xref: /openbmc/linux/drivers/dma/k3dma.c (revision 12eb4683)
1 /*
2  * Copyright (c) 2013 Linaro Ltd.
3  * Copyright (c) 2013 Hisilicon Limited.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 #include <linux/sched.h>
10 #include <linux/device.h>
11 #include <linux/dmaengine.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
19 #include <linux/of_device.h>
20 #include <linux/of.h>
21 #include <linux/clk.h>
22 #include <linux/of_dma.h>
23 
24 #include "virt-dma.h"
25 
26 #define DRIVER_NAME		"k3-dma"
27 #define DMA_ALIGN		3
28 #define DMA_MAX_SIZE		0x1ffc
29 
30 #define INT_STAT		0x00
31 #define INT_TC1			0x04
32 #define INT_ERR1		0x0c
33 #define INT_ERR2		0x10
34 #define INT_TC1_MASK		0x18
35 #define INT_ERR1_MASK		0x20
36 #define INT_ERR2_MASK		0x24
37 #define INT_TC1_RAW		0x600
38 #define INT_ERR1_RAW		0x608
39 #define INT_ERR2_RAW		0x610
40 #define CH_PRI			0x688
41 #define CH_STAT			0x690
42 #define CX_CUR_CNT		0x704
43 #define CX_LLI			0x800
44 #define CX_CNT			0x810
45 #define CX_SRC			0x814
46 #define CX_DST			0x818
47 #define CX_CFG			0x81c
48 #define AXI_CFG			0x820
49 #define AXI_CFG_DEFAULT		0x201201
50 
51 #define CX_LLI_CHAIN_EN		0x2
52 #define CX_CFG_EN		0x1
53 #define CX_CFG_MEM2PER		(0x1 << 2)
54 #define CX_CFG_PER2MEM		(0x2 << 2)
55 #define CX_CFG_SRCINCR		(0x1 << 31)
56 #define CX_CFG_DSTINCR		(0x1 << 30)
57 
58 struct k3_desc_hw {
59 	u32 lli;
60 	u32 reserved[3];
61 	u32 count;
62 	u32 saddr;
63 	u32 daddr;
64 	u32 config;
65 } __aligned(32);
66 
67 struct k3_dma_desc_sw {
68 	struct virt_dma_desc	vd;
69 	dma_addr_t		desc_hw_lli;
70 	size_t			desc_num;
71 	size_t			size;
72 	struct k3_desc_hw	desc_hw[0];
73 };
74 
75 struct k3_dma_phy;
76 
77 struct k3_dma_chan {
78 	u32			ccfg;
79 	struct virt_dma_chan	vc;
80 	struct k3_dma_phy	*phy;
81 	struct list_head	node;
82 	enum dma_transfer_direction dir;
83 	dma_addr_t		dev_addr;
84 	enum dma_status		status;
85 };
86 
87 struct k3_dma_phy {
88 	u32			idx;
89 	void __iomem		*base;
90 	struct k3_dma_chan	*vchan;
91 	struct k3_dma_desc_sw	*ds_run;
92 	struct k3_dma_desc_sw	*ds_done;
93 };
94 
95 struct k3_dma_dev {
96 	struct dma_device	slave;
97 	void __iomem		*base;
98 	struct tasklet_struct	task;
99 	spinlock_t		lock;
100 	struct list_head	chan_pending;
101 	struct k3_dma_phy	*phy;
102 	struct k3_dma_chan	*chans;
103 	struct clk		*clk;
104 	u32			dma_channels;
105 	u32			dma_requests;
106 };
107 
108 #define to_k3_dma(dmadev) container_of(dmadev, struct k3_dma_dev, slave)
109 
110 static struct k3_dma_chan *to_k3_chan(struct dma_chan *chan)
111 {
112 	return container_of(chan, struct k3_dma_chan, vc.chan);
113 }
114 
115 static void k3_dma_pause_dma(struct k3_dma_phy *phy, bool on)
116 {
117 	u32 val = 0;
118 
119 	if (on) {
120 		val = readl_relaxed(phy->base + CX_CFG);
121 		val |= CX_CFG_EN;
122 		writel_relaxed(val, phy->base + CX_CFG);
123 	} else {
124 		val = readl_relaxed(phy->base + CX_CFG);
125 		val &= ~CX_CFG_EN;
126 		writel_relaxed(val, phy->base + CX_CFG);
127 	}
128 }
129 
130 static void k3_dma_terminate_chan(struct k3_dma_phy *phy, struct k3_dma_dev *d)
131 {
132 	u32 val = 0;
133 
134 	k3_dma_pause_dma(phy, false);
135 
136 	val = 0x1 << phy->idx;
