1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
5 * Copyright (C) 2008 Atmel Corporation
7 * This supports the Atmel AHB DMA Controller found in several Atmel SoCs.
8 * The only Atmel DMA Controller that is not covered by this driver is the one
9 * found on AT91SAM9263.
12 #include <dt-bindings/dma/at91.h>
13 #include <linux/clk.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmapool.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
22 #include <linux/of_device.h>
23 #include <linux/of_dma.h>
25 #include "at_hdmac_regs.h"
26 #include "dmaengine.h"
32 * at_hdmac : Name of the ATmel AHB DMA Controller
33 * at_dma_ / atdma : ATmel DMA controller entity related
34 * atc_ / atchan : ATmel DMA Channel entity related
37 #define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO)
38 #define ATC_DEFAULT_CTRLB (ATC_SIF(AT_DMA_MEM_IF) \
39 |ATC_DIF(AT_DMA_MEM_IF))
40 #define ATC_DMA_BUSWIDTHS\
41 (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\
42 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\
43 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\
44 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
46 #define ATC_MAX_DSCR_TRIALS 10
49 * Initial number of descriptors to allocate for each channel. This could
50 * be increased during dma usage.
52 static unsigned int init_nr_desc_per_channel = 64;
53 module_param(init_nr_desc_per_channel, uint, 0644);
54 MODULE_PARM_DESC(init_nr_desc_per_channel,
55 "initial descriptors per channel (default: 64)");
58 * struct at_dma_platform_data - Controller configuration parameters
59 * @nr_channels: Number of channels supported by hardware (max 8)
60 * @cap_mask: dma_capability flags supported by the platform
62 struct at_dma_platform_data {
63 unsigned int nr_channels;
64 dma_cap_mask_t cap_mask;
68 * struct at_dma_slave - Controller-specific information about a slave
69 * @dma_dev: required DMA master device
70 * @cfg: Platform-specific initializer for the CFG register
73 struct device *dma_dev;
78 static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
79 static void atc_issue_pending(struct dma_chan *chan);
82 /*----------------------------------------------------------------------*/
84 static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst,
89 if (!((src | dst | len) & 3))
91 else if (!((src | dst | len) & 1))
99 static struct at_desc *atc_first_active(struct at_dma_chan *atchan)
101 return list_first_entry(&atchan->active_list,
102 struct at_desc, desc_node);
105 static struct at_desc *atc_first_queued(struct at_dma_chan *atchan)
107 return list_first_entry(&atchan->queue,
108 struct at_desc, desc_node);
112 * atc_alloc_descriptor - allocate and return an initialized descriptor
113 * @chan: the channel to allocate descriptors for
114 * @gfp_flags: GFP allocation flags
116 * Note: The ack-bit is positioned in the descriptor flag at creation time
117 * to make initial allocation more convenient. This bit will be cleared
118 * and control will be given to client at usage time (during
119 * preparation functions).
121 static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan,
124 struct at_desc *desc = NULL;
125 struct at_dma *atdma = to_at_dma(chan->device);
128 desc = dma_pool_zalloc(atdma->dma_desc_pool, gfp_flags, &phys);
130 INIT_LIST_HEAD(&desc->tx_list);
131 dma_async_tx_descriptor_init(&desc->txd, chan);
132 /* txd.flags will be overwritten in prep functions */
133 desc->txd.flags = DMA_CTRL_ACK;
134 desc->txd.tx_submit = atc_tx_submit;
135 desc->txd.phys = phys;
142 * atc_desc_get - get an unused descriptor from free_list
143 * @atchan: channel we want a new descriptor for
145 static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
147 struct at_desc *desc, *_desc;
148 struct at_desc *ret = NULL;
152 spin_lock_irqsave(&atchan->lock, flags);
153 list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
155 if (async_tx_test_ack(&desc->txd)) {
156 list_del(&desc->desc_node);
160 dev_dbg(chan2dev(&atchan->chan_common),
161 "desc %p not ACKed\n", desc);
163 spin_unlock_irqrestore(&atchan->lock, flags);
164 dev_vdbg(chan2dev(&atchan->chan_common),
165 "scanned %u descriptors on freelist\n", i);
167 /* no more descriptor available in initial pool: create one more */
169 ret = atc_alloc_descriptor(&atchan->chan_common, GFP_NOWAIT);
175 * atc_desc_put - move a descriptor, including any children, to the free list
176 * @atchan: channel we work on
177 * @desc: descriptor, at the head of a chain, to move to free list
179 static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
182 struct at_desc *child;
185 spin_lock_irqsave(&atchan->lock, flags);
186 list_for_each_entry(child, &desc->tx_list, desc_node)
187 dev_vdbg(chan2dev(&atchan->chan_common),
188 "moving child desc %p to freelist\n",
190 list_splice_init(&desc->tx_list, &atchan->free_list);
191 dev_vdbg(chan2dev(&atchan->chan_common),
192 "moving desc %p to freelist\n", desc);
193 list_add(&desc->desc_node, &atchan->free_list);
194 spin_unlock_irqrestore(&atchan->lock, flags);
199 * atc_desc_chain - build chain adding a descriptor
200 * @first: address of first descriptor of the chain
201 * @prev: address of previous descriptor of the chain
202 * @desc: descriptor to queue
204 * Called from prep_* functions
206 static void atc_desc_chain(struct at_desc **first, struct at_desc **prev,
207 struct at_desc *desc)
212 /* inform the HW lli about chaining */
213 (*prev)->lli.dscr = desc->txd.phys;
214 /* insert the link descriptor to the LD ring */
215 list_add_tail(&desc->desc_node,
222 * atc_dostart - starts the DMA engine for real
223 * @atchan: the channel we want to start
224 * @first: first descriptor in the list we want to begin with
226 * Called with atchan->lock held and bh disabled
228 static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
230 struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
232 /* ASSERT: channel is idle */
233 if (atc_chan_is_enabled(atchan)) {
234 dev_err(chan2dev(&atchan->chan_common),
235 "BUG: Attempted to start non-idle channel\n");
236 dev_err(chan2dev(&atchan->chan_common),
237 " channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
238 channel_readl(atchan, SADDR),
239 channel_readl(atchan, DADDR),
240 channel_readl(atchan, CTRLA),
241 channel_readl(atchan, CTRLB),
242 channel_readl(atchan, DSCR));
244 /* The tasklet will hopefully advance the queue... */
248 vdbg_dump_regs(atchan);
250 channel_writel(atchan, SADDR, 0);
251 channel_writel(atchan, DADDR, 0);
252 channel_writel(atchan, CTRLA, 0);
253 channel_writel(atchan, CTRLB, 0);
254 channel_writel(atchan, DSCR, first->txd.phys);
255 channel_writel(atchan, SPIP, ATC_SPIP_HOLE(first->src_hole) |
256 ATC_SPIP_BOUNDARY(first->boundary));
257 channel_writel(atchan, DPIP, ATC_DPIP_HOLE(first->dst_hole) |
258 ATC_DPIP_BOUNDARY(first->boundary));
259 /* Don't allow CPU to reorder channel enable. */
261 dma_writel(atdma, CHER, atchan->mask);
263 vdbg_dump_regs(atchan);
267 * atc_get_desc_by_cookie - get the descriptor of a cookie
268 * @atchan: the DMA channel
269 * @cookie: the cookie to get the descriptor for
271 static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan,
274 struct at_desc *desc, *_desc;
276 list_for_each_entry_safe(desc, _desc, &atchan->queue, desc_node) {
277 if (desc->txd.cookie == cookie)
281 list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
282 if (desc->txd.cookie == cookie)
290 * atc_calc_bytes_left - calculates the number of bytes left according to the
291 * value read from CTRLA.
