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  1/*
  2 *  Copyright (C) 2013, Lars-Peter Clausen <lars@metafoo.de>
  3 *  JZ4740 DMAC support
  4 *
  5 *  This program is free software; you can redistribute it and/or modify it
  6 *  under  the terms of the GNU General	 Public License as published by the
  7 *  Free Software Foundation;  either version 2 of the License, or (at your
  8 *  option) any later version.
  9 *
 10 */
 11
 12#include <linux/dmaengine.h>
 13#include <linux/dma-mapping.h>
 14#include <linux/err.h>
 15#include <linux/init.h>
 16#include <linux/list.h>
 17#include <linux/module.h>
 18#include <linux/platform_device.h>
 19#include <linux/slab.h>
 20#include <linux/spinlock.h>
 21#include <linux/irq.h>
 22#include <linux/clk.h>
 23
 24#include "virt-dma.h"
 25
 26#define JZ_DMA_NR_CHANS 6
 27
 28#define JZ_REG_DMA_SRC_ADDR(x)		(0x00 + (x) * 0x20)
 29#define JZ_REG_DMA_DST_ADDR(x)		(0x04 + (x) * 0x20)
 30#define JZ_REG_DMA_TRANSFER_COUNT(x)	(0x08 + (x) * 0x20)
 31#define JZ_REG_DMA_REQ_TYPE(x)		(0x0C + (x) * 0x20)
 32#define JZ_REG_DMA_STATUS_CTRL(x)	(0x10 + (x) * 0x20)
 33#define JZ_REG_DMA_CMD(x)		(0x14 + (x) * 0x20)
 34#define JZ_REG_DMA_DESC_ADDR(x)		(0x18 + (x) * 0x20)
 35
 36#define JZ_REG_DMA_CTRL			0x300
 37#define JZ_REG_DMA_IRQ			0x304
 38#define JZ_REG_DMA_DOORBELL		0x308
 39#define JZ_REG_DMA_DOORBELL_SET		0x30C
 40
 41#define JZ_DMA_STATUS_CTRL_NO_DESC		BIT(31)
 42#define JZ_DMA_STATUS_CTRL_DESC_INV		BIT(6)
 43#define JZ_DMA_STATUS_CTRL_ADDR_ERR		BIT(4)
 44#define JZ_DMA_STATUS_CTRL_TRANSFER_DONE	BIT(3)
 45#define JZ_DMA_STATUS_CTRL_HALT			BIT(2)
 46#define JZ_DMA_STATUS_CTRL_COUNT_TERMINATE	BIT(1)
 47#define JZ_DMA_STATUS_CTRL_ENABLE		BIT(0)
 48
 49#define JZ_DMA_CMD_SRC_INC			BIT(23)
 50#define JZ_DMA_CMD_DST_INC			BIT(22)
 51#define JZ_DMA_CMD_RDIL_MASK			(0xf << 16)
 52#define JZ_DMA_CMD_SRC_WIDTH_MASK		(0x3 << 14)
 53#define JZ_DMA_CMD_DST_WIDTH_MASK		(0x3 << 12)
 54#define JZ_DMA_CMD_INTERVAL_LENGTH_MASK		(0x7 << 8)
 55#define JZ_DMA_CMD_BLOCK_MODE			BIT(7)
 56#define JZ_DMA_CMD_DESC_VALID			BIT(4)
 57#define JZ_DMA_CMD_DESC_VALID_MODE		BIT(3)
 58#define JZ_DMA_CMD_VALID_IRQ_ENABLE		BIT(2)
 59#define JZ_DMA_CMD_TRANSFER_IRQ_ENABLE		BIT(1)
 60#define JZ_DMA_CMD_LINK_ENABLE			BIT(0)
 61
 62#define JZ_DMA_CMD_FLAGS_OFFSET 22
 63#define JZ_DMA_CMD_RDIL_OFFSET 16
 64#define JZ_DMA_CMD_SRC_WIDTH_OFFSET 14
 65#define JZ_DMA_CMD_DST_WIDTH_OFFSET 12
 66#define JZ_DMA_CMD_TRANSFER_SIZE_OFFSET 8
 67#define JZ_DMA_CMD_MODE_OFFSET 7
 68
 69#define JZ_DMA_CTRL_PRIORITY_MASK		(0x3 << 8)
 70#define JZ_DMA_CTRL_HALT			BIT(3)
 71#define JZ_DMA_CTRL_ADDRESS_ERROR		BIT(2)
 72#define JZ_DMA_CTRL_ENABLE			BIT(0)
 73
 74enum jz4740_dma_width {
 75	JZ4740_DMA_WIDTH_32BIT	= 0,
 76	JZ4740_DMA_WIDTH_8BIT	= 1,
 77	JZ4740_DMA_WIDTH_16BIT	= 2,
 78};
 79
 80enum jz4740_dma_transfer_size {
 81	JZ4740_DMA_TRANSFER_SIZE_4BYTE	= 0,
 82	JZ4740_DMA_TRANSFER_SIZE_1BYTE	= 1,
 83	JZ4740_DMA_TRANSFER_SIZE_2BYTE	= 2,
