xref: /openbmc/linux/drivers/dma/txx9dmac.c (revision 9cdb81c7)
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 #include "txx9dmac.h"
19 
20 static struct txx9dmac_chan *to_txx9dmac_chan(struct dma_chan *chan)
21 {
22 	return container_of(chan, struct txx9dmac_chan, chan);
23 }
24 
25 static struct txx9dmac_cregs __iomem *__dma_regs(const struct txx9dmac_chan *dc)
26 {
27 	return dc->ch_regs;
28 }
29 
30 static struct txx9dmac_cregs32 __iomem *__dma_regs32(
31 	const struct txx9dmac_chan *dc)
32 {
33 	return dc->ch_regs;
34 }
35 
36 #define channel64_readq(dc, name) \
37 	__raw_readq(&(__dma_regs(dc)->name))
38 #define channel64_writeq(dc, name, val) \
39 	__raw_writeq((val), &(__dma_regs(dc)->name))
40 #define channel64_readl(dc, name) \
41 	__raw_readl(&(__dma_regs(dc)->name))
42 #define channel64_writel(dc, name, val) \
43 	__raw_writel((val), &(__dma_regs(dc)->name))
44 
45 #define channel32_readl(dc, name) \
46 	__raw_readl(&(__dma_regs32(dc)->name))
47 #define channel32_writel(dc, name, val) \
48 	__raw_writel((val), &(__dma_regs32(dc)->name))
49 
50 #define channel_readq(dc, name) channel64_readq(dc, name)
51 #define channel_writeq(dc, name, val) channel64_writeq(dc, name, val)
52 #define channel_readl(dc, name) \
53 	(is_dmac64(dc) ? \
54 	 channel64_readl(dc, name) : channel32_readl(dc, name))
55 #define channel_writel(dc, name, val) \
56 	(is_dmac64(dc) ? \
57 	 channel64_writel(dc, name, val) : channel32_writel(dc, name, val))
58 
59 static dma_addr_t channel64_read_CHAR(const struct txx9dmac_chan *dc)
60 {
61 	if (sizeof(__dma_regs(dc)->CHAR) == sizeof(u64))
62 		return channel64_readq(dc, CHAR);
63 	else
64 		return channel64_readl(dc, CHAR);
65 }
66 
67 static void channel64_write_CHAR(const struct txx9dmac_chan *dc, dma_addr_t val)
68 {
69 	if (sizeof(__dma_regs(dc)->CHAR) == sizeof(u64))
70 		channel64_writeq(dc, CHAR, val);
71 	else
72 		channel64_writel(dc, CHAR, val);
73 }
74 
75 static void channel64_clear_CHAR(const struct txx9dmac_chan *dc)
76 {
77 #if defined(CONFIG_32BIT) && !defined(CONFIG_64BIT_PHYS_ADDR)
78 	channel64_writel(dc, CHAR, 0);
79 	channel64_writel(dc, __pad_CHAR, 0);
80 #else
81 	channel64_writeq(dc, CHAR, 0);
82 #endif
83 }
84 
85 static dma_addr_t channel_read_CHAR(const struct txx9dmac_chan *dc)
86 {
87 	if (is_dmac64(dc))
88 		return channel64_read_CHAR(dc);
89 	else
90 		return channel32_readl(dc, CHAR);
91 }
92 
93 static void channel_write_CHAR(const struct txx9dmac_chan *dc, dma_addr_t val)
94 {
95 	if (is_dmac64(dc))
96 		channel64_write_CHAR(dc, val);
97 	else
98 		channel32_writel(dc, CHAR, val);
99 }
100 
101 static struct txx9dmac_regs __iomem *__txx9dmac_regs(
102 	const struct txx9dmac_dev *ddev)
103 {
104 	return ddev->regs;
105 }
106 
107 static struct txx9dmac_regs32 __iomem *__txx9dmac_regs32(
108 	const struct txx9dmac_dev *ddev)
109 {
110 	return ddev->regs;
111 }
112 
113 #define dma64_readl(ddev, name) \
114 	__raw_readl(&(__txx9dmac_regs(ddev)->name))
115 #define dma64_writel(ddev, name, val) \
116 	__raw_writel((val), &(__txx9dmac_regs(ddev)->name))
117 
118 #define dma32_readl(ddev, name) \
119 	__raw_readl(&(__txx9dmac_regs32(ddev)->name))
120 #define dma32_writel(ddev, name, val) \
121 	__raw_writel((val), &(__txx9dmac_regs32(ddev)->name))
122 
123 #define dma_readl(ddev, name) \
124 	(__is_dmac64(ddev) ? \
125 	dma64_readl(ddev, name) : dma32_readl(ddev, name))
126 #define dma_writel(ddev, name, val) \
127 	(__is_dmac64(ddev) ? \
128 	dma64_writel(ddev, name, val) : dma32_writel(ddev, name, val))
129 
130 static struct device *chan2dev(struct dma_chan *chan)
131 {
132 	return &chan->dev->device;
133 }
134 static struct device *chan2parent(struct dma_chan *chan)
135 {
136 	return chan->dev->device.parent;
137 }
138 
139 static struct txx9dmac_desc *
140 txd_to_txx9dmac_desc(struct dma_async_tx_descriptor *txd)
141 {
142 	return container_of(txd, struct txx9dmac_desc, txd);
143 }
144 
145 static dma_addr_t desc_read_CHAR(const struct txx9dmac_chan *dc,
146 				 const struct txx9dmac_desc *desc)
147 {
148 	return is_dmac64(dc) ? desc->hwdesc.CHAR : desc->hwdesc32.CHAR;
149 }
150 
151 static void desc_write_CHAR(const struct txx9dmac_chan *dc,
152 			    struct txx9dmac_desc *desc, dma_addr_t val)
153 {
154 	if (is_dmac64(dc))
155 		desc->hwdesc.CHAR = val;
156 	else
157 		desc->hwdesc32.CHAR = val;
158 }
159 
160 #define TXX9_DMA_MAX_COUNT	0x04000000
161 
162 #define TXX9_DMA_INITIAL_DESC_COUNT	64
163 
164 static struct txx9dmac_desc *txx9dmac_first_active(struct txx9dmac_chan *dc)
165 {
166 	return list_entry(dc->active_list.next,
167 			  struct txx9dmac_desc, desc_node);
168 }
169 
170 static struct txx9dmac_desc *txx9dmac_last_active(struct txx9dmac_chan *dc)
171 {
172 	return list_entry(dc->active_list.prev,
173 			  struct txx9dmac_desc, desc_node);
174 }
175 
176 static struct txx9dmac_desc *txx9dmac_first_queued(struct txx9dmac_chan *dc)
177 {
178 	return list_entry(dc->queue.next, struct txx9dmac_desc, desc_node);
