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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);
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 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19/* Supports:
20 * Timberdale FPGA DMA engine
21 */
22
23#include <linux/dmaengine.h>
24#include <linux/dma-mapping.h>
25#include <linux/init.h>
26#include <linux/interrupt.h>
27#include <linux/io.h>
28#include <linux/module.h>
29#include <linux/platform_device.h>
30#include <linux/slab.h>
31
32#include <linux/timb_dma.h>
33
34#define DRIVER_NAME "timb-dma"
35
36/* Global DMA registers */
37#define TIMBDMA_ACR 0x34
38#define TIMBDMA_32BIT_ADDR 0x01
39
40#define TIMBDMA_ISR 0x080000
41#define TIMBDMA_IPR 0x080004
42#define TIMBDMA_IER 0x080008
43
44/* Channel specific registers */
45/* RX instances base addresses are 0x00, 0x40, 0x80 ...
46 * TX instances base addresses are 0x18, 0x58, 0x98 ...
47 */
48#define TIMBDMA_INSTANCE_OFFSET 0x40
49#define TIMBDMA_INSTANCE_TX_OFFSET 0x18
50
51/* RX registers, relative the instance base */
52#define TIMBDMA_OFFS_RX_DHAR 0x00
53#define TIMBDMA_OFFS_RX_DLAR 0x04
54#define TIMBDMA_OFFS_RX_LR 0x0C
55#define TIMBDMA_OFFS_RX_BLR 0x10
56#define TIMBDMA_OFFS_RX_ER 0x14
57#define TIMBDMA_RX_EN 0x01
58/* bytes per Row, video specific register
59 * which is placed after the TX registers...
60 */
61#define TIMBDMA_OFFS_RX_BPRR 0x30
62
63/* TX registers, relative the instance base */
64#define TIMBDMA_OFFS_TX_DHAR 0x00
65#define TIMBDMA_OFFS_TX_DLAR 0x04
66#define TIMBDMA_OFFS_TX_BLR 0x0C
67#define TIMBDMA_OFFS_TX_LR 0x14
68
69
70#define TIMB_DMA_DESC_SIZE 8
71
72struct timb_dma_desc {
73 struct list_head desc_node;
74 struct dma_async_tx_descriptor txd;
75 u8 *desc_list;
76 unsigned int desc_list_len;
77 bool interrupt;
78};
79
80struct timb_dma_chan {
81 struct dma_chan chan;
82 void __iomem *membase;
83 spinlock_t lock; /* Used to protect data structures,
84 especially the lists and descriptors,
85 from races between the tasklet and calls
86 from above */
87 dma_cookie_t last_completed_cookie;
88 bool ongoing;
89 struct list_head active_list;
90 struct list_head queue;
91 struct list_head free_list;
92 unsigned int bytes_per_line;
93 enum dma_data_direction direction;
94 unsigned int descs; /* Descriptors to allocate */
95 unsigned int desc_elems; /* number of elems per descriptor */
96};
97
98struct timb_dma {
99 struct dma_device dma;
100 void __iomem *membase;
101 struct tasklet_struct tasklet;
102 struct timb_dma_chan channels[0];
103};
104
105static struct device *chan2dev(struct dma_chan *chan)
106{
107 return &chan->dev->device;
108}
109static struct device *chan2dmadev(struct dma_chan *chan)
110{
111 return chan2dev(chan)->parent->parent;
112}
113
114static struct timb_dma *tdchantotd(struct timb_dma_chan *td_chan)
115{
116 int id = td_chan->chan.chan_id;
117 return (struct timb_dma *)((u8 *)td_chan -
118 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
119}
120
121/* Must be called with the spinlock held */
122static void __td_enable_chan_irq(struct timb_dma_chan *td_chan)
123{
124 int id = td_chan->chan.chan_id;
125 struct timb_dma *td = tdchantotd(td_chan);
126 u32 ier;
127
128 /* enable interrupt for this channel */
129 ier = ioread32(td->membase + TIMBDMA_IER);
130 ier |= 1 << id;
131 dev_dbg(chan2dev(&td_chan->chan), "Enabling irq: %d, IER: 0x%x\n", id,
