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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[linux-2.6/btrfs-unstable.git] / drivers / dma / moxart-dma.c
blob3258e484e4f647777a29ccd5337f120da0370121
1 /*
2 * MOXA ART SoCs DMA Engine support.
3 *
4 * Copyright (C) 2013 Jonas Jensen
5 *
6 * Jonas Jensen <jonas.jensen@gmail.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13 #include <linux/dmaengine.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/spinlock.h>
23 #include <linux/of_address.h>
24 #include <linux/of_irq.h>
25 #include <linux/of_dma.h>
26 #include <linux/bitops.h>
27
28 #include <asm/cacheflush.h>
29
30 #include "dmaengine.h"
31 #include "virt-dma.h"
32
33 #define APB_DMA_MAX_CHANNEL 4
34
35 #define REG_OFF_ADDRESS_SOURCE 0
36 #define REG_OFF_ADDRESS_DEST 4
37 #define REG_OFF_CYCLES 8
38 #define REG_OFF_CTRL 12
39 #define REG_OFF_CHAN_SIZE 16
40
41 #define APB_DMA_ENABLE BIT(0)
42 #define APB_DMA_FIN_INT_STS BIT(1)
43 #define APB_DMA_FIN_INT_EN BIT(2)
44 #define APB_DMA_BURST_MODE BIT(3)
45 #define APB_DMA_ERR_INT_STS BIT(4)
46 #define APB_DMA_ERR_INT_EN BIT(5)
47
48 /*
49 * Unset: APB
50 * Set: AHB
51 */
52 #define APB_DMA_SOURCE_SELECT 0x40
53 #define APB_DMA_DEST_SELECT 0x80
54
55 #define APB_DMA_SOURCE 0x100
56 #define APB_DMA_DEST 0x1000
57
58 #define APB_DMA_SOURCE_MASK 0x700
59 #define APB_DMA_DEST_MASK 0x7000
60
61 /*
62 * 000: No increment
63 * 001: +1 (Burst=0), +4 (Burst=1)
64 * 010: +2 (Burst=0), +8 (Burst=1)
65 * 011: +4 (Burst=0), +16 (Burst=1)
66 * 101: -1 (Burst=0), -4 (Burst=1)
67 * 110: -2 (Burst=0), -8 (Burst=1)
68 * 111: -4 (Burst=0), -16 (Burst=1)
69 */
70 #define APB_DMA_SOURCE_INC_0 0
71 #define APB_DMA_SOURCE_INC_1_4 0x100
72 #define APB_DMA_SOURCE_INC_2_8 0x200
73 #define APB_DMA_SOURCE_INC_4_16 0x300
74 #define APB_DMA_SOURCE_DEC_1_4 0x500
75 #define APB_DMA_SOURCE_DEC_2_8 0x600
76 #define APB_DMA_SOURCE_DEC_4_16 0x700
77 #define APB_DMA_DEST_INC_0 0
78 #define APB_DMA_DEST_INC_1_4 0x1000
79 #define APB_DMA_DEST_INC_2_8 0x2000
80 #define APB_DMA_DEST_INC_4_16 0x3000
81 #define APB_DMA_DEST_DEC_1_4 0x5000
82 #define APB_DMA_DEST_DEC_2_8 0x6000
83 #define APB_DMA_DEST_DEC_4_16 0x7000
84
85 /*
86 * Request signal select source/destination address for DMA hardware handshake.
87 *
88 * The request line number is a property of the DMA controller itself,
89 * e.g. MMC must always request channels where dma_slave_config->slave_id is 5.
