xref: /openbmc/linux/drivers/dma/txx9dmac.c (revision 63dc02bd)
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 	if (!ds) {
423 		dma_addr_t dmaaddr;
424 		if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
425 			dmaaddr = is_dmac64(dc) ?
426 				desc->hwdesc.DAR : desc->hwdesc32.DAR;
427 			if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
428 				dma_unmap_single(chan2parent(&dc->chan),
429 					dmaaddr, desc->len, DMA_FROM_DEVICE);
430 			else
431 				dma_unmap_page(chan2parent(&dc->chan),
432 					dmaaddr, desc->len, DMA_FROM_DEVICE);
433 		}
434 		if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
435 			dmaaddr = is_dmac64(dc) ?
436 				desc->hwdesc.SAR : desc->hwdesc32.SAR;
437 			if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
438 				dma_unmap_single(chan2parent(&dc->chan),
439 					dmaaddr, desc->len, DMA_TO_DEVICE);
440 			else
441 				dma_unmap_page(chan2parent(&dc->chan),
442 					dmaaddr, desc->len, DMA_TO_DEVICE);
443 		}
444 	}
445 
446 	/*
447 	 * The API requires that no submissions are done from a
448 	 * callback, so we don't need to drop the lock here
449 	 */
450 	if (callback)
451 		callback(param);
452 	dma_run_dependencies(txd);
453 }
454 
455 static void txx9dmac_dequeue(struct txx9dmac_chan *dc, struct list_head *list)
456 {
457 	struct txx9dmac_dev *ddev = dc->ddev;
458 	struct txx9dmac_desc *desc;
459 	struct txx9dmac_desc *prev = NULL;
460 
461 	BUG_ON(!list_empty(list));
462 	do {
463 		desc = txx9dmac_first_queued(dc);
464 		if (prev) {
465 			desc_write_CHAR(dc, prev, desc->txd.phys);
466 			dma_sync_single_for_device(chan2parent(&dc->chan),
467 				prev->txd.phys, ddev->descsize,
468 				DMA_TO_DEVICE);
469 		}
470 		prev = txx9dmac_last_child(desc);
471 		list_move_tail(&desc->desc_node, list);
472 		/* Make chain-completion interrupt happen */
473 		if ((desc->txd.flags & DMA_PREP_INTERRUPT) &&
474 		    !txx9dmac_chan_INTENT(dc))
475 			break;
476 	} while (!list_empty(&dc->queue));
477 }
478 
479 static void txx9dmac_complete_all(struct txx9dmac_chan *dc)
480 {
481 	struct txx9dmac_desc *desc, *_desc;
482 	LIST_HEAD(list);
483 
484 	/*
485 	 * Submit queued descriptors ASAP, i.e. before we go through
486 	 * the completed ones.
487 	 */
488 	list_splice_init(&dc->active_list, &list);
489 	if (!list_empty(&dc->queue)) {
490 		txx9dmac_dequeue(dc, &dc->active_list);
491 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
492 	}
493 
494 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
495 		txx9dmac_descriptor_complete(dc, desc);
496 }
497 
498 static void txx9dmac_dump_desc(struct txx9dmac_chan *dc,
499 			       struct txx9dmac_hwdesc *desc)
500 {
501 	if (is_dmac64(dc)) {
502 #ifdef TXX9_DMA_USE_SIMPLE_CHAIN
503 		dev_crit(chan2dev(&dc->chan),
504 			 "  desc: ch%#llx s%#llx d%#llx c%#x\n",
505 			 (u64)desc->CHAR, desc->SAR, desc->DAR, desc->CNTR);
506 #else
507 		dev_crit(chan2dev(&dc->chan),
508 			 "  desc: ch%#llx s%#llx d%#llx c%#x"
509 			 " si%#x di%#x cc%#x cs%#x\n",
510 			 (u64)desc->CHAR, desc->SAR, desc->DAR, desc->CNTR,
511 			 desc->SAIR, desc->DAIR, desc->CCR, desc->CSR);
512 #endif
513 	} else {
514 		struct txx9dmac_hwdesc32 *d = (struct txx9dmac_hwdesc32 *)desc;
515 #ifdef TXX9_DMA_USE_SIMPLE_CHAIN
516 		dev_crit(chan2dev(&dc->chan),
517 			 "  desc: ch%#x s%#x d%#x c%#x\n",
518 			 d->CHAR, d->SAR, d->DAR, d->CNTR);
519 #else
520 		dev_crit(chan2dev(&dc->chan),
521 			 "  desc: ch%#x s%#x d%#x c%#x"
522 			 " si%#x di%#x cc%#x cs%#x\n",
523 			 d->CHAR, d->SAR, d->DAR, d->CNTR,
524 			 d->SAIR, d->DAIR, d->CCR, d->CSR);
525 #endif
526 	}
527 }
528 
529 static void txx9dmac_handle_error(struct txx9dmac_chan *dc, u32 csr)
530 {
531 	struct txx9dmac_desc *bad_desc;
532 	struct txx9dmac_desc *child;
533 	u32 errors;
534 
535 	/*
536 	 * The descriptor currently at the head of the active list is
537 	 * borked. Since we don't have any way to report errors, we'll
538 	 * just have to scream loudly and try to carry on.
