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Merge branch 'batman-adv/merge-oopsonly' of git://git.open-mesh.org/ecsv/linux-merge
[mv-sheeva.git] / drivers / dma / shdma.c
1 /*
2  * Renesas SuperH DMA Engine support
3  *
4  * base is drivers/dma/flsdma.c
5  *
6  * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
7  * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
8  * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
9  *
10  * This is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * - DMA of SuperH does not have Hardware DMA chain mode.
16  * - MAX DMA size is 16MB.
17  *
18  */
19
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/dmaengine.h>
25 #include <linux/delay.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/platform_device.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/sh_dma.h>
30 #include <linux/notifier.h>
31 #include <linux/kdebug.h>
32 #include <linux/spinlock.h>
33 #include <linux/rculist.h>
34 #include "shdma.h"
35
36 /* DMA descriptor control */
37 enum sh_dmae_desc_status {
38         DESC_IDLE,
39         DESC_PREPARED,
40         DESC_SUBMITTED,
41         DESC_COMPLETED, /* completed, have to call callback */
42         DESC_WAITING,   /* callback called, waiting for ack / re-submit */
43 };
44
45 #define NR_DESCS_PER_CHANNEL 32
46 /* Default MEMCPY transfer size = 2^2 = 4 bytes */
47 #define LOG2_DEFAULT_XFER_SIZE  2
48
49 /*
50  * Used for write-side mutual exclusion for the global device list,
51  * read-side synchronization by way of RCU.
52  */
53 static DEFINE_SPINLOCK(sh_dmae_lock);
54 static LIST_HEAD(sh_dmae_devices);
55
56 /* A bitmask with bits enough for enum sh_dmae_slave_chan_id */
57 static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SH_DMA_SLAVE_NUMBER)];
58
59 static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);
60
61 static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
62 {
63         __raw_writel(data, sh_dc->base + reg / sizeof(u32));
64 }
65
66 static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg)
67 {
68         return __raw_readl(sh_dc->base + reg / sizeof(u32));
69 }
70
71 static u16 dmaor_read(struct sh_dmae_device *shdev)
72 {
73         return __raw_readw(shdev->chan_reg + DMAOR / sizeof(u32));
74 }
75
76 static void dmaor_write(struct sh_dmae_device *shdev, u16 data)
77 {
78         __raw_writew(data, shdev->chan_reg + DMAOR / sizeof(u32));
79 }
80
81 /*
82  * Reset DMA controller
83  *
84  * SH7780 has two DMAOR register
85  */
86 static void sh_dmae_ctl_stop(struct sh_dmae_device *shdev)
87 {
88         unsigned short dmaor = dmaor_read(shdev);
89
90         dmaor_write(shdev, dmaor & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME));
91 }
92
93 static int sh_dmae_rst(struct sh_dmae_device *shdev)
94 {
95         unsigned short dmaor;
96
97         sh_dmae_ctl_stop(shdev);
98         dmaor = dmaor_read(shdev) | shdev->pdata->dmaor_init;
99
100         dmaor_write(shdev, dmaor);
101         if (dmaor_read(shdev) & (DMAOR_AE | DMAOR_NMIF)) {
102                 pr_warning("dma-sh: Can't initialize DMAOR.\n");
103                 return -EINVAL;
104         }
105         return 0;
106 }
107
108 static bool dmae_is_busy(struct sh_dmae_chan *sh_chan)
109 {
110         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
111
112         if ((chcr & (CHCR_DE | CHCR_TE)) == CHCR_DE)
113                 return true; /* working */
114
115         return false; /* waiting */
116 }
117
118 static unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan, u32 chcr)
119 {
120         struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
121                                                 struct sh_dmae_device, common);
122         struct sh_dmae_pdata *pdata = shdev->pdata;
123         int cnt = ((chcr & pdata->ts_low_mask) >> pdata->ts_low_shift) |
124                 ((chcr & pdata->ts_high_mask) >> pdata->ts_high_shift);
125
126         if (cnt >= pdata->ts_shift_num)
127                 cnt = 0;
128
129         return pdata->ts_shift[cnt];
130 }
131
132 static u32 log2size_to_chcr(struct sh_dmae_chan *sh_chan, int l2size)
133 {
134         struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
135                                                 struct sh_dmae_device, common);
136         struct sh_dmae_pdata *pdata = shdev->pdata;
137         int i;
138
139         for (i = 0; i < pdata->ts_shift_num; i++)
140                 if (pdata->ts_shift[i] == l2size)
141                         break;
142
143         if (i == pdata->ts_shift_num)
144                 i = 0;
145
146         return ((i << pdata->ts_low_shift) & pdata->ts_low_mask) |
147                 ((i << pdata->ts_high_shift) & pdata->ts_high_mask);
148 }
149
150 static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
151 {
152         sh_dmae_writel(sh_chan, hw->sar, SAR);
153         sh_dmae_writel(sh_chan, hw->dar, DAR);
154         sh_dmae_writel(sh_chan, hw->tcr >> sh_chan->xmit_shift, TCR);
155 }
156
157 static void dmae_start(struct sh_dmae_chan *sh_chan)
158 {
159         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
160
161         chcr |= CHCR_DE | CHCR_IE;
162         sh_dmae_writel(sh_chan, chcr & ~CHCR_TE, CHCR);
163 }
164
165 static void dmae_halt(struct sh_dmae_chan *sh_chan)
166 {
167         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
168
169         chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE);
170         sh_dmae_writel(sh_chan, chcr, CHCR);
171 }
172
173 static void dmae_init(struct sh_dmae_chan *sh_chan)
174 {
175         /*
176          * Default configuration for dual address memory-memory transfer.
177          * 0x400 represents auto-request.
