xref: /linux/drivers/dma/sh/rz-dmac.c (revision 1fd1dc41724319406b0aff221a352a400b0ddfc5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas RZ/G2L DMA Controller Driver
4  *
5  * Based on imx-dma.c
6  *
7  * Copyright (C) 2021 Renesas Electronics Corp.
8  * Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
9  * Copyright 2012 Javier Martin, Vista Silicon <javier.martin@vista-silicon.com>
10  */
11 
12 #include <linux/bitfield.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/dmaengine.h>
15 #include <linux/interrupt.h>
16 #include <linux/iopoll.h>
17 #include <linux/irqchip/irq-renesas-rzv2h.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_dma.h>
22 #include <linux/of_platform.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/reset.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 
29 #include "../dmaengine.h"
30 #include "../virt-dma.h"
31 
32 enum  rz_dmac_prep_type {
33 	RZ_DMAC_DESC_MEMCPY,
34 	RZ_DMAC_DESC_SLAVE_SG,
35 };
36 
37 struct rz_lmdesc {
38 	u32 header;
39 	u32 sa;
40 	u32 da;
41 	u32 tb;
42 	u32 chcfg;
43 	u32 chitvl;
44 	u32 chext;
45 	u32 nxla;
46 };
47 
48 struct rz_dmac_desc {
49 	struct virt_dma_desc vd;
50 	dma_addr_t src;
51 	dma_addr_t dest;
52 	size_t len;
53 	struct list_head node;
54 	enum dma_transfer_direction direction;
55 	enum rz_dmac_prep_type type;
56 	/* For slave sg */
57 	struct scatterlist *sg;
58 	unsigned int sgcount;
59 };
60 
61 #define to_rz_dmac_desc(d)	container_of(d, struct rz_dmac_desc, vd)
62 
63 struct rz_dmac_chan {
64 	struct virt_dma_chan vc;
65 	void __iomem *ch_base;
66 	void __iomem *ch_cmn_base;
67 	unsigned int index;
68 	struct rz_dmac_desc *desc;
69 	int descs_allocated;
70 
71 	dma_addr_t src_per_address;
72 	dma_addr_t dst_per_address;
73 
74 	u32 chcfg;
75 	u32 chctrl;
76 	int mid_rid;
77 
78 	struct list_head ld_free;
79 	struct list_head ld_queue;
80 	struct list_head ld_active;
81 
82 	struct {
83 		struct rz_lmdesc *base;
84 		struct rz_lmdesc *head;
85 		struct rz_lmdesc *tail;
86 		dma_addr_t base_dma;
87 	} lmdesc;
88 };
89 
90 #define to_rz_dmac_chan(c)	container_of(c, struct rz_dmac_chan, vc.chan)
91 
92 struct rz_dmac_icu {
93 	struct platform_device *pdev;
94 	u8 dmac_index;
95 };
96 
97 struct rz_dmac {
98 	struct dma_device engine;
99 	struct rz_dmac_icu icu;
100 	struct device *dev;
101 	struct reset_control *rstc;
102 	void __iomem *base;
103 	void __iomem *ext_base;
104 
105 	unsigned int n_channels;
106 	struct rz_dmac_chan *channels;
107 
108 	bool has_icu;
109 
110 	DECLARE_BITMAP(modules, 1024);
111 };
112 
113 #define to_rz_dmac(d)	container_of(d, struct rz_dmac, engine)
114 
115 /*
116  * -----------------------------------------------------------------------------
117  * Registers
118  */
119 
120 #define CHSTAT				0x0024
121 #define CHCTRL				0x0028
122 #define CHCFG				0x002c
123 #define NXLA				0x0038
124 
125 #define DCTRL				0x0000
126 
127 #define EACH_CHANNEL_OFFSET		0x0040
128 #define CHANNEL_0_7_OFFSET		0x0000
129 #define CHANNEL_0_7_COMMON_BASE		0x0300
130 #define CHANNEL_8_15_OFFSET		0x0400
131 #define CHANNEL_8_15_COMMON_BASE	0x0700
132 
133 #define CHSTAT_ER			BIT(4)
134 #define CHSTAT_EN			BIT(0)
135 
136 #define CHCTRL_CLRINTMSK		BIT(17)
137 #define CHCTRL_CLRSUS			BIT(9)
138 #define CHCTRL_CLRTC			BIT(6)
139 #define CHCTRL_CLREND			BIT(5)
140 #define CHCTRL_CLRRQ			BIT(4)
141 #define CHCTRL_SWRST			BIT(3)
142 #define CHCTRL_STG			BIT(2)
143 #define CHCTRL_CLREN			BIT(1)
144 #define CHCTRL_SETEN			BIT(0)
145 #define CHCTRL_DEFAULT			(CHCTRL_CLRINTMSK | CHCTRL_CLRSUS | \
146 					 CHCTRL_CLRTC |	CHCTRL_CLREND | \
147 					 CHCTRL_CLRRQ | CHCTRL_SWRST | \
148 					 CHCTRL_CLREN)
149 
150 #define CHCFG_DMS			BIT(31)
151 #define CHCFG_DEM			BIT(24)
152 #define CHCFG_DAD			BIT(21)
153 #define CHCFG_SAD			BIT(20)
