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  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			unsigned long flags;
289
290			spin_lock_irqsave(&c->vc.lock, flags);
291			if (c->cyclic) {
292				vchan_cyclic_callback(&p->ds_run->vd);
293			} else {
294				vchan_cookie_complete(&p->ds_run->vd);
295				p->ds_done = p->ds_run;
296				task = 1;
297			}
298			spin_unlock_irqrestore(&c->vc.lock, flags);
299			irq_chan |= BIT(i);
300		}
301	}
302
303	if (serr || derr || cfg)
304		dev_warn(d->slave.dev, "DMA ERR src 0x%x, dst 0x%x, cfg 0x%x\n",
305			 serr, derr, cfg);
306
307	writel_relaxed(irq_chan, d->base + REG_ZX_TC_IRQ_RAW);
308	writel_relaxed(serr, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
309	writel_relaxed(derr, d->base + REG_ZX_DST_ERR_IRQ_RAW);
310	writel_relaxed(cfg, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
311
312	if (task)
313		zx_dma_task(d);
314	return IRQ_HANDLED;
315}
316
317static void zx_dma_free_chan_resources(struct dma_chan *chan)
318{
319	struct zx_dma_chan *c = to_zx_chan(chan);
320	struct zx_dma_dev *d = to_zx_dma(chan->device);
321	unsigned long flags;
322
323	spin_lock_irqsave(&d->lock, flags);
324	list_del_init(&c->node);
325	spin_unlock_irqrestore(&d->lock, flags);
326
327	vchan_free_chan_resources(&c->vc);
328	c->ccfg = 0;
329}
330
331static enum dma_status zx_dma_tx_status(struct dma_chan *chan,
332					dma_cookie_t cookie,
333					struct dma_tx_state *state)
334{
335	struct zx_dma_chan *c = to_zx_chan(chan);
336	struct zx_dma_phy *p;
337	struct virt_dma_desc *vd;
338	unsigned long flags;
339	enum dma_status ret;
340	size_t bytes = 0;
341
342	ret = dma_cookie_status(&c->vc.chan, cookie, state);
343	if (ret == DMA_COMPLETE || !state)
344		return ret;
345
346	spin_lock_irqsave(&c->vc.lock, flags);
347	p = c->phy;
348	ret = c->status;
349
350	/*
351	 * If the cookie is on our issue queue, then the residue is
352	 * its total size.
353	 */
354	vd = vchan_find_desc(&c->vc, cookie);
355	if (vd) {
356		bytes = container_of(vd, struct zx_dma_desc_sw, vd)->size;
357	} else if ((!p) || (!p->ds_run)) {
358		bytes = 0;
359	} else {
360		struct zx_dma_desc_sw *ds = p->ds_run;
361		u32 clli = 0, index = 0;
362
363		bytes = 0;
364		clli = zx_dma_get_curr_lli(p);
365		index = (clli - ds->desc_hw_lli) /
366				sizeof(struct zx_desc_hw) + 1;
367		for (; index < ds->desc_num; index++) {
368			bytes += ds->desc_hw[index].src_x;
369			/* end of lli */
370			if (!ds->desc_hw[index].lli)
371				break;
372		}
373	}
374	spin_unlock_irqrestore(&c->vc.lock, flags);
375	dma_set_residue(state, bytes);
376	return ret;
377}
378
379static void zx_dma_issue_pending(struct dma_chan *chan)
380{
381	struct zx_dma_chan *c = to_zx_chan(chan);
382	struct zx_dma_dev *d = to_zx_dma(chan->device);
383	unsigned long flags;
384	int issue = 0;
385
386	spin_lock_irqsave(&c->vc.lock, flags);
387	/* add request to vc->desc_issued */
388	if (vchan_issue_pending(&c->vc)) {
389		spin_lock(&d->lock);
390		if (!c->phy && list_empty(&c->node)) {
391			/* if new channel, add chan_pending */
392			list_add_tail(&c->node, &d->chan_pending);
393			issue = 1;
