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1/*****************************************************************************
2* Copyright 2004 - 2008 Broadcom Corporation. All rights reserved.
3*
4* Unless you and Broadcom execute a separate written software license
5* agreement governing use of this software, this software is licensed to you
6* under the terms of the GNU General Public License version 2, available at
7* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
8*
9* Notwithstanding the above, under no circumstances may you combine this
10* software in any way with any other Broadcom software provided under a
11* license other than the GPL, without Broadcom's express prior written
12* consent.
13*****************************************************************************/
14
15/****************************************************************************/
16/**
17* @file dma.c
18*
19* @brief Implements the DMA interface.
20*/
21/****************************************************************************/
22
23/* ---- Include Files ---------------------------------------------------- */
24
25#include <linux/module.h>
26#include <linux/device.h>
27#include <linux/dma-mapping.h>
28#include <linux/interrupt.h>
29#include <linux/sched.h>
30#include <linux/irqreturn.h>
31#include <linux/proc_fs.h>
32#include <linux/slab.h>
33
34#include <mach/timer.h>
35
36#include <linux/pfn.h>
37#include <linux/atomic.h>
38#include <mach/dma.h>
39
40/* ---- Public Variables ------------------------------------------------- */
41
42/* ---- Private Constants and Types -------------------------------------- */
43
44#define MAKE_HANDLE(controllerIdx, channelIdx) (((controllerIdx) << 4) | (channelIdx))
45
46#define CONTROLLER_FROM_HANDLE(handle) (((handle) >> 4) & 0x0f)
47#define CHANNEL_FROM_HANDLE(handle) ((handle) & 0x0f)
48
49
50/* ---- Private Variables ------------------------------------------------ */
51
52static DMA_Global_t gDMA;
53static struct proc_dir_entry *gDmaDir;
54
55#include "dma_device.c"
56
57/* ---- Private Function Prototypes -------------------------------------- */
58
59/* ---- Functions ------------------------------------------------------- */
60
61/****************************************************************************/
62/**
63* Displays information for /proc/dma/channels
64*/
65/****************************************************************************/
66
67static int dma_proc_read_channels(char *buf, char **start, off_t offset,
68 int count, int *eof, void *data)
69{
70 int controllerIdx;
71 int channelIdx;
72 int limit = count - 200;
73 int len = 0;
74 DMA_Channel_t *channel;
75
76 if (down_interruptible(&gDMA.lock) < 0) {
77 return -ERESTARTSYS;
78 }
79
80 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
81 controllerIdx++) {
82 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
83 channelIdx++) {
84 if (len >= limit) {
85 break;
86 }
87
88 channel =
89 &gDMA.controller[controllerIdx].channel[channelIdx];
90
91 len +=
92 sprintf(buf + len, "%d:%d ", controllerIdx,
93 channelIdx);
94
95 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
96 0) {
97 len +=
98 sprintf(buf + len, "Dedicated for %s ",
99 DMA_gDeviceAttribute[channel->
100 devType].name);
101 } else {
102 len += sprintf(buf + len, "Shared ");
103 }
104
105 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) != 0) {
106 len += sprintf(buf + len, "No ISR ");
107 }
108
109 if ((channel->flags & DMA_CHANNEL_FLAG_LARGE_FIFO) != 0) {
110 len += sprintf(buf + len, "Fifo: 128 ");
111 } else {
112 len += sprintf(buf + len, "Fifo: 64 ");
113 }
114
115 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
116 len +=
117 sprintf(buf + len, "InUse by %s",
118 DMA_gDeviceAttribute[channel->
119 devType].name);
120#if (DMA_DEBUG_TRACK_RESERVATION)
121 len +=
122 sprintf(buf + len, " (%s:%d)",
123 channel->fileName,
124 channel->lineNum);
125#endif
126 } else {
127 len += sprintf(buf + len, "Avail ");
128 }
129
130 if (channel->lastDevType != DMA_DEVICE_NONE) {
131 len +=
132 sprintf(buf + len, "Last use: %s ",
133 DMA_gDeviceAttribute[channel->
134 lastDevType].
135 name);
136 }
137
138 len += sprintf(buf + len, "\n");
139 }
140 }
141 up(&gDMA.lock);
142 *eof = 1;
143
144 return len;
145}
146
147/****************************************************************************/
148/**
149* Displays information for /proc/dma/devices
150*/
151/****************************************************************************/
152
153static int dma_proc_read_devices(char *buf, char **start, off_t offset,
154 int count, int *eof, void *data)
155{
156 int limit = count - 200;
157 int len = 0;
158 int devIdx;
159
160 if (down_interruptible(&gDMA.lock) < 0) {
161 return -ERESTARTSYS;
162 }
163
164 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
165 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
166
167 if (devAttr->name == NULL) {
168 continue;
169 }
170
171 if (len >= limit) {
172 break;
173 }
174
175 len += sprintf(buf + len, "%-12s ", devAttr->name);
176
177 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
178 len +=
179 sprintf(buf + len, "Dedicated %d:%d ",
180 devAttr->dedicatedController,
181 devAttr->dedicatedChannel);
182 } else {
183 len += sprintf(buf + len, "Shared DMA:");
184 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA0) != 0) {
185 len += sprintf(buf + len, "0");
186 }
187 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA1) != 0) {
188 len += sprintf(buf + len, "1");
189 }
190 len += sprintf(buf + len, " ");
191 }
192 if ((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0) {
193 len += sprintf(buf + len, "NoISR ");
194 }
195 if ((devAttr->flags & DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO) != 0) {
196 len += sprintf(buf + len, "Allow-128 ");
197 }
198
199 len +=
200 sprintf(buf + len,
201 "Xfer #: %Lu Ticks: %Lu Bytes: %Lu DescLen: %u\n",
202 devAttr->numTransfers, devAttr->transferTicks,
203 devAttr->transferBytes,
204 devAttr->ring.bytesAllocated);
205
206 }
207
208 up(&gDMA.lock);
209 *eof = 1;
210
211 return len;
212}
213
214/****************************************************************************/
215/**
216* Determines if a DMA_Device_t is "valid".
