1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MOXA ART SoCs DMA Engine support.
4 *
5 * Copyright (C) 2013 Jonas Jensen
6 *
7 * Jonas Jensen <jonas.jensen@gmail.com>
8 */
9
10 #include <linux/dmaengine.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/of_address.h>
21 #include <linux/of_irq.h>
22 #include <linux/of_dma.h>
23 #include <linux/bitops.h>
24
25 #include <asm/cacheflush.h>
26
27 #include "dmaengine.h"
28 #include "virt-dma.h"
29
30 #define APB_DMA_MAX_CHANNEL 4
31
32 #define REG_OFF_ADDRESS_SOURCE 0
33 #define REG_OFF_ADDRESS_DEST 4
34 #define REG_OFF_CYCLES 8
35 #define REG_OFF_CTRL 12
36 #define REG_OFF_CHAN_SIZE 16
37
38 #define APB_DMA_ENABLE BIT(0)
39 #define APB_DMA_FIN_INT_STS BIT(1)
40 #define APB_DMA_FIN_INT_EN BIT(2)
41 #define APB_DMA_BURST_MODE BIT(3)
42 #define APB_DMA_ERR_INT_STS BIT(4)
43 #define APB_DMA_ERR_INT_EN BIT(5)
44
45 /*
46 * Unset: APB
47 * Set: AHB
48 */
49 #define APB_DMA_SOURCE_SELECT 0x40
50 #define APB_DMA_DEST_SELECT 0x80
51
52 #define APB_DMA_SOURCE 0x100
53 #define APB_DMA_DEST 0x1000
54
55 #define APB_DMA_SOURCE_MASK 0x700
56 #define APB_DMA_DEST_MASK 0x7000
57
58 /*
59 * 000: No increment
60 * 001: +1 (Burst=0), +4 (Burst=1)
61 * 010: +2 (Burst=0), +8 (Burst=1)
62 * 011: +4 (Burst=0), +16 (Burst=1)
63 * 101: -1 (Burst=0), -4 (Burst=1)
64 * 110: -2 (Burst=0), -8 (Burst=1)
65 * 111: -4 (Burst=0), -16 (Burst=1)
66 */
67 #define APB_DMA_SOURCE_INC_0 0
68 #define APB_DMA_SOURCE_INC_1_4 0x100
69 #define APB_DMA_SOURCE_INC_2_8 0x200
70 #define APB_DMA_SOURCE_INC_4_16 0x300
71 #define APB_DMA_SOURCE_DEC_1_4 0x500
72 #define APB_DMA_SOURCE_DEC_2_8 0x600
73 #define APB_DMA_SOURCE_DEC_4_16 0x700
74 #define APB_DMA_DEST_INC_0 0
75 #define APB_DMA_DEST_INC_1_4 0x1000
76 #define APB_DMA_DEST_INC_2_8 0x2000
77 #define APB_DMA_DEST_INC_4_16 0x3000
78 #define APB_DMA_DEST_DEC_1_4 0x5000
79 #define APB_DMA_DEST_DEC_2_8 0x6000
80 #define APB_DMA_DEST_DEC_4_16 0x7000
81
82 /*
83 * Request signal select source/destination address for DMA hardware handshake.
84 *
85 * The request line number is a property of the DMA controller itself,
86 * e.g. MMC must always request channels where dma_slave_config->slave_id is 5.