394			dev_dbg(d->slave.dev, "vchan %p: issued\n", &c->vc);
395		}
396		spin_unlock(&d->lock);
397	} else {
398		dev_dbg(d->slave.dev, "vchan %p: nothing to issue\n", &c->vc);
399	}
400	spin_unlock_irqrestore(&c->vc.lock, flags);
401
402	if (issue)
403		zx_dma_task(d);
404}
405
406static void zx_dma_fill_desc(struct zx_dma_desc_sw *ds, dma_addr_t dst,
407			     dma_addr_t src, size_t len, u32 num, u32 ccfg)
408{
409	if ((num + 1) < ds->desc_num)
410		ds->desc_hw[num].lli = ds->desc_hw_lli + (num + 1) *
411			sizeof(struct zx_desc_hw);
412	ds->desc_hw[num].saddr = src;
413	ds->desc_hw[num].daddr = dst;
414	ds->desc_hw[num].src_x = len;
415	ds->desc_hw[num].ctr = ccfg;
416}
417
418static struct zx_dma_desc_sw *zx_alloc_desc_resource(int num,
419						     struct dma_chan *chan)
420{
421	struct zx_dma_chan *c = to_zx_chan(chan);
422	struct zx_dma_desc_sw *ds;
423	struct zx_dma_dev *d = to_zx_dma(chan->device);
424	int lli_limit = LLI_BLOCK_SIZE / sizeof(struct zx_desc_hw);
425
426	if (num > lli_limit) {
427		dev_dbg(chan->device->dev, "vch %p: sg num %d exceed max %d\n",
428			&c->vc, num, lli_limit);
429		return NULL;
430	}
431
432	ds = kzalloc(sizeof(*ds), GFP_ATOMIC);
433	if (!ds)
434		return NULL;
435
436	ds->desc_hw = dma_pool_zalloc(d->pool, GFP_NOWAIT, &ds->desc_hw_lli);
437	if (!ds->desc_hw) {
438		dev_dbg(chan->device->dev, "vch %p: dma alloc fail\n", &c->vc);
439		kfree(ds);
440		return NULL;
441	}
442	ds->desc_num = num;
443	return ds;
444}
445
446static enum zx_dma_burst_width zx_dma_burst_width(enum dma_slave_buswidth width)
447{
448	switch (width) {
449	case DMA_SLAVE_BUSWIDTH_1_BYTE:
450	case DMA_SLAVE_BUSWIDTH_2_BYTES:
451	case DMA_SLAVE_BUSWIDTH_4_BYTES:
452	case DMA_SLAVE_BUSWIDTH_8_BYTES:
453		return ffs(width) - 1;
454	default:
455		return ZX_DMA_WIDTH_32BIT;
456	}
457}
458
459static int zx_pre_config(struct zx_dma_chan *c, enum dma_transfer_direction dir)
460{
461	struct dma_slave_config *cfg = &c->slave_cfg;
462	enum zx_dma_burst_width src_width;
463	enum zx_dma_burst_width dst_width;
464	u32 maxburst = 0;
465
466	switch (dir) {
467	case DMA_MEM_TO_MEM:
468		c->ccfg = ZX_CH_ENABLE | ZX_SOFT_REQ
469			| ZX_SRC_BURST_LEN(ZX_MAX_BURST_LEN - 1)
470			| ZX_SRC_BURST_WIDTH(ZX_DMA_WIDTH_32BIT)
471			| ZX_DST_BURST_WIDTH(ZX_DMA_WIDTH_32BIT);
472		break;
473	case DMA_MEM_TO_DEV:
474		c->dev_addr = cfg->dst_addr;
475		/* dst len is calculated from src width, len and dst width.
476		 * We need make sure dst len not exceed MAX LEN.
477		 * Trailing single transaction that does not fill a full
478		 * burst also require identical src/dst data width.
479		 */
480		dst_width = zx_dma_burst_width(cfg->dst_addr_width);
481		maxburst = cfg->dst_maxburst;
482		maxburst = maxburst < ZX_MAX_BURST_LEN ?
483				maxburst : ZX_MAX_BURST_LEN;
484		c->ccfg = ZX_DST_FIFO_MODE | ZX_CH_ENABLE
485			| ZX_SRC_BURST_LEN(maxburst - 1)
486			| ZX_SRC_BURST_WIDTH(dst_width)
487			| ZX_DST_BURST_WIDTH(dst_width);
488		break;
489	case DMA_DEV_TO_MEM:
490		c->dev_addr = cfg->src_addr;
491		src_width = zx_dma_burst_width(cfg->src_addr_width);
492		maxburst = cfg->src_maxburst;
493		maxburst = maxburst < ZX_MAX_BURST_LEN ?