 84	JZ4740_DMA_TRANSFER_SIZE_16BYTE = 3,
 85	JZ4740_DMA_TRANSFER_SIZE_32BYTE = 4,
 86};
 87
 88enum jz4740_dma_flags {
 89	JZ4740_DMA_SRC_AUTOINC = 0x2,
 90	JZ4740_DMA_DST_AUTOINC = 0x1,
 91};
 92
 93enum jz4740_dma_mode {
 94	JZ4740_DMA_MODE_SINGLE	= 0,
 95	JZ4740_DMA_MODE_BLOCK	= 1,
 96};
 97
 98struct jz4740_dma_sg {
 99	dma_addr_t addr;
100	unsigned int len;
101};
102
103struct jz4740_dma_desc {
104	struct virt_dma_desc vdesc;
105
106	enum dma_transfer_direction direction;
107	bool cyclic;
108
109	unsigned int num_sgs;
110	struct jz4740_dma_sg sg[];
111};
112
113struct jz4740_dmaengine_chan {
114	struct virt_dma_chan vchan;
115	unsigned int id;
116
117	dma_addr_t fifo_addr;
118	unsigned int transfer_shift;
119
120	struct jz4740_dma_desc *desc;
121	unsigned int next_sg;
122};
123
124struct jz4740_dma_dev {
125	struct dma_device ddev;
126	void __iomem *base;
127	struct clk *clk;
128
129	struct jz4740_dmaengine_chan chan[JZ_DMA_NR_CHANS];
130};
131
132static struct jz4740_dma_dev *jz4740_dma_chan_get_dev(
133	struct jz4740_dmaengine_chan *chan)
134{
135	return container_of(chan->vchan.chan.device, struct jz4740_dma_dev,
136		ddev);
137}
138
139static struct jz4740_dmaengine_chan *to_jz4740_dma_chan(struct dma_chan *c)
140{
141	return container_of(c, struct jz4740_dmaengine_chan, vchan.chan);
142}
143
144static struct jz4740_dma_desc *to_jz4740_dma_desc(struct virt_dma_desc *vdesc)
145{
146	return container_of(vdesc, struct jz4740_dma_desc, vdesc);
147}
148
149static inline uint32_t jz4740_dma_read(struct jz4740_dma_dev *dmadev,
150	unsigned int reg)
151{
152	return readl(dmadev->base + reg);
153}
154
155static inline void jz4740_dma_write(struct jz4740_dma_dev *dmadev,
156	unsigned reg, uint32_t val)
157{
158	writel(val, dmadev->base + reg);
159}
160
161static inline void jz4740_dma_write_mask(struct jz4740_dma_dev *dmadev,
162	unsigned int reg, uint32_t val, uint32_t mask)
163{
164	uint32_t tmp;
165
166	tmp = jz4740_dma_read(dmadev, reg);
167	tmp &= ~mask;
168	tmp |= val;
169	jz4740_dma_write(dmadev, reg, tmp);
170}
171
172static struct jz4740_dma_desc *jz4740_dma_alloc_desc(unsigned int num_sgs)
173{
174	return kzalloc(sizeof(struct jz4740_dma_desc) +
175		sizeof(struct jz4740_dma_sg) * num_sgs, GFP_ATOMIC);
176}
177
178static enum jz4740_dma_width jz4740_dma_width(enum dma_slave_buswidth width)
179{
180	switch (width) {
181	case DMA_SLAVE_BUSWIDTH_1_BYTE:
182		return JZ4740_DMA_WIDTH_8BIT;
183	case DMA_SLAVE_BUSWIDTH_2_BYTES:
184		return JZ4740_DMA_WIDTH_16BIT;
185	case DMA_SLAVE_BUSWIDTH_4_BYTES:
186		return JZ4740_DMA_WIDTH_32BIT;
187	default:
188		return JZ4740_DMA_WIDTH_32BIT;
189	}
190}
191
192static enum jz4740_dma_transfer_size jz4740_dma_maxburst(u32 maxburst)
193{
194	if (maxburst <= 1)
195		return JZ4740_DMA_TRANSFER_SIZE_1BYTE;
196	else if (maxburst <= 3)
197		return JZ4740_DMA_TRANSFER_SIZE_2BYTE;
198	else if (maxburst <= 15)
199		return JZ4740_DMA_TRANSFER_SIZE_4BYTE;
200	else if (maxburst <= 31)
201		return JZ4740_DMA_TRANSFER_SIZE_16BYTE;
