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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * drivers/dma/fsl-edma.c
  4 *
  5 * Copyright 2013-2014 Freescale Semiconductor, Inc.
  6 *
  7 * Driver for the Freescale eDMA engine with flexible channel multiplexing
  8 * capability for DMA request sources. The eDMA block can be found on some
  9 * Vybrid and Layerscape SoCs.
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/interrupt.h>
 14#include <linux/clk.h>
 15#include <linux/of.h>
 16#include <linux/of_device.h>
 17#include <linux/of_address.h>
 18#include <linux/of_irq.h>
 19#include <linux/of_dma.h>
 20#include <linux/dma-mapping.h>
 21
 22#include "fsl-edma-common.h"
 23
 24static void fsl_edma_synchronize(struct dma_chan *chan)
 25{
 26	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
 27
 28	vchan_synchronize(&fsl_chan->vchan);
 29}
 30
 31static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
 32{
 33	struct fsl_edma_engine *fsl_edma = dev_id;
 34	unsigned int intr, ch;
 35	struct edma_regs *regs = &fsl_edma->regs;
 36	struct fsl_edma_chan *fsl_chan;
 37
 38	intr = edma_readl(fsl_edma, regs->intl);
 39	if (!intr)
 40		return IRQ_NONE;
 41
 42	for (ch = 0; ch < fsl_edma->n_chans; ch++) {
 43		if (intr & (0x1 << ch)) {
 44			edma_writeb(fsl_edma, EDMA_CINT_CINT(ch), regs->cint);
 45
 46			fsl_chan = &fsl_edma->chans[ch];
 47
 48			spin_lock(&fsl_chan->vchan.lock);
 49
 50			if (!fsl_chan->edesc) {
 51				/* terminate_all called before */
 52				spin_unlock(&fsl_chan->vchan.lock);
 53				continue;
 54			}
 55
 56			if (!fsl_chan->edesc->iscyclic) {
 57				list_del(&fsl_chan->edesc->vdesc.node);
 58				vchan_cookie_complete(&fsl_chan->edesc->vdesc);
 59				fsl_chan->edesc = NULL;
 60				fsl_chan->status = DMA_COMPLETE;
 61				fsl_chan->idle = true;
 62			} else {
 63				vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
 64			}
 65
 66			if (!fsl_chan->edesc)
 67				fsl_edma_xfer_desc(fsl_chan);
 68
 69			spin_unlock(&fsl_chan->vchan.lock);
 70		}
 71	}
 72	return IRQ_HANDLED;
 73}
 74
 75static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
 76{
 77	struct fsl_edma_engine *fsl_edma = dev_id;
 78	unsigned int err, ch;
 79	struct edma_regs *regs = &fsl_edma->regs;
 80
 81	err = edma_readl(fsl_edma, regs->errl);
 82	if (!err)
 83		return IRQ_NONE;
 84
 85	for (ch = 0; ch < fsl_edma->n_chans; ch++) {
 86		if (err & (0x1 << ch)) {
 87			fsl_edma_disable_request(&fsl_edma->chans[ch]);
 88			edma_writeb(fsl_edma, EDMA_CERR_CERR(ch), regs->cerr);
 89			fsl_edma->chans[ch].status = DMA_ERROR;
 90			fsl_edma->chans[ch].idle = true;
 91		}
 92	}
 93	return IRQ_HANDLED;
 94}
 95
 96static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
 97{
 98	if (fsl_edma_tx_handler(irq, dev_id) == IRQ_HANDLED)
 99		return IRQ_HANDLED;
100
101	return fsl_edma_err_handler(irq, dev_id);
