2 * Freescale MPC85xx, MPC83xx DMA Engine support
4 * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
7 * Zhang Wei <wei.zhang@freescale.com>, Jul 2007
8 * Ebony Zhu <ebony.zhu@freescale.com>, May 2007
11 * DMA engine driver for Freescale MPC8540 DMA controller, which is
12 * also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
13 * The support for MPC8349 DMA controller is also added.
15 * This driver instructs the DMA controller to issue the PCI Read Multiple
16 * command for PCI read operations, instead of using the default PCI Read Line
17 * command. Please be aware that this setting may result in read pre-fetching
20 * This is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; either version 2 of the License, or
23 * (at your option) any later version.
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/pci.h>
30 #include <linux/slab.h>
31 #include <linux/interrupt.h>
32 #include <linux/dmaengine.h>
33 #include <linux/delay.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/dmapool.h>
36 #include <linux/of_platform.h>
38 #include "dmaengine.h"
41 #define chan_dbg(chan, fmt, arg...) \
42 dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
43 #define chan_err(chan, fmt, arg...) \
44 dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
46 static const char msg_ld_oom[] = "No free memory for link descriptor";
52 static void set_sr(struct fsldma_chan *chan, u32 val)
54 DMA_OUT(chan, &chan->regs->sr, val, 32);
57 static u32 get_sr(struct fsldma_chan *chan)
59 return DMA_IN(chan, &chan->regs->sr, 32);
62 static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
64 DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
67 static dma_addr_t get_cdar(struct fsldma_chan *chan)
69 return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
72 static u32 get_bcr(struct fsldma_chan *chan)
74 return DMA_IN(chan, &chan->regs->bcr, 32);
81 static void set_desc_cnt(struct fsldma_chan *chan,
82 struct fsl_dma_ld_hw *hw, u32 count)
84 hw->count = CPU_TO_DMA(chan, count, 32);
87 static u32 get_desc_cnt(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
89 return DMA_TO_CPU(chan, desc->hw.count, 32);
92 static void set_desc_src(struct fsldma_chan *chan,
93 struct fsl_dma_ld_hw *hw, dma_addr_t src)
97 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
98 ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
99 hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
102 static dma_addr_t get_desc_src(struct fsldma_chan *chan,
103 struct fsl_desc_sw *desc)
107 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
108 ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
109 return DMA_TO_CPU(chan, desc->hw.src_addr, 64) & ~snoop_bits;
112 static void set_desc_dst(struct fsldma_chan *chan,
113 struct fsl_dma_ld_hw *hw, dma_addr_t dst)
117 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
118 ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
119 hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
122 static dma_addr_t get_desc_dst(struct fsldma_chan *chan,
123 struct fsl_desc_sw *desc)
127 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
128 ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
129 return DMA_TO_CPU(chan, desc->hw.dst_addr, 64) & ~snoop_bits;
132 static void set_desc_next(struct fsldma_chan *chan,
133 struct fsl_dma_ld_hw *hw, dma_addr_t next)
137 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
139 hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
142 static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
146 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
149 desc->hw.next_ln_addr = CPU_TO_DMA(chan,
150 DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
155 * DMA Engine Hardware Control Helpers
158 static void dma_init(struct fsldma_chan *chan)
160 /* Reset the channel */
161 DMA_OUT(chan, &chan->regs->mr, 0, 32);
163 switch (chan->feature & FSL_DMA_IP_MASK) {
164 case FSL_DMA_IP_85XX:
165 /* Set the channel to below modes:
166 * EIE - Error interrupt enable
167 * EOLNIE - End of links interrupt enable
168 * BWC - Bandwidth sharing among channels
170 DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC
171 | FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE, 32);
173 case FSL_DMA_IP_83XX:
174 /* Set the channel to below modes:
175 * EOTIE - End-of-transfer interrupt enable
176 * PRC_RM - PCI read multiple
178 DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
179 | FSL_DMA_MR_PRC_RM, 32);
184 static int dma_is_idle(struct fsldma_chan *chan)
186 u32 sr = get_sr(chan);
187 return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
191 * Start the DMA controller
194 * - the CDAR register must point to the start descriptor
195 * - the MRn[CS] bit must be cleared
197 static void dma_start(struct fsldma_chan *chan)
201 mode = DMA_IN(chan, &chan->regs->mr, 32);
203 if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
204 DMA_OUT(chan, &chan->regs->bcr, 0, 32);
205 mode |= FSL_DMA_MR_EMP_EN;
207 mode &= ~FSL_DMA_MR_EMP_EN;
210 if (chan->feature & FSL_DMA_CHAN_START_EXT) {
211 mode |= FSL_DMA_MR_EMS_EN;
213 mode &= ~FSL_DMA_MR_EMS_EN;
214 mode |= FSL_DMA_MR_CS;
217 DMA_OUT(chan, &chan->regs->mr, mode, 32);
220 static void dma_halt(struct fsldma_chan *chan)
225 /* read the mode register */
226 mode = DMA_IN(chan, &chan->regs->mr, 32);
229 * The 85xx controller supports channel abort, which will stop
230 * the current transfer. On 83xx, this bit is the transfer error
231 * mask bit, which should not be changed.
