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>
40 #define chan_dbg(chan, fmt, arg...) \
41 dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
42 #define chan_err(chan, fmt, arg...) \
43 dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
45 static const char msg_ld_oom[] = "No free memory for link descriptor";
51 static void set_sr(struct fsldma_chan *chan, u32 val)
53 DMA_OUT(chan, &chan->regs->sr, val, 32);
56 static u32 get_sr(struct fsldma_chan *chan)
58 return DMA_IN(chan, &chan->regs->sr, 32);
61 static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
63 DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
66 static dma_addr_t get_cdar(struct fsldma_chan *chan)
68 return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
71 static dma_addr_t get_ndar(struct fsldma_chan *chan)
73 return DMA_IN(chan, &chan->regs->ndar, 64);
76 static u32 get_bcr(struct fsldma_chan *chan)
78 return DMA_IN(chan, &chan->regs->bcr, 32);
85 static void set_desc_cnt(struct fsldma_chan *chan,
86 struct fsl_dma_ld_hw *hw, u32 count)
88 hw->count = CPU_TO_DMA(chan, count, 32);
91 static void set_desc_src(struct fsldma_chan *chan,
92 struct fsl_dma_ld_hw *hw, dma_addr_t src)
96 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
97 ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
98 hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
101 static void set_desc_dst(struct fsldma_chan *chan,
102 struct fsl_dma_ld_hw *hw, dma_addr_t dst)
106 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
107 ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
108 hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
111 static void set_desc_next(struct fsldma_chan *chan,
112 struct fsl_dma_ld_hw *hw, dma_addr_t next)
116 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
118 hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
121 static void set_ld_eol(struct fsldma_chan *chan,
122 struct fsl_desc_sw *desc)
126 snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
129 desc->hw.next_ln_addr = CPU_TO_DMA(chan,
130 DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
135 * DMA Engine Hardware Control Helpers
138 static void dma_init(struct fsldma_chan *chan)
140 /* Reset the channel */
141 DMA_OUT(chan, &chan->regs->mr, 0, 32);
143 switch (chan->feature & FSL_DMA_IP_MASK) {
144 case FSL_DMA_IP_85XX:
145 /* Set the channel to below modes:
146 * EIE - Error interrupt enable
147 * EOSIE - End of segments interrupt enable (basic mode)
148 * EOLNIE - End of links interrupt enable
149 * BWC - Bandwidth sharing among channels
151 DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC
152 | FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE
153 | FSL_DMA_MR_EOSIE, 32);
155 case FSL_DMA_IP_83XX:
156 /* Set the channel to below modes:
157 * EOTIE - End-of-transfer interrupt enable
158 * PRC_RM - PCI read multiple
160 DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
161 | FSL_DMA_MR_PRC_RM, 32);
166 static int dma_is_idle(struct fsldma_chan *chan)
168 u32 sr = get_sr(chan);
169 return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
172 static void dma_start(struct fsldma_chan *chan)
176 mode = DMA_IN(chan, &chan->regs->mr, 32);
178 if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
179 if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
180 DMA_OUT(chan, &chan->regs->bcr, 0, 32);
181 mode |= FSL_DMA_MR_EMP_EN;
183 mode &= ~FSL_DMA_MR_EMP_EN;
187 if (chan->feature & FSL_DMA_CHAN_START_EXT)
188 mode |= FSL_DMA_MR_EMS_EN;
190 mode |= FSL_DMA_MR_CS;
192 DMA_OUT(chan, &chan->regs->mr, mode, 32);
195 static void dma_halt(struct fsldma_chan *chan)
200 mode = DMA_IN(chan, &chan->regs->mr, 32);
201 mode |= FSL_DMA_MR_CA;
202 DMA_OUT(chan, &chan->regs->mr, mode, 32);
204 mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA);
205 DMA_OUT(chan, &chan->regs->mr, mode, 32);
207 for (i = 0; i < 100; i++) {
208 if (dma_is_idle(chan))
214 if (!dma_is_idle(chan))
215 chan_err(chan, "DMA halt timeout!\n");
219 * fsl_chan_set_src_loop_size - Set source address hold transfer size
220 * @chan : Freescale DMA channel
221 * @size : Address loop size, 0 for disable loop
223 * The set source address hold transfer size. The source
224 * address hold or loop transfer size is when the DMA transfer
225 * data from source address (SA), if the loop size is 4, the DMA will
226 * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
227 * SA + 1 ... and so on.
