan_common.device = &atdma->dma_common; | |
1897 | dma_cookie_init(&atchan->chan_common); | |
1898 | list_add_tail(&atchan->chan_common.device_node, | |
1899 | &atdma->dma_common.channels); | |
1900 | ||
1901 | atchan->ch_regs = atdma->regs + ch_regs(i); | |
1902 | spin_lock_init(&atchan->lock); | |
1903 | atchan->mask = 1 << i; | |
1904 | ||
1905 | INIT_LIST_HEAD(&atchan->active_list); | |
1906 | INIT_LIST_HEAD(&atchan->queue); | |
1907 | INIT_LIST_HEAD(&atchan->free_list); | |
1908 | ||
1909 | tasklet_init(&atchan->tasklet, atc_tasklet, | |
1910 | (unsigned long)atchan); | |
1911 | atc_enable_chan_irq(atdma, i); | |
1912 | } | |
1913 | ||
1914 | /* set base routines */ | |
1915 | atdma->dma_common.device_alloc_chan_resources = atc_alloc_chan_resources; | |
1916 | atdma->dma_common.device_free_chan_resources = atc_free_chan_resources; | |
1917 | atdma->dma_common.device_tx_status = atc_tx_status; | |
1918 | atdma->dma_common.device_issue_pending = atc_issue_pending; | |
1919 | atdma->dma_common.dev = &pdev->dev; | |
1920 | ||
1921 | /* set prep routines based on capability */ | |
1922 | if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_common.cap_mask)) | |
1923 | atdma->dma_common.device_prep_interleaved_dma = atc_prep_dma_interleaved; | |
1924 | ||
1925 | if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask)) | |
1926 | atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy; | |
1927 | ||
1928 | if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) { | |
1929 | atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset; | |
1930 | atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg; | |
1931 | atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES; | |
1932 | } | |
1933 | ||
1934 | if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) { | |
1935 | atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg; | |
1936 | /* controller can do slave DMA: can trigger cyclic transfers */ | |
1937 | dma_cap_set(DMA_CYCLIC, atdma->dma_common.cap_mask); | |
1938 | atdma->dma_common.device_prep_dma_cyclic = atc_prep_dma_cyclic; | |
1939 | atdma->dma_common.device_config = atc_config; | |
1940 | atdma->dma_common.device_pause = atc_pause; | |
1941 | atdma->dma_common.device_resume = atc_resume; | |
1942 | atdma->dma_common.device_terminate_all = atc_terminate_all; | |
1943 | atdma->dma_common.src_addr_widths = ATC_DMA_BUSWIDTHS; | |
1944 | atdma->dma_common.dst_addr_widths = ATC_DMA_BUSWIDTHS; | |
1945 | atdma->dma_common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); | |
1946 | atdma->dma_common.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; | |
1947 | } | |
1948 | ||
1949 | dma_writel(atdma, EN, AT_DMA_ENABLE); | |
1950 | ||
1951 | dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n", | |
1952 | dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "", | |
1953 | dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask) ? "set " : "", | |
1954 | dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask) ? "slave " : "", | |
1955 | plat_dat->nr_channels); | |
1956 | ||
1957 | dma_async_device_register(&atdma->dma_common); | |
1958 | ||
1959 | /* | |
1960 | * Do not return an error if the dmac node is not present in order to | |
1961 | * not break the existing way of requesting channel with | |
1962 | * dma_request_channel(). | |
1963 | */ | |
1964 | if (pdev->dev.of_node) { | |
1965 | err = of_dma_controller_register(pdev->dev.of_node, | |
1966 | at_dma_xlate, atdma); | |
1967 | if (err) { | |
1968 | dev_err(&pdev->dev, "could not register of_dma_controller\n"); | |
1969 | goto err_of_dma_controller_register; | |
1970 | } | |
1971 | } | |
1972 | ||
1973 | return 0; | |
