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Subject[PATCH v2 1/2] bus: tegra-aconnect: use devm_clk_*() helpers
Date
aconnect bus driver is using pm_clk_*() interface for managing clocks.
With this, clocks seem to be always ON. 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 calls to
BPMP are always blocking. When pm_clk_*() interface is used on such
Tegra devices, clock prepare count is not balanced till driver remove()
gets executed 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/bus/tegra-aconnect.c | 64 ++++++++++++++++++++++++++++++--------------
1 file changed, 44 insertions(+), 20 deletions(-)

diff --git a/drivers/bus/tegra-aconnect.c b/drivers/bus/tegra-aconnect.c
index 084ae28..9349157 100644
--- a/drivers/bus/tegra-aconnect.c
+++ b/drivers/bus/tegra-aconnect.c
@@ -12,28 +12,38 @@
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
-#include <linux/pm_clock.h>
#include <linux/pm_runtime.h>

+struct tegra_aconnect {
+ struct clk *ape_clk;
+ struct clk *apb2ape_clk;
+};
+
static int tegra_aconnect_probe(struct platform_device *pdev)
{
- int ret;
+ struct tegra_aconnect *aconnect;

if (!pdev->dev.of_node)
return -EINVAL;

- ret = pm_clk_create(&pdev->dev);
- if (ret)
- return ret;
+ aconnect = devm_kzalloc(&pdev->dev, sizeof(struct tegra_aconnect),
+ GFP_KERNEL);
+ if (!aconnect)
+ return -ENOMEM;

- ret = of_pm_clk_add_clk(&pdev->dev, "ape");
- if (ret)
- goto clk_destroy;
+ aconnect->ape_clk = devm_clk_get(&pdev->dev, "ape");
+ if (IS_ERR(aconnect->ape_clk)) {
+ dev_err(&pdev->dev, "Can't retrieve ape clock\n");
+ return PTR_ERR(aconnect->ape_clk);
+ }

- ret = of_pm_clk_add_clk(&pdev->dev, "apb2ape");
- if (ret)
- goto clk_destroy;
+ aconnect->apb2ape_clk = devm_clk_get(&pdev->dev, "apb2ape");
+ if (IS_ERR(aconnect->apb2ape_clk)) {
+ dev_err(&pdev->dev, "Can't retrieve apb2ape clock\n");
+ return PTR_ERR(aconnect->apb2ape_clk);
+ }

+ dev_set_drvdata(&pdev->dev, aconnect);
pm_runtime_enable(&pdev->dev);

of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
@@ -41,30 +51,44 @@ static int tegra_aconnect_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "Tegra ACONNECT bus registered\n");

return 0;
-
-clk_destroy:
- pm_clk_destroy(&pdev->dev);
-
- return ret;
}

static int tegra_aconnect_remove(struct platform_device *pdev)
{
pm_runtime_disable(&pdev->dev);

- pm_clk_destroy(&pdev->dev);
-
return 0;
}

static int tegra_aconnect_runtime_resume(struct device *dev)
{
- return pm_clk_resume(dev);
+ struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(aconnect->ape_clk);
+ if (ret) {
+ dev_err(dev, "ape clk_enable failed: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(aconnect->apb2ape_clk);
+ if (ret) {
+ clk_disable_unprepare(aconnect->ape_clk);
+ dev_err(dev, "apb2ape clk_enable failed: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
}

static int tegra_aconnect_runtime_suspend(struct device *dev)
{
- return pm_clk_suspend(dev);
+ struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(aconnect->ape_clk);
+ clk_disable_unprepare(aconnect->apb2ape_clk);
+
+ return 0;
}

static const struct dev_pm_ops tegra_aconnect_pm_ops = {
--
2.7.4
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