[PATCH v16 4/8] coresight-tpdm: Add DSB dataset support

[Mao Jinlong <quic_jinlmao@quicinc.com>]

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@arm.com>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 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