137 	writel_relaxed(val, d->base + INT_TC1_RAW);
138 	writel_relaxed(val, d->base + INT_ERR1_RAW);
139 	writel_relaxed(val, d->base + INT_ERR2_RAW);
140 }
141 
142 static void k3_dma_set_desc(struct k3_dma_phy *phy, struct k3_desc_hw *hw)
143 {
144 	writel_relaxed(hw->lli, phy->base + CX_LLI);
145 	writel_relaxed(hw->count, phy->base + CX_CNT);
146 	writel_relaxed(hw->saddr, phy->base + CX_SRC);
147 	writel_relaxed(hw->daddr, phy->base + CX_DST);
148 	writel_relaxed(AXI_CFG_DEFAULT, phy->base + AXI_CFG);
149 	writel_relaxed(hw->config, phy->base + CX_CFG);
150 }
151 
152 static u32 k3_dma_get_curr_cnt(struct k3_dma_dev *d, struct k3_dma_phy *phy)
153 {
154 	u32 cnt = 0;
155 
156 	cnt = readl_relaxed(d->base + CX_CUR_CNT + phy->idx * 0x10);
157 	cnt &= 0xffff;
158 	return cnt;
159 }
160 
161 static u32 k3_dma_get_curr_lli(struct k3_dma_phy *phy)
162 {
163 	return readl_relaxed(phy->base + CX_LLI);
164 }
165 
166 static u32 k3_dma_get_chan_stat(struct k3_dma_dev *d)
167 {
168 	return readl_relaxed(d->base + CH_STAT);
169 }
170 
171 static void k3_dma_enable_dma(struct k3_dma_dev *d, bool on)
172 {
173 	if (on) {
174 		/* set same priority */
175 		writel_relaxed(0x0, d->base + CH_PRI);
176 
177 		/* unmask irq */
178 		writel_relaxed(0xffff, d->base + INT_TC1_MASK);
179 		writel_relaxed(0xffff, d->base + INT_ERR1_MASK);
180 		writel_relaxed(0xffff, d->base + INT_ERR2_MASK);
181 	} else {
182 		/* mask irq */
183 		writel_relaxed(0x0, d->base + INT_TC1_MASK);
184 		writel_relaxed(0x0, d->base + INT_ERR1_MASK);
185 		writel_relaxed(0x0, d->base + INT_ERR2_MASK);
186 	}
187 }
188 
189 static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
190 {
191 	struct k3_dma_dev *d = (struct k3_dma_dev *)dev_id;
192 	struct k3_dma_phy *p;
193 	struct k3_dma_chan *c;
194 	u32 stat = readl_relaxed(d->base + INT_STAT);
195 	u32 tc1  = readl_relaxed(d->base + INT_TC1);
196 	u32 err1 = readl_relaxed(d->base + INT_ERR1);
197 	u32 err2 = readl_relaxed(d->base + INT_ERR2);
198 	u32 i, irq_chan = 0;
199 
200 	while (stat) {
201 		i = __ffs(stat);
202 		stat &= (stat - 1);
203 		if (likely(tc1 & BIT(i))) {
204 			p = &d->phy[i];
205 			c = p->vchan;
206 			if (c) {
207 				unsigned long flags;
208 
209 				spin_lock_irqsave(&c->vc.lock, flags);
210 				vchan_cookie_complete(&p->ds_run->vd);
211 				p->ds_done = p->ds_run;
212 				spin_unlock_irqrestore(&c->vc.lock, flags);
213 			}
214 			irq_chan |= BIT(i);
215 		}
216 		if (unlikely((err1 & BIT(i)) || (err2 & BIT(i))))
217 			dev_warn(d->slave.dev, "DMA ERR\n");
218 	}
219 
220 	writel_relaxed(irq_chan, d->base + INT_TC1_RAW);
221 	writel_relaxed(err1, d->base + INT_ERR1_RAW);
222 	writel_relaxed(err2, d->base + INT_ERR2_RAW);
223 
224 	if (irq_chan) {
225 		tasklet_schedule(&d->task);
226 		return IRQ_HANDLED;
227 	} else
228 		return IRQ_NONE;
229 }
230 
231 static int k3_dma_start_txd(struct k3_dma_chan *c)
232 {
233 	struct k3_dma_dev *d = to_k3_dma(c->vc.chan.device);
234 	struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
235 
236 	if (!c->phy)
237 		return -EAGAIN;
238 
239 	if (BIT(c->phy->idx) & k3_dma_get_chan_stat(d))
240 		return -EAGAIN;
241 
242 	if (vd) {
243 		struct k3_dma_desc_sw *ds =
244 			container_of(vd, struct k3_dma_desc_sw, vd);
