[PATCH v3 1/2] dmaengine: tegra210-adma: use devm_clk_*() helpers

[PATCH v3 1/2] dmaengine: tegra210-adma: use devm_clk_*() helpers

[Sameer Pujar]

adma driver is using pm_clk_*() interface for managing clock resources.
With this it is observed that clocks remain ON always. This happens on
Tegra devices which use BPMP co-processor to manage clock resources,
where clocks are enabled during prepare phase. This is necessary because
clocks to BPMP are always blocking. When pm_clk_*() interface is used on
such Tegra devices, clock prepare count is not balanced till remove call
happens for the driver and hence clocks are seen ON always. Thus this
patch replaces pm_clk_*() with devm_clk_*() framework.

Suggested-by: Mohan Kumar D <mkumard@nvidia.com>
Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
---
 drivers/dma/tegra210-adma.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
index 5ec0dd9..650cd9c 100644
--- a/drivers/dma/tegra210-adma.c
+++ b/drivers/dma/tegra210-adma.c
@@ -22,7 +22,6 @@
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/of_irq.h>
-#include <linux/pm_clock.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 
@@ -141,6 +140,7 @@ struct tegra_adma {
 	struct dma_device		dma_dev;
 	struct device			*dev;
 	void __iomem			*base_addr;
+	struct clk			*ahub_clk;
 	unsigned int			nr_channels;
 	unsigned long			rx_requests_reserved;
 	unsigned long			tx_requests_reserved;
@@ -637,8 +637,9 @@ static int tegra_adma_runtime_suspend(struct device *dev)
 	struct tegra_adma *tdma = dev_get_drvdata(dev);
 
 	tdma->global_cmd = tdma_read(tdma, ADMA_GLOBAL_CMD);
+	clk_disable_unprepare(tdma->ahub_clk);
 
-	return pm_clk_suspend(dev);
+	return 0;
 }
 
 static int tegra_adma_runtime_resume(struct device *dev)
@@ -646,10 +647,11 @@ static int tegra_adma_runtime_resume(struct device *dev)
 	struct tegra_adma *tdma = dev_get_drvdata(dev);
 	int ret;
 
-	ret = pm_clk_resume(dev);
-	if (ret)
+	ret = clk_prepare_enable(tdma->ahub_clk);
+	if (ret) {
+		dev_err(dev, "ahub clk_enable failed: %d\n", ret);
 		return ret;
-
+	}
 	tdma_write(tdma, ADMA_GLOBAL_CMD, tdma->global_cmd);
 
 	return 0;
@@ -693,13 +695,11 @@ static int tegra_adma_probe(struct platform_device *pdev)
 	if (IS_ERR(tdma->base_addr))
 		return PTR_ERR(tdma->base_addr);
 
-	ret = pm_clk_create(&pdev->dev);
-	if (ret)
-		return ret;
-
-	ret = of_pm_clk_add_clk(&pdev->dev, "d_audio");
-	if (ret)
-		goto clk_destroy;
+	tdma->ahub_clk = devm_clk_get(&pdev->dev, "d_audio");
+	if (IS_ERR(tdma->ahub_clk)) {
+		dev_err(&pdev->dev, "Error: Missing ahub controller clock\n");
+		return PTR_ERR(tdma->ahub_clk);
+	}
 
 	pm_runtime_enable(&pdev->dev);
 
@@ -776,8 +776,6 @@ static int tegra_adma_probe(struct platform_device *pdev)
 	pm_runtime_put_sync(&pdev->dev);
 rpm_disable:
 	pm_runtime_disable(&pdev->dev);
-clk_destroy:
-	pm_clk_destroy(&pdev->dev);
 
 	return ret;
 }
@@ -794,7 +792,6 @@ static int tegra_adma_remove(struct platform_device *pdev)
 
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
-	pm_clk_destroy(&pdev->dev);
 
 	return 0;
 }
-- 
2.7.4

[PATCH v3 2/2] dmaengine: tegra210-adma: update system sleep callbacks

[Sameer Pujar]

If the driver is active till late suspend, where runtime PM cannot run,
force suspend is essential in such case to put the device in low power
state. Thus pm_runtime_force_suspend and pm_runtime_force_resume are
used as system sleep callbacks during system wide PM transitions.
Late system sleep callbacks are used to ensure, for instance, that the
sound core has suspended any on-going activity, including stopping the
ADMA if active, before we attempt to suspend the ADMA.

