GNU Linux-libre 6.9.1-gnu
[releases.git] / drivers / dma / sf-pdma / sf-pdma.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SiFive FU540 Platform DMA driver
4  * Copyright (C) 2019 SiFive
5  *
6  * Based partially on:
7  * - drivers/dma/fsl-edma.c
8  * - drivers/dma/dw-edma/
9  * - drivers/dma/pxa-dma.c
10  *
11  * See the following sources for further documentation:
12  * - Chapter 12 "Platform DMA Engine (PDMA)" of
13  *   SiFive FU540-C000 v1.0
14  *   https://static.dev.sifive.com/FU540-C000-v1.0.pdf
15  */
16 #include <linux/module.h>
17 #include <linux/device.h>
18 #include <linux/kernel.h>
19 #include <linux/platform_device.h>
20 #include <linux/mod_devicetable.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/of.h>
23 #include <linux/of_dma.h>
24 #include <linux/slab.h>
25
26 #include "sf-pdma.h"
27
28 #define PDMA_QUIRK_NO_STRICT_ORDERING   BIT(0)
29
30 #ifndef readq
31 static inline unsigned long long readq(void __iomem *addr)
32 {
33         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
34 }
35 #endif
36
37 #ifndef writeq
38 static inline void writeq(unsigned long long v, void __iomem *addr)
39 {
40         writel(lower_32_bits(v), addr);
41         writel(upper_32_bits(v), addr + 4);
42 }
43 #endif
44
45 static inline struct sf_pdma_chan *to_sf_pdma_chan(struct dma_chan *dchan)
46 {
47         return container_of(dchan, struct sf_pdma_chan, vchan.chan);
48 }
49
50 static inline struct sf_pdma_desc *to_sf_pdma_desc(struct virt_dma_desc *vd)
51 {
52         return container_of(vd, struct sf_pdma_desc, vdesc);
53 }
54
55 static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan)
56 {
57         struct sf_pdma_desc *desc;
58
59         desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
60         if (!desc)
61                 return NULL;
62
63         desc->chan = chan;
64
65         return desc;
66 }
67
68 static void sf_pdma_fill_desc(struct sf_pdma_desc *desc,
69                               u64 dst, u64 src, u64 size)
70 {
71         desc->xfer_type =  desc->chan->pdma->transfer_type;
72         desc->xfer_size = size;
73         desc->dst_addr = dst;
74         desc->src_addr = src;
75 }
76
77 static void sf_pdma_disclaim_chan(struct sf_pdma_chan *chan)
78 {
79         struct pdma_regs *regs = &chan->regs;
80
81         writel(PDMA_CLEAR_CTRL, regs->ctrl);
82 }
83
84 static struct dma_async_tx_descriptor *
85 sf_pdma_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dest, dma_addr_t src,
86                         size_t len, unsigned long flags)
87 {
88         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
89         struct sf_pdma_desc *desc;
90         unsigned long iflags;
91
92         if (chan && (!len || !dest || !src)) {
93                 dev_err(chan->pdma->dma_dev.dev,
94                         "Please check dma len, dest, src!\n");
95                 return NULL;
96         }
97
98         desc = sf_pdma_alloc_desc(chan);
99         if (!desc)
100                 return NULL;
101
102         desc->dirn = DMA_MEM_TO_MEM;
103         desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
104
105         spin_lock_irqsave(&chan->vchan.lock, iflags);
106         sf_pdma_fill_desc(desc, dest, src, len);
107         spin_unlock_irqrestore(&chan->vchan.lock, iflags);
108
109         return desc->async_tx;
110 }
111
112 static int sf_pdma_slave_config(struct dma_chan *dchan,
113                                 struct dma_slave_config *cfg)
114 {
115         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
116
117         memcpy(&chan->cfg, cfg, sizeof(*cfg));
118
119         return 0;
120 }
121
122 static int sf_pdma_alloc_chan_resources(struct dma_chan *dchan)