102}
103
104static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
105		struct of_dma *ofdma)
106{
107	struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
108	struct dma_chan *chan, *_chan;
109	struct fsl_edma_chan *fsl_chan;
110	u32 dmamux_nr = fsl_edma->drvdata->dmamuxs;
111	unsigned long chans_per_mux = fsl_edma->n_chans / dmamux_nr;
112
113	if (dma_spec->args_count != 2)
114		return NULL;
115
116	mutex_lock(&fsl_edma->fsl_edma_mutex);
117	list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels, device_node) {
118		if (chan->client_count)
119			continue;
120		if ((chan->chan_id / chans_per_mux) == dma_spec->args[0]) {
121			chan = dma_get_slave_channel(chan);
122			if (chan) {
123				chan->device->privatecnt++;
124				fsl_chan = to_fsl_edma_chan(chan);
125				fsl_chan->slave_id = dma_spec->args[1];
126				fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id,
127						true);
128				mutex_unlock(&fsl_edma->fsl_edma_mutex);
129				return chan;
130			}
131		}
132	}
133	mutex_unlock(&fsl_edma->fsl_edma_mutex);
134	return NULL;
135}
136
137static int
138fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
139{
140	int ret;
141
142	fsl_edma->txirq = platform_get_irq_byname(pdev, "edma-tx");
143	if (fsl_edma->txirq < 0)
144		return fsl_edma->txirq;
145
146	fsl_edma->errirq = platform_get_irq_byname(pdev, "edma-err");
147	if (fsl_edma->errirq < 0)
148		return fsl_edma->errirq;
149
150	if (fsl_edma->txirq == fsl_edma->errirq) {
151		ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
152				fsl_edma_irq_handler, 0, "eDMA", fsl_edma);
153		if (ret) {
154			dev_err(&pdev->dev, "Can't register eDMA IRQ.\n");
155			return ret;
156		}
157	} else {
158		ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
159				fsl_edma_tx_handler, 0, "eDMA tx", fsl_edma);
160		if (ret) {
161			dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
162			return ret;
163		}
164
165		ret = devm_request_irq(&pdev->dev, fsl_edma->errirq,
166				fsl_edma_err_handler, 0, "eDMA err", fsl_edma);
167		if (ret) {
168			dev_err(&pdev->dev, "Can't register eDMA err IRQ.\n");
169			return ret;
170		}
171	}
172
173	return 0;
174}
175
176static int
177fsl_edma2_irq_init(struct platform_device *pdev,
178		   struct fsl_edma_engine *fsl_edma)
179{
180	int i, ret, irq;
181	int count;
182
183	count = platform_irq_count(pdev);
184	dev_dbg(&pdev->dev, "%s Found %d interrupts\r\n", __func__, count);
185	if (count <= 2) {
186		dev_err(&pdev->dev, "Interrupts in DTS not correct.\n");
187		return -EINVAL;
188	}
189	/*
190	 * 16 channel independent interrupts + 1 error interrupt on i.mx7ulp.
191	 * 2 channel share one interrupt, for example, ch0/ch16, ch1/ch17...
192	 * For now, just simply request irq without IRQF_SHARED flag, since 16
193	 * channels are enough on i.mx7ulp whose M4 domain own some peripherals.