539 	 */
540 	dev_crit(chan2dev(&dc->chan), "Abnormal Chain Completion\n");
541 	txx9dmac_dump_regs(dc);
542 
543 	bad_desc = txx9dmac_first_active(dc);
544 	list_del_init(&bad_desc->desc_node);
545 
546 	/* Clear all error flags and try to restart the controller */
547 	errors = csr & (TXX9_DMA_CSR_ABCHC |
548 			TXX9_DMA_CSR_CFERR | TXX9_DMA_CSR_CHERR |
549 			TXX9_DMA_CSR_DESERR | TXX9_DMA_CSR_SORERR);
550 	channel_writel(dc, CSR, errors);
551 
552 	if (list_empty(&dc->active_list) && !list_empty(&dc->queue))
553 		txx9dmac_dequeue(dc, &dc->active_list);
554 	if (!list_empty(&dc->active_list))
555 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
556 
557 	dev_crit(chan2dev(&dc->chan),
558 		 "Bad descriptor submitted for DMA! (cookie: %d)\n",
559 		 bad_desc->txd.cookie);
560 	txx9dmac_dump_desc(dc, &bad_desc->hwdesc);
561 	list_for_each_entry(child, &bad_desc->tx_list, desc_node)
562 		txx9dmac_dump_desc(dc, &child->hwdesc);
563 	/* Pretend the descriptor completed successfully */
564 	txx9dmac_descriptor_complete(dc, bad_desc);
565 }
566 
567 static void txx9dmac_scan_descriptors(struct txx9dmac_chan *dc)
568 {
569 	dma_addr_t chain;
570 	struct txx9dmac_desc *desc, *_desc;
571 	struct txx9dmac_desc *child;
572 	u32 csr;
573 
574 	if (is_dmac64(dc)) {
575 		chain = channel64_read_CHAR(dc);
576 		csr = channel64_readl(dc, CSR);
577 		channel64_writel(dc, CSR, csr);
578 	} else {
579 		chain = channel32_readl(dc, CHAR);
580 		csr = channel32_readl(dc, CSR);
581 		channel32_writel(dc, CSR, csr);
582 	}
583 	/* For dynamic chain, we should look at XFACT instead of NCHNC */
584 	if (!(csr & (TXX9_DMA_CSR_XFACT | TXX9_DMA_CSR_ABCHC))) {
585 		/* Everything we've submitted is done */
586 		txx9dmac_complete_all(dc);
587 		return;
588 	}
589 	if (!(csr & TXX9_DMA_CSR_CHNEN))
590 		chain = 0;	/* last descriptor of this chain */
591 
592 	dev_vdbg(chan2dev(&dc->chan), "scan_descriptors: char=%#llx\n",
593 		 (u64)chain);
594 
595 	list_for_each_entry_safe(desc, _desc, &dc->active_list, desc_node) {
596 		if (desc_read_CHAR(dc, desc) == chain) {
597 			/* This one is currently in progress */
598 			if (csr & TXX9_DMA_CSR_ABCHC)
599 				goto scan_done;
600 			return;
601 		}
602 
603 		list_for_each_entry(child, &desc->tx_list, desc_node)
604 			if (desc_read_CHAR(dc, child) == chain) {
605 				/* Currently in progress */
606 				if (csr & TXX9_DMA_CSR_ABCHC)
607 					goto scan_done;
608 				return;
609 			}
610 
611 		/*
612 		 * No descriptors so far seem to be in progress, i.e.
613 		 * this one must be done.
