2 * DMA controller driver for CSR SiRFprimaII
4 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
6 * Licensed under GPLv2 or later.
9 #include <linux/module.h>
10 #include <linux/dmaengine.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/interrupt.h>
14 #include <linux/slab.h>
15 #include <linux/of_irq.h>
16 #include <linux/of_address.h>
17 #include <linux/of_device.h>
18 #include <linux/of_platform.h>
19 #include <linux/sirfsoc_dma.h>
21 #define SIRFSOC_DMA_DESCRIPTORS 16
22 #define SIRFSOC_DMA_CHANNELS 16
24 #define SIRFSOC_DMA_CH_ADDR 0x00
25 #define SIRFSOC_DMA_CH_XLEN 0x04
26 #define SIRFSOC_DMA_CH_YLEN 0x08
27 #define SIRFSOC_DMA_CH_CTRL 0x0C
29 #define SIRFSOC_DMA_WIDTH_0 0x100
30 #define SIRFSOC_DMA_CH_VALID 0x140
31 #define SIRFSOC_DMA_CH_INT 0x144
32 #define SIRFSOC_DMA_INT_EN 0x148
33 #define SIRFSOC_DMA_CH_LOOP_CTRL 0x150
35 #define SIRFSOC_DMA_MODE_CTRL_BIT 4
36 #define SIRFSOC_DMA_DIR_CTRL_BIT 5
38 /* xlen and dma_width register is in 4 bytes boundary */
39 #define SIRFSOC_DMA_WORD_LEN 4
41 struct sirfsoc_dma_desc {
42 struct dma_async_tx_descriptor desc;
43 struct list_head node;
45 /* SiRFprimaII 2D-DMA parameters */
47 int xlen; /* DMA xlen */
48 int ylen; /* DMA ylen */
49 int width; /* DMA width */
51 bool cyclic; /* is loop DMA? */
52 u32 addr; /* DMA buffer address */
55 struct sirfsoc_dma_chan {
57 struct list_head free;
58 struct list_head prepared;
59 struct list_head queued;
60 struct list_head active;
61 struct list_head completed;
62 unsigned long happened_cyclic;
63 unsigned long completed_cyclic;
65 /* Lock for this structure */
72 struct dma_device dma;
73 struct tasklet_struct tasklet;
74 struct sirfsoc_dma_chan channels[SIRFSOC_DMA_CHANNELS];
79 #define DRV_NAME "sirfsoc_dma"
81 /* Convert struct dma_chan to struct sirfsoc_dma_chan */
83 struct sirfsoc_dma_chan *dma_chan_to_sirfsoc_dma_chan(struct dma_chan *c)
85 return container_of(c, struct sirfsoc_dma_chan, chan);
88 /* Convert struct dma_chan to struct sirfsoc_dma */
89 static inline struct sirfsoc_dma *dma_chan_to_sirfsoc_dma(struct dma_chan *c)
91 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(c);
92 return container_of(schan, struct sirfsoc_dma, channels[c->chan_id]);
95 /* Execute all queued DMA descriptors */
96 static void sirfsoc_dma_execute(struct sirfsoc_dma_chan *schan)
98 struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
99 int cid = schan->chan.chan_id;
100 struct sirfsoc_dma_desc *sdesc = NULL;
103 * lock has been held by functions calling this, so we don't hold
107 sdesc = list_first_entry(&schan->queued, struct sirfsoc_dma_desc,
109 /* Move the first queued descriptor to active list */
110 list_move_tail(&schan->queued, &schan->active);
112 /* Start the DMA transfer */
113 writel_relaxed(sdesc->width, sdma->base + SIRFSOC_DMA_WIDTH_0 +
115 writel_relaxed(cid | (schan->mode << SIRFSOC_DMA_MODE_CTRL_BIT) |
116 (sdesc->dir << SIRFSOC_DMA_DIR_CTRL_BIT),
117 sdma->base + cid * 0x10 + SIRFSOC_DMA_CH_CTRL);
118 writel_relaxed(sdesc->xlen, sdma->base + cid * 0x10 +
119 SIRFSOC_DMA_CH_XLEN);
120 writel_relaxed(sdesc->ylen, sdma->base + cid * 0x10 +
121 SIRFSOC_DMA_CH_YLEN);
122 writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN) |
123 (1 << cid), sdma->base + SIRFSOC_DMA_INT_EN);
126 * writel has an implict memory write barrier to make sure data is
