xref: /openbmc/linux/drivers/dma/sh/rz-dmac.c (revision e65e175b)
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/dma-mapping.h>
13 #include <linux/dmaengine.h>
14 #include <linux/interrupt.h>
15 #include <linux/iopoll.h>
16 #include <linux/list.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_dma.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/slab.h>
24 #include <linux/spinlock.h>
25 
26 #include "../dmaengine.h"
27 #include "../virt-dma.h"
28 
29 enum  rz_dmac_prep_type {
30 	RZ_DMAC_DESC_MEMCPY,
31 	RZ_DMAC_DESC_SLAVE_SG,
32 };
33 
34 struct rz_lmdesc {
35 	u32 header;
36 	u32 sa;
37 	u32 da;
38 	u32 tb;
39 	u32 chcfg;
40 	u32 chitvl;
41 	u32 chext;
42 	u32 nxla;
43 };
44 
45 struct rz_dmac_desc {
46 	struct virt_dma_desc vd;
47 	dma_addr_t src;
48 	dma_addr_t dest;
49 	size_t len;
50 	struct list_head node;
51 	enum dma_transfer_direction direction;
52 	enum rz_dmac_prep_type type;
53 	/* For slave sg */
54 	struct scatterlist *sg;
55 	unsigned int sgcount;
56 };
57 
58 #define to_rz_dmac_desc(d)	container_of(d, struct rz_dmac_desc, vd)
59 
60 struct rz_dmac_chan {
61 	struct virt_dma_chan vc;
62 	void __iomem *ch_base;
63 	void __iomem *ch_cmn_base;
64 	unsigned int index;
65 	int irq;
66 	struct rz_dmac_desc *desc;
67 	int descs_allocated;
68 
69 	enum dma_slave_buswidth src_word_size;
70 	enum dma_slave_buswidth dst_word_size;
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 {
93 	struct dma_device engine;
94 	struct device *dev;
95 	void __iomem *base;
96 	void __iomem *ext_base;
97 
98 	unsigned int n_channels;
99 	struct rz_dmac_chan *channels;
100 
101 	DECLARE_BITMAP(modules, 1024);
102 };
103 
104 #define to_rz_dmac(d)	container_of(d, struct rz_dmac, engine)
105 
106 /*
107  * -----------------------------------------------------------------------------
108  * Registers
109  */
110 
111 #define CHSTAT				0x0024
112 #define CHCTRL				0x0028
113 #define CHCFG				0x002c
114 #define NXLA				0x0038
115 
116 #define DCTRL				0x0000
117 
118 #define EACH_CHANNEL_OFFSET		0x0040
119 #define CHANNEL_0_7_OFFSET		0x0000
120 #define CHANNEL_0_7_COMMON_BASE		0x0300
121 #define CHANNEL_8_15_OFFSET		0x0400
122 #define CHANNEL_8_15_COMMON_BASE	0x0700
123 
124 #define CHSTAT_ER			BIT(4)
125 #define CHSTAT_EN			BIT(0)
126 
127 #define CHCTRL_CLRINTMSK		BIT(17)
128 #define CHCTRL_CLRSUS			BIT(9)
129 #define CHCTRL_CLRTC			BIT(6)
130 #define CHCTRL_CLREND			BIT(5)
131 #define CHCTRL_CLRRQ			BIT(4)
132 #define CHCTRL_SWRST			BIT(3)
133 #define CHCTRL_STG			BIT(2)
134 #define CHCTRL_CLREN			BIT(1)
135 #define CHCTRL_SETEN			BIT(0)
136 #define CHCTRL_DEFAULT			(CHCTRL_CLRINTMSK | CHCTRL_CLRSUS | \
137 					 CHCTRL_CLRTC |	CHCTRL_CLREND | \
138 					 CHCTRL_CLRRQ | CHCTRL_SWRST | \
139 					 CHCTRL_CLREN)
140 
141 #define CHCFG_DMS			BIT(31)
142 #define CHCFG_DEM			BIT(24)
143 #define CHCFG_DAD			BIT(21)
144 #define CHCFG_SAD			BIT(20)
145 #define CHCFG_REQD			BIT(3)
146 #define CHCFG_SEL(bits)			((bits) & 0x07)
147 #define CHCFG_MEM_COPY			(0x80400008)
148 #define CHCFG_FILL_DDS(a)		(((a) << 16) & GENMASK(19, 16))
149 #define CHCFG_FILL_SDS(a)		(((a) << 12) & GENMASK(15, 12))
150 #define CHCFG_FILL_TM(a)		(((a) & BIT(5)) << 22)
151 #define CHCFG_FILL_AM(a)		(((a) & GENMASK(4, 2)) << 6)
152 #define CHCFG_FILL_LVL(a)		(((a) & BIT(1)) << 5)
153 #define CHCFG_FILL_HIEN(a)		(((a) & BIT(0)) << 5)
154 
155 #define MID_RID_MASK			GENMASK(9, 0)
156 #define CHCFG_MASK			GENMASK(15, 10)
157 #define CHCFG_DS_INVALID		0xFF
