2 * Core driver for the Intel integrated DMA 64-bit
4 * Copyright (C) 2015 Intel Corporation
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/bitops.h>
13 #include <linux/delay.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmapool.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
24 /* Platform driver name */
25 #define DRV_NAME "idma64"
27 /* For now we support only two channels */
28 #define IDMA64_NR_CHAN 2
30 /* ---------------------------------------------------------------------- */
32 static struct device *chan2dev(struct dma_chan *chan)
34 return &chan->dev->device;
37 /* ---------------------------------------------------------------------- */
39 static void idma64_off(struct idma64 *idma64)
41 unsigned short count = 100;
43 dma_writel(idma64, CFG, 0);
45 channel_clear_bit(idma64, MASK(XFER), idma64->all_chan_mask);
46 channel_clear_bit(idma64, MASK(BLOCK), idma64->all_chan_mask);
47 channel_clear_bit(idma64, MASK(SRC_TRAN), idma64->all_chan_mask);
48 channel_clear_bit(idma64, MASK(DST_TRAN), idma64->all_chan_mask);
49 channel_clear_bit(idma64, MASK(ERROR), idma64->all_chan_mask);
53 } while (dma_readl(idma64, CFG) & IDMA64_CFG_DMA_EN && --count);
56 static void idma64_on(struct idma64 *idma64)
58 dma_writel(idma64, CFG, IDMA64_CFG_DMA_EN);
61 /* ---------------------------------------------------------------------- */
63 static void idma64_chan_init(struct idma64 *idma64, struct idma64_chan *idma64c)
65 u32 cfghi = IDMA64C_CFGH_SRC_PER(1) | IDMA64C_CFGH_DST_PER(0);
68 /* Set default burst alignment */
69 cfglo |= IDMA64C_CFGL_DST_BURST_ALIGN | IDMA64C_CFGL_SRC_BURST_ALIGN;
71 channel_writel(idma64c, CFG_LO, cfglo);
72 channel_writel(idma64c, CFG_HI, cfghi);
74 /* Enable interrupts */
75 channel_set_bit(idma64, MASK(XFER), idma64c->mask);
76 channel_set_bit(idma64, MASK(ERROR), idma64c->mask);
79 * Enforce the controller to be turned on.
81 * The iDMA is turned off in ->probe() and looses context during system
82 * suspend / resume cycle. That's why we have to enable it each time we
88 static void idma64_chan_stop(struct idma64 *idma64, struct idma64_chan *idma64c)
90 channel_clear_bit(idma64, CH_EN, idma64c->mask);
93 static void idma64_chan_start(struct idma64 *idma64, struct idma64_chan *idma64c)
95 struct idma64_desc *desc = idma64c->desc;
96 struct idma64_hw_desc *hw = &desc->hw[0];
98 channel_writeq(idma64c, SAR, 0);
99 channel_writeq(idma64c, DAR, 0);
101 channel_writel(idma64c, CTL_HI, IDMA64C_CTLH_BLOCK_TS(~0UL));
102 channel_writel(idma64c, CTL_LO, IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN);
104 channel_writeq(idma64c, LLP, hw->llp);
106 channel_set_bit(idma64, CH_EN, idma64c->mask);
109 static void idma64_stop_transfer(struct idma64_chan *idma64c)
111 struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device);
113 idma64_chan_stop(idma64, idma64c);
116 static void idma64_start_transfer(struct idma64_chan *idma64c)
118 struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device);
119 struct virt_dma_desc *vdesc;
121 /* Get the next descriptor */
122 vdesc = vchan_next_desc(&idma64c->vchan);
124 idma64c->desc = NULL;
128 list_del(&vdesc->node);
129 idma64c->desc = to_idma64_desc(vdesc);
131 /* Configure the channel */
132 idma64_chan_init(idma64, idma64c);
134 /* Start the channel with a new descriptor */