87 *
88 * 0: No request / Grant signal
89 * 1-15: Request / Grant signal
90 */
91 #define APB_DMA_SOURCE_REQ_NO 0x1000000
92 #define APB_DMA_SOURCE_REQ_NO_MASK 0xf000000
93 #define APB_DMA_DEST_REQ_NO 0x10000
94 #define APB_DMA_DEST_REQ_NO_MASK 0xf0000
95
96 #define APB_DMA_DATA_WIDTH 0x100000
97 #define APB_DMA_DATA_WIDTH_MASK 0x300000
98 /*
99 * Data width of transfer:
100 *
101 * 00: Word
102 * 01: Half
103 * 10: Byte
104 */
105 #define APB_DMA_DATA_WIDTH_4 0
106 #define APB_DMA_DATA_WIDTH_2 0x100000
107 #define APB_DMA_DATA_WIDTH_1 0x200000
108
109 #define APB_DMA_CYCLES_MASK 0x00ffffff
110
111 #define MOXART_DMA_DATA_TYPE_S8 0x00
112 #define MOXART_DMA_DATA_TYPE_S16 0x01
113 #define MOXART_DMA_DATA_TYPE_S32 0x02
114
115 struct moxart_sg {
116 dma_addr_t addr;
117 uint32_t len;
118 };
119
120 struct moxart_desc {
121 enum dma_transfer_direction dma_dir;
122 dma_addr_t dev_addr;
123 unsigned int sglen;
124 unsigned int dma_cycles;
125 struct virt_dma_desc vd;
126 uint8_t es;
127 struct moxart_sg sg[];
128 };
129
130 struct moxart_chan {
131 struct virt_dma_chan vc;
132
133 void __iomem *base;
134 struct moxart_desc *desc;
135
136 struct dma_slave_config cfg;
137
138 bool allocated;
139 bool error;
140 int ch_num;
141 unsigned int line_reqno;
142 unsigned int sgidx;
143 };
144
145 struct moxart_dmadev {
146 struct dma_device dma_slave;
147 struct moxart_chan slave_chans[APB_DMA_MAX_CHANNEL];
148 unsigned int irq;
149 };
150
151 struct moxart_filter_data {
152 struct moxart_dmadev *mdc;
153 struct of_phandle_args *dma_spec;
154 };
155
156 static const unsigned int es_bytes[] = {
157 [MOXART_DMA_DATA_TYPE_S8] = 1,
158 [MOXART_DMA_DATA_TYPE_S16] = 2,
159 [MOXART_DMA_DATA_TYPE_S32] = 4,
160 };
161
chan2dev(struct dma_chan * chan)162 static struct device *chan2dev(struct dma_chan *chan)
163 {
164 return &chan->dev->device;
165 }
166
to_moxart_dma_chan(struct dma_chan * c)167 static inline struct moxart_chan *to_moxart_dma_chan(struct dma_chan *c)
168 {
169 return container_of(c, struct moxart_chan, vc.chan);
170 }
171
to_moxart_dma_desc(struct dma_async_tx_descriptor * t)172 static inline struct moxart_desc *to_moxart_dma_desc(
173 struct dma_async_tx_descriptor *t)
174 {
175 return container_of(t, struct moxart_desc, vd.tx);
176 }
177
moxart_dma_desc_free(struct virt_dma_desc * vd)178 static void moxart_dma_desc_free(struct virt_dma_desc *vd)
179 {
180 kfree(container_of(vd, struct moxart_desc, vd));
181 }
182
moxart_terminate_all(struct dma_chan * chan)183 static int moxart_terminate_all(struct dma_chan *chan)
184 {
185 struct moxart_chan *ch = to_moxart_dma_chan(chan);
186 unsigned long flags;
187 LIST_HEAD(head);
188 u32 ctrl;
189
190 dev_dbg(chan2dev(chan), "%s: ch=%p\n", __func__, ch);
191
192 spin_lock_irqsave(&ch->vc.lock, flags);
193
194 if (ch->desc) {
195 moxart_dma_desc_free(&ch->desc->vd);
196 ch->desc = NULL;
197 }
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
moxart_slave_config(struct dma_chan * chan,struct dma_slave_config * cfg)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
moxart_prep_slave_sg(struct dma_chan * chan,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction dir,unsigned long tx_flags,void * context)266 static struct dma_async_tx_descriptor *moxart_prep_slave_sg(
267 struct dma_chan *chan, struct scatterlist *sgl,
