From 5c14af7b5f2c61e55044c7e28ebc50bb99548632 Mon Sep 17 00:00:00 2001
From: Jingchang Lu <jingchang.lu@freescale.com>
Date: Thu, 18 Sep 2014 10:11:36 +0800
Subject: dmaengine: fsl-edma: add PM suspend/resume support

This adds eDMA power management suspend/resume support.

Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
---
This patch depends on patch "dmaengine: fsl-edma: fixup reg offset
and hw S/G support in big-endian model", and the upstream will be
done after that patch upstreamed.
Change-Id: I596bf0934ea1ee4292f2cc64f9db8996becca14c
Reviewed-on: http://git.am.freescale.net:8181/21930
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Huan Wang <alison.wang@freescale.com>
Reviewed-by: Zhengxiong Jin <Jason.Jin@freescale.com>

diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
index 1cc536b..eadb155 100644
--- a/drivers/dma/fsl-edma.c
+++ b/drivers/dma/fsl-edma.c
@@ -147,6 +147,7 @@ struct fsl_edma_slave_config {
 struct fsl_edma_chan {
 	struct virt_dma_chan		vchan;
 	enum dma_status			status;
+	u32				slave_id;
 	struct fsl_edma_engine		*edma;
 	struct fsl_edma_desc		*edesc;
 	struct fsl_edma_slave_config	fsc;
@@ -774,6 +775,7 @@ 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)
@@ -787,8 +789,10 @@ 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;
 			}
@@ -817,6 +821,7 @@ static void fsl_edma_free_chan_resources(struct dma_chan *chan)
 	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
 	fsl_edma_disable_request(fsl_chan);
 	fsl_edma_chan_mux(fsl_chan, 0, false);
+	fsl_chan->slave_id = 0;
 	fsl_chan->edesc = NULL;
 	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
 	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
@@ -1005,6 +1010,41 @@ static int fsl_edma_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int fsl_edma_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_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));
+		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;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(fsl_edma_pm_ops, fsl_edma_suspend, fsl_edma_resume);
+
 static const struct of_device_id fsl_edma_dt_ids[] = {
 	{ .compatible = "fsl,vf610-edma", },
 	{ /* sentinel */ }
@@ -1016,6 +1056,7 @@ static struct platform_driver fsl_edma_driver = {
 		.name	= "fsl-edma",
 		.owner  = THIS_MODULE,
 		.of_match_table = fsl_edma_dt_ids,
+		.pm	= &fsl_edma_pm_ops,
 	},
 	.probe          = fsl_edma_probe,
 	.remove		= fsl_edma_remove,
-- 
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