135 idma64_chan_start(idma64, idma64c);
138 /* ---------------------------------------------------------------------- */
140 static void idma64_chan_irq(struct idma64 *idma64, unsigned short c,
141 u32 status_err, u32 status_xfer)
143 struct idma64_chan *idma64c = &idma64->chan[c];
144 struct idma64_desc *desc;
147 spin_lock_irqsave(&idma64c->vchan.lock, flags);
148 desc = idma64c->desc;
150 if (status_err & (1 << c)) {
151 dma_writel(idma64, CLEAR(ERROR), idma64c->mask);
152 desc->status = DMA_ERROR;
153 } else if (status_xfer & (1 << c)) {
154 dma_writel(idma64, CLEAR(XFER), idma64c->mask);
155 desc->status = DMA_COMPLETE;
156 vchan_cookie_complete(&desc->vdesc);
157 idma64_start_transfer(idma64c);
160 /* idma64_start_transfer() updates idma64c->desc */
161 if (idma64c->desc == NULL || desc->status == DMA_ERROR)
162 idma64_stop_transfer(idma64c);
164 spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
167 static irqreturn_t idma64_irq(int irq, void *dev)
169 struct idma64 *idma64 = dev;
170 u32 status = dma_readl(idma64, STATUS_INT);
175 dev_vdbg(idma64->dma.dev, "%s: status=%#x\n", __func__, status);
177 /* Check if we have any interrupt from the DMA controller */
181 status_xfer = dma_readl(idma64, RAW(XFER));
182 status_err = dma_readl(idma64, RAW(ERROR));
184 for (i = 0; i < idma64->dma.chancnt; i++)
185 idma64_chan_irq(idma64, i, status_err, status_xfer);
190 /* ---------------------------------------------------------------------- */
192 static struct idma64_desc *idma64_alloc_desc(unsigned int ndesc)
194 struct idma64_desc *desc;
196 desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
200 desc->hw = kcalloc(ndesc, sizeof(*desc->hw), GFP_NOWAIT);
209 static void idma64_desc_free(struct idma64_chan *idma64c,
210 struct idma64_desc *desc)
212 struct idma64_hw_desc *hw;
215 unsigned int i = desc->ndesc;
219 dma_pool_free(idma64c->pool, hw->lli, hw->llp);
227 static void idma64_vdesc_free(struct virt_dma_desc *vdesc)
229 struct idma64_chan *idma64c = to_idma64_chan(vdesc->tx.chan);
231 idma64_desc_free(idma64c, to_idma64_desc(vdesc));
234 static void idma64_hw_desc_fill(struct idma64_hw_desc *hw,
235 struct dma_slave_config *config,
236 enum dma_transfer_direction direction, u64 llp)
238 struct idma64_lli *lli = hw->lli;
240 u32 ctlhi = IDMA64C_CTLH_BLOCK_TS(hw->len);
241 u32 ctllo = IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN;
242 u32 src_width, dst_width;
244 if (direction == DMA_MEM_TO_DEV) {
246 dar = config->dst_addr;
247 ctllo |= IDMA64C_CTLL_DST_FIX | IDMA64C_CTLL_SRC_INC |
249 src_width = __ffs(sar | hw->len | 4);
250 dst_width = __ffs(config->dst_addr_width);
251 } else { /* DMA_DEV_TO_MEM */
252 sar = config->src_addr;
254 ctllo |= IDMA64C_CTLL_DST_INC | IDMA64C_CTLL_SRC_FIX |
256 src_width = __ffs(config->src_addr_width);
257 dst_width = __ffs(dar | hw->len | 4);
265 IDMA64C_CTLL_SRC_MSIZE(config->src_maxburst) |
266 IDMA64C_CTLL_DST_MSIZE(config->dst_maxburst) |
267 IDMA64C_CTLL_DST_WIDTH(dst_width) |
268 IDMA64C_CTLL_SRC_WIDTH(src_width);
273 static void idma64_desc_fill(struct idma64_chan *idma64c,
274 struct idma64_desc *desc)
276 struct dma_slave_config *config = &idma64c->config;
277 unsigned int i = desc->ndesc;
278 struct idma64_hw_desc *hw = &desc->hw[i - 1];
279 struct idma64_lli *lli = hw->lli;