178          */
179         u32 chcr = DM_INC | SM_INC | 0x400 | log2size_to_chcr(sh_chan,
180                                                    LOG2_DEFAULT_XFER_SIZE);
181         sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr);
182         sh_dmae_writel(sh_chan, chcr, CHCR);
183 }
184
185 static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val)
186 {
187         /* When DMA was working, can not set data to CHCR */
188         if (dmae_is_busy(sh_chan))
189                 return -EBUSY;
190
191         sh_chan->xmit_shift = calc_xmit_shift(sh_chan, val);
192         sh_dmae_writel(sh_chan, val, CHCR);
193
194         return 0;
195 }
196
197 static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
198 {
199         struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
200                                                 struct sh_dmae_device, common);
201         struct sh_dmae_pdata *pdata = shdev->pdata;
202         const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->id];
203         u16 __iomem *addr = shdev->dmars + chan_pdata->dmars / sizeof(u16);
204         int shift = chan_pdata->dmars_bit;
205
206         if (dmae_is_busy(sh_chan))
207                 return -EBUSY;
208
209         __raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift),
210                      addr);
211
212         return 0;
213 }
214
215 static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
216 {
217         struct sh_desc *desc = tx_to_sh_desc(tx), *chunk, *last = desc, *c;
218         struct sh_dmae_chan *sh_chan = to_sh_chan(tx->chan);
219         dma_async_tx_callback callback = tx->callback;
220         dma_cookie_t cookie;
221
222         spin_lock_bh(&sh_chan->desc_lock);
223
224         cookie = sh_chan->common.cookie;
225         cookie++;
226         if (cookie < 0)
227                 cookie = 1;
228
229         sh_chan->common.cookie = cookie;
230         tx->cookie = cookie;
231
232         /* Mark all chunks of this descriptor as submitted, move to the queue */
233         list_for_each_entry_safe(chunk, c, desc->node.prev, node) {
234                 /*
235                  * All chunks are on the global ld_free, so, we have to find
236                  * the end of the chain ourselves
237                  */
238                 if (chunk != desc && (chunk->mark == DESC_IDLE ||
239                                       chunk->async_tx.cookie > 0 ||
240                                       chunk->async_tx.cookie == -EBUSY ||
241                                       &chunk->node == &sh_chan->ld_free))
242                         break;
243                 chunk->mark = DESC_SUBMITTED;
244                 /* Callback goes to the last chunk */
245                 chunk->async_tx.callback = NULL;
246                 chunk->cookie = cookie;
247                 list_move_tail(&chunk->node, &sh_chan->ld_queue);
248                 last = chunk;
249         }
250
251         last->async_tx.callback = callback;
252         last->async_tx.callback_param = tx->callback_param;
253
254         dev_dbg(sh_chan->dev, "submit #%d@%p on %d: %x[%d] -> %x\n",
255                 tx->cookie, &last->async_tx, sh_chan->id,
256                 desc->hw.sar, desc->hw.tcr, desc->hw.dar);
257
258         spin_unlock_bh(&sh_chan->desc_lock);
259
260         return cookie;
261 }
262
263 /* Called with desc_lock held */
264 static struct sh_desc *sh_dmae_get_desc(struct sh_dmae_chan *sh_chan)
265 {
266         struct sh_desc *desc;
267
268         list_for_each_entry(desc, &sh_chan->ld_free, node)
269                 if (desc->mark != DESC_PREPARED) {
270                         BUG_ON(desc->mark != DESC_IDLE);
271                         list_del(&desc->node);
272                         return desc;
273                 }
274
275         return NULL;
276 }
277
278 static const struct sh_dmae_slave_config *sh_dmae_find_slave(
279         struct sh_dmae_chan *sh_chan, struct sh_dmae_slave *param)
280 {
281         struct dma_device *dma_dev = sh_chan->common.device;
282         struct sh_dmae_device *shdev = container_of(dma_dev,
283                                         struct sh_dmae_device, common);
284         struct sh_dmae_pdata *pdata = shdev->pdata;
285         int i;
286
287         if (param->slave_id >= SH_DMA_SLAVE_NUMBER)
288                 return NULL;
289
290         for (i = 0; i < pdata->slave_num; i++)
291                 if (pdata->slave[i].slave_id == param->slave_id)
292                         return pdata->slave + i;
293
294         return NULL;
295 }
296
297 static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
298 {
299         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
300         struct sh_desc *desc;
301         struct sh_dmae_slave *param = chan->private;
302         int ret;
303
304         pm_runtime_get_sync(sh_chan->dev);
305
306         /*
307          * This relies on the guarantee from dmaengine that alloc_chan_resources
308          * never runs concurrently with itself or free_chan_resources.
309          */
310         if (param) {
311                 const struct sh_dmae_slave_config *cfg;
312
313                 cfg = sh_dmae_find_slave(sh_chan, param);
314                 if (!cfg) {
315                         ret = -EINVAL;
316                         goto efindslave;
317                 }
318
319                 if (test_and_set_bit(param->slave_id, sh_dmae_slave_used)) {
320                         ret = -EBUSY;
321                         goto etestused;
322                 }
323
324                 param->config = cfg;
325
326                 dmae_set_dmars(sh_chan, cfg->mid_rid);
327                 dmae_set_chcr(sh_chan, cfg->chcr);
328         } else if ((sh_dmae_readl(sh_chan, CHCR) & 0xf00) != 0x400) {
329                 dmae_init(sh_chan);
330         }
331
332         spin_lock_bh(&sh_chan->desc_lock);
333         while (sh_chan->descs_allocated < NR_DESCS_PER_CHANNEL) {
334                 spin_unlock_bh(&sh_chan->desc_lock);
335                 desc = kzalloc(sizeof(struct sh_desc), GFP_KERNEL);
336                 if (!desc) {
337                         spin_lock_bh(&sh_chan->desc_lock);
338                         break;
339                 }
340                 dma_async_tx_descriptor_init(&desc->async_tx,
341                                         &sh_chan->common);
342                 desc->async_tx.tx_submit = sh_dmae_tx_submit;
343                 desc->mark = DESC_IDLE;
344
345                 spin_lock_bh(&sh_chan->desc_lock);
346                 list_add(&desc->node, &sh_chan->ld_free);
347                 sh_chan->descs_allocated++;
348         }
349         spin_unlock_bh(&sh_chan->desc_lock);
350
351         if (!sh_chan->descs_allocated) {
352                 ret = -ENOMEM;
353                 goto edescalloc;
354         }
355
356         return sh_chan->descs_allocated;
357
358 edescalloc:
359         if (param)
360                 clear_bit(param->slave_id, sh_dmae_slave_used);
361 etestused:
362 efindslave:
363         pm_runtime_put(sh_chan->dev);
364         return ret;
365 }
366
367 /*
368  * sh_dma_free_chan_resources - Free all resources of the channel.
