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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * timb_dma.c timberdale FPGA DMA driver
4 * Copyright (c) 2010 Intel Corporation
5 */
6
7/* Supports:
8 * Timberdale FPGA DMA engine
9 */
10
11#include <linux/dmaengine.h>
12#include <linux/dma-mapping.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/io.h>
16#include <linux/module.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19
20#include <linux/timb_dma.h>
21
22#include "dmaengine.h"
23
24#define DRIVER_NAME "timb-dma"
25
26/* Global DMA registers */
27#define TIMBDMA_ACR 0x34
28#define TIMBDMA_32BIT_ADDR 0x01
29
30#define TIMBDMA_ISR 0x080000
31#define TIMBDMA_IPR 0x080004
32#define TIMBDMA_IER 0x080008
33
34/* Channel specific registers */
35/* RX instances base addresses are 0x00, 0x40, 0x80 ...
36 * TX instances base addresses are 0x18, 0x58, 0x98 ...
37 */
38#define TIMBDMA_INSTANCE_OFFSET 0x40
39#define TIMBDMA_INSTANCE_TX_OFFSET 0x18
40
41/* RX registers, relative the instance base */
42#define TIMBDMA_OFFS_RX_DHAR 0x00
43#define TIMBDMA_OFFS_RX_DLAR 0x04
44#define TIMBDMA_OFFS_RX_LR 0x0C
45#define TIMBDMA_OFFS_RX_BLR 0x10
46#define TIMBDMA_OFFS_RX_ER 0x14
47#define TIMBDMA_RX_EN 0x01
48/* bytes per Row, video specific register
49 * which is placed after the TX registers...
50 */
51#define TIMBDMA_OFFS_RX_BPRR 0x30
52
53/* TX registers, relative the instance base */
54#define TIMBDMA_OFFS_TX_DHAR 0x00
55#define TIMBDMA_OFFS_TX_DLAR 0x04
56#define TIMBDMA_OFFS_TX_BLR 0x0C
57#define TIMBDMA_OFFS_TX_LR 0x14
58
59
60#define TIMB_DMA_DESC_SIZE 8
61
62struct timb_dma_desc {
63 struct list_head desc_node;
64 struct dma_async_tx_descriptor txd;
65 u8 *desc_list;
66 unsigned int desc_list_len;
67 bool interrupt;
68};
69
70struct timb_dma_chan {
71 struct dma_chan chan;
72 void __iomem *membase;
73 spinlock_t lock; /* Used to protect data structures,
74 especially the lists and descriptors,
75 from races between the tasklet and calls
76 from above */
77 bool ongoing;
78 struct list_head active_list;
79 struct list_head queue;
80 struct list_head free_list;
81 unsigned int bytes_per_line;
82 enum dma_transfer_direction direction;
83 unsigned int descs; /* Descriptors to allocate */
84 unsigned int desc_elems; /* number of elems per descriptor */
85};
86
87struct timb_dma {
88 struct dma_device dma;
89 void __iomem *membase;
90 struct tasklet_struct tasklet;
91 struct timb_dma_chan channels[];
92};
93
94static struct device *chan2dev(struct dma_chan *chan)
95{
96 return &chan->dev->device;
97}
98static struct device *chan2dmadev(struct dma_chan *chan)
99{
100 return chan2dev(chan)->parent->parent;
101}
102
103static struct timb_dma *tdchantotd(struct timb_dma_chan *td_chan)
104{
105 int id = td_chan->chan.chan_id;
106 return (struct timb_dma *)((u8 *)td_chan -
107 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
108}
109
110/* Must be called with the spinlock held */
111static void __td_enable_chan_irq(struct timb_dma_chan *td_chan)
112{
113 int id = td_chan->chan.chan_id;
114 struct timb_dma *td = tdchantotd(td_chan);
115 u32 ier;
116
117 /* enable interrupt for this channel */
118 ier = ioread32(td->membase + TIMBDMA_IER);
119 ier |= 1 << id;
120 dev_dbg(chan2dev(&td_chan->chan), "Enabling irq: %d, IER: 0x%x\n", id,
121 ier);
122 iowrite32(ier, td->membase + TIMBDMA_IER);
123}
124
125/* Should be called with the spinlock held */
126static bool __td_dma_done_ack(struct timb_dma_chan *td_chan)
127{
128 int id = td_chan->chan.chan_id;
129 struct timb_dma *td = (struct timb_dma *)((u8 *)td_chan -
130 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
131 u32 isr;
132 bool done = false;
133
134 dev_dbg(chan2dev(&td_chan->chan), "Checking irq: %d, td: %p\n", id, td);
135
136 isr = ioread32(td->membase + TIMBDMA_ISR) & (1 << id);
137 if (isr) {
138 iowrite32(isr, td->membase + TIMBDMA_ISR);
139 done = true;
140 }
141
142 return done;
143}
144
145static int td_fill_desc(struct timb_dma_chan *td_chan, u8 *dma_desc,
146 struct scatterlist *sg, bool last)
147{
148 if (sg_dma_len(sg) > USHRT_MAX) {
149 dev_err(chan2dev(&td_chan->chan), "Too big sg element\n");
150 return -EINVAL;
151 }
152
153 /* length must be word aligned */
154 if (sg_dma_len(sg) % sizeof(u32)) {
155 dev_err(chan2dev(&td_chan->chan), "Incorrect length: %d\n",
156 sg_dma_len(sg));
157 return -EINVAL;
158 }
159
160 dev_dbg(chan2dev(&td_chan->chan), "desc: %p, addr: 0x%llx\n",
161 dma_desc, (unsigned long long)sg_dma_address(sg));
162
163 dma_desc[7] = (sg_dma_address(sg) >> 24) & 0xff;
164 dma_desc[6] = (sg_dma_address(sg) >> 16) & 0xff;
165 dma_desc[5] = (sg_dma_address(sg) >> 8) & 0xff;
166 dma_desc[4] = (sg_dma_address(sg) >> 0) & 0xff;
167
168 dma_desc[3] = (sg_dma_len(sg) >> 8) & 0xff;
169 dma_desc[2] = (sg_dma_len(sg) >> 0) & 0xff;
170
171 dma_desc[1] = 0x00;
172 dma_desc[0] = 0x21 | (last ? 0x02 : 0); /* tran, valid */
173
174 return 0;
175}
176
177/* Must be called with the spinlock held */
178static void __td_start_dma(struct timb_dma_chan *td_chan)
179{
180 struct timb_dma_desc *td_desc;
181
182 if (td_chan->ongoing) {
183 dev_err(chan2dev(&td_chan->chan),
184 "Transfer already ongoing\n");
185 return;
186 }
187
188 td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
189 desc_node);
190
191 dev_dbg(chan2dev(&td_chan->chan),
192 "td_chan: %p, chan: %d, membase: %p\n",
193 td_chan, td_chan->chan.chan_id, td_chan->membase);
194
195 if (td_chan->direction == DMA_DEV_TO_MEM) {
196
197 /* descriptor address */