233 if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
234 mode |= FSL_DMA_MR_CA;
235 DMA_OUT(chan, &chan->regs->mr, mode, 32);
237 mode &= ~FSL_DMA_MR_CA;
240 /* stop the DMA controller */
241 mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
242 DMA_OUT(chan, &chan->regs->mr, mode, 32);
244 /* wait for the DMA controller to become idle */
245 for (i = 0; i < 100; i++) {
246 if (dma_is_idle(chan))
252 if (!dma_is_idle(chan))
253 chan_err(chan, "DMA halt timeout!\n");
257 * fsl_chan_set_src_loop_size - Set source address hold transfer size
258 * @chan : Freescale DMA channel
259 * @size : Address loop size, 0 for disable loop
261 * The set source address hold transfer size. The source
262 * address hold or loop transfer size is when the DMA transfer
263 * data from source address (SA), if the loop size is 4, the DMA will
264 * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
265 * SA + 1 ... and so on.
267 static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
271 mode = DMA_IN(chan, &chan->regs->mr, 32);
275 mode &= ~FSL_DMA_MR_SAHE;
281 mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
285 DMA_OUT(chan, &chan->regs->mr, mode, 32);
289 * fsl_chan_set_dst_loop_size - Set destination address hold transfer size
290 * @chan : Freescale DMA channel
291 * @size : Address loop size, 0 for disable loop
293 * The set destination address hold transfer size. The destination
294 * address hold or loop transfer size is when the DMA transfer
295 * data to destination address (TA), if the loop size is 4, the DMA will
296 * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
297 * TA + 1 ... and so on.
299 static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
303 mode = DMA_IN(chan, &chan->regs->mr, 32);
307 mode &= ~FSL_DMA_MR_DAHE;
313 mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
317 DMA_OUT(chan, &chan->regs->mr, mode, 32);
321 * fsl_chan_set_request_count - Set DMA Request Count for external control
322 * @chan : Freescale DMA channel
323 * @size : Number of bytes to transfer in a single request
325 * The Freescale DMA channel can be controlled by the external signal DREQ#.
326 * The DMA request count is how many bytes are allowed to transfer before
327 * pausing the channel, after which a new assertion of DREQ# resumes channel
330 * A size of 0 disables external pause control. The maximum size is 1024.
332 static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
338 mode = DMA_IN(chan, &chan->regs->mr, 32);
339 mode |= (__ilog2(size) << 24) & 0x0f000000;
341 DMA_OUT(chan, &chan->regs->mr, mode, 32);
345 * fsl_chan_toggle_ext_pause - Toggle channel external pause status
346 * @chan : Freescale DMA channel
347 * @enable : 0 is disabled, 1 is enabled.
349 * The Freescale DMA channel can be controlled by the external signal DREQ#.
350 * The DMA Request Count feature should be used in addition to this feature
351 * to set the number of bytes to transfer before pausing the channel.
353 static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
356 chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
358 chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
362 * fsl_chan_toggle_ext_start - Toggle channel external start status
363 * @chan : Freescale DMA channel
364 * @enable : 0 is disabled, 1 is enabled.
366 * If enable the external start, the channel can be started by an
367 * external DMA start pin. So the dma_start() does not start the
368 * transfer immediately. The DMA channel will wait for the
369 * control pin asserted.
371 static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
374 chan->feature |= FSL_DMA_CHAN_START_EXT;
376 chan->feature &= ~FSL_DMA_CHAN_START_EXT;
379 static void append_ld_queue(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
381 struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
383 if (list_empty(&chan->ld_pending))
387 * Add the hardware descriptor to the chain of hardware descriptors
388 * that already exists in memory.
