xref: /openbmc/linux/drivers/dma/txx9dmac.c (revision 77d84ff8)
1 /*
2  * Driver for the TXx9 SoC DMA Controller
3  *
4  * Copyright (C) 2009 Atsushi Nemoto
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 version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/dma-mapping.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 #include <linux/scatterlist.h>
18 
19 #include "dmaengine.h"
20 #include "txx9dmac.h"
21 
22 static struct txx9dmac_chan *to_txx9dmac_chan(struct dma_chan *chan)
23 {
24 	return container_of(chan, struct txx9dmac_chan, chan);
25 }
26 
27 static struct txx9dmac_cregs __iomem *__dma_regs(const struct txx9dmac_chan *dc)
28 {
29 	return dc->ch_regs;
30 }
31 
32 static struct txx9dmac_cregs32 __iomem *__dma_regs32(
33 	const struct txx9dmac_chan *dc)
34 {
35 	return dc->ch_regs;
36 }
37 
38 #define channel64_readq(dc, name) \
39 	__raw_readq(&(__dma_regs(dc)->name))
40 #define channel64_writeq(dc, name, val) \
41 	__raw_writeq((val), &(__dma_regs(dc)->name))
42 #define channel64_readl(dc, name) \
43 	__raw_readl(&(__dma_regs(dc)->name))
44 #define channel64_writel(dc, name, val) \
45 	__raw_writel((val), &(__dma_regs(dc)->name))
46 
47 #define channel32_readl(dc, name) \
48 	__raw_readl(&(__dma_regs32(dc)->name))
49 #define channel32_writel(dc, name, val) \
50 	__raw_writel((val), &(__dma_regs32(dc)->name))
51 
52 #define channel_readq(dc, name) channel64_readq(dc, name)
53 #define channel_writeq(dc, name, val) channel64_writeq(dc, name, val)
54 #define channel_readl(dc, name) \
55 	(is_dmac64(dc) ? \
56 	 channel64_readl(dc, name) : channel32_readl(dc, name))
57 #define channel_writel(dc, name, val) \
58 	(is_dmac64(dc) ? \
59 	 channel64_writel(dc, name, val) : channel32_writel(dc, name, val))
60 
61 static dma_addr_t channel64_read_CHAR(const struct txx9dmac_chan *dc)
62 {
63 	if (sizeof(__dma_regs(dc)->CHAR) == sizeof(u64))
64 		return channel64_readq(dc, CHAR);
65 	else
66 		return channel64_readl(dc, CHAR);
67 }
68 
69 static void channel64_write_CHAR(const struct txx9dmac_chan *dc, dma_addr_t val)
70 {
71 	if (sizeof(__dma_regs(dc)->CHAR) == sizeof(u64))
72 		channel64_writeq(dc, CHAR, val);
73 	else
74 		channel64_writel(dc, CHAR, val);
75 }
76 
77 static void channel64_clear_CHAR(const struct txx9dmac_chan *dc)
78 {
79 #if defined(CONFIG_32BIT) && !defined(CONFIG_64BIT_PHYS_ADDR)
80 	channel64_writel(dc, CHAR, 0);
81 	channel64_writel(dc, __pad_CHAR, 0);
82 #else
83 	channel64_writeq(dc, CHAR, 0);
84 #endif
85 }
86 
87 static dma_addr_t channel_read_CHAR(const struct txx9dmac_chan *dc)
88 {
89 	if (is_dmac64(dc))
90 		return channel64_read_CHAR(dc);
91 	else
92 		return channel32_readl(dc, CHAR);
93 }
94 
95 static void channel_write_CHAR(const struct txx9dmac_chan *dc, dma_addr_t val)
96 {
97 	if (is_dmac64(dc))
98 		channel64_write_CHAR(dc, val);
99 	else
100 		channel32_writel(dc, CHAR, val);
101 }
102 
103 static struct txx9dmac_regs __iomem *__txx9dmac_regs(
104 	const struct txx9dmac_dev *ddev)
105 {
106 	return ddev->regs;
107 }
108 
109 static struct txx9dmac_regs32 __iomem *__txx9dmac_regs32(
110 	const struct txx9dmac_dev *ddev)
111 {
112 	return ddev->regs;
113 }
114 
115 #define dma64_readl(ddev, name) \
116 	__raw_readl(&(__txx9dmac_regs(ddev)->name))
117 #define dma64_writel(ddev, name, val) \
118 	__raw_writel((val), &(__txx9dmac_regs(ddev)->name))
119 
120 #define dma32_readl(ddev, name) \
121 	__raw_readl(&(__txx9dmac_regs32(ddev)->name))
122 #define dma32_writel(ddev, name, val) \
123 	__raw_writel((val), &(__txx9dmac_regs32(ddev)->name))
124 
125 #define dma_readl(ddev, name) \
126 	(__is_dmac64(ddev) ? \
127 	dma64_readl(ddev, name) : dma32_readl(ddev, name))
128 #define dma_writel(ddev, name, val) \
129 	(__is_dmac64(ddev) ? \
130 	dma64_writel(ddev, name, val) : dma32_writel(ddev, name, val))
131 
132 static struct device *chan2dev(struct dma_chan *chan)
133 {
134 	return &chan->dev->device;
135 }
136 static struct device *chan2parent(struct dma_chan *chan)
137 {
138 	return chan->dev->device.parent;
139 }
140 
141 static struct txx9dmac_desc *
142 txd_to_txx9dmac_desc(struct dma_async_tx_descriptor *txd)
143 {
144 	return container_of(txd, struct txx9dmac_desc, txd);
145 }
146 
147 static dma_addr_t desc_read_CHAR(const struct txx9dmac_chan *dc,
148 				 const struct txx9dmac_desc *desc)
149 {
150 	return is_dmac64(dc) ? desc->hwdesc.CHAR : desc->hwdesc32.CHAR;
151 }
152 
153 static void desc_write_CHAR(const struct txx9dmac_chan *dc,
154 			    struct txx9dmac_desc *desc, dma_addr_t val)
155 {
156 	if (is_dmac64(dc))
157 		desc->hwdesc.CHAR = val;
158 	else
159 		desc->hwdesc32.CHAR = val;
160 }
161 
162 #define TXX9_DMA_MAX_COUNT	0x04000000
163 
164 #define TXX9_DMA_INITIAL_DESC_COUNT	64
165 
166 static struct txx9dmac_desc *txx9dmac_first_active(struct txx9dmac_chan *dc)
167 {
168 	return list_entry(dc->active_list.next,
169 			  struct txx9dmac_desc, desc_node);
170 }
171 
172 static struct txx9dmac_desc *txx9dmac_last_active(struct txx9dmac_chan *dc)
173 {
174 	return list_entry(dc->active_list.prev,
175 			  struct txx9dmac_desc, desc_node);
176 }
177 
178 static struct txx9dmac_desc *txx9dmac_first_queued(struct txx9dmac_chan *dc)
179 {