614 		 */
615 		txx9dmac_descriptor_complete(dc, desc);
616 	}
617 scan_done:
618 	if (csr & TXX9_DMA_CSR_ABCHC) {
619 		txx9dmac_handle_error(dc, csr);
620 		return;
621 	}
622 
623 	dev_err(chan2dev(&dc->chan),
624 		"BUG: All descriptors done, but channel not idle!\n");
625 
626 	/* Try to continue after resetting the channel... */
627 	txx9dmac_reset_chan(dc);
628 
629 	if (!list_empty(&dc->queue)) {
630 		txx9dmac_dequeue(dc, &dc->active_list);
631 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
632 	}
633 }
634 
635 static void txx9dmac_chan_tasklet(unsigned long data)
636 {
637 	int irq;
638 	u32 csr;
639 	struct txx9dmac_chan *dc;
640 
641 	dc = (struct txx9dmac_chan *)data;
642 	csr = channel_readl(dc, CSR);
643 	dev_vdbg(chan2dev(&dc->chan), "tasklet: status=%x\n", csr);
644 
645 	spin_lock(&dc->lock);
646 	if (csr & (TXX9_DMA_CSR_ABCHC | TXX9_DMA_CSR_NCHNC |
647 		   TXX9_DMA_CSR_NTRNFC))
648 		txx9dmac_scan_descriptors(dc);
649 	spin_unlock(&dc->lock);
650 	irq = dc->irq;
651 
652 	enable_irq(irq);
653 }
654 
655 static irqreturn_t txx9dmac_chan_interrupt(int irq, void *dev_id)
656 {
657 	struct txx9dmac_chan *dc = dev_id;
658 
659 	dev_vdbg(chan2dev(&dc->chan), "interrupt: status=%#x\n",
660 			channel_readl(dc, CSR));
661 
662 	tasklet_schedule(&dc->tasklet);
663 	/*
664 	 * Just disable the interrupts. We'll turn them back on in the
665 	 * softirq handler.
666 	 */
667 	disable_irq_nosync(irq);
668 
669 	return IRQ_HANDLED;
670 }
671 
672 static void txx9dmac_tasklet(unsigned long data)
673 {
674 	int irq;
675 	u32 csr;
676 	struct txx9dmac_chan *dc;
677 
678 	struct txx9dmac_dev *ddev = (struct txx9dmac_dev *)data;
679 	u32 mcr;
680 	int i;
681 
682 	mcr = dma_readl(ddev, MCR);
683 	dev_vdbg(ddev->chan[0]->dma.dev, "tasklet: mcr=%x\n", mcr);
684 	for (i = 0; i < TXX9_DMA_MAX_NR_CHANNELS; i++) {
685 		if ((mcr >> (24 + i)) & 0x11) {
686 			dc = ddev->chan[i];
687 			csr = channel_readl(dc, CSR);
688 			dev_vdbg(chan2dev(&dc->chan), "tasklet: status=%x\n",
689 				 csr);
690 			spin_lock(&dc->lock);
691 			if (csr & (TXX9_DMA_CSR_ABCHC | TXX9_DMA_CSR_NCHNC |
692 				   TXX9_DMA_CSR_NTRNFC))
693 				txx9dmac_scan_descriptors(dc);
694 			spin_unlock(&dc->lock);
695 		}
696 	}
697 	irq = ddev->irq;
698 
699 	enable_irq(irq);
700 }
701 
702 static irqreturn_t txx9dmac_interrupt(int irq, void *dev_id)
703 {
704 	struct txx9dmac_dev *ddev = dev_id;
705 
706 	dev_vdbg(ddev->chan[0]->dma.dev, "interrupt: status=%#x\n",
707 			dma_readl(ddev, MCR));
708 
709 	tasklet_schedule(&ddev->tasklet);
710 	/*
711 	 * Just disable the interrupts. We'll turn them back on in the
712 	 * softirq handler.
713 	 */
714 	disable_irq_nosync(irq);
715 
716 	return IRQ_HANDLED;
717 }
718 
719 /*----------------------------------------------------------------------*/
720 
721 static dma_cookie_t txx9dmac_tx_submit(struct dma_async_tx_descriptor *tx)
722 {
723 	struct txx9dmac_desc *desc = txd_to_txx9dmac_desc(tx);
724 	struct txx9dmac_chan *dc = to_txx9dmac_chan(tx->chan);
725 	dma_cookie_t cookie;
726 
727 	spin_lock_bh(&dc->lock);
728 	cookie = dma_cookie_assign(tx);
729 
730 	dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u %p\n",
731 		 desc->txd.cookie, desc);
732 
733 	list_add_tail(&desc->desc_node, &dc->queue);
734 	spin_unlock_bh(&dc->lock);
735 
736 	return cookie;
737 }
738 
739 static struct dma_async_tx_descriptor *
740 txx9dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
741 		size_t len, unsigned long flags)
742 {
743 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
744 	struct txx9dmac_dev *ddev = dc->ddev;
745 	struct txx9dmac_desc *desc;
