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coresight: dynamic-replicator: Claim device for use
authorSuzuki K Poulose <suzuki.poulose@arm.com>
Thu, 20 Sep 2018 19:18:15 +0000 (13:18 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 25 Sep 2018 18:09:19 +0000 (20:09 +0200)
Use CLAIM protocol to make sure the device is available for use.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/coresight/coresight-dynamic-replicator.c

index 97f4673..299667b 100644 (file)
@@ -41,8 +41,11 @@ static void replicator_reset(struct replicator_state *drvdata)
 {
        CS_UNLOCK(drvdata->base);
 
-       writel_relaxed(0xff, drvdata->base + REPLICATOR_IDFILTER0);
-       writel_relaxed(0xff, drvdata->base + REPLICATOR_IDFILTER1);
+       if (!coresight_claim_device_unlocked(drvdata->base)) {
+               writel_relaxed(0xff, drvdata->base + REPLICATOR_IDFILTER0);
+               writel_relaxed(0xff, drvdata->base + REPLICATOR_IDFILTER1);
+               coresight_disclaim_device_unlocked(drvdata->base);
+       }
 
        CS_LOCK(drvdata->base);
 }
@@ -50,6 +53,7 @@ static void replicator_reset(struct replicator_state *drvdata)
 static int replicator_enable(struct coresight_device *csdev, int inport,
                              int outport)
 {
+       int rc = 0;
        u32 reg;
        struct replicator_state *drvdata = dev_get_drvdata(csdev->dev.parent);
 
@@ -67,13 +71,19 @@ static int replicator_enable(struct coresight_device *csdev, int inport,
 
        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. */
-       writel_relaxed(0x00, drvdata->base + reg);
+       if (!rc) {
+               writel_relaxed(0x00, drvdata->base + reg);
+               dev_dbg(drvdata->dev, "REPLICATOR enabled\n");
+       }
+
        CS_LOCK(drvdata->base);
 
-       dev_dbg(drvdata->dev, "REPLICATOR enabled\n");
-       return 0;
+       return rc;
 }
 
 static void replicator_disable(struct coresight_device *csdev, int inport,
@@ -99,6 +109,9 @@ static void replicator_disable(struct coresight_device *csdev, int inport,
        /* disable the flow of ATB data through port */
        writel_relaxed(0xff, drvdata->base + reg);
 
+       if ((readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0) == 0xff) &&
+           (readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1) == 0xff))
+               coresight_disclaim_device_unlocked(drvdata->base);
        CS_LOCK(drvdata->base);
 
        dev_dbg(drvdata->dev, "REPLICATOR disabled\n");