coresight-tpda: Add support to configure CMB element

Read the CMB element size from the device tree. Set the register
bit that controls the CMB element size of the corresponding port.

Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/1707024641-22460-6-git-send-email-quic_taozha@quicinc.com

drivers/hwtracing/coresight/coresight-tpda.c

@@ -18,6 +18,7 @@
 #include "coresight-priv.h"
 #include "coresight-tpda.h"
 #include "coresight-trace-id.h"
+#include "coresight-tpdm.h"
 
 DEFINE_CORESIGHT_DEVLIST(tpda_devs, "tpda");
 
@@ -28,24 +29,59 @@ static bool coresight_device_is_tpdm(struct coresight_device *csdev)
 			CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM);
 }
 
-/*
+static void tpda_clear_element_size(struct coresight_device *csdev)
- * Read the DSB element size from the TPDM device
- * Returns
- *    The dsb element size read from the devicetree if available.
- *    0 - Otherwise, with a warning once.
- */
-static int tpdm_read_dsb_element_size(struct coresight_device *csdev)
 {
-	int rc = 0;
+	struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
-	u8 size = 0;
+
+	drvdata->dsb_esize = 0;
+	drvdata->cmb_esize = 0;
+}
+
+static void tpda_set_element_size(struct tpda_drvdata *drvdata, u32 *val)
+{
+	/* Clear all relevant fields */
+	*val &= ~(TPDA_Pn_CR_DSBSIZE | TPDA_Pn_CR_CMBSIZE);
+
+	if (drvdata->dsb_esize == 64)
+		*val |= TPDA_Pn_CR_DSBSIZE;
+	else if (drvdata->dsb_esize == 32)
+		*val &= ~TPDA_Pn_CR_DSBSIZE;
+
+	if (drvdata->cmb_esize == 64)
+		*val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x2);
+	else if (drvdata->cmb_esize == 32)
+		*val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x1);
+	else if (drvdata->cmb_esize == 8)
+		*val &= ~TPDA_Pn_CR_CMBSIZE;
+}
+
+/*
+ * Read the element size from the TPDM device. One TPDM must have at least one of the
+ * element size property.
+ * Returns
+ *    0 - The element size property is read
+ *    Others - Cannot read the property of the element size
+ */
+static int tpdm_read_element_size(struct tpda_drvdata *drvdata,
+				  struct coresight_device *csdev)
+{
+	int rc = -EINVAL;
+	struct tpdm_drvdata *tpdm_data = dev_get_drvdata(csdev->dev.parent);
+
+	if (tpdm_has_dsb_dataset(tpdm_data)) {
+		rc = fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
+				"qcom,dsb-element-size", &drvdata->dsb_esize);
+	}
+	if (tpdm_has_cmb_dataset(tpdm_data)) {
+		rc = fwnode_property_read_u32(dev_fwnode(csdev->dev.parent),
+				"qcom,cmb-element-bits", &drvdata->cmb_esize);
+	}
 
-	rc = fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
-			"qcom,dsb-element-size", &size);
 	if (rc)
 		dev_warn_once(&csdev->dev,
-			"Failed to read TPDM DSB Element size: %d\n", rc);
+			"Failed to read TPDM Element size: %d\n", rc);
 
-	return size;
+	return rc;
 }
 
 /*
@@ -56,11 +92,12 @@ static int tpdm_read_dsb_element_size(struct coresight_device *csdev)
  * Parameter "inport" is used to pass in the input port number
  * of TPDA, and it is set to -1 in the recursize call.
  */
-static int tpda_get_element_size(struct coresight_device *csdev,
+static int tpda_get_element_size(struct tpda_drvdata *drvdata,
+				 struct coresight_device *csdev,
 				 int inport)
 {
-	int dsb_size = -ENOENT;
+	int rc = 0;
-	int i, size;
+	int i;
 	struct coresight_device *in;
 
 	for (i = 0; i < csdev->pdata->nr_inconns; i++) {
@@ -69,30 +106,26 @@ static int tpda_get_element_size(struct coresight_device *csdev,
 			continue;
 
