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 e217268..fb2c7bf 100644 (file)
--- 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,