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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
50
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
63
64
65
66
67
68
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
87
88
89
90
91
92
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
103
104
105
106
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
118struct moxart_sg {
119 dma_addr_t addr;
120 uint32_t len;
121};
122
123struct 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
133struct 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
148struct moxart_dmadev {
149 struct dma_device dma_slave;
150 struct moxart_chan slave_chans[APB_DMA_MAX_CHANNEL];
151};
152
153struct moxart_filter_data {
154 struct moxart_dmadev *mdc;
155 struct of_phandle_args *dma_spec;
156};
157
158static 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
164static struct device *chan2dev(struct dma_chan *chan)
165{
166 return &chan->dev->device;
167}
168
169static 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
174static 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
180static void moxart_dma_desc_free(struct virt_dma_desc *vd)
181{
182 kfree(container_of(vd, struct moxart_desc, vd));
183}
184
185static 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 moxart_dma_desc_free(&ch->desc->vd);
198 ch->desc = NULL;
199 }
200
201 ctrl = readl(ch->base + REG_OFF_CTRL);
202 ctrl &= ~(APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
203 writel(ctrl, ch->base + REG_OFF_CTRL);
204
205 vchan_get_all_descriptors(&ch->vc, &head);
206 spin_unlock_irqrestore(&ch->vc.lock, flags);
207 vchan_dma_desc_free_list(&ch->vc, &head);
208
209 return 0;
210}
211
212static int moxart_slave_config(struct dma_chan *chan,
213 struct dma_slave_config *cfg)
214{
215 struct moxart_chan *ch = to_moxart_dma_chan(chan);
216 u32 ctrl;
217
218 ch->cfg = *cfg;
219
220 ctrl = readl(ch->base + REG_OFF_CTRL);
221 ctrl |= APB_DMA_BURST_MODE;
222 ctrl &= ~(APB_DMA_DEST_MASK | APB_DMA_SOURCE_MASK);
223 ctrl &= ~(APB_DMA_DEST_REQ_NO_MASK | APB_DMA_SOURCE_REQ_NO_MASK);
224
225 switch (ch->cfg.src_addr_width) {
226 case DMA_SLAVE_BUSWIDTH_1_BYTE:
227 ctrl |= APB_DMA_DATA_WIDTH_1;
228 if (ch->cfg.direction != DMA_MEM_TO_DEV)
229 ctrl |= APB_DMA_DEST_INC_1_4;
230 else
231 ctrl |= APB_DMA_SOURCE_INC_1_4;
232 break;
233 case DMA_SLAVE_BUSWIDTH_2_BYTES:
234 ctrl |= APB_DMA_DATA_WIDTH_2;
235 if (ch->cfg.direction != DMA_MEM_TO_DEV)
236 ctrl |= APB_DMA_DEST_INC_2_8;
237 else
238 ctrl |= APB_DMA_SOURCE_INC_2_8;
239 break;
240 case DMA_SLAVE_BUSWIDTH_4_BYTES:
241 ctrl &= ~APB_DMA_DATA_WIDTH;
242 if (ch->cfg.direction != DMA_MEM_TO_DEV)
243 ctrl |= APB_DMA_DEST_INC_4_16;
244 else
245 ctrl |= APB_DMA_SOURCE_INC_4_16;
246 break;
247 default:
248 return -EINVAL;
249 }
250
251 if (ch->cfg.direction == DMA_MEM_TO_DEV) {
252 ctrl &= ~APB_DMA_DEST_SELECT;
253 ctrl |= APB_DMA_SOURCE_SELECT;
254 ctrl |= (ch->line_reqno << 16 &
255 APB_DMA_DEST_REQ_NO_MASK);
256 } else {
257 ctrl |= APB_DMA_DEST_SELECT;
258 ctrl &= ~APB_DMA_SOURCE_SELECT;
259 ctrl |= (ch->line_reqno << 24 &
260 APB_DMA_SOURCE_REQ_NO_MASK);
261 }
262
263 writel(ctrl, ch->base + REG_OFF_CTRL);
264
265 return 0;
266}
267
268static struct dma_async_tx_descriptor *moxart_prep_slave_sg(
269 struct dma_chan *chan, struct scatterlist *sgl,
270 unsigned int sg_len, enum dma_transfer_direction dir,
271 unsigned long tx_flags, void *context)
272{
273 struct moxart_chan *ch = to_moxart_dma_chan(chan);
274 struct moxart_desc *d;