268 unsigned int sg_len, enum dma_transfer_direction dir,
269 unsigned long tx_flags, void *context)
270 {
271 struct moxart_chan *ch = to_moxart_dma_chan(chan);
272 struct moxart_desc *d;
273 enum dma_slave_buswidth dev_width;
274 dma_addr_t dev_addr;
275 struct scatterlist *sgent;
276 unsigned int es;
277 unsigned int i;
278
279 if (!is_slave_direction(dir)) {
280 dev_err(chan2dev(chan), "%s: invalid DMA direction\n",
281 __func__);
282 return NULL;
283 }
284
285 if (dir == DMA_DEV_TO_MEM) {
286 dev_addr = ch->cfg.src_addr;
287 dev_width = ch->cfg.src_addr_width;
288 } else {
289 dev_addr = ch->cfg.dst_addr;
290 dev_width = ch->cfg.dst_addr_width;
291 }
292
293 switch (dev_width) {
294 case DMA_SLAVE_BUSWIDTH_1_BYTE:
295 es = MOXART_DMA_DATA_TYPE_S8;
296 break;
297 case DMA_SLAVE_BUSWIDTH_2_BYTES:
298 es = MOXART_DMA_DATA_TYPE_S16;
299 break;
300 case DMA_SLAVE_BUSWIDTH_4_BYTES:
301 es = MOXART_DMA_DATA_TYPE_S32;
302 break;
303 default:
304 dev_err(chan2dev(chan), "%s: unsupported data width (%u)\n",
305 __func__, dev_width);
306 return NULL;
307 }
308
309 d = kzalloc(struct_size(d, sg, sg_len), GFP_ATOMIC);
310 if (!d)
311 return NULL;
312
313 d->dma_dir = dir;
314 d->dev_addr = dev_addr;
315 d->es = es;
316
317 for_each_sg(sgl, sgent, sg_len, i) {
318 d->sg[i].addr = sg_dma_address(sgent);
319 d->sg[i].len = sg_dma_len(sgent);
320 }
321
322 d->sglen = sg_len;
323
324 ch->error = 0;
325
326 return vchan_tx_prep(&ch->vc, &d->vd, tx_flags);
327 }
328
moxart_of_xlate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)329 static struct dma_chan *moxart_of_xlate(struct of_phandle_args *dma_spec,
330 struct of_dma *ofdma)
331 {
332 struct moxart_dmadev *mdc = ofdma->of_dma_data;
333 struct dma_chan *chan;
334 struct moxart_chan *ch;
335
336 chan = dma_get_any_slave_channel(&mdc->dma_slave);
337 if (!chan)
338 return NULL;
339
340 ch = to_moxart_dma_chan(chan);
341 ch->line_reqno = dma_spec->args[0];
342
343 return chan;
344 }
345
moxart_alloc_chan_resources(struct dma_chan * chan)346 static int moxart_alloc_chan_resources(struct dma_chan *chan)
347 {
348 struct moxart_chan *ch = to_moxart_dma_chan(chan);
349
350 dev_dbg(chan2dev(chan), "%s: allocating channel #%u\n",
351 __func__, ch->ch_num);
352 ch->allocated = 1;
353
354 return 0;
355 }
356
moxart_free_chan_resources(struct dma_chan * chan)357 static void moxart_free_chan_resources(struct dma_chan *chan)
358 {
359 struct moxart_chan *ch = to_moxart_dma_chan(chan);
360
361 vchan_free_chan_resources(&ch->vc);
362
363 dev_dbg(chan2dev(chan), "%s: freeing channel #%u\n",
364 __func__, ch->ch_num);
365 ch->allocated = 0;
366 }
367
moxart_dma_set_params(struct moxart_chan * ch,dma_addr_t src_addr,dma_addr_t dst_addr)368 static void moxart_dma_set_params(struct moxart_chan *ch, dma_addr_t src_addr,
369 dma_addr_t dst_addr)
370 {
371 writel(src_addr, ch->base + REG_OFF_ADDRESS_SOURCE);
372 writel(dst_addr, ch->base + REG_OFF_ADDRESS_DEST);
373 }
374
moxart_set_transfer_params(struct moxart_chan * ch,unsigned int len)375 static void moxart_set_transfer_params(struct moxart_chan *ch, unsigned int len)
376 {
377 struct moxart_desc *d = ch->desc;
378 unsigned int sglen_div = es_bytes[d->es];
379
380 d->dma_cycles = len >> sglen_div;
381
382 /*
383 * There are 4 cycles on 64 bytes copied, i.e. one cycle copies 16
384 * bytes ( when width is APB_DMAB_DATA_WIDTH_4 ).