127 * flushed into memory before starting DMA
129 writel(sdesc->addr >> 2, sdma->base + cid * 0x10 + SIRFSOC_DMA_CH_ADDR);
132 writel((1 << cid) | 1 << (cid + 16) |
133 readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL),
134 sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
135 schan->happened_cyclic = schan->completed_cyclic = 0;
139 /* Interrupt handler */
140 static irqreturn_t sirfsoc_dma_irq(int irq, void *data)
142 struct sirfsoc_dma *sdma = data;
143 struct sirfsoc_dma_chan *schan;
144 struct sirfsoc_dma_desc *sdesc = NULL;
148 is = readl(sdma->base + SIRFSOC_DMA_CH_INT);
149 while ((ch = fls(is) - 1) >= 0) {
151 writel_relaxed(1 << ch, sdma->base + SIRFSOC_DMA_CH_INT);
152 schan = &sdma->channels[ch];
154 spin_lock(&schan->lock);
156 sdesc = list_first_entry(&schan->active, struct sirfsoc_dma_desc,
158 if (!sdesc->cyclic) {
159 /* Execute queued descriptors */
160 list_splice_tail_init(&schan->active, &schan->completed);
161 if (!list_empty(&schan->queued))
162 sirfsoc_dma_execute(schan);
164 schan->happened_cyclic++;
166 spin_unlock(&schan->lock);
169 /* Schedule tasklet */
170 tasklet_schedule(&sdma->tasklet);
175 /* process completed descriptors */
176 static void sirfsoc_dma_process_completed(struct sirfsoc_dma *sdma)
178 dma_cookie_t last_cookie = 0;
179 struct sirfsoc_dma_chan *schan;
180 struct sirfsoc_dma_desc *sdesc;
181 struct dma_async_tx_descriptor *desc;
183 unsigned long happened_cyclic;
187 for (i = 0; i < sdma->dma.chancnt; i++) {
188 schan = &sdma->channels[i];
190 /* Get all completed descriptors */
191 spin_lock_irqsave(&schan->lock, flags);
192 if (!list_empty(&schan->completed)) {
193 list_splice_tail_init(&schan->completed, &list);
194 spin_unlock_irqrestore(&schan->lock, flags);
196 /* Execute callbacks and run dependencies */
197 list_for_each_entry(sdesc, &list, node) {
201 desc->callback(desc->callback_param);
203 last_cookie = desc->cookie;
204 dma_run_dependencies(desc);
207 /* Free descriptors */
208 spin_lock_irqsave(&schan->lock, flags);
209 list_splice_tail_init(&list, &schan->free);
210 schan->chan.completed_cookie = last_cookie;
211 spin_unlock_irqrestore(&schan->lock, flags);
213 /* for cyclic channel, desc is always in active list */
214 sdesc = list_first_entry(&schan->active, struct sirfsoc_dma_desc,
217 if (!sdesc || (sdesc && !sdesc->cyclic)) {
218 /* without active cyclic DMA */
219 spin_unlock_irqrestore(&schan->lock, flags);
224 happened_cyclic = schan->happened_cyclic;
225 spin_unlock_irqrestore(&schan->lock, flags);
228 while (happened_cyclic != schan->completed_cyclic) {
230 desc->callback(desc->callback_param);
231 schan->completed_cyclic++;
238 static void sirfsoc_dma_tasklet(unsigned long data)
240 struct sirfsoc_dma *sdma = (void *)data;
242 sirfsoc_dma_process_completed(sdma);
245 /* Submit descriptor to hardware */
246 static dma_cookie_t sirfsoc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
248 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(txd->chan);
249 struct sirfsoc_dma_desc *sdesc;
253 sdesc = container_of(txd, struct sirfsoc_dma_desc, desc);
255 spin_lock_irqsave(&schan->lock, flags);
257 /* Move descriptor to queue */
258 list_move_tail(&sdesc->node, &schan->queued);
260 cookie = dma_cookie_assign(txd);
262 spin_unlock_irqrestore(&schan->lock, flags);