293 * @current_len: the number of bytes left before reading CTRLA
294 * @ctrla: the value of CTRLA
296 static inline int atc_calc_bytes_left(int current_len, u32 ctrla)
298 u32 btsize = (ctrla & ATC_BTSIZE_MAX);
299 u32 src_width = ATC_REG_TO_SRC_WIDTH(ctrla);
302 * According to the datasheet, when reading the Control A Register
303 * (ctrla), the Buffer Transfer Size (btsize) bitfield refers to the
304 * number of transfers completed on the Source Interface.
305 * So btsize is always a number of source width transfers.
307 return current_len - (btsize << src_width);
311 * atc_get_bytes_left - get the number of bytes residue for a cookie
313 * @cookie: transaction identifier to check status of
315 static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
317 struct at_dma_chan *atchan = to_at_dma_chan(chan);
318 struct at_desc *desc_first = atc_first_active(atchan);
319 struct at_desc *desc;
325 * If the cookie doesn't match to the currently running transfer then
326 * we can return the total length of the associated DMA transfer,
327 * because it is still queued.
329 desc = atc_get_desc_by_cookie(atchan, cookie);
332 else if (desc != desc_first)
333 return desc->total_len;
335 /* cookie matches to the currently running transfer */
336 ret = desc_first->total_len;
338 if (desc_first->lli.dscr) {
339 /* hardware linked list transfer */
342 * Calculate the residue by removing the length of the child
343 * descriptors already transferred from the total length.
344 * To get the current child descriptor we can use the value of
345 * the channel's DSCR register and compare it against the value
346 * of the hardware linked list structure of each child
349 * The CTRLA register provides us with the amount of data
350 * already read from the source for the current child
351 * descriptor. So we can compute a more accurate residue by also
352 * removing the number of bytes corresponding to this amount of
355 * However, the DSCR and CTRLA registers cannot be read both
356 * atomically. Hence a race condition may occur: the first read
357 * register may refer to one child descriptor whereas the second
358 * read may refer to a later child descriptor in the list
359 * because of the DMA transfer progression inbetween the two
362 * One solution could have been to pause the DMA transfer, read
363 * the DSCR and CTRLA then resume the DMA transfer. Nonetheless,
364 * this approach presents some drawbacks:
365 * - If the DMA transfer is paused, RX overruns or TX underruns
366 * are more likey to occur depending on the system latency.
367 * Taking the USART driver as an example, it uses a cyclic DMA
368 * transfer to read data from the Receive Holding Register
369 * (RHR) to avoid RX overruns since the RHR is not protected
370 * by any FIFO on most Atmel SoCs. So pausing the DMA transfer
371 * to compute the residue would break the USART driver design.
372 * - The atc_pause() function masks interrupts but we'd rather
373 * avoid to do so for system latency purpose.
375 * Then we'd rather use another solution: the DSCR is read a
376 * first time, the CTRLA is read in turn, next the DSCR is read
377 * a second time. If the two consecutive read values of the DSCR
378 * are the same then we assume both refers to the very same
379 * child descriptor as well as the CTRLA value read inbetween
380 * does. For cyclic tranfers, the assumption is that a full loop
382 * If the two DSCR values are different, we read again the CTRLA
383 * then the DSCR till two consecutive read values from DSCR are
384 * equal or till the maxium trials is reach.
385 * This algorithm is very unlikely not to find a stable value for
389 dscr = channel_readl(atchan, DSCR);
390 rmb(); /* ensure DSCR is read before CTRLA */
391 ctrla = channel_readl(atchan, CTRLA);
392 for (i = 0; i < ATC_MAX_DSCR_TRIALS; ++i) {
395 rmb(); /* ensure DSCR is read after CTRLA */
396 new_dscr = channel_readl(atchan, DSCR);
399 * If the DSCR register value has not changed inside the
400 * DMA controller since the previous read, we assume
401 * that both the dscr and ctrla values refers to the
402 * very same descriptor.
404 if (likely(new_dscr == dscr))
408 * DSCR has changed inside the DMA controller, so the
409 * previouly read value of CTRLA may refer to an already
410 * processed descriptor hence could be outdated.
411 * We need to update ctrla to match the current
415 rmb(); /* ensure DSCR is read before CTRLA */
416 ctrla = channel_readl(atchan, CTRLA);
418 if (unlikely(i == ATC_MAX_DSCR_TRIALS))
421 /* for the first descriptor we can be more accurate */
422 if (desc_first->lli.dscr == dscr)
423 return atc_calc_bytes_left(ret, ctrla);
425 ret -= desc_first->len;
426 list_for_each_entry(desc, &desc_first->tx_list, desc_node) {
427 if (desc->lli.dscr == dscr)
434 * For the current descriptor in the chain we can calculate
435 * the remaining bytes using the channel's register.
437 ret = atc_calc_bytes_left(ret, ctrla);
439 /* single transfer */
440 ctrla = channel_readl(atchan, CTRLA);
441 ret = atc_calc_bytes_left(ret, ctrla);
448 * atc_chain_complete - finish work for one transaction chain
449 * @atchan: channel we work on
450 * @desc: descriptor at the head of the chain we want do complete
453 atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
455 struct dma_async_tx_descriptor *txd = &desc->txd;
456 struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
459 dev_vdbg(chan2dev(&atchan->chan_common),
460 "descriptor %u complete\n", txd->cookie);
462 spin_lock_irqsave(&atchan->lock, flags);
464 /* mark the descriptor as complete for non cyclic cases only */
465 if (!atc_chan_is_cyclic(atchan))
466 dma_cookie_complete(txd);
468 spin_unlock_irqrestore(&atchan->lock, flags);
470 dma_descriptor_unmap(txd);
471 /* for cyclic transfers,
472 * no need to replay callback function while stopping */
473 if (!atc_chan_is_cyclic(atchan))
474 dmaengine_desc_get_callback_invoke(txd, NULL);
476 dma_run_dependencies(txd);
478 spin_lock_irqsave(&atchan->lock, flags);
479 /* move children to free_list */
480 list_splice_init(&desc->tx_list, &atchan->free_list);
481 /* add myself to free_list */
482 list_add(&desc->desc_node, &atchan->free_list);
483 spin_unlock_irqrestore(&atchan->lock, flags);
485 /* If the transfer was a memset, free our temporary buffer */
486 if (desc->memset_buffer) {
487 dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
489 desc->memset_buffer = false;
494 * atc_advance_work - at the end of a transaction, move forward
495 * @atchan: channel where the transaction ended
497 static void atc_advance_work(struct at_dma_chan *atchan)
499 struct at_desc *desc;
502 dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
504 spin_lock_irqsave(&atchan->lock, flags);
505 if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
506 return spin_unlock_irqrestore(&atchan->lock, flags);
508 desc = atc_first_active(atchan);
509 /* Remove the transfer node from the active list. */
510 list_del_init(&desc->desc_node);
511 spin_unlock_irqrestore(&atchan->lock, flags);
512 atc_chain_complete(atchan, desc);
515 spin_lock_irqsave(&atchan->lock, flags);
516 if (!list_empty(&atchan->active_list)) {
517 desc = atc_first_queued(atchan);
518 list_move_tail(&desc->desc_node, &atchan->active_list);
519 atc_dostart(atchan, desc);
521 spin_unlock_irqrestore(&atchan->lock, flags);
526 * atc_handle_error - handle errors reported by DMA controller
527 * @atchan: channel where error occurs
529 static void atc_handle_error(struct at_dma_chan *atchan)
531 struct at_desc *bad_desc;
532 struct at_desc *desc;
533 struct at_desc *child;
536 spin_lock_irqsave(&atchan->lock, flags);
538 * The descriptor currently at the head of the active list is
539 * broked. Since we don't have any way to report errors, we'll
540 * just have to scream loudly and try to carry on.