282 /* Fill the hardware descriptors and link them to a list */
285 idma64_hw_desc_fill(hw, config, desc->direction, llp);
287 desc->length += hw->len;
290 /* Trigger an interrupt after the last block is transfered */
291 lli->ctllo |= IDMA64C_CTLL_INT_EN;
294 static struct dma_async_tx_descriptor *idma64_prep_slave_sg(
295 struct dma_chan *chan, struct scatterlist *sgl,
296 unsigned int sg_len, enum dma_transfer_direction direction,
297 unsigned long flags, void *context)
299 struct idma64_chan *idma64c = to_idma64_chan(chan);
300 struct idma64_desc *desc;
301 struct scatterlist *sg;
304 desc = idma64_alloc_desc(sg_len);
308 for_each_sg(sgl, sg, sg_len, i) {
309 struct idma64_hw_desc *hw = &desc->hw[i];
311 /* Allocate DMA capable memory for hardware descriptor */
312 hw->lli = dma_pool_alloc(idma64c->pool, GFP_NOWAIT, &hw->llp);
315 idma64_desc_free(idma64c, desc);
319 hw->phys = sg_dma_address(sg);
320 hw->len = sg_dma_len(sg);
323 desc->ndesc = sg_len;
324 desc->direction = direction;
325 desc->status = DMA_IN_PROGRESS;
327 idma64_desc_fill(idma64c, desc);
328 return vchan_tx_prep(&idma64c->vchan, &desc->vdesc, flags);
331 static void idma64_issue_pending(struct dma_chan *chan)
333 struct idma64_chan *idma64c = to_idma64_chan(chan);
336 spin_lock_irqsave(&idma64c->vchan.lock, flags);
337 if (vchan_issue_pending(&idma64c->vchan) && !idma64c->desc)
338 idma64_start_transfer(idma64c);
339 spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
342 static size_t idma64_active_desc_size(struct idma64_chan *idma64c)
344 struct idma64_desc *desc = idma64c->desc;
345 struct idma64_hw_desc *hw;
346 size_t bytes = desc->length;
347 u64 llp = channel_readq(idma64c, LLP);
348 u32 ctlhi = channel_readl(idma64c, CTL_HI);
356 } while (++i < desc->ndesc);
361 /* The current chunk is not fully transfered yet */
362 bytes += desc->hw[--i].len;
364 return bytes - IDMA64C_CTLH_BLOCK_TS(ctlhi);
367 static enum dma_status idma64_tx_status(struct dma_chan *chan,
368 dma_cookie_t cookie, struct dma_tx_state *state)
370 struct idma64_chan *idma64c = to_idma64_chan(chan);
371 struct virt_dma_desc *vdesc;
372 enum dma_status status;
376 status = dma_cookie_status(chan, cookie, state);
377 if (status == DMA_COMPLETE)
380 spin_lock_irqsave(&idma64c->vchan.lock, flags);
381 vdesc = vchan_find_desc(&idma64c->vchan, cookie);
382 if (idma64c->desc && cookie == idma64c->desc->vdesc.tx.cookie) {
383 bytes = idma64_active_desc_size(idma64c);
384 dma_set_residue(state, bytes);
385 status = idma64c->desc->status;
387 bytes = to_idma64_desc(vdesc)->length;
388 dma_set_residue(state, bytes);
390 spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
395 static void convert_burst(u32 *maxburst)
398 *maxburst = __fls(*maxburst);
403 static int idma64_slave_config(struct dma_chan *chan,
404 struct dma_slave_config *config)
406 struct idma64_chan *idma64c = to_idma64_chan(chan);
408 /* Check if chan will be configured for slave transfers */
409 if (!is_slave_direction(config->direction))
412 memcpy(&idma64c->config, config, sizeof(idma64c->config));
414 convert_burst(&idma64c->config.src_maxburst);
415 convert_burst(&idma64c->config.dst_maxburst);
420 static void idma64_chan_deactivate(struct idma64_chan *idma64c, bool drain)
422 unsigned short count = 100;
425 cfglo = channel_readl(idma64c, CFG_LO);