90 *
91 * 0: No request / Grant signal
92 * 1-15: Request / Grant signal
93 */
94 #define APB_DMA_SOURCE_REQ_NO 0x1000000
95 #define APB_DMA_SOURCE_REQ_NO_MASK 0xf000000
96 #define APB_DMA_DEST_REQ_NO 0x10000
97 #define APB_DMA_DEST_REQ_NO_MASK 0xf0000
98
99 #define APB_DMA_DATA_WIDTH 0x100000
100 #define APB_DMA_DATA_WIDTH_MASK 0x300000
101 /*
102 * Data width of transfer:
103 *
104 * 00: Word
105 * 01: Half
106 * 10: Byte
107 */
108 #define APB_DMA_DATA_WIDTH_4 0
109 #define APB_DMA_DATA_WIDTH_2 0x100000
110 #define APB_DMA_DATA_WIDTH_1 0x200000
111
112 #define APB_DMA_CYCLES_MASK 0x00ffffff
113
114 #define MOXART_DMA_DATA_TYPE_S8 0x00
115 #define MOXART_DMA_DATA_TYPE_S16 0x01
116 #define MOXART_DMA_DATA_TYPE_S32 0x02
117
118 struct moxart_sg {
119 dma_addr_t addr;
120 uint32_t len;
121 };
122
123 struct moxart_desc {
124 enum dma_transfer_direction dma_dir;
125 dma_addr_t dev_addr;
126 unsigned int sglen;
127 unsigned int dma_cycles;
128 struct virt_dma_desc vd;
129 uint8_t es;
130 struct moxart_sg sg[0];
131 };
132
133 struct moxart_chan {
134 struct virt_dma_chan vc;
135
136 void __iomem *base;
137 struct moxart_desc *desc;
138
139 struct dma_slave_config cfg;
140
141 bool allocated;
142 bool error;
143 int ch_num;
144 unsigned int line_reqno;
145 unsigned int sgidx;
146 };
147
148 struct moxart_dmadev {
149 struct dma_device dma_slave;
150 struct moxart_chan slave_chans[APB_DMA_MAX_CHANNEL];
151 };
152
153 struct moxart_filter_data {
154 struct moxart_dmadev *mdc;
155 struct of_phandle_args *dma_spec;
156 };
157
158 static const unsigned int es_bytes[] = {
159 [MOXART_DMA_DATA_TYPE_S8] = 1,
160 [MOXART_DMA_DATA_TYPE_S16] = 2,
161 [MOXART_DMA_DATA_TYPE_S32] = 4,
162 };
163
164 static struct device *chan2dev(struct dma_chan *chan)
165 {
166 return &chan->dev->device;
167 }
168
169 static inline struct moxart_chan *to_moxart_dma_chan(struct dma_chan *c)
170 {
171 return container_of(c, struct moxart_chan, vc.chan);
172 }
173
174 static inline struct moxart_desc *to_moxart_dma_desc(
175 struct dma_async_tx_descriptor *t)
176 {
177 return container_of(t, struct moxart_desc, vd.tx);
178 }
179
180 static void moxart_dma_desc_free(struct virt_dma_desc *vd)
181 {
182 kfree(container_of(vd, struct moxart_desc, vd));
183 }
184
185 static int moxart_terminate_all(struct dma_chan *chan)
186 {
187 struct moxart_chan *ch = to_moxart_dma_chan(chan);
188 unsigned long flags;
189 LIST_HEAD(head);
190 u32 ctrl;
191
192 dev_dbg(chan2dev(chan), "%s: ch=%p\n", __func__, ch);
193
194 spin_lock_irqsave(&ch->vc.lock, flags);
195
196 if (ch->desc)
197 ch->desc = NULL;
198
199 ctrl = readl(ch->base + REG_OFF_CTRL);
200 ctrl &= ~(APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
201 writel(ctrl, ch->base + REG_OFF_CTRL);
202
203 vchan_get_all_descriptors(&ch->vc, &head);
204 spin_unlock_irqrestore(&ch->vc.lock, flags);
205 vchan_dma_desc_free_list(&ch->vc, &head);
206
207 return 0;
208 }
209
210 static int moxart_slave_config(struct dma_chan *chan,
211 struct dma_slave_config *cfg)
212 {
213 struct moxart_chan *ch = to_moxart_dma_chan(chan);
214 u32 ctrl;
215
216 ch->cfg = *cfg;
217
218 ctrl = readl(ch->base + REG_OFF_CTRL);
219 ctrl |= APB_DMA_BURST_MODE;