202
203	return JZ4740_DMA_TRANSFER_SIZE_32BYTE;
204}
205
206static int jz4740_dma_slave_config(struct dma_chan *c,
207				   struct dma_slave_config *config)
208{
209	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
210	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
211	enum jz4740_dma_width src_width;
212	enum jz4740_dma_width dst_width;
213	enum jz4740_dma_transfer_size transfer_size;
214	enum jz4740_dma_flags flags;
215	uint32_t cmd;
216
217	switch (config->direction) {
218	case DMA_MEM_TO_DEV:
219		flags = JZ4740_DMA_SRC_AUTOINC;
220		transfer_size = jz4740_dma_maxburst(config->dst_maxburst);
221		chan->fifo_addr = config->dst_addr;
222		break;
223	case DMA_DEV_TO_MEM:
224		flags = JZ4740_DMA_DST_AUTOINC;
225		transfer_size = jz4740_dma_maxburst(config->src_maxburst);
226		chan->fifo_addr = config->src_addr;
227		break;
228	default:
229		return -EINVAL;
230	}
231
232	src_width = jz4740_dma_width(config->src_addr_width);
233	dst_width = jz4740_dma_width(config->dst_addr_width);
234
235	switch (transfer_size) {
236	case JZ4740_DMA_TRANSFER_SIZE_2BYTE:
237		chan->transfer_shift = 1;
238		break;
239	case JZ4740_DMA_TRANSFER_SIZE_4BYTE:
240		chan->transfer_shift = 2;
241		break;
242	case JZ4740_DMA_TRANSFER_SIZE_16BYTE:
243		chan->transfer_shift = 4;
244		break;
245	case JZ4740_DMA_TRANSFER_SIZE_32BYTE:
246		chan->transfer_shift = 5;
247		break;
248	default:
249		chan->transfer_shift = 0;
250		break;
251	}
252
253	cmd = flags << JZ_DMA_CMD_FLAGS_OFFSET;
254	cmd |= src_width << JZ_DMA_CMD_SRC_WIDTH_OFFSET;
255	cmd |= dst_width << JZ_DMA_CMD_DST_WIDTH_OFFSET;
256	cmd |= transfer_size << JZ_DMA_CMD_TRANSFER_SIZE_OFFSET;
257	cmd |= JZ4740_DMA_MODE_SINGLE << JZ_DMA_CMD_MODE_OFFSET;
258	cmd |= JZ_DMA_CMD_TRANSFER_IRQ_ENABLE;
259
260	jz4740_dma_write(dmadev, JZ_REG_DMA_CMD(chan->id), cmd);
261	jz4740_dma_write(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0);
262	jz4740_dma_write(dmadev, JZ_REG_DMA_REQ_TYPE(chan->id),
263		config->slave_id);
264
265	return 0;
266}
267
268static int jz4740_dma_terminate_all(struct dma_chan *c)
269{
270	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
271	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
272	unsigned long flags;
273	LIST_HEAD(head);
274
275	spin_lock_irqsave(&chan->vchan.lock, flags);
276	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0,
277			JZ_DMA_STATUS_CTRL_ENABLE);
278	chan->desc = NULL;
279	vchan_get_all_descriptors(&chan->vchan, &head);
280	spin_unlock_irqrestore(&chan->vchan.lock, flags);
281
282	vchan_dma_desc_free_list(&chan->vchan, &head);
283
284	return 0;
285}
286
287static int jz4740_dma_start_transfer(struct jz4740_dmaengine_chan *chan)
288{
289	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
290	dma_addr_t src_addr, dst_addr;
291	struct virt_dma_desc *vdesc;
292	struct jz4740_dma_sg *sg;
293
294	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0,
295			JZ_DMA_STATUS_CTRL_ENABLE);
296
297	if (!chan->desc) {
298		vdesc = vchan_next_desc(&chan->vchan);
