1/*
2 * timb_dma.c timberdale FPGA DMA driver
3 * Copyright (c) 2010 Intel Corporation
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 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19/* Supports:
20 * Timberdale FPGA DMA engine
21 */
22
23#include <linux/dmaengine.h>
24#include <linux/dma-mapping.h>
25#include <linux/init.h>
26#include <linux/interrupt.h>
27#include <linux/io.h>
28#include <linux/module.h>
29#include <linux/platform_device.h>
30#include <linux/slab.h>
31
32#include <linux/timb_dma.h>
33
34#include "dmaengine.h"
35
36#define DRIVER_NAME "timb-dma"
37
38/* Global DMA registers */
39#define TIMBDMA_ACR		0x34
40#define TIMBDMA_32BIT_ADDR	0x01
41
42#define TIMBDMA_ISR		0x080000
43#define TIMBDMA_IPR		0x080004
44#define TIMBDMA_IER		0x080008
45
46/* Channel specific registers */
47/* RX instances base addresses are 0x00, 0x40, 0x80 ...
48 * TX instances base addresses are 0x18, 0x58, 0x98 ...
49 */
50#define TIMBDMA_INSTANCE_OFFSET		0x40
51#define TIMBDMA_INSTANCE_TX_OFFSET	0x18
52
53/* RX registers, relative the instance base */
54#define TIMBDMA_OFFS_RX_DHAR	0x00
55#define TIMBDMA_OFFS_RX_DLAR	0x04
56#define TIMBDMA_OFFS_RX_LR	0x0C
57#define TIMBDMA_OFFS_RX_BLR	0x10
58#define TIMBDMA_OFFS_RX_ER	0x14
59#define TIMBDMA_RX_EN		0x01
60/* bytes per Row, video specific register
61 * which is placed after the TX registers...
62 */
63#define TIMBDMA_OFFS_RX_BPRR	0x30
64
65/* TX registers, relative the instance base */
66#define TIMBDMA_OFFS_TX_DHAR	0x00
67#define TIMBDMA_OFFS_TX_DLAR	0x04
68#define TIMBDMA_OFFS_TX_BLR	0x0C
69#define TIMBDMA_OFFS_TX_LR	0x14
70
71
72#define TIMB_DMA_DESC_SIZE	8
73
74struct timb_dma_desc {
75	struct list_head		desc_node;
76	struct dma_async_tx_descriptor	txd;
77	u8				*desc_list;
78	unsigned int			desc_list_len;
79	bool				interrupt;
80};
81
82struct timb_dma_chan {
83	struct dma_chan		chan;
84	void __iomem		*membase;
85	spinlock_t		lock; /* Used to protect data structures,
86					especially the lists and descriptors,
87					from races between the tasklet and calls
88					from above */
89	bool			ongoing;
90	struct list_head	active_list;
91	struct list_head	queue;
92	struct list_head	free_list;
93	unsigned int		bytes_per_line;
94	enum dma_transfer_direction	direction;
95	unsigned int		descs; /* Descriptors to allocate */
96	unsigned int		desc_elems; /* number of elems per descriptor */
97};
98
99struct timb_dma {
100	struct dma_device	dma;
101	void __iomem		*membase;
102	struct tasklet_struct	tasklet;
103	struct timb_dma_chan	channels[0];
104};
105
106static struct device *chan2dev(struct dma_chan *chan)
107{
108	return &chan->dev->device;
109}
110static struct device *chan2dmadev(struct dma_chan *chan)
111{
112	return chan2dev(chan)->parent->parent;
113}
114
115static struct timb_dma *tdchantotd(struct timb_dma_chan *td_chan)
116{
117	int id = td_chan->chan.chan_id;
118	return (struct timb_dma *)((u8 *)td_chan -
119		id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
120}
121
122/* Must be called with the spinlock held */
123static void __td_enable_chan_irq(struct timb_dma_chan *td_chan)
124{