154 #define CHCFG_REQD			BIT(3)
155 #define CHCFG_SEL(bits)			((bits) & 0x07)
156 #define CHCFG_MEM_COPY			(0x80400008)
157 #define CHCFG_FILL_DDS_MASK		GENMASK(19, 16)
158 #define CHCFG_FILL_SDS_MASK		GENMASK(15, 12)
159 #define CHCFG_FILL_TM(a)		(((a) & BIT(5)) << 22)
160 #define CHCFG_FILL_AM(a)		(((a) & GENMASK(4, 2)) << 6)
161 #define CHCFG_FILL_LVL(a)		(((a) & BIT(1)) << 5)
162 #define CHCFG_FILL_HIEN(a)		(((a) & BIT(0)) << 5)
163 
164 #define MID_RID_MASK			GENMASK(9, 0)
165 #define CHCFG_MASK			GENMASK(15, 10)
166 #define CHCFG_DS_INVALID		0xFF
167 #define DCTRL_LVINT			BIT(1)
168 #define DCTRL_PR			BIT(0)
169 #define DCTRL_DEFAULT			(DCTRL_LVINT | DCTRL_PR)
170 
171 /* LINK MODE DESCRIPTOR */
172 #define HEADER_LV			BIT(0)
173 
174 #define RZ_DMAC_MAX_CHAN_DESCRIPTORS	16
175 #define RZ_DMAC_MAX_CHANNELS		16
176 #define DMAC_NR_LMDESC			64
177 
178 /* RZ/V2H ICU related */
179 #define RZV2H_MAX_DMAC_INDEX		4
180 
181 /*
182  * -----------------------------------------------------------------------------
183  * Device access
184  */
185 
186 static void rz_dmac_writel(struct rz_dmac *dmac, unsigned int val,
187 			   unsigned int offset)
188 {
189 	writel(val, dmac->base + offset);
190 }
191 
192 static void rz_dmac_ext_writel(struct rz_dmac *dmac, unsigned int val,
193 			       unsigned int offset)
194 {
195 	writel(val, dmac->ext_base + offset);
196 }
197 
198 static u32 rz_dmac_ext_readl(struct rz_dmac *dmac, unsigned int offset)
199 {
200 	return readl(dmac->ext_base + offset);
201 }
202 
203 static void rz_dmac_ch_writel(struct rz_dmac_chan *channel, unsigned int val,
204 			      unsigned int offset, int which)
205 {
206 	if (which)
207 		writel(val, channel->ch_base + offset);
208 	else
209 		writel(val, channel->ch_cmn_base + offset);
210 }
211 
212 static u32 rz_dmac_ch_readl(struct rz_dmac_chan *channel,
213 			    unsigned int offset, int which)
214 {
215 	if (which)
216 		return readl(channel->ch_base + offset);
217 	else
218 		return readl(channel->ch_cmn_base + offset);
219 }
220 
221 /*
222  * -----------------------------------------------------------------------------
223  * Initialization
224  */
225 
226 static void rz_lmdesc_setup(struct rz_dmac_chan *channel,
227 			    struct rz_lmdesc *lmdesc)
228 {
229 	u32 nxla;
230 
231 	channel->lmdesc.base = lmdesc;
232 	channel->lmdesc.head = lmdesc;
233 	channel->lmdesc.tail = lmdesc;
234 	nxla = channel->lmdesc.base_dma;
235 	while (lmdesc < (channel->lmdesc.base + (DMAC_NR_LMDESC - 1))) {
236 		lmdesc->header = 0;
237 		nxla += sizeof(*lmdesc);
238 		lmdesc->nxla = nxla;
239 		lmdesc++;
240 	}
241 
242 	lmdesc->header = 0;
243 	lmdesc->nxla = channel->lmdesc.base_dma;
244 }
245 
246 /*
247  * -----------------------------------------------------------------------------
248  * Descriptors preparation
249  */
250 
251 static void rz_dmac_lmdesc_recycle(struct rz_dmac_chan *channel)
252 {
253 	struct rz_lmdesc *lmdesc = channel->lmdesc.head;
254 
255 	while (!(lmdesc->header & HEADER_LV)) {
256 		lmdesc->header = 0;
257 		lmdesc++;
258 		if (lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC))
259 			lmdesc = channel->lmdesc.base;
260 	}
261 	channel->lmdesc.head = lmdesc;
262 }
263 
264 static void rz_dmac_enable_hw(struct rz_dmac_chan *channel)
265 {
266 	struct dma_chan *chan = &channel->vc.chan;
267 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
268 	unsigned long flags;
269 	u32 nxla;
270 	u32 chctrl;
271 	u32 chstat;
272 
273 	dev_dbg(dmac->dev, "%s channel %d\n", __func__, channel->index);
274 
275 	local_irq_save(flags);
276 
277 	rz_dmac_lmdesc_recycle(channel);
278 
279 	nxla = channel->lmdesc.base_dma +
280 		(sizeof(struct rz_lmdesc) * (channel->lmdesc.head -
281 					     channel->lmdesc.base));
282 