267 static int sirfsoc_dma_slave_config(struct sirfsoc_dma_chan *schan,
268 struct dma_slave_config *config)
272 if ((config->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
273 (config->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES))
276 spin_lock_irqsave(&schan->lock, flags);
277 schan->mode = (config->src_maxburst == 4 ? 1 : 0);
278 spin_unlock_irqrestore(&schan->lock, flags);
283 static int sirfsoc_dma_terminate_all(struct sirfsoc_dma_chan *schan)
285 struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
286 int cid = schan->chan.chan_id;
289 writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN) &
290 ~(1 << cid), sdma->base + SIRFSOC_DMA_INT_EN);
291 writel_relaxed(1 << cid, sdma->base + SIRFSOC_DMA_CH_VALID);
293 writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL)
294 & ~((1 << cid) | 1 << (cid + 16)),
295 sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
297 spin_lock_irqsave(&schan->lock, flags);
298 list_splice_tail_init(&schan->active, &schan->free);
299 list_splice_tail_init(&schan->queued, &schan->free);
300 spin_unlock_irqrestore(&schan->lock, flags);
305 static int sirfsoc_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
308 struct dma_slave_config *config;
309 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
312 case DMA_TERMINATE_ALL:
313 return sirfsoc_dma_terminate_all(schan);
314 case DMA_SLAVE_CONFIG:
315 config = (struct dma_slave_config *)arg;
316 return sirfsoc_dma_slave_config(schan, config);
325 /* Alloc channel resources */
326 static int sirfsoc_dma_alloc_chan_resources(struct dma_chan *chan)
328 struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
329 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
330 struct sirfsoc_dma_desc *sdesc;
335 /* Alloc descriptors for this channel */
336 for (i = 0; i < SIRFSOC_DMA_DESCRIPTORS; i++) {
337 sdesc = kzalloc(sizeof(*sdesc), GFP_KERNEL);
339 dev_notice(sdma->dma.dev, "Memory allocation error. "
340 "Allocated only %u descriptors\n", i);
344 dma_async_tx_descriptor_init(&sdesc->desc, chan);
345 sdesc->desc.flags = DMA_CTRL_ACK;
346 sdesc->desc.tx_submit = sirfsoc_dma_tx_submit;
348 list_add_tail(&sdesc->node, &descs);
351 /* Return error only if no descriptors were allocated */
355 spin_lock_irqsave(&schan->lock, flags);
357 list_splice_tail_init(&descs, &schan->free);
358 spin_unlock_irqrestore(&schan->lock, flags);
363 /* Free channel resources */
364 static void sirfsoc_dma_free_chan_resources(struct dma_chan *chan)
366 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
367 struct sirfsoc_dma_desc *sdesc, *tmp;
371 spin_lock_irqsave(&schan->lock, flags);
373 /* Channel must be idle */
374 BUG_ON(!list_empty(&schan->prepared));
375 BUG_ON(!list_empty(&schan->queued));
376 BUG_ON(!list_empty(&schan->active));
377 BUG_ON(!list_empty(&schan->completed));
380 list_splice_tail_init(&schan->free, &descs);
382 spin_unlock_irqrestore(&schan->lock, flags);
384 /* Free descriptors */
385 list_for_each_entry_safe(sdesc, tmp, &descs, node)
389 /* Send pending descriptor to hardware */
390 static void sirfsoc_dma_issue_pending(struct dma_chan *chan)
392 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
395 spin_lock_irqsave(&schan->lock, flags);
397 if (list_empty(&schan->active) && !list_empty(&schan->queued))
398 sirfsoc_dma_execute(schan);
400 spin_unlock_irqrestore(&schan->lock, flags);
