Commit 8f3ce74c authored by Sai Prakash Ranjan's avatar Sai Prakash Ranjan Committed by Greg Kroah-Hartman
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coresight: replicator: Reset replicator if context is lost 



On some QCOM SoCs, replicators in Always-On domain loses its
context as soon as the clock is disabled. Currently as a part
of pm_runtime workqueue, clock is disabled after the replicator
is initialized by amba_pm_runtime_suspend assuming that context
is not lost which is not true for replicators with such
limitations. So add a new property "qcom,replicator-loses-context"
to identify such replicators and reset them.

Suggested-by: default avatarMike Leach <mike.leach@linaro.org>
Reviewed-by: default avatarMike Leach <mike.leach@linaro.org>
Signed-off-by: default avatarSai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200716175746.3338735-6-mathieu.poirier@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7f1a1c2c

drivers/hwtracing/coresight/coresight-replicator.c

+38 −17
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/err.h>

#include <linux/slab.h>

#include <linux/pm_runtime.h>

#include <linux/property.h>

#include <linux/clk.h>

#include <linux/of.h>

#include <linux/coresight.h>
@@ -32,12 +33,14 @@ DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator"); 
 * @atclk:	optional clock for the core parts of the replicator.

 * @csdev:	component vitals needed by the framework

 * @spinlock:	serialize enable/disable operations.

 * @check_idfilter_val: check if the context is lost upon clock removal.

 */

struct replicator_drvdata {

	void __iomem		*base;

	struct clk		*atclk;

	struct coresight_device	*csdev;

	spinlock_t		spinlock;

	bool			check_idfilter_val;

};



static void dynamic_replicator_reset(struct replicator_drvdata *drvdata)
@@ -66,29 +69,43 @@ static int dynamic_replicator_enable(struct replicator_drvdata *drvdata, 
				     int inport, int outport)

{

	int rc = 0;

	u32 reg;

	u32 id0val, id1val;



	CS_UNLOCK(drvdata->base);



	id0val = readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0);

	id1val = readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1);



	/*

	 * Some replicator designs lose context when AMBA clocks are removed,

	 * so have a check for this.

	 */

	if (drvdata->check_idfilter_val && id0val == 0x0 && id1val == 0x0)

		id0val = id1val = 0xff;



	if (id0val == 0xff && id1val == 0xff)

		rc = coresight_claim_device_unlocked(drvdata->base);



	if (!rc) {

		switch (outport) {

		case 0:

		reg = REPLICATOR_IDFILTER0;

			id0val = 0x0;

			break;

		case 1:

		reg = REPLICATOR_IDFILTER1;

			id1val = 0x0;

			break;

		default:

			WARN_ON(1);

		return -EINVAL;

			rc = -EINVAL;

		}

	}



	CS_UNLOCK(drvdata->base);



	if ((readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0) == 0xff) &&

	    (readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1) == 0xff))

		rc = coresight_claim_device_unlocked(drvdata->base);



	/* Ensure that the outport is enabled. */

	if (!rc)

		writel_relaxed(0x00, drvdata->base + reg);

	if (!rc) {

		writel_relaxed(id0val, drvdata->base + REPLICATOR_IDFILTER0);

		writel_relaxed(id1val, drvdata->base + REPLICATOR_IDFILTER1);

	}



	CS_LOCK(drvdata->base);



	return rc;
@@ -239,6 +256,10 @@ static int replicator_probe(struct device *dev, struct resource *res) 
		desc.groups = replicator_groups;

	}



	if (fwnode_property_present(dev_fwnode(dev),

				    "qcom,replicator-loses-context"))

		drvdata->check_idfilter_val = true;



	dev_set_drvdata(dev, drvdata);



	pdata = coresight_get_platform_data(dev);

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