180 	return list_entry(dc->queue.next, struct txx9dmac_desc, desc_node);
181 }
182 
183 static struct txx9dmac_desc *txx9dmac_last_child(struct txx9dmac_desc *desc)
184 {
185 	if (!list_empty(&desc->tx_list))
186 		desc = list_entry(desc->tx_list.prev, typeof(*desc), desc_node);
187 	return desc;
188 }
189 
190 static dma_cookie_t txx9dmac_tx_submit(struct dma_async_tx_descriptor *tx);
191 
192 static struct txx9dmac_desc *txx9dmac_desc_alloc(struct txx9dmac_chan *dc,
193 						 gfp_t flags)
194 {
195 	struct txx9dmac_dev *ddev = dc->ddev;
196 	struct txx9dmac_desc *desc;
197 
198 	desc = kzalloc(sizeof(*desc), flags);
199 	if (!desc)
200 		return NULL;
201 	INIT_LIST_HEAD(&desc->tx_list);
202 	dma_async_tx_descriptor_init(&desc->txd, &dc->chan);
203 	desc->txd.tx_submit = txx9dmac_tx_submit;
204 	/* txd.flags will be overwritten in prep funcs */
205 	desc->txd.flags = DMA_CTRL_ACK;
206 	desc->txd.phys = dma_map_single(chan2parent(&dc->chan), &desc->hwdesc,
207 					ddev->descsize, DMA_TO_DEVICE);
208 	return desc;
209 }
210 
211 static struct txx9dmac_desc *txx9dmac_desc_get(struct txx9dmac_chan *dc)
212 {
213 	struct txx9dmac_desc *desc, *_desc;
214 	struct txx9dmac_desc *ret = NULL;
215 	unsigned int i = 0;
216 
217 	spin_lock_bh(&dc->lock);
218 	list_for_each_entry_safe(desc, _desc, &dc->free_list, desc_node) {
219 		if (async_tx_test_ack(&desc->txd)) {
220 			list_del(&desc->desc_node);
221 			ret = desc;
222 			break;
223 		}
224 		dev_dbg(chan2dev(&dc->chan), "desc %p not ACKed\n", desc);
225 		i++;
226 	}
227 	spin_unlock_bh(&dc->lock);
228 
229 	dev_vdbg(chan2dev(&dc->chan), "scanned %u descriptors on freelist\n",
230 		 i);
231 	if (!ret) {
232 		ret = txx9dmac_desc_alloc(dc, GFP_ATOMIC);
233 		if (ret) {
234 			spin_lock_bh(&dc->lock);
235 			dc->descs_allocated++;
236 			spin_unlock_bh(&dc->lock);
237 		} else
238 			dev_err(chan2dev(&dc->chan),
239 				"not enough descriptors available\n");
240 	}
241 	return ret;
242 }
243 
244 static void txx9dmac_sync_desc_for_cpu(struct txx9dmac_chan *dc,
245 				       struct txx9dmac_desc *desc)
246 {
247 	struct txx9dmac_dev *ddev = dc->ddev;
248 	struct txx9dmac_desc *child;
249 
250 	list_for_each_entry(child, &desc->tx_list, desc_node)
251 		dma_sync_single_for_cpu(chan2parent(&dc->chan),
252 				child->txd.phys, ddev->descsize,
253 				DMA_TO_DEVICE);
254 	dma_sync_single_for_cpu(chan2parent(&dc->chan),
255 			desc->txd.phys, ddev->descsize,
256 			DMA_TO_DEVICE);
257 }
258 
259 /*
260  * Move a descriptor, including any children, to the free list.
261  * `desc' must not be on any lists.
262  */
263 static void txx9dmac_desc_put(struct txx9dmac_chan *dc,
264 			      struct txx9dmac_desc *desc)
265 {
266 	if (desc) {
267 		struct txx9dmac_desc *child;
268 
269 		txx9dmac_sync_desc_for_cpu(dc, desc);
270 
271 		spin_lock_bh(&dc->lock);
272 		list_for_each_entry(child, &desc->tx_list, desc_node)
273 			dev_vdbg(chan2dev(&dc->chan),
274 				 "moving child desc %p to freelist\n",
275 				 child);
276 		list_splice_init(&desc->tx_list, &dc->free_list);
277 		dev_vdbg(chan2dev(&dc->chan), "moving desc %p to freelist\n",
278 			 desc);
279 		list_add(&desc->desc_node, &dc->free_list);
280 		spin_unlock_bh(&dc->lock);
281 	}
282 }
283 
284 /*----------------------------------------------------------------------*/
285 
286 static void txx9dmac_dump_regs(struct txx9dmac_chan *dc)
287 {
288 	if (is_dmac64(dc))
289 		dev_err(chan2dev(&dc->chan),
290 			"  CHAR: %#llx SAR: %#llx DAR: %#llx CNTR: %#x"
291 			" SAIR: %#x DAIR: %#x CCR: %#x CSR: %#x\n",
292 			(u64)channel64_read_CHAR(dc),
293 			channel64_readq(dc, SAR),
294 			channel64_readq(dc, DAR),
295 			channel64_readl(dc, CNTR),
296 			channel64_readl(dc, SAIR),
297 			channel64_readl(dc, DAIR),
298 			channel64_readl(dc, CCR),
299 			channel64_readl(dc, CSR));
300 	else
301 		dev_err(chan2dev(&dc->chan),
302 			"  CHAR: %#x SAR: %#x DAR: %#x CNTR: %#x"
303 			" SAIR: %#x DAIR: %#x CCR: %#x CSR: %#x\n",
304 			channel32_readl(dc, CHAR),
305 			channel32_readl(dc, SAR),
306 			channel32_readl(dc, DAR),
307 			channel32_readl(dc, CNTR),
308 			channel32_readl(dc, SAIR),
309 			channel32_readl(dc, DAIR),
310 			channel32_readl(dc, CCR),
311 			channel32_readl(dc, CSR));
312 }
313 
314 static void txx9dmac_reset_chan(struct txx9dmac_chan *dc)
315 {
316 	channel_writel(dc, CCR, TXX9_DMA_CCR_CHRST);
317 	if (is_dmac64(dc)) {
318 		channel64_clear_CHAR(dc);
319 		channel_writeq(dc, SAR, 0);
320 		channel_writeq(dc, DAR, 0);
321 	} else {
322 		channel_writel(dc, CHAR, 0);
323 		channel_writel(dc, SAR, 0);
324 		channel_writel(dc, DAR, 0);
325 	}
326 	channel_writel(dc, CNTR, 0);
327 	channel_writel(dc, SAIR, 0);
328 	channel_writel(dc, DAIR, 0);
329 	channel_writel(dc, CCR, 0);
330 	mmiowb();
331 }
332 
333 /* Called with dc->lock held and bh disabled */
334 static void txx9dmac_dostart(struct txx9dmac_chan *dc,
335 			     struct txx9dmac_desc *first)
336 {
337 	struct txx9dmac_slave *ds = dc->chan.private;
338 	u32 sai, dai;
339 
340 	dev_vdbg(chan2dev(&dc->chan), "dostart %u %p\n",
341 		 first->txd.cookie, first);
342 	/* ASSERT:  channel is idle */
343 	if (channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT) {
344 		dev_err(chan2dev(&dc->chan),