403 /* Check request completion status */
404 static enum dma_status
405 sirfsoc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
406 struct dma_tx_state *txstate)
408 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
412 spin_lock_irqsave(&schan->lock, flags);
413 ret = dma_cookie_status(chan, cookie, txstate);
414 spin_unlock_irqrestore(&schan->lock, flags);
419 static struct dma_async_tx_descriptor *sirfsoc_dma_prep_interleaved(
420 struct dma_chan *chan, struct dma_interleaved_template *xt,
423 struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
424 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
425 struct sirfsoc_dma_desc *sdesc = NULL;
426 unsigned long iflags;
429 if ((xt->dir != DMA_MEM_TO_DEV) || (xt->dir != DMA_DEV_TO_MEM)) {
434 /* Get free descriptor */
435 spin_lock_irqsave(&schan->lock, iflags);
436 if (!list_empty(&schan->free)) {
437 sdesc = list_first_entry(&schan->free, struct sirfsoc_dma_desc,
439 list_del(&sdesc->node);
441 spin_unlock_irqrestore(&schan->lock, iflags);
444 /* try to free completed descriptors */
445 sirfsoc_dma_process_completed(sdma);
450 /* Place descriptor in prepared list */
451 spin_lock_irqsave(&schan->lock, iflags);
454 * Number of chunks in a frame can only be 1 for prima2
455 * and ylen (number of frame - 1) must be at least 0
457 if ((xt->frame_size == 1) && (xt->numf > 0)) {
459 sdesc->xlen = xt->sgl[0].size / SIRFSOC_DMA_WORD_LEN;
460 sdesc->width = (xt->sgl[0].size + xt->sgl[0].icg) /
461 SIRFSOC_DMA_WORD_LEN;
462 sdesc->ylen = xt->numf - 1;
463 if (xt->dir == DMA_MEM_TO_DEV) {
464 sdesc->addr = xt->src_start;
467 sdesc->addr = xt->dst_start;
471 list_add_tail(&sdesc->node, &schan->prepared);
473 pr_err("sirfsoc DMA Invalid xfer\n");
477 spin_unlock_irqrestore(&schan->lock, iflags);
481 spin_unlock_irqrestore(&schan->lock, iflags);
487 static struct dma_async_tx_descriptor *
488 sirfsoc_dma_prep_cyclic(struct dma_chan *chan, dma_addr_t addr,
489 size_t buf_len, size_t period_len,
490 enum dma_transfer_direction direction)
492 struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
493 struct sirfsoc_dma_desc *sdesc = NULL;
494 unsigned long iflags;
497 * we only support cycle transfer with 2 period
498 * If the X-length is set to 0, it would be the loop mode.
499 * The DMA address keeps increasing until reaching the end of a loop
500 * area whose size is defined by (DMA_WIDTH x (Y_LENGTH + 1)). Then
501 * the DMA address goes back to the beginning of this area.
502 * In loop mode, the DMA data region is divided into two parts, BUFA
503 * and BUFB. DMA controller generates interrupts twice in each loop:
504 * when the DMA address reaches the end of BUFA or the end of the
507 if (buf_len != 2 * period_len)
508 return ERR_PTR(-EINVAL);
510 /* Get free descriptor */
511 spin_lock_irqsave(&schan->lock, iflags);
512 if (!list_empty(&schan->free)) {
513 sdesc = list_first_entry(&schan->free, struct sirfsoc_dma_desc,
515 list_del(&sdesc->node);
517 spin_unlock_irqrestore(&schan->lock, iflags);
522 /* Place descriptor in prepared list */
523 spin_lock_irqsave(&schan->lock, iflags);
527 sdesc->ylen = buf_len / SIRFSOC_DMA_WORD_LEN - 1;
529 list_add_tail(&sdesc->node, &schan->prepared);
530 spin_unlock_irqrestore(&schan->lock, iflags);
536 * The DMA controller consists of 16 independent DMA channels.