217*
218* @return
219* TRUE - dma device is valid
220* FALSE - dma device isn't valid
221*/
222/****************************************************************************/
223
224static inline int IsDeviceValid(DMA_Device_t device)
225{
226 return (device >= 0) && (device < DMA_NUM_DEVICE_ENTRIES);
227}
228
229/****************************************************************************/
230/**
231* Translates a DMA handle into a pointer to a channel.
232*
233* @return
234* non-NULL - pointer to DMA_Channel_t
235* NULL - DMA Handle was invalid
236*/
237/****************************************************************************/
238
239static inline DMA_Channel_t *HandleToChannel(DMA_Handle_t handle)
240{
241 int controllerIdx;
242 int channelIdx;
243
244 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
245 channelIdx = CHANNEL_FROM_HANDLE(handle);
246
247 if ((controllerIdx > DMA_NUM_CONTROLLERS)
248 || (channelIdx > DMA_NUM_CHANNELS)) {
249 return NULL;
250 }
251 return &gDMA.controller[controllerIdx].channel[channelIdx];
252}
253
254/****************************************************************************/
255/**
256* Interrupt handler which is called to process DMA interrupts.
257*/
258/****************************************************************************/
259
260static irqreturn_t dma_interrupt_handler(int irq, void *dev_id)
261{
262 DMA_Channel_t *channel;
263 DMA_DeviceAttribute_t *devAttr;
264 int irqStatus;
265
266 channel = (DMA_Channel_t *) dev_id;
267
268 /* Figure out why we were called, and knock down the interrupt */
269
270 irqStatus = dmacHw_getInterruptStatus(channel->dmacHwHandle);
271 dmacHw_clearInterrupt(channel->dmacHwHandle);
272
273 if ((channel->devType < 0)
274 || (channel->devType > DMA_NUM_DEVICE_ENTRIES)) {
275 printk(KERN_ERR "dma_interrupt_handler: Invalid devType: %d\n",
276 channel->devType);
277 return IRQ_NONE;
278 }
279 devAttr = &DMA_gDeviceAttribute[channel->devType];
280
281 /* Update stats */
282
283 if ((irqStatus & dmacHw_INTERRUPT_STATUS_TRANS) != 0) {
284 devAttr->transferTicks +=
285 (timer_get_tick_count() - devAttr->transferStartTime);
286 }
287
288 if ((irqStatus & dmacHw_INTERRUPT_STATUS_ERROR) != 0) {
289 printk(KERN_ERR
290 "dma_interrupt_handler: devType :%d DMA error (%s)\n",
291 channel->devType, devAttr->name);
292 } else {
293 devAttr->numTransfers++;
294 devAttr->transferBytes += devAttr->numBytes;
295 }
296
297 /* Call any installed handler */
298
299 if (devAttr->devHandler != NULL) {
300 devAttr->devHandler(channel->devType, irqStatus,
301 devAttr->userData);
302 }
303
304 return IRQ_HANDLED;
305}
306
307/****************************************************************************/
308/**
309* Allocates memory to hold a descriptor ring. The descriptor ring then
310* needs to be populated by making one or more calls to
311* dna_add_descriptors.
312*
313* The returned descriptor ring will be automatically initialized.
314*
315* @return
316* 0 Descriptor ring was allocated successfully
317* -EINVAL Invalid parameters passed in
318* -ENOMEM Unable to allocate memory for the desired number of descriptors.
319*/
320/****************************************************************************/
321
322int dma_alloc_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to populate */
323 int numDescriptors /* Number of descriptors that need to be allocated. */
324 ) {
325 size_t bytesToAlloc = dmacHw_descriptorLen(numDescriptors);
326
327 if ((ring == NULL) || (numDescriptors <= 0)) {
328 return -EINVAL;
329 }
330
331 ring->physAddr = 0;
332 ring->descriptorsAllocated = 0;
333 ring->bytesAllocated = 0;
334
335 ring->virtAddr = dma_alloc_writecombine(NULL,
336 bytesToAlloc,
337 &ring->physAddr,
338 GFP_KERNEL);
339 if (ring->virtAddr == NULL) {
340 return -ENOMEM;
341 }
342
343 ring->bytesAllocated = bytesToAlloc;
344 ring->descriptorsAllocated = numDescriptors;
345
346 return dma_init_descriptor_ring(ring, numDescriptors);
347}
348
349EXPORT_SYMBOL(dma_alloc_descriptor_ring);
350
351/****************************************************************************/
352/**
353* Releases the memory which was previously allocated for a descriptor ring.
354*/
355/****************************************************************************/
356
357void dma_free_descriptor_ring(DMA_DescriptorRing_t *ring /* Descriptor to release */
358 ) {
359 if (ring->virtAddr != NULL) {
360 dma_free_writecombine(NULL,
361 ring->bytesAllocated,
362 ring->virtAddr, ring->physAddr);
363 }
364
365 ring->bytesAllocated = 0;
366 ring->descriptorsAllocated = 0;
367 ring->virtAddr = NULL;
368 ring->physAddr = 0;
369}
370
371EXPORT_SYMBOL(dma_free_descriptor_ring);
372
373/****************************************************************************/
374/**
375* Initializes a descriptor ring, so that descriptors can be added to it.
376* Once a descriptor ring has been allocated, it may be reinitialized for
377* use with additional/different regions of memory.
378*
379* Note that if 7 descriptors are allocated, it's perfectly acceptable to
380* initialize the ring with a smaller number of descriptors. The amount
381* of memory allocated for the descriptor ring will not be reduced, and
382* the descriptor ring may be reinitialized later
383*
384* @return
385* 0 Descriptor ring was initialized successfully
386* -ENOMEM The descriptor which was passed in has insufficient space
387* to hold the desired number of descriptors.