179 }
180 
181 static struct txx9dmac_desc *txx9dmac_last_child(struct txx9dmac_desc *desc)
182 {
183 	if (!list_empty(&desc->tx_list))
184 		desc = list_entry(desc->tx_list.prev, typeof(*desc), desc_node);
185 	return desc;
186 }
187 
188 static dma_cookie_t txx9dmac_tx_submit(struct dma_async_tx_descriptor *tx);
189 
190 static struct txx9dmac_desc *txx9dmac_desc_alloc(struct txx9dmac_chan *dc,
191 						 gfp_t flags)
192 {
193 	struct txx9dmac_dev *ddev = dc->ddev;
194 	struct txx9dmac_desc *desc;
195 
196 	desc = kzalloc(sizeof(*desc), flags);
197 	if (!desc)
198 		return NULL;
199 	INIT_LIST_HEAD(&desc->tx_list);
200 	dma_async_tx_descriptor_init(&desc->txd, &dc->chan);
201 	desc->txd.tx_submit = txx9dmac_tx_submit;
202 	/* txd.flags will be overwritten in prep funcs */
203 	desc->txd.flags = DMA_CTRL_ACK;
204 	desc->txd.phys = dma_map_single(chan2parent(&dc->chan), &desc->hwdesc,
205 					ddev->descsize, DMA_TO_DEVICE);
206 	return desc;
207 }
208 
209 static struct txx9dmac_desc *txx9dmac_desc_get(struct txx9dmac_chan *dc)
210 {
211 	struct txx9dmac_desc *desc, *_desc;
212 	struct txx9dmac_desc *ret = NULL;
213 	unsigned int i = 0;
214 
215 	spin_lock_bh(&dc->lock);
216 	list_for_each_entry_safe(desc, _desc, &dc->free_list, desc_node) {
217 		if (async_tx_test_ack(&desc->txd)) {
218 			list_del(&desc->desc_node);
219 			ret = desc;
220 			break;
221 		}
222 		dev_dbg(chan2dev(&dc->chan), "desc %p not ACKed\n", desc);
223 		i++;
224 	}
225 	spin_unlock_bh(&dc->lock);
226 
227 	dev_vdbg(chan2dev(&dc->chan), "scanned %u descriptors on freelist\n",
228 		 i);
229 	if (!ret) {
230 		ret = txx9dmac_desc_alloc(dc, GFP_ATOMIC);
231 		if (ret) {
232 			spin_lock_bh(&dc->lock);
233 			dc->descs_allocated++;
234 			spin_unlock_bh(&dc->lock);
235 		} else
236 			dev_err(chan2dev(&dc->chan),
237 				"not enough descriptors available\n");
238 	}
239 	return ret;
240 }
241 
242 static void txx9dmac_sync_desc_for_cpu(struct txx9dmac_chan *dc,
243 				       struct txx9dmac_desc *desc)
244 {
245 	struct txx9dmac_dev *ddev = dc->ddev;
246 	struct txx9dmac_desc *child;
247 
248 	list_for_each_entry(child, &desc->tx_list, desc_node)
249 		dma_sync_single_for_cpu(chan2parent(&dc->chan),
250 				child->txd.phys, ddev->descsize,
251 				DMA_TO_DEVICE);
252 	dma_sync_single_for_cpu(chan2parent(&dc->chan),
253 			desc->txd.phys, ddev->descsize,
254 			DMA_TO_DEVICE);
255 }
256 
257 /*
258  * Move a descriptor, including any children, to the free list.
259  * `desc' must not be on any lists.
260  */
261 static void txx9dmac_desc_put(struct txx9dmac_chan *dc,
262 			      struct txx9dmac_desc *desc)
263 {
264 	if (desc) {
265 		struct txx9dmac_desc *child;
266 
267 		txx9dmac_sync_desc_for_cpu(dc, desc);
268 
269 		spin_lock_bh(&dc->lock);
270 		list_for_each_entry(child, &desc->tx_list, desc_node)
271 			dev_vdbg(chan2dev(&dc->chan),
272 				 "moving child desc %p to freelist\n",
273 				 child);
274 		list_splice_init(&desc->tx_list, &dc->free_list);
275 		dev_vdbg(chan2dev(&dc->chan), "moving desc %p to freelist\n",
276 			 desc);
277 		list_add(&desc->desc_node, &dc->free_list);
278 		spin_unlock_bh(&dc->lock);
279 	}
280 }
281 
282 /* Called with dc->lock held and bh disabled */
283 static dma_cookie_t
284 txx9dmac_assign_cookie(struct txx9dmac_chan *dc, struct txx9dmac_desc *desc)
285 {
286 	dma_cookie_t cookie = dc->chan.cookie;
287 
288 	if (++cookie < 0)
289 		cookie = 1;
290 
291 	dc->chan.cookie = cookie;
292 	desc->txd.cookie = cookie;
293 
294 	return cookie;
295 }
296 
297 /*----------------------------------------------------------------------*/
298 
299 static void txx9dmac_dump_regs(struct txx9dmac_chan *dc)
300 {
301 	if (is_dmac64(dc))
302 		dev_err(chan2dev(&dc->chan),
303 			"  CHAR: %#llx SAR: %#llx DAR: %#llx CNTR: %#x"
304 			" SAIR: %#x DAIR: %#x CCR: %#x CSR: %#x\n",
305 			(u64)channel64_read_CHAR(dc),
306 			channel64_readq(dc, SAR),
307 			channel64_readq(dc, DAR),
308 			channel64_readl(dc, CNTR),
309 			channel64_readl(dc, SAIR),
310 			channel64_readl(dc, DAIR),
311 			channel64_readl(dc, CCR),
312 			channel64_readl(dc, CSR));
313 	else
314 		dev_err(chan2dev(&dc->chan),
315 			"  CHAR: %#x SAR: %#x DAR: %#x CNTR: %#x"
316 			" SAIR: %#x DAIR: %#x CCR: %#x CSR: %#x\n",
317 			channel32_readl(dc, CHAR),
318 			channel32_readl(dc, SAR),
319 			channel32_readl(dc, DAR),
320 			channel32_readl(dc, CNTR),
321 			channel32_readl(dc, SAIR),
322 			channel32_readl(dc, DAIR),
323 			channel32_readl(dc, CCR),
324 			channel32_readl(dc, CSR));
325 }
326 
327 static void txx9dmac_reset_chan(struct txx9dmac_chan *dc)
328 {
329 	channel_writel(dc, CCR, TXX9_DMA_CCR_CHRST);
330 	if (is_dmac64(dc)) {
331 		channel64_clear_CHAR(dc);
332 		channel_writeq(dc, SAR, 0);
333 		channel_writeq(dc, DAR, 0);
334 	} else {
335 		channel_writel(dc, CHAR, 0);
336 		channel_writel(dc, SAR, 0);
337 		channel_writel(dc, DAR, 0);
338 	}