194	 */
195	for (i = 0; i < count; i++) {
196		irq = platform_get_irq(pdev, i);
197		if (irq < 0)
198			return -ENXIO;
199
200		sprintf(fsl_edma->chans[i].chan_name, "eDMA2-CH%02d", i);
201
202		/* The last IRQ is for eDMA err */
203		if (i == count - 1)
204			ret = devm_request_irq(&pdev->dev, irq,
205						fsl_edma_err_handler,
206						0, "eDMA2-ERR", fsl_edma);
207		else
208			ret = devm_request_irq(&pdev->dev, irq,
209						fsl_edma_tx_handler, 0,
210						fsl_edma->chans[i].chan_name,
211						fsl_edma);
212		if (ret)
213			return ret;
214	}
215
216	return 0;
217}
218
219static void fsl_edma_irq_exit(
220		struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
221{
222	if (fsl_edma->txirq == fsl_edma->errirq) {
223		devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
224	} else {
225		devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
226		devm_free_irq(&pdev->dev, fsl_edma->errirq, fsl_edma);
227	}
228}
229
230static void fsl_disable_clocks(struct fsl_edma_engine *fsl_edma, int nr_clocks)
231{
232	int i;
233
234	for (i = 0; i < nr_clocks; i++)
235		clk_disable_unprepare(fsl_edma->muxclk[i]);
236}
237
238static struct fsl_edma_drvdata vf610_data = {
239	.version = v1,
240	.dmamuxs = DMAMUX_NR,
241	.setup_irq = fsl_edma_irq_init,
242};
243
244static struct fsl_edma_drvdata ls1028a_data = {
245	.version = v1,
246	.dmamuxs = DMAMUX_NR,
247	.mux_swap = true,
248	.setup_irq = fsl_edma_irq_init,
249};
250
251static struct fsl_edma_drvdata imx7ulp_data = {
252	.version = v3,
253	.dmamuxs = 1,
254	.has_dmaclk = true,
255	.setup_irq = fsl_edma2_irq_init,
256};
257
258static const struct of_device_id fsl_edma_dt_ids[] = {
259	{ .compatible = "fsl,vf610-edma", .data = &vf610_data},
260	{ .compatible = "fsl,ls1028a-edma", .data = &ls1028a_data},
261	{ .compatible = "fsl,imx7ulp-edma", .data = &imx7ulp_data},
262	{ /* sentinel */ }
263};
264MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
265
266static int fsl_edma_probe(struct platform_device *pdev)
267{
268	const struct of_device_id *of_id =
269			of_match_device(fsl_edma_dt_ids, &pdev->dev);
270	struct device_node *np = pdev->dev.of_node;
271	struct fsl_edma_engine *fsl_edma;
272	const struct fsl_edma_drvdata *drvdata = NULL;
273	struct fsl_edma_chan *fsl_chan;
274	struct edma_regs *regs;
275	struct resource *res;
276	int len, chans;
277	int ret, i;
278
279	if (of_id)
280		drvdata = of_id->data;
281	if (!drvdata) {
282		dev_err(&pdev->dev, "unable to find driver data\n");
283		return -EINVAL;
284	}
285
286	ret = of_property_read_u32(np, "dma-channels", &chans);
287	if (ret) {
288		dev_err(&pdev->dev, "Can't get dma-channels.\n");
289		return ret;
290	}
291
292	len = sizeof(*fsl_edma) + sizeof(*fsl_chan) * chans;
293	fsl_edma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
294	if (!fsl_edma)
295		return -ENOMEM;
296
297	fsl_edma->drvdata = drvdata;
298	fsl_edma->n_chans = chans;
299	mutex_init(&fsl_edma->fsl_edma_mutex);
300
301	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
302	fsl_edma->membase = devm_ioremap_resource(&pdev->dev, res);
303	if (IS_ERR(fsl_edma->membase))
304		return PTR_ERR(fsl_edma->membase);
305
306	fsl_edma_setup_regs(fsl_edma);
307	regs = &fsl_edma->regs;
308
309	if (drvdata->has_dmaclk) {
310		fsl_edma->dmaclk = devm_clk_get(&pdev->dev, "dma");
311		if (IS_ERR(fsl_edma->dmaclk)) {
312			dev_err(&pdev->dev, "Missing DMA block clock.\n");
313			return PTR_ERR(fsl_edma->dmaclk);
