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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Freescale MPC85xx, MPC83xx DMA Engine support
4 *
5 * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
6 *
7 * Author:
8 * Zhang Wei <wei.zhang@freescale.com>, Jul 2007
9 * Ebony Zhu <ebony.zhu@freescale.com>, May 2007
10 *
11 * Description:
12 * DMA engine driver for Freescale MPC8540 DMA controller, which is
13 * also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
14 * The support for MPC8349 DMA controller is also added.
15 *
16 * This driver instructs the DMA controller to issue the PCI Read Multiple
17 * command for PCI read operations, instead of using the default PCI Read Line
18 * command. Please be aware that this setting may result in read pre-fetching
19 * on some platforms.
20 */
21
22#include <linux/init.h>
23#include <linux/module.h>
24#include <linux/pci.h>
25#include <linux/slab.h>
26#include <linux/interrupt.h>
27#include <linux/dmaengine.h>
28#include <linux/delay.h>
29#include <linux/dma-mapping.h>
30#include <linux/dmapool.h>
31#include <linux/of.h>
32#include <linux/of_address.h>
33#include <linux/of_irq.h>
34#include <linux/platform_device.h>
35#include <linux/fsldma.h>
36#include "dmaengine.h"
37#include "fsldma.h"
38
39#define chan_dbg(chan, fmt, arg...) \
40 dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
41#define chan_err(chan, fmt, arg...) \
42 dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
43
44static const char msg_ld_oom[] = "No free memory for link descriptor";
45
46/*
47 * Register Helpers
48 */
49
50static void set_sr(struct fsldma_chan *chan, u32 val)
51{
52 FSL_DMA_OUT(chan, &chan->regs->sr, val, 32);
53}
54
55static u32 get_sr(struct fsldma_chan *chan)
56{
57 return FSL_DMA_IN(chan, &chan->regs->sr, 32);
58}
59
60static void set_mr(struct fsldma_chan *chan, u32 val)
61{
62 FSL_DMA_OUT(chan, &chan->regs->mr, val, 32);
63}
64
65static u32 get_mr(struct fsldma_chan *chan)
66{
67 return FSL_DMA_IN(chan, &chan->regs->mr, 32);
68}
69
70static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
71{
72 FSL_DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
73}
74
75static dma_addr_t get_cdar(struct fsldma_chan *chan)
76{
77 return FSL_DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
78}
79
80static void set_bcr(struct fsldma_chan *chan, u32 val)
81{
82 FSL_DMA_OUT(chan, &chan->regs->bcr, val, 32);
83}
84
85static u32 get_bcr(struct fsldma_chan *chan)
86{
87 return FSL_DMA_IN(chan, &chan->regs->bcr, 32);
88}
89
90/*
91 * Descriptor Helpers
92 */
93
94static void set_desc_cnt(struct fsldma_chan *chan,
95 struct fsl_dma_ld_hw *hw, u32 count)
96{
97 hw->count = CPU_TO_DMA(chan, count, 32);
98}
99
100static void set_desc_src(struct fsldma_chan *chan,
101 struct fsl_dma_ld_hw *hw, dma_addr_t src)
102{
103 u64 snoop_bits;
104
105 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
106 ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
107 hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
108}
109
110static void set_desc_dst(struct fsldma_chan *chan,
111 struct fsl_dma_ld_hw *hw, dma_addr_t dst)
112{
113 u64 snoop_bits;
114
115 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
116 ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
117 hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
118}
119
120static void set_desc_next(struct fsldma_chan *chan,
121 struct fsl_dma_ld_hw *hw, dma_addr_t next)
122{
123 u64 snoop_bits;
124
125 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
126 ? FSL_DMA_SNEN : 0;
127 hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
128}
129
130static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
131{
132 u64 snoop_bits;
133
134 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
135 ? FSL_DMA_SNEN : 0;
136
137 desc->hw.next_ln_addr = CPU_TO_DMA(chan,
138 DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
139 | snoop_bits, 64);
140}
141
142/*
143 * DMA Engine Hardware Control Helpers
144 */
145
146static void dma_init(struct fsldma_chan *chan)
147{
148 /* Reset the channel */
149 set_mr(chan, val: 0);
150
151 switch (chan->feature & FSL_DMA_IP_MASK) {
152 case FSL_DMA_IP_85XX:
153 /* Set the channel to below modes:
154 * EIE - Error interrupt enable
155 * EOLNIE - End of links interrupt enable
156 * BWC - Bandwidth sharing among channels
157 */
158 set_mr(chan, FSL_DMA_MR_BWC | FSL_DMA_MR_EIE
159 | FSL_DMA_MR_EOLNIE);
160 break;
161 case FSL_DMA_IP_83XX:
162 /* Set the channel to below modes:
163 * EOTIE - End-of-transfer interrupt enable
164 * PRC_RM - PCI read multiple
165 */
166 set_mr(chan, FSL_DMA_MR_EOTIE | FSL_DMA_MR_PRC_RM);
167 break;
168 }
169}
170
171static int dma_is_idle(struct fsldma_chan *chan)
172{
173 u32 sr = get_sr(chan);
174 return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
175}
176
177/*
178 * Start the DMA controller
179 *
180 * Preconditions:
181 * - the CDAR register must point to the start descriptor
182 * - the MRn[CS] bit must be cleared
183 */
184static void dma_start(struct fsldma_chan *chan)
185{
186 u32 mode;
187
188 mode = get_mr(chan);
189
190 if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
191 set_bcr(chan, val: 0);
192 mode |= FSL_DMA_MR_EMP_EN;
193 } else {
194 mode &= ~FSL_DMA_MR_EMP_EN;
195 }
196
197 if (chan->feature & FSL_DMA_CHAN_START_EXT) {
198 mode |= FSL_DMA_MR_EMS_EN;
199 } else {
200 mode &= ~FSL_DMA_MR_EMS_EN;
201 mode |= FSL_DMA_MR_CS;
202 }
203
204 set_mr(chan, val: mode);
205}
206
207static void dma_halt(struct fsldma_chan *chan)
208{
209 u32 mode;
210 int i;
211
212 /* read the mode register */
213 mode = get_mr(chan);
214
215 /*
216 * The 85xx controller supports channel abort, which will stop
217 * the current transfer. On 83xx, this bit is the transfer error
218 * mask bit, which should not be changed.
