xref: /kernel/linux/linux-5.10/drivers/dma/zx_dma.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2015 Linaro.
4 */
5#include <linux/sched.h>
6#include <linux/device.h>
7#include <linux/dmaengine.h>
8#include <linux/dma-mapping.h>
9#include <linux/dmapool.h>
10#include <linux/init.h>
11#include <linux/interrupt.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/platform_device.h>
15#include <linux/slab.h>
16#include <linux/spinlock.h>
17#include <linux/of_device.h>
18#include <linux/of.h>
19#include <linux/clk.h>
20#include <linux/of_dma.h>
21
22#include "virt-dma.h"
23
24#define DRIVER_NAME		"zx-dma"
25#define DMA_ALIGN		4
26#define DMA_MAX_SIZE		(0x10000 - 512)
27#define LLI_BLOCK_SIZE		(4 * PAGE_SIZE)
28
29#define REG_ZX_SRC_ADDR			0x00
30#define REG_ZX_DST_ADDR			0x04
31#define REG_ZX_TX_X_COUNT		0x08
32#define REG_ZX_TX_ZY_COUNT		0x0c
33#define REG_ZX_SRC_ZY_STEP		0x10
34#define REG_ZX_DST_ZY_STEP		0x14
35#define REG_ZX_LLI_ADDR			0x1c
36#define REG_ZX_CTRL			0x20
37#define REG_ZX_TC_IRQ			0x800
38#define REG_ZX_SRC_ERR_IRQ		0x804
39#define REG_ZX_DST_ERR_IRQ		0x808
40#define REG_ZX_CFG_ERR_IRQ		0x80c
41#define REG_ZX_TC_IRQ_RAW		0x810
42#define REG_ZX_SRC_ERR_IRQ_RAW		0x814
43#define REG_ZX_DST_ERR_IRQ_RAW		0x818
44#define REG_ZX_CFG_ERR_IRQ_RAW		0x81c
45#define REG_ZX_STATUS			0x820
46#define REG_ZX_DMA_GRP_PRIO		0x824
47#define REG_ZX_DMA_ARB			0x828
48
49#define ZX_FORCE_CLOSE			BIT(31)
50#define ZX_DST_BURST_WIDTH(x)		(((x) & 0x7) << 13)
51#define ZX_MAX_BURST_LEN		16
52#define ZX_SRC_BURST_LEN(x)		(((x) & 0xf) << 9)
53#define ZX_SRC_BURST_WIDTH(x)		(((x) & 0x7) << 6)
54#define ZX_IRQ_ENABLE_ALL		(3 << 4)
55#define ZX_DST_FIFO_MODE		BIT(3)
56#define ZX_SRC_FIFO_MODE		BIT(2)
57#define ZX_SOFT_REQ			BIT(1)
58#define ZX_CH_ENABLE			BIT(0)
59
60#define ZX_DMA_BUSWIDTHS \
61	(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
62	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
63	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
64	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
65	BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
66
67enum zx_dma_burst_width {
68	ZX_DMA_WIDTH_8BIT	= 0,
69	ZX_DMA_WIDTH_16BIT	= 1,
70	ZX_DMA_WIDTH_32BIT	= 2,
71	ZX_DMA_WIDTH_64BIT	= 3,
72};
73
74struct zx_desc_hw {
75	u32 saddr;
76	u32 daddr;
77	u32 src_x;
78	u32 src_zy;
79	u32 src_zy_step;
80	u32 dst_zy_step;
81	u32 reserved1;
82	u32 lli;
83	u32 ctr;
84	u32 reserved[7]; /* pack as hardware registers region size */
85} __aligned(32);
86
87struct zx_dma_desc_sw {
88	struct virt_dma_desc	vd;
89	dma_addr_t		desc_hw_lli;
90	size_t			desc_num;
91	size_t			size;
92	struct zx_desc_hw	*desc_hw;
93};
94
95struct zx_dma_phy;
96
97struct zx_dma_chan {
98	struct dma_slave_config slave_cfg;
99	int			id; /* Request phy chan id */
100	u32			ccfg;
101	u32			cyclic;
102	struct virt_dma_chan	vc;
103	struct zx_dma_phy	*phy;
104	struct list_head	node;
105	dma_addr_t		dev_addr;
106	enum dma_status		status;
107};
108
109struct zx_dma_phy {
110	u32			idx;
111	void __iomem		*base;
112	struct zx_dma_chan	*vchan;
113	struct zx_dma_desc_sw	*ds_run;
114	struct zx_dma_desc_sw	*ds_done;
115};
116
117struct zx_dma_dev {
118	struct dma_device	slave;
119	void __iomem		*base;
120	spinlock_t		lock; /* lock for ch and phy */
121	struct list_head	chan_pending;
122	struct zx_dma_phy	*phy;
123	struct zx_dma_chan	*chans;
124	struct clk		*clk;
125	struct dma_pool		*pool;