345 			"BUG: Attempted to start non-idle channel\n");
346 		txx9dmac_dump_regs(dc);
347 		/* The tasklet will hopefully advance the queue... */
348 		return;
349 	}
350 
351 	if (is_dmac64(dc)) {
352 		channel64_writel(dc, CNTR, 0);
353 		channel64_writel(dc, CSR, 0xffffffff);
354 		if (ds) {
355 			if (ds->tx_reg) {
356 				sai = ds->reg_width;
357 				dai = 0;
358 			} else {
359 				sai = 0;
360 				dai = ds->reg_width;
361 			}
362 		} else {
363 			sai = 8;
364 			dai = 8;
365 		}
366 		channel64_writel(dc, SAIR, sai);
367 		channel64_writel(dc, DAIR, dai);
368 		/* All 64-bit DMAC supports SMPCHN */
369 		channel64_writel(dc, CCR, dc->ccr);
370 		/* Writing a non zero value to CHAR will assert XFACT */
371 		channel64_write_CHAR(dc, first->txd.phys);
372 	} else {
373 		channel32_writel(dc, CNTR, 0);
374 		channel32_writel(dc, CSR, 0xffffffff);
375 		if (ds) {
376 			if (ds->tx_reg) {
377 				sai = ds->reg_width;
378 				dai = 0;
379 			} else {
380 				sai = 0;
381 				dai = ds->reg_width;
382 			}
383 		} else {
384 			sai = 4;
385 			dai = 4;
386 		}
387 		channel32_writel(dc, SAIR, sai);
388 		channel32_writel(dc, DAIR, dai);
389 		if (txx9_dma_have_SMPCHN()) {
390 			channel32_writel(dc, CCR, dc->ccr);
391 			/* Writing a non zero value to CHAR will assert XFACT */
392 			channel32_writel(dc, CHAR, first->txd.phys);
393 		} else {
394 			channel32_writel(dc, CHAR, first->txd.phys);
395 			channel32_writel(dc, CCR, dc->ccr);
396 		}
397 	}
398 }
399 
400 /*----------------------------------------------------------------------*/
401 
402 static void
403 txx9dmac_descriptor_complete(struct txx9dmac_chan *dc,
404 			     struct txx9dmac_desc *desc)
405 {
406 	dma_async_tx_callback callback;
407 	void *param;
408 	struct dma_async_tx_descriptor *txd = &desc->txd;
409 	struct txx9dmac_slave *ds = dc->chan.private;
410 
411 	dev_vdbg(chan2dev(&dc->chan), "descriptor %u %p complete\n",
412 		 txd->cookie, desc);
413 
414 	dma_cookie_complete(txd);
415 	callback = txd->callback;
416 	param = txd->callback_param;
417 
418 	txx9dmac_sync_desc_for_cpu(dc, desc);
419 	list_splice_init(&desc->tx_list, &dc->free_list);
420 	list_move(&desc->desc_node, &dc->free_list);
421 
422 	dma_descriptor_unmap(txd);
423 	/*
424 	 * The API requires that no submissions are done from a
425 	 * callback, so we don't need to drop the lock here
426 	 */
427 	if (callback)
428 		callback(param);
429 	dma_run_dependencies(txd);
430 }
431 
432 static void txx9dmac_dequeue(struct txx9dmac_chan *dc, struct list_head *list)
433 {
434 	struct txx9dmac_dev *ddev = dc->ddev;
435 	struct txx9dmac_desc *desc;
436 	struct txx9dmac_desc *prev = NULL;
437 
438 	BUG_ON(!list_empty(list));
439 	do {
440 		desc = txx9dmac_first_queued(dc);
441 		if (prev) {
442 			desc_write_CHAR(dc, prev, desc->txd.phys);
443 			dma_sync_single_for_device(chan2parent(&dc->chan),
444 				prev->txd.phys, ddev->descsize,
445 				DMA_TO_DEVICE);
446 		}
447 		prev = txx9dmac_last_child(desc);
448 		list_move_tail(&desc->desc_node, list);
449 		/* Make chain-completion interrupt happen */
450 		if ((desc->txd.flags & DMA_PREP_INTERRUPT) &&
451 		    !txx9dmac_chan_INTENT(dc))
452 			break;
453 	} while (!list_empty(&dc->queue));
454 }
455 
456 static void txx9dmac_complete_all(struct txx9dmac_chan *dc)
457 {
458 	struct txx9dmac_desc *desc, *_desc;
459 	LIST_HEAD(list);
460 
461 	/*
462 	 * Submit queued descriptors ASAP, i.e. before we go through
463 	 * the completed ones.
464 	 */
465 	list_splice_init(&dc->active_list, &list);
466 	if (!list_empty(&dc->queue)) {
467 		txx9dmac_dequeue(dc, &dc->active_list);
468 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
469 	}
470 
471 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
472 		txx9dmac_descriptor_complete(dc, desc);
473 }
474 
475 static void txx9dmac_dump_desc(struct txx9dmac_chan *dc,
476 			       struct txx9dmac_hwdesc *desc)
477 {
478 	if (is_dmac64(dc)) {
479 #ifdef TXX9_DMA_USE_SIMPLE_CHAIN
480 		dev_crit(chan2dev(&dc->chan),
481 			 "  desc: ch%#llx s%#llx d%#llx c%#x\n",
482 			 (u64)desc->CHAR, desc->SAR, desc->DAR, desc->CNTR);
483 #else
484 		dev_crit(chan2dev(&dc->chan),
485 			 "  desc: ch%#llx s%#llx d%#llx c%#x"
486 			 " si%#x di%#x cc%#x cs%#x\n",
487 			 (u64)desc->CHAR, desc->SAR, desc->DAR, desc->CNTR,
488 			 desc->SAIR, desc->DAIR, desc->CCR, desc->CSR);
489 #endif
490 	} else {
491 		struct txx9dmac_hwdesc32 *d = (struct txx9dmac_hwdesc32 *)desc;
492 #ifdef TXX9_DMA_USE_SIMPLE_CHAIN
493 		dev_crit(chan2dev(&dc->chan),
494 			 "  desc: ch%#x s%#x d%#x c%#x\n",
495 			 d->CHAR, d->SAR, d->DAR, d->CNTR);
496 #else
497 		dev_crit(chan2dev(&dc->chan),
498 			 "  desc: ch%#x s%#x d%#x c%#x"
499 			 " si%#x di%#x cc%#x cs%#x\n",
500 			 d->CHAR, d->SAR, d->DAR, d->CNTR,
501 			 d->SAIR, d->DAIR, d->CCR, d->CSR);
502 #endif
503 	}
504 }
505 
506 static void txx9dmac_handle_error(struct txx9dmac_chan *dc, u32 csr)
507 {
508 	struct txx9dmac_desc *bad_desc;
509 	struct txx9dmac_desc *child;
510 	u32 errors;
511 
512 	/*
513 	 * The descriptor currently at the head of the active list is
514 	 * borked. Since we don't have any way to report errors, we'll
515 	 * just have to scream loudly and try to carry on.