123 {
124         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
125         struct pdma_regs *regs = &chan->regs;
126
127         dma_cookie_init(dchan);
128         writel(PDMA_CLAIM_MASK, regs->ctrl);
129
130         return 0;
131 }
132
133 static void sf_pdma_disable_request(struct sf_pdma_chan *chan)
134 {
135         struct pdma_regs *regs = &chan->regs;
136
137         writel(readl(regs->ctrl) & ~PDMA_RUN_MASK, regs->ctrl);
138 }
139
140 static void sf_pdma_free_chan_resources(struct dma_chan *dchan)
141 {
142         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
143         unsigned long flags;
144         LIST_HEAD(head);
145
146         spin_lock_irqsave(&chan->vchan.lock, flags);
147         sf_pdma_disable_request(chan);
148         kfree(chan->desc);
149         chan->desc = NULL;
150         vchan_get_all_descriptors(&chan->vchan, &head);
151         sf_pdma_disclaim_chan(chan);
152         spin_unlock_irqrestore(&chan->vchan.lock, flags);
153         vchan_dma_desc_free_list(&chan->vchan, &head);
154 }
155
156 static size_t sf_pdma_desc_residue(struct sf_pdma_chan *chan,
157                                    dma_cookie_t cookie)
158 {
159         struct virt_dma_desc *vd = NULL;
160         struct pdma_regs *regs = &chan->regs;
161         unsigned long flags;
162         u64 residue = 0;
163         struct sf_pdma_desc *desc;
164         struct dma_async_tx_descriptor *tx = NULL;
165
166         spin_lock_irqsave(&chan->vchan.lock, flags);
167
168         list_for_each_entry(vd, &chan->vchan.desc_submitted, node)
169                 if (vd->tx.cookie == cookie)
170                         tx = &vd->tx;
171
172         if (!tx)
173                 goto out;
174
175         if (cookie == tx->chan->completed_cookie)
176                 goto out;
177
178         if (cookie == tx->cookie) {
179                 residue = readq(regs->residue);
180         } else {
181                 vd = vchan_find_desc(&chan->vchan, cookie);
182                 if (!vd)
183                         goto out;
184
185                 desc = to_sf_pdma_desc(vd);
186                 residue = desc->xfer_size;
187         }
188
189 out:
190         spin_unlock_irqrestore(&chan->vchan.lock, flags);
191         return residue;
192 }
193
194 static enum dma_status
195 sf_pdma_tx_status(struct dma_chan *dchan,
196                   dma_cookie_t cookie,
197                   struct dma_tx_state *txstate)
198 {
199         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
200         enum dma_status status;
201
202         status = dma_cookie_status(dchan, cookie, txstate);
203
204         if (txstate && status != DMA_ERROR)
205                 dma_set_residue(txstate, sf_pdma_desc_residue(chan, cookie));
206
207         return status;
208 }
209
210 static int sf_pdma_terminate_all(struct dma_chan *dchan)
211 {
212         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
213         unsigned long flags;
214         LIST_HEAD(head);
215
216         spin_lock_irqsave(&chan->vchan.lock, flags);
217         sf_pdma_disable_request(chan);
218         kfree(chan->desc);
219         chan->desc = NULL;
220         chan->xfer_err = false;
221         vchan_get_all_descriptors(&chan->vchan, &head);
222         spin_unlock_irqrestore(&chan->vchan.lock, flags);
223         vchan_dma_desc_free_list(&chan->vchan, &head);
224
225         return 0;
226 }
227
228 static void sf_pdma_enable_request(struct sf_pdma_chan *chan)
229 {
230         struct pdma_regs *regs = &chan->regs;
231         u32 v;
232
233         v = PDMA_CLAIM_MASK |
234                 PDMA_ENABLE_DONE_INT_MASK |