494				maxburst : ZX_MAX_BURST_LEN;
495		c->ccfg = ZX_SRC_FIFO_MODE | ZX_CH_ENABLE
496			| ZX_SRC_BURST_LEN(maxburst - 1)
497			| ZX_SRC_BURST_WIDTH(src_width)
498			| ZX_DST_BURST_WIDTH(src_width);
499		break;
500	default:
501		return -EINVAL;
502	}
503	return 0;
504}
505
506static struct dma_async_tx_descriptor *zx_dma_prep_memcpy(
507	struct dma_chan *chan,	dma_addr_t dst, dma_addr_t src,
508	size_t len, unsigned long flags)
509{
510	struct zx_dma_chan *c = to_zx_chan(chan);
511	struct zx_dma_desc_sw *ds;
512	size_t copy = 0;
513	int num = 0;
514
515	if (!len)
516		return NULL;
517
518	if (zx_pre_config(c, DMA_MEM_TO_MEM))
519		return NULL;
520
521	num = DIV_ROUND_UP(len, DMA_MAX_SIZE);
522
523	ds = zx_alloc_desc_resource(num, chan);
524	if (!ds)
525		return NULL;
526
527	ds->size = len;
528	num = 0;
529
530	do {
531		copy = min_t(size_t, len, DMA_MAX_SIZE);
532		zx_dma_fill_desc(ds, dst, src, copy, num++, c->ccfg);
533
534		src += copy;
535		dst += copy;
536		len -= copy;
537	} while (len);
538
539	c->cyclic = 0;
540	ds->desc_hw[num - 1].lli = 0;	/* end of link */
541	ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
542	return vchan_tx_prep(&c->vc, &ds->vd, flags);
543}
544
545static struct dma_async_tx_descriptor *zx_dma_prep_slave_sg(
546	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sglen,
547	enum dma_transfer_direction dir, unsigned long flags, void *context)
548{
549	struct zx_dma_chan *c = to_zx_chan(chan);
550	struct zx_dma_desc_sw *ds;
551	size_t len, avail, total = 0;
552	struct scatterlist *sg;
553	dma_addr_t addr, src = 0, dst = 0;
554	int num = sglen, i;
555
556	if (!sgl)
557		return NULL;
558
559	if (zx_pre_config(c, dir))
560		return NULL;
561
562	for_each_sg(sgl, sg, sglen, i) {
563		avail = sg_dma_len(sg);
564		if (avail > DMA_MAX_SIZE)
565			num += DIV_ROUND_UP(avail, DMA_MAX_SIZE) - 1;
566	}
567
568	ds = zx_alloc_desc_resource(num, chan);
569	if (!ds)
570		return NULL;
571
572	c->cyclic = 0;
573	num = 0;
574	for_each_sg(sgl, sg, sglen, i) {
575		addr = sg_dma_address(sg);
576		avail = sg_dma_len(sg);
577		total += avail;
578
579		do {
580			len = min_t(size_t, avail, DMA_MAX_SIZE);
581
582			if (dir == DMA_MEM_TO_DEV) {
583				src = addr;
584				dst = c->dev_addr;
585			} else if (dir == DMA_DEV_TO_MEM) {
586				src = c->dev_addr;
587				dst = addr;
588			}
589
590			zx_dma_fill_desc(ds, dst, src, len, num++, c->ccfg);
591
592			addr += len;
593			avail -= len;
594		} while (avail);
595	}
596
597	ds->desc_hw[num - 1].lli = 0;	/* end of link */
598	ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
599	ds->size = total;
600	return vchan_tx_prep(&c->vc, &ds->vd, flags);
601}
602
603static struct dma_async_tx_descriptor *zx_dma_prep_dma_cyclic(
604		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
605		size_t period_len, enum dma_transfer_direction dir,
606		unsigned long flags)
607{
608	struct zx_dma_chan *c = to_zx_chan(chan);
609	struct zx_dma_desc_sw *ds;
610	dma_addr_t src = 0, dst = 0;
611	int num_periods = buf_len / period_len;
