xref: /linux/drivers/dma/sh/shdmac.c (revision 6084a6e23c971ef703229ee1aec68d01688578d6)
1 /*
2  * Renesas SuperH DMA Engine support
3  *
4  * base is drivers/dma/flsdma.c
5  *
6  * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
7  * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
8  * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
9  * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
10  *
11  * This is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * - DMA of SuperH does not have Hardware DMA chain mode.
17  * - MAX DMA size is 16MB.
18  *
19  */
20 
21 #include <linux/delay.h>
22 #include <linux/dmaengine.h>
23 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/kdebug.h>
27 #include <linux/module.h>
28 #include <linux/notifier.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31 #include <linux/platform_device.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/rculist.h>
34 #include <linux/sh_dma.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 
38 #include "../dmaengine.h"
39 #include "shdma.h"
40 
41 /* DMA register */
42 #define SAR	0x00
43 #define DAR	0x04
44 #define TCR	0x08
45 #define CHCR	0x0C
46 #define DMAOR	0x40
47 
48 #define TEND	0x18 /* USB-DMAC */
49 
50 #define SH_DMAE_DRV_NAME "sh-dma-engine"
51 
52 /* Default MEMCPY transfer size = 2^2 = 4 bytes */
53 #define LOG2_DEFAULT_XFER_SIZE	2
54 #define SH_DMA_SLAVE_NUMBER 256
55 #define SH_DMA_TCR_MAX (16 * 1024 * 1024 - 1)
56 
57 /*
58  * Used for write-side mutual exclusion for the global device list,
59  * read-side synchronization by way of RCU, and per-controller data.
60  */
61 static DEFINE_SPINLOCK(sh_dmae_lock);
62 static LIST_HEAD(sh_dmae_devices);
63 
64 /*
65  * Different DMAC implementations provide different ways to clear DMA channels:
66  * (1) none - no CHCLR registers are available
67  * (2) one CHCLR register per channel - 0 has to be written to it to clear
68  *     channel buffers
69  * (3) one CHCLR per several channels - 1 has to be written to the bit,
70  *     corresponding to the specific channel to reset it
71  */
72 static void channel_clear(struct sh_dmae_chan *sh_dc)
73 {
74 	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
75 	const struct sh_dmae_channel *chan_pdata = shdev->pdata->channel +
76 		sh_dc->shdma_chan.id;
77 	u32 val = shdev->pdata->chclr_bitwise ? 1 << chan_pdata->chclr_bit : 0;
78 
79 	__raw_writel(val, shdev->chan_reg + chan_pdata->chclr_offset);
80 }
81 
82 static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
83 {
84 	__raw_writel(data, sh_dc->base + reg);
85 }
86 
87 static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg)
88 {
89 	return __raw_readl(sh_dc->base + reg);
90 }
91 
92 static u16 dmaor_read(struct sh_dmae_device *shdev)
93 {
94 	void __iomem *addr = shdev->chan_reg + DMAOR;
95 
96 	if (shdev->pdata->dmaor_is_32bit)
97 		return __raw_readl(addr);
98 	else
99 		return __raw_readw(addr);
100 }
101 
102 static void dmaor_write(struct sh_dmae_device *shdev, u16 data)
103 {
104 	void __iomem *addr = shdev->chan_reg + DMAOR;
105 
106 	if (shdev->pdata->dmaor_is_32bit)
107 		__raw_writel(data, addr);
108 	else
109 		__raw_writew(data, addr);
110 }
111 
112 static void chcr_write(struct sh_dmae_chan *sh_dc, u32 data)
113 {
114 	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
115 
116 	__raw_writel(data, sh_dc->base + shdev->chcr_offset);
117 }
118 
119 static u32 chcr_read(struct sh_dmae_chan *sh_dc)
120 {
121 	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