158 #define DCTRL_LVINT			BIT(1)
159 #define DCTRL_PR			BIT(0)
160 #define DCTRL_DEFAULT			(DCTRL_LVINT | DCTRL_PR)
161 
162 /* LINK MODE DESCRIPTOR */
163 #define HEADER_LV			BIT(0)
164 
165 #define RZ_DMAC_MAX_CHAN_DESCRIPTORS	16
166 #define RZ_DMAC_MAX_CHANNELS		16
167 #define DMAC_NR_LMDESC			64
168 
169 /*
170  * -----------------------------------------------------------------------------
171  * Device access
172  */
173 
174 static void rz_dmac_writel(struct rz_dmac *dmac, unsigned int val,
175 			   unsigned int offset)
176 {
177 	writel(val, dmac->base + offset);
178 }
179 
180 static void rz_dmac_ext_writel(struct rz_dmac *dmac, unsigned int val,
181 			       unsigned int offset)
182 {
183 	writel(val, dmac->ext_base + offset);
184 }
185 
186 static u32 rz_dmac_ext_readl(struct rz_dmac *dmac, unsigned int offset)
187 {
188 	return readl(dmac->ext_base + offset);
189 }
190 
191 static void rz_dmac_ch_writel(struct rz_dmac_chan *channel, unsigned int val,
192 			      unsigned int offset, int which)
193 {
194 	if (which)
195 		writel(val, channel->ch_base + offset);
196 	else
197 		writel(val, channel->ch_cmn_base + offset);
198 }
199 
200 static u32 rz_dmac_ch_readl(struct rz_dmac_chan *channel,
201 			    unsigned int offset, int which)
202 {
203 	if (which)
204 		return readl(channel->ch_base + offset);
205 	else
206 		return readl(channel->ch_cmn_base + offset);
207 }
208 
209 /*
210  * -----------------------------------------------------------------------------
211  * Initialization
212  */
213 
214 static void rz_lmdesc_setup(struct rz_dmac_chan *channel,
215 			    struct rz_lmdesc *lmdesc)
216 {
217 	u32 nxla;
218 
219 	channel->lmdesc.base = lmdesc;
220 	channel->lmdesc.head = lmdesc;
221 	channel->lmdesc.tail = lmdesc;
222 	nxla = channel->lmdesc.base_dma;
223 	while (lmdesc < (channel->lmdesc.base + (DMAC_NR_LMDESC - 1))) {
224 		lmdesc->header = 0;
225 		nxla += sizeof(*lmdesc);
226 		lmdesc->nxla = nxla;
227 		lmdesc++;
228 	}
229 
230 	lmdesc->header = 0;
231 	lmdesc->nxla = channel->lmdesc.base_dma;
232 }
233 
234 /*
235  * -----------------------------------------------------------------------------
236  * Descriptors preparation
237  */
238 
239 static void rz_dmac_lmdesc_recycle(struct rz_dmac_chan *channel)
240 {
241 	struct rz_lmdesc *lmdesc = channel->lmdesc.head;
242 
243 	while (!(lmdesc->header & HEADER_LV)) {
244 		lmdesc->header = 0;
245 		lmdesc++;
246 		if (lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC))
247 			lmdesc = channel->lmdesc.base;
248 	}
249 	channel->lmdesc.head = lmdesc;
250 }
251 
252 static void rz_dmac_enable_hw(struct rz_dmac_chan *channel)
253 {
254 	struct dma_chan *chan = &channel->vc.chan;
255 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
256 	unsigned long flags;
257 	u32 nxla;
258 	u32 chctrl;
259 	u32 chstat;
260 
261 	dev_dbg(dmac->dev, "%s channel %d\n", __func__, channel->index);
262 
263 	local_irq_save(flags);
264 
265 	rz_dmac_lmdesc_recycle(channel);
266 
267 	nxla = channel->lmdesc.base_dma +
268 		(sizeof(struct rz_lmdesc) * (channel->lmdesc.head -
269 					     channel->lmdesc.base));
270 
271 	chstat = rz_dmac_ch_readl(channel, CHSTAT, 1);
272 	if (!(chstat & CHSTAT_EN)) {
273 		chctrl = (channel->chctrl | CHCTRL_SETEN);
274 		rz_dmac_ch_writel(channel, nxla, NXLA, 1);
275 		rz_dmac_ch_writel(channel, channel->chcfg, CHCFG, 1);
276 		rz_dmac_ch_writel(channel, CHCTRL_SWRST, CHCTRL, 1);
277 		rz_dmac_ch_writel(channel, chctrl, CHCTRL, 1);