126	u32			dma_channels;
127	u32			dma_requests;
128	int 			irq;
129};
130
131#define to_zx_dma(dmadev) container_of(dmadev, struct zx_dma_dev, slave)
132
133static struct zx_dma_chan *to_zx_chan(struct dma_chan *chan)
134{
135	return container_of(chan, struct zx_dma_chan, vc.chan);
136}
137
138static void zx_dma_terminate_chan(struct zx_dma_phy *phy, struct zx_dma_dev *d)
139{
140	u32 val = 0;
141
142	val = readl_relaxed(phy->base + REG_ZX_CTRL);
143	val &= ~ZX_CH_ENABLE;
144	val |= ZX_FORCE_CLOSE;
145	writel_relaxed(val, phy->base + REG_ZX_CTRL);
146
147	val = 0x1 << phy->idx;
148	writel_relaxed(val, d->base + REG_ZX_TC_IRQ_RAW);
149	writel_relaxed(val, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
150	writel_relaxed(val, d->base + REG_ZX_DST_ERR_IRQ_RAW);
151	writel_relaxed(val, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
152}
153
154static void zx_dma_set_desc(struct zx_dma_phy *phy, struct zx_desc_hw *hw)
155{
156	writel_relaxed(hw->saddr, phy->base + REG_ZX_SRC_ADDR);
157	writel_relaxed(hw->daddr, phy->base + REG_ZX_DST_ADDR);
158	writel_relaxed(hw->src_x, phy->base + REG_ZX_TX_X_COUNT);
159	writel_relaxed(0, phy->base + REG_ZX_TX_ZY_COUNT);
160	writel_relaxed(0, phy->base + REG_ZX_SRC_ZY_STEP);
161	writel_relaxed(0, phy->base + REG_ZX_DST_ZY_STEP);
162	writel_relaxed(hw->lli, phy->base + REG_ZX_LLI_ADDR);
163	writel_relaxed(hw->ctr, phy->base + REG_ZX_CTRL);
164}
165
166static u32 zx_dma_get_curr_lli(struct zx_dma_phy *phy)
167{
168	return readl_relaxed(phy->base + REG_ZX_LLI_ADDR);
169}
170
171static u32 zx_dma_get_chan_stat(struct zx_dma_dev *d)
172{
173	return readl_relaxed(d->base + REG_ZX_STATUS);
174}
175
176static void zx_dma_init_state(struct zx_dma_dev *d)
177{
178	/* set same priority */
179	writel_relaxed(0x0, d->base + REG_ZX_DMA_ARB);
180	/* clear all irq */
181	writel_relaxed(0xffffffff, d->base + REG_ZX_TC_IRQ_RAW);
182	writel_relaxed(0xffffffff, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
183	writel_relaxed(0xffffffff, d->base + REG_ZX_DST_ERR_IRQ_RAW);
184	writel_relaxed(0xffffffff, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
185}
186
187static int zx_dma_start_txd(struct zx_dma_chan *c)
188{
189	struct zx_dma_dev *d = to_zx_dma(c->vc.chan.device);
190	struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
191
192	if (!c->phy)
193		return -EAGAIN;
194
195	if (BIT(c->phy->idx) & zx_dma_get_chan_stat(d))
196		return -EAGAIN;
197
198	if (vd) {
199		struct zx_dma_desc_sw *ds =
200			container_of(vd, struct zx_dma_desc_sw, vd);
201		/*
202		 * fetch and remove request from vc->desc_issued
203		 * so vc->desc_issued only contains desc pending
204		 */
205		list_del(&ds->vd.node);
206		c->phy->ds_run = ds;
207		c->phy->ds_done = NULL;
208		/* start dma */
209		zx_dma_set_desc(c->phy, ds->desc_hw);
210		return 0;
211	}
212	c->phy->ds_done = NULL;
213	c->phy->ds_run = NULL;
214	return -EAGAIN;
215}
216
217static void zx_dma_task(struct zx_dma_dev *d)
218{
219	struct zx_dma_phy *p;
220	struct zx_dma_chan *c, *cn;
221	unsigned pch, pch_alloc = 0;
222	unsigned long flags;
223
224	/* check new dma request of running channel in vc->desc_issued */
225	list_for_each_entry_safe(c, cn, &d->slave.channels,
226				 vc.chan.device_node) {
227		spin_lock_irqsave(&c->vc.lock, flags);
228		p = c->phy;
229		if (p && p->ds_done && zx_dma_start_txd(c)) {
230			/* No current txd associated with this channel */