229 static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
233 mode = DMA_IN(chan, &chan->regs->mr, 32);
237 mode &= ~FSL_DMA_MR_SAHE;
243 mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
247 DMA_OUT(chan, &chan->regs->mr, mode, 32);
251 * fsl_chan_set_dst_loop_size - Set destination address hold transfer size
252 * @chan : Freescale DMA channel
253 * @size : Address loop size, 0 for disable loop
255 * The set destination address hold transfer size. The destination
256 * address hold or loop transfer size is when the DMA transfer
257 * data to destination address (TA), if the loop size is 4, the DMA will
258 * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
259 * TA + 1 ... and so on.
261 static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
265 mode = DMA_IN(chan, &chan->regs->mr, 32);
269 mode &= ~FSL_DMA_MR_DAHE;
275 mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
279 DMA_OUT(chan, &chan->regs->mr, mode, 32);
283 * fsl_chan_set_request_count - Set DMA Request Count for external control
284 * @chan : Freescale DMA channel
285 * @size : Number of bytes to transfer in a single request
287 * The Freescale DMA channel can be controlled by the external signal DREQ#.
288 * The DMA request count is how many bytes are allowed to transfer before
289 * pausing the channel, after which a new assertion of DREQ# resumes channel
292 * A size of 0 disables external pause control. The maximum size is 1024.
294 static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
300 mode = DMA_IN(chan, &chan->regs->mr, 32);
301 mode |= (__ilog2(size) << 24) & 0x0f000000;
303 DMA_OUT(chan, &chan->regs->mr, mode, 32);
307 * fsl_chan_toggle_ext_pause - Toggle channel external pause status
308 * @chan : Freescale DMA channel
309 * @enable : 0 is disabled, 1 is enabled.
311 * The Freescale DMA channel can be controlled by the external signal DREQ#.
312 * The DMA Request Count feature should be used in addition to this feature
313 * to set the number of bytes to transfer before pausing the channel.
315 static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
318 chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
320 chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
324 * fsl_chan_toggle_ext_start - Toggle channel external start status
325 * @chan : Freescale DMA channel
326 * @enable : 0 is disabled, 1 is enabled.
328 * If enable the external start, the channel can be started by an
329 * external DMA start pin. So the dma_start() does not start the
330 * transfer immediately. The DMA channel will wait for the
331 * control pin asserted.
333 static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
336 chan->feature |= FSL_DMA_CHAN_START_EXT;
338 chan->feature &= ~FSL_DMA_CHAN_START_EXT;
341 static void append_ld_queue(struct fsldma_chan *chan,
342 struct fsl_desc_sw *desc)
344 struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
346 if (list_empty(&chan->ld_pending))
350 * Add the hardware descriptor to the chain of hardware descriptors
351 * that already exists in memory.
353 * This will un-set the EOL bit of the existing transaction, and the
354 * last link in this transaction will become the EOL descriptor.
356 set_desc_next(chan, &tail->hw, desc->async_tx.phys);
359 * Add the software descriptor and all children to the list
360 * of pending transactions
363 list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
366 static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
368 struct fsldma_chan *chan = to_fsl_chan(tx->chan);
369 struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
370 struct fsl_desc_sw *child;
374 spin_lock_irqsave(&chan->desc_lock, flags);
377 * assign cookies to all of the software descriptors
378 * that make up this transaction
380 cookie = chan->common.cookie;
381 list_for_each_entry(child, &desc->tx_list, node) {
386 child->async_tx.cookie = cookie;
389 chan->common.cookie = cookie;
391 /* put this transaction onto the tail of the pending queue */
392 append_ld_queue(chan, desc);
394 spin_unlock_irqrestore(&chan->desc_lock, flags);
400 * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
401 * @chan : Freescale DMA channel
403 * Return - The descriptor allocated. NULL for failed.