516 	 */
517 	dev_crit(chan2dev(&dc->chan), "Abnormal Chain Completion\n");
518 	txx9dmac_dump_regs(dc);
519 
520 	bad_desc = txx9dmac_first_active(dc);
521 	list_del_init(&bad_desc->desc_node);
522 
523 	/* Clear all error flags and try to restart the controller */
524 	errors = csr & (TXX9_DMA_CSR_ABCHC |
525 			TXX9_DMA_CSR_CFERR | TXX9_DMA_CSR_CHERR |
526 			TXX9_DMA_CSR_DESERR | TXX9_DMA_CSR_SORERR);
527 	channel_writel(dc, CSR, errors);
528 
529 	if (list_empty(&dc->active_list) && !list_empty(&dc->queue))
530 		txx9dmac_dequeue(dc, &dc->active_list);
531 	if (!list_empty(&dc->active_list))
532 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
533 
534 	dev_crit(chan2dev(&dc->chan),
535 		 "Bad descriptor submitted for DMA! (cookie: %d)\n",
536 		 bad_desc->txd.cookie);
537 	txx9dmac_dump_desc(dc, &bad_desc->hwdesc);
538 	list_for_each_entry(child, &bad_desc->tx_list, desc_node)
539 		txx9dmac_dump_desc(dc, &child->hwdesc);
540 	/* Pretend the descriptor completed successfully */
541 	txx9dmac_descriptor_complete(dc, bad_desc);
542 }
543 
544 static void txx9dmac_scan_descriptors(struct txx9dmac_chan *dc)
545 {
546 	dma_addr_t chain;
547 	struct txx9dmac_desc *desc, *_desc;
548 	struct txx9dmac_desc *child;
549 	u32 csr;
550 
551 	if (is_dmac64(dc)) {
552 		chain = channel64_read_CHAR(dc);
553 		csr = channel64_readl(dc, CSR);
554 		channel64_writel(dc, CSR, csr);
555 	} else {
556 		chain = channel32_readl(dc, CHAR);
557 		csr = channel32_readl(dc, CSR);
558 		channel32_writel(dc, CSR, csr);
559 	}
560 	/* For dynamic chain, we should look at XFACT instead of NCHNC */
561 	if (!(csr & (TXX9_DMA_CSR_XFACT | TXX9_DMA_CSR_ABCHC))) {
562 		/* Everything we've submitted is done */
563 		txx9dmac_complete_all(dc);
564 		return;
565 	}
566 	if (!(csr & TXX9_DMA_CSR_CHNEN))
567 		chain = 0;	/* last descriptor of this chain */
568 
569 	dev_vdbg(chan2dev(&dc->chan), "scan_descriptors: char=%#llx\n",
570 		 (u64)chain);
571 
572 	list_for_each_entry_safe(desc, _desc, &dc->active_list, desc_node) {
573 		if (desc_read_CHAR(dc, desc) == chain) {
574 			/* This one is currently in progress */
575 			if (csr & TXX9_DMA_CSR_ABCHC)
576 				goto scan_done;
577 			return;
578 		}
579 
580 		list_for_each_entry(child, &desc->tx_list, desc_node)
581 			if (desc_read_CHAR(dc, child) == chain) {
582 				/* Currently in progress */
583 				if (csr & TXX9_DMA_CSR_ABCHC)
584 					goto scan_done;
585 				return;
586 			}
587 
588 		/*
589 		 * No descriptors so far seem to be in progress, i.e.
590 		 * this one must be done.
591 		 */
592 		txx9dmac_descriptor_complete(dc, desc);
593 	}
594 scan_done:
595 	if (csr & TXX9_DMA_CSR_ABCHC) {
596 		txx9dmac_handle_error(dc, csr);
597 		return;
598 	}
599 
600 	dev_err(chan2dev(&dc->chan),
601 		"BUG: All descriptors done, but channel not idle!\n");
602 
603 	/* Try to continue after resetting the channel... */
604 	txx9dmac_reset_chan(dc);
605 
606 	if (!list_empty(&dc->queue)) {
607 		txx9dmac_dequeue(dc, &dc->active_list);
608 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
609 	}
610 }
611 
612 static void txx9dmac_chan_tasklet(unsigned long data)
613 {
614 	int irq;
615 	u32 csr;
616 	struct txx9dmac_chan *dc;
617 
618 	dc = (struct txx9dmac_chan *)data;
619 	csr = channel_readl(dc, CSR);
620 	dev_vdbg(chan2dev(&dc->chan), "tasklet: status=%x\n", csr);
621 
622 	spin_lock(&dc->lock);
623 	if (csr & (TXX9_DMA_CSR_ABCHC | TXX9_DMA_CSR_NCHNC |
624 		   TXX9_DMA_CSR_NTRNFC))
625 		txx9dmac_scan_descriptors(dc);
626 	spin_unlock(&dc->lock);
627 	irq = dc->irq;
628 
629 	enable_irq(irq);
630 }
631 
632 static irqreturn_t txx9dmac_chan_interrupt(int irq, void *dev_id)
633 {
634 	struct txx9dmac_chan *dc = dev_id;
635 
636 	dev_vdbg(chan2dev(&dc->chan), "interrupt: status=%#x\n",
637 			channel_readl(dc, CSR));
638 
639 	tasklet_schedule(&dc->tasklet);
640 	/*
641 	 * Just disable the interrupts. We'll turn them back on in the
642 	 * softirq handler.