369  */
370 static void sh_dmae_free_chan_resources(struct dma_chan *chan)
371 {
372         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
373         struct sh_desc *desc, *_desc;
374         LIST_HEAD(list);
375         int descs = sh_chan->descs_allocated;
376
377         dmae_halt(sh_chan);
378
379         /* Prepared and not submitted descriptors can still be on the queue */
380         if (!list_empty(&sh_chan->ld_queue))
381                 sh_dmae_chan_ld_cleanup(sh_chan, true);
382
383         if (chan->private) {
384                 /* The caller is holding dma_list_mutex */
385                 struct sh_dmae_slave *param = chan->private;
386                 clear_bit(param->slave_id, sh_dmae_slave_used);
387         }
388
389         spin_lock_bh(&sh_chan->desc_lock);
390
391         list_splice_init(&sh_chan->ld_free, &list);
392         sh_chan->descs_allocated = 0;
393
394         spin_unlock_bh(&sh_chan->desc_lock);
395
396         if (descs > 0)
397                 pm_runtime_put(sh_chan->dev);
398
399         list_for_each_entry_safe(desc, _desc, &list, node)
400                 kfree(desc);
401 }
402
403 /**
404  * sh_dmae_add_desc - get, set up and return one transfer descriptor
405  * @sh_chan:    DMA channel
406  * @flags:      DMA transfer flags
407  * @dest:       destination DMA address, incremented when direction equals
408  *              DMA_FROM_DEVICE or DMA_BIDIRECTIONAL
409  * @src:        source DMA address, incremented when direction equals
410  *              DMA_TO_DEVICE or DMA_BIDIRECTIONAL
411  * @len:        DMA transfer length
412  * @first:      if NULL, set to the current descriptor and cookie set to -EBUSY
413  * @direction:  needed for slave DMA to decide which address to keep constant,
414  *              equals DMA_BIDIRECTIONAL for MEMCPY
415  * Returns 0 or an error
416  * Locks: called with desc_lock held
417  */
418 static struct sh_desc *sh_dmae_add_desc(struct sh_dmae_chan *sh_chan,
419         unsigned long flags, dma_addr_t *dest, dma_addr_t *src, size_t *len,
420         struct sh_desc **first, enum dma_data_direction direction)
421 {
422         struct sh_desc *new;
423         size_t copy_size;
424
425         if (!*len)
426                 return NULL;
427
428         /* Allocate the link descriptor from the free list */
429         new = sh_dmae_get_desc(sh_chan);
430         if (!new) {
431                 dev_err(sh_chan->dev, "No free link descriptor available\n");
432                 return NULL;
433         }
434
435         copy_size = min(*len, (size_t)SH_DMA_TCR_MAX + 1);
436
437         new->hw.sar = *src;
438         new->hw.dar = *dest;
439         new->hw.tcr = copy_size;
440
441         if (!*first) {
442                 /* First desc */
443                 new->async_tx.cookie = -EBUSY;
444                 *first = new;
445         } else {
446                 /* Other desc - invisible to the user */
447                 new->async_tx.cookie = -EINVAL;
448         }
449
450         dev_dbg(sh_chan->dev,
451                 "chaining (%u/%u)@%x -> %x with %p, cookie %d, shift %d\n",
452                 copy_size, *len, *src, *dest, &new->async_tx,
453                 new->async_tx.cookie, sh_chan->xmit_shift);
454
455         new->mark = DESC_PREPARED;
456         new->async_tx.flags = flags;
457         new->direction = direction;
458
459         *len -= copy_size;
460         if (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE)
461                 *src += copy_size;
462         if (direction == DMA_BIDIRECTIONAL || direction == DMA_FROM_DEVICE)
463                 *dest += copy_size;
464
465         return new;
466 }
467
468 /*
469  * sh_dmae_prep_sg - prepare transfer descriptors from an SG list
470  *
471  * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also
472  * converted to scatter-gather to guarantee consistent locking and a correct
473  * list manipulation. For slave DMA direction carries the usual meaning, and,
474  * logically, the SG list is RAM and the addr variable contains slave address,
475  * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_BIDIRECTIONAL
476  * and the SG list contains only one element and points at the source buffer.
