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Florian Meier96286b52014-01-06 20:18:24 +01001/*
2 * BCM2835 DMA engine support
3 *
4 * This driver only supports cyclic DMA transfers
5 * as needed for the I2S module.
6 *
7 * Author: Florian Meier <florian.meier@koalo.de>
8 * Copyright 2013
9 *
10 * Based on
11 * OMAP DMAengine support by Russell King
12 *
13 * BCM2708 DMA Driver
14 * Copyright (C) 2010 Broadcom
15 *
16 * Raspberry Pi PCM I2S ALSA Driver
17 * Copyright (c) by Phil Poole 2013
18 *
19 * MARVELL MMP Peripheral DMA Driver
20 * Copyright 2012 Marvell International Ltd.
21 *
22 * This program is free software; you can redistribute it and/or modify
23 * it under the terms of the GNU General Public License as published by
24 * the Free Software Foundation; either version 2 of the License, or
25 * (at your option) any later version.
26 *
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 * GNU General Public License for more details.
31 */
32#include <linux/dmaengine.h>
33#include <linux/dma-mapping.h>
34#include <linux/err.h>
35#include <linux/init.h>
36#include <linux/interrupt.h>
37#include <linux/list.h>
38#include <linux/module.h>
39#include <linux/platform_device.h>
40#include <linux/slab.h>
41#include <linux/io.h>
42#include <linux/spinlock.h>
43#include <linux/of.h>
44#include <linux/of_dma.h>
45
46#include "virt-dma.h"
47
48struct bcm2835_dmadev {
49 struct dma_device ddev;
50 spinlock_t lock;
51 void __iomem *base;
52 struct device_dma_parameters dma_parms;
53};
54
55struct bcm2835_dma_cb {
56 uint32_t info;
57 uint32_t src;
58 uint32_t dst;
59 uint32_t length;
60 uint32_t stride;
61 uint32_t next;
62 uint32_t pad[2];
63};
64
65struct bcm2835_chan {
66 struct virt_dma_chan vc;
67 struct list_head node;
68
69 struct dma_slave_config cfg;
70 bool cyclic;
71 unsigned int dreq;
72
73 int ch;
74 struct bcm2835_desc *desc;
75
76 void __iomem *chan_base;
77 int irq_number;
78};
79
80struct bcm2835_desc {
81 struct virt_dma_desc vd;
82 enum dma_transfer_direction dir;
83
84 unsigned int control_block_size;
85 struct bcm2835_dma_cb *control_block_base;
86 dma_addr_t control_block_base_phys;
87
88 unsigned int frames;
89 size_t size;
90};
91
92#define BCM2835_DMA_CS 0x00
93#define BCM2835_DMA_ADDR 0x04
94#define BCM2835_DMA_SOURCE_AD 0x0c
95#define BCM2835_DMA_DEST_AD 0x10
96#define BCM2835_DMA_NEXTCB 0x1C
97
98/* DMA CS Control and Status bits */
99#define BCM2835_DMA_ACTIVE BIT(0)
100#define BCM2835_DMA_INT BIT(2)
101#define BCM2835_DMA_ISPAUSED BIT(4) /* Pause requested or not active */
102#define BCM2835_DMA_ISHELD BIT(5) /* Is held by DREQ flow control */
103#define BCM2835_DMA_ERR BIT(8)
104#define BCM2835_DMA_ABORT BIT(30) /* Stop current CB, go to next, WO */
105#define BCM2835_DMA_RESET BIT(31) /* WO, self clearing */
106
107#define BCM2835_DMA_INT_EN BIT(0)
108#define BCM2835_DMA_D_INC BIT(4)
109#define BCM2835_DMA_D_DREQ BIT(6)
110#define BCM2835_DMA_S_INC BIT(8)
111#define BCM2835_DMA_S_DREQ BIT(10)
112
113#define BCM2835_DMA_PER_MAP(x) ((x) << 16)
114
115#define BCM2835_DMA_DATA_TYPE_S8 1
116#define BCM2835_DMA_DATA_TYPE_S16 2
117#define BCM2835_DMA_DATA_TYPE_S32 4
118#define BCM2835_DMA_DATA_TYPE_S128 16
119
120#define BCM2835_DMA_BULK_MASK BIT(0)
121#define BCM2835_DMA_FIQ_MASK (BIT(2) | BIT(3))
122
123/* Valid only for channels 0 - 14, 15 has its own base address */