643 	 */
644 	disable_irq_nosync(irq);
645 
646 	return IRQ_HANDLED;
647 }
648 
649 static void txx9dmac_tasklet(unsigned long data)
650 {
651 	int irq;
652 	u32 csr;
653 	struct txx9dmac_chan *dc;
654 
655 	struct txx9dmac_dev *ddev = (struct txx9dmac_dev *)data;
656 	u32 mcr;
657 	int i;
658 
659 	mcr = dma_readl(ddev, MCR);
660 	dev_vdbg(ddev->chan[0]->dma.dev, "tasklet: mcr=%x\n", mcr);
661 	for (i = 0; i < TXX9_DMA_MAX_NR_CHANNELS; i++) {
662 		if ((mcr >> (24 + i)) & 0x11) {
663 			dc = ddev->chan[i];
664 			csr = channel_readl(dc, CSR);
665 			dev_vdbg(chan2dev(&dc->chan), "tasklet: status=%x\n",
666 				 csr);
667 			spin_lock(&dc->lock);
668 			if (csr & (TXX9_DMA_CSR_ABCHC | TXX9_DMA_CSR_NCHNC |
669 				   TXX9_DMA_CSR_NTRNFC))
670 				txx9dmac_scan_descriptors(dc);
671 			spin_unlock(&dc->lock);
672 		}
673 	}
674 	irq = ddev->irq;
675 
676 	enable_irq(irq);
677 }
678 
679 static irqreturn_t txx9dmac_interrupt(int irq, void *dev_id)
680 {
681 	struct txx9dmac_dev *ddev = dev_id;
682 
683 	dev_vdbg(ddev->chan[0]->dma.dev, "interrupt: status=%#x\n",
684 			dma_readl(ddev, MCR));
685 
686 	tasklet_schedule(&ddev->tasklet);
687 	/*
688 	 * Just disable the interrupts. We'll turn them back on in the
689 	 * softirq handler.
690 	 */
691 	disable_irq_nosync(irq);
692 
693 	return IRQ_HANDLED;
694 }
695 
696 /*----------------------------------------------------------------------*/
697 
698 static dma_cookie_t txx9dmac_tx_submit(struct dma_async_tx_descriptor *tx)
699 {
700 	struct txx9dmac_desc *desc = txd_to_txx9dmac_desc(tx);
701 	struct txx9dmac_chan *dc = to_txx9dmac_chan(tx->chan);
702 	dma_cookie_t cookie;
703 
704 	spin_lock_bh(&dc->lock);
705 	cookie = dma_cookie_assign(tx);
706 
707 	dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u %p\n",
708 		 desc->txd.cookie, desc);
709 
710 	list_add_tail(&desc->desc_node, &dc->queue);
711 	spin_unlock_bh(&dc->lock);
712 
713 	return cookie;
714 }
715 
716 static struct dma_async_tx_descriptor *
717 txx9dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
718 		size_t len, unsigned long flags)
719 {
720 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
721 	struct txx9dmac_dev *ddev = dc->ddev;
722 	struct txx9dmac_desc *desc;
723 	struct txx9dmac_desc *first;
724 	struct txx9dmac_desc *prev;
725 	size_t xfer_count;
726 	size_t offset;
727 
728 	dev_vdbg(chan2dev(chan), "prep_dma_memcpy d%#llx s%#llx l%#zx f%#lx\n",
729 		 (u64)dest, (u64)src, len, flags);
730 
731 	if (unlikely(!len)) {
732 		dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
733 		return NULL;
734 	}
735 
736 	prev = first = NULL;
737 
738 	for (offset = 0; offset < len; offset += xfer_count) {
739 		xfer_count = min_t(size_t, len - offset, TXX9_DMA_MAX_COUNT);
740 		/*
741 		 * Workaround for ERT-TX49H2-033, ERT-TX49H3-020,
742 		 * ERT-TX49H4-016 (slightly conservative)
743 		 */
744 		if (__is_dmac64(ddev)) {
745 			if (xfer_count > 0x100 &&
746 			    (xfer_count & 0xff) >= 0xfa &&
747 			    (xfer_count & 0xff) <= 0xff)
748 				xfer_count -= 0x20;
749 		} else {
750 			if (xfer_count > 0x80 &&
751 			    (xfer_count & 0x7f) >= 0x7e &&
752 			    (xfer_count & 0x7f) <= 0x7f)
753 				xfer_count -= 0x20;
754 		}
755 
756 		desc = txx9dmac_desc_get(dc);
757 		if (!desc) {
758 			txx9dmac_desc_put(dc, first);
759 			return NULL;
760 		}
761 
762 		if (__is_dmac64(ddev)) {
763 			desc->hwdesc.SAR = src + offset;
764 			desc->hwdesc.DAR = dest + offset;
765 			desc->hwdesc.CNTR = xfer_count;
766 			txx9dmac_desc_set_nosimple(ddev, desc, 8, 8,
767 					dc->ccr | TXX9_DMA_CCR_XFACT);
768 		} else {
769 			desc->hwdesc32.SAR = src + offset;
770 			desc->hwdesc32.DAR = dest + offset;
771 			desc->hwdesc32.CNTR = xfer_count;
772 			txx9dmac_desc_set_nosimple(ddev, desc, 4, 4,
773 					dc->ccr | TXX9_DMA_CCR_XFACT);
774 		}
775 
776 		/*
777 		 * The descriptors on tx_list are not reachable from
778 		 * the dc->queue list or dc->active_list after a
779 		 * submit.  If we put all descriptors on active_list,
780 		 * calling of callback on the completion will be more
781 		 * complex.