219 */
220 if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
221 mode |= FSL_DMA_MR_CA;
222 set_mr(chan, val: mode);
223
224 mode &= ~FSL_DMA_MR_CA;
225 }
226
227 /* stop the DMA controller */
228 mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
229 set_mr(chan, val: mode);
230
231 /* wait for the DMA controller to become idle */
232 for (i = 0; i < 100; i++) {
233 if (dma_is_idle(chan))
234 return;
235
236 udelay(usec: 10);
237 }
238
239 if (!dma_is_idle(chan))
240 chan_err(chan, "DMA halt timeout!\n");
241}
242
243/**
244 * fsl_chan_set_src_loop_size - Set source address hold transfer size
245 * @chan : Freescale DMA channel
246 * @size : Address loop size, 0 for disable loop
247 *
248 * The set source address hold transfer size. The source
249 * address hold or loop transfer size is when the DMA transfer
250 * data from source address (SA), if the loop size is 4, the DMA will
251 * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
252 * SA + 1 ... and so on.
253 */
254static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
255{
256 u32 mode;
257
258 mode = get_mr(chan);
259
260 switch (size) {
261 case 0:
262 mode &= ~FSL_DMA_MR_SAHE;
263 break;
264 case 1:
265 case 2:
266 case 4:
267 case 8:
268 mode &= ~FSL_DMA_MR_SAHTS_MASK;
269 mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
270 break;
271 }
272
273 set_mr(chan, val: mode);
274}
275
276/**
277 * fsl_chan_set_dst_loop_size - Set destination address hold transfer size
278 * @chan : Freescale DMA channel
279 * @size : Address loop size, 0 for disable loop
280 *
281 * The set destination address hold transfer size. The destination
282 * address hold or loop transfer size is when the DMA transfer
283 * data to destination address (TA), if the loop size is 4, the DMA will
284 * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
285 * TA + 1 ... and so on.
286 */
287static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
288{
289 u32 mode;
290
291 mode = get_mr(chan);
292
293 switch (size) {
294 case 0:
295 mode &= ~FSL_DMA_MR_DAHE;
296 break;
297 case 1:
298 case 2:
299 case 4:
300 case 8:
301 mode &= ~FSL_DMA_MR_DAHTS_MASK;
302 mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
303 break;
304 }
305
306 set_mr(chan, val: mode);
307}
308
309/**
310 * fsl_chan_set_request_count - Set DMA Request Count for external control
311 * @chan : Freescale DMA channel
312 * @size : Number of bytes to transfer in a single request
313 *
314 * The Freescale DMA channel can be controlled by the external signal DREQ#.
315 * The DMA request count is how many bytes are allowed to transfer before
316 * pausing the channel, after which a new assertion of DREQ# resumes channel
317 * operation.
318 *
319 * A size of 0 disables external pause control. The maximum size is 1024.
320 */
321static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
322{
323 u32 mode;
324
325 BUG_ON(size > 1024);
326
327 mode = get_mr(chan);
328 mode &= ~FSL_DMA_MR_BWC_MASK;
329 mode |= (__ilog2(size) << 24) & FSL_DMA_MR_BWC_MASK;
330
331 set_mr(chan, val: mode);
332}
333
334/**
335 * fsl_chan_toggle_ext_pause - Toggle channel external pause status
336 * @chan : Freescale DMA channel
337 * @enable : 0 is disabled, 1 is enabled.
338 *
339 * The Freescale DMA channel can be controlled by the external signal DREQ#.
340 * The DMA Request Count feature should be used in addition to this feature
341 * to set the number of bytes to transfer before pausing the channel.
342 */
343static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
344{
345 if (enable)
346 chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
347 else
348 chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
349}
350
351/**
352 * fsl_chan_toggle_ext_start - Toggle channel external start status
353 * @chan : Freescale DMA channel
354 * @enable : 0 is disabled, 1 is enabled.
355 *
356 * If enable the external start, the channel can be started by an
357 * external DMA start pin. So the dma_start() does not start the
358 * transfer immediately. The DMA channel will wait for the
359 * control pin asserted.
360 */
361static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
362{
363 if (enable)
364 chan->feature |= FSL_DMA_CHAN_START_EXT;
365 else
366 chan->feature &= ~FSL_DMA_CHAN_START_EXT;
367}
368
369int fsl_dma_external_start(struct dma_chan *dchan, int enable)
370{
371 struct fsldma_chan *chan;
372
373 if (!dchan)
374 return -EINVAL;
375
376 chan = to_fsl_chan(dchan);
377
378 fsl_chan_toggle_ext_start(chan, enable);
379 return 0;
380}
381EXPORT_SYMBOL_GPL(fsl_dma_external_start);
382
383static void append_ld_queue(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
384{
385 struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
386
387 if (list_empty(head: &chan->ld_pending))
388 goto out_splice;
389
390 /*
391 * Add the hardware descriptor to the chain of hardware descriptors
392 * that already exists in memory.
393 *
394 * This will un-set the EOL bit of the existing transaction, and the
395 * last link in this transaction will become the EOL descriptor.