124#define BCM2835_DMA_CHAN(n) ((n) << 8) /* Base address */
125#define BCM2835_DMA_CHANIO(base, n) ((base) + BCM2835_DMA_CHAN(n))
126
127static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d)
128{
129 return container_of(d, struct bcm2835_dmadev, ddev);
130}
131
132static inline struct bcm2835_chan *to_bcm2835_dma_chan(struct dma_chan *c)
133{
134 return container_of(c, struct bcm2835_chan, vc.chan);
135}
136
137static inline struct bcm2835_desc *to_bcm2835_dma_desc(
138 struct dma_async_tx_descriptor *t)
139{
140 return container_of(t, struct bcm2835_desc, vd.tx);
141}
142
143static void bcm2835_dma_desc_free(struct virt_dma_desc *vd)
144{
145 struct bcm2835_desc *desc = container_of(vd, struct bcm2835_desc, vd);
146 dma_free_coherent(desc->vd.tx.chan->device->dev,
147 desc->control_block_size,
148 desc->control_block_base,
149 desc->control_block_base_phys);
150 kfree(desc);
151}
152
153static int bcm2835_dma_abort(void __iomem *chan_base)
154{
155 unsigned long cs;
156 long int timeout = 10000;
157
158 cs = readl(chan_base + BCM2835_DMA_CS);
159 if (!(cs & BCM2835_DMA_ACTIVE))
160 return 0;
161
162 /* Write 0 to the active bit - Pause the DMA */
163 writel(0, chan_base + BCM2835_DMA_CS);
164
165 /* Wait for any current AXI transfer to complete */
166 while ((cs & BCM2835_DMA_ISPAUSED) && --timeout) {
167 cpu_relax();
168 cs = readl(chan_base + BCM2835_DMA_CS);
169 }
170
171 /* We'll un-pause when we set of our next DMA */
172 if (!timeout)
173 return -ETIMEDOUT;
174
175 if (!(cs & BCM2835_DMA_ACTIVE))
176 return 0;
177
178 /* Terminate the control block chain */
179 writel(0, chan_base + BCM2835_DMA_NEXTCB);
180
181 /* Abort the whole DMA */
182 writel(BCM2835_DMA_ABORT | BCM2835_DMA_ACTIVE,
183 chan_base + BCM2835_DMA_CS);
184
185 return 0;
186}
187
188static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
189{
190 struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
191 struct bcm2835_desc *d;
192
193 if (!vd) {
194 c->desc = NULL;
195 return;
196 }
197
198 list_del(&vd->node);
199
200 c->desc = d = to_bcm2835_dma_desc(&vd->tx);
201
202 writel(d->control_block_base_phys, c->chan_base + BCM2835_DMA_ADDR);
203 writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS);
204}
205
206static irqreturn_t bcm2835_dma_callback(int irq, void *data)
207{
208 struct bcm2835_chan *c = data;
209 struct bcm2835_desc *d;
210 unsigned long flags;
211
212 spin_lock_irqsave(&c->vc.lock, flags);
213
214 /* Acknowledge interrupt */
215 writel(BCM2835_DMA_INT, c->chan_base + BCM2835_DMA_CS);
216
217 d = c->desc;
218
219 if (d) {
220 /* TODO Only works for cyclic DMA */
221 vchan_cyclic_callback(&d->vd);
222 }
223
224 /* Keep the DMA engine running */
225 writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS);
226
227 spin_unlock_irqrestore(&c->vc.lock, flags);
228
229 return IRQ_HANDLED;
230}
231
232static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan)
233{
234 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
235
236 dev_dbg(c->vc.chan.device->dev,
237 "Allocating DMA channel %d\n", c->ch);
238
239 return request_irq(c->irq_number,
240 bcm2835_dma_callback, 0, "DMA IRQ", c);
241}
242
243static void bcm2835_dma_free_chan_resources(struct dma_chan *chan)
244{
245 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
246
247 vchan_free_chan_resources(&c->vc);
248 free_irq(c->irq_number, c);
