[PATCH v6 04/10] coresight-tpdm: Add DSB dataset support

[Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>]

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.

Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
Signed-off-by: Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>
---
 drivers/hwtracing/coresight/coresight-tpdm.c | 58 ++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tpdm.h | 23 ++++++++
 2 files changed, 81 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 6a4e2a35053d..70df888ac565 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 & BIT(TPDM_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;
 	mutex_unlock(&drvdata->lock);
 
@@ -39,7 +61,29 @@ 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 & BIT(TPDM_DS_DSB))
+		tpdm_disable_dsb(drvdata);
+
+	CS_LOCK(drvdata->base);
+
+}
+
 static void tpdm_disable(struct coresight_device *csdev,
 			 struct perf_event *event)
 {
@@ -51,6 +95,7 @@ static void tpdm_disable(struct coresight_device *csdev,
 		return;
 	}
 
+	_tpdm_disable(drvdata);
 	drvdata->enable = false;
 	mutex_unlock(&drvdata->lock);
 
@@ -66,6 +111,18 @@ static const struct coresight_ops tpdm_cs_ops = {
 	.source_ops	= &tpdm_source_ops,
 };
 
+static void tpdm_init_default_data(struct tpdm_drvdata *drvdata)
+{
+	int i;
+	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)
 {
 	struct device *dev = &adev->dev;
@@ -104,6 +161,7 @@ static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
 	if (IS_ERR(drvdata->csdev))
 		return PTR_ERR(drvdata->csdev);
 
+	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 94a7748a5426..f95aaad9c653 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -6,6 +6,27 @@
 #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)
+
+/**
+ * This enum is for PERIPHIDR0 register of TPDM.
+ * 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
+ */
+enum tpdm_dataset {
+	TPDM_DS_IMPLDEF,
+	TPDM_DS_DSB,
+};
+
 /**
  * struct tpdm_drvdata - specifics associated to an TPDM component
  * @base:       memory mapped base address for this component.
@@ -13,6 +34,7 @@
  * @csdev:      component vitals needed by the framework.
  * @lock:       lock for the enable value.
  * @enable:     enable status of the component.
+ * @datasets:   The datasets types present of the TPDM.
  */
 
 struct tpdm_drvdata {
@@ -21,6 +43,7 @@ struct tpdm_drvdata {
 	struct coresight_device	*csdev;
 	struct mutex		lock;
 	bool			enable;
+	unsigned long		datasets;
 };
 
 #endif  /* _CORESIGHT_CORESIGHT_TPDM_H */
-- 
2.17.1