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authorLinus Walleij <linus.walleij@linaro.org>2015-05-19 18:55:18 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-24 20:12:08 +0200
commit9875cd9ce2b5363528b5518ddd3e3b670da74161 (patch)
tree9ad906d3830685e44ce888af25760aaa9153eba2
parentcoresight: funnel: retrieve and handle atclk (diff)
downloadlinux-9875cd9ce2b5363528b5518ddd3e3b670da74161.tar.xz
linux-9875cd9ce2b5363528b5518ddd3e3b670da74161.zip
coresight: replicator: retrieve and handle atclk
As can be seen from the datasheet of the CoreSight Components, DDI0314 table A-4 the funnel has a clock signal apart from the AHB interconnect ("amba_pclk", that we're already handling) called ATCLK, ARM Trace Clock, that SoC implementers may provide from an entirely different clock source. So to model this correctly create an optional path for handling ATCLK alongside the PCLK so we don't break old platforms that only define PCLK ("amba_pclk") but still makes it possible for SoCs that have both clock signals (such as the DB8500) to fetch and prepare/enable/disable/ unprepare both clocks. The ATCLK is enabled and disabled using the runtime PM callbacks. As the replicator is a platform device, the code is a bit different from the other CoreSight components and the bus core does not activate runtime PM by default, so we need a few extra calls. Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/hwtracing/coresight/coresight-replicator.c71
1 files changed, 67 insertions, 4 deletions
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index 75b9abd804e6..7974b7c3da6b 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -18,6 +18,7 @@
#include <linux/io.h>
#include <linux/err.h>
#include <linux/slab.h>
+#include <linux/pm_runtime.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/coresight.h>
@@ -27,10 +28,12 @@
/**
* struct replicator_drvdata - specifics associated to a replicator component
* @dev: the device entity associated with this component
+ * @atclk: optional clock for the core parts of the replicator.
* @csdev: component vitals needed by the framework
*/
struct replicator_drvdata {
struct device *dev;
+ struct clk *atclk;
struct coresight_device *csdev;
};
@@ -39,6 +42,7 @@ static int replicator_enable(struct coresight_device *csdev, int inport,
{
struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ pm_runtime_get_sync(drvdata->dev);
dev_info(drvdata->dev, "REPLICATOR enabled\n");
return 0;
}
@@ -48,6 +52,7 @@ static void replicator_disable(struct coresight_device *csdev, int inport,
{
struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ pm_runtime_put(drvdata->dev);
dev_info(drvdata->dev, "REPLICATOR disabled\n");
}
@@ -62,6 +67,7 @@ static const struct coresight_ops replicator_cs_ops = {
static int replicator_probe(struct platform_device *pdev)
{
+ int ret;
struct device *dev = &pdev->dev;
struct coresight_platform_data *pdata = NULL;
struct replicator_drvdata *drvdata;
@@ -80,11 +86,22 @@ static int replicator_probe(struct platform_device *pdev)
return -ENOMEM;
drvdata->dev = &pdev->dev;
+ drvdata->atclk = devm_clk_get(&pdev->dev, "atclk"); /* optional */
+ if (!IS_ERR(drvdata->atclk)) {
+ ret = clk_prepare_enable(drvdata->atclk);
+ if (ret)
+ return ret;
+ }
+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
platform_set_drvdata(pdev, drvdata);
desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
- if (!desc)
- return -ENOMEM;
+ if (!desc) {
+ ret = -ENOMEM;
+ goto out_disable_pm;
+ }
desc->type = CORESIGHT_DEV_TYPE_LINK;
desc->subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_SPLIT;
@@ -92,11 +109,23 @@ static int replicator_probe(struct platform_device *pdev)
desc->pdata = pdev->dev.platform_data;
desc->dev = &pdev->dev;
drvdata->csdev = coresight_register(desc);
- if (IS_ERR(drvdata->csdev))
- return PTR_ERR(drvdata->csdev);
+ if (IS_ERR(drvdata->csdev)) {
+ ret = PTR_ERR(drvdata->csdev);
+ goto out_disable_pm;
+ }
+
+ pm_runtime_put(&pdev->dev);
dev_info(dev, "REPLICATOR initialized\n");
return 0;
+
+out_disable_pm:
+ if (!IS_ERR(drvdata->atclk))
+ clk_disable_unprepare(drvdata->atclk);
+ pm_runtime_put_noidle(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
+ return ret;
}
static int replicator_remove(struct platform_device *pdev)
@@ -104,9 +133,42 @@ static int replicator_remove(struct platform_device *pdev)
struct replicator_drvdata *drvdata = platform_get_drvdata(pdev);
coresight_unregister(drvdata->csdev);
+ pm_runtime_get_sync(&pdev->dev);
+ if (!IS_ERR(drvdata->atclk))
+ clk_disable_unprepare(drvdata->atclk);
+ pm_runtime_put_noidle(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int replicator_runtime_suspend(struct device *dev)
+{
+ struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
+
+ if (drvdata && !IS_ERR(drvdata->atclk))
+ clk_disable_unprepare(drvdata->atclk);
+
return 0;
}
+static int replicator_runtime_resume(struct device *dev)
+{
+ struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
+
+ if (drvdata && !IS_ERR(drvdata->atclk))
+ clk_prepare_enable(drvdata->atclk);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops replicator_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(replicator_runtime_suspend,
+ replicator_runtime_resume, NULL)
+};
+
static const struct of_device_id replicator_match[] = {
{.compatible = "arm,coresight-replicator"},
{}
@@ -118,6 +180,7 @@ static struct platform_driver replicator_driver = {
.driver = {
.name = "coresight-replicator",
.of_match_table = replicator_match,
+ .pm = &replicator_dev_pm_ops,
},
};