1 /*****************************************************************************
2 * Copyright 2004 - 2008 Broadcom Corporation. All rights reserved.
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").
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
13 *****************************************************************************/
15 /****************************************************************************/
19 * @brief Implements the DMA interface.
21 /****************************************************************************/
23 /* ---- Include Files ---------------------------------------------------- */
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>
34 #include <mach/timer.h>
36 #include <linux/pfn.h>
37 #include <linux/atomic.h>
38 #include <linux/sched.h>
41 /* ---- Public Variables ------------------------------------------------- */
43 /* ---- Private Constants and Types -------------------------------------- */
45 #define MAKE_HANDLE(controllerIdx, channelIdx) (((controllerIdx) << 4) | (channelIdx))
47 #define CONTROLLER_FROM_HANDLE(handle) (((handle) >> 4) & 0x0f)
48 #define CHANNEL_FROM_HANDLE(handle) ((handle) & 0x0f)
51 /* ---- Private Variables ------------------------------------------------ */
53 static DMA_Global_t gDMA;
54 static struct proc_dir_entry *gDmaDir;
56 #include "dma_device.c"
58 /* ---- Private Function Prototypes -------------------------------------- */
60 /* ---- Functions ------------------------------------------------------- */
62 /****************************************************************************/
64 * Displays information for /proc/dma/channels
66 /****************************************************************************/
68 static int dma_proc_read_channels(char *buf, char **start, off_t offset,
69 int count, int *eof, void *data)
73 int limit = count - 200;
75 DMA_Channel_t *channel;
77 if (down_interruptible(&gDMA.lock) < 0) {
81 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
83 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
90 &gDMA.controller[controllerIdx].channel[channelIdx];
93 sprintf(buf + len, "%d:%d ", controllerIdx,
96 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
99 sprintf(buf + len, "Dedicated for %s ",
100 DMA_gDeviceAttribute[channel->
103 len += sprintf(buf + len, "Shared ");
106 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) != 0) {
107 len += sprintf(buf + len, "No ISR ");
110 if ((channel->flags & DMA_CHANNEL_FLAG_LARGE_FIFO) != 0) {
111 len += sprintf(buf + len, "Fifo: 128 ");
113 len += sprintf(buf + len, "Fifo: 64 ");
116 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
118 sprintf(buf + len, "InUse by %s",
119 DMA_gDeviceAttribute[channel->
121 #if (DMA_DEBUG_TRACK_RESERVATION)
123 sprintf(buf + len, " (%s:%d)",
128 len += sprintf(buf + len, "Avail ");
131 if (channel->lastDevType != DMA_DEVICE_NONE) {
133 sprintf(buf + len, "Last use: %s ",
134 DMA_gDeviceAttribute[channel->
139 len += sprintf(buf + len, "\n");
148 /****************************************************************************/
150 * Displays information for /proc/dma/devices
152 /****************************************************************************/
154 static int dma_proc_read_devices(char *buf, char **start, off_t offset,
155 int count, int *eof, void *data)
157 int limit = count - 200;
161 if (down_interruptible(&gDMA.lock) < 0) {
165 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
166 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
168 if (devAttr->name == NULL) {
176 len += sprintf(buf + len, "%-12s ", devAttr->name);
178 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
180 sprintf(buf + len, "Dedicated %d:%d ",
181 devAttr->dedicatedController,
182 devAttr->dedicatedChannel);
184 len += sprintf(buf + len, "Shared DMA:");
185 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA0) != 0) {
186 len += sprintf(buf + len, "0");
188 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA1) != 0) {
189 len += sprintf(buf + len, "1");
191 len += sprintf(buf + len, " ");
193 if ((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0) {
194 len += sprintf(buf + len, "NoISR ");
196 if ((devAttr->flags & DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO) != 0) {
197 len += sprintf(buf + len, "Allow-128 ");
202 "Xfer #: %Lu Ticks: %Lu Bytes: %Lu DescLen: %u\n",
203 devAttr->numTransfers, devAttr->transferTicks,
204 devAttr->transferBytes,
205 devAttr->ring.bytesAllocated);
215 /****************************************************************************/
217 * Determines if a DMA_Device_t is "valid".
220 * TRUE - dma device is valid
221 * FALSE - dma device isn't valid
223 /****************************************************************************/
225 static inline int IsDeviceValid(DMA_Device_t device)
227 return (device >= 0) && (device < DMA_NUM_DEVICE_ENTRIES);
230 /****************************************************************************/
232 * Translates a DMA handle into a pointer to a channel.
