dma: zynqmp_dma: Add runtime pm support

This patch adds runtime pm support in the driver.

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index 78737daf6bdbac5a4ed40a40b4ef91a32149fe46..da3c8331df9557b97b9dc16c84e68c294dd1e1f2 100644 (file)
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -23,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/pm_runtime.h>
 
 #include "../dmaengine.h"
 
@@ -139,6 +140,8 @@
 #define ZYNQMP_DMA_BUS_WIDTH_64                64
 #define ZYNQMP_DMA_BUS_WIDTH_128       128
 
+#define ZDMA_PM_TIMEOUT                        100
+
 #define ZYNQMP_DMA_DESC_SIZE(chan)     (chan->desc_size)
 
 #define to_chan(chan)          container_of(chan, struct zynqmp_dma_chan, \
@@ -212,8 +215,6 @@ struct zynqmp_dma_desc_sw {
  * @bus_width: Bus width
  * @src_burst_len: Source burst length
  * @dst_burst_len: Dest burst length
- * @clk_main: Pointer to main clock
- * @clk_apb: Pointer to apb clock
  */
 struct zynqmp_dma_chan {
        struct zynqmp_dma_device *zdev;
@@ -238,8 +239,6 @@ struct zynqmp_dma_chan {
        u32 bus_width;
        u32 src_burst_len;
        u32 dst_burst_len;
-       struct clk *clk_main;
-       struct clk *clk_apb;
 };
 
 /**
@@ -247,11 +246,15 @@ struct zynqmp_dma_chan {
  * @dev: Device Structure
  * @common: DMA device structure
  * @chan: Driver specific DMA channel
+ * @clk_main: Pointer to main clock
+ * @clk_apb: Pointer to apb clock
  */
 struct zynqmp_dma_device {
        struct device *dev;
        struct dma_device common;
        struct zynqmp_dma_chan *chan;
+       struct clk *clk_main;
+       struct clk *clk_apb;
 };
 
 static inline void zynqmp_dma_writeq(struct zynqmp_dma_chan *chan, u32 reg,
@@ -462,7 +465,11 @@ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan)
 {
        struct zynqmp_dma_chan *chan = to_chan(dchan);
        struct zynqmp_dma_desc_sw *desc;
-       int i;
+       int i, ret;
+
+       ret = pm_runtime_get_sync(chan->dev);
+       if (ret < 0)
+               return ret;
 
        chan->sw_desc_pool = kzalloc(sizeof(*desc) * ZYNQMP_DMA_NUM_DESCS,
                                     GFP_KERNEL);
@@ -668,6 +675,8 @@ static void zynqmp_dma_free_chan_resources(struct dma_chan *dchan)
                (2 * ZYNQMP_DMA_DESC_SIZE(chan) * ZYNQMP_DMA_NUM_DESCS),
                chan->desc_pool_v, chan->desc_pool_p);
        kfree(chan->sw_desc_pool);
+       pm_runtime_mark_last_busy(chan->dev);
+       pm_runtime_put_autosuspend(chan->dev);
 }
 
 /**
@@ -940,8 +949,6 @@ static void zynqmp_dma_chan_remove(struct zynqmp_dma_chan *chan)
        devm_free_irq(chan->zdev->dev, chan->irq, chan);
        tasklet_kill(&chan->tasklet);
        list_del(&chan->common.device_node);
-       clk_disable_unprepare(chan->clk_apb);
-       clk_disable_unprepare(chan->clk_main);
 }
 
 /**
@@ -1006,30 +1013,6 @@ static int zynqmp_dma_chan_probe(struct zynqmp_dma_device *zdev,
                               "zynqmp-dma", chan);
        if (err)
                return err;
-       chan->clk_main = devm_clk_get(&pdev->dev, "clk_main");
-       if (IS_ERR(chan->clk_main)) {
-               dev_err(&pdev->dev, "main clock not found.\n");
-               return PTR_ERR(chan->clk_main);
-       }
-
-       chan->clk_apb = devm_clk_get(&pdev->dev, "clk_apb");
-       if (IS_ERR(chan->clk_apb)) {
-               dev_err(&pdev->dev, "apb clock not found.\n");
-               return PTR_ERR(chan->clk_apb);
-       }
-
-       err = clk_prepare_enable(chan->clk_main);
-       if (err) {
-               dev_err(&pdev->dev, "Unable to enable main clock.\n");
-               return err;
-       }
-
-       err = clk_prepare_enable(chan->clk_apb);
-       if (err) {
-               clk_disable_unprepare(chan->clk_main);
-               dev_err(&pdev->dev, "Unable to enable apb clock.\n");
-               return err;
-       }
 
        chan->desc_size = sizeof(struct zynqmp_dma_desc_ll);
        chan->idle = true;
@@ -1051,6 +1034,87 @@ static struct dma_chan *of_zynqmp_dma_xlate(struct of_phandle_args *dma_spec,
        return dma_get_slave_channel(&zdev->chan->common);
 }
 