388*/
389/****************************************************************************/
390
391int dma_init_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to initialize */
392 int numDescriptors /* Number of descriptors to initialize. */
393 ) {
394 if (ring->virtAddr == NULL) {
395 return -EINVAL;
396 }
397 if (dmacHw_initDescriptor(ring->virtAddr,
398 ring->physAddr,
399 ring->bytesAllocated, numDescriptors) < 0) {
400 printk(KERN_ERR
401 "dma_init_descriptor_ring: dmacHw_initDescriptor failed\n");
402 return -ENOMEM;
403 }
404
405 return 0;
406}
407
408EXPORT_SYMBOL(dma_init_descriptor_ring);
409
410/****************************************************************************/
411/**
412* Determines the number of descriptors which would be required for a
413* transfer of the indicated memory region.
414*
415* This function also needs to know which DMA device this transfer will
416* be destined for, so that the appropriate DMA configuration can be retrieved.
417* DMA parameters such as transfer width, and whether this is a memory-to-memory
418* or memory-to-peripheral, etc can all affect the actual number of descriptors
419* required.
420*
421* @return
422* > 0 Returns the number of descriptors required for the indicated transfer
423* -ENODEV - Device handed in is invalid.
424* -EINVAL Invalid parameters
425* -ENOMEM Memory exhausted
426*/
427/****************************************************************************/
428
429int dma_calculate_descriptor_count(DMA_Device_t device, /* DMA Device that this will be associated with */
430 dma_addr_t srcData, /* Place to get data to write to device */
431 dma_addr_t dstData, /* Pointer to device data address */
432 size_t numBytes /* Number of bytes to transfer to the device */
433 ) {
434 int numDescriptors;
435 DMA_DeviceAttribute_t *devAttr;
436
437 if (!IsDeviceValid(device)) {
438 return -ENODEV;
439 }
440 devAttr = &DMA_gDeviceAttribute[device];
441
442 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
443 (void *)srcData,
444 (void *)dstData,
445 numBytes);
446 if (numDescriptors < 0) {
447 printk(KERN_ERR
448 "dma_calculate_descriptor_count: dmacHw_calculateDescriptorCount failed\n");
449 return -EINVAL;
450 }
451
452 return numDescriptors;
453}
454
455EXPORT_SYMBOL(dma_calculate_descriptor_count);
456
457/****************************************************************************/
458/**
459* Adds a region of memory to the descriptor ring. Note that it may take
460* multiple descriptors for each region of memory. It is the callers
461* responsibility to allocate a sufficiently large descriptor ring.
462*
463* @return
464* 0 Descriptors were added successfully
465* -ENODEV Device handed in is invalid.
466* -EINVAL Invalid parameters
467* -ENOMEM Memory exhausted
468*/
469/****************************************************************************/
470
471int dma_add_descriptors(DMA_DescriptorRing_t *ring, /* Descriptor ring to add descriptors to */
472 DMA_Device_t device, /* DMA Device that descriptors are for */
473 dma_addr_t srcData, /* Place to get data (memory or device) */
474 dma_addr_t dstData, /* Place to put data (memory or device) */
475 size_t numBytes /* Number of bytes to transfer to the device */
476 ) {
477 int rc;
478 DMA_DeviceAttribute_t *devAttr;
479
480 if (!IsDeviceValid(device)) {
481 return -ENODEV;
482 }
483 devAttr = &DMA_gDeviceAttribute[device];
484
485 rc = dmacHw_setDataDescriptor(&devAttr->config,
486 ring->virtAddr,
487 (void *)srcData,
488 (void *)dstData, numBytes);
489 if (rc < 0) {
490 printk(KERN_ERR
491 "dma_add_descriptors: dmacHw_setDataDescriptor failed with code: %d\n",
492 rc);
493 return -ENOMEM;
494 }
495
496 return 0;
497}
498
499EXPORT_SYMBOL(dma_add_descriptors);
500
501/****************************************************************************/
502/**
503* Sets the descriptor ring associated with a device.
504*
505* Once set, the descriptor ring will be associated with the device, even
506* across channel request/free calls. Passing in a NULL descriptor ring
507* will release any descriptor ring currently associated with the device.
508*
509* Note: If you call dma_transfer, or one of the other dma_alloc_ functions
510* the descriptor ring may be released and reallocated.
511*
512* Note: This function will release the descriptor memory for any current
513* descriptor ring associated with this device.
514*
515* @return
516* 0 Descriptors were added successfully
517* -ENODEV Device handed in is invalid.
518*/
519/****************************************************************************/
520
521int dma_set_device_descriptor_ring(DMA_Device_t device, /* Device to update the descriptor ring for. */
522 DMA_DescriptorRing_t *ring /* Descriptor ring to add descriptors to */
523 ) {
524 DMA_DeviceAttribute_t *devAttr;
525
526 if (!IsDeviceValid(device)) {
527 return -ENODEV;
528 }
529 devAttr = &DMA_gDeviceAttribute[device];
530
531 /* Free the previously allocated descriptor ring */
532
533 dma_free_descriptor_ring(&devAttr->ring);
534
535 if (ring != NULL) {
536 /* Copy in the new one */
537
538 devAttr->ring = *ring;
539 }
540
541 /* Set things up so that if dma_transfer is called then this descriptor */
542 /* ring will get freed. */
543
544 devAttr->prevSrcData = 0;
545 devAttr->prevDstData = 0;
546 devAttr->prevNumBytes = 0;
547
548 return 0;
549}
550
551EXPORT_SYMBOL(dma_set_device_descriptor_ring);
552
553/****************************************************************************/
554/**
555* Retrieves the descriptor ring associated with a device.
556*
557* @return
558* 0 Descriptors were added successfully
559* -ENODEV Device handed in is invalid.