132 ier);
133 iowrite32(ier, td->membase + TIMBDMA_IER);
134}
135
136/* Should be called with the spinlock held */
137static bool __td_dma_done_ack(struct timb_dma_chan *td_chan)
138{
139 int id = td_chan->chan.chan_id;
140 struct timb_dma *td = (struct timb_dma *)((u8 *)td_chan -
141 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
142 u32 isr;
143 bool done = false;
144
145 dev_dbg(chan2dev(&td_chan->chan), "Checking irq: %d, td: %p\n", id, td);
146
147 isr = ioread32(td->membase + TIMBDMA_ISR) & (1 << id);
148 if (isr) {
149 iowrite32(isr, td->membase + TIMBDMA_ISR);
150 done = true;
151 }
152
153 return done;
154}
155
156static void __td_unmap_desc(struct timb_dma_chan *td_chan, const u8 *dma_desc,
157 bool single)
158{
159 dma_addr_t addr;
160 int len;
161
162 addr = (dma_desc[7] << 24) | (dma_desc[6] << 16) | (dma_desc[5] << 8) |
163 dma_desc[4];
164
165 len = (dma_desc[3] << 8) | dma_desc[2];
166
167 if (single)
168 dma_unmap_single(chan2dev(&td_chan->chan), addr, len,
169 td_chan->direction);
170 else
171 dma_unmap_page(chan2dev(&td_chan->chan), addr, len,
172 td_chan->direction);
173}
174
175static void __td_unmap_descs(struct timb_dma_desc *td_desc, bool single)
176{
177 struct timb_dma_chan *td_chan = container_of(td_desc->txd.chan,
178 struct timb_dma_chan, chan);
179 u8 *descs;
180
181 for (descs = td_desc->desc_list; ; descs += TIMB_DMA_DESC_SIZE) {
182 __td_unmap_desc(td_chan, descs, single);
183 if (descs[0] & 0x02)
184 break;
185 }
186}
187
188static int td_fill_desc(struct timb_dma_chan *td_chan, u8 *dma_desc,
189 struct scatterlist *sg, bool last)
190{
191 if (sg_dma_len(sg) > USHRT_MAX) {
192 dev_err(chan2dev(&td_chan->chan), "Too big sg element\n");
193 return -EINVAL;
194 }
195
196 /* length must be word aligned */
197 if (sg_dma_len(sg) % sizeof(u32)) {
198 dev_err(chan2dev(&td_chan->chan), "Incorrect length: %d\n",
199 sg_dma_len(sg));
200 return -EINVAL;
201 }
202
203 dev_dbg(chan2dev(&td_chan->chan), "desc: %p, addr: 0x%llx\n",
204 dma_desc, (unsigned long long)sg_dma_address(sg));
205
206 dma_desc[7] = (sg_dma_address(sg) >> 24) & 0xff;
207 dma_desc[6] = (sg_dma_address(sg) >> 16) & 0xff;
208 dma_desc[5] = (sg_dma_address(sg) >> 8) & 0xff;
209 dma_desc[4] = (sg_dma_address(sg) >> 0) & 0xff;
210
211 dma_desc[3] = (sg_dma_len(sg) >> 8) & 0xff;
212 dma_desc[2] = (sg_dma_len(sg) >> 0) & 0xff;
213
214 dma_desc[1] = 0x00;
215 dma_desc[0] = 0x21 | (last ? 0x02 : 0); /* tran, valid */
216
217 return 0;
218}
219
220/* Must be called with the spinlock held */
221static void __td_start_dma(struct timb_dma_chan *td_chan)
222{
223 struct timb_dma_desc *td_desc;
224
225 if (td_chan->ongoing) {
226 dev_err(chan2dev(&td_chan->chan),
227 "Transfer already ongoing\n");
228 return;
229 }
230
231 td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
232 desc_node);
233
234 dev_dbg(chan2dev(&td_chan->chan),
235 "td_chan: %p, chan: %d, membase: %p\n",
236 td_chan, td_chan->chan.chan_id, td_chan->membase);
237
238 if (td_chan->direction == DMA_FROM_DEVICE) {
239
240 /* descriptor address */
241 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_DHAR);
242 iowrite32(td_desc->txd.phys, td_chan->membase +
243 TIMBDMA_OFFS_RX_DLAR);
244 /* Bytes per line */
245 iowrite32(td_chan->bytes_per_line, td_chan->membase +
246 TIMBDMA_OFFS_RX_BPRR);
247 /* enable RX */
