[PATCH v17 4/9] coresight-tpdm: Add DSB dataset support

From: Mao Jinlong
Date: Tue Jan 17 2023 - 09:57:46 EST


TPDM serves as data collection component for various dataset types.
DSB(Discrete Single Bit) is one of the dataset types. DSB subunit
can be enabled for data collection by writing 1 to the first bit of
DSB_CR register. This change is to add enable/disable function for
DSB dataset by writing DSB_CR register.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
Signed-off-by: Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-tpdm.c | 56 ++++++++++++++++++++
drivers/hwtracing/coresight/coresight-tpdm.h | 22 ++++++++
2 files changed, 78 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 95dbf4badfd2..4a37ae6054b4 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -20,7 +20,28 @@

DEFINE_CORESIGHT_DEVLIST(tpdm_devs, "tpdm");

+static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
+{
+ u32 val;
+
+ /* Set the enable bit of DSB control register to 1 */
+ val = readl_relaxed(drvdata->base + TPDM_DSB_CR);
+ val |= TPDM_DSB_CR_ENA;
+ writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
+}
+
/* TPDM enable operations */
+static void __tpdm_enable(struct tpdm_drvdata *drvdata)
+{
+ CS_UNLOCK(drvdata->base);
+
+ /* Check if DSB datasets is present for TPDM. */
+ if (drvdata->datasets & TPDM_PIDR0_DS_DSB)
+ tpdm_enable_dsb(drvdata);
+
+ CS_LOCK(drvdata->base);
+}
+
static int tpdm_enable(struct coresight_device *csdev,
struct perf_event *event, u32 mode)
{
@@ -32,6 +53,7 @@ static int tpdm_enable(struct coresight_device *csdev,
return -EBUSY;
}

+ __tpdm_enable(drvdata);
drvdata->enable = true;
spin_unlock(&drvdata->spinlock);

@@ -39,7 +61,28 @@ static int tpdm_enable(struct coresight_device *csdev,
return 0;
}

+static void tpdm_disable_dsb(struct tpdm_drvdata *drvdata)
+{
+ u32 val;
+
+ /* Set the enable bit of DSB control register to 0 */
+ val = readl_relaxed(drvdata->base + TPDM_DSB_CR);
+ val &= ~TPDM_DSB_CR_ENA;
+ writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
+}
+
/* TPDM disable operations */
+static void __tpdm_disable(struct tpdm_drvdata *drvdata)
+{
+ CS_UNLOCK(drvdata->base);
+
+ /* Check if DSB datasets is present for TPDM. */
+ if (drvdata->datasets & TPDM_PIDR0_DS_DSB)
+ tpdm_disable_dsb(drvdata);
+
+ CS_LOCK(drvdata->base);
+}
+
static void tpdm_disable(struct coresight_device *csdev,
struct perf_event *event)
{
@@ -51,6 +94,7 @@ static void tpdm_disable(struct coresight_device *csdev,
return;
}

+ __tpdm_disable(drvdata);
drvdata->enable = false;
spin_unlock(&drvdata->spinlock);

@@ -66,6 +110,17 @@ static const struct coresight_ops tpdm_cs_ops = {
.source_ops = &tpdm_source_ops,
};

+static void tpdm_init_default_data(struct tpdm_drvdata *drvdata)
+{
+ u32 pidr;
+
+ CS_UNLOCK(drvdata->base);
+ /* Get the datasets present on the TPDM. */
+ pidr = readl_relaxed(drvdata->base + CORESIGHT_PERIPHIDR0);
+ drvdata->datasets |= pidr & GENMASK(TPDM_DATASETS - 1, 0);
+ CS_LOCK(drvdata->base);
+}
+
static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
{
void __iomem *base;
@@ -107,6 +162,7 @@ static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
return PTR_ERR(drvdata->csdev);

spin_lock_init(&drvdata->spinlock);
+ tpdm_init_default_data(drvdata);
/* Decrease pm refcount when probe is done.*/
pm_runtime_put(&adev->dev);

diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
index 2ec8a6810771..3f7ee37b6303 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -6,6 +6,26 @@
#ifndef _CORESIGHT_CORESIGHT_TPDM_H
#define _CORESIGHT_CORESIGHT_TPDM_H

+/* The max number of the datasets that TPDM supports */
+#define TPDM_DATASETS 7
+
+/* DSB Subunit Registers */
+#define TPDM_DSB_CR (0x780)
+/* Enable bit for DSB subunit */
+#define TPDM_DSB_CR_ENA BIT(0)
+
+/**
+ * The bits of PERIPHIDR0 register.
+ * The fields [6:0] of PERIPHIDR0 are used to determine what
+ * interfaces and subunits are present on a given TPDM.
+ *
+ * PERIPHIDR0[0] : Fix to 1 if ImplDef subunit present, else 0
+ * PERIPHIDR0[1] : Fix to 1 if DSB subunit present, else 0
+ */
+
+#define TPDM_PIDR0_DS_IMPDEF BIT(0)
+#define TPDM_PIDR0_DS_DSB BIT(1)
+
/**
* struct tpdm_drvdata - specifics associated to an TPDM component
* @base: memory mapped base address for this component.
@@ -13,6 +33,7 @@
* @csdev: component vitals needed by the framework.
* @spinlock: lock for the drvdata value.
* @enable: enable status of the component.
+ * @datasets: The datasets types present of the TPDM.
*/

struct tpdm_drvdata {
@@ -21,6 +42,7 @@ struct tpdm_drvdata {
struct coresight_device *csdev;
spinlock_t spinlock;
bool enable;
+ unsigned long datasets;
};

#endif /* _CORESIGHT_CORESIGHT_TPDM_H */
--
2.39.0