405 static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
406 struct fsldma_chan *chan)
408 struct fsl_desc_sw *desc;
411 desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
413 chan_dbg(chan, "out of memory for link descriptor\n");
417 memset(desc, 0, sizeof(*desc));
418 INIT_LIST_HEAD(&desc->tx_list);
419 dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
420 desc->async_tx.tx_submit = fsl_dma_tx_submit;
421 desc->async_tx.phys = pdesc;
428 * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
429 * @chan : Freescale DMA channel
431 * This function will create a dma pool for descriptor allocation.
433 * Return - The number of descriptors allocated.
435 static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
437 struct fsldma_chan *chan = to_fsl_chan(dchan);
439 /* Has this channel already been allocated? */
444 * We need the descriptor to be aligned to 32bytes
445 * for meeting FSL DMA specification requirement.
447 chan->desc_pool = dma_pool_create(chan->name, chan->dev,
448 sizeof(struct fsl_desc_sw),
449 __alignof__(struct fsl_desc_sw), 0);
450 if (!chan->desc_pool) {
451 chan_err(chan, "unable to allocate descriptor pool\n");
455 /* there is at least one descriptor free to be allocated */
460 * fsldma_free_desc_list - Free all descriptors in a queue
461 * @chan: Freescae DMA channel
462 * @list: the list to free
464 * LOCKING: must hold chan->desc_lock
466 static void fsldma_free_desc_list(struct fsldma_chan *chan,
467 struct list_head *list)
469 struct fsl_desc_sw *desc, *_desc;
471 list_for_each_entry_safe(desc, _desc, list, node) {
472 list_del(&desc->node);
473 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
477 static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
478 struct list_head *list)
480 struct fsl_desc_sw *desc, *_desc;
482 list_for_each_entry_safe_reverse(desc, _desc, list, node) {
483 list_del(&desc->node);
484 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
489 * fsl_dma_free_chan_resources - Free all resources of the channel.
490 * @chan : Freescale DMA channel
492 static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
494 struct fsldma_chan *chan = to_fsl_chan(dchan);
497 chan_dbg(chan, "free all channel resources\n");
498 spin_lock_irqsave(&chan->desc_lock, flags);
499 fsldma_free_desc_list(chan, &chan->ld_pending);
500 fsldma_free_desc_list(chan, &chan->ld_running);
501 spin_unlock_irqrestore(&chan->desc_lock, flags);
503 dma_pool_destroy(chan->desc_pool);
504 chan->desc_pool = NULL;
507 static struct dma_async_tx_descriptor *
508 fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags)
510 struct fsldma_chan *chan;
511 struct fsl_desc_sw *new;
516 chan = to_fsl_chan(dchan);
518 new = fsl_dma_alloc_descriptor(chan);
520 chan_err(chan, "%s\n", msg_ld_oom);
524 new->async_tx.cookie = -EBUSY;
525 new->async_tx.flags = flags;
527 /* Insert the link descriptor to the LD ring */
528 list_add_tail(&new->node, &new->tx_list);
530 /* Set End-of-link to the last link descriptor of new list*/
531 set_ld_eol(chan, new);
533 return &new->async_tx;
536 static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
537 struct dma_chan *dchan, dma_addr_t dma_dst, dma_addr_t dma_src,
538 size_t len, unsigned long flags)
540 struct fsldma_chan *chan;
541 struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
550 chan = to_fsl_chan(dchan);
554 /* Allocate the link descriptor from DMA pool */
555 new = fsl_dma_alloc_descriptor(chan);
557 chan_err(chan, "%s\n", msg_ld_oom);
560 #ifdef FSL_DMA_LD_DEBUG
561 chan_dbg(chan, "new link desc alloc %p\n", new);
564 copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
566 set_desc_cnt(chan, &new->hw, copy);
567 set_desc_src(chan, &new->hw, dma_src);
568 set_desc_dst(chan, &new->hw, dma_dst);
573 set_desc_next(chan, &prev->hw, new->async_tx.phys);
575 new->async_tx.cookie = 0;
576 async_tx_ack(&new->async_tx);
583 /* Insert the link descriptor to the LD ring */
584 list_add_tail(&new->node, &first->tx_list);
587 new->async_tx.flags = flags; /* client is in control of this ack */
588 new->async_tx.cookie = -EBUSY;
590 /* Set End-of-link to the last link descriptor of new list*/
591 set_ld_eol(chan, new);
593 return &first->async_tx;
599 fsldma_free_desc_list_reverse(chan, &first->tx_list);
603 static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
604 struct scatterlist *dst_sg, unsigned int dst_nents,
605 struct scatterlist *src_sg, unsigned int src_nents,
608 struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
609 struct fsldma_chan *chan = to_fsl_chan(dchan);
610 size_t dst_avail, src_avail;
614 /* basic sanity checks */
615 if (dst_nents == 0 || src_nents == 0)
618 if (dst_sg == NULL || src_sg == NULL)
622 * TODO: should we check that both scatterlists have the same
623 * TODO: number of bytes in total? Is that really an error?