283 	chstat = rz_dmac_ch_readl(channel, CHSTAT, 1);
284 	if (!(chstat & CHSTAT_EN)) {
285 		chctrl = (channel->chctrl | CHCTRL_SETEN);
286 		rz_dmac_ch_writel(channel, nxla, NXLA, 1);
287 		rz_dmac_ch_writel(channel, channel->chcfg, CHCFG, 1);
288 		rz_dmac_ch_writel(channel, CHCTRL_SWRST, CHCTRL, 1);
289 		rz_dmac_ch_writel(channel, chctrl, CHCTRL, 1);
290 	}
291 
292 	local_irq_restore(flags);
293 }
294 
295 static void rz_dmac_disable_hw(struct rz_dmac_chan *channel)
296 {
297 	struct dma_chan *chan = &channel->vc.chan;
298 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
299 	unsigned long flags;
300 
301 	dev_dbg(dmac->dev, "%s channel %d\n", __func__, channel->index);
302 
303 	local_irq_save(flags);
304 	rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1);
305 	local_irq_restore(flags);
306 }
307 
308 static void rz_dmac_set_dmars_register(struct rz_dmac *dmac, int nr, u32 dmars)
309 {
310 	u32 dmars_offset = (nr / 2) * 4;
311 	u32 shift = (nr % 2) * 16;
312 	u32 dmars32;
313 
314 	dmars32 = rz_dmac_ext_readl(dmac, dmars_offset);
315 	dmars32 &= ~(0xffff << shift);
316 	dmars32 |= dmars << shift;
317 
318 	rz_dmac_ext_writel(dmac, dmars32, dmars_offset);
319 }
320 
321 static void rz_dmac_prepare_desc_for_memcpy(struct rz_dmac_chan *channel)
322 {
323 	struct dma_chan *chan = &channel->vc.chan;
324 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
325 	struct rz_lmdesc *lmdesc = channel->lmdesc.tail;
326 	struct rz_dmac_desc *d = channel->desc;
327 	u32 chcfg = CHCFG_MEM_COPY;
328 
329 	/* prepare descriptor */
330 	lmdesc->sa = d->src;
331 	lmdesc->da = d->dest;
332 	lmdesc->tb = d->len;
333 	lmdesc->chcfg = chcfg;
334 	lmdesc->chitvl = 0;
335 	lmdesc->chext = 0;
336 	lmdesc->header = HEADER_LV;
337 
338 	if (dmac->has_icu) {
339 		rzv2h_icu_register_dma_req(dmac->icu.pdev, dmac->icu.dmac_index,
340 					   channel->index,
341 					   RZV2H_ICU_DMAC_REQ_NO_DEFAULT);
342 	} else {
343 		rz_dmac_set_dmars_register(dmac, channel->index, 0);
344 	}
345 
346 	channel->chcfg = chcfg;
347 	channel->chctrl = CHCTRL_STG | CHCTRL_SETEN;
348 }
349 
350 static void rz_dmac_prepare_descs_for_slave_sg(struct rz_dmac_chan *channel)
351 {
352 	struct dma_chan *chan = &channel->vc.chan;
353 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
354 	struct rz_dmac_desc *d = channel->desc;
355 	struct scatterlist *sg, *sgl = d->sg;
356 	struct rz_lmdesc *lmdesc;
357 	unsigned int i, sg_len = d->sgcount;
358 
359 	channel->chcfg |= CHCFG_SEL(channel->index) | CHCFG_DEM | CHCFG_DMS;
360 
361 	if (d->direction == DMA_DEV_TO_MEM) {
362 		channel->chcfg |= CHCFG_SAD;
363 		channel->chcfg &= ~CHCFG_REQD;
364 	} else {
365 		channel->chcfg |= CHCFG_DAD | CHCFG_REQD;
366 	}
367 
368 	lmdesc = channel->lmdesc.tail;
369 
370 	for (i = 0, sg = sgl; i < sg_len; i++, sg = sg_next(sg)) {
371 		if (d->direction == DMA_DEV_TO_MEM) {
372 			lmdesc->sa = channel->src_per_address;
373 			lmdesc->da = sg_dma_address(sg);
374 		} else {
375 			lmdesc->sa = sg_dma_address(sg);
376 			lmdesc->da = channel->dst_per_address;
377 		}
378 
379 		lmdesc->tb = sg_dma_len(sg);
380 		lmdesc->chitvl = 0;
381 		lmdesc->chext = 0;
382 		if (i == (sg_len - 1)) {
383 			lmdesc->chcfg = (channel->chcfg & ~CHCFG_DEM);
384 			lmdesc->header = HEADER_LV;
385 		} else {
386 			lmdesc->chcfg = channel->chcfg;
387 			lmdesc->header = HEADER_LV;
388 		}
389 		if (++lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC))
390 			lmdesc = channel->lmdesc.base;
391 	}
392 
393 	channel->lmdesc.tail = lmdesc;
394 
395 	if (dmac->has_icu) {
396 		rzv2h_icu_register_dma_req(dmac->icu.pdev, dmac->icu.dmac_index,
397 					   channel->index, channel->mid_rid);
398 	} else {
399 		rz_dmac_set_dmars_register(dmac, channel->index, channel->mid_rid);
400 	}
401 
402 	channel->chctrl = CHCTRL_SETEN;