477  */
478 static struct dma_async_tx_descriptor *sh_dmae_prep_sg(struct sh_dmae_chan *sh_chan,
479         struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr,
480         enum dma_data_direction direction, unsigned long flags)
481 {
482         struct scatterlist *sg;
483         struct sh_desc *first = NULL, *new = NULL /* compiler... */;
484         LIST_HEAD(tx_list);
485         int chunks = 0;
486         int i;
487
488         if (!sg_len)
489                 return NULL;
490
491         for_each_sg(sgl, sg, sg_len, i)
492                 chunks += (sg_dma_len(sg) + SH_DMA_TCR_MAX) /
493                         (SH_DMA_TCR_MAX + 1);
494
495         /* Have to lock the whole loop to protect against concurrent release */
496         spin_lock_bh(&sh_chan->desc_lock);
497
498         /*
499          * Chaining:
500          * first descriptor is what user is dealing with in all API calls, its
501          *      cookie is at first set to -EBUSY, at tx-submit to a positive
502          *      number
503          * if more than one chunk is needed further chunks have cookie = -EINVAL
504          * the last chunk, if not equal to the first, has cookie = -ENOSPC
505          * all chunks are linked onto the tx_list head with their .node heads
506          *      only during this function, then they are immediately spliced
507          *      back onto the free list in form of a chain
508          */
509         for_each_sg(sgl, sg, sg_len, i) {
510                 dma_addr_t sg_addr = sg_dma_address(sg);
511                 size_t len = sg_dma_len(sg);
512
513                 if (!len)
514                         goto err_get_desc;
515
516                 do {
517                         dev_dbg(sh_chan->dev, "Add SG #%d@%p[%d], dma %llx\n",
518                                 i, sg, len, (unsigned long long)sg_addr);
519
520                         if (direction == DMA_FROM_DEVICE)
521                                 new = sh_dmae_add_desc(sh_chan, flags,
522                                                 &sg_addr, addr, &len, &first,
523                                                 direction);
524                         else
525                                 new = sh_dmae_add_desc(sh_chan, flags,
526                                                 addr, &sg_addr, &len, &first,
527                                                 direction);
528                         if (!new)
529                                 goto err_get_desc;
530
531                         new->chunks = chunks--;
532                         list_add_tail(&new->node, &tx_list);
533                 } while (len);
534         }
535
536         if (new != first)
537                 new->async_tx.cookie = -ENOSPC;
538
539         /* Put them back on the free list, so, they don't get lost */
540         list_splice_tail(&tx_list, &sh_chan->ld_free);
541
542         spin_unlock_bh(&sh_chan->desc_lock);
543
544         return &first->async_tx;
545
546 err_get_desc:
547         list_for_each_entry(new, &tx_list, node)
548                 new->mark = DESC_IDLE;
549         list_splice(&tx_list, &sh_chan->ld_free);
550
551         spin_unlock_bh(&sh_chan->desc_lock);
552
553         return NULL;
554 }
555
556 static struct dma_async_tx_descriptor *sh_dmae_prep_memcpy(
557         struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
558         size_t len, unsigned long flags)
559 {
560         struct sh_dmae_chan *sh_chan;
561         struct scatterlist sg;
562
563         if (!chan || !len)
564                 return NULL;
565
566         chan->private = NULL;
567
568         sh_chan = to_sh_chan(chan);
569
570         sg_init_table(&sg, 1);
571         sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_src)), len,
572                     offset_in_page(dma_src));
573         sg_dma_address(&sg) = dma_src;
574         sg_dma_len(&sg) = len;
575
576         return sh_dmae_prep_sg(sh_chan, &sg, 1, &dma_dest, DMA_BIDIRECTIONAL,
577                                flags);
578 }
579
580 static struct dma_async_tx_descriptor *sh_dmae_prep_slave_sg(
581         struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
582         enum dma_data_direction direction, unsigned long flags)
583 {
584         struct sh_dmae_slave *param;
585         struct sh_dmae_chan *sh_chan;
586         dma_addr_t slave_addr;
587
588         if (!chan)
589                 return NULL;
590
591         sh_chan = to_sh_chan(chan);
592         param = chan->private;
593
594         /* Someone calling slave DMA on a public channel? */
595         if (!param || !sg_len) {
596                 dev_warn(sh_chan->dev, "%s: bad parameter: %p, %d, %d\n",
597                          __func__, param, sg_len, param ? param->slave_id : -1);
598                 return NULL;
599         }
600
601         slave_addr = param->config->addr;
602
603         /*
604          * if (param != NULL), this is a successfully requested slave channel,
605          * therefore param->config != NULL too.
606          */
607         return sh_dmae_prep_sg(sh_chan, sgl, sg_len, &slave_addr,
608                                direction, flags);
609 }
610
611 static int sh_dmae_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
612                            unsigned long arg)
613 {
614         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
615
616         /* Only supports DMA_TERMINATE_ALL */
617         if (cmd != DMA_TERMINATE_ALL)
618                 return -ENXIO;
619
620         if (!chan)
621                 return -EINVAL;
622
623         dmae_halt(sh_chan);
624
625         spin_lock_bh(&sh_chan->desc_lock);
626         if (!list_empty(&sh_chan->ld_queue)) {
627                 /* Record partial transfer */
628                 struct sh_desc *desc = list_entry(sh_chan->ld_queue.next,
629                                                   struct sh_desc, node);
630                 desc->partial = (desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
631                         sh_chan->xmit_shift;
632
633         }
634         spin_unlock_bh(&sh_chan->desc_lock);
635
636         sh_dmae_chan_ld_cleanup(sh_chan, true);
637
638         return 0;
639 }
640
641 static dma_async_tx_callback __ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
642 {
643         struct sh_desc *desc, *_desc;
644         /* Is the "exposed" head of a chain acked? */
645         bool head_acked = false;