125	int id = td_chan->chan.chan_id;
126	struct timb_dma *td = tdchantotd(td_chan);
127	u32 ier;
128
129	/* enable interrupt for this channel */
130	ier = ioread32(td->membase + TIMBDMA_IER);
131	ier |= 1 << id;
132	dev_dbg(chan2dev(&td_chan->chan), "Enabling irq: %d, IER: 0x%x\n", id,
133		ier);
134	iowrite32(ier, td->membase + TIMBDMA_IER);
135}
136
137/* Should be called with the spinlock held */
138static bool __td_dma_done_ack(struct timb_dma_chan *td_chan)
139{
140	int id = td_chan->chan.chan_id;
141	struct timb_dma *td = (struct timb_dma *)((u8 *)td_chan -
142		id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
143	u32 isr;
144	bool done = false;
145
146	dev_dbg(chan2dev(&td_chan->chan), "Checking irq: %d, td: %p\n", id, td);
147
148	isr = ioread32(td->membase + TIMBDMA_ISR) & (1 << id);
149	if (isr) {
150		iowrite32(isr, td->membase + TIMBDMA_ISR);
151		done = true;
152	}
153
154	return done;
155}
156
157static int td_fill_desc(struct timb_dma_chan *td_chan, u8 *dma_desc,
158	struct scatterlist *sg, bool last)
159{
160	if (sg_dma_len(sg) > USHRT_MAX) {
161		dev_err(chan2dev(&td_chan->chan), "Too big sg element\n");
162		return -EINVAL;
163	}
164
165	/* length must be word aligned */
166	if (sg_dma_len(sg) % sizeof(u32)) {
167		dev_err(chan2dev(&td_chan->chan), "Incorrect length: %d\n",
168			sg_dma_len(sg));
169		return -EINVAL;
170	}
171
172	dev_dbg(chan2dev(&td_chan->chan), "desc: %p, addr: 0x%llx\n",
173		dma_desc, (unsigned long long)sg_dma_address(sg));
174
175	dma_desc[7] = (sg_dma_address(sg) >> 24) & 0xff;
176	dma_desc[6] = (sg_dma_address(sg) >> 16) & 0xff;
177	dma_desc[5] = (sg_dma_address(sg) >> 8) & 0xff;
178	dma_desc[4] = (sg_dma_address(sg) >> 0) & 0xff;
179
180	dma_desc[3] = (sg_dma_len(sg) >> 8) & 0xff;
181	dma_desc[2] = (sg_dma_len(sg) >> 0) & 0xff;
182
183	dma_desc[1] = 0x00;
184	dma_desc[0] = 0x21 | (last ? 0x02 : 0); /* tran, valid */
185
186	return 0;
187}
188
189/* Must be called with the spinlock held */
190static void __td_start_dma(struct timb_dma_chan *td_chan)
191{
192	struct timb_dma_desc *td_desc;
193
194	if (td_chan->ongoing) {
195		dev_err(chan2dev(&td_chan->chan),
196			"Transfer already ongoing\n");
197		return;
198	}
199
200	td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
201		desc_node);
202
203	dev_dbg(chan2dev(&td_chan->chan),
204		"td_chan: %p, chan: %d, membase: %p\n",
205		td_chan, td_chan->chan.chan_id, td_chan->membase);
206
207	if (td_chan->direction == DMA_DEV_TO_MEM) {
208
209		/* descriptor address */
210		iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_DHAR);
211		iowrite32(td_desc->txd.phys, td_chan->membase +
212			TIMBDMA_OFFS_RX_DLAR);
213		/* Bytes per line */
214		iowrite32(td_chan->bytes_per_line, td_chan->membase +
215			TIMBDMA_OFFS_RX_BPRR);
216		/* enable RX */
217		iowrite32(TIMBDMA_RX_EN, td_chan->membase + TIMBDMA_OFFS_RX_ER);
218	} else {
219		/* address high */
220		iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DHAR);
221		iowrite32(td_desc->txd.phys, td_chan->membase +
222			TIMBDMA_OFFS_TX_DLAR);
223	}
224
225	td_chan->ongoing = true;
226
227	if (td_desc->interrupt)