314		}
315
316		ret = clk_prepare_enable(fsl_edma->dmaclk);
317		if (ret) {
318			dev_err(&pdev->dev, "DMA clk block failed.\n");
319			return ret;
320		}
321	}
322
323	for (i = 0; i < fsl_edma->drvdata->dmamuxs; i++) {
324		char clkname[32];
325
326		res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
327		fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res);
328		if (IS_ERR(fsl_edma->muxbase[i])) {
329			/* on error: disable all previously enabled clks */
330			fsl_disable_clocks(fsl_edma, i);
331			return PTR_ERR(fsl_edma->muxbase[i]);
332		}
333
334		sprintf(clkname, "dmamux%d", i);
335		fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname);
336		if (IS_ERR(fsl_edma->muxclk[i])) {
337			dev_err(&pdev->dev, "Missing DMAMUX block clock.\n");
338			/* on error: disable all previously enabled clks */
339			fsl_disable_clocks(fsl_edma, i);
340			return PTR_ERR(fsl_edma->muxclk[i]);
341		}
342
343		ret = clk_prepare_enable(fsl_edma->muxclk[i]);
344		if (ret)
345			/* on error: disable all previously enabled clks */
346			fsl_disable_clocks(fsl_edma, i);
347
348	}
349
350	fsl_edma->big_endian = of_property_read_bool(np, "big-endian");
351
352	INIT_LIST_HEAD(&fsl_edma->dma_dev.channels);
353	for (i = 0; i < fsl_edma->n_chans; i++) {
354		struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];
355
356		fsl_chan->edma = fsl_edma;
357		fsl_chan->pm_state = RUNNING;
358		fsl_chan->slave_id = 0;
359		fsl_chan->idle = true;
360		fsl_chan->dma_dir = DMA_NONE;
361		fsl_chan->vchan.desc_free = fsl_edma_free_desc;
362		vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
363
364		edma_writew(fsl_edma, 0x0, &regs->tcd[i].csr);
365		fsl_edma_chan_mux(fsl_chan, 0, false);
366	}
367
368	edma_writel(fsl_edma, ~0, regs->intl);
369	ret = fsl_edma->drvdata->setup_irq(pdev, fsl_edma);
370	if (ret)
371		return ret;
372
373	dma_cap_set(DMA_PRIVATE, fsl_edma->dma_dev.cap_mask);
374	dma_cap_set(DMA_SLAVE, fsl_edma->dma_dev.cap_mask);
375	dma_cap_set(DMA_CYCLIC, fsl_edma->dma_dev.cap_mask);
376	dma_cap_set(DMA_MEMCPY, fsl_edma->dma_dev.cap_mask);
377
378	fsl_edma->dma_dev.dev = &pdev->dev;
379	fsl_edma->dma_dev.device_alloc_chan_resources
380		= fsl_edma_alloc_chan_resources;
381	fsl_edma->dma_dev.device_free_chan_resources
382		= fsl_edma_free_chan_resources;
383	fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
384	fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
385	fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
386	fsl_edma->dma_dev.device_prep_dma_memcpy = fsl_edma_prep_memcpy;
387	fsl_edma->dma_dev.device_config = fsl_edma_slave_config;
388	fsl_edma->dma_dev.device_pause = fsl_edma_pause;
389	fsl_edma->dma_dev.device_resume = fsl_edma_resume;
390	fsl_edma->dma_dev.device_terminate_all = fsl_edma_terminate_all;
391	fsl_edma->dma_dev.device_synchronize = fsl_edma_synchronize;
392	fsl_edma->dma_dev.device_issue_pending = fsl_edma_issue_pending;
393
394	fsl_edma->dma_dev.src_addr_widths = FSL_EDMA_BUSWIDTHS;
395	fsl_edma->dma_dev.dst_addr_widths = FSL_EDMA_BUSWIDTHS;
396	fsl_edma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
397
398	fsl_edma->dma_dev.copy_align = DMAENGINE_ALIGN_32_BYTES;
399	/* Per worst case 'nbytes = 1' take CITER as the max_seg_size */
400	dma_set_max_seg_size(fsl_edma->dma_dev.dev, 0x3fff);
401
402	platform_set_drvdata(pdev, fsl_edma);
403
404	ret = dma_async_device_register(&fsl_edma->dma_dev);