235 * non-NULL - pointer to DMA_Channel_t
236 * NULL - DMA Handle was invalid
238 /****************************************************************************/
240 static inline DMA_Channel_t *HandleToChannel(DMA_Handle_t handle)
245 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
246 channelIdx = CHANNEL_FROM_HANDLE(handle);
248 if ((controllerIdx > DMA_NUM_CONTROLLERS)
249 || (channelIdx > DMA_NUM_CHANNELS)) {
252 return &gDMA.controller[controllerIdx].channel[channelIdx];
255 /****************************************************************************/
257 * Interrupt handler which is called to process DMA interrupts.
259 /****************************************************************************/
261 static irqreturn_t dma_interrupt_handler(int irq, void *dev_id)
263 DMA_Channel_t *channel;
264 DMA_DeviceAttribute_t *devAttr;
267 channel = (DMA_Channel_t *) dev_id;
269 /* Figure out why we were called, and knock down the interrupt */
271 irqStatus = dmacHw_getInterruptStatus(channel->dmacHwHandle);
272 dmacHw_clearInterrupt(channel->dmacHwHandle);
274 if ((channel->devType < 0)
275 || (channel->devType > DMA_NUM_DEVICE_ENTRIES)) {
276 printk(KERN_ERR "dma_interrupt_handler: Invalid devType: %d\n",
280 devAttr = &DMA_gDeviceAttribute[channel->devType];
284 if ((irqStatus & dmacHw_INTERRUPT_STATUS_TRANS) != 0) {
285 devAttr->transferTicks +=
286 (timer_get_tick_count() - devAttr->transferStartTime);
289 if ((irqStatus & dmacHw_INTERRUPT_STATUS_ERROR) != 0) {
291 "dma_interrupt_handler: devType :%d DMA error (%s)\n",
292 channel->devType, devAttr->name);
294 devAttr->numTransfers++;
295 devAttr->transferBytes += devAttr->numBytes;
298 /* Call any installed handler */
300 if (devAttr->devHandler != NULL) {
301 devAttr->devHandler(channel->devType, irqStatus,
308 /****************************************************************************/
310 * Allocates memory to hold a descriptor ring. The descriptor ring then
311 * needs to be populated by making one or more calls to
312 * dna_add_descriptors.
314 * The returned descriptor ring will be automatically initialized.
317 * 0 Descriptor ring was allocated successfully
318 * -EINVAL Invalid parameters passed in
319 * -ENOMEM Unable to allocate memory for the desired number of descriptors.
321 /****************************************************************************/
323 int dma_alloc_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to populate */
324 int numDescriptors /* Number of descriptors that need to be allocated. */
326 size_t bytesToAlloc = dmacHw_descriptorLen(numDescriptors);
328 if ((ring == NULL) || (numDescriptors <= 0)) {
333 ring->descriptorsAllocated = 0;
334 ring->bytesAllocated = 0;
336 ring->virtAddr = dma_alloc_writecombine(NULL,
340 if (ring->virtAddr == NULL) {
344 ring->bytesAllocated = bytesToAlloc;
345 ring->descriptorsAllocated = numDescriptors;
347 return dma_init_descriptor_ring(ring, numDescriptors);
350 EXPORT_SYMBOL(dma_alloc_descriptor_ring);
352 /****************************************************************************/
354 * Releases the memory which was previously allocated for a descriptor ring.
356 /****************************************************************************/
358 void dma_free_descriptor_ring(DMA_DescriptorRing_t *ring /* Descriptor to release */
360 if (ring->virtAddr != NULL) {
361 dma_free_writecombine(NULL,
362 ring->bytesAllocated,
363 ring->virtAddr, ring->physAddr);
366 ring->bytesAllocated = 0;
367 ring->descriptorsAllocated = 0;
368 ring->virtAddr = NULL;
372 EXPORT_SYMBOL(dma_free_descriptor_ring);
374 /****************************************************************************/
376 * Initializes a descriptor ring, so that descriptors can be added to it.
377 * Once a descriptor ring has been allocated, it may be reinitialized for
378 * use with additional/different regions of memory.
380 * Note that if 7 descriptors are allocated, it's perfectly acceptable to
381 * initialize the ring with a smaller number of descriptors. The amount
382 * of memory allocated for the descriptor ring will not be reduced, and
383 * the descriptor ring may be reinitialized later
386 * 0 Descriptor ring was initialized successfully
387 * -ENOMEM The descriptor which was passed in has insufficient space
388 * to hold the desired number of descriptors.
