summaryrefslogtreecommitdiff
path: root/drivers/dma/sf-pdma/sf-pdma.c
blob: d1c6956af45201bd61271ce6c50f29533fd487f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * SiFive FU540 Platform DMA driver
 * Copyright (C) 2019 SiFive
 *
 * Based partially on:
 * - drivers/dma/fsl-edma.c
 * - drivers/dma/dw-edma/
 * - drivers/dma/pxa-dma.c
 *
 * See the following sources for further documentation:
 * - Chapter 12 "Platform DMA Engine (PDMA)" of
 *   SiFive FU540-C000 v1.0
 *   https://static.dev.sifive.com/FU540-C000-v1.0.pdf
 */
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/slab.h>

#include "sf-pdma.h"

#ifndef readq
static inline unsigned long long readq(void __iomem *addr)
{
	return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
}
#endif

#ifndef writeq
static inline void writeq(unsigned long long v, void __iomem *addr)
{
	writel(lower_32_bits(v), addr);
	writel(upper_32_bits(v), addr + 4);
}
#endif

static inline struct sf_pdma_chan *to_sf_pdma_chan(struct dma_chan *dchan)
{
	return container_of(dchan, struct sf_pdma_chan, vchan.chan);
}

static inline struct sf_pdma_desc *to_sf_pdma_desc(struct virt_dma_desc *vd)
{
	return container_of(vd, struct sf_pdma_desc, vdesc);
}

static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan)
{
	struct sf_pdma_desc *desc;

	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
	if (!desc)
		return NULL;

	desc->chan = chan;

	return desc;
}

static void sf_pdma_fill_desc(struct sf_pdma_desc *desc,
			      u64 dst, u64 src, u64 size)
{
	desc->xfer_type = PDMA_FULL_SPEED;
	desc->xfer_size = size;
	desc->dst_addr = dst;
	desc->src_addr = src;
}

static void sf_pdma_disclaim_chan(struct sf_pdma_chan *chan)
{
	struct pdma_regs *regs = &chan->regs;

	writel(PDMA_CLEAR_CTRL, regs->ctrl);
}

static struct dma_async_tx_descriptor *
sf_pdma_prep_dma_memcpy(struct dma_chan *dchan,	dma_addr_t dest, dma_addr_t src,
			size_t len, unsigned long flags)
{
	struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
	struct sf_pdma_desc *desc;
	unsigned long iflags;

	if (chan && (!len || !dest || !src)) {
		dev_err(chan->pdma->dma_dev.dev,
			"Please check dma len, dest, src!\n");
		return NULL;
	}

	desc = sf_pdma_alloc_desc(chan);
	if (!desc)
		return NULL;

	desc->dirn = DMA_MEM_TO_MEM;
	desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);

	spin_lock_irqsave(&chan->vchan.lock, iflags);
	sf_pdma_fill_desc(desc, dest, src, len);
	spin_unlock_irqrestore(&chan->vchan.lock, iflags);

	return desc->async_tx;
}

static int sf_pdma_slave_config(struct dma_chan *dchan,
				struct dma_slave_config *cfg)
{
	struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);

	memcpy(&chan->cfg, cfg, sizeof(*cfg));

	return 0;
}

static int sf_pdma_alloc_chan_resources(struct dma_chan *dchan)
{
	struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
	struct pdma_regs *regs = &chan->regs;

	dma_cookie_init(dchan);
	writel(PDMA_CLAIM_MASK, regs->ctrl);

	return 0;
}

static void sf_pdma_disable_request(struct sf_pdma_chan *chan)
{
	struct pdma_regs *regs = &chan->regs;

	writel(readl(regs->ctrl) & ~PDMA_RUN_MASK, regs->ctrl);
}

static void sf_pdma_free_chan_resources(struct dma_chan *dchan)
{
	struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&chan->vchan.lock, flags);
	sf_pdma_disable_request(chan);
	kfree(chan->desc);
	chan->desc = NULL;
	vchan_get_all_descriptors(&chan->vchan, &head);
	sf_pdma_disclaim_chan(chan);
	spin_unlock_irqrestore(&chan->vchan.lock, flags);
	vchan_dma_desc_free_list(&chan->vchan, &head);
}