235                 PDMA_ENABLE_ERR_INT_MASK |
236                 PDMA_RUN_MASK;
237
238         writel(v, regs->ctrl);
239 }
240
241 static struct sf_pdma_desc *sf_pdma_get_first_pending_desc(struct sf_pdma_chan *chan)
242 {
243         struct virt_dma_chan *vchan = &chan->vchan;
244         struct virt_dma_desc *vdesc;
245
246         if (list_empty(&vchan->desc_issued))
247                 return NULL;
248
249         vdesc = list_first_entry(&vchan->desc_issued, struct virt_dma_desc, node);
250
251         return container_of(vdesc, struct sf_pdma_desc, vdesc);
252 }
253
254 static void sf_pdma_xfer_desc(struct sf_pdma_chan *chan)
255 {
256         struct sf_pdma_desc *desc = chan->desc;
257         struct pdma_regs *regs = &chan->regs;
258
259         if (!desc) {
260                 dev_err(chan->pdma->dma_dev.dev, "NULL desc.\n");
261                 return;
262         }
263
264         writel(desc->xfer_type, regs->xfer_type);
265         writeq(desc->xfer_size, regs->xfer_size);
266         writeq(desc->dst_addr, regs->dst_addr);
267         writeq(desc->src_addr, regs->src_addr);
268
269         chan->desc = desc;
270         chan->status = DMA_IN_PROGRESS;
271         sf_pdma_enable_request(chan);
272 }
273
274 static void sf_pdma_issue_pending(struct dma_chan *dchan)
275 {
276         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
277         unsigned long flags;
278
279         spin_lock_irqsave(&chan->vchan.lock, flags);
280
281         if (!chan->desc && vchan_issue_pending(&chan->vchan)) {
282                 /* vchan_issue_pending has made a check that desc in not NULL */
283                 chan->desc = sf_pdma_get_first_pending_desc(chan);
284                 sf_pdma_xfer_desc(chan);
285         }
286
287         spin_unlock_irqrestore(&chan->vchan.lock, flags);
288 }
289
290 static void sf_pdma_free_desc(struct virt_dma_desc *vdesc)
291 {
292         struct sf_pdma_desc *desc;
293
294         desc = to_sf_pdma_desc(vdesc);
295         kfree(desc);
296 }
297
298 static void sf_pdma_donebh_tasklet(struct tasklet_struct *t)
299 {
300         struct sf_pdma_chan *chan = from_tasklet(chan, t, done_tasklet);
301         unsigned long flags;
302
303         spin_lock_irqsave(&chan->lock, flags);
304         if (chan->xfer_err) {
305                 chan->retries = MAX_RETRY;
306                 chan->status = DMA_COMPLETE;
307                 chan->xfer_err = false;
308         }
309         spin_unlock_irqrestore(&chan->lock, flags);
310
311         spin_lock_irqsave(&chan->vchan.lock, flags);
312         list_del(&chan->desc->vdesc.node);
313         vchan_cookie_complete(&chan->desc->vdesc);
314
315         chan->desc = sf_pdma_get_first_pending_desc(chan);
316         if (chan->desc)
317                 sf_pdma_xfer_desc(chan);
318
319         spin_unlock_irqrestore(&chan->vchan.lock, flags);
320 }
321
322 static void sf_pdma_errbh_tasklet(struct tasklet_struct *t)
323 {
324         struct sf_pdma_chan *chan = from_tasklet(chan, t, err_tasklet);
325         struct sf_pdma_desc *desc = chan->desc;
326         unsigned long flags;
327
328         spin_lock_irqsave(&chan->lock, flags);
329         if (chan->retries <= 0) {
330                 /* fail to recover */
331                 spin_unlock_irqrestore(&chan->lock, flags);
332                 dmaengine_desc_get_callback_invoke(desc->async_tx, NULL);
333         } else {
334                 /* retry */
335                 chan->retries--;
336                 chan->xfer_err = true;
337                 chan->status = DMA_ERROR;
338
339                 sf_pdma_enable_request(chan);