299		if (!vdesc)
300			return 0;
301		chan->desc = to_jz4740_dma_desc(vdesc);
302		chan->next_sg = 0;
303	}
304
305	if (chan->next_sg == chan->desc->num_sgs)
306		chan->next_sg = 0;
307
308	sg = &chan->desc->sg[chan->next_sg];
309
310	if (chan->desc->direction == DMA_MEM_TO_DEV) {
311		src_addr = sg->addr;
312		dst_addr = chan->fifo_addr;
313	} else {
314		src_addr = chan->fifo_addr;
315		dst_addr = sg->addr;
316	}
317	jz4740_dma_write(dmadev, JZ_REG_DMA_SRC_ADDR(chan->id), src_addr);
318	jz4740_dma_write(dmadev, JZ_REG_DMA_DST_ADDR(chan->id), dst_addr);
319	jz4740_dma_write(dmadev, JZ_REG_DMA_TRANSFER_COUNT(chan->id),
320			sg->len >> chan->transfer_shift);
321
322	chan->next_sg++;
323
324	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id),
325			JZ_DMA_STATUS_CTRL_NO_DESC | JZ_DMA_STATUS_CTRL_ENABLE,
326			JZ_DMA_STATUS_CTRL_HALT | JZ_DMA_STATUS_CTRL_NO_DESC |
327			JZ_DMA_STATUS_CTRL_ENABLE);
328
329	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_CTRL,
330			JZ_DMA_CTRL_ENABLE,
331			JZ_DMA_CTRL_HALT | JZ_DMA_CTRL_ENABLE);
332
333	return 0;
334}
335
336static void jz4740_dma_chan_irq(struct jz4740_dmaengine_chan *chan)
337{
338	spin_lock(&chan->vchan.lock);
339	if (chan->desc) {
340		if (chan->desc->cyclic) {
341			vchan_cyclic_callback(&chan->desc->vdesc);
342		} else {
343			if (chan->next_sg == chan->desc->num_sgs) {
344				list_del(&chan->desc->vdesc.node);
345				vchan_cookie_complete(&chan->desc->vdesc);
346				chan->desc = NULL;
347			}
348		}
349	}
350	jz4740_dma_start_transfer(chan);
351	spin_unlock(&chan->vchan.lock);
352}
353
354static irqreturn_t jz4740_dma_irq(int irq, void *devid)
355{
356	struct jz4740_dma_dev *dmadev = devid;
357	uint32_t irq_status;
358	unsigned int i;
359
360	irq_status = readl(dmadev->base + JZ_REG_DMA_IRQ);
361
362	for (i = 0; i < 6; ++i) {
363		if (irq_status & (1 << i)) {
364			jz4740_dma_write_mask(dmadev,
365				JZ_REG_DMA_STATUS_CTRL(i), 0,
366				JZ_DMA_STATUS_CTRL_ENABLE |
367				JZ_DMA_STATUS_CTRL_TRANSFER_DONE);
368
369			jz4740_dma_chan_irq(&dmadev->chan[i]);
370		}
371	}
372
373	return IRQ_HANDLED;
374}
375
376static void jz4740_dma_issue_pending(struct dma_chan *c)
377{
378	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
379	unsigned long flags;
380
381	spin_lock_irqsave(&chan->vchan.lock, flags);
382	if (vchan_issue_pending(&chan->vchan) && !chan->desc)
383		jz4740_dma_start_transfer(chan);
384	spin_unlock_irqrestore(&chan->vchan.lock, flags);
385}
386
387static struct dma_async_tx_descriptor *jz4740_dma_prep_slave_sg(
388	struct dma_chan *c, struct scatterlist *sgl,
389	unsigned int sg_len, enum dma_transfer_direction direction,
390	unsigned long flags, void *context)
391{
392	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
393	struct jz4740_dma_desc *desc;
394	struct scatterlist *sg;
395	unsigned int i;
396
397	desc = jz4740_dma_alloc_desc(sg_len);
398	if (!desc)
399		return NULL;
400
401	for_each_sg(sgl, sg, sg_len, i) {
402		desc->sg[i].addr = sg_dma_address(sg);