390 /****************************************************************************/
392 int dma_init_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to initialize */
393 int numDescriptors /* Number of descriptors to initialize. */
395 if (ring->virtAddr == NULL) {
398 if (dmacHw_initDescriptor(ring->virtAddr,
400 ring->bytesAllocated, numDescriptors) < 0) {
402 "dma_init_descriptor_ring: dmacHw_initDescriptor failed\n");
409 EXPORT_SYMBOL(dma_init_descriptor_ring);
411 /****************************************************************************/
413 * Determines the number of descriptors which would be required for a
414 * transfer of the indicated memory region.
416 * This function also needs to know which DMA device this transfer will
417 * be destined for, so that the appropriate DMA configuration can be retrieved.
418 * DMA parameters such as transfer width, and whether this is a memory-to-memory
419 * or memory-to-peripheral, etc can all affect the actual number of descriptors
423 * > 0 Returns the number of descriptors required for the indicated transfer
424 * -ENODEV - Device handed in is invalid.
425 * -EINVAL Invalid parameters
426 * -ENOMEM Memory exhausted
428 /****************************************************************************/
430 int dma_calculate_descriptor_count(DMA_Device_t device, /* DMA Device that this will be associated with */
431 dma_addr_t srcData, /* Place to get data to write to device */
432 dma_addr_t dstData, /* Pointer to device data address */
433 size_t numBytes /* Number of bytes to transfer to the device */
436 DMA_DeviceAttribute_t *devAttr;
438 if (!IsDeviceValid(device)) {
441 devAttr = &DMA_gDeviceAttribute[device];
443 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
447 if (numDescriptors < 0) {
449 "dma_calculate_descriptor_count: dmacHw_calculateDescriptorCount failed\n");
453 return numDescriptors;
456 EXPORT_SYMBOL(dma_calculate_descriptor_count);
458 /****************************************************************************/
460 * Adds a region of memory to the descriptor ring. Note that it may take
461 * multiple descriptors for each region of memory. It is the callers
462 * responsibility to allocate a sufficiently large descriptor ring.
465 * 0 Descriptors were added successfully
466 * -ENODEV Device handed in is invalid.
467 * -EINVAL Invalid parameters
468 * -ENOMEM Memory exhausted
470 /****************************************************************************/
472 int dma_add_descriptors(DMA_DescriptorRing_t *ring, /* Descriptor ring to add descriptors to */
473 DMA_Device_t device, /* DMA Device that descriptors are for */
474 dma_addr_t srcData, /* Place to get data (memory or device) */
475 dma_addr_t dstData, /* Place to put data (memory or device) */
476 size_t numBytes /* Number of bytes to transfer to the device */
479 DMA_DeviceAttribute_t *devAttr;
481 if (!IsDeviceValid(device)) {
484 devAttr = &DMA_gDeviceAttribute[device];
486 rc = dmacHw_setDataDescriptor(&devAttr->config,
489 (void *)dstData, numBytes);
492 "dma_add_descriptors: dmacHw_setDataDescriptor failed with code: %d\n",
500 EXPORT_SYMBOL(dma_add_descriptors);
502 /****************************************************************************/
504 * Sets the descriptor ring associated with a device.
506 * Once set, the descriptor ring will be associated with the device, even
507 * across channel request/free calls. Passing in a NULL descriptor ring
508 * will release any descriptor ring currently associated with the device.
510 * Note: If you call dma_transfer, or one of the other dma_alloc_ functions
511 * the descriptor ring may be released and reallocated.
513 * Note: This function will release the descriptor memory for any current
514 * descriptor ring associated with this device.
517 * 0 Descriptors were added successfully
518 * -ENODEV Device handed in is invalid.
520 /****************************************************************************/
522 int dma_set_device_descriptor_ring(DMA_Device_t device, /* Device to update the descriptor ring for. */
523 DMA_DescriptorRing_t *ring /* Descriptor ring to add descriptors to */
525 DMA_DeviceAttribute_t *devAttr;
527 if (!IsDeviceValid(device)) {
530 devAttr = &DMA_gDeviceAttribute[device];
532 /* Free the previously allocated descriptor ring */
534 dma_free_descriptor_ring(&devAttr->ring);
537 /* Copy in the new one */
539 devAttr->ring = *ring;
542 /* Set things up so that if dma_transfer is called then this descriptor */
543 /* ring will get freed. */
545 devAttr->prevSrcData = 0;
546 devAttr->prevDstData = 0;
547 devAttr->prevNumBytes = 0;
552 EXPORT_SYMBOL(dma_set_device_descriptor_ring);
554 /****************************************************************************/
556 * Retrieves the descriptor ring associated with a device.
559 * 0 Descriptors were added successfully
560 * -ENODEV Device handed in is invalid.