248 iowrite32(TIMBDMA_RX_EN, td_chan->membase + TIMBDMA_OFFS_RX_ER);
249 } else {
250 /* address high */
251 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DHAR);
252 iowrite32(td_desc->txd.phys, td_chan->membase +
253 TIMBDMA_OFFS_TX_DLAR);
254 }
255
256 td_chan->ongoing = true;
257
258 if (td_desc->interrupt)
259 __td_enable_chan_irq(td_chan);
260}
261
262static void __td_finish(struct timb_dma_chan *td_chan)
263{
264 dma_async_tx_callback callback;
265 void *param;
266 struct dma_async_tx_descriptor *txd;
267 struct timb_dma_desc *td_desc;
268
269 /* can happen if the descriptor is canceled */
270 if (list_empty(&td_chan->active_list))
271 return;
272
273 td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
274 desc_node);
275 txd = &td_desc->txd;
276
277 dev_dbg(chan2dev(&td_chan->chan), "descriptor %u complete\n",
278 txd->cookie);
279
280 /* make sure to stop the transfer */
281 if (td_chan->direction == DMA_FROM_DEVICE)
282 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_ER);
283/* Currently no support for stopping DMA transfers
284 else
285 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DLAR);
286*/
287 td_chan->last_completed_cookie = txd->cookie;
288 td_chan->ongoing = false;
289
290 callback = txd->callback;
291 param = txd->callback_param;
292
293 list_move(&td_desc->desc_node, &td_chan->free_list);
294
295 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP))
296 __td_unmap_descs(td_desc,
297 txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE);
298
299 /*
300 * The API requires that no submissions are done from a
301 * callback, so we don't need to drop the lock here
302 */
303 if (callback)
304 callback(param);
305}
306
307static u32 __td_ier_mask(struct timb_dma *td)
308{
309 int i;
310 u32 ret = 0;
311
312 for (i = 0; i < td->dma.chancnt; i++) {
313 struct timb_dma_chan *td_chan = td->channels + i;
314 if (td_chan->ongoing) {
315 struct timb_dma_desc *td_desc =
316 list_entry(td_chan->active_list.next,
317 struct timb_dma_desc, desc_node);
318 if (td_desc->interrupt)
319 ret |= 1 << i;
320 }
321 }
322
323 return ret;
324}
325
326static void __td_start_next(struct timb_dma_chan *td_chan)
327{
328 struct timb_dma_desc *td_desc;
329
330 BUG_ON(list_empty(&td_chan->queue));
331 BUG_ON(td_chan->ongoing);
332
333 td_desc = list_entry(td_chan->queue.next, struct timb_dma_desc,
334 desc_node);
335
336 dev_dbg(chan2dev(&td_chan->chan), "%s: started %u\n",
337 __func__, td_desc->txd.cookie);
338
339 list_move(&td_desc->desc_node, &td_chan->active_list);
340 __td_start_dma(td_chan);
341}
342
343static dma_cookie_t td_tx_submit(struct dma_async_tx_descriptor *txd)
344{
345 struct timb_dma_desc *td_desc = container_of(txd, struct timb_dma_desc,
346 txd);
347 struct timb_dma_chan *td_chan = container_of(txd->chan,
348 struct timb_dma_chan, chan);
349 dma_cookie_t cookie;
350
351 spin_lock_bh(&td_chan->lock);
352
353 cookie = txd->chan->cookie;
354 if (++cookie < 0)
355 cookie = 1;
356 txd->chan->cookie = cookie;
357 txd->cookie = cookie;
358
359 if (list_empty(&td_chan->active_list)) {
360 dev_dbg(chan2dev(txd->chan), "%s: started %u\n", __func__,
361 txd->cookie);
362 list_add_tail(&td_desc->desc_node, &td_chan->active_list);
363 __td_start_dma(td_chan);
364 } else {
365 dev_dbg(chan2dev(txd->chan), "tx_submit: queued %u\n",
366 txd->cookie);
367