275 enum dma_slave_buswidth dev_width;
276 dma_addr_t dev_addr;
277 struct scatterlist *sgent;
278 unsigned int es;
279 unsigned int i;
280
281 if (!is_slave_direction(dir)) {
282 dev_err(chan2dev(chan), "%s: invalid DMA direction\n",
283 __func__);
284 return NULL;
285 }
286
287 if (dir == DMA_DEV_TO_MEM) {
288 dev_addr = ch->cfg.src_addr;
289 dev_width = ch->cfg.src_addr_width;
290 } else {
291 dev_addr = ch->cfg.dst_addr;
292 dev_width = ch->cfg.dst_addr_width;
293 }
294
295 switch (dev_width) {
296 case DMA_SLAVE_BUSWIDTH_1_BYTE:
297 es = MOXART_DMA_DATA_TYPE_S8;
298 break;
299 case DMA_SLAVE_BUSWIDTH_2_BYTES:
300 es = MOXART_DMA_DATA_TYPE_S16;
301 break;
302 case DMA_SLAVE_BUSWIDTH_4_BYTES:
303 es = MOXART_DMA_DATA_TYPE_S32;
304 break;
305 default:
306 dev_err(chan2dev(chan), "%s: unsupported data width (%u)\n",
307 __func__, dev_width);
308 return NULL;
309 }
310
311 d = kzalloc(sizeof(*d) + sg_len * sizeof(d->sg[0]), GFP_ATOMIC);
312 if (!d)
313 return NULL;
314
315 d->dma_dir = dir;
316 d->dev_addr = dev_addr;
317 d->es = es;
318
319 for_each_sg(sgl, sgent, sg_len, i) {
320 d->sg[i].addr = sg_dma_address(sgent);
321 d->sg[i].len = sg_dma_len(sgent);
322 }
323
324 d->sglen = sg_len;
325
326 ch->error = 0;
327
328 return vchan_tx_prep(&ch->vc, &d->vd, tx_flags);
329}
330
331static struct dma_chan *moxart_of_xlate(struct of_phandle_args *dma_spec,
332 struct of_dma *ofdma)
333{
334 struct moxart_dmadev *mdc = ofdma->of_dma_data;
335 struct dma_chan *chan;
336 struct moxart_chan *ch;
337
338 chan = dma_get_any_slave_channel(&mdc->dma_slave);
339 if (!chan)
340 return NULL;
341
342 ch = to_moxart_dma_chan(chan);
343 ch->line_reqno = dma_spec->args[0];
344
345 return chan;
346}
347
348static int moxart_alloc_chan_resources(struct dma_chan *chan)
349{
350 struct moxart_chan *ch = to_moxart_dma_chan(chan);
351
352 dev_dbg(chan2dev(chan), "%s: allocating channel #%u\n",
353 __func__, ch->ch_num);
354 ch->allocated = 1;
355
356 return 0;
357}
358
359static void moxart_free_chan_resources(struct dma_chan *chan)
360{
361 struct moxart_chan *ch = to_moxart_dma_chan(chan);
362
363 vchan_free_chan_resources(&ch->vc);
364
365 dev_dbg(chan2dev(chan), "%s: freeing channel #%u\n",
366 __func__, ch->ch_num);
367 ch->allocated = 0;
368}
369
370static void moxart_dma_set_params(struct moxart_chan *ch, dma_addr_t src_addr,
371 dma_addr_t dst_addr)
372{
373 writel(src_addr, ch->base + REG_OFF_ADDRESS_SOURCE);
374 writel(dst_addr, ch->base + REG_OFF_ADDRESS_DEST);
375}
376
377static void moxart_set_transfer_params(struct moxart_chan *ch, unsigned int len)
378{
379 struct moxart_desc *d = ch->desc;
380 unsigned int sglen_div = es_bytes[d->es];
381
382 d->dma_cycles = len >> sglen_div;
383
384
385
386
387
388 writel(d->dma_cycles, ch->base + REG_OFF_CYCLES);
389
390 dev_dbg(chan2dev(&ch->vc.chan), "%s: set %u DMA cycles (len=%u)\n",
391 __func__, d->dma_cycles, len);
392}
393
394static void moxart_start_dma(struct moxart_chan *ch)
395{
396 u32 ctrl;
397
398 ctrl = readl(ch->base + REG_OFF_CTRL);
399 ctrl |= (APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
400 writel(ctrl, ch->base + REG_OFF_CTRL);
401}
402
403static void moxart_dma_start_sg(struct moxart_chan *ch, unsigned int idx)
404{
405 struct moxart_desc *d = ch->desc;
406 struct moxart_sg *sg = ch->desc->sg + idx;
407
408 if (ch->desc->dma_dir == DMA_MEM_TO_DEV)
409 moxart_dma_set_params(ch, sg->addr, d->dev_addr);
410 else if (ch->desc->dma_dir == DMA_DEV_TO_MEM)
411 moxart_dma_set_params(ch, d->dev_addr, sg->addr);
412
413 moxart_set_transfer_params(ch, sg->len);
414
415 moxart_start_dma(ch);
416}
417
418static void moxart_dma_start_desc(struct dma_chan *chan)
419{
420 struct moxart_chan *ch = to_moxart_dma_chan(chan);
421 struct virt_dma_desc *vd;
422
423 vd = vchan_next_desc(&ch->vc);
424
425 if (!vd) {
426 ch->desc = NULL;
427 return;
428 }
429
430 list_del(&vd->node);
431
432 ch->desc = to_moxart_dma_desc(&vd->tx);
433 ch->sgidx = 0;
434
435 moxart_dma_start_sg(ch, 0);
436}
437
438static void moxart_issue_pending(struct dma_chan *chan)
439{
440 struct moxart_chan *ch = to_moxart_dma_chan(chan);
441 unsigned long flags;
442
443 spin_lock_irqsave(&ch->vc.lock, flags);
444 if (vchan_issue_pending(&ch->vc) && !ch->desc)
445 moxart_dma_start_desc(chan);
446 spin_unlock_irqrestore(&ch->vc.lock, flags);
447}
448
449static size_t moxart_dma_desc_size(struct moxart_desc *d,
450 unsigned int completed_sgs)
451{
452 unsigned int i;
453 size_t size;
454
455 for (size = i = completed_sgs; i < d->sglen; i++)
456 size += d->sg[i].len;
457
458 return size;
459}
460
461static size_t moxart_dma_desc_size_in_flight(struct moxart_chan *ch)
462{
463 size_t size;
464 unsigned int completed_cycles, cycles;
465
466 size = moxart_dma_desc_size(ch->desc, ch->sgidx);
467 cycles = readl(ch->base + REG_OFF_CYCLES);
468 completed_cycles = (ch->desc->dma_cycles - cycles);
469 size -= completed_cycles << es_bytes[ch->desc->es];
470
471 dev_dbg(chan2dev(&ch->vc.chan), "%s: size=%zu\n", __func__, size);
472
473 return size;
474}
475
476static enum dma_status moxart_tx_status(struct dma_chan *chan,
477 dma_cookie_t cookie,
478 struct dma_tx_state *txstate)
479{
480 struct moxart_chan *ch = to_moxart_dma_chan(chan);
481 struct virt_dma_desc *vd;
482 struct moxart_desc *d;
483 enum dma_status ret;
484 unsigned long flags;
485
486
487
488
489 ret = dma_cookie_status(chan, cookie, txstate);
490
491 spin_lock_irqsave(&ch->vc.lock, flags);
492 vd = vchan_find_desc(&ch->vc, cookie);
493 if (vd) {
494 d = to_moxart_dma_desc(&vd->tx);
495 txstate->residue = moxart_dma_desc_size(d, 0);
496 } else if (ch->desc && ch->desc->vd.tx.cookie == cookie) {
497 txstate->residue = moxart_dma_desc_size_in_flight(ch);
498 }
499 spin_unlock_irqrestore(&ch->vc.lock, flags);
500
501 if (ch->error)
502 return DMA_ERROR;
503
504 return ret;
505}
506
507static void moxart_dma_init(struct dma_device *dma, struct device *dev)
508{
509 dma->device_prep_slave_sg = moxart_prep_slave_sg;
510 dma->device_alloc_chan_resources = moxart_alloc_chan_resources;
511 dma->device_free_chan_resources = moxart_free_chan_resources;
512 dma->device_issue_pending = moxart_issue_pending;
513 dma->device_tx_status = moxart_tx_status;
514 dma->device_config = moxart_slave_config;
515 dma->device_terminate_all = moxart_terminate_all;
516 dma->dev = dev;
517
518 INIT_LIST_HEAD(&dma->channels);
519}
520
521static irqreturn_t moxart_dma_interrupt(int irq, void *devid)
522{
523 struct moxart_dmadev *mc = devid;
524 struct moxart_chan *ch = &mc->slave_chans[0];
525 unsigned int i;
526 unsigned long flags;
527 u32 ctrl;
528
529 dev_dbg(chan2dev(&ch->vc.chan), "%s\n", __func__);
530
531 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
532 if (!ch->allocated)
533 continue;
534
535 ctrl = readl(ch->base + REG_OFF_CTRL);
536
537 dev_dbg(chan2dev(&ch->vc.chan), "%s: ch=%p ch->base=%p ctrl=%x\n",
538 __func__, ch, ch->base, ctrl);
539
540 if (ctrl & APB_DMA_FIN_INT_STS) {
541 ctrl &= ~APB_DMA_FIN_INT_STS;
542 if (ch->desc) {
543 spin_lock_irqsave(&ch->vc.lock, flags);
544 if (++ch->sgidx < ch->desc->sglen) {
545 moxart_dma_start_sg(ch, ch->sgidx);
546 } else {
547 vchan_cookie_complete(&ch->desc->vd);
548 moxart_dma_start_desc(&ch->vc.chan);
549 }
550 spin_unlock_irqrestore(&ch->vc.lock, flags);
551 }
552 }
553
554 if (ctrl & APB_DMA_ERR_INT_STS) {
555 ctrl &= ~APB_DMA_ERR_INT_STS;
556 ch->error = 1;
557 }
558
559 writel(ctrl, ch->base + REG_OFF_CTRL);
560 }
561
562 return IRQ_HANDLED;
563}
564
565static int moxart_probe(struct platform_device *pdev)
566{
567 struct device *dev = &pdev->dev;
568 struct device_node *node = dev->of_node;
569 struct resource *res;
570 static void __iomem *dma_base_addr;
571 int ret, i;
572 unsigned int irq;
573 struct moxart_chan *ch;
574 struct moxart_dmadev *mdc;
575
576 mdc = devm_kzalloc(dev, sizeof(*mdc), GFP_KERNEL);
577 if (!mdc) {
578 dev_err(dev, "can't allocate DMA container\n");
579 return -ENOMEM;
580 }
581
582 irq = irq_of_parse_and_map(node, 0);
583 if (irq == NO_IRQ) {
584 dev_err(dev, "no IRQ resource\n");
585 return -EINVAL;
586 }
587
588 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
589 dma_base_addr = devm_ioremap_resource(dev, res);
590 if (IS_ERR(dma_base_addr))
591 return PTR_ERR(dma_base_addr);
592
593 dma_cap_zero(mdc->dma_slave.cap_mask);
594 dma_cap_set(DMA_SLAVE, mdc->dma_slave.cap_mask);
595 dma_cap_set(DMA_PRIVATE, mdc->dma_slave.cap_mask);
596
597 moxart_dma_init(&mdc->dma_slave, dev);
598
599 ch = &mdc->slave_chans[0];
600 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
601 ch->ch_num = i;
602 ch->base = dma_base_addr + i * REG_OFF_CHAN_SIZE;
603 ch->allocated = 0;
604
605 ch->vc.desc_free = moxart_dma_desc_free;
606 vchan_init(&ch->vc, &mdc->dma_slave);
607
608 dev_dbg(dev, "%s: chs[%d]: ch->ch_num=%u ch->base=%p\n",
609 __func__, i, ch->ch_num, ch->base);
610 }
611
612 platform_set_drvdata(pdev, mdc);
613
614 ret = devm_request_irq(dev, irq, moxart_dma_interrupt, 0,
615 "moxart-dma-engine", mdc);
616 if (ret) {
617 dev_err(dev, "devm_request_irq failed\n");
618 return ret;
619 }
620
621 ret = dma_async_device_register(&mdc->dma_slave);
622 if (ret) {
623 dev_err(dev, "dma_async_device_register failed\n");
624 return ret;
625 }
626
627 ret = of_dma_controller_register(node, moxart_of_xlate, mdc);
628 if (ret) {
629 dev_err(dev, "of_dma_controller_register failed\n");
630 dma_async_device_unregister(&mdc->dma_slave);
631 return ret;
632 }
633
634 dev_dbg(dev, "%s: IRQ=%u\n", __func__, irq);
635
636 return 0;
637}
638
639static int moxart_remove(struct platform_device *pdev)
640{
641 struct moxart_dmadev *m = platform_get_drvdata(pdev);
642
643 dma_async_device_unregister(&m->dma_slave);
644
645 if (pdev->dev.of_node)
646 of_dma_controller_free(pdev->dev.of_node);
647
648 return 0;
649}
650
651static const struct of_device_id moxart_dma_match[] = {
652 { .compatible = "moxa,moxart-dma" },
653 { }
654};
655MODULE_DEVICE_TABLE(of, moxart_dma_match);
656
657static struct platform_driver moxart_driver = {
658 .probe = moxart_probe,
659 .remove = moxart_remove,
660 .driver = {
661 .name = "moxart-dma-engine",
662 .of_match_table = moxart_dma_match,
663 },
664};
665
666static int moxart_init(void)
667{
668 return platform_driver_register(&moxart_driver);
669}
670subsys_initcall(moxart_init);
671
672static void __exit moxart_exit(void)
673{
674 platform_driver_unregister(&moxart_driver);
675}
676module_exit(moxart_exit);
677
678MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
679MODULE_DESCRIPTION("MOXART DMA engine driver");
680MODULE_LICENSE("GPL v2");
681