562 /****************************************************************************/
564 int dma_get_device_descriptor_ring(DMA_Device_t device, /* Device to retrieve the descriptor ring for. */
565 DMA_DescriptorRing_t *ring /* Place to store retrieved ring */
567 DMA_DeviceAttribute_t *devAttr;
569 memset(ring, 0, sizeof(*ring));
571 if (!IsDeviceValid(device)) {
574 devAttr = &DMA_gDeviceAttribute[device];
576 *ring = devAttr->ring;
581 EXPORT_SYMBOL(dma_get_device_descriptor_ring);
583 /****************************************************************************/
585 * Configures a DMA channel.
588 * >= 0 - Initialization was successful.
590 * -EBUSY - Device is currently being used.
591 * -ENODEV - Device handed in is invalid.
593 /****************************************************************************/
595 static int ConfigChannel(DMA_Handle_t handle)
597 DMA_Channel_t *channel;
598 DMA_DeviceAttribute_t *devAttr;
601 channel = HandleToChannel(handle);
602 if (channel == NULL) {
605 devAttr = &DMA_gDeviceAttribute[channel->devType];
606 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
608 if ((devAttr->flags & DMA_DEVICE_FLAG_PORT_PER_DMAC) != 0) {
609 if (devAttr->config.transferType ==
610 dmacHw_TRANSFER_TYPE_MEM_TO_PERIPHERAL) {
611 devAttr->config.dstPeripheralPort =
612 devAttr->dmacPort[controllerIdx];
613 } else if (devAttr->config.transferType ==
614 dmacHw_TRANSFER_TYPE_PERIPHERAL_TO_MEM) {
615 devAttr->config.srcPeripheralPort =
616 devAttr->dmacPort[controllerIdx];
620 if (dmacHw_configChannel(channel->dmacHwHandle, &devAttr->config) != 0) {
621 printk(KERN_ERR "ConfigChannel: dmacHw_configChannel failed\n");
628 /****************************************************************************/
630 * Initializes all of the data structures associated with the DMA.
632 * >= 0 - Initialization was successful.
634 * -EBUSY - Device is currently being used.
635 * -ENODEV - Device handed in is invalid.
637 /****************************************************************************/
645 DMA_Channel_t *channel;
646 DMA_Handle_t dedicatedHandle;
648 memset(&gDMA, 0, sizeof(gDMA));
650 sema_init(&gDMA.lock, 0);
651 init_waitqueue_head(&gDMA.freeChannelQ);
653 /* Initialize the Hardware */
657 /* Start off by marking all of the DMA channels as shared. */
659 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
661 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
664 &gDMA.controller[controllerIdx].channel[channelIdx];
667 channel->devType = DMA_DEVICE_NONE;
668 channel->lastDevType = DMA_DEVICE_NONE;
670 #if (DMA_DEBUG_TRACK_RESERVATION)
671 channel->fileName = "";
672 channel->lineNum = 0;
675 channel->dmacHwHandle =
676 dmacHw_getChannelHandle(dmacHw_MAKE_CHANNEL_ID
679 dmacHw_initChannel(channel->dmacHwHandle);
683 /* Record any special attributes that channels may have */
685 gDMA.controller[0].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
686 gDMA.controller[0].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
687 gDMA.controller[1].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
688 gDMA.controller[1].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
690 /* Now walk through and record the dedicated channels. */
692 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
693 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
695 if (((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0)
696 && ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0)) {
698 "DMA Device: %s Can only request NO_ISR for dedicated devices\n",
704 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
705 /* This is a dedicated device. Mark the channel as being reserved. */
707 if (devAttr->dedicatedController >= DMA_NUM_CONTROLLERS) {
709 "DMA Device: %s DMA Controller %d is out of range\n",
711 devAttr->dedicatedController);
716 if (devAttr->dedicatedChannel >= DMA_NUM_CHANNELS) {
718 "DMA Device: %s DMA Channel %d is out of range\n",
720 devAttr->dedicatedChannel);
726 MAKE_HANDLE(devAttr->dedicatedController,
727 devAttr->dedicatedChannel);
728 channel = HandleToChannel(dedicatedHandle);
730 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
733 ("DMA Device: %s attempting to use same DMA Controller:Channel (%d:%d) as %s\n",