396 */
397 set_desc_next(chan, hw: &tail->hw, next: desc->async_tx.phys);
398
399 /*
400 * Add the software descriptor and all children to the list
401 * of pending transactions
402 */
403out_splice:
404 list_splice_tail_init(list: &desc->tx_list, head: &chan->ld_pending);
405}
406
407static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
408{
409 struct fsldma_chan *chan = to_fsl_chan(tx->chan);
410 struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
411 struct fsl_desc_sw *child;
412 dma_cookie_t cookie = -EINVAL;
413
414 spin_lock_bh(lock: &chan->desc_lock);
415
416#ifdef CONFIG_PM
417 if (unlikely(chan->pm_state != RUNNING)) {
418 chan_dbg(chan, "cannot submit due to suspend\n");
419 spin_unlock_bh(lock: &chan->desc_lock);
420 return -1;
421 }
422#endif
423
424 /*
425 * assign cookies to all of the software descriptors
426 * that make up this transaction
427 */
428 list_for_each_entry(child, &desc->tx_list, node) {
429 cookie = dma_cookie_assign(tx: &child->async_tx);
430 }
431
432 /* put this transaction onto the tail of the pending queue */
433 append_ld_queue(chan, desc);
434
435 spin_unlock_bh(lock: &chan->desc_lock);
436
437 return cookie;
438}
439
440/**
441 * fsl_dma_free_descriptor - Free descriptor from channel's DMA pool.
442 * @chan : Freescale DMA channel
443 * @desc: descriptor to be freed
444 */
445static void fsl_dma_free_descriptor(struct fsldma_chan *chan,
446 struct fsl_desc_sw *desc)
447{
448 list_del(entry: &desc->node);
449 chan_dbg(chan, "LD %p free\n", desc);
450 dma_pool_free(pool: chan->desc_pool, vaddr: desc, addr: desc->async_tx.phys);
451}
452
453/**
454 * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
455 * @chan : Freescale DMA channel
456 *
457 * Return - The descriptor allocated. NULL for failed.
458 */
459static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
460{
461 struct fsl_desc_sw *desc;
462 dma_addr_t pdesc;
463
464 desc = dma_pool_zalloc(pool: chan->desc_pool, GFP_ATOMIC, handle: &pdesc);
465 if (!desc) {
466 chan_dbg(chan, "out of memory for link descriptor\n");
467 return NULL;
468 }
469
470 INIT_LIST_HEAD(list: &desc->tx_list);
471 dma_async_tx_descriptor_init(tx: &desc->async_tx, chan: &chan->common);
472 desc->async_tx.tx_submit = fsl_dma_tx_submit;
473 desc->async_tx.phys = pdesc;
474
475 chan_dbg(chan, "LD %p allocated\n", desc);
476
477 return desc;
478}
479
480/**
481 * fsldma_clean_completed_descriptor - free all descriptors which
482 * has been completed and acked
483 * @chan: Freescale DMA channel
484 *
485 * This function is used on all completed and acked descriptors.
486 * All descriptors should only be freed in this function.
487 */
488static void fsldma_clean_completed_descriptor(struct fsldma_chan *chan)
489{
490 struct fsl_desc_sw *desc, *_desc;
491
492 /* Run the callback for each descriptor, in order */
493 list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node)
494 if (async_tx_test_ack(tx: &desc->async_tx))
495 fsl_dma_free_descriptor(chan, desc);
496}
497
498/**
499 * fsldma_run_tx_complete_actions - cleanup a single link descriptor
500 * @chan: Freescale DMA channel
501 * @desc: descriptor to cleanup and free
502 * @cookie: Freescale DMA transaction identifier
503 *
504 * This function is used on a descriptor which has been executed by the DMA
505 * controller. It will run any callbacks, submit any dependencies.
506 */
507static dma_cookie_t fsldma_run_tx_complete_actions(struct fsldma_chan *chan,
508 struct fsl_desc_sw *desc, dma_cookie_t cookie)
509{
510 struct dma_async_tx_descriptor *txd = &desc->async_tx;
511 dma_cookie_t ret = cookie;
512
513 BUG_ON(txd->cookie < 0);
514
515 if (txd->cookie > 0) {
516 ret = txd->cookie;
517
518 dma_descriptor_unmap(tx: txd);
519 /* Run the link descriptor callback function */
520 dmaengine_desc_get_callback_invoke(tx: txd, NULL);
521 }
522
523 /* Run any dependencies */
524 dma_run_dependencies(tx: txd);
525
526 return ret;
527}
528
529/**
530 * fsldma_clean_running_descriptor - move the completed descriptor from
531 * ld_running to ld_completed
532 * @chan: Freescale DMA channel
533 * @desc: the descriptor which is completed
534 *
535 * Free the descriptor directly if acked by async_tx api, or move it to
536 * queue ld_completed.
537 */
538static void fsldma_clean_running_descriptor(struct fsldma_chan *chan,
539 struct fsl_desc_sw *desc)
540{
541 /* Remove from the list of transactions */
542 list_del(entry: &desc->node);
543
544 /*
545 * the client is allowed to attach dependent operations
546 * until 'ack' is set
547 */
548 if (!async_tx_test_ack(tx: &desc->async_tx)) {
549 /*
550 * Move this descriptor to the list of descriptors which is
551 * completed, but still awaiting the 'ack' bit to be set.