626 /* get prepared for the loop */
627 dst_avail = sg_dma_len(dst_sg);
628 src_avail = sg_dma_len(src_sg);
630 /* run until we are out of scatterlist entries */
633 /* create the largest transaction possible */
634 len = min_t(size_t, src_avail, dst_avail);
635 len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
639 dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
640 src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
642 /* allocate and populate the descriptor */
643 new = fsl_dma_alloc_descriptor(chan);
645 chan_err(chan, "%s\n", msg_ld_oom);
648 #ifdef FSL_DMA_LD_DEBUG
649 chan_dbg(chan, "new link desc alloc %p\n", new);
652 set_desc_cnt(chan, &new->hw, len);
653 set_desc_src(chan, &new->hw, src);
654 set_desc_dst(chan, &new->hw, dst);
659 set_desc_next(chan, &prev->hw, new->async_tx.phys);
661 new->async_tx.cookie = 0;
662 async_tx_ack(&new->async_tx);
665 /* Insert the link descriptor to the LD ring */
666 list_add_tail(&new->node, &first->tx_list);
668 /* update metadata */
673 /* fetch the next dst scatterlist entry */
674 if (dst_avail == 0) {
676 /* no more entries: we're done */
680 /* fetch the next entry: if there are no more: done */
681 dst_sg = sg_next(dst_sg);
686 dst_avail = sg_dma_len(dst_sg);
689 /* fetch the next src scatterlist entry */
690 if (src_avail == 0) {
692 /* no more entries: we're done */
696 /* fetch the next entry: if there are no more: done */
697 src_sg = sg_next(src_sg);
702 src_avail = sg_dma_len(src_sg);
706 new->async_tx.flags = flags; /* client is in control of this ack */
707 new->async_tx.cookie = -EBUSY;
709 /* Set End-of-link to the last link descriptor of new list */
710 set_ld_eol(chan, new);
712 return &first->async_tx;
718 fsldma_free_desc_list_reverse(chan, &first->tx_list);
723 * fsl_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
725 * @sgl: scatterlist to transfer to/from
726 * @sg_len: number of entries in @scatterlist
727 * @direction: DMA direction
728 * @flags: DMAEngine flags
730 * Prepare a set of descriptors for a DMA_SLAVE transaction. Following the
731 * DMA_SLAVE API, this gets the device-specific information from the
732 * chan->private variable.
734 static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
735 struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
736 enum dma_data_direction direction, unsigned long flags)
739 * This operation is not supported on the Freescale DMA controller
741 * However, we need to provide the function pointer to allow the
742 * device_control() method to work.