278 	}
279 
280 	local_irq_restore(flags);
281 }
282 
283 static void rz_dmac_disable_hw(struct rz_dmac_chan *channel)
284 {
285 	struct dma_chan *chan = &channel->vc.chan;
286 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
287 	unsigned long flags;
288 
289 	dev_dbg(dmac->dev, "%s channel %d\n", __func__, channel->index);
290 
291 	local_irq_save(flags);
292 	rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1);
293 	local_irq_restore(flags);
294 }
295 
296 static void rz_dmac_set_dmars_register(struct rz_dmac *dmac, int nr, u32 dmars)
297 {
298 	u32 dmars_offset = (nr / 2) * 4;
299 	u32 shift = (nr % 2) * 16;
300 	u32 dmars32;
301 
302 	dmars32 = rz_dmac_ext_readl(dmac, dmars_offset);
303 	dmars32 &= ~(0xffff << shift);
304 	dmars32 |= dmars << shift;
305 
306 	rz_dmac_ext_writel(dmac, dmars32, dmars_offset);
307 }
308 
309 static void rz_dmac_prepare_desc_for_memcpy(struct rz_dmac_chan *channel)
310 {
311 	struct dma_chan *chan = &channel->vc.chan;
312 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
313 	struct rz_lmdesc *lmdesc = channel->lmdesc.tail;
314 	struct rz_dmac_desc *d = channel->desc;
315 	u32 chcfg = CHCFG_MEM_COPY;
316 
317 	/* prepare descriptor */
318 	lmdesc->sa = d->src;
319 	lmdesc->da = d->dest;
320 	lmdesc->tb = d->len;
321 	lmdesc->chcfg = chcfg;
322 	lmdesc->chitvl = 0;
323 	lmdesc->chext = 0;
324 	lmdesc->header = HEADER_LV;
325 
326 	rz_dmac_set_dmars_register(dmac, channel->index, 0);
327 
328 	channel->chcfg = chcfg;
329 	channel->chctrl = CHCTRL_STG | CHCTRL_SETEN;
330 }
331 
332 static void rz_dmac_prepare_descs_for_slave_sg(struct rz_dmac_chan *channel)
333 {
334 	struct dma_chan *chan = &channel->vc.chan;
335 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
336 	struct rz_dmac_desc *d = channel->desc;
337 	struct scatterlist *sg, *sgl = d->sg;
338 	struct rz_lmdesc *lmdesc;
339 	unsigned int i, sg_len = d->sgcount;
340 
341 	channel->chcfg |= CHCFG_SEL(channel->index) | CHCFG_DEM | CHCFG_DMS;
342 
343 	if (d->direction == DMA_DEV_TO_MEM) {
344 		channel->chcfg |= CHCFG_SAD;
345 		channel->chcfg &= ~CHCFG_REQD;
346 	} else {
347 		channel->chcfg |= CHCFG_DAD | CHCFG_REQD;
348 	}
349 
350 	lmdesc = channel->lmdesc.tail;
351 
352 	for (i = 0, sg = sgl; i < sg_len; i++, sg = sg_next(sg)) {
353 		if (d->direction == DMA_DEV_TO_MEM) {
354 			lmdesc->sa = channel->src_per_address;
355 			lmdesc->da = sg_dma_address(sg);
356 		} else {
357 			lmdesc->sa = sg_dma_address(sg);
358 			lmdesc->da = channel->dst_per_address;
359 		}
360 
361 		lmdesc->tb = sg_dma_len(sg);
362 		lmdesc->chitvl = 0;
363 		lmdesc->chext = 0;
364 		if (i == (sg_len - 1)) {
365 			lmdesc->chcfg = (channel->chcfg & ~CHCFG_DEM);
366 			lmdesc->header = HEADER_LV;
367 		} else {
368 			lmdesc->chcfg = channel->chcfg;
369 			lmdesc->header = HEADER_LV;
370 		}
371 		if (++lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC))
372 			lmdesc = channel->lmdesc.base;
373 	}
374 
375 	channel->lmdesc.tail = lmdesc;
376 
377 	rz_dmac_set_dmars_register(dmac, channel->index, channel->mid_rid);
378 	channel->chctrl = CHCTRL_SETEN;
379 }
380 
381 static int rz_dmac_xfer_desc(struct rz_dmac_chan *chan)
382 {
383 	struct rz_dmac_desc *d = chan->desc;
384 	struct virt_dma_desc *vd;
385 
386 	vd = vchan_next_desc(&chan->vc);
387 	if (!vd)
388 		return 0;
389 
390 	list_del(&vd->node);
391 
392 	switch (d->type) {
393 	case RZ_DMAC_DESC_MEMCPY:
394 		rz_dmac_prepare_desc_for_memcpy(chan);
395 		break;