220 ctrl &= ~(APB_DMA_DEST_MASK | APB_DMA_SOURCE_MASK);
221 ctrl &= ~(APB_DMA_DEST_REQ_NO_MASK | APB_DMA_SOURCE_REQ_NO_MASK);
222
223 switch (ch->cfg.src_addr_width) {
224 case DMA_SLAVE_BUSWIDTH_1_BYTE:
225 ctrl |= APB_DMA_DATA_WIDTH_1;
226 if (ch->cfg.direction != DMA_MEM_TO_DEV)
227 ctrl |= APB_DMA_DEST_INC_1_4;
228 else
229 ctrl |= APB_DMA_SOURCE_INC_1_4;
230 break;
231 case DMA_SLAVE_BUSWIDTH_2_BYTES:
232 ctrl |= APB_DMA_DATA_WIDTH_2;
233 if (ch->cfg.direction != DMA_MEM_TO_DEV)
234 ctrl |= APB_DMA_DEST_INC_2_8;
235 else
236 ctrl |= APB_DMA_SOURCE_INC_2_8;
237 break;
238 case DMA_SLAVE_BUSWIDTH_4_BYTES:
239 ctrl &= ~APB_DMA_DATA_WIDTH;
240 if (ch->cfg.direction != DMA_MEM_TO_DEV)
241 ctrl |= APB_DMA_DEST_INC_4_16;
242 else
243 ctrl |= APB_DMA_SOURCE_INC_4_16;
244 break;
245 default:
246 return -EINVAL;
247 }
248
249 if (ch->cfg.direction == DMA_MEM_TO_DEV) {
250 ctrl &= ~APB_DMA_DEST_SELECT;
251 ctrl |= APB_DMA_SOURCE_SELECT;
252 ctrl |= (ch->line_reqno << 16 &
253 APB_DMA_DEST_REQ_NO_MASK);
254 } else {
255 ctrl |= APB_DMA_DEST_SELECT;
256 ctrl &= ~APB_DMA_SOURCE_SELECT;
257 ctrl |= (ch->line_reqno << 24 &
258 APB_DMA_SOURCE_REQ_NO_MASK);
259 }
260
261 writel(ctrl, ch->base + REG_OFF_CTRL);
262
263 return 0;
264 }
265
266 static int moxart_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
267 unsigned long arg)
268 {
269 int ret = 0;
270
271 switch (cmd) {
272 case DMA_PAUSE:
273 case DMA_RESUME:
274 return -EINVAL;
275 case DMA_TERMINATE_ALL:
276 moxart_terminate_all(chan);
277 break;
278 case DMA_SLAVE_CONFIG:
279 ret = moxart_slave_config(chan, (struct dma_slave_config *)arg);
280 break;
281 default:
282 ret = -ENOSYS;
283 }
284
285 return ret;
286 }
287
288 static struct dma_async_tx_descriptor *moxart_prep_slave_sg(
289 struct dma_chan *chan, struct scatterlist *sgl,
290 unsigned int sg_len, enum dma_transfer_direction dir,
291 unsigned long tx_flags, void *context)
292 {
293 struct moxart_chan *ch = to_moxart_dma_chan(chan);
294 struct moxart_desc *d;
295 enum dma_slave_buswidth dev_width;
296 dma_addr_t dev_addr;
297 struct scatterlist *sgent;
298 unsigned int es;
299 unsigned int i;
300
301 if (!is_slave_direction(dir)) {
302 dev_err(chan2dev(chan), "%s: invalid DMA direction\n",
303 __func__);
304 return NULL;
305 }
306
307 if (dir == DMA_DEV_TO_MEM) {
308 dev_addr = ch->cfg.src_addr;
309 dev_width = ch->cfg.src_addr_width;
310 } else {
311 dev_addr = ch->cfg.dst_addr;
312 dev_width = ch->cfg.dst_addr_width;
313 }
314
315 switch (dev_width) {
316 case DMA_SLAVE_BUSWIDTH_1_BYTE:
317 es = MOXART_DMA_DATA_TYPE_S8;
318 break;
319 case DMA_SLAVE_BUSWIDTH_2_BYTES:
320 es = MOXART_DMA_DATA_TYPE_S16;
321 break;
322 case DMA_SLAVE_BUSWIDTH_4_BYTES:
323 es = MOXART_DMA_DATA_TYPE_S32;
324 break;
325 default:
326 dev_err(chan2dev(chan), "%s: unsupported data width (%u)\n",
327 __func__, dev_width);
328 return NULL;
329 }
330
331 d = kzalloc(sizeof(*d) + sg_len * sizeof(d->sg[0]), GFP_ATOMIC);
332 if (!d)
333 return NULL;
334
335 d->dma_dir = dir;
336 d->dev_addr = dev_addr;
337 d->es = es;
338
339 for_each_sg(sgl, sgent, sg_len, i) {
340 d->sg[i].addr = sg_dma_address(sgent);
341 d->sg[i].len = sg_dma_len(sgent);
342 }
343