403 }
404 
405 static int rz_dmac_xfer_desc(struct rz_dmac_chan *chan)
406 {
407 	struct rz_dmac_desc *d = chan->desc;
408 	struct virt_dma_desc *vd;
409 
410 	vd = vchan_next_desc(&chan->vc);
411 	if (!vd)
412 		return 0;
413 
414 	list_del(&vd->node);
415 
416 	switch (d->type) {
417 	case RZ_DMAC_DESC_MEMCPY:
418 		rz_dmac_prepare_desc_for_memcpy(chan);
419 		break;
420 
421 	case RZ_DMAC_DESC_SLAVE_SG:
422 		rz_dmac_prepare_descs_for_slave_sg(chan);
423 		break;
424 
425 	default:
426 		return -EINVAL;
427 	}
428 
429 	rz_dmac_enable_hw(chan);
430 
431 	return 0;
432 }
433 
434 /*
435  * -----------------------------------------------------------------------------
436  * DMA engine operations
437  */
438 
439 static int rz_dmac_alloc_chan_resources(struct dma_chan *chan)
440 {
441 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
442 
443 	while (channel->descs_allocated < RZ_DMAC_MAX_CHAN_DESCRIPTORS) {
444 		struct rz_dmac_desc *desc;
445 
446 		desc = kzalloc_obj(*desc);
447 		if (!desc)
448 			break;
449 
450 		list_add_tail(&desc->node, &channel->ld_free);
451 		channel->descs_allocated++;
452 	}
453 
454 	if (!channel->descs_allocated)
455 		return -ENOMEM;
456 
457 	return channel->descs_allocated;
458 }
459 
460 static void rz_dmac_free_chan_resources(struct dma_chan *chan)
461 {
462 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
463 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
464 	struct rz_lmdesc *lmdesc = channel->lmdesc.base;
465 	struct rz_dmac_desc *desc, *_desc;
466 	unsigned long flags;
467 	unsigned int i;
468 
469 	spin_lock_irqsave(&channel->vc.lock, flags);
470 
471 	for (i = 0; i < DMAC_NR_LMDESC; i++)
472 		lmdesc[i].header = 0;
473 
474 	rz_dmac_disable_hw(channel);
475 	list_splice_tail_init(&channel->ld_active, &channel->ld_free);
476 	list_splice_tail_init(&channel->ld_queue, &channel->ld_free);
477 
478 	if (channel->mid_rid >= 0) {
479 		clear_bit(channel->mid_rid, dmac->modules);
480 		channel->mid_rid = -EINVAL;
481 	}
482 
483 	spin_unlock_irqrestore(&channel->vc.lock, flags);
484 
485 	list_for_each_entry_safe(desc, _desc, &channel->ld_free, node) {
486 		kfree(desc);
487 		channel->descs_allocated--;
488 	}
489 
490 	INIT_LIST_HEAD(&channel->ld_free);
491 	vchan_free_chan_resources(&channel->vc);
492 }
493 
494 static struct dma_async_tx_descriptor *
495 rz_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
496 			size_t len, unsigned long flags)
497 {
498 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
499 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
500 	struct rz_dmac_desc *desc;
501 
502 	dev_dbg(dmac->dev, "%s channel: %d src=0x%pad dst=0x%pad len=%zu\n",
503 		__func__, channel->index, &src, &dest, len);
504 
505 	if (list_empty(&channel->ld_free))
506 		return NULL;
507 
508 	desc = list_first_entry(&channel->ld_free, struct rz_dmac_desc, node);
509 
510 	desc->type = RZ_DMAC_DESC_MEMCPY;
511 	desc->src = src;
512 	desc->dest = dest;
513 	desc->len = len;
514 	desc->direction = DMA_MEM_TO_MEM;
515 
516 	list_move_tail(channel->ld_free.next, &channel->ld_queue);
517 	return vchan_tx_prep(&channel->vc, &desc->vd, flags);
518 }
519 
520 static struct dma_async_tx_descriptor *
521 rz_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
522 		      unsigned int sg_len,
523 		      enum dma_transfer_direction direction,
524 		      unsigned long flags, void *context)
525 {
526 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
527 	struct rz_dmac_desc *desc;
528 	struct scatterlist *sg;
529 	int dma_length = 0;
530 	int i = 0;
531 
532 	if (list_empty(&channel->ld_free))
533 		return NULL;
534 
535 	desc = list_first_entry(&channel->ld_free, struct rz_dmac_desc, node);
536 
537 	for_each_sg(sgl, sg, sg_len, i) {
538 		dma_length += sg_dma_len(sg);