746 	struct txx9dmac_desc *first;
747 	struct txx9dmac_desc *prev;
748 	size_t xfer_count;
749 	size_t offset;
750 
751 	dev_vdbg(chan2dev(chan), "prep_dma_memcpy d%#llx s%#llx l%#zx f%#lx\n",
752 		 (u64)dest, (u64)src, len, flags);
753 
754 	if (unlikely(!len)) {
755 		dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
756 		return NULL;
757 	}
758 
759 	prev = first = NULL;
760 
761 	for (offset = 0; offset < len; offset += xfer_count) {
762 		xfer_count = min_t(size_t, len - offset, TXX9_DMA_MAX_COUNT);
763 		/*
764 		 * Workaround for ERT-TX49H2-033, ERT-TX49H3-020,
765 		 * ERT-TX49H4-016 (slightly conservative)
766 		 */
767 		if (__is_dmac64(ddev)) {
768 			if (xfer_count > 0x100 &&
769 			    (xfer_count & 0xff) >= 0xfa &&
770 			    (xfer_count & 0xff) <= 0xff)
771 				xfer_count -= 0x20;
772 		} else {
773 			if (xfer_count > 0x80 &&
774 			    (xfer_count & 0x7f) >= 0x7e &&
775 			    (xfer_count & 0x7f) <= 0x7f)
776 				xfer_count -= 0x20;
777 		}
778 
779 		desc = txx9dmac_desc_get(dc);
780 		if (!desc) {
781 			txx9dmac_desc_put(dc, first);
782 			return NULL;
783 		}
784 
785 		if (__is_dmac64(ddev)) {
786 			desc->hwdesc.SAR = src + offset;
787 			desc->hwdesc.DAR = dest + offset;
788 			desc->hwdesc.CNTR = xfer_count;
789 			txx9dmac_desc_set_nosimple(ddev, desc, 8, 8,
790 					dc->ccr | TXX9_DMA_CCR_XFACT);
791 		} else {
792 			desc->hwdesc32.SAR = src + offset;
793 			desc->hwdesc32.DAR = dest + offset;
794 			desc->hwdesc32.CNTR = xfer_count;
795 			txx9dmac_desc_set_nosimple(ddev, desc, 4, 4,
796 					dc->ccr | TXX9_DMA_CCR_XFACT);
797 		}
798 
799 		/*
800 		 * The descriptors on tx_list are not reachable from
801 		 * the dc->queue list or dc->active_list after a
802 		 * submit.  If we put all descriptors on active_list,
803 		 * calling of callback on the completion will be more
804 		 * complex.
805 		 */
806 		if (!first) {
807 			first = desc;
808 		} else {
809 			desc_write_CHAR(dc, prev, desc->txd.phys);
810 			dma_sync_single_for_device(chan2parent(&dc->chan),
811 					prev->txd.phys, ddev->descsize,
812 					DMA_TO_DEVICE);
813 			list_add_tail(&desc->desc_node, &first->tx_list);
814 		}
815 		prev = desc;
816 	}
817 
818 	/* Trigger interrupt after last block */
819 	if (flags & DMA_PREP_INTERRUPT)
820 		txx9dmac_desc_set_INTENT(ddev, prev);
821 
822 	desc_write_CHAR(dc, prev, 0);
823 	dma_sync_single_for_device(chan2parent(&dc->chan),
824 			prev->txd.phys, ddev->descsize,
825 			DMA_TO_DEVICE);
826 
827 	first->txd.flags = flags;
828 	first->len = len;
829 
830 	return &first->txd;
831 }
832 
833 static struct dma_async_tx_descriptor *
834 txx9dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
835 		unsigned int sg_len, enum dma_transfer_direction direction,
836 		unsigned long flags, void *context)
837 {
838 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
839 	struct txx9dmac_dev *ddev = dc->ddev;
840 	struct txx9dmac_slave *ds = chan->private;
841 	struct txx9dmac_desc *prev;
842 	struct txx9dmac_desc *first;
843 	unsigned int i;
844 	struct scatterlist *sg;
845 
846 	dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
847 
848 	BUG_ON(!ds || !ds->reg_width);
849 	if (ds->tx_reg)
850 		BUG_ON(direction != DMA_MEM_TO_DEV);
851 	else
852 		BUG_ON(direction != DMA_DEV_TO_MEM);
853 	if (unlikely(!sg_len))
854 		return NULL;
855 
856 	prev = first = NULL;
857 
858 	for_each_sg(sgl, sg, sg_len, i) {
859 		struct txx9dmac_desc *desc;
860 		dma_addr_t mem;
861 		u32 sai, dai;
862 
863 		desc = txx9dmac_desc_get(dc);
864 		if (!desc) {
865 			txx9dmac_desc_put(dc, first);
866 			return NULL;
867 		}
868 
869 		mem = sg_dma_address(sg);
870 