542 bad_desc = atc_first_active(atchan);
543 list_del_init(&bad_desc->desc_node);
545 /* Try to restart the controller */
546 if (!list_empty(&atchan->active_list)) {
547 desc = atc_first_queued(atchan);
548 list_move_tail(&desc->desc_node, &atchan->active_list);
549 atc_dostart(atchan, desc);
553 * KERN_CRITICAL may seem harsh, but since this only happens
554 * when someone submits a bad physical address in a
555 * descriptor, we should consider ourselves lucky that the
556 * controller flagged an error instead of scribbling over
557 * random memory locations.
559 dev_crit(chan2dev(&atchan->chan_common),
560 "Bad descriptor submitted for DMA!\n");
561 dev_crit(chan2dev(&atchan->chan_common),
562 " cookie: %d\n", bad_desc->txd.cookie);
563 atc_dump_lli(atchan, &bad_desc->lli);
564 list_for_each_entry(child, &bad_desc->tx_list, desc_node)
565 atc_dump_lli(atchan, &child->lli);
567 spin_unlock_irqrestore(&atchan->lock, flags);
569 /* Pretend the descriptor completed successfully */
570 atc_chain_complete(atchan, bad_desc);
574 * atc_handle_cyclic - at the end of a period, run callback function
575 * @atchan: channel used for cyclic operations
577 static void atc_handle_cyclic(struct at_dma_chan *atchan)
579 struct at_desc *first = atc_first_active(atchan);
580 struct dma_async_tx_descriptor *txd = &first->txd;
582 dev_vdbg(chan2dev(&atchan->chan_common),
583 "new cyclic period llp 0x%08x\n",
584 channel_readl(atchan, DSCR));
586 dmaengine_desc_get_callback_invoke(txd, NULL);
589 /*-- IRQ & Tasklet ---------------------------------------------------*/
591 static void atc_tasklet(struct tasklet_struct *t)
593 struct at_dma_chan *atchan = from_tasklet(atchan, t, tasklet);
595 if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status))
596 return atc_handle_error(atchan);
598 if (atc_chan_is_cyclic(atchan))
599 return atc_handle_cyclic(atchan);
601 atc_advance_work(atchan);
604 static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
606 struct at_dma *atdma = (struct at_dma *)dev_id;
607 struct at_dma_chan *atchan;
609 u32 status, pending, imr;
613 imr = dma_readl(atdma, EBCIMR);
614 status = dma_readl(atdma, EBCISR);
615 pending = status & imr;
620 dev_vdbg(atdma->dma_common.dev,
621 "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n",
622 status, imr, pending);
624 for (i = 0; i < atdma->dma_common.chancnt; i++) {
625 atchan = &atdma->chan[i];
626 if (pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))) {
627 if (pending & AT_DMA_ERR(i)) {
628 /* Disable channel on AHB error */
629 dma_writel(atdma, CHDR,
630 AT_DMA_RES(i) | atchan->mask);
631 /* Give information to tasklet */
632 set_bit(ATC_IS_ERROR, &atchan->status);
634 tasklet_schedule(&atchan->tasklet);
645 /*-- DMA Engine API --------------------------------------------------*/
648 * atc_tx_submit - set the prepared descriptor(s) to be executed by the engine
649 * @tx: descriptor at the head of the transaction chain
651 * Queue chain if DMA engine is working already
653 * Cookie increment and adding to active_list or queue must be atomic
655 static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx)
657 struct at_desc *desc = txd_to_at_desc(tx);
658 struct at_dma_chan *atchan = to_at_dma_chan(tx->chan);
662 spin_lock_irqsave(&atchan->lock, flags);
663 cookie = dma_cookie_assign(tx);
665 list_add_tail(&desc->desc_node, &atchan->queue);
666 spin_unlock_irqrestore(&atchan->lock, flags);
668 dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
674 * atc_prep_dma_interleaved - prepare memory to memory interleaved operation
675 * @chan: the channel to prepare operation on
676 * @xt: Interleaved transfer template
677 * @flags: tx descriptor status flags
679 static struct dma_async_tx_descriptor *
680 atc_prep_dma_interleaved(struct dma_chan *chan,
681 struct dma_interleaved_template *xt,
684 struct at_dma_chan *atchan = to_at_dma_chan(chan);
685 struct data_chunk *first;
686 struct at_desc *desc = NULL;
694 if (unlikely(!xt || xt->numf != 1 || !xt->frame_size))
699 dev_info(chan2dev(chan),
700 "%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n",
701 __func__, &xt->src_start, &xt->dst_start, xt->numf,
702 xt->frame_size, flags);
705 * The controller can only "skip" X bytes every Y bytes, so we
706 * need to make sure we are given a template that fit that
707 * description, ie a template with chunks that always have the
708 * same size, with the same ICGs.
710 for (i = 0; i < xt->frame_size; i++) {
711 struct data_chunk *chunk = xt->sgl + i;
713 if ((chunk->size != xt->sgl->size) ||
714 (dmaengine_get_dst_icg(xt, chunk) != dmaengine_get_dst_icg(xt, first)) ||
715 (dmaengine_get_src_icg(xt, chunk) != dmaengine_get_src_icg(xt, first))) {
716 dev_err(chan2dev(chan),
717 "%s: the controller can transfer only identical chunks\n",
725 dwidth = atc_get_xfer_width(xt->src_start,
728 xfer_count = len >> dwidth;
729 if (xfer_count > ATC_BTSIZE_MAX) {
730 dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__);
734 ctrla = ATC_SRC_WIDTH(dwidth) |
735 ATC_DST_WIDTH(dwidth);
737 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN
738 | ATC_SRC_ADDR_MODE_INCR
739 | ATC_DST_ADDR_MODE_INCR
744 /* create the transfer */
745 desc = atc_desc_get(atchan);
747 dev_err(chan2dev(chan),
748 "%s: couldn't allocate our descriptor\n", __func__);
752 desc->lli.saddr = xt->src_start;
753 desc->lli.daddr = xt->dst_start;
754 desc->lli.ctrla = ctrla | xfer_count;
755 desc->lli.ctrlb = ctrlb;
757 desc->boundary = first->size >> dwidth;
758 desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1;
759 desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1;
761 desc->txd.cookie = -EBUSY;
762 desc->total_len = desc->len = len;
764 /* set end-of-link to the last link descriptor of list*/
767 desc->txd.flags = flags; /* client is in control of this ack */
773 * atc_prep_dma_memcpy - prepare a memcpy operation
774 * @chan: the channel to prepare operation on
775 * @dest: operation virtual destination address
776 * @src: operation virtual source address
777 * @len: operation length
778 * @flags: tx descriptor status flags
780 static struct dma_async_tx_descriptor *
781 atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
782 size_t len, unsigned long flags)
784 struct at_dma_chan *atchan = to_at_dma_chan(chan);
785 struct at_desc *desc = NULL;
786 struct at_desc *first = NULL;
787 struct at_desc *prev = NULL;
790 unsigned int src_width;
791 unsigned int dst_width;
795 dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n",
796 &dest, &src, len, flags);
798 if (unlikely(!len)) {
799 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
803 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN
804 | ATC_SRC_ADDR_MODE_INCR
805 | ATC_DST_ADDR_MODE_INCR
809 * We can be a lot more clever here, but this should take care
810 * of the most common optimization.
