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