747 static int fsl_dma_device_control(struct dma_chan *dchan,
748 enum dma_ctrl_cmd cmd, unsigned long arg)
750 struct dma_slave_config *config;
751 struct fsldma_chan *chan;
758 chan = to_fsl_chan(dchan);
761 case DMA_TERMINATE_ALL:
762 /* Halt the DMA engine */
765 spin_lock_irqsave(&chan->desc_lock, flags);
767 /* Remove and free all of the descriptors in the LD queue */
768 fsldma_free_desc_list(chan, &chan->ld_pending);
769 fsldma_free_desc_list(chan, &chan->ld_running);
771 spin_unlock_irqrestore(&chan->desc_lock, flags);
774 case DMA_SLAVE_CONFIG:
775 config = (struct dma_slave_config *)arg;
777 /* make sure the channel supports setting burst size */
778 if (!chan->set_request_count)
781 /* we set the controller burst size depending on direction */
782 if (config->direction == DMA_TO_DEVICE)
783 size = config->dst_addr_width * config->dst_maxburst;
785 size = config->src_addr_width * config->src_maxburst;
787 chan->set_request_count(chan, size);
790 case FSLDMA_EXTERNAL_START:
792 /* make sure the channel supports external start */
793 if (!chan->toggle_ext_start)
796 chan->toggle_ext_start(chan, arg);
807 * fsl_dma_update_completed_cookie - Update the completed cookie.
808 * @chan : Freescale DMA channel
812 static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan)
814 struct fsl_desc_sw *desc;
818 spin_lock_irqsave(&chan->desc_lock, flags);
820 if (list_empty(&chan->ld_running)) {
821 chan_dbg(chan, "no running descriptors\n");
825 /* Get the last descriptor, update the cookie to that */
826 desc = to_fsl_desc(chan->ld_running.prev);
827 if (dma_is_idle(chan))
828 cookie = desc->async_tx.cookie;
830 cookie = desc->async_tx.cookie - 1;
831 if (unlikely(cookie < DMA_MIN_COOKIE))
832 cookie = DMA_MAX_COOKIE;
835 chan->completed_cookie = cookie;
838 spin_unlock_irqrestore(&chan->desc_lock, flags);
842 * fsldma_desc_status - Check the status of a descriptor
843 * @chan: Freescale DMA channel
844 * @desc: DMA SW descriptor
846 * This function will return the status of the given descriptor
848 static enum dma_status fsldma_desc_status(struct fsldma_chan *chan,
849 struct fsl_desc_sw *desc)
851 return dma_async_is_complete(desc->async_tx.cookie,
852 chan->completed_cookie,
853 chan->common.cookie);
857 * fsl_chan_ld_cleanup - Clean up link descriptors
858 * @chan : Freescale DMA channel
860 * This function clean up the ld_queue of DMA channel.
862 static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
864 struct fsl_desc_sw *desc, *_desc;
867 spin_lock_irqsave(&chan->desc_lock, flags);
869 chan_dbg(chan, "chan completed_cookie = %d\n", chan->completed_cookie);
870 list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
871 dma_async_tx_callback callback;
872 void *callback_param;
874 if (fsldma_desc_status(chan, desc) == DMA_IN_PROGRESS)
877 /* Remove from the list of running transactions */
878 list_del(&desc->node);
880 /* Run the link descriptor callback function */
881 callback = desc->async_tx.callback;
882 callback_param = desc->async_tx.callback_param;
884 spin_unlock_irqrestore(&chan->desc_lock, flags);
885 chan_dbg(chan, "LD %p callback\n", desc);
886 callback(callback_param);
887 spin_lock_irqsave(&chan->desc_lock, flags);
890 /* Run any dependencies, then free the descriptor */
891 dma_run_dependencies(&desc->async_tx);
892 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
895 spin_unlock_irqrestore(&chan->desc_lock, flags);
899 * fsl_chan_xfer_ld_queue - transfer any pending transactions
900 * @chan : Freescale DMA channel
902 * This will make sure that any pending transactions will be run.
903 * If the DMA controller is idle, it will be started. Otherwise,
904 * the DMA controller's interrupt handler will start any pending
905 * transactions when it becomes idle.