249
250 dev_dbg(c->vc.chan.device->dev, "Freeing DMA channel %u\n", c->ch);
251}
252
253static size_t bcm2835_dma_desc_size(struct bcm2835_desc *d)
254{
255 return d->size;
256}
257
258static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr)
259{
260 unsigned int i;
261 size_t size;
262
263 for (size = i = 0; i < d->frames; i++) {
264 struct bcm2835_dma_cb *control_block =
265 &d->control_block_base[i];
266 size_t this_size = control_block->length;
267 dma_addr_t dma;
268
269 if (d->dir == DMA_DEV_TO_MEM)
270 dma = control_block->dst;
271 else
272 dma = control_block->src;
273
274 if (size)
275 size += this_size;
276 else if (addr >= dma && addr < dma + this_size)
277 size += dma + this_size - addr;
278 }
279
280 return size;
281}
282
283static enum dma_status bcm2835_dma_tx_status(struct dma_chan *chan,
284 dma_cookie_t cookie, struct dma_tx_state *txstate)
285{
286 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
287 struct virt_dma_desc *vd;
288 enum dma_status ret;
289 unsigned long flags;
290
291 ret = dma_cookie_status(chan, cookie, txstate);
292 if (ret == DMA_COMPLETE || !txstate)
293 return ret;
294
295 spin_lock_irqsave(&c->vc.lock, flags);
296 vd = vchan_find_desc(&c->vc, cookie);
297 if (vd) {
298 txstate->residue =
299 bcm2835_dma_desc_size(to_bcm2835_dma_desc(&vd->tx));
300 } else if (c->desc && c->desc->vd.tx.cookie == cookie) {
301 struct bcm2835_desc *d = c->desc;
302 dma_addr_t pos;
303
304 if (d->dir == DMA_MEM_TO_DEV)
305 pos = readl(c->chan_base + BCM2835_DMA_SOURCE_AD);
306 else if (d->dir == DMA_DEV_TO_MEM)
307 pos = readl(c->chan_base + BCM2835_DMA_DEST_AD);
308 else
309 pos = 0;
310
311 txstate->residue = bcm2835_dma_desc_size_pos(d, pos);
312 } else {
313 txstate->residue = 0;
314 }
315
316 spin_unlock_irqrestore(&c->vc.lock, flags);
317
318 return ret;
319}
320
321static void bcm2835_dma_issue_pending(struct dma_chan *chan)
322{
323 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
324 unsigned long flags;
325
326 c->cyclic = true; /* Nothing else is implemented */
327
328 spin_lock_irqsave(&c->vc.lock, flags);
329 if (vchan_issue_pending(&c->vc) && !c->desc)
330 bcm2835_dma_start_desc(c);
331
332 spin_unlock_irqrestore(&c->vc.lock, flags);
333}
334
335static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
336 struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
337 size_t period_len, enum dma_transfer_direction direction,
Laurent Pinchart31c1e5a2014-08-01 12:20:10 +0200338 unsigned long flags)
Florian Meier96286b52014-01-06 20:18:24 +0100339{
340 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
341 enum dma_slave_buswidth dev_width;
342 struct bcm2835_desc *d;
343 dma_addr_t dev_addr;
344 unsigned int es, sync_type;
345 unsigned int frame;
346
347 /* Grab configuration */
348 if (!is_slave_direction(direction)) {
349 dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
350 return NULL;
351 }
352
353 if (direction == DMA_DEV_TO_MEM) {
354 dev_addr = c->cfg.src_addr;
355 dev_width = c->cfg.src_addr_width;
356 sync_type = BCM2835_DMA_S_DREQ;
357 } else {
358 dev_addr = c->cfg.dst_addr;
359 dev_width = c->cfg.dst_addr_width;
360 sync_type = BCM2835_DMA_D_DREQ;
361 }
362
363 /* Bus width translates to the element size (ES) */
364 switch (dev_width) {
365 case DMA_SLAVE_BUSWIDTH_4_BYTES:
366 es = BCM2835_DMA_DATA_TYPE_S32;
367 break;
368 default:
369 return NULL;
370 }
371
372 /* Now allocate and setup the descriptor. */
373 d = kzalloc(sizeof(*d), GFP_NOWAIT);
374 if (!d)
375 return NULL;
376
377 d->dir = direction;
378 d->frames = buf_len / period_len;
379
380 /* Allocate memory for control blocks */
381 d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb);
382 d->control_block_base = dma_zalloc_coherent(chan->device->dev,
383 d->control_block_size, &d->control_block_base_phys,
384 GFP_NOWAIT);
385
386 if (!d->control_block_base) {
387 kfree(d);
388 return NULL;
389 }
390
391 /*
392 * Iterate over all frames, create a control block
393 * for each frame and link them together.
394 */
395 for (frame = 0; frame < d->frames; frame++) {
396 struct bcm2835_dma_cb *control_block =
397 &d->control_block_base[frame];
398
399 /* Setup adresses */
400 if (d->dir == DMA_DEV_TO_MEM) {
401 control_block->info = BCM2835_DMA_D_INC;
402 control_block->src = dev_addr;
403 control_block->dst = buf_addr + frame * period_len;
404 } else {
405 control_block->info = BCM2835_DMA_S_INC;
406 control_block->src = buf_addr + frame * period_len;
407 control_block->dst = dev_addr;
408 }
409
410 /* Enable interrupt */
411 control_block->info |= BCM2835_DMA_INT_EN;
412
413 /* Setup synchronization */
414 if (sync_type != 0)
415 control_block->info |= sync_type;
416
417 /* Setup DREQ channel */
418 if (c->dreq != 0)
419 control_block->info |=
420 BCM2835_DMA_PER_MAP(c->dreq);
421
422 /* Length of a frame */
423 control_block->length = period_len;
424 d->size += control_block->length;
425
426 /*
427 * Next block is the next frame.
428 * This DMA engine driver currently only supports cyclic DMA.
429 * Therefore, wrap around at number of frames.
430 */
431 control_block->next = d->control_block_base_phys +
432 sizeof(struct bcm2835_dma_cb)
433 * ((frame + 1) % d->frames);
434 }
435
436 return vchan_tx_prep(&c->vc, &d->vd, flags);
437}
438
Maxime Ripard39159be2014-11-17 14:42:08 +0100439static int bcm2835_dma_slave_config(struct dma_chan *chan,
440 struct dma_slave_config *cfg)
Florian Meier96286b52014-01-06 20:18:24 +0100441{
Maxime Ripard39159be2014-11-17 14:42:08 +0100442 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
443
Florian Meier96286b52014-01-06 20:18:24 +0100444 if ((cfg->direction == DMA_DEV_TO_MEM &&
445 cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
446 (cfg->direction == DMA_MEM_TO_DEV &&
447 cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
448 !is_slave_direction(cfg->direction)) {
449 return -EINVAL;
450 }
451
452 c->cfg = *cfg;
453
454 return 0;
455}
456
Maxime Ripard39159be2014-11-17 14:42:08 +0100457static int bcm2835_dma_terminate_all(struct dma_chan *chan)
Florian Meier96286b52014-01-06 20:18:24 +0100458{
Maxime Ripard39159be2014-11-17 14:42:08 +0100459 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
Florian Meier96286b52014-01-06 20:18:24 +0100460 struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device);
461 unsigned long flags;
462 int timeout = 10000;
463 LIST_HEAD(head);
464
465 spin_lock_irqsave(&c->vc.lock, flags);
466
467 /* Prevent this channel being scheduled */
468 spin_lock(&d->lock);
469 list_del_init(&c->node);
470 spin_unlock(&d->lock);
471
472 /*
473 * Stop DMA activity: we assume the callback will not be called
474 * after bcm_dma_abort() returns (even if it does, it will see
475 * c->desc is NULL and exit.)