539 	}
540 
541 	desc->type = RZ_DMAC_DESC_SLAVE_SG;
542 	desc->sg = sgl;
543 	desc->sgcount = sg_len;
544 	desc->len = dma_length;
545 	desc->direction = direction;
546 
547 	if (direction == DMA_DEV_TO_MEM)
548 		desc->src = channel->src_per_address;
549 	else
550 		desc->dest = channel->dst_per_address;
551 
552 	list_move_tail(channel->ld_free.next, &channel->ld_queue);
553 	return vchan_tx_prep(&channel->vc, &desc->vd, flags);
554 }
555 
556 static int rz_dmac_terminate_all(struct dma_chan *chan)
557 {
558 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
559 	struct rz_lmdesc *lmdesc = channel->lmdesc.base;
560 	unsigned long flags;
561 	unsigned int i;
562 	LIST_HEAD(head);
563 
564 	rz_dmac_disable_hw(channel);
565 	spin_lock_irqsave(&channel->vc.lock, flags);
566 	for (i = 0; i < DMAC_NR_LMDESC; i++)
567 		lmdesc[i].header = 0;
568 
569 	list_splice_tail_init(&channel->ld_active, &channel->ld_free);
570 	list_splice_tail_init(&channel->ld_queue, &channel->ld_free);
571 	vchan_get_all_descriptors(&channel->vc, &head);
572 	spin_unlock_irqrestore(&channel->vc.lock, flags);
573 	vchan_dma_desc_free_list(&channel->vc, &head);
574 
575 	return 0;
576 }
577 
578 static void rz_dmac_issue_pending(struct dma_chan *chan)
579 {
580 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
581 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
582 	struct rz_dmac_desc *desc;
583 	unsigned long flags;
584 
585 	spin_lock_irqsave(&channel->vc.lock, flags);
586 
587 	if (!list_empty(&channel->ld_queue)) {
588 		desc = list_first_entry(&channel->ld_queue,
589 					struct rz_dmac_desc, node);
590 		channel->desc = desc;
591 		if (vchan_issue_pending(&channel->vc)) {
592 			if (rz_dmac_xfer_desc(channel) < 0)
593 				dev_warn(dmac->dev, "ch: %d couldn't issue DMA xfer\n",
594 					 channel->index);
595 			else
596 				list_move_tail(channel->ld_queue.next,
597 					       &channel->ld_active);
598 		}
599 	}
600 
601 	spin_unlock_irqrestore(&channel->vc.lock, flags);
602 }
603 
604 static u8 rz_dmac_ds_to_val_mapping(enum dma_slave_buswidth ds)
605 {
606 	u8 i;
607 	static const enum dma_slave_buswidth ds_lut[] = {
608 		DMA_SLAVE_BUSWIDTH_1_BYTE,
609 		DMA_SLAVE_BUSWIDTH_2_BYTES,
610 		DMA_SLAVE_BUSWIDTH_4_BYTES,
611 		DMA_SLAVE_BUSWIDTH_8_BYTES,
612 		DMA_SLAVE_BUSWIDTH_16_BYTES,
613 		DMA_SLAVE_BUSWIDTH_32_BYTES,
614 		DMA_SLAVE_BUSWIDTH_64_BYTES,
615 		DMA_SLAVE_BUSWIDTH_128_BYTES,
616 	};
617 
618 	for (i = 0; i < ARRAY_SIZE(ds_lut); i++) {
619 		if (ds_lut[i] == ds)
620 			return i;
621 	}
622 
623 	return CHCFG_DS_INVALID;
624 }
625 
626 static int rz_dmac_config(struct dma_chan *chan,
627 			  struct dma_slave_config *config)
628 {
629 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
630 	u32 val;
631 
632 	channel->dst_per_address = config->dst_addr;
633 	channel->chcfg &= ~CHCFG_FILL_DDS_MASK;
634 	if (channel->dst_per_address) {
635 		val = rz_dmac_ds_to_val_mapping(config->dst_addr_width);
636 		if (val == CHCFG_DS_INVALID)
637 			return -EINVAL;
638 
639 		channel->chcfg |= FIELD_PREP(CHCFG_FILL_DDS_MASK, val);
640 	}
641 
642 	channel->src_per_address = config->src_addr;
643 	channel->chcfg &= ~CHCFG_FILL_SDS_MASK;
644 	if (channel->src_per_address) {
645 		val = rz_dmac_ds_to_val_mapping(config->src_addr_width);
646 		if (val == CHCFG_DS_INVALID)
647 			return -EINVAL;
648 
649 		channel->chcfg |= FIELD_PREP(CHCFG_FILL_SDS_MASK, val);
650 	}
651 
652 	return 0;
653 }
654 
655 static void rz_dmac_virt_desc_free(struct virt_dma_desc *vd)
656 {
657 	/*
658 	 * Place holder
659 	 * Descriptor allocation is done during alloc_chan_resources and
660 	 * get freed during free_chan_resources.
661 	 * list is used to manage the descriptors and avoid any memory
662 	 * allocation/free during DMA read/write.