560*/
561/****************************************************************************/
562
563int dma_get_device_descriptor_ring(DMA_Device_t device, /* Device to retrieve the descriptor ring for. */
564 DMA_DescriptorRing_t *ring /* Place to store retrieved ring */
565 ) {
566 DMA_DeviceAttribute_t *devAttr;
567
568 memset(ring, 0, sizeof(*ring));
569
570 if (!IsDeviceValid(device)) {
571 return -ENODEV;
572 }
573 devAttr = &DMA_gDeviceAttribute[device];
574
575 *ring = devAttr->ring;
576
577 return 0;
578}
579
580EXPORT_SYMBOL(dma_get_device_descriptor_ring);
581
582/****************************************************************************/
583/**
584* Configures a DMA channel.
585*
586* @return
587* >= 0 - Initialization was successful.
588*
589* -EBUSY - Device is currently being used.
590* -ENODEV - Device handed in is invalid.
591*/
592/****************************************************************************/
593
594static int ConfigChannel(DMA_Handle_t handle)
595{
596 DMA_Channel_t *channel;
597 DMA_DeviceAttribute_t *devAttr;
598 int controllerIdx;
599
600 channel = HandleToChannel(handle);
601 if (channel == NULL) {
602 return -ENODEV;
603 }
604 devAttr = &DMA_gDeviceAttribute[channel->devType];
605 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
606
607 if ((devAttr->flags & DMA_DEVICE_FLAG_PORT_PER_DMAC) != 0) {
608 if (devAttr->config.transferType ==
609 dmacHw_TRANSFER_TYPE_MEM_TO_PERIPHERAL) {
610 devAttr->config.dstPeripheralPort =
611 devAttr->dmacPort[controllerIdx];
612 } else if (devAttr->config.transferType ==
613 dmacHw_TRANSFER_TYPE_PERIPHERAL_TO_MEM) {
614 devAttr->config.srcPeripheralPort =
615 devAttr->dmacPort[controllerIdx];
616 }
617 }
618
619 if (dmacHw_configChannel(channel->dmacHwHandle, &devAttr->config) != 0) {
620 printk(KERN_ERR "ConfigChannel: dmacHw_configChannel failed\n");
621 return -EIO;
622 }
623
624 return 0;
625}
626
627/****************************************************************************/
628/**
629* Initializes all of the data structures associated with the DMA.
630* @return
631* >= 0 - Initialization was successful.
632*
633* -EBUSY - Device is currently being used.
634* -ENODEV - Device handed in is invalid.
635*/
636/****************************************************************************/
637
638int dma_init(void)
639{
640 int rc = 0;
641 int controllerIdx;
642 int channelIdx;
643 DMA_Device_t devIdx;
644 DMA_Channel_t *channel;
645 DMA_Handle_t dedicatedHandle;
646
647 memset(&gDMA, 0, sizeof(gDMA));
648
649 sema_init(&gDMA.lock, 0);
650 init_waitqueue_head(&gDMA.freeChannelQ);
651
652 /* Initialize the Hardware */
653
654 dmacHw_initDma();
655
656 /* Start off by marking all of the DMA channels as shared. */
657
658 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
659 controllerIdx++) {
660 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
661 channelIdx++) {
662 channel =
663 &gDMA.controller[controllerIdx].channel[channelIdx];
664
665 channel->flags = 0;
666 channel->devType = DMA_DEVICE_NONE;
667 channel->lastDevType = DMA_DEVICE_NONE;
668
669#if (DMA_DEBUG_TRACK_RESERVATION)
670 channel->fileName = "";
671 channel->lineNum = 0;
672#endif
673
674 channel->dmacHwHandle =
675 dmacHw_getChannelHandle(dmacHw_MAKE_CHANNEL_ID
676 (controllerIdx,
677 channelIdx));
678 dmacHw_initChannel(channel->dmacHwHandle);
679 }
680 }
681
682 /* Record any special attributes that channels may have */
683
684 gDMA.controller[0].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
685 gDMA.controller[0].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
686 gDMA.controller[1].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
687 gDMA.controller[1].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
688
689 /* Now walk through and record the dedicated channels. */
690
691 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
692 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
693
694 if (((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0)
695 && ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0)) {
696 printk(KERN_ERR
697 "DMA Device: %s Can only request NO_ISR for dedicated devices\n",
698 devAttr->name);
699 rc = -EINVAL;
700 goto out;
701 }
702
703 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
704 /* This is a dedicated device. Mark the channel as being reserved. */
705
706 if (devAttr->dedicatedController >= DMA_NUM_CONTROLLERS) {
707 printk(KERN_ERR
708 "DMA Device: %s DMA Controller %d is out of range\n",
709 devAttr->name,
710 devAttr->dedicatedController);
711 rc = -EINVAL;
712 goto out;
713 }
714
715 if (devAttr->dedicatedChannel >= DMA_NUM_CHANNELS) {
716 printk(KERN_ERR
717 "DMA Device: %s DMA Channel %d is out of range\n",
718 devAttr->name,
719 devAttr->dedicatedChannel);
720 rc = -EINVAL;
721 goto out;
722 }
723
724 dedicatedHandle =
725 MAKE_HANDLE(devAttr->dedicatedController,
726 devAttr->dedicatedChannel);
727 channel = HandleToChannel(dedicatedHandle);
728
729 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
730 0) {
731 printk
732 ("DMA Device: %s attempting to use same DMA Controller:Channel (%d:%d) as %s\n",
733 devAttr->name,
734 devAttr->dedicatedController,
735 devAttr->dedicatedChannel,
736 DMA_gDeviceAttribute[channel->devType].
737 name);
738 rc = -EBUSY;
739 goto out;
740 }
741
742 channel->flags |= DMA_CHANNEL_FLAG_IS_DEDICATED;
743 channel->devType = devIdx;
744
745 if (devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) {
746 channel->flags |= DMA_CHANNEL_FLAG_NO_ISR;
747 }
748
749 /* For dedicated channels, we can go ahead and configure the DMA channel now */
750 /* as well. */
751
752 ConfigChannel(dedicatedHandle);
753 }
754 }
755
756 /* Go through and register the interrupt handlers */
757
758 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
759 controllerIdx++) {
760 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
761 channelIdx++) {
762 channel =
763 &gDMA.controller[controllerIdx].channel[channelIdx];