812 src_width = dst_width = atc_get_xfer_width(src, dest, len);
814 ctrla = ATC_SRC_WIDTH(src_width) |
815 ATC_DST_WIDTH(dst_width);
817 for (offset = 0; offset < len; offset += xfer_count << src_width) {
818 xfer_count = min_t(size_t, (len - offset) >> src_width,
821 desc = atc_desc_get(atchan);
825 desc->lli.saddr = src + offset;
826 desc->lli.daddr = dest + offset;
827 desc->lli.ctrla = ctrla | xfer_count;
828 desc->lli.ctrlb = ctrlb;
830 desc->txd.cookie = 0;
831 desc->len = xfer_count << src_width;
833 atc_desc_chain(&first, &prev, desc);
836 /* First descriptor of the chain embedds additional information */
837 first->txd.cookie = -EBUSY;
838 first->total_len = len;
840 /* set end-of-link to the last link descriptor of list*/
843 first->txd.flags = flags; /* client is in control of this ack */
848 atc_desc_put(atchan, first);
852 static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
857 struct at_dma_chan *atchan = to_at_dma_chan(chan);
858 struct at_desc *desc;
861 u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2);
862 u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
863 ATC_SRC_ADDR_MODE_FIXED |
864 ATC_DST_ADDR_MODE_INCR |
867 xfer_count = len >> 2;
868 if (xfer_count > ATC_BTSIZE_MAX) {
869 dev_err(chan2dev(chan), "%s: buffer is too big\n",
874 desc = atc_desc_get(atchan);
876 dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
881 desc->lli.saddr = psrc;
882 desc->lli.daddr = pdst;
883 desc->lli.ctrla = ctrla | xfer_count;
884 desc->lli.ctrlb = ctrlb;
886 desc->txd.cookie = 0;
893 * atc_prep_dma_memset - prepare a memcpy operation
894 * @chan: the channel to prepare operation on
895 * @dest: operation virtual destination address
896 * @value: value to set memory buffer to
897 * @len: operation length
898 * @flags: tx descriptor status flags
900 static struct dma_async_tx_descriptor *
901 atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
902 size_t len, unsigned long flags)
904 struct at_dma *atdma = to_at_dma(chan->device);
905 struct at_desc *desc;
909 dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__,
910 &dest, value, len, flags);
912 if (unlikely(!len)) {
913 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
917 if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
918 dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n",
923 vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr);
925 dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
929 *(u32*)vaddr = value;
931 desc = atc_create_memset_desc(chan, paddr, dest, len);
933 dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
935 goto err_free_buffer;
938 desc->memset_paddr = paddr;
939 desc->memset_vaddr = vaddr;
940 desc->memset_buffer = true;
942 desc->txd.cookie = -EBUSY;
943 desc->total_len = len;
945 /* set end-of-link on the descriptor */
948 desc->txd.flags = flags;
953 dma_pool_free(atdma->memset_pool, vaddr, paddr);
957 static struct dma_async_tx_descriptor *
958 atc_prep_dma_memset_sg(struct dma_chan *chan,
959 struct scatterlist *sgl,
960 unsigned int sg_len, int value,
963 struct at_dma_chan *atchan = to_at_dma_chan(chan);
964 struct at_dma *atdma = to_at_dma(chan->device);
965 struct at_desc *desc = NULL, *first = NULL, *prev = NULL;
966 struct scatterlist *sg;
969 size_t total_len = 0;
972 dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
973 value, sg_len, flags);
975 if (unlikely(!sgl || !sg_len)) {
976 dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n",
981 vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr);
983 dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
987 *(u32*)vaddr = value;
989 for_each_sg(sgl, sg, sg_len, i) {
990 dma_addr_t dest = sg_dma_address(sg);
991 size_t len = sg_dma_len(sg);
993 dev_vdbg(chan2dev(chan), "%s: d%pad, l0x%zx\n",
994 __func__, &dest, len);
996 if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
997 dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
1002 desc = atc_create_memset_desc(chan, paddr, dest, len);
1006 atc_desc_chain(&first, &prev, desc);
1012 * Only set the buffer pointers on the last descriptor to
1013 * avoid free'ing while we have our transfer still going
1015 desc->memset_paddr = paddr;
1016 desc->memset_vaddr = vaddr;
1017 desc->memset_buffer = true;
1019 first->txd.cookie = -EBUSY;
1020 first->total_len = total_len;
1022 /* set end-of-link on the descriptor */
1025 first->txd.flags = flags;
1030 atc_desc_put(atchan, first);
1035 * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
1036 * @chan: DMA channel
1037 * @sgl: scatterlist to transfer to/from
1038 * @sg_len: number of entries in @scatterlist
1039 * @direction: DMA direction
1040 * @flags: tx descriptor status flags
1041 * @context: transaction context (ignored)
1043 static struct dma_async_tx_descriptor *
1044 atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
1045 unsigned int sg_len, enum dma_transfer_direction direction,
1046 unsigned long flags, void *context)
1048 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1049 struct at_dma_slave *atslave = chan->private;
1050 struct dma_slave_config *sconfig = &atchan->dma_sconfig;
1051 struct at_desc *first = NULL;
1052 struct at_desc *prev = NULL;
1056 unsigned int reg_width;
1057 unsigned int mem_width;
1059 struct scatterlist *sg;
1060 size_t total_len = 0;
1062 dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n",
1064 direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
1067 if (unlikely(!atslave || !sg_len)) {
1068 dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n");
1072 ctrla = ATC_SCSIZE(sconfig->src_maxburst)
1073 | ATC_DCSIZE(sconfig->dst_maxburst);
1076 switch (direction) {
1077 case DMA_MEM_TO_DEV:
1078 reg_width = convert_buswidth(sconfig->dst_addr_width);
1079 ctrla |= ATC_DST_WIDTH(reg_width);
1080 ctrlb |= ATC_DST_ADDR_MODE_FIXED
1081 | ATC_SRC_ADDR_MODE_INCR
1083 | ATC_SIF(atchan->mem_if) | ATC_DIF(atchan->per_if);
1084 reg = sconfig->dst_addr;
1085 for_each_sg(sgl, sg, sg_len, i) {
1086 struct at_desc *desc;
1090 desc = atc_desc_get(atchan);
1094 mem = sg_dma_address(sg);
1095 len = sg_dma_len(sg);
1096 if (unlikely(!len)) {
1097 dev_dbg(chan2dev(chan),
1098 "prep_slave_sg: sg(%d) data length is zero\n", i);
1102 if (unlikely(mem & 3 || len & 3))
1105 desc->lli.saddr = mem;
1106 desc->lli.daddr = reg;
1107 desc->lli.ctrla = ctrla
1108 | ATC_SRC_WIDTH(mem_width)
1110 desc->lli.ctrlb = ctrlb;
1113 atc_desc_chain(&first, &prev, desc);
1117 case DMA_DEV_TO_MEM:
1118 reg_width = convert_buswidth(sconfig->src_addr_width);
1119 ctrla |= ATC_SRC_WIDTH(reg_width);
1120 ctrlb |= ATC_DST_ADDR_MODE_INCR
1121 | ATC_SRC_ADDR_MODE_FIXED
1123 | ATC_SIF(atchan->per_if) | ATC_DIF(atchan->mem_if);
1125 reg = sconfig->src_addr;
1126 for_each_sg(sgl, sg, sg_len, i) {
1127 struct at_desc *desc;
1131 desc = atc_desc_get(atchan);