245 		/*
246 		 * fetch and remove request from vc->desc_issued
247 		 * so vc->desc_issued only contains desc pending
248 		 */
249 		list_del(&ds->vd.node);
250 		c->phy->ds_run = ds;
251 		c->phy->ds_done = NULL;
252 		/* start dma */
253 		k3_dma_set_desc(c->phy, &ds->desc_hw[0]);
254 		return 0;
255 	}
256 	c->phy->ds_done = NULL;
257 	c->phy->ds_run = NULL;
258 	return -EAGAIN;
259 }
260 
261 static void k3_dma_tasklet(unsigned long arg)
262 {
263 	struct k3_dma_dev *d = (struct k3_dma_dev *)arg;
264 	struct k3_dma_phy *p;
265 	struct k3_dma_chan *c, *cn;
266 	unsigned pch, pch_alloc = 0;
267 
268 	/* check new dma request of running channel in vc->desc_issued */
269 	list_for_each_entry_safe(c, cn, &d->slave.channels, vc.chan.device_node) {
270 		spin_lock_irq(&c->vc.lock);
271 		p = c->phy;
272 		if (p && p->ds_done) {
273 			if (k3_dma_start_txd(c)) {
274 				/* No current txd associated with this channel */
275 				dev_dbg(d->slave.dev, "pchan %u: free\n", p->idx);
276 				/* Mark this channel free */
277 				c->phy = NULL;
278 				p->vchan = NULL;
279 			}
280 		}
281 		spin_unlock_irq(&c->vc.lock);
282 	}
283 
284 	/* check new channel request in d->chan_pending */
285 	spin_lock_irq(&d->lock);
286 	for (pch = 0; pch < d->dma_channels; pch++) {
287 		p = &d->phy[pch];
288 
289 		if (p->vchan == NULL && !list_empty(&d->chan_pending)) {
290 			c = list_first_entry(&d->chan_pending,
291 				struct k3_dma_chan, node);
292 			/* remove from d->chan_pending */
293 			list_del_init(&c->node);
294 			pch_alloc |= 1 << pch;
295 			/* Mark this channel allocated */
296 			p->vchan = c;
297 			c->phy = p;
298 			dev_dbg(d->slave.dev, "pchan %u: alloc vchan %p\n", pch, &c->vc);
299 		}
300 	}
301 	spin_unlock_irq(&d->lock);
302 
303 	for (pch = 0; pch < d->dma_channels; pch++) {
304 		if (pch_alloc & (1 << pch)) {
305 			p = &d->phy[pch];
306 			c = p->vchan;
307 			if (c) {
308 				spin_lock_irq(&c->vc.lock);
309 				k3_dma_start_txd(c);
310 				spin_unlock_irq(&c->vc.lock);
311 			}
312 		}
313 	}
314 }
315 
316 static int k3_dma_alloc_chan_resources(struct dma_chan *chan)
317 {
318 	return 0;
319 }
320 
321 static void k3_dma_free_chan_resources(struct dma_chan *chan)
322 {
323 	struct k3_dma_chan *c = to_k3_chan(chan);
324 	struct k3_dma_dev *d = to_k3_dma(chan->device);
325 	unsigned long flags;
326 
327 	spin_lock_irqsave(&d->lock, flags);
328 	list_del_init(&c->node);
329 	spin_unlock_irqrestore(&d->lock, flags);
330 
331 	vchan_free_chan_resources(&c->vc);
332 	c->ccfg = 0;
333 }
334 
335 static enum dma_status k3_dma_tx_status(struct dma_chan *chan,
336 	dma_cookie_t cookie, struct dma_tx_state *state)
337 {
338 	struct k3_dma_chan *c = to_k3_chan(chan);
339 	struct k3_dma_dev *d = to_k3_dma(chan->device);
340 	struct k3_dma_phy *p;
341 	struct virt_dma_desc *vd;
342 	unsigned long flags;
343 	enum dma_status ret;
344 	size_t bytes = 0;
345 
346 	ret = dma_cookie_status(&c->vc.chan, cookie, state);
347 	if (ret == DMA_COMPLETE)
348 		return ret;
349 
350 	spin_lock_irqsave(&c->vc.lock, flags);
351 	p = c->phy;
352 	ret = c->status;
353 
354 	/*
355 	 * If the cookie is on our issue queue, then the residue is
356 	 * its total size.