231			dev_dbg(d->slave.dev, "pchan %u: free\n", p->idx);
232			/* Mark this channel free */
233			c->phy = NULL;
234			p->vchan = NULL;
235		}
236		spin_unlock_irqrestore(&c->vc.lock, flags);
237	}
238
239	/* check new channel request in d->chan_pending */
240	spin_lock_irqsave(&d->lock, flags);
241	while (!list_empty(&d->chan_pending)) {
242		c = list_first_entry(&d->chan_pending,
243				     struct zx_dma_chan, node);
244		p = &d->phy[c->id];
245		if (!p->vchan) {
246			/* remove from d->chan_pending */
247			list_del_init(&c->node);
248			pch_alloc |= 1 << c->id;
249			/* Mark this channel allocated */
250			p->vchan = c;
251			c->phy = p;
252		} else {
253			dev_dbg(d->slave.dev, "pchan %u: busy!\n", c->id);
254		}
255	}
256	spin_unlock_irqrestore(&d->lock, flags);
257
258	for (pch = 0; pch < d->dma_channels; pch++) {
259		if (pch_alloc & (1 << pch)) {
260			p = &d->phy[pch];
261			c = p->vchan;
262			if (c) {
263				spin_lock_irqsave(&c->vc.lock, flags);
264				zx_dma_start_txd(c);
265				spin_unlock_irqrestore(&c->vc.lock, flags);
266			}
267		}
268	}
269}
270
271static irqreturn_t zx_dma_int_handler(int irq, void *dev_id)
272{
273	struct zx_dma_dev *d = (struct zx_dma_dev *)dev_id;
274	struct zx_dma_phy *p;
275	struct zx_dma_chan *c;
276	u32 tc = readl_relaxed(d->base + REG_ZX_TC_IRQ);
277	u32 serr = readl_relaxed(d->base + REG_ZX_SRC_ERR_IRQ);
278	u32 derr = readl_relaxed(d->base + REG_ZX_DST_ERR_IRQ);
279	u32 cfg = readl_relaxed(d->base + REG_ZX_CFG_ERR_IRQ);
280	u32 i, irq_chan = 0, task = 0;
281
282	while (tc) {
283		i = __ffs(tc);
284		tc &= ~BIT(i);
285		p = &d->phy[i];
286		c = p->vchan;
287		if (c) {
288			spin_lock(&c->vc.lock);
289			if (c->cyclic) {
290				vchan_cyclic_callback(&p->ds_run->vd);
291			} else {
292				vchan_cookie_complete(&p->ds_run->vd);
293				p->ds_done = p->ds_run;
294				task = 1;
295			}
296			spin_unlock(&c->vc.lock);
297			irq_chan |= BIT(i);
298		}
299	}
300
301	if (serr || derr || cfg)
302		dev_warn(d->slave.dev, "DMA ERR src 0x%x, dst 0x%x, cfg 0x%x\n",
303			 serr, derr, cfg);
304
305	writel_relaxed(irq_chan, d->base + REG_ZX_TC_IRQ_RAW);
306	writel_relaxed(serr, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
307	writel_relaxed(derr, d->base + REG_ZX_DST_ERR_IRQ_RAW);
308	writel_relaxed(cfg, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
309
310	if (task)
311		zx_dma_task(d);
312	return IRQ_HANDLED;
313}
314
315static void zx_dma_free_chan_resources(struct dma_chan *chan)
316{
317	struct zx_dma_chan *c = to_zx_chan(chan);
318	struct zx_dma_dev *d = to_zx_dma(chan->device);
319	unsigned long flags;
320
321	spin_lock_irqsave(&d->lock, flags);
322	list_del_init(&c->node);
323	spin_unlock_irqrestore(&d->lock, flags);
324
325	vchan_free_chan_resources(&c->vc);
326	c->ccfg = 0;
327}
328
329static enum dma_status zx_dma_tx_status(struct dma_chan *chan,
330					dma_cookie_t cookie,
331					struct dma_tx_state *state)
332{
333	struct zx_dma_chan *c = to_zx_chan(chan);
334	struct zx_dma_phy *p;
335	struct virt_dma_desc *vd;
336	unsigned long flags;
337	enum dma_status ret;
338	size_t bytes = 0;
339
340	ret = dma_cookie_status(&c->vc.chan, cookie, state);
341	if (ret == DMA_COMPLETE || !state)
342		return ret;
343
344	spin_lock_irqsave(&c->vc.lock, flags);
345	p = c->phy;
346	ret = c->status;
347
348	/*
349	 * If the cookie is on our issue queue, then the residue is
350	 * its total size.