552 */
553 list_add_tail(new: &desc->node, head: &chan->ld_completed);
554 return;
555 }
556
557 dma_pool_free(pool: chan->desc_pool, vaddr: desc, addr: desc->async_tx.phys);
558}
559
560/**
561 * fsl_chan_xfer_ld_queue - transfer any pending transactions
562 * @chan : Freescale DMA channel
563 *
564 * HARDWARE STATE: idle
565 * LOCKING: must hold chan->desc_lock
566 */
567static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
568{
569 struct fsl_desc_sw *desc;
570
571 /*
572 * If the list of pending descriptors is empty, then we
573 * don't need to do any work at all
574 */
575 if (list_empty(head: &chan->ld_pending)) {
576 chan_dbg(chan, "no pending LDs\n");
577 return;
578 }
579
580 /*
581 * The DMA controller is not idle, which means that the interrupt
582 * handler will start any queued transactions when it runs after
583 * this transaction finishes
584 */
585 if (!chan->idle) {
586 chan_dbg(chan, "DMA controller still busy\n");
587 return;
588 }
589
590 /*
591 * If there are some link descriptors which have not been
592 * transferred, we need to start the controller
593 */
594
595 /*
596 * Move all elements from the queue of pending transactions
597 * onto the list of running transactions
598 */
599 chan_dbg(chan, "idle, starting controller\n");
600 desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
601 list_splice_tail_init(list: &chan->ld_pending, head: &chan->ld_running);
602
603 /*
604 * The 85xx DMA controller doesn't clear the channel start bit
605 * automatically at the end of a transfer. Therefore we must clear
606 * it in software before starting the transfer.
607 */
608 if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
609 u32 mode;
610
611 mode = get_mr(chan);
612 mode &= ~FSL_DMA_MR_CS;
613 set_mr(chan, val: mode);
614 }
615
616 /*
617 * Program the descriptor's address into the DMA controller,
618 * then start the DMA transaction
619 */
620 set_cdar(chan, addr: desc->async_tx.phys);
621 get_cdar(chan);
622
623 dma_start(chan);
624 chan->idle = false;
625}
626
627/**
628 * fsldma_cleanup_descriptors - cleanup link descriptors which are completed
629 * and move them to ld_completed to free until flag 'ack' is set
630 * @chan: Freescale DMA channel
631 *
632 * This function is used on descriptors which have been executed by the DMA
633 * controller. It will run any callbacks, submit any dependencies, then
634 * free these descriptors if flag 'ack' is set.
635 */
636static void fsldma_cleanup_descriptors(struct fsldma_chan *chan)
637{
638 struct fsl_desc_sw *desc, *_desc;
639 dma_cookie_t cookie = 0;
640 dma_addr_t curr_phys = get_cdar(chan);
641 int seen_current = 0;
642
643 fsldma_clean_completed_descriptor(chan);
644
645 /* Run the callback for each descriptor, in order */
646 list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
647 /*
648 * do not advance past the current descriptor loaded into the
649 * hardware channel, subsequent descriptors are either in
650 * process or have not been submitted
651 */
652 if (seen_current)
653 break;
654
655 /*
656 * stop the search if we reach the current descriptor and the
657 * channel is busy
658 */
659 if (desc->async_tx.phys == curr_phys) {
660 seen_current = 1;
661 if (!dma_is_idle(chan))
662 break;
663 }
664
665 cookie = fsldma_run_tx_complete_actions(chan, desc, cookie);
666
667 fsldma_clean_running_descriptor(chan, desc);
668 }
669
670 /*
671 * Start any pending transactions automatically
672 *
673 * In the ideal case, we keep the DMA controller busy while we go
674 * ahead and free the descriptors below.
675 */
676 fsl_chan_xfer_ld_queue(chan);
677
678 if (cookie > 0)
679 chan->common.completed_cookie = cookie;
680}
681
682/**
683 * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
684 * @chan : Freescale DMA channel
685 *
686 * This function will create a dma pool for descriptor allocation.
687 *
688 * Return - The number of descriptors allocated.
689 */
690static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
691{
692 struct fsldma_chan *chan = to_fsl_chan(dchan);
693
694 /* Has this channel already been allocated? */
695 if (chan->desc_pool)
696 return 1;
697
698 /*
699 * We need the descriptor to be aligned to 32bytes
700 * for meeting FSL DMA specification requirement.
701 */
702 chan->desc_pool = dma_pool_create(name: chan->name, dev: chan->dev,
703 size: sizeof(struct fsl_desc_sw),
704 align: __alignof__(struct fsl_desc_sw), boundary: 0);
705 if (!chan->desc_pool) {
706 chan_err(chan, "unable to allocate descriptor pool\n");
707 return -ENOMEM;
708 }
709
710 /* there is at least one descriptor free to be allocated */
711 return 1;
712}
713
714/**
715 * fsldma_free_desc_list - Free all descriptors in a queue
716 * @chan: Freescae DMA channel
717 * @list: the list to free
718 *
719 * LOCKING: must hold chan->desc_lock
720 */
721static void fsldma_free_desc_list(struct fsldma_chan *chan,
722 struct list_head *list)
723{
724 struct fsl_desc_sw *desc, *_desc;
725
726 list_for_each_entry_safe(desc, _desc, list, node)
727 fsl_dma_free_descriptor(chan, desc);
728}
729
730static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
731 struct list_head *list)
732{
733 struct fsl_desc_sw *desc, *_desc;
734
735 list_for_each_entry_safe_reverse(desc, _desc, list, node)
736 fsl_dma_free_descriptor(chan, desc);
737}
738
739/**
740 * fsl_dma_free_chan_resources - Free all resources of the channel.