646         dma_cookie_t cookie = 0;
647         dma_async_tx_callback callback = NULL;
648         void *param = NULL;
649
650         spin_lock_bh(&sh_chan->desc_lock);
651         list_for_each_entry_safe(desc, _desc, &sh_chan->ld_queue, node) {
652                 struct dma_async_tx_descriptor *tx = &desc->async_tx;
653
654                 BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie);
655                 BUG_ON(desc->mark != DESC_SUBMITTED &&
656                        desc->mark != DESC_COMPLETED &&
657                        desc->mark != DESC_WAITING);
658
659                 /*
660                  * queue is ordered, and we use this loop to (1) clean up all
661                  * completed descriptors, and to (2) update descriptor flags of
662                  * any chunks in a (partially) completed chain
663                  */
664                 if (!all && desc->mark == DESC_SUBMITTED &&
665                     desc->cookie != cookie)
666                         break;
667
668                 if (tx->cookie > 0)
669                         cookie = tx->cookie;
670
671                 if (desc->mark == DESC_COMPLETED && desc->chunks == 1) {
672                         if (sh_chan->completed_cookie != desc->cookie - 1)
673                                 dev_dbg(sh_chan->dev,
674                                         "Completing cookie %d, expected %d\n",
675                                         desc->cookie,
676                                         sh_chan->completed_cookie + 1);
677                         sh_chan->completed_cookie = desc->cookie;
678                 }
679
680                 /* Call callback on the last chunk */
681                 if (desc->mark == DESC_COMPLETED && tx->callback) {
682                         desc->mark = DESC_WAITING;
683                         callback = tx->callback;
684                         param = tx->callback_param;
685                         dev_dbg(sh_chan->dev, "descriptor #%d@%p on %d callback\n",
686                                 tx->cookie, tx, sh_chan->id);
687                         BUG_ON(desc->chunks != 1);
688                         break;
689                 }
690
691                 if (tx->cookie > 0 || tx->cookie == -EBUSY) {
692                         if (desc->mark == DESC_COMPLETED) {
693                                 BUG_ON(tx->cookie < 0);
694                                 desc->mark = DESC_WAITING;
695                         }
696                         head_acked = async_tx_test_ack(tx);
697                 } else {
698                         switch (desc->mark) {
699                         case DESC_COMPLETED:
700                                 desc->mark = DESC_WAITING;
701                                 /* Fall through */
702                         case DESC_WAITING:
703                                 if (head_acked)
704                                         async_tx_ack(&desc->async_tx);
705                         }
706                 }
707
708                 dev_dbg(sh_chan->dev, "descriptor %p #%d completed.\n",
709                         tx, tx->cookie);
710
711                 if (((desc->mark == DESC_COMPLETED ||
712                       desc->mark == DESC_WAITING) &&
713                      async_tx_test_ack(&desc->async_tx)) || all) {
714                         /* Remove from ld_queue list */
715                         desc->mark = DESC_IDLE;
716                         list_move(&desc->node, &sh_chan->ld_free);
717                 }
718         }
719         spin_unlock_bh(&sh_chan->desc_lock);
720
721         if (callback)
722                 callback(param);
723
724         return callback;
725 }
726
727 /*
728  * sh_chan_ld_cleanup - Clean up link descriptors
729  *
730  * This function cleans up the ld_queue of DMA channel.
731  */
732 static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
733 {
734         while (__ld_cleanup(sh_chan, all))
735                 ;
736
737         if (all)
738                 /* Terminating - forgive uncompleted cookies */
739                 sh_chan->completed_cookie = sh_chan->common.cookie;
740 }
741
742 static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan)
743 {
744         struct sh_desc *desc;
745
746         spin_lock_bh(&sh_chan->desc_lock);
747         /* DMA work check */
748         if (dmae_is_busy(sh_chan)) {
749                 spin_unlock_bh(&sh_chan->desc_lock);
750                 return;
751         }
752
753         /* Find the first not transferred desciptor */
754         list_for_each_entry(desc, &sh_chan->ld_queue, node)
755                 if (desc->mark == DESC_SUBMITTED) {
756                         dev_dbg(sh_chan->dev, "Queue #%d to %d: %u@%x -> %x\n",
757                                 desc->async_tx.cookie, sh_chan->id,
758                                 desc->hw.tcr, desc->hw.sar, desc->hw.dar);
759                         /* Get the ld start address from ld_queue */
760                         dmae_set_reg(sh_chan, &desc->hw);
761                         dmae_start(sh_chan);
762                         break;
763                 }
764
765         spin_unlock_bh(&sh_chan->desc_lock);
766 }
767
768 static void sh_dmae_memcpy_issue_pending(struct dma_chan *chan)
769 {
770         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
771         sh_chan_xfer_ld_queue(sh_chan);
772 }
773
774 static enum dma_status sh_dmae_tx_status(struct dma_chan *chan,
775                                         dma_cookie_t cookie,
776                                         struct dma_tx_state *txstate)
777 {
778         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
779         dma_cookie_t last_used;
780         dma_cookie_t last_complete;
781         enum dma_status status;
782
783         sh_dmae_chan_ld_cleanup(sh_chan, false);
784
785         last_used = chan->cookie;
786         last_complete = sh_chan->completed_cookie;
787         BUG_ON(last_complete < 0);
788         dma_set_tx_state(txstate, last_complete, last_used, 0);
789
790         spin_lock_bh(&sh_chan->desc_lock);
791
792         status = dma_async_is_complete(cookie, last_complete, last_used);
793
794         /*
795          * If we don't find cookie on the queue, it has been aborted and we have
796          * to report error
797          */
798         if (status != DMA_SUCCESS) {
799                 struct sh_desc *desc;
800                 status = DMA_ERROR;