907 static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
909 struct fsl_desc_sw *desc;
912 spin_lock_irqsave(&chan->desc_lock, flags);
915 * If the list of pending descriptors is empty, then we
916 * don't need to do any work at all
918 if (list_empty(&chan->ld_pending)) {
919 chan_dbg(chan, "no pending LDs\n");
924 * The DMA controller is not idle, which means the interrupt
925 * handler will start any queued transactions when it runs
926 * at the end of the current transaction
928 if (!dma_is_idle(chan)) {
929 chan_dbg(chan, "DMA controller still busy\n");
935 * make sure the dma_halt() function really un-wedges the
936 * controller as much as possible
941 * If there are some link descriptors which have not been
942 * transferred, we need to start the controller
946 * Move all elements from the queue of pending transactions
947 * onto the list of running transactions
949 desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
950 list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
953 * Program the descriptor's address into the DMA controller,
954 * then start the DMA transaction
956 set_cdar(chan, desc->async_tx.phys);
960 spin_unlock_irqrestore(&chan->desc_lock, flags);
964 * fsl_dma_memcpy_issue_pending - Issue the DMA start command
965 * @chan : Freescale DMA channel
967 static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
969 struct fsldma_chan *chan = to_fsl_chan(dchan);
970 fsl_chan_xfer_ld_queue(chan);
974 * fsl_tx_status - Determine the DMA status
975 * @chan : Freescale DMA channel
977 static enum dma_status fsl_tx_status(struct dma_chan *dchan,
979 struct dma_tx_state *txstate)
981 struct fsldma_chan *chan = to_fsl_chan(dchan);
982 dma_cookie_t last_used;
983 dma_cookie_t last_complete;
985 fsl_chan_ld_cleanup(chan);
987 last_used = dchan->cookie;
988 last_complete = chan->completed_cookie;
990 dma_set_tx_state(txstate, last_complete, last_used, 0);
992 return dma_async_is_complete(cookie, last_complete, last_used);
995 /*----------------------------------------------------------------------------*/
996 /* Interrupt Handling */
997 /*----------------------------------------------------------------------------*/
999 static irqreturn_t fsldma_chan_irq(int irq, void *data)
1001 struct fsldma_chan *chan = data;
1002 int update_cookie = 0;
1006 /* save and clear the status register */
1007 stat = get_sr(chan);
1009 chan_dbg(chan, "irq: stat = 0x%x\n", stat);
1011 stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
1015 if (stat & FSL_DMA_SR_TE)
1016 chan_err(chan, "Transfer Error!\n");
1020 * The DMA_INTERRUPT async_tx is a NULL transfer, which will
1021 * triger a PE interrupt.
1023 if (stat & FSL_DMA_SR_PE) {
1024 chan_dbg(chan, "irq: Programming Error INT\n");
1025 if (get_bcr(chan) == 0) {
1026 /* BCR register is 0, this is a DMA_INTERRUPT async_tx.
1027 * Now, update the completed cookie, and continue the
1028 * next uncompleted transfer.
1033 stat &= ~FSL_DMA_SR_PE;
1037 * If the link descriptor segment transfer finishes,
1038 * we will recycle the used descriptor.
1040 if (stat & FSL_DMA_SR_EOSI) {
1041 chan_dbg(chan, "irq: End-of-segments INT\n");
1042 chan_dbg(chan, "irq: clndar 0x%llx, nlndar 0x%llx\n",
1043 (unsigned long long)get_cdar(chan),
1044 (unsigned long long)get_ndar(chan));
1045 stat &= ~FSL_DMA_SR_EOSI;
1050 * For MPC8349, EOCDI event need to update cookie
1051 * and start the next transfer if it exist.
1053 if (stat & FSL_DMA_SR_EOCDI) {
1054 chan_dbg(chan, "irq: End-of-Chain link INT\n");
1055 stat &= ~FSL_DMA_SR_EOCDI;
1061 * If it current transfer is the end-of-transfer,
1062 * we should clear the Channel Start bit for
1063 * prepare next transfer.