344 d->sglen = sg_len;
345
346 ch->error = 0;
347
348 return vchan_tx_prep(&ch->vc, &d->vd, tx_flags);
349 }
350
351 static struct dma_chan *moxart_of_xlate(struct of_phandle_args *dma_spec,
352 struct of_dma *ofdma)
353 {
354 struct moxart_dmadev *mdc = ofdma->of_dma_data;
355 struct dma_chan *chan;
356 struct moxart_chan *ch;
357
358 chan = dma_get_any_slave_channel(&mdc->dma_slave);
359 if (!chan)
360 return NULL;
361
362 ch = to_moxart_dma_chan(chan);
363 ch->line_reqno = dma_spec->args[0];
364
365 return chan;
366 }
367
368 static int moxart_alloc_chan_resources(struct dma_chan *chan)
369 {
370 struct moxart_chan *ch = to_moxart_dma_chan(chan);
371
372 dev_dbg(chan2dev(chan), "%s: allocating channel #%u\n",
373 __func__, ch->ch_num);
374 ch->allocated = 1;
375
376 return 0;
377 }
378
379 static void moxart_free_chan_resources(struct dma_chan *chan)
380 {
381 struct moxart_chan *ch = to_moxart_dma_chan(chan);
382
383 vchan_free_chan_resources(&ch->vc);
384
385 dev_dbg(chan2dev(chan), "%s: freeing channel #%u\n",
386 __func__, ch->ch_num);
387 ch->allocated = 0;
388 }
389
390 static void moxart_dma_set_params(struct moxart_chan *ch, dma_addr_t src_addr,
391 dma_addr_t dst_addr)
392 {
393 writel(src_addr, ch->base + REG_OFF_ADDRESS_SOURCE);
394 writel(dst_addr, ch->base + REG_OFF_ADDRESS_DEST);
395 }
396
397 static void moxart_set_transfer_params(struct moxart_chan *ch, unsigned int len)
398 {
399 struct moxart_desc *d = ch->desc;
400 unsigned int sglen_div = es_bytes[d->es];
401
402 d->dma_cycles = len >> sglen_div;
403
404 /*
405 * There are 4 cycles on 64 bytes copied, i.e. one cycle copies 16
406 * bytes ( when width is APB_DMAB_DATA_WIDTH_4 ).
407 */
408 writel(d->dma_cycles, ch->base + REG_OFF_CYCLES);
409
410 dev_dbg(chan2dev(&ch->vc.chan), "%s: set %u DMA cycles (len=%u)\n",
411 __func__, d->dma_cycles, len);
412 }
413
414 static void moxart_start_dma(struct moxart_chan *ch)
415 {
416 u32 ctrl;
417
418 ctrl = readl(ch->base + REG_OFF_CTRL);
419 ctrl |= (APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
420 writel(ctrl, ch->base + REG_OFF_CTRL);
421 }
422
423 static void moxart_dma_start_sg(struct moxart_chan *ch, unsigned int idx)
424 {
425 struct moxart_desc *d = ch->desc;
426 struct moxart_sg *sg = ch->desc->sg + idx;
427
428 if (ch->desc->dma_dir == DMA_MEM_TO_DEV)
429 moxart_dma_set_params(ch, sg->addr, d->dev_addr);
430 else if (ch->desc->dma_dir == DMA_DEV_TO_MEM)
431 moxart_dma_set_params(ch, d->dev_addr, sg->addr);
432
433 moxart_set_transfer_params(ch, sg->len);
434
435 moxart_start_dma(ch);
436 }
437
438 static void moxart_dma_start_desc(struct dma_chan *chan)
439 {
440 struct moxart_chan *ch = to_moxart_dma_chan(chan);
441 struct virt_dma_desc *vd;
442
443 vd = vchan_next_desc(&ch->vc);
444
445 if (!vd) {
446 ch->desc = NULL;
447 return;
448 }
449
450 list_del(&vd->node);
451
452 ch->desc = to_moxart_dma_desc(&vd->tx);
453 ch->sgidx = 0;
454
455 moxart_dma_start_sg(ch, 0);
456 }
457
458 static void moxart_issue_pending(struct dma_chan *chan)
459 {
460 struct moxart_chan *ch = to_moxart_dma_chan(chan);
461 unsigned long flags;
462
463 spin_lock_irqsave(&ch->vc.lock, flags);
464 if (vchan_issue_pending(&ch->vc) && !ch->desc)