122 
123 	return __raw_readl(sh_dc->base + shdev->chcr_offset);
124 }
125 
126 /*
127  * Reset DMA controller
128  *
129  * SH7780 has two DMAOR register
130  */
131 static void sh_dmae_ctl_stop(struct sh_dmae_device *shdev)
132 {
133 	unsigned short dmaor;
134 	unsigned long flags;
135 
136 	spin_lock_irqsave(&sh_dmae_lock, flags);
137 
138 	dmaor = dmaor_read(shdev);
139 	dmaor_write(shdev, dmaor & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME));
140 
141 	spin_unlock_irqrestore(&sh_dmae_lock, flags);
142 }
143 
144 static int sh_dmae_rst(struct sh_dmae_device *shdev)
145 {
146 	unsigned short dmaor;
147 	unsigned long flags;
148 
149 	spin_lock_irqsave(&sh_dmae_lock, flags);
150 
151 	dmaor = dmaor_read(shdev) & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME);
152 
153 	if (shdev->pdata->chclr_present) {
154 		int i;
155 		for (i = 0; i < shdev->pdata->channel_num; i++) {
156 			struct sh_dmae_chan *sh_chan = shdev->chan[i];
157 			if (sh_chan)
158 				channel_clear(sh_chan);
159 		}
160 	}
161 
162 	dmaor_write(shdev, dmaor | shdev->pdata->dmaor_init);
163 
164 	dmaor = dmaor_read(shdev);
165 
166 	spin_unlock_irqrestore(&sh_dmae_lock, flags);
167 
168 	if (dmaor & (DMAOR_AE | DMAOR_NMIF)) {
169 		dev_warn(shdev->shdma_dev.dma_dev.dev, "Can't initialize DMAOR.\n");
170 		return -EIO;
171 	}
172 	if (shdev->pdata->dmaor_init & ~dmaor)
173 		dev_warn(shdev->shdma_dev.dma_dev.dev,
174 			 "DMAOR=0x%x hasn't latched the initial value 0x%x.\n",
175 			 dmaor, shdev->pdata->dmaor_init);
176 	return 0;
177 }
178 
179 static bool dmae_is_busy(struct sh_dmae_chan *sh_chan)
180 {
181 	u32 chcr = chcr_read(sh_chan);
182 
183 	if ((chcr & (CHCR_DE | CHCR_TE)) == CHCR_DE)
184 		return true; /* working */
185 
186 	return false; /* waiting */
187 }
188 
189 static unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan, u32 chcr)
190 {
191 	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
192 	const struct sh_dmae_pdata *pdata = shdev->pdata;
193 	int cnt = ((chcr & pdata->ts_low_mask) >> pdata->ts_low_shift) |
194 		((chcr & pdata->ts_high_mask) >> pdata->ts_high_shift);
195 
196 	if (cnt >= pdata->ts_shift_num)
197 		cnt = 0;
198 
199 	return pdata->ts_shift[cnt];
200 }
201 
202 static u32 log2size_to_chcr(struct sh_dmae_chan *sh_chan, int l2size)
203 {
204 	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
205 	const struct sh_dmae_pdata *pdata = shdev->pdata;
206 	int i;
207 
208 	for (i = 0; i < pdata->ts_shift_num; i++)
209 		if (pdata->ts_shift[i] == l2size)
210 			break;
211 
212 	if (i == pdata->ts_shift_num)
213 		i = 0;
214 
215 	return ((i << pdata->ts_low_shift) & pdata->ts_low_mask) |
216 		((i << pdata->ts_high_shift) & pdata->ts_high_mask);
217 }
218 
219 static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
220 {
221 	sh_dmae_writel(sh_chan, hw->sar, SAR);
222 	sh_dmae_writel(sh_chan, hw->dar, DAR);
223 	sh_dmae_writel(sh_chan, hw->tcr >> sh_chan->xmit_shift, TCR);
224 }
225 
226 static void dmae_start(struct sh_dmae_chan *sh_chan)
227 {
228 	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
229 	u32 chcr = chcr_read(sh_chan);
230 
231 	if (shdev->pdata->needs_tend_set)
232 		sh_dmae_writel(sh_chan, 0xFFFFFFFF, TEND);
233 
234 	chcr |= CHCR_DE | shdev->chcr_ie_bit;
235 	chcr_write(sh_chan, chcr & ~CHCR_TE);
236 }
237 
238 static void dmae_init(struct sh_dmae_chan *sh_chan)
239 {
240 	/*
241 	 * Default configuration for dual address memory-memory transfer.
242 	 * 0x400 represents auto-request.