764
765 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) == 0) {
766 snprintf(channel->name, sizeof(channel->name),
767 "dma %d:%d %s", controllerIdx,
768 channelIdx,
769 channel->devType ==
770 DMA_DEVICE_NONE ? "" :
771 DMA_gDeviceAttribute[channel->devType].
772 name);
773
774 rc =
775 request_irq(IRQ_DMA0C0 +
776 (controllerIdx *
777 DMA_NUM_CHANNELS) +
778 channelIdx,
779 dma_interrupt_handler,
780 IRQF_DISABLED, channel->name,
781 channel);
782 if (rc != 0) {
783 printk(KERN_ERR
784 "request_irq for IRQ_DMA%dC%d failed\n",
785 controllerIdx, channelIdx);
786 }
787 }
788 }
789 }
790
791 /* Create /proc/dma/channels and /proc/dma/devices */
792
793 gDmaDir = proc_mkdir("dma", NULL);
794
795 if (gDmaDir == NULL) {
796 printk(KERN_ERR "Unable to create /proc/dma\n");
797 } else {
798 create_proc_read_entry("channels", 0, gDmaDir,
799 dma_proc_read_channels, NULL);
800 create_proc_read_entry("devices", 0, gDmaDir,
801 dma_proc_read_devices, NULL);
802 }
803
804out:
805
806 up(&gDMA.lock);
807
808 return rc;
809}
810
811/****************************************************************************/
812/**
813* Reserves a channel for use with @a dev. If the device is setup to use
814* a shared channel, then this function will block until a free channel
815* becomes available.
816*
817* @return
818* >= 0 - A valid DMA Handle.
819* -EBUSY - Device is currently being used.
820* -ENODEV - Device handed in is invalid.
821*/
822/****************************************************************************/
823
824#if (DMA_DEBUG_TRACK_RESERVATION)
825DMA_Handle_t dma_request_channel_dbg
826 (DMA_Device_t dev, const char *fileName, int lineNum)
827#else
828DMA_Handle_t dma_request_channel(DMA_Device_t dev)
829#endif
830{
831 DMA_Handle_t handle;
832 DMA_DeviceAttribute_t *devAttr;
833 DMA_Channel_t *channel;
834 int controllerIdx;
835 int controllerIdx2;
836 int channelIdx;
837
838 if (down_interruptible(&gDMA.lock) < 0) {
839 return -ERESTARTSYS;
840 }
841
842 if ((dev < 0) || (dev >= DMA_NUM_DEVICE_ENTRIES)) {
843 handle = -ENODEV;
844 goto out;
845 }
846 devAttr = &DMA_gDeviceAttribute[dev];
847
848#if (DMA_DEBUG_TRACK_RESERVATION)
849 {
850 char *s;
851
852 s = strrchr(fileName, '/');
853 if (s != NULL) {
854 fileName = s + 1;
855 }
856 }
857#endif
858 if ((devAttr->flags & DMA_DEVICE_FLAG_IN_USE) != 0) {
859 /* This device has already been requested and not been freed */
860
861 printk(KERN_ERR "%s: device %s is already requested\n",
862 __func__, devAttr->name);
863 handle = -EBUSY;
864 goto out;
865 }
866
867 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
868 /* This device has a dedicated channel. */
869
870 channel =
871 &gDMA.controller[devAttr->dedicatedController].
872 channel[devAttr->dedicatedChannel];
873 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
874 handle = -EBUSY;
875 goto out;
876 }
877
878 channel->flags |= DMA_CHANNEL_FLAG_IN_USE;
879 devAttr->flags |= DMA_DEVICE_FLAG_IN_USE;
880
881#if (DMA_DEBUG_TRACK_RESERVATION)
882 channel->fileName = fileName;
883 channel->lineNum = lineNum;
884#endif
885 handle =
886 MAKE_HANDLE(devAttr->dedicatedController,
887 devAttr->dedicatedChannel);
888 goto out;
889 }
890
891 /* This device needs to use one of the shared channels. */
892
893 handle = DMA_INVALID_HANDLE;
894 while (handle == DMA_INVALID_HANDLE) {
895 /* Scan through the shared channels and see if one is available */
896
897 for (controllerIdx2 = 0; controllerIdx2 < DMA_NUM_CONTROLLERS;
898 controllerIdx2++) {
899 /* Check to see if we should try on controller 1 first. */
900
901 controllerIdx = controllerIdx2;
902 if ((devAttr->
903 flags & DMA_DEVICE_FLAG_ALLOC_DMA1_FIRST) != 0) {
904 controllerIdx = 1 - controllerIdx;
905 }
906
907 /* See if the device is available on the controller being tested */
908
909 if ((devAttr->
910 flags & (DMA_DEVICE_FLAG_ON_DMA0 << controllerIdx))
911 != 0) {
912 for (channelIdx = 0;
913 channelIdx < DMA_NUM_CHANNELS;
914 channelIdx++) {
915 channel =
916 &gDMA.controller[controllerIdx].