396 
397 	case RZ_DMAC_DESC_SLAVE_SG:
398 		rz_dmac_prepare_descs_for_slave_sg(chan);
399 		break;
400 
401 	default:
402 		return -EINVAL;
403 	}
404 
405 	rz_dmac_enable_hw(chan);
406 
407 	return 0;
408 }
409 
410 /*
411  * -----------------------------------------------------------------------------
412  * DMA engine operations
413  */
414 
415 static int rz_dmac_alloc_chan_resources(struct dma_chan *chan)
416 {
417 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
418 
419 	while (channel->descs_allocated < RZ_DMAC_MAX_CHAN_DESCRIPTORS) {
420 		struct rz_dmac_desc *desc;
421 
422 		desc = kzalloc(sizeof(*desc), GFP_KERNEL);
423 		if (!desc)
424 			break;
425 
426 		list_add_tail(&desc->node, &channel->ld_free);
427 		channel->descs_allocated++;
428 	}
429 
430 	if (!channel->descs_allocated)
431 		return -ENOMEM;
432 
433 	return channel->descs_allocated;
434 }
435 
436 static void rz_dmac_free_chan_resources(struct dma_chan *chan)
437 {
438 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
439 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
440 	struct rz_lmdesc *lmdesc = channel->lmdesc.base;
441 	struct rz_dmac_desc *desc, *_desc;
442 	unsigned long flags;
443 	unsigned int i;
444 
445 	spin_lock_irqsave(&channel->vc.lock, flags);
446 
447 	for (i = 0; i < DMAC_NR_LMDESC; i++)
448 		lmdesc[i].header = 0;
449 
450 	rz_dmac_disable_hw(channel);
451 	list_splice_tail_init(&channel->ld_active, &channel->ld_free);
452 	list_splice_tail_init(&channel->ld_queue, &channel->ld_free);
453 
454 	if (channel->mid_rid >= 0) {
455 		clear_bit(channel->mid_rid, dmac->modules);
456 		channel->mid_rid = -EINVAL;
457 	}
458 
459 	spin_unlock_irqrestore(&channel->vc.lock, flags);
460 
461 	list_for_each_entry_safe(desc, _desc, &channel->ld_free, node) {
462 		kfree(desc);
463 		channel->descs_allocated--;
464 	}
465 
466 	INIT_LIST_HEAD(&channel->ld_free);
467 	vchan_free_chan_resources(&channel->vc);
468 }
469 
470 static struct dma_async_tx_descriptor *
471 rz_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
472 			size_t len, unsigned long flags)
473 {
474 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
475 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
476 	struct rz_dmac_desc *desc;
477 
478 	dev_dbg(dmac->dev, "%s channel: %d src=0x%pad dst=0x%pad len=%zu\n",
479 		__func__, channel->index, &src, &dest, len);
480 
481 	if (list_empty(&channel->ld_free))
482 		return NULL;
483 
484 	desc = list_first_entry(&channel->ld_free, struct rz_dmac_desc, node);
485 
486 	desc->type = RZ_DMAC_DESC_MEMCPY;
487 	desc->src = src;
488 	desc->dest = dest;
489 	desc->len = len;
490 	desc->direction = DMA_MEM_TO_MEM;
491 
492 	list_move_tail(channel->ld_free.next, &channel->ld_queue);
493 	return vchan_tx_prep(&channel->vc, &desc->vd, flags);
494 }
495 
496 static struct dma_async_tx_descriptor *
497 rz_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
498 		      unsigned int sg_len,
499 		      enum dma_transfer_direction direction,
500 		      unsigned long flags, void *context)
501 {
502 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
503 	struct rz_dmac_desc *desc;
504 	struct scatterlist *sg;
505 	int dma_length = 0;
506 	int i = 0;
507 
508 	if (list_empty(&channel->ld_free))
509 		return NULL;
510 
511 	desc = list_first_entry(&channel->ld_free, struct rz_dmac_desc, node);
512 
513 	for_each_sg(sgl, sg, sg_len, i) {
514 		dma_length += sg_dma_len(sg);
515 	}
516 
517 	desc->type = RZ_DMAC_DESC_SLAVE_SG;