228		__td_enable_chan_irq(td_chan);
229}
230
231static void __td_finish(struct timb_dma_chan *td_chan)
232{
233	dma_async_tx_callback		callback;
234	void				*param;
235	struct dma_async_tx_descriptor	*txd;
236	struct timb_dma_desc		*td_desc;
237
238	/* can happen if the descriptor is canceled */
239	if (list_empty(&td_chan->active_list))
240		return;
241
242	td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
243		desc_node);
244	txd = &td_desc->txd;
245
246	dev_dbg(chan2dev(&td_chan->chan), "descriptor %u complete\n",
247		txd->cookie);
248
249	/* make sure to stop the transfer */
250	if (td_chan->direction == DMA_DEV_TO_MEM)
251		iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_ER);
252/* Currently no support for stopping DMA transfers
253	else
254		iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DLAR);
255*/
256	dma_cookie_complete(txd);
257	td_chan->ongoing = false;
258
259	callback = txd->callback;
260	param = txd->callback_param;
261
262	list_move(&td_desc->desc_node, &td_chan->free_list);
263
264	dma_descriptor_unmap(txd);
265	/*
266	 * The API requires that no submissions are done from a
267	 * callback, so we don't need to drop the lock here
268	 */
269	if (callback)
270		callback(param);
271}
272
273static u32 __td_ier_mask(struct timb_dma *td)
274{
275	int i;
276	u32 ret = 0;
277
278	for (i = 0; i < td->dma.chancnt; i++) {
279		struct timb_dma_chan *td_chan = td->channels + i;
280		if (td_chan->ongoing) {
281			struct timb_dma_desc *td_desc =
282				list_entry(td_chan->active_list.next,
283				struct timb_dma_desc, desc_node);
284			if (td_desc->interrupt)
285				ret |= 1 << i;
286		}
287	}
288
289	return ret;
290}
291
292static void __td_start_next(struct timb_dma_chan *td_chan)
293{
294	struct timb_dma_desc *td_desc;
295
296	BUG_ON(list_empty(&td_chan->queue));
297	BUG_ON(td_chan->ongoing);
298
299	td_desc = list_entry(td_chan->queue.next, struct timb_dma_desc,
300		desc_node);
301
302	dev_dbg(chan2dev(&td_chan->chan), "%s: started %u\n",
303		__func__, td_desc->txd.cookie);
304
305	list_move(&td_desc->desc_node, &td_chan->active_list);
306	__td_start_dma(td_chan);
307}
308
309static dma_cookie_t td_tx_submit(struct dma_async_tx_descriptor *txd)
310{
311	struct timb_dma_desc *td_desc = container_of(txd, struct timb_dma_desc,
312		txd);
313	struct timb_dma_chan *td_chan = container_of(txd->chan,
314		struct timb_dma_chan, chan);
315	dma_cookie_t cookie;
316
317	spin_lock_bh(&td_chan->lock);
318	cookie = dma_cookie_assign(txd);
319
320	if (list_empty(&td_chan->active_list)) {
321		dev_dbg(chan2dev(txd->chan), "%s: started %u\n", __func__,
322			txd->cookie);
323		list_add_tail(&td_desc->desc_node, &td_chan->active_list);
324		__td_start_dma(td_chan);
325	} else {
326		dev_dbg(chan2dev(txd->chan), "tx_submit: queued %u\n",
327			txd->cookie);
328
329		list_add_tail(&td_desc->desc_node, &td_chan->queue);
330	}
331
332	spin_unlock_bh(&td_chan->lock);
333
334	return cookie;
335}
336
337static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
338{
339	struct dma_chan *chan = &td_chan->chan;
340	struct timb_dma_desc *td_desc;
341	int err;
342