663 	 */
664 }
665 
666 static void rz_dmac_device_synchronize(struct dma_chan *chan)
667 {
668 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
669 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
670 	u32 chstat;
671 	int ret;
672 
673 	ret = read_poll_timeout(rz_dmac_ch_readl, chstat, !(chstat & CHSTAT_EN),
674 				100, 100000, false, channel, CHSTAT, 1);
675 	if (ret < 0)
676 		dev_warn(dmac->dev, "DMA Timeout");
677 
678 	if (dmac->has_icu) {
679 		rzv2h_icu_register_dma_req(dmac->icu.pdev, dmac->icu.dmac_index,
680 					   channel->index,
681 					   RZV2H_ICU_DMAC_REQ_NO_DEFAULT);
682 	} else {
683 		rz_dmac_set_dmars_register(dmac, channel->index, 0);
684 	}
685 }
686 
687 /*
688  * -----------------------------------------------------------------------------
689  * IRQ handling
690  */
691 
692 static void rz_dmac_irq_handle_channel(struct rz_dmac_chan *channel)
693 {
694 	struct dma_chan *chan = &channel->vc.chan;
695 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
696 	u32 chstat, chctrl;
697 
698 	chstat = rz_dmac_ch_readl(channel, CHSTAT, 1);
699 	if (chstat & CHSTAT_ER) {
700 		dev_err(dmac->dev, "DMAC err CHSTAT_%d = %08X\n",
701 			channel->index, chstat);
702 		rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1);
703 		goto done;
704 	}
705 
706 	chctrl = rz_dmac_ch_readl(channel, CHCTRL, 1);
707 	rz_dmac_ch_writel(channel, chctrl | CHCTRL_CLREND, CHCTRL, 1);
708 done:
709 	return;
710 }
711 
712 static irqreturn_t rz_dmac_irq_handler(int irq, void *dev_id)
713 {
714 	struct rz_dmac_chan *channel = dev_id;
715 
716 	if (channel) {
717 		rz_dmac_irq_handle_channel(channel);
718 		return IRQ_WAKE_THREAD;
719 	}
720 	/* handle DMAERR irq */
721 	return IRQ_HANDLED;
722 }
723 
724 static irqreturn_t rz_dmac_irq_handler_thread(int irq, void *dev_id)
725 {
726 	struct rz_dmac_chan *channel = dev_id;
727 	struct rz_dmac_desc *desc = NULL;
728 	unsigned long flags;
729 
730 	spin_lock_irqsave(&channel->vc.lock, flags);
731 
732 	if (list_empty(&channel->ld_active)) {
733 		/* Someone might have called terminate all */
734 		goto out;
735 	}
736 
737 	desc = list_first_entry(&channel->ld_active, struct rz_dmac_desc, node);
738 	vchan_cookie_complete(&desc->vd);
739 	list_move_tail(channel->ld_active.next, &channel->ld_free);
740 	if (!list_empty(&channel->ld_queue)) {
741 		desc = list_first_entry(&channel->ld_queue, struct rz_dmac_desc,
742 					node);
743 		channel->desc = desc;
744 		if (rz_dmac_xfer_desc(channel) == 0)
745 			list_move_tail(channel->ld_queue.next, &channel->ld_active);
746 	}
747 out:
748 	spin_unlock_irqrestore(&channel->vc.lock, flags);
749 
750 	return IRQ_HANDLED;
751 }
752 
753 /*
754  * -----------------------------------------------------------------------------
755  * OF xlate and channel filter
756  */
757 
758 static bool rz_dmac_chan_filter(struct dma_chan *chan, void *arg)
759 {
760 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
761 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
762 	struct of_phandle_args *dma_spec = arg;
763 	u32 ch_cfg;
764 
765 	channel->mid_rid = dma_spec->args[0] & MID_RID_MASK;
766 	ch_cfg = (dma_spec->args[0] & CHCFG_MASK) >> 10;
767 	channel->chcfg = CHCFG_FILL_TM(ch_cfg) | CHCFG_FILL_AM(ch_cfg) |
768 			 CHCFG_FILL_LVL(ch_cfg) | CHCFG_FILL_HIEN(ch_cfg);
769 
770 	return !test_and_set_bit(channel->mid_rid, dmac->modules);
771 }
772 
773 static struct dma_chan *rz_dmac_of_xlate(struct of_phandle_args *dma_spec,
774 					 struct of_dma *ofdma)
775 {
776 	dma_cap_mask_t mask;
777 
778 	if (dma_spec->args_count != 1)
779 		return NULL;
780 
781 	/* Only slave DMA channels can be allocated via DT */
782 	dma_cap_zero(mask);
783 	dma_cap_set(DMA_SLAVE, mask);
784 
785 	return __dma_request_channel(&mask, rz_dmac_chan_filter, dma_spec,
786 				     ofdma->of_node);
787 }
788 
789 /*
790  * -----------------------------------------------------------------------------
791  * Probe and remove
792  */
793 
794 static int rz_dmac_chan_probe(struct rz_dmac *dmac,
795 			      struct rz_dmac_chan *channel,
796 			      u8 index)
797 {
798 	struct platform_device *pdev = to_platform_device(dmac->dev);
799 	struct rz_lmdesc *lmdesc;
800 	char pdev_irqname[6];
801 	char *irqname;
802 	int irq, ret;
803 
804 	channel->index = index;
805 	channel->mid_rid = -EINVAL;
806 
807 	/* Request the channel interrupt. */