357 	 */
358 	vd = vchan_find_desc(&c->vc, cookie);
359 	if (vd) {
360 		bytes = container_of(vd, struct k3_dma_desc_sw, vd)->size;
361 	} else if ((!p) || (!p->ds_run)) {
362 		bytes = 0;
363 	} else {
364 		struct k3_dma_desc_sw *ds = p->ds_run;
365 		u32 clli = 0, index = 0;
366 
367 		bytes = k3_dma_get_curr_cnt(d, p);
368 		clli = k3_dma_get_curr_lli(p);
369 		index = (clli - ds->desc_hw_lli) / sizeof(struct k3_desc_hw);
370 		for (; index < ds->desc_num; index++) {
371 			bytes += ds->desc_hw[index].count;
372 			/* end of lli */
373 			if (!ds->desc_hw[index].lli)
374 				break;
375 		}
376 	}
377 	spin_unlock_irqrestore(&c->vc.lock, flags);
378 	dma_set_residue(state, bytes);
379 	return ret;
380 }
381 
382 static void k3_dma_issue_pending(struct dma_chan *chan)
383 {
384 	struct k3_dma_chan *c = to_k3_chan(chan);
385 	struct k3_dma_dev *d = to_k3_dma(chan->device);
386 	unsigned long flags;
387 
388 	spin_lock_irqsave(&c->vc.lock, flags);
389 	/* add request to vc->desc_issued */
390 	if (vchan_issue_pending(&c->vc)) {
391 		spin_lock(&d->lock);
392 		if (!c->phy) {
393 			if (list_empty(&c->node)) {
394 				/* if new channel, add chan_pending */
395 				list_add_tail(&c->node, &d->chan_pending);
396 				/* check in tasklet */
397 				tasklet_schedule(&d->task);
398 				dev_dbg(d->slave.dev, "vchan %p: issued\n", &c->vc);
399 			}
400 		}
401 		spin_unlock(&d->lock);
402 	} else
403 		dev_dbg(d->slave.dev, "vchan %p: nothing to issue\n", &c->vc);
404 	spin_unlock_irqrestore(&c->vc.lock, flags);
405 }
406 
407 static void k3_dma_fill_desc(struct k3_dma_desc_sw *ds, dma_addr_t dst,
408 			dma_addr_t src, size_t len, u32 num, u32 ccfg)
409 {
410 	if ((num + 1) < ds->desc_num)
411 		ds->desc_hw[num].lli = ds->desc_hw_lli + (num + 1) *
412 			sizeof(struct k3_desc_hw);
413 	ds->desc_hw[num].lli |= CX_LLI_CHAIN_EN;
414 	ds->desc_hw[num].count = len;
415 	ds->desc_hw[num].saddr = src;
416 	ds->desc_hw[num].daddr = dst;
417 	ds->desc_hw[num].config = ccfg;
418 }
419 
420 static struct dma_async_tx_descriptor *k3_dma_prep_memcpy(
421 	struct dma_chan *chan,	dma_addr_t dst, dma_addr_t src,
422 	size_t len, unsigned long flags)
423 {
424 	struct k3_dma_chan *c = to_k3_chan(chan);
425 	struct k3_dma_desc_sw *ds;
426 	size_t copy = 0;
427 	int num = 0;
428 
429 	if (!len)
430 		return NULL;
431 
432 	num = DIV_ROUND_UP(len, DMA_MAX_SIZE);
433 	ds = kzalloc(sizeof(*ds) + num * sizeof(ds->desc_hw[0]), GFP_ATOMIC);
434 	if (!ds) {
435 		dev_dbg(chan->device->dev, "vchan %p: kzalloc fail\n", &c->vc);
436 		return NULL;
437 	}
438 	ds->desc_hw_lli = __virt_to_phys((unsigned long)&ds->desc_hw[0]);
439 	ds->size = len;
440 	ds->desc_num = num;
441 	num = 0;
442 
443 	if (!c->ccfg) {
444 		/* default is memtomem, without calling device_control */