static size_t sf_pdma_desc_residue(struct sf_pdma_chan *chan,
				   dma_cookie_t cookie)
{
	struct virt_dma_desc *vd = NULL;
	struct pdma_regs *regs = &chan->regs;
	unsigned long flags;
	u64 residue = 0;
	struct sf_pdma_desc *desc;
	struct dma_async_tx_descriptor *tx = NULL;

	spin_lock_irqsave(&chan->vchan.lock, flags);

	list_for_each_entry(vd, &chan->vchan.desc_submitted, node)
		if (vd->tx.cookie == cookie)
			tx = &vd->tx;

	if (!tx)
		goto out;

	if (cookie == tx->chan->completed_cookie)
		goto out;

	if (cookie == tx->cookie) {
		residue = readq(regs->residue);
	} else {
		vd = vchan_find_desc(&chan->vchan, cookie);
		if (!vd)
			goto out;

		desc = to_sf_pdma_desc(vd);
		residue = desc->xfer_size;
	}

out:
	spin_unlock_irqrestore(&chan->vchan.lock, flags);
	return residue;
}

static enum dma_status
sf_pdma_tx_status(struct dma_chan *dchan,
		  dma_cookie_t cookie,
		  struct dma_tx_state *txstate)
{
	struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
	enum dma_status status;

	status = dma_cookie_status(dchan, cookie, txstate);

	if (txstate && status != DMA_ERROR)
		dma_set_residue(txstate, sf_pdma_desc_residue(chan, cookie));

	return status;
}

static int sf_pdma_terminate_all(struct dma_chan *dchan)
{
	struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&chan->vchan.lock, flags);
	sf_pdma_disable_request(chan);
	kfree(chan->desc);
	chan->desc = NULL;
	chan->xfer_err = false;
	vchan_get_all_descriptors(&chan->vchan, &head);
	spin_unlock_irqrestore(&chan->vchan.lock, flags);
	vchan_dma_desc_free_list(&chan->vchan, &head);

	return 0;
}

static void sf_pdma_enable_request(struct sf_pdma_chan *chan)
{
	struct pdma_regs *regs = &chan->regs;
	u32 v;

	v = PDMA_CLAIM_MASK |
		PDMA_ENABLE_DONE_INT_MASK |
		PDMA_ENABLE_ERR_INT_MASK |
		PDMA_RUN_MASK;

	writel(v, regs->ctrl);
}

static struct sf_pdma_desc *sf_pdma_get_first_pending_desc(struct sf_pdma_chan *chan)
{
	struct virt_dma_chan *vchan = &chan->vchan;
	struct virt_dma_desc *vdesc;

	if (list_empty(&vchan->desc_issued))
		return NULL;

	vdesc = list_first_entry(&vchan->desc_issued, struct virt_dma_desc, node);

	return container_of(vdesc, struct sf_pdma_desc, vdesc);
}

static void sf_pdma_xfer_desc(struct sf_pdma_chan *chan)
{
	struct sf_pdma_desc *desc = chan->desc;
	struct pdma_regs *regs = &chan->regs;

	if (!desc) {
		dev_err(chan->pdma->dma_dev.dev, "NULL desc.\n");
		return;
	}

	writel(desc->xfer_type, regs->xfer_type);
	writeq(desc->xfer_size, regs->xfer_size);
	writeq(desc->dst_addr, regs->dst_addr);
	writeq(desc->src_addr, regs->src_addr);

	chan->desc = desc;
	chan->status = DMA_IN_PROGRESS;
	sf_pdma_enable_request(chan);
}

static void sf_pdma_issue_pending(struct dma_chan *dchan)
{
	struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
	unsigned long flags;

	spin_lock_irqsave(&chan->vchan.lock, flags);