339 	channel_writel(dc, CNTR, 0);
340 	channel_writel(dc, SAIR, 0);
341 	channel_writel(dc, DAIR, 0);
342 	channel_writel(dc, CCR, 0);
343 	mmiowb();
344 }
345 
346 /* Called with dc->lock held and bh disabled */
347 static void txx9dmac_dostart(struct txx9dmac_chan *dc,
348 			     struct txx9dmac_desc *first)
349 {
350 	struct txx9dmac_slave *ds = dc->chan.private;
351 	u32 sai, dai;
352 
353 	dev_vdbg(chan2dev(&dc->chan), "dostart %u %p\n",
354 		 first->txd.cookie, first);
355 	/* ASSERT:  channel is idle */
356 	if (channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT) {
357 		dev_err(chan2dev(&dc->chan),
358 			"BUG: Attempted to start non-idle channel\n");
359 		txx9dmac_dump_regs(dc);
360 		/* The tasklet will hopefully advance the queue... */
361 		return;
362 	}
363 
364 	if (is_dmac64(dc)) {
365 		channel64_writel(dc, CNTR, 0);
366 		channel64_writel(dc, CSR, 0xffffffff);
367 		if (ds) {
368 			if (ds->tx_reg) {
369 				sai = ds->reg_width;
370 				dai = 0;
371 			} else {
372 				sai = 0;
373 				dai = ds->reg_width;
374 			}
375 		} else {
376 			sai = 8;
377 			dai = 8;
378 		}
379 		channel64_writel(dc, SAIR, sai);
380 		channel64_writel(dc, DAIR, dai);
381 		/* All 64-bit DMAC supports SMPCHN */
382 		channel64_writel(dc, CCR, dc->ccr);
383 		/* Writing a non zero value to CHAR will assert XFACT */
384 		channel64_write_CHAR(dc, first->txd.phys);
385 	} else {
386 		channel32_writel(dc, CNTR, 0);
387 		channel32_writel(dc, CSR, 0xffffffff);
388 		if (ds) {
389 			if (ds->tx_reg) {
390 				sai = ds->reg_width;
391 				dai = 0;
392 			} else {
393 				sai = 0;
394 				dai = ds->reg_width;
395 			}
396 		} else {
397 			sai = 4;
398 			dai = 4;
399 		}
400 		channel32_writel(dc, SAIR, sai);
401 		channel32_writel(dc, DAIR, dai);
402 		if (txx9_dma_have_SMPCHN()) {
403 			channel32_writel(dc, CCR, dc->ccr);
404 			/* Writing a non zero value to CHAR will assert XFACT */
405 			channel32_writel(dc, CHAR, first->txd.phys);
406 		} else {
407 			channel32_writel(dc, CHAR, first->txd.phys);
408 			channel32_writel(dc, CCR, dc->ccr);
409 		}
410 	}
411 }
412 
413 /*----------------------------------------------------------------------*/
414 
415 static void
416 txx9dmac_descriptor_complete(struct txx9dmac_chan *dc,
417 			     struct txx9dmac_desc *desc)
418 {
419 	dma_async_tx_callback callback;
420 	void *param;
421 	struct dma_async_tx_descriptor *txd = &desc->txd;
422 	struct txx9dmac_slave *ds = dc->chan.private;
423 
424 	dev_vdbg(chan2dev(&dc->chan), "descriptor %u %p complete\n",
425 		 txd->cookie, desc);
426 
427 	dc->completed = txd->cookie;
428 	callback = txd->callback;
429 	param = txd->callback_param;
430 
431 	txx9dmac_sync_desc_for_cpu(dc, desc);
432 	list_splice_init(&desc->tx_list, &dc->free_list);
433 	list_move(&desc->desc_node, &dc->free_list);
434 
435 	if (!ds) {
436 		dma_addr_t dmaaddr;
437 		if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
438 			dmaaddr = is_dmac64(dc) ?
439 				desc->hwdesc.DAR : desc->hwdesc32.DAR;
440 			if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
441 				dma_unmap_single(chan2parent(&dc->chan),
442 					dmaaddr, desc->len, DMA_FROM_DEVICE);
443 			else
444 				dma_unmap_page(chan2parent(&dc->chan),
445 					dmaaddr, desc->len, DMA_FROM_DEVICE);
446 		}
447 		if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
448 			dmaaddr = is_dmac64(dc) ?
449 				desc->hwdesc.SAR : desc->hwdesc32.SAR;
450 			if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
451 				dma_unmap_single(chan2parent(&dc->chan),
452 					dmaaddr, desc->len, DMA_TO_DEVICE);
453 			else
454 				dma_unmap_page(chan2parent(&dc->chan),
455 					dmaaddr, desc->len, DMA_TO_DEVICE);
456 		}
457 	}
458 
459 	/*
460 	 * The API requires that no submissions are done from a
461 	 * callback, so we don't need to drop the lock here
462 	 */
463 	if (callback)
464 		callback(param);
465 	dma_run_dependencies(txd);
466 }
467 
468 static void txx9dmac_dequeue(struct txx9dmac_chan *dc, struct list_head *list)
469 {
470 	struct txx9dmac_dev *ddev = dc->ddev;
471 	struct txx9dmac_desc *desc;
472 	struct txx9dmac_desc *prev = NULL;
473 
474 	BUG_ON(!list_empty(list));
475 	do {
476 		desc = txx9dmac_first_queued(dc);
477 		if (prev) {
478 			desc_write_CHAR(dc, prev, desc->txd.phys);
479 			dma_sync_single_for_device(chan2parent(&dc->chan),
480 				prev->txd.phys, ddev->descsize,
481 				DMA_TO_DEVICE);
482 		}
483 		prev = txx9dmac_last_child(desc);
484 		list_move_tail(&desc->desc_node, list);
485 		/* Make chain-completion interrupt happen */
486 		if ((desc->txd.flags & DMA_PREP_INTERRUPT) &&
487 		    !txx9dmac_chan_INTENT(dc))
488 			break;
489 	} while (!list_empty(&dc->queue));
490 }
491 
492 static void txx9dmac_complete_all(struct txx9dmac_chan *dc)
493 {
494 	struct txx9dmac_desc *desc, *_desc;
495 	LIST_HEAD(list);
496 
497 	/*
498 	 * Submit queued descriptors ASAP, i.e. before we go through
499 	 * the completed ones.