368 list_add_tail(&td_desc->desc_node, &td_chan->queue);
369 }
370
371 spin_unlock_bh(&td_chan->lock);
372
373 return cookie;
374}
375
376static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
377{
378 struct dma_chan *chan = &td_chan->chan;
379 struct timb_dma_desc *td_desc;
380 int err;
381
382 td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
383 if (!td_desc) {
384 dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
385 goto out;
386 }
387
388 td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
389
390 td_desc->desc_list = kzalloc(td_desc->desc_list_len, GFP_KERNEL);
391 if (!td_desc->desc_list) {
392 dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
393 goto err;
394 }
395
396 dma_async_tx_descriptor_init(&td_desc->txd, chan);
397 td_desc->txd.tx_submit = td_tx_submit;
398 td_desc->txd.flags = DMA_CTRL_ACK;
399
400 td_desc->txd.phys = dma_map_single(chan2dmadev(chan),
401 td_desc->desc_list, td_desc->desc_list_len, DMA_TO_DEVICE);
402
403 err = dma_mapping_error(chan2dmadev(chan), td_desc->txd.phys);
404 if (err) {
405 dev_err(chan2dev(chan), "DMA mapping error: %d\n", err);
406 goto err;
407 }
408
409 return td_desc;
410err:
411 kfree(td_desc->desc_list);
412 kfree(td_desc);
413out:
414 return NULL;
415
416}
417
418static void td_free_desc(struct timb_dma_desc *td_desc)
419{
420 dev_dbg(chan2dev(td_desc->txd.chan), "Freeing desc: %p\n", td_desc);
421 dma_unmap_single(chan2dmadev(td_desc->txd.chan), td_desc->txd.phys,
422 td_desc->desc_list_len, DMA_TO_DEVICE);
423
424 kfree(td_desc->desc_list);
425 kfree(td_desc);
426}
427
428static void td_desc_put(struct timb_dma_chan *td_chan,
429 struct timb_dma_desc *td_desc)
430{
431 dev_dbg(chan2dev(&td_chan->chan), "Putting desc: %p\n", td_desc);
432
433 spin_lock_bh(&td_chan->lock);
434 list_add(&td_desc->desc_node, &td_chan->free_list);
435 spin_unlock_bh(&td_chan->lock);
436}
437
438static struct timb_dma_desc *td_desc_get(struct timb_dma_chan *td_chan)
439{
440 struct timb_dma_desc *td_desc, *_td_desc;
441 struct timb_dma_desc *ret = NULL;
442
443 spin_lock_bh(&td_chan->lock);
444 list_for_each_entry_safe(td_desc, _td_desc, &td_chan->free_list,
445 desc_node) {
446 if (async_tx_test_ack(&td_desc->txd)) {
447 list_del(&td_desc->desc_node);
448 ret = td_desc;
449 break;
450 }
451 dev_dbg(chan2dev(&td_chan->chan), "desc %p not ACKed\n",
452 td_desc);
453 }
454 spin_unlock_bh(&td_chan->lock);
455
456 return ret;
457}
458
459static int td_alloc_chan_resources(struct dma_chan *chan)
460{
461 struct timb_dma_chan *td_chan =
462 container_of(chan, struct timb_dma_chan, chan);
463 int i;
464
465 dev_dbg(chan2dev(chan), "%s: entry\n", __func__);
466
467 BUG_ON(!list_empty(&td_chan->free_list));
468 for (i = 0; i < td_chan->descs; i++) {
469 struct timb_dma_desc *td_desc = td_alloc_init_desc(td_chan);
470 if (!td_desc) {
471 if (i)
472 break;
473 else {
474 dev_err(chan2dev(chan),
475 "Couldnt allocate any descriptors\n");
476 return -ENOMEM;
477 }
478 }
479
480 td_desc_put(td_chan, td_desc);
481 }
482
483 spin_lock_bh(&td_chan->lock);
484 td_chan->last_completed_cookie = 1;
485 chan->cookie = 1;
486 spin_unlock_bh(&td_chan->lock);
487
488 return 0;
489}
490
491static void td_free_chan_resources(struct dma_chan *chan)
492{
493 struct timb_dma_chan *td_chan =
494 container_of(chan, struct timb_dma_chan, chan);