Suggested-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
---
 drivers/dma/tegra210-adma.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
index 650cd9c..253d312 100644
--- a/drivers/dma/tegra210-adma.c
+++ b/drivers/dma/tegra210-adma.c
@@ -796,17 +796,11 @@ static int tegra_adma_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int tegra_adma_pm_suspend(struct device *dev)
-{
-	return pm_runtime_suspended(dev) == false;
-}
-#endif
-
 static const struct dev_pm_ops tegra_adma_dev_pm_ops = {
 	SET_RUNTIME_PM_OPS(tegra_adma_runtime_suspend,
 			   tegra_adma_runtime_resume, NULL)
-	SET_SYSTEM_SLEEP_PM_OPS(tegra_adma_pm_suspend, NULL)
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				     pm_runtime_force_resume)
 };
 
 static struct platform_driver tegra_admac_driver = {
-- 
2.7.4

Re: [PATCH v3 2/2] dmaengine: tegra210-adma: update system sleep callbacks

[Jon Hunter]

On 13/03/2019 11:32, Sameer Pujar wrote:
> If the driver is active till late suspend, where runtime PM cannot run,
> force suspend is essential in such case to put the device in low power
> state. Thus pm_runtime_force_suspend and pm_runtime_force_resume are
> used as system sleep callbacks during system wide PM transitions.
> Late system sleep callbacks are used to ensure, for instance, that the
> sound core has suspended any on-going activity, including stopping the
> ADMA if active, before we attempt to suspend the ADMA.
> 
> Suggested-by: Jonathan Hunter <jonathanh@nvidia.com>
> Signed-off-by: Sameer Pujar <spujar@nvidia.com>
> ---
>  drivers/dma/tegra210-adma.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
> index 650cd9c..253d312 100644
> --- a/drivers/dma/tegra210-adma.c
> +++ b/drivers/dma/tegra210-adma.c
> @@ -796,17 +796,11 @@ static int tegra_adma_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -#ifdef CONFIG_PM_SLEEP
> -static int tegra_adma_pm_suspend(struct device *dev)
> -{
> -	return pm_runtime_suspended(dev) == false;
> -}
> -#endif
> -
>  static const struct dev_pm_ops tegra_adma_dev_pm_ops = {
>  	SET_RUNTIME_PM_OPS(tegra_adma_runtime_suspend,
>  			   tegra_adma_runtime_resume, NULL)
> -	SET_SYSTEM_SLEEP_PM_OPS(tegra_adma_pm_suspend, NULL)
> +	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				     pm_runtime_force_resume)
>  };
>  
>  static struct platform_driver tegra_admac_driver = {

Acked-by: Jon Hunter <jonathanh@nvidia.com>

Cheers
Jon

-- 
nvpublic

Re: [PATCH v3 1/2] dmaengine: tegra210-adma: use devm_clk_*() helpers

[Vinod Koul]

On 13-03-19, 17:02, Sameer Pujar wrote:
> adma driver is using pm_clk_*() interface for managing clock resources.
> With this it is observed that clocks remain ON always. This happens on
> Tegra devices which use BPMP co-processor to manage clock resources,
> where clocks are enabled during prepare phase. This is necessary because
> clocks to BPMP are always blocking. When pm_clk_*() interface is used on
> such Tegra devices, clock prepare count is not balanced till remove call
> happens for the driver and hence clocks are seen ON always. Thus this
> patch replaces pm_clk_*() with devm_clk_*() framework.

Both applied, thanks

-- 
~Vinod