500 	 */
501 	list_splice_init(&dc->active_list, &list);
502 	if (!list_empty(&dc->queue)) {
503 		txx9dmac_dequeue(dc, &dc->active_list);
504 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
505 	}
506 
507 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
508 		txx9dmac_descriptor_complete(dc, desc);
509 }
510 
511 static void txx9dmac_dump_desc(struct txx9dmac_chan *dc,
512 			       struct txx9dmac_hwdesc *desc)
513 {
514 	if (is_dmac64(dc)) {
515 #ifdef TXX9_DMA_USE_SIMPLE_CHAIN
516 		dev_crit(chan2dev(&dc->chan),
517 			 "  desc: ch%#llx s%#llx d%#llx c%#x\n",
518 			 (u64)desc->CHAR, desc->SAR, desc->DAR, desc->CNTR);
519 #else
520 		dev_crit(chan2dev(&dc->chan),
521 			 "  desc: ch%#llx s%#llx d%#llx c%#x"
522 			 " si%#x di%#x cc%#x cs%#x\n",
523 			 (u64)desc->CHAR, desc->SAR, desc->DAR, desc->CNTR,
524 			 desc->SAIR, desc->DAIR, desc->CCR, desc->CSR);
525 #endif
526 	} else {
527 		struct txx9dmac_hwdesc32 *d = (struct txx9dmac_hwdesc32 *)desc;
528 #ifdef TXX9_DMA_USE_SIMPLE_CHAIN
529 		dev_crit(chan2dev(&dc->chan),
530 			 "  desc: ch%#x s%#x d%#x c%#x\n",
531 			 d->CHAR, d->SAR, d->DAR, d->CNTR);
532 #else
533 		dev_crit(chan2dev(&dc->chan),
534 			 "  desc: ch%#x s%#x d%#x c%#x"
535 			 " si%#x di%#x cc%#x cs%#x\n",
536 			 d->CHAR, d->SAR, d->DAR, d->CNTR,
537 			 d->SAIR, d->DAIR, d->CCR, d->CSR);
538 #endif
539 	}
540 }
541 
542 static void txx9dmac_handle_error(struct txx9dmac_chan *dc, u32 csr)
543 {
544 	struct txx9dmac_desc *bad_desc;
545 	struct txx9dmac_desc *child;
546 	u32 errors;
547 
548 	/*
549 	 * The descriptor currently at the head of the active list is
550 	 * borked. Since we don't have any way to report errors, we'll
551 	 * just have to scream loudly and try to carry on.
552 	 */
553 	dev_crit(chan2dev(&dc->chan), "Abnormal Chain Completion\n");
554 	txx9dmac_dump_regs(dc);
555 
556 	bad_desc = txx9dmac_first_active(dc);
557 	list_del_init(&bad_desc->desc_node);
558 
559 	/* Clear all error flags and try to restart the controller */
560 	errors = csr & (TXX9_DMA_CSR_ABCHC |
561 			TXX9_DMA_CSR_CFERR | TXX9_DMA_CSR_CHERR |
562 			TXX9_DMA_CSR_DESERR | TXX9_DMA_CSR_SORERR);
563 	channel_writel(dc, CSR, errors);
564 
565 	if (list_empty(&dc->active_list) && !list_empty(&dc->queue))
566 		txx9dmac_dequeue(dc, &dc->active_list);
567 	if (!list_empty(&dc->active_list))
568 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
569 
570 	dev_crit(chan2dev(&dc->chan),
571 		 "Bad descriptor submitted for DMA! (cookie: %d)\n",
572 		 bad_desc->txd.cookie);
573 	txx9dmac_dump_desc(dc, &bad_desc->hwdesc);
574 	list_for_each_entry(child, &bad_desc->tx_list, desc_node)
575 		txx9dmac_dump_desc(dc, &child->hwdesc);
576 	/* Pretend the descriptor completed successfully */
577 	txx9dmac_descriptor_complete(dc, bad_desc);
578 }
579 
580 static void txx9dmac_scan_descriptors(struct txx9dmac_chan *dc)
581 {
582 	dma_addr_t chain;
583 	struct txx9dmac_desc *desc, *_desc;
584 	struct txx9dmac_desc *child;
585 	u32 csr;
586 
587 	if (is_dmac64(dc)) {
588 		chain = channel64_read_CHAR(dc);
589 		csr = channel64_readl(dc, CSR);
590 		channel64_writel(dc, CSR, csr);
591 	} else {
592 		chain = channel32_readl(dc, CHAR);
593 		csr = channel32_readl(dc, CSR);
594 		channel32_writel(dc, CSR, csr);
595 	}
596 	/* For dynamic chain, we should look at XFACT instead of NCHNC */
597 	if (!(csr & (TXX9_DMA_CSR_XFACT | TXX9_DMA_CSR_ABCHC))) {
598 		/* Everything we've submitted is done */
599 		txx9dmac_complete_all(dc);
600 		return;
601 	}
602 	if (!(csr & TXX9_DMA_CSR_CHNEN))
603 		chain = 0;	/* last descriptor of this chain */
604 
605 	dev_vdbg(chan2dev(&dc->chan), "scan_descriptors: char=%#llx\n",
606 		 (u64)chain);
607 
608 	list_for_each_entry_safe(desc, _desc, &dc->active_list, desc_node) {
609 		if (desc_read_CHAR(dc, desc) == chain) {
610 			/* This one is currently in progress */
611 			if (csr & TXX9_DMA_CSR_ABCHC)
612 				goto scan_done;
613 			return;
614 		}
615 
616 		list_for_each_entry(child, &desc->tx_list, desc_node)
617 			if (desc_read_CHAR(dc, child) == chain) {
618 				/* Currently in progress */
619 				if (csr & TXX9_DMA_CSR_ABCHC)
620 					goto scan_done;
621 				return;
622 			}
623 
624 		/*
625 		 * No descriptors so far seem to be in progress, i.e.
626 		 * this one must be done.
627 		 */
628 		txx9dmac_descriptor_complete(dc, desc);
629 	}
630 scan_done:
631 	if (csr & TXX9_DMA_CSR_ABCHC) {
632 		txx9dmac_handle_error(dc, csr);
633 		return;
634 	}
635 
636 	dev_err(chan2dev(&dc->chan),
637 		"BUG: All descriptors done, but channel not idle!\n");
638 
639 	/* Try to continue after resetting the channel... */
640 	txx9dmac_reset_chan(dc);
641 
642 	if (!list_empty(&dc->queue)) {
643 		txx9dmac_dequeue(dc, &dc->active_list);
644 		txx9dmac_dostart(dc, txx9dmac_first_active(dc));
645 	}
646 }
647 
648 static void txx9dmac_chan_tasklet(unsigned long data)
649 {
650 	int irq;
651 	u32 csr;
652 	struct txx9dmac_chan *dc;
653 
654 	dc = (struct txx9dmac_chan *)data;
655 	csr = channel_readl(dc, CSR);
656 	dev_vdbg(chan2dev(&dc->chan), "tasklet: status=%x\n", csr);
657 
658 	spin_lock(&dc->lock);
659 	if (csr & (TXX9_DMA_CSR_ABCHC | TXX9_DMA_CSR_NCHNC |
660 		   TXX9_DMA_CSR_NTRNFC))
661 		txx9dmac_scan_descriptors(dc);
662 	spin_unlock(&dc->lock);
663 	irq = dc->irq;
664 
665 	enable_irq(irq);
666 }
667 
668 static irqreturn_t txx9dmac_chan_interrupt(int irq, void *dev_id)
669 {
670 	struct txx9dmac_chan *dc = dev_id;
671 
672 	dev_vdbg(chan2dev(&dc->chan), "interrupt: status=%#x\n",
673 			channel_readl(dc, CSR));
674 
675 	tasklet_schedule(&dc->tasklet);
676 	/*
677 	 * Just disable the interrupts. We'll turn them back on in the
678 	 * softirq handler.