735 devAttr->dedicatedController,
736 devAttr->dedicatedChannel,
737 DMA_gDeviceAttribute[channel->devType].
743 channel->flags |= DMA_CHANNEL_FLAG_IS_DEDICATED;
744 channel->devType = devIdx;
746 if (devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) {
747 channel->flags |= DMA_CHANNEL_FLAG_NO_ISR;
750 /* For dedicated channels, we can go ahead and configure the DMA channel now */
753 ConfigChannel(dedicatedHandle);
757 /* Go through and register the interrupt handlers */
759 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
761 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
764 &gDMA.controller[controllerIdx].channel[channelIdx];
766 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) == 0) {
767 snprintf(channel->name, sizeof(channel->name),
768 "dma %d:%d %s", controllerIdx,
771 DMA_DEVICE_NONE ? "" :
772 DMA_gDeviceAttribute[channel->devType].
776 request_irq(IRQ_DMA0C0 +
780 dma_interrupt_handler,
781 IRQF_DISABLED, channel->name,
785 "request_irq for IRQ_DMA%dC%d failed\n",
786 controllerIdx, channelIdx);
792 /* Create /proc/dma/channels and /proc/dma/devices */
794 gDmaDir = proc_mkdir("dma", NULL);
796 if (gDmaDir == NULL) {
797 printk(KERN_ERR "Unable to create /proc/dma\n");
799 create_proc_read_entry("channels", 0, gDmaDir,
800 dma_proc_read_channels, NULL);
801 create_proc_read_entry("devices", 0, gDmaDir,
802 dma_proc_read_devices, NULL);
812 /****************************************************************************/
814 * Reserves a channel for use with @a dev. If the device is setup to use
815 * a shared channel, then this function will block until a free channel
819 * >= 0 - A valid DMA Handle.
820 * -EBUSY - Device is currently being used.
821 * -ENODEV - Device handed in is invalid.
823 /****************************************************************************/
825 #if (DMA_DEBUG_TRACK_RESERVATION)
826 DMA_Handle_t dma_request_channel_dbg
827 (DMA_Device_t dev, const char *fileName, int lineNum)
829 DMA_Handle_t dma_request_channel(DMA_Device_t dev)
833 DMA_DeviceAttribute_t *devAttr;
834 DMA_Channel_t *channel;
839 if (down_interruptible(&gDMA.lock) < 0) {
843 if ((dev < 0) || (dev >= DMA_NUM_DEVICE_ENTRIES)) {
847 devAttr = &DMA_gDeviceAttribute[dev];
849 #if (DMA_DEBUG_TRACK_RESERVATION)
853 s = strrchr(fileName, '/');
859 if ((devAttr->flags & DMA_DEVICE_FLAG_IN_USE) != 0) {
860 /* This device has already been requested and not been freed */
862 printk(KERN_ERR "%s: device %s is already requested\n",
863 __func__, devAttr->name);
868 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
869 /* This device has a dedicated channel. */
872 &gDMA.controller[devAttr->dedicatedController].
873 channel[devAttr->dedicatedChannel];
874 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
879 channel->flags |= DMA_CHANNEL_FLAG_IN_USE;
880 devAttr->flags |= DMA_DEVICE_FLAG_IN_USE;
882 #if (DMA_DEBUG_TRACK_RESERVATION)
883 channel->fileName = fileName;
884 channel->lineNum = lineNum;
887 MAKE_HANDLE(devAttr->dedicatedController,
888 devAttr->dedicatedChannel);
892 /* This device needs to use one of the shared channels. */
894 handle = DMA_INVALID_HANDLE;
895 while (handle == DMA_INVALID_HANDLE) {
896 /* Scan through the shared channels and see if one is available */
898 for (controllerIdx2 = 0; controllerIdx2 < DMA_NUM_CONTROLLERS;
900 /* Check to see if we should try on controller 1 first. */
902 controllerIdx = controllerIdx2;
904 flags & DMA_DEVICE_FLAG_ALLOC_DMA1_FIRST) != 0) {
905 controllerIdx = 1 - controllerIdx;
908 /* See if the device is available on the controller being tested */
911 flags & (DMA_DEVICE_FLAG_ON_DMA0 << controllerIdx))
914 channelIdx < DMA_NUM_CHANNELS;
917 &gDMA.controller[controllerIdx].