390 * This will un-set the EOL bit of the existing transaction, and the
391 * last link in this transaction will become the EOL descriptor.
393 set_desc_next(chan, &tail->hw, desc->async_tx.phys);
396 * Add the software descriptor and all children to the list
397 * of pending transactions
400 list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
403 static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
405 struct fsldma_chan *chan = to_fsl_chan(tx->chan);
406 struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
407 struct fsl_desc_sw *child;
411 spin_lock_irqsave(&chan->desc_lock, flags);
414 * assign cookies to all of the software descriptors
415 * that make up this transaction
417 cookie = chan->common.cookie;
418 list_for_each_entry(child, &desc->tx_list, node) {
420 if (cookie < DMA_MIN_COOKIE)
421 cookie = DMA_MIN_COOKIE;
423 child->async_tx.cookie = cookie;
426 chan->common.cookie = cookie;
428 /* put this transaction onto the tail of the pending queue */
429 append_ld_queue(chan, desc);
431 spin_unlock_irqrestore(&chan->desc_lock, flags);
437 * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
438 * @chan : Freescale DMA channel
440 * Return - The descriptor allocated. NULL for failed.
442 static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
444 struct fsl_desc_sw *desc;
447 desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
449 chan_dbg(chan, "out of memory for link descriptor\n");
453 memset(desc, 0, sizeof(*desc));
454 INIT_LIST_HEAD(&desc->tx_list);
455 dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
456 desc->async_tx.tx_submit = fsl_dma_tx_submit;
457 desc->async_tx.phys = pdesc;
459 #ifdef FSL_DMA_LD_DEBUG
460 chan_dbg(chan, "LD %p allocated\n", desc);
467 * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
468 * @chan : Freescale DMA channel
470 * This function will create a dma pool for descriptor allocation.
472 * Return - The number of descriptors allocated.
474 static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
476 struct fsldma_chan *chan = to_fsl_chan(dchan);
478 /* Has this channel already been allocated? */
483 * We need the descriptor to be aligned to 32bytes
484 * for meeting FSL DMA specification requirement.
486 chan->desc_pool = dma_pool_create(chan->name, chan->dev,
487 sizeof(struct fsl_desc_sw),
488 __alignof__(struct fsl_desc_sw), 0);
489 if (!chan->desc_pool) {
490 chan_err(chan, "unable to allocate descriptor pool\n");
494 /* there is at least one descriptor free to be allocated */
499 * fsldma_free_desc_list - Free all descriptors in a queue
500 * @chan: Freescae DMA channel
501 * @list: the list to free
503 * LOCKING: must hold chan->desc_lock
505 static void fsldma_free_desc_list(struct fsldma_chan *chan,
506 struct list_head *list)
508 struct fsl_desc_sw *desc, *_desc;
510 list_for_each_entry_safe(desc, _desc, list, node) {
511 list_del(&desc->node);
512 #ifdef FSL_DMA_LD_DEBUG
513 chan_dbg(chan, "LD %p free\n", desc);
515 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
519 static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
520 struct list_head *list)
522 struct fsl_desc_sw *desc, *_desc;
524 list_for_each_entry_safe_reverse(desc, _desc, list, node) {
525 list_del(&desc->node);
526 #ifdef FSL_DMA_LD_DEBUG
527 chan_dbg(chan, "LD %p free\n", desc);
529 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
534 * fsl_dma_free_chan_resources - Free all resources of the channel.