	if (!chan->desc && vchan_issue_pending(&chan->vchan)) {
		/* vchan_issue_pending has made a check that desc in not NULL */
		chan->desc = sf_pdma_get_first_pending_desc(chan);
		sf_pdma_xfer_desc(chan);
	}

	spin_unlock_irqrestore(&chan->vchan.lock, flags);
}

static void sf_pdma_free_desc(struct virt_dma_desc *vdesc)
{
	struct sf_pdma_desc *desc;

	desc = to_sf_pdma_desc(vdesc);
	kfree(desc);
}

static void sf_pdma_donebh_tasklet(struct tasklet_struct *t)
{
	struct sf_pdma_chan *chan = from_tasklet(chan, t, done_tasklet);
	unsigned long flags;

	spin_lock_irqsave(&chan->lock, flags);
	if (chan->xfer_err) {
		chan->retries = MAX_RETRY;
		chan->status = DMA_COMPLETE;
		chan->xfer_err = false;
	}
	spin_unlock_irqrestore(&chan->lock, flags);

	spin_lock_irqsave(&chan->vchan.lock, flags);
	list_del(&chan->desc->vdesc.node);
	vchan_cookie_complete(&chan->desc->vdesc);

	chan->desc = sf_pdma_get_first_pending_desc(chan);
	if (chan->desc)
		sf_pdma_xfer_desc(chan);

	spin_unlock_irqrestore(&chan->vchan.lock, flags);
}

static void sf_pdma_errbh_tasklet(struct tasklet_struct *t)
{
	struct sf_pdma_chan *chan = from_tasklet(chan, t, err_tasklet);
	struct sf_pdma_desc *desc = chan->desc;
	unsigned long flags;

	spin_lock_irqsave(&chan->lock, flags);
	if (chan->retries <= 0) {
		/* fail to recover */
		spin_unlock_irqrestore(&chan->lock, flags);
		dmaengine_desc_get_callback_invoke(desc->async_tx, NULL);
	} else {
		/* retry */
		chan->retries--;
		chan->xfer_err = true;
		chan->status = DMA_ERROR;

		sf_pdma_enable_request(chan);
		spin_unlock_irqrestore(&chan->lock, flags);
	}
}

static irqreturn_t sf_pdma_done_isr(int irq, void *dev_id)
{
	struct sf_pdma_chan *chan = dev_id;
	struct pdma_regs *regs = &chan->regs;
	u64 residue;

	spin_lock(&chan->vchan.lock);
	writel((readl(regs->ctrl)) & ~PDMA_DONE_STATUS_MASK, regs->ctrl);
	residue = readq(regs->residue);

	if (!residue) {
		tasklet_hi_schedule(&chan->done_tasklet);
	} else {
		/* submit next trascatioin if possible */
		struct sf_pdma_desc *desc = chan->desc;

		desc->src_addr += desc->xfer_size - residue;
		desc->dst_addr += desc->xfer_size - residue;
		desc->xfer_size = residue;

		sf_pdma_xfer_desc(chan);
	}

	spin_unlock(&chan->vchan.lock);

	return IRQ_HANDLED;
}

static irqreturn_t sf_pdma_err_isr(int irq, void *dev_id)
{
	struct sf_pdma_chan *chan = dev_id;
	struct pdma_regs *regs = &chan->regs;

	spin_lock(&chan->lock);
	writel((readl(regs->ctrl)) & ~PDMA_ERR_STATUS_MASK, regs->ctrl);
	spin_unlock(&chan->lock);

	tasklet_schedule(&chan->err_tasklet);

	return IRQ_HANDLED;
}

/**
 * sf_pdma_irq_init() - Init PDMA IRQ Handlers
 * @pdev: pointer of platform_device
 * @pdma: pointer of PDMA engine. Caller should check NULL
 *
 * Initialize DONE and ERROR interrupt handler for 4 channels. Caller should
 * make sure the pointer passed in are non-NULL. This function should be called
 * only one time during the device probe.
 *
 * Context: Any context.
 *
 * Return:
 * * 0		- OK to init all IRQ handlers
 * * -EINVAL	- Fail to request IRQ
 */
static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma)
{
	int irq, r, i;
	struct sf_pdma_chan *chan;