340                 spin_unlock_irqrestore(&chan->lock, flags);
341         }
342 }
343
344 static irqreturn_t sf_pdma_done_isr(int irq, void *dev_id)
345 {
346         struct sf_pdma_chan *chan = dev_id;
347         struct pdma_regs *regs = &chan->regs;
348         u64 residue;
349
350         spin_lock(&chan->vchan.lock);
351         writel((readl(regs->ctrl)) & ~PDMA_DONE_STATUS_MASK, regs->ctrl);
352         residue = readq(regs->residue);
353
354         if (!residue) {
355                 tasklet_hi_schedule(&chan->done_tasklet);
356         } else {
357                 /* submit next trascatioin if possible */
358                 struct sf_pdma_desc *desc = chan->desc;
359
360                 desc->src_addr += desc->xfer_size - residue;
361                 desc->dst_addr += desc->xfer_size - residue;
362                 desc->xfer_size = residue;
363
364                 sf_pdma_xfer_desc(chan);
365         }
366
367         spin_unlock(&chan->vchan.lock);
368
369         return IRQ_HANDLED;
370 }
371
372 static irqreturn_t sf_pdma_err_isr(int irq, void *dev_id)
373 {
374         struct sf_pdma_chan *chan = dev_id;
375         struct pdma_regs *regs = &chan->regs;
376
377         spin_lock(&chan->lock);
378         writel((readl(regs->ctrl)) & ~PDMA_ERR_STATUS_MASK, regs->ctrl);
379         spin_unlock(&chan->lock);
380
381         tasklet_schedule(&chan->err_tasklet);
382
383         return IRQ_HANDLED;
384 }
385
386 /**
387  * sf_pdma_irq_init() - Init PDMA IRQ Handlers
388  * @pdev: pointer of platform_device
389  * @pdma: pointer of PDMA engine. Caller should check NULL
390  *
391  * Initialize DONE and ERROR interrupt handler for 4 channels. Caller should
392  * make sure the pointer passed in are non-NULL. This function should be called
393  * only one time during the device probe.
394  *
395  * Context: Any context.
396  *
397  * Return:
398  * * 0          - OK to init all IRQ handlers
399  * * -EINVAL    - Fail to request IRQ
400  */
401 static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma)
402 {
403         int irq, r, i;
404         struct sf_pdma_chan *chan;
405
406         for (i = 0; i < pdma->n_chans; i++) {
407                 chan = &pdma->chans[i];
408
409                 irq = platform_get_irq(pdev, i * 2);
410                 if (irq < 0)
411                         return -EINVAL;
412
413                 r = devm_request_irq(&pdev->dev, irq, sf_pdma_done_isr, 0,
414                                      dev_name(&pdev->dev), (void *)chan);
415                 if (r) {
416                         dev_err(&pdev->dev, "Fail to attach done ISR: %d\n", r);
417                         return -EINVAL;
418                 }
419
420                 chan->txirq = irq;
421
422                 irq = platform_get_irq(pdev, (i * 2) + 1);
423                 if (irq < 0)
424                         return -EINVAL;
425
426                 r = devm_request_irq(&pdev->dev, irq, sf_pdma_err_isr, 0,
427                                      dev_name(&pdev->dev), (void *)chan);
428                 if (r) {
429                         dev_err(&pdev->dev, "Fail to attach err ISR: %d\n", r);
430                         return -EINVAL;
431                 }
432
433                 chan->errirq = irq;
434         }
435
436         return 0;
437 }
438
439 /**
440  * sf_pdma_setup_chans() - Init settings of each channel
441  * @pdma: pointer of PDMA engine. Caller should check NULL
442  *
443  * Initialize all data structure and register base. Caller should make sure
444  * the pointer passed in are non-NULL. This function should be called only
445  * one time during the device probe.
446  *
447  * Context: Any context.