535 * @chan : Freescale DMA channel
537 static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
539 struct fsldma_chan *chan = to_fsl_chan(dchan);
542 chan_dbg(chan, "free all channel resources\n");
543 spin_lock_irqsave(&chan->desc_lock, flags);
544 fsldma_free_desc_list(chan, &chan->ld_pending);
545 fsldma_free_desc_list(chan, &chan->ld_running);
546 spin_unlock_irqrestore(&chan->desc_lock, flags);
548 dma_pool_destroy(chan->desc_pool);
549 chan->desc_pool = NULL;
552 static struct dma_async_tx_descriptor *
553 fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags)
555 struct fsldma_chan *chan;
556 struct fsl_desc_sw *new;
561 chan = to_fsl_chan(dchan);
563 new = fsl_dma_alloc_descriptor(chan);
565 chan_err(chan, "%s\n", msg_ld_oom);
569 new->async_tx.cookie = -EBUSY;
570 new->async_tx.flags = flags;
572 /* Insert the link descriptor to the LD ring */
573 list_add_tail(&new->node, &new->tx_list);
575 /* Set End-of-link to the last link descriptor of new list */
576 set_ld_eol(chan, new);
578 return &new->async_tx;
581 static struct dma_async_tx_descriptor *
582 fsl_dma_prep_memcpy(struct dma_chan *dchan,
583 dma_addr_t dma_dst, dma_addr_t dma_src,
584 size_t len, unsigned long flags)
586 struct fsldma_chan *chan;
587 struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
596 chan = to_fsl_chan(dchan);
600 /* Allocate the link descriptor from DMA pool */
601 new = fsl_dma_alloc_descriptor(chan);
603 chan_err(chan, "%s\n", msg_ld_oom);
607 copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
609 set_desc_cnt(chan, &new->hw, copy);
610 set_desc_src(chan, &new->hw, dma_src);
611 set_desc_dst(chan, &new->hw, dma_dst);
616 set_desc_next(chan, &prev->hw, new->async_tx.phys);
618 new->async_tx.cookie = 0;
619 async_tx_ack(&new->async_tx);
626 /* Insert the link descriptor to the LD ring */
627 list_add_tail(&new->node, &first->tx_list);
630 new->async_tx.flags = flags; /* client is in control of this ack */
631 new->async_tx.cookie = -EBUSY;
633 /* Set End-of-link to the last link descriptor of new list */
634 set_ld_eol(chan, new);
636 return &first->async_tx;
642 fsldma_free_desc_list_reverse(chan, &first->tx_list);
646 static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
647 struct scatterlist *dst_sg, unsigned int dst_nents,
648 struct scatterlist *src_sg, unsigned int src_nents,
651 struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
652 struct fsldma_chan *chan = to_fsl_chan(dchan);
653 size_t dst_avail, src_avail;
657 /* basic sanity checks */
658 if (dst_nents == 0 || src_nents == 0)
661 if (dst_sg == NULL || src_sg == NULL)
665 * TODO: should we check that both scatterlists have the same
666 * TODO: number of bytes in total? Is that really an error?
669 /* get prepared for the loop */
670 dst_avail = sg_dma_len(dst_sg);
671 src_avail = sg_dma_len(src_sg);
673 /* run until we are out of scatterlist entries */
676 /* create the largest transaction possible */
677 len = min_t(size_t, src_avail, dst_avail);
678 len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
682 dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
683 src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
685 /* allocate and populate the descriptor */
686 new = fsl_dma_alloc_descriptor(chan);
688 chan_err(chan, "%s\n", msg_ld_oom);
692 set_desc_cnt(chan, &new->hw, len);
693 set_desc_src(chan, &new->hw, src);
694 set_desc_dst(chan, &new->hw, dst);
699 set_desc_next(chan, &prev->hw, new->async_tx.phys);
701 new->async_tx.cookie = 0;
702 async_tx_ack(&new->async_tx);
705 /* Insert the link descriptor to the LD ring */
706 list_add_tail(&new->node, &first->tx_list);
708 /* update metadata */
713 /* fetch the next dst scatterlist entry */
714 if (dst_avail == 0) {
716 /* no more entries: we're done */
720 /* fetch the next entry: if there are no more: done */
721 dst_sg = sg_next(dst_sg);
726 dst_avail = sg_dma_len(dst_sg);
729 /* fetch the next src scatterlist entry */
730 if (src_avail == 0) {
732 /* no more entries: we're done */
736 /* fetch the next entry: if there are no more: done */
737 src_sg = sg_next(src_sg);
742 src_avail = sg_dma_len(src_sg);
746 new->async_tx.flags = flags; /* client is in control of this ack */
747 new->async_tx.cookie = -EBUSY;
749 /* Set End-of-link to the last link descriptor of new list */
750 set_ld_eol(chan, new);
752 return &first->async_tx;
758 fsldma_free_desc_list_reverse(chan, &first->tx_list);
763 * fsl_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
765 * @sgl: scatterlist to transfer to/from
766 * @sg_len: number of entries in @scatterlist
767 * @direction: DMA direction
768 * @flags: DMAEngine flags
770 * Prepare a set of descriptors for a DMA_SLAVE transaction. Following the
771 * DMA_SLAVE API, this gets the device-specific information from the
772 * chan->private variable.
774 static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
775 struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
776 enum dma_transfer_direction direction, unsigned long flags)
779 * This operation is not supported on the Freescale DMA controller
781 * However, we need to provide the function pointer to allow the
782 * device_control() method to work.