871 		if (__is_dmac64(ddev)) {
872 			if (direction == DMA_MEM_TO_DEV) {
873 				desc->hwdesc.SAR = mem;
874 				desc->hwdesc.DAR = ds->tx_reg;
875 			} else {
876 				desc->hwdesc.SAR = ds->rx_reg;
877 				desc->hwdesc.DAR = mem;
878 			}
879 			desc->hwdesc.CNTR = sg_dma_len(sg);
880 		} else {
881 			if (direction == DMA_MEM_TO_DEV) {
882 				desc->hwdesc32.SAR = mem;
883 				desc->hwdesc32.DAR = ds->tx_reg;
884 			} else {
885 				desc->hwdesc32.SAR = ds->rx_reg;
886 				desc->hwdesc32.DAR = mem;
887 			}
888 			desc->hwdesc32.CNTR = sg_dma_len(sg);
889 		}
890 		if (direction == DMA_MEM_TO_DEV) {
891 			sai = ds->reg_width;
892 			dai = 0;
893 		} else {
894 			sai = 0;
895 			dai = ds->reg_width;
896 		}
897 		txx9dmac_desc_set_nosimple(ddev, desc, sai, dai,
898 					dc->ccr | TXX9_DMA_CCR_XFACT);
899 
900 		if (!first) {
901 			first = desc;
902 		} else {
903 			desc_write_CHAR(dc, prev, desc->txd.phys);
904 			dma_sync_single_for_device(chan2parent(&dc->chan),
905 					prev->txd.phys,
906 					ddev->descsize,
907 					DMA_TO_DEVICE);
908 			list_add_tail(&desc->desc_node, &first->tx_list);
909 		}
910 		prev = desc;
911 	}
912 
913 	/* Trigger interrupt after last block */
914 	if (flags & DMA_PREP_INTERRUPT)
915 		txx9dmac_desc_set_INTENT(ddev, prev);
916 
917 	desc_write_CHAR(dc, prev, 0);
918 	dma_sync_single_for_device(chan2parent(&dc->chan),
919 			prev->txd.phys, ddev->descsize,
920 			DMA_TO_DEVICE);
921 
922 	first->txd.flags = flags;
923 	first->len = 0;
924 
925 	return &first->txd;
926 }
927 
928 static int txx9dmac_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
929 			    unsigned long arg)
930 {
931 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
932 	struct txx9dmac_desc *desc, *_desc;
933 	LIST_HEAD(list);
934 
935 	/* Only supports DMA_TERMINATE_ALL */
936 	if (cmd != DMA_TERMINATE_ALL)
937 		return -EINVAL;
938 
939 	dev_vdbg(chan2dev(chan), "terminate_all\n");
940 	spin_lock_bh(&dc->lock);
941 
942 	txx9dmac_reset_chan(dc);
943 
944 	/* active_list entries will end up before queued entries */
945 	list_splice_init(&dc->queue, &list);
946 	list_splice_init(&dc->active_list, &list);
947 
948 	spin_unlock_bh(&dc->lock);
949 
950 	/* Flush all pending and queued descriptors */
951 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
952 		txx9dmac_descriptor_complete(dc, desc);
953 
954 	return 0;
955 }
956 
957 static enum dma_status
958 txx9dmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
959 		   struct dma_tx_state *txstate)
960 {
961 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
962 	enum dma_status ret;
963 
964 	ret = dma_cookie_status(chan, cookie, txstate);
965 	if (ret != DMA_SUCCESS) {
966 		spin_lock_bh(&dc->lock);
967 		txx9dmac_scan_descriptors(dc);
968 		spin_unlock_bh(&dc->lock);
969 
970 		ret = dma_cookie_status(chan, cookie, txstate);
971 	}
972 
973 	return ret;
974 }
975 
976 static void txx9dmac_chain_dynamic(struct txx9dmac_chan *dc,
977 				   struct txx9dmac_desc *prev)
978 {
979 	struct txx9dmac_dev *ddev = dc->ddev;
980 	struct txx9dmac_desc *desc;
981 	LIST_HEAD(list);
982 
983 	prev = txx9dmac_last_child(prev);
984 	txx9dmac_dequeue(dc, &list);
985 	desc = list_entry(list.next, struct txx9dmac_desc, desc_node);
986 	desc_write_CHAR(dc, prev, desc->txd.phys);
987 	dma_sync_single_for_device(chan2parent(&dc->chan),
988 				   prev->txd.phys, ddev->descsize,
989 				   DMA_TO_DEVICE);
990 	mmiowb();
991 	if (!(channel_readl(dc, CSR) & TXX9_DMA_CSR_CHNEN) &&
992 	    channel_read_CHAR(dc) == prev->txd.phys)
993 		/* Restart chain DMA */
994 		channel_write_CHAR(dc, desc->txd.phys);
995 	list_splice_tail(&list, &dc->active_list);
