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coresight: replicator: Reset replicator if context is lost

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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: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200716175746.3338735-6-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sai Prakash Ranjan 2020-07-16 11:57:34 -06:00 committed by Greg Kroah-Hartman
parent 7f1a1c2c57
commit 8f3ce74c20
1 changed files with 38 additions and 17 deletions
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55
drivers/hwtracing/coresight/coresight-replicator.c
View file

@ -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;
switch (outport) {
case 0:
reg = REPLICATOR_IDFILTER0;
break;
case 1:
reg = REPLICATOR_IDFILTER1;
break;
default:
WARN_ON(1);
return -EINVAL;
}
u32 id0val, id1val;
CS_UNLOCK(drvdata->base);
if ((readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0) == 0xff) &&
(readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1) == 0xff))
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:
id0val = 0x0;
break;
case 1:
id1val = 0x0;
break;
default:
WARN_ON(1);
rc = -EINVAL;
}
}
/* 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);