917 channel[channelIdx];
918
919 if (((channel->
920 flags &
921 DMA_CHANNEL_FLAG_IS_DEDICATED) ==
922 0)
923 &&
924 ((channel->
925 flags & DMA_CHANNEL_FLAG_IN_USE)
926 == 0)) {
927 if (((channel->
928 flags &
929 DMA_CHANNEL_FLAG_LARGE_FIFO)
930 != 0)
931 &&
932 ((devAttr->
933 flags &
934 DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO)
935 == 0)) {
936 /* This channel is a large fifo - don't tie it up */
937 /* with devices that we don't want using it. */
938
939 continue;
940 }
941
942 channel->flags |=
943 DMA_CHANNEL_FLAG_IN_USE;
944 channel->devType = dev;
945 devAttr->flags |=
946 DMA_DEVICE_FLAG_IN_USE;
947
948#if (DMA_DEBUG_TRACK_RESERVATION)
949 channel->fileName = fileName;
950 channel->lineNum = lineNum;
951#endif
952 handle =
953 MAKE_HANDLE(controllerIdx,
954 channelIdx);
955
956 /* Now that we've reserved the channel - we can go ahead and configure it */
957
958 if (ConfigChannel(handle) != 0) {
959 handle = -EIO;
960 printk(KERN_ERR
961 "dma_request_channel: ConfigChannel failed\n");
962 }
963 goto out;
964 }
965 }
966 }
967 }
968
969 /* No channels are currently available. Let's wait for one to free up. */
970
971 {
972 DEFINE_WAIT(wait);
973
974 prepare_to_wait(&gDMA.freeChannelQ, &wait,
975 TASK_INTERRUPTIBLE);
976 up(&gDMA.lock);
977 schedule();
978 finish_wait(&gDMA.freeChannelQ, &wait);
979
980 if (signal_pending(current)) {
981 /* We don't currently hold gDMA.lock, so we return directly */
982
983 return -ERESTARTSYS;
984 }
985 }
986
987 if (down_interruptible(&gDMA.lock)) {
988 return -ERESTARTSYS;
989 }
990 }
991
992out:
993 up(&gDMA.lock);
994
995 return handle;
996}
997
998/* Create both _dbg and non _dbg functions for modules. */
999
1000#if (DMA_DEBUG_TRACK_RESERVATION)
1001#undef dma_request_channel
1002DMA_Handle_t dma_request_channel(DMA_Device_t dev)
1003{
1004 return dma_request_channel_dbg(dev, __FILE__, __LINE__);
1005}
1006
1007EXPORT_SYMBOL(dma_request_channel_dbg);
1008#endif
1009EXPORT_SYMBOL(dma_request_channel);
1010
1011/****************************************************************************/
1012/**
1013* Frees a previously allocated DMA Handle.
1014*/
1015/****************************************************************************/
1016
1017int dma_free_channel(DMA_Handle_t handle /* DMA handle. */
1018 ) {
1019 int rc = 0;
1020 DMA_Channel_t *channel;
1021 DMA_DeviceAttribute_t *devAttr;
1022
1023 if (down_interruptible(&gDMA.lock) < 0) {
1024 return -ERESTARTSYS;
1025 }
1026
1027 channel = HandleToChannel(handle);
1028 if (channel == NULL) {
1029 rc = -EINVAL;
1030 goto out;
1031 }
1032
1033 devAttr = &DMA_gDeviceAttribute[channel->devType];
1034
1035 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) == 0) {
1036 channel->lastDevType = channel->devType;
1037 channel->devType = DMA_DEVICE_NONE;
1038 }
1039 channel->flags &= ~DMA_CHANNEL_FLAG_IN_USE;
1040 devAttr->flags &= ~DMA_DEVICE_FLAG_IN_USE;
1041
1042out:
1043 up(&gDMA.lock);
1044
1045 wake_up_interruptible(&gDMA.freeChannelQ);
1046
1047 return rc;
1048}
1049
1050EXPORT_SYMBOL(dma_free_channel);
1051
1052/****************************************************************************/
1053/**
1054* Determines if a given device has been configured as using a shared
1055* channel.
1056*
1057* @return
1058* 0 Device uses a dedicated channel
1059* > zero Device uses a shared channel
1060* < zero Error code
1061*/
1062/****************************************************************************/
1063
1064int dma_device_is_channel_shared(DMA_Device_t device /* Device to check. */
1065 ) {
1066 DMA_DeviceAttribute_t *devAttr;
1067
1068 if (!IsDeviceValid(device)) {
1069 return -ENODEV;
1070 }
1071 devAttr = &DMA_gDeviceAttribute[device];
1072
1073 return ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0);
1074}
1075
1076EXPORT_SYMBOL(dma_device_is_channel_shared);
1077
1078/****************************************************************************/
1079/**
1080* Allocates buffers for the descriptors. This is normally done automatically
1081* but needs to be done explicitly when initiating a dma from interrupt
1082* context.
1083*
1084* @return
1085* 0 Descriptors were allocated successfully
1086* -EINVAL Invalid device type for this kind of transfer
1087* (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1088* -ENOMEM Memory exhausted
1089*/
1090/****************************************************************************/
1091
1092int dma_alloc_descriptors(DMA_Handle_t handle, /* DMA Handle */
1093 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1094 dma_addr_t srcData, /* Place to get data to write to device */
1095 dma_addr_t dstData, /* Pointer to device data address */
1096 size_t numBytes /* Number of bytes to transfer to the device */
1097 ) {
1098 DMA_Channel_t *channel;
1099 DMA_DeviceAttribute_t *devAttr;
1100 int numDescriptors;
1101 size_t ringBytesRequired;
1102 int rc = 0;
1103
1104 channel = HandleToChannel(handle);
1105 if (channel == NULL) {
1106 return -ENODEV;
1107 }
1108
1109 devAttr = &DMA_gDeviceAttribute[channel->devType];
1110
1111 if (devAttr->config.transferType != transferType) {
1112 return -EINVAL;
1113 }
1114
1115 /* Figure out how many descriptors we need. */
1116
1117 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1118 /* srcData, dstData, numBytes); */
1119
1120 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
1121 (void *)srcData,
1122 (void *)dstData,
1123 numBytes);
1124 if (numDescriptors < 0) {
1125 printk(KERN_ERR "%s: dmacHw_calculateDescriptorCount failed\n",
1126 __func__);
1127 return -EINVAL;
1128 }
1129
1130 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1131 /* a new one. */
1132
1133 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1134
1135 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1136
1137 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1138 /* Make sure that this code path is never taken from interrupt context. */
1139 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1140 /* allocation needs to have already been done. */
1141
1142 might_sleep();
1143
1144 /* Free the old descriptor ring and allocate a new one. */
1145
1146 dma_free_descriptor_ring(&devAttr->ring);