996 }
997 
998 static void txx9dmac_issue_pending(struct dma_chan *chan)
999 {
1000 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1001 
1002 	spin_lock_bh(&dc->lock);
1003 
1004 	if (!list_empty(&dc->active_list))
1005 		txx9dmac_scan_descriptors(dc);
1006 	if (!list_empty(&dc->queue)) {
1007 		if (list_empty(&dc->active_list)) {
1008 			txx9dmac_dequeue(dc, &dc->active_list);
1009 			txx9dmac_dostart(dc, txx9dmac_first_active(dc));
1010 		} else if (txx9_dma_have_SMPCHN()) {
1011 			struct txx9dmac_desc *prev = txx9dmac_last_active(dc);
1012 
1013 			if (!(prev->txd.flags & DMA_PREP_INTERRUPT) ||
1014 			    txx9dmac_chan_INTENT(dc))
1015 				txx9dmac_chain_dynamic(dc, prev);
1016 		}
1017 	}
1018 
1019 	spin_unlock_bh(&dc->lock);
1020 }
1021 
1022 static int txx9dmac_alloc_chan_resources(struct dma_chan *chan)
1023 {
1024 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1025 	struct txx9dmac_slave *ds = chan->private;
1026 	struct txx9dmac_desc *desc;
1027 	int i;
1028 
1029 	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
1030 
1031 	/* ASSERT:  channel is idle */
1032 	if (channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT) {
1033 		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1034 		return -EIO;
1035 	}
1036 
1037 	dma_cookie_init(chan);
1038 
1039 	dc->ccr = TXX9_DMA_CCR_IMMCHN | TXX9_DMA_CCR_INTENE | CCR_LE;
1040 	txx9dmac_chan_set_SMPCHN(dc);
1041 	if (!txx9_dma_have_SMPCHN() || (dc->ccr & TXX9_DMA_CCR_SMPCHN))
1042 		dc->ccr |= TXX9_DMA_CCR_INTENC;
1043 	if (chan->device->device_prep_dma_memcpy) {
1044 		if (ds)
1045 			return -EINVAL;
1046 		dc->ccr |= TXX9_DMA_CCR_XFSZ_X8;
1047 	} else {
1048 		if (!ds ||
1049 		    (ds->tx_reg && ds->rx_reg) || (!ds->tx_reg && !ds->rx_reg))
1050 			return -EINVAL;
1051 		dc->ccr |= TXX9_DMA_CCR_EXTRQ |
1052 			TXX9_DMA_CCR_XFSZ(__ffs(ds->reg_width));
1053 		txx9dmac_chan_set_INTENT(dc);
1054 	}
1055 
1056 	spin_lock_bh(&dc->lock);
1057 	i = dc->descs_allocated;
1058 	while (dc->descs_allocated < TXX9_DMA_INITIAL_DESC_COUNT) {
1059 		spin_unlock_bh(&dc->lock);
1060 
1061 		desc = txx9dmac_desc_alloc(dc, GFP_KERNEL);
1062 		if (!desc) {
1063 			dev_info(chan2dev(chan),
1064 				"only allocated %d descriptors\n", i);
1065 			spin_lock_bh(&dc->lock);
1066 			break;
1067 		}
1068 		txx9dmac_desc_put(dc, desc);
1069 
1070 		spin_lock_bh(&dc->lock);
1071 		i = ++dc->descs_allocated;
1072 	}
1073 	spin_unlock_bh(&dc->lock);
1074 
1075 	dev_dbg(chan2dev(chan),
1076 		"alloc_chan_resources allocated %d descriptors\n", i);
1077 
1078 	return i;
1079 }
1080 
1081 static void txx9dmac_free_chan_resources(struct dma_chan *chan)
1082 {
1083 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1084 	struct txx9dmac_dev *ddev = dc->ddev;
1085 	struct txx9dmac_desc *desc, *_desc;
1086 	LIST_HEAD(list);
1087 
1088 	dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
1089 			dc->descs_allocated);
1090 
1091 	/* ASSERT:  channel is idle */
1092 	BUG_ON(!list_empty(&dc->active_list));
1093 	BUG_ON(!list_empty(&dc->queue));
1094 	BUG_ON(channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT);
1095 
1096 	spin_lock_bh(&dc->lock);
1097 	list_splice_init(&dc->free_list, &list);
1098 	dc->descs_allocated = 0;
1099 	spin_unlock_bh(&dc->lock);
1100 
1101 	list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1102 		dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1103 		dma_unmap_single(chan2parent(chan), desc->txd.phys,
1104 				 ddev->descsize, DMA_TO_DEVICE);
1105 		kfree(desc);
1106 	}
1107 
1108 	dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
1109 }
1110 