495 struct timb_dma_desc *td_desc, *_td_desc;
496 LIST_HEAD(list);
497
498 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
499
500 /* check that all descriptors are free */
501 BUG_ON(!list_empty(&td_chan->active_list));
502 BUG_ON(!list_empty(&td_chan->queue));
503
504 spin_lock_bh(&td_chan->lock);
505 list_splice_init(&td_chan->free_list, &list);
506 spin_unlock_bh(&td_chan->lock);
507
508 list_for_each_entry_safe(td_desc, _td_desc, &list, desc_node) {
509 dev_dbg(chan2dev(chan), "%s: Freeing desc: %p\n", __func__,
510 td_desc);
511 td_free_desc(td_desc);
512 }
513}
514
515static enum dma_status td_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
516 struct dma_tx_state *txstate)
517{
518 struct timb_dma_chan *td_chan =
519 container_of(chan, struct timb_dma_chan, chan);
520 dma_cookie_t last_used;
521 dma_cookie_t last_complete;
522 int ret;
523
524 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
525
526 last_complete = td_chan->last_completed_cookie;
527 last_used = chan->cookie;
528
529 ret = dma_async_is_complete(cookie, last_complete, last_used);
530
531 dma_set_tx_state(txstate, last_complete, last_used, 0);
532
533 dev_dbg(chan2dev(chan),
534 "%s: exit, ret: %d, last_complete: %d, last_used: %d\n",
535 __func__, ret, last_complete, last_used);
536
537 return ret;
538}
539
540static void td_issue_pending(struct dma_chan *chan)
541{
542 struct timb_dma_chan *td_chan =
543 container_of(chan, struct timb_dma_chan, chan);
544
545 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
546 spin_lock_bh(&td_chan->lock);
547
548 if (!list_empty(&td_chan->active_list))
549 /* transfer ongoing */
550 if (__td_dma_done_ack(td_chan))
551 __td_finish(td_chan);
552
553 if (list_empty(&td_chan->active_list) && !list_empty(&td_chan->queue))
554 __td_start_next(td_chan);
555
556 spin_unlock_bh(&td_chan->lock);
557}
558
559static struct dma_async_tx_descriptor *td_prep_slave_sg(struct dma_chan *chan,
560 struct scatterlist *sgl, unsigned int sg_len,
561 enum dma_data_direction direction, unsigned long flags)
562{
563 struct timb_dma_chan *td_chan =
564 container_of(chan, struct timb_dma_chan, chan);
565 struct timb_dma_desc *td_desc;
566 struct scatterlist *sg;
567 unsigned int i;
568 unsigned int desc_usage = 0;
569
570 if (!sgl || !sg_len) {
571 dev_err(chan2dev(chan), "%s: No SG list\n", __func__);
572 return NULL;
573 }
574
575 /* even channels are for RX, odd for TX */
576 if (td_chan->direction != direction) {
577 dev_err(chan2dev(chan),
578 "Requesting channel in wrong direction\n");
579 return NULL;
580 }
581
582 td_desc = td_desc_get(td_chan);
583 if (!td_desc) {
584 dev_err(chan2dev(chan), "Not enough descriptors available\n");
585 return NULL;
586 }
587
588 td_desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
589
590 for_each_sg(sgl, sg, sg_len, i) {
591 int err;
592 if (desc_usage > td_desc->desc_list_len) {
593 dev_err(chan2dev(chan), "No descriptor space\n");
594 return NULL;
595 }
596
597 err = td_fill_desc(td_chan, td_desc->desc_list + desc_usage, sg,
598 i == (sg_len - 1));
599 if (err) {
600 dev_err(chan2dev(chan), "Failed to update desc: %d\n",
601 err);
602 td_desc_put(td_chan, td_desc);
603 return NULL;
604 }
605 desc_usage += TIMB_DMA_DESC_SIZE;
606 }
607
608 dma_sync_single_for_device(chan2dmadev(chan), td_desc->txd.phys,
609 td_desc->desc_list_len, DMA_TO_DEVICE);
610