801                 list_for_each_entry(desc, &sh_chan->ld_queue, node)
802                         if (desc->cookie == cookie) {
803                                 status = DMA_IN_PROGRESS;
804                                 break;
805                         }
806         }
807
808         spin_unlock_bh(&sh_chan->desc_lock);
809
810         return status;
811 }
812
813 static irqreturn_t sh_dmae_interrupt(int irq, void *data)
814 {
815         irqreturn_t ret = IRQ_NONE;
816         struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
817         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
818
819         if (chcr & CHCR_TE) {
820                 /* DMA stop */
821                 dmae_halt(sh_chan);
822
823                 ret = IRQ_HANDLED;
824                 tasklet_schedule(&sh_chan->tasklet);
825         }
826
827         return ret;
828 }
829
830 static unsigned int sh_dmae_reset(struct sh_dmae_device *shdev)
831 {
832         unsigned int handled = 0;
833         int i;
834
835         /* halt the dma controller */
836         sh_dmae_ctl_stop(shdev);
837
838         /* We cannot detect, which channel caused the error, have to reset all */
839         for (i = 0; i < SH_DMAC_MAX_CHANNELS; i++) {
840                 struct sh_dmae_chan *sh_chan = shdev->chan[i];
841                 struct sh_desc *desc;
842
843                 if (!sh_chan)
844                         continue;
845
846                 /* Stop the channel */
847                 dmae_halt(sh_chan);
848
849                 /* Complete all  */
850                 list_for_each_entry(desc, &sh_chan->ld_queue, node) {
851                         struct dma_async_tx_descriptor *tx = &desc->async_tx;
852                         desc->mark = DESC_IDLE;
853                         if (tx->callback)
854                                 tx->callback(tx->callback_param);
855                 }
856
857                 list_splice_init(&sh_chan->ld_queue, &sh_chan->ld_free);
858                 handled++;
859         }
860
861         sh_dmae_rst(shdev);
862
863         return !!handled;
864 }
865
866 static irqreturn_t sh_dmae_err(int irq, void *data)
867 {
868         return IRQ_RETVAL(sh_dmae_reset(data));
869 }
870
871 static void dmae_do_tasklet(unsigned long data)
872 {
873         struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
874         struct sh_desc *desc;
875         u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
876         u32 dar_buf = sh_dmae_readl(sh_chan, DAR);
877
878         spin_lock(&sh_chan->desc_lock);
879         list_for_each_entry(desc, &sh_chan->ld_queue, node) {
880                 if (desc->mark == DESC_SUBMITTED &&
881                     ((desc->direction == DMA_FROM_DEVICE &&
882                       (desc->hw.dar + desc->hw.tcr) == dar_buf) ||
883                      (desc->hw.sar + desc->hw.tcr) == sar_buf)) {
884                         dev_dbg(sh_chan->dev, "done #%d@%p dst %u\n",
885                                 desc->async_tx.cookie, &desc->async_tx,
886                                 desc->hw.dar);
887                         desc->mark = DESC_COMPLETED;
888                         break;
889                 }
890         }
891         spin_unlock(&sh_chan->desc_lock);
892
893         /* Next desc */
894         sh_chan_xfer_ld_queue(sh_chan);
895         sh_dmae_chan_ld_cleanup(sh_chan, false);
896 }
897
898 static bool sh_dmae_nmi_notify(struct sh_dmae_device *shdev)
899 {
900         unsigned int handled;
901
902         /* Fast path out if NMIF is not asserted for this controller */
903         if ((dmaor_read(shdev) & DMAOR_NMIF) == 0)
904                 return false;
905
906         handled = sh_dmae_reset(shdev);
907         if (handled)
908                 return true;
909
910         return false;
911 }
912
913 static int sh_dmae_nmi_handler(struct notifier_block *self,
914                                unsigned long cmd, void *data)
915 {
916         struct sh_dmae_device *shdev;
917         int ret = NOTIFY_DONE;
918         bool triggered;
919
920         /*
921          * Only concern ourselves with NMI events.
922          *
923          * Normally we would check the die chain value, but as this needs
924          * to be architecture independent, check for NMI context instead.
925          */
926         if (!in_nmi())
927                 return NOTIFY_DONE;
928
929         rcu_read_lock();
930         list_for_each_entry_rcu(shdev, &sh_dmae_devices, node) {
931                 /*
932                  * Only stop if one of the controllers has NMIF asserted,
933                  * we do not want to interfere with regular address error
934                  * handling or NMI events that don't concern the DMACs.
935                  */
936                 triggered = sh_dmae_nmi_notify(shdev);
937                 if (triggered == true)
938                         ret = NOTIFY_OK;
939         }
940         rcu_read_unlock();
941
942         return ret;
943 }
944
945 static struct notifier_block sh_dmae_nmi_notifier __read_mostly = {
946         .notifier_call  = sh_dmae_nmi_handler,
947
948         /* Run before NMI debug handler and KGDB */
949         .priority       = 1,
950 };
951
952 static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
953                                         int irq, unsigned long flags)
954 {
955         int err;
956         const struct sh_dmae_channel *chan_pdata = &shdev->pdata->channel[id];
957         struct platform_device *pdev = to_platform_device(shdev->common.dev);
958         struct sh_dmae_chan *new_sh_chan;
959
960         /* alloc channel */
961         new_sh_chan = kzalloc(sizeof(struct sh_dmae_chan), GFP_KERNEL);
962         if (!new_sh_chan) {
963                 dev_err(shdev->common.dev,
964                         "No free memory for allocating dma channels!\n");
965                 return -ENOMEM;
966         }
967
968         /* copy struct dma_device */
969         new_sh_chan->common.device = &shdev->common;
970
971         new_sh_chan->dev = shdev->common.dev;
972         new_sh_chan->id = id;
973         new_sh_chan->irq = irq;
974         new_sh_chan->base = shdev->chan_reg + chan_pdata->offset / sizeof(u32);
975
976         /* Init DMA tasklet */
977         tasklet_init(&new_sh_chan->tasklet, dmae_do_tasklet,
978                         (unsigned long)new_sh_chan);
979
980         /* Init the channel */