808 	scnprintf(pdev_irqname, sizeof(pdev_irqname), "ch%u", index);
809 	irq = platform_get_irq_byname(pdev, pdev_irqname);
810 	if (irq < 0)
811 		return irq;
812 
813 	irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u",
814 				 dev_name(dmac->dev), index);
815 	if (!irqname)
816 		return -ENOMEM;
817 
818 	ret = devm_request_threaded_irq(dmac->dev, irq, rz_dmac_irq_handler,
819 					rz_dmac_irq_handler_thread, 0,
820 					irqname, channel);
821 	if (ret) {
822 		dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", irq, ret);
823 		return ret;
824 	}
825 
826 	/* Set io base address for each channel */
827 	if (index < 8) {
828 		channel->ch_base = dmac->base + CHANNEL_0_7_OFFSET +
829 			EACH_CHANNEL_OFFSET * index;
830 		channel->ch_cmn_base = dmac->base + CHANNEL_0_7_COMMON_BASE;
831 	} else {
832 		channel->ch_base = dmac->base + CHANNEL_8_15_OFFSET +
833 			EACH_CHANNEL_OFFSET * (index - 8);
834 		channel->ch_cmn_base = dmac->base + CHANNEL_8_15_COMMON_BASE;
835 	}
836 
837 	/* Allocate descriptors */
838 	lmdesc = dma_alloc_coherent(&pdev->dev,
839 				    sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC,
840 				    &channel->lmdesc.base_dma, GFP_KERNEL);
841 	if (!lmdesc) {
842 		dev_err(&pdev->dev, "Can't allocate memory (lmdesc)\n");
843 		return -ENOMEM;
844 	}
845 	rz_lmdesc_setup(channel, lmdesc);
846 
847 	/* Initialize register for each channel */
848 	rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1);
849 
850 	channel->vc.desc_free = rz_dmac_virt_desc_free;
851 	vchan_init(&channel->vc, &dmac->engine);
852 	INIT_LIST_HEAD(&channel->ld_queue);
853 	INIT_LIST_HEAD(&channel->ld_free);
854 	INIT_LIST_HEAD(&channel->ld_active);
855 
856 	return 0;
857 }
858 
859 static void rz_dmac_put_device(void *_dev)
860 {
861 	struct device *dev = _dev;
862 
863 	put_device(dev);
864 }
865 
866 static int rz_dmac_parse_of_icu(struct device *dev, struct rz_dmac *dmac)
867 {
868 	struct device_node *np = dev->of_node;
869 	struct of_phandle_args args;
870 	uint32_t dmac_index;
871 	int ret;
872 
873 	ret = of_parse_phandle_with_fixed_args(np, "renesas,icu", 1, 0, &args);
874 	if (ret == -ENOENT)
875 		return 0;
876 	if (ret)
877 		return ret;
878 
879 	dmac->has_icu = true;
880 
881 	dmac->icu.pdev = of_find_device_by_node(args.np);
882 	of_node_put(args.np);
883 	if (!dmac->icu.pdev) {
884 		dev_err(dev, "ICU device not found.\n");
885 		return -ENODEV;
886 	}
887 
888 	ret = devm_add_action_or_reset(dev, rz_dmac_put_device, &dmac->icu.pdev->dev);
889 	if (ret)
890 		return ret;
891 
892 	dmac_index = args.args[0];
893 	if (dmac_index > RZV2H_MAX_DMAC_INDEX) {
894 		dev_err(dev, "DMAC index %u invalid.\n", dmac_index);
895 		return -EINVAL;
896 	}
897 	dmac->icu.dmac_index = dmac_index;
898 
899 	return 0;
900 }
901 
902 static int rz_dmac_parse_of(struct device *dev, struct rz_dmac *dmac)
903 {
904 	struct device_node *np = dev->of_node;
905 	int ret;
906 
907 	ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels);
908 	if (ret < 0) {
909 		dev_err(dev, "unable to read dma-channels property\n");
910 		return ret;
911 	}
912 
913 	if (!dmac->n_channels || dmac->n_channels > RZ_DMAC_MAX_CHANNELS) {
914 		dev_err(dev, "invalid number of channels %u\n", dmac->n_channels);
915 		return -EINVAL;
916 	}
917 
918 	return rz_dmac_parse_of_icu(dev, dmac);
919 }
920 
921 static int rz_dmac_probe(struct platform_device *pdev)
922 {
923 	const char *irqname = "error";
924 	struct dma_device *engine;
925 	struct rz_dmac *dmac;
926 	int channel_num;
927 	int ret;
928 	int irq;
929 	u8 i;
930 
931 	dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
932 	if (!dmac)
933 		return -ENOMEM;
934 
935 	dmac->dev = &pdev->dev;
936 	platform_set_drvdata(pdev, dmac);
937 
938 	ret = rz_dmac_parse_of(&pdev->dev, dmac);
939 	if (ret < 0)
940 		return ret;
941 
942 	dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
943 				      sizeof(*dmac->channels), GFP_KERNEL);
944 	if (!dmac->channels)
945 		return -ENOMEM;
946 
947 	/* Request resources */
948 	dmac->base = devm_platform_ioremap_resource(pdev, 0);
949 	if (IS_ERR(dmac->base))
950 		return PTR_ERR(dmac->base);
951 
952 	if (!dmac->has_icu) {
953 		dmac->ext_base = devm_platform_ioremap_resource(pdev, 1);
954 		if (IS_ERR(dmac->ext_base))
955 			return PTR_ERR(dmac->ext_base);
956 	}
957 
958 	/* Register interrupt handler for error */
959 	irq = platform_get_irq_byname(pdev, irqname);