611 return &td_desc->txd;
612}
613
614static int td_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
615 unsigned long arg)
616{
617 struct timb_dma_chan *td_chan =
618 container_of(chan, struct timb_dma_chan, chan);
619 struct timb_dma_desc *td_desc, *_td_desc;
620
621 dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
622
623 if (cmd != DMA_TERMINATE_ALL)
624 return -ENXIO;
625
626 /* first the easy part, put the queue into the free list */
627 spin_lock_bh(&td_chan->lock);
628 list_for_each_entry_safe(td_desc, _td_desc, &td_chan->queue,
629 desc_node)
630 list_move(&td_desc->desc_node, &td_chan->free_list);
631
632 /* now tear down the running */
633 __td_finish(td_chan);
634 spin_unlock_bh(&td_chan->lock);
635
636 return 0;
637}
638
639static void td_tasklet(unsigned long data)
640{
641 struct timb_dma *td = (struct timb_dma *)data;
642 u32 isr;
643 u32 ipr;
644 u32 ier;
645 int i;
646
647 isr = ioread32(td->membase + TIMBDMA_ISR);
648 ipr = isr & __td_ier_mask(td);
649
650 /* ack the interrupts */
651 iowrite32(ipr, td->membase + TIMBDMA_ISR);
652
653 for (i = 0; i < td->dma.chancnt; i++)
654 if (ipr & (1 << i)) {
655 struct timb_dma_chan *td_chan = td->channels + i;
656 spin_lock(&td_chan->lock);
657 __td_finish(td_chan);
658 if (!list_empty(&td_chan->queue))
659 __td_start_next(td_chan);
660 spin_unlock(&td_chan->lock);
661 }
662
663 ier = __td_ier_mask(td);
664 iowrite32(ier, td->membase + TIMBDMA_IER);
665}
666
667
668static irqreturn_t td_irq(int irq, void *devid)
669{
670 struct timb_dma *td = devid;
671 u32 ipr = ioread32(td->membase + TIMBDMA_IPR);
672
673 if (ipr) {
674 /* disable interrupts, will be re-enabled in tasklet */
675 iowrite32(0, td->membase + TIMBDMA_IER);
676
677 tasklet_schedule(&td->tasklet);
678
679 return IRQ_HANDLED;
680 } else
681 return IRQ_NONE;
682}
683
684
685static int __devinit td_probe(struct platform_device *pdev)
686{
687 struct timb_dma_platform_data *pdata = pdev->dev.platform_data;
688 struct timb_dma *td;
689 struct resource *iomem;
690 int irq;
691 int err;
692 int i;
693
694 if (!pdata) {
695 dev_err(&pdev->dev, "No platform data\n");
696 return -EINVAL;
697 }
698
699 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
700 if (!iomem)
701 return -EINVAL;
702
703 irq = platform_get_irq(pdev, 0);
704 if (irq < 0)
705 return irq;
706
707 if (!request_mem_region(iomem->start, resource_size(iomem),
708 DRIVER_NAME))
709 return -EBUSY;
710
711 td = kzalloc(sizeof(struct timb_dma) +
712 sizeof(struct timb_dma_chan) * pdata->nr_channels, GFP_KERNEL);
713 if (!td) {
714 err = -ENOMEM;
715 goto err_release_region;
716 }
717
718 dev_dbg(&pdev->dev, "Allocated TD: %p\n", td);
719
720 td->membase = ioremap(iomem->start, resource_size(iomem));
721 if (!td->membase) {
722 dev_err(&pdev->dev, "Failed to remap I/O memory\n");
723 err = -ENOMEM;
724 goto err_free_mem;
725 }
726
727 /* 32bit addressing */
728 iowrite32(TIMBDMA_32BIT_ADDR, td->membase + TIMBDMA_ACR);
729
730 /* disable and clear any interrupts */
731 iowrite32(0x0, td->membase + TIMBDMA_IER);
732 iowrite32(0xFFFFFFFF, td->membase + TIMBDMA_ISR);
733
734 tasklet_init(&td->tasklet, td_tasklet, (unsigned long)td);
735
736 err = request_irq(irq, td_irq, IRQF_SHARED, DRIVER_NAME, td);
737 if (err) {
738 dev_err(&pdev->dev, "Failed to request IRQ\n");
739 goto err_tasklet_kill;
740 }
741