465 moxart_dma_start_desc(chan);
466 spin_unlock_irqrestore(&ch->vc.lock, flags);
467 }
468
469 static size_t moxart_dma_desc_size(struct moxart_desc *d,
470 unsigned int completed_sgs)
471 {
472 unsigned int i;
473 size_t size;
474
475 for (size = i = completed_sgs; i < d->sglen; i++)
476 size += d->sg[i].len;
477
478 return size;
479 }
480
481 static size_t moxart_dma_desc_size_in_flight(struct moxart_chan *ch)
482 {
483 size_t size;
484 unsigned int completed_cycles, cycles;
485
486 size = moxart_dma_desc_size(ch->desc, ch->sgidx);
487 cycles = readl(ch->base + REG_OFF_CYCLES);
488 completed_cycles = (ch->desc->dma_cycles - cycles);
489 size -= completed_cycles << es_bytes[ch->desc->es];
490
491 dev_dbg(chan2dev(&ch->vc.chan), "%s: size=%zu\n", __func__, size);
492
493 return size;
494 }
495
496 static enum dma_status moxart_tx_status(struct dma_chan *chan,
497 dma_cookie_t cookie,
498 struct dma_tx_state *txstate)
499 {
500 struct moxart_chan *ch = to_moxart_dma_chan(chan);
501 struct virt_dma_desc *vd;
502 struct moxart_desc *d;
503 enum dma_status ret;
504 unsigned long flags;
505
506 /*
507 * dma_cookie_status() assigns initial residue value.
508 */
509 ret = dma_cookie_status(chan, cookie, txstate);
510
511 spin_lock_irqsave(&ch->vc.lock, flags);
512 vd = vchan_find_desc(&ch->vc, cookie);
513 if (vd) {
514 d = to_moxart_dma_desc(&vd->tx);
515 txstate->residue = moxart_dma_desc_size(d, 0);
516 } else if (ch->desc && ch->desc->vd.tx.cookie == cookie) {
517 txstate->residue = moxart_dma_desc_size_in_flight(ch);
518 }
519 spin_unlock_irqrestore(&ch->vc.lock, flags);
520
521 if (ch->error)
522 return DMA_ERROR;
523
524 return ret;
525 }
526
527 static void moxart_dma_init(struct dma_device *dma, struct device *dev)
528 {
529 dma->device_prep_slave_sg = moxart_prep_slave_sg;
530 dma->device_alloc_chan_resources = moxart_alloc_chan_resources;
531 dma->device_free_chan_resources = moxart_free_chan_resources;
532 dma->device_issue_pending = moxart_issue_pending;
533 dma->device_tx_status = moxart_tx_status;
534 dma->device_control = moxart_control;
535 dma->dev = dev;
536
537 INIT_LIST_HEAD(&dma->channels);
538 }
539
540 static irqreturn_t moxart_dma_interrupt(int irq, void *devid)
541 {
542 struct moxart_dmadev *mc = devid;
543 struct moxart_chan *ch = &mc->slave_chans[0];
544 unsigned int i;
545 unsigned long flags;
546 u32 ctrl;
547
548 dev_dbg(chan2dev(&ch->vc.chan), "%s\n", __func__);
549
550 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
551 if (!ch->allocated)
552 continue;
553
554 ctrl = readl(ch->base + REG_OFF_CTRL);
555
556 dev_dbg(chan2dev(&ch->vc.chan), "%s: ch=%p ch->base=%p ctrl=%x\n",
557 __func__, ch, ch->base, ctrl);
558
559 if (ctrl & APB_DMA_FIN_INT_STS) {
560 ctrl &= ~APB_DMA_FIN_INT_STS;
561 if (ch->desc) {
562 spin_lock_irqsave(&ch->vc.lock, flags);
563 if (++ch->sgidx < ch->desc->sglen) {
564 moxart_dma_start_sg(ch, ch->sgidx);
565 } else {
566 vchan_cookie_complete(&ch->desc->vd);
567 moxart_dma_start_desc(&ch->vc.chan);
568 }
569 spin_unlock_irqrestore(&ch->vc.lock, flags);
570 }
571 }
572
573 if (ctrl & APB_DMA_ERR_INT_STS) {
574 ctrl &= ~APB_DMA_ERR_INT_STS;
575 ch->error = 1;
576 }
577