385 */
386 writel(d->dma_cycles, ch->base + REG_OFF_CYCLES);
387
388 dev_dbg(chan2dev(&ch->vc.chan), "%s: set %u DMA cycles (len=%u)\n",
389 __func__, d->dma_cycles, len);
390 }
391
moxart_start_dma(struct moxart_chan * ch)392 static void moxart_start_dma(struct moxart_chan *ch)
393 {
394 u32 ctrl;
395
396 ctrl = readl(ch->base + REG_OFF_CTRL);
397 ctrl |= (APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
398 writel(ctrl, ch->base + REG_OFF_CTRL);
399 }
400
moxart_dma_start_sg(struct moxart_chan * ch,unsigned int idx)401 static void moxart_dma_start_sg(struct moxart_chan *ch, unsigned int idx)
402 {
403 struct moxart_desc *d = ch->desc;
404 struct moxart_sg *sg = ch->desc->sg + idx;
405
406 if (ch->desc->dma_dir == DMA_MEM_TO_DEV)
407 moxart_dma_set_params(ch, sg->addr, d->dev_addr);
408 else if (ch->desc->dma_dir == DMA_DEV_TO_MEM)
409 moxart_dma_set_params(ch, d->dev_addr, sg->addr);
410
411 moxart_set_transfer_params(ch, sg->len);
412
413 moxart_start_dma(ch);
414 }
415
moxart_dma_start_desc(struct dma_chan * chan)416 static void moxart_dma_start_desc(struct dma_chan *chan)
417 {
418 struct moxart_chan *ch = to_moxart_dma_chan(chan);
419 struct virt_dma_desc *vd;
420
421 vd = vchan_next_desc(&ch->vc);
422
423 if (!vd) {
424 ch->desc = NULL;
425 return;
426 }
427
428 list_del(&vd->node);
429
430 ch->desc = to_moxart_dma_desc(&vd->tx);
431 ch->sgidx = 0;
432
433 moxart_dma_start_sg(ch, 0);
434 }
435
moxart_issue_pending(struct dma_chan * chan)436 static void moxart_issue_pending(struct dma_chan *chan)
437 {
438 struct moxart_chan *ch = to_moxart_dma_chan(chan);
439 unsigned long flags;
440
441 spin_lock_irqsave(&ch->vc.lock, flags);
442 if (vchan_issue_pending(&ch->vc) && !ch->desc)
443 moxart_dma_start_desc(chan);
444 spin_unlock_irqrestore(&ch->vc.lock, flags);
445 }
446
moxart_dma_desc_size(struct moxart_desc * d,unsigned int completed_sgs)447 static size_t moxart_dma_desc_size(struct moxart_desc *d,
448 unsigned int completed_sgs)
449 {
450 unsigned int i;
451 size_t size;
452
453 for (size = i = completed_sgs; i < d->sglen; i++)
454 size += d->sg[i].len;
455
456 return size;
457 }
458
moxart_dma_desc_size_in_flight(struct moxart_chan * ch)459 static size_t moxart_dma_desc_size_in_flight(struct moxart_chan *ch)
460 {
461 size_t size;
462 unsigned int completed_cycles, cycles;
463
464 size = moxart_dma_desc_size(ch->desc, ch->sgidx);
465 cycles = readl(ch->base + REG_OFF_CYCLES);
466 completed_cycles = (ch->desc->dma_cycles - cycles);
467 size -= completed_cycles << es_bytes[ch->desc->es];
468
469 dev_dbg(chan2dev(&ch->vc.chan), "%s: size=%zu\n", __func__, size);
470
471 return size;
472 }
473
moxart_tx_status(struct dma_chan * chan,dma_cookie_t cookie,struct dma_tx_state * txstate)474 static enum dma_status moxart_tx_status(struct dma_chan *chan,
475 dma_cookie_t cookie,
476 struct dma_tx_state *txstate)
477 {
478 struct moxart_chan *ch = to_moxart_dma_chan(chan);
479 struct virt_dma_desc *vd;
480 struct moxart_desc *d;
481 enum dma_status ret;
482 unsigned long flags;
483
484 /*
485 * dma_cookie_status() assigns initial residue value.