679 	 */
680 	disable_irq_nosync(irq);
681 
682 	return IRQ_HANDLED;
683 }
684 
685 static void txx9dmac_tasklet(unsigned long data)
686 {
687 	int irq;
688 	u32 csr;
689 	struct txx9dmac_chan *dc;
690 
691 	struct txx9dmac_dev *ddev = (struct txx9dmac_dev *)data;
692 	u32 mcr;
693 	int i;
694 
695 	mcr = dma_readl(ddev, MCR);
696 	dev_vdbg(ddev->chan[0]->dma.dev, "tasklet: mcr=%x\n", mcr);
697 	for (i = 0; i < TXX9_DMA_MAX_NR_CHANNELS; i++) {
698 		if ((mcr >> (24 + i)) & 0x11) {
699 			dc = ddev->chan[i];
700 			csr = channel_readl(dc, CSR);
701 			dev_vdbg(chan2dev(&dc->chan), "tasklet: status=%x\n",
702 				 csr);
703 			spin_lock(&dc->lock);
704 			if (csr & (TXX9_DMA_CSR_ABCHC | TXX9_DMA_CSR_NCHNC |
705 				   TXX9_DMA_CSR_NTRNFC))
706 				txx9dmac_scan_descriptors(dc);
707 			spin_unlock(&dc->lock);
708 		}
709 	}
710 	irq = ddev->irq;
711 
712 	enable_irq(irq);
713 }
714 
715 static irqreturn_t txx9dmac_interrupt(int irq, void *dev_id)
716 {
717 	struct txx9dmac_dev *ddev = dev_id;
718 
719 	dev_vdbg(ddev->chan[0]->dma.dev, "interrupt: status=%#x\n",
720 			dma_readl(ddev, MCR));
721 
722 	tasklet_schedule(&ddev->tasklet);
723 	/*
724 	 * Just disable the interrupts. We'll turn them back on in the
725 	 * softirq handler.
726 	 */
727 	disable_irq_nosync(irq);
728 
729 	return IRQ_HANDLED;
730 }
731 
732 /*----------------------------------------------------------------------*/
733 
734 static dma_cookie_t txx9dmac_tx_submit(struct dma_async_tx_descriptor *tx)
735 {
736 	struct txx9dmac_desc *desc = txd_to_txx9dmac_desc(tx);
737 	struct txx9dmac_chan *dc = to_txx9dmac_chan(tx->chan);
738 	dma_cookie_t cookie;
739 
740 	spin_lock_bh(&dc->lock);
741 	cookie = txx9dmac_assign_cookie(dc, desc);
742 
743 	dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u %p\n",
744 		 desc->txd.cookie, desc);
745 
746 	list_add_tail(&desc->desc_node, &dc->queue);
747 	spin_unlock_bh(&dc->lock);
748 
749 	return cookie;
750 }
751 
752 static struct dma_async_tx_descriptor *
753 txx9dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
754 		size_t len, unsigned long flags)
755 {
756 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
757 	struct txx9dmac_dev *ddev = dc->ddev;
758 	struct txx9dmac_desc *desc;
759 	struct txx9dmac_desc *first;
760 	struct txx9dmac_desc *prev;
761 	size_t xfer_count;
762 	size_t offset;
763 
764 	dev_vdbg(chan2dev(chan), "prep_dma_memcpy d%#llx s%#llx l%#zx f%#lx\n",
765 		 (u64)dest, (u64)src, len, flags);
766 
767 	if (unlikely(!len)) {
768 		dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
769 		return NULL;
770 	}
771 
772 	prev = first = NULL;
773 
774 	for (offset = 0; offset < len; offset += xfer_count) {
775 		xfer_count = min_t(size_t, len - offset, TXX9_DMA_MAX_COUNT);
776 		/*
777 		 * Workaround for ERT-TX49H2-033, ERT-TX49H3-020,
778 		 * ERT-TX49H4-016 (slightly conservative)
779 		 */
780 		if (__is_dmac64(ddev)) {
781 			if (xfer_count > 0x100 &&
782 			    (xfer_count & 0xff) >= 0xfa &&
783 			    (xfer_count & 0xff) <= 0xff)
784 				xfer_count -= 0x20;
785 		} else {
786 			if (xfer_count > 0x80 &&
787 			    (xfer_count & 0x7f) >= 0x7e &&
788 			    (xfer_count & 0x7f) <= 0x7f)
789 				xfer_count -= 0x20;
790 		}
791 
792 		desc = txx9dmac_desc_get(dc);
793 		if (!desc) {
794 			txx9dmac_desc_put(dc, first);
795 			return NULL;
796 		}
797 
798 		if (__is_dmac64(ddev)) {
799 			desc->hwdesc.SAR = src + offset;
800 			desc->hwdesc.DAR = dest + offset;
801 			desc->hwdesc.CNTR = xfer_count;
802 			txx9dmac_desc_set_nosimple(ddev, desc, 8, 8,
803 					dc->ccr | TXX9_DMA_CCR_XFACT);
804 		} else {
805 			desc->hwdesc32.SAR = src + offset;
806 			desc->hwdesc32.DAR = dest + offset;
807 			desc->hwdesc32.CNTR = xfer_count;
808 			txx9dmac_desc_set_nosimple(ddev, desc, 4, 4,
809 					dc->ccr | TXX9_DMA_CCR_XFACT);
810 		}
811 
812 		/*
813 		 * The descriptors on tx_list are not reachable from
814 		 * the dc->queue list or dc->active_list after a
815 		 * submit.  If we put all descriptors on active_list,
816 		 * calling of callback on the completion will be more
817 		 * complex.