351	 */
352	vd = vchan_find_desc(&c->vc, cookie);
353	if (vd) {
354		bytes = container_of(vd, struct zx_dma_desc_sw, vd)->size;
355	} else if ((!p) || (!p->ds_run)) {
356		bytes = 0;
357	} else {
358		struct zx_dma_desc_sw *ds = p->ds_run;
359		u32 clli = 0, index = 0;
360
361		bytes = 0;
362		clli = zx_dma_get_curr_lli(p);
363		index = (clli - ds->desc_hw_lli) /
364				sizeof(struct zx_desc_hw) + 1;
365		for (; index < ds->desc_num; index++) {
366			bytes += ds->desc_hw[index].src_x;
367			/* end of lli */
368			if (!ds->desc_hw[index].lli)
369				break;
370		}
371	}
372	spin_unlock_irqrestore(&c->vc.lock, flags);
373	dma_set_residue(state, bytes);
374	return ret;
375}
376
377static void zx_dma_issue_pending(struct dma_chan *chan)
378{
379	struct zx_dma_chan *c = to_zx_chan(chan);
380	struct zx_dma_dev *d = to_zx_dma(chan->device);
381	unsigned long flags;
382	int issue = 0;
383
384	spin_lock_irqsave(&c->vc.lock, flags);
385	/* add request to vc->desc_issued */
386	if (vchan_issue_pending(&c->vc)) {
387		spin_lock(&d->lock);
388		if (!c->phy && list_empty(&c->node)) {
389			/* if new channel, add chan_pending */
390			list_add_tail(&c->node, &d->chan_pending);
391			issue = 1;
392			dev_dbg(d->slave.dev, "vchan %p: issued\n", &c->vc);
393		}
394		spin_unlock(&d->lock);
395	} else {
396		dev_dbg(d->slave.dev, "vchan %p: nothing to issue\n", &c->vc);
397	}
398	spin_unlock_irqrestore(&c->vc.lock, flags);
399
400	if (issue)
401		zx_dma_task(d);
402}
403
404static void zx_dma_fill_desc(struct zx_dma_desc_sw *ds, dma_addr_t dst,
405			     dma_addr_t src, size_t len, u32 num, u32 ccfg)
406{
407	if ((num + 1) < ds->desc_num)
408		ds->desc_hw[num].lli = ds->desc_hw_lli + (num + 1) *
409			sizeof(struct zx_desc_hw);
410	ds->desc_hw[num].saddr = src;
411	ds->desc_hw[num].daddr = dst;
412	ds->desc_hw[num].src_x = len;
413	ds->desc_hw[num].ctr = ccfg;
414}
415
416static struct zx_dma_desc_sw *zx_alloc_desc_resource(int num,
417						     struct dma_chan *chan)
418{
419	struct zx_dma_chan *c = to_zx_chan(chan);
420	struct zx_dma_desc_sw *ds;
421	struct zx_dma_dev *d = to_zx_dma(chan->device);
422	int lli_limit = LLI_BLOCK_SIZE / sizeof(struct zx_desc_hw);
423
424	if (num > lli_limit) {
425		dev_dbg(chan->device->dev, "vch %p: sg num %d exceed max %d\n",
426			&c->vc, num, lli_limit);
427		return NULL;
428	}
429
430	ds = kzalloc(sizeof(*ds), GFP_ATOMIC);
431	if (!ds)
432		return NULL;
433
434	ds->desc_hw = dma_pool_zalloc(d->pool, GFP_NOWAIT, &ds->desc_hw_lli);
435	if (!ds->desc_hw) {
436		dev_dbg(chan->device->dev, "vch %p: dma alloc fail\n", &c->vc);
437		kfree(ds);
438		return NULL;
439	}
440	ds->desc_num = num;
441	return ds;
442}
443
444static enum zx_dma_burst_width zx_dma_burst_width(enum dma_slave_buswidth width)
445{
446	switch (width) {
447	case DMA_SLAVE_BUSWIDTH_1_BYTE:
448	case DMA_SLAVE_BUSWIDTH_2_BYTES:
449	case DMA_SLAVE_BUSWIDTH_4_BYTES:
450	case DMA_SLAVE_BUSWIDTH_8_BYTES:
451		return ffs(width) - 1;
452	default:
453		return ZX_DMA_WIDTH_32BIT;
454	}
455}
456
457static int zx_pre_config(struct zx_dma_chan *c, enum dma_transfer_direction dir)
458{
459	struct dma_slave_config *cfg = &c->slave_cfg;
460	enum zx_dma_burst_width src_width;
461	enum zx_dma_burst_width dst_width;
462	u32 maxburst = 0;
463
464	switch (dir) {
465	case DMA_MEM_TO_MEM:
466		c->ccfg = ZX_CH_ENABLE | ZX_SOFT_REQ
467			| ZX_SRC_BURST_LEN(ZX_MAX_BURST_LEN - 1)
468			| ZX_SRC_BURST_WIDTH(ZX_DMA_WIDTH_32BIT)
469			| ZX_DST_BURST_WIDTH(ZX_DMA_WIDTH_32BIT);
470		break;
471	case DMA_MEM_TO_DEV:
472		c->dev_addr = cfg->dst_addr;
473		/* dst len is calculated from src width, len and dst width.