405	if (ret) {
406		dev_err(&pdev->dev,
407			"Can't register Freescale eDMA engine. (%d)\n", ret);
408		fsl_disable_clocks(fsl_edma, fsl_edma->drvdata->dmamuxs);
409		return ret;
410	}
411
412	ret = of_dma_controller_register(np, fsl_edma_xlate, fsl_edma);
413	if (ret) {
414		dev_err(&pdev->dev,
415			"Can't register Freescale eDMA of_dma. (%d)\n", ret);
416		dma_async_device_unregister(&fsl_edma->dma_dev);
417		fsl_disable_clocks(fsl_edma, fsl_edma->drvdata->dmamuxs);
418		return ret;
419	}
420
421	/* enable round robin arbitration */
422	edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);
423
424	return 0;
425}
426
427static int fsl_edma_remove(struct platform_device *pdev)
428{
429	struct device_node *np = pdev->dev.of_node;
430	struct fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);
431
432	fsl_edma_irq_exit(pdev, fsl_edma);
433	fsl_edma_cleanup_vchan(&fsl_edma->dma_dev);
434	of_dma_controller_free(np);
435	dma_async_device_unregister(&fsl_edma->dma_dev);
436	fsl_disable_clocks(fsl_edma, fsl_edma->drvdata->dmamuxs);
437
438	return 0;
439}
440
441static int fsl_edma_suspend_late(struct device *dev)
442{
443	struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
444	struct fsl_edma_chan *fsl_chan;
445	unsigned long flags;
446	int i;
447
448	for (i = 0; i < fsl_edma->n_chans; i++) {
449		fsl_chan = &fsl_edma->chans[i];
450		spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
451		/* Make sure chan is idle or will force disable. */
452		if (unlikely(!fsl_chan->idle)) {
453			dev_warn(dev, "WARN: There is non-idle channel.");
454			fsl_edma_disable_request(fsl_chan);
455			fsl_edma_chan_mux(fsl_chan, 0, false);
456		}
457
458		fsl_chan->pm_state = SUSPENDED;
459		spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
460	}
461
462	return 0;
463}
464
465static int fsl_edma_resume_early(struct device *dev)
466{
467	struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
468	struct fsl_edma_chan *fsl_chan;
469	struct edma_regs *regs = &fsl_edma->regs;
470	int i;
471
472	for (i = 0; i < fsl_edma->n_chans; i++) {
473		fsl_chan = &fsl_edma->chans[i];
474		fsl_chan->pm_state = RUNNING;
475		edma_writew(fsl_edma, 0x0, &regs->tcd[i].csr);
476		if (fsl_chan->slave_id != 0)
477			fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id, true);
478	}
479
480	edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);
481
482	return 0;
483}
484
485/*
486 * eDMA provides the service to others, so it should be suspend late
487 * and resume early. When eDMA suspend, all of the clients should stop
488 * the DMA data transmission and let the channel idle.
489 */
490static const struct dev_pm_ops fsl_edma_pm_ops = {
491	.suspend_late   = fsl_edma_suspend_late,
492	.resume_early   = fsl_edma_resume_early,
493};
494
495static struct platform_driver fsl_edma_driver = {
496	.driver		= {
497		.name	= "fsl-edma",
498		.of_match_table = fsl_edma_dt_ids,
499		.pm     = &fsl_edma_pm_ops,
500	},
501	.probe          = fsl_edma_probe,
502	.remove		= fsl_edma_remove,
503};
504
505static int __init fsl_edma_init(void)
506{
507	return platform_driver_register(&fsl_edma_driver);
508}
509subsys_initcall(fsl_edma_init);
510
511static void __exit fsl_edma_exit(void)
512{
513	platform_driver_unregister(&fsl_edma_driver);
514}
515module_exit(fsl_edma_exit);
516
517MODULE_ALIAS("platform:fsl-edma");
518MODULE_DESCRIPTION("Freescale eDMA engine driver");
519MODULE_LICENSE("GPL v2");