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Commit 82d149b8 authored by Yuan Yao's avatar Yuan Yao Committed by Vinod Koul
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dmaengine: fsl-edma: add PM suspend/resume support



This add power management suspend/resume support for the fsl-edma
driver.

eDMA acted as a basic function used by others. What it needs to do
is the two steps below to support power management.

In fsl_edma_suspend_late:
Check whether the DMA chan is idle, if it is not idle disable DMA
request.

In fsl_edma_resume_early:
Enable the eDMA and wait for being used.

Signed-off-by: default avatarYuan Yao <yao.yuan@freescale.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent f0579c8c
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+82 −3
Original line number Original line Diff line number Diff line
@@ -116,6 +116,10 @@
				BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
				BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
				BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
				BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
				BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)
				BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)
enum fsl_edma_pm_state {
	RUNNING = 0,
	SUSPENDED,
};


struct fsl_edma_hw_tcd {
struct fsl_edma_hw_tcd {
	__le32	saddr;
	__le32	saddr;
@@ -147,6 +151,9 @@ struct fsl_edma_slave_config {
struct fsl_edma_chan {
struct fsl_edma_chan {
	struct virt_dma_chan		vchan;
	struct virt_dma_chan		vchan;
	enum dma_status			status;
	enum dma_status			status;
	enum fsl_edma_pm_state		pm_state;
	bool				idle;
	u32				slave_id;
	struct fsl_edma_engine		*edma;
	struct fsl_edma_engine		*edma;
	struct fsl_edma_desc		*edesc;
	struct fsl_edma_desc		*edesc;
	struct fsl_edma_slave_config	fsc;
	struct fsl_edma_slave_config	fsc;
@@ -298,6 +305,7 @@ static int fsl_edma_terminate_all(struct dma_chan *chan)
	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	fsl_edma_disable_request(fsl_chan);
	fsl_edma_disable_request(fsl_chan);
	fsl_chan->edesc = NULL;
	fsl_chan->edesc = NULL;
	fsl_chan->idle = true;
	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
@@ -313,6 +321,7 @@ static int fsl_edma_pause(struct dma_chan *chan)
	if (fsl_chan->edesc) {
	if (fsl_chan->edesc) {
		fsl_edma_disable_request(fsl_chan);
		fsl_edma_disable_request(fsl_chan);
		fsl_chan->status = DMA_PAUSED;
		fsl_chan->status = DMA_PAUSED;
		fsl_chan->idle = true;
	}
	}
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	return 0;
	return 0;
@@ -327,6 +336,7 @@ static int fsl_edma_resume(struct dma_chan *chan)
	if (fsl_chan->edesc) {
	if (fsl_chan->edesc) {
		fsl_edma_enable_request(fsl_chan);
		fsl_edma_enable_request(fsl_chan);
		fsl_chan->status = DMA_IN_PROGRESS;
		fsl_chan->status = DMA_IN_PROGRESS;
		fsl_chan->idle = false;
	}
	}
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	return 0;
	return 0;
@@ -648,6 +658,7 @@ static void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)
	fsl_edma_set_tcd_regs(fsl_chan, fsl_chan->edesc->tcd[0].vtcd);
	fsl_edma_set_tcd_regs(fsl_chan, fsl_chan->edesc->tcd[0].vtcd);
	fsl_edma_enable_request(fsl_chan);
	fsl_edma_enable_request(fsl_chan);
	fsl_chan->status = DMA_IN_PROGRESS;
	fsl_chan->status = DMA_IN_PROGRESS;
	fsl_chan->idle = false;
}
}


static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
@@ -676,6 +687,7 @@ static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
				vchan_cookie_complete(&fsl_chan->edesc->vdesc);
				vchan_cookie_complete(&fsl_chan->edesc->vdesc);
				fsl_chan->edesc = NULL;
				fsl_chan->edesc = NULL;
				fsl_chan->status = DMA_COMPLETE;
				fsl_chan->status = DMA_COMPLETE;
				fsl_chan->idle = true;
			} else {
			} else {
				vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
				vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
			}
			}
@@ -704,6 +716,7 @@ static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
			edma_writeb(fsl_edma, EDMA_CERR_CERR(ch),
			edma_writeb(fsl_edma, EDMA_CERR_CERR(ch),
				fsl_edma->membase + EDMA_CERR);
				fsl_edma->membase + EDMA_CERR);
			fsl_edma->chans[ch].status = DMA_ERROR;
			fsl_edma->chans[ch].status = DMA_ERROR;
			fsl_edma->chans[ch].idle = true;
		}
		}
	}
	}
	return IRQ_HANDLED;
	return IRQ_HANDLED;
@@ -724,6 +737,12 @@ static void fsl_edma_issue_pending(struct dma_chan *chan)