612	int buf = 0, num = 0;
613
614	if (period_len > DMA_MAX_SIZE) {
615		dev_err(chan->device->dev, "maximum period size exceeded\n");
616		return NULL;
617	}
618
619	if (zx_pre_config(c, dir))
620		return NULL;
621
622	ds = zx_alloc_desc_resource(num_periods, chan);
623	if (!ds)
624		return NULL;
625	c->cyclic = 1;
626
627	while (buf < buf_len) {
628		if (dir == DMA_MEM_TO_DEV) {
629			src = dma_addr;
630			dst = c->dev_addr;
631		} else if (dir == DMA_DEV_TO_MEM) {
632			src = c->dev_addr;
633			dst = dma_addr;
634		}
635		zx_dma_fill_desc(ds, dst, src, period_len, num++,
636				 c->ccfg | ZX_IRQ_ENABLE_ALL);
637		dma_addr += period_len;
638		buf += period_len;
639	}
640
641	ds->desc_hw[num - 1].lli = ds->desc_hw_lli;
642	ds->size = buf_len;
643	return vchan_tx_prep(&c->vc, &ds->vd, flags);
644}
645
646static int zx_dma_config(struct dma_chan *chan,
647			 struct dma_slave_config *cfg)
648{
649	struct zx_dma_chan *c = to_zx_chan(chan);
650
651	if (!cfg)
652		return -EINVAL;
653
654	memcpy(&c->slave_cfg, cfg, sizeof(*cfg));
655
656	return 0;
657}
658
659static int zx_dma_terminate_all(struct dma_chan *chan)
660{
661	struct zx_dma_chan *c = to_zx_chan(chan);
662	struct zx_dma_dev *d = to_zx_dma(chan->device);
663	struct zx_dma_phy *p = c->phy;
664	unsigned long flags;
665	LIST_HEAD(head);
666
667	dev_dbg(d->slave.dev, "vchan %p: terminate all\n", &c->vc);
668
669	/* Prevent this channel being scheduled */
670	spin_lock(&d->lock);
671	list_del_init(&c->node);
672	spin_unlock(&d->lock);
673
674	/* Clear the tx descriptor lists */
675	spin_lock_irqsave(&c->vc.lock, flags);
676	vchan_get_all_descriptors(&c->vc, &head);
677	if (p) {
678		/* vchan is assigned to a pchan - stop the channel */
679		zx_dma_terminate_chan(p, d);
680		c->phy = NULL;
681		p->vchan = NULL;
682		p->ds_run = NULL;
683		p->ds_done = NULL;
684	}
685	spin_unlock_irqrestore(&c->vc.lock, flags);
686	vchan_dma_desc_free_list(&c->vc, &head);
687
688	return 0;
689}
690
691static int zx_dma_transfer_pause(struct dma_chan *chan)
692{
693	struct zx_dma_chan *c = to_zx_chan(chan);
694	u32 val = 0;
695
696	val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
697	val &= ~ZX_CH_ENABLE;
698	writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
699
700	return 0;
701}
702
703static int zx_dma_transfer_resume(struct dma_chan *chan)
704{
705	struct zx_dma_chan *c = to_zx_chan(chan);
706	u32 val = 0;
707
708	val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
709	val |= ZX_CH_ENABLE;
710	writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
711
712	return 0;
713}
714
715static void zx_dma_free_desc(struct virt_dma_desc *vd)
716{
717	struct zx_dma_desc_sw *ds =
718		container_of(vd, struct zx_dma_desc_sw, vd);
719	struct zx_dma_dev *d = to_zx_dma(vd->tx.chan->device);
720
721	dma_pool_free(d->pool, ds->desc_hw, ds->desc_hw_lli);
722	kfree(ds);
723}
724
725static const struct of_device_id zx6702_dma_dt_ids[] = {
726	{ .compatible = "zte,zx296702-dma", },
727	{}
728};
729MODULE_DEVICE_TABLE(of, zx6702_dma_dt_ids);
730