1135 mem = sg_dma_address(sg);
1136 len = sg_dma_len(sg);
1137 if (unlikely(!len)) {
1138 dev_dbg(chan2dev(chan),
1139 "prep_slave_sg: sg(%d) data length is zero\n", i);
1143 if (unlikely(mem & 3 || len & 3))
1146 desc->lli.saddr = reg;
1147 desc->lli.daddr = mem;
1148 desc->lli.ctrla = ctrla
1149 | ATC_DST_WIDTH(mem_width)
1151 desc->lli.ctrlb = ctrlb;
1154 atc_desc_chain(&first, &prev, desc);
1162 /* set end-of-link to the last link descriptor of list*/
1165 /* First descriptor of the chain embedds additional information */
1166 first->txd.cookie = -EBUSY;
1167 first->total_len = total_len;
1169 /* first link descriptor of list is responsible of flags */
1170 first->txd.flags = flags; /* client is in control of this ack */
1175 dev_err(chan2dev(chan), "not enough descriptors available\n");
1177 atc_desc_put(atchan, first);
1182 * atc_dma_cyclic_check_values
1183 * Check for too big/unaligned periods and unaligned DMA buffer
1186 atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
1189 if (period_len > (ATC_BTSIZE_MAX << reg_width))
1191 if (unlikely(period_len & ((1 << reg_width) - 1)))
1193 if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1203 * atc_dma_cyclic_fill_desc - Fill one period descriptor
1206 atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
1207 unsigned int period_index, dma_addr_t buf_addr,
1208 unsigned int reg_width, size_t period_len,
1209 enum dma_transfer_direction direction)
1211 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1212 struct dma_slave_config *sconfig = &atchan->dma_sconfig;
1215 /* prepare common CRTLA value */
1216 ctrla = ATC_SCSIZE(sconfig->src_maxburst)
1217 | ATC_DCSIZE(sconfig->dst_maxburst)
1218 | ATC_DST_WIDTH(reg_width)
1219 | ATC_SRC_WIDTH(reg_width)
1220 | period_len >> reg_width;
1222 switch (direction) {
1223 case DMA_MEM_TO_DEV:
1224 desc->lli.saddr = buf_addr + (period_len * period_index);
1225 desc->lli.daddr = sconfig->dst_addr;
1226 desc->lli.ctrla = ctrla;
1227 desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
1228 | ATC_SRC_ADDR_MODE_INCR
1230 | ATC_SIF(atchan->mem_if)
1231 | ATC_DIF(atchan->per_if);
1232 desc->len = period_len;
1235 case DMA_DEV_TO_MEM:
1236 desc->lli.saddr = sconfig->src_addr;
1237 desc->lli.daddr = buf_addr + (period_len * period_index);
1238 desc->lli.ctrla = ctrla;
1239 desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
1240 | ATC_SRC_ADDR_MODE_FIXED
1242 | ATC_SIF(atchan->per_if)
1243 | ATC_DIF(atchan->mem_if);
1244 desc->len = period_len;
1255 * atc_prep_dma_cyclic - prepare the cyclic DMA transfer
1256 * @chan: the DMA channel to prepare
1257 * @buf_addr: physical DMA address where the buffer starts
1258 * @buf_len: total number of bytes for the entire buffer
1259 * @period_len: number of bytes for each period
1260 * @direction: transfer direction, to or from device
1261 * @flags: tx descriptor status flags
1263 static struct dma_async_tx_descriptor *
1264 atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
1265 size_t period_len, enum dma_transfer_direction direction,
1266 unsigned long flags)
1268 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1269 struct at_dma_slave *atslave = chan->private;
1270 struct dma_slave_config *sconfig = &atchan->dma_sconfig;
1271 struct at_desc *first = NULL;
1272 struct at_desc *prev = NULL;
1273 unsigned long was_cyclic;
1274 unsigned int reg_width;
1275 unsigned int periods = buf_len / period_len;
1278 dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@%pad - %d (%d/%d)\n",
1279 direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
1281 periods, buf_len, period_len);
1283 if (unlikely(!atslave || !buf_len || !period_len)) {
1284 dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n");
1288 was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status);
1290 dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n");
1294 if (unlikely(!is_slave_direction(direction)))
1297 if (direction == DMA_MEM_TO_DEV)
1298 reg_width = convert_buswidth(sconfig->dst_addr_width);
1300 reg_width = convert_buswidth(sconfig->src_addr_width);
1302 /* Check for too big/unaligned periods and unaligned DMA buffer */
1303 if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
1306 /* build cyclic linked list */
1307 for (i = 0; i < periods; i++) {
1308 struct at_desc *desc;
1310 desc = atc_desc_get(atchan);
1314 if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr,
1315 reg_width, period_len, direction))
1318 atc_desc_chain(&first, &prev, desc);
1321 /* lets make a cyclic list */
1322 prev->lli.dscr = first->txd.phys;
1324 /* First descriptor of the chain embedds additional information */
1325 first->txd.cookie = -EBUSY;
1326 first->total_len = buf_len;
1331 dev_err(chan2dev(chan), "not enough descriptors available\n");
1332 atc_desc_put(atchan, first);
1334 clear_bit(ATC_IS_CYCLIC, &atchan->status);
1338 static int atc_config(struct dma_chan *chan,
1339 struct dma_slave_config *sconfig)
1341 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1343 dev_vdbg(chan2dev(chan), "%s\n", __func__);
1345 /* Check if it is chan is configured for slave transfers */
1349 memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig));
1351 convert_burst(&atchan->dma_sconfig.src_maxburst);
1352 convert_burst(&atchan->dma_sconfig.dst_maxburst);
1357 static int atc_pause(struct dma_chan *chan)
1359 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1360 struct at_dma *atdma = to_at_dma(chan->device);
1361 int chan_id = atchan->chan_common.chan_id;
1362 unsigned long flags;
1364 dev_vdbg(chan2dev(chan), "%s\n", __func__);
1366 spin_lock_irqsave(&atchan->lock, flags);
1368 dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
1369 set_bit(ATC_IS_PAUSED, &atchan->status);
1371 spin_unlock_irqrestore(&atchan->lock, flags);
1376 static int atc_resume(struct dma_chan *chan)
1378 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1379 struct at_dma *atdma = to_at_dma(chan->device);
1380 int chan_id = atchan->chan_common.chan_id;
1381 unsigned long flags;
1383 dev_vdbg(chan2dev(chan), "%s\n", __func__);
1385 if (!atc_chan_is_paused(atchan))
1388 spin_lock_irqsave(&atchan->lock, flags);
1390 dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
1391 clear_bit(ATC_IS_PAUSED, &atchan->status);
1393 spin_unlock_irqrestore(&atchan->lock, flags);
1398 static int atc_terminate_all(struct dma_chan *chan)
1400 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1401 struct at_dma *atdma = to_at_dma(chan->device);
1402 int chan_id = atchan->chan_common.chan_id;
1403 unsigned long flags;
1405 dev_vdbg(chan2dev(chan), "%s\n", __func__);
1408 * This is only called when something went wrong elsewhere, so
1409 * we don't really care about the data. Just disable the
1410 * channel. We still have to poll the channel enable bit due
1411 * to AHB/HSB limitations.