474		 * We need make sure dst len not exceed MAX LEN.
475		 * Trailing single transaction that does not fill a full
476		 * burst also require identical src/dst data width.
477		 */
478		dst_width = zx_dma_burst_width(cfg->dst_addr_width);
479		maxburst = cfg->dst_maxburst;
480		maxburst = maxburst < ZX_MAX_BURST_LEN ?
481				maxburst : ZX_MAX_BURST_LEN;
482		c->ccfg = ZX_DST_FIFO_MODE | ZX_CH_ENABLE
483			| ZX_SRC_BURST_LEN(maxburst - 1)
484			| ZX_SRC_BURST_WIDTH(dst_width)
485			| ZX_DST_BURST_WIDTH(dst_width);
486		break;
487	case DMA_DEV_TO_MEM:
488		c->dev_addr = cfg->src_addr;
489		src_width = zx_dma_burst_width(cfg->src_addr_width);
490		maxburst = cfg->src_maxburst;
491		maxburst = maxburst < ZX_MAX_BURST_LEN ?
492				maxburst : ZX_MAX_BURST_LEN;
493		c->ccfg = ZX_SRC_FIFO_MODE | ZX_CH_ENABLE
494			| ZX_SRC_BURST_LEN(maxburst - 1)
495			| ZX_SRC_BURST_WIDTH(src_width)
496			| ZX_DST_BURST_WIDTH(src_width);
497		break;
498	default:
499		return -EINVAL;
500	}
501	return 0;
502}
503
504static struct dma_async_tx_descriptor *zx_dma_prep_memcpy(
505	struct dma_chan *chan,	dma_addr_t dst, dma_addr_t src,
506	size_t len, unsigned long flags)
507{
508	struct zx_dma_chan *c = to_zx_chan(chan);
509	struct zx_dma_desc_sw *ds;
510	size_t copy = 0;
511	int num = 0;
512
513	if (!len)
514		return NULL;
515
516	if (zx_pre_config(c, DMA_MEM_TO_MEM))
517		return NULL;
518
519	num = DIV_ROUND_UP(len, DMA_MAX_SIZE);
520
521	ds = zx_alloc_desc_resource(num, chan);
522	if (!ds)
523		return NULL;
524
525	ds->size = len;
526	num = 0;
527
528	do {
529		copy = min_t(size_t, len, DMA_MAX_SIZE);
530		zx_dma_fill_desc(ds, dst, src, copy, num++, c->ccfg);
531
532		src += copy;
533		dst += copy;
534		len -= copy;
535	} while (len);
536
537	c->cyclic = 0;
538	ds->desc_hw[num - 1].lli = 0;	/* end of link */
539	ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
540	return vchan_tx_prep(&c->vc, &ds->vd, flags);
541}
542
543static struct dma_async_tx_descriptor *zx_dma_prep_slave_sg(
544	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sglen,
545	enum dma_transfer_direction dir, unsigned long flags, void *context)
546{
547	struct zx_dma_chan *c = to_zx_chan(chan);
548	struct zx_dma_desc_sw *ds;
549	size_t len, avail, total = 0;
550	struct scatterlist *sg;
551	dma_addr_t addr, src = 0, dst = 0;
552	int num = sglen, i;
553
554	if (!sgl)
555		return NULL;
556
557	if (zx_pre_config(c, dir))
558		return NULL;
559
560	for_each_sg(sgl, sg, sglen, i) {
561		avail = sg_dma_len(sg);
562		if (avail > DMA_MAX_SIZE)
563			num += DIV_ROUND_UP(avail, DMA_MAX_SIZE) - 1;
564	}
565
566	ds = zx_alloc_desc_resource(num, chan);
567	if (!ds)
568		return NULL;
569
570	c->cyclic = 0;
571	num = 0;
572	for_each_sg(sgl, sg, sglen, i) {
573		addr = sg_dma_address(sg);
574		avail = sg_dma_len(sg);
575		total += avail;
576
577		do {
578			len = min_t(size_t, avail, DMA_MAX_SIZE);
579
580			if (dir == DMA_MEM_TO_DEV) {
581				src = addr;
582				dst = c->dev_addr;
583			} else if (dir == DMA_DEV_TO_MEM) {
584				src = c->dev_addr;
585				dst = addr;
586			}
587
588			zx_dma_fill_desc(ds, dst, src, len, num++, c->ccfg);
589
590			addr += len;
591			avail -= len;
592		} while (avail);
593	}
594