476 */
477 if (c->desc) {
Peter Ujfalusif9317822015-03-27 13:35:53 +0200478 bcm2835_dma_desc_free(&c->desc->vd);
Florian Meier96286b52014-01-06 20:18:24 +0100479 c->desc = NULL;
480 bcm2835_dma_abort(c->chan_base);
481
482 /* Wait for stopping */
483 while (--timeout) {
484 if (!(readl(c->chan_base + BCM2835_DMA_CS) &
485 BCM2835_DMA_ACTIVE))
486 break;
487
488 cpu_relax();
489 }
490
491 if (!timeout)
492 dev_err(d->ddev.dev, "DMA transfer could not be terminated\n");
493 }
494
495 vchan_get_all_descriptors(&c->vc, &head);
496 spin_unlock_irqrestore(&c->vc.lock, flags);
497 vchan_dma_desc_free_list(&c->vc, &head);
498
499 return 0;
500}
501
Florian Meier96286b52014-01-06 20:18:24 +0100502static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq)
503{
504 struct bcm2835_chan *c;
505
506 c = devm_kzalloc(d->ddev.dev, sizeof(*c), GFP_KERNEL);
507 if (!c)
508 return -ENOMEM;
509
510 c->vc.desc_free = bcm2835_dma_desc_free;
511 vchan_init(&c->vc, &d->ddev);
512 INIT_LIST_HEAD(&c->node);
513
Florian Meier96286b52014-01-06 20:18:24 +0100514 c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id);
515 c->ch = chan_id;
516 c->irq_number = irq;
517
518 return 0;
519}
520
521static void bcm2835_dma_free(struct bcm2835_dmadev *od)
522{
523 struct bcm2835_chan *c, *next;
524
525 list_for_each_entry_safe(c, next, &od->ddev.channels,
526 vc.chan.device_node) {
527 list_del(&c->vc.chan.device_node);
528 tasklet_kill(&c->vc.task);
529 }
530}
531
532static const struct of_device_id bcm2835_dma_of_match[] = {
533 { .compatible = "brcm,bcm2835-dma", },
534 {},
535};
536MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match);
537
538static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec,
539 struct of_dma *ofdma)
540{
541 struct bcm2835_dmadev *d = ofdma->of_dma_data;
542 struct dma_chan *chan;
543
544 chan = dma_get_any_slave_channel(&d->ddev);
545 if (!chan)
546 return NULL;
547
548 /* Set DREQ from param */
549 to_bcm2835_dma_chan(chan)->dreq = spec->args[0];
550
551 return chan;
552}
553
Florian Meier96286b52014-01-06 20:18:24 +0100554static int bcm2835_dma_probe(struct platform_device *pdev)
555{
556 struct bcm2835_dmadev *od;
557 struct resource *res;
558 void __iomem *base;
559 int rc;
560 int i;
561 int irq;
562 uint32_t chans_available;
563
564 if (!pdev->dev.dma_mask)
565 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
566
567 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
568 if (rc)
569 return rc;
570
571 od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
572 if (!od)
573 return -ENOMEM;
574
575 pdev->dev.dma_parms = &od->dma_parms;
576 dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF);
577
578 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
579 base = devm_ioremap_resource(&pdev->dev, res);
580 if (IS_ERR(base))
581 return PTR_ERR(base);
582
583 od->base = base;
584
585 dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
Florian Meier7f5ae352014-01-17 18:06:29 +0100586 dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask);