1065 if (stat & FSL_DMA_SR_EOLNI) {
1066 chan_dbg(chan, "irq: End-of-link INT\n");
1067 stat &= ~FSL_DMA_SR_EOLNI;
1072 fsl_dma_update_completed_cookie(chan);
1074 fsl_chan_xfer_ld_queue(chan);
1076 chan_dbg(chan, "irq: unhandled sr 0x%08x\n", stat);
1078 chan_dbg(chan, "irq: Exit\n");
1079 tasklet_schedule(&chan->tasklet);
1083 static void dma_do_tasklet(unsigned long data)
1085 struct fsldma_chan *chan = (struct fsldma_chan *)data;
1086 fsl_chan_ld_cleanup(chan);
1089 static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
1091 struct fsldma_device *fdev = data;
1092 struct fsldma_chan *chan;
1093 unsigned int handled = 0;
1097 gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
1098 : in_le32(fdev->regs);
1100 dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
1102 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1103 chan = fdev->chan[i];
1108 dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
1109 fsldma_chan_irq(irq, chan);
1117 return IRQ_RETVAL(handled);
1120 static void fsldma_free_irqs(struct fsldma_device *fdev)
1122 struct fsldma_chan *chan;
1125 if (fdev->irq != NO_IRQ) {
1126 dev_dbg(fdev->dev, "free per-controller IRQ\n");
1127 free_irq(fdev->irq, fdev);
1131 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1132 chan = fdev->chan[i];
1133 if (chan && chan->irq != NO_IRQ) {
1134 chan_dbg(chan, "free per-channel IRQ\n");
1135 free_irq(chan->irq, chan);
1140 static int fsldma_request_irqs(struct fsldma_device *fdev)
1142 struct fsldma_chan *chan;
1146 /* if we have a per-controller IRQ, use that */
1147 if (fdev->irq != NO_IRQ) {
1148 dev_dbg(fdev->dev, "request per-controller IRQ\n");
1149 ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED,
1150 "fsldma-controller", fdev);
1154 /* no per-controller IRQ, use the per-channel IRQs */
1155 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1156 chan = fdev->chan[i];
1160 if (chan->irq == NO_IRQ) {
1161 chan_err(chan, "interrupts property missing in device tree\n");
1166 chan_dbg(chan, "request per-channel IRQ\n");
1167 ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
1168 "fsldma-chan", chan);
1170 chan_err(chan, "unable to request per-channel IRQ\n");
1178 for (/* none */; i >= 0; i--) {
1179 chan = fdev->chan[i];
1183 if (chan->irq == NO_IRQ)
1186 free_irq(chan->irq, chan);
1192 /*----------------------------------------------------------------------------*/
1193 /* OpenFirmware Subsystem */
1194 /*----------------------------------------------------------------------------*/
1196 static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
1197 struct device_node *node, u32 feature, const char *compatible)
1199 struct fsldma_chan *chan;
1200 struct resource res;
1204 chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1206 dev_err(fdev->dev, "no free memory for DMA channels!\n");
1211 /* ioremap registers for use */
1212 chan->regs = of_iomap(node, 0);
1214 dev_err(fdev->dev, "unable to ioremap registers\n");
1219 err = of_address_to_resource(node, 0, &res);
1221 dev_err(fdev->dev, "unable to find 'reg' property\n");
1222 goto out_iounmap_regs;
1225 chan->feature = feature;
1227 fdev->feature = chan->feature;
1230 * If the DMA device's feature is different than the feature
1231 * of its channels, report the bug
1233 WARN_ON(fdev->feature != chan->feature);
1235 chan->dev = fdev->dev;
1236 chan->id = ((res.start - 0x100) & 0xfff) >> 7;
1237 if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
1238 dev_err(fdev->dev, "too many channels for device\n");
1240 goto out_iounmap_regs;
1243 fdev->chan[chan->id] = chan;
1244 tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
1245 snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
1247 /* Initialize the channel */
1250 /* Clear cdar registers */
1253 switch (chan->feature & FSL_DMA_IP_MASK) {
1254 case FSL_DMA_IP_85XX:
1255 chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
1256 case FSL_DMA_IP_83XX:
1257 chan->toggle_ext_start = fsl_chan_toggle_ext_start;
1258 chan->set_src_loop_size = fsl_chan_set_src_loop_size;
1259 chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
1260 chan->set_request_count = fsl_chan_set_request_count;
1263 spin_lock_init(&chan->desc_lock);
1264 INIT_LIST_HEAD(&chan->ld_pending);
1265 INIT_LIST_HEAD(&chan->ld_running);
1267 chan->common.device = &fdev->common;
1269 /* find the IRQ line, if it exists in the device tree */