518 	desc->sg = sgl;
519 	desc->sgcount = sg_len;
520 	desc->len = dma_length;
521 	desc->direction = direction;
522 
523 	if (direction == DMA_DEV_TO_MEM)
524 		desc->src = channel->src_per_address;
525 	else
526 		desc->dest = channel->dst_per_address;
527 
528 	list_move_tail(channel->ld_free.next, &channel->ld_queue);
529 	return vchan_tx_prep(&channel->vc, &desc->vd, flags);
530 }
531 
532 static int rz_dmac_terminate_all(struct dma_chan *chan)
533 {
534 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
535 	unsigned long flags;
536 	LIST_HEAD(head);
537 
538 	rz_dmac_disable_hw(channel);
539 	spin_lock_irqsave(&channel->vc.lock, flags);
540 	list_splice_tail_init(&channel->ld_active, &channel->ld_free);
541 	list_splice_tail_init(&channel->ld_queue, &channel->ld_free);
542 	spin_unlock_irqrestore(&channel->vc.lock, flags);
543 	vchan_get_all_descriptors(&channel->vc, &head);
544 	vchan_dma_desc_free_list(&channel->vc, &head);
545 
546 	return 0;
547 }
548 
549 static void rz_dmac_issue_pending(struct dma_chan *chan)
550 {
551 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
552 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
553 	struct rz_dmac_desc *desc;
554 	unsigned long flags;
555 
556 	spin_lock_irqsave(&channel->vc.lock, flags);
557 
558 	if (!list_empty(&channel->ld_queue)) {
559 		desc = list_first_entry(&channel->ld_queue,
560 					struct rz_dmac_desc, node);
561 		channel->desc = desc;
562 		if (vchan_issue_pending(&channel->vc)) {
563 			if (rz_dmac_xfer_desc(channel) < 0)
564 				dev_warn(dmac->dev, "ch: %d couldn't issue DMA xfer\n",
565 					 channel->index);
566 			else
567 				list_move_tail(channel->ld_queue.next,
568 					       &channel->ld_active);
569 		}
570 	}
571 
572 	spin_unlock_irqrestore(&channel->vc.lock, flags);
573 }
574 
575 static u8 rz_dmac_ds_to_val_mapping(enum dma_slave_buswidth ds)
576 {
577 	u8 i;
578 	static const enum dma_slave_buswidth ds_lut[] = {
579 		DMA_SLAVE_BUSWIDTH_1_BYTE,
580 		DMA_SLAVE_BUSWIDTH_2_BYTES,
581 		DMA_SLAVE_BUSWIDTH_4_BYTES,
582 		DMA_SLAVE_BUSWIDTH_8_BYTES,
583 		DMA_SLAVE_BUSWIDTH_16_BYTES,
584 		DMA_SLAVE_BUSWIDTH_32_BYTES,
585 		DMA_SLAVE_BUSWIDTH_64_BYTES,
586 		DMA_SLAVE_BUSWIDTH_128_BYTES,
587 	};
588 
589 	for (i = 0; i < ARRAY_SIZE(ds_lut); i++) {
590 		if (ds_lut[i] == ds)
591 			return i;
592 	}
593 
594 	return CHCFG_DS_INVALID;
595 }
596 
597 static int rz_dmac_config(struct dma_chan *chan,
598 			  struct dma_slave_config *config)
599 {
600 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
601 	u32 val;
602 
603 	channel->src_per_address = config->src_addr;
604 	channel->src_word_size = config->src_addr_width;
605 	channel->dst_per_address = config->dst_addr;
606 	channel->dst_word_size = config->dst_addr_width;
607 
608 	val = rz_dmac_ds_to_val_mapping(config->dst_addr_width);
609 	if (val == CHCFG_DS_INVALID)
610 		return -EINVAL;
611 
612 	channel->chcfg |= CHCFG_FILL_DDS(val);
613 
614 	val = rz_dmac_ds_to_val_mapping(config->src_addr_width);
615 	if (val == CHCFG_DS_INVALID)
616 		return -EINVAL;
617 
618 	channel->chcfg |= CHCFG_FILL_SDS(val);
619 
620 	return 0;
621 }
622 
623 static void rz_dmac_virt_desc_free(struct virt_dma_desc *vd)
624 {
625 	/*
626 	 * Place holder
627 	 * Descriptor allocation is done during alloc_chan_resources and
628 	 * get freed during free_chan_resources.
629 	 * list is used to manage the descriptors and avoid any memory
630 	 * allocation/free during DMA read/write.