1974 | ||
1975 | err_of_dma_controller_register: | |
1976 | dma_async_device_unregister(&atdma->dma_common); | |
1977 | dma_pool_destroy(atdma->memset_pool); | |
1978 | err_memset_pool_create: | |
1979 | dma_pool_destroy(atdma->dma_desc_pool); | |
1980 | err_desc_pool_create: | |
1981 | free_irq(platform_get_irq(pdev, 0), atdma); | |
1982 | err_irq: | |
1983 | clk_disable_unprepare(atdma->clk); | |
1984 | err_clk_prepare: | |
1985 | clk_put(atdma->clk); | |
1986 | err_clk: | |
1987 | iounmap(atdma->regs); | |
1988 | atdma->regs = NULL; | |
1989 | err_release_r: | |
1990 | release_mem_region(io->start, size); | |
1991 | err_kfree: | |
1992 | kfree(atdma); | |
1993 | return err; | |
1994 | } | |
1995 | ||
1996 | static int at_dma_remove(struct platform_device *pdev) | |
1997 | { | |
1998 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
1999 | struct dma_chan *chan, *_chan; | |
2000 | struct resource *io; | |
2001 | ||
2002 | at_dma_off(atdma); | |
2003 | dma_async_device_unregister(&atdma->dma_common); | |
2004 | ||
2005 | dma_pool_destroy(atdma->memset_pool); | |
2006 | dma_pool_destroy(atdma->dma_desc_pool); | |
2007 | free_irq(platform_get_irq(pdev, 0), atdma); | |
2008 | ||
2009 | list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, | |
2010 | device_node) { | |
2011 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
2012 | ||
2013 | /* Disable interrupts */ | |
2014 | atc_disable_chan_irq(atdma, chan->chan_id); | |
2015 | ||
2016 | tasklet_kill(&atchan->tasklet); | |
2017 | list_del(&chan->device_node); | |
2018 | } | |
2019 | ||
2020 | clk_disable_unprepare(atdma->clk); | |
2021 | clk_put(atdma->clk); | |
2022 | ||
2023 | iounmap(atdma->regs); | |
2024 | atdma->regs = NULL; | |
2025 | ||
2026 | io = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
2027 | release_mem_region(io->start, resource_size(io)); | |
2028 | ||
2029 | kfree(atdma); | |
2030 | ||
2031 | return 0; | |
2032 | } | |
2033 | ||
2034 | static void at_dma_shutdown(struct platform_device *pdev) | |
2035 | { | |
2036 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
2037 | ||
2038 | at_dma_off(platform_get_drvdata(pdev)); | |
2039 | clk_disable_unprepare(atdma->clk); | |
2040 | } | |
2041 | ||
2042 | static int at_dma_prepare(struct device *dev) | |
2043 | { | |
2044 | struct platform_device *pdev = to_platform_device(dev); | |
2045 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
2046 | struct dma_chan *chan, *_chan; | |
2047 | ||
2048 | list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, | |
2049 | device_node) { | |
2050 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
2051 | /* wait for transaction completion (except in cyclic case) */ | |
2052 | if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan)) | |
2053 | return -EAGAIN; | |
2054 | } | |
2055 | return 0; | |
2056 | } | |
2057 | ||
2058 | static void atc_suspend_cyclic(struct at_dma_chan *atchan) | |
2059 | { | |
2060 | struct dma_chan *chan = &atchan->chan_common; | |
2061 | ||
2062 | /* Channel should be paused by user | |
2063 | * do it anyway even if it is not done already */ | |
2064 | if (!atc_chan_is_paused(atchan)) { | |
2065 | dev_warn(chan2dev(chan), | |
2066 | "cyclic channel not paused, should be done by channel user\n"); | |
2067 | atc_pause(chan); | |
2068 | } | |
2069 | ||
2070 | /* now preserve additional data for cyclic operations */ | |
2071 | /* next descriptor address in the cyclic list */ | |
2072 | atchan->save_dscr = channel_readl(atchan, DSCR); | |
2073 | ||
2074 | vdbg_dump_regs(atchan); | |
2075 | } | |
2076 | ||
2077 | static int at_dma_suspend_noirq(struct device *dev) | |
2078 | { | |