1111 /*----------------------------------------------------------------------*/
1112 
1113 static void txx9dmac_off(struct txx9dmac_dev *ddev)
1114 {
1115 	dma_writel(ddev, MCR, 0);
1116 	mmiowb();
1117 }
1118 
1119 static int __init txx9dmac_chan_probe(struct platform_device *pdev)
1120 {
1121 	struct txx9dmac_chan_platform_data *cpdata = pdev->dev.platform_data;
1122 	struct platform_device *dmac_dev = cpdata->dmac_dev;
1123 	struct txx9dmac_platform_data *pdata = dmac_dev->dev.platform_data;
1124 	struct txx9dmac_chan *dc;
1125 	int err;
1126 	int ch = pdev->id % TXX9_DMA_MAX_NR_CHANNELS;
1127 	int irq;
1128 
1129 	dc = devm_kzalloc(&pdev->dev, sizeof(*dc), GFP_KERNEL);
1130 	if (!dc)
1131 		return -ENOMEM;
1132 
1133 	dc->dma.dev = &pdev->dev;
1134 	dc->dma.device_alloc_chan_resources = txx9dmac_alloc_chan_resources;
1135 	dc->dma.device_free_chan_resources = txx9dmac_free_chan_resources;
1136 	dc->dma.device_control = txx9dmac_control;
1137 	dc->dma.device_tx_status = txx9dmac_tx_status;
1138 	dc->dma.device_issue_pending = txx9dmac_issue_pending;
1139 	if (pdata && pdata->memcpy_chan == ch) {
1140 		dc->dma.device_prep_dma_memcpy = txx9dmac_prep_dma_memcpy;
1141 		dma_cap_set(DMA_MEMCPY, dc->dma.cap_mask);
1142 	} else {
1143 		dc->dma.device_prep_slave_sg = txx9dmac_prep_slave_sg;
1144 		dma_cap_set(DMA_SLAVE, dc->dma.cap_mask);
1145 		dma_cap_set(DMA_PRIVATE, dc->dma.cap_mask);
1146 	}
1147 
1148 	INIT_LIST_HEAD(&dc->dma.channels);
1149 	dc->ddev = platform_get_drvdata(dmac_dev);
1150 	if (dc->ddev->irq < 0) {
1151 		irq = platform_get_irq(pdev, 0);
1152 		if (irq < 0)
1153 			return irq;
1154 		tasklet_init(&dc->tasklet, txx9dmac_chan_tasklet,
1155 				(unsigned long)dc);
1156 		dc->irq = irq;
1157 		err = devm_request_irq(&pdev->dev, dc->irq,
1158 			txx9dmac_chan_interrupt, 0, dev_name(&pdev->dev), dc);
1159 		if (err)
1160 			return err;
1161 	} else
1162 		dc->irq = -1;
1163 	dc->ddev->chan[ch] = dc;
1164 	dc->chan.device = &dc->dma;
1165 	list_add_tail(&dc->chan.device_node, &dc->chan.device->channels);
1166 	dma_cookie_init(&dc->chan);
1167 
1168 	if (is_dmac64(dc))
1169 		dc->ch_regs = &__txx9dmac_regs(dc->ddev)->CHAN[ch];
1170 	else
1171 		dc->ch_regs = &__txx9dmac_regs32(dc->ddev)->CHAN[ch];
1172 	spin_lock_init(&dc->lock);
1173 
1174 	INIT_LIST_HEAD(&dc->active_list);
1175 	INIT_LIST_HEAD(&dc->queue);
1176 	INIT_LIST_HEAD(&dc->free_list);
1177 
1178 	txx9dmac_reset_chan(dc);
1179 
1180 	platform_set_drvdata(pdev, dc);
1181 
1182 	err = dma_async_device_register(&dc->dma);
1183 	if (err)
1184 		return err;
1185 	dev_dbg(&pdev->dev, "TXx9 DMA Channel (dma%d%s%s)\n",
1186 		dc->dma.dev_id,
1187 		dma_has_cap(DMA_MEMCPY, dc->dma.cap_mask) ? " memcpy" : "",
1188 		dma_has_cap(DMA_SLAVE, dc->dma.cap_mask) ? " slave" : "");
1189 
1190 	return 0;
1191 }
1192 
1193 static int __exit txx9dmac_chan_remove(struct platform_device *pdev)
1194 {
1195 	struct txx9dmac_chan *dc = platform_get_drvdata(pdev);
1196 
1197 	dma_async_device_unregister(&dc->dma);
1198 	if (dc->irq >= 0)
1199 		tasklet_kill(&dc->tasklet);
1200 	dc->ddev->chan[pdev->id % TXX9_DMA_MAX_NR_CHANNELS] = NULL;
1201 	return 0;
1202 }
1203 
1204 static int __init txx9dmac_probe(struct platform_device *pdev)
1205 {
1206 	struct txx9dmac_platform_data *pdata = pdev->dev.platform_data;
1207 	struct resource *io;
1208 	struct txx9dmac_dev *ddev;
1209 	u32 mcr;
1210 	int err;
1211 
1212 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1213 	if (!io)
1214 		return -EINVAL;
1215 
1216 	ddev = devm_kzalloc(&pdev->dev, sizeof(*ddev), GFP_KERNEL);
1217 	if (!ddev)
1218 		return -ENOMEM;
1219 
1220 	if (!devm_request_mem_region(&pdev->dev, io->start, resource_size(io),