243 	 */
244 	u32 chcr = DM_INC | SM_INC | 0x400 | log2size_to_chcr(sh_chan,
245 						   LOG2_DEFAULT_XFER_SIZE);
246 	sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr);
247 	chcr_write(sh_chan, chcr);
248 }
249 
250 static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val)
251 {
252 	/* If DMA is active, cannot set CHCR. TODO: remove this superfluous check */
253 	if (dmae_is_busy(sh_chan))
254 		return -EBUSY;
255 
256 	sh_chan->xmit_shift = calc_xmit_shift(sh_chan, val);
257 	chcr_write(sh_chan, val);
258 
259 	return 0;
260 }
261 
262 static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
263 {
264 	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
265 	const struct sh_dmae_pdata *pdata = shdev->pdata;
266 	const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->shdma_chan.id];
267 	void __iomem *addr = shdev->dmars;
268 	unsigned int shift = chan_pdata->dmars_bit;
269 
270 	if (dmae_is_busy(sh_chan))
271 		return -EBUSY;
272 
273 	if (pdata->no_dmars)
274 		return 0;
275 
276 	/* in the case of a missing DMARS resource use first memory window */
277 	if (!addr)
278 		addr = shdev->chan_reg;
279 	addr += chan_pdata->dmars;
280 
281 	__raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift),
282 		     addr);
283 
284 	return 0;
285 }
286 
287 static void sh_dmae_start_xfer(struct shdma_chan *schan,
288 			       struct shdma_desc *sdesc)
289 {
290 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
291 						    shdma_chan);
292 	struct sh_dmae_desc *sh_desc = container_of(sdesc,
293 					struct sh_dmae_desc, shdma_desc);
294 	dev_dbg(sh_chan->shdma_chan.dev, "Queue #%d to %d: %u@%x -> %x\n",
295 		sdesc->async_tx.cookie, sh_chan->shdma_chan.id,
296 		sh_desc->hw.tcr, sh_desc->hw.sar, sh_desc->hw.dar);
297 	/* Get the ld start address from ld_queue */
298 	dmae_set_reg(sh_chan, &sh_desc->hw);
299 	dmae_start(sh_chan);
300 }
301 
302 static bool sh_dmae_channel_busy(struct shdma_chan *schan)
303 {
304 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
305 						    shdma_chan);
306 	return dmae_is_busy(sh_chan);
307 }
308 
309 static void sh_dmae_setup_xfer(struct shdma_chan *schan,
310 			       int slave_id)
311 {
312 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
313 						    shdma_chan);
314 
315 	if (slave_id >= 0) {
316 		const struct sh_dmae_slave_config *cfg =
317 			sh_chan->config;
318 
319 		dmae_set_dmars(sh_chan, cfg->mid_rid);
320 		dmae_set_chcr(sh_chan, cfg->chcr);
321 	} else {
322 		dmae_init(sh_chan);
323 	}
324 }
325 
326 /*
327  * Find a slave channel configuration from the contoller list by either a slave
328  * ID in the non-DT case, or by a MID/RID value in the DT case
329  */
330 static const struct sh_dmae_slave_config *dmae_find_slave(
331 	struct sh_dmae_chan *sh_chan, int match)
332 {
333 	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
334 	const struct sh_dmae_pdata *pdata = shdev->pdata;
335 	const struct sh_dmae_slave_config *cfg;
336 	int i;
337 
338 	if (!sh_chan->shdma_chan.dev->of_node) {
339 		if (match >= SH_DMA_SLAVE_NUMBER)
340 			return NULL;
341 
342 		for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
343 			if (cfg->slave_id == match)
344 				return cfg;
345 	} else {
346 		for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
347 			if (cfg->mid_rid == match) {
348 				sh_chan->shdma_chan.slave_id = i;
349 				return cfg;
350 			}
351 	}
352 
353 	return NULL;
354 }
355 
356 static int sh_dmae_set_slave(struct shdma_chan *schan,
357 			     int slave_id, dma_addr_t slave_addr, bool try)
358 {
359 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
360 						    shdma_chan);
361 	const struct sh_dmae_slave_config *cfg = dmae_find_slave(sh_chan, slave_id);
362 	if (!cfg)
363 		return -ENXIO;