2079 | struct platform_device *pdev = to_platform_device(dev); | |
2080 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
2081 | struct dma_chan *chan, *_chan; | |
2082 | ||
2083 | /* preserve data */ | |
2084 | list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, | |
2085 | device_node) { | |
2086 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
2087 | ||
2088 | if (atc_chan_is_cyclic(atchan)) | |
2089 | atc_suspend_cyclic(atchan); | |
2090 | atchan->save_cfg = channel_readl(atchan, CFG); | |
2091 | } | |
2092 | atdma->save_imr = dma_readl(atdma, EBCIMR); | |
2093 | ||
2094 | /* disable DMA controller */ | |
2095 | at_dma_off(atdma); | |
2096 | clk_disable_unprepare(atdma->clk); | |
2097 | return 0; | |
2098 | } | |
2099 | ||
2100 | static void atc_resume_cyclic(struct at_dma_chan *atchan) | |
2101 | { | |
2102 | struct at_dma *atdma = to_at_dma(atchan->chan_common.device); | |
2103 | ||
2104 | /* restore channel status for cyclic descriptors list: | |
2105 | * next descriptor in the cyclic list at the time of suspend */ | |
2106 | channel_writel(atchan, SADDR, 0); | |
2107 | channel_writel(atchan, DADDR, 0); | |
2108 | channel_writel(atchan, CTRLA, 0); | |
2109 | channel_writel(atchan, CTRLB, 0); | |
2110 | channel_writel(atchan, DSCR, atchan->save_dscr); | |
2111 | dma_writel(atdma, CHER, atchan->mask); | |
2112 | ||
2113 | /* channel pause status should be removed by channel user | |
2114 | * We cannot take the initiative to do it here */ | |
2115 | ||
2116 | vdbg_dump_regs(atchan); | |
2117 | } | |
2118 | ||
2119 | static int at_dma_resume_noirq(struct device *dev) | |
2120 | { | |
2121 | struct platform_device *pdev = to_platform_device(dev); | |
2122 | struct at_dma *atdma = platform_get_drvdata(pdev); | |
2123 | struct dma_chan *chan, *_chan; | |
2124 | ||
2125 | /* bring back DMA controller */ | |
2126 | clk_prepare_enable(atdma->clk); | |
2127 | dma_writel(atdma, EN, AT_DMA_ENABLE); | |
2128 | ||
2129 | /* clear any pending interrupt */ | |
2130 | while (dma_readl(atdma, EBCISR)) | |
2131 | cpu_relax(); | |
2132 | ||
2133 | /* restore saved data */ | |
2134 | dma_writel(atdma, EBCIER, atdma->save_imr); | |
2135 | list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, | |
2136 | device_node) { | |
2137 | struct at_dma_chan *atchan = to_at_dma_chan(chan); | |
2138 | ||
2139 | channel_writel(atchan, CFG, atchan->save_cfg); | |
2140 | if (atc_chan_is_cyclic(atchan)) | |
2141 | atc_resume_cyclic(atchan); | |
2142 | } | |
2143 | return 0; | |
2144 | } | |
2145 | ||
2146 | static const struct dev_pm_ops at_dma_dev_pm_ops = { | |
2147 | .prepare = at_dma_prepare, | |
2148 | .suspend_noirq = at_dma_suspend_noirq, | |
2149 | .resume_noirq = at_dma_resume_noirq, | |
2150 | }; | |
2151 | ||
2152 | static struct platform_driver at_dma_driver = { | |
2153 | .remove = at_dma_remove, | |
2154 | .shutdown = at_dma_shutdown, | |
2155 | .id_table = atdma_devtypes, | |
2156 | .driver = { | |
2157 | .name = "at_hdmac", | |
2158 | .pm = &at_dma_dev_pm_ops, | |
2159 | .of_match_table = of_match_ptr(atmel_dma_dt_ids), | |
2160 | }, | |
2161 | }; | |
2162 | ||
2163 | static int __init at_dma_init(void) | |
2164 | { | |
2165 | return platform_driver_probe(&at_dma_driver, at_dma_probe); | |
2166 | } | |
2167 | subsys_initcall(at_dma_init); | |
2168 | ||
2169 | static void __exit at_dma_exit(void) | |
2170 | { | |
2171 | platform_driver_unregister(&at_dma_driver); | |
2172 | } | |
2173 | module_exit(at_dma_exit); | |
2174 | ||
2175 | MODULE_DESCRIPTION("Atmel AHB DMA Controller driver"); | |
2176 | MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>"); | |
2177 | MODULE_LICENSE("GPL"); | |
2178 | MODULE_ALIAS("platform:at_hdmac"); |