1221 				     dev_name(&pdev->dev)))
1222 		return -EBUSY;
1223 
1224 	ddev->regs = devm_ioremap(&pdev->dev, io->start, resource_size(io));
1225 	if (!ddev->regs)
1226 		return -ENOMEM;
1227 	ddev->have_64bit_regs = pdata->have_64bit_regs;
1228 	if (__is_dmac64(ddev))
1229 		ddev->descsize = sizeof(struct txx9dmac_hwdesc);
1230 	else
1231 		ddev->descsize = sizeof(struct txx9dmac_hwdesc32);
1232 
1233 	/* force dma off, just in case */
1234 	txx9dmac_off(ddev);
1235 
1236 	ddev->irq = platform_get_irq(pdev, 0);
1237 	if (ddev->irq >= 0) {
1238 		tasklet_init(&ddev->tasklet, txx9dmac_tasklet,
1239 				(unsigned long)ddev);
1240 		err = devm_request_irq(&pdev->dev, ddev->irq,
1241 			txx9dmac_interrupt, 0, dev_name(&pdev->dev), ddev);
1242 		if (err)
1243 			return err;
1244 	}
1245 
1246 	mcr = TXX9_DMA_MCR_MSTEN | MCR_LE;
1247 	if (pdata && pdata->memcpy_chan >= 0)
1248 		mcr |= TXX9_DMA_MCR_FIFUM(pdata->memcpy_chan);
1249 	dma_writel(ddev, MCR, mcr);
1250 
1251 	platform_set_drvdata(pdev, ddev);
1252 	return 0;
1253 }
1254 
1255 static int __exit txx9dmac_remove(struct platform_device *pdev)
1256 {
1257 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1258 
1259 	txx9dmac_off(ddev);
1260 	if (ddev->irq >= 0)
1261 		tasklet_kill(&ddev->tasklet);
1262 	return 0;
1263 }
1264 
1265 static void txx9dmac_shutdown(struct platform_device *pdev)
1266 {
1267 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1268 
1269 	txx9dmac_off(ddev);
1270 }
1271 
1272 static int txx9dmac_suspend_noirq(struct device *dev)
1273 {
1274 	struct platform_device *pdev = to_platform_device(dev);
1275 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1276 
1277 	txx9dmac_off(ddev);
1278 	return 0;
1279 }
1280 
1281 static int txx9dmac_resume_noirq(struct device *dev)
1282 {
1283 	struct platform_device *pdev = to_platform_device(dev);
1284 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1285 	struct txx9dmac_platform_data *pdata = pdev->dev.platform_data;
1286 	u32 mcr;
1287 
1288 	mcr = TXX9_DMA_MCR_MSTEN | MCR_LE;
1289 	if (pdata && pdata->memcpy_chan >= 0)
1290 		mcr |= TXX9_DMA_MCR_FIFUM(pdata->memcpy_chan);
1291 	dma_writel(ddev, MCR, mcr);
1292 	return 0;
1293 
1294 }
1295 
1296 static const struct dev_pm_ops txx9dmac_dev_pm_ops = {
1297 	.suspend_noirq = txx9dmac_suspend_noirq,
1298 	.resume_noirq = txx9dmac_resume_noirq,
1299 };
1300 
1301 static struct platform_driver txx9dmac_chan_driver = {
1302 	.remove		= __exit_p(txx9dmac_chan_remove),
1303 	.driver = {
1304 		.name	= "txx9dmac-chan",
1305 	},
1306 };
1307 
1308 static struct platform_driver txx9dmac_driver = {
1309 	.remove		= __exit_p(txx9dmac_remove),
1310 	.shutdown	= txx9dmac_shutdown,
1311 	.driver = {
1312 		.name	= "txx9dmac",
1313 		.pm	= &txx9dmac_dev_pm_ops,
1314 	},
1315 };
1316 
1317 static int __init txx9dmac_init(void)
1318 {
1319 	int rc;
1320 
1321 	rc = platform_driver_probe(&txx9dmac_driver, txx9dmac_probe);
1322 	if (!rc) {
1323 		rc = platform_driver_probe(&txx9dmac_chan_driver,
1324 					   txx9dmac_chan_probe);
1325 		if (rc)
1326 			platform_driver_unregister(&txx9dmac_driver);
1327 	}
1328 	return rc;
1329 }
1330 module_init(txx9dmac_init);
1331 
1332 static void __exit txx9dmac_exit(void)
1333 {
1334 	platform_driver_unregister(&txx9dmac_chan_driver);
1335 	platform_driver_unregister(&txx9dmac_driver);
1336 }
1337 module_exit(txx9dmac_exit);
1338 
1339 MODULE_LICENSE("GPL");
1340 MODULE_DESCRIPTION("TXx9 DMA Controller driver");
1341 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
1342 MODULE_ALIAS("platform:txx9dmac");
1343 MODULE_ALIAS("platform:txx9dmac-chan");
1344