364 
365 	if (!try) {
366 		sh_chan->config = cfg;
367 		sh_chan->slave_addr = slave_addr ? : cfg->addr;
368 	}
369 
370 	return 0;
371 }
372 
373 static void dmae_halt(struct sh_dmae_chan *sh_chan)
374 {
375 	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
376 	u32 chcr = chcr_read(sh_chan);
377 
378 	chcr &= ~(CHCR_DE | CHCR_TE | shdev->chcr_ie_bit);
379 	chcr_write(sh_chan, chcr);
380 }
381 
382 static int sh_dmae_desc_setup(struct shdma_chan *schan,
383 			      struct shdma_desc *sdesc,
384 			      dma_addr_t src, dma_addr_t dst, size_t *len)
385 {
386 	struct sh_dmae_desc *sh_desc = container_of(sdesc,
387 					struct sh_dmae_desc, shdma_desc);
388 
389 	if (*len > schan->max_xfer_len)
390 		*len = schan->max_xfer_len;
391 
392 	sh_desc->hw.sar = src;
393 	sh_desc->hw.dar = dst;
394 	sh_desc->hw.tcr = *len;
395 
396 	return 0;
397 }
398 
399 static void sh_dmae_halt(struct shdma_chan *schan)
400 {
401 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
402 						    shdma_chan);
403 	dmae_halt(sh_chan);
404 }
405 
406 static bool sh_dmae_chan_irq(struct shdma_chan *schan, int irq)
407 {
408 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
409 						    shdma_chan);
410 
411 	if (!(chcr_read(sh_chan) & CHCR_TE))
412 		return false;
413 
414 	/* DMA stop */
415 	dmae_halt(sh_chan);
416 
417 	return true;
418 }
419 
420 static size_t sh_dmae_get_partial(struct shdma_chan *schan,
421 				  struct shdma_desc *sdesc)
422 {
423 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
424 						    shdma_chan);
425 	struct sh_dmae_desc *sh_desc = container_of(sdesc,
426 					struct sh_dmae_desc, shdma_desc);
427 	return sh_desc->hw.tcr -
428 		(sh_dmae_readl(sh_chan, TCR) << sh_chan->xmit_shift);
429 }
430 
431 /* Called from error IRQ or NMI */
432 static bool sh_dmae_reset(struct sh_dmae_device *shdev)
433 {
434 	bool ret;
435 
436 	/* halt the dma controller */
437 	sh_dmae_ctl_stop(shdev);
438 
439 	/* We cannot detect, which channel caused the error, have to reset all */
440 	ret = shdma_reset(&shdev->shdma_dev);
441 
442 	sh_dmae_rst(shdev);
443 
444 	return ret;
445 }
446 
447 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARM)
448 static irqreturn_t sh_dmae_err(int irq, void *data)
449 {
450 	struct sh_dmae_device *shdev = data;
451 
452 	if (!(dmaor_read(shdev) & DMAOR_AE))
453 		return IRQ_NONE;
454 
455 	sh_dmae_reset(shdev);
456 	return IRQ_HANDLED;
457 }
458 #endif
459 
460 static bool sh_dmae_desc_completed(struct shdma_chan *schan,
461 				   struct shdma_desc *sdesc)
462 {
463 	struct sh_dmae_chan *sh_chan = container_of(schan,
464 					struct sh_dmae_chan, shdma_chan);
465 	struct sh_dmae_desc *sh_desc = container_of(sdesc,
466 					struct sh_dmae_desc, shdma_desc);
467 	u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
468 	u32 dar_buf = sh_dmae_readl(sh_chan, DAR);
469 
470 	return	(sdesc->direction == DMA_DEV_TO_MEM &&
471 		 (sh_desc->hw.dar + sh_desc->hw.tcr) == dar_buf) ||
472 		(sdesc->direction != DMA_DEV_TO_MEM &&
473 		 (sh_desc->hw.sar + sh_desc->hw.tcr) == sar_buf);
474 }
475 
476 static bool sh_dmae_nmi_notify(struct sh_dmae_device *shdev)
477 {
478 	/* Fast path out if NMIF is not asserted for this controller */
479 	if ((dmaor_read(shdev) & DMAOR_NMIF) == 0)
480 		return false;
481 
482 	return sh_dmae_reset(shdev);
483 }
484 
485 static int sh_dmae_nmi_handler(struct notifier_block *self,
486 			       unsigned long cmd, void *data)
487 {
488 	struct sh_dmae_device *shdev;
489 	int ret = NOTIFY_DONE;
490 	bool triggered;
491 
492 	/*
493 	 * Only concern ourselves with NMI events.
494 	 *
495 	 * Normally we would check the die chain value, but as this needs
496 	 * to be architecture independent, check for NMI context instead.
