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authorFlorian Meier <florian.meier@koalo.de>2014-01-06 14:18:24 -0500
committerVinod Koul <vinod.koul@intel.com>2014-01-07 11:06:39 -0500
commit96286b57669073e81870e33a3e5ce476433d115f (patch)
tree26a0f4ba89dd2b55db3f7fa48519f8c75b8923c6 /drivers/dma
parent0adcdeed6f87ac7230c9a0364ac785b8e70ad275 (diff)
dmaengine: Add support for BCM2835
Add support for DMA controller of BCM2835 as used in the Raspberry Pi. Currently it only supports cyclic DMA. Signed-off-by: Florian Meier <florian.meier@koalo.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/Kconfig6
-rw-r--r--drivers/dma/Makefile1
-rw-r--r--drivers/dma/bcm2835-dma.c706
3 files changed, 713 insertions, 0 deletions
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 446687cc2334..cff5f1e39cf7 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -301,6 +301,12 @@ config DMA_OMAP
301 select DMA_ENGINE 301 select DMA_ENGINE
302 select DMA_VIRTUAL_CHANNELS 302 select DMA_VIRTUAL_CHANNELS
303 303
304config DMA_BCM2835
305 tristate "BCM2835 DMA engine support"
306 depends on (ARCH_BCM2835 || MACH_BCM2708)
307 select DMA_ENGINE
308 select DMA_VIRTUAL_CHANNELS
309
304config TI_CPPI41 310config TI_CPPI41
305 tristate "AM33xx CPPI41 DMA support" 311 tristate "AM33xx CPPI41 DMA support"
306 depends on ARCH_OMAP 312 depends on ARCH_OMAP
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 0ce2da97e429..0a6f08edf2c8 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_EP93XX_DMA) += ep93xx_dma.o
38obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o 38obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o
39obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o 39obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
40obj-$(CONFIG_DMA_OMAP) += omap-dma.o 40obj-$(CONFIG_DMA_OMAP) += omap-dma.o
41obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
41obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o 42obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
42obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o 43obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
43obj-$(CONFIG_TI_CPPI41) += cppi41.o 44obj-$(CONFIG_TI_CPPI41) += cppi41.o
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
new file mode 100644
index 000000000000..6ae070825f3f
--- /dev/null
+++ b/drivers/dma/bcm2835-dma.c
@@ -0,0 +1,706 @@
1/*
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,
338 unsigned long flags, void *context)
339{
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
439static int bcm2835_dma_slave_config(struct bcm2835_chan *c,
440 struct dma_slave_config *cfg)
441{
442 if ((cfg->direction == DMA_DEV_TO_MEM &&
443 cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
444 (cfg->direction == DMA_MEM_TO_DEV &&
445 cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
446 !is_slave_direction(cfg->direction)) {
447 return -EINVAL;
448 }
449
450 c->cfg = *cfg;
451
452 return 0;
453}
454
455static int bcm2835_dma_terminate_all(struct bcm2835_chan *c)
456{
457 struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device);
458 unsigned long flags;
459 int timeout = 10000;
460 LIST_HEAD(head);
461
462 spin_lock_irqsave(&c->vc.lock, flags);
463
464 /* Prevent this channel being scheduled */
465 spin_lock(&d->lock);
466 list_del_init(&c->node);
467 spin_unlock(&d->lock);
468
469 /*
470 * Stop DMA activity: we assume the callback will not be called
471 * after bcm_dma_abort() returns (even if it does, it will see
472 * c->desc is NULL and exit.)
473 */
474 if (c->desc) {
475 c->desc = NULL;
476 bcm2835_dma_abort(c->chan_base);
477
478 /* Wait for stopping */
479 while (--timeout) {
480 if (!(readl(c->chan_base + BCM2835_DMA_CS) &
481 BCM2835_DMA_ACTIVE))
482 break;
483
484 cpu_relax();
485 }
486
487 if (!timeout)
488 dev_err(d->ddev.dev, "DMA transfer could not be terminated\n");
489 }
490
491 vchan_get_all_descriptors(&c->vc, &head);
492 spin_unlock_irqrestore(&c->vc.lock, flags);
493 vchan_dma_desc_free_list(&c->vc, &head);
494
495 return 0;
496}
497
498static int bcm2835_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
499 unsigned long arg)
500{
501 struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
502
503 switch (cmd) {
504 case DMA_SLAVE_CONFIG:
505 return bcm2835_dma_slave_config(c,
506 (struct dma_slave_config *)arg);
507
508 case DMA_TERMINATE_ALL:
509 return bcm2835_dma_terminate_all(c);
510
511 default:
512 return -ENXIO;
513 }
514}
515
516static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq)
517{
518 struct bcm2835_chan *c;
519
520 c = devm_kzalloc(d->ddev.dev, sizeof(*c), GFP_KERNEL);
521 if (!c)
522 return -ENOMEM;
523
524 c->vc.desc_free = bcm2835_dma_desc_free;
525 vchan_init(&c->vc, &d->ddev);
526 INIT_LIST_HEAD(&c->node);
527
528 d->ddev.chancnt++;
529
530 c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id);