445 		c->ccfg = CX_CFG_SRCINCR | CX_CFG_DSTINCR | CX_CFG_EN;
446 		c->ccfg |= (0xf << 20) | (0xf << 24);	/* burst = 16 */
447 		c->ccfg |= (0x3 << 12) | (0x3 << 16);	/* width = 64 bit */
448 	}
449 
450 	do {
451 		copy = min_t(size_t, len, DMA_MAX_SIZE);
452 		k3_dma_fill_desc(ds, dst, src, copy, num++, c->ccfg);
453 
454 		if (c->dir == DMA_MEM_TO_DEV) {
455 			src += copy;
456 		} else if (c->dir == DMA_DEV_TO_MEM) {
457 			dst += copy;
458 		} else {
459 			src += copy;
460 			dst += copy;
461 		}
462 		len -= copy;
463 	} while (len);
464 
465 	ds->desc_hw[num-1].lli = 0;	/* end of link */
466 	return vchan_tx_prep(&c->vc, &ds->vd, flags);
467 }
468 
469 static struct dma_async_tx_descriptor *k3_dma_prep_slave_sg(
470 	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sglen,
471 	enum dma_transfer_direction dir, unsigned long flags, void *context)
472 {
473 	struct k3_dma_chan *c = to_k3_chan(chan);
474 	struct k3_dma_desc_sw *ds;
475 	size_t len, avail, total = 0;
476 	struct scatterlist *sg;
477 	dma_addr_t addr, src = 0, dst = 0;
478 	int num = sglen, i;
479 
480 	if (sgl == 0)
481 		return NULL;
482 
483 	for_each_sg(sgl, sg, sglen, i) {
484 		avail = sg_dma_len(sg);
485 		if (avail > DMA_MAX_SIZE)
486 			num += DIV_ROUND_UP(avail, DMA_MAX_SIZE) - 1;
487 	}
488 
489 	ds = kzalloc(sizeof(*ds) + num * sizeof(ds->desc_hw[0]), GFP_ATOMIC);
490 	if (!ds) {
491 		dev_dbg(chan->device->dev, "vchan %p: kzalloc fail\n", &c->vc);
492 		return NULL;
493 	}
494 	ds->desc_hw_lli = __virt_to_phys((unsigned long)&ds->desc_hw[0]);
495 	ds->desc_num = num;
496 	num = 0;
497 
498 	for_each_sg(sgl, sg, sglen, i) {
499 		addr = sg_dma_address(sg);
500 		avail = sg_dma_len(sg);
501 		total += avail;
502 
503 		do {
504 			len = min_t(size_t, avail, DMA_MAX_SIZE);
505 
506 			if (dir == DMA_MEM_TO_DEV) {
507 				src = addr;
508 				dst = c->dev_addr;
509 			} else if (dir == DMA_DEV_TO_MEM) {
510 				src = c->dev_addr;
511 				dst = addr;
512 			}
513 
514 			k3_dma_fill_desc(ds, dst, src, len, num++, c->ccfg);
515 
516 			addr += len;
517 			avail -= len;
518 		} while (avail);
519 	}
520 
521 	ds->desc_hw[num-1].lli = 0;	/* end of link */
522 	ds->size = total;
523 	return vchan_tx_prep(&c->vc, &ds->vd, flags);
524 }
525 
526 static int k3_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
527 	unsigned long arg)
528 {
529 	struct k3_dma_chan *c = to_k3_chan(chan);
530 	struct k3_dma_dev *d = to_k3_dma(chan->device);
531 	struct dma_slave_config *cfg = (void *)arg;
532 	struct k3_dma_phy *p = c->phy;
533 	unsigned long flags;
534 	u32 maxburst = 0, val = 0;
535 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
536 	LIST_HEAD(head);
537 
538 	switch (cmd) {
539 	case DMA_SLAVE_CONFIG:
540 		if (cfg == NULL)
541 			return -EINVAL;
542 		c->dir = cfg->direction;