818 		 */
819 		if (!first) {
820 			first = desc;
821 		} else {
822 			desc_write_CHAR(dc, prev, desc->txd.phys);
823 			dma_sync_single_for_device(chan2parent(&dc->chan),
824 					prev->txd.phys, ddev->descsize,
825 					DMA_TO_DEVICE);
826 			list_add_tail(&desc->desc_node, &first->tx_list);
827 		}
828 		prev = desc;
829 	}
830 
831 	/* Trigger interrupt after last block */
832 	if (flags & DMA_PREP_INTERRUPT)
833 		txx9dmac_desc_set_INTENT(ddev, prev);
834 
835 	desc_write_CHAR(dc, prev, 0);
836 	dma_sync_single_for_device(chan2parent(&dc->chan),
837 			prev->txd.phys, ddev->descsize,
838 			DMA_TO_DEVICE);
839 
840 	first->txd.flags = flags;
841 	first->len = len;
842 
843 	return &first->txd;
844 }
845 
846 static struct dma_async_tx_descriptor *
847 txx9dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
848 		unsigned int sg_len, enum dma_transfer_direction direction,
849 		unsigned long flags)
850 {
851 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
852 	struct txx9dmac_dev *ddev = dc->ddev;
853 	struct txx9dmac_slave *ds = chan->private;
854 	struct txx9dmac_desc *prev;
855 	struct txx9dmac_desc *first;
856 	unsigned int i;
857 	struct scatterlist *sg;
858 
859 	dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
860 
861 	BUG_ON(!ds || !ds->reg_width);
862 	if (ds->tx_reg)
863 		BUG_ON(direction != DMA_MEM_TO_DEV);
864 	else
865 		BUG_ON(direction != DMA_DEV_TO_MEM);
866 	if (unlikely(!sg_len))
867 		return NULL;
868 
869 	prev = first = NULL;
870 
871 	for_each_sg(sgl, sg, sg_len, i) {
872 		struct txx9dmac_desc *desc;
873 		dma_addr_t mem;
874 		u32 sai, dai;
875 
876 		desc = txx9dmac_desc_get(dc);
877 		if (!desc) {
878 			txx9dmac_desc_put(dc, first);
879 			return NULL;
880 		}
881 
882 		mem = sg_dma_address(sg);
883 
884 		if (__is_dmac64(ddev)) {
885 			if (direction == DMA_MEM_TO_DEV) {
886 				desc->hwdesc.SAR = mem;
887 				desc->hwdesc.DAR = ds->tx_reg;
888 			} else {
889 				desc->hwdesc.SAR = ds->rx_reg;
890 				desc->hwdesc.DAR = mem;
891 			}
892 			desc->hwdesc.CNTR = sg_dma_len(sg);
893 		} else {
894 			if (direction == DMA_MEM_TO_DEV) {
895 				desc->hwdesc32.SAR = mem;
896 				desc->hwdesc32.DAR = ds->tx_reg;
897 			} else {
898 				desc->hwdesc32.SAR = ds->rx_reg;
899 				desc->hwdesc32.DAR = mem;
900 			}
901 			desc->hwdesc32.CNTR = sg_dma_len(sg);
902 		}
903 		if (direction == DMA_MEM_TO_DEV) {
904 			sai = ds->reg_width;
905 			dai = 0;
906 		} else {
907 			sai = 0;
908 			dai = ds->reg_width;
909 		}
910 		txx9dmac_desc_set_nosimple(ddev, desc, sai, dai,
911 					dc->ccr | TXX9_DMA_CCR_XFACT);
912 
913 		if (!first) {
914 			first = desc;
915 		} else {
916 			desc_write_CHAR(dc, prev, desc->txd.phys);
917 			dma_sync_single_for_device(chan2parent(&dc->chan),
918 					prev->txd.phys,
919 					ddev->descsize,
920 					DMA_TO_DEVICE);
921 			list_add_tail(&desc->desc_node, &first->tx_list);
922 		}
923 		prev = desc;
924 	}
925 
926 	/* Trigger interrupt after last block */
927 	if (flags & DMA_PREP_INTERRUPT)
928 		txx9dmac_desc_set_INTENT(ddev, prev);
929 
930 	desc_write_CHAR(dc, prev, 0);
931 	dma_sync_single_for_device(chan2parent(&dc->chan),
932 			prev->txd.phys, ddev->descsize,
933 			DMA_TO_DEVICE);
934 
935 	first->txd.flags = flags;
936 	first->len = 0;
937 
938 	return &first->txd;
939 }
940 
941 static int txx9dmac_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
942 			    unsigned long arg)
943 {
944 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
945 	struct txx9dmac_desc *desc, *_desc;
946 	LIST_HEAD(list);
947 
948 	/* Only supports DMA_TERMINATE_ALL */
949 	if (cmd != DMA_TERMINATE_ALL)
950 		return -EINVAL;
951 
952 	dev_vdbg(chan2dev(chan), "terminate_all\n");
953 	spin_lock_bh(&dc->lock);
954 
955 	txx9dmac_reset_chan(dc);
956 
957 	/* active_list entries will end up before queued entries */
958 	list_splice_init(&dc->queue, &list);
959 	list_splice_init(&dc->active_list, &list);
960 
961 	spin_unlock_bh(&dc->lock);
962 
963 	/* Flush all pending and queued descriptors */
964 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
965 		txx9dmac_descriptor_complete(dc, desc);
966 
967 	return 0;
968 }
969 
970 static enum dma_status
971 txx9dmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
972 		   struct dma_tx_state *txstate)
973 {
974 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
975 	dma_cookie_t last_used;
976 	dma_cookie_t last_complete;
977 	int ret;
978 
979 	last_complete = dc->completed;
980 	last_used = chan->cookie;
981 
982 	ret = dma_async_is_complete(cookie, last_complete, last_used);
983 	if (ret != DMA_SUCCESS) {
984 		spin_lock_bh(&dc->lock);
985 		txx9dmac_scan_descriptors(dc);
986 		spin_unlock_bh(&dc->lock);
987 
988 		last_complete = dc->completed;
989 		last_used = chan->cookie;
990 
991 		ret = dma_async_is_complete(cookie, last_complete, last_used);
992 	}
993 
994 	dma_set_tx_state(txstate, last_complete, last_used, 0);
995 
996 	return ret;
997 }
998 
999 static void txx9dmac_chain_dynamic(struct txx9dmac_chan *dc,
1000 				   struct txx9dmac_desc *prev)
1001 {
1002 	struct txx9dmac_dev *ddev = dc->ddev;
1003 	struct txx9dmac_desc *desc;
1004 	LIST_HEAD(list);
1005 
1006 	prev = txx9dmac_last_child(prev);
1007 	txx9dmac_dequeue(dc, &list);
1008 	desc = list_entry(list.next, struct txx9dmac_desc, desc_node);
1009 	desc_write_CHAR(dc, prev, desc->txd.phys);
1010 	dma_sync_single_for_device(chan2parent(&dc->chan),
1011 				   prev->txd.phys, ddev->descsize,
1012 				   DMA_TO_DEVICE);
1013 	mmiowb();
1014 	if (!(channel_readl(dc, CSR) & TXX9_DMA_CSR_CHNEN) &&