	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);


	if (unlikely(fsl_chan->pm_state != RUNNING)) {
		spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
		/* cannot submit due to suspend */
		return;
	}

	if (vchan_issue_pending(&fsl_chan->vchan) && !fsl_chan->edesc)
	if (vchan_issue_pending(&fsl_chan->vchan) && !fsl_chan->edesc)
		fsl_edma_xfer_desc(fsl_chan);
		fsl_edma_xfer_desc(fsl_chan);


@@ -735,6 +754,7 @@ static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
{
{
	struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
	struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
	struct dma_chan *chan, *_chan;
	struct dma_chan *chan, *_chan;
	struct fsl_edma_chan *fsl_chan;
	unsigned long chans_per_mux = fsl_edma->n_chans / DMAMUX_NR;
	unsigned long chans_per_mux = fsl_edma->n_chans / DMAMUX_NR;


	if (dma_spec->args_count != 2)
	if (dma_spec->args_count != 2)
@@ -748,8 +768,10 @@ static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
			chan = dma_get_slave_channel(chan);
			chan = dma_get_slave_channel(chan);
			if (chan) {
			if (chan) {
				chan->device->privatecnt++;
				chan->device->privatecnt++;
				fsl_edma_chan_mux(to_fsl_edma_chan(chan),
				fsl_chan = to_fsl_edma_chan(chan);
					dma_spec->args[1], true);
				fsl_chan->slave_id = dma_spec->args[1];
				fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id,
						true);
				mutex_unlock(&fsl_edma->fsl_edma_mutex);
				mutex_unlock(&fsl_edma->fsl_edma_mutex);
				return chan;
				return chan;
			}
			}
@@ -888,7 +910,9 @@ static int fsl_edma_probe(struct platform_device *pdev)
		struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];
		struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];


		fsl_chan->edma = fsl_edma;
		fsl_chan->edma = fsl_edma;

		fsl_chan->pm_state = RUNNING;
		fsl_chan->slave_id = 0;
		fsl_chan->idle = true;
		fsl_chan->vchan.desc_free = fsl_edma_free_desc;
		fsl_chan->vchan.desc_free = fsl_edma_free_desc;
		vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
		vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);


@@ -959,6 +983,60 @@ static int fsl_edma_remove(struct platform_device *pdev)
	return 0;
	return 0;
}
}


static int fsl_edma_suspend_late(struct device *dev)
{
	struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
	struct fsl_edma_chan *fsl_chan;
	unsigned long flags;
	int i;

	for (i = 0; i < fsl_edma->n_chans; i++) {
		fsl_chan = &fsl_edma->chans[i];
		spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
		/* Make sure chan is idle or will force disable. */
		if (unlikely(!fsl_chan->idle)) {
			dev_warn(dev, "WARN: There is non-idle channel.");
			fsl_edma_disable_request(fsl_chan);
			fsl_edma_chan_mux(fsl_chan, 0, false);
		}

		fsl_chan->pm_state = SUSPENDED;
		spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	}

	return 0;
}

static int fsl_edma_resume_early(struct device *dev)
{
	struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
	struct fsl_edma_chan *fsl_chan;
	int i;

	for (i = 0; i < fsl_edma->n_chans; i++) {
		fsl_chan = &fsl_edma->chans[i];
		fsl_chan->pm_state = RUNNING;
		edma_writew(fsl_edma, 0x0, fsl_edma->membase + EDMA_TCD_CSR(i));
		if (fsl_chan->slave_id != 0)
			fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id, true);
	}

	edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA,
			fsl_edma->membase + EDMA_CR);

	return 0;
}

/*
 * eDMA provides the service to others, so it should be suspend late
 * and resume early. When eDMA suspend, all of the clients should stop
 * the DMA data transmission and let the channel idle.
 */
static const struct dev_pm_ops fsl_edma_pm_ops = {
	.suspend_late   = fsl_edma_suspend_late,
	.resume_early   = fsl_edma_resume_early,
};

static const struct of_device_id fsl_edma_dt_ids[] = {
static const struct of_device_id fsl_edma_dt_ids[] = {
	{ .compatible = "fsl,vf610-edma", },
	{ .compatible = "fsl,vf610-edma", },
	{ /* sentinel */ }
	{ /* sentinel */ }
@@ -969,6 +1047,7 @@ static struct platform_driver fsl_edma_driver = {
	.driver		= {
	.driver		= {
		.name	= "fsl-edma",
		.name	= "fsl-edma",
		.of_match_table = fsl_edma_dt_ids,
		.of_match_table = fsl_edma_dt_ids,
		.pm     = &fsl_edma_pm_ops,
	},
	},
	.probe          = fsl_edma_probe,
	.probe          = fsl_edma_probe,
	.remove		= fsl_edma_remove,
	.remove		= fsl_edma_remove,