497 	 */
498 	if (!in_nmi())
499 		return NOTIFY_DONE;
500 
501 	rcu_read_lock();
502 	list_for_each_entry_rcu(shdev, &sh_dmae_devices, node) {
503 		/*
504 		 * Only stop if one of the controllers has NMIF asserted,
505 		 * we do not want to interfere with regular address error
506 		 * handling or NMI events that don't concern the DMACs.
507 		 */
508 		triggered = sh_dmae_nmi_notify(shdev);
509 		if (triggered == true)
510 			ret = NOTIFY_OK;
511 	}
512 	rcu_read_unlock();
513 
514 	return ret;
515 }
516 
517 static struct notifier_block sh_dmae_nmi_notifier __read_mostly = {
518 	.notifier_call	= sh_dmae_nmi_handler,
519 
520 	/* Run before NMI debug handler and KGDB */
521 	.priority	= 1,
522 };
523 
524 static int sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
525 					int irq, unsigned long flags)
526 {
527 	const struct sh_dmae_channel *chan_pdata = &shdev->pdata->channel[id];
528 	struct shdma_dev *sdev = &shdev->shdma_dev;
529 	struct platform_device *pdev = to_platform_device(sdev->dma_dev.dev);
530 	struct sh_dmae_chan *sh_chan;
531 	struct shdma_chan *schan;
532 	int err;
533 
534 	sh_chan = devm_kzalloc(sdev->dma_dev.dev, sizeof(struct sh_dmae_chan),
535 			       GFP_KERNEL);
536 	if (!sh_chan) {
537 		dev_err(sdev->dma_dev.dev,
538 			"No free memory for allocating dma channels!\n");
539 		return -ENOMEM;
540 	}
541 
542 	schan = &sh_chan->shdma_chan;
543 	schan->max_xfer_len = SH_DMA_TCR_MAX + 1;
544 
545 	shdma_chan_probe(sdev, schan, id);
546 
547 	sh_chan->base = shdev->chan_reg + chan_pdata->offset;
548 
549 	/* set up channel irq */
550 	if (pdev->id >= 0)
551 		snprintf(sh_chan->dev_id, sizeof(sh_chan->dev_id),
552 			 "sh-dmae%d.%d", pdev->id, id);
553 	else
554 		snprintf(sh_chan->dev_id, sizeof(sh_chan->dev_id),
555 			 "sh-dma%d", id);
556 
557 	err = shdma_request_irq(schan, irq, flags, sh_chan->dev_id);
558 	if (err) {
559 		dev_err(sdev->dma_dev.dev,
560 			"DMA channel %d request_irq error %d\n",
561 			id, err);
562 		goto err_no_irq;
563 	}
564 
565 	shdev->chan[id] = sh_chan;
566 	return 0;
567 
568 err_no_irq:
569 	/* remove from dmaengine device node */
570 	shdma_chan_remove(schan);
571 	return err;
572 }
573 
574 static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
575 {
576 	struct dma_device *dma_dev = &shdev->shdma_dev.dma_dev;
577 	struct shdma_chan *schan;
578 	int i;
579 
580 	shdma_for_each_chan(schan, &shdev->shdma_dev, i) {
581 		BUG_ON(!schan);
582 
583 		shdma_chan_remove(schan);
584 	}
585 	dma_dev->chancnt = 0;
586 }
587 
588 static void sh_dmae_shutdown(struct platform_device *pdev)
589 {
590 	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
591 	sh_dmae_ctl_stop(shdev);
592 }
593 
594 static int sh_dmae_runtime_suspend(struct device *dev)
595 {
596 	return 0;
597 }
598 
599 static int sh_dmae_runtime_resume(struct device *dev)
600 {
601 	struct sh_dmae_device *shdev = dev_get_drvdata(dev);
602 
603 	return sh_dmae_rst(shdev);
604 }
605 
606 #ifdef CONFIG_PM
607 static int sh_dmae_suspend(struct device *dev)
608 {
609 	return 0;
610 }
611 
612 static int sh_dmae_resume(struct device *dev)
613 {
614 	struct sh_dmae_device *shdev = dev_get_drvdata(dev);
615 	int i, ret;
616 
617 	ret = sh_dmae_rst(shdev);
618 	if (ret < 0)
619 		dev_err(dev, "Failed to reset!\n");