922 DMA_CHANNEL_FLAG_IS_DEDICATED) ==
926 flags & DMA_CHANNEL_FLAG_IN_USE)
930 DMA_CHANNEL_FLAG_LARGE_FIFO)
935 DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO)
937 /* This channel is a large fifo - don't tie it up */
938 /* with devices that we don't want using it. */
944 DMA_CHANNEL_FLAG_IN_USE;
945 channel->devType = dev;
947 DMA_DEVICE_FLAG_IN_USE;
949 #if (DMA_DEBUG_TRACK_RESERVATION)
950 channel->fileName = fileName;
951 channel->lineNum = lineNum;
954 MAKE_HANDLE(controllerIdx,
957 /* Now that we've reserved the channel - we can go ahead and configure it */
959 if (ConfigChannel(handle) != 0) {
962 "dma_request_channel: ConfigChannel failed\n");
970 /* No channels are currently available. Let's wait for one to free up. */
975 prepare_to_wait(&gDMA.freeChannelQ, &wait,
979 finish_wait(&gDMA.freeChannelQ, &wait);
981 if (signal_pending(current)) {
982 /* We don't currently hold gDMA.lock, so we return directly */
988 if (down_interruptible(&gDMA.lock)) {
999 /* Create both _dbg and non _dbg functions for modules. */
1001 #if (DMA_DEBUG_TRACK_RESERVATION)
1002 #undef dma_request_channel
1003 DMA_Handle_t dma_request_channel(DMA_Device_t dev)
1005 return dma_request_channel_dbg(dev, __FILE__, __LINE__);
1008 EXPORT_SYMBOL(dma_request_channel_dbg);
1010 EXPORT_SYMBOL(dma_request_channel);
1012 /****************************************************************************/
1014 * Frees a previously allocated DMA Handle.
1016 /****************************************************************************/
1018 int dma_free_channel(DMA_Handle_t handle /* DMA handle. */
1021 DMA_Channel_t *channel;
1022 DMA_DeviceAttribute_t *devAttr;
1024 if (down_interruptible(&gDMA.lock) < 0) {
1025 return -ERESTARTSYS;
1028 channel = HandleToChannel(handle);
1029 if (channel == NULL) {
1034 devAttr = &DMA_gDeviceAttribute[channel->devType];
1036 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) == 0) {
1037 channel->lastDevType = channel->devType;
1038 channel->devType = DMA_DEVICE_NONE;
1040 channel->flags &= ~DMA_CHANNEL_FLAG_IN_USE;
1041 devAttr->flags &= ~DMA_DEVICE_FLAG_IN_USE;
1046 wake_up_interruptible(&gDMA.freeChannelQ);
1051 EXPORT_SYMBOL(dma_free_channel);
1053 /****************************************************************************/
1055 * Determines if a given device has been configured as using a shared
1059 * 0 Device uses a dedicated channel
1060 * > zero Device uses a shared channel
1063 /****************************************************************************/
1065 int dma_device_is_channel_shared(DMA_Device_t device /* Device to check. */
1067 DMA_DeviceAttribute_t *devAttr;
1069 if (!IsDeviceValid(device)) {
1072 devAttr = &DMA_gDeviceAttribute[device];
1074 return ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0);
1077 EXPORT_SYMBOL(dma_device_is_channel_shared);
1079 /****************************************************************************/
1081 * Allocates buffers for the descriptors. This is normally done automatically
1082 * but needs to be done explicitly when initiating a dma from interrupt
1086 * 0 Descriptors were allocated successfully
1087 * -EINVAL Invalid device type for this kind of transfer
1088 * (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1089 * -ENOMEM Memory exhausted
1091 /****************************************************************************/
1093 int dma_alloc_descriptors(DMA_Handle_t handle, /* DMA Handle */
1094 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1095 dma_addr_t srcData, /* Place to get data to write to device */
1096 dma_addr_t dstData, /* Pointer to device data address */
1097 size_t numBytes /* Number of bytes to transfer to the device */
1099 DMA_Channel_t *channel;
1100 DMA_DeviceAttribute_t *devAttr;
1102 size_t ringBytesRequired;
1105 channel = HandleToChannel(handle);
1106 if (channel == NULL) {
1110 devAttr = &DMA_gDeviceAttribute[channel->devType];
1112 if (devAttr->config.transferType != transferType) {
1116 /* Figure out how many descriptors we need. */
1118 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1119 /* srcData, dstData, numBytes); */
1121 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
1125 if (numDescriptors < 0) {
1126 printk(KERN_ERR "%s: dmacHw_calculateDescriptorCount failed\n",
1131 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1134 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1136 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1138 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1139 /* Make sure that this code path is never taken from interrupt context. */
1140 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1141 /* allocation needs to have already been done. */
1145 /* Free the old descriptor ring and allocate a new one. */
1147 dma_free_descriptor_ring(&devAttr->ring);
1149 /* And allocate a new one. */
1152 dma_alloc_descriptor_ring(&devAttr->ring,
1156 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1157 __func__, numDescriptors);
1160 /* Setup the descriptor for this transfer */
1162 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1163 devAttr->ring.physAddr,
1164 devAttr->ring.bytesAllocated,
1165 numDescriptors) < 0) {
1166 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n",
1171 /* We've already got enough ring buffer allocated. All we need to do is reset */
1172 /* any control information, just in case the previous DMA was stopped. */
1174 dmacHw_resetDescriptorControl(devAttr->ring.virtAddr);
1177 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1178 /* as last time, then we don't need to call setDataDescriptor again. */
1180 if (dmacHw_setDataDescriptor(&devAttr->config,
1181 devAttr->ring.virtAddr,
1183 (void *)dstData, numBytes) < 0) {
1184 printk(KERN_ERR "%s: dmacHw_setDataDescriptor failed\n",
1189 /* Remember the critical information for this transfer so that we can eliminate */
1190 /* another call to dma_alloc_descriptors if the caller reuses the same buffers */
1192 devAttr->prevSrcData = srcData;
1193 devAttr->prevDstData = dstData;
1194 devAttr->prevNumBytes = numBytes;
1199 EXPORT_SYMBOL(dma_alloc_descriptors);
1201 /****************************************************************************/
1203 * Allocates and sets up descriptors for a double buffered circular buffer.