741 * @chan : Freescale DMA channel
742 */
743static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
744{
745 struct fsldma_chan *chan = to_fsl_chan(dchan);
746
747 chan_dbg(chan, "free all channel resources\n");
748 spin_lock_bh(lock: &chan->desc_lock);
749 fsldma_cleanup_descriptors(chan);
750 fsldma_free_desc_list(chan, list: &chan->ld_pending);
751 fsldma_free_desc_list(chan, list: &chan->ld_running);
752 fsldma_free_desc_list(chan, list: &chan->ld_completed);
753 spin_unlock_bh(lock: &chan->desc_lock);
754
755 dma_pool_destroy(pool: chan->desc_pool);
756 chan->desc_pool = NULL;
757}
758
759static struct dma_async_tx_descriptor *
760fsl_dma_prep_memcpy(struct dma_chan *dchan,
761 dma_addr_t dma_dst, dma_addr_t dma_src,
762 size_t len, unsigned long flags)
763{
764 struct fsldma_chan *chan;
765 struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
766 size_t copy;
767
768 if (!dchan)
769 return NULL;
770
771 if (!len)
772 return NULL;
773
774 chan = to_fsl_chan(dchan);
775
776 do {
777
778 /* Allocate the link descriptor from DMA pool */
779 new = fsl_dma_alloc_descriptor(chan);
780 if (!new) {
781 chan_err(chan, "%s\n", msg_ld_oom);
782 goto fail;
783 }
784
785 copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
786
787 set_desc_cnt(chan, hw: &new->hw, count: copy);
788 set_desc_src(chan, hw: &new->hw, src: dma_src);
789 set_desc_dst(chan, hw: &new->hw, dst: dma_dst);
790
791 if (!first)
792 first = new;
793 else
794 set_desc_next(chan, hw: &prev->hw, next: new->async_tx.phys);
795
796 new->async_tx.cookie = 0;
797 async_tx_ack(tx: &new->async_tx);
798
799 prev = new;
800 len -= copy;
801 dma_src += copy;
802 dma_dst += copy;
803
804 /* Insert the link descriptor to the LD ring */
805 list_add_tail(new: &new->node, head: &first->tx_list);
806 } while (len);
807
808 new->async_tx.flags = flags; /* client is in control of this ack */
809 new->async_tx.cookie = -EBUSY;
810
811 /* Set End-of-link to the last link descriptor of new list */
812 set_ld_eol(chan, desc: new);
813
814 return &first->async_tx;
815
816fail:
817 if (!first)
818 return NULL;
819
820 fsldma_free_desc_list_reverse(chan, list: &first->tx_list);
821 return NULL;
822}
823
824static int fsl_dma_device_terminate_all(struct dma_chan *dchan)
825{
826 struct fsldma_chan *chan;
827
828 if (!dchan)
829 return -EINVAL;
830
831 chan = to_fsl_chan(dchan);
832
833 spin_lock_bh(lock: &chan->desc_lock);
834
835 /* Halt the DMA engine */
836 dma_halt(chan);
837
838 /* Remove and free all of the descriptors in the LD queue */
839 fsldma_free_desc_list(chan, list: &chan->ld_pending);
840 fsldma_free_desc_list(chan, list: &chan->ld_running);
841 fsldma_free_desc_list(chan, list: &chan->ld_completed);
842 chan->idle = true;
843
844 spin_unlock_bh(lock: &chan->desc_lock);
845 return 0;
846}
847
848static int fsl_dma_device_config(struct dma_chan *dchan,
849 struct dma_slave_config *config)
850{
851 struct fsldma_chan *chan;
852 int size;
853
854 if (!dchan)
855 return -EINVAL;
856
857 chan = to_fsl_chan(dchan);
858
859 /* make sure the channel supports setting burst size */
860 if (!chan->set_request_count)
861 return -ENXIO;
862
863 /* we set the controller burst size depending on direction */
864 if (config->direction == DMA_MEM_TO_DEV)
865 size = config->dst_addr_width * config->dst_maxburst;
866 else
867 size = config->src_addr_width * config->src_maxburst;
868
869 chan->set_request_count(chan, size);
870 return 0;
871}
872
873
874/**
875 * fsl_dma_memcpy_issue_pending - Issue the DMA start command
876 * @chan : Freescale DMA channel
877 */
878static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
879{
880 struct fsldma_chan *chan = to_fsl_chan(dchan);
881
882 spin_lock_bh(lock: &chan->desc_lock);
883 fsl_chan_xfer_ld_queue(chan);
884 spin_unlock_bh(lock: &chan->desc_lock);
885}
886
887/**
888 * fsl_tx_status - Determine the DMA status
889 * @chan : Freescale DMA channel
890 */
891static enum dma_status fsl_tx_status(struct dma_chan *dchan,
892 dma_cookie_t cookie,
893 struct dma_tx_state *txstate)
894{
895 struct fsldma_chan *chan = to_fsl_chan(dchan);
896 enum dma_status ret;
897
898 ret = dma_cookie_status(chan: dchan, cookie, state: txstate);
899 if (ret == DMA_COMPLETE)
900 return ret;
901
902 spin_lock_bh(lock: &chan->desc_lock);
903 fsldma_cleanup_descriptors(chan);
904 spin_unlock_bh(lock: &chan->desc_lock);
905
906 return dma_cookie_status(chan: dchan, cookie, state: txstate);
907}
908
909/*----------------------------------------------------------------------------*/
910/* Interrupt Handling */
911/*----------------------------------------------------------------------------*/
912
913static irqreturn_t fsldma_chan_irq(int irq, void *data)
914{
915 struct fsldma_chan *chan = data;
916 u32 stat;
917
918 /* save and clear the status register */
919 stat = get_sr(chan);
920 set_sr(chan, val: stat);
921 chan_dbg(chan, "irq: stat = 0x%x\n", stat);
922
923 /* check that this was really our device */
924 stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
925 if (!stat)
926 return IRQ_NONE;
927
928 if (stat & FSL_DMA_SR_TE)
929 chan_err(chan, "Transfer Error!\n");
930
931 /*
932 * Programming Error
933 * The DMA_INTERRUPT async_tx is a NULL transfer, which will
934 * trigger a PE interrupt.