595	ds->desc_hw[num - 1].lli = 0;	/* end of link */
596	ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
597	ds->size = total;
598	return vchan_tx_prep(&c->vc, &ds->vd, flags);
599}
600
601static struct dma_async_tx_descriptor *zx_dma_prep_dma_cyclic(
602		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
603		size_t period_len, enum dma_transfer_direction dir,
604		unsigned long flags)
605{
606	struct zx_dma_chan *c = to_zx_chan(chan);
607	struct zx_dma_desc_sw *ds;
608	dma_addr_t src = 0, dst = 0;
609	int num_periods = buf_len / period_len;
610	int buf = 0, num = 0;
611
612	if (period_len > DMA_MAX_SIZE) {
613		dev_err(chan->device->dev, "maximum period size exceeded\n");
614		return NULL;
615	}
616
617	if (zx_pre_config(c, dir))
618		return NULL;
619
620	ds = zx_alloc_desc_resource(num_periods, chan);
621	if (!ds)
622		return NULL;
623	c->cyclic = 1;
624
625	while (buf < buf_len) {
626		if (dir == DMA_MEM_TO_DEV) {
627			src = dma_addr;
628			dst = c->dev_addr;
629		} else if (dir == DMA_DEV_TO_MEM) {
630			src = c->dev_addr;
631			dst = dma_addr;
632		}
633		zx_dma_fill_desc(ds, dst, src, period_len, num++,
634				 c->ccfg | ZX_IRQ_ENABLE_ALL);
635		dma_addr += period_len;
636		buf += period_len;
637	}
638
639	ds->desc_hw[num - 1].lli = ds->desc_hw_lli;
640	ds->size = buf_len;
641	return vchan_tx_prep(&c->vc, &ds->vd, flags);
642}
643
644static int zx_dma_config(struct dma_chan *chan,
645			 struct dma_slave_config *cfg)
646{
647	struct zx_dma_chan *c = to_zx_chan(chan);
648
649	if (!cfg)
650		return -EINVAL;
651
652	memcpy(&c->slave_cfg, cfg, sizeof(*cfg));
653
654	return 0;
655}
656
657static int zx_dma_terminate_all(struct dma_chan *chan)
658{
659	struct zx_dma_chan *c = to_zx_chan(chan);
660	struct zx_dma_dev *d = to_zx_dma(chan->device);
661	struct zx_dma_phy *p = c->phy;
662	unsigned long flags;
663	LIST_HEAD(head);
664
665	dev_dbg(d->slave.dev, "vchan %p: terminate all\n", &c->vc);
666
667	/* Prevent this channel being scheduled */
668	spin_lock(&d->lock);
669	list_del_init(&c->node);
670	spin_unlock(&d->lock);
671
672	/* Clear the tx descriptor lists */
673	spin_lock_irqsave(&c->vc.lock, flags);
674	vchan_get_all_descriptors(&c->vc, &head);
675	if (p) {
676		/* vchan is assigned to a pchan - stop the channel */
677		zx_dma_terminate_chan(p, d);
678		c->phy = NULL;
679		p->vchan = NULL;
680		p->ds_run = NULL;
681		p->ds_done = NULL;
682	}
683	spin_unlock_irqrestore(&c->vc.lock, flags);
684	vchan_dma_desc_free_list(&c->vc, &head);
685
686	return 0;
687}
688
689static int zx_dma_transfer_pause(struct dma_chan *chan)
690{
691	struct zx_dma_chan *c = to_zx_chan(chan);
692	u32 val = 0;
693
694	val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
695	val &= ~ZX_CH_ENABLE;
696	writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
697
698	return 0;
699}
700
701static int zx_dma_transfer_resume(struct dma_chan *chan)
702{
703	struct zx_dma_chan *c = to_zx_chan(chan);
704	u32 val = 0;
705
706	val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
707	val |= ZX_CH_ENABLE;
708	writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
709
710	return 0;
711}
712
713static void zx_dma_free_desc(struct virt_dma_desc *vd)
714{
715	struct zx_dma_desc_sw *ds =