537 * Each channel is allocated to a different function
539 bool sirfsoc_dma_filter_id(struct dma_chan *chan, void *chan_id)
541 unsigned int ch_nr = (unsigned int) chan_id;
543 if (ch_nr == chan->chan_id +
544 chan->device->dev_id * SIRFSOC_DMA_CHANNELS)
549 EXPORT_SYMBOL(sirfsoc_dma_filter_id);
551 static int __devinit sirfsoc_dma_probe(struct platform_device *op)
553 struct device_node *dn = op->dev.of_node;
554 struct device *dev = &op->dev;
555 struct dma_device *dma;
556 struct sirfsoc_dma *sdma;
557 struct sirfsoc_dma_chan *schan;
559 ulong regs_start, regs_size;
563 sdma = devm_kzalloc(dev, sizeof(*sdma), GFP_KERNEL);
565 dev_err(dev, "Memory exhausted!\n");
569 if (of_property_read_u32(dn, "cell-index", &id)) {
570 dev_err(dev, "Fail to get DMAC index\n");
575 sdma->irq = irq_of_parse_and_map(dn, 0);
576 if (sdma->irq == NO_IRQ) {
577 dev_err(dev, "Error mapping IRQ!\n");
582 ret = of_address_to_resource(dn, 0, &res);
584 dev_err(dev, "Error parsing memory region!\n");
588 regs_start = res.start;
589 regs_size = resource_size(&res);
591 sdma->base = devm_ioremap(dev, regs_start, regs_size);
593 dev_err(dev, "Error mapping memory region!\n");
598 ret = devm_request_irq(dev, sdma->irq, &sirfsoc_dma_irq, 0, DRV_NAME,
601 dev_err(dev, "Error requesting IRQ!\n");
608 dma->chancnt = SIRFSOC_DMA_CHANNELS;
610 dma->device_alloc_chan_resources = sirfsoc_dma_alloc_chan_resources;
611 dma->device_free_chan_resources = sirfsoc_dma_free_chan_resources;
612 dma->device_issue_pending = sirfsoc_dma_issue_pending;
613 dma->device_control = sirfsoc_dma_control;
614 dma->device_tx_status = sirfsoc_dma_tx_status;
615 dma->device_prep_interleaved_dma = sirfsoc_dma_prep_interleaved;
616 dma->device_prep_dma_cyclic = sirfsoc_dma_prep_cyclic;
618 INIT_LIST_HEAD(&dma->channels);
619 dma_cap_set(DMA_SLAVE, dma->cap_mask);
620 dma_cap_set(DMA_CYCLIC, dma->cap_mask);
621 dma_cap_set(DMA_INTERLEAVE, dma->cap_mask);
622 dma_cap_set(DMA_PRIVATE, dma->cap_mask);
624 for (i = 0; i < dma->chancnt; i++) {
625 schan = &sdma->channels[i];
627 schan->chan.device = dma;
628 dma_cookie_init(&schan->chan);
630 INIT_LIST_HEAD(&schan->free);
631 INIT_LIST_HEAD(&schan->prepared);
632 INIT_LIST_HEAD(&schan->queued);
633 INIT_LIST_HEAD(&schan->active);
634 INIT_LIST_HEAD(&schan->completed);
636 spin_lock_init(&schan->lock);
637 list_add_tail(&schan->chan.device_node, &dma->channels);
640 tasklet_init(&sdma->tasklet, sirfsoc_dma_tasklet, (unsigned long)sdma);
642 /* Register DMA engine */
643 dev_set_drvdata(dev, sdma);
644 ret = dma_async_device_register(dma);
648 dev_info(dev, "initialized SIRFSOC DMAC driver\n");
653 devm_free_irq(dev, sdma->irq, sdma);
655 irq_dispose_mapping(sdma->irq);
659 devm_kfree(dev, sdma);
663 static int __devexit sirfsoc_dma_remove(struct platform_device *op)
665 struct device *dev = &op->dev;
666 struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
668 dma_async_device_unregister(&sdma->dma);
669 devm_free_irq(dev, sdma->irq, sdma);
670 irq_dispose_mapping(sdma->irq);
672 devm_kfree(dev, sdma);
676 static struct of_device_id sirfsoc_dma_match[] = {
677 { .compatible = "sirf,prima2-dmac", },
681 static struct platform_driver sirfsoc_dma_driver = {
682 .probe = sirfsoc_dma_probe,
683 .remove = __devexit_p(sirfsoc_dma_remove),
686 .owner = THIS_MODULE,
687 .of_match_table = sirfsoc_dma_match,
691 module_platform_driver(sirfsoc_dma_driver);
693 MODULE_AUTHOR("Rongjun Ying <rongjun.ying@csr.com>, "
694 "Barry Song <baohua.song@csr.com>");
695 MODULE_DESCRIPTION("SIRFSOC DMA control driver");
696 MODULE_LICENSE("GPL v2");