935 */
936 if (stat & FSL_DMA_SR_PE) {
937 chan_dbg(chan, "irq: Programming Error INT\n");
938 stat &= ~FSL_DMA_SR_PE;
939 if (get_bcr(chan) != 0)
940 chan_err(chan, "Programming Error!\n");
941 }
942
943 /*
944 * For MPC8349, EOCDI event need to update cookie
945 * and start the next transfer if it exist.
946 */
947 if (stat & FSL_DMA_SR_EOCDI) {
948 chan_dbg(chan, "irq: End-of-Chain link INT\n");
949 stat &= ~FSL_DMA_SR_EOCDI;
950 }
951
952 /*
953 * If it current transfer is the end-of-transfer,
954 * we should clear the Channel Start bit for
955 * prepare next transfer.
956 */
957 if (stat & FSL_DMA_SR_EOLNI) {
958 chan_dbg(chan, "irq: End-of-link INT\n");
959 stat &= ~FSL_DMA_SR_EOLNI;
960 }
961
962 /* check that the DMA controller is really idle */
963 if (!dma_is_idle(chan))
964 chan_err(chan, "irq: controller not idle!\n");
965
966 /* check that we handled all of the bits */
967 if (stat)
968 chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
969
970 /*
971 * Schedule the tasklet to handle all cleanup of the current
972 * transaction. It will start a new transaction if there is
973 * one pending.
974 */
975 tasklet_schedule(t: &chan->tasklet);
976 chan_dbg(chan, "irq: Exit\n");
977 return IRQ_HANDLED;
978}
979
980static void dma_do_tasklet(struct tasklet_struct *t)
981{
982 struct fsldma_chan *chan = from_tasklet(chan, t, tasklet);
983
984 chan_dbg(chan, "tasklet entry\n");
985
986 spin_lock(lock: &chan->desc_lock);
987
988 /* the hardware is now idle and ready for more */
989 chan->idle = true;
990
991 /* Run all cleanup for descriptors which have been completed */
992 fsldma_cleanup_descriptors(chan);
993
994 spin_unlock(lock: &chan->desc_lock);
995
996 chan_dbg(chan, "tasklet exit\n");
997}
998
999static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
1000{
1001 struct fsldma_device *fdev = data;
1002 struct fsldma_chan *chan;
1003 unsigned int handled = 0;
1004 u32 gsr, mask;
1005 int i;
1006
1007 gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
1008 : in_le32(fdev->regs);
1009 mask = 0xff000000;
1010 dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
1011
1012 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1013 chan = fdev->chan[i];
1014 if (!chan)
1015 continue;
1016
1017 if (gsr & mask) {
1018 dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
1019 fsldma_chan_irq(irq, data: chan);
1020 handled++;
1021 }
1022
1023 gsr &= ~mask;
1024 mask >>= 8;
1025 }
1026
1027 return IRQ_RETVAL(handled);
1028}
1029
1030static void fsldma_free_irqs(struct fsldma_device *fdev)
1031{
1032 struct fsldma_chan *chan;
1033 int i;
1034
1035 if (fdev->irq) {
1036 dev_dbg(fdev->dev, "free per-controller IRQ\n");
1037 free_irq(fdev->irq, fdev);
1038 return;
1039 }
1040
1041 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1042 chan = fdev->chan[i];
1043 if (chan && chan->irq) {
1044 chan_dbg(chan, "free per-channel IRQ\n");
1045 free_irq(chan->irq, chan);
1046 }
1047 }
1048}
1049
1050static int fsldma_request_irqs(struct fsldma_device *fdev)
1051{
1052 struct fsldma_chan *chan;
1053 int ret;
1054 int i;
1055
1056 /* if we have a per-controller IRQ, use that */
1057 if (fdev->irq) {
1058 dev_dbg(fdev->dev, "request per-controller IRQ\n");
1059 ret = request_irq(irq: fdev->irq, handler: fsldma_ctrl_irq, IRQF_SHARED,
1060 name: "fsldma-controller", dev: fdev);
1061 return ret;
1062 }
1063
1064 /* no per-controller IRQ, use the per-channel IRQs */
1065 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1066 chan = fdev->chan[i];
1067 if (!chan)
1068 continue;
1069
1070 if (!chan->irq) {
1071 chan_err(chan, "interrupts property missing in device tree\n");
1072 ret = -ENODEV;
1073 goto out_unwind;
1074 }
1075
1076 chan_dbg(chan, "request per-channel IRQ\n");
1077 ret = request_irq(irq: chan->irq, handler: fsldma_chan_irq, IRQF_SHARED,
1078 name: "fsldma-chan", dev: chan);
1079 if (ret) {
1080 chan_err(chan, "unable to request per-channel IRQ\n");
1081 goto out_unwind;
1082 }
1083 }
1084
1085 return 0;
1086
1087out_unwind:
1088 for (/* none */; i >= 0; i--) {
1089 chan = fdev->chan[i];
1090 if (!chan)
1091 continue;
1092
1093 if (!chan->irq)
1094 continue;
1095
1096 free_irq(chan->irq, chan);
1097 }
1098
1099 return ret;
1100}
1101
1102/*----------------------------------------------------------------------------*/
1103/* OpenFirmware Subsystem */
1104/*----------------------------------------------------------------------------*/
1105
1106static int fsl_dma_chan_probe(struct fsldma_device *fdev,
1107 struct device_node *node, u32 feature, const char *compatible)
1108{
1109 struct fsldma_chan *chan;
1110 struct resource res;
1111 int err;
1112
1113 /* alloc channel */
1114 chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1115 if (!chan) {
1116 err = -ENOMEM;
1117 goto out_return;
1118 }
1119
1120 /* ioremap registers for use */
1121 chan->regs = of_iomap(node, index: 0);
1122 if (!chan->regs) {
1123 dev_err(fdev->dev, "unable to ioremap registers\n");
1124 err = -ENOMEM;
1125 goto out_free_chan;
1126 }
1127
1128 err = of_address_to_resource(dev: node, index: 0, r: &res);
1129 if (err) {
1130 dev_err(fdev->dev, "unable to find 'reg' property\n");
1131 goto out_iounmap_regs;
1132 }
1133
1134 chan->feature = feature;
1135 if (!fdev->feature)
1136 fdev->feature = chan->feature;
1137
1138 /*
1139 * If the DMA device's feature is different than the feature
1140 * of its channels, report the bug
1141 */
1142 WARN_ON(fdev->feature != chan->feature);
1143
1144 chan->dev = fdev->dev;
1145 chan->id = (res.start & 0xfff) < 0x300 ?