716		container_of(vd, struct zx_dma_desc_sw, vd);
717	struct zx_dma_dev *d = to_zx_dma(vd->tx.chan->device);
718
719	dma_pool_free(d->pool, ds->desc_hw, ds->desc_hw_lli);
720	kfree(ds);
721}
722
723static const struct of_device_id zx6702_dma_dt_ids[] = {
724	{ .compatible = "zte,zx296702-dma", },
725	{}
726};
727MODULE_DEVICE_TABLE(of, zx6702_dma_dt_ids);
728
729static struct dma_chan *zx_of_dma_simple_xlate(struct of_phandle_args *dma_spec,
730					       struct of_dma *ofdma)
731{
732	struct zx_dma_dev *d = ofdma->of_dma_data;
733	unsigned int request = dma_spec->args[0];
734	struct dma_chan *chan;
735	struct zx_dma_chan *c;
736
737	if (request >= d->dma_requests)
738		return NULL;
739
740	chan = dma_get_any_slave_channel(&d->slave);
741	if (!chan) {
742		dev_err(d->slave.dev, "get channel fail in %s.\n", __func__);
743		return NULL;
744	}
745	c = to_zx_chan(chan);
746	c->id = request;
747	dev_info(d->slave.dev, "zx_dma: pchan %u: alloc vchan %p\n",
748		 c->id, &c->vc);
749	return chan;
750}
751
752static int zx_dma_probe(struct platform_device *op)
753{
754	struct zx_dma_dev *d;
755	int i, ret = 0;
756
757	d = devm_kzalloc(&op->dev, sizeof(*d), GFP_KERNEL);
758	if (!d)
759		return -ENOMEM;
760
761	d->base = devm_platform_ioremap_resource(op, 0);
762	if (IS_ERR(d->base))
763		return PTR_ERR(d->base);
764
765	of_property_read_u32((&op->dev)->of_node,
766			     "dma-channels", &d->dma_channels);
767	of_property_read_u32((&op->dev)->of_node,
768			     "dma-requests", &d->dma_requests);
769	if (!d->dma_requests || !d->dma_channels)
770		return -EINVAL;
771
772	d->clk = devm_clk_get(&op->dev, NULL);
773	if (IS_ERR(d->clk)) {
774		dev_err(&op->dev, "no dma clk\n");
775		return PTR_ERR(d->clk);
776	}
777
778	d->irq = platform_get_irq(op, 0);
779	ret = devm_request_irq(&op->dev, d->irq, zx_dma_int_handler,
780			       0, DRIVER_NAME, d);
781	if (ret)
782		return ret;
783
784	/* A DMA memory pool for LLIs, align on 32-byte boundary */
785	d->pool = dmam_pool_create(DRIVER_NAME, &op->dev,
786			LLI_BLOCK_SIZE, 32, 0);
787	if (!d->pool)
788		return -ENOMEM;
789
790	/* init phy channel */
791	d->phy = devm_kcalloc(&op->dev,
792		d->dma_channels, sizeof(struct zx_dma_phy), GFP_KERNEL);
793	if (!d->phy)
794		return -ENOMEM;
795
796	for (i = 0; i < d->dma_channels; i++) {
797		struct zx_dma_phy *p = &d->phy[i];
798
799		p->idx = i;
800		p->base = d->base + i * 0x40;
801	}
802
803	INIT_LIST_HEAD(&d->slave.channels);
804	dma_cap_set(DMA_SLAVE, d->slave.cap_mask);
805	dma_cap_set(DMA_MEMCPY, d->slave.cap_mask);
806	dma_cap_set(DMA_CYCLIC, d->slave.cap_mask);
807	dma_cap_set(DMA_PRIVATE, d->slave.cap_mask);
808	d->slave.dev = &op->dev;
809	d->slave.device_free_chan_resources = zx_dma_free_chan_resources;
810	d->slave.device_tx_status = zx_dma_tx_status;
811	d->slave.device_prep_dma_memcpy = zx_dma_prep_memcpy;
812	d->slave.device_prep_slave_sg = zx_dma_prep_slave_sg;
813	d->slave.device_prep_dma_cyclic = zx_dma_prep_dma_cyclic;
814	d->slave.device_issue_pending = zx_dma_issue_pending;
815	d->slave.device_config = zx_dma_config;
816	d->slave.device_terminate_all = zx_dma_terminate_all;
817	d->slave.device_pause = zx_dma_transfer_pause;
818	d->slave.device_resume = zx_dma_transfer_resume;