448  *
449  * Return: none
450  */
451 static void sf_pdma_setup_chans(struct sf_pdma *pdma)
452 {
453         int i;
454         struct sf_pdma_chan *chan;
455
456         INIT_LIST_HEAD(&pdma->dma_dev.channels);
457
458         for (i = 0; i < pdma->n_chans; i++) {
459                 chan = &pdma->chans[i];
460
461                 chan->regs.ctrl =
462                         SF_PDMA_REG_BASE(i) + PDMA_CTRL;
463                 chan->regs.xfer_type =
464                         SF_PDMA_REG_BASE(i) + PDMA_XFER_TYPE;
465                 chan->regs.xfer_size =
466                         SF_PDMA_REG_BASE(i) + PDMA_XFER_SIZE;
467                 chan->regs.dst_addr =
468                         SF_PDMA_REG_BASE(i) + PDMA_DST_ADDR;
469                 chan->regs.src_addr =
470                         SF_PDMA_REG_BASE(i) + PDMA_SRC_ADDR;
471                 chan->regs.act_type =
472                         SF_PDMA_REG_BASE(i) + PDMA_ACT_TYPE;
473                 chan->regs.residue =
474                         SF_PDMA_REG_BASE(i) + PDMA_REMAINING_BYTE;
475                 chan->regs.cur_dst_addr =
476                         SF_PDMA_REG_BASE(i) + PDMA_CUR_DST_ADDR;
477                 chan->regs.cur_src_addr =
478                         SF_PDMA_REG_BASE(i) + PDMA_CUR_SRC_ADDR;
479
480                 chan->pdma = pdma;
481                 chan->pm_state = RUNNING;
482                 chan->slave_id = i;
483                 chan->xfer_err = false;
484                 spin_lock_init(&chan->lock);
485
486                 chan->vchan.desc_free = sf_pdma_free_desc;
487                 vchan_init(&chan->vchan, &pdma->dma_dev);
488
489                 writel(PDMA_CLEAR_CTRL, chan->regs.ctrl);
490
491                 tasklet_setup(&chan->done_tasklet, sf_pdma_donebh_tasklet);
492                 tasklet_setup(&chan->err_tasklet, sf_pdma_errbh_tasklet);
493         }
494 }
495
496 static int sf_pdma_probe(struct platform_device *pdev)
497 {
498         const struct sf_pdma_driver_platdata *ddata;
499         struct sf_pdma *pdma;
500         int ret, n_chans;
501         const enum dma_slave_buswidth widths =
502                 DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
503                 DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES |
504                 DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
505                 DMA_SLAVE_BUSWIDTH_64_BYTES;
506
507         ret = of_property_read_u32(pdev->dev.of_node, "dma-channels", &n_chans);
508         if (ret) {
509                 /* backwards-compatibility for no dma-channels property */
510                 dev_dbg(&pdev->dev, "set number of channels to default value: 4\n");
511                 n_chans = PDMA_MAX_NR_CH;
512         } else if (n_chans > PDMA_MAX_NR_CH) {
513                 dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
514                 return -EINVAL;
515         }
516
517         pdma = devm_kzalloc(&pdev->dev, struct_size(pdma, chans, n_chans),
518                             GFP_KERNEL);
519         if (!pdma)
520                 return -ENOMEM;
521
522         pdma->n_chans = n_chans;
523
524         pdma->transfer_type = PDMA_FULL_SPEED | PDMA_STRICT_ORDERING;
525
526         ddata  = device_get_match_data(&pdev->dev);
527         if (ddata) {
528                 if (ddata->quirks & PDMA_QUIRK_NO_STRICT_ORDERING)
529                         pdma->transfer_type &= ~PDMA_STRICT_ORDERING;
530         }
531
532         pdma->membase = devm_platform_ioremap_resource(pdev, 0);
533         if (IS_ERR(pdma->membase))
534                 return PTR_ERR(pdma->membase);
535
536         ret = sf_pdma_irq_init(pdev, pdma);
537         if (ret)
538                 return ret;
539
540         sf_pdma_setup_chans(pdma);
541
542         pdma->dma_dev.dev = &pdev->dev;
543
544         /* Setup capability */
545         dma_cap_set(DMA_MEMCPY, pdma->dma_dev.cap_mask);
546         pdma->dma_dev.copy_align = 2;