1270 chan->irq = irq_of_parse_and_map(node, 0);
1272 /* Add the channel to DMA device channel list */
1273 list_add_tail(&chan->common.device_node, &fdev->common.channels);
1274 fdev->common.chancnt++;
1276 dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
1277 chan->irq != NO_IRQ ? chan->irq : fdev->irq);
1282 iounmap(chan->regs);
1289 static void fsl_dma_chan_remove(struct fsldma_chan *chan)
1291 irq_dispose_mapping(chan->irq);
1292 list_del(&chan->common.device_node);
1293 iounmap(chan->regs);
1297 static int __devinit fsldma_of_probe(struct platform_device *op,
1298 const struct of_device_id *match)
1300 struct fsldma_device *fdev;
1301 struct device_node *child;
1304 fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
1306 dev_err(&op->dev, "No enough memory for 'priv'\n");
1311 fdev->dev = &op->dev;
1312 INIT_LIST_HEAD(&fdev->common.channels);
1314 /* ioremap the registers for use */
1315 fdev->regs = of_iomap(op->dev.of_node, 0);
1317 dev_err(&op->dev, "unable to ioremap registers\n");
1322 /* map the channel IRQ if it exists, but don't hookup the handler yet */
1323 fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
1325 dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
1326 dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
1327 dma_cap_set(DMA_SG, fdev->common.cap_mask);
1328 dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
1329 fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
1330 fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
1331 fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt;
1332 fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
1333 fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
1334 fdev->common.device_tx_status = fsl_tx_status;
1335 fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
1336 fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg;
1337 fdev->common.device_control = fsl_dma_device_control;
1338 fdev->common.dev = &op->dev;
1340 dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
1342 dev_set_drvdata(&op->dev, fdev);
1345 * We cannot use of_platform_bus_probe() because there is no
1346 * of_platform_bus_remove(). Instead, we manually instantiate every DMA
1349 for_each_child_of_node(op->dev.of_node, child) {
1350 if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
1351 fsl_dma_chan_probe(fdev, child,
1352 FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
1353 "fsl,eloplus-dma-channel");
1356 if (of_device_is_compatible(child, "fsl,elo-dma-channel")) {
1357 fsl_dma_chan_probe(fdev, child,
1358 FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
1359 "fsl,elo-dma-channel");
1364 * Hookup the IRQ handler(s)
1366 * If we have a per-controller interrupt, we prefer that to the
1367 * per-channel interrupts to reduce the number of shared interrupt
1368 * handlers on the same IRQ line
1370 err = fsldma_request_irqs(fdev);
1372 dev_err(fdev->dev, "unable to request IRQs\n");
1376 dma_async_device_register(&fdev->common);
1380 irq_dispose_mapping(fdev->irq);
1386 static int fsldma_of_remove(struct platform_device *op)
1388 struct fsldma_device *fdev;
1391 fdev = dev_get_drvdata(&op->dev);
1392 dma_async_device_unregister(&fdev->common);
1394 fsldma_free_irqs(fdev);
1396 for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1398 fsl_dma_chan_remove(fdev->chan[i]);
1401 iounmap(fdev->regs);
1402 dev_set_drvdata(&op->dev, NULL);
1408 static const struct of_device_id fsldma_of_ids[] = {
1409 { .compatible = "fsl,eloplus-dma", },
1410 { .compatible = "fsl,elo-dma", },
1414 static struct of_platform_driver fsldma_of_driver = {
1416 .name = "fsl-elo-dma",
1417 .owner = THIS_MODULE,
1418 .of_match_table = fsldma_of_ids,
1420 .probe = fsldma_of_probe,
1421 .remove = fsldma_of_remove,
1424 /*----------------------------------------------------------------------------*/
1425 /* Module Init / Exit */
1426 /*----------------------------------------------------------------------------*/
1428 static __init int fsldma_init(void)
1432 pr_info("Freescale Elo / Elo Plus DMA driver\n");
1434 ret = of_register_platform_driver(&fsldma_of_driver);
1436 pr_err("fsldma: failed to register platform driver\n");
1441 static void __exit fsldma_exit(void)
1443 of_unregister_platform_driver(&fsldma_of_driver);
1446 subsys_initcall(fsldma_init);
1447 module_exit(fsldma_exit);
1449 MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver");
1450 MODULE_LICENSE("GPL");