+/**
+ * zynqmp_dma_suspend - Suspend method for the driver
+ * @dev:       Address of the device structure
+ *
+ * Put the driver into low power mode.
+ * Return: 0 on success and failure value on error
+ */
+static int __maybe_unused zynqmp_dma_suspend(struct device *dev)
+{
+       if (!device_may_wakeup(dev))
+               return pm_runtime_force_suspend(dev);
+
+       return 0;
+}
+
+/**
+ * zynqmp_dma_resume - Resume from suspend
+ * @dev:       Address of the device structure
+ *
+ * Resume operation after suspend.
+ * Return: 0 on success and failure value on error
+ */
+static int __maybe_unused zynqmp_dma_resume(struct device *dev)
+{
+       if (!device_may_wakeup(dev))
+               return pm_runtime_force_resume(dev);
+
+       return 0;
+}
+
+/**
+ * zynqmp_dma_runtime_suspend - Runtime suspend method for the driver
+ * @dev:       Address of the device structure
+ *
+ * Put the driver into low power mode.
+ * Return: 0 always
+ */
+static int __maybe_unused zynqmp_dma_runtime_suspend(struct device *dev)
+{
+       struct zynqmp_dma_device *zdev = dev_get_drvdata(dev);
+
+       clk_disable_unprepare(zdev->clk_main);
+       clk_disable_unprepare(zdev->clk_apb);
+
+       return 0;
+}
+
+/**
+ * zynqmp_dma_runtime_resume - Runtime suspend method for the driver
+ * @dev:       Address of the device structure
+ *
+ * Put the driver into low power mode.
+ * Return: 0 always
+ */
+static int __maybe_unused zynqmp_dma_runtime_resume(struct device *dev)
+{
+       struct zynqmp_dma_device *zdev = dev_get_drvdata(dev);
+       int err;
+
+       err = clk_prepare_enable(zdev->clk_main);
+       if (err) {
+               dev_err(dev, "Unable to enable main clock.\n");
+               return err;
+       }
+
+       err = clk_prepare_enable(zdev->clk_apb);
+       if (err) {
+               dev_err(dev, "Unable to enable apb clock.\n");
+               clk_disable_unprepare(zdev->clk_main);
+               return err;
+       }
+
+       return 0;
+}
+
+static const struct dev_pm_ops zynqmp_dma_dev_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(zynqmp_dma_suspend, zynqmp_dma_resume)
+       SET_RUNTIME_PM_OPS(zynqmp_dma_runtime_suspend,
+                          zynqmp_dma_runtime_resume, NULL)
+};
+
 /**
  * zynqmp_dma_probe - Driver probe function
  * @pdev: Pointer to the platform_device structure
@@ -1085,12 +1149,28 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
        p->device_config = zynqmp_dma_device_config;
        p->dev = &pdev->dev;
 
+       zdev->clk_main = devm_clk_get(&pdev->dev, "clk_main");
+       if (IS_ERR(zdev->clk_main)) {
+               dev_err(&pdev->dev, "main clock not found.\n");
+               return PTR_ERR(zdev->clk_main);
+       }
+
+       zdev->clk_apb = devm_clk_get(&pdev->dev, "clk_apb");
+       if (IS_ERR(zdev->clk_apb)) {
+               dev_err(&pdev->dev, "apb clock not found.\n");
+               return PTR_ERR(zdev->clk_apb);
+       }
+
        platform_set_drvdata(pdev, zdev);
+       pm_runtime_set_autosuspend_delay(zdev->dev, ZDMA_PM_TIMEOUT);
+       pm_runtime_use_autosuspend(zdev->dev);
+       pm_runtime_enable(zdev->dev);
+       pm_runtime_get_sync(zdev->dev);
 
        ret = zynqmp_dma_chan_probe(zdev, pdev);
        if (ret) {
                dev_err(&pdev->dev, "Probing channel failed\n");
-               goto free_chan_resources;
+               goto err_disable_pm;
        }
 
        p->dst_addr_widths = BIT(zdev->chan->bus_width / 8);
@@ -1106,10 +1186,16 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
                goto free_chan_resources;
        }
 
+       pm_runtime_mark_last_busy(zdev->dev);
+       pm_runtime_put_sync_autosuspend(zdev->dev);
+
        dev_info(&pdev->dev, "ZynqMP DMA driver Probe success\n");
 
        return 0;
 
+err_disable_pm:
+       pm_runtime_put_sync_suspend(zdev->dev);
+       pm_runtime_disable(zdev->dev);
 free_chan_resources:
        zynqmp_dma_chan_remove(zdev->chan);
        return ret;
@@ -1129,6 +1215,7 @@ static int zynqmp_dma_remove(struct platform_device *pdev)
        dma_async_device_unregister(&zdev->common);
 
        zynqmp_dma_chan_remove(zdev->chan);
+       pm_runtime_disable(zdev->dev);
 
        return 0;
 }
@@ -1143,6 +1230,7 @@ static struct platform_driver zynqmp_dma_driver = {
        .driver = {
                .name = "xilinx-zynqmp-dma",
                .of_match_table = zynqmp_dma_of_match,
+               .pm = &zynqmp_dma_dev_pm_ops,
        },
        .probe = zynqmp_dma_probe,
        .remove = zynqmp_dma_remove,