dmaengine: img-mdc: Add runtime PM

Add runtime PM support to disable the clock when the h/w is not in use.
The existing clock_prepare_enable is removed from probe() as the clock
is no longer permanently enabled.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/img-mdc-dma.c b/drivers/dma/img-mdc-dma.c
index c4d8d5a..0391f93 100644 (file)
--- a/drivers/dma/img-mdc-dma.c
+++ b/drivers/dma/img-mdc-dma.c
@@ -23,6 +23,7 @@
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -730,14 +731,23 @@ static int mdc_slave_config(struct dma_chan *chan,
        return 0;
 }
 
+static int mdc_alloc_chan_resources(struct dma_chan *chan)
+{
+       struct mdc_chan *mchan = to_mdc_chan(chan);
+       struct device *dev = mdma2dev(mchan->mdma);
+
+       return pm_runtime_get_sync(dev);
+}
+
 static void mdc_free_chan_resources(struct dma_chan *chan)
 {
        struct mdc_chan *mchan = to_mdc_chan(chan);
        struct mdc_dma *mdma = mchan->mdma;
+       struct device *dev = mdma2dev(mdma);
 
        mdc_terminate_all(chan);
-
        mdma->soc->disable_chan(mchan);
+       pm_runtime_put(dev);
 }
 
 static irqreturn_t mdc_chan_irq(int irq, void *dev_id)
@@ -854,6 +864,22 @@ static const struct of_device_id mdc_dma_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
 
+static int img_mdc_runtime_suspend(struct device *dev)
+{
+       struct mdc_dma *mdma = dev_get_drvdata(dev);
+
+       clk_disable_unprepare(mdma->clk);
+
+       return 0;
+}
+
+static int img_mdc_runtime_resume(struct device *dev)
+{
+       struct mdc_dma *mdma = dev_get_drvdata(dev);
+
+       return clk_prepare_enable(mdma->clk);
+}
+
 static int mdc_dma_probe(struct platform_device *pdev)
 {
        struct mdc_dma *mdma;
@@ -883,10 +909,6 @@ static int mdc_dma_probe(struct platform_device *pdev)
        if (IS_ERR(mdma->clk))
                return PTR_ERR(mdma->clk);
 
-       ret = clk_prepare_enable(mdma->clk);
-       if (ret)
-               return ret;
-
        dma_cap_zero(mdma->dma_dev.cap_mask);
        dma_cap_set(DMA_SLAVE, mdma->dma_dev.cap_mask);
        dma_cap_set(DMA_PRIVATE, mdma->dma_dev.cap_mask);
@@ -919,12 +941,13 @@ static int mdc_dma_probe(struct platform_device *pdev)
                                   "img,max-burst-multiplier",
                                   &mdma->max_burst_mult);
        if (ret)
-               goto disable_clk;
+               return ret;
 
        mdma->dma_dev.dev = &pdev->dev;
        mdma->dma_dev.device_prep_slave_sg = mdc_prep_slave_sg;
        mdma->dma_dev.device_prep_dma_cyclic = mdc_prep_dma_cyclic;
        mdma->dma_dev.device_prep_dma_memcpy = mdc_prep_dma_memcpy;
+       mdma->dma_dev.device_alloc_chan_resources = mdc_alloc_chan_resources;
        mdma->dma_dev.device_free_chan_resources = mdc_free_chan_resources;
        mdma->dma_dev.device_tx_status = mdc_tx_status;
        mdma->dma_dev.device_issue_pending = mdc_issue_pending;
@@ -945,15 +968,14 @@ static int mdc_dma_probe(struct platform_device *pdev)
                mchan->mdma = mdma;
                mchan->chan_nr = i;
                mchan->irq = platform_get_irq(pdev, i);
-               if (mchan->irq < 0) {
-                       ret = mchan->irq;
-                       goto disable_clk;
-               }
+               if (mchan->irq < 0)
+                       return mchan->irq;
+
                ret = devm_request_irq(&pdev->dev, mchan->irq, mdc_chan_irq,
                                       IRQ_TYPE_LEVEL_HIGH,
                                       dev_name(&pdev->dev), mchan);
                if (ret < 0)
-                       goto disable_clk;
+                       return ret;
 
                mchan->vc.desc_free = mdc_desc_free;
                vchan_init(&mchan->vc, &mdma->dma_dev);
@@ -962,14 +984,19 @@ static int mdc_dma_probe(struct platform_device *pdev)
        mdma->desc_pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
                                           sizeof(struct mdc_hw_list_desc),
                                           4, 0);
-       if (!mdma->desc_pool) {
-               ret = -ENOMEM;
-               goto disable_clk;
+       if (!mdma->desc_pool)
+               return -ENOMEM;
+
+       pm_runtime_enable(&pdev->dev);
+       if (!pm_runtime_enabled(&pdev->dev)) {
+               ret = img_mdc_runtime_resume(&pdev->dev);
+               if (ret)
+                       return ret;
        }
 
        ret = dma_async_device_register(&mdma->dma_dev);
        if (ret)
-               goto disable_clk;
+               goto suspend;
 
        ret = of_dma_controller_register(pdev->dev.of_node, mdc_of_xlate, mdma);
        if (ret)
@@ -982,8 +1009,10 @@ static int mdc_dma_probe(struct platform_device *pdev)
 
 unregister:
        dma_async_device_unregister(&mdma->dma_dev);
-disable_clk:
-       clk_disable_unprepare(mdma->clk);
+suspend:
+       if (!pm_runtime_enabled(&pdev->dev))
+               img_mdc_runtime_suspend(&pdev->dev);
+       pm_runtime_disable(&pdev->dev);
        return ret;
 }
 
@@ -1004,7 +1033,9 @@ static int mdc_dma_remove(struct platform_device *pdev)
                tasklet_kill(&mchan->vc.task);
        }
 
-       clk_disable_unprepare(mdma->clk);
+       pm_runtime_disable(&pdev->dev);
+       if (!pm_runtime_status_suspended(&pdev->dev))
+               img_mdc_runtime_suspend(&pdev->dev);
 
        return 0;
 }
@@ -1023,20 +1054,18 @@ static int img_mdc_suspend_late(struct device *dev)
                        return -EBUSY;
        }
 
-       clk_disable_unprepare(mdma->clk);
-
-       return 0;
+       return pm_runtime_force_suspend(dev);
 }
 
 static int img_mdc_resume_early(struct device *dev)
 {
-       struct mdc_dma *mdma = dev_get_drvdata(dev);
-
-       return clk_prepare_enable(mdma->clk);
+       return pm_runtime_force_resume(dev);
 }
 #endif /* CONFIG_PM_SLEEP */
 
 static const struct dev_pm_ops img_mdc_pm_ops = {
+       SET_RUNTIME_PM_OPS(img_mdc_runtime_suspend,
+                          img_mdc_runtime_resume, NULL)
        SET_LATE_SYSTEM_SLEEP_PM_OPS(img_mdc_suspend_late,
                                     img_mdc_resume_early)
 };