1205 * This is primarily intended to be used for things like the ingress samples
1206 * from a microphone.
1209 * > 0 Number of descriptors actually allocated.
1210 * -EINVAL Invalid device type for this kind of transfer
1211 * (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1212 * -ENOMEM Memory exhausted
1214 /****************************************************************************/
1216 int dma_alloc_double_dst_descriptors(DMA_Handle_t handle, /* DMA Handle */
1217 dma_addr_t srcData, /* Physical address of source data */
1218 dma_addr_t dstData1, /* Physical address of first destination buffer */
1219 dma_addr_t dstData2, /* Physical address of second destination buffer */
1220 size_t numBytes /* Number of bytes in each destination buffer */
1222 DMA_Channel_t *channel;
1223 DMA_DeviceAttribute_t *devAttr;
1224 int numDst1Descriptors;
1225 int numDst2Descriptors;
1227 size_t ringBytesRequired;
1230 channel = HandleToChannel(handle);
1231 if (channel == NULL) {
1235 devAttr = &DMA_gDeviceAttribute[channel->devType];
1237 /* Figure out how many descriptors we need. */
1239 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1240 /* srcData, dstData, numBytes); */
1242 numDst1Descriptors =
1243 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1244 (void *)dstData1, numBytes);
1245 if (numDst1Descriptors < 0) {
1248 numDst2Descriptors =
1249 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1250 (void *)dstData2, numBytes);
1251 if (numDst2Descriptors < 0) {
1254 numDescriptors = numDst1Descriptors + numDst2Descriptors;
1255 /* printk("numDescriptors: %d\n", numDescriptors); */
1257 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1260 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1262 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1264 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1265 /* Make sure that this code path is never taken from interrupt context. */
1266 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1267 /* allocation needs to have already been done. */
1271 /* Free the old descriptor ring and allocate a new one. */
1273 dma_free_descriptor_ring(&devAttr->ring);
1275 /* And allocate a new one. */
1278 dma_alloc_descriptor_ring(&devAttr->ring,
1282 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1283 __func__, ringBytesRequired);
1288 /* Setup the descriptor for this transfer. Since this function is used with */
1289 /* CONTINUOUS DMA operations, we need to reinitialize every time, otherwise */
1290 /* setDataDescriptor will keep trying to append onto the end. */
1292 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1293 devAttr->ring.physAddr,
1294 devAttr->ring.bytesAllocated,
1295 numDescriptors) < 0) {
1296 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n", __func__);
1300 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1301 /* as last time, then we don't need to call setDataDescriptor again. */
1303 if (dmacHw_setDataDescriptor(&devAttr->config,
1304 devAttr->ring.virtAddr,
1306 (void *)dstData1, numBytes) < 0) {
1307 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 1 failed\n",
1311 if (dmacHw_setDataDescriptor(&devAttr->config,
1312 devAttr->ring.virtAddr,
1314 (void *)dstData2, numBytes) < 0) {
1315 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 2 failed\n",
1320 /* You should use dma_start_transfer rather than dma_transfer_xxx so we don't */
1321 /* try to make the 'prev' variables right. */
1323 devAttr->prevSrcData = 0;
1324 devAttr->prevDstData = 0;
1325 devAttr->prevNumBytes = 0;
1327 return numDescriptors;
1330 EXPORT_SYMBOL(dma_alloc_double_dst_descriptors);
1332 /****************************************************************************/
1334 * Initiates a transfer when the descriptors have already been setup.