742 td->dma.device_alloc_chan_resources = td_alloc_chan_resources;
743 td->dma.device_free_chan_resources = td_free_chan_resources;
744 td->dma.device_tx_status = td_tx_status;
745 td->dma.device_issue_pending = td_issue_pending;
746
747 dma_cap_set(DMA_SLAVE, td->dma.cap_mask);
748 dma_cap_set(DMA_PRIVATE, td->dma.cap_mask);
749 td->dma.device_prep_slave_sg = td_prep_slave_sg;
750 td->dma.device_control = td_control;
751
752 td->dma.dev = &pdev->dev;
753
754 INIT_LIST_HEAD(&td->dma.channels);
755
756 for (i = 0; i < pdata->nr_channels; i++, td->dma.chancnt++) {
757 struct timb_dma_chan *td_chan = &td->channels[i];
758 struct timb_dma_platform_data_channel *pchan =
759 pdata->channels + i;
760
761 /* even channels are RX, odd are TX */
762 if ((i % 2) == pchan->rx) {
763 dev_err(&pdev->dev, "Wrong channel configuration\n");
764 err = -EINVAL;
765 goto err_tasklet_kill;
766 }
767
768 td_chan->chan.device = &td->dma;
769 td_chan->chan.cookie = 1;
770 td_chan->chan.chan_id = i;
771 spin_lock_init(&td_chan->lock);
772 INIT_LIST_HEAD(&td_chan->active_list);
773 INIT_LIST_HEAD(&td_chan->queue);
774 INIT_LIST_HEAD(&td_chan->free_list);
775
776 td_chan->descs = pchan->descriptors;
777 td_chan->desc_elems = pchan->descriptor_elements;
778 td_chan->bytes_per_line = pchan->bytes_per_line;
779 td_chan->direction = pchan->rx ? DMA_FROM_DEVICE :
780 DMA_TO_DEVICE;
781
782 td_chan->membase = td->membase +
783 (i / 2) * TIMBDMA_INSTANCE_OFFSET +
784 (pchan->rx ? 0 : TIMBDMA_INSTANCE_TX_OFFSET);
785
786 dev_dbg(&pdev->dev, "Chan: %d, membase: %p\n",
787 i, td_chan->membase);
788
789 list_add_tail(&td_chan->chan.device_node, &td->dma.channels);
790 }
791
792 err = dma_async_device_register(&td->dma);
793 if (err) {
794 dev_err(&pdev->dev, "Failed to register async device\n");
795 goto err_free_irq;
796 }
797
798 platform_set_drvdata(pdev, td);
799
800 dev_dbg(&pdev->dev, "Probe result: %d\n", err);
801 return err;
802
803err_free_irq:
804 free_irq(irq, td);
805err_tasklet_kill:
806 tasklet_kill(&td->tasklet);
807 iounmap(td->membase);
808err_free_mem:
809 kfree(td);
810err_release_region:
811 release_mem_region(iomem->start, resource_size(iomem));
812
813 return err;
814
815}
816
817static int __devexit td_remove(struct platform_device *pdev)
818{
819 struct timb_dma *td = platform_get_drvdata(pdev);
820 struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
821 int irq = platform_get_irq(pdev, 0);
822
823 dma_async_device_unregister(&td->dma);
824 free_irq(irq, td);
825 tasklet_kill(&td->tasklet);
826 iounmap(td->membase);
827 kfree(td);
828 release_mem_region(iomem->start, resource_size(iomem));
829
830 platform_set_drvdata(pdev, NULL);
831
832 dev_dbg(&pdev->dev, "Removed...\n");
833 return 0;
834}
835
836static struct platform_driver td_driver = {
837 .driver = {
838 .name = DRIVER_NAME,
839 .owner = THIS_MODULE,
840 },
841 .probe = td_probe,
842 .remove = __exit_p(td_remove),
843};
844
845static int __init td_init(void)
846{
847 return platform_driver_register(&td_driver);
848}
849module_init(td_init);
850
851static void __exit td_exit(void)
852{
853 platform_driver_unregister(&td_driver);
854}
855module_exit(td_exit);
856
857MODULE_LICENSE("GPL v2");
858MODULE_DESCRIPTION("Timberdale DMA controller driver");
859MODULE_AUTHOR("Pelagicore AB <info@pelagicore.com>");
860MODULE_ALIAS("platform:"DRIVER_NAME);