543 		if (c->dir == DMA_DEV_TO_MEM) {
544 			c->ccfg = CX_CFG_DSTINCR;
545 			c->dev_addr = cfg->src_addr;
546 			maxburst = cfg->src_maxburst;
547 			width = cfg->src_addr_width;
548 		} else if (c->dir == DMA_MEM_TO_DEV) {
549 			c->ccfg = CX_CFG_SRCINCR;
550 			c->dev_addr = cfg->dst_addr;
551 			maxburst = cfg->dst_maxburst;
552 			width = cfg->dst_addr_width;
553 		}
554 		switch (width) {
555 		case DMA_SLAVE_BUSWIDTH_1_BYTE:
556 		case DMA_SLAVE_BUSWIDTH_2_BYTES:
557 		case DMA_SLAVE_BUSWIDTH_4_BYTES:
558 		case DMA_SLAVE_BUSWIDTH_8_BYTES:
559 			val =  __ffs(width);
560 			break;
561 		default:
562 			val = 3;
563 			break;
564 		}
565 		c->ccfg |= (val << 12) | (val << 16);
566 
567 		if ((maxburst == 0) || (maxburst > 16))
568 			val = 16;
569 		else
570 			val = maxburst - 1;
571 		c->ccfg |= (val << 20) | (val << 24);
572 		c->ccfg |= CX_CFG_MEM2PER | CX_CFG_EN;
573 
574 		/* specific request line */
575 		c->ccfg |= c->vc.chan.chan_id << 4;
576 		break;
577 
578 	case DMA_TERMINATE_ALL:
579 		dev_dbg(d->slave.dev, "vchan %p: terminate all\n", &c->vc);
580 
581 		/* Prevent this channel being scheduled */
582 		spin_lock(&d->lock);
583 		list_del_init(&c->node);
584 		spin_unlock(&d->lock);
585 
586 		/* Clear the tx descriptor lists */
587 		spin_lock_irqsave(&c->vc.lock, flags);
588 		vchan_get_all_descriptors(&c->vc, &head);
589 		if (p) {
590 			/* vchan is assigned to a pchan - stop the channel */
591 			k3_dma_terminate_chan(p, d);
592 			c->phy = NULL;
593 			p->vchan = NULL;
594 			p->ds_run = p->ds_done = NULL;
595 		}
596 		spin_unlock_irqrestore(&c->vc.lock, flags);
597 		vchan_dma_desc_free_list(&c->vc, &head);
598 		break;
599 
600 	case DMA_PAUSE:
601 		dev_dbg(d->slave.dev, "vchan %p: pause\n", &c->vc);
602 		if (c->status == DMA_IN_PROGRESS) {
603 			c->status = DMA_PAUSED;
604 			if (p) {
605 				k3_dma_pause_dma(p, false);
606 			} else {
607 				spin_lock(&d->lock);
608 				list_del_init(&c->node);
609 				spin_unlock(&d->lock);
610 			}
611 		}
612 		break;
613 
614 	case DMA_RESUME:
615 		dev_dbg(d->slave.dev, "vchan %p: resume\n", &c->vc);
616 		spin_lock_irqsave(&c->vc.lock, flags);
617 		if (c->status == DMA_PAUSED) {
618 			c->status = DMA_IN_PROGRESS;
619 			if (p) {
620 				k3_dma_pause_dma(p, true);
621 			} else if (!list_empty(&c->vc.desc_issued)) {
622 				spin_lock(&d->lock);
623 				list_add_tail(&c->node, &d->chan_pending);
624 				spin_unlock(&d->lock);
625 			}
626 		}
627 		spin_unlock_irqrestore(&c->vc.lock, flags);
628 		break;
629 	default:
630 		return -ENXIO;
631 	}
632 	return 0;
633 }
634 
635 static void k3_dma_free_desc(struct virt_dma_desc *vd)
636 {
637 	struct k3_dma_desc_sw *ds =
638 		container_of(vd, struct k3_dma_desc_sw, vd);
639 
640 	kfree(ds);
641 }
642 
643 static struct of_device_id k3_pdma_dt_ids[] = {