1146 ((res.start - 0x100) & 0xfff) >> 7 :
1147 ((res.start - 0x200) & 0xfff) >> 7;
1148 if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
1149 dev_err(fdev->dev, "too many channels for device\n");
1150 err = -EINVAL;
1151 goto out_iounmap_regs;
1152 }
1153
1154 fdev->chan[chan->id] = chan;
1155 tasklet_setup(t: &chan->tasklet, callback: dma_do_tasklet);
1156 snprintf(buf: chan->name, size: sizeof(chan->name), fmt: "chan%d", chan->id);
1157
1158 /* Initialize the channel */
1159 dma_init(chan);
1160
1161 /* Clear cdar registers */
1162 set_cdar(chan, addr: 0);
1163
1164 switch (chan->feature & FSL_DMA_IP_MASK) {
1165 case FSL_DMA_IP_85XX:
1166 chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
1167 fallthrough;
1168 case FSL_DMA_IP_83XX:
1169 chan->toggle_ext_start = fsl_chan_toggle_ext_start;
1170 chan->set_src_loop_size = fsl_chan_set_src_loop_size;
1171 chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
1172 chan->set_request_count = fsl_chan_set_request_count;
1173 }
1174
1175 spin_lock_init(&chan->desc_lock);
1176 INIT_LIST_HEAD(list: &chan->ld_pending);
1177 INIT_LIST_HEAD(list: &chan->ld_running);
1178 INIT_LIST_HEAD(list: &chan->ld_completed);
1179 chan->idle = true;
1180#ifdef CONFIG_PM
1181 chan->pm_state = RUNNING;
1182#endif
1183
1184 chan->common.device = &fdev->common;
1185 dma_cookie_init(chan: &chan->common);
1186
1187 /* find the IRQ line, if it exists in the device tree */
1188 chan->irq = irq_of_parse_and_map(node, index: 0);
1189
1190 /* Add the channel to DMA device channel list */
1191 list_add_tail(new: &chan->common.device_node, head: &fdev->common.channels);
1192
1193 dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
1194 chan->irq ? chan->irq : fdev->irq);
1195
1196 return 0;
1197
1198out_iounmap_regs:
1199 iounmap(addr: chan->regs);
1200out_free_chan:
1201 kfree(objp: chan);
1202out_return:
1203 return err;
1204}
1205
1206static void fsl_dma_chan_remove(struct fsldma_chan *chan)
1207{
1208 irq_dispose_mapping(virq: chan->irq);
1209 list_del(entry: &chan->common.device_node);
1210 iounmap(addr: chan->regs);
1211 kfree(objp: chan);
1212}
1213
1214static int fsldma_of_probe(struct platform_device *op)
1215{
1216 struct fsldma_device *fdev;
1217 struct device_node *child;
1218 unsigned int i;
1219 int err;
1220
1221 fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
1222 if (!fdev) {
1223 err = -ENOMEM;
1224 goto out_return;
1225 }
1226
1227 fdev->dev = &op->dev;
1228 INIT_LIST_HEAD(list: &fdev->common.channels);
1229 /* The DMA address bits supported for this device. */
1230 fdev->addr_bits = (long)device_get_match_data(dev: fdev->dev);
1231
1232 /* ioremap the registers for use */
1233 fdev->regs = of_iomap(node: op->dev.of_node, index: 0);
1234 if (!fdev->regs) {
1235 dev_err(&op->dev, "unable to ioremap registers\n");
1236 err = -ENOMEM;
1237 goto out_free;
1238 }
1239
1240 /* map the channel IRQ if it exists, but don't hookup the handler yet */
1241 fdev->irq = irq_of_parse_and_map(node: op->dev.of_node, index: 0);
1242
1243 dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
1244 dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
1245 fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
1246 fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
1247 fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
1248 fdev->common.device_tx_status = fsl_tx_status;
1249 fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
1250 fdev->common.device_config = fsl_dma_device_config;
1251 fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
1252 fdev->common.dev = &op->dev;
1253
1254 fdev->common.src_addr_widths = FSL_DMA_BUSWIDTHS;
1255 fdev->common.dst_addr_widths = FSL_DMA_BUSWIDTHS;
1256 fdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1257 fdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1258
1259 dma_set_mask(dev: &(op->dev), DMA_BIT_MASK(fdev->addr_bits));
1260
1261 platform_set_drvdata(pdev: op, data: fdev);
1262
1263 /*
1264 * We cannot use of_platform_bus_probe() because there is no
1265 * of_platform_bus_remove(). Instead, we manually instantiate every DMA
1266 * channel object.