403		desc->sg[i].len = sg_dma_len(sg);
404	}
405
406	desc->num_sgs = sg_len;
407	desc->direction = direction;
408	desc->cyclic = false;
409
410	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
411}
412
413static struct dma_async_tx_descriptor *jz4740_dma_prep_dma_cyclic(
414	struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
415	size_t period_len, enum dma_transfer_direction direction,
416	unsigned long flags)
417{
418	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
419	struct jz4740_dma_desc *desc;
420	unsigned int num_periods, i;
421
422	if (buf_len % period_len)
423		return NULL;
424
425	num_periods = buf_len / period_len;
426
427	desc = jz4740_dma_alloc_desc(num_periods);
428	if (!desc)
429		return NULL;
430
431	for (i = 0; i < num_periods; i++) {
432		desc->sg[i].addr = buf_addr;
433		desc->sg[i].len = period_len;
434		buf_addr += period_len;
435	}
436
437	desc->num_sgs = num_periods;
438	desc->direction = direction;
439	desc->cyclic = true;
440
441	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
442}
443
444static size_t jz4740_dma_desc_residue(struct jz4740_dmaengine_chan *chan,
445	struct jz4740_dma_desc *desc, unsigned int next_sg)
446{
447	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
448	unsigned int residue, count;
449	unsigned int i;
450
451	residue = 0;
452
453	for (i = next_sg; i < desc->num_sgs; i++)
454		residue += desc->sg[i].len;
455
456	if (next_sg != 0) {
457		count = jz4740_dma_read(dmadev,
458			JZ_REG_DMA_TRANSFER_COUNT(chan->id));
459		residue += count << chan->transfer_shift;
460	}
461
462	return residue;
463}
464
465static enum dma_status jz4740_dma_tx_status(struct dma_chan *c,
466	dma_cookie_t cookie, struct dma_tx_state *state)
467{
468	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
469	struct virt_dma_desc *vdesc;
470	enum dma_status status;
471	unsigned long flags;
472
473	status = dma_cookie_status(c, cookie, state);
474	if (status == DMA_COMPLETE || !state)
475		return status;
476
477	spin_lock_irqsave(&chan->vchan.lock, flags);
478	vdesc = vchan_find_desc(&chan->vchan, cookie);
479	if (cookie == chan->desc->vdesc.tx.cookie) {
480		state->residue = jz4740_dma_desc_residue(chan, chan->desc,
481				chan->next_sg);
482	} else if (vdesc) {
483		state->residue = jz4740_dma_desc_residue(chan,
484				to_jz4740_dma_desc(vdesc), 0);
485	} else {
486		state->residue = 0;
487	}
488	spin_unlock_irqrestore(&chan->vchan.lock, flags);
489
490	return status;
491}
492
493static void jz4740_dma_free_chan_resources(struct dma_chan *c)
494{
495	vchan_free_chan_resources(to_virt_chan(c));
496}
497
498static void jz4740_dma_desc_free(struct virt_dma_desc *vdesc)
499{
500	kfree(container_of(vdesc, struct jz4740_dma_desc, vdesc));
501}
502
503#define JZ4740_DMA_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
504	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
505
506static int jz4740_dma_probe(struct platform_device *pdev)
507{
508	struct jz4740_dmaengine_chan *chan;