1413 spin_lock_irqsave(&atchan->lock, flags);
1415 /* disabling channel: must also remove suspend state */
1416 dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
1418 /* confirm that this channel is disabled */
1419 while (dma_readl(atdma, CHSR) & atchan->mask)
1422 /* active_list entries will end up before queued entries */
1423 list_splice_tail_init(&atchan->queue, &atchan->free_list);
1424 list_splice_tail_init(&atchan->active_list, &atchan->free_list);
1426 clear_bit(ATC_IS_PAUSED, &atchan->status);
1427 /* if channel dedicated to cyclic operations, free it */
1428 clear_bit(ATC_IS_CYCLIC, &atchan->status);
1430 spin_unlock_irqrestore(&atchan->lock, flags);
1436 * atc_tx_status - poll for transaction completion
1437 * @chan: DMA channel
1438 * @cookie: transaction identifier to check status of
1439 * @txstate: if not %NULL updated with transaction state
1441 * If @txstate is passed in, upon return it reflect the driver
1442 * internal state and can be used with dma_async_is_complete() to check
1443 * the status of multiple cookies without re-checking hardware state.
1445 static enum dma_status
1446 atc_tx_status(struct dma_chan *chan,
1447 dma_cookie_t cookie,
1448 struct dma_tx_state *txstate)
1450 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1451 unsigned long flags;
1452 enum dma_status ret;
1455 ret = dma_cookie_status(chan, cookie, txstate);
1456 if (ret == DMA_COMPLETE)
1459 * There's no point calculating the residue if there's
1460 * no txstate to store the value.
1465 spin_lock_irqsave(&atchan->lock, flags);
1467 /* Get number of bytes left in the active transactions */
1468 bytes = atc_get_bytes_left(chan, cookie);
1470 spin_unlock_irqrestore(&atchan->lock, flags);
1472 if (unlikely(bytes < 0)) {
1473 dev_vdbg(chan2dev(chan), "get residual bytes error\n");
1476 dma_set_residue(txstate, bytes);
1479 dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %d\n",
1480 ret, cookie, bytes);
1486 * atc_issue_pending - takes the first transaction descriptor in the pending
1487 * queue and starts the transfer.
1488 * @chan: target DMA channel
1490 static void atc_issue_pending(struct dma_chan *chan)
1492 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1493 struct at_desc *desc;
1494 unsigned long flags;
1496 dev_vdbg(chan2dev(chan), "issue_pending\n");
1498 spin_lock_irqsave(&atchan->lock, flags);
1499 if (atc_chan_is_enabled(atchan) || list_empty(&atchan->queue))
1500 return spin_unlock_irqrestore(&atchan->lock, flags);
1502 desc = atc_first_queued(atchan);
1503 list_move_tail(&desc->desc_node, &atchan->active_list);
1504 atc_dostart(atchan, desc);
1505 spin_unlock_irqrestore(&atchan->lock, flags);
1509 * atc_alloc_chan_resources - allocate resources for DMA channel
1510 * @chan: allocate descriptor resources for this channel
1512 * return - the number of allocated descriptors
1514 static int atc_alloc_chan_resources(struct dma_chan *chan)
1516 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1517 struct at_dma *atdma = to_at_dma(chan->device);
1518 struct at_desc *desc;
1519 struct at_dma_slave *atslave;
1523 dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
1525 /* ASSERT: channel is idle */
1526 if (atc_chan_is_enabled(atchan)) {
1527 dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
1531 if (!list_empty(&atchan->free_list)) {
1532 dev_dbg(chan2dev(chan), "can't allocate channel resources (channel not freed from a previous use)\n");
1536 cfg = ATC_DEFAULT_CFG;
1538 atslave = chan->private;
1541 * We need controller-specific data to set up slave
1544 BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_common.dev);
1546 /* if cfg configuration specified take it instead of default */
1551 /* Allocate initial pool of descriptors */
1552 for (i = 0; i < init_nr_desc_per_channel; i++) {
1553 desc = atc_alloc_descriptor(chan, GFP_KERNEL);
1555 dev_err(atdma->dma_common.dev,
1556 "Only %d initial descriptors\n", i);
1559 list_add_tail(&desc->desc_node, &atchan->free_list);
1562 dma_cookie_init(chan);
1564 /* channel parameters */
1565 channel_writel(atchan, CFG, cfg);
1567 dev_dbg(chan2dev(chan),
1568 "alloc_chan_resources: allocated %d descriptors\n", i);
1574 * atc_free_chan_resources - free all channel resources
1575 * @chan: DMA channel
1577 static void atc_free_chan_resources(struct dma_chan *chan)
1579 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1580 struct at_dma *atdma = to_at_dma(chan->device);
1581 struct at_desc *desc, *_desc;
1584 /* ASSERT: channel is idle */
1585 BUG_ON(!list_empty(&atchan->active_list));
1586 BUG_ON(!list_empty(&atchan->queue));
1587 BUG_ON(atc_chan_is_enabled(atchan));
1589 list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
1590 dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
1591 list_del(&desc->desc_node);
1592 /* free link descriptor */
1593 dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
1595 list_splice_init(&atchan->free_list, &list);
1599 * Free atslave allocated in at_dma_xlate()
1601 kfree(chan->private);
1602 chan->private = NULL;
1604 dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
1608 static bool at_dma_filter(struct dma_chan *chan, void *slave)
1610 struct at_dma_slave *atslave = slave;
1612 if (atslave->dma_dev == chan->device->dev) {
1613 chan->private = atslave;
1620 static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
1621 struct of_dma *of_dma)
1623 struct dma_chan *chan;
1624 struct at_dma_chan *atchan;
1625 struct at_dma_slave *atslave;
1626 dma_cap_mask_t mask;
1627 unsigned int per_id;
1628 struct platform_device *dmac_pdev;
1630 if (dma_spec->args_count != 2)
1633 dmac_pdev = of_find_device_by_node(dma_spec->np);
1638 dma_cap_set(DMA_SLAVE, mask);
1640 atslave = kmalloc(sizeof(*atslave), GFP_KERNEL);
1642 put_device(&dmac_pdev->dev);
1646 atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW;
1648 * We can fill both SRC_PER and DST_PER, one of these fields will be
1649 * ignored depending on DMA transfer direction.