960 	if (irq < 0)
961 		return irq;
962 
963 	ret = devm_request_irq(&pdev->dev, irq, rz_dmac_irq_handler, 0,
964 			       irqname, NULL);
965 	if (ret) {
966 		dev_err(&pdev->dev, "failed to request IRQ %u (%d)\n",
967 			irq, ret);
968 		return ret;
969 	}
970 
971 	/* Initialize the channels. */
972 	INIT_LIST_HEAD(&dmac->engine.channels);
973 
974 	dmac->rstc = devm_reset_control_array_get_optional_exclusive(&pdev->dev);
975 	if (IS_ERR(dmac->rstc))
976 		return dev_err_probe(&pdev->dev, PTR_ERR(dmac->rstc),
977 				     "failed to get resets\n");
978 
979 	pm_runtime_enable(&pdev->dev);
980 	ret = pm_runtime_resume_and_get(&pdev->dev);
981 	if (ret < 0) {
982 		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
983 		goto err_pm_disable;
984 	}
985 
986 	ret = reset_control_deassert(dmac->rstc);
987 	if (ret)
988 		goto err_pm_runtime_put;
989 
990 	for (i = 0; i < dmac->n_channels; i++) {
991 		ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i);
992 		if (ret < 0)
993 			goto err;
994 	}
995 
996 	/* Register the DMAC as a DMA provider for DT. */
997 	ret = of_dma_controller_register(pdev->dev.of_node, rz_dmac_of_xlate,
998 					 NULL);
999 	if (ret < 0)
1000 		goto err;
1001 
1002 	/* Register the DMA engine device. */
1003 	engine = &dmac->engine;
1004 	dma_cap_set(DMA_SLAVE, engine->cap_mask);
1005 	dma_cap_set(DMA_MEMCPY, engine->cap_mask);
1006 	rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_0_7_COMMON_BASE + DCTRL);
1007 	rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_8_15_COMMON_BASE + DCTRL);
1008 
1009 	engine->dev = &pdev->dev;
1010 
1011 	engine->device_alloc_chan_resources = rz_dmac_alloc_chan_resources;
1012 	engine->device_free_chan_resources = rz_dmac_free_chan_resources;
1013 	engine->device_tx_status = dma_cookie_status;
1014 	engine->device_prep_slave_sg = rz_dmac_prep_slave_sg;
1015 	engine->device_prep_dma_memcpy = rz_dmac_prep_dma_memcpy;
1016 	engine->device_config = rz_dmac_config;
1017 	engine->device_terminate_all = rz_dmac_terminate_all;
1018 	engine->device_issue_pending = rz_dmac_issue_pending;
1019 	engine->device_synchronize = rz_dmac_device_synchronize;
1020 
1021 	engine->copy_align = DMAENGINE_ALIGN_1_BYTE;
1022 	dma_set_max_seg_size(engine->dev, U32_MAX);
1023 
1024 	ret = dma_async_device_register(engine);
1025 	if (ret < 0) {
1026 		dev_err(&pdev->dev, "unable to register\n");
1027 		goto dma_register_err;
1028 	}
1029 	return 0;
1030 
1031 dma_register_err:
1032 	of_dma_controller_free(pdev->dev.of_node);
1033 err:
1034 	channel_num = i ? i - 1 : 0;
1035 	for (i = 0; i < channel_num; i++) {
1036 		struct rz_dmac_chan *channel = &dmac->channels[i];
1037 
1038 		dma_free_coherent(&pdev->dev,
1039 				  sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC,
1040 				  channel->lmdesc.base,
1041 				  channel->lmdesc.base_dma);
1042 	}
1043 
1044 	reset_control_assert(dmac->rstc);
1045 err_pm_runtime_put:
1046 	pm_runtime_put(&pdev->dev);
1047 err_pm_disable:
1048 	pm_runtime_disable(&pdev->dev);
1049 
1050 	return ret;
1051 }
1052 
1053 static void rz_dmac_remove(struct platform_device *pdev)
1054 {
1055 	struct rz_dmac *dmac = platform_get_drvdata(pdev);
1056 	unsigned int i;
1057 
1058 	dma_async_device_unregister(&dmac->engine);
1059 	of_dma_controller_free(pdev->dev.of_node);
1060 	for (i = 0; i < dmac->n_channels; i++) {
1061 		struct rz_dmac_chan *channel = &dmac->channels[i];
1062 
1063 		dma_free_coherent(&pdev->dev,
1064 				  sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC,
1065 				  channel->lmdesc.base,
1066 				  channel->lmdesc.base_dma);
1067 	}
1068 	reset_control_assert(dmac->rstc);
1069 	pm_runtime_put(&pdev->dev);
1070 	pm_runtime_disable(&pdev->dev);
1071 }
1072 
1073 static const struct of_device_id of_rz_dmac_match[] = {
1074 	{ .compatible = "renesas,r9a09g057-dmac", },
1075 	{ .compatible = "renesas,rz-dmac", },
1076 	{ /* Sentinel */ }
1077 };
1078 MODULE_DEVICE_TABLE(of, of_rz_dmac_match);
1079 
1080 static struct platform_driver rz_dmac_driver = {
1081 	.driver		= {
1082 		.name	= "rz-dmac",
1083 		.of_match_table = of_rz_dmac_match,
1084 	},
1085 	.probe		= rz_dmac_probe,
1086 	.remove		= rz_dmac_remove,
1087 };
1088 
1089 module_platform_driver(rz_dmac_driver);
1090 
1091 MODULE_DESCRIPTION("Renesas RZ/G2L DMA Controller Driver");
1092 MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
1093 MODULE_LICENSE("GPL v2");
1094