509	struct jz4740_dma_dev *dmadev;
510	struct dma_device *dd;
511	unsigned int i;
512	struct resource *res;
513	int ret;
514	int irq;
515
516	dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
517	if (!dmadev)
518		return -EINVAL;
519
520	dd = &dmadev->ddev;
521
522	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
523	dmadev->base = devm_ioremap_resource(&pdev->dev, res);
524	if (IS_ERR(dmadev->base))
525		return PTR_ERR(dmadev->base);
526
527	dmadev->clk = clk_get(&pdev->dev, "dma");
528	if (IS_ERR(dmadev->clk))
529		return PTR_ERR(dmadev->clk);
530
531	clk_prepare_enable(dmadev->clk);
532
533	dma_cap_set(DMA_SLAVE, dd->cap_mask);
534	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
535	dd->device_free_chan_resources = jz4740_dma_free_chan_resources;
536	dd->device_tx_status = jz4740_dma_tx_status;
537	dd->device_issue_pending = jz4740_dma_issue_pending;
538	dd->device_prep_slave_sg = jz4740_dma_prep_slave_sg;
539	dd->device_prep_dma_cyclic = jz4740_dma_prep_dma_cyclic;
540	dd->device_config = jz4740_dma_slave_config;
541	dd->device_terminate_all = jz4740_dma_terminate_all;
542	dd->src_addr_widths = JZ4740_DMA_BUSWIDTHS;
543	dd->dst_addr_widths = JZ4740_DMA_BUSWIDTHS;
544	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
545	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
546	dd->dev = &pdev->dev;
547	INIT_LIST_HEAD(&dd->channels);
548
549	for (i = 0; i < JZ_DMA_NR_CHANS; i++) {
550		chan = &dmadev->chan[i];
551		chan->id = i;
552		chan->vchan.desc_free = jz4740_dma_desc_free;
553		vchan_init(&chan->vchan, dd);
554	}
555
556	ret = dma_async_device_register(dd);
557	if (ret)
558		return ret;
559
560	irq = platform_get_irq(pdev, 0);
561	ret = request_irq(irq, jz4740_dma_irq, 0, dev_name(&pdev->dev), dmadev);
562	if (ret)
563		goto err_unregister;
564
565	platform_set_drvdata(pdev, dmadev);
566
567	return 0;
568
569err_unregister:
570	dma_async_device_unregister(dd);
571	return ret;
572}
573
574static void jz4740_cleanup_vchan(struct dma_device *dmadev)
575{
576	struct jz4740_dmaengine_chan *chan, *_chan;
577
578	list_for_each_entry_safe(chan, _chan,
579				&dmadev->channels, vchan.chan.device_node) {
580		list_del(&chan->vchan.chan.device_node);
581		tasklet_kill(&chan->vchan.task);
582	}
583}
584
585
586static int jz4740_dma_remove(struct platform_device *pdev)
587{
588	struct jz4740_dma_dev *dmadev = platform_get_drvdata(pdev);
589	int irq = platform_get_irq(pdev, 0);
590
591	free_irq(irq, dmadev);
592
593	jz4740_cleanup_vchan(&dmadev->ddev);
594	dma_async_device_unregister(&dmadev->ddev);
595	clk_disable_unprepare(dmadev->clk);
596
597	return 0;
598}
599
600static struct platform_driver jz4740_dma_driver = {
601	.probe = jz4740_dma_probe,
602	.remove = jz4740_dma_remove,
603	.driver = {
604		.name = "jz4740-dma",
605	},
606};
607module_platform_driver(jz4740_dma_driver);
608
609MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
610MODULE_DESCRIPTION("JZ4740 DMA driver");
611MODULE_LICENSE("GPL v2");