787 static int fsl_dma_device_control(struct dma_chan *dchan,
788 enum dma_ctrl_cmd cmd, unsigned long arg)
790 struct dma_slave_config *config;
791 struct fsldma_chan *chan;
798 chan = to_fsl_chan(dchan);
801 case DMA_TERMINATE_ALL:
802 spin_lock_irqsave(&chan->desc_lock, flags);
804 /* Halt the DMA engine */
807 /* Remove and free all of the descriptors in the LD queue */
808 fsldma_free_desc_list(chan, &chan->ld_pending);
809 fsldma_free_desc_list(chan, &chan->ld_running);
812 spin_unlock_irqrestore(&chan->desc_lock, flags);
815 case DMA_SLAVE_CONFIG:
816 config = (struct dma_slave_config *)arg;
818 /* make sure the channel supports setting burst size */
819 if (!chan->set_request_count)
822 /* we set the controller burst size depending on direction */
823 if (config->direction == DMA_MEM_TO_DEV)
824 size = config->dst_addr_width * config->dst_maxburst;
826 size = config->src_addr_width * config->src_maxburst;
828 chan->set_request_count(chan, size);
831 case FSLDMA_EXTERNAL_START:
833 /* make sure the channel supports external start */
834 if (!chan->toggle_ext_start)
837 chan->toggle_ext_start(chan, arg);
848 * fsldma_cleanup_descriptor - cleanup and free a single link descriptor
849 * @chan: Freescale DMA channel
850 * @desc: descriptor to cleanup and free
852 * This function is used on a descriptor which has been executed by the DMA
853 * controller. It will run any callbacks, submit any dependencies, and then
854 * free the descriptor.
856 static void fsldma_cleanup_descriptor(struct fsldma_chan *chan,
857 struct fsl_desc_sw *desc)
859 struct dma_async_tx_descriptor *txd = &desc->async_tx;
860 struct device *dev = chan->common.device->dev;
861 dma_addr_t src = get_desc_src(chan, desc);
862 dma_addr_t dst = get_desc_dst(chan, desc);
863 u32 len = get_desc_cnt(chan, desc);
865 /* Run the link descriptor callback function */
867 #ifdef FSL_DMA_LD_DEBUG
868 chan_dbg(chan, "LD %p callback\n", desc);
870 txd->callback(txd->callback_param);
873 /* Run any dependencies */
874 dma_run_dependencies(txd);
876 /* Unmap the dst buffer, if requested */
877 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
878 if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
879 dma_unmap_single(dev, dst, len, DMA_FROM_DEVICE);
881 dma_unmap_page(dev, dst, len, DMA_FROM_DEVICE);
884 /* Unmap the src buffer, if requested */
885 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
886 if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
887 dma_unmap_single(dev, src, len, DMA_TO_DEVICE);
889 dma_unmap_page(dev, src, len, DMA_TO_DEVICE);
892 #ifdef FSL_DMA_LD_DEBUG
893 chan_dbg(chan, "LD %p free\n", desc);
895 dma_pool_free(chan->desc_pool, desc, txd->phys);
899 * fsl_chan_xfer_ld_queue - transfer any pending transactions
900 * @chan : Freescale DMA channel
902 * HARDWARE STATE: idle
903 * LOCKING: must hold chan->desc_lock
905 static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
907 struct fsl_desc_sw *desc;
910 * If the list of pending descriptors is empty, then we
911 * don't need to do any work at all
913 if (list_empty(&chan->ld_pending)) {
914 chan_dbg(chan, "no pending LDs\n");
919 * The DMA controller is not idle, which means that the interrupt
920 * handler will start any queued transactions when it runs after
921 * this transaction finishes
924 chan_dbg(chan, "DMA controller still busy\n");
929 * If there are some link descriptors which have not been
930 * transferred, we need to start the controller
934 * Move all elements from the queue of pending transactions
935 * onto the list of running transactions
937 chan_dbg(chan, "idle, starting controller\n");
938 desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
939 list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
942 * The 85xx DMA controller doesn't clear the channel start bit
943 * automatically at the end of a transfer. Therefore we must clear
944 * it in software before starting the transfer.