547         pdma->dma_dev.src_addr_widths = widths;
548         pdma->dma_dev.dst_addr_widths = widths;
549         pdma->dma_dev.directions = BIT(DMA_MEM_TO_MEM);
550         pdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
551         pdma->dma_dev.descriptor_reuse = true;
552
553         /* Setup DMA APIs */
554         pdma->dma_dev.device_alloc_chan_resources =
555                 sf_pdma_alloc_chan_resources;
556         pdma->dma_dev.device_free_chan_resources =
557                 sf_pdma_free_chan_resources;
558         pdma->dma_dev.device_tx_status = sf_pdma_tx_status;
559         pdma->dma_dev.device_prep_dma_memcpy = sf_pdma_prep_dma_memcpy;
560         pdma->dma_dev.device_config = sf_pdma_slave_config;
561         pdma->dma_dev.device_terminate_all = sf_pdma_terminate_all;
562         pdma->dma_dev.device_issue_pending = sf_pdma_issue_pending;
563
564         platform_set_drvdata(pdev, pdma);
565
566         ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
567         if (ret)
568                 dev_warn(&pdev->dev,
569                          "Failed to set DMA mask. Fall back to default.\n");
570
571         ret = dma_async_device_register(&pdma->dma_dev);
572         if (ret) {
573                 dev_err(&pdev->dev,
574                         "Can't register SiFive Platform DMA. (%d)\n", ret);
575                 return ret;
576         }
577
578         ret = of_dma_controller_register(pdev->dev.of_node,
579                                          of_dma_xlate_by_chan_id, pdma);
580         if (ret < 0) {
581                 dev_err(&pdev->dev,
582                         "Can't register SiFive Platform OF_DMA. (%d)\n", ret);
583                 goto err_unregister;
584         }
585
586         return 0;
587
588 err_unregister:
589         dma_async_device_unregister(&pdma->dma_dev);
590
591         return ret;
592 }
593
594 static void sf_pdma_remove(struct platform_device *pdev)
595 {
596         struct sf_pdma *pdma = platform_get_drvdata(pdev);
597         struct sf_pdma_chan *ch;
598         int i;
599
600         for (i = 0; i < pdma->n_chans; i++) {
601                 ch = &pdma->chans[i];
602
603                 devm_free_irq(&pdev->dev, ch->txirq, ch);
604                 devm_free_irq(&pdev->dev, ch->errirq, ch);
605                 list_del(&ch->vchan.chan.device_node);
606                 tasklet_kill(&ch->vchan.task);
607                 tasklet_kill(&ch->done_tasklet);
608                 tasklet_kill(&ch->err_tasklet);
609         }
610
611         if (pdev->dev.of_node)
612                 of_dma_controller_free(pdev->dev.of_node);
613
614         dma_async_device_unregister(&pdma->dma_dev);
615 }
616
617 static const struct sf_pdma_driver_platdata mpfs_pdma = {
618         .quirks = PDMA_QUIRK_NO_STRICT_ORDERING,
619 };
620
621 static const struct of_device_id sf_pdma_dt_ids[] = {
622         {
623                 .compatible = "sifive,fu540-c000-pdma",
624         }, {
625                 .compatible = "sifive,pdma0",
626         }, {
627                 .compatible = "microchip,mpfs-pdma",
628                 .data       = &mpfs_pdma,
629         },
630         {},
631 };
632 MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
633
634 static struct platform_driver sf_pdma_driver = {
635         .probe          = sf_pdma_probe,
636         .remove_new     = sf_pdma_remove,
637         .driver         = {
638                 .name   = "sf-pdma",
639                 .of_match_table = sf_pdma_dt_ids,
640         },
641 };
642
643 static int __init sf_pdma_init(void)
644 {
645         return platform_driver_register(&sf_pdma_driver);
646 }
647
648 static void __exit sf_pdma_exit(void)
649 {
650         platform_driver_unregister(&sf_pdma_driver);
651 }
652
653 /* do early init */
654 subsys_initcall(sf_pdma_init);
655 module_exit(sf_pdma_exit);
656
657 MODULE_LICENSE("GPL v2");
658 MODULE_DESCRIPTION("SiFive Platform DMA driver");
659 MODULE_AUTHOR("Green Wan <green.wan@sifive.com>");