486 */
487 ret = dma_cookie_status(chan, cookie, txstate);
488
489 spin_lock_irqsave(&ch->vc.lock, flags);
490 vd = vchan_find_desc(&ch->vc, cookie);
491 if (vd) {
492 d = to_moxart_dma_desc(&vd->tx);
493 txstate->residue = moxart_dma_desc_size(d, 0);
494 } else if (ch->desc && ch->desc->vd.tx.cookie == cookie) {
495 txstate->residue = moxart_dma_desc_size_in_flight(ch);
496 }
497 spin_unlock_irqrestore(&ch->vc.lock, flags);
498
499 if (ch->error)
500 return DMA_ERROR;
501
502 return ret;
503 }
504
moxart_dma_init(struct dma_device * dma,struct device * dev)505 static void moxart_dma_init(struct dma_device *dma, struct device *dev)
506 {
507 dma->device_prep_slave_sg = moxart_prep_slave_sg;
508 dma->device_alloc_chan_resources = moxart_alloc_chan_resources;
509 dma->device_free_chan_resources = moxart_free_chan_resources;
510 dma->device_issue_pending = moxart_issue_pending;
511 dma->device_tx_status = moxart_tx_status;
512 dma->device_config = moxart_slave_config;
513 dma->device_terminate_all = moxart_terminate_all;
514 dma->dev = dev;
515
516 INIT_LIST_HEAD(&dma->channels);
517 }
518
moxart_dma_interrupt(int irq,void * devid)519 static irqreturn_t moxart_dma_interrupt(int irq, void *devid)
520 {
521 struct moxart_dmadev *mc = devid;
522 struct moxart_chan *ch = &mc->slave_chans[0];
523 unsigned int i;
524 u32 ctrl;
525
526 dev_dbg(chan2dev(&ch->vc.chan), "%s\n", __func__);
527
528 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
529 if (!ch->allocated)
530 continue;
531
532 ctrl = readl(ch->base + REG_OFF_CTRL);
533
534 dev_dbg(chan2dev(&ch->vc.chan), "%s: ch=%p ch->base=%p ctrl=%x\n",
535 __func__, ch, ch->base, ctrl);
536
537 if (ctrl & APB_DMA_FIN_INT_STS) {
538 ctrl &= ~APB_DMA_FIN_INT_STS;
539 if (ch->desc) {
540 spin_lock(&ch->vc.lock);
541 if (++ch->sgidx < ch->desc->sglen) {
542 moxart_dma_start_sg(ch, ch->sgidx);
543 } else {
544 vchan_cookie_complete(&ch->desc->vd);
545 moxart_dma_start_desc(&ch->vc.chan);
546 }
547 spin_unlock(&ch->vc.lock);
548 }
549 }
550
551 if (ctrl & APB_DMA_ERR_INT_STS) {
552 ctrl &= ~APB_DMA_ERR_INT_STS;
553 ch->error = 1;
554 }
555
556 writel(ctrl, ch->base + REG_OFF_CTRL);
557 }
558
559 return IRQ_HANDLED;
560 }
561
moxart_probe(struct platform_device * pdev)562 static int moxart_probe(struct platform_device *pdev)
563 {
564 struct device *dev = &pdev->dev;
565 struct device_node *node = dev->of_node;
566 void __iomem *dma_base_addr;
567 int ret, i;
568 unsigned int irq;
569 struct moxart_chan *ch;
570 struct moxart_dmadev *mdc;
571
572 mdc = devm_kzalloc(dev, sizeof(*mdc), GFP_KERNEL);
573 if (!mdc)
574 return -ENOMEM;
575
576 irq = irq_of_parse_and_map(node, 0);
577 if (!irq) {