644 	{ .compatible = "hisilicon,k3-dma-1.0", },
645 	{}
646 };
647 MODULE_DEVICE_TABLE(of, k3_pdma_dt_ids);
648 
649 static struct dma_chan *k3_of_dma_simple_xlate(struct of_phandle_args *dma_spec,
650 						struct of_dma *ofdma)
651 {
652 	struct k3_dma_dev *d = ofdma->of_dma_data;
653 	unsigned int request = dma_spec->args[0];
654 
655 	if (request > d->dma_requests)
656 		return NULL;
657 
658 	return dma_get_slave_channel(&(d->chans[request].vc.chan));
659 }
660 
661 static int k3_dma_probe(struct platform_device *op)
662 {
663 	struct k3_dma_dev *d;
664 	const struct of_device_id *of_id;
665 	struct resource *iores;
666 	int i, ret, irq = 0;
667 
668 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
669 	if (!iores)
670 		return -EINVAL;
671 
672 	d = devm_kzalloc(&op->dev, sizeof(*d), GFP_KERNEL);
673 	if (!d)
674 		return -ENOMEM;
675 
676 	d->base = devm_ioremap_resource(&op->dev, iores);
677 	if (IS_ERR(d->base))
678 		return PTR_ERR(d->base);
679 
680 	of_id = of_match_device(k3_pdma_dt_ids, &op->dev);
681 	if (of_id) {
682 		of_property_read_u32((&op->dev)->of_node,
683 				"dma-channels", &d->dma_channels);
684 		of_property_read_u32((&op->dev)->of_node,
685 				"dma-requests", &d->dma_requests);
686 	}
687 
688 	d->clk = devm_clk_get(&op->dev, NULL);
689 	if (IS_ERR(d->clk)) {
690 		dev_err(&op->dev, "no dma clk\n");
691 		return PTR_ERR(d->clk);
692 	}
693 
694 	irq = platform_get_irq(op, 0);
695 	ret = devm_request_irq(&op->dev, irq,
696 			k3_dma_int_handler, 0, DRIVER_NAME, d);
697 	if (ret)
698 		return ret;
699 
700 	/* init phy channel */
701 	d->phy = devm_kzalloc(&op->dev,
702 		d->dma_channels * sizeof(struct k3_dma_phy), GFP_KERNEL);
703 	if (d->phy == NULL)
704 		return -ENOMEM;
705 
706 	for (i = 0; i < d->dma_channels; i++) {
707 		struct k3_dma_phy *p = &d->phy[i];
708 
709 		p->idx = i;
710 		p->base = d->base + i * 0x40;
711 	}
712 
713 	INIT_LIST_HEAD(&d->slave.channels);
714 	dma_cap_set(DMA_SLAVE, d->slave.cap_mask);
715 	dma_cap_set(DMA_MEMCPY, d->slave.cap_mask);
716 	d->slave.dev = &op->dev;
717 	d->slave.device_alloc_chan_resources = k3_dma_alloc_chan_resources;
718 	d->slave.device_free_chan_resources = k3_dma_free_chan_resources;
719 	d->slave.device_tx_status = k3_dma_tx_status;
720 	d->slave.device_prep_dma_memcpy = k3_dma_prep_memcpy;
721 	d->slave.device_prep_slave_sg = k3_dma_prep_slave_sg;
722 	d->slave.device_issue_pending = k3_dma_issue_pending;
723 	d->slave.device_control = k3_dma_control;
724 	d->slave.copy_align = DMA_ALIGN;
725 	d->slave.chancnt = d->dma_requests;
726 
727 	/* init virtual channel */
728 	d->chans = devm_kzalloc(&op->dev,
729 		d->dma_requests * sizeof(struct k3_dma_chan), GFP_KERNEL);
730 	if (d->chans == NULL)
731 		return -ENOMEM;
732 