1267 */
1268 for_each_child_of_node(op->dev.of_node, child) {
1269 if (of_device_is_compatible(device: child, "fsl,eloplus-dma-channel")) {
1270 fsl_dma_chan_probe(fdev, node: child,
1271 FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
1272 compatible: "fsl,eloplus-dma-channel");
1273 }
1274
1275 if (of_device_is_compatible(device: child, "fsl,elo-dma-channel")) {
1276 fsl_dma_chan_probe(fdev, node: child,
1277 FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
1278 compatible: "fsl,elo-dma-channel");
1279 }
1280 }
1281
1282 /*
1283 * Hookup the IRQ handler(s)
1284 *
1285 * If we have a per-controller interrupt, we prefer that to the
1286 * per-channel interrupts to reduce the number of shared interrupt
1287 * handlers on the same IRQ line
1288 */
1289 err = fsldma_request_irqs(fdev);
1290 if (err) {
1291 dev_err(fdev->dev, "unable to request IRQs\n");
1292 goto out_free_fdev;
1293 }
1294
1295 dma_async_device_register(device: &fdev->common);
1296 return 0;
1297
1298out_free_fdev:
1299 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1300 if (fdev->chan[i])
1301 fsl_dma_chan_remove(chan: fdev->chan[i]);
1302 }
1303 irq_dispose_mapping(virq: fdev->irq);
1304 iounmap(addr: fdev->regs);
1305out_free:
1306 kfree(objp: fdev);
1307out_return:
1308 return err;
1309}
1310
1311static void fsldma_of_remove(struct platform_device *op)
1312{
1313 struct fsldma_device *fdev;
1314 unsigned int i;
1315
1316 fdev = platform_get_drvdata(pdev: op);
1317 dma_async_device_unregister(device: &fdev->common);
1318
1319 fsldma_free_irqs(fdev);
1320
1321 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1322 if (fdev->chan[i])
1323 fsl_dma_chan_remove(chan: fdev->chan[i]);
1324 }
1325 irq_dispose_mapping(virq: fdev->irq);
1326
1327 iounmap(addr: fdev->regs);
1328 kfree(objp: fdev);
1329}
1330
1331#ifdef CONFIG_PM
1332static int fsldma_suspend_late(struct device *dev)
1333{
1334 struct fsldma_device *fdev = dev_get_drvdata(dev);
1335 struct fsldma_chan *chan;
1336 int i;
1337
1338 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1339 chan = fdev->chan[i];
1340 if (!chan)
1341 continue;
1342
1343 spin_lock_bh(lock: &chan->desc_lock);
1344 if (unlikely(!chan->idle))
1345 goto out;
1346 chan->regs_save.mr = get_mr(chan);
1347 chan->pm_state = SUSPENDED;
1348 spin_unlock_bh(lock: &chan->desc_lock);
1349 }
1350 return 0;
1351
1352out:
1353 for (; i >= 0; i--) {
1354 chan = fdev->chan[i];
1355 if (!chan)
1356 continue;
1357 chan->pm_state = RUNNING;
1358 spin_unlock_bh(lock: &chan->desc_lock);
1359 }
1360 return -EBUSY;
1361}
1362
1363static int fsldma_resume_early(struct device *dev)
1364{
1365 struct fsldma_device *fdev = dev_get_drvdata(dev);
1366 struct fsldma_chan *chan;
1367 u32 mode;
1368 int i;
1369
1370 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1371 chan = fdev->chan[i];
1372 if (!chan)
1373 continue;
1374
1375 spin_lock_bh(lock: &chan->desc_lock);
1376 mode = chan->regs_save.mr
1377 & ~FSL_DMA_MR_CS & ~FSL_DMA_MR_CC & ~FSL_DMA_MR_CA;
1378 set_mr(chan, val: mode);
1379 chan->pm_state = RUNNING;
1380 spin_unlock_bh(lock: &chan->desc_lock);
1381 }
1382
1383 return 0;
1384}
1385
1386static const struct dev_pm_ops fsldma_pm_ops = {
1387 .suspend_late = fsldma_suspend_late,
1388 .resume_early = fsldma_resume_early,
1389};
1390#endif
1391
1392/* The .data field is used for dma-bit-mask. */
1393static const struct of_device_id fsldma_of_ids[] = {
1394 {
1395 .compatible = "fsl,elo3-dma",
1396 .data = (void *)40,
1397 },
1398 {
1399 .compatible = "fsl,eloplus-dma",
1400 .data = (void *)36,
1401 },
1402 {
1403 .compatible = "fsl,elo-dma",
1404 .data = (void *)32,
1405 },
1406 {}
1407};
1408MODULE_DEVICE_TABLE(of, fsldma_of_ids);
1409
1410static struct platform_driver fsldma_of_driver = {
1411 .driver = {
1412 .name = "fsl-elo-dma",
1413 .of_match_table = fsldma_of_ids,
1414#ifdef CONFIG_PM
1415 .pm = &fsldma_pm_ops,
1416#endif
1417 },
1418 .probe = fsldma_of_probe,
1419 .remove = fsldma_of_remove,
1420};
1421
1422/*----------------------------------------------------------------------------*/
1423/* Module Init / Exit */
1424/*----------------------------------------------------------------------------*/
1425
1426static __init int fsldma_init(void)
1427{
1428 pr_info("Freescale Elo series DMA driver\n");
1429 return platform_driver_register(&fsldma_of_driver);
1430}
1431
1432static void __exit fsldma_exit(void)
1433{
1434 platform_driver_unregister(&fsldma_of_driver);
1435}
1436
1437subsys_initcall(fsldma_init);
1438module_exit(fsldma_exit);
1439
1440MODULE_DESCRIPTION("Freescale Elo series DMA driver");
1441MODULE_LICENSE("GPL");
1442

source code of linux/drivers/dma/fsldma.c