631 	 */
632 }
633 
634 static void rz_dmac_device_synchronize(struct dma_chan *chan)
635 {
636 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
637 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
638 	u32 chstat;
639 	int ret;
640 
641 	ret = read_poll_timeout(rz_dmac_ch_readl, chstat, !(chstat & CHSTAT_EN),
642 				100, 100000, false, channel, CHSTAT, 1);
643 	if (ret < 0)
644 		dev_warn(dmac->dev, "DMA Timeout");
645 
646 	rz_dmac_set_dmars_register(dmac, channel->index, 0);
647 }
648 
649 /*
650  * -----------------------------------------------------------------------------
651  * IRQ handling
652  */
653 
654 static void rz_dmac_irq_handle_channel(struct rz_dmac_chan *channel)
655 {
656 	struct dma_chan *chan = &channel->vc.chan;
657 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
658 	u32 chstat, chctrl;
659 
660 	chstat = rz_dmac_ch_readl(channel, CHSTAT, 1);
661 	if (chstat & CHSTAT_ER) {
662 		dev_err(dmac->dev, "DMAC err CHSTAT_%d = %08X\n",
663 			channel->index, chstat);
664 		rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1);
665 		goto done;
666 	}
667 
668 	chctrl = rz_dmac_ch_readl(channel, CHCTRL, 1);
669 	rz_dmac_ch_writel(channel, chctrl | CHCTRL_CLREND, CHCTRL, 1);
670 done:
671 	return;
672 }
673 
674 static irqreturn_t rz_dmac_irq_handler(int irq, void *dev_id)
675 {
676 	struct rz_dmac_chan *channel = dev_id;
677 
678 	if (channel) {
679 		rz_dmac_irq_handle_channel(channel);
680 		return IRQ_WAKE_THREAD;
681 	}
682 	/* handle DMAERR irq */
683 	return IRQ_HANDLED;
684 }
685 
686 static irqreturn_t rz_dmac_irq_handler_thread(int irq, void *dev_id)
687 {
688 	struct rz_dmac_chan *channel = dev_id;
689 	struct rz_dmac_desc *desc = NULL;
690 	unsigned long flags;
691 
692 	spin_lock_irqsave(&channel->vc.lock, flags);
693 
694 	if (list_empty(&channel->ld_active)) {
695 		/* Someone might have called terminate all */
696 		goto out;
697 	}
698 
699 	desc = list_first_entry(&channel->ld_active, struct rz_dmac_desc, node);
700 	vchan_cookie_complete(&desc->vd);
701 	list_move_tail(channel->ld_active.next, &channel->ld_free);
702 	if (!list_empty(&channel->ld_queue)) {
703 		desc = list_first_entry(&channel->ld_queue, struct rz_dmac_desc,
704 					node);
705 		channel->desc = desc;
706 		if (rz_dmac_xfer_desc(channel) == 0)
707 			list_move_tail(channel->ld_queue.next, &channel->ld_active);
708 	}
709 out:
710 	spin_unlock_irqrestore(&channel->vc.lock, flags);
711 
712 	return IRQ_HANDLED;
713 }
714 
715 /*
716  * -----------------------------------------------------------------------------
717  * OF xlate and channel filter
718  */
719 
720 static bool rz_dmac_chan_filter(struct dma_chan *chan, void *arg)
721 {
722 	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
723 	struct rz_dmac *dmac = to_rz_dmac(chan->device);
724 	struct of_phandle_args *dma_spec = arg;
725 	u32 ch_cfg;
726 
727 	channel->mid_rid = dma_spec->args[0] & MID_RID_MASK;
728 	ch_cfg = (dma_spec->args[0] & CHCFG_MASK) >> 10;
729 	channel->chcfg = CHCFG_FILL_TM(ch_cfg) | CHCFG_FILL_AM(ch_cfg) |
730 			 CHCFG_FILL_LVL(ch_cfg) | CHCFG_FILL_HIEN(ch_cfg);
731 
732 	return !test_and_set_bit(channel->mid_rid, dmac->modules);
733 }
734 
735 static struct dma_chan *rz_dmac_of_xlate(struct of_phandle_args *dma_spec,
736 					 struct of_dma *ofdma)
737 {
738 	dma_cap_mask_t mask;
739 
740 	if (dma_spec->args_count != 1)
741 		return NULL;
742 
743 	/* Only slave DMA channels can be allocated via DT */
744 	dma_cap_zero(mask);
745 	dma_cap_set(DMA_SLAVE, mask);
746 
747 	return dma_request_channel(mask, rz_dmac_chan_filter, dma_spec);
748 }
749 
750 /*
751  * -----------------------------------------------------------------------------
752  * Probe and remove
753  */
754 
755 static int rz_dmac_chan_probe(struct rz_dmac *dmac,