782 		 */
783 		if (!first) {
784 			first = desc;
785 		} else {
786 			desc_write_CHAR(dc, prev, desc->txd.phys);
787 			dma_sync_single_for_device(chan2parent(&dc->chan),
788 					prev->txd.phys, ddev->descsize,
789 					DMA_TO_DEVICE);
790 			list_add_tail(&desc->desc_node, &first->tx_list);
791 		}
792 		prev = desc;
793 	}
794 
795 	/* Trigger interrupt after last block */
796 	if (flags & DMA_PREP_INTERRUPT)
797 		txx9dmac_desc_set_INTENT(ddev, prev);
798 
799 	desc_write_CHAR(dc, prev, 0);
800 	dma_sync_single_for_device(chan2parent(&dc->chan),
801 			prev->txd.phys, ddev->descsize,
802 			DMA_TO_DEVICE);
803 
804 	first->txd.flags = flags;
805 	first->len = len;
806 
807 	return &first->txd;
808 }
809 
810 static struct dma_async_tx_descriptor *
811 txx9dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
812 		unsigned int sg_len, enum dma_transfer_direction direction,
813 		unsigned long flags, void *context)
814 {
815 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
816 	struct txx9dmac_dev *ddev = dc->ddev;
817 	struct txx9dmac_slave *ds = chan->private;
818 	struct txx9dmac_desc *prev;
819 	struct txx9dmac_desc *first;
820 	unsigned int i;
821 	struct scatterlist *sg;
822 
823 	dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
824 
825 	BUG_ON(!ds || !ds->reg_width);
826 	if (ds->tx_reg)
827 		BUG_ON(direction != DMA_MEM_TO_DEV);
828 	else
829 		BUG_ON(direction != DMA_DEV_TO_MEM);
830 	if (unlikely(!sg_len))
831 		return NULL;
832 
833 	prev = first = NULL;
834 
835 	for_each_sg(sgl, sg, sg_len, i) {
836 		struct txx9dmac_desc *desc;
837 		dma_addr_t mem;
838 		u32 sai, dai;
839 
840 		desc = txx9dmac_desc_get(dc);
841 		if (!desc) {
842 			txx9dmac_desc_put(dc, first);
843 			return NULL;
844 		}
845 
846 		mem = sg_dma_address(sg);
847 
848 		if (__is_dmac64(ddev)) {
849 			if (direction == DMA_MEM_TO_DEV) {
850 				desc->hwdesc.SAR = mem;
851 				desc->hwdesc.DAR = ds->tx_reg;
852 			} else {
853 				desc->hwdesc.SAR = ds->rx_reg;
854 				desc->hwdesc.DAR = mem;
855 			}
856 			desc->hwdesc.CNTR = sg_dma_len(sg);
857 		} else {
858 			if (direction == DMA_MEM_TO_DEV) {
859 				desc->hwdesc32.SAR = mem;
860 				desc->hwdesc32.DAR = ds->tx_reg;
861 			} else {
862 				desc->hwdesc32.SAR = ds->rx_reg;
863 				desc->hwdesc32.DAR = mem;
864 			}
865 			desc->hwdesc32.CNTR = sg_dma_len(sg);
866 		}
867 		if (direction == DMA_MEM_TO_DEV) {
868 			sai = ds->reg_width;
869 			dai = 0;
870 		} else {
871 			sai = 0;
872 			dai = ds->reg_width;
873 		}
874 		txx9dmac_desc_set_nosimple(ddev, desc, sai, dai,
875 					dc->ccr | TXX9_DMA_CCR_XFACT);
876 
877 		if (!first) {
878 			first = desc;
879 		} else {
880 			desc_write_CHAR(dc, prev, desc->txd.phys);
881 			dma_sync_single_for_device(chan2parent(&dc->chan),
882 					prev->txd.phys,
883 					ddev->descsize,
884 					DMA_TO_DEVICE);
885 			list_add_tail(&desc->desc_node, &first->tx_list);
886 		}
887 		prev = desc;
888 	}
889 
890 	/* Trigger interrupt after last block */
891 	if (flags & DMA_PREP_INTERRUPT)
892 		txx9dmac_desc_set_INTENT(ddev, prev);
893 
894 	desc_write_CHAR(dc, prev, 0);
895 	dma_sync_single_for_device(chan2parent(&dc->chan),
896 			prev->txd.phys, ddev->descsize,
897 			DMA_TO_DEVICE);
898 
899 	first->txd.flags = flags;
900 	first->len = 0;
901 
902 	return &first->txd;
903 }
904 
905 static int txx9dmac_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
906 			    unsigned long arg)
907 {
908 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
909 	struct txx9dmac_desc *desc, *_desc;
910 	LIST_HEAD(list);
911 
912 	/* Only supports DMA_TERMINATE_ALL */
913 	if (cmd != DMA_TERMINATE_ALL)
914 		return -EINVAL;
915 
916 	dev_vdbg(chan2dev(chan), "terminate_all\n");
917 	spin_lock_bh(&dc->lock);
918 
919 	txx9dmac_reset_chan(dc);
920 
921 	/* active_list entries will end up before queued entries */
922 	list_splice_init(&dc->queue, &list);
923 	list_splice_init(&dc->active_list, &list);
924 
925 	spin_unlock_bh(&dc->lock);
926 
927 	/* Flush all pending and queued descriptors */
928 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
929 		txx9dmac_descriptor_complete(dc, desc);
930 
931 	return 0;
932 }
933 
934 static enum dma_status
935 txx9dmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
936 		   struct dma_tx_state *txstate)
937 {
938 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
939 	enum dma_status ret;
940 
941 	ret = dma_cookie_status(chan, cookie, txstate);
942 	if (ret == DMA_COMPLETE)
943 		return DMA_COMPLETE;
944 
945 	spin_lock_bh(&dc->lock);
946 	txx9dmac_scan_descriptors(dc);
947 	spin_unlock_bh(&dc->lock);
948 
949 	return dma_cookie_status(chan, cookie, txstate);
950 }
951 
952 static void txx9dmac_chain_dynamic(struct txx9dmac_chan *dc,
953 				   struct txx9dmac_desc *prev)
954 {
955 	struct txx9dmac_dev *ddev = dc->ddev;
956 	struct txx9dmac_desc *desc;
957 	LIST_HEAD(list);
958 
959 	prev = txx9dmac_last_child(prev);
960 	txx9dmac_dequeue(dc, &list);
961 	desc = list_entry(list.next, struct txx9dmac_desc, desc_node);
962 	desc_write_CHAR(dc, prev, desc->txd.phys);
963 	dma_sync_single_for_device(chan2parent(&dc->chan),
964 				   prev->txd.phys, ddev->descsize,
965 				   DMA_TO_DEVICE);
966 	mmiowb();
967 	if (!(channel_readl(dc, CSR) & TXX9_DMA_CSR_CHNEN) &&
968 	    channel_read_CHAR(dc) == prev->txd.phys)
969 		/* Restart chain DMA */
970 		channel_write_CHAR(dc, desc->txd.phys);
971 	list_splice_tail(&list, &dc->active_list);