1015 	    channel_read_CHAR(dc) == prev->txd.phys)
1016 		/* Restart chain DMA */
1017 		channel_write_CHAR(dc, desc->txd.phys);
1018 	list_splice_tail(&list, &dc->active_list);
1019 }
1020 
1021 static void txx9dmac_issue_pending(struct dma_chan *chan)
1022 {
1023 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1024 
1025 	spin_lock_bh(&dc->lock);
1026 
1027 	if (!list_empty(&dc->active_list))
1028 		txx9dmac_scan_descriptors(dc);
1029 	if (!list_empty(&dc->queue)) {
1030 		if (list_empty(&dc->active_list)) {
1031 			txx9dmac_dequeue(dc, &dc->active_list);
1032 			txx9dmac_dostart(dc, txx9dmac_first_active(dc));
1033 		} else if (txx9_dma_have_SMPCHN()) {
1034 			struct txx9dmac_desc *prev = txx9dmac_last_active(dc);
1035 
1036 			if (!(prev->txd.flags & DMA_PREP_INTERRUPT) ||
1037 			    txx9dmac_chan_INTENT(dc))
1038 				txx9dmac_chain_dynamic(dc, prev);
1039 		}
1040 	}
1041 
1042 	spin_unlock_bh(&dc->lock);
1043 }
1044 
1045 static int txx9dmac_alloc_chan_resources(struct dma_chan *chan)
1046 {
1047 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1048 	struct txx9dmac_slave *ds = chan->private;
1049 	struct txx9dmac_desc *desc;
1050 	int i;
1051 
1052 	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
1053 
1054 	/* ASSERT:  channel is idle */
1055 	if (channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT) {
1056 		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1057 		return -EIO;
1058 	}
1059 
1060 	dc->completed = chan->cookie = 1;
1061 
1062 	dc->ccr = TXX9_DMA_CCR_IMMCHN | TXX9_DMA_CCR_INTENE | CCR_LE;
1063 	txx9dmac_chan_set_SMPCHN(dc);
1064 	if (!txx9_dma_have_SMPCHN() || (dc->ccr & TXX9_DMA_CCR_SMPCHN))
1065 		dc->ccr |= TXX9_DMA_CCR_INTENC;
1066 	if (chan->device->device_prep_dma_memcpy) {
1067 		if (ds)
1068 			return -EINVAL;
1069 		dc->ccr |= TXX9_DMA_CCR_XFSZ_X8;
1070 	} else {
1071 		if (!ds ||
1072 		    (ds->tx_reg && ds->rx_reg) || (!ds->tx_reg && !ds->rx_reg))
1073 			return -EINVAL;
1074 		dc->ccr |= TXX9_DMA_CCR_EXTRQ |
1075 			TXX9_DMA_CCR_XFSZ(__ffs(ds->reg_width));
1076 		txx9dmac_chan_set_INTENT(dc);
1077 	}
1078 
1079 	spin_lock_bh(&dc->lock);
1080 	i = dc->descs_allocated;
1081 	while (dc->descs_allocated < TXX9_DMA_INITIAL_DESC_COUNT) {
1082 		spin_unlock_bh(&dc->lock);
1083 
1084 		desc = txx9dmac_desc_alloc(dc, GFP_KERNEL);
1085 		if (!desc) {
1086 			dev_info(chan2dev(chan),
1087 				"only allocated %d descriptors\n", i);
1088 			spin_lock_bh(&dc->lock);
1089 			break;
1090 		}
1091 		txx9dmac_desc_put(dc, desc);
1092 
1093 		spin_lock_bh(&dc->lock);
1094 		i = ++dc->descs_allocated;
1095 	}
1096 	spin_unlock_bh(&dc->lock);
1097 
1098 	dev_dbg(chan2dev(chan),
1099 		"alloc_chan_resources allocated %d descriptors\n", i);
1100 
1101 	return i;
1102 }
1103 
1104 static void txx9dmac_free_chan_resources(struct dma_chan *chan)
1105 {
1106 	struct txx9dmac_chan *dc = to_txx9dmac_chan(chan);
1107 	struct txx9dmac_dev *ddev = dc->ddev;
1108 	struct txx9dmac_desc *desc, *_desc;
1109 	LIST_HEAD(list);
1110 
1111 	dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
1112 			dc->descs_allocated);
1113 
1114 	/* ASSERT:  channel is idle */
1115 	BUG_ON(!list_empty(&dc->active_list));
1116 	BUG_ON(!list_empty(&dc->queue));
1117 	BUG_ON(channel_readl(dc, CSR) & TXX9_DMA_CSR_XFACT);
1118 
1119 	spin_lock_bh(&dc->lock);
1120 	list_splice_init(&dc->free_list, &list);
1121 	dc->descs_allocated = 0;
1122 	spin_unlock_bh(&dc->lock);
1123 
1124 	list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1125 		dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1126 		dma_unmap_single(chan2parent(chan), desc->txd.phys,
1127 				 ddev->descsize, DMA_TO_DEVICE);
1128 		kfree(desc);
1129 	}
1130 
1131 	dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
1132 }
1133 
1134 /*----------------------------------------------------------------------*/
1135 
1136 static void txx9dmac_off(struct txx9dmac_dev *ddev)
1137 {
1138 	dma_writel(ddev, MCR, 0);
1139 	mmiowb();
1140 }
1141 
1142 static int __init txx9dmac_chan_probe(struct platform_device *pdev)
1143 {
1144 	struct txx9dmac_chan_platform_data *cpdata = pdev->dev.platform_data;
1145 	struct platform_device *dmac_dev = cpdata->dmac_dev;
1146 	struct txx9dmac_platform_data *pdata = dmac_dev->dev.platform_data;
1147 	struct txx9dmac_chan *dc;
1148 	int err;
1149 	int ch = pdev->id % TXX9_DMA_MAX_NR_CHANNELS;
1150 	int irq;
1151 
1152 	dc = devm_kzalloc(&pdev->dev, sizeof(*dc), GFP_KERNEL);
1153 	if (!dc)
1154 		return -ENOMEM;
1155 
1156 	dc->dma.dev = &pdev->dev;
1157 	dc->dma.device_alloc_chan_resources = txx9dmac_alloc_chan_resources;
1158 	dc->dma.device_free_chan_resources = txx9dmac_free_chan_resources;
1159 	dc->dma.device_control = txx9dmac_control;
1160 	dc->dma.device_tx_status = txx9dmac_tx_status;
1161 	dc->dma.device_issue_pending = txx9dmac_issue_pending;
1162 	if (pdata && pdata->memcpy_chan == ch) {
1163 		dc->dma.device_prep_dma_memcpy = txx9dmac_prep_dma_memcpy;
1164 		dma_cap_set(DMA_MEMCPY, dc->dma.cap_mask);
1165 	} else {
1166 		dc->dma.device_prep_slave_sg = txx9dmac_prep_slave_sg;
1167 		dma_cap_set(DMA_SLAVE, dc->dma.cap_mask);
1168 		dma_cap_set(DMA_PRIVATE, dc->dma.cap_mask);
1169 	}
1170 
1171 	INIT_LIST_HEAD(&dc->dma.channels);
1172 	dc->ddev = platform_get_drvdata(dmac_dev);
1173 	if (dc->ddev->irq < 0) {
1174 		irq = platform_get_irq(pdev, 0);
1175 		if (irq < 0)
1176 			return irq;
1177 		tasklet_init(&dc->tasklet, txx9dmac_chan_tasklet,
1178 				(unsigned long)dc);
1179 		dc->irq = irq;
1180 		err = devm_request_irq(&pdev->dev, dc->irq,