343	td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
344	if (!td_desc) {
345		dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
346		goto out;
347	}
348
349	td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
350
351	td_desc->desc_list = kzalloc(td_desc->desc_list_len, GFP_KERNEL);
352	if (!td_desc->desc_list) {
353		dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
354		goto err;
355	}
356
357	dma_async_tx_descriptor_init(&td_desc->txd, chan);
358	td_desc->txd.tx_submit = td_tx_submit;
359	td_desc->txd.flags = DMA_CTRL_ACK;
360
361	td_desc->txd.phys = dma_map_single(chan2dmadev(chan),
362		td_desc->desc_list, td_desc->desc_list_len, DMA_TO_DEVICE);
363
364	err = dma_mapping_error(chan2dmadev(chan), td_desc->txd.phys);
365	if (err) {
366		dev_err(chan2dev(chan), "DMA mapping error: %d\n", err);
367		goto err;
368	}
369
370	return td_desc;
371err:
372	kfree(td_desc->desc_list);
373	kfree(td_desc);
374out:
375	return NULL;
376
377}
378
379static void td_free_desc(struct timb_dma_desc *td_desc)
380{
381	dev_dbg(chan2dev(td_desc->txd.chan), "Freeing desc: %p\n", td_desc);
382	dma_unmap_single(chan2dmadev(td_desc->txd.chan), td_desc->txd.phys,
383		td_desc->desc_list_len, DMA_TO_DEVICE);
384
385	kfree(td_desc->desc_list);
386	kfree(td_desc);
387}
388
389static void td_desc_put(struct timb_dma_chan *td_chan,
390	struct timb_dma_desc *td_desc)
391{
392	dev_dbg(chan2dev(&td_chan->chan), "Putting desc: %p\n", td_desc);
393
394	spin_lock_bh(&td_chan->lock);
395	list_add(&td_desc->desc_node, &td_chan->free_list);
396	spin_unlock_bh(&td_chan->lock);
397}
398
399static struct timb_dma_desc *td_desc_get(struct timb_dma_chan *td_chan)
400{
401	struct timb_dma_desc *td_desc, *_td_desc;
402	struct timb_dma_desc *ret = NULL;
403
404	spin_lock_bh(&td_chan->lock);
405	list_for_each_entry_safe(td_desc, _td_desc, &td_chan->free_list,
406		desc_node) {
407		if (async_tx_test_ack(&td_desc->txd)) {
408			list_del(&td_desc->desc_node);
409			ret = td_desc;
410			break;
411		}
412		dev_dbg(chan2dev(&td_chan->chan), "desc %p not ACKed\n",
413			td_desc);
414	}
415	spin_unlock_bh(&td_chan->lock);
416
417	return ret;
418}
419
420static int td_alloc_chan_resources(struct dma_chan *chan)
421{
422	struct timb_dma_chan *td_chan =
423		container_of(chan, struct timb_dma_chan, chan);
424	int i;
425
426	dev_dbg(chan2dev(chan), "%s: entry\n", __func__);
427
428	BUG_ON(!list_empty(&td_chan->free_list));
429	for (i = 0; i < td_chan->descs; i++) {
430		struct timb_dma_desc *td_desc = td_alloc_init_desc(td_chan);
431		if (!td_desc) {
432			if (i)
433				break;
434			else {
435				dev_err(chan2dev(chan),
436					"Couldnt allocate any descriptors\n");
437				return -ENOMEM;
438			}
439		}
440
441		td_desc_put(td_chan, td_desc);
442	}
443
444	spin_lock_bh(&td_chan->lock);
445	dma_cookie_init(chan);
446	spin_unlock_bh(&td_chan->lock);
447
448	return 0;
449}
450
451static void td_free_chan_resources(struct dma_chan *chan)
452{
453	struct timb_dma_chan *td_chan =
454		container_of(chan, struct timb_dma_chan, chan);
455	struct timb_dma_desc *td_desc, *_td_desc;
456	LIST_HEAD(list);
457