946 if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
949 mode = DMA_IN(chan, &chan->regs->mr, 32);
950 mode &= ~FSL_DMA_MR_CS;
951 DMA_OUT(chan, &chan->regs->mr, mode, 32);
955 * Program the descriptor's address into the DMA controller,
956 * then start the DMA transaction
958 set_cdar(chan, desc->async_tx.phys);
966 * fsl_dma_memcpy_issue_pending - Issue the DMA start command
967 * @chan : Freescale DMA channel
969 static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
971 struct fsldma_chan *chan = to_fsl_chan(dchan);
974 spin_lock_irqsave(&chan->desc_lock, flags);
975 fsl_chan_xfer_ld_queue(chan);
976 spin_unlock_irqrestore(&chan->desc_lock, flags);
980 * fsl_tx_status - Determine the DMA status
981 * @chan : Freescale DMA channel
983 static enum dma_status fsl_tx_status(struct dma_chan *dchan,
985 struct dma_tx_state *txstate)
987 struct fsldma_chan *chan = to_fsl_chan(dchan);
988 dma_cookie_t last_complete;
989 dma_cookie_t last_used;
992 spin_lock_irqsave(&chan->desc_lock, flags);
994 last_complete = dchan->completed_cookie;
995 last_used = dchan->cookie;
997 spin_unlock_irqrestore(&chan->desc_lock, flags);
999 dma_set_tx_state(txstate, last_complete, last_used, 0);
1000 return dma_async_is_complete(cookie, last_complete, last_used);
1003 /*----------------------------------------------------------------------------*/
1004 /* Interrupt Handling */
1005 /*----------------------------------------------------------------------------*/
1007 static irqreturn_t fsldma_chan_irq(int irq, void *data)
1009 struct fsldma_chan *chan = data;
1012 /* save and clear the status register */
1013 stat = get_sr(chan);
1015 chan_dbg(chan, "irq: stat = 0x%x\n", stat);
1017 /* check that this was really our device */
1018 stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
1022 if (stat & FSL_DMA_SR_TE)
1023 chan_err(chan, "Transfer Error!\n");
1027 * The DMA_INTERRUPT async_tx is a NULL transfer, which will
1028 * triger a PE interrupt.
1030 if (stat & FSL_DMA_SR_PE) {
1031 chan_dbg(chan, "irq: Programming Error INT\n");
1032 stat &= ~FSL_DMA_SR_PE;
1033 if (get_bcr(chan) != 0)
1034 chan_err(chan, "Programming Error!\n");
1038 * For MPC8349, EOCDI event need to update cookie
1039 * and start the next transfer if it exist.
1041 if (stat & FSL_DMA_SR_EOCDI) {
1042 chan_dbg(chan, "irq: End-of-Chain link INT\n");
1043 stat &= ~FSL_DMA_SR_EOCDI;
1047 * If it current transfer is the end-of-transfer,
1048 * we should clear the Channel Start bit for
1049 * prepare next transfer.
1051 if (stat & FSL_DMA_SR_EOLNI) {
1052 chan_dbg(chan, "irq: End-of-link INT\n");
1053 stat &= ~FSL_DMA_SR_EOLNI;
1056 /* check that the DMA controller is really idle */
1057 if (!dma_is_idle(chan))
1058 chan_err(chan, "irq: controller not idle!\n");
1060 /* check that we handled all of the bits */
1062 chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
1065 * Schedule the tasklet to handle all cleanup of the current
1066 * transaction. It will start a new transaction if there is
1069 tasklet_schedule(&chan->tasklet);
1070 chan_dbg(chan, "irq: Exit\n");
1074 static void dma_do_tasklet(unsigned long data)
1076 struct fsldma_chan *chan = (struct fsldma_chan *)data;
1077 struct fsl_desc_sw *desc, *_desc;
1078 LIST_HEAD(ld_cleanup);
1079 unsigned long flags;
1081 chan_dbg(chan, "tasklet entry\n");
1083 spin_lock_irqsave(&chan->desc_lock, flags);
1085 /* update the cookie if we have some descriptors to cleanup */
1086 if (!list_empty(&chan->ld_running)) {
1087 dma_cookie_t cookie;
1089 desc = to_fsl_desc(chan->ld_running.prev);
1090 cookie = desc->async_tx.cookie;
1092 chan->common.completed_cookie = cookie;
1093 chan_dbg(chan, "completed_cookie=%d\n", cookie);
1097 * move the descriptors to a temporary list so we can drop the lock
1098 * during the entire cleanup operation
1100 list_splice_tail_init(&chan->ld_running, &ld_cleanup);
1102 /* the hardware is now idle and ready for more */
1106 * Start any pending transactions automatically
1108 * In the ideal case, we keep the DMA controller busy while we go
1109 * ahead and free the descriptors below.