756 			      struct rz_dmac_chan *channel,
757 			      unsigned int index)
758 {
759 	struct platform_device *pdev = to_platform_device(dmac->dev);
760 	struct rz_lmdesc *lmdesc;
761 	char pdev_irqname[5];
762 	char *irqname;
763 	int ret;
764 
765 	channel->index = index;
766 	channel->mid_rid = -EINVAL;
767 
768 	/* Request the channel interrupt. */
769 	sprintf(pdev_irqname, "ch%u", index);
770 	channel->irq = platform_get_irq_byname(pdev, pdev_irqname);
771 	if (channel->irq < 0)
772 		return channel->irq;
773 
774 	irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u",
775 				 dev_name(dmac->dev), index);
776 	if (!irqname)
777 		return -ENOMEM;
778 
779 	ret = devm_request_threaded_irq(dmac->dev, channel->irq,
780 					rz_dmac_irq_handler,
781 					rz_dmac_irq_handler_thread, 0,
782 					irqname, channel);
783 	if (ret) {
784 		dev_err(dmac->dev, "failed to request IRQ %u (%d)\n",
785 			channel->irq, ret);
786 		return ret;
787 	}
788 
789 	/* Set io base address for each channel */
790 	if (index < 8) {
791 		channel->ch_base = dmac->base + CHANNEL_0_7_OFFSET +
792 			EACH_CHANNEL_OFFSET * index;
793 		channel->ch_cmn_base = dmac->base + CHANNEL_0_7_COMMON_BASE;
794 	} else {
795 		channel->ch_base = dmac->base + CHANNEL_8_15_OFFSET +
796 			EACH_CHANNEL_OFFSET * (index - 8);
797 		channel->ch_cmn_base = dmac->base + CHANNEL_8_15_COMMON_BASE;
798 	}
799 
800 	/* Allocate descriptors */
801 	lmdesc = dma_alloc_coherent(&pdev->dev,
802 				    sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC,
803 				    &channel->lmdesc.base_dma, GFP_KERNEL);
804 	if (!lmdesc) {
805 		dev_err(&pdev->dev, "Can't allocate memory (lmdesc)\n");
806 		return -ENOMEM;
807 	}
808 	rz_lmdesc_setup(channel, lmdesc);
809 
810 	/* Initialize register for each channel */
811 	rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1);
812 
813 	channel->vc.desc_free = rz_dmac_virt_desc_free;
814 	vchan_init(&channel->vc, &dmac->engine);
815 	INIT_LIST_HEAD(&channel->ld_queue);
816 	INIT_LIST_HEAD(&channel->ld_free);
817 	INIT_LIST_HEAD(&channel->ld_active);
818 
819 	return 0;
820 }
821 
822 static int rz_dmac_parse_of(struct device *dev, struct rz_dmac *dmac)
823 {
824 	struct device_node *np = dev->of_node;
825 	int ret;
826 
827 	ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels);
828 	if (ret < 0) {
829 		dev_err(dev, "unable to read dma-channels property\n");
830 		return ret;
831 	}
832 
833 	if (!dmac->n_channels || dmac->n_channels > RZ_DMAC_MAX_CHANNELS) {
834 		dev_err(dev, "invalid number of channels %u\n", dmac->n_channels);
835 		return -EINVAL;
836 	}
837 
838 	return 0;
839 }
840 
841 static int rz_dmac_probe(struct platform_device *pdev)
842 {
843 	const char *irqname = "error";
844 	struct dma_device *engine;
845 	struct rz_dmac *dmac;
846 	int channel_num;
847 	unsigned int i;
848 	int ret;
849 	int irq;
850 
851 	dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
852 	if (!dmac)
853 		return -ENOMEM;
854 
855 	dmac->dev = &pdev->dev;
856 	platform_set_drvdata(pdev, dmac);
857 
858 	ret = rz_dmac_parse_of(&pdev->dev, dmac);
859 	if (ret < 0)
860 		return ret;
861 
862 	dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
863 				      sizeof(*dmac->channels), GFP_KERNEL);
864 	if (!dmac->channels)
865 		return -ENOMEM;
866 
867 	/* Request resources */
868 	dmac->base = devm_platform_ioremap_resource(pdev, 0);
869 	if (IS_ERR(dmac->base))
870 		return PTR_ERR(dmac->base);
871 
872 	dmac->ext_base = devm_platform_ioremap_resource(pdev, 1);
873 	if (IS_ERR(dmac->ext_base))
874 		return PTR_ERR(dmac->ext_base);
875 
876 	/* Register interrupt handler for error */
877 	irq = platform_get_irq_byname(pdev, irqname);
878 	if (irq < 0)
879 		return irq;
880 
881 	ret = devm_request_irq(&pdev->dev, irq, rz_dmac_irq_handler, 0,
