From: Huang Shijie <b32955@freescale.com>
Date: Wed, 7 May 2014 06:04:09 +0000 (+0800)
Subject: MLK-9810 dma: mxs-dma: add power management support
X-Git-Tag: C0P2-H0.0--20200415~4550
X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=f7722b9f49fe670e6a270dad674dd22897abd601;p=linux.git

MLK-9810 dma: mxs-dma: add power management support

this patch adds power management support for mxs-dma driver.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Allen Xu <b45815@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
(cherry picked from commit 7a59828eeda36457e6e60383705a0bc5831ffbf7)
---

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index e217268c7098..fb2c7bf007d0 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2011-2015 Freescale Semiconductor, Inc. All Rights Reserved.
  *
  * Refer to drivers/dma/imx-sdma.c
  *
@@ -28,7 +28,7 @@
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/list.h>
-
+#include <linux/pm_runtime.h>
 #include <asm/irq.h>
 
 #include "dmaengine.h"
@@ -690,7 +690,7 @@ static enum dma_status mxs_dma_tx_status(struct dma_chan *chan,
 	return mxs_chan->status;
 }
 
-static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
+static int mxs_dma_init(struct mxs_dma_engine *mxs_dma)
 {
 	int ret;
 
@@ -832,6 +832,7 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
 
 	mxs_dma->pdev = pdev;
 	mxs_dma->dma_device.dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, mxs_dma);
 
 	/* mxs_dma gets 65535 bytes maximum sg size */
 	mxs_dma->dma_device.dev->dma_parms = &mxs_dma->dma_parms;
@@ -869,9 +870,56 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int mxs_dma_runtime_suspend(struct device *dev)
+{
+	struct mxs_dma_engine *mxs_dma = dev_get_drvdata(dev);
+
+	clk_disable(mxs_dma->clk);
+	return 0;
+}
+
+static int mxs_dma_runtime_resume(struct device *dev)
+{
+	struct mxs_dma_engine *mxs_dma = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(mxs_dma->clk);
+	if (ret < 0) {
+		dev_err(dev, "clk_enable failed: %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int mxs_dma_pm_suspend(struct device *dev)
+{
+	/*
+	 * We do not save any registers here, since the gpmi will release its
+	 * DMA channel.
+	 */
+	return 0;
+}
+
+static int mxs_dma_pm_resume(struct device *dev)
+{
+	struct mxs_dma_engine *mxs_dma = dev_get_drvdata(dev);
+	int ret;
+
+	ret = mxs_dma_init(mxs_dma);
+	if (ret)
+		return ret;
+	return 0;
+}
+
+static const struct dev_pm_ops mxs_dma_pm_ops = {
+	SET_RUNTIME_PM_OPS(mxs_dma_runtime_suspend, mxs_dma_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(mxs_dma_pm_suspend, mxs_dma_pm_resume)
+};
+
 static struct platform_driver mxs_dma_driver = {
 	.driver		= {
 		.name	= "mxs-dma",
+		.pm = &mxs_dma_pm_ops,
 		.of_match_table = mxs_dma_dt_ids,
 	},
 	.id_table	= mxs_dma_ids,