1147
1148 /* And allocate a new one. */
1149
1150 rc =
1151 dma_alloc_descriptor_ring(&devAttr->ring,
1152 numDescriptors);
1153 if (rc < 0) {
1154 printk(KERN_ERR
1155 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1156 __func__, numDescriptors);
1157 return rc;
1158 }
1159 /* Setup the descriptor for this transfer */
1160
1161 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1162 devAttr->ring.physAddr,
1163 devAttr->ring.bytesAllocated,
1164 numDescriptors) < 0) {
1165 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n",
1166 __func__);
1167 return -EINVAL;
1168 }
1169 } else {
1170 /* We've already got enough ring buffer allocated. All we need to do is reset */
1171 /* any control information, just in case the previous DMA was stopped. */
1172
1173 dmacHw_resetDescriptorControl(devAttr->ring.virtAddr);
1174 }
1175
1176 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1177 /* as last time, then we don't need to call setDataDescriptor again. */
1178
1179 if (dmacHw_setDataDescriptor(&devAttr->config,
1180 devAttr->ring.virtAddr,
1181 (void *)srcData,
1182 (void *)dstData, numBytes) < 0) {
1183 printk(KERN_ERR "%s: dmacHw_setDataDescriptor failed\n",
1184 __func__);
1185 return -EINVAL;
1186 }
1187
1188 /* Remember the critical information for this transfer so that we can eliminate */
1189 /* another call to dma_alloc_descriptors if the caller reuses the same buffers */
1190
1191 devAttr->prevSrcData = srcData;
1192 devAttr->prevDstData = dstData;
1193 devAttr->prevNumBytes = numBytes;
1194
1195 return 0;
1196}
1197
1198EXPORT_SYMBOL(dma_alloc_descriptors);
1199
1200/****************************************************************************/
1201/**
1202* Allocates and sets up descriptors for a double buffered circular buffer.
1203*
1204* This is primarily intended to be used for things like the ingress samples
1205* from a microphone.
1206*
1207* @return
1208* > 0 Number of descriptors actually allocated.
1209* -EINVAL Invalid device type for this kind of transfer
1210* (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1211* -ENOMEM Memory exhausted
1212*/
1213/****************************************************************************/
1214
1215int dma_alloc_double_dst_descriptors(DMA_Handle_t handle, /* DMA Handle */
1216 dma_addr_t srcData, /* Physical address of source data */
1217 dma_addr_t dstData1, /* Physical address of first destination buffer */
1218 dma_addr_t dstData2, /* Physical address of second destination buffer */
1219 size_t numBytes /* Number of bytes in each destination buffer */
1220 ) {
1221 DMA_Channel_t *channel;
1222 DMA_DeviceAttribute_t *devAttr;
1223 int numDst1Descriptors;
1224 int numDst2Descriptors;
1225 int numDescriptors;
1226 size_t ringBytesRequired;
1227 int rc = 0;
1228
1229 channel = HandleToChannel(handle);
1230 if (channel == NULL) {
1231 return -ENODEV;
1232 }
1233
1234 devAttr = &DMA_gDeviceAttribute[channel->devType];
1235
1236 /* Figure out how many descriptors we need. */
1237
1238 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1239 /* srcData, dstData, numBytes); */
1240
1241 numDst1Descriptors =
1242 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1243 (void *)dstData1, numBytes);
1244 if (numDst1Descriptors < 0) {
1245 return -EINVAL;
1246 }
1247 numDst2Descriptors =
1248 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1249 (void *)dstData2, numBytes);
1250 if (numDst2Descriptors < 0) {
1251 return -EINVAL;
1252 }
1253 numDescriptors = numDst1Descriptors + numDst2Descriptors;
1254 /* printk("numDescriptors: %d\n", numDescriptors); */
1255
1256 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1257 /* a new one. */
1258
1259 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1260
1261 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1262
1263 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1264 /* Make sure that this code path is never taken from interrupt context. */
1265 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1266 /* allocation needs to have already been done. */
1267
1268 might_sleep();
1269
1270 /* Free the old descriptor ring and allocate a new one. */
1271
1272 dma_free_descriptor_ring(&devAttr->ring);
1273
1274 /* And allocate a new one. */
1275
1276 rc =
1277 dma_alloc_descriptor_ring(&devAttr->ring,
1278 numDescriptors);
1279 if (rc < 0) {
1280 printk(KERN_ERR
1281 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1282 __func__, ringBytesRequired);
1283 return rc;
1284 }
1285 }
1286
1287 /* Setup the descriptor for this transfer. Since this function is used with */
1288 /* CONTINUOUS DMA operations, we need to reinitialize every time, otherwise */
1289 /* setDataDescriptor will keep trying to append onto the end. */
1290
1291 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1292 devAttr->ring.physAddr,
1293 devAttr->ring.bytesAllocated,
1294 numDescriptors) < 0) {
1295 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n", __func__);
1296 return -EINVAL;
1297 }
1298
1299 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1300 /* as last time, then we don't need to call setDataDescriptor again. */
1301
1302 if (dmacHw_setDataDescriptor(&devAttr->config,
1303 devAttr->ring.virtAddr,
1304 (void *)srcData,
1305 (void *)dstData1, numBytes) < 0) {
1306 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 1 failed\n",
1307 __func__);
1308 return -EINVAL;
1309 }
1310 if (dmacHw_setDataDescriptor(&devAttr->config,
1311 devAttr->ring.virtAddr,
1312 (void *)srcData,
1313 (void *)dstData2, numBytes) < 0) {
1314 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 2 failed\n",
1315 __func__);
1316 return -EINVAL;
1317 }
1318
1319 /* You should use dma_start_transfer rather than dma_transfer_xxx so we don't */
1320 /* try to make the 'prev' variables right. */
1321
1322 devAttr->prevSrcData = 0;
1323 devAttr->prevDstData = 0;
1324 devAttr->prevNumBytes = 0;
1325
1326 return numDescriptors;
1327}
1328
1329EXPORT_SYMBOL(dma_alloc_double_dst_descriptors);
1330
1331/****************************************************************************/
1332/**
1333* Initiates a transfer when the descriptors have already been setup.