620 
621 	for (i = 0; i < shdev->pdata->channel_num; i++) {
622 		struct sh_dmae_chan *sh_chan = shdev->chan[i];
623 
624 		if (!sh_chan->shdma_chan.desc_num)
625 			continue;
626 
627 		if (sh_chan->shdma_chan.slave_id >= 0) {
628 			const struct sh_dmae_slave_config *cfg = sh_chan->config;
629 			dmae_set_dmars(sh_chan, cfg->mid_rid);
630 			dmae_set_chcr(sh_chan, cfg->chcr);
631 		} else {
632 			dmae_init(sh_chan);
633 		}
634 	}
635 
636 	return 0;
637 }
638 #else
639 #define sh_dmae_suspend NULL
640 #define sh_dmae_resume NULL
641 #endif
642 
643 static const struct dev_pm_ops sh_dmae_pm = {
644 	.suspend		= sh_dmae_suspend,
645 	.resume			= sh_dmae_resume,
646 	.runtime_suspend	= sh_dmae_runtime_suspend,
647 	.runtime_resume		= sh_dmae_runtime_resume,
648 };
649 
650 static dma_addr_t sh_dmae_slave_addr(struct shdma_chan *schan)
651 {
652 	struct sh_dmae_chan *sh_chan = container_of(schan,
653 					struct sh_dmae_chan, shdma_chan);
654 
655 	/*
656 	 * Implicit BUG_ON(!sh_chan->config)
657 	 * This is an exclusive slave DMA operation, may only be called after a
658 	 * successful slave configuration.
659 	 */
660 	return sh_chan->slave_addr;
661 }
662 
663 static struct shdma_desc *sh_dmae_embedded_desc(void *buf, int i)
664 {
665 	return &((struct sh_dmae_desc *)buf)[i].shdma_desc;
666 }
667 
668 static const struct shdma_ops sh_dmae_shdma_ops = {
669 	.desc_completed = sh_dmae_desc_completed,
670 	.halt_channel = sh_dmae_halt,
671 	.channel_busy = sh_dmae_channel_busy,
672 	.slave_addr = sh_dmae_slave_addr,
673 	.desc_setup = sh_dmae_desc_setup,
674 	.set_slave = sh_dmae_set_slave,
675 	.setup_xfer = sh_dmae_setup_xfer,
676 	.start_xfer = sh_dmae_start_xfer,
677 	.embedded_desc = sh_dmae_embedded_desc,
678 	.chan_irq = sh_dmae_chan_irq,
679 	.get_partial = sh_dmae_get_partial,
680 };
681 
682 static const struct of_device_id sh_dmae_of_match[] = {
683 	{.compatible = "renesas,shdma-r8a73a4", .data = r8a73a4_shdma_devid,},
684 	{}
685 };
686 MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
687 
688 static int sh_dmae_probe(struct platform_device *pdev)
689 {
690 	const struct sh_dmae_pdata *pdata;
691 	unsigned long chan_flag[SH_DMAE_MAX_CHANNELS] = {};
692 	int chan_irq[SH_DMAE_MAX_CHANNELS];
693 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARM)
694 	unsigned long irqflags = 0;
695 	int errirq;
696 #endif
697 	int err, i, irq_cnt = 0, irqres = 0, irq_cap = 0;
698 	struct sh_dmae_device *shdev;
699 	struct dma_device *dma_dev;
700 	struct resource *chan, *dmars, *errirq_res, *chanirq_res;
701 
702 	if (pdev->dev.of_node)
703 		pdata = of_match_device(sh_dmae_of_match, &pdev->dev)->data;
704 	else
705 		pdata = dev_get_platdata(&pdev->dev);
706 
707 	/* get platform data */
708 	if (!pdata || !pdata->channel_num)
709 		return -ENODEV;
710 
711 	chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
712 	/* DMARS area is optional */
713 	dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
714 	/*
715 	 * IRQ resources:
716 	 * 1. there always must be at least one IRQ IO-resource. On SH4 it is
717 	 *    the error IRQ, in which case it is the only IRQ in this resource:
718 	 *    start == end. If it is the only IRQ resource, all channels also
719 	 *    use the same IRQ.