458	dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
459
460	/* check that all descriptors are free */
461	BUG_ON(!list_empty(&td_chan->active_list));
462	BUG_ON(!list_empty(&td_chan->queue));
463
464	spin_lock_bh(&td_chan->lock);
465	list_splice_init(&td_chan->free_list, &list);
466	spin_unlock_bh(&td_chan->lock);
467
468	list_for_each_entry_safe(td_desc, _td_desc, &list, desc_node) {
469		dev_dbg(chan2dev(chan), "%s: Freeing desc: %p\n", __func__,
470			td_desc);
471		td_free_desc(td_desc);
472	}
473}
474
475static enum dma_status td_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
476				    struct dma_tx_state *txstate)
477{
478	enum dma_status ret;
479
480	dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
481
482	ret = dma_cookie_status(chan, cookie, txstate);
483
484	dev_dbg(chan2dev(chan), "%s: exit, ret: %d\n", 	__func__, ret);
485
486	return ret;
487}
488
489static void td_issue_pending(struct dma_chan *chan)
490{
491	struct timb_dma_chan *td_chan =
492		container_of(chan, struct timb_dma_chan, chan);
493
494	dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
495	spin_lock_bh(&td_chan->lock);
496
497	if (!list_empty(&td_chan->active_list))
498		/* transfer ongoing */
499		if (__td_dma_done_ack(td_chan))
500			__td_finish(td_chan);
501
502	if (list_empty(&td_chan->active_list) && !list_empty(&td_chan->queue))
503		__td_start_next(td_chan);
504
505	spin_unlock_bh(&td_chan->lock);
506}
507
508static struct dma_async_tx_descriptor *td_prep_slave_sg(struct dma_chan *chan,
509	struct scatterlist *sgl, unsigned int sg_len,
510	enum dma_transfer_direction direction, unsigned long flags,
511	void *context)
512{
513	struct timb_dma_chan *td_chan =
514		container_of(chan, struct timb_dma_chan, chan);
515	struct timb_dma_desc *td_desc;
516	struct scatterlist *sg;
517	unsigned int i;
518	unsigned int desc_usage = 0;
519
520	if (!sgl || !sg_len) {
521		dev_err(chan2dev(chan), "%s: No SG list\n", __func__);
522		return NULL;
523	}
524
525	/* even channels are for RX, odd for TX */
526	if (td_chan->direction != direction) {
527		dev_err(chan2dev(chan),
528			"Requesting channel in wrong direction\n");
529		return NULL;
530	}
531
532	td_desc = td_desc_get(td_chan);
533	if (!td_desc) {
534		dev_err(chan2dev(chan), "Not enough descriptors available\n");
535		return NULL;
536	}
537
538	td_desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
539
540	for_each_sg(sgl, sg, sg_len, i) {
541		int err;
542		if (desc_usage > td_desc->desc_list_len) {
543			dev_err(chan2dev(chan), "No descriptor space\n");
544			return NULL;
545		}
546
547		err = td_fill_desc(td_chan, td_desc->desc_list + desc_usage, sg,
548			i == (sg_len - 1));
549		if (err) {
550			dev_err(chan2dev(chan), "Failed to update desc: %d\n",
551				err);
552			td_desc_put(td_chan, td_desc);
553			return NULL;
554		}
555		desc_usage += TIMB_DMA_DESC_SIZE;
556	}
557
558	dma_sync_single_for_device(chan2dmadev(chan), td_desc->txd.phys,
559		td_desc->desc_list_len, DMA_MEM_TO_DEV);
560
561	return &td_desc->txd;
562}
563
564static int td_terminate_all(struct dma_chan *chan)
565{
566	struct timb_dma_chan *td_chan =