972 }
973 
974 static void txx9dmac_issue_pending(struct dma_chan *chan)
975 {
976 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
977 
978 	spin_lock_bh(&dc->lock);
979 
980 	if (!list_empty(&dc->active_list))
981 		txx9dmac_scan_descriptors(dc);
982 	if (!list_empty(&dc->queue)) {
983 		if (list_empty(&dc->active_list)) {
984 			txx9dmac_dequeue(dc, &dc->active_list);
985 			txx9dmac_dostart(dc, txx9dmac_first_active(dc));
986 		} else if (txx9_dma_have_SMPCHN()) {
987 			struct txx9dmac_desc *prev = txx9dmac_last_active(dc);
988 
989 			if (!(prev->txd.flags & DMA_PREP_INTERRUPT) ||
990 			    txx9dmac_chan_INTENT(dc))
991 				txx9dmac_chain_dynamic(dc, prev);
992 		}
993 	}
994 
995 	spin_unlock_bh(&dc->lock);
996 }
997 
998 static int txx9dmac_alloc_chan_resources(struct dma_chan *chan)
999 {
1000 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1001 	struct txx9dmac_slave *ds = chan->private;
1002 	struct txx9dmac_desc *desc;
1003 	int i;
1004 
1005 	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
1006 
1007 	/* ASSERT:  channel is idle */
1008 	if (channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT) {
1009 		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1010 		return -EIO;
1011 	}
1012 
1013 	dma_cookie_init(chan);
1014 
1015 	dc->ccr = TXX9_DMA_CCR_IMMCHN | TXX9_DMA_CCR_INTENE | CCR_LE;
1016 	txx9dmac_chan_set_SMPCHN(dc);
1017 	if (!txx9_dma_have_SMPCHN() || (dc->ccr & TXX9_DMA_CCR_SMPCHN))
1018 		dc->ccr |= TXX9_DMA_CCR_INTENC;
1019 	if (chan->device->device_prep_dma_memcpy) {
1020 		if (ds)
1021 			return -EINVAL;
1022 		dc->ccr |= TXX9_DMA_CCR_XFSZ_X8;
1023 	} else {
1024 		if (!ds ||
1025 		    (ds->tx_reg && ds->rx_reg) || (!ds->tx_reg && !ds->rx_reg))
1026 			return -EINVAL;
1027 		dc->ccr |= TXX9_DMA_CCR_EXTRQ |
1028 			TXX9_DMA_CCR_XFSZ(__ffs(ds->reg_width));
1029 		txx9dmac_chan_set_INTENT(dc);
1030 	}
1031 
1032 	spin_lock_bh(&dc->lock);
1033 	i = dc->descs_allocated;
1034 	while (dc->descs_allocated < TXX9_DMA_INITIAL_DESC_COUNT) {
1035 		spin_unlock_bh(&dc->lock);
1036 
1037 		desc = txx9dmac_desc_alloc(dc, GFP_KERNEL);
1038 		if (!desc) {
1039 			dev_info(chan2dev(chan),
1040 				"only allocated %d descriptors\n", i);
1041 			spin_lock_bh(&dc->lock);
1042 			break;
1043 		}
1044 		txx9dmac_desc_put(dc, desc);
1045 
1046 		spin_lock_bh(&dc->lock);
1047 		i = ++dc->descs_allocated;
1048 	}
1049 	spin_unlock_bh(&dc->lock);
1050 
1051 	dev_dbg(chan2dev(chan),
1052 		"alloc_chan_resources allocated %d descriptors\n", i);
1053 
1054 	return i;
1055 }
1056 
1057 static void txx9dmac_free_chan_resources(struct dma_chan *chan)
1058 {
1059 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1060 	struct txx9dmac_dev *ddev = dc->ddev;
1061 	struct txx9dmac_desc *desc, *_desc;
1062 	LIST_HEAD(list);
1063 
1064 	dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
1065 			dc->descs_allocated);
1066 
1067 	/* ASSERT:  channel is idle */
1068 	BUG_ON(!list_empty(&dc->active_list));
1069 	BUG_ON(!list_empty(&dc->queue));
1070 	BUG_ON(channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT);
1071 
1072 	spin_lock_bh(&dc->lock);
1073 	list_splice_init(&dc->free_list, &list);
1074 	dc->descs_allocated = 0;
1075 	spin_unlock_bh(&dc->lock);
1076 
1077 	list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1078 		dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1079 		dma_unmap_single(chan2parent(chan), desc->txd.phys,
1080 				 ddev->descsize, DMA_TO_DEVICE);
1081 		kfree(desc);
1082 	}
1083 
1084 	dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
1085 }
1086 
1087 /*----------------------------------------------------------------------*/
1088 
1089 static void txx9dmac_off(struct txx9dmac_dev *ddev)
1090 {
1091 	dma_writel(ddev, MCR, 0);
1092 	mmiowb();
1093 }
1094 
1095 static int __init txx9dmac_chan_probe(struct platform_device *pdev)
1096 {
1097 	struct txx9dmac_chan_platform_data *cpdata =
1098 			dev_get_platdata(&pdev->dev);
1099 	struct platform_device *dmac_dev = cpdata->dmac_dev;
1100 	struct txx9dmac_platform_data *pdata = dev_get_platdata(&dmac_dev->dev);
1101 	struct txx9dmac_chan *dc;
1102 	int err;
1103 	int ch = pdev->id % TXX9_DMA_MAX_NR_CHANNELS;
1104 	int irq;
1105 
1106 	dc = devm_kzalloc(&pdev->dev, sizeof(*dc), GFP_KERNEL);
1107 	if (!dc)
1108 		return -ENOMEM;
1109 
1110 	dc->dma.dev = &pdev->dev;
1111 	dc->dma.device_alloc_chan_resources = txx9dmac_alloc_chan_resources;
1112 	dc->dma.device_free_chan_resources = txx9dmac_free_chan_resources;
1113 	dc->dma.device_control = txx9dmac_control;
1114 	dc->dma.device_tx_status = txx9dmac_tx_status;
1115 	dc->dma.device_issue_pending = txx9dmac_issue_pending;
1116 	if (pdata && pdata->memcpy_chan == ch) {
1117 		dc->dma.device_prep_dma_memcpy = txx9dmac_prep_dma_memcpy;
1118 		dma_cap_set(DMA_MEMCPY, dc->dma.cap_mask);
1119 	} else {
1120 		dc->dma.device_prep_slave_sg = txx9dmac_prep_slave_sg;
1121 		dma_cap_set(DMA_SLAVE, dc->dma.cap_mask);
1122 		dma_cap_set(DMA_PRIVATE, dc->dma.cap_mask);
1123 	}
1124 
1125 	INIT_LIST_HEAD(&dc->dma.channels);
1126 	dc->ddev = platform_get_drvdata(dmac_dev);
1127 	if (dc->ddev->irq < 0) {
1128 		irq = platform_get_irq(pdev, 0);
1129 		if (irq < 0)
1130 			return irq;
1131 		tasklet_init(&dc->tasklet, txx9dmac_chan_tasklet,
1132 				(unsigned long)dc);
1133 		dc->irq = irq;
1134 		err = devm_request_irq(&pdev->dev, dc->irq,
1135 			txx9dmac_chan_interrupt, 0, dev_name(&pdev->dev), dc);