578 writel(ctrl, ch->base + REG_OFF_CTRL);
579 }
580
581 return IRQ_HANDLED;
582 }
583
584 static int moxart_probe(struct platform_device *pdev)
585 {
586 struct device *dev = &pdev->dev;
587 struct device_node *node = dev->of_node;
588 struct resource *res;
589 static void __iomem *dma_base_addr;
590 int ret, i;
591 unsigned int irq;
592 struct moxart_chan *ch;
593 struct moxart_dmadev *mdc;
594
595 mdc = devm_kzalloc(dev, sizeof(*mdc), GFP_KERNEL);
596 if (!mdc) {
597 dev_err(dev, "can't allocate DMA container\n");
598 return -ENOMEM;
599 }
600
601 irq = irq_of_parse_and_map(node, 0);
602 if (irq == NO_IRQ) {
603 dev_err(dev, "no IRQ resource\n");
604 return -EINVAL;
605 }
606
607 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
608 dma_base_addr = devm_ioremap_resource(dev, res);
609 if (IS_ERR(dma_base_addr))
610 return PTR_ERR(dma_base_addr);
611
612 dma_cap_zero(mdc->dma_slave.cap_mask);
613 dma_cap_set(DMA_SLAVE, mdc->dma_slave.cap_mask);
614 dma_cap_set(DMA_PRIVATE, mdc->dma_slave.cap_mask);
615
616 moxart_dma_init(&mdc->dma_slave, dev);
617
618 ch = &mdc->slave_chans[0];
619 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
620 ch->ch_num = i;
621 ch->base = dma_base_addr + i * REG_OFF_CHAN_SIZE;
622 ch->allocated = 0;
623
624 ch->vc.desc_free = moxart_dma_desc_free;
625 vchan_init(&ch->vc, &mdc->dma_slave);
626
627 dev_dbg(dev, "%s: chs[%d]: ch->ch_num=%u ch->base=%p\n",
628 __func__, i, ch->ch_num, ch->base);
629 }
630
631 platform_set_drvdata(pdev, mdc);
632
633 ret = devm_request_irq(dev, irq, moxart_dma_interrupt, 0,
634 "moxart-dma-engine", mdc);
635 if (ret) {
636 dev_err(dev, "devm_request_irq failed\n");
637 return ret;
638 }
639
640 ret = dma_async_device_register(&mdc->dma_slave);
641 if (ret) {
642 dev_err(dev, "dma_async_device_register failed\n");
643 return ret;
644 }
645
646 ret = of_dma_controller_register(node, moxart_of_xlate, mdc);
647 if (ret) {
648 dev_err(dev, "of_dma_controller_register failed\n");
649 dma_async_device_unregister(&mdc->dma_slave);
650 return ret;
651 }
652
653 dev_dbg(dev, "%s: IRQ=%u\n", __func__, irq);
654
655 return 0;
656 }
657
658 static int moxart_remove(struct platform_device *pdev)
659 {
660 struct moxart_dmadev *m = platform_get_drvdata(pdev);
661
662 dma_async_device_unregister(&m->dma_slave);
663
664 if (pdev->dev.of_node)
665 of_dma_controller_free(pdev->dev.of_node);
666
667 return 0;
668 }
669
670 static const struct of_device_id moxart_dma_match[] = {
671 { .compatible = "moxa,moxart-dma" },
672 { }
673 };
674
675 static struct platform_driver moxart_driver = {
676 .probe = moxart_probe,
677 .remove = moxart_remove,
678 .driver = {
679 .name = "moxart-dma-engine",
680 .owner = THIS_MODULE,
681 .of_match_table = moxart_dma_match,
682 },
683 };
684
685 static int moxart_init(void)
686 {
687 return platform_driver_register(&moxart_driver);
688 }
689 subsys_initcall(moxart_init);
690
691 static void __exit moxart_exit(void)
692 {
693 platform_driver_unregister(&moxart_driver);
694 }
695 module_exit(moxart_exit);
696
697 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
698 MODULE_DESCRIPTION("MOXART DMA engine driver");
699 MODULE_LICENSE("GPL v2");
(deprecated) Btrfs devel tree