1111 fsl_chan_xfer_ld_queue(chan);
1112 spin_unlock_irqrestore(&chan->desc_lock, flags);
1114 /* Run the callback for each descriptor, in order */
1115 list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) {
1117 /* Remove from the list of transactions */
1118 list_del(&desc->node);
1120 /* Run all cleanup for this descriptor */
1121 fsldma_cleanup_descriptor(chan, desc);
1124 chan_dbg(chan, "tasklet exit\n");
1127 static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
1129 struct fsldma_device *fdev = data;
1130 struct fsldma_chan *chan;
1131 unsigned int handled = 0;
1135 gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
1136 : in_le32(fdev->regs);
1138 dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
1140 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1141 chan = fdev->chan[i];
1146 dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
1147 fsldma_chan_irq(irq, chan);
1155 return IRQ_RETVAL(handled);
1158 static void fsldma_free_irqs(struct fsldma_device *fdev)
1160 struct fsldma_chan *chan;
1163 if (fdev->irq != NO_IRQ) {
1164 dev_dbg(fdev->dev, "free per-controller IRQ\n");
1165 free_irq(fdev->irq, fdev);
1169 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1170 chan = fdev->chan[i];
1171 if (chan && chan->irq != NO_IRQ) {
1172 chan_dbg(chan, "free per-channel IRQ\n");
1173 free_irq(chan->irq, chan);
1178 static int fsldma_request_irqs(struct fsldma_device *fdev)
1180 struct fsldma_chan *chan;
1184 /* if we have a per-controller IRQ, use that */
1185 if (fdev->irq != NO_IRQ) {
1186 dev_dbg(fdev->dev, "request per-controller IRQ\n");
1187 ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED,
1188 "fsldma-controller", fdev);
1192 /* no per-controller IRQ, use the per-channel IRQs */
1193 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1194 chan = fdev->chan[i];
1198 if (chan->irq == NO_IRQ) {
1199 chan_err(chan, "interrupts property missing in device tree\n");
1204 chan_dbg(chan, "request per-channel IRQ\n");
1205 ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
1206 "fsldma-chan", chan);
1208 chan_err(chan, "unable to request per-channel IRQ\n");
1216 for (/* none */; i >= 0; i--) {
1217 chan = fdev->chan[i];
1221 if (chan->irq == NO_IRQ)
1224 free_irq(chan->irq, chan);
1230 /*----------------------------------------------------------------------------*/
1231 /* OpenFirmware Subsystem */
1232 /*----------------------------------------------------------------------------*/
1234 static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
1235 struct device_node *node, u32 feature, const char *compatible)
1237 struct fsldma_chan *chan;
1238 struct resource res;
1242 chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1244 dev_err(fdev->dev, "no free memory for DMA channels!\n");
1249 /* ioremap registers for use */
1250 chan->regs = of_iomap(node, 0);
1252 dev_err(fdev->dev, "unable to ioremap registers\n");
1257 err = of_address_to_resource(node, 0, &res);
1259 dev_err(fdev->dev, "unable to find 'reg' property\n");
1260 goto out_iounmap_regs;
1263 chan->feature = feature;
1265 fdev->feature = chan->feature;
1268 * If the DMA device's feature is different than the feature
1269 * of its channels, report the bug
1271 WARN_ON(fdev->feature != chan->feature);
1273 chan->dev = fdev->dev;
1274 chan->id = ((res.start - 0x100) & 0xfff) >> 7;
1275 if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
1276 dev_err(fdev->dev, "too many channels for device\n");
1278 goto out_iounmap_regs;
1281 fdev->chan[chan->id] = chan;
1282 tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
1283 snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
1285 /* Initialize the channel */
1288 /* Clear cdar registers */
1291 switch (chan->feature & FSL_DMA_IP_MASK) {
1292 case FSL_DMA_IP_85XX:
1293 chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
1294 case FSL_DMA_IP_83XX:
1295 chan->toggle_ext_start = fsl_chan_toggle_ext_start;
1296 chan->set_src_loop_size = fsl_chan_set_src_loop_size;
1297 chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
1298 chan->set_request_count = fsl_chan_set_request_count;
1301 spin_lock_init(&chan->desc_lock);
1302 INIT_LIST_HEAD(&chan->ld_pending);
1303 INIT_LIST_HEAD(&chan->ld_running);
1306 chan->common.device = &fdev->common;
1308 /* find the IRQ line, if it exists in the device tree */