1136 		if (err)
1137 			return err;
1138 	} else
1139 		dc->irq = -1;
1140 	dc->ddev->chan[ch] = dc;
1141 	dc->chan.device = &dc->dma;
1142 	list_add_tail(&dc->chan.device_node, &dc->chan.device->channels);
1143 	dma_cookie_init(&dc->chan);
1144 
1145 	if (is_dmac64(dc))
1146 		dc->ch_regs = &__txx9dmac_regs(dc->ddev)->CHAN[ch];
1147 	else
1148 		dc->ch_regs = &__txx9dmac_regs32(dc->ddev)->CHAN[ch];
1149 	spin_lock_init(&dc->lock);
1150 
1151 	INIT_LIST_HEAD(&dc->active_list);
1152 	INIT_LIST_HEAD(&dc->queue);
1153 	INIT_LIST_HEAD(&dc->free_list);
1154 
1155 	txx9dmac_reset_chan(dc);
1156 
1157 	platform_set_drvdata(pdev, dc);
1158 
1159 	err = dma_async_device_register(&dc->dma);
1160 	if (err)
1161 		return err;
1162 	dev_dbg(&pdev->dev, "TXx9 DMA Channel (dma%d%s%s)\n",
1163 		dc->dma.dev_id,
1164 		dma_has_cap(DMA_MEMCPY, dc->dma.cap_mask) ? " memcpy" : "",
1165 		dma_has_cap(DMA_SLAVE, dc->dma.cap_mask) ? " slave" : "");
1166 
1167 	return 0;
1168 }
1169 
1170 static int txx9dmac_chan_remove(struct platform_device *pdev)
1171 {
1172 	struct txx9dmac_chan *dc = platform_get_drvdata(pdev);
1173 
1174 	dma_async_device_unregister(&dc->dma);
1175 	if (dc->irq >= 0)
1176 		tasklet_kill(&dc->tasklet);
1177 	dc->ddev->chan[pdev->id % TXX9_DMA_MAX_NR_CHANNELS] = NULL;
1178 	return 0;
1179 }
1180 
1181 static int __init txx9dmac_probe(struct platform_device *pdev)
1182 {
1183 	struct txx9dmac_platform_data *pdata = dev_get_platdata(&pdev->dev);
1184 	struct resource *io;
1185 	struct txx9dmac_dev *ddev;
1186 	u32 mcr;
1187 	int err;
1188 
1189 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1190 	if (!io)
1191 		return -EINVAL;
1192 
1193 	ddev = devm_kzalloc(&pdev->dev, sizeof(*ddev), GFP_KERNEL);
1194 	if (!ddev)
1195 		return -ENOMEM;
1196 
1197 	if (!devm_request_mem_region(&pdev->dev, io->start, resource_size(io),
1198 				     dev_name(&pdev->dev)))
1199 		return -EBUSY;
1200 
1201 	ddev->regs = devm_ioremap(&pdev->dev, io->start, resource_size(io));
1202 	if (!ddev->regs)
1203 		return -ENOMEM;
1204 	ddev->have_64bit_regs = pdata->have_64bit_regs;
1205 	if (__is_dmac64(ddev))
1206 		ddev->descsize = sizeof(struct txx9dmac_hwdesc);
1207 	else
1208 		ddev->descsize = sizeof(struct txx9dmac_hwdesc32);
1209 
1210 	/* force dma off, just in case */
1211 	txx9dmac_off(ddev);
1212 
1213 	ddev->irq = platform_get_irq(pdev, 0);
1214 	if (ddev->irq >= 0) {
1215 		tasklet_init(&ddev->tasklet, txx9dmac_tasklet,
1216 				(unsigned long)ddev);
1217 		err = devm_request_irq(&pdev->dev, ddev->irq,
1218 			txx9dmac_interrupt, 0, dev_name(&pdev->dev), ddev);
1219 		if (err)
1220 			return err;
1221 	}
1222 
1223 	mcr = TXX9_DMA_MCR_MSTEN | MCR_LE;
1224 	if (pdata && pdata->memcpy_chan >= 0)
1225 		mcr |= TXX9_DMA_MCR_FIFUM(pdata->memcpy_chan);
1226 	dma_writel(ddev, MCR, mcr);
1227 
1228 	platform_set_drvdata(pdev, ddev);
1229 	return 0;
1230 }
1231 
1232 static int txx9dmac_remove(struct platform_device *pdev)
1233 {
1234 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1235 
1236 	txx9dmac_off(ddev);
1237 	if (ddev->irq >= 0)
1238 		tasklet_kill(&ddev->tasklet);
1239 	return 0;
1240 }
1241 
1242 static void txx9dmac_shutdown(struct platform_device *pdev)
1243 {
1244 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1245 
1246 	txx9dmac_off(ddev);
1247 }
1248 
1249 static int txx9dmac_suspend_noirq(struct device *dev)
1250 {
1251 	struct platform_device *pdev = to_platform_device(dev);
1252 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1253 
1254 	txx9dmac_off(ddev);
1255 	return 0;
1256 }
1257 
1258 static int txx9dmac_resume_noirq(struct device *dev)
1259 {
1260 	struct platform_device *pdev = to_platform_device(dev);
1261 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1262 	struct txx9dmac_platform_data *pdata = dev_get_platdata(&pdev->dev);
1263 	u32 mcr;
1264 
1265 	mcr = TXX9_DMA_MCR_MSTEN | MCR_LE;
1266 	if (pdata && pdata->memcpy_chan >= 0)
1267 		mcr |= TXX9_DMA_MCR_FIFUM(pdata->memcpy_chan);
1268 	dma_writel(ddev, MCR, mcr);
1269 	return 0;
1270 
1271 }
1272 
1273 static const struct dev_pm_ops txx9dmac_dev_pm_ops = {
1274 	.suspend_noirq = txx9dmac_suspend_noirq,
1275 	.resume_noirq = txx9dmac_resume_noirq,
1276 };
1277 
1278 static struct platform_driver txx9dmac_chan_driver = {
1279 	.remove		= txx9dmac_chan_remove,
1280 	.driver = {
1281 		.name	= "txx9dmac-chan",
1282 	},
1283 };
1284 
1285 static struct platform_driver txx9dmac_driver = {
1286 	.remove		= txx9dmac_remove,
1287 	.shutdown	= txx9dmac_shutdown,
1288 	.driver = {
1289 		.name	= "txx9dmac",
1290 		.pm	= &txx9dmac_dev_pm_ops,
1291 	},
1292 };
1293 
1294 static int __init txx9dmac_init(void)
1295 {
1296 	int rc;
1297 
1298 	rc = platform_driver_probe(&txx9dmac_driver, txx9dmac_probe);
1299 	if (!rc) {
1300 		rc = platform_driver_probe(&txx9dmac_chan_driver,
1301 					   txx9dmac_chan_probe);
1302 		if (rc)
1303 			platform_driver_unregister(&txx9dmac_driver);
1304 	}
1305 	return rc;
1306 }
1307 module_init(txx9dmac_init);
1308 
1309 static void __exit txx9dmac_exit(void)
1310 {
1311 	platform_driver_unregister(&txx9dmac_chan_driver);
1312 	platform_driver_unregister(&txx9dmac_driver);
1313 }
1314 module_exit(txx9dmac_exit);
1315 
1316 MODULE_LICENSE("GPL");
1317 MODULE_DESCRIPTION("TXx9 DMA Controller driver");
1318 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
1319 MODULE_ALIAS("platform:txx9dmac");
1320 MODULE_ALIAS("platform:txx9dmac-chan");
1321