1651 per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK;
1652 atslave->cfg |= ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id)
1653 | ATC_SRC_PER_MSB(per_id) | ATC_SRC_PER(per_id);
1655 * We have to translate the value we get from the device tree since
1656 * the half FIFO configuration value had to be 0 to keep backward
1659 switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) {
1660 case AT91_DMA_CFG_FIFOCFG_ALAP:
1661 atslave->cfg |= ATC_FIFOCFG_LARGESTBURST;
1663 case AT91_DMA_CFG_FIFOCFG_ASAP:
1664 atslave->cfg |= ATC_FIFOCFG_ENOUGHSPACE;
1666 case AT91_DMA_CFG_FIFOCFG_HALF:
1668 atslave->cfg |= ATC_FIFOCFG_HALFFIFO;
1670 atslave->dma_dev = &dmac_pdev->dev;
1672 chan = dma_request_channel(mask, at_dma_filter, atslave);
1674 put_device(&dmac_pdev->dev);
1679 atchan = to_at_dma_chan(chan);
1680 atchan->per_if = dma_spec->args[0] & 0xff;
1681 atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff;
1686 static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
1687 struct of_dma *of_dma)
1693 /*-- Module Management -----------------------------------------------*/
1695 /* cap_mask is a multi-u32 bitfield, fill it with proper C code. */
1696 static struct at_dma_platform_data at91sam9rl_config = {
1699 static struct at_dma_platform_data at91sam9g45_config = {
1703 #if defined(CONFIG_OF)
1704 static const struct of_device_id atmel_dma_dt_ids[] = {
1706 .compatible = "atmel,at91sam9rl-dma",
1707 .data = &at91sam9rl_config,
1709 .compatible = "atmel,at91sam9g45-dma",
1710 .data = &at91sam9g45_config,
1716 MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
1719 static const struct platform_device_id atdma_devtypes[] = {
1721 .name = "at91sam9rl_dma",
1722 .driver_data = (unsigned long) &at91sam9rl_config,
1724 .name = "at91sam9g45_dma",
1725 .driver_data = (unsigned long) &at91sam9g45_config,
1731 static inline const struct at_dma_platform_data * __init at_dma_get_driver_data(
1732 struct platform_device *pdev)
1734 if (pdev->dev.of_node) {
1735 const struct of_device_id *match;
1736 match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node);
1741 return (struct at_dma_platform_data *)
1742 platform_get_device_id(pdev)->driver_data;
1746 * at_dma_off - disable DMA controller
1747 * @atdma: the Atmel HDAMC device
1749 static void at_dma_off(struct at_dma *atdma)
1751 dma_writel(atdma, EN, 0);
1753 /* disable all interrupts */
1754 dma_writel(atdma, EBCIDR, -1L);
1756 /* confirm that all channels are disabled */
1757 while (dma_readl(atdma, CHSR) & atdma->all_chan_mask)
1761 static int __init at_dma_probe(struct platform_device *pdev)
1763 struct resource *io;
1764 struct at_dma *atdma;
1769 const struct at_dma_platform_data *plat_dat;
1771 /* setup platform data for each SoC */
1772 dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask);
1773 dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask);
1774 dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
1775 dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask);
1776 dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask);
1777 dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask);
1778 dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
1780 /* get DMA parameters from controller type */
1781 plat_dat = at_dma_get_driver_data(pdev);
1785 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1789 irq = platform_get_irq(pdev, 0);
1793 size = sizeof(struct at_dma);
1794 size += plat_dat->nr_channels * sizeof(struct at_dma_chan);
1795 atdma = kzalloc(size, GFP_KERNEL);
1799 /* discover transaction capabilities */
1800 atdma->dma_common.cap_mask = plat_dat->cap_mask;
1801 atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1;
1803 size = resource_size(io);
1804 if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
1809 atdma->regs = ioremap(io->start, size);
1815 atdma->clk = clk_get(&pdev->dev, "dma_clk");
1816 if (IS_ERR(atdma->clk)) {
1817 err = PTR_ERR(atdma->clk);
1820 err = clk_prepare_enable(atdma->clk);
1822 goto err_clk_prepare;
1824 /* force dma off, just in case */
1827 err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma);
1831 platform_set_drvdata(pdev, atdma);
1833 /* create a pool of consistent memory blocks for hardware descriptors */
1834 atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool",
1835 &pdev->dev, sizeof(struct at_desc),
1836 4 /* word alignment */, 0);
1837 if (!atdma->dma_desc_pool) {
1838 dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
1840 goto err_desc_pool_create;
1843 /* create a pool of consistent memory blocks for memset blocks */
1844 atdma->memset_pool = dma_pool_create("at_hdmac_memset_pool",
1845 &pdev->dev, sizeof(int), 4, 0);
1846 if (!atdma->memset_pool) {
1847 dev_err(&pdev->dev, "No memory for memset dma pool\n");
1849 goto err_memset_pool_create;
1852 /* clear any pending interrupt */
1853 while (dma_readl(atdma, EBCISR))
1856 /* initialize channels related values */
1857 INIT_LIST_HEAD(&atdma->dma_common.channels);
1858 for (i = 0; i < plat_dat->nr_channels; i++) {
1859 struct at_dma_chan *atchan = &atdma->chan[i];
1861 atchan->mem_if = AT_DMA_MEM_IF;
1862 atchan->per_if = AT_DMA_PER_IF;
1863 atchan->chan_common.device = &atdma->dma_common;
1864 dma_cookie_init(&atchan->chan_common);
1865 list_add_tail(&atchan->chan_common.device_node,
1866 &atdma->dma_common.channels);
1868 atchan->ch_regs = atdma->regs + ch_regs(i);
1869 spin_lock_init(&atchan->lock);
1870 atchan->mask = 1 << i;
1872 INIT_LIST_HEAD(&atchan->active_list);
1873 INIT_LIST_HEAD(&atchan->queue);
1874 INIT_LIST_HEAD(&atchan->free_list);
1876 tasklet_setup(&atchan->tasklet, atc_tasklet);
1877 atc_enable_chan_irq(atdma, i);
1880 /* set base routines */
1881 atdma->dma_common.device_alloc_chan_resources = atc_alloc_chan_resources;
1882 atdma->dma_common.device_free_chan_resources = atc_free_chan_resources;
1883 atdma->dma_common.device_tx_status = atc_tx_status;
1884 atdma->dma_common.device_issue_pending = atc_issue_pending;
1885 atdma->dma_common.dev = &pdev->dev;
1887 /* set prep routines based on capability */
1888 if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_common.cap_mask))
1889 atdma->dma_common.device_prep_interleaved_dma = atc_prep_dma_interleaved;
1891 if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask))
1892 atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy;
1894 if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) {
1895 atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset;
1896 atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
1897 atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES;
1900 if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {
1901 atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;
1902 /* controller can do slave DMA: can trigger cyclic transfers */
1903 dma_cap_set(DMA_CYCLIC, atdma->dma_common.cap_mask);
1904 atdma->dma_common.device_prep_dma_cyclic = atc_prep_dma_cyclic;
1905 atdma->dma_common.device_config = atc_config;
1906 atdma->dma_common.device_pause = atc_pause;
1907 atdma->dma_common.device_resume = atc_resume;
1908 atdma->dma_common.device_terminate_all = atc_terminate_all;
1909 atdma->dma_common.src_addr_widths = ATC_DMA_BUSWIDTHS;
1910 atdma->dma_common.dst_addr_widths = ATC_DMA_BUSWIDTHS;
1911 atdma->dma_common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1912 atdma->dma_common.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1915 dma_writel(atdma, EN, AT_DMA_ENABLE);
1917 dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n",
1918 dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
1919 dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask) ? "set " : "",
1920 dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask) ? "slave " : "",
1921 plat_dat->nr_channels);
1923 err = dma_async_device_register(&atdma->dma_common);
1925 dev_err(&pdev->dev, "Unable to register: %d.\n", err);
1926 goto err_dma_async_device_register;
1930 * Do not return an error if the dmac node is not present in order to
1931 * not break the existing way of requesting channel with
1932 * dma_request_channel().