981         dmae_init(new_sh_chan);
982
983         spin_lock_init(&new_sh_chan->desc_lock);
984
985         /* Init descripter manage list */
986         INIT_LIST_HEAD(&new_sh_chan->ld_queue);
987         INIT_LIST_HEAD(&new_sh_chan->ld_free);
988
989         /* Add the channel to DMA device channel list */
990         list_add_tail(&new_sh_chan->common.device_node,
991                         &shdev->common.channels);
992         shdev->common.chancnt++;
993
994         if (pdev->id >= 0)
995                 snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
996                          "sh-dmae%d.%d", pdev->id, new_sh_chan->id);
997         else
998                 snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
999                          "sh-dma%d", new_sh_chan->id);
1000
1001         /* set up channel irq */
1002         err = request_irq(irq, &sh_dmae_interrupt, flags,
1003                           new_sh_chan->dev_id, new_sh_chan);
1004         if (err) {
1005                 dev_err(shdev->common.dev, "DMA channel %d request_irq error "
1006                         "with return %d\n", id, err);
1007                 goto err_no_irq;
1008         }
1009
1010         shdev->chan[id] = new_sh_chan;
1011         return 0;
1012
1013 err_no_irq:
1014         /* remove from dmaengine device node */
1015         list_del(&new_sh_chan->common.device_node);
1016         kfree(new_sh_chan);
1017         return err;
1018 }
1019
1020 static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
1021 {
1022         int i;
1023
1024         for (i = shdev->common.chancnt - 1 ; i >= 0 ; i--) {
1025                 if (shdev->chan[i]) {
1026                         struct sh_dmae_chan *sh_chan = shdev->chan[i];
1027
1028                         free_irq(sh_chan->irq, sh_chan);
1029
1030                         list_del(&sh_chan->common.device_node);
1031                         kfree(sh_chan);
1032                         shdev->chan[i] = NULL;
1033                 }
1034         }
1035         shdev->common.chancnt = 0;
1036 }
1037
1038 static int __init sh_dmae_probe(struct platform_device *pdev)
1039 {
1040         struct sh_dmae_pdata *pdata = pdev->dev.platform_data;
1041         unsigned long irqflags = IRQF_DISABLED,
1042                 chan_flag[SH_DMAC_MAX_CHANNELS] = {};
1043         unsigned long flags;
1044         int errirq, chan_irq[SH_DMAC_MAX_CHANNELS];
1045         int err, i, irq_cnt = 0, irqres = 0;
1046         struct sh_dmae_device *shdev;
1047         struct resource *chan, *dmars, *errirq_res, *chanirq_res;
1048
1049         /* get platform data */
1050         if (!pdata || !pdata->channel_num)
1051                 return -ENODEV;
1052
1053         chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1054         /* DMARS area is optional, if absent, this controller cannot do slave DMA */
1055         dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1056         /*
1057          * IRQ resources:
1058          * 1. there always must be at least one IRQ IO-resource. On SH4 it is
1059          *    the error IRQ, in which case it is the only IRQ in this resource:
1060          *    start == end. If it is the only IRQ resource, all channels also
1061          *    use the same IRQ.
1062          * 2. DMA channel IRQ resources can be specified one per resource or in
1063          *    ranges (start != end)
1064          * 3. iff all events (channels and, optionally, error) on this
1065          *    controller use the same IRQ, only one IRQ resource can be
1066          *    specified, otherwise there must be one IRQ per channel, even if
1067          *    some of them are equal
1068          * 4. if all IRQs on this controller are equal or if some specific IRQs
1069          *    specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be
1070          *    requested with the IRQF_SHARED flag
1071          */
1072         errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1073         if (!chan || !errirq_res)
1074                 return -ENODEV;
1075
1076         if (!request_mem_region(chan->start, resource_size(chan), pdev->name)) {
1077                 dev_err(&pdev->dev, "DMAC register region already claimed\n");
1078                 return -EBUSY;
1079         }
1080
1081         if (dmars && !request_mem_region(dmars->start, resource_size(dmars), pdev->name)) {
1082                 dev_err(&pdev->dev, "DMAC DMARS region already claimed\n");
1083                 err = -EBUSY;
1084                 goto ermrdmars;
1085         }
1086
1087         err = -ENOMEM;
1088         shdev = kzalloc(sizeof(struct sh_dmae_device), GFP_KERNEL);
1089         if (!shdev) {
1090                 dev_err(&pdev->dev, "Not enough memory\n");
1091                 goto ealloc;
1092         }
1093
1094         shdev->chan_reg = ioremap(chan->start, resource_size(chan));
1095         if (!shdev->chan_reg)
1096                 goto emapchan;
1097         if (dmars) {
1098                 shdev->dmars = ioremap(dmars->start, resource_size(dmars));
1099                 if (!shdev->dmars)
1100                         goto emapdmars;
1101         }
1102
1103         /* platform data */
1104         shdev->pdata = pdata;
1105
1106         pm_runtime_enable(&pdev->dev);
1107         pm_runtime_get_sync(&pdev->dev);
1108
1109         spin_lock_irqsave(&sh_dmae_lock, flags);
1110         list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
1111         spin_unlock_irqrestore(&sh_dmae_lock, flags);
1112
1113         /* reset dma controller */
1114         err = sh_dmae_rst(shdev);
1115         if (err)
1116                 goto rst_err;
1117
1118         INIT_LIST_HEAD(&shdev->common.channels);
1119
1120         dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
1121         if (dmars)
1122                 dma_cap_set(DMA_SLAVE, shdev->common.cap_mask);
1123
1124         shdev->common.device_alloc_chan_resources
1125                 = sh_dmae_alloc_chan_resources;
1126         shdev->common.device_free_chan_resources = sh_dmae_free_chan_resources;
1127         shdev->common.device_prep_dma_memcpy = sh_dmae_prep_memcpy;
1128         shdev->common.device_tx_status = sh_dmae_tx_status;
1129         shdev->common.device_issue_pending = sh_dmae_memcpy_issue_pending;
1130
1131         /* Compulsory for DMA_SLAVE fields */
1132         shdev->common.device_prep_slave_sg = sh_dmae_prep_slave_sg;