720 	 * 2. DMA channel IRQ resources can be specified one per resource or in
721 	 *    ranges (start != end)
722 	 * 3. iff all events (channels and, optionally, error) on this
723 	 *    controller use the same IRQ, only one IRQ resource can be
724 	 *    specified, otherwise there must be one IRQ per channel, even if
725 	 *    some of them are equal
726 	 * 4. if all IRQs on this controller are equal or if some specific IRQs
727 	 *    specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be
728 	 *    requested with the IRQF_SHARED flag
729 	 */
730 	errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
731 	if (!chan || !errirq_res)
732 		return -ENODEV;
733 
734 	shdev = devm_kzalloc(&pdev->dev, sizeof(struct sh_dmae_device),
735 			     GFP_KERNEL);
736 	if (!shdev) {
737 		dev_err(&pdev->dev, "Not enough memory\n");
738 		return -ENOMEM;
739 	}
740 
741 	dma_dev = &shdev->shdma_dev.dma_dev;
742 
743 	shdev->chan_reg = devm_ioremap_resource(&pdev->dev, chan);
744 	if (IS_ERR(shdev->chan_reg))
745 		return PTR_ERR(shdev->chan_reg);
746 	if (dmars) {
747 		shdev->dmars = devm_ioremap_resource(&pdev->dev, dmars);
748 		if (IS_ERR(shdev->dmars))
749 			return PTR_ERR(shdev->dmars);
750 	}
751 
752 	if (!pdata->slave_only)
753 		dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
754 	if (pdata->slave && pdata->slave_num)
755 		dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
756 
757 	/* Default transfer size of 32 bytes requires 32-byte alignment */
758 	dma_dev->copy_align = LOG2_DEFAULT_XFER_SIZE;
759 
760 	shdev->shdma_dev.ops = &sh_dmae_shdma_ops;
761 	shdev->shdma_dev.desc_size = sizeof(struct sh_dmae_desc);
762 	err = shdma_init(&pdev->dev, &shdev->shdma_dev,
763 			      pdata->channel_num);
764 	if (err < 0)
765 		goto eshdma;
766 
767 	/* platform data */
768 	shdev->pdata = pdata;
769 
770 	if (pdata->chcr_offset)
771 		shdev->chcr_offset = pdata->chcr_offset;
772 	else
773 		shdev->chcr_offset = CHCR;
774 
775 	if (pdata->chcr_ie_bit)
776 		shdev->chcr_ie_bit = pdata->chcr_ie_bit;
777 	else
778 		shdev->chcr_ie_bit = CHCR_IE;
779 
780 	platform_set_drvdata(pdev, shdev);
781 
782 	pm_runtime_enable(&pdev->dev);
783 	err = pm_runtime_get_sync(&pdev->dev);
784 	if (err < 0)
785 		dev_err(&pdev->dev, "%s(): GET = %d\n", __func__, err);
786 
787 	spin_lock_irq(&sh_dmae_lock);
788 	list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
789 	spin_unlock_irq(&sh_dmae_lock);
790 
791 	/* reset dma controller - only needed as a test */
792 	err = sh_dmae_rst(shdev);
793 	if (err)
794 		goto rst_err;
795 
796 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
797 	chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
798 
799 	if (!chanirq_res)
800 		chanirq_res = errirq_res;
801 	else
802 		irqres++;
803 
804 	if (chanirq_res == errirq_res ||
805 	    (errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE)
806 		irqflags = IRQF_SHARED;
807 
808 	errirq = errirq_res->start;
809 
810 	err = devm_request_irq(&pdev->dev, errirq, sh_dmae_err, irqflags,
811 			       "DMAC Address Error", shdev);
812 	if (err) {
813 		dev_err(&pdev->dev,
814 			"DMA failed requesting irq #%d, error %d\n",
815 			errirq, err);
816 		goto eirq_err;
817 	}
818 
819 #else
820 	chanirq_res = errirq_res;
821 #endif /* CONFIG_CPU_SH4 || CONFIG_ARCH_SHMOBILE */
822 
823 	if (chanirq_res->start == chanirq_res->end &&
824 	    !platform_get_resource(pdev, IORESOURCE_IRQ, 1)) {
825 		/* Special case - all multiplexed */