882 			       irqname, NULL);
883 	if (ret) {
884 		dev_err(&pdev->dev, "failed to request IRQ %u (%d)\n",
885 			irq, ret);
886 		return ret;
887 	}
888 
889 	/* Initialize the channels. */
890 	INIT_LIST_HEAD(&dmac->engine.channels);
891 
892 	pm_runtime_enable(&pdev->dev);
893 	ret = pm_runtime_resume_and_get(&pdev->dev);
894 	if (ret < 0) {
895 		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
896 		goto err_pm_disable;
897 	}
898 
899 	for (i = 0; i < dmac->n_channels; i++) {
900 		ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i);
901 		if (ret < 0)
902 			goto err;
903 	}
904 
905 	/* Register the DMAC as a DMA provider for DT. */
906 	ret = of_dma_controller_register(pdev->dev.of_node, rz_dmac_of_xlate,
907 					 NULL);
908 	if (ret < 0)
909 		goto err;
910 
911 	/* Register the DMA engine device. */
912 	engine = &dmac->engine;
913 	dma_cap_set(DMA_SLAVE, engine->cap_mask);
914 	dma_cap_set(DMA_MEMCPY, engine->cap_mask);
915 	rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_0_7_COMMON_BASE + DCTRL);
916 	rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_8_15_COMMON_BASE + DCTRL);
917 
918 	engine->dev = &pdev->dev;
919 
920 	engine->device_alloc_chan_resources = rz_dmac_alloc_chan_resources;
921 	engine->device_free_chan_resources = rz_dmac_free_chan_resources;
922 	engine->device_tx_status = dma_cookie_status;
923 	engine->device_prep_slave_sg = rz_dmac_prep_slave_sg;
924 	engine->device_prep_dma_memcpy = rz_dmac_prep_dma_memcpy;
925 	engine->device_config = rz_dmac_config;
926 	engine->device_terminate_all = rz_dmac_terminate_all;
927 	engine->device_issue_pending = rz_dmac_issue_pending;
928 	engine->device_synchronize = rz_dmac_device_synchronize;
929 
930 	engine->copy_align = DMAENGINE_ALIGN_1_BYTE;
931 	dma_set_max_seg_size(engine->dev, U32_MAX);
932 
933 	ret = dma_async_device_register(engine);
934 	if (ret < 0) {
935 		dev_err(&pdev->dev, "unable to register\n");
936 		goto dma_register_err;
937 	}
938 	return 0;
939 
940 dma_register_err:
941 	of_dma_controller_free(pdev->dev.of_node);
942 err:
943 	channel_num = i ? i - 1 : 0;
944 	for (i = 0; i < channel_num; i++) {
945 		struct rz_dmac_chan *channel = &dmac->channels[i];
946 
947 		dma_free_coherent(&pdev->dev,
948 				  sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC,
949 				  channel->lmdesc.base,
950 				  channel->lmdesc.base_dma);
951 	}
952 
953 	pm_runtime_put(&pdev->dev);
954 err_pm_disable:
955 	pm_runtime_disable(&pdev->dev);
956 
957 	return ret;
958 }
959 
960 static int rz_dmac_remove(struct platform_device *pdev)
961 {
962 	struct rz_dmac *dmac = platform_get_drvdata(pdev);
963 	unsigned int i;
964 
965 	for (i = 0; i < dmac->n_channels; i++) {
966 		struct rz_dmac_chan *channel = &dmac->channels[i];
967 
968 		dma_free_coherent(&pdev->dev,
969 				  sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC,
970 				  channel->lmdesc.base,
971 				  channel->lmdesc.base_dma);
972 	}
973 	of_dma_controller_free(pdev->dev.of_node);
974 	dma_async_device_unregister(&dmac->engine);
975 	pm_runtime_put(&pdev->dev);
976 	pm_runtime_disable(&pdev->dev);
977 
978 	return 0;
979 }
980 
981 static const struct of_device_id of_rz_dmac_match[] = {
982 	{ .compatible = "renesas,rz-dmac", },
983 	{ /* Sentinel */ }
984 };
985 MODULE_DEVICE_TABLE(of, of_rz_dmac_match);
986 
987 static struct platform_driver rz_dmac_driver = {
988 	.driver		= {
989 		.name	= "rz-dmac",
990 		.of_match_table = of_rz_dmac_match,
991 	},
992 	.probe		= rz_dmac_probe,
993 	.remove		= rz_dmac_remove,
994 };
995 
996 module_platform_driver(rz_dmac_driver);
997 
998 MODULE_DESCRIPTION("Renesas RZ/G2L DMA Controller Driver");
999 MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
1000 MODULE_LICENSE("GPL v2");
1001