1934 if (pdev->dev.of_node) {
1935 err = of_dma_controller_register(pdev->dev.of_node,
1936 at_dma_xlate, atdma);
1938 dev_err(&pdev->dev, "could not register of_dma_controller\n");
1939 goto err_of_dma_controller_register;
1945 err_of_dma_controller_register:
1946 dma_async_device_unregister(&atdma->dma_common);
1947 err_dma_async_device_register:
1948 dma_pool_destroy(atdma->memset_pool);
1949 err_memset_pool_create:
1950 dma_pool_destroy(atdma->dma_desc_pool);
1951 err_desc_pool_create:
1952 free_irq(platform_get_irq(pdev, 0), atdma);
1954 clk_disable_unprepare(atdma->clk);
1956 clk_put(atdma->clk);
1958 iounmap(atdma->regs);
1961 release_mem_region(io->start, size);
1967 static int at_dma_remove(struct platform_device *pdev)
1969 struct at_dma *atdma = platform_get_drvdata(pdev);
1970 struct dma_chan *chan, *_chan;
1971 struct resource *io;
1974 if (pdev->dev.of_node)
1975 of_dma_controller_free(pdev->dev.of_node);
1976 dma_async_device_unregister(&atdma->dma_common);
1978 dma_pool_destroy(atdma->memset_pool);
1979 dma_pool_destroy(atdma->dma_desc_pool);
1980 free_irq(platform_get_irq(pdev, 0), atdma);
1982 list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
1984 struct at_dma_chan *atchan = to_at_dma_chan(chan);
1986 /* Disable interrupts */
1987 atc_disable_chan_irq(atdma, chan->chan_id);
1989 tasklet_kill(&atchan->tasklet);
1990 list_del(&chan->device_node);
1993 clk_disable_unprepare(atdma->clk);
1994 clk_put(atdma->clk);
1996 iounmap(atdma->regs);
1999 io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2000 release_mem_region(io->start, resource_size(io));
2007 static void at_dma_shutdown(struct platform_device *pdev)
2009 struct at_dma *atdma = platform_get_drvdata(pdev);
2011 at_dma_off(platform_get_drvdata(pdev));
2012 clk_disable_unprepare(atdma->clk);
2015 static int at_dma_prepare(struct device *dev)
2017 struct at_dma *atdma = dev_get_drvdata(dev);
2018 struct dma_chan *chan, *_chan;
2020 list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
2022 struct at_dma_chan *atchan = to_at_dma_chan(chan);
2023 /* wait for transaction completion (except in cyclic case) */
2024 if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan))
2030 static void atc_suspend_cyclic(struct at_dma_chan *atchan)
2032 struct dma_chan *chan = &atchan->chan_common;
2034 /* Channel should be paused by user
2035 * do it anyway even if it is not done already */
2036 if (!atc_chan_is_paused(atchan)) {
2037 dev_warn(chan2dev(chan),
2038 "cyclic channel not paused, should be done by channel user\n");
2042 /* now preserve additional data for cyclic operations */
2043 /* next descriptor address in the cyclic list */
2044 atchan->save_dscr = channel_readl(atchan, DSCR);
2046 vdbg_dump_regs(atchan);
2049 static int at_dma_suspend_noirq(struct device *dev)
2051 struct at_dma *atdma = dev_get_drvdata(dev);
2052 struct dma_chan *chan, *_chan;
2055 list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
2057 struct at_dma_chan *atchan = to_at_dma_chan(chan);
2059 if (atc_chan_is_cyclic(atchan))
2060 atc_suspend_cyclic(atchan);
2061 atchan->save_cfg = channel_readl(atchan, CFG);
2063 atdma->save_imr = dma_readl(atdma, EBCIMR);
2065 /* disable DMA controller */
2067 clk_disable_unprepare(atdma->clk);
2071 static void atc_resume_cyclic(struct at_dma_chan *atchan)
2073 struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
2075 /* restore channel status for cyclic descriptors list:
2076 * next descriptor in the cyclic list at the time of suspend */
2077 channel_writel(atchan, SADDR, 0);
2078 channel_writel(atchan, DADDR, 0);
2079 channel_writel(atchan, CTRLA, 0);
2080 channel_writel(atchan, CTRLB, 0);
2081 channel_writel(atchan, DSCR, atchan->save_dscr);
2082 dma_writel(atdma, CHER, atchan->mask);
2084 /* channel pause status should be removed by channel user
2085 * We cannot take the initiative to do it here */
2087 vdbg_dump_regs(atchan);
2090 static int at_dma_resume_noirq(struct device *dev)
2092 struct at_dma *atdma = dev_get_drvdata(dev);
2093 struct dma_chan *chan, *_chan;
2095 /* bring back DMA controller */
2096 clk_prepare_enable(atdma->clk);
2097 dma_writel(atdma, EN, AT_DMA_ENABLE);
2099 /* clear any pending interrupt */
2100 while (dma_readl(atdma, EBCISR))
2103 /* restore saved data */
2104 dma_writel(atdma, EBCIER, atdma->save_imr);
2105 list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
2107 struct at_dma_chan *atchan = to_at_dma_chan(chan);
2109 channel_writel(atchan, CFG, atchan->save_cfg);
2110 if (atc_chan_is_cyclic(atchan))
2111 atc_resume_cyclic(atchan);
2116 static const struct dev_pm_ops at_dma_dev_pm_ops = {
2117 .prepare = at_dma_prepare,
2118 .suspend_noirq = at_dma_suspend_noirq,
2119 .resume_noirq = at_dma_resume_noirq,
2122 static struct platform_driver at_dma_driver = {
2123 .remove = at_dma_remove,
2124 .shutdown = at_dma_shutdown,
2125 .id_table = atdma_devtypes,
2128 .pm = &at_dma_dev_pm_ops,
2129 .of_match_table = of_match_ptr(atmel_dma_dt_ids),
2133 static int __init at_dma_init(void)
2135 return platform_driver_probe(&at_dma_driver, at_dma_probe);
2137 subsys_initcall(at_dma_init);
2139 static void __exit at_dma_exit(void)
2141 platform_driver_unregister(&at_dma_driver);
2143 module_exit(at_dma_exit);
2145 MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
2146 MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
2147 MODULE_LICENSE("GPL");
2148 MODULE_ALIAS("platform:at_hdmac");