1336 * This is a special case, and normally, the dma_transfer_xxx functions should
1340 * 0 Transfer was started successfully
1341 * -ENODEV Invalid handle
1343 /****************************************************************************/
1345 int dma_start_transfer(DMA_Handle_t handle)
1347 DMA_Channel_t *channel;
1348 DMA_DeviceAttribute_t *devAttr;
1350 channel = HandleToChannel(handle);
1351 if (channel == NULL) {
1354 devAttr = &DMA_gDeviceAttribute[channel->devType];
1356 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1357 devAttr->ring.virtAddr);
1359 /* Since we got this far, everything went successfully */
1364 EXPORT_SYMBOL(dma_start_transfer);
1366 /****************************************************************************/
1368 * Stops a previously started DMA transfer.
1371 * 0 Transfer was stopped successfully
1372 * -ENODEV Invalid handle
1374 /****************************************************************************/
1376 int dma_stop_transfer(DMA_Handle_t handle)
1378 DMA_Channel_t *channel;
1380 channel = HandleToChannel(handle);
1381 if (channel == NULL) {
1385 dmacHw_stopTransfer(channel->dmacHwHandle);
1390 EXPORT_SYMBOL(dma_stop_transfer);
1392 /****************************************************************************/
1394 * Waits for a DMA to complete by polling. This function is only intended
1395 * to be used for testing. Interrupts should be used for most DMA operations.
1397 /****************************************************************************/
1399 int dma_wait_transfer_done(DMA_Handle_t handle)
1401 DMA_Channel_t *channel;
1402 dmacHw_TRANSFER_STATUS_e status;
1404 channel = HandleToChannel(handle);
1405 if (channel == NULL) {
1410 dmacHw_transferCompleted(channel->dmacHwHandle)) ==
1411 dmacHw_TRANSFER_STATUS_BUSY) {
1415 if (status == dmacHw_TRANSFER_STATUS_ERROR) {
1416 printk(KERN_ERR "%s: DMA transfer failed\n", __func__);
1422 EXPORT_SYMBOL(dma_wait_transfer_done);
1424 /****************************************************************************/
1426 * Initiates a DMA, allocating the descriptors as required.
1429 * 0 Transfer was started successfully
1430 * -EINVAL Invalid device type for this kind of transfer
1431 * (i.e. the device is _DEV_TO_MEM and not _MEM_TO_DEV)
1433 /****************************************************************************/
1435 int dma_transfer(DMA_Handle_t handle, /* DMA Handle */
1436 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1437 dma_addr_t srcData, /* Place to get data to write to device */
1438 dma_addr_t dstData, /* Pointer to device data address */
1439 size_t numBytes /* Number of bytes to transfer to the device */
1441 DMA_Channel_t *channel;
1442 DMA_DeviceAttribute_t *devAttr;
1445 channel = HandleToChannel(handle);
1446 if (channel == NULL) {
1450 devAttr = &DMA_gDeviceAttribute[channel->devType];
1452 if (devAttr->config.transferType != transferType) {
1456 /* We keep track of the information about the previous request for this */
1457 /* device, and if the attributes match, then we can use the descriptors we setup */
1458 /* the last time, and not have to reinitialize everything. */
1462 dma_alloc_descriptors(handle, transferType, srcData,
1469 /* And kick off the transfer */
1471 devAttr->numBytes = numBytes;
1472 devAttr->transferStartTime = timer_get_tick_count();
1474 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1475 devAttr->ring.virtAddr);
1477 /* Since we got this far, everything went successfully */
1482 EXPORT_SYMBOL(dma_transfer);
1484 /****************************************************************************/
1486 * Set the callback function which will be called when a transfer completes.
1487 * If a NULL callback function is set, then no callback will occur.
1489 * @note @a devHandler will be called from IRQ context.
1493 * -ENODEV - Device handed in is invalid.
1495 /****************************************************************************/
1497 int dma_set_device_handler(DMA_Device_t dev, /* Device to set the callback for. */
1498 DMA_DeviceHandler_t devHandler, /* Function to call when the DMA completes */
1499 void *userData /* Pointer which will be passed to devHandler. */
1501 DMA_DeviceAttribute_t *devAttr;
1502 unsigned long flags;
1504 if (!IsDeviceValid(dev)) {
1507 devAttr = &DMA_gDeviceAttribute[dev];
1509 local_irq_save(flags);
1511 devAttr->userData = userData;
1512 devAttr->devHandler = devHandler;
1514 local_irq_restore(flags);
1519 EXPORT_SYMBOL(dma_set_device_handler);