1181 			txx9dmac_chan_interrupt, 0, dev_name(&pdev->dev), dc);
1182 		if (err)
1183 			return err;
1184 	} else
1185 		dc->irq = -1;
1186 	dc->ddev->chan[ch] = dc;
1187 	dc->chan.device = &dc->dma;
1188 	list_add_tail(&dc->chan.device_node, &dc->chan.device->channels);
1189 	dc->chan.cookie = dc->completed = 1;
1190 
1191 	if (is_dmac64(dc))
1192 		dc->ch_regs = &__txx9dmac_regs(dc->ddev)->CHAN[ch];
1193 	else
1194 		dc->ch_regs = &__txx9dmac_regs32(dc->ddev)->CHAN[ch];
1195 	spin_lock_init(&dc->lock);
1196 
1197 	INIT_LIST_HEAD(&dc->active_list);
1198 	INIT_LIST_HEAD(&dc->queue);
1199 	INIT_LIST_HEAD(&dc->free_list);
1200 
1201 	txx9dmac_reset_chan(dc);
1202 
1203 	platform_set_drvdata(pdev, dc);
1204 
1205 	err = dma_async_device_register(&dc->dma);
1206 	if (err)
1207 		return err;
1208 	dev_dbg(&pdev->dev, "TXx9 DMA Channel (dma%d%s%s)\n",
1209 		dc->dma.dev_id,
1210 		dma_has_cap(DMA_MEMCPY, dc->dma.cap_mask) ? " memcpy" : "",
1211 		dma_has_cap(DMA_SLAVE, dc->dma.cap_mask) ? " slave" : "");
1212 
1213 	return 0;
1214 }
1215 
1216 static int __exit txx9dmac_chan_remove(struct platform_device *pdev)
1217 {
1218 	struct txx9dmac_chan *dc = platform_get_drvdata(pdev);
1219 
1220 	dma_async_device_unregister(&dc->dma);
1221 	if (dc->irq >= 0)
1222 		tasklet_kill(&dc->tasklet);
1223 	dc->ddev->chan[pdev->id % TXX9_DMA_MAX_NR_CHANNELS] = NULL;
1224 	return 0;
1225 }
1226 
1227 static int __init txx9dmac_probe(struct platform_device *pdev)
1228 {
1229 	struct txx9dmac_platform_data *pdata = pdev->dev.platform_data;
1230 	struct resource *io;
1231 	struct txx9dmac_dev *ddev;
1232 	u32 mcr;
1233 	int err;
1234 
1235 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1236 	if (!io)
1237 		return -EINVAL;
1238 
1239 	ddev = devm_kzalloc(&pdev->dev, sizeof(*ddev), GFP_KERNEL);
1240 	if (!ddev)
1241 		return -ENOMEM;
1242 
1243 	if (!devm_request_mem_region(&pdev->dev, io->start, resource_size(io),
1244 				     dev_name(&pdev->dev)))
1245 		return -EBUSY;
1246 
1247 	ddev->regs = devm_ioremap(&pdev->dev, io->start, resource_size(io));
1248 	if (!ddev->regs)
1249 		return -ENOMEM;
1250 	ddev->have_64bit_regs = pdata->have_64bit_regs;
1251 	if (__is_dmac64(ddev))
1252 		ddev->descsize = sizeof(struct txx9dmac_hwdesc);
1253 	else
1254 		ddev->descsize = sizeof(struct txx9dmac_hwdesc32);
1255 
1256 	/* force dma off, just in case */
1257 	txx9dmac_off(ddev);
1258 
1259 	ddev->irq = platform_get_irq(pdev, 0);
1260 	if (ddev->irq >= 0) {
1261 		tasklet_init(&ddev->tasklet, txx9dmac_tasklet,
1262 				(unsigned long)ddev);
1263 		err = devm_request_irq(&pdev->dev, ddev->irq,
1264 			txx9dmac_interrupt, 0, dev_name(&pdev->dev), ddev);
1265 		if (err)
1266 			return err;
1267 	}
1268 
1269 	mcr = TXX9_DMA_MCR_MSTEN | MCR_LE;
1270 	if (pdata && pdata->memcpy_chan >= 0)
1271 		mcr |= TXX9_DMA_MCR_FIFUM(pdata->memcpy_chan);
1272 	dma_writel(ddev, MCR, mcr);
1273 
1274 	platform_set_drvdata(pdev, ddev);
1275 	return 0;
1276 }
1277 
1278 static int __exit txx9dmac_remove(struct platform_device *pdev)
1279 {
1280 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1281 
1282 	txx9dmac_off(ddev);
1283 	if (ddev->irq >= 0)
1284 		tasklet_kill(&ddev->tasklet);
1285 	return 0;
1286 }
1287 
1288 static void txx9dmac_shutdown(struct platform_device *pdev)
1289 {
1290 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1291 
1292 	txx9dmac_off(ddev);
1293 }
1294 
1295 static int txx9dmac_suspend_noirq(struct device *dev)
1296 {
1297 	struct platform_device *pdev = to_platform_device(dev);
1298 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1299 
1300 	txx9dmac_off(ddev);
1301 	return 0;
1302 }
1303 
1304 static int txx9dmac_resume_noirq(struct device *dev)
1305 {
1306 	struct platform_device *pdev = to_platform_device(dev);
1307 	struct txx9dmac_dev *ddev = platform_get_drvdata(pdev);
1308 	struct txx9dmac_platform_data *pdata = pdev->dev.platform_data;
1309 	u32 mcr;
1310 
1311 	mcr = TXX9_DMA_MCR_MSTEN | MCR_LE;
1312 	if (pdata && pdata->memcpy_chan >= 0)
1313 		mcr |= TXX9_DMA_MCR_FIFUM(pdata->memcpy_chan);
1314 	dma_writel(ddev, MCR, mcr);
1315 	return 0;
1316 
1317 }
1318 
1319 static const struct dev_pm_ops txx9dmac_dev_pm_ops = {
1320 	.suspend_noirq = txx9dmac_suspend_noirq,
1321 	.resume_noirq = txx9dmac_resume_noirq,
1322 };
1323 
1324 static struct platform_driver txx9dmac_chan_driver = {
1325 	.remove		= __exit_p(txx9dmac_chan_remove),
1326 	.driver = {
1327 		.name	= "txx9dmac-chan",
1328 	},
1329 };
1330 
1331 static struct platform_driver txx9dmac_driver = {
1332 	.remove		= __exit_p(txx9dmac_remove),
1333 	.shutdown	= txx9dmac_shutdown,
1334 	.driver = {
1335 		.name	= "txx9dmac",
1336 		.pm	= &txx9dmac_dev_pm_ops,
1337 	},
1338 };
1339 
1340 static int __init txx9dmac_init(void)
1341 {
1342 	int rc;
1343 
1344 	rc = platform_driver_probe(&txx9dmac_driver, txx9dmac_probe);
1345 	if (!rc) {
1346 		rc = platform_driver_probe(&txx9dmac_chan_driver,
1347 					   txx9dmac_chan_probe);
1348 		if (rc)
1349 			platform_driver_unregister(&txx9dmac_driver);
1350 	}
1351 	return rc;
1352 }
1353 module_init(txx9dmac_init);
1354 
1355 static void __exit txx9dmac_exit(void)
1356 {
1357 	platform_driver_unregister(&txx9dmac_chan_driver);
1358 	platform_driver_unregister(&txx9dmac_driver);
1359 }
1360 module_exit(txx9dmac_exit);
1361 
1362 MODULE_LICENSE("GPL");
1363 MODULE_DESCRIPTION("TXx9 DMA Controller driver");
1364 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
1365 MODULE_ALIAS("platform:txx9dmac");
1366 MODULE_ALIAS("platform:txx9dmac-chan");
1367