567		container_of(chan, struct timb_dma_chan, chan);
568	struct timb_dma_desc *td_desc, *_td_desc;
569
570	dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
571
572	/* first the easy part, put the queue into the free list */
573	spin_lock_bh(&td_chan->lock);
574	list_for_each_entry_safe(td_desc, _td_desc, &td_chan->queue,
575		desc_node)
576		list_move(&td_desc->desc_node, &td_chan->free_list);
577
578	/* now tear down the running */
579	__td_finish(td_chan);
580	spin_unlock_bh(&td_chan->lock);
581
582	return 0;
583}
584
585static void td_tasklet(unsigned long data)
586{
587	struct timb_dma *td = (struct timb_dma *)data;
588	u32 isr;
589	u32 ipr;
590	u32 ier;
591	int i;
592
593	isr = ioread32(td->membase + TIMBDMA_ISR);
594	ipr = isr & __td_ier_mask(td);
595
596	/* ack the interrupts */
597	iowrite32(ipr, td->membase + TIMBDMA_ISR);
598
599	for (i = 0; i < td->dma.chancnt; i++)
600		if (ipr & (1 << i)) {
601			struct timb_dma_chan *td_chan = td->channels + i;
602			spin_lock(&td_chan->lock);
603			__td_finish(td_chan);
604			if (!list_empty(&td_chan->queue))
605				__td_start_next(td_chan);
606			spin_unlock(&td_chan->lock);
607		}
608
609	ier = __td_ier_mask(td);
610	iowrite32(ier, td->membase + TIMBDMA_IER);
611}
612
613
614static irqreturn_t td_irq(int irq, void *devid)
615{
616	struct timb_dma *td = devid;
617	u32 ipr = ioread32(td->membase + TIMBDMA_IPR);
618
619	if (ipr) {
620		/* disable interrupts, will be re-enabled in tasklet */
621		iowrite32(0, td->membase + TIMBDMA_IER);
622
623		tasklet_schedule(&td->tasklet);
624
625		return IRQ_HANDLED;
626	} else
627		return IRQ_NONE;
628}
629
630
631static int td_probe(struct platform_device *pdev)
632{
633	struct timb_dma_platform_data *pdata = dev_get_platdata(&pdev->dev);
634	struct timb_dma *td;
635	struct resource *iomem;
636	int irq;
637	int err;
638	int i;
639
640	if (!pdata) {
641		dev_err(&pdev->dev, "No platform data\n");
642		return -EINVAL;
643	}
644
645	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
646	if (!iomem)
647		return -EINVAL;
648
649	irq = platform_get_irq(pdev, 0);
650	if (irq < 0)
651		return irq;
652
653	if (!request_mem_region(iomem->start, resource_size(iomem),
654		DRIVER_NAME))
655		return -EBUSY;
656
657	td  = kzalloc(sizeof(struct timb_dma) +
658		sizeof(struct timb_dma_chan) * pdata->nr_channels, GFP_KERNEL);
659	if (!td) {
660		err = -ENOMEM;
661		goto err_release_region;
662	}
663
664	dev_dbg(&pdev->dev, "Allocated TD: %p\n", td);
665
666	td->membase = ioremap(iomem->start, resource_size(iomem));
667	if (!td->membase) {
668		dev_err(&pdev->dev, "Failed to remap I/O memory\n");
669		err = -ENOMEM;
670		goto err_free_mem;
671	}
672
673	/* 32bit addressing */
674	iowrite32(TIMBDMA_32BIT_ADDR, td->membase + TIMBDMA_ACR);
675
676	/* disable and clear any interrupts */
677	iowrite32(0x0, td->membase + TIMBDMA_IER);
678	iowrite32(0xFFFFFFFF, td->membase + TIMBDMA_ISR);
679
680	tasklet_init(&td->tasklet, td_tasklet, (unsigned long)td);
681
682	err = request_irq(irq, td_irq, IRQF_SHARED, DRIVER_NAME, td);
683	if (err) {
684		dev_err(&pdev->dev, "Failed to request IRQ\n");