198 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_DHAR);
199 iowrite32(td_desc->txd.phys, td_chan->membase +
200 TIMBDMA_OFFS_RX_DLAR);
201 /* Bytes per line */
202 iowrite32(td_chan->bytes_per_line, td_chan->membase +
203 TIMBDMA_OFFS_RX_BPRR);
204 /* enable RX */
205 iowrite32(TIMBDMA_RX_EN, td_chan->membase + TIMBDMA_OFFS_RX_ER);
206 } else {
207 /* address high */
208 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DHAR);
209 iowrite32(td_desc->txd.phys, td_chan->membase +
210 TIMBDMA_OFFS_TX_DLAR);
211 }
212
213 td_chan->ongoing = true;
214
215 if (td_desc->interrupt)
216 __td_enable_chan_irq(td_chan);
217}
218
219static void __td_finish(struct timb_dma_chan *td_chan)
220{
221 struct dmaengine_desc_callback cb;
222 struct dma_async_tx_descriptor *txd;
223 struct timb_dma_desc *td_desc;
224
225 /* can happen if the descriptor is canceled */
226 if (list_empty(&td_chan->active_list))
227 return;
228
229 td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
230 desc_node);
231 txd = &td_desc->txd;
232
233 dev_dbg(chan2dev(&td_chan->chan), "descriptor %u complete\n",
234 txd->cookie);
235
236 /* make sure to stop the transfer */
237 if (td_chan->direction == DMA_DEV_TO_MEM)
238 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_ER);
239/* Currently no support for stopping DMA transfers
240 else
241 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DLAR);
242*/
243 dma_cookie_complete(txd);
244 td_chan->ongoing = false;
245
246 dmaengine_desc_get_callback(txd, &cb);
247
248 list_move(&td_desc->desc_node, &td_chan->free_list);
249
250 dma_descriptor_unmap(txd);
251 /*
252 * The API requires that no submissions are done from a
253 * callback, so we don't need to drop the lock here
254 */
255 dmaengine_desc_callback_invoke(&cb, NULL);
256}
257
258static u32 __td_ier_mask(struct timb_dma *td)
259{
260 int i;
261 u32 ret = 0;
262
263 for (i = 0; i < td->dma.chancnt; i++) {
264 struct timb_dma_chan *td_chan = td->channels + i;
265 if (td_chan->ongoing) {
266 struct timb_dma_desc *td_desc =
267 list_entry(td_chan->active_list.next,
268 struct timb_dma_desc, desc_node);
269 if (td_desc->interrupt)
270 ret |= 1 << i;
271 }
272 }
273
274 return ret;
275}
276
277static void __td_start_next(struct timb_dma_chan *td_chan)
278{
279 struct timb_dma_desc *td_desc;
280
281 BUG_ON(list_empty(&td_chan->queue));
282 BUG_ON(td_chan->ongoing);
283
284 td_desc = list_entry(td_chan->queue.next, struct timb_dma_desc,
285 desc_node);
286
287 dev_dbg(chan2dev(&td_chan->chan), "%s: started %u\n",
288 __func__, td_desc->txd.cookie);
289
290 list_move(&td_desc->desc_node, &td_chan->active_list);
291 __td_start_dma(td_chan);
292}
293
294static dma_cookie_t td_tx_submit(struct dma_async_tx_descriptor *txd)
295{
296 struct timb_dma_desc *td_desc = container_of(txd, struct timb_dma_desc,
297 txd);
298 struct timb_dma_chan *td_chan = container_of(txd->chan,
299 struct timb_dma_chan, chan);
300 dma_cookie_t cookie;
301
302 spin_lock_bh(&td_chan->lock);
303 cookie = dma_cookie_assign(txd);
304
305 if (list_empty(&td_chan->active_list)) {
306 dev_dbg(chan2dev(txd->chan), "%s: started %u\n", __func__,
307 txd->cookie);
308 list_add_tail(&td_desc->desc_node, &td_chan->active_list);
309 __td_start_dma(td_chan);
310 } else {
311 dev_dbg(chan2dev(txd->chan), "tx_submit: queued %u\n",
312 txd->cookie);
313
314 list_add_tail(&td_desc->desc_node, &td_chan->queue);
315 }
316
317 spin_unlock_bh(&td_chan->lock);
318
319 return cookie;
320}
321
322static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
323{
324 struct dma_chan *chan = &td_chan->chan;
325 struct timb_dma_desc *td_desc;
326 int err;
327
328 td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
329 if (!td_desc)
330 goto out;
331
332 td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
333
334 td_desc->desc_list = kzalloc(td_desc->desc_list_len, GFP_KERNEL);
335 if (!td_desc->desc_list)
336 goto err;
337
338 dma_async_tx_descriptor_init(&td_desc->txd, chan);
339 td_desc->txd.tx_submit = td_tx_submit;
340 td_desc->txd.flags = DMA_CTRL_ACK;
341
342 td_desc->txd.phys = dma_map_single(chan2dmadev(chan),
343 td_desc->desc_list, td_desc->desc_list_len, DMA_TO_DEVICE);
344
345 err = dma_mapping_error(chan2dmadev(chan), td_desc->txd.phys);
346 if (err) {
347 dev_err(chan2dev(chan), "DMA mapping error: %d\n", err);
348 goto err;
349 }
350
351 return td_desc;
352err:
353 kfree(td_desc->desc_list);
354 kfree(td_desc);
355out:
356 return NULL;
357
358}
359
360static void td_free_desc(struct timb_dma_desc *td_desc)
361{
362 dev_dbg(chan2dev(td_desc->txd.chan), "Freeing desc: %p\n", td_desc);
363 dma_unmap_single(chan2dmadev(td_desc->txd.chan), td_desc->txd.phys,
364 td_desc->desc_list_len, DMA_TO_DEVICE);
365
366 kfree(td_desc->desc_list);
367 kfree(td_desc);
368}
369
370static void td_desc_put(struct timb_dma_chan *td_chan,
371 struct timb_dma_desc *td_desc)
372{
373 dev_dbg(chan2dev(&td_chan->chan), "Putting desc: %p\n", td_desc);
374
375 spin_lock_bh(&td_chan->lock);
376 list_add(&td_desc->desc_node, &td_chan->free_list);
377 spin_unlock_bh(&td_chan->lock);
378}
379
380static struct timb_dma_desc *td_desc_get(struct timb_dma_chan *td_chan)
381{
382 struct timb_dma_desc *td_desc, *_td_desc;
383 struct timb_dma_desc *ret = NULL;
384
385 spin_lock_bh(&td_chan->lock);
386 list_for_each_entry_safe(td_desc, _td_desc, &td_chan->free_list,
387 desc_node) {
388 if (async_tx_test_ack(&td_desc->txd)) {
389 list_del(&td_desc->desc_node);
390 ret = td_desc;
391 break;
392 }
393 dev_dbg(chan2dev(&td_chan->chan), "desc %p not ACKed\n",