	for (i = 0; i < pdma->n_chans; i++) {
		chan = &pdma->chans[i];

		irq = platform_get_irq(pdev, i * 2);
		if (irq < 0)
			return -EINVAL;

		r = devm_request_irq(&pdev->dev, irq, sf_pdma_done_isr, 0,
				     dev_name(&pdev->dev), (void *)chan);
		if (r) {
			dev_err(&pdev->dev, "Fail to attach done ISR: %d\n", r);
			return -EINVAL;
		}

		chan->txirq = irq;

		irq = platform_get_irq(pdev, (i * 2) + 1);
		if (irq < 0)
			return -EINVAL;

		r = devm_request_irq(&pdev->dev, irq, sf_pdma_err_isr, 0,
				     dev_name(&pdev->dev), (void *)chan);
		if (r) {
			dev_err(&pdev->dev, "Fail to attach err ISR: %d\n", r);
			return -EINVAL;
		}

		chan->errirq = irq;
	}

	return 0;
}

/**
 * sf_pdma_setup_chans() - Init settings of each channel
 * @pdma: pointer of PDMA engine. Caller should check NULL
 *
 * Initialize all data structure and register base. Caller should make sure
 * the pointer passed in are non-NULL. This function should be called only
 * one time during the device probe.
 *
 * Context: Any context.
 *
 * Return: none
 */
static void sf_pdma_setup_chans(struct sf_pdma *pdma)
{
	int i;
	struct sf_pdma_chan *chan;

	INIT_LIST_HEAD(&pdma->dma_dev.channels);

	for (i = 0; i < pdma->n_chans; i++) {
		chan = &pdma->chans[i];

		chan->regs.ctrl =
			SF_PDMA_REG_BASE(i) + PDMA_CTRL;
		chan->regs.xfer_type =
			SF_PDMA_REG_BASE(i) + PDMA_XFER_TYPE;
		chan->regs.xfer_size =
			SF_PDMA_REG_BASE(i) + PDMA_XFER_SIZE;
		chan->regs.dst_addr =
			SF_PDMA_REG_BASE(i) + PDMA_DST_ADDR;
		chan->regs.src_addr =
			SF_PDMA_REG_BASE(i) + PDMA_SRC_ADDR;
		chan->regs.act_type =
			SF_PDMA_REG_BASE(i) + PDMA_ACT_TYPE;
		chan->regs.residue =
			SF_PDMA_REG_BASE(i) + PDMA_REMAINING_BYTE;
		chan->regs.cur_dst_addr =
			SF_PDMA_REG_BASE(i) + PDMA_CUR_DST_ADDR;
		chan->regs.cur_src_addr =
			SF_PDMA_REG_BASE(i) + PDMA_CUR_SRC_ADDR;

		chan->pdma = pdma;
		chan->pm_state = RUNNING;
		chan->slave_id = i;
		chan->xfer_err = false;
		spin_lock_init(&chan->lock);

		chan->vchan.desc_free = sf_pdma_free_desc;
		vchan_init(&chan->vchan, &pdma->dma_dev);

		writel(PDMA_CLEAR_CTRL, chan->regs.ctrl);

		tasklet_setup(&chan->done_tasklet, sf_pdma_donebh_tasklet);
		tasklet_setup(&chan->err_tasklet, sf_pdma_errbh_tasklet);
	}
}

static int sf_pdma_probe(struct platform_device *pdev)
{
	struct sf_pdma *pdma;
	int ret, n_chans;
	const enum dma_slave_buswidth widths =
		DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
		DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES |
		DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
		DMA_SLAVE_BUSWIDTH_64_BYTES;