685		goto err_tasklet_kill;
686	}
687
688	td->dma.device_alloc_chan_resources	= td_alloc_chan_resources;
689	td->dma.device_free_chan_resources	= td_free_chan_resources;
690	td->dma.device_tx_status		= td_tx_status;
691	td->dma.device_issue_pending		= td_issue_pending;
692
693	dma_cap_set(DMA_SLAVE, td->dma.cap_mask);
694	dma_cap_set(DMA_PRIVATE, td->dma.cap_mask);
695	td->dma.device_prep_slave_sg = td_prep_slave_sg;
696	td->dma.device_terminate_all = td_terminate_all;
697
698	td->dma.dev = &pdev->dev;
699
700	INIT_LIST_HEAD(&td->dma.channels);
701
702	for (i = 0; i < pdata->nr_channels; i++) {
703		struct timb_dma_chan *td_chan = &td->channels[i];
704		struct timb_dma_platform_data_channel *pchan =
705			pdata->channels + i;
706
707		/* even channels are RX, odd are TX */
708		if ((i % 2) == pchan->rx) {
709			dev_err(&pdev->dev, "Wrong channel configuration\n");
710			err = -EINVAL;
711			goto err_free_irq;
712		}
713
714		td_chan->chan.device = &td->dma;
715		dma_cookie_init(&td_chan->chan);
716		spin_lock_init(&td_chan->lock);
717		INIT_LIST_HEAD(&td_chan->active_list);
718		INIT_LIST_HEAD(&td_chan->queue);
719		INIT_LIST_HEAD(&td_chan->free_list);
720
721		td_chan->descs = pchan->descriptors;
722		td_chan->desc_elems = pchan->descriptor_elements;
723		td_chan->bytes_per_line = pchan->bytes_per_line;
724		td_chan->direction = pchan->rx ? DMA_DEV_TO_MEM :
725			DMA_MEM_TO_DEV;
726
727		td_chan->membase = td->membase +
728			(i / 2) * TIMBDMA_INSTANCE_OFFSET +
729			(pchan->rx ? 0 : TIMBDMA_INSTANCE_TX_OFFSET);
730
731		dev_dbg(&pdev->dev, "Chan: %d, membase: %p\n",
732			i, td_chan->membase);
733
734		list_add_tail(&td_chan->chan.device_node, &td->dma.channels);
735	}
736
737	err = dma_async_device_register(&td->dma);
738	if (err) {
739		dev_err(&pdev->dev, "Failed to register async device\n");
740		goto err_free_irq;
741	}
742
743	platform_set_drvdata(pdev, td);
744
745	dev_dbg(&pdev->dev, "Probe result: %d\n", err);
746	return err;
747
748err_free_irq:
749	free_irq(irq, td);
750err_tasklet_kill:
751	tasklet_kill(&td->tasklet);
752	iounmap(td->membase);
753err_free_mem:
754	kfree(td);
755err_release_region:
756	release_mem_region(iomem->start, resource_size(iomem));
757
758	return err;
759
760}
761
762static int td_remove(struct platform_device *pdev)
763{
764	struct timb_dma *td = platform_get_drvdata(pdev);
765	struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
766	int irq = platform_get_irq(pdev, 0);
767
768	dma_async_device_unregister(&td->dma);
769	free_irq(irq, td);
770	tasklet_kill(&td->tasklet);
771	iounmap(td->membase);
772	kfree(td);
773	release_mem_region(iomem->start, resource_size(iomem));
774
775	dev_dbg(&pdev->dev, "Removed...\n");
776	return 0;
777}
778
779static struct platform_driver td_driver = {
780	.driver = {
781		.name	= DRIVER_NAME,
782	},
783	.probe	= td_probe,
784	.remove	= td_remove,
785};
786
787module_platform_driver(td_driver);
788
789MODULE_LICENSE("GPL v2");
790MODULE_DESCRIPTION("Timberdale DMA controller driver");
791MODULE_AUTHOR("Pelagicore AB <info@pelagicore.com>");
792MODULE_ALIAS("platform:"DRIVER_NAME);
793