819	d->slave.copy_align = DMA_ALIGN;
820	d->slave.src_addr_widths = ZX_DMA_BUSWIDTHS;
821	d->slave.dst_addr_widths = ZX_DMA_BUSWIDTHS;
822	d->slave.directions = BIT(DMA_MEM_TO_MEM) | BIT(DMA_MEM_TO_DEV)
823			| BIT(DMA_DEV_TO_MEM);
824	d->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
825
826	/* init virtual channel */
827	d->chans = devm_kcalloc(&op->dev,
828		d->dma_requests, sizeof(struct zx_dma_chan), GFP_KERNEL);
829	if (!d->chans)
830		return -ENOMEM;
831
832	for (i = 0; i < d->dma_requests; i++) {
833		struct zx_dma_chan *c = &d->chans[i];
834
835		c->status = DMA_IN_PROGRESS;
836		INIT_LIST_HEAD(&c->node);
837		c->vc.desc_free = zx_dma_free_desc;
838		vchan_init(&c->vc, &d->slave);
839	}
840
841	/* Enable clock before accessing registers */
842	ret = clk_prepare_enable(d->clk);
843	if (ret < 0) {
844		dev_err(&op->dev, "clk_prepare_enable failed: %d\n", ret);
845		goto zx_dma_out;
846	}
847
848	zx_dma_init_state(d);
849
850	spin_lock_init(&d->lock);
851	INIT_LIST_HEAD(&d->chan_pending);
852	platform_set_drvdata(op, d);
853
854	ret = dma_async_device_register(&d->slave);
855	if (ret)
856		goto clk_dis;
857
858	ret = of_dma_controller_register((&op->dev)->of_node,
859					 zx_of_dma_simple_xlate, d);
860	if (ret)
861		goto of_dma_register_fail;
862
863	dev_info(&op->dev, "initialized\n");
864	return 0;
865
866of_dma_register_fail:
867	dma_async_device_unregister(&d->slave);
868clk_dis:
869	clk_disable_unprepare(d->clk);
870zx_dma_out:
871	return ret;
872}
873
874static int zx_dma_remove(struct platform_device *op)
875{
876	struct zx_dma_chan *c, *cn;
877	struct zx_dma_dev *d = platform_get_drvdata(op);
878
879	/* explictly free the irq */
880	devm_free_irq(&op->dev, d->irq, d);
881
882	dma_async_device_unregister(&d->slave);
883	of_dma_controller_free((&op->dev)->of_node);
884
885	list_for_each_entry_safe(c, cn, &d->slave.channels,
886				 vc.chan.device_node) {
887		list_del(&c->vc.chan.device_node);
888	}
889	clk_disable_unprepare(d->clk);
890
891	return 0;
892}
893
894#ifdef CONFIG_PM_SLEEP
895static int zx_dma_suspend_dev(struct device *dev)
896{
897	struct zx_dma_dev *d = dev_get_drvdata(dev);
898	u32 stat = 0;
899
900	stat = zx_dma_get_chan_stat(d);
901	if (stat) {
902		dev_warn(d->slave.dev,
903			 "chan %d is running fail to suspend\n", stat);
904		return -1;
905	}
906	clk_disable_unprepare(d->clk);
907	return 0;
908}
909
910static int zx_dma_resume_dev(struct device *dev)
911{
912	struct zx_dma_dev *d = dev_get_drvdata(dev);
913	int ret = 0;
914
915	ret = clk_prepare_enable(d->clk);
916	if (ret < 0) {
917		dev_err(d->slave.dev, "clk_prepare_enable failed: %d\n", ret);
918		return ret;
919	}
920	zx_dma_init_state(d);
921	return 0;
922}
923#endif
924
925static SIMPLE_DEV_PM_OPS(zx_dma_pmops, zx_dma_suspend_dev, zx_dma_resume_dev);
926
927static struct platform_driver zx_pdma_driver = {
928	.driver		= {
929		.name	= DRIVER_NAME,
930		.pm	= &zx_dma_pmops,
931		.of_match_table = zx6702_dma_dt_ids,
932	},
933	.probe		= zx_dma_probe,
934	.remove		= zx_dma_remove,
935};
936
937module_platform_driver(zx_pdma_driver);
938
939MODULE_DESCRIPTION("ZTE ZX296702 DMA Driver");
940MODULE_AUTHOR("Jun Nie jun.nie@linaro.org");
941MODULE_LICENSE("GPL v2");
942