427 cfglo |= IDMA64C_CFGL_CH_DRAIN;
429 cfglo &= ~IDMA64C_CFGL_CH_DRAIN;
431 channel_writel(idma64c, CFG_LO, cfglo | IDMA64C_CFGL_CH_SUSP);
434 cfglo = channel_readl(idma64c, CFG_LO);
435 } while (!(cfglo & IDMA64C_CFGL_FIFO_EMPTY) && --count);
438 static void idma64_chan_activate(struct idma64_chan *idma64c)
442 cfglo = channel_readl(idma64c, CFG_LO);
443 channel_writel(idma64c, CFG_LO, cfglo & ~IDMA64C_CFGL_CH_SUSP);
446 static int idma64_pause(struct dma_chan *chan)
448 struct idma64_chan *idma64c = to_idma64_chan(chan);
451 spin_lock_irqsave(&idma64c->vchan.lock, flags);
452 if (idma64c->desc && idma64c->desc->status == DMA_IN_PROGRESS) {
453 idma64_chan_deactivate(idma64c, false);
454 idma64c->desc->status = DMA_PAUSED;
456 spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
461 static int idma64_resume(struct dma_chan *chan)
463 struct idma64_chan *idma64c = to_idma64_chan(chan);
466 spin_lock_irqsave(&idma64c->vchan.lock, flags);
467 if (idma64c->desc && idma64c->desc->status == DMA_PAUSED) {
468 idma64c->desc->status = DMA_IN_PROGRESS;
469 idma64_chan_activate(idma64c);
471 spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
476 static int idma64_terminate_all(struct dma_chan *chan)
478 struct idma64_chan *idma64c = to_idma64_chan(chan);
482 spin_lock_irqsave(&idma64c->vchan.lock, flags);
483 idma64_chan_deactivate(idma64c, true);
484 idma64_stop_transfer(idma64c);
486 idma64_vdesc_free(&idma64c->desc->vdesc);
487 idma64c->desc = NULL;
489 vchan_get_all_descriptors(&idma64c->vchan, &head);
490 spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
492 vchan_dma_desc_free_list(&idma64c->vchan, &head);
496 static int idma64_alloc_chan_resources(struct dma_chan *chan)
498 struct idma64_chan *idma64c = to_idma64_chan(chan);
500 /* Create a pool of consistent memory blocks for hardware descriptors */
501 idma64c->pool = dma_pool_create(dev_name(chan2dev(chan)),
503 sizeof(struct idma64_lli), 8, 0);
504 if (!idma64c->pool) {
505 dev_err(chan2dev(chan), "No memory for descriptors\n");
512 static void idma64_free_chan_resources(struct dma_chan *chan)
514 struct idma64_chan *idma64c = to_idma64_chan(chan);
516 vchan_free_chan_resources(to_virt_chan(chan));
517 dma_pool_destroy(idma64c->pool);
518 idma64c->pool = NULL;
521 /* ---------------------------------------------------------------------- */
523 #define IDMA64_BUSWIDTHS \
524 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
525 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
526 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
528 static int idma64_probe(struct idma64_chip *chip)
530 struct idma64 *idma64;
531 unsigned short nr_chan = IDMA64_NR_CHAN;
535 idma64 = devm_kzalloc(chip->dev, sizeof(*idma64), GFP_KERNEL);
539 idma64->regs = chip->regs;
540 chip->idma64 = idma64;
542 idma64->chan = devm_kcalloc(chip->dev, nr_chan, sizeof(*idma64->chan),
547 idma64->all_chan_mask = (1 << nr_chan) - 1;
549 /* Turn off iDMA controller */
552 ret = devm_request_irq(chip->dev, chip->irq, idma64_irq, IRQF_SHARED,
553 dev_name(chip->dev), idma64);
557 INIT_LIST_HEAD(&idma64->dma.channels);
558 for (i = 0; i < nr_chan; i++) {
559 struct idma64_chan *idma64c = &idma64->chan[i];
561 idma64c->vchan.desc_free = idma64_vdesc_free;
562 vchan_init(&idma64c->vchan, &idma64->dma);