1334*
1335* This is a special case, and normally, the dma_transfer_xxx functions should
1336* be used.
1337*
1338* @return
1339* 0 Transfer was started successfully
1340* -ENODEV Invalid handle
1341*/
1342/****************************************************************************/
1343
1344int dma_start_transfer(DMA_Handle_t handle)
1345{
1346 DMA_Channel_t *channel;
1347 DMA_DeviceAttribute_t *devAttr;
1348
1349 channel = HandleToChannel(handle);
1350 if (channel == NULL) {
1351 return -ENODEV;
1352 }
1353 devAttr = &DMA_gDeviceAttribute[channel->devType];
1354
1355 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1356 devAttr->ring.virtAddr);
1357
1358 /* Since we got this far, everything went successfully */
1359
1360 return 0;
1361}
1362
1363EXPORT_SYMBOL(dma_start_transfer);
1364
1365/****************************************************************************/
1366/**
1367* Stops a previously started DMA transfer.
1368*
1369* @return
1370* 0 Transfer was stopped successfully
1371* -ENODEV Invalid handle
1372*/
1373/****************************************************************************/
1374
1375int dma_stop_transfer(DMA_Handle_t handle)
1376{
1377 DMA_Channel_t *channel;
1378
1379 channel = HandleToChannel(handle);
1380 if (channel == NULL) {
1381 return -ENODEV;
1382 }
1383
1384 dmacHw_stopTransfer(channel->dmacHwHandle);
1385
1386 return 0;
1387}
1388
1389EXPORT_SYMBOL(dma_stop_transfer);
1390
1391/****************************************************************************/
1392/**
1393* Waits for a DMA to complete by polling. This function is only intended
1394* to be used for testing. Interrupts should be used for most DMA operations.
1395*/
1396/****************************************************************************/
1397
1398int dma_wait_transfer_done(DMA_Handle_t handle)
1399{
1400 DMA_Channel_t *channel;
1401 dmacHw_TRANSFER_STATUS_e status;
1402
1403 channel = HandleToChannel(handle);
1404 if (channel == NULL) {
1405 return -ENODEV;
1406 }
1407
1408 while ((status =
1409 dmacHw_transferCompleted(channel->dmacHwHandle)) ==
1410 dmacHw_TRANSFER_STATUS_BUSY) {
1411 ;
1412 }
1413
1414 if (status == dmacHw_TRANSFER_STATUS_ERROR) {
1415 printk(KERN_ERR "%s: DMA transfer failed\n", __func__);
1416 return -EIO;
1417 }
1418 return 0;
1419}
1420
1421EXPORT_SYMBOL(dma_wait_transfer_done);
1422
1423/****************************************************************************/
1424/**
1425* Initiates a DMA, allocating the descriptors as required.
1426*
1427* @return
1428* 0 Transfer was started successfully
1429* -EINVAL Invalid device type for this kind of transfer
1430* (i.e. the device is _DEV_TO_MEM and not _MEM_TO_DEV)
1431*/
1432/****************************************************************************/
1433
1434int dma_transfer(DMA_Handle_t handle, /* DMA Handle */
1435 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1436 dma_addr_t srcData, /* Place to get data to write to device */
1437 dma_addr_t dstData, /* Pointer to device data address */
1438 size_t numBytes /* Number of bytes to transfer to the device */
1439 ) {
1440 DMA_Channel_t *channel;
1441 DMA_DeviceAttribute_t *devAttr;
1442 int rc = 0;
1443
1444 channel = HandleToChannel(handle);
1445 if (channel == NULL) {
1446 return -ENODEV;
1447 }
1448
1449 devAttr = &DMA_gDeviceAttribute[channel->devType];
1450
1451 if (devAttr->config.transferType != transferType) {
1452 return -EINVAL;
1453 }
1454
1455 /* We keep track of the information about the previous request for this */
1456 /* device, and if the attributes match, then we can use the descriptors we setup */
1457 /* the last time, and not have to reinitialize everything. */
1458
1459 {
1460 rc =
1461 dma_alloc_descriptors(handle, transferType, srcData,
1462 dstData, numBytes);
1463 if (rc != 0) {
1464 return rc;
1465 }
1466 }
1467
1468 /* And kick off the transfer */
1469
1470 devAttr->numBytes = numBytes;
1471 devAttr->transferStartTime = timer_get_tick_count();
1472
1473 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1474 devAttr->ring.virtAddr);
1475
1476 /* Since we got this far, everything went successfully */
1477
1478 return 0;
1479}
1480
1481EXPORT_SYMBOL(dma_transfer);
1482
1483/****************************************************************************/
1484/**
1485* Set the callback function which will be called when a transfer completes.
1486* If a NULL callback function is set, then no callback will occur.
1487*
1488* @note @a devHandler will be called from IRQ context.
1489*
1490* @return
1491* 0 - Success
1492* -ENODEV - Device handed in is invalid.
1493*/
1494/****************************************************************************/
1495
1496int dma_set_device_handler(DMA_Device_t dev, /* Device to set the callback for. */
1497 DMA_DeviceHandler_t devHandler, /* Function to call when the DMA completes */
1498 void *userData /* Pointer which will be passed to devHandler. */
1499 ) {
1500 DMA_DeviceAttribute_t *devAttr;
1501 unsigned long flags;
1502
1503 if (!IsDeviceValid(dev)) {
1504 return -ENODEV;
1505 }
1506 devAttr = &DMA_gDeviceAttribute[dev];
1507
1508 local_irq_save(flags);
1509
1510 devAttr->userData = userData;
1511 devAttr->devHandler = devHandler;
1512
1513 local_irq_restore(flags);
1514
1515 return 0;
1516}
1517
1518EXPORT_SYMBOL(dma_set_device_handler);