 		/* Ignore the paths that do not match port */
-		if (inport > 0 &&
+		if (inport >= 0 &&
 		    csdev->pdata->in_conns[i]->dest_port != inport)
 			continue;
 
 		if (coresight_device_is_tpdm(in)) {
-			size = tpdm_read_dsb_element_size(in);
+			if (drvdata->dsb_esize || drvdata->cmb_esize)
+				return -EEXIST;
+			rc = tpdm_read_element_size(drvdata, in);
+			if (rc)
+				return rc;
 		} else {
 			/* Recurse down the path */
-			size = tpda_get_element_size(in, -1);
+			rc = tpda_get_element_size(drvdata, in, -1);
-		}
+			if (rc)
-
+				return rc;
-		if (size < 0)
-			return size;
-
-		if (dsb_size < 0) {
-			/* Found a size, save it. */
-			dsb_size = size;
-		} else {
-			/* Found duplicate TPDMs */
-			return -EEXIST;
 		}
 	}
 
-	return dsb_size;
+
+	return rc;
 }
 
 /* Settings pre enabling port control register */
@@ -109,37 +142,24 @@ static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
 static int tpda_enable_port(struct tpda_drvdata *drvdata, int port)
 {
 	u32 val;
-	int size;
+	int rc;
 
 	val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
-	/*
+	tpda_clear_element_size(drvdata->csdev);
-	 * Configure aggregator port n DSB data set element size
+	rc = tpda_get_element_size(drvdata, drvdata->csdev, port);
-	 * Set the bit to 0 if the size is 32
+	if (!rc && (drvdata->dsb_esize || drvdata->cmb_esize)) {
-	 * Set the bit to 1 if the size is 64
+		tpda_set_element_size(drvdata, &val);
-	 */
+		/* Enable the port */
-	size = tpda_get_element_size(drvdata->csdev, port);
+		val |= TPDA_Pn_CR_ENA;
-	switch (size) {
+		writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
-	case 32:
+	} else if (rc == -EEXIST)
-		val &= ~TPDA_Pn_CR_DSBSIZE;
-		break;
-	case 64:
-		val |= TPDA_Pn_CR_DSBSIZE;
-		break;
-	case 0:
-		return -EEXIST;
-	case -EEXIST:
 		dev_warn_once(&drvdata->csdev->dev,
-			"Detected multiple TPDMs on port %d", -EEXIST);
+			      "Detected multiple TPDMs on port %d", port);
-		return -EEXIST;
+	else
-	default:
+		dev_warn_once(&drvdata->csdev->dev,
-		return -EINVAL;
+			      "Didn't find TPDM element size");
-	}
 
-	/* Enable the port */
+	return rc;
-	val |= TPDA_Pn_CR_ENA;
-	writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
-
-	return 0;
 }
 
 static int __tpda_enable(struct tpda_drvdata *drvdata, int port)

drivers/hwtracing/coresight/coresight-tpda.h

@@ -10,6 +10,8 @@
 #define TPDA_Pn_CR(n)		(0x004 + (n * 4))
 /* Aggregator port enable bit */
 #define TPDA_Pn_CR_ENA		BIT(0)
+/* Aggregator port CMB data set element size bit */
+#define TPDA_Pn_CR_CMBSIZE		GENMASK(7, 6)
 /* Aggregator port DSB data set element size bit */
 #define TPDA_Pn_CR_DSBSIZE		BIT(8)
 
@@ -25,6 +27,8 @@
  * @csdev:      component vitals needed by the framework.
  * @spinlock:   lock for the drvdata value.
  * @enable:     enable status of the component.
+ * @dsb_esize   Record the DSB element size.
+ * @cmb_esize   Record the CMB element size.
  */
 struct tpda_drvdata {
 	void __iomem		*base;
@@ -32,6 +36,8 @@ struct tpda_drvdata {
 	struct coresight_device	*csdev;
 	spinlock_t		spinlock;
 	u8			atid;
+	u8			dsb_esize;
+	u32			cmb_esize;
 };
 
 #endif  /* _CORESIGHT_CORESIGHT_TPDA_H */