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

drivers/dma/fsl-edma.c

+82 −3
Original line number Diff line number Diff line
@@ -116,6 +116,10 @@ 
				BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \

				BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \

				BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)

enum fsl_edma_pm_state {

	RUNNING = 0,

	SUSPENDED,

};



struct fsl_edma_hw_tcd {

	__le32	saddr;
@@ -147,6 +151,9 @@ struct fsl_edma_slave_config { 
struct fsl_edma_chan {

	struct virt_dma_chan		vchan;

	enum dma_status			status;

	enum fsl_edma_pm_state		pm_state;

	bool				idle;

	u32				slave_id;

	struct fsl_edma_engine		*edma;

	struct fsl_edma_desc		*edesc;

	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);

	fsl_edma_disable_request(fsl_chan);

	fsl_chan->edesc = NULL;

	fsl_chan->idle = true;

	vchan_get_all_descriptors(&fsl_chan->vchan, &head);

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

	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) {

		fsl_edma_disable_request(fsl_chan);

		fsl_chan->status = DMA_PAUSED;

		fsl_chan->idle = true;

	}

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

	return 0;
@@ -327,6 +336,7 @@ static int fsl_edma_resume(struct dma_chan *chan) 
	if (fsl_chan->edesc) {

		fsl_edma_enable_request(fsl_chan);

		fsl_chan->status = DMA_IN_PROGRESS;

		fsl_chan->idle = false;

	}

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

	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_enable_request(fsl_chan);

	fsl_chan->status = DMA_IN_PROGRESS;

	fsl_chan->idle = false;

}



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);

				fsl_chan->edesc = NULL;

				fsl_chan->status = DMA_COMPLETE;

				fsl_chan->idle = true;

			} else {

				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),

				fsl_edma->membase + EDMA_CERR);

			fsl_edma->chans[ch].status = DMA_ERROR;

			fsl_edma->chans[ch].idle = true;

		}

	}

	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);



	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)

		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 dma_chan *chan, *_chan;

	struct fsl_edma_chan *fsl_chan;

	unsigned long chans_per_mux = fsl_edma->n_chans / DMAMUX_NR;



	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);

			if (chan) {

				chan->device->privatecnt++;

				fsl_edma_chan_mux(to_fsl_edma_chan(chan),

					dma_spec->args[1], true);

				fsl_chan = to_fsl_edma_chan(chan);

				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);

				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];



		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;

		vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
@@ -959,6 +983,60 @@ static int fsl_edma_remove(struct platform_device *pdev) 
	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[] = {

	{ .compatible = "fsl,vf610-edma", },

	{ /* sentinel */ }
@@ -969,6 +1047,7 @@ static struct platform_driver fsl_edma_driver = { 
	.driver		= {

		.name	= "fsl-edma",

		.of_match_table = fsl_edma_dt_ids,

		.pm     = &fsl_edma_pm_ops,

	},

	.probe          = fsl_edma_probe,

	.remove		= fsl_edma_remove,

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