[PATCH 2/2] dmaengine: fsl-edma: add PM suspend/resume support

Hi Stefan,

Thanks for your review, now I will take over the eDMA.
I have some different in understanding with PM suspend/resume support. And I will send a patch for RFC later.
Also please check my comment in line for this patch.
I hope you can help to review it for me.

Thanks.

Best Regards,
Yuan Yao

On 2015-1-30 21:01,  Stefan Agner wrote:

On Tue, Dec 30, 2014 at 04:41:47PM +0800, Jingchang Lu wrote:

quoted

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

Signed-off-by: Jingchang Lu <redacted>
---
 drivers/dma/fsl-edma.c | 38

++++++++++++++++++++++++++++++++++++++

quoted

 1 file changed, 38 insertions(+)

diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c index

e0bd517..6a81699 100644

--- a/drivers/dma/fsl-edma.c
+++ b/drivers/dma/fsl-edma.c

@@ -1017,6 +1017,43 @@ static int fsl_edma_remove(struct

platform_device *pdev)

quoted

 	return 0;
 }

+#ifdef CONFIG_PM_SLEEP
+static int fsl_edma_pm_suspend(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_edma_chan_mux(fsl_chan, 0, false);
+	}
+
+	return 0;
+}
+
+static int fsl_edma_pm_resume(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];
+		edma_writew(fsl_edma, 0x0, fsl_edma->membase +

EDMA_TCD_CSR(i));

quoted

+		/* restore the channel slave id configuration */
+		fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id, true);

Wouldnt this be reconfigured? Should you do this for all channels or active ones.
Also I dont see you pausing or suspending active channels or checking for them?

No, here is no need more reconfigured. I will send a new patch for what your consideration.
Thanks.

--
~Vinod

quoted

+	}
+
+	edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA,
+		    fsl_edma->membase + EDMA_CR);
+
+	return 0;
+}
+#endif
+static
+SIMPLE_DEV_PM_OPS(fsl_edma_pm_ops, fsl_edma_pm_suspend,
+fsl_edma_pm_resume);
+
 static const struct of_device_id fsl_edma_dt_ids[] = {
 	{ .compatible = "fsl,vf610-edma", },
 	{ /* sentinel */ }

@@ -1027,6 +1064,7 @@ 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,
--

1.8.0

--

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