578 dev_err(dev, "no IRQ resource\n");
579 return -EINVAL;
580 }
581
582 dma_base_addr = devm_platform_ioremap_resource(pdev, 0);
583 if (IS_ERR(dma_base_addr))
584 return PTR_ERR(dma_base_addr);
585
586 dma_cap_zero(mdc->dma_slave.cap_mask);
587 dma_cap_set(DMA_SLAVE, mdc->dma_slave.cap_mask);
588 dma_cap_set(DMA_PRIVATE, mdc->dma_slave.cap_mask);
589
590 moxart_dma_init(&mdc->dma_slave, dev);
591
592 ch = &mdc->slave_chans[0];
593 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
594 ch->ch_num = i;
595 ch->base = dma_base_addr + i * REG_OFF_CHAN_SIZE;
596 ch->allocated = 0;
597
598 ch->vc.desc_free = moxart_dma_desc_free;
599 vchan_init(&ch->vc, &mdc->dma_slave);
600
601 dev_dbg(dev, "%s: chs[%d]: ch->ch_num=%u ch->base=%p\n",
602 __func__, i, ch->ch_num, ch->base);
603 }
604
605 platform_set_drvdata(pdev, mdc);
606
607 ret = devm_request_irq(dev, irq, moxart_dma_interrupt, 0,
608 "moxart-dma-engine", mdc);
609 if (ret) {
610 dev_err(dev, "devm_request_irq failed\n");
611 return ret;
612 }
613 mdc->irq = irq;
614
615 ret = dma_async_device_register(&mdc->dma_slave);
616 if (ret) {
617 dev_err(dev, "dma_async_device_register failed\n");
618 return ret;
619 }
620
621 ret = of_dma_controller_register(node, moxart_of_xlate, mdc);
622 if (ret) {
623 dev_err(dev, "of_dma_controller_register failed\n");
624 dma_async_device_unregister(&mdc->dma_slave);
625 return ret;
626 }
627
628 dev_dbg(dev, "%s: IRQ=%u\n", __func__, irq);
629
630 return 0;
631 }
632
moxart_remove(struct platform_device * pdev)633 static int moxart_remove(struct platform_device *pdev)
634 {
635 struct moxart_dmadev *m = platform_get_drvdata(pdev);
636
637 devm_free_irq(&pdev->dev, m->irq, m);
638
639 dma_async_device_unregister(&m->dma_slave);
640
641 if (pdev->dev.of_node)
642 of_dma_controller_free(pdev->dev.of_node);
643
644 return 0;
645 }
646
647 static const struct of_device_id moxart_dma_match[] = {
648 { .compatible = "moxa,moxart-dma" },
649 { }
650 };
651 MODULE_DEVICE_TABLE(of, moxart_dma_match);
652
653 static struct platform_driver moxart_driver = {
654 .probe = moxart_probe,
655 .remove = moxart_remove,
656 .driver = {
657 .name = "moxart-dma-engine",
658 .of_match_table = moxart_dma_match,
659 },
660 };
661
moxart_init(void)662 static int moxart_init(void)
663 {
664 return platform_driver_register(&moxart_driver);
665 }
666 subsys_initcall(moxart_init);
667
moxart_exit(void)668 static void __exit moxart_exit(void)
669 {
670 platform_driver_unregister(&moxart_driver);
671 }
672 module_exit(moxart_exit);
673
674 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
675 MODULE_DESCRIPTION("MOXART DMA engine driver");
676 MODULE_LICENSE("GPL v2");
677