531 c->ch = chan_id;
532 c->irq_number = irq;
533
534 return 0;
535}
536
537static void bcm2835_dma_free(struct bcm2835_dmadev *od)
538{
539 struct bcm2835_chan *c, *next;
540
541 list_for_each_entry_safe(c, next, &od->ddev.channels,
542 vc.chan.device_node) {
543 list_del(&c->vc.chan.device_node);
544 tasklet_kill(&c->vc.task);
545 }
546}
547
548static const struct of_device_id bcm2835_dma_of_match[] = {
549 { .compatible = "brcm,bcm2835-dma", },
550 {},
551};
552MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match);
553
554static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec,
555 struct of_dma *ofdma)
556{
557 struct bcm2835_dmadev *d = ofdma->of_dma_data;
558 struct dma_chan *chan;
559
560 chan = dma_get_any_slave_channel(&d->ddev);
561 if (!chan)
562 return NULL;
563
564 /* Set DREQ from param */
565 to_bcm2835_dma_chan(chan)->dreq = spec->args[0];
566
567 return chan;
568}
569
570static int bcm2835_dma_device_slave_caps(struct dma_chan *dchan,
571 struct dma_slave_caps *caps)
572{
573 caps->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
574 caps->dstn_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
575 caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
576 caps->cmd_pause = false;
577 caps->cmd_terminate = true;
578
579 return 0;
580}
581
582static int bcm2835_dma_probe(struct platform_device *pdev)
583{
584 struct bcm2835_dmadev *od;
585 struct resource *res;
586 void __iomem *base;
587 int rc;
588 int i;
589 int irq;
590 uint32_t chans_available;
591
592 if (!pdev->dev.dma_mask)
593 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
594
595 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
596 if (rc)
597 return rc;
598
599 od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
600 if (!od)
601 return -ENOMEM;
602
603 pdev->dev.dma_parms = &od->dma_parms;
604 dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF);
605
606 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
607 base = devm_ioremap_resource(&pdev->dev, res);
608 if (IS_ERR(base))
609 return PTR_ERR(base);
610
611 od->base = base;
612
613 dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
614 dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
615 od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources;
616 od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources;
617 od->ddev.device_tx_status = bcm2835_dma_tx_status;
618 od->ddev.device_issue_pending = bcm2835_dma_issue_pending;
619 od->ddev.device_slave_caps = bcm2835_dma_device_slave_caps;
620 od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic;
621 od->ddev.device_control = bcm2835_dma_control;
622 od->ddev.dev = &pdev->dev;
623 INIT_LIST_HEAD(&od->ddev.channels);
624 spin_lock_init(&od->lock);
625
626 platform_set_drvdata(pdev, od);
627
628 /* Request DMA channel mask from device tree */
629 if (of_property_read_u32(pdev->dev.of_node,
630 "brcm,dma-channel-mask",
631 &chans_available)) {
632 dev_err(&pdev->dev, "Failed to get channel mask\n");
633 rc = -EINVAL;
634 goto err_no_dma;
635 }
636
637 /*
638 * Do not use the FIQ and BULK channels,
639 * because they are used by the GPU.
640 */
641 chans_available &= ~(BCM2835_DMA_FIQ_MASK | BCM2835_DMA_BULK_MASK);
642
643 for (i = 0; i < pdev->num_resources; i++) {
644 irq = platform_get_irq(pdev, i);
645 if (irq < 0)
646 break;
647
648 if (chans_available & (1 << i)) {
649 rc = bcm2835_dma_chan_init(od, i, irq);
650 if (rc)
651 goto err_no_dma;
652 }
653 }
654
655 dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i);
656
657 /* Device-tree DMA controller registration */
658 rc = of_dma_controller_register(pdev->dev.of_node,
659 bcm2835_dma_xlate, od);
660 if (rc) {
661 dev_err(&pdev->dev, "Failed to register DMA controller\n");
662 goto err_no_dma;
663 }
664
665 rc = dma_async_device_register(&od->ddev);
666 if (rc) {
667 dev_err(&pdev->dev,
668 "Failed to register slave DMA engine device: %d\n", rc);
669 goto err_no_dma;
670 }
671
672 dev_dbg(&pdev->dev, "Load BCM2835 DMA engine driver\n");
673
674 return 0;
675
676err_no_dma:
677 bcm2835_dma_free(od);
678 return rc;
679}
680
681static int bcm2835_dma_remove(struct platform_device *pdev)
682{
683 struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
684
685 dma_async_device_unregister(&od->ddev);
686 bcm2835_dma_free(od);
687
688 return 0;
689}
690
691static struct platform_driver bcm2835_dma_driver = {
692 .probe = bcm2835_dma_probe,
693 .remove = bcm2835_dma_remove,
694 .driver = {
695 .name = "bcm2835-dma",
696 .owner = THIS_MODULE,
697 .of_match_table = of_match_ptr(bcm2835_dma_of_match),
698 },
699};
700
701module_platform_driver(bcm2835_dma_driver);
702
703MODULE_ALIAS("platform:bcm2835-dma");
704MODULE_DESCRIPTION("BCM2835 DMA engine driver");
705MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>");
706MODULE_LICENSE("GPL v2");