826 		for (; irq_cnt < pdata->channel_num; irq_cnt++) {
827 			if (irq_cnt < SH_DMAE_MAX_CHANNELS) {
828 				chan_irq[irq_cnt] = chanirq_res->start;
829 				chan_flag[irq_cnt] = IRQF_SHARED;
830 			} else {
831 				irq_cap = 1;
832 				break;
833 			}
834 		}
835 	} else {
836 		do {
837 			for (i = chanirq_res->start; i <= chanirq_res->end; i++) {
838 				if (irq_cnt >= SH_DMAE_MAX_CHANNELS) {
839 					irq_cap = 1;
840 					break;
841 				}
842 
843 				if ((errirq_res->flags & IORESOURCE_BITS) ==
844 				    IORESOURCE_IRQ_SHAREABLE)
845 					chan_flag[irq_cnt] = IRQF_SHARED;
846 				else
847 					chan_flag[irq_cnt] = 0;
848 				dev_dbg(&pdev->dev,
849 					"Found IRQ %d for channel %d\n",
850 					i, irq_cnt);
851 				chan_irq[irq_cnt++] = i;
852 			}
853 
854 			if (irq_cnt >= SH_DMAE_MAX_CHANNELS)
855 				break;
856 
857 			chanirq_res = platform_get_resource(pdev,
858 						IORESOURCE_IRQ, ++irqres);
859 		} while (irq_cnt < pdata->channel_num && chanirq_res);
860 	}
861 
862 	/* Create DMA Channel */
863 	for (i = 0; i < irq_cnt; i++) {
864 		err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]);
865 		if (err)
866 			goto chan_probe_err;
867 	}
868 
869 	if (irq_cap)
870 		dev_notice(&pdev->dev, "Attempting to register %d DMA "
871 			   "channels when a maximum of %d are supported.\n",
872 			   pdata->channel_num, SH_DMAE_MAX_CHANNELS);
873 
874 	pm_runtime_put(&pdev->dev);
875 
876 	err = dma_async_device_register(&shdev->shdma_dev.dma_dev);
877 	if (err < 0)
878 		goto edmadevreg;
879 
880 	return err;
881 
882 edmadevreg:
883 	pm_runtime_get(&pdev->dev);
884 
885 chan_probe_err:
886 	sh_dmae_chan_remove(shdev);
887 
888 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
889 eirq_err:
890 #endif
891 rst_err:
892 	spin_lock_irq(&sh_dmae_lock);
893 	list_del_rcu(&shdev->node);
894 	spin_unlock_irq(&sh_dmae_lock);
895 
896 	pm_runtime_put(&pdev->dev);
897 	pm_runtime_disable(&pdev->dev);
898 
899 	shdma_cleanup(&shdev->shdma_dev);
900 eshdma:
901 	synchronize_rcu();
902 
903 	return err;
904 }
905 
906 static int sh_dmae_remove(struct platform_device *pdev)
907 {
908 	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
909 	struct dma_device *dma_dev = &shdev->shdma_dev.dma_dev;
910 
911 	dma_async_device_unregister(dma_dev);
912 
913 	spin_lock_irq(&sh_dmae_lock);
914 	list_del_rcu(&shdev->node);
915 	spin_unlock_irq(&sh_dmae_lock);
916 
917 	pm_runtime_disable(&pdev->dev);
918 
919 	sh_dmae_chan_remove(shdev);
920 	shdma_cleanup(&shdev->shdma_dev);
921 
922 	synchronize_rcu();
923 
924 	return 0;
925 }
926 
927 static struct platform_driver sh_dmae_driver = {
928 	.driver 	= {
929 		.owner	= THIS_MODULE,
930 		.pm	= &sh_dmae_pm,
931 		.name	= SH_DMAE_DRV_NAME,
932 		.of_match_table = sh_dmae_of_match,
933 	},
934 	.remove		= sh_dmae_remove,
935 	.shutdown	= sh_dmae_shutdown,
936 };
937 
938 static int __init sh_dmae_init(void)
939 {
940 	/* Wire up NMI handling */
941 	int err = register_die_notifier(&sh_dmae_nmi_notifier);
942 	if (err)
943 		return err;
944 
945 	return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
946 }
947 module_init(sh_dmae_init);
948 
949 static void __exit sh_dmae_exit(void)
950 {
951 	platform_driver_unregister(&sh_dmae_driver);
952 
953 	unregister_die_notifier(&sh_dmae_nmi_notifier);
954 }
955 module_exit(sh_dmae_exit);
956 
957 MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
958 MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
959 MODULE_LICENSE("GPL");
960 MODULE_ALIAS("platform:" SH_DMAE_DRV_NAME);
961