731static struct dma_chan *zx_of_dma_simple_xlate(struct of_phandle_args *dma_spec,
732					       struct of_dma *ofdma)
733{
734	struct zx_dma_dev *d = ofdma->of_dma_data;
735	unsigned int request = dma_spec->args[0];
736	struct dma_chan *chan;
737	struct zx_dma_chan *c;
738
739	if (request >= d->dma_requests)
740		return NULL;
741
742	chan = dma_get_any_slave_channel(&d->slave);
743	if (!chan) {
744		dev_err(d->slave.dev, "get channel fail in %s.\n", __func__);
745		return NULL;
746	}
747	c = to_zx_chan(chan);
748	c->id = request;
749	dev_info(d->slave.dev, "zx_dma: pchan %u: alloc vchan %p\n",
750		 c->id, &c->vc);
751	return chan;
752}
753
754static int zx_dma_probe(struct platform_device *op)
755{
756	struct zx_dma_dev *d;
757	int i, ret = 0;
758
759	d = devm_kzalloc(&op->dev, sizeof(*d), GFP_KERNEL);
760	if (!d)
761		return -ENOMEM;
762
763	d->base = devm_platform_ioremap_resource(op, 0);
764	if (IS_ERR(d->base))
765		return PTR_ERR(d->base);
766
767	of_property_read_u32((&op->dev)->of_node,
768			     "dma-channels", &d->dma_channels);
769	of_property_read_u32((&op->dev)->of_node,
770			     "dma-requests", &d->dma_requests);
771	if (!d->dma_requests || !d->dma_channels)
772		return -EINVAL;
773
774	d->clk = devm_clk_get(&op->dev, NULL);
775	if (IS_ERR(d->clk)) {
776		dev_err(&op->dev, "no dma clk\n");
777		return PTR_ERR(d->clk);
778	}
779
780	d->irq = platform_get_irq(op, 0);
781	ret = devm_request_irq(&op->dev, d->irq, zx_dma_int_handler,
782			       0, DRIVER_NAME, d);
783	if (ret)
784		return ret;
785
786	/* A DMA memory pool for LLIs, align on 32-byte boundary */
787	d->pool = dmam_pool_create(DRIVER_NAME, &op->dev,
788			LLI_BLOCK_SIZE, 32, 0);
789	if (!d->pool)
790		return -ENOMEM;
791
792	/* init phy channel */
793	d->phy = devm_kcalloc(&op->dev,
794		d->dma_channels, sizeof(struct zx_dma_phy), GFP_KERNEL);
795	if (!d->phy)
796		return -ENOMEM;
797
798	for (i = 0; i < d->dma_channels; i++) {
799		struct zx_dma_phy *p = &d->phy[i];
800
801		p->idx = i;
802		p->base = d->base + i * 0x40;
803	}
804
805	INIT_LIST_HEAD(&d->slave.channels);
806	dma_cap_set(DMA_SLAVE, d->slave.cap_mask);
807	dma_cap_set(DMA_MEMCPY, d->slave.cap_mask);
808	dma_cap_set(DMA_CYCLIC, d->slave.cap_mask);
809	dma_cap_set(DMA_PRIVATE, d->slave.cap_mask);
810	d->slave.dev = &op->dev;
811	d->slave.device_free_chan_resources = zx_dma_free_chan_resources;
812	d->slave.device_tx_status = zx_dma_tx_status;
813	d->slave.device_prep_dma_memcpy = zx_dma_prep_memcpy;
814	d->slave.device_prep_slave_sg = zx_dma_prep_slave_sg;
815	d->slave.device_prep_dma_cyclic = zx_dma_prep_dma_cyclic;
816	d->slave.device_issue_pending = zx_dma_issue_pending;
817	d->slave.device_config = zx_dma_config;
818	d->slave.device_terminate_all = zx_dma_terminate_all;
819	d->slave.device_pause = zx_dma_transfer_pause;
820	d->slave.device_resume = zx_dma_transfer_resume;
821	d->slave.copy_align = DMA_ALIGN;
822	d->slave.src_addr_widths = ZX_DMA_BUSWIDTHS;
823	d->slave.dst_addr_widths = ZX_DMA_BUSWIDTHS;
824	d->slave.directions = BIT(DMA_MEM_TO_MEM) | BIT(DMA_MEM_TO_DEV)