1309 chan->irq = irq_of_parse_and_map(node, 0);
1311 /* Add the channel to DMA device channel list */
1312 list_add_tail(&chan->common.device_node, &fdev->common.channels);
1313 fdev->common.chancnt++;
1315 dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
1316 chan->irq != NO_IRQ ? chan->irq : fdev->irq);
1321 iounmap(chan->regs);
1328 static void fsl_dma_chan_remove(struct fsldma_chan *chan)
1330 irq_dispose_mapping(chan->irq);
1331 list_del(&chan->common.device_node);
1332 iounmap(chan->regs);
1336 static int __devinit fsldma_of_probe(struct platform_device *op)
1338 struct fsldma_device *fdev;
1339 struct device_node *child;
1342 fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
1344 dev_err(&op->dev, "No enough memory for 'priv'\n");
1349 fdev->dev = &op->dev;
1350 INIT_LIST_HEAD(&fdev->common.channels);
1352 /* ioremap the registers for use */
1353 fdev->regs = of_iomap(op->dev.of_node, 0);
1355 dev_err(&op->dev, "unable to ioremap registers\n");
1360 /* map the channel IRQ if it exists, but don't hookup the handler yet */
1361 fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
1363 dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
1364 dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
1365 dma_cap_set(DMA_SG, fdev->common.cap_mask);
1366 dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
1367 fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
1368 fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
1369 fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt;
1370 fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
1371 fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
1372 fdev->common.device_tx_status = fsl_tx_status;
1373 fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
1374 fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg;
1375 fdev->common.device_control = fsl_dma_device_control;
1376 fdev->common.dev = &op->dev;
1378 dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
1380 dev_set_drvdata(&op->dev, fdev);
1383 * We cannot use of_platform_bus_probe() because there is no
1384 * of_platform_bus_remove(). Instead, we manually instantiate every DMA
1387 for_each_child_of_node(op->dev.of_node, child) {
1388 if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
1389 fsl_dma_chan_probe(fdev, child,
1390 FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
1391 "fsl,eloplus-dma-channel");
1394 if (of_device_is_compatible(child, "fsl,elo-dma-channel")) {
1395 fsl_dma_chan_probe(fdev, child,
1396 FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
1397 "fsl,elo-dma-channel");
1402 * Hookup the IRQ handler(s)
1404 * If we have a per-controller interrupt, we prefer that to the
1405 * per-channel interrupts to reduce the number of shared interrupt
1406 * handlers on the same IRQ line
1408 err = fsldma_request_irqs(fdev);
1410 dev_err(fdev->dev, "unable to request IRQs\n");
1414 dma_async_device_register(&fdev->common);
1418 irq_dispose_mapping(fdev->irq);
1424 static int fsldma_of_remove(struct platform_device *op)
1426 struct fsldma_device *fdev;
1429 fdev = dev_get_drvdata(&op->dev);
1430 dma_async_device_unregister(&fdev->common);
1432 fsldma_free_irqs(fdev);
1434 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1436 fsl_dma_chan_remove(fdev->chan[i]);
1439 iounmap(fdev->regs);
1440 dev_set_drvdata(&op->dev, NULL);
1446 static const struct of_device_id fsldma_of_ids[] = {
1447 { .compatible = "fsl,eloplus-dma", },
1448 { .compatible = "fsl,elo-dma", },
1452 static struct platform_driver fsldma_of_driver = {
1454 .name = "fsl-elo-dma",
1455 .owner = THIS_MODULE,
1456 .of_match_table = fsldma_of_ids,
1458 .probe = fsldma_of_probe,
1459 .remove = fsldma_of_remove,
1462 /*----------------------------------------------------------------------------*/
1463 /* Module Init / Exit */
1464 /*----------------------------------------------------------------------------*/
1466 static __init int fsldma_init(void)
1468 pr_info("Freescale Elo / Elo Plus DMA driver\n");
1469 return platform_driver_register(&fsldma_of_driver);
1472 static void __exit fsldma_exit(void)
1474 platform_driver_unregister(&fsldma_of_driver);
1477 subsys_initcall(fsldma_init);
1478 module_exit(fsldma_exit);
1480 MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver");
1481 MODULE_LICENSE("GPL");