1133         shdev->common.device_control = sh_dmae_control;
1134
1135         shdev->common.dev = &pdev->dev;
1136         /* Default transfer size of 32 bytes requires 32-byte alignment */
1137         shdev->common.copy_align = LOG2_DEFAULT_XFER_SIZE;
1138
1139 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
1140         chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
1141
1142         if (!chanirq_res)
1143                 chanirq_res = errirq_res;
1144         else
1145                 irqres++;
1146
1147         if (chanirq_res == errirq_res ||
1148             (errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE)
1149                 irqflags = IRQF_SHARED;
1150
1151         errirq = errirq_res->start;
1152
1153         err = request_irq(errirq, sh_dmae_err, irqflags,
1154                           "DMAC Address Error", shdev);
1155         if (err) {
1156                 dev_err(&pdev->dev,
1157                         "DMA failed requesting irq #%d, error %d\n",
1158                         errirq, err);
1159                 goto eirq_err;
1160         }
1161
1162 #else
1163         chanirq_res = errirq_res;
1164 #endif /* CONFIG_CPU_SH4 || CONFIG_ARCH_SHMOBILE */
1165
1166         if (chanirq_res->start == chanirq_res->end &&
1167             !platform_get_resource(pdev, IORESOURCE_IRQ, 1)) {
1168                 /* Special case - all multiplexed */
1169                 for (; irq_cnt < pdata->channel_num; irq_cnt++) {
1170                         chan_irq[irq_cnt] = chanirq_res->start;
1171                         chan_flag[irq_cnt] = IRQF_SHARED;
1172                 }
1173         } else {
1174                 do {
1175                         for (i = chanirq_res->start; i <= chanirq_res->end; i++) {
1176                                 if ((errirq_res->flags & IORESOURCE_BITS) ==
1177                                     IORESOURCE_IRQ_SHAREABLE)
1178                                         chan_flag[irq_cnt] = IRQF_SHARED;
1179                                 else
1180                                         chan_flag[irq_cnt] = IRQF_DISABLED;
1181                                 dev_dbg(&pdev->dev,
1182                                         "Found IRQ %d for channel %d\n",
1183                                         i, irq_cnt);
1184                                 chan_irq[irq_cnt++] = i;
1185                         }
1186                         chanirq_res = platform_get_resource(pdev,
1187                                                 IORESOURCE_IRQ, ++irqres);
1188                 } while (irq_cnt < pdata->channel_num && chanirq_res);
1189         }
1190
1191         if (irq_cnt < pdata->channel_num)
1192                 goto eirqres;
1193
1194         /* Create DMA Channel */
1195         for (i = 0; i < pdata->channel_num; i++) {
1196                 err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]);
1197                 if (err)
1198                         goto chan_probe_err;
1199         }
1200
1201         pm_runtime_put(&pdev->dev);
1202
1203         platform_set_drvdata(pdev, shdev);
1204         dma_async_device_register(&shdev->common);
1205
1206         return err;
1207
1208 chan_probe_err:
1209         sh_dmae_chan_remove(shdev);
1210 eirqres:
1211 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
1212         free_irq(errirq, shdev);
1213 eirq_err:
1214 #endif
1215 rst_err:
1216         spin_lock_irqsave(&sh_dmae_lock, flags);
1217         list_del_rcu(&shdev->node);
1218         spin_unlock_irqrestore(&sh_dmae_lock, flags);
1219
1220         pm_runtime_put(&pdev->dev);
1221         if (dmars)
1222                 iounmap(shdev->dmars);
1223 emapdmars:
1224         iounmap(shdev->chan_reg);
1225 emapchan:
1226         kfree(shdev);
1227 ealloc:
1228         if (dmars)
1229                 release_mem_region(dmars->start, resource_size(dmars));
1230 ermrdmars:
1231         release_mem_region(chan->start, resource_size(chan));
1232
1233         return err;
1234 }
1235
1236 static int __exit sh_dmae_remove(struct platform_device *pdev)
1237 {
1238         struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
1239         struct resource *res;
1240         unsigned long flags;
1241         int errirq = platform_get_irq(pdev, 0);
1242
1243         dma_async_device_unregister(&shdev->common);
1244
1245         if (errirq > 0)
1246                 free_irq(errirq, shdev);
1247
1248         spin_lock_irqsave(&sh_dmae_lock, flags);
1249         list_del_rcu(&shdev->node);
1250         spin_unlock_irqrestore(&sh_dmae_lock, flags);
1251
1252         /* channel data remove */
1253         sh_dmae_chan_remove(shdev);
1254
1255         pm_runtime_disable(&pdev->dev);
1256
1257         if (shdev->dmars)
1258                 iounmap(shdev->dmars);
1259         iounmap(shdev->chan_reg);
1260
1261         kfree(shdev);
1262
1263         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1264         if (res)
1265                 release_mem_region(res->start, resource_size(res));
1266         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1267         if (res)
1268                 release_mem_region(res->start, resource_size(res));
1269
1270         return 0;
1271 }
1272
1273 static void sh_dmae_shutdown(struct platform_device *pdev)
1274 {
1275         struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
1276         sh_dmae_ctl_stop(shdev);
1277 }
1278
1279 static struct platform_driver sh_dmae_driver = {
1280         .remove         = __exit_p(sh_dmae_remove),
1281         .shutdown       = sh_dmae_shutdown,
1282         .driver = {
1283                 .owner  = THIS_MODULE,
1284                 .name   = "sh-dma-engine",
1285         },
1286 };
1287
1288 static int __init sh_dmae_init(void)
1289 {
1290         /* Wire up NMI handling */
1291         int err = register_die_notifier(&sh_dmae_nmi_notifier);
1292         if (err)
1293                 return err;
1294
1295         return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
1296 }
1297 module_init(sh_dmae_init);
1298
1299 static void __exit sh_dmae_exit(void)
1300 {
1301         platform_driver_unregister(&sh_dmae_driver);
1302
1303         unregister_die_notifier(&sh_dmae_nmi_notifier);
1304 }
1305 module_exit(sh_dmae_exit);
1306
1307 MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
1308 MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
1309 MODULE_LICENSE("GPL");
1310 MODULE_ALIAS("platform:sh-dma-engine");