825			| BIT(DMA_DEV_TO_MEM);
826	d->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
827
828	/* init virtual channel */
829	d->chans = devm_kcalloc(&op->dev,
830		d->dma_requests, sizeof(struct zx_dma_chan), GFP_KERNEL);
831	if (!d->chans)
832		return -ENOMEM;
833
834	for (i = 0; i < d->dma_requests; i++) {
835		struct zx_dma_chan *c = &d->chans[i];
836
837		c->status = DMA_IN_PROGRESS;
838		INIT_LIST_HEAD(&c->node);
839		c->vc.desc_free = zx_dma_free_desc;
840		vchan_init(&c->vc, &d->slave);
841	}
842
843	/* Enable clock before accessing registers */
844	ret = clk_prepare_enable(d->clk);
845	if (ret < 0) {
846		dev_err(&op->dev, "clk_prepare_enable failed: %d\n", ret);
847		goto zx_dma_out;
848	}
849
850	zx_dma_init_state(d);
851
852	spin_lock_init(&d->lock);
853	INIT_LIST_HEAD(&d->chan_pending);
854	platform_set_drvdata(op, d);
855
856	ret = dma_async_device_register(&d->slave);
857	if (ret)
858		goto clk_dis;
859
860	ret = of_dma_controller_register((&op->dev)->of_node,
861					 zx_of_dma_simple_xlate, d);
862	if (ret)
863		goto of_dma_register_fail;
864
865	dev_info(&op->dev, "initialized\n");
866	return 0;
867
868of_dma_register_fail:
869	dma_async_device_unregister(&d->slave);
870clk_dis:
871	clk_disable_unprepare(d->clk);
872zx_dma_out:
873	return ret;
874}
875
876static int zx_dma_remove(struct platform_device *op)
877{
878	struct zx_dma_chan *c, *cn;
879	struct zx_dma_dev *d = platform_get_drvdata(op);
880
881	/* explictly free the irq */
882	devm_free_irq(&op->dev, d->irq, d);
883
884	dma_async_device_unregister(&d->slave);
885	of_dma_controller_free((&op->dev)->of_node);
886
887	list_for_each_entry_safe(c, cn, &d->slave.channels,
888				 vc.chan.device_node) {
889		list_del(&c->vc.chan.device_node);
890	}
891	clk_disable_unprepare(d->clk);
892
893	return 0;
894}
895
896#ifdef CONFIG_PM_SLEEP
897static int zx_dma_suspend_dev(struct device *dev)
898{
899	struct zx_dma_dev *d = dev_get_drvdata(dev);
900	u32 stat = 0;
901
902	stat = zx_dma_get_chan_stat(d);
903	if (stat) {
904		dev_warn(d->slave.dev,
905			 "chan %d is running fail to suspend\n", stat);
906		return -1;
907	}
908	clk_disable_unprepare(d->clk);
909	return 0;
910}
911
912static int zx_dma_resume_dev(struct device *dev)
913{
914	struct zx_dma_dev *d = dev_get_drvdata(dev);
915	int ret = 0;
916
917	ret = clk_prepare_enable(d->clk);
918	if (ret < 0) {
919		dev_err(d->slave.dev, "clk_prepare_enable failed: %d\n", ret);
920		return ret;
921	}
922	zx_dma_init_state(d);
923	return 0;
924}
925#endif
926
927static SIMPLE_DEV_PM_OPS(zx_dma_pmops, zx_dma_suspend_dev, zx_dma_resume_dev);
928
929static struct platform_driver zx_pdma_driver = {
930	.driver		= {
931		.name	= DRIVER_NAME,
932		.pm	= &zx_dma_pmops,
933		.of_match_table = zx6702_dma_dt_ids,
934	},
935	.probe		= zx_dma_probe,
936	.remove		= zx_dma_remove,
937};
938
939module_platform_driver(zx_pdma_driver);
940
941MODULE_DESCRIPTION("ZTE ZX296702 DMA Driver");
942MODULE_AUTHOR("Jun Nie jun.nie@linaro.org");
943MODULE_LICENSE("GPL v2");