564 idma64c->regs = idma64->regs + i * IDMA64_CH_LENGTH;
565 idma64c->mask = BIT(i);
568 dma_cap_set(DMA_SLAVE, idma64->dma.cap_mask);
569 dma_cap_set(DMA_PRIVATE, idma64->dma.cap_mask);
571 idma64->dma.device_alloc_chan_resources = idma64_alloc_chan_resources;
572 idma64->dma.device_free_chan_resources = idma64_free_chan_resources;
574 idma64->dma.device_prep_slave_sg = idma64_prep_slave_sg;
576 idma64->dma.device_issue_pending = idma64_issue_pending;
577 idma64->dma.device_tx_status = idma64_tx_status;
579 idma64->dma.device_config = idma64_slave_config;
580 idma64->dma.device_pause = idma64_pause;
581 idma64->dma.device_resume = idma64_resume;
582 idma64->dma.device_terminate_all = idma64_terminate_all;
584 idma64->dma.src_addr_widths = IDMA64_BUSWIDTHS;
585 idma64->dma.dst_addr_widths = IDMA64_BUSWIDTHS;
586 idma64->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
587 idma64->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
589 idma64->dma.dev = chip->dev;
591 dma_set_max_seg_size(idma64->dma.dev, IDMA64C_CTLH_BLOCK_TS_MASK);
593 ret = dma_async_device_register(&idma64->dma);
597 dev_info(chip->dev, "Found Intel integrated DMA 64-bit\n");
601 static int idma64_remove(struct idma64_chip *chip)
603 struct idma64 *idma64 = chip->idma64;
606 dma_async_device_unregister(&idma64->dma);
609 * Explicitly call devm_request_irq() to avoid the side effects with
610 * the scheduled tasklets.
612 devm_free_irq(chip->dev, chip->irq, idma64);
614 for (i = 0; i < idma64->dma.chancnt; i++) {
615 struct idma64_chan *idma64c = &idma64->chan[i];
617 tasklet_kill(&idma64c->vchan.task);
623 /* ---------------------------------------------------------------------- */
625 static int idma64_platform_probe(struct platform_device *pdev)
627 struct idma64_chip *chip;
628 struct device *dev = &pdev->dev;
629 struct resource *mem;
632 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
636 chip->irq = platform_get_irq(pdev, 0);
640 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
641 chip->regs = devm_ioremap_resource(dev, mem);
642 if (IS_ERR(chip->regs))
643 return PTR_ERR(chip->regs);
645 ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
651 ret = idma64_probe(chip);
655 platform_set_drvdata(pdev, chip);
659 static int idma64_platform_remove(struct platform_device *pdev)
661 struct idma64_chip *chip = platform_get_drvdata(pdev);
663 return idma64_remove(chip);
666 #ifdef CONFIG_PM_SLEEP
668 static int idma64_pm_suspend(struct device *dev)
670 struct platform_device *pdev = to_platform_device(dev);
671 struct idma64_chip *chip = platform_get_drvdata(pdev);
673 idma64_off(chip->idma64);
677 static int idma64_pm_resume(struct device *dev)
679 struct platform_device *pdev = to_platform_device(dev);
680 struct idma64_chip *chip = platform_get_drvdata(pdev);
682 idma64_on(chip->idma64);
686 #endif /* CONFIG_PM_SLEEP */
688 static const struct dev_pm_ops idma64_dev_pm_ops = {
689 SET_SYSTEM_SLEEP_PM_OPS(idma64_pm_suspend, idma64_pm_resume)
692 static struct platform_driver idma64_platform_driver = {
693 .probe = idma64_platform_probe,
694 .remove = idma64_platform_remove,
697 .pm = &idma64_dev_pm_ops,
701 module_platform_driver(idma64_platform_driver);
703 MODULE_LICENSE("GPL v2");
704 MODULE_DESCRIPTION("iDMA64 core driver");
706 MODULE_ALIAS("platform:" DRV_NAME);