[PATCH 10/13] coresight: funnel: Claim devices before use

Suzuki K Poulose
2018-08-06T13:43:33Z

Use the CLAIM protocol to grab the ownership of the component.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/coresight-funnel.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index ee7a30b..9279251 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -25,6 +25,7 @@
#define FUNNEL_HOLDTIME_MASK 0xf00
#define FUNNEL_HOLDTIME_SHFT 0x8
#define FUNNEL_HOLDTIME (0x7 << FUNNEL_HOLDTIME_SHFT)
+#define FUNNEL_ENSx_MASK 0xff

/**
* struct funnel_drvdata - specifics associated to a funnel component
@@ -42,31 +43,42 @@ struct funnel_drvdata {
unsigned long priority;
};

-static void funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
+static int funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
{
u32 functl;
+ int rc = 0;

CS_UNLOCK(drvdata->base);

functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
+ /* Claim the device only when we enable the first slave */
+ if (!(functl & FUNNEL_ENSx_MASK)) {
+ rc = coresight_claim_device_unlocked(drvdata->base);
+ if (rc)
+ goto done;
+ }
+
functl &= ~FUNNEL_HOLDTIME_MASK;
functl |= FUNNEL_HOLDTIME;
functl |= (1 << port);
writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
writel_relaxed(drvdata->priority, drvdata->base + FUNNEL_PRICTL);
-
+done:
CS_LOCK(drvdata->base);
+ return rc;
}

static int funnel_enable(struct coresight_device *csdev, int inport,
int outport)
{
+ int rc;
struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

- funnel_enable_hw(drvdata, inport);
+ rc = funnel_enable_hw(drvdata, inport);

- dev_dbg(drvdata->dev, "FUNNEL inport %d enabled\n", inport);
- return 0;
+ if (!rc)
+ dev_dbg(drvdata->dev, "FUNNEL inport %d enabled\n", inport);
+ return rc;
}

static void funnel_disable_hw(struct funnel_drvdata *drvdata, int inport)
@@ -79,6 +91,10 @@ static void funnel_disable_hw(struct funnel_drvdata *drvdata, int inport)
functl &= ~(1 << inport);
writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);

+ /* Disclaim the device if none of the slaves are now active */
+ if (!(functl & FUNNEL_ENSx_MASK))
+ coresight_disclaim_device_unlocked(drvdata->base);
+
CS_LOCK(drvdata->base);
}

--
2.7.4