	ret = of_property_read_u32(pdev->dev.of_node, "dma-channels", &n_chans);
	if (ret) {
		/* backwards-compatibility for no dma-channels property */
		dev_dbg(&pdev->dev, "set number of channels to default value: 4\n");
		n_chans = PDMA_MAX_NR_CH;
	} else if (n_chans > PDMA_MAX_NR_CH) {
		dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
		return -EINVAL;
	}

	pdma = devm_kzalloc(&pdev->dev, struct_size(pdma, chans, n_chans),
			    GFP_KERNEL);
	if (!pdma)
		return -ENOMEM;

	pdma->n_chans = n_chans;

	pdma->membase = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(pdma->membase))
		return PTR_ERR(pdma->membase);

	ret = sf_pdma_irq_init(pdev, pdma);
	if (ret)
		return ret;

	sf_pdma_setup_chans(pdma);

	pdma->dma_dev.dev = &pdev->dev;

	/* Setup capability */
	dma_cap_set(DMA_MEMCPY, pdma->dma_dev.cap_mask);
	pdma->dma_dev.copy_align = 2;
	pdma->dma_dev.src_addr_widths = widths;
	pdma->dma_dev.dst_addr_widths = widths;
	pdma->dma_dev.directions = BIT(DMA_MEM_TO_MEM);
	pdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
	pdma->dma_dev.descriptor_reuse = true;

	/* Setup DMA APIs */
	pdma->dma_dev.device_alloc_chan_resources =
		sf_pdma_alloc_chan_resources;
	pdma->dma_dev.device_free_chan_resources =
		sf_pdma_free_chan_resources;
	pdma->dma_dev.device_tx_status = sf_pdma_tx_status;
	pdma->dma_dev.device_prep_dma_memcpy = sf_pdma_prep_dma_memcpy;
	pdma->dma_dev.device_config = sf_pdma_slave_config;
	pdma->dma_dev.device_terminate_all = sf_pdma_terminate_all;
	pdma->dma_dev.device_issue_pending = sf_pdma_issue_pending;

	platform_set_drvdata(pdev, pdma);

	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (ret)
		dev_warn(&pdev->dev,
			 "Failed to set DMA mask. Fall back to default.\n");

	ret = dma_async_device_register(&pdma->dma_dev);
	if (ret) {
		dev_err(&pdev->dev,
			"Can't register SiFive Platform DMA. (%d)\n", ret);
		return ret;
	}

	return 0;
}

static int sf_pdma_remove(struct platform_device *pdev)
{
	struct sf_pdma *pdma = platform_get_drvdata(pdev);
	struct sf_pdma_chan *ch;
	int i;

	for (i = 0; i < pdma->n_chans; i++) {
		ch = &pdma->chans[i];

		devm_free_irq(&pdev->dev, ch->txirq, ch);
		devm_free_irq(&pdev->dev, ch->errirq, ch);
		list_del(&ch->vchan.chan.device_node);
		tasklet_kill(&ch->vchan.task);
		tasklet_kill(&ch->done_tasklet);
		tasklet_kill(&ch->err_tasklet);
	}

	dma_async_device_unregister(&pdma->dma_dev);

	return 0;
}

static const struct of_device_id sf_pdma_dt_ids[] = {
	{ .compatible = "sifive,fu540-c000-pdma" },
	{ .compatible = "sifive,pdma0" },
	{},
};
MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);

static struct platform_driver sf_pdma_driver = {
	.probe		= sf_pdma_probe,
	.remove		= sf_pdma_remove,
	.driver		= {
		.name	= "sf-pdma",
		.of_match_table = sf_pdma_dt_ids,
	},
};

static int __init sf_pdma_init(void)
{
	return platform_driver_register(&sf_pdma_driver);
}

static void __exit sf_pdma_exit(void)
{
	platform_driver_unregister(&sf_pdma_driver);
}

/* do early init */
subsys_initcall(sf_pdma_init);
module_exit(sf_pdma_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("SiFive Platform DMA driver");
MODULE_AUTHOR("Green Wan <green.wan@sifive.com>");