733 	for (i = 0; i < d->dma_requests; i++) {
734 		struct k3_dma_chan *c = &d->chans[i];
735 
736 		c->status = DMA_IN_PROGRESS;
737 		INIT_LIST_HEAD(&c->node);
738 		c->vc.desc_free = k3_dma_free_desc;
739 		vchan_init(&c->vc, &d->slave);
740 	}
741 
742 	/* Enable clock before accessing registers */
743 	ret = clk_prepare_enable(d->clk);
744 	if (ret < 0) {
745 		dev_err(&op->dev, "clk_prepare_enable failed: %d\n", ret);
746 		return ret;
747 	}
748 
749 	k3_dma_enable_dma(d, true);
750 
751 	ret = dma_async_device_register(&d->slave);
752 	if (ret)
753 		return ret;
754 
755 	ret = of_dma_controller_register((&op->dev)->of_node,
756 					k3_of_dma_simple_xlate, d);
757 	if (ret)
758 		goto of_dma_register_fail;
759 
760 	spin_lock_init(&d->lock);
761 	INIT_LIST_HEAD(&d->chan_pending);
762 	tasklet_init(&d->task, k3_dma_tasklet, (unsigned long)d);
763 	platform_set_drvdata(op, d);
764 	dev_info(&op->dev, "initialized\n");
765 
766 	return 0;
767 
768 of_dma_register_fail:
769 	dma_async_device_unregister(&d->slave);
770 	return ret;
771 }
772 
773 static int k3_dma_remove(struct platform_device *op)
774 {
775 	struct k3_dma_chan *c, *cn;
776 	struct k3_dma_dev *d = platform_get_drvdata(op);
777 
778 	dma_async_device_unregister(&d->slave);
779 	of_dma_controller_free((&op->dev)->of_node);
780 
781 	list_for_each_entry_safe(c, cn, &d->slave.channels, vc.chan.device_node) {
782 		list_del(&c->vc.chan.device_node);
783 		tasklet_kill(&c->vc.task);
784 	}
785 	tasklet_kill(&d->task);
786 	clk_disable_unprepare(d->clk);
787 	return 0;
788 }
789 
790 static int k3_dma_suspend(struct device *dev)
791 {
792 	struct k3_dma_dev *d = dev_get_drvdata(dev);
793 	u32 stat = 0;
794 
795 	stat = k3_dma_get_chan_stat(d);
796 	if (stat) {
797 		dev_warn(d->slave.dev,
798 			"chan %d is running fail to suspend\n", stat);
799 		return -1;
800 	}
801 	k3_dma_enable_dma(d, false);
802 	clk_disable_unprepare(d->clk);
803 	return 0;
804 }
805 
806 static int k3_dma_resume(struct device *dev)
807 {
808 	struct k3_dma_dev *d = dev_get_drvdata(dev);
809 	int ret = 0;
810 
811 	ret = clk_prepare_enable(d->clk);
812 	if (ret < 0) {
813 		dev_err(d->slave.dev, "clk_prepare_enable failed: %d\n", ret);
814 		return ret;
815 	}
816 	k3_dma_enable_dma(d, true);
817 	return 0;
818 }
819 
820 SIMPLE_DEV_PM_OPS(k3_dma_pmops, k3_dma_suspend, k3_dma_resume);
821 
822 static struct platform_driver k3_pdma_driver = {
823 	.driver		= {
824 		.name	= DRIVER_NAME,
825 		.owner  = THIS_MODULE,
826 		.pm	= &k3_dma_pmops,
827 		.of_match_table = k3_pdma_dt_ids,
828 	},
829 	.probe		= k3_dma_probe,
830 	.remove		= k3_dma_remove,
831 };
832 
833 module_platform_driver(k3_pdma_driver);
834 
835 MODULE_DESCRIPTION("Hisilicon k3 DMA Driver");
836 MODULE_ALIAS("platform:k3dma");
837 MODULE_LICENSE("GPL v2");
838