Florian Meier96286b52014-01-06 20:18:24 +0100587 dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
588 od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources;
589 od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources;
590 od->ddev.device_tx_status = bcm2835_dma_tx_status;
591 od->ddev.device_issue_pending = bcm2835_dma_issue_pending;
Florian Meier96286b52014-01-06 20:18:24 +0100592 od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic;
Maxime Ripard39159be2014-11-17 14:42:08 +0100593 od->ddev.device_config = bcm2835_dma_slave_config;
594 od->ddev.device_terminate_all = bcm2835_dma_terminate_all;
Maxime Ripardb5743682014-11-17 14:42:45 +0100595 od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
596 od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
597 od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
Florian Meier96286b52014-01-06 20:18:24 +0100598 od->ddev.dev = &pdev->dev;
599 INIT_LIST_HEAD(&od->ddev.channels);
600 spin_lock_init(&od->lock);
601
602 platform_set_drvdata(pdev, od);
603
604 /* Request DMA channel mask from device tree */
605 if (of_property_read_u32(pdev->dev.of_node,
606 "brcm,dma-channel-mask",
607 &chans_available)) {
608 dev_err(&pdev->dev, "Failed to get channel mask\n");
609 rc = -EINVAL;
610 goto err_no_dma;
611 }
612
613 /*
614 * Do not use the FIQ and BULK channels,
615 * because they are used by the GPU.
616 */
617 chans_available &= ~(BCM2835_DMA_FIQ_MASK | BCM2835_DMA_BULK_MASK);
618
619 for (i = 0; i < pdev->num_resources; i++) {
620 irq = platform_get_irq(pdev, i);
621 if (irq < 0)
622 break;
623
624 if (chans_available & (1 << i)) {
625 rc = bcm2835_dma_chan_init(od, i, irq);
626 if (rc)
627 goto err_no_dma;
628 }
629 }
630
631 dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i);
632
633 /* Device-tree DMA controller registration */
634 rc = of_dma_controller_register(pdev->dev.of_node,
635 bcm2835_dma_xlate, od);
636 if (rc) {
637 dev_err(&pdev->dev, "Failed to register DMA controller\n");
638 goto err_no_dma;
639 }
640
641 rc = dma_async_device_register(&od->ddev);
642 if (rc) {
643 dev_err(&pdev->dev,
644 "Failed to register slave DMA engine device: %d\n", rc);
645 goto err_no_dma;
646 }
647
648 dev_dbg(&pdev->dev, "Load BCM2835 DMA engine driver\n");
649
650 return 0;
651
652err_no_dma:
653 bcm2835_dma_free(od);
654 return rc;
655}
656
657static int bcm2835_dma_remove(struct platform_device *pdev)
658{
659 struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
660
661 dma_async_device_unregister(&od->ddev);
662 bcm2835_dma_free(od);
663
664 return 0;
665}
666
667static struct platform_driver bcm2835_dma_driver = {
668 .probe = bcm2835_dma_probe,
669 .remove = bcm2835_dma_remove,
670 .driver = {
671 .name = "bcm2835-dma",
Florian Meier96286b52014-01-06 20:18:24 +0100672 .of_match_table = of_match_ptr(bcm2835_dma_of_match),
673 },
674};
675
676module_platform_driver(bcm2835_dma_driver);
677
678MODULE_ALIAS("platform:bcm2835-dma");
679MODULE_DESCRIPTION("BCM2835 DMA engine driver");
680MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>");
681MODULE_LICENSE("GPL v2");