394 td_desc);
395 }
396 spin_unlock_bh(&td_chan->lock);
397
398 return ret;
399}
400
401static int td_alloc_chan_resources(struct dma_chan *chan)
402{
403 struct timb_dma_chan *td_chan =
404 container_of(chan, struct timb_dma_chan, chan);
405 int i;
406
407 dev_dbg(chan2dev(chan), "%s: entry\n", __func__);
408
409 BUG_ON(!list_empty(&td_chan->free_list));
410 for (i = 0; i < td_chan->descs; i++) {
411 struct timb_dma_desc *td_desc = td_alloc_init_desc(td_chan);
412 if (!td_desc) {
413 if (i)
414 break;
415 else {
416 dev_err(chan2dev(chan),
417 "Couldn't allocate any descriptors\n");
418 return -ENOMEM;
419 }
420 }
421
422 td_desc_put(td_chan, td_desc);
423 }
424
425 spin_lock_bh(&td_chan->lock);
426 dma_cookie_init(chan);
427 spin_unlock_bh(&td_chan->lock);
428
429 return 0;
430}
431
432static void td_free_chan_resources(struct dma_chan *chan)
433{
434 struct timb_dma_chan *td_chan =
435 container_of(chan, struct timb_dma_chan, chan);
436 struct timb_dma_desc *td_desc, *_td_desc;
437 LIST_HEAD(list);
438
439 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
440
441 /* check that all descriptors are free */
442 BUG_ON(!list_empty(&td_chan->active_list));
443 BUG_ON(!list_empty(&td_chan->queue));
444
445 spin_lock_bh(&td_chan->lock);
446 list_splice_init(&td_chan->free_list, &list);
447 spin_unlock_bh(&td_chan->lock);
448
449 list_for_each_entry_safe(td_desc, _td_desc, &list, desc_node) {
450 dev_dbg(chan2dev(chan), "%s: Freeing desc: %p\n", __func__,
451 td_desc);
452 td_free_desc(td_desc);
453 }
454}
455
456static enum dma_status td_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
457 struct dma_tx_state *txstate)
458{
459 enum dma_status ret;
460
461 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
462
463 ret = dma_cookie_status(chan, cookie, txstate);
464
465 dev_dbg(chan2dev(chan), "%s: exit, ret: %d\n", __func__, ret);
466
467 return ret;
468}
469
470static void td_issue_pending(struct dma_chan *chan)
471{
472 struct timb_dma_chan *td_chan =
473 container_of(chan, struct timb_dma_chan, chan);
474
475 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
476 spin_lock_bh(&td_chan->lock);
477
478 if (!list_empty(&td_chan->active_list))
479 /* transfer ongoing */
480 if (__td_dma_done_ack(td_chan))
481 __td_finish(td_chan);
482
483 if (list_empty(&td_chan->active_list) && !list_empty(&td_chan->queue))
484 __td_start_next(td_chan);
485
486 spin_unlock_bh(&td_chan->lock);
487}
488
489static struct dma_async_tx_descriptor *td_prep_slave_sg(struct dma_chan *chan,
490 struct scatterlist *sgl, unsigned int sg_len,
491 enum dma_transfer_direction direction, unsigned long flags,
492 void *context)
493{
494 struct timb_dma_chan *td_chan =
495 container_of(chan, struct timb_dma_chan, chan);
496 struct timb_dma_desc *td_desc;
497 struct scatterlist *sg;
498 unsigned int i;
499 unsigned int desc_usage = 0;
500
501 if (!sgl || !sg_len) {
502 dev_err(chan2dev(chan), "%s: No SG list\n", __func__);
503 return NULL;
504 }
505
506 /* even channels are for RX, odd for TX */
507 if (td_chan->direction != direction) {
508 dev_err(chan2dev(chan),
509 "Requesting channel in wrong direction\n");
510 return NULL;
511 }
512
513 td_desc = td_desc_get(td_chan);
514 if (!td_desc) {
515 dev_err(chan2dev(chan), "Not enough descriptors available\n");
516 return NULL;
517 }
518
519 td_desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
520
521 for_each_sg(sgl, sg, sg_len, i) {
522 int err;
523 if (desc_usage > td_desc->desc_list_len) {
524 dev_err(chan2dev(chan), "No descriptor space\n");
525 return NULL;
526 }
527
528 err = td_fill_desc(td_chan, td_desc->desc_list + desc_usage, sg,
529 i == (sg_len - 1));
530 if (err) {
531 dev_err(chan2dev(chan), "Failed to update desc: %d\n",
532 err);
533 td_desc_put(td_chan, td_desc);
534 return NULL;
535 }
536 desc_usage += TIMB_DMA_DESC_SIZE;
537 }
538
539 dma_sync_single_for_device(chan2dmadev(chan), td_desc->txd.phys,
540 td_desc->desc_list_len, DMA_TO_DEVICE);
541
542 return &td_desc->txd;
543}
544
545static int td_terminate_all(struct dma_chan *chan)
546{
547 struct timb_dma_chan *td_chan =
548 container_of(chan, struct timb_dma_chan, chan);
549 struct timb_dma_desc *td_desc, *_td_desc;
550
551 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
552
553 /* first the easy part, put the queue into the free list */
554 spin_lock_bh(&td_chan->lock);
555 list_for_each_entry_safe(td_desc, _td_desc, &td_chan->queue,
556 desc_node)
557 list_move(&td_desc->desc_node, &td_chan->free_list);
558
559 /* now tear down the running */
560 __td_finish(td_chan);
561 spin_unlock_bh(&td_chan->lock);
562
563 return 0;
564}
565
566static void td_tasklet(struct tasklet_struct *t)
567{
568 struct timb_dma *td = from_tasklet(td, t, tasklet);
569 u32 isr;
570 u32 ipr;
571 u32 ier;
572 int i;
573
574 isr = ioread32(td->membase + TIMBDMA_ISR);
575 ipr = isr & __td_ier_mask(td);
576
577 /* ack the interrupts */
578 iowrite32(ipr, td->membase + TIMBDMA_ISR);
579
580 for (i = 0; i < td->dma.chancnt; i++)
581 if (ipr & (1 << i)) {
582 struct timb_dma_chan *td_chan = td->channels + i;
583 spin_lock(&td_chan->lock);
584 __td_finish(td_chan);
585 if (!list_empty(&td_chan->queue))
586 __td_start_next(td_chan);
587 spin_unlock(&td_chan->lock);
588 }
589
590 ier = __td_ier_mask(td);
591 iowrite32(ier, td->membase + TIMBDMA_IER);
592}
593
594
595static irqreturn_t td_irq(int irq, void *devid)
596{
597 struct timb_dma *td = devid;
598 u32 ipr = ioread32(td->membase + TIMBDMA_IPR);
599
600 if (ipr) {
601 /* disable interrupts, will be re-enabled in tasklet */
602 iowrite32(0, td->membase + TIMBDMA_IER);
603
604 tasklet_schedule(&td->tasklet);
605
606 return IRQ_HANDLED;
607 } else
608 return IRQ_NONE;
609}
610
611
612static int td_probe(struct platform_device *pdev)
613{
614 struct timb_dma_platform_data *pdata = dev_get_platdata(&pdev->dev);
615 struct timb_dma *td;
616 struct resource *iomem;
617 int irq;
618 int err;
619 int i;
620
621 if (!pdata) {
622 dev_err(&pdev->dev, "No platform data\n");
623 return -EINVAL;
624 }
625
626 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
627 if (!iomem)
628 return -EINVAL;
629
630 irq = platform_get_irq(pdev, 0);
631 if (irq < 0)
632 return irq;
633
634 if (!request_mem_region(iomem->start, resource_size(iomem),
635 DRIVER_NAME))
636 return -EBUSY;
637
638 td = kzalloc(struct_size(td, channels, pdata->nr_channels),
639 GFP_KERNEL);
640 if (!td) {
641 err = -ENOMEM;
642 goto err_release_region;
643 }
644
645 dev_dbg(&pdev->dev, "Allocated TD: %p\n", td);
646
647 td->membase = ioremap(iomem->start, resource_size(iomem));
648 if (!td->membase) {
649 dev_err(&pdev->dev, "Failed to remap I/O memory\n");
650 err = -ENOMEM;
651 goto err_free_mem;
652 }
653
654 /* 32bit addressing */
655 iowrite32(TIMBDMA_32BIT_ADDR, td->membase + TIMBDMA_ACR);
656
657 /* disable and clear any interrupts */
658 iowrite32(0x0, td->membase + TIMBDMA_IER);
659 iowrite32(0xFFFFFFFF, td->membase + TIMBDMA_ISR);
660
661 tasklet_setup(&td->tasklet, td_tasklet);
662
663 err = request_irq(irq, td_irq, IRQF_SHARED, DRIVER_NAME, td);
664 if (err) {
665 dev_err(&pdev->dev, "Failed to request IRQ\n");
666 goto err_tasklet_kill;
667 }
668
669 td->dma.device_alloc_chan_resources = td_alloc_chan_resources;
670 td->dma.device_free_chan_resources = td_free_chan_resources;
671 td->dma.device_tx_status = td_tx_status;
672 td->dma.device_issue_pending = td_issue_pending;
673
674 dma_cap_set(DMA_SLAVE, td->dma.cap_mask);
675 dma_cap_set(DMA_PRIVATE, td->dma.cap_mask);
676 td->dma.device_prep_slave_sg = td_prep_slave_sg;
677 td->dma.device_terminate_all = td_terminate_all;
678
679 td->dma.dev = &pdev->dev;
680
681 INIT_LIST_HEAD(&td->dma.channels);
682
683 for (i = 0; i < pdata->nr_channels; i++) {
684 struct timb_dma_chan *td_chan = &td->channels[i];
685 struct timb_dma_platform_data_channel *pchan =
686 pdata->channels + i;
687
688 /* even channels are RX, odd are TX */
689 if ((i % 2) == pchan->rx) {
690 dev_err(&pdev->dev, "Wrong channel configuration\n");
691 err = -EINVAL;
692 goto err_free_irq;
693 }
694
695 td_chan->chan.device = &td->dma;
696 dma_cookie_init(&td_chan->chan);
697 spin_lock_init(&td_chan->lock);
698 INIT_LIST_HEAD(&td_chan->active_list);
699 INIT_LIST_HEAD(&td_chan->queue);
700 INIT_LIST_HEAD(&td_chan->free_list);
701
702 td_chan->descs = pchan->descriptors;
703 td_chan->desc_elems = pchan->descriptor_elements;
704 td_chan->bytes_per_line = pchan->bytes_per_line;
705 td_chan->direction = pchan->rx ? DMA_DEV_TO_MEM :
706 DMA_MEM_TO_DEV;
707
708 td_chan->membase = td->membase +
709 (i / 2) * TIMBDMA_INSTANCE_OFFSET +
710 (pchan->rx ? 0 : TIMBDMA_INSTANCE_TX_OFFSET);
711
712 dev_dbg(&pdev->dev, "Chan: %d, membase: %p\n",
713 i, td_chan->membase);
714
715 list_add_tail(&td_chan->chan.device_node, &td->dma.channels);
716 }
717
718 err = dma_async_device_register(&td->dma);
719 if (err) {
720 dev_err(&pdev->dev, "Failed to register async device\n");
721 goto err_free_irq;
722 }
723
724 platform_set_drvdata(pdev, td);
725
726 dev_dbg(&pdev->dev, "Probe result: %d\n", err);
727 return err;
728
729err_free_irq:
730 free_irq(irq, td);
731err_tasklet_kill:
732 tasklet_kill(&td->tasklet);
733 iounmap(td->membase);
734err_free_mem:
735 kfree(td);
736err_release_region:
737 release_mem_region(iomem->start, resource_size(iomem));
738
739 return err;
740
741}
742
743static void td_remove(struct platform_device *pdev)
744{
745 struct timb_dma *td = platform_get_drvdata(pdev);
746 struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
747 int irq = platform_get_irq(pdev, 0);
748
749 dma_async_device_unregister(&td->dma);
750 free_irq(irq, td);
751 tasklet_kill(&td->tasklet);
752 iounmap(td->membase);
753 kfree(td);
754 release_mem_region(iomem->start, resource_size(iomem));
755
756 dev_dbg(&pdev->dev, "Removed...\n");
757}
758
759static struct platform_driver td_driver = {
760 .driver = {
761 .name = DRIVER_NAME,
762 },
763 .probe = td_probe,
764 .remove_new = td_remove,
765};
766
767module_platform_driver(td_driver);
768
769MODULE_LICENSE("GPL v2");
770MODULE_DESCRIPTION("Timberdale DMA controller driver");
771MODULE_AUTHOR("Pelagicore AB <info@pelagicore.com>");
772MODULE_ALIAS("platform:"DRIVER_NAME);
1/*
2 * timb_dma.c timberdale FPGA DMA driver
3 * Copyright (c) 2010 Intel Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15/* Supports:
16 * Timberdale FPGA DMA engine
17 */
18
19#include <linux/dmaengine.h>
20#include <linux/dma-mapping.h>
21#include <linux/init.h>
22#include <linux/interrupt.h>
23#include <linux/io.h>
24#include <linux/module.h>
25#include <linux/platform_device.h>
26#include <linux/slab.h>
27
28#include <linux/timb_dma.h>
29
30#include "dmaengine.h"
31
32#define DRIVER_NAME "timb-dma"
33
34/* Global DMA registers */
35#define TIMBDMA_ACR 0x34
36#define TIMBDMA_32BIT_ADDR 0x01
37
38#define TIMBDMA_ISR 0x080000
39#define TIMBDMA_IPR 0x080004
40#define TIMBDMA_IER 0x080008
41
42/* Channel specific registers */
43/* RX instances base addresses are 0x00, 0x40, 0x80 ...
44 * TX instances base addresses are 0x18, 0x58, 0x98 ...
45 */
46#define TIMBDMA_INSTANCE_OFFSET 0x40
47#define TIMBDMA_INSTANCE_TX_OFFSET 0x18
48
49/* RX registers, relative the instance base */
50#define TIMBDMA_OFFS_RX_DHAR 0x00
51#define TIMBDMA_OFFS_RX_DLAR 0x04
52#define TIMBDMA_OFFS_RX_LR 0x0C
53#define TIMBDMA_OFFS_RX_BLR 0x10
54#define TIMBDMA_OFFS_RX_ER 0x14
55#define TIMBDMA_RX_EN 0x01
56/* bytes per Row, video specific register
57 * which is placed after the TX registers...
58 */
59#define TIMBDMA_OFFS_RX_BPRR 0x30
60
61/* TX registers, relative the instance base */
62#define TIMBDMA_OFFS_TX_DHAR 0x00
63#define TIMBDMA_OFFS_TX_DLAR 0x04
64#define TIMBDMA_OFFS_TX_BLR 0x0C
65#define TIMBDMA_OFFS_TX_LR 0x14
66
67
68#define TIMB_DMA_DESC_SIZE 8
69
70struct timb_dma_desc {
71 struct list_head desc_node;
72 struct dma_async_tx_descriptor txd;
73 u8 *desc_list;
74 unsigned int desc_list_len;
75 bool interrupt;
76};
77
78struct timb_dma_chan {
79 struct dma_chan chan;
80 void __iomem *membase;
81 spinlock_t lock; /* Used to protect data structures,
82 especially the lists and descriptors,
83 from races between the tasklet and calls
84 from above */
85 bool ongoing;
86 struct list_head active_list;
87 struct list_head queue;
88 struct list_head free_list;
89 unsigned int bytes_per_line;
90 enum dma_transfer_direction direction;
91 unsigned int descs; /* Descriptors to allocate */
92 unsigned int desc_elems; /* number of elems per descriptor */
93};
94
95struct timb_dma {
96 struct dma_device dma;
97 void __iomem *membase;
98 struct tasklet_struct tasklet;
99 struct timb_dma_chan channels[0];
100};
101
102static struct device *chan2dev(struct dma_chan *chan)
103{
104 return &chan->dev->device;
105}
106static struct device *chan2dmadev(struct dma_chan *chan)
107{
108 return chan2dev(chan)->parent->parent;
109}
110
111static struct timb_dma *tdchantotd(struct timb_dma_chan *td_chan)
112{
113 int id = td_chan->chan.chan_id;
114 return (struct timb_dma *)((u8 *)td_chan -
115 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
116}
117
118/* Must be called with the spinlock held */
119static void __td_enable_chan_irq(struct timb_dma_chan *td_chan)
120{
121 int id = td_chan->chan.chan_id;
122 struct timb_dma *td = tdchantotd(td_chan);
123 u32 ier;
124
125 /* enable interrupt for this channel */
126 ier = ioread32(td->membase + TIMBDMA_IER);
127 ier |= 1 << id;
128 dev_dbg(chan2dev(&td_chan->chan), "Enabling irq: %d, IER: 0x%x\n", id,
129 ier);
130 iowrite32(ier, td->membase + TIMBDMA_IER);
131}
132
133/* Should be called with the spinlock held */
134static bool __td_dma_done_ack(struct timb_dma_chan *td_chan)
135{
136 int id = td_chan->chan.chan_id;
137 struct timb_dma *td = (struct timb_dma *)((u8 *)td_chan -
138 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
139 u32 isr;
140 bool done = false;
141
142 dev_dbg(chan2dev(&td_chan->chan), "Checking irq: %d, td: %p\n", id, td);
143
144 isr = ioread32(td->membase + TIMBDMA_ISR) & (1 << id);
145 if (isr) {
146 iowrite32(isr, td->membase + TIMBDMA_ISR);
147 done = true;
148 }
149
150 return done;
151}
152
153static int td_fill_desc(struct timb_dma_chan *td_chan, u8 *dma_desc,
154 struct scatterlist *sg, bool last)
155{
156 if (sg_dma_len(sg) > USHRT_MAX) {
157 dev_err(chan2dev(&td_chan->chan), "Too big sg element\n");
158 return -EINVAL;
159 }
160
161 /* length must be word aligned */
162 if (sg_dma_len(sg) % sizeof(u32)) {
163 dev_err(chan2dev(&td_chan->chan), "Incorrect length: %d\n",
164 sg_dma_len(sg));
165 return -EINVAL;
166 }
167
168 dev_dbg(chan2dev(&td_chan->chan), "desc: %p, addr: 0x%llx\n",
169 dma_desc, (unsigned long long)sg_dma_address(sg));
170
171 dma_desc[7] = (sg_dma_address(sg) >> 24) & 0xff;
172 dma_desc[6] = (sg_dma_address(sg) >> 16) & 0xff;
173 dma_desc[5] = (sg_dma_address(sg) >> 8) & 0xff;
174 dma_desc[4] = (sg_dma_address(sg) >> 0) & 0xff;
175
176 dma_desc[3] = (sg_dma_len(sg) >> 8) & 0xff;
177 dma_desc[2] = (sg_dma_len(sg) >> 0) & 0xff;
178
179 dma_desc[1] = 0x00;
180 dma_desc[0] = 0x21 | (last ? 0x02 : 0); /* tran, valid */
181
182 return 0;
183}
184
185/* Must be called with the spinlock held */
186static void __td_start_dma(struct timb_dma_chan *td_chan)
187{
188 struct timb_dma_desc *td_desc;
189
190 if (td_chan->ongoing) {
191 dev_err(chan2dev(&td_chan->chan),
192 "Transfer already ongoing\n");
193 return;
194 }
195
196 td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
197 desc_node);
198
199 dev_dbg(chan2dev(&td_chan->chan),
200 "td_chan: %p, chan: %d, membase: %p\n",
201 td_chan, td_chan->chan.chan_id, td_chan->membase);
202
203 if (td_chan->direction == DMA_DEV_TO_MEM) {
204
205 /* descriptor address */
206 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_DHAR);
207 iowrite32(td_desc->txd.phys, td_chan->membase +
208 TIMBDMA_OFFS_RX_DLAR);
209 /* Bytes per line */
210 iowrite32(td_chan->bytes_per_line, td_chan->membase +
211 TIMBDMA_OFFS_RX_BPRR);
212 /* enable RX */
213 iowrite32(TIMBDMA_RX_EN, td_chan->membase + TIMBDMA_OFFS_RX_ER);
214 } else {
215 /* address high */
216 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DHAR);
217 iowrite32(td_desc->txd.phys, td_chan->membase +
218 TIMBDMA_OFFS_TX_DLAR);
219 }
220
221 td_chan->ongoing = true;
222
223 if (td_desc->interrupt)
224 __td_enable_chan_irq(td_chan);
225}
226
227static void __td_finish(struct timb_dma_chan *td_chan)
228{
229 dma_async_tx_callback callback;
230 void *param;
231 struct dma_async_tx_descriptor *txd;
232 struct timb_dma_desc *td_desc;
233
234 /* can happen if the descriptor is canceled */
235 if (list_empty(&td_chan->active_list))
236 return;
237
238 td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
239 desc_node);
240 txd = &td_desc->txd;
241
242 dev_dbg(chan2dev(&td_chan->chan), "descriptor %u complete\n",
243 txd->cookie);
244
245 /* make sure to stop the transfer */
246 if (td_chan->direction == DMA_DEV_TO_MEM)
247 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_ER);
248/* Currently no support for stopping DMA transfers
249 else
250 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DLAR);
251*/
252 dma_cookie_complete(txd);
253 td_chan->ongoing = false;
254
255 callback = txd->callback;
256 param = txd->callback_param;
257
258 list_move(&td_desc->desc_node, &td_chan->free_list);
259
260 dma_descriptor_unmap(txd);
261 /*
262 * The API requires that no submissions are done from a
263 * callback, so we don't need to drop the lock here
264 */
265 if (callback)
266 callback(param);
267}
268
269static u32 __td_ier_mask(struct timb_dma *td)
270{
271 int i;
272 u32 ret = 0;
273
274 for (i = 0; i < td->dma.chancnt; i++) {
275 struct timb_dma_chan *td_chan = td->channels + i;
276 if (td_chan->ongoing) {
277 struct timb_dma_desc *td_desc =
278 list_entry(td_chan->active_list.next,
279 struct timb_dma_desc, desc_node);
280 if (td_desc->interrupt)
281 ret |= 1 << i;
282 }
283 }
284
285 return ret;
286}
287
288static void __td_start_next(struct timb_dma_chan *td_chan)
289{
290 struct timb_dma_desc *td_desc;
291
292 BUG_ON(list_empty(&td_chan->queue));
293 BUG_ON(td_chan->ongoing);
294
295 td_desc = list_entry(td_chan->queue.next, struct timb_dma_desc,
296 desc_node);
297
298 dev_dbg(chan2dev(&td_chan->chan), "%s: started %u\n",
299 __func__, td_desc->txd.cookie);
300
301 list_move(&td_desc->desc_node, &td_chan->active_list);
302 __td_start_dma(td_chan);
303}
304
305static dma_cookie_t td_tx_submit(struct dma_async_tx_descriptor *txd)
306{
307 struct timb_dma_desc *td_desc = container_of(txd, struct timb_dma_desc,
308 txd);
309 struct timb_dma_chan *td_chan = container_of(txd->chan,
310 struct timb_dma_chan, chan);
311 dma_cookie_t cookie;
312
313 spin_lock_bh(&td_chan->lock);
314 cookie = dma_cookie_assign(txd);
315
316 if (list_empty(&td_chan->active_list)) {
317 dev_dbg(chan2dev(txd->chan), "%s: started %u\n", __func__,
318 txd->cookie);
319 list_add_tail(&td_desc->desc_node, &td_chan->active_list);
320 __td_start_dma(td_chan);
321 } else {
322 dev_dbg(chan2dev(txd->chan), "tx_submit: queued %u\n",
323 txd->cookie);
324
325 list_add_tail(&td_desc->desc_node, &td_chan->queue);
326 }
327
328 spin_unlock_bh(&td_chan->lock);
329
330 return cookie;
331}
332
333static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
334{
335 struct dma_chan *chan = &td_chan->chan;
336 struct timb_dma_desc *td_desc;
337 int err;
338
339 td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
340 if (!td_desc) {
341 dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
342 goto out;
343 }
344
345 td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
346
347 td_desc->desc_list = kzalloc(td_desc->desc_list_len, GFP_KERNEL);
348 if (!td_desc->desc_list) {
349 dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
350 goto err;
351 }
352
353 dma_async_tx_descriptor_init(&td_desc->txd, chan);
354 td_desc->txd.tx_submit = td_tx_submit;
355 td_desc->txd.flags = DMA_CTRL_ACK;
356
357 td_desc->txd.phys = dma_map_single(chan2dmadev(chan),
358 td_desc->desc_list, td_desc->desc_list_len, DMA_TO_DEVICE);
359
360 err = dma_mapping_error(chan2dmadev(chan), td_desc->txd.phys);
361 if (err) {
362 dev_err(chan2dev(chan), "DMA mapping error: %d\n", err);
363 goto err;
364 }
365
366 return td_desc;
367err:
368 kfree(td_desc->desc_list);
369 kfree(td_desc);
370out:
371 return NULL;
372
373}
374
375static void td_free_desc(struct timb_dma_desc *td_desc)
376{
377 dev_dbg(chan2dev(td_desc->txd.chan), "Freeing desc: %p\n", td_desc);
378 dma_unmap_single(chan2dmadev(td_desc->txd.chan), td_desc->txd.phys,
379 td_desc->desc_list_len, DMA_TO_DEVICE);
380
381 kfree(td_desc->desc_list);
382 kfree(td_desc);
383}
384
385static void td_desc_put(struct timb_dma_chan *td_chan,
386 struct timb_dma_desc *td_desc)
387{
388 dev_dbg(chan2dev(&td_chan->chan), "Putting desc: %p\n", td_desc);
389
390 spin_lock_bh(&td_chan->lock);
391 list_add(&td_desc->desc_node, &td_chan->free_list);
392 spin_unlock_bh(&td_chan->lock);
393}
394
395static struct timb_dma_desc *td_desc_get(struct timb_dma_chan *td_chan)
396{
397 struct timb_dma_desc *td_desc, *_td_desc;
398 struct timb_dma_desc *ret = NULL;
399
400 spin_lock_bh(&td_chan->lock);
401 list_for_each_entry_safe(td_desc, _td_desc, &td_chan->free_list,
402 desc_node) {
403 if (async_tx_test_ack(&td_desc->txd)) {
404 list_del(&td_desc->desc_node);
405 ret = td_desc;
406 break;
407 }
408 dev_dbg(chan2dev(&td_chan->chan), "desc %p not ACKed\n",
409 td_desc);
410 }
411 spin_unlock_bh(&td_chan->lock);
412
413 return ret;
414}
415
416static int td_alloc_chan_resources(struct dma_chan *chan)
417{
418 struct timb_dma_chan *td_chan =
419 container_of(chan, struct timb_dma_chan, chan);
420 int i;
421
422 dev_dbg(chan2dev(chan), "%s: entry\n", __func__);
423
424 BUG_ON(!list_empty(&td_chan->free_list));
425 for (i = 0; i < td_chan->descs; i++) {
426 struct timb_dma_desc *td_desc = td_alloc_init_desc(td_chan);
427 if (!td_desc) {
428 if (i)
429 break;
430 else {
431 dev_err(chan2dev(chan),
432 "Couldnt allocate any descriptors\n");
433 return -ENOMEM;
434 }
435 }
436
437 td_desc_put(td_chan, td_desc);
438 }
439
440 spin_lock_bh(&td_chan->lock);
441 dma_cookie_init(chan);
442 spin_unlock_bh(&td_chan->lock);
443
444 return 0;
445}
446
447static void td_free_chan_resources(struct dma_chan *chan)
448{
449 struct timb_dma_chan *td_chan =
450 container_of(chan, struct timb_dma_chan, chan);
451 struct timb_dma_desc *td_desc, *_td_desc;
452 LIST_HEAD(list);
453
454 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
455
456 /* check that all descriptors are free */
457 BUG_ON(!list_empty(&td_chan->active_list));
458 BUG_ON(!list_empty(&td_chan->queue));
459
460 spin_lock_bh(&td_chan->lock);
461 list_splice_init(&td_chan->free_list, &list);
462 spin_unlock_bh(&td_chan->lock);
463
464 list_for_each_entry_safe(td_desc, _td_desc, &list, desc_node) {
465 dev_dbg(chan2dev(chan), "%s: Freeing desc: %p\n", __func__,
466 td_desc);
467 td_free_desc(td_desc);
468 }
469}
470
471static enum dma_status td_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
472 struct dma_tx_state *txstate)
473{
474 enum dma_status ret;
475
476 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
477
478 ret = dma_cookie_status(chan, cookie, txstate);
479
480 dev_dbg(chan2dev(chan), "%s: exit, ret: %d\n", __func__, ret);
481
482 return ret;
483}
484
485static void td_issue_pending(struct dma_chan *chan)
486{
487 struct timb_dma_chan *td_chan =
488 container_of(chan, struct timb_dma_chan, chan);
489
490 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
491 spin_lock_bh(&td_chan->lock);
492
493 if (!list_empty(&td_chan->active_list))
494 /* transfer ongoing */
495 if (__td_dma_done_ack(td_chan))
496 __td_finish(td_chan);
497
498 if (list_empty(&td_chan->active_list) && !list_empty(&td_chan->queue))
499 __td_start_next(td_chan);
500
501 spin_unlock_bh(&td_chan->lock);
502}
503
504static struct dma_async_tx_descriptor *td_prep_slave_sg(struct dma_chan *chan,
505 struct scatterlist *sgl, unsigned int sg_len,
506 enum dma_transfer_direction direction, unsigned long flags,
507 void *context)
508{
509 struct timb_dma_chan *td_chan =
510 container_of(chan, struct timb_dma_chan, chan);
511 struct timb_dma_desc *td_desc;
512 struct scatterlist *sg;
513 unsigned int i;
514 unsigned int desc_usage = 0;
515
516 if (!sgl || !sg_len) {
517 dev_err(chan2dev(chan), "%s: No SG list\n", __func__);
518 return NULL;
519 }
520
521 /* even channels are for RX, odd for TX */
522 if (td_chan->direction != direction) {
523 dev_err(chan2dev(chan),
524 "Requesting channel in wrong direction\n");
525 return NULL;
526 }
527
528 td_desc = td_desc_get(td_chan);
529 if (!td_desc) {
530 dev_err(chan2dev(chan), "Not enough descriptors available\n");
531 return NULL;
532 }
533
534 td_desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
535
536 for_each_sg(sgl, sg, sg_len, i) {
537 int err;
538 if (desc_usage > td_desc->desc_list_len) {
539 dev_err(chan2dev(chan), "No descriptor space\n");
540 return NULL;
541 }
542
543 err = td_fill_desc(td_chan, td_desc->desc_list + desc_usage, sg,
544 i == (sg_len - 1));
545 if (err) {
546 dev_err(chan2dev(chan), "Failed to update desc: %d\n",
547 err);
548 td_desc_put(td_chan, td_desc);
549 return NULL;
550 }
551 desc_usage += TIMB_DMA_DESC_SIZE;
552 }
553
554 dma_sync_single_for_device(chan2dmadev(chan), td_desc->txd.phys,
555 td_desc->desc_list_len, DMA_MEM_TO_DEV);
556
557 return &td_desc->txd;
558}
559
560static int td_terminate_all(struct dma_chan *chan)
561{
562 struct timb_dma_chan *td_chan =
563 container_of(chan, struct timb_dma_chan, chan);
564 struct timb_dma_desc *td_desc, *_td_desc;
565
566 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
567
568 /* first the easy part, put the queue into the free list */
569 spin_lock_bh(&td_chan->lock);
570 list_for_each_entry_safe(td_desc, _td_desc, &td_chan->queue,
571 desc_node)
572 list_move(&td_desc->desc_node, &td_chan->free_list);
573
574 /* now tear down the running */
575 __td_finish(td_chan);
576 spin_unlock_bh(&td_chan->lock);
577
578 return 0;
579}
580
581static void td_tasklet(unsigned long data)
582{
583 struct timb_dma *td = (struct timb_dma *)data;
584 u32 isr;
585 u32 ipr;
586 u32 ier;
587 int i;
588
589 isr = ioread32(td->membase + TIMBDMA_ISR);
590 ipr = isr & __td_ier_mask(td);
591
592 /* ack the interrupts */
593 iowrite32(ipr, td->membase + TIMBDMA_ISR);
594
595 for (i = 0; i < td->dma.chancnt; i++)
596 if (ipr & (1 << i)) {
597 struct timb_dma_chan *td_chan = td->channels + i;
598 spin_lock(&td_chan->lock);
599 __td_finish(td_chan);
600 if (!list_empty(&td_chan->queue))
601 __td_start_next(td_chan);
602 spin_unlock(&td_chan->lock);
603 }
604
605 ier = __td_ier_mask(td);
606 iowrite32(ier, td->membase + TIMBDMA_IER);
607}
608
609
610static irqreturn_t td_irq(int irq, void *devid)
611{
612 struct timb_dma *td = devid;
613 u32 ipr = ioread32(td->membase + TIMBDMA_IPR);
614
615 if (ipr) {
616 /* disable interrupts, will be re-enabled in tasklet */
617 iowrite32(0, td->membase + TIMBDMA_IER);
618
619 tasklet_schedule(&td->tasklet);
620
621 return IRQ_HANDLED;
622 } else
623 return IRQ_NONE;
624}
625
626
627static int td_probe(struct platform_device *pdev)
628{
629 struct timb_dma_platform_data *pdata = dev_get_platdata(&pdev->dev);
630 struct timb_dma *td;
631 struct resource *iomem;
632 int irq;
633 int err;
634 int i;
635
636 if (!pdata) {
637 dev_err(&pdev->dev, "No platform data\n");
638 return -EINVAL;
639 }
640
641 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
642 if (!iomem)
643 return -EINVAL;
644
645 irq = platform_get_irq(pdev, 0);
646 if (irq < 0)
647 return irq;
648
649 if (!request_mem_region(iomem->start, resource_size(iomem),
650 DRIVER_NAME))
651 return -EBUSY;
652
653 td = kzalloc(sizeof(struct timb_dma) +
654 sizeof(struct timb_dma_chan) * pdata->nr_channels, GFP_KERNEL);
655 if (!td) {
656 err = -ENOMEM;
657 goto err_release_region;
658 }
659
660 dev_dbg(&pdev->dev, "Allocated TD: %p\n", td);
661
662 td->membase = ioremap(iomem->start, resource_size(iomem));
663 if (!td->membase) {
664 dev_err(&pdev->dev, "Failed to remap I/O memory\n");
665 err = -ENOMEM;
666 goto err_free_mem;
667 }
668
669 /* 32bit addressing */
670 iowrite32(TIMBDMA_32BIT_ADDR, td->membase + TIMBDMA_ACR);
671
672 /* disable and clear any interrupts */
673 iowrite32(0x0, td->membase + TIMBDMA_IER);
674 iowrite32(0xFFFFFFFF, td->membase + TIMBDMA_ISR);
675
676 tasklet_init(&td->tasklet, td_tasklet, (unsigned long)td);
677
678 err = request_irq(irq, td_irq, IRQF_SHARED, DRIVER_NAME, td);
679 if (err) {
680 dev_err(&pdev->dev, "Failed to request IRQ\n");
681 goto err_tasklet_kill;
682 }
683
684 td->dma.device_alloc_chan_resources = td_alloc_chan_resources;
685 td->dma.device_free_chan_resources = td_free_chan_resources;
686 td->dma.device_tx_status = td_tx_status;
687 td->dma.device_issue_pending = td_issue_pending;
688
689 dma_cap_set(DMA_SLAVE, td->dma.cap_mask);
690 dma_cap_set(DMA_PRIVATE, td->dma.cap_mask);
691 td->dma.device_prep_slave_sg = td_prep_slave_sg;
692 td->dma.device_terminate_all = td_terminate_all;
693
694 td->dma.dev = &pdev->dev;
695
696 INIT_LIST_HEAD(&td->dma.channels);
697
698 for (i = 0; i < pdata->nr_channels; i++) {
699 struct timb_dma_chan *td_chan = &td->channels[i];
700 struct timb_dma_platform_data_channel *pchan =
701 pdata->channels + i;
702
703 /* even channels are RX, odd are TX */
704 if ((i % 2) == pchan->rx) {
705 dev_err(&pdev->dev, "Wrong channel configuration\n");
706 err = -EINVAL;
707 goto err_free_irq;
708 }
709
710 td_chan->chan.device = &td->dma;
711 dma_cookie_init(&td_chan->chan);
712 spin_lock_init(&td_chan->lock);
713 INIT_LIST_HEAD(&td_chan->active_list);
714 INIT_LIST_HEAD(&td_chan->queue);
715 INIT_LIST_HEAD(&td_chan->free_list);
716
717 td_chan->descs = pchan->descriptors;
718 td_chan->desc_elems = pchan->descriptor_elements;
719 td_chan->bytes_per_line = pchan->bytes_per_line;
720 td_chan->direction = pchan->rx ? DMA_DEV_TO_MEM :
721 DMA_MEM_TO_DEV;
722
723 td_chan->membase = td->membase +
724 (i / 2) * TIMBDMA_INSTANCE_OFFSET +
725 (pchan->rx ? 0 : TIMBDMA_INSTANCE_TX_OFFSET);
726
727 dev_dbg(&pdev->dev, "Chan: %d, membase: %p\n",
728 i, td_chan->membase);
729
730 list_add_tail(&td_chan->chan.device_node, &td->dma.channels);
731 }
732
733 err = dma_async_device_register(&td->dma);
734 if (err) {
735 dev_err(&pdev->dev, "Failed to register async device\n");
736 goto err_free_irq;
737 }
738
739 platform_set_drvdata(pdev, td);
740
741 dev_dbg(&pdev->dev, "Probe result: %d\n", err);
742 return err;
743
744err_free_irq:
745 free_irq(irq, td);
746err_tasklet_kill:
747 tasklet_kill(&td->tasklet);
748 iounmap(td->membase);
749err_free_mem:
750 kfree(td);
751err_release_region:
752 release_mem_region(iomem->start, resource_size(iomem));
753
754 return err;
755
756}
757
758static int td_remove(struct platform_device *pdev)
759{
760 struct timb_dma *td = platform_get_drvdata(pdev);
761 struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
762 int irq = platform_get_irq(pdev, 0);
763
764 dma_async_device_unregister(&td->dma);
765 free_irq(irq, td);
766 tasklet_kill(&td->tasklet);
767 iounmap(td->membase);
768 kfree(td);
769 release_mem_region(iomem->start, resource_size(iomem));
770
771 dev_dbg(&pdev->dev, "Removed...\n");
772 return 0;
773}
774
775static struct platform_driver td_driver = {
776 .driver = {
777 .name = DRIVER_NAME,
778 },
779 .probe = td_probe,
780 .remove = td_remove,
781};
782
783module_platform_driver(td_driver);
784
785MODULE_LICENSE("GPL v2");
786MODULE_DESCRIPTION("Timberdale DMA controller driver");
787MODULE_AUTHOR("Pelagicore AB